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Sample records for holmium laser enucleation

  1. Laser Prostatectomy: Holmium Laser Enucleation and Photoselective Laser Vaporization of the Prostate

    PubMed Central

    Bostanci, Yakup; Kazzazi, Amir; Djavan, Bob

    2013-01-01

    Historically, transurethral resection of the prostate has been the gold standard for the treatment of benign prostatic hyperplasia (BPH). Laser technology has been used to treat BPH for > 15 years. Over the past decade, it has gained wide acceptance by experienced urologists. This review provides an evidence-based update on laser surgery for BPH with a focus on photoselective laser vaporization and holmium laser enucleation of the prostate surgeries and assesses the safety, efficacy, and durability of these techniques. PMID:23671400

  2. Holmium laser enucleation of the prostate: a paradigm shift in benign prostatic hyperplasia surgery

    PubMed Central

    2013-01-01

    Holmium laser enucleation (HoLEP) was developed in the 1990s as a more efficient and cost effective method of benign prostatic hyperplasia surgery than laser vaporization and resection techniques. As a true anatomical enucleation it mimics open prostatectomy and is as durable. There is a significant body of level 1 evidence in support of HoLEP, including 2 meta-analyses and 14 randomized trials which compare HoLEP with a number of other procedures. This review describes the development of and summarizes the evidence for HoLEP. PMID:24082919

  3. Holmium laser enucleation of the prostate: a paradigm shift in benign prostatic hyperplasia surgery.

    PubMed

    Aho, Tevita F

    2013-10-01

    Holmium laser enucleation (HoLEP) was developed in the 1990s as a more efficient and cost effective method of benign prostatic hyperplasia surgery than laser vaporization and resection techniques. As a true anatomical enucleation it mimics open prostatectomy and is as durable. There is a significant body of level 1 evidence in support of HoLEP, including 2 meta-analyses and 14 randomized trials which compare HoLEP with a number of other procedures. This review describes the development of and summarizes the evidence for HoLEP. PMID:24082919

  4. Holmium laser enucleation of the prostate: a review of the clinical trial evidence.

    PubMed

    Cynk, Mark

    2014-04-01

    Transurethral resection of the prostate (TURP) has remained the procedure of choice for the surgical treatment of bladder outflow obstruction for almost five decades, but holmium laser enucleation of the prostate (HoLEP) is now emerging as a challenger as the gold standard procedure. This review summarizes the evidence base for HoLEP, with particular reference to randomized, controlled (level 1) evidence. PMID:24688602

  5. Holmium laser enucleation of the prostate: a review of the clinical trial evidence

    PubMed Central

    2014-01-01

    Transurethral resection of the prostate (TURP) has remained the procedure of choice for the surgical treatment of bladder outflow obstruction for almost five decades, but holmium laser enucleation of the prostate (HoLEP) is now emerging as a challenger as the gold standard procedure. This review summarizes the evidence base for HoLEP, with particular reference to randomized, controlled (level 1) evidence. PMID:24688602

  6. Bipolar, Monopolar, Photovaporization of the Prostate, or Holmium Laser Enucleation of the Prostate: How to Choose What's Best?

    PubMed

    Cornu, Jean-Nicolas

    2016-08-01

    Endoscopic management of benign prostatic obstruction is based on resection, vaporization, or enucleation. Enucleation provides the best efficacy and long-term outcome. Lasers have advantages in patients at high risk of bleeding. Holmium enucleation is the best evaluated technique, but has a steep learning curve. Greenlight photovaporization is a safe alternative to transurethral resection of the prostate (TURP) in prostates of less than 100 mL, especially in patients at high risk of bleeding. Bipolar devices can be used for resection, vaporization, and enucleation and provides efficacy results similar to TURP in the short term with better safety. PMID:27476130

  7. Holmium Laser Enucleation of the Prostate and Iatrogenic Arteriovenous Fistula Treated by Superselective Arterial Embolization

    PubMed Central

    Dutto, Lorenzo; Preziosi, Paolo; Spera, Enrico; Micali, Francesco; De Carolis, Andrea; Iorio, Beniamino

    2016-01-01

    Iatrogenic pelvic pseudoaneurysm with concomitant arteriovenous fistula has been described as a rare and challenging complication, which may occur during transurethral resection of the prostate. We provide the first report of this complication after holmium laser enucleation of the prostate for the treatment of benign prostatic hyperplasia. The attempt to control the bleeding by conversion to open surgery and placement of haemostatic stitches into the prostatic fossa failed. Angiography with superselective arterial embolization proved to be a modern, quick, safe, and efficient treatment of this uncommon complication. PMID:27022498

  8. Technical Aspects of Holmium Laser Enucleation of the Prostate for Benign Prostatic Hyperplasia

    PubMed Central

    Kim, Myong; Lee, Hahn-Ey

    2013-01-01

    Holmium laser enucleation of the prostate (HoLEP) is a minimally invasive procedure and a size-independent treatment for benign prostatic hyperplasia with excellent long-term surgical outcome. HoLEP has become an alternative to conventional transurethral resection of the prostate or open prostatectomy owing to its efficacy and safety. Although HoLEP is known to have a steep learning curve, very few articles have addressed the technical aspects of HoLEP. Herein, we described detailed techniques and tips for HoLEP as performed at Seoul National University Hospital in a step-by-step manner with extensive review of the literature. PMID:24044089

  9. Holmium Laser Enucleation of the Prostate and Iatrogenic Arteriovenous Fistula Treated by Superselective Arterial Embolization.

    PubMed

    Asimakopoulos, Anastasios D; Dutto, Lorenzo; Preziosi, Paolo; Spera, Enrico; Micali, Francesco; De Carolis, Andrea; Iorio, Beniamino

    2016-01-01

    Iatrogenic pelvic pseudoaneurysm with concomitant arteriovenous fistula has been described as a rare and challenging complication, which may occur during transurethral resection of the prostate. We provide the first report of this complication after holmium laser enucleation of the prostate for the treatment of benign prostatic hyperplasia. The attempt to control the bleeding by conversion to open surgery and placement of haemostatic stitches into the prostatic fossa failed. Angiography with superselective arterial embolization proved to be a modern, quick, safe, and efficient treatment of this uncommon complication. PMID:27022498

  10. Technical aspects of holmium laser enucleation of the prostate for benign prostatic hyperplasia.

    PubMed

    Kim, Myong; Lee, Hahn-Ey; Oh, Seung-June

    2013-09-01

    Holmium laser enucleation of the prostate (HoLEP) is a minimally invasive procedure and a size-independent treatment for benign prostatic hyperplasia with excellent long-term surgical outcome. HoLEP has become an alternative to conventional transurethral resection of the prostate or open prostatectomy owing to its efficacy and safety. Although HoLEP is known to have a steep learning curve, very few articles have addressed the technical aspects of HoLEP. Herein, we described detailed techniques and tips for HoLEP as performed at Seoul National University Hospital in a step-by-step manner with extensive review of the literature. PMID:24044089

  11. Acute abdominal compartment syndrome as a complication of Holmium laser enucleation of the prostate: a case report

    PubMed Central

    2014-01-01

    Background In 1996, Holmium laser enucleation of the prostate was introduced and has been shown to be safe and highly effective. Case presentation We report a case of a rare complication that resulted in intra-abdominal compartment syndrome with prolonged intubation and intensive care, involving an 74-year-old male after holmium laser enucleation of prostate, with a massive irrigant fluid leakage into the retroperitoneal space. The elevated abdominal pressure was reduced by forced diuresis. The tracheal tube was removed 18 hours after the patient’s transfer to the ICU. The patient was discharged to home one week after the operation. Conclusion In rare cases when no obvious ruptures of the prostate capsule or the bladder occur during laser enucleation of prostate, knowledge regarding possible emersion of massive amounts of irrigant fluid into the retroperitoneal space leading to intra-abdominal compartment syndrome aids in the diagnosis and subsequent successful therapy of intra-abdominal hypertension. PMID:24910537

  12. Holmium Laser Enucleation of the Prostate in a 400 cc Prostate: Case Report

    PubMed Central

    Hong, Matthew K.H.; Pham, Trung

    2016-01-01

    Abstract The modality of choice in the surgical management of benign prostatic hyperplasia for large prostates has traditionally been open prostatectomy. Advances in minimally invasive techniques have begun to challenge this notion with advantages such as lower bleeding and transfusion rates and shorter hospital stay. In this case report, we illustrate the use of holmium laser enucleation of the prostate (HoLEP) in a gland measuring more than 400 cc. We describe the case of a 71-year-old man with persistent voiding urinary symptoms despite two previous transurethral resections of his prostate. With greater experience in HoLEP and declining experience in open prostatectomy, there may be a shift toward HoLEP as the preferred treatment choice for large prostate glands. PMID:27579406

  13. Holmium Laser Enucleation of the Prostate in a 400 cc Prostate: Case Report.

    PubMed

    Gopee, Esha L; Hong, Matthew K H; Pham, Trung

    2016-01-01

    The modality of choice in the surgical management of benign prostatic hyperplasia for large prostates has traditionally been open prostatectomy. Advances in minimally invasive techniques have begun to challenge this notion with advantages such as lower bleeding and transfusion rates and shorter hospital stay. In this case report, we illustrate the use of holmium laser enucleation of the prostate (HoLEP) in a gland measuring more than 400 cc. We describe the case of a 71-year-old man with persistent voiding urinary symptoms despite two previous transurethral resections of his prostate. With greater experience in HoLEP and declining experience in open prostatectomy, there may be a shift toward HoLEP as the preferred treatment choice for large prostate glands. PMID:27579406

  14. Holmium Laser Enucleation of Prostate for Benign Prostatic Hyperplasia: Seoul National University Hospital Experience

    PubMed Central

    Bae, Jungbum; Choo, Minsoo; Park, Ji Hyun; Oh, Jin Kyu; Paick, Jae-Seung

    2011-01-01

    Purpose The objective of this study was to report the experience acquired at the Seoul National University Hospital with Holmium Laser Enucleation of Prostate (HoLEP), combined with mechanical morcellation for symptomatic benign prostatic hyperplasia (BPH). Methods A retrospective review was performed on the clinical data of 309 consecutive patients who underwent HoLEP at our institution between July 2008 and June 2010. All patients were evaluated preoperatively for prostate volume by transrectal ultrasound, maximum urinary flow rate (Qmax), International Prostate Symptoms Score (IPSS) and quality of life (QoL) score. Peri- and postoperative parameters were evaluated and patients were followed-up at 1-, 3-, 6-, and 12- months with the aforementioned investigations. Results The patients' mean age was 68.3 (±6.5) years and mean prostate volume was 55.6 (±23.6) mL. Mean enucleation time was 56.2 (±25.1) minutes, mean morcellation time was 11.3 (±9.5) minutes, and the mean resected weight of the prostate was 20.8 (±16.9) g. The mean catheter indwelling period was 1.9 (±1.7) days and mean hospital stay was 2.9 (±1.5) days. Significant improvement was noted in Qmax, IPSS, and QoL at the 1-year follow-up compared with baseline (P<0.01). At 1 month 17.2% of patients complained of irritative urinary symptoms, which were typically self-limiting within 3 months. Transient stress incontinence was reported in 15.2% of patients. No patient experienced persistent obstructive symptoms that required reoperation. Conclusions Our study showed that HoLEP is a safe and effective therapeutic modality for BPH. PMID:21468284

  15. Salvage Holmium laser enucleation of prostate to treat residual benign prostatic hyperplasia

    PubMed Central

    Oh, Jin Kyu; Bae, Jungbum; Jeong, Chang Wook; Paick, Jae-Seung; Oh, Seung-June

    2014-01-01

    Introduction: The Holmium laser enucleation of the prostate (HoLEP) technique to remove residual adenoma has not been reported. Salvage HoLEP enables anatomical enucleation of residual adenoma in patients who have previously undergone surgical treatment. We describe not only anatomical insights into the frequent location of adenoma recurrence, but also the feasibility of the salvage HoLEP technique. Methods: We retrospectively reviewed a database containing HoLEP video records for 35 patients out of a total of 535 individuals on whom HoLEP was performed by 2 surgeons (SJO & JSP) between July 2008 and June 2011. Group 1 consisted of patients who underwent salvage HoLEP due to recurring adenoma and Group 2 of patients who underwent HoLEP as an initially surgical management to treat benign prostate hyperplasia (BPH). We compared the dataset of pre-, intra- and postoperative parameters between Groups 1 and 2. Results: In the analysis of the video records of Group 1 (n = 35), there was significant remnant tissue around the verumontanum and the lateral lobes were also incompletely removed by previous conventional procedures. When we compared pre-, intra- and postoperative parameters between the 2 groups, there were no significant differences, including operation time, duration of hospital stay. However, the duration of the catheterization of Group 1 was shorter than that of Group 2 (1.38 ± 0.55 vs. 1.90 ± 1.81 days, p < 0.001). Conclusions: Even for cases of residual BPH, salvage HoLEP is a feasible and effective procedure for treating residual adenoma along the anatomical plane. PMID:24839489

  16. Efficacy of Holmium Laser Enucleation of the Prostate Based on Patient Preoperative Characteristics

    PubMed Central

    Suh, Yoon Seok; Kim, Tae Heon; Sung, Hyun Hwan; Jeong, Jeongyun

    2015-01-01

    Purpose: To evaluate the efficacy of holmium laser enucleation of the prostate (HoLEP) in relation to prostate size and urodynamic parameters, including bladder outlet obstruction index (BOOI), presence of detrusor overactivity, and detrusor contractility, and to investigate factors predictive of HoLEP success. Methods: This retrospective analysis of prospective data included 174 consecutive patients treated with HoLEP at Samsung Medical Center from 2009 to 2013. Prostate-specific antigen, prostate size, urodynamic parameters, and International Prostate Symptom Score (IPSS)/quality of life (QoL) were evaluated preoperatively, while prostate-specific antigen, uroflowmetry/postvoid residual (PVR) urine, and IPSS were measured six months after HoLEP. Two definitions of treatment success were established based on the following three variables: IPSS, maximum flow rate (Qmax), and QoL index. Factors predictive of HoLEP success were identified using multiple logistic regression analysis. Results: IPSS/QoL, Qmax, and PVR improved significantly following HoLEP. Improvements in IPSS and PVR were more significant in the BOOI≥40 group compared to the BOOI<40 group, with overall success rates of 93.7% and 73.6%, respectively. Thus, the BOOI≥40 group had a significantly higher success rate, and BOOI≥40 was a significant predictor of HoLEP success based on the multivariate analyses. Conclusions: We found good surgical outcomes after HoLEP, and specifically patients with a higher BOOI had a greater chance of surgical success. PMID:26739183

  17. An Improved Morcellation Procedure for Holmium Laser Enucleation of the Prostate

    PubMed Central

    Chen, Qi; Chen, Yan-Bo; Zheng, Da-Chao; Cai, Zhi-Kang; Li, Wen-Ji; Zhou, Juan

    2012-01-01

    Abstract Purpose We modified the conventional morcellation procedure for holmium laser enucleation of the prostate (HoLEP), and its outcomes are presented in this article. Materials and Methods As 395 patients were included, the conventional morcellation procedure was performed in the first 100 cases (group 1, cases 1–100), and an improved procedure was used in the last 100 cases (group 2, cases 296–395). The improved morcellation process has three steps to execute. The morcellation time, collected tissue weight, morcellation rate, and associated complications were recorded. Results The tissue-resected weight was similar between group 1 (60.7±33.9 g) and group 2 (62.4±36.8 g). The mean morcellation time in group 1 was greater than that in group 2 (11.3±7.1 and 8.3±4.1 minutes, respectively), and the mean morcellation rate was better in group 2 than in group 1 (5.75±1.7 g/minutes in group 1 v 7.3±1.1 g/minutes in group 2). Complications, such as bladder injury, were similar in both groups. Conclusion The improved morcellation procedure described in this article can be used in various situations of suction and can be performed in a more fluent manner and with better efficiency. PMID:22788738

  18. Holmium Laser Enucleation of the Prostate is Safe for Patients Above 80 Years: A Prospective Study

    PubMed Central

    2016-01-01

    Purpose: To evaluate the effect of age on the efficacy and safety of holmium laser enucleation of the prostate (HoLEP) for the treatment of symptomatic benign prostatic hyperplasia (BPH). Methods: A total of 579 patients underwent HoLEP procedure performed by a single surgeon (SJO) between December 2009 and May 2013. The perioperative and functional outcomes of patients in the age groups of 50–59 (group A, n=44), 60–69 (group B, n=253), 70–79 (group C, n=244), and ≥80 years (group D, n=38) were compared. The Clavien-Dindo system was used to evaluate clinical outcomes. The International Prostate Symptom Score (IPSS), maximum urinary flow rate (Qmax), postvoid residual (PVR) urine volume, and urinary continence were used to assess functional outcomes. Results: In this study, the patients ≥80 years had significantly higher presence of hypertension (P=0.007), total prostate volumes (P=0.024), transitional zone volume (P=0.002), American Society of Anesthesiologists scores (P=0.006), urinary retention (P=0.032), and anticoagulation use (P=0.008) at preoperative period. Moreover, the mean values of operation time, enucleation time, morcellation time, and enucleation weight were higher in group D compared with other group patients (P=0.002, P=0.010, P<0.01, and P=0.009, respectively). Patients aged ≥80 years had a longer hospital stay time (2.9±1.8 days) than other groups (group A, 2.3±0.7 days; group B, 2.3±0.7 days vs. group C, 2.4±0.7 days; P=0.001). All groups were similar in regard to the incidence of complications (Clavien-Dindo grade) post operatively (P>0.05). All the patients in the present study showed improvement in functional outcomes after HoLEP. By the sixth month, there were no significant differences in IPSS, quality of life, Qmax, and PVR among the groups (P>0.05). Conclusions: Compared with younger patients, the patients aged ≥80 years had a similar overall morbidity and 6-month functional outcomes of HoLEP. HoLEP is a safe and

  19. Risk Factors for Transient Urinary Incontinence after Holmium Laser Enucleation of the Prostate

    PubMed Central

    Nam, Jong Kil; Kim, Hyeon Woo; Lee, Dong Hoon; Han, Ji-Yeon; Lee, Jeong Zoo

    2015-01-01

    Purpose To investigate the factors associated with the occurrence of and recovery from transient urinary incontinence (TUI) after holmium laser enucleation of the prostate (HoLEP). Materials and Methods From March 2009 to December 2012, 391 consecutive patients treated with HoLEP for benign prostatic hyperplasia were enrolled. Information regarding age, prostate volume, International Prostate Symptom Score, Overactive Bladder Symptom Score, peak urinary flow rate, postvoid residual urine, and operation time was collected. TUI was defined as a patient complaint of urine leakage, regardless of type. Logistic regression was used to investigate the factors associated with the occurrence of TUI, and the Kaplan-Meier test was used to analyze the TUI recovery period. Results TUI after HoLEP occurred in 65 patients (16.6%), 52 patients of whom (80.0%) showed recovery within three months. Stress and urge urinary incontinence and postvoid dribbling occurred in 16 patients (4.1%), 29 patients (7.4%), and 33 patients (8.4%), respectively. Age (odds ratio [OR]=3.494; 95% confidence interval [CI]=1.565~7.803; p=0.002) and total operation time (OR=3.849; 95% CI=1.613~9.185; p=0.002) were factors that significantly affected the occurrence of TUI. Conclusions TUI, defined as any type of urine leakage, occurred after HoLEP in some patients, most of whom recovered within three months. Stress urinary incontinence occurred in only 4% of patients after HoLEP. Age and total operation time were associated with the occurrence of postoperative TUI. PMID:26331125

  20. Predictive risk factors of postoperative urinary incontinence following holmium laser enucleation of the prostate during the initial learning period

    PubMed Central

    Kobayashi, Shuichiro; Yano, Masataka; Nakayama, Takayuki; Kitahara, Satoshi

    2016-01-01

    ABSTRACT Purpose: To determine the predictive factors for postoperative urinary incontinence (UI) following holmium laser enucleation of the prostate (HoLEP) during the initial learning period. Patients and Methods: We evaluated 127 patients with benign prostatic hyperplasia who underwent HoLEP between January 2011 and December 2013. We recorded clinical variables, including blood loss, serum prostate-specific antigen levels, and the presence or absence of UI. Blood loss was estimated as a decline in postoperative hemoglobin levels. The predictive factors for postoperative UI were determined using a multivariable logistic regression analysis. Results: Postoperative UI occurred in 31 patients (24.4%), but it cured in 29 patients (93.5%) after a mean duration of 12 weeks. Enucleation time >100 min (p=0.043) and blood loss >2.5g/dL (p=0.032) were identified as significant and independent risk factors for postoperative UI. Conclusions: Longer enucleation time and increased blood loss were independent predictors of postoperative UI in patients who underwent HoLEP during the initial learning period. Surgeons in training should take care to perform speedy enucleation maneuver with hemostasis. PMID:27564285

  1. Factors Affecting De Novo Urinary Retention after Holmium Laser Enucleation of the Prostate

    PubMed Central

    Kim, Sung Han; Yoo, Changwon; Choo, Minsoo; Paick, Jae-Seung; Oh, Seung-June

    2014-01-01

    Objective Patients can experience urinary retention (UR) after Holmium laser enucleation of the prostate (HoLEP) that requires bladder distension during the procedure. The aim of this retrospective study is to identify factors affecting the UR after HoLEP. Materials and Methods 336 patients, which underwent HoLEP for a symptomatic benign prostatic hyperplasia between July 2008 and March 2012, were included in this study. Urethral catheters were routinely removed one or two days after surgery. UR was defined as the need for an indwelling catheter placement following a failure to void after catheter removal. Demographic and clinical parameters were compared between the UR (n = 37) and the non-urinary retention (non-UR; n = 299) groups. Results The mean age of patients was 68.3 (±6.5) years and the mean operative time was 75.3 (±37.4) min. Thirty seven patients (11.0%) experienced a postoperative UR. UR patients voided catheter free an average of 1.9 (±1.7) days after UR. With regard to the causes of UR, 24 (7.1%) and 13 (3.9%) patients experienced a blood clot-related UR and a non-clot related UR respectively. Using multivariate analysis (p<0.05), we found significant differences between the UR and the non-UR groups with regard to a morcellation efficiency (OR 0.701, 95% CI 0.498–0.988) and a bleeding-related complication, such as, a reoperation for bleeding (OR 0.039, 95% CI 0.004–0.383) or a transfusion (OR 0.144, 95% CI 0.027–0.877). Age, history of diabetes, prostate volume, pre-operative post-void residual, bladder contractility index, learning curve, and operative time were not significantly associated with the UR (p>0.05). Conclusions De novo UR after HoLEP was found to be self-limited and it was not related to learning curve, patient age, diabetes, or operative time. Efficient morcellation and careful control of bleeding, which reduces clot formation, decrease the risk of UR after HoLEP. PMID:24465454

  2. Clinical and Pathological Characteristics of Hard Nodules Resistant to Morcellation During Holmium Laser Enucleation of the Prostate

    PubMed Central

    Piao, Songzhe; Choo, Min Soo; Wang, Yue; Lee, Young Ju; Bae, Jungbum; Oh, Seung-June

    2015-01-01

    Purpose: To identify the clinical and pathological characteristics of hard nodules resistant to morcellation (HNRM) during holmium laser enucleation of the prostate (HoLEP) for benign prostatic hyperplasia (BPH). Methods: Between July 2008 and October 2011, 246 patients underwent HoLEP for symptomatic BPH. The first 30 patients were excluded from the analysis due to the learning curve of the procedure. The remaining patients were divided into HNRM (n=29) and non-HNRM groups (n=187), and comparative analysis of the clinical parameters of the two groups was performed. International prostate symptom score analysis and urodynamic studies were performed preoperatively. Histological analysis was performed after hematoxylin and eosin staining and Masson trichrome staining of the HNRM specimens. Results: Twenty-nine patients (13.4%) had HNRM. The patients in the HNRM group had significantly higher proportions of advanced age (≥65 years, P=0.029), total prostate volume ≥65 mL (P<0.001), transition zone volume ≥35 mL (P<0.001), serum prostate-specific antigen levels ≥10 ng/mL (P=0.007), and functional urethral length ≥70 mm (P=0.009); larger enucleation weight (P<0.001); longer operation (P=0.001), enucleation (P=0.042), and morcellation times (P<0.001); and higher enucleation ratio (P=0.028) and enucleation efficacy (P=0.001). After adjusting for confounding factors, multivariate logistic regression analysis revealed that age ≥65 years and total prostate volume ≥65 mL were independent risk factors for HNRM. Pathological examination did not reveal any malignant cells, with mainly dense fibrous tissue found in the HNRM. Conclusions: HNRM can make morcellation cumbersome and time-consuming, and older patients with larger prostates have a higher incidence of HNRM. However, the histopathology of HNRM revealed mainly fibrotic tissue. PMID:26126438

  3. The Impact of Increased Bladder Blood Flow on Storage Symptoms after Holmium Laser Enucleation of the Prostate.

    PubMed

    Saito, Keisuke; Hisasue, Shin-ichi; Ide, Hisamitsu; Aoki, Hiroaki; Muto, Satoru; Yamaguchi, Raizo; Tsujimura, Akira; Horie, Shigeo

    2015-01-01

    In order to investigate how holmium laser enucleation of the prostate (HoLEP) improves urinary storage symptoms, we assessed blood flow in the urinary bladder mucosa of patients with benign prostatic hyperplasia (BPH) before and after laser surgery. Seventy-four consecutive patients with BPH (median age 69 years, range; 53-88) underwent HoLEP at our institution and are included in this study. We prospectively assessed the International Prostate Symptom Score (IPSS), IPSS-QOL Score, the Overactive Bladder Symptom Score (OABSS), uroflowmetry, and blood flow in the urinary bladder, before and after surgery. Blood flow in the bladder mucosa was measured using the OMEGA FLOW (OMEGAWAVE, Tokyo, Japan) laser Doppler flowmeter. The median volume of the enucleated adenomas was 45.0 g (range: 25.0 to 83.2). The median IPSS improved significantly from 20 (range: 6-35) to 3 (0-22) (p < 0.001; Wilcoxon signed-rank test), as did the storage symptoms score, which decreased from 13 (2-20) to 3 (1-8) (p < 0.001). Median bladder blood flow increased at the trigone from 9.57 ± 0.83 ml/sec to 17.60 ± 1.08 ml/sec. Multiple regression analysis for the improved storage symptom score eliminated all explanatory variables except increased bladder perfusion. The data suggest that HoLEP improves blood flow in the bladder mucosa, which independently leads to the improvement of storage symptoms. PMID:26090819

  4. The Impact of Increased Bladder Blood Flow on Storage Symptoms after Holmium Laser Enucleation of the Prostate

    PubMed Central

    Ide, Hisamitsu; Aoki, Hiroaki; Muto, Satoru; Yamaguchi, Raizo; Tsujimura, Akira; Horie, Shigeo

    2015-01-01

    In order to investigate how holmium laser enucleation of the prostate (HoLEP) improves urinary storage symptoms, we assessed blood flow in the urinary bladder mucosa of patients with benign prostatic hyperplasia (BPH) before and after laser surgery. Seventy-four consecutive patients with BPH (median age 69 years, range; 53–88) underwent HoLEP at our institution and are included in this study. We prospectively assessed the International Prostate Symptom Score (IPSS), IPSS-QOL Score, the Overactive Bladder Symptom Score (OABSS), uroflowmetry, and blood flow in the urinary bladder, before and after surgery. Blood flow in the bladder mucosa was measured using the OMEGA FLOW (OMEGAWAVE, Tokyo, Japan) laser Doppler flowmeter. The median volume of the enucleated adenomas was 45.0 g (range: 25.0 to 83.2). The median IPSS improved significantly from 20 (range: 6–35) to 3 (0–22) (p<0.001; Wilcoxon signed-rank test), as did the storage symptoms score, which decreased from 13 (2–20) to 3 (1–8) (p<0.001). Median bladder blood flow increased at the trigone from 9.57±0.83 ml/sec to 17.60±1.08 ml/sec. Multiple regression analysis for the improved storage symptom score eliminated all explanatory variables except increased bladder perfusion. The data suggest that HoLEP improves blood flow in the bladder mucosa, which independently leads to the improvement of storage symptoms. PMID:26090819

  5. [Investigation of changes in sexual and ejaculatory functions after holmium laser enucleation of the prostate (HoLEP)].

    PubMed

    Ishikawa, Ryuta; Shitara, Toshiya; Hirayama, Takahiro; Wakatabe, Yoji; Dobashi, Masato; Sugita, Yoshiko; Kubo, Seiichi; Fujita, Tetsuo; Iwamura, Masatsugu; Baba, Shiro

    2014-06-01

    Changes in sexual function and ejaculatory function in patients who had undergone holmium laser enucleation of the prostate (HoLEP) were investigated using questionnaires. In this study, 77 patients on whom HoLEP was performed at our department from July 2010 to December 2010 were included. Of the 77 patients, the number of patients who could achieve an erection increased from 36 (46.8%) preoperatively to 52 (67.5%) postoperatively after HoLEP. Although postoperative ejaculatory dysfunction was found in 38 (73%) of 52 patients, 47 (90%) experienced orgasms, regardless of ejaculation, which is a high rate. With respect to ejaculatory satisfaction, patients who experienced an ejaculation had significantly higher satisfaction levels than those who did not. These results suggest that changes in postoperative ejaculatory function might affect satisfaction levels of ejaculation. PMID:25001640

  6. Transurethral Surgical Anatomy of the Arterial Bleeder in the Enucleated Capsular Plane of Enlarged Prostates During Holmium Laser Enucleation of the Prostate

    PubMed Central

    Choo, Min Soo; Lee, Hahn-Ey; Bae, Jungbum; Cho, Sung Yong

    2014-01-01

    Purpose To identify the endoscopic vascular anatomy of the prostate during Holmium laser enucleation of the prostate (HoLEP), and analyze the clinical risk factors associated with significant arterial bleeding. Methods We identified 107 consecutive patients with benign prostatic hyperplasia who underwent HoLEP between September 2009 and August 2010, performed by a single surgeon (S.J.O.). Two independent reviewers reviewed the surgery video database and completed a prespecified form. The location of bleeding arteries was marked at the level of the bladder neck, proximal prostate, distal prostate, and verumontanum. Arterial bleeding was classified into one of three grades according to bleeding severity (grades 2 and 3 indicate significant bleeding). Results The mean prostate volume was 65.1±31.5 mL, and the mean prostate-specific antigen (PSA) level was 3.69±3.58 ng/mL. During the HoLEP procedure, the most common locations of significant bleeders were the 2-5 and 7-10 o'clock positions in the proximal prostate. The average number of bleeding arteries was 12.1±7.9 per procedure, and 1.93±1.20 per 10 mL of prostate volume. Multivariate analysis revealed that prostate volume and serum PSA were significant parameters for estimating the number of bleeding vessels. Conclusions During the HoLEP procedure, the most common locations of significant bleeders were the 2-5 and 7-10 o'clock positions in the proximal prostate. Prostate volume was associated with the number of bleeders. A careful approach to the capsular plane of the proximal prostate facilitates early hemostasis during the HoLEP procedure, especially with larger adenomas. PMID:25279241

  7. Comparison of Photoselective Vaporization versus Holmium Laser Enucleation for Treatment of Benign Prostate Hyperplasia in a Small Prostate Volume

    PubMed Central

    Kim, Kang Sup; Choi, Jin Bong; Bae, Woong Jin; Kim, Su Jin; Cho, Hyuk Jin; Hong, Sung-Hoo; Lee, Ji Youl; Kim, Sang Hoon; Kim, Hyun Woo; Cho, Su Yeon; Kim, Sae Woong

    2016-01-01

    Objective Photoselective vaporization of the prostate (PVP) using GreenLight and Holmium laser enucleation of the prostate (HoLEP) is an important surgical technique for management of benign prostate hyperplasia (BPH). We aimed to compare the effectiveness and safety of PVP using a 120 W GreenLight laser with HoLEP in a small prostate volume. Methods Patients who underwent PVP or HoLEP surgery for BPH at our institutions were reviewed from May 2009 to December 2014 in this retrospective study. Among them, patients with prostate volumes < 40 mL based on preoperative trans-rectal ultrasonography were included in this study. Peri-operative and post-operative parameters—such as International Prostate Symptom Score (IPSS), quality of life (QoL), maximum urinary flow rate (Qmax), post-void residual urine volume (PVR), and complications—were compared between the groups. Results PVP was performed in 176 patients and HoLEP in162 patients. Preoperative demographic data were similar in both groups, with the exception of PVR. Operative time and catheter duration did not show significant difference. Significant improvements compared to preoperative values were verified at the postoperative evaluation in both groups in terms of IPSS, QoL, Qmax, and PVR. Comparison of the postoperative parameters between the PVP and HoLEP groups demonstrated no significant difference, with the exception of IPSS voiding subscore at 1 month postoperatively (5.9 vs. 3.8, P< 0.001). There was no significant difference in postoperative complications between the two groups. Conclusion Our data suggest that PVP and HoLEP are efficient and safe surgical treatment options for patients with small prostate volume. PMID:27227564

  8. Introducing holmium laser enucleation of the prostate alongside transurethral resection of the prostate improves outcomes of each procedure

    PubMed Central

    Wilson, N; Acher, P; Lodge, R; Young, A

    2013-01-01

    Introduction Holmium laser enucleation of the prostate (HoLEP) is recognised as an alternative to transurethral resection of the prostate (TURP). HoLEP has been demonstrated to be at least as effective as TURP with less morbidity but its introduction to practice has been limited in part by the learning curve of a novel procedure. This study examined the effects of introducing HoLEP alongside an established practice of TURP on early morbidity and length of hospital stay (LOS). Methods A retrospective review of all patients who underwent HoLEP and TURP between April 2007 and July 2011 was undertaken. HoLEP was introduced in April 2008; patients undergoing TURP before this were considered as a historical control group. Data were collected concerning resection/enucleation weight, blood transfusions and LOS. Results Overall, 772 patients underwent HoLEP or TURP within the 52-month study period: 164 underwent TURP prior to the introduction of HoLEP (TURP-A), 425 had TURP after the introduction of HoLEP (TURP-B) and 183 underwent HoLEP. The mean removed weight was 24g (standard deviation [SD]: 21g) for TURP-A, 19g for TURP-B (SD: 16g) and 38g (SD: 32g) for HoLEP (p<0.005). Blood transfusion rates were 5.5%, 2.2% and 1.6% for the TURP-A, TURP-B and HoLEP groups respectively (p<0.05). For TURP-A patients, the mean LOS was 5.6 days (SD: 3.5 days, 95% confidence interval [CI]: 5.3–6.0 days). The mean LOS for TURP-B patients was 4.4 days (SD: 4.4 days, 95% CI: 4.2–4.8 days). HoLEP patients had a mean LOS of 3.0 days (SD: 3.0 days, 95% CI: 2.6–3.4 days). Conclusions The introduction of HoLEP alongside TURP is associated with lower rates of blood transfusion and shorter LOS for all patients. This is likely to be due to the use of HoLEP rather than TURP in patients with larger prostates, who are more likely to have complications. PMID:23838502

  9. Holmium laser enucleation of the prostate: surgical, functional, and quality-of-life outcomes upon extended follow-up

    PubMed Central

    Alkan, Ilter; Ozveri, Hakan; Akin, Yigit; Ipekci, Tumay; Alican, Yusuf

    2016-01-01

    ABSTRACT Objectives: To evaluate the long-term surgical, functional, and quality-of-life (QoL) outcomes after Holmium laser enucleation of the prostate (HoLEP) in patients with symptomatic benign prostatic hyperplasia (BPH). Materials and Methods: We retrospectively reviewed recorded data on patients who underwent HoLEP between June 2002 and February 2005. Ninety-six patients were enrolled. Demographic, perioperative, and postoperative data were recorded. On follow-up, International Prostate Symptom Scores (IPSSs), prostate-specific antigen (PSA) levels, QoL scores, peak uroflowmetric data (Qmax values), and post-voiding residual urine volumes (PVR volumes), were recorded. Complications were scored using the Clavien system. Statistical significance was set at p<0.05. Results: The mean follow-up time was 41.8±34.6 months and the mean patient age 73.2±8.7 years. The mean prostate volume was 74.6±34.3mL. Significant improvements in Qmax values, QoL, and IPSSs and decreases in PSA levels and PVR volumes were noted during follow-up (all p values=0.001). The most common complication was a requirement for re-catheterisation because of urinary retention. Two patients had concomitant bladder tumours that did not invade the muscles. Eight patients (8.3%) required re-operations; three had residual adenoma, three urethral strictures, and two residual prostate tissue in the bladder. Stress incontinence occurred in one patient (1%). All complications were of Clavien Grade 3a. We noted no Clavien 3b, 4, or 5 complications during follow-up. Conclusions: HoLEP improved IPSSs, Qmax values, PVR volumes, and QoL and was associated with a low complication rate, during extended follow-up. Thus, HoLEP can be a viable option to transurethral resection of the prostate. PMID:27256184

  10. Holmium Laser Enucleation of the Prostate for Benign Prostatic Hyperplasia: Effectiveness, Safety, and Overcoming of the Learning Curve

    PubMed Central

    Hwang, Jin Chul; Park, Sang Myung

    2010-01-01

    Purpose To examine the efficacy and safety of holmium laser enucleation of the prostate (HoLEP) for the surgical treatment of benign prostatic hyperplasia and to estimate the time to overcome the learning curve. Materials and Methods From May 2008 to October 2009, 164 consecutive patients treated with HoLEP were enrolled in this study. International Prostate Symptom Score (IPSS), peak urinary flow rate (Qmax), and postvoid residual urine (PVR) were documented preoperatively and at 6 weeks and 3, 6, 12, and 18 months postoperatively. The 164 study subjects were divided into 3 groups (group 1 the first 50 patients treated, group 2 the second 50, and group 3 the third 64), and perioperative data and complications were analyzed in these groups to determine the learning curve. In addition, the inverse and upward techniques were compared in terms of the effects and the stability of morcellation. Results The mean patient age was 69 years, and the average operation time was 62 minutes (range, 20-208 minutes). Mean prostate volume was 54.2 ml and mean resected tissue weight was 18.6 g. Postoperatively, IPSS and PVR decreased and Qmax increased significantly. Postoperative complications were transient incontinence (8.5%), urinary retention (4.3%), hematuria (3.0%), urinary tract infection (1.2%), and urethral stricture (0.6%), and intraoperative complications were minor capsular perforation (4%) and bladder injury (8%). Conclusions HoLEP was found to be effective and safe regardless of prostate size. We recommend that a systematic educational program be established to reduce the learning curve. PMID:20856646

  11. Preoperative Factors Affecting Postoperative Early Quality of Life During the Learning Curve of Holmium Laser Enucleation of the Prostate

    PubMed Central

    Cho, Kang Jun; Kim, Hyo Sin; Koh, Jun Sung; Han, Seung Bum; Kim, Sang Hoon; Kim, Hyun Woo; Cho, Su Yeon

    2013-01-01

    Purpose The aim of this study was to investigate the preoperative factors related to early quality of life (QoL) in patients with benign prostatic hyperplasia after holmium laser enucleation of the prostate (HoLEP) during the surgeon's learning curve. Methods The medical records of 82 patients with a follow-up period of at least 3 months who were treated with HoLEP during the time of a surgeon's learning curve were analyzed retrospectively. We divided the patients into two groups on the basis of the QoL component of the International Prostate Symptom Score (IPSS) 3 months after HoLEP: the high QoL group (IPSS/QoL≤3) and the low QoL group (IPSS/QoL≥4). Preoperative factors in each group were compared, including prostate volume, prostate-specific antigen, history of acute urinary retention (AUR), urgency incontinence, IPSS, and urodynamic parameters. Detrusor underactivity was defined as a bladder contractility index less than 100 on urodynamic study. Results A total of 61 patients (74.3%) had a high QoL, whereas 21 (25.7%) had a low QoL. A history of AUR, detrusor pressure on maximal flow (PdetQmax), bladder outlet obstruction grade, bladder contractility index, and detrusor underactivity were associated with postoperative QoL in the univariate analysis. In the multivariate analysis, a history of AUR and PdetQmax were independent factors affecting postoperative QoL. Conclusions A history of AUR and bladder contractility affect early QoL, and preoperative urodynamic study plays an important role in the proper selection of patients during the HoLEP learning curve. PMID:23869273

  12. Holmium Laser Enucleation of the Prostate: Comparison of Immediate Postoperative Outcomes in Patients with and without Antithrombotic Therapy

    PubMed Central

    Bishop, Conrad V.; Liddell, Heath; Ischia, Joseph; Paul, Eldho; Appu, Sree; Frydenberg, Mark; Pham, Trung

    2013-01-01

    Objective To compare the immediate postoperative outcomes of patients with benign prostatic hyperplasia undergoing Holmium laser enucleation of the prostate (HOLEP) with and without full anticoagulation or antiplatelet therapy at the time of surgery. Materials and Methods A retrospective review was performed on a series of consecutive patients undergoing HOLEP at our institution by a single surgeon from February 2004 to September 2010. Demographic, surgical, pathological and outcome data were collected. Two cohorts were identified on the basis of antithrombotic therapy at the time of surgery. Patients who continued on aspirin, aspirin/dipyridamole, clopidogrel and warfarin throughout the surgery were included in the antithrombotic cohort. Univariate analysis was performed to determine differences in outcomes between the 2 cohorts. Results Total 125 consecutive patients underwent HOLEP with 52 patients on antithrombotic therapy at the time of surgery and 73 patients were not on antithrombotic therapy during surgery. Patients in the antithrombotic group were older (75.1 ±7.5 vs. 71.7 ± 8.3 years; p = 0.02) and had a higher median ASA physical status (3 (3-3) vs. 2 (2-3), p < 0.0001). The mean operating time and median specimen volume were not significantly different between the 2 cohorts. The median length of stay (2 (1-3) vs. 1 (1-2) d, p = 0.014) was longer in the antithrombotic cohort. The transfusion rate (7.7 vs. 0%, p = 0.028) was predictably higher in the antithrombotic cohort. No patients required re-operation for bleeding. Conclusions The use of HOLEP in patients on antithrombotic therapy is safe despite the higher surgical risk profile of that particular patient population and the potential increased risk for significant bleeding. PMID:24917753

  13. Relationship of Postoperative Recatheterization and Intraoperative Bladder Distention Volume in Holmium Laser Enucleation of the Prostate for Benign Prostatic Hyperplasia

    PubMed Central

    Kim, Hyeon Jun; Lee, Han Yi; Song, Sang Hun

    2013-01-01

    Purpose The purpose of this study was to identify the risk factors for recatheterization after holmium laser enucleation of the prostate (HoLEP). Materials and Methods A total of 166 consecutive patients treated with HoLEP by a single surgeon from January 2010 to June 2011 were enrolled in this study. We collected data on preoperative and intraoperative parameters, including intraoperative bladder distention volume. The patients were divided into two groups. Group 1 included patients who voided successfully after removal of the catheter, and group 2 included patients who required recatheterization. Analysis and comparison of the perioperative parameters of both groups was performed for identification of risk factors for recatheterization. Results Recatheterization was required in 9 of 166 (5.4%) patients. No significant differences in age or preoperative parameters, including prostate-specific antigen, prostate volume, International Prostate Symptom Score, peak flow rate, postvoid residual urine, maximal bladder capacity, and Abrahams Griffiths number, were observed between the two groups. Of the intraoperative parameters, intraoperative bladder distention volume was significantly smaller in group 1 than in group 2 (700.65 mL vs. 897.78 mL, p<0.001). In the multivariate logistic regression analysis, after adjustment for other variables, intraoperative bladder distention volume was found to be a statistically significant risk factor for postoperative recatheterization (hazard ratio, 1.006; confidence interval, 1.002 to 1.010; p=0.002). Conclusions Nine of 166 (5.4%) patients failed to void after HoLEP and required catheterization. Intraoperative bladder distention volume was found to be a statistically significant risk factor for recatheterization in this patient group. PMID:23549294

  14. Postoperative Infectious Complications in Our Early Experience With Holmium Laser Enucleation of the Prostate for Benign Prostatic Hyperplasia

    PubMed Central

    Tanaka, Kazushi; Haraguchi, Takahiro; Yamamichi, Fukashi; Muramaki, Mototsugu; Miyake, Hideaki; Fujisawa, Masato

    2013-01-01

    Purpose The objective of this study was to retrospectively investigate postoperative infectious complications (PICs) in our early experience with holmium laser enucleation of the prostate (HoLEP) followed by mechanical morcellation for symptomatic benign prostatic hyperplasia. Materials and Methods A retrospective review was performed of the clinical data for 90 consecutive patients who underwent HoLEP at our institution between February 2008 and March 2011. All patients were evaluated for the emergence of PICs, including prophylactic antibiotic administration (PAA) and the influence of the kind or duration of PAA on PIC. The details of cases with PICs were also examined. Results The patients' mean age was 71 years (range, 50 to 95 years), and their mean prostate volume was 60 mL (range, 2 to 250 mL). There were 7 cases (7.78%) with PICs; in detail, 3 patients were diagnosed with prostatitis, 2 with pyelonephritis, and 2 with epididymitis. Three patients had positive urine cultures: 1 had Serratia marcescens/Proteus mirabilis, 1 had S. marcescens, and 1 had Klebsiella pneumonia; only one case had urological sepsis. Our statistical data showed no significant differences between 2 or fewer days and 3 or more days of PAA and PIC occurrence. There was also no significant effect on PIC occurrence of sulbactam/ampicillin compared with other antibiotics. Conclusions The results of this retrospective study showed that PIC occurrence did not depend on the duration or the kind of PAA. Further prospective study is necessary for the evaluation and establishment of prophylactic measures for PICs. PMID:23526729

  15. Towards optimizing prostate tissue retrieval following holmium laser enucleation of the prostate (HoLEP): Assessment of two morcellators and review of literature

    PubMed Central

    Elshal, Ahmed M.; Mekkawy, Ramy; Laymon, Mahmoud; El-Assmy, Ahmed; El-Nahas, Ahmed R.

    2015-01-01

    Introduction: We assess different approaches to retrieve the enucleated adenoma after transurethral enucleation of the prostate, particularly using the holmium laser. Methods: A retrospective review through our prospectively maintained database was performed looking for safety and efficacy of two morcellators. The enucleation phase of the holmium laser enucleation of the prostate (HoLEP) was classically performed followed by retrieval of the intravesical adenoma using either the Piranha (Wolf Inc., Knittlingen, Germany) or VersaCut (Lumenis) morcellator. A PubMed-MEDLINE search was conducted for all transurethral enucleation procedures and relevant data regarding methods of prostate tissue retrieval were extracted. Results: Strictly limiting the study to 3 reusable blades with each morcellator, we performed 67 and 55 consecutive procedures with Piranha and VersaCut, respectively. There was no significant difference between the two morcellators regarding perioperative complications, apart from 5 bladder mucosal injuries with the VersaCut (9%). Furthermore, there were similar retrieved tissue weight, mechanical problems-rate, catheter-time and hospital-stay in both morcellators. However, the Piranha morcellator needed significantly less morcellation-time, needed to use cold loop to remove non-morcellated pieces and to score the adenoma by laser for better bite of the adenoma, and had a higher median morcellation-rate 6.2 (rate: 2.8–12) g/min. Despite little reporting on morcellation, we had data on the tissue retrieval rate (2.6 to 6.5 g/min with Piranha and 1.9 to 11 g/min with VersaCut. Furthermore, bladder mucosal injury was reported in 1.4% and 0.7 to 5.7% with Piranha and VersaCut, respectively; bladder perforation with VersaCut was experienced in about 0.1 to 1.5% of patients. Our study is limited by its non-randomization. Conclusion: The Piranha morcellator was the most efficient and safe way to retrieve tissue after a transurethral enucleation of a prostate

  16. Holmium laser enucleation versus simple prostatectomy for treating large prostates: Results of a systematic review and meta-analysis

    PubMed Central

    Jones, Patrick; Alzweri, Laith; Rai, Bhavan Prasad; Somani, Bhaskar K.; Bates, Chris; Aboumarzouk, Omar M.

    2015-01-01

    Objective To compare and evaluate the safety and efficacy of holmium laser enucleation of the prostate (HoLEP) and simple prostatectomy for large prostate burdens, as discussion and debate continue about the optimal surgical intervention for this common pathology. Materials and methods A systematic search was conducted for studies comparing HoLEP with simple prostatectomy [open (OP), robot-assisted, laparoscopic] using a sensitive strategy and in accordance with Cochrane collaboration guidelines. Primary parameters of interest were objective measurements including maximum urinary flow rate (Qmax) and post-void residual urine volume (PVR), and subjective outcomes including International Prostate Symptom Score (IPSS) and quality of life (QoL). Secondary outcomes of interest included volume of tissue retrieved, catheterisation time, hospital stay, blood loss and serum sodium decrease. Data on baseline characteristics and complications were also collected. Where possible, comparable data were combined and meta-analysis was conducted. Results In all, 310 articles were identified and after screening abstracts (114) and full manuscripts (14), three randomised studies (263 patients) were included, which met our pre-defined inclusion criteria. All these compared HoLEP with OP. The mean transrectal ultrasonography (TRUS) volume was 113.9 mL in the HoLEP group and 119.4 mL in the OP group. There was no statistically significant difference in Qmax, PVR, IPSS and QoL at 12 and 24 months between the two interventions. OP was associated with a significantly shorter operative time (P = 0.01) and greater tissue retrieved (P < 0.001). However, with HoLEP there was significantly less blood loss (P < 0.001), patients had a shorter hospital stay (P = 0.03), and were catheterised for significantly fewer hours (P = 0.01). There were no significant differences in the total number of complications recorded amongst HoLEP and OP (P = 0.80). Conclusion The results of the meta

  17. Efficacy and Safety of 120-W Thulium:Yttrium-Aluminum-Garnet Vapoenucleation of Prostates Compared with Holmium Laser Enucleation of Prostates for Benign Prostatic Hyperplasia

    PubMed Central

    Hong, Kai; Liu, Yu-Qing; Lu, Jian; Xiao, Chun-Lei; Huang, Yi; Ma, Lu-Lin

    2015-01-01

    Background: This study compared the efficacy and safety between 120-W thulium:yttrium-aluminum-garnet (Tm:YAG) vapoenucleation of prostates (ThuVEP) and holmium laser enucleation of prostates (HoLEP) for patients with lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH). Methods: A retrospective analysis of 88 consecutive patients with symptomatic BPH was carried out, who underwent either 120-W ThuVEP or HoLEP nonrandomly. Patient demographics and peri-operative and 12-month follow-up data were analyzed with the International Prostate Symptom Score (IPSS), quality of life (QoL) score, maximum flow rate (Qmax), postvoid residual urine volume (PVR), and rates of peri-operative and late complications. Results: The patients in each group showed no significant difference in preoperative parameters. Compared with the HoLEP group, patients in the 120-W ThuVEP group required significantly shorter time for laser enucleation (58.3 ± 12.8 min vs. 70.5 ± 22.3 min, P = 0.003), and resulted in a significant superiority in laser efficiency (resected prostate weight/laser enucleation time) for 120-W Tm:YAG laser compared to holmium:YAG laser (0.69 ± 0.18 vs. 0.61 ± 0.19, P = 0.048). During 1, 6, and 12 months of follow-ups, the procedures did not demonstrate a significant difference in IPSS, QoL score, Qmax, or PVR (P > 0.05). Mean peri-operative decrease of hemoglobin in the HoLEP group was similar to the ThuVEP group (17.1 ± 12.0 g/L vs. 15.2 ± 10.1 g/L, P = 0.415). Early and late incidences of complications were low and did not differ significantly between the two groups of 120-W ThuVEP and HoLEP patients (P > 0.05). Conclusions: 120-W ThuVEP and HoLEP are potent, safe and efficient modalities of minimally invasive surgeries for patients with LUTS due to BPH. Compared with HoLEP, 120-W ThuVEP offers advantages of reduction of laser enucleation time and improvement of laser efficiency. PMID:25836607

  18. Transurethral holmium laser enucleation of prostates (HoLEP) larger than 80 g

    NASA Astrophysics Data System (ADS)

    Kuntz, Rainer M.; Lehrich, Karin; Fayad, Amr

    2001-05-01

    In this prospective study, the efficiency of HoLEP inpatients with prostates larger than 80 grams was to be evaluated. 64 urodynamically obstructed patients with prostate glands of 103 (80-230) grams of weight underwent HoLEP (80 W, 2.0 J, 40 Hz, 550 nm bare laser fibers). The resected weight was 70 (50-200) grams, the resection time was 120.5 (83-170) min., the average resection weight was 0.7 gm/min. The postoperative catheter time was 1.3 (1-3) days. The postoperative hospital stay was 2.5 (1-7) days. HoLEP induced a significant, pronounced and immediate improvement of lower urinary tract symptoms and micturition. The symptom score decreased from 22.3 preoperatively to 5.7 one week and 2.8 one year postoperatively. The peak urinary flow rate of 4.3 ml/sec preoperatively increased to 22 ml/sec one week and 32 ml/sec one year postoperatively. The residual urine dropped from 267 ml preoperatively to 11.5 ml one week and 5.0 ml one year postoperatively. There was one incident of postoperative arterial bleeding, one patient developed urethral stricture and two patients needed a second HoLEP. HoLEP appeared to be a highly effective treatment for prostates larger than 80 grams, with excellent functional results, minor blood loss, low complication rate and very short catheter time and hospital stay.

  19. Holmium Laser Enucleation of the Prostate With Percutaneous Nephrostomy Into the Transplanted Kidney in Patient With Severe Benign Prostatic Hyperplasia With Vesicoureteral Reflux - A Case Report.

    PubMed

    Nohara, Takahiro; Matsuyama, Satoko; Shima, Takashi; Kawaguchi, Shohei; Seto, Chikashi

    2016-01-01

    A 66-year-old male, who had received renal transplantation 10 years before, was admitted to our hospital with urinary retention. The prostate volume was 169.2 ml. Furthermore, grade 5 vesicoureteral reflux (VUR) was shown in the cystography. Holmium laser enucleation of prostate (HoLEP) was performed, and percutaneous nephrostomy to the transplanted kidney was performed simultaneously to prevent from severe perioperative infection. After that, renal graft function improved and no urinary retention reoccurred, although surgical repair against VUR was necessary 10 months after HoLEP. We conclude that surgical treatment for BPH after kidney transplantation should be strongly considered with care for infections. PMID:26793574

  20. Holmium Laser Enucleation of the Prostate With Percutaneous Nephrostomy Into the Transplanted Kidney in Patient With Severe Benign Prostatic Hyperplasia With Vesicoureteral Reflux – A Case Report

    PubMed Central

    Nohara, Takahiro; Matsuyama, Satoko; Shima, Takashi; Kawaguchi, Shohei; Seto, Chikashi

    2015-01-01

    A 66-year-old male, who had received renal transplantation 10 years before, was admitted to our hospital with urinary retention. The prostate volume was 169.2 ml. Furthermore, grade 5 vesicoureteral reflux (VUR) was shown in the cystography. Holmium laser enucleation of prostate (HoLEP) was performed, and percutaneous nephrostomy to the transplanted kidney was performed simultaneously to prevent from severe perioperative infection. After that, renal graft function improved and no urinary retention reoccurred, although surgical repair against VUR was necessary 10 months after HoLEP. We conclude that surgical treatment for BPH after kidney transplantation should be strongly considered with care for infections. PMID:26793574

  1. Efficacy and safety of holmium laser enucleation of the prostate for extremely large prostatic adenoma in patients with benign prostatic hyperplasia

    PubMed Central

    Kim, Myong; Piao, Songzhe; Lee, Hahn-Ey; Kim, Sung Han

    2015-01-01

    Purpose To evaluate the efficacy and safety of holmium laser enucleation of the prostate (HoLEP) for extremely large prostates. Materials and Methods Patients undergoing HoLEP between July 2008 and December 2013 from the Seoul National University Hospital Benign Prostatic Hyperplasia Database Registry were retrospectively analyzed. The patients were divided into three groups according to their total prostate volume (TPV): group A (TPV<100 mL), group B (100 mL≤TPV<200 mL), and group C (TPV≥200 mL); the clinical data of the three groups were compared. All patients were followed up 2 weeks, 3 months, and 6 months after surgery. Results A total of 502 patients (group A, 426; group B, 70; group C, 6) with a mean age of 69.0 (standard deviation, ±7.3) years were included in our analysis. The mean prostate volume and prostate-specific antigen level were 68.7±36.9 mL and 4.15±4.24 ng/mL, respectively. The enucleation and morcellation times were longer in group C (p<0.001), and the enucleation efficacy was higher in this group (p<0.001, R2=0.399). Moreover, the mean postoperative catheterization and hospitalization periods were significantly longer in group C (p=0.004 and p=0.011, respectively). However, there were no significant differences between the groups in any other postoperative events, including recatheterization, reoperation, urinary tract infection, clot retention, and bladder neck contracture (p range, 0.516-0.913). One patient in group C experienced recurrence of the urethral stricture. Conclusions HoLEP in patients with an extremely large prostate can be performed efficiently and safely. PMID:25763126

  2. Pilot study of the clinical efficacy of ejaculatory hood sparing technique for ejaculation preservation in Holmium laser enucleation of the prostate.

    PubMed

    Kim, M; Song, S H; Ku, J H; Kim, H-J; Paick, J-S

    2015-01-01

    We explored the effectiveness of ejaculatory hood sparing technique to Holmium laser enucleation of the prostate (HoLEP) for ejaculation preservation. From June 2010 to July 2011, 52 sexually active patients with sufficient ejaculate underwent HoLEP. Twenty-six patients received the ejaulatory hood sparing technique during HoLEP (EH-HoLEP group). The other 26 patients underwent conventional HoLEP (conventional-HoLEP group). In the EH-HoLEP group, paracollicular and supracollicular tissue >1 cm proximal to the verumontanum was preserved. The mean follow-up period was 9.7 months (range 3-12). There was no significant difference in patient characteristics and perioperative parameters, including age, prostate volume, International Index of Erectile Function score, operation time, weight of the enucleated tissue and the amount of laser energy. Semen was unchanged, decreased or vanished in 4 (15.4%), 8 (30.8%) and 17 (53.8%) EH-HoLEP patients, respectively. In the conventional-HoLEP group, semen was unchanged, decreased or vanished in 0 (0.0%%), 7 (26.9%) and 19 (73.1%) patients, respectively. Overall success rate of ejaculation preservation was 46.2% in the EH-HoLEP group and 26.9% in the conventional-HoLEP group (P = 0.249). Application of an ejaculatory hood sparing technique to HoLEP could not improve the success rate for ejaculation preservation. This was likely due to the surgical characteristics of HoLEP, which enable complete removal of the apical tissue. In this condition, simply preserved ejaculatory hood tissue seems not to be sufficient to obviate retrograde ejaculation. For the maintenance of antegrade ejaculation, it is postulated that a part of apical tissue should be preserved as well. PMID:25007827

  3. AB070. Comparison of photoselective vaporization versus holmium laser enucleation for treatment of benign prostate hyperplasia in a small prostate volume

    PubMed Central

    Bae, Woong Jin; Bashraheel, Fahad; Choi, Sae Woong; Kim, Su Jin; Yoon, Byung Il; Kim, Sae Woong

    2016-01-01

    Objective Photoselective vaporization of the prostate (PVP) using GreenLight and Holmium laser enucleation of the prostate (HoLEP) is an important surgical technique for management of benign prostate hyperplasia (BPH). We aimed to compare the effectiveness and safety of PVP using a 120 W GreenLight laser with HoLEP in a small prostate volume. Methods Patients who underwent PVP or HoLEP surgery for BPH at our institutions were reviewed from May 2009 to December 2014 in this retrospective study. Among them, patients with prostate volumes <40 mL based on preoperative trans-rectal ultrasonography were included in this study. Peri-operative and post-operative parameters—such as International Prostate Symptom Score (IPSS), quality of life (QoL), maximum urinary flow rate (Qmax), post-void residual urine volume (PVR), and complications—were compared between the groups. Results PVP was performed in 176 patients and HoLEP in162 patients. Preoperative demographic data were similar in both groups, with the exception of PVR. Operative time and catheter duration did not show significant difference. Significant improvements compared to preoperative values were verified at the postoperative evaluation in both groups in terms of IPSS, QoL, Qmax, and PVR. Comparison of the postoperative parameters between the PVP and HoLEP groups demonstrated no significant difference, with the exception of IPSS voiding subscore at one month postoperatively (5.9 vs. 3.8, P<0.001). There was no significant difference in postoperative complications between the two groups. Conclusions Our data suggest that PVP and HoLEP are efficient and safe surgical treatment options for patients with small prostate volume.

  4. Nonspecific Genitourinary Pain Improves after Prostatectomy Using Holmium Laser Enucleation of Prostate in Patients with Benign Prostatic Hyperplasia: A Prospective Study

    PubMed Central

    Kim, Sung Han; Oh, Seung-June

    2014-01-01

    Objective To investigate changes in nonspecific genitourinary discomfort or pain (GUDP) before and after holmium laser enucleation of prostate (HoLEP). GUDP associated with lower urinary tract symptoms (LUTS) is a common complaint among benign prostatic hyperplasia (BPH) patients, but very little is known about this clinical entity. Methods From February 2010 to August 2011, 100 HoLEP patients with complete clinical data at a single institution were enrolled in the study to analyze the degree of GUDP with a visual analog scale (VAS) from 0 to 10 points at baseline and at 3 and 6 months postoperatively, and to investigate any relationships between GUDP and urodynamics, uroflowmetry, and scores from the International Prostate Symptom Score (IPSS) questionnaire. Results Fifty-six patients had LUTS only, while the remaining 44 had both LUTS and GUDP. Pain was located in the suprapubic (42.0%), perineal/penile (33.0%), back (17.0%), and perianal (8.0%) regions. During the post-operative period, at six months, the VAS, IPSS, peak flow rate and post-void residual volume had improved significantly in 44 GUDP patients (p<0.010). GUDP had completely resolved in 40 (90.9%) patients and had decreased in four (9.1%) patients, while seven (12.5%) patients developed GUDP with voiding in the urethral and perineal areas by the third month postoperatively. When compared to patients with complete resolution, those with persistent GUDP were found to have a significantly higher preoperative presence of bladder outlet obstruction (BOO) as an independent risk factor (OR 6.173, 95% CI 1.132–1.323). Conclusion Both GUDP and LUTS improved significantly after HoLEP. Patients with significant preoperative BOO tended to have persistent GUDP after surgery. PMID:24901224

  5. Application of the Modified Clavien Classification System to 402 Cases of Holmium Laser Enucleation of the Prostate for Benign Prostatic Hyperplasia

    PubMed Central

    Choi, Jong In; Moon, Kyung Young; Yoon, Jong Hyun; Na, Woong

    2014-01-01

    Purpose We attempted to evaluate the perioperative complications of holmium laser enucleation of the prostate (HoLEP) for benign prostatic hyperplasia by using the modified Clavien classification system (MCCS). Materials and Methods Targeting 402 patients who underwent HoLEP for benign prostatic hyperplasia performed by a single surgeon between July 2008 and January 2011, we investigated complications that occurred during and within 1 month after surgery and classified them into grade I to grade V on the basis of the MCCS. If two or more complications occurred in one patient, each complication was graded and counted. Results The mean age, prostate volume, operation time, hospital stay, and average follow-up period of 402 patients who underwent HoLEP were 68.8 years (range, 52-84 years), 53.2 g (range, 23-228 g), 58.2 minutes (range, 20-230 minutes), 4.5 days (range, 2-7 days), and 9 months (range, 4-27 months), respectively; 78 complications occurred in 71 of the patients (morbidity rate, 17.6%). In MCCS grade I, complications occurred in 54 cases (69.2%); in grade II, complications occurred in 19 cases (24.3%); in grade III, complications occurred in 4 cases (5.1%); and in grade IV, 1 patient required intensive care unit care because of cerebral infarction (1.2%). There were no grade V complications. Conclusions The HoLEP-based MCCS complications classification was performed very quickly. However, MCCS, when compared with other measures of endoscopic prostate surgery experiences, including HoLEP, exposed the lack of accuracy in low grade classification and the inability to include late complications. PMID:24648872

  6. Holmium Laser Enucleation of the Prostate is Effective in the Treatment of Symptomatic Benign Prostatic Hyperplasia of Any Size Including a Small Prostate

    PubMed Central

    Lee, Min Ho; Yang, Hee Jo; Kim, Doo Sang; Lee, Chang Ho

    2014-01-01

    Purpose Although transurethral resection of the prostate (TURP) is considered the standard surgical treatment for benign prostatic hyperplasia (BPH), Holmium laser enucleation of the prostate (HoLEP) is replacing TURP. We compared TURP with HoLEP with matching for prostate size. Materials and Methods We retrospectively reviewed the medical charts of patients who underwent TURP and HoLEP performed by one surgeon at our institute. All patients were categorized into 3 groups on the basis of prostate size (group 1, <40 g; group 2, 40-79 g; and group 3, >80 g), and 45 patients were selected for each method. Results No major intraoperative complications were encountered. The mean resected tissue weight was 6.3, 18.3, and 28.0 g for groups 1, 2, and 3, respectively, for TURP and 8.7, 25.0, and 39.8 g, respectively, for HoLEP. The mean operation time was 51.8, 89.3, and 101.9 minutes for TURP and 83.6, 122.8, and 131.2 minutes for HoLEP in groups 1, 2, and 3, respectively. HoLEP had better resection efficacy than TURP for any size prostate, but there was no statistical difference between the methods. Both methods resulted in an immediate and significant improvement of International Prostate Symptom Score, peak urinary flow rates, and postvoid residual urine volume. Conclusions HoLEP is effective for BPH treatment, regardless of prostate size, even in a small prostate. The perioperative morbidity of HoLEP is also comparable to that of TURP. PMID:25405016

  7. Comparison of Predictive Factors for Postoperative Incontinence of Holmium Laser Enucleation of the Prostate by the Surgeons’ Experience During Learning Curve

    PubMed Central

    Tanaka, Kazushi; Yamamichi, Fukashi; Chiba, Koji; Fujisawa, Masato

    2016-01-01

    Purpose: To detect predictive factors for postoperative incontinence following holmium laser enucleation of the prostate (HoLEP) according to surgeon experience (beginner or experienced) and preoperative clinical data. Methods: Of 224 patients, a total of 203 with available data on incontinence were investigated. The potential predictive factors for post-HoLEP incontinence included clinical factors, such as patient age, and preoperative urodynamic study results, including detrusor overactivity (DO). We also classified the surgeons performing the procedure according to their HoLEP experience: beginner (<21 cases) and experienced (≥21 cases). Results: Our statistical data showed DO was a significant predictive factor at the super-short period (the next day of catheter removal: odds ratio [OR], 3.375; P=0.000). Additionally, patient age, surgeon mentorship (inverse correlation), and prostate volume were significant predictive factors at the 1-month interval after HoLEP (OR, 1.072; P=0.004; OR, 0.251; P=0.002; and OR, 1.008; P=0.049, respectively). With regards to surgeon experience, DO and preoperative International Prostate Symptom Score (inverse) at the super-short period, and patient age and mentorship (inverse correlation) at the 1-month interval after HoLEP (OR, 3.952; P=0.002; OR, 1.084; P=0.015; and OR,1.084; P=0.015; OR, 0.358; P=0.003, respectively) were significant predictive factors for beginners, and first desire to void (FDV) at 1 month after HoLEP (OR, 1.009; P=0.012) was a significant predictive factor for experienced surgeons in multivariate analysis. Conclusions: Preoperative DO, IPSS, patient age, and surgeon mentorship were significant predictive factors of postoperative patient incontinence for beginner surgeons, while FDV was a significant predictive factors for experienced surgeons. These findings should be taken into account by surgeons performing HoLEP to maximize the patient’s quality of life with regards to urinary continence. PMID

  8. Holmium Laser Enucleation versus Transurethral Resection in Patients with Benign Prostate Hyperplasia: An Updated Systematic Review with Meta-Analysis and Trial Sequential Analysis

    PubMed Central

    Ruan, Xiao-Lan; Weng, Hong; Liu, Tong-Zu; Wang, Xiao; Zhang, Chao; Meng, Zhe; Wang, Xing-Huan

    2014-01-01

    Background Holmium laser enucleation (HoLEP) in surgical treatment of benign prostate hyperplasia (BPH) potentially offers advantages over transurethral resection of the prostate (TURP). Methods Published randomized controlled trials (RCTs) were identified from PubMed, EMBASE, Science Citation Index, and the Cochrane Library up to October 10, 2013 (updated on February 5, 2014). After methodological quality assessment and data extraction, meta-analysis was performed using STATA 12.0 and Trial Sequential Analysis (TSA) 0.9 software. Results Fifteen studies including 8 RCTs involving 855 patients met the criteria. The results of meta-analysis showed that: a) efficacy indicators: there was no significant difference in quality of life between the two groups (P>0.05), but compared with the TURP group, Qmax was better at 3 months and 12 months, PVR was less at 6, 12 months, and IPSS was lower at 12 months in the HoLEP, b) safety indicators: compared with the TURP, HoLEP had less blood transfusion (RR 0.17, 95% CI 0.06 to 0.47), but there was no significant difference in early and late postoperative complications (P>0.05), and c) perioperative indicators: HoLEP was associated with longer operation time (WMD 14.19 min, 95% CI 6.30 to 22.08 min), shorter catheterization time (WMD −19.97 h, 95% CI −24.24 to −15.70 h) and hospital stay (WMD −25.25 h, 95% CI −29.81 to −20.68 h). Conclusions In conventional meta-analyses, there is no clinically relevant difference in early and late postoperative complications between the two techniques, but HoLEP is preferable due to advantage in the curative effect, less blood transfusion rate, shorter catheterization duration time and hospital stay. However, trial sequential analysis does not allow us to draw any solid conclusion in overall clinical benefit comparison between the two approaches. Further large, well-designed, multicentre/international RCTs with long-term data and the comparison between the two approaches remain open

  9. Holmium laser pumped with a neodymium laser

    SciTech Connect

    Bowman, S.R.; Rabinovich, W.S.

    1991-07-30

    This patent describes a solid-state laser device. It comprises a holmium laser having a first host material doped with an amount of holmium ions sufficient to produce an output laser emission at about 3 {mu}m when the holmium ions in the holmium laser are pumped by a pump beam at a wavelength of about 1.1 {mu}m; and neodymium laser pump source means for supplying a pump beam to pump the holmium ions in the holmium laser at a wavelength of about 1.1 {mu}m.

  10. Holmium laser for treatment of benign prostatic hyperplasia: old wine in a new bottle?

    NASA Astrophysics Data System (ADS)

    Nelius, Thomas; de Riese, Werner T. W.

    2003-06-01

    Urinary tract symptoms related to benign prostatic hyperplasia affect 70% of men older than 70 years. Complications are common problems and a significant cause of morbidity in this population, placing a considerable burden on health services. In the early 1990s laser treatment of benign prostatic hyperplasia became widely used after the introduction of the side-firing neodym: YAG laser. However, because of technical limitations and inferior results compared to classical transurethral resection of the prostate many Urologists became desinterested in this device. With the introduction of the holmium: YAG laser a new laser generation became available for use in Urology. Beside several other applications the holmium: YAG laser can be used for incision, ablation, resection, and more recently enucleation of the prostate. In this paper we reviewed the current literature regarding the holmium: YAG laser resection and enucleation of the prostate compared to transurethral resection of the prostate and open prostatectomy. The holmium: YAG laser technique is an effective and durable surgical alternative to standard transurethral resection of the prostate. Interestingly, enucleation of the prostate with this device seems to be a safe and effective procedure for large prostatic adenomas, it may become an attractive alternative to open prostatectomy.

  11. Holmium:YAG surgical lasers.

    PubMed

    1995-03-01

    "Holmium:YAG (Ho:YAG)" is the shorthand name for a family of solid-state lasers that use the doping element holmium in a laser crystal (e.g., YAG [yttrium-aluminum-garnet]) and that emit energy at approximately 2.1 microns. This wavelength is relatively new to medicine and has been used in laser surgery for only about the last six years. Like the carbon dioxide (CO2) laser when it was first used clinically, the Ho:YAG laser is poised for rapid and wide-spread use. Ho:YAG lasers, like CO2 lasers, offer precise cutting with minimal damage to adjacent tissue; however, unlike CO2 lasers, they also offer fiberoptic delivery (which is ideal for endoscopic use) and the ability to treat tissue in a liquid-filled environment (e.g., saline, blood). The initial specialty for which the Ho:YAG laser was used was arthroscopic surgery, especially diskectomy. Today, it is effectively used in many surgical specialties, including general surgery, urology, laparoscopy, neurosurgery, lithotripsy, angioplasty, orthopedic surgery (which includes procedures such as meniscectomy, bone sculpting [may also be performed in plastic surgery], and some experimental surgery, such as cartilage shrinking to tighten loose joints), and dentistry. Because of its broad range of potential applications, it has been called the "Swiss Army Knife" of lasers. High-powered Ho:YAG lasers, which enable surgeons to work more quickly and cut more smoothly, have been made available only within the last three years (units offering > 20 W) to 18 months (units offering > 60 W). Because of this rapid increase, high-powered units are still relatively expensive, and it is not yet clear whether maximum power outputs will continue to increase or whether the cost of higher-power units will begin to come down. Although low-power and high-power Ho:YAG lasers can be used for the same procedures, their different ranges of possible clinical techniques make them better suited to different applications: low-power units are

  12. Early complications with the holmium laser

    NASA Astrophysics Data System (ADS)

    Beaghler, Marc A.; Stewart, Steven C.; Ruckle, Herbert C.; Poon, Michael W.

    1997-05-01

    The purpose of this study is to report early complications in our initial experience with the holmium laser in 133 patients. A retrospective study of patients undergoing endourological procedures with the holmium laser was performed. Complications included urinary tract infection (3), post-operative bradycardia (1), inverted T-waves (1), intractable flank pain (1), urinary retention (1), inability to access a lower pole calyx with a 365 micron fiber (9), stone migration (5), termination of procedure due to poor visualization (2). No ureteral perforations or strictures occurred. The holmium laser was capable of fragmenting all urinary calculi in this study. In our initial experience, the holmium laser is safe and effective in the treatment of genitourinary pathology. Use of laser fibers larger than 200 microns occasionally limit deflection into a lower pole or dependent calyx.

  13. Semiconductor disk laser-pumped subpicosecond holmium fibre laser

    SciTech Connect

    Chamorovskiy, A Yu; Marakulin, A V; Leinonen, T; Kurkov, Andrei S; Okhotnikov, Oleg G

    2012-01-31

    The first passively mode-locked holmium fibre laser has been demonstrated, with a semiconductor saturable absorber mirror (SESAM) as a mode locker. Semiconductor disk lasers have been used for the first time to pump holmium fibre lasers. We obtained 830-fs pulses at a repetition rate of 34 MHz with an average output power of 6.6 mW.

  14. [A Case of Holmium: YAG Laser Resection of Superficial Bladder Tumor (HoLRBT)].

    PubMed

    Sugita, Yoshiko; Shitara, Toshiya; Hirayama, Takahiro; Fujita, Tetsuo; Yoshida, Kazunari; Kubo, Seiichi; Iwamura, Masatsugu

    2015-10-01

    We present a case of holmium : YAG laser resection of superficial bladder tumor (HoLRBT). A 73-year-old male was referred to our hospital with elevated prostatic specific antigen. Due to difficulty of urination, holmium : YAG laser enucleation of the prostate was performed under the diagnosis of benign prostatic hyperplasia. During the surgery, superficial bladder tumor was incidentally identified, and HoLRBT was performed. After the operation, histopathological examination revealed urothelial carcinoma, G2 > G1, pTa. The patient has been subsequently followed up for 9 months, and there areno evidence of recurrence. Changing the holmium : YAG laser energy setting can potentially be effective and safe to approach a superficial bladder tumor. PMID:26563623

  15. Evaluation of holmium laser for transurethral deroofing of severe and multiloculated prostatic abscesses

    PubMed Central

    Lee, Chan Ho; Ku, Ja Yoon; Park, Young Joo; Lee, Jeong Zoo

    2015-01-01

    Purpose Our objective was to evaluate the use of a holmium laser for transurethral deroofing of a prostatic abscess in patients with severe and multiloculated prostatic abscesses. Materials and Methods From January 2011 to April 2014, eight patients who were diagnosed with prostatic abscesses and who underwent transurethral holmium laser deroofing at Pusan National University Hospital were retrospectively reviewed. Results Multiloculated or multifocal abscess cavities were found on the preoperative computed tomography (CT) scan in all eight patients. All patients who underwent transurethral holmium laser deroofing of a prostatic abscess had successful outcomes, without the need for secondary surgery. Of the eight patients, seven underwent holmium laser enucleation of the prostate (HoLEP) for the removal of residual adenoma. Markedly reduced multiloculated abscess cavities were found in the follow-up CT in all patients. No prostatic abscess recurrence was found. Transient stress urinary incontinence was observed in three patients. The stress urinary incontinence subsided within 3 weeks in two patients and improved with conservative management within 2 months in the remaining patient. Conclusions Transurethral holmium laser deroofing of prostatic abscesses ensures successful drainage of the entire abscess cavity. Because we resolved the predisposing conditions of prostatic abscess, such as bladder outlet obstruction and prostatic calcification, by simultaneously conducting HoLEP, there was no recurrence of the prostatic abscesses after surgery. We recommend our method in patients requiring transurethral drainage. PMID:25685303

  16. Holmium laser for multifunctional use in urology

    NASA Astrophysics Data System (ADS)

    Watson, Graham M.; Shroff, Sunil; Thomas, Robert; Kellett, Michael

    1994-05-01

    The holmium laser pulsed at 350 microsecond cuts tissue and fragments calculi. It has been assessed for minimally invasive urological intervention. It is useful for partly excising and partly coagulating tumors, incising strictures and the obstructed PUJ. It partly drill and partly fragments urinary calculi however hard. Other lasers are more effective at any one particular application, but this laser is a useful compromise as a multifunctional device.

  17. Holmium laser lithotripsy of bladder calculi

    NASA Astrophysics Data System (ADS)

    Beaghler, Marc A.; Poon, Michael W.

    1998-07-01

    Although the overall incidence of bladder calculi has been decreasing, it is still a significant disease affecting adults and children. Prior treatment options have included open cystolitholapaxy, blind lithotripsy, extracorporeal shock wave lithotripsy, and visual lithotripsy with ultrasonic or electrohydraulic probes. The holmium laser has been found to be extremely effective in the treatment of upper tract calculi. This technology has also been applied to the treatment of bladder calculi. We report our experience with the holmium laser in the treatment of bladder calculi. Twenty- five patients over a year and a half had their bladder calculi treated with the Holmium laser. This study was retrospective in nature. Patient demographics, stone burden, and intraoperative and post-operative complications were noted. The mean stone burden was 31 mm with a range of 10 to 60 mm. Preoperative diagnosis was made with either an ultrasound, plain film of the abdomen or intravenous pyelogram. Cystoscopy was then performed to confirm the presence and determine the size of the stone. The patients were then taken to the operating room and given a regional or general anesthetic. A rigid cystoscope was placed into the bladder and the bladder stone was then vaporized using the holmium laser. Remaining fragments were washed out. Adjunctive procedures were performed on 10 patients. These included transurethral resection of the prostate, transurethral incision of the prostate, optic internal urethrotomy, and incision of ureteroceles. No major complications occurred and all patients were rendered stone free. We conclude that the Holmium laser is an effective and safe modality for the treatment of bladder calculi. It was able to vaporize all bladder calculi and provides a single modality of treating other associated genitourinary pathology.

  18. Holmium: YAG laser resection of the prostate.

    PubMed

    Bukala, B; Denstedt, J D

    1999-04-01

    The holmium laser is a relatively new multipurpose medical laser that recently became available for use in urology. There has been considerable interest in this device, as it seems to combine the cutting properties of the carbon dioxide laser with the coagulating properties of the neodymium:YAG laser, making it particularly appealing for many surgical applications. The last decade has seen enthusiasm for the use of laser energy for the treatment of benign prostatic hyperplasia. In this article, we review the technique of Ho:YAG laser resection of the prostate, including the essential equipment and perioperative patient care. PMID:10360503

  19. Holmium fibre laser with record quantum efficiency

    SciTech Connect

    Kurkov, Andrei S; Sholokhov, E M; Tsvetkov, V B; Marakulin, A V; Minashina, L A; Medvedkov, O I; Kosolapov, A F

    2011-06-30

    We report holmium-doped fibre lasers with a Ho{sup 3+} concentration of 1.6 x 10{sup 19} cm{sup -3} and lasing wavelengths of 2.02, 2.05, 2.07 and 2.1 {mu}m at a pump wavelength of 1.15 {mu}m. The slope efficiency of the lasers has been measured. The maximum efficiency, 0.455, has been obtained at a lasing wavelength of 2.05 {mu}m. The laser efficiency is influenced by both the optical loss in the wing of a vibrational absorption band of silica and active-ion clustering. (lasers)

  20. Percutaneous holmium laser fulguration of calyceal diverticula.

    PubMed

    Alwaal, Amjad; Azhar, Raed A; Andonian, Sero

    2012-01-01

    Introduction. Calyceal diverticular stones are uncommon findings that represent a challenge in their treatment, due to the technical difficulty in accessing the diverticulum, and the high risk of their recurrence. Current percutaneous technique for calyceal diverticular stones involves establishing a renal access, clearing the stone, and fulguration of the diverticular lining with a roller-ball cautery electrode using hypotonic irrigation solution such as sterile water or glycine solution which may be associated with the absorption of hypotonic fluids with its inherent electrolyte disturbances. Case Report. In this paper, we present for the first time percutaneous holmium laser fulguration of calyceal diverticula in 2 patients using normal saline. Their immediate postoperative sodium was unchanged and their follow-up imaging showed absence of stones. Both patients remain asymptomatic at 30 months post-operatively. Conclusion. This demonstrates that holmium laser is a safe alternative method to fulgurate the calyceal diverticulum after clearing the stone percutaneously. PMID:22606636

  1. Percutaneous laser disc decompression with the holmium: YAG laser.

    PubMed

    Casper, G D; Hartman, V L; Mullins, L L

    1995-06-01

    This article discusses the evolution of the percutaneous laser disc decompression (PLDD) method using a holmium:YAG laser. Advantages of using this wavelength and several techniques for its use in PLDD are reviewed. The article also discusses the current devices and delivery systems available for this application. PMID:10150646

  2. Holmium laser resection of the prostate.

    PubMed

    Matsuoka, K; Iida, S; Tomiyasu, K; Shimada, A; Suekane, S; Noda, S

    1998-06-01

    A total of 35 patients with benign prostatic hyperplasia (BPH) were treated with the Ho: YAG laser using a new technique termed holmium laser resection of the prostate or HoLRP. The laser energy was applied directly to prostatic tissue exclusively through the use of a standard 550 micron end-firing fiber. A high-powered holmium laser was used and was set at 2.4 J per pulse at 25 pulses per second for an average power of 60 W. The mean preoperative AUA Symptom Score was 24. Postoperatively, the score dropped to 10.9, 8.2, 5.2, and 4.6 at 1 week, 1 month, 3 months, and 6 months, respectively. The peak urine flow rate improved from 6.3 mL/sec preoperatively to 15.1, 15.3 and 16 mL/sec at 1 week, 1 month, 3 months, and 6 months. A foley catheter was removed within 24 hours of completion of the operation in 31 patients (89%), and voiding was improved. The HoLRP technique was bloodless, and the short-term results were satisfactory. Most importantly, the defect produced by HoLRP is identical to that of a conventional transurethral resection. These initial results demonstrate that HoLRP is a useful surgical alternative in the treatment of patients with obstructive BPH. PMID:9658303

  3. Perspectives of holmium laser resection of the prostate: cutting effects with the holmium:YAG laser

    NASA Astrophysics Data System (ADS)

    Eichenauer, Rolf H.; Droege, Gerit; Brinkmann, Ralf; Neuss, Malte; Gafumbegete, Evariste; Jocham, Dieter

    1998-07-01

    Laser prostatectomy shows an improvement in peak urinary flow rates, in post-void residual urine volumes and also a symptomatic improvement when compared to the transurethral resection of the prostate (TUR-P). Time to achieve symptomatic improvement is delayed with many established laser procedures compared to standard resection. However, this disadvantage can be solved with a new resection technique using a pulsed holmium laser. Nevertheless, this advanced technique shows a few problems in a first clinical trial. Besides this clinical study, in vitro experiments were carried out in order to determine the optimal irradiation parameters with respect to resection rate, incision/ablation quality and handling. Prostate tissue of radical prostatectomies and chicken breast as model were irradiated with a pulsed holmium-laser in vitro with different laser parameters using a bare fiber in contact to tissue. The incision quality (depths and coagulation/vaporization effects) was analyzed with regard to pulse energy (speed of incision, angle of incision) and fiber diameter. Fast flash photography was performed to analyze thermo-mechanical side-effects. Fast flash photography reveals cavitation bubble up to 7 mm length in water and dissections in tissue. The ablation rate increases proportional to the laser pulse energy. The Holmium Laser Resection of the Prostate (HOLRP) in humans with available instrumentation right now shows equieffective results compared to the transurethral resection, no need for transfusion, no transurethral resection syndrome, short time for catheterization. Further technical approvement may significantly improve holmium laser prostate resection. We present a new application system for the laser resection.

  4. Holmium:YAG laser stapedotomy: preliminary evaluation

    NASA Astrophysics Data System (ADS)

    Stubig, Ingrid M.; Reder, Paul A.; Facer, G. W.; Rylander, Henry G.; Welch, Ashley J.

    1993-07-01

    This study investigated the use of a pulsed Holmium:YAG ((lambda) equals 2.09 micrometers ) laser- fiber microsurgical system for laser stapedotomy. This system ablates human stapes bones effectively with minimal thermal damage. The study was designed to determine the effectiveness of the Ho:YAG laser (Schwartz Electro Optics, Inc., Orlando, FL) for stapedotomy and to evaluate temperature changes within the cochlea during the ablation process. Human cadaveric temporal bones were obtained and the stapes portion of the ossicular chain was removed. A 200 micrometers diameter low OH quartz fiber was used to irradiate these stapes bones in an air environment. The laser was pulsed at 2 Hz, 250 microsecond(s) ec pulse width and an irradiance range of 100 - 240 J/cm2 was used to ablate holes in the stapes footplate. The resultant stapedotomies created had smooth 300 micrometers diameter holes with a minimum of circumferential charring. Animal studies in-vivo were carried out in chinchillas to determine the caloric spread within the cochlea. A 0.075 mm Type T thermocouple was placed in the round window. Average temperature change during irradiation of the stapes footplate recorded in the round window was 3.6 degree(s)C. The data suggest that stapedotomy using the Ho:YAG laser can result in a controlled ablation of the stapes footplate with minimal thermal damage to the surrounding stapes. Optical coupling using fiberoptic silica fibers is an ideal method for delivering laser energy to the stapes during stapedotomy.

  5. Laser cooling, trapping, and Rydberg spectroscopy of neutral holmium atoms

    NASA Astrophysics Data System (ADS)

    Hostetter, James Allen

    This thesis focuses on progress towards using ensembles of neutral holmium for use in quantum computing operations. We are particularly interested in using a switchable interaction between neutral atoms, the Rydberg blockade, to implement a universal set of quantum gates in a collective encoding scheme that presents many benefits over quantum computing schemes which rely on physically distinct qubits. We show that holmium is uniquely suited for operations in a collective encoding basis because it has 128 ground hyperfine states, the largest number of any stable, neutral atom. Holmium is a rare earth atom that is very poorly described for our purposes as it has never been cooled and trapped, its spectrum is largely unknown, and it presents several unique experimental challenges related to its complicated atomic structure and short wavelength transitions. We demonstrate important progress towards overcoming these challenges. We produce the first laser cooling and trapping of holmium into a MOT. Because we use a broad cooling transition, our cooling technique does not require the use of a Zeeman slower. Using MOT depletion spectroscopy, we provide precise measurements of holmium's Rydberg states and its ionization potential. Our work continues towards cooling holmium into a dipole trap by calculating holmium's AC polarizability and demonstrating the results of early attempts at an optical dipole trap. We provide details of future upgrades to the experimental apparatus and discuss interesting potential for using holmium in quantum computing using single atoms in a magnetically trapped lattice. This thesis shows several promising indicators for continued work in this field.

  6. Midline Prostatic Cyst Marsupialization Using Holmium Laser.

    PubMed

    Kilinc, Mehmet; Goger, Yunus Emre; Piskin, Mesut; Balasar, Mehmet; Kandemir, Abdulkadir

    2015-01-01

    Many of the prostatic cysts are asymptomatic and only 5% are symptomatic (Hamper et al., 1990; Higashi et al., 1990). These symptoms include pelvic pain, hematospermia, infertility, voiding dysfunction, prostatitis-like syndrome, and painful ejaculation. Treatment of prostatic cysts includes TRUSG guided drainage, endoscopic transurethral resection, and in some cases even open surgery. In the literature, endoscopic interventions use marsupialization of the midline prostatic cyst with transurethral resection (TUR) or transurethral incision with endoscopic urethrotomy (Dik et al., 1996; Terris, 1995). Holmium: YAG laser was employed for the marsupialization of the cyst wall in midline prostatic cyst treatment for the first time in the present study. Symptoms, treatment, and follow-up are presented in this paper. PMID:26101688

  7. Midline Prostatic Cyst Marsupialization Using Holmium Laser

    PubMed Central

    Kilinc, Mehmet; Goger, Yunus Emre; Piskin, Mesut; Balasar, Mehmet; Kandemir, Abdulkadir

    2015-01-01

    Many of the prostatic cysts are asymptomatic and only 5% are symptomatic (Hamper et al., 1990; Higashi et al., 1990). These symptoms include pelvic pain, hematospermia, infertility, voiding dysfunction, prostatitis-like syndrome, and painful ejaculation. Treatment of prostatic cysts includes TRUSG guided drainage, endoscopic transurethral resection, and in some cases even open surgery. In the literature, endoscopic interventions use marsupialization of the midline prostatic cyst with transurethral resection (TUR) or transurethral incision with endoscopic urethrotomy (Dik et al., 1996; Terris, 1995). Holmium: YAG laser was employed for the marsupialization of the cyst wall in midline prostatic cyst treatment for the first time in the present study. Symptoms, treatment, and follow-up are presented in this paper. PMID:26101688

  8. Holmium laser urethrotomy for urethral stricture.

    PubMed

    Hossain, A Z M Z; Khan, S A; Hossain, S; Salam, M A

    2004-08-01

    A prospective cross-sectional study was carried-out in the department of urology, Dhaka Medical College Hospital (DMCH) to evaluate the outcome of Laser urethrotomy for the treatment of urethral stricture. For this purpose, 30 male patients aged 15 to 60 years with short segment anterior urethral stricture (>2cm) were treated by HO:YAG Laser. The energy used for this purpose was 0.8 to 1.5 joules by LISA 80 Watt Holmium Laser machine. All patients were catheterized for less than 24 hours and were followed up for 6 to 12 months postoperatively by uroflowmetry and by retrograde with voiding cystourethrogram 3 monthly. The study revealed that out of 30 patients, 27(90%) showed good flow of urine (Qave>16.0 ml/sec) and adequate caliber urethra in retrograde urethrogram (RGU). Only 3(10%) patients showed narrow stream of urine (Qave<8.0 ml/sec) and recurrent stricture in RGU which were managed by optical internal urethrotomy (OIU) and clean intermittent self catheterization (CISC). The study showed satisfactory results in 90% cases with short term follow up. The study concludes that HO:YAG Laser urethrotomy for the treatment of short segment urethral stricture is highly effective. The study further reveals that the method is simple, safe and thus, it can be considered favorably as a new therapeutic option for the treatment of urethral stricture. However, long term follow up is necessary for making a final comment on this issue. PMID:15813486

  9. Spectral performance of monolithic holmium and thulium lasers

    NASA Technical Reports Server (NTRS)

    Storm, Mark E.

    1991-01-01

    Fabry-Perot resonators have been used to demonstrate single-mode lasing of holmium and neodymium YAG. The previous demonstration in the holmium laser required TE cooling the crystal to -15 C in order to achieve threshold. The present study extends that result, demonstrating +25 C operation in a 1-mm thick plano/plano resonator. The experimental configuration of lasing both the holmium and thulium lasers used a 500-mW diode laser which was collimated, circularized, and focused into a beam radius of 60 microns. The single-frequency lasing spectrum of the holmium laser is shown. By adjusting the mirror reflectivity, the ability to control the laser's wavelength is demonstrated. This laser operated with 11 mW of optical power, a 57-percent slope efficiency, and 120-mW threshold vs absorbed diode power laser for the 60-micron beam radius. The thulium laser operated very efficiently at room temperature, but on seven longitudinal modes. The Tm:TAG laser exhibits typical characteristics of spatial hole burning not seen in the Ho:Tm:YAG for flat/flat resonators.

  10. Hemangioma of the prostatic urethra: holmium laser treatment.

    PubMed

    de León, Javier Ponce; Arce, Jacobo; Gausa, Luís; Villavicencio, Humberto

    2008-01-01

    Urethral hemangiomas are benign vascular tumors that are found in perimontanal prostatic localization and less frequently in the urethra. Although different urethral procedures have been postulated for its treatment, the best results are achieved using lasers. A patient who underwent endoscopic holmium laser treatment for such hemangiomas is presented. Total disappearance of the lesions without any complications was achieved. PMID:18204245

  11. Use of the holmium:YAG laser in urology

    NASA Astrophysics Data System (ADS)

    Mattioli, Stefano

    1997-12-01

    The Holmium-YAG is a versatile laser with multiple soft- tissue applications including tissue incision and vaporization, and pulsed-laser applications such as lithotripsy. At 2140 nanometers, the wavelength is highly absorbed by tissue water. Further, like CO2 laser, the Holmium produces immediate tissue vaporization while minimizing deep thermal damage to surrounding tissues. It is an excellent instrument for endopyelotomy, internal urethrotomy, bladder neck incisions and it can be used to resect the prostate. The Holmium creates an acute TUR defect which gives immediate results like the TURP. More than 50 patients were treated from Jan. 1996 to Jan. 1997 for obstructive symptoms due to benign prostatic hyperplasia, bladder neck stricture, urethral stenosis, and superficial bladder tumors.

  12. Holmium:YAG laser coronary angioplasty in acute myocardial infarction

    NASA Astrophysics Data System (ADS)

    Topaz, On; Luxenberg, Michael; Schumacher, Audrey

    1994-07-01

    Patients who sustain complicated acute myocardial infarction in whom thrombolytic agents either fail or are contraindicated often need mechanical revascularization other than PTCA. In 24 patients with acute infarction complicated by continuous chest pain and ischemia who either received lytics or with contraindication to lytics, a holmium:YAG laser (Eclipse Surgical Technologies, Palo Alto, CA) was utilized for thrombolysis and plaque ablation. Clinical success was achieved in 23/24 patients, with 23 patients (94%) surviving the acute infarction. Holmium:YAG laser is very effective and safe in thrombolysis and revascularization in this complicated clinical setting.

  13. Holmium YAG laser treatment of superficial bladder carcinoma.

    PubMed

    Hossain, M Z; Khan, S A; Salam, M A; Hossain, S; Islam, R

    2005-01-01

    Holmium YAG laser is one of the new modalities of treatment of urinary bladder tumor. Thirty patients of superficial bladder carcinoma were selected from the Urology out patient department of Dhaka Medical College Hospital from January 2004 to July 2004. Among thirty cases, 18 were recurrent and 12 were primary superficial bladder carcinoma. Out of thirty patients, 24 were male and six were female. Patients were treated with Holmium YAG laser under spinal anesthesia. Before resection, cold cup biopsy were taken from the apex and after resection of the tumor, another cold cup biopsy were taken from the base of the tumor. Holmium YAG laser therapy was given with a 550 micron end firing quartz laser fiber through the working element of resectoscope. Small tumors (< 1 cm) were ablated and large tumors (1-4 cm) were resected. The initial laser setting was 0.5 to 0.8 J and 10 Hz. For resection of the tumor, a slightly higher energy of 1 to 1.2 J was used at 10 to 12 Hz. After resection, bleeding vessels were coagulated. The resected tumor was evacuated by Elik's evacuator. All cases were followed for 6 to 12 months by history, physical examination, urine analysis, sonogram and cystoscopy three monthly. Bleeding was minimum during the procedure and no transfusion was required. Complications like obturator jerk, clot retention or perforation were not developed. No recurrence was found during the 6 to 12 months follow up period. The procedure was found safe, effective, and acceptable. The study was conducted to evaluate the initial result of Holmium YAG laser for the treatment of superficial bladder carcinoma. We warrants further studies in this regard. PMID:15695945

  14. Femtosecond laser based enucleation of porcine oocytes for somatic cell nuclear transfer

    NASA Astrophysics Data System (ADS)

    Kütemeyer, K.; Lucas-Hahn, A.; Petersen, B.; Hassel, P.; Lemme, E.; Niemann, H.; Heisterkamp, A.

    2009-07-01

    Cloning of several mammalian species has been achieved by somatic cell nuclear transfer (SCNT) in recent years. However, this method still results in very low efficiencies around 1% which originate from suboptimal culture conditions and highly invasive techniques for oocyte enucleation and injection of the donor cell using micromanipulators. In this paper, we present a new minimal invasive method for oocyte imaging and enucleation based on the application of femtosecond (fs) laser pulses. After imaging of the oocyte with multiphoton microscopy, ultrashort pulses are focused onto the metaphase plate of MII-oocytes in order to ablate the DNA molecules. We show that fs laser based enucleation of porcine oocytes completely inhibits the first mitotic cleavage after parthenogenetic activation while maintaining intact oocyte morphology in most cases. In contrast, control groups without previous irradiation of the metaphase plate are able to develop to the blastocyst stage. Further experiments have to clarify the suitability of fs laser based enucleated oocytes for SCNT.

  15. Treatment of pulmonary diseases with Holmium:YAG laser

    NASA Astrophysics Data System (ADS)

    Zhang, Mei-Jue; Zhu, Jing; Zhang, Hui-Guo; Wang, Fu-Juan; Ke, Lin; Ma, Wei; Luo, Qun-Hua; Zhang, Yue-E.

    1998-11-01

    We report 5 cases of pulmonary disease treated with Holmium:YAG laser through fibrous bronchoscope. 1 inflammatory granuloma was cured after three times of treatment. Compared with conventional methods such as electrocautery and microwave treatment, laser has the merit of good hemostasis effect and quick recovery of the operation area. The other 4 patients who were suffered late lung cancer received 3-7 times of palliative treatment. After the treatment, the tumor tissues become smaller variably, and tact were unobstructed, symptoms of tract- obstructed obviously alleviated. We think that laser treatment has some practical significance in alleviating tract blocking of pulmonary diseases of late stage, and therefore raise the life quality.

  16. Intracorporeal lithotripsy with the holmium:YAG laser

    NASA Astrophysics Data System (ADS)

    Denstedt, John D.; Razvi, Hassan A.; Chun, Samuel S.; Sales, Jack L.

    1995-05-01

    A variety of devices are currently available for intracorporeal stone fragmentation. Recently a new wavelength of laser, the Holmium:YAG, has demonstrated a variety of potential urologic applications including ablation of soft tissue lesions as well as stone fragmentation. This laser has a wavelength of 2100 nm and operates in a pulsed mode. Energy is delivered through a 400 um quartz end-firing fiber. In this presentation we review our clinical experience with the Holmium:YAG laser for the treatment of renal and ureteral calculi. Over a 23 month period, 63 patients underwent 67 procedures. Seven procedures consisted of percutaneous nephrolithotripsy for large or staghorn renal calculi. Sixty procedures were performed for ureteral stones. Procedures for proximal ureteral stones (6) employed a retrograde approach using flexible ureteroscopes (8.5 or 9.8). Stones in the mid ureter (12) and distal ureter (42) were approached transurethrally using a 6.9 rigid ureteroscope. Complete stone fragmentation without the need for additional procedures was achieved in 82% of cases. Treatment failures included 1 stone migration into the renal pelvis during laser activation, 6 patients who had incomplete fragmentation and 3 patients in which laser malfunction precluded complete fragmentation. Stone analysis available in 23 patients revealed calcium oxalate monohydrate (15), calcium oxalate dihydrate (2), cystine (2), uric acid (3) and calcium phosphate (1). A single complication of ureteral perforation occurred when the laser was fired without direct visual guidance. Radiographic follow-up at an average of 16 weeks is available in 22 patients and has identified 2 patients with ureteral strictures that are not believed to be related to laser lithotripsy. In summary, we have found the Holmium:YAG laser to be a reliable and versatile device for intracorporeal lithotripsy. Its safety and efficacy make it a suitable alternative for performing intracorporeal lithotripsy of urinary

  17. Holmium:YAG laser angioplasty: treatment of acute myocardial infarction

    NASA Astrophysics Data System (ADS)

    Topaz, On

    1993-06-01

    We report our clinical experience with a group of 14 patients who presented with acute myocardial infarction. A holmium:YAG laser was applied to the infarct-related artery. This laser emits 250 - 600 mJ per pulse, with a pulse length of 250 microseconds and repetition rate of 5 Hz. Potential benefits of acute thrombolysis by lasers include the absence of systemic lytic state; a shortened thrombus clearing time relative to using thrombolytics; safe removal of the intracoronary thrombus and facilitation of adjunct balloon angioplasty. Potential clinical difficulties include targeting the obstructive clot and plaque, creation of debris and distal emboli and laser-tissue damage. It is conceivable that holmium:YAG laser can be a successful thrombolytic device as its wave length (2.1 microns) coincides with strong water absorption peaks. Since it is common to find an atherosclerotic plaque located under or distal to the thrombotic occlusion, this laser can also be applied for plaque ablation, and the patient presenting with acute myocardial infarction can clearly benefit from the combined function of this laser system.

  18. Experimental studies on the usage possibilities of the holmium laser in cataract surgery

    NASA Astrophysics Data System (ADS)

    Kecik, Tadeusz; Kecik, Dariusz; Kasprzak, Jan; Pratnicki, Antoni; Jankiewicz, Zdzislaw; Zajac, Andrzej

    1996-03-01

    The authors present initial investigations of used holmium laser during experimental cataract surgery. The investigations were performed 'in vitro' and 'in vivo.' The presented results of the experiments show that structure of the lens can be emulsified with the use of the holmium laser.

  19. Combined multiphoton imaging and automated functional enucleation of porcine oocytes using femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Kuetemeyer, Kai; Lucas-Hahn, Andrea; Petersen, Bjoern; Lemme, Erika; Hassel, Petra; Niemann, Heiner; Heisterkamp, Alexander

    2010-07-01

    Since the birth of ``Dolly'' as the first mammal cloned from a differentiated cell, somatic cell cloning has been successful in several mammalian species, albeit at low success rates. The highly invasive mechanical enucleation step of a cloning protocol requires sophisticated, expensive equipment and considerable micromanipulation skill. We present a novel noninvasive method for combined oocyte imaging and automated functional enucleation using femtosecond (fs) laser pulses. After three-dimensional imaging of Hoechst-labeled porcine oocytes by multiphoton microscopy, our self-developed software automatically identified the metaphase plate. Subsequent irradiation of the metaphase chromosomes with the very same laser at higher pulse energies in the low-density-plasma regime was used for metaphase plate ablation (functional enucleation). We show that fs laser-based functional enucleation of porcine oocytes completely inhibited the parthenogenetic development without affecting the oocyte morphology. In contrast, nonirradiated oocytes were able to develop parthenogenetically to the blastocyst stage without significant differences to controls. Our results indicate that fs laser systems have great potential for oocyte imaging and functional enucleation and may improve the efficiency of somatic cell cloning.

  20. Femtosecond mode-locked holmium fiber laser pumped by semiconductor disk laser.

    PubMed

    Chamorovskiy, A; Marakulin, A V; Ranta, S; Tavast, M; Rautiainen, J; Leinonen, T; Kurkov, A S; Okhotnikov, O G

    2012-05-01

    We report on a 2085 nm holmium-doped silica fiber laser passively mode-locked by semiconductor saturable absorber mirror and carbon nanotube absorber. The laser, pumped by a 1.16 μm semiconductor disk laser, produces 890 femtosecond pulses with the average power of 46 mW and the repetition rate of 15.7 MHz. PMID:22555700

  1. Laser-assisted hair transplantation: histologic comparison between holmium:YAG and CO2 lasers

    NASA Astrophysics Data System (ADS)

    Chu, Eugene A.; Rabinov, C. Rose; Wong, Brian J.; Krugman, Mark E.

    1999-06-01

    The histological effects of flash-scanned CO2 (λ=10.6μm) and pulsed Holmium:YAG (Ho:YAG, λ=2.12μm) lasers were evaluated in human scalp following the creation of hair transplant recipient channels. Ho:YAG laser irradiation created larger zones of thermal injury adjacent to the laser channels than irradiation with the CO2 laser device. When the two lasers created recipient sites of nearly equal depth, the Holmium:YAG laser caused a larger region of lateral thermal damage (589.30μm) than the CO2 laser (118.07μm). In addition, Holmium:YAG irradiated specimens exhibited fractures or discontinuities beyond the region of clear thermal injury. This shearing effect is consistent with the photoacoustic mechanism of ablation associated with pulsed mid-IR laser irradiation. In contrast, channels created with the CO2 exhibited minimal epithelial disruption and significantly less lateral thermal damage. While the Holmium:YAG laser is a useful tool for ablation soft tissue with minimal char in select applications (sinus surgery, arthroscopic surgery), this study suggests that the use of the CO2 laser for the creation of transplantation recipient channels result in significantly less lateral thermal injury for the laser parameters employed.

  2. Holmium laser lithotripsy for ureteral calculi: an outpatient procedure.

    PubMed

    Yip, K H; Lee, C W; Tam, P C

    1998-06-01

    A retrospective review was conducted to evaluate the efficacy of ureteroscopic lithotripsy using the holmium laser with a semirigid endoscope in a newly established day surgery center. In 1996, 69 consecutive patients (40 male and 29 female) with a mean age of 46.7 (range 21-73) years and ASA status I or II underwent ureteroscopic lithotripsy for their ureteral calculi using the holmium laser (365-micron fiber; power setting 0.5-1.4 J/5 Hz) and 8.5F semirigid ureteroscope in a day surgery setting. Stone features, postoperative pain scores, readmissions, and complications were evaluated. Eighteen upper, 17 middle, and 34 lower ureteral stones were treated, with a mean size measuring 12.1 (5-45) mm. The mean operative time was 61 minutes including the anesthetic time (range 15-150 minutes), and the success rate was 91% (63/69). The complication rate was 10% (7/69) including four unscheduled readmissions (6%). Telephone follow-up on postoperative Day 1 and Day 3 revealed mean pain scores of 2 and 1, respectively (on a 0-10 scale) and an analgesic requirement of 1 tablet of Dologesic (containing 32.5 mg of dextropropoxyphene + 320 mg of paracetamol) four times a day on both days. Ureteroscopic lithotripsy using the holmium laser and a semirigid endoscope is highly successful and well tolerated and carries a low complication rate. It is indicated as an ambulatory and minimally invasive treatment modality in low-risk patients with ureteral stones. PMID:9658294

  3. Buckshot colic: utilizing holmium:yag laser for ureteroscopic removal of a bullet fragment within the proximal ureter.

    PubMed

    Ziegelmann, Matthew; Carrasco, Alonso; Knoedler, John; Krambeck, Amy E

    2016-06-01

    Buckshot colic is a rare phenomenon, presenting as firearm-induced urinary tract obstruction. We present a case of gunshot-induced ureteral obstruction in a 49-year-old male, treated endoscopically with the holmium:YAG (holmium) laser. CT revealed a 1 cm bullet fragment within the left proximal ureter. A percutaneous nephrolithotomy was performed utilizing the holmium laser to fragment the metal into basket-retrievable pieces. At 4 month follow up the patient is without evidence of stricture. To our knowledge, this is the first reported utilization of the holmium laser to treat "buckshot colic". Endoscopy with holmium laser appears a feasible and safe treatment option. PMID:27347630

  4. Office Hysteroscopic Laser Enucleation of Submucous Myomas without Mass Extraction: A Case Series Study

    PubMed Central

    Haimovich, Sergio; López-Yarto, Maite; Urresta Ávila, Julio; Saavedra Tascón, Alejandro; Hernández, José L.; Carreras Collado, Ramón

    2015-01-01

    Background and Objectives. A new two-step hysteroscopic myomectomy carried out in the office setting and without anesthesia was feasible for the excision of submucous myomas. The objective of this study was to assess whether removal of submucous myomas from the uterine cavity after hysteroscopic laser enucleation is necessary. Methods. Between June 2009 and April 2013, all outpatients with symptomatic myomatosis (bleeding, pelvic pain, and infertility) assessed ultrasonographically were eligible to participate in a prospective study. All patients underwent office hysteroscopic enucleation of submucous myomas. Enucleated myomas were left in the uterine cavity. Neither anesthesia nor antibiotic prophylaxis was used. Results. Sixty-one women (mean age: 47.3 years) were included. Regardless of hysteroscopic localization and grading, all myomas were enucleated. The mean (standard deviation, SD) diameter of the myoma as measured by the ultrasound scan was 22.6 (8.5) mm. In 29 cases (47.5%), the diameter of the resected myoma was >20 mm and in 10 cases (16.4%) >30 mm. After a mean follow-up of 68.2 (16.5) days, none of the patients showed a residual myoma inside the uterine cavity. Conclusions. The present results indicate that leaving laser-enucleated submucous myoma in the uterine cavity is a feasible and safe therapeutic option. PMID:26090457

  5. Combination of erbium and holmium laser radiation for tissue ablation

    NASA Astrophysics Data System (ADS)

    Pratisto, Hans S.; Frenz, Martin; Koenz, Flurin; Altermatt, Hans J.; Weber, Heinz P.

    1996-05-01

    Erbium lasers emitting at 2.94 micrometers and holmium lasers emitting at 2.1 micrometers are interesting tools for cutting, drilling, smoothing and welding of water containing tissues. The high absorption coefficient of water at these wavelengths leads to their good ablation efficiency with controlled thermally altered zones around the ablation sites. Combination of pulses with both wavelengths transmitted through one fiber were used to perform incisions in soft tissue and impacts in bone disks. Histological results and scanning electron microscope evaluations reveal the strong influence of the absorption coefficient on tissue effects, especially on the ablation efficiency and the zone of thermally damaged tissue. It is demonstrated that the combination of high ablation rates and deep coagulation zones can be achieved. The results indicate that this laser system can be considered as a first step towards a multi-functional medical instrument.

  6. Effect of the active-ion concentration on the lasing dynamics of holmium fibre lasers

    SciTech Connect

    Kurkov, Andrei S; Sholokhov, E M; Marakulin, A V; Minashina, L A

    2010-12-09

    The lasing dynamics of fibre lasers with a core based on quartz glass doped with holmium ions to concentrations in the range of 10{sup 19}-10{sup 20} cm{sup -3} is investigated. It is shown that fibre lasers with a high concentration of active holmium ions generate pulses, but a decrease in the holmium concentration changes the lasing from pulsed to cw regime. At the same time, a decrease in the active-ion concentration and the corresponding increase in the fibre length in the cavity reduce the lasing efficiency. (lasers)

  7. Effect of active-ion concentration on holmium fibre laser efficiency

    SciTech Connect

    Kurkov, Andrei S; Sholokhov, E M; Marakulin, A V; Minashina, L A

    2010-08-03

    We have measured the fraction of holmium ions that relax nonradiatively to the ground level as a result of interaction at a metastable level in optical fibres with a silica-based core doped with holmium ions to 2 x 10{sup 19} - 2 x 10{sup 20} cm{sup -3}. The percentage of such ions has been shown to depend on the absolute active-ion concentration. The fibres have been used to make a number of 2.05-{mu}m lasers, and their slope efficiency has been measured. The laser efficiency decreases with increasing holmium concentration in the fibres (lasers)

  8. Functional enucleation of porcine oocytes for somatic cell nuclear transfer using femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Kuetemeyer, K.; Lucas-Hahn, A.; Petersen, B.; Hassel, P.; Lemme, E.; Niemann, H.; Heisterkamp, A.

    2010-02-01

    Cloning of several mammalian species has been achieved by somatic cell nuclear transfer over the last decade. However, this method still results in very low efficiencies originating from biological and technical aspects. The highly-invasive mechanical enucleation belongs to the technical aspects and requires considerable micromanipulation skill. In this paper, we present a novel non-invasive method for combined oocyte imaging and automated functional enucleation using femtosecond (fs) laser pulses. After three-dimensional imaging of Hoechst-labeled porcine oocytes by multiphoton microscopy, our self-developed software automatically determined the metaphase plate position and shape. Subsequent irradiation of this volume with the very same laser at higher pulse energies in the low-density-plasma regime was used for metaphase plate ablation. We show that functional fs laser-based enucleation of porcine oocytes completely inhibited further embryonic development while maintaining intact oocyte morphology. In contrast, non-irradiated oocytes were able to develop to the blastocyst stage without significant differences to control oocytes. Our results indicate that fs laser systems offer great potential for oocyte imaging and enucleation as a fast, easy to use and reliable tool which may improve the efficiency of somatic cell clone production.

  9. Clinical development of holmium:YAG laser prostatectomy

    NASA Astrophysics Data System (ADS)

    Kabalin, John N.

    1996-05-01

    Holmium:YAG (Ho:YAG) laser vaporization and resection of the prostate offers advantages in immediate tissue removal compared to the Neodymium:YAG (Nd:YAG) laser. Ongoing development of appropriate operative techniques and Ho:YAG laser delivery systems suitable for endoscopic prostate surgery, including side-firing optical delivery fibers, have facilitated this approach. We performed Ho:YAG laser prostatectomy in 20 human subjects, including 2 men treated immediately prior to radical prostatectomy to assess Ho:YAG laser effects in the prostate. A total of 18 men were treated in an initial clinical trial of Ho:YAG prostatectomy. Estimated excess hyperplastic prostate tissue averaged 24 g (range 5 - 50 g). A mean of 129 kj Ho:YAG laser energy was delivered, combined with a mean of 11 kj Nd:YAG energy to provide supplemental coagulation for hemostasis. We have observed no significant perioperative or late complications. No significant intraoperative changes in hematocrit or serum electrolytes were documented. In addition to providing acute removal of obstructing prostate tissue, Ho:YAG laser resection allowed tissue specimen to be obtained for histologic examination. A total of 16 of 18 patients (90%) underwent successful removal of their urinary catheter and voiding trial within 24 hours following surgery. Immediate improvement in voiding, comparable to classic transurethral electrocautery resection of the prostate (TURP), was reported by all patients. Ho:YAG laser resection of the prostate appears to be a viable surgical technique associated with minimal morbidity and immediate improvement in voiding.

  10. Comparison of holmium:YAG and thulium fiber lasers for lithotripsy

    NASA Astrophysics Data System (ADS)

    Blackmon, Richard L.; Irby, Pierce B.; Fried, Nathaniel M.

    2010-02-01

    The Holmium:YAG laser is currently the most common laser lithotripter. However, recent experimental studies have demonstrated that the Thulium fiber laser is also capable of vaporizing urinary stones. The high-temperature water absorption coefficient for the Thulium wavelength (μa = 160 cm-1 at λ = 1908 nm) is significantly greater than for the Holmium wavelength (μa = 28 cm-1 at λ = 2120 nm). We hypothesize that this should translate into more efficient laser lithotripsy using the Thulium fiber laser. This study directly compares stone vaporization rates for Holmium and Thulium fiber lasers. Holmium laser radiation pulsed at 3 Hz with 70 mJ pulse energy and 220 μs pulse duration was delivered through a 100-μm-core silica fiber to human uric acid (UA) and calcium oxalate monohydrate (COM) stones, ex vivo (n = 10 each). Thulium fiber laser radiation pulsed at 10 Hz with 70 mJ pulse energy and 1 ms pulse duration was also delivered through a 100-μm fiber for the same sets of 10 stones. For same number of pulses and total energy (126 J) delivered to each stone, mass loss averaged 2.4 +/- 0.6 mg (UA) and 0.7 +/- 0.2 mg (COM) for Holmium laser and 12.6 +/- 2.5 mg (UA) and 6.8 +/- 1.7 (COM) for Thulium fiber laser. UA and COM stone vaporization rates for Thulium fiber laser averaged 5-10 times higher than for Holmium laser at 70 mJ pulse energies. With further development, the Thulium fiber laser may represent an alternative to the conventional Holmium laser for more efficient laser lithotripsy.

  11. Holmium laser use in the treatment of selected dry eye syndrome complications

    NASA Astrophysics Data System (ADS)

    Kecik, Dariusz; Kecik, Tadeusz; Kasprzak, Jan; Kecik, Mariusz

    1996-03-01

    The authors present initial results of treatment selected complications of dry eye syndrome with holmium laser. The lacrimal puncta obliteration and coagulation of the corneal ulcer surface were done.

  12. Thulium laser enucleation of the prostate is a safe and a highly effective modality for the treatment of benign prostatic hyperplasia - Our experience of 236 patients

    PubMed Central

    Ketan, P. Vartak; Prashant, H. Salvi

    2016-01-01

    Context: Thulium LASER is fast emerging as a safe and effective modality for benign prostatic hyperplasia (BPH). Still, compared to holmium laser transurethral enucleation of the prostate (HoLEP) the number of institutes all over the world using Thulium LASER are limited. This is our effort to bring the statistical facts about the safety and effectivity of Thulium LASER. Aims: To study the efficacy of thulium laser enucleation of the prostate (ThuLEP). Settings and Design: All patients in the stipulated period were documented for all parameters and were evaluated. The results were tabulated. Subjects and Materials: (1) Two hundred and thirty-six patients with symptomatic BPH were treated with ThuLEP between March 2010 and September 2014 at our institute by a single surgeon. (2) The inclusion criteria were maximum urinary flow rate (Qmax) <15 ml/s, International Prostate Symptoms Score (IPSS) >15 or acute retention of urine with the failure of catheter trial or Acute retention of urine with prior history of severe bladder outlet obstruction. (3) Patients evaluated by: Digital rectal examination, uroflowmetry, IPSS, prostate-specific antigen (PSA), blood and urine routine tests, abdominal usage with trains rectal ultrasonography (TRUS), TRUS guided biopsies. Statistical Analysis Used: Not used. Results: (1) ThuLEP was a highly effective procedure as compared to all other procedures like HOLEP, TURP in terms of catheterization time, hospital stay, and drop in hemoglobin (Hb). (2) Catheterization time: 25.22 h (224 patients within 24 h and 12 patients within 48 h). (3) Hospital stay: 24–36 h 218 patients (92.3%), 36–48 h 18 patients (7.6%). (4) Drop in Hb: 0.8 ± 0.42 g/dl. (5) Average operative time: 56.91 min. Conclusions: Thulium LASER is a safe and highly effective LASER in terms of blood loss, speed of tissue resection, drop in serum PSA, and versatility of prostatic resection. PMID:26834407

  13. Efficient holmium:yttrium lithium fluoride laser longitudinally pumped by a semiconductor laser array

    NASA Technical Reports Server (NTRS)

    Hemmati, H.

    1987-01-01

    Optical pumping of a holmium:yttrium lithium floride (Ho:YLF) crystal with a 790-nm continuous-wave diode-laser array has generated 56 mW of 2.1-micron laser radiation with an optical-to-optical conversion slope efficiency of 33 percent while the crystal temperature is held at 77 K. The lasing threshold occurs at 7 mW of input power, and laser operation continues up to a crystal temperature of 124 K.

  14. Non-radiative decay of holmium-doped laser materials

    NASA Astrophysics Data System (ADS)

    Bowman, Steven R.; O'Connor, Shawn; Condon, Nicholas J.; Friebele, E. Joseph; Kim, Woohong; Shaw, B.; Quimby, R. S.

    2013-03-01

    Anti-Stokes fluorescence cooling has been demonstrated in a number rare earth doped materials. Ytterbium doped oxides and fluorides, such as ZBLAN, YLF, and YAG, were the first materials to exhibit cooling.1,2,3 These materials were originally developed as laser gain media and fluorescence cooling was eventually incorporated into the 1μm lasers to reduce detrimental thermal loading.4 Anti-Stokes cooling can offset quantum defect heating allowing laser power to be scaled to very high average powers. Since the early work in ytterbium, fluorescence cooling has been demonstrated in both erbium and thulium doped materials.5,6 These materials were also initially developed as lasing media and their fluorescence cooling could be used to increase laser powers at 1.5μm and 2.0μm. In this study we examine the radiative efficiency of holmium and ask the question, "Can anti-Stokes fluorescence cooling be extended beyond 2μm?"

  15. Holmium:YAG laser in dentistry: photoconditioning of dentinal surfaces

    NASA Astrophysics Data System (ADS)

    Holt, Raleigh A.; Nordquist, Robert E.

    1994-09-01

    This in vitro study was undertaken to determine energy levels necessary to produce tubule closure and surface smoothing on dentinal surfaces of human teeth and their resultant temperature increases within the pulpal canals with the Holmium:YAG laser. An optimal working spot size and even absorption pattern were produced by defocusing the laser beam and evaluated by images produced on light exposed and developed photographic paper. The surface effects on dentin were examined by scanning electron microscopy. A thermocouple was positioned in the canals of fresh dissected dog jaws and attached to a recorder which produced a graph of the temperature changes. The in vitro research model for intrapulpal temperatures changes was verified by comparing premortem and postmortem temperature readings. The same protocol was used to evaluate temperature changes in fresh human extracted teeth. In vivo histological studies were conducted to evaluate the effects of HO:YAG laser energy on pulpal tissues. The results of these studies indicate the HO:YAG laser at a wavelength of 2.12 microns can be safely and effectively used for photoconditioning of the dentinal surfaces of teeth in clinical conditions.

  16. Laser angioplasty with lensed fibers and a holmium:YAG laser in iliac artery occlusions

    NASA Astrophysics Data System (ADS)

    White, Christopher J.; Ramee, Stephen R.; Mesa, Juan E.; Collins, Tyrone J.; Kotmel, Robert; Godfrey, Maureen A.

    1991-05-01

    Holmium-YAG (2.1 (mu) ) laser recanalization was attempted in 10 totally occluded miniature swine iliac arteries using a lensed fiber delivery system. The iliac artery occlusions were created in a Yucatan miniature swine model of atherosclerosis by means of a high cholesterol diet and balloon endothelial denudation. In order to increase the spot size, a spherical silica lens was attached to the distal end of a 300 micrometers core diameter silica optical fiber. The holmium-YAG laser was operated in the free-running mode with 250 microsecond(s) ec pulses at 4 Hz. The energy delivered was 225 mJ per pulse for the 1.0 mm lensed fiber and 200 mJ per pulse for the 1.3 mm lensed fiber. Laser energy was delivered in 2 to 5 second bursts. Successful recanalization was achieved in all 10 arteries attempted without perforation of the arterial wall. The average length of the occlusions was 5.0 +/- 1.8 cm. Following successful laser recanalization significant stenoses (>50%) remained in all of the arteries as judged by angiography. In conclusion, the lensed fibers coupled to the pulsed holmium-YAG laser were safe and effective in recanalizing these difficult lesions in relatively straight iliac arteries. There is potential clinical utility for this system as an adjunct to balloon angioplasty in patients with lesions which are unable to be crossed with guidewires.

  17. Proximal fiber tip damage during Holmium:YAG and thulium fiber laser ablation of kidney stones

    NASA Astrophysics Data System (ADS)

    Wilson, Christopher R.; Hardy, Luke A.; Irby, Pierce B.; Fried, Nathaniel M.

    2016-02-01

    The Thulium fiber laser (TFL) is being studied as an alternative to Holmium:YAG laser for lithotripsy. TFL beam originates within an 18-μm-core thulium doped silica fiber, and its near single mode, Gaussian beam profile enables transmission of higher laser power through smaller fibers than possible during Holmium laser lithotripsy. This study examines whether TFL beam profile also reduces proximal fiber tip damage compared to Holmium laser multimodal beam. TFL beam at wavelength of 1908 nm was coupled into 105-μm-core silica fibers, with 35-mJ energy, 500-μs pulse duration, and pulse rates of 50-500 Hz. For each pulse rate, 500,000 pulses were delivered. Magnified images of proximal fiber surfaces were taken before and after each trial. For comparison, 20 single-use, 270-μm-core fibers were collected after clinical Holmium laser lithotripsy procedures using standard settings (600 mJ, 350 μs, 6 Hz). Total laser energy, number of laser pulses, and laser irradiation time were recorded, and fibers were rated for damage. For TFL studies, output power was stable, and no proximal fiber damage was observed after delivery of 500,000 pulses at settings up to 35 mJ, 500 Hz, and 17.5 W average power. In contrast, confocal microscopy images of fiber tips after Holmium lithotripsy showed proximal fiber tip degradation in all 20 fibers. The proximal fiber tip of a 105-μm-core fiber transmitted 17.5 W of TFL power without degradation, compared to degradation of 270-μm-core fibers after transmission of 3.6 W of Holmium laser power. The smaller and more uniform TFL beam profile may improve fiber lifetime, and potentially reduce costs for the surgical disposables as well.

  18. Safety and efficacy of holmium:YAG laser lithotripsy in patients with bleeding diatheses

    NASA Astrophysics Data System (ADS)

    Watterson, James D.; Girvan, Andrew R.; Cook, Anthony J.; Beiko, Darren T.; Nott, Linda; Auge, Brian K.; Preminger, Glenn M.; Denstedt, John D.

    2003-06-01

    Purpose: To assess the safety and efficacy of ureteroscopy and holmium:YAG (yttrium-aluminum-garnet) laser lithotripsy in the treatment of upper urinary tract calculi in patients with known and uncorrected bleeding diatheses. Materials and Methods: A retrospective chart review from 2 tertiary stone centers was performed to identify patients with known bleeding diatheses who were treated with holmium:YAG laser lithotripsy for upper urinary tract calculi. Twenty-five patients with 29 upper urinary tract calculi were treated with ureteroscopic holmium laser lithotripsy. Bleeding diatheses identified were coumadin administration for various conditions (17), liver dysfunction (3), thrombocytopenia (4), and von Willebrand's disease (1). Mean international normalized ratio (INR), platelet count and bleeding time were 2.3, 50 x 109/L, and > 16 minutes, for patients receiving coumadin or with liver dysfunction, thrombocytopenia, or von Willebrand's disease, respectively. Results: Overall, the stone-free rate was 96% (27/28) and 29 of 30 procedures were completed successfully without significant complication. One patient who was treated concomitantly with electrohydraulic lithotripsy (EHL) had a significant retroperitoneal hemorrhage that required blood transfusion. Conclusions: Treatment of upper tract urinary calculi in patients with uncorrected bleeding diatheses can be safely performed using contemporary small caliber ureteroscopes and holmium laser as the sole modality of lithotripsy. Ureteroscopic holmium laser lithotripsy without preoperative correction of hemostatic parameters limits the risk of thromboembolic complications and costs associated with an extended hospital stay. Avoidance of the use of EHL is crucial in reducing bleeding complications in this cohort of patients.

  19. Spectroscopic properties, energy transfer dynamics, and laser performance of thulium-holmium doped laser systems

    SciTech Connect

    Kalisky, Y.; Rotman, S.R.; Boulon, G.; Pedrini, C.; Brenier, A.

    1994-12-31

    Spectroscopic studies using laser induced fluorescence and numerical modeling of energy transfer and back transfer mechanism are reported in Er:Tm:Ho:YLF, Cr:Tm:Ho:YAG and Cr:Tm:YAG laser crystals at various temperatures (10 K-300 K). Direct energy transfer from Tm{sup 3+} excited states to Ho{sup 3+} {sup 5}I{sub 7} emitting level was observed and analyzed both in YAG and YLF. Further analysis of Cr{sup 3+} and Tm{sup 3+} time-dependent emission curves indicate a strong correlation of chromium-thulium pairs. Pulsed operation of holmium laser at high temperature will be presented.

  20. Histological evaluation of coagulation foci produced in the human lens with a holmium laser

    NASA Astrophysics Data System (ADS)

    Kecik, Dariusz; Kecik, Tadeusz; Pratnicki, Antoni; Kasprzak, Jan; Kecik, Mariusz

    1997-10-01

    We present the results of histological evaluation of human lenses treated with the holmium laser. The lenses, extracted at the time of extracapsular surgery for cataract, were placed in containers filled with Ringer's solution. After treatment with laser-emitted radiation they were histologically evaluated. The formation of crater-like defects was found in the material studied.

  1. Combination of fiber-guided pulsed erbium and holmium laser radiation for tissue ablation under water

    NASA Astrophysics Data System (ADS)

    Pratisto, Hans; Frenz, Martin; Ith, Michael; Altermatt, Hans J.; Jansen, E. Duco; Weber, Heinz P.

    1996-07-01

    Because of the high absorption of near-infrared laser radiation in biological tissue, erbium lasers and holmium lasers emitting at 3 and 2 mu m, respectively, have been proven to have optimal qualities for cutting or welding and coagulating tissue. To combine the advantages of both wavelengths, we realized a multiwavelength laser system by simultaneously guiding erbium and holmium laser radiation by means of a single zirconium fluoride (ZrF4) fiber. Laser-induced channel formation in water and poly(acrylamide) gel was investigated by the use of a time-resolved flash-photography setup, while pressure transients were recorded simultaneously with a needle hydrophone. The shapes and depths of vapor channels produced in water and in a submerged gel after single erbium and after combination erbium-holmium radiation delivered by means of a 400- mu m ZrF4 fiber were measured. Transmission measurements were performed to determine the amount of pulse energy available for tissue ablation. The effects of laser wavelength and the delay time between pulses of different wavelengths on the photomechanical and photothermal responses of meniscal tissue were evaluated in vitro by the use of histology. It was observed that the use of a short (200- mu s, 100-mJ) holmium laser pulse as a prepulse to generate a vapor bubble through which the ablating erbium laser pulse can be transmitted (delay time, 100 mu s) increases the cutting depth in meniscus from 450 to 1120 mu m as compared with the depth following a single erbium pulse. The results indicate that a combination of erbium and holmium laser radiation precisely and efficiently cuts tissue under water with 20-50- mu m collateral tissue damage. wave, cavitation, channel formation, infrared-fiber-delivery system, tissue damage, cartilage.

  2. Holmium:YAG laser-assisted otolaryngologic surgery: Lahey Clinic experience

    NASA Astrophysics Data System (ADS)

    Shapshay, Stanley M.; Rebeiz, Elie E.; Pankratov, Michail M.

    1993-07-01

    The Holmium:YAG laser was used to assist in 36 rhinologic procedures including surgery for chronic sinus disease, chronic dacryocystitis, recurrent choanal stenosis, and a sphenoid sinus mucocele. There were no laser related complications. The laser permitted controlled ablation of bone and soft tissue in all cases with satisfactory results. The Ho:YAG laser can be used in otolaryngology to assist in cases where surgical access is difficult or when controlled, precise bone and soft tissue ablation is necessary.

  3. Are Histological Findings of Thulium Laser Vapo-Enucleation Versus Transurethral Resection of the Prostate Comparable?

    PubMed

    Carmignani, Luca; Macchi, Alberto; Ratti, Dario; Finkelberg, Elisabetta; Casellato, Stefano; Bozzini, Giorgio; Maruccia, Serena; Marenghi, Carlo; Picozzi, Stefano

    2015-09-01

    We investigated if an adequate histological diagnosis can be made from tissue after Thulium laser vapo-enucleation of the prostate (ThuVEP) and whether it is comparable to transurethral prostate resection (TURP) tissue findings in patients with symptomatic benign prostatic hyperplasia. We analyzed 350 ThuLEP and 100 matched TURP tissue specimens from patients who underwent one of the two procedures between January 2009 and June 2014. Thulium Laser Enucleation of Prostate (ThuVEP) was combined with mechanical morcellation of the resected lobe. Each histological specimen was reviewed by two pathologists. Preoperative prostate ultrasound volume, total serum prostatic specific antigen and postoperative tissue weight were evaluated. Microscopic histological diagnosis was assessed by standard histological techniques and immunohistochemical evaluation. Patients were comparable in terms of age and preoperative total serum prostate specific antigen. Incidental adenocarcinoma and high grade PIN of the prostate were diagnosed in a comparable percent of specimens in the 2 groups (2.5 % in the ThuVEP group versus 3 % in the TURP group). Tissue thermal artifacts induced by the Thulium laser are mostly due to coagulation as that of the conventional monopolar diathermy in TURP. Tissue quality was maintained in the ThuVEP histological specimens. Tissue maintain histological characteristics and proprieties without modification for successive immunoistochemical analysis. The pathologist ability to detect incidental prostate cancer and PIN was maintained even if there is a quoted of vaporized tissue. PMID:25862670

  4. Holmium:YAG laser coronary angioplasty: quantitative angiography and clinical results in a large experience of a single medical center

    NASA Astrophysics Data System (ADS)

    Topaz, On; Luxenberg, Michael; Schumacher, Audrey

    1994-07-01

    Clinical experience with the mid IR holmium:YAG laser in a single medical center (St. Paul Ramsey Medical Center, University of Minnesota Medical School, St. Paul, MN) includes 112 patients who underwent holmium laser coronary angioplasty. Utilizing a unique lasing technique; `pulse and retreat,' we applied this laser to thrombotic and nonthrombotic lesions in patients presenting with unstable angina, stable angina, and acute myocardial infarction. A very high clinical success and very low complication rates were achieved. Holmium:YAG laser is effective and safe therapy for patients with symptomatic coronary artery disease. Unlike excimer lasers, the clinical success, efficacy and safety of holmium laser angioplasty is not compromised when thrombus is present.

  5. Fiber-optic manipulation of urinary stone phantoms using holmium:YAG and thulium fiber lasers.

    PubMed

    Blackmon, Richard L; Case, Jason R; Trammell, Susan R; Irby, Pierce B; Fried, Nathaniel M

    2013-02-01

    Fiber-optic attraction of urinary stones during laser lithotripsy may be exploited to manipulate stone fragments inside the urinary tract without mechanical grasping tools, saving the urologist time and space in the ureteroscope working channel. We compare thulium fiber laser (TFL) high pulse rate/low pulse energy operation to conventional holmium:YAG low pulse rate/high pulse energy operation for fiber-optic suctioning of plaster-of-paris (PoP) stone phantoms. A TFL (wavelength of 1908 nm, pulse energy of 35 mJ, pulse duration of 500 μs, and pulse rate of 10 to 350 Hz) and a holmium laser (wavelength of 2120 nm, pulse energy of 35 to 360 mJ, pulse duration of 300 μs, and pulse rate of 20 Hz) were tested using 270-μm-core optical fibers. A peak drag speed of ~2.5 mm/s was measured for both TFL (35 mJ and 150 to 250 Hz) and holmium laser (210 mJ and 20 Hz). Particle image velocimetry and thermal imaging were used to track water flow for all parameters. Fiber-optic suctioning of urinary stone phantoms is feasible. TFL operation at high pulse rates/low pulse energies is preferable to holmium operation at low pulse rates/high pulse energies for rapid and smooth stone pulling. With further development, this novel technique may be useful for manipulating stone fragments in the urinary tract. PMID:23377013

  6. Fiber-optic manipulation of urinary stone phantoms using holmium:YAG and thulium fiber lasers

    NASA Astrophysics Data System (ADS)

    Blackmon, Richard L.; Case, Jason R.; Trammell, Susan R.; Irby, Pierce B.; Fried, Nathaniel M.

    2013-02-01

    Fiber-optic attraction of urinary stones during laser lithotripsy may be exploited to manipulate stone fragments inside the urinary tract without mechanical grasping tools, saving the urologist time and space in the ureteroscope working channel. We compare thulium fiber laser (TFL) high pulse rate/low pulse energy operation to conventional holmium:YAG low pulse rate/high pulse energy operation for fiber-optic suctioning of plaster-of-paris (PoP) stone phantoms. A TFL (wavelength of 1908 nm, pulse energy of 35 mJ, pulse duration of 500 μs, and pulse rate of 10 to 350 Hz) and a holmium laser (wavelength of 2120 nm, pulse energy of 35 to 360 mJ, pulse duration of 300 μs, and pulse rate of 20 Hz) were tested using 270-μm-core optical fibers. A peak drag speed of ˜2.5 mm/s was measured for both TFL (35 mJ and 150 to 250 Hz) and holmium laser (210 mJ and 20 Hz). Particle image velocimetry and thermal imaging were used to track water flow for all parameters. Fiber-optic suctioning of urinary stone phantoms is feasible. TFL operation at high pulse rates/low pulse energies is preferable to holmium operation at low pulse rates/high pulse energies for rapid and smooth stone pulling. With further development, this novel technique may be useful for manipulating stone fragments in the urinary tract.

  7. Influence of water environment on holmium laser ablation performance for hard tissues.

    PubMed

    Lü, Tao; Xiao, Qing; Li, Zhengjia

    2012-05-01

    This study clarifies the ablation differences in air and in water for hard biological tissues, which are irradiated by fiber-guided long-pulsed holmium lasers. High-speed photography is used to record the dynamic characteristics of ablation plumes and vaporization bubbles induced by pulsed holmium lasers. The ablation morphologies and depth of hard tissues are quantitatively measured by optical coherence microscopy. Explosive vaporization effects in water play a positive role in the contact ablation process and are directly responsible for significant ablation enhancement. Furthermore, water layer depth can also contribute to ablation performance. Under the same laser parameters for fiber-tissue contact ablation in air and water, ablation performances are comparable for a single-laser pulse, but for more laser pulses the ablation performances in water are better than those in air. Comprehensive knowledge of ablation differences under various environments is important, especially in medical procedures that are performed in a liquid environment. PMID:22614434

  8. Effect of holmium and erbium laser action on the human lens: an in-vitro study

    NASA Astrophysics Data System (ADS)

    Kasprzak, Jan; Kecik, Dariusz

    1997-10-01

    We investigated the holmium and erbium lasers operating at the medium IR range, used for cataract surgery. The main advantage of these lasers action on biological structures is total absorption of radiation by superficial layers. During the study of the lens emulsification process we found that the mechanical properties of the lens nucleus were of crucial importance for the rate of emulsification. The soft lenses were fragmented and emulsified after 200-700 pulses, while the hard lens required 5000 or more pulses while complete emulsification was not achieved. The results are promising and show that the holmium and erbium lasers can be used for human lens emulsification during ECCE. For clinical purposes, however, it is necessary to construct a suitable fiberoptic tip to be used in cataract removal. It seems that lasers whose beam is in the medium IR range could be used in many ophthalmic operations.

  9. Mathematical modelling of dispersion-managed thulium/holmium fibre lasers

    SciTech Connect

    Yarutkina, I A; Shtyrina, O V

    2013-11-30

    The mathematical model of a dispersion-managed thulium/holmium fibre laser is described; the results of numerical calculations and their comparison with the experimental data are presented. Qualitative agreement of the results of the mathematical modelling with those of the experiment is obtained. Using the methods of mathematical modelling, the variation in the characteristics of the optical pulses due to the change in the average cavity dispersion is analysed. (control of laser radiation parameters)

  10. A novel one lobe technique of thulium laser enucleation of the prostate: 'All-in-One' technique

    PubMed Central

    Kim, Yeon Joo; Lee, Yoon Hyung; Kwon, Joon Beom; Cho, Sung Ryong

    2015-01-01

    Purpose The thulium laser is the most recently introduced technology for the surgical treatment of benign prostatic hyperplasia (BPH). Until recently, most thulium laser enucleation of the prostate (ThuLEP) was performed by use of the three-lobe technique. We introduce a novel one-lobe enucleation technique for ThuLEP called the "All-in-One" technique. We report our initial experiences here. Materials and Methods From June 2013 to May 2014, a total of 47 patients underwent the All-in-One technique of ThuLEP for symptomatic BPH performed by a single surgeon. All patients were assessed with the International Prostate Symptom Score (IPSS), transrectal ultrasonography, serum prostate-specific antigen (PSA), maximal urine flow rate (Qmax), and postvoid residual urine volume (PVR) before and 1 month after surgery. We reassessed IPSS, Qmax, and PVR 3 months after surgery. To assess the efficacy of the All-in-One technique, we checked the PSA reduction ratio, transitional zone volume reduction ratio, and enucleation failure rate. Results The mean operative time was 82.1±33.3 minutes. The mean enucleation time and morcellation time were 52.7±21.7 minutes and 8.2±7.0 minutes, respectively. The mean resected tissue weight and decrease in hemoglobin were 36.9±24.6 g and 0.4±0.8 g/dL, respectively. All perioperative parameters showed significant improvement (p<0.05). No major complications were observed. The PSA reduction ratio, transitional zone volume reduction ratio, and enucleation failure rate were 0.81, 0.92, and 4.3%, respectively. Conclusions The All-in-One technique of ThuLEP showed efficacy and effectiveness comparable to that of other techniques. We expect that this new technique could reduce the operation time and the bleeding and improve the effectiveness of enucleation. PMID:26568795

  11. Soft-tissue applications of the holmium:YAG laser in urology

    NASA Astrophysics Data System (ADS)

    Denstedt, John D.; Razvi, Hassan A.; Chun, Samuel S.; Sales, Jack L.

    1995-05-01

    The ideal surgical laser for the treatment of soft tissue pathology should possess both ablative and hemostatic abilities. As well, for use in urologic conditions the laser must also be suitable for endoscopic use. The Holmium:YAG laser possesses these qualities and in preliminary clinical use has demonstrated a variety of potential urologic applications. In this study we review our initial experience with the Holmium:YAG laser over a 18 month period. A total of 51 patients underwent 53 procedures for a variety of soft tissue conditions including: bladder tumor ablation (25), incision of ureteral stricture (15), incision of urethral stricture (6), treatment of ureteropelvic junction obstruction (3), incision of bladder neck contracture (2), and ablation of a ureteral tumor (2). Satisfactory hemostasis was achieved in all cases. Procedures were considered successful (no further intervention being required to treat the condition) in 81% of the cases. Two patients with dense bladder neck contractures required electroincision under the same anesthetic for completion of the procedure. A single complication, that of urinary extravasation following incision of a urethral stricture resolved with conservative management. In summary, the Holmium:YAG laser has demonstrated safety and proficiency in the treatment of a variety of urologic soft tissue conditions.

  12. Microscopic analysis of laser-induced proximal fiber tip damage during holmium:YAG and thulium fiber laser lithotripsy

    NASA Astrophysics Data System (ADS)

    Wilson, Christopher R.; Hardy, Luke A.; Irby, Pierce B.; Fried, Nathaniel M.

    2016-04-01

    The thulium fiber laser (TFL) is being studied as an alternative to the standard holmium:YAG laser for lithotripsy. The TFL beam originates within an 18-μm-core thulium-doped silica fiber, and its near single mode, Gaussian beam profile enables transmission of higher laser power through smaller (e.g., 50- to 150-μm core) fibers than possible during holmium laser lithotripsy. This study examines whether the more uniform TFL beam profile also reduces proximal fiber tip damage compared with the holmium laser multimodal beam. Light and confocal microscopy images were taken of the proximal surface of each fiber to inspect for possible laser-induced damage. A TFL beam at a wavelength of 1908 nm was coupled into 105-μm-core silica fibers, with 35-mJ energy, and 500-μs pulse duration, and 100,000 pulses were delivered at each pulse rate setting of 50, 100, 200, 300, and 400 Hz. For comparison, single use, 270-μm-core fibers were collected after clinical holmium laser lithotripsy procedures performed with standard settings (600 mJ, 350 μs, 6 Hz). Total laser energy, number of laser pulses, and laser irradiation time were recorded, and fibers were rated for damage. For TFL studies, output pulse energy and average power were stable, and no proximal fiber damage was observed at settings up to 35 mJ, 400 Hz, and 14 W average power (n=5). In contrast, confocal microscopy images of fiber tips after holmium lithotripsy showed proximal fiber tip degradation, indicated by small ablation craters on the scale of several micrometers in all fibers (n=20). In summary, the proximal fiber tip of a 105-μm-core fiber transmitted up to 14 W of TFL power without degradation, compared to degradation of 270-μm-core fibers after transmission of 3.6 W of holmium laser power. The smaller and more uniform TFL beam profile may improve fiber lifetime, and potentially translate into lower costs for the surgical disposables as well.

  13. Successful treatment of recurrent vesicourethral stricture after radical prostatectomy with holmium laser: report of three cases.

    PubMed

    Hayashi, Tetsuo; Yoshinaga, Atsushi; Ohno, Rena; Ishii, Nobuyuki; Watanabe, Toru; Yamada, Takumi; Kihara, Kazunori

    2005-04-01

    We report three cases with severe anastomotic strictures, which recurred several times after radical prostatectomy despite repeated treatments of urethral dilation, internal urethrotomy and/or transurethral resection. All three cases were finally treated with holmium laser successfully without any intraoperative or postoperative complications after repeated failures of each treatment. There were two specific characteristics in these three cases: the early onset of the stricture and the pinhole opening located on the top (12-o'clock) of the stricture wall. PMID:15948734

  14. Erbium:YAG and holmium:YAG laser root resection of extracted human teeth.

    PubMed

    Komori, T; Yokoyama, K; Matsumoto, Y; Matsumoto, K

    1997-02-01

    Root resection of extracted human teeth was performed using the erbium:YAG (Er:YAG) and holmium:YAG (Ho:YAG) laser to investigate the clinical application of lasers on hard tissue. The CO2 laser and the mechanical drill were also used for comparison. After resection using these technologies, the morphological changes of the cut surface were investigated by optical and scanning electron microscope. Er:YAG laser irradiation produced smooth, clean resected surfaces without signs of thermal damages. Complete obturation of the root canal was maintained after Er:YAG laser irradiation. Ho:YAG laser irradiation, however, produced some signs of thermal damage. Relatively large voids between the gutta-percha and the canal walls were revealed after Ho:YAG laser irradiation. The sealing of the dentinal tubules was not completely attained as stipulated by original conditions of this study. PMID:9467336

  15. Ureteroscopy and holmium:YAG laser lithotripsy: an emerging definitive management strategy for symptomatic ureteral calculi in pregnancy

    NASA Astrophysics Data System (ADS)

    Watterson, James D.; Girvan, Andrew R.; Beiko, Darren T.; Nott, Linda; Wollin, Timothy A.; Razvi, Hassan A.; Denstedt, John D.

    2003-06-01

    Objectives: Symptomatic urolithiasis in pregnancy that does not respond to conservative measures has traditionally been managed with ureteral stent insertion or percutaneous nephrostomy (PCN). Holmium:yttrium-aluminum-garnet (YAG) laser lithotripsy using state-of-the-art ureteroscopes represents an emerging strategy for definitive stone management in pregnancy. The purpose of this study was to review the results of holmium laser lithotripsy in a cohort of patients who presented with symptomatic urolithiasis in pregnancy. Methods: A retrospective analysis was conducted at 2 tertiary stone centers from January 1996 to August 2001 to identify pregnant patients who were treated with ureteroscopic holmium laser lithotripsy for symptomatic urolithiasis or encrusted stents. Eight patients with a total of 10 symptomatic ureteral calculi and 2 encrusted ureteral stents were treated. Mean gestational age at presentation was 22 weeks. Mean stone size was 8.1 mm. Stones were located in the proximal ureter/ureteropelvic junction (UPJ) (3), mid ureter (1), and distal ureter (6). Results: Complete stone fragmentation and/or removal of encrusted ureteral stents were achieved in all patients using the holmium:YAG laser. The overall procedural success rate was 91%. The overall stone-free rate was 89%. No obstetrical or urological complications were encountered. Conclusions: Ureteroscopy and holmium laser lithotripsy can be performed safely in all stages of pregnancy providing definitive management of symptomatic ureteral calculi. The procedure can be done with minimal or no fluoroscopy and avoids the undesirable features of stents or nephrostomy tubes.

  16. [Critical evaluation of indications for the holmium:YAG laser and the neodymium:YAG laser in orthopedic surgery based on an in vitro study].

    PubMed

    Anders, J O; Pietsch, S; Staupendahl, G

    1999-04-01

    This is an in vitro study of the biophysical effects of holmium:YAG and neodymium-YAG lasers that was prompted by the poor clinical results obtained with lumbar percutaneous laser discus decompression (PLDD). In the absence of adequate cooling, ablation of tissue with the holmium:YAG laser causes thermal damage to the surrounding tissues. Utilizing the immediate colour-independent laser coupling effect, the holmium:YAG laser removes soft and hard tissue immediately. The low tissue penetrating power (max. 0.32 mm), together with the use of irrigation, avoids thermal problems, and this laser type with its high pulse energy and frequency is to be recommended for arthroscopic surgery. In contrast, the effects of the neodymium:YAG laser are highly dependent on tissue colour. Using this laser on light-coloured tissue only diffuse warming but no ablation of soft tissue was often seen. The depth of tissue penetration seen in our study was 0.58 mm, but is greatly dependent on the duration of application, and is much larger with long application times. In conclusion, we believe that the neodymium:YAG laser is more suitable for percutaneous intradiscal procedures than the holmium:YAG laser. For arthroscopic surgery, the holmium:YAG laser will be the better choice. The effect of each type of laser depends not only on its physical properties, but also on tissue properties (light or dark-coloured, thermal conductivity) and duration of application. PMID:10379068

  17. Benign Prostatic Hyperplasia Treatment by Transurethral Enucleation of the Prostate Using a 2-μm Laser.

    PubMed

    Guo, He-Qing; Zhou, Gao-Biao; Liu, Hong-Ming; Sun, Bin; Pan, Guang-Xin; Mu, Da-Wei; Yan, Jing-Ming; Xing, Ji-Zhang; Li, Di; Hong, Quan

    2015-12-01

    This study investigates the efficacy of benign prostatic hyperplasia (BPH) treatment by prostate transurethral enucleation using a 2-μm laser. A total of 107 patients with BPH were treated by prostate transurethral enucleation using a RevoLix 2-μm laser surgery system. Bleeding volume, operation time, catheterization time, voiding situation, maximum urinary flow rate, and hospital stay were observed. The mean operation time was 74 min ± 12 min (range 45 to 150 min), the mean follow-up period was 2 to 6 months, the mean catheter time was 5 days, and the mean peak urinary flow rate increased from 6.3 ± 0.6 to 17.5 ± 1.5 mL/s. The International Prostate Symptom Score and quality of life significantly declined (p < 0.01). No significant differences were observed in the hemoglobin and blood electrolytes before and after operation. Prostate transurethral enucleation using a 2-μm laser is safe and efficient for BPH treatment. PMID:27011513

  18. Retrograde flexible ureterorenoscopic holmium-YAG laser lithotripsy: the new gold standard.

    PubMed

    Gould, D L

    1998-03-01

    To demonstrate the efficacy of flexible retrograde ureterorenoscopic holmium-YAG intracorporeal laser lithotripsy for the treatment of renal calculi, a total of 86 patients presenting to our hospital with renal calculi underwent flexible retrograde ureterorenoscopic holmium-YAG intracorporeal laser lithotripsy of their stones, and the data were collected prospectively. As extracorporeal shock wave lithotripsy is not available at our institution, all patients with renal calculi in this study were treated in a retrograde fashion using the Richard Wolf 6.0F semirigid ureteroscope, the 7.5F flexible ureterorenoscope, and the holmium-YAG laser by Coherent Inc. Except for inhospital consults or patients requiring admission secondary to infection, all cases were performed on an ambulatory basis. All renal calculi 3 cm or smaller were approached in a retrograde fashion. Where possible, the stones were initially debulked using the semirigid ureteroscope and the 550-microm fiber followed by the flexible ureterorenoscope in combination with the 360- or 200-microm laser fiber depending on stone position. Stones were fragmented until they were small enough to be removed by hydrocleansing. Using this technique, stone-free success rates for calculi 2.5 cm or smaller after a single treatment, regardless of stone composition or location, are superior to those of extracorporeal shock wave lithotripsy. For calculi between 2.5 and 3 cm, the results also are noted to be superior. We conclude that for calculi larger than 3 cm or for partial staghorn calculi, the treatment of choice appears to be a percutaneous approach. PMID:9568772

  19. Optimization of dosimetry and safety using the holmium laser for urology

    NASA Astrophysics Data System (ADS)

    van Swol, Christiaan F. P.; Verdaasdonck, Rudolf M.; Zeijlemaker, Bram Y. W.; Grimbergen, Matthijs C. M.; Boon, Tom A.

    1998-07-01

    The holmium laser has become accepted as a versatile instrument for urological applications, such as prostate resection, urethrotomy, tumor coagulation and lithotripsy. Presently, more powerful lasers have become available generating pulses up to 4 J at 80 W. The necessity of these high power systems in urology is ambiguous. In this study, the dosimetry as to efficacy and especially safety was investigated for various applications. The holmium laser ((lambda) equals 2.1 micrometer) emits its energy in 350 microsecond pulses which instantly turn water into vapor. Using high-speed photography explosive vapor bubbles with diameters over 10 mm were captured. The mechanical force of these bubbles, effectively fragments stones but may dilate and rupture a small lumen like the ureter. After implosion of the bubble, the energy of vaporization turns into heat. Depending on pulse energy and pulse repetition rate, tissue can be thermally affected up to 5 mm. For soft tissue applications, e.g., urethrotomy, prostatectomy or tumor coagulation, pulse energies of 0.5 - 1.5 J were applied at a high repetition rate (20 - 40 Hz) to provide sufficient coagulative and hemostatic effects. At higher pulse energies, the fiber tip was vibrating vigorously and the tissue was ripped to pieces decreasing hemostasis and visibility. For hard tissue applications, bursts of 0.5 J pulses at 5 Hz, proved to be sufficient to fragment all types of stones (including cystine) in the ureter and the bladder without mechanical or thermal damage to surrounding tissue. At higher settings, targeting the stone was less controlled and effective due to 'jumping' of the fiber tip with resulting mechanical and thermal trauma to the surrounding tissue. The holmium laser can be used effectively to coagulate and cut soft tissue and fragment stones at relatively low energy and power settings, thus minimizing the risk of complications.

  20. Acute and chronic response of meniscal fibrocartilage to holmium:YAG laser irradiation

    NASA Astrophysics Data System (ADS)

    Horan, Patrick J.; Popovic, Neven A.; Islinger, Richard B.; Kuklo, Timothy R.; Dick, Edward J.

    1997-05-01

    The acute and chronic (10 week) histological effects of the holmium:YAG laser during partial meniscectomy in an in vivo rabbit model were investigated. Twenty-four adult male New Zealand rabbits underwent bilateral parapatellar medial knee arthrotomies. In the right knee, a partial medial meniscectomy was done through the avascular zone using a standard surgical blade. In the left knee, an anatomically similar partial medial meniscectomy was performed using a Ho:YAG laser (Coherent, USA). This study indicates that the laser creates two zones of damage in the meniscal fibrocartilage and that the zone of thermal change may act as a barrier to healing. The zone of thermal change which is eventually debrided was thought at the time of surgery to be viable. In the laser cut menisci, the synovium appears to have greater inflammation early and to be equivalent with the scalpel cut after three weeks. At all time periods there appeared more cellular damage in the laser specimens.

  1. Cavitation effect of holmium laser pulse applied to ablation of hard tissue underwater.

    PubMed

    Lü, Tao; Xiao, Qing; Xia, Danqing; Ruan, Kai; Li, Zhengjia

    2010-01-01

    To overcome the inconsecutive drawback of shadow and schlieren photography, the complete dynamics of cavitation bubble oscillation or ablation products induced by a single holmium laser pulse [2.12 microm, 300 micros (FWHM)] transmitted in different core diameter (200, 400, and 600 microm) fibers is recorded by means of high-speed photography. Consecutive images from high-speed cameras can stand for the true and complete process of laser-water or laser-tissue interaction. Both laser pulse energy and fiber diameter determine cavitation bubble size, which further determines acoustic transient amplitudes. Based on the pictures taken by high-speed camera and scanned by an optical coherent microscopy (OCM) system, it is easily seen that the liquid layer at the distal end of the fiber plays an important role during the process of laser-tissue interaction, which can increase ablation efficiency, decrease heat side effects, and reduce cost. PMID:20799845

  2. Percutaneous Endoscopic Holmium Laser Lithotripsy for Management of Complicated Biliary Calculi

    PubMed Central

    Healy, Kelly; Chamsuddin, Abbas; Spivey, James; Martin, Louis; Nieh, Peter

    2009-01-01

    Background and Objectives: Advances in endoscopic techniques have transformed the management of urolithiasis. We sought to evaluate the role of such urological interventions for the treatment of complex biliary calculi. Methods: We conducted a retrospective review of all patients (n=9) undergoing percutaneous holmium laser lithotripsy for complicated biliary calculi over a 4-year period (12/2003 to 12/2007). All previously failed standard techniques include ERCP with sphincterotomy (n=6), PTHC (n=7), or both of these. Access to the biliary system was obtained via an existing percutaneous transhepatic catheter or T-tube tracts. Endoscopic holmium laser lithotripsy was performed via a flexible cystoscope or ureteroscope. Stone clearance was confirmed intra- and postoperatively. A percutaneous transhepatic drain was left indwelling for follow-up imaging. Results: Mean patient age was 65.6 years (range, 38 to 92). Total stone burden ranged from 1.7 cm to 5 cm. All 9 patients had stones located in the CBD, with 2 patients also having additional stones within the hepatic ducts. All 9 patients (100%) were visually stone-free after one endoscopic procedure. No major perioperative complications occurred. Mean length of stay was 2.4 days. At a mean radiological follow-up of 5.4 months (range, 0.5 to 21), no stone recurrence was noted. Conclusions: Percutaneous endoscopic holmium laser lithotripsy is a minimally invasive alternative to open salvage surgery for complex biliary calculi refractory to standard approaches. This treatment is both safe and efficacious. Success depends on a multidisciplinary approach. PMID:19660213

  3. Endoscopic removal of a proximal urethral stent using a holmium laser: Case report and literature review

    PubMed Central

    Botelho, Francisco; Thomas, Anil A.; Miocinovic, Ranko; Angermeier, Kenneth W.

    2012-01-01

    Urethral stents were initially developed for the management of urethral strictures and obstructive voiding disorders in select patients. Urethral stent complications are common and may require stent explantation, which is often quite challenging. We present our experience with endoscopic removal of an encrusted UroLume proximal urethral stent in a 72-year-old male using a holmium laser. The literature on various management options and outcomes for urethral stent removal is reviewed. Endoscopic removal of proximal urethral stents is feasible and safe and should be considered as the primary treatment option in patients requiring stent extraction. PMID:23248530

  4. Sexual outcome of patients undergoing thulium laser enucleation of the prostate for benign prostatic hyperplasia.

    PubMed

    Carmignani, Luca; Bozzini, Giorgio; Macchi, Alberto; Maruccia, Serena; Picozzi, Stefano; Casellato, Stefano

    2015-01-01

    Treatment of patients with lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH) may affect the quality of sexual function and ejaculation. The effect of new surgical procedures, which are currently available to treat BPH, on erection and ejaculation, has been poorly studied. This study aimed to assess the effect of thulium laser enucleation of the prostate (ThuLEP) on sexual function and retrograde ejaculation in patients with LUTS secondary to BPH. We performed a prospective study in 110 consecutive patients who had undergone ThuLEP to analyze changes in sexual function and urinary symptoms. To evaluate changes in erection and ejaculation, and the effect of urinary symptoms on the quality of life (QoL), five validated questionnaires were used: the ICIQ-MLUTSsex, MSHQ-EjD, International Index of Erectile Function 5, International Prognostic Scoring System (IPSS) questionnaire, and QoL index of the intraclass correlation coefficients. Patients also underwent IPSS and flowmetry to assess the outcome of flow. Patients were evaluated before surgery and 3-6 months after ThuLEP, whereas those with previous abdominal surgery were excluded. The patients' mean age was 67.83 years. Postoperative urinary symptoms improved after surgery. No significant differences in erectile function before and after surgery were observed. As compared with other techniques described in the literature, the percentage of patients with conserved ejaculation increased by 52.7% after ThuLEP. ThuLEP positively affects urinary symptoms and their effect on the QoL of patients as assessed by questionnaire scores. While endoscopic management of BPH (e.g. transurethral resection of the prostate) causes retrograde ejaculation in most patients, those who undergo ThuLEP have conserved ejaculation and erectile function. PMID:25652616

  5. Sexual outcome of patients undergoing thulium laser enucleation of the prostate for benign prostatic hyperplasia

    PubMed Central

    Carmignani, Luca; Bozzini, Giorgio; Macchi, Alberto; Maruccia, Serena; Picozzi, Stefano; Casellato, Stefano

    2015-01-01

    Treatment of patients with lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH) may affect the quality of sexual function and ejaculation. The effect of new surgical procedures, which are currently available to treat BPH, on erection and ejaculation, has been poorly studied. This study aimed to assess the effect of thulium laser enucleation of the prostate (ThuLEP) on sexual function and retrograde ejaculation in patients with LUTS secondary to BPH. We performed a prospective study in 110 consecutive patients who had undergone ThuLEP to analyze changes in sexual function and urinary symptoms. To evaluate changes in erection and ejaculation, and the effect of urinary symptoms on the quality of life (QoL), five validated questionnaires were used: the ICIQ-MLUTSsex, MSHQ-EjD, International Index of Erectile Function 5, International Prognostic Scoring System (IPSS) questionnaire, and QoL index of the intraclass correlation coefficients. Patients also underwent IPSS and flowmetry to assess the outcome of flow. Patients were evaluated before surgery and 3–6 months after ThuLEP, whereas those with previous abdominal surgery were excluded. The patients’ mean age was 67.83 years. Postoperative urinary symptoms improved after surgery. No significant differences in erectile function before and after surgery were observed. As compared with other techniques described in the literature, the percentage of patients with conserved ejaculation increased by 52.7% after ThuLEP. ThuLEP positively affects urinary symptoms and their effect on the QoL of patients as assessed by questionnaire scores. While endoscopic management of BPH (e.g. transurethral resection of the prostate) causes retrograde ejaculation in most patients, those who undergo ThuLEP have conserved ejaculation and erectile function. PMID:25652616

  6. Influence of pulse duration on erbium and holmium laser ablation under water

    NASA Astrophysics Data System (ADS)

    Ith, Michael; Frenz, Martin; Pratisto, Hans S.; Weber, Heinz P.; Altermatt, Hans J.; Staeubli, Hans U.; Asshauer, Thomas; Delacretaz, Guy P.; Salathe, Rene-Paul; Gerber, Bruno E.

    1995-01-01

    Erbium and Holmium lasers are ideally suited for cutting and drilling biological tissue. This is due to the fact that their wavelengths (Er:YSGG at 2.79 micrometers and Ho:YAG at 2.12 micrometers ) are strongly absorbed in water which is present in all tissues. Combined with an optical fiber these lasers seem to be optimal instruments for endoscopic and/or minimal invasive applications in surgery. In this study we focused our interest on cutting of human meniscus in the knee where, besides a very limited operation field, the standard arthroscopic treatment is performed in a liquid, highly absorbing environment. The bubble formation process, therefore, has to be well understood because it mainly determines relevant aspects of tissue ablation. The influence of the laser parameters in general and the influence of pulse duration in particular are determined in this paper for two different laser wavelengths. The goal was to determine the optimum laser parameters in view of a high ablation efficiency, a high precision and a minimal destruction of the adjacent tissue. To determine the optimum pulse duration for ablating tissue under water and to obtain a better understanding of the channel formation process, transmission and pressure measurements together with video flash photography were performed. Additionally, we determined experimentally the ratio between initial laser pulse energy and energy available for tissue treatment under water. To prove the results obtained, cuts in human meniscus were performed, sectioned and evaluated. The comparison between the results obtained with the Erbium and Holmium laser revealed a strong influence of the absorption coefficients on the tissue effects, especially on the ablation efficiency and on the zone of thermally and mechanically damaged tissue.

  7. Operation of the nose using Nd-YAG and holmium laser

    NASA Astrophysics Data System (ADS)

    Kukwa, Andrzej; Tulibacki, Marek P.; Zajac, Andrzej; Dudziec, Katarzyna

    2000-06-01

    During more than 5 years Nd:YAG and Holmium laser has been used in our ENT Department for the treatment of varies pathological changes. Most of our cases were previously treated many times because of recurrences of the nasal polyps. As a rule the treatment was given in one to three sessions. Each patient was very closely monitored. The time period between the session was 2-4 weeks. The consequent application of laser was dependent on healing process. All adults' patients were treated in local anesthesia using 1,5 percent of Cocaine and 10 percent Xylocaine applied in a spray; no other anesthetics were needed, although in some patients 10 mg Valium was administered before first session of laser application. We do not observe a severe bleeding needed sponge or a nose package. Among advantages we have to concentrate on two: the recurrences of nasal polyps are definitely much rare and patient may appear at work at the same day.

  8. High power operation of cladding pumped holmium-doped silica fibre lasers.

    PubMed

    Hemming, Alexander; Bennetts, Shayne; Simakov, Nikita; Davidson, Alan; Haub, John; Carter, Adrian

    2013-02-25

    We report the highest power operation of a resonantly cladding-pumped, holmium-doped silica fibre laser. The cladding pumped all-glass fibre utilises a fluorine doped glass layer to provide low loss cladding guidance of the 1.95 µm pump radiation. The operation of both single mode and large-mode area fibre lasers was demonstrated, with up to 140 W of output power achieved. A slope efficiency of 59% versus launched pump power was demonstrated. The free running emission was measured to be 2.12-2.15 µm demonstrating the potential of this architecture to address the long wavelength operation of silica based fibre lasers with high efficiency. PMID:23481989

  9. Experience with endoscopic holmium laser in the pediatric population

    NASA Astrophysics Data System (ADS)

    Merguerian, Paul A.; Reddy, Pramod P.; Barrieras, Diego; Bagli, Darius J.; McLorie, Gordon A.; Khoury, Antoine E.

    1999-06-01

    Introduction: Due to the unavailability of suitable endoscopic instruments, pediatric patients have not benefited fully from the technological advances in the endoscopic management of the upper urinary tract. This limitation may be overcome with the Holmuim:Yttrium-Aluminum-Garnet(Ho:YAG) laser delivered via small instruments. To date, there is no published report on the use of this modality in children. Purpose: We evaluated the indications, efficacy, and complications of endourological Ho:YAG laser surgery in the treatment of pediatric urolithiasis, posterior urethral valves, ureterocele and ureteropelvic junction obstruction. Methods: The patient population included 10 children with renal, ureteral and bladder calculi, 2 children with posterior urethral valves, 2 children with obstructing ureteroceles, 2 children with ureteropelvic junction obstruction and 1 child with a urethral stricture. Access to the lesions was either antegrade via a percutaneous nephrostomy tract or retrograde via the urethra. A solid state Ho:YAG laser with maximum output of 30 watts (New Star lasers, Auburn, CA) was utilized as the energy source. Results: A total of 10 patients underwent laser lithotripsy. The means age of the patients was 9 yrs (5-13 yrs). The average surface area of the calculi as 425.2 mm2 (92-1645 mm2). 8 of the patients required one procedure to render them stone free, one patient had a staghorn calculus filling every calyx of a solitary kidney requiring multiple treatments and one other patient with a staghorn calculus required 2 treatments. There were no complications related to the laser lithotripsy. Two newborn underwent successful ablation of po sterious urethral valves. Two infants underwent incision of obstructing ureteroceles with decompression of the ureterocele on postoperative ultrasound. Two children underwent endypyelotomy for ureteropelvic junction obstruction. One was successful an done required an open procedure to correct the obstruction. One child

  10. Holmium:YAG laser: effect on pulpal tissues and root surfaces

    NASA Astrophysics Data System (ADS)

    Holt, Raleigh A.; Nordquist, Robert E.

    1996-04-01

    The effects of the Holmium:YAG irradiation on the pulpal tissues and surface topography on root surface dentin in human teeth in vivo were studied. The exposed root surfaces of seventeen pre-immediate denture patients were scaled and root planed with a Gracey 3 - 4 curette apical to the dentinoenamel junction until smooth and hard. The prepared root surfaces of two teeth per patient were exposed with Holmium:YAG laser energy after an application of nonfilled resin/fluoride mixture. The laser exposed areas were below the dentinoenamel junction around one-half of each root surface. The opposing sides of each of the teeth received resin/fluoride but no laser energy. A third tooth was identified as a nontreated control. The HO:YAG at 2.12 microns wavelength with a defocused beam size of 3 mm was used. The amount of laser energy delivered per 3 X 5 mm area was 0.450 (+/- .05) joules with a fluence of 2.66 - 3.30 J/cm2. The teeth were extracted after periods of 45 - 120 days. The specimens were fixed in formalin and prepared for histological examination using hematoxylin and eosin stains. Microscopic evaluation of room surfaces showed increased smoothness on the laser treated sites compared to their opposing non-lased sides. Histological examination of the pulpal tissues exhibited no abnormal changes. No clinical symptoms of pulpal pathology were produced. HO:YAG laser energy proved safe for treating room surfaces of human teeth in vivo under conditions presented in this study.

  11. Treatment of Parapelvic Cyst by Internal Drainage Technology Using Ureteroscope and Holmium Laser

    PubMed Central

    Zhao, Q; Huang, S; Li, Q; Xu, L; Wei, X; Huang, S; Li, S; Liu, Z

    2015-01-01

    ABSTRACT Background: The aim of parapelvic cyst treatment is to have complete drainage of cyst fluid and prevent its further compression of the kidney and collective system. This study explores the efficacy and safety of surgical approaches with holmium laser ureteroscopic internal drainage in the treatment of parapelvic cyst. Methods: The compression effect of parapelvic cyst on the renal collective system was observed by rigid ureteroscope using retrograde ureteroscopic technology. With direct vision, the cyst wall on the obvious parapelvic compression site was cut. The diameter of the cyst wall cut was about 1 cm. The internal drainage was obtained by double-J tubes. When the cyst was in the inferior pole of kidney or where the rigid ureteroscope could not reach, a flexible ureteroscope was used. Results: In 28 cases of operation, 27 cases were successful. The cyst treatment time was eight to 40 minutes (average 26 minutes). During the operation, no massive haemorrhage, damage of nearby organ and ureter, or other complications happened. Time of follow-up was 10–72 months (average 39 months). The results of follow-up showed that in 22 cases, the cyst disappeared; the diameter of the cyst in four cases was reduced by more than half, and one case recurred. Conclusion: The treatment of parapelvic cyst by internal drainage operation using holmium laser and ureteroscopy was effective. The operation was safe with few complications. PMID:26426175

  12. Posterior Urethral Polyp: First Holmium-YAG Laser Ablation on a 3-Month-Old Infant

    PubMed Central

    Keskin, Ercument; Yapanoglu, Turgut; Adanur, Senol; Ziypak, Tevfik; Altay, Mehmet Sefa; Aksoy, Yılmaz

    2016-01-01

    Abstract Background: Urethral polyps are rare benign pathologies seen in the male posterior urethra, more frequently originating from verumontanum. In this article, we aimed to discuss diagnosis and treatment of a urethral polyp causing hematuria and urinary infection in a 3-month-old male infant. This is the first case in the literature in which a urethral polyp is treated with Holmium yttrium-aluminum-garnet (YAG) laser. Case Presentation: The patient was a 3-month-old male infant, and complains were hematuria and crying during micturition. Ultrasonography and voiding cystourethrogram were used for diagnosis. Urethral polyp was observed on urethrocystoscopy. Ablation was performed with a newborn cystoscope. Conclusion: Urethral polyp can cause hematuria and urinary obstruction and should be considered in the differential diagnosis of pathologies such as posterior urethral valve and cecoureterocele that could cause infravesical obstruction. Holmium-YAG laser is a good choice of treatment with easy application possibilities using a newborn cystoscope, especially for newborns and infants who have thin urethra. PMID:27579428

  13. Endoscopic goniotomy probe for holmium:YAG laser delivery

    NASA Astrophysics Data System (ADS)

    Joos, Karen M.; Shen, Jin-Hui; Ren, Qiushi

    1994-06-01

    Goniotomy is an effective treatment for primary infantile glaucoma. Because a cloudy cornea may prevent a clear view of the anterior chamber angle through the operating microscope, we investigated whether an endoscope can be combined with a cutting laser to perform laser goniotomy in a surgical model of primary infantile glaucoma. The anterior chambers of cadaver procine eyes were deepened with a viscoelastic material. A 300-micron-diameter silica fiber coupled to an Olympus 0.8-mm-diameter flexible fiber optic endoscope entered the anterior chambers through 4-mm corneal incisions. The anterior chamber angles were clearly observed on a videoscreen as the endoscopic fiber optic laser scalpel approached the pectinate ligaments. With the guidance of a He-Ne aiming beam, the anterior chamber angle pectinate ligaments were cut over a 160 degree arc with a pulsed Ho:YAG laser (2.1 micrometers wavelength, 50 mJ, 5 Hz repetition). The specimens were fixed in glutaraldehyde and processed for scanning electron microscopy, or fixed in formalin and processed for light microscopy. The treated area demonstrated incision of the pectinate ligaments with opening of the underlying trabecular meshwork. The edoscopic fiber optic laser scalpel is capable of cutting the pectinate ligaments in a surgical model of primary infantile glaucoma. Therefore, it may be a useful instrument for performing goniotomy when a cloudy cornea in primary infantile glaucoma prevents visualization of the anterior chamber angle with a goniotomy lens.

  14. Evaluation of holmium laser versus cold knife in optical internal urethrotomy for the management of short segment urethral stricture

    PubMed Central

    Jain, Sudhir Kumar; Kaza, Ram Chandra Murthy; Singh, Bipin Kumar

    2014-01-01

    Objectives: Sachse cold knife is conventionally used for optical internal urethrotomy intended to manage urethral strictures and Ho: YAG laser is an alternative to it. The aim of this study was to evaluate the role of urethral stricture treatment outcomes, efficacy, and complications using cold knife and Ho: YAG (Holmium laser) for optical internal urethrotomy Materials and Methods: In this prospective study included, 90 male patients age >18 years, with diagnosis of urethral stricture admitted for internal optical urethrotomy during April 2010 to March 2012. The patients were randomized into two groups containing 45 patients each using computer generated random number. In group A (Holmium group), internal urethrotomy was done with Holmium laser and in group B (Cold knife group) Sachse cold knife was used. Patients were followed up for 6 months after surgery in Out Patient Department on 15, 30 and 180 post-operative days. At each follow up visit physical examination, and uroflowmetry was performed along with noting complaints, if any. Results: The peak flow rates (PFR) were compared between the two groups on each follow up. At 180 days (6 month interval) the difference between mean of PFR for Holmium and Cold knife group was statistically highly significant (P < 0.001). Complications were seen in 12.22% of cases. Conclusion: Both modalities are effective in providing immediate relief to patients with single and short segment (<2 cm long) urethral strictures but more sustained response was attained with Cold knife urethrotomy. PMID:25371611

  15. Holmium laser ablation of cartilage: effects of cavitation bubbles

    NASA Astrophysics Data System (ADS)

    Asshauer, Thomas; Jansen, Thomas; Oberthur, Thorsten; Delacretaz, Guy P.; Gerber, Bruno E.

    1995-05-01

    The ablation of fresh harvested porcine femur patellar groove cartilage by a 2.12 micrometers Cr:Tm:Ho:YAG laser in clinically used irradiation conditions was studied. Laser pulses were delivered via a 600 micrometers diameter fiber in isotonic saline. Ablation was investigated as a function of the angle of incidence of the delivery fiber with respect to the cartilage surface (0-90 degrees) and of radiant exposure. Laser pulses with energies of 0.5, 1.0 and 1.5 J and a duration of 250 microseconds were used. A constant fiber tip-tissue distance of 1 mm was maintained for all experiments. The dynamics of the induced vapor bubble and of the ablation process was monitored by time resolved flash videography with a 1 microseconds illumination. Acoustic transients were measured with a piezoelectric PVDF needle probe hydrophone. Bubble attachment to the cartilage surface during the collapse phase, leading to the direct exposition of the cartilage surface to the maximal pressure generated, was observed in all investigated irradiation conditions. Maximal pressure transients of up to 200 bars (at 1 mm distance from the collapse center) were measured at the bubble collapse at irradiation angles >= 60 degrees. No significant pressure variation was observed in perpendicular irradiation conditions as a function of radiant exposure. A significant reduction of the induced pressure for irradiation angles

  16. Application of 2-um wavelength holmium lasers for treatment of skin diseases

    NASA Astrophysics Data System (ADS)

    Shcherbakov, Ivan A.; Klimov, Igor V.; Tsvetkov, Vladimir B.; Nerobeev, Alexander I.; Sadovnikova, Lija B.; Eliseenko, Vladimir I.

    1994-09-01

    Theoretical and experimental analysis of the efficiency of application of 2 micrometers pulsed holmium laser for cosmetic and plastic surgery and dermatology is carried out. Preliminary experiments were carried out on rats. Solid state 2 micrometers pulsed laser was allowed to operate in free running mode with pulse energy up to 1.5 J and pulse repetition rate up to 5 Hz. To deliver emission to the object a flexible quartz fiber without further focusing of 2.5 m in length and 400 micrometers of the core diameter was used. The effect of the different power density emission on the skin was studied. The second stage was the study of the influence of 2 micrometers emission on human skin. The results of the removal of hemangioma, papilloma, telangiectasia, nevus, nevus acantholytic, xanthelasma palpebral, verruca, chloasma, pigmental spots, tattoos, etc. are presented. Precision, simplicity, efficiency, and the high cosmetic effect of these operations is noted.

  17. Changes in corneal collagen induced by holmium:YAG laser irradiation

    NASA Astrophysics Data System (ADS)

    Timberlake, George T.; Reinke, Martin H.; Miller, Alvin

    1996-05-01

    Holmium:YAG laser thermokeratoplasty corrects hyperopia (farsightedness) by producing small areas of corneal collagen shrinkage that cause the central cornea to bulge outward, increasing optical power. Collagen shrinkage is probably caused by laser-heated corneal water, but details of the shrinkage mechanism are not known. We investigated the shrinkage mechanism by measuring changes in corneal ultrastructure, surface shrinkage, water content, and strength following Ho:YAG laser exposures. Morphological changes in collagen were documented by measurements from electron micrographs. Corneal adhesive strength was determined by measuring tearing force in a plane parallel to the corneal surface. Laser-induced water loss was measured by weighing corneal samples before and after exposure. Corneal surface shrinkage was assessed by photographing the movement of particles on the cornea. Lasered collagen fibrils increased in diameter, lost their orderly arrangement, and appeared `frayed.' The corneal surface contracted toward lasered areas with a maximal shift of approximately 190 micrometers , more than could be explained by a model based on collagen fibril changes. Water loss plays a minor role in corneal shrinkage since corneal samples lost about only about 1.4% of their weight after massive laser exposure. Despite marked changes in collagen structure, corneal adhesive force was unchanged.

  18. Laboratory investigation of the efficacy of holmium:YAG laser irradiation in removing intracanal debris

    NASA Astrophysics Data System (ADS)

    Nuebler-Moritz, Michael; Gutknecht, Norbert; Sailer, Hermann F.; Hering, Peter; Prettl, Wilhelm

    1997-05-01

    Current endodontic therapy involves debridement and disinfection of the root canal by means of mechanical instrumentation and chemical irrigation. However, several studies have shown that these techniques fail to achieve complete cleansing. Recently, lasers have been suggested for use within root canals. This study was conducted to determine the efficacy of Holmium:YAG laser irradiation in removing intracanal debris and smear layer. Root canal surfaces of freshly-extracted human teeth were exposed to pulsed Ho:YAG laser radiation. Subsequently, laser induced structural changes were investigated using scanning electron microscopy. Temperature measurements during irradiation were performed by means of thermocouples. The result of this survey give a preliminary indication of the ability of the Ho:YAG laser to improve current endodontic treatment survey give a preliminary indication of the ability of the Ho:YAG laser to improve current endodontic treatment modalities. However, limitations exist with regard to circumscribed and well-quantified irradiation of root canal surfaces, due to the lack of perpendicular delivery of the laser beam. Additional studies will be required to develop suitable optical transmission systems, in order to achieve complete cleansing and to avoid damage to the periradicular tissues, respectively.

  19. Metals fact sheet: Holmium/thulium

    SciTech Connect

    1996-02-01

    This article discusses the geology, exploitation, market, and applications of holmium and thulium. Holmium and thulium are important part in the development of specific laser technologies, x-ray film and high-temperature superconductors.

  20. Q-switching of a thulium-doped fibre laser using a holmium-doped fibre saturable absorber

    SciTech Connect

    Sadovnikova, Ya E; Kamynin, V A; Kurkov, A S; Medvedkov, O I; Marakulin, A V; Minashina, L A

    2014-01-31

    We have proposed and demonstrated a new passively Q-switched thulium-doped fibre laser configuration. A distinctive feature of this configuration is the use of a heavily holmium-doped fibre for Q-switching. Lasing was obtained at 1.96 μm, with a pulse energy of 3 μJ and pulse duration of 600 ns. The highest pulse repetition rate was 80 kHz. (control of laser radiation parameters)

  1. Risk factors of infectious complications following flexible ureteroscope with a holmium laser: a retrospective study

    PubMed Central

    Fan, Song; Gong, Binbin; Hao, Zongyao; Zhang, Li; Zhou, Jun; Zhang, Yifei; Liang, Chaozhao

    2015-01-01

    Purpose: We aimed to evaluate the effectiveness of flexible ureteroscope for treating kidney stones and the risk factors for infectious complications following flexible ureteroscope (FURS) with a holmium laser. Methods: We retrospectively reviewed the data of 227 patients with kidney stones who underwent flexible ureteroscope with a holmium laser at our hospital from January 2012 to September 2014, including gender, age, comorbidity, urine analysis results, urine culture results, blood test results, stone size, operative duration, and residual stones. Patients with and without infectious complications were assigned to groups A and B, respectively. The dependent variables were postoperative infectious complications, and the risk factors for infectious complications following FURS were assessed using Chi-square tests and multivariate logistic regression analyses. Results: All the surgeries were successfully completed. The total stone-free rate was 81.9% (n = 186), and the incidence of infectious complications after FURS was 8.37% (n = 19). Fifteen patients (6.61%) developed fever postoperatively, 10 patients (4.41%) developed systemic inflammatory response syndrome (SIRS), 6 patients with fever were considered to have SIRS (2.64%), and 2 patients had sepsis (0.88%). Univariate analyses of groups A and B indicated that pyuria, stone size, operative duration, and infectious stones were risk factors for infectious complications after FURS (P < 0.05). Multivariate logistic regression analyses indicated that pyuria (P = 0.017), operative duration (P = 0.026), and infectious stones (P = 0.030) were independently related to infectious complications. Conclusion: Pyuria, operative duration, and infectious stones were risk factors for infectious complications following FURS. Hence, routine urinalysis findings should be carefully considered, particularly the finding of pyuria. PMID:26379932

  2. Percutaneous Transhepatic Endoscopic Holmium Laser Lithotripsy for Intrahepatic and Choledochal Biliary Stones

    SciTech Connect

    Rimon, Uri; Kleinmann, Nir; Bensaid, Paul; Golan, Gil; Garniek, Alexander; Khaitovich, Boris; Winkler, Harry

    2011-12-15

    Purpose: To report our approach for treating complicated biliary calculi by percutaneous transhepatic endoscopic biliary holmium laser lithotripsy (PTBL). Patients and Methods: Twenty-two symptomatic patients (11 men and 11 women, age range 51 to 88 years) with intrahepatic or common bile duct calculi underwent PTBL. Nine patients had undergone previous gastrectomy and small-bowel anastomosis, thus precluding endoscopic retrograde cholangiopancreatography. In the other 13 patients, stone removal attempts by ERCP failed due to failed access or very large calculi. We used a 7.5F flexible ureteroscope and a 200-{mu}m holmium laser fiber by way of a percutaneous transhepatic tract, with graded fluoroscopy, to fragment the calculi with direct vision. Balloon dilatation was added when a stricture was seen. The procedure was performed with the patient under general anaesthesia. A biliary drainage tube was left at the end of the procedure. Results: All stones were completely fragmented and flushed into the small bowel under direct vision except for one patient in whom the procedure was aborted. In 18 patients, 1 session sufficed, and in 3 patients, 2 sessions were needed. In 7 patients, balloon dilatation was performed for benign stricture after Whipple operation (n = 3), for choledochalenteric anastomosis (n = 3), and for recurrent cholangitis (n = 1). Adjunctive 'balloon push' (n = 4) and 'rendezvous' (n = 1) procedures were needed to completely clean the biliary tree. None of these patients needed surgery. Conclusion: Complicated or large biliary calculi can be treated successfully using PTBL. We suggest that this approach should become the first choice of treatment before laparoscopic or open surgery is considered.

  3. Correlation of thermal and mechanical effects of the holmium laser for various clinical applications

    NASA Astrophysics Data System (ADS)

    Grimbergen, Matthijs C. M.; Verdaasdonck, Rudolf M.; van Swol, Christiaan F. P.

    1998-05-01

    The Holmium laser has become established in orthopedic surgery and urology due to its unique combination of mechanical and thermal properties induced by explosive vapor bubbles. In a specialized setup, real-time high-speed and thermal images of dynamic vapor bubbles and thermal relaxation at a water tissue interface were obtained simultaneously. The thermal effects in the tissue model were correlated to the characteristics of the bubbles dependent on pulse energy (0.2 - 4 J), pulse repetition frequency (5 - 40 Hz), distance and angle of fiber delivery system (diameter 365 micrometer) to the tissue surface. Up to a fiber-to-tissue distance of 50% of the radius of the bubble, only a superficial tissue layer was heated. During bubble implosion, the tissue surface was attracted to the fiber, ripping of irregularities, and was effectively cooled by turbulence. In case of hard tissues, the bubble detached from the fiber imploding towards the hard surface. At closer distances (less than 50% of bubble radius), the tissue itself was vaporized resulting in mechanical damage and thermal relaxation into the tissue, especially above repetition rates of 5 Hz. There is a strong correlation between the path length of the free beam within the bubble and the degree of mechanical and thermal damage in the tissue directly irradiated by this beam. During clinical applications the surgeon should be aware of the size of the vapor bubble in relation to the distance and angle with the tissue for safe optimal use of the mechanical and thermal properties of the Holmium laser.

  4. A review of thulium laser vapo-enucleation of the prostate: A novel laser-based strategy for benign prostate enlargement

    PubMed Central

    Jones, Patrick; Rai, Bhavan Prasad; Somani, Bhaskar K.; Aboumarzouk, Omar M.

    2015-01-01

    Thulium laser vapo-enucleation of the prostate is the latest addition to the arsenal of minimally invasive therapies available for the surgical treatment of lower urinary tract symptoms secondary to benign prostate hyperplasia. The potential advantages include smoother vaporisation, a clearer visual field and the option of both continuous-wave and pulsed modes, which also potentiate the haemostatic properties of this endoscopic method. Short-term results show that it yields significant improvements in both subjective and objective outcomes, with a strong safety profile. Large-scale randomised studies with a longer follow-up are warranted to determine the durability of this laser procedure. PMID:26413349

  5. A review of thulium laser vapo-enucleation of the prostate: A novel laser-based strategy for benign prostate enlargement.

    PubMed

    Jones, Patrick; Rai, Bhavan Prasad; Somani, Bhaskar K; Aboumarzouk, Omar M

    2015-09-01

    Thulium laser vapo-enucleation of the prostate is the latest addition to the arsenal of minimally invasive therapies available for the surgical treatment of lower urinary tract symptoms secondary to benign prostate hyperplasia. The potential advantages include smoother vaporisation, a clearer visual field and the option of both continuous-wave and pulsed modes, which also potentiate the haemostatic properties of this endoscopic method. Short-term results show that it yields significant improvements in both subjective and objective outcomes, with a strong safety profile. Large-scale randomised studies with a longer follow-up are warranted to determine the durability of this laser procedure. PMID:26413349

  6. Management of Benign Prostatic Hyperplasia Larger than 100 ml: Simple Open Enucleation Versus Transurethral Laser Prostatectomy.

    PubMed

    Elkoushy, Mohamed A; Elhilali, Mostafa M

    2016-06-01

    Benign prostatic hyperplasia (BPH) is one of the most common causes of lower urinary tract symptoms (LUTS) in aging men. Over the age of 60, more than a half of men have BPH and/or bothersome LUTS. Contemporary guidelines advocate surgery as the standard of care for symptomatic BPH after failure of medical therapy, where the choice of the appropriate surgical procedure depends on the prostate size. Transurethral resection of the prostate (TURP) and simple open prostatectomy (OP) have been considered for decades the reference-standard techniques for men with prostate smaller and larger than 80 ml, respectively. However, both procedures are potentially associated with considerable perioperative morbidity which prompted the introduction of a variety of minimally invasive surgical techniques with comparable long-term outcomes compared to TURP and OP. Nevertheless, the management of prostates larger than 100 ml remains a clinical challenge. Transurethral anatomical enucleation of the prostate utilizing different laser energy represents an excellent alternative concept in transurethral BPH surgery. These procedures gained popularity and demonstrated similar outcomes to OP with the advantages of favorable morbidity profiles and shorter catheter time and hospital stay. Despite the fact that OP remains a viable treatment option for patients with bothersome LUTS secondary to very large prostates, this procedure has been to a large extent replaced by these emerging enucleation techniques. Given the advent of surgical alternatives, the current review presents an evidence-based comparison of the efficacy and safety profile of the currently available transurethral laser techniques with the standard OP for the management of BPH due to adenomas larger than 100 ml. PMID:27048160

  7. Efficacy of Holmium Laser Urethrotomy in Combination with Intralesional Triamcinolone in the Treatment of Anterior Urethral Stricture

    PubMed Central

    Kapoor, Ankur; Ganesamoni, Raguram; Nanjappa, Bhuvanesh; Sharma, Varun; Mete, Uttam K

    2012-01-01

    Purpose To evaluate the outcome of visual internal urethrotomy with a holmium:yttrium-aluminum-garnet laser along with intralesional triamcinolone injection. Materials and Methods Patients with an anterior urethral stricture less than 3 cm in length were evaluated by clinical history, physical examination, uroflowmetry, and retrograde urethrogram preoperatively. All patients were treated with holmium laser urethrotomy and intralesional triamcinolone (80 mg) injection under general or regional anesthesia. An 18 F urethral catheter was placed for 5 days. All patients were followed up for 12 months postoperatively by history, uroflowmetry, and if required, retrograde urethrogram or urethroscopy every 3 months. Results The mean age of the patients was 42.9 years (range, 14 to 70 years). The overall recurrence rate was 24%. The success rate in patients with strictures less than 1 cm in length was 95.8%, whereas that in patients with strictures of 1 to 3 cm in length was 57.7% (p=0.002). The outcome did not depend on age, duration of symptoms, etiology, or location of stricture. Conclusions Holmium laser urethrotomy with intralesional triamcinolone is a safe and effective minimally invasive therapeutic modality for urethral strictures. This procedure has an encouraging success rate, especially in those with stricture segments of less than 1 cm in length. PMID:23060998

  8. Single-frequency, single-polarization holmium-doped ZBLAN fiber laser

    NASA Astrophysics Data System (ADS)

    Zhu, X.; Zong, J.; Miller, A.; Wiersma, K.; Norwood, R. A.; Prasad, N. S.; Chavez-Pirson, A.; Peyghambarian, N.

    2013-02-01

    We present the performance of a single frequency, single-polarization holmium (Ho3+)-doped ZBLAN (ZrF4-BaF2-LaF3- AlF3-NaF) fiber laser at 1200 nm. This distributed Bragg reflector (DBR) fiber laser was developed by splicing a 22 mm long highly Ho3+-doped ZBLAN fiber to a pair of silica fiber Bragg gratings (FBG). The successful fusion splicing of silica fiber to ZBLAN fiber, with their very different melting temperatures, was accomplished by using NP Photonics proprietary splicing technique. The 3 mol% Ho3+-doped ZBLAN fiber had a core diameter of 6.5 μm and a cladding diameter of 125 μm. The threshold of this laser was seen to be about 260 mW, and when the pump power was 520 mW, the output power was about 10 mW. The efficiency of the 1200 nm single-frequency fiber laser, i.e. the ratio of the output power to the launched pump power, was about 3.8%. The linewidth of the 1200 nm single-frequency fiber laser was estimated to be about 100 kHz by comparing the measured frequency noise of the 1200 nm single-frequency fiber laser with that of 1 μm NP Photonics single-frequency fiber lasers whose linewidths have been measured to be in the 1- 10 kHz range. The relative intensity noise of this DBR all-fiber laser was measured to be < 110 dB/Hz at the relaxation oscillation peak and the polarization extinction ratio was measured to be > 19 dB. Due to its low phonon energy and long radiative lifetimes, rare-earth-doped ZBLAN allows various transitions that are typically terminated in silica glass, resulting in ultraviolet, visible, and infrared rare-earth doped ZBLAN lasers. Therefore, our results highlight the exciting prospect that the accessible wavelength range of single-frequency DBR fiber lasers can be expanded significantly by using rare-earth-doped ZBLAN fibers.

  9. Holmium-doped 2.1 μm waveguide chip laser with an output power > 1 W.

    PubMed

    Lancaster, D G; Stevens, V J; Michaud-Belleau, V; Gross, S; Fuerbach, A; Monro, T M

    2015-12-14

    We demonstrate the increasing applicability of compact ultra-fast laser inscribed glass guided-wave lasers and report the highest-power glass waveguide laser with over 1.1 W of output power in monolithic operation in the short-infrared near 2070 nm achieved (51% incident slope efficiency). The holmium doped ZBLAN chip laser is in-band pumped by a 1945 nm thulium fiber laser. When operated in an extended-cavity configuration, over 1 W of output power is realized in a linearly polarized beam. Broad and continuous tunability of the extended-cavity laser is demonstrated from 2004 nm to 2099 nm. Considering its excellent beam quality of M² = 1.08, this laser shows potential as a flexible master oscillator for single frequency and mode-locking applications. PMID:26699055

  10. Kidney stone ablation times and peak saline temperatures during Holmium:YAG and Thulium fiber laser lithotripsy, in vitro, in a ureteral model

    NASA Astrophysics Data System (ADS)

    Hardy, Luke A.; Wilson, Christopher R.; Irby, Pierce B.; Fried, Nathaniel M.

    2015-02-01

    Using a validated in vitro ureter model for laser lithotripsy, the performance of an experimental Thulium fiber laser (TFL) was studied and compared to clinical gold standard Holmium:YAG laser. The Holmium laser (λ = 2120 nm) was operated with standard parameters of 600 mJ, 350 μs, 6 Hz, and 270-μm-core optical fiber. TFL (λ = 1908 nm) was operated with 35 mJ, 500 μs, 150-500 Hz, and 100-μm-core fiber. Urinary stones (60% calcium oxalate monohydrate / 40% calcium phosphate), of uniform mass and diameter (4-5 mm) were laser ablated with fibers through a flexible video-ureteroscope under saline irrigation with flow rates of 22.7 ml/min and 13.7 ml/min for the TFL and Holmium laser, respectively. The temperature 3 mm from tube's center and 1 mm above mesh sieve was measured by a thermocouple and recorded during experiments. Total laser and operation times were recorded once all stone fragments passed through a 1.5-mm sieve. Holmium laser time measured 167 +/- 41 s (n = 12). TFL times measured 111 +/- 49 s, 39 +/- 11 s, and 23 +/- 4 s, for pulse rates of 150, 300, and 500 Hz (n = 12 each). Mean peak saline irrigation temperatures reached 24 +/- 1 °C for Holmium, and 33 +/- 3 °C, 33 +/- 7 °C, and 39 +/- 6 °C, for TFL at pulse rates of 150, 300, and 500 Hz. To avoid thermal buildup and provide a sufficient safety margin, TFL lithotripsy should be performed with pulse rates below 500 Hz and/or increased saline irrigation rates. The TFL rapidly fragmented kidney stones due in part to its high pulse rate, high power density, high average power, and reduced stone retropulsion, and may provide a clinical alternative to the conventional Holmium laser for lithotripsy.

  11. The evaluation of tissue mass loss in the incision line of prostate with benign hyperplasia performed using holmium laser and cutting electrode

    PubMed Central

    Szewczyk, Mariusz; Jesionek–Kupnicka, Dorota; Lipinski, Piotr; Różański, Waldemar

    2014-01-01

    Introduction The aim of this study is to compare the changes in the incision line of prostatic adenoma using a monopolar cutting electrode and holmium laser, as well as the assessment of associated tissue mass and volume loss of benign prostatic hyperplasia (BPH). Material and methods The material used in this study consisted of 74 preparations of prostatic adenoma obtained via open retropubic adenomectomy, with an average volume of 120.7 ml. The material obtained cut in vitro before fixation in formaldehyde. One lobe was cut using holmium laser, the other using a monopolar cutting electrode. After the incision was made, tissue mass and volume loss were evaluated. Thermocoagulation changes in the incision line were examinedunder light microscope. Results In the case of the holmium laser incision, the average tissue mass loss was 1.73 g, tissue volume loss 3.57 ml and the depth of thermocoagulation was 1.17 mm. When the monopolar cutting electrode was used average tissue mass loss was 0.807 g, tissue volume loss 2.48 ml and the depth of thermocoagulation was 0.19 mm. Conclusions Where holmium laser was used, it was observed that the layer of tissue with thermocoagulation changes was deeper than in the case of the monopolar cutting electrode. Moreover, it was noticed that holmium laser caused bigger tissue mass and volume loss than the cutting electrode. PMID:25247088

  12. Effectiveness and Safety of Ureteroscopic Holmium Laser Lithotripsy for Upper Urinary Tract Calculi in Elderly Patients.

    PubMed

    Yoshioka, Takashi; Otsuki, Hideo; Uehara, Shinya; Shimizu, Toshihiro; Murao, Wataru; Fujio, Koji; Fujio, Kei; Wada, Koichiro; Araki, Motoo; Nasu, Yasutomo

    2016-06-01

    Upper urinary tract calculi are common; however, there is no recommended treatment selection for elderly patients. Ureteroscopic holmium laser lithotripsy (URS lithotripsy) is minimally invasive, and it provides a high stone-free rate (SFR) treatment for upper urinary tract calculi. Here, we retrospectively evaluated the surgical outcomes of URS lithotripsy after dividing the 189 cases into 3 groups by patient age: the '<65 group' (<65 years old, n=108), the '65-74 group' (65-74 years old, n=42), and the ' 75 group' ( 75 years old, n=39). The patients' characteristics, stone status, and perioperative outcomes were assessed. The 65-74 group and the 75 group had a significantly higher prevalence of hypertension compared to the<65 group. Compared to the<65 group, the 65-74 group had a significantly higher prevalence of hyperlipidemia, and the 75 group had significantly higher the American Society of Anesthesiologists (ASA) scores. Despite these preoperative risk factors, SFR and postoperative pyelonephritis in the 65-74 group and the 75 group were similar to those of the<65 group. In conclusion, URS lithotripsy is the preferred treatment for upper urinary tract calculi, even for elderly patients who have multiple preoperative risk factors. PMID:27339204

  13. Use of the holmium:YAG laser for percutaneous photothermal ablation of cervical invertebral disks in dogs

    NASA Astrophysics Data System (ADS)

    Rochat, Mark; Henry, George A.; Campbell, Gregory A.; Stair, Ernest L.; Bartels, Kenneth E.; Dickey, Tom

    1999-06-01

    Holmium:YAG laser ablation of thoracolumbar disks in dogs has been shown to be an effective alternative to standard surgical fenestration techniques. Our hypothesis was the Holmium:YAG laser could be equally effective and safe when used to ablate cervical intervertebral disks. Six normal chondrodystrophoid breed dogs were used. A sterile, cleaved, 320 micrometers , low-OH quartz optical fiber was inserted into each needle and the laser activated for 40 s at 2 W mean power and a 15 Hz pulse repetition rate for a total of 80 J. Dogs were observed in pain, neurological deficits, or other complications for 24 weeks. At 24 weeks, dogs were euthanatized and cervical disks collected and placed in 10 percent neutral buffered formalin. Disks were decalcified, sectioned at 5 micrometers , and stained with H and E. No problems were encountered during the procedure except occasional difficulties passing the needle by the shoulder to enter the C6-7 disk space. No complications, including neurologic deficits or pain were observe during the 24 weeks. Histologic examination revealed varying degrees of necrosis and defects created in the nucleus pulposus by laser irradiation. In some instances there was evidence of mild adjacent annular and bony thermal injury. On the basis of these result, the Ho:YAG laser appears to be a safe and efficacious method for ablation of canine cervical disks.

  14. [Experimental liver and kidney surgery with CO2, CO, holmium, and neodym lasers. Cutting effect, hemostasis, histopathology, and healing (author's transl)].

    PubMed

    Karbe, E; Königsmann, G; Beck, R

    1980-01-01

    Various laser devices (CO2, CO, Nd: YAG, and holmium: YAG lasers) have been used on pig livers and on dog kidneys for comparison with conventional surgical instruments (electroscalpel, cryoscalpel, and scalpel). CO2 and CO lasers caused the least tissue damage, followed by the holmium laser; severe damage was caused by the Nd: YAG laser. The order was reverse for coagulative effect. The conventional reference instruments showed a weaker hemostatic effect. Surfaces cut by laser healed in four to eight weeks without complications. Remnants of charred tissue in various quantities could still be detected after eight weeks in all cases where CO2, CO, and Nd: YAG lasers had been used. This obviously did not affect scar formation. PMID:6779065

  15. Holmium YLF amplifier performance and the prospects for multi-Joule energies using diode-laser pumping

    NASA Technical Reports Server (NTRS)

    Storm, Mark E.

    1993-01-01

    Laser studies were performed to examine the amplifier characteristics of holmium-doped yttrium lithium fluoride (YLF) at 300 K. An inversion ratio of 0.37 was reached resulting in a measured small-signal gain coefficient of 0.50/cm. In a flashlamp pumping experiment, an output energy of 240 mJ was achieved for 38.5 mJ of input energy resulting in a large gain of 6.2. An amplifier model was developed for diode laser pumping and adapted to consider this flashlamp-pumped case. There is good agreement between the theory and experiment. Multipass amplifier calculations using the model suggest that the Ho: Tm: YLF laser crystal can support a 12 percent electrical to optical efficiency at 300 K even in the presence of upconversion.

  16. Thulium/holmium-doped fiber laser passively mode locked by black phosphorus nanoplatelets-based saturable absorber.

    PubMed

    Yu, Hao; Zheng, Xin; Yin, Ke; Cheng, Xiang'ai; Jiang, Tian

    2015-12-01

    By coupling black phosphorus (BP) nanoplatelets (NPs) with a fiber-taper evanescent light field, a saturable absorber (SA) based on the BP NPs has been successfully fabricated and used in a thulium/holmium-doped fiber laser as the mode locker. The SA had a modulation depth of ∼9.8% measured at 1.93 μm. A stable mode-locking operation at 1898 nm was achieved with a pulse width of 1.58 ps and a fundamental mode-lock repetition rate of 19.2 MHz. By increasing the pump intensity, phenomena of multi-pulsing operations, including harmonic mode-locked states and soliton bunches, were obtained in the experiment, showing that the BP NPs possess an ultrafast optical response time. This work suggests that the BP NPs-based SA is potentially useful for ultrashort, pulsed laser operations in the eye-safe region of 2 μm. PMID:26836690

  17. Histological changes and wound healing response following noncontact holmium: YAG laser thermal keratoplasty.

    PubMed Central

    Koch, D D

    1996-01-01

    PURPOSE: To evaluate acute histological changes and the induced wound healing response in corneal tissue following noncontact holmium:YAG laser thermal keratoplasty (LTK). METHODS: LTK using 10 pulses and a range of radiant energies was performed on 3 human corneas one day prior ro their removal at penetrating keratoplasty. Rabbit corneas were treated with 10-pulse and 5-pulse LTK and followed for up to 3 months. Tissues were studies with light and transmission electron microscopy and immunohistochemistry. RESULTS: The amount of acute tissue injury increased with increasing pulse radiant energy. In human corneas, changes in the irradiated zones included epithelial cell injury and death loss of fine filamentous structure in Bowman's layer, disruption of stromal lamallae, and keratocyte injury and death. In the rabbit corneas, similar acute changes were noted. By 3 weeks, epithelial hyperplasia and stromal contraction were present. Wound healing in the rabbit corneas included repair of the epithelial attachment complex, keratocyte activation, synthesis of type I collagen, partial restoration of stromal keratan sulfate and type VI collagen, and retrocorneal membrane formation. Compared to 10-pulse treatments, 5-pulse treatments produced less acute tissue injury and had more rapid restoration of normal stromal architecture. CONCLUSION: Noncontact LTK produces acute epithelial and stromal tissue changes and in rabbit corneas stimulates a brisk wound healing response. These changes could contribute to postoperative regression of induced refractive correction. Further work is required to determine if reductions in the magnitude of acute tissue injury and induced wound healing response will enhance the efficacy and stability of LTK. Images FIGURE 1A FIGURE 1B FIGURE 2A FIGURE 2B FIGURE 3A FIGURE 3B FIGURE 4A FIGURE 4B FIGURE 4C FIGURE 4D FIGURE 5A FIGURE 5B FIGURE 5C FIGURE 5D FIGURE 6A FIGURE 6B FIGURE 6C FIGURE 6D FIGURE 7A FIGURE 7B FIGURE 8A FIGURE 8B FIGURE 8C FIGURE

  18. Ex vivo pyelotomy, nephroscopy and holmium laser lithotripsy of a staghorn stone in a donor kidney prior to renal transplant

    PubMed Central

    Janczak, Dariusz; Bolanowska, Barbara; Jankowski, Paweł; Dorobisz, Tadeusz; Dorobisz, Karolina; Chabowski, Mariusz; Janczak, Dawid

    2015-01-01

    This case report presents the diagnostic and treatment procedures of stone removal from the kidney of a 67-year-old donor, the transplantation of the kidney to a 65-year-old recipient, and the postoperative course until the end of hospitalization. Computed tomography performed before collecting the organ showed a staghorn stone in the renal pelvis and lower calyces in the right donor kidney. The stones were removed ex-vivo using a rigid ureteroscope and a holmium laser prior to transplantation. Then the organ was transplanted to the left iliac fossa of a 65-year-old man with end-stage renal failure. The authors think there is a possibility of increasing the kidney pool, by using organs containing large calculi. In such cases stones should be removed before the operation and the patient should be monitored regularly, especially in the first months after the transplant. PMID:26240630

  19. Treatment of Urethral/Bladder Neck Stricture After High-Intensity Focused Ultrasound for Prostate Cancer With Holmium: Yttrium-Aluminium-Garnet Laser

    PubMed Central

    Cho, Won Jin; Kim, Tae Heon; Lee, Hyo Serk; Chung, Jin Woo; Lee, Ha Na

    2013-01-01

    Purpose To evaluate the efficacy and safety of the Holmium: yttrium-aluminium-garnet (YAG) laser for the treatment of urethral/bladder neck strictures after high-intensity focused ultrasound for prostate cancer. Methods Between February 2007 and July 2010, Holmium: YAG laser urethrotomies were performed in eleven patients for bladder neck strictures or prostatic urethral strictures. The laser was used with a 550-µm fiber at 2 J and frequency 30 to 50 Hz. The medical records were retrospectively reviewed for medical history, perioperative and postoperative data, uroflowmetry, International Prostate Symptoms Score/quality of life, and stricture recurrence. Results At a median follow-up of 12.0 months (range, 4 to 35 months), the mean postoperative maximal flow rate and residual volume were improved significantly (P<0.05). The mean postoperative total, voiding and quality of life of international prostate symptom score were improved significantly (P<0.05). Of the 11 patients, 7 patients required one treatment, 4 patients two treatment, and 1 patients three treatment. 2 patients who had a documented urinary incontinence prior to the laser treatment subsequently required artificial urinary sphincter implantation and reported satisfaction without developing any recurrent strictures or artificial urinary sphincter erosion. All patients exhibited well-healed strictures and could void without difficulty. Conclusions Holmium: YAG laser therapy represents a safe, effective and minimally invasive treatment for urethral/bladder neck strictures occurring secondary to high-intensity focused ultrasound for prostate cancer. PMID:23610708

  20. Holmium laser transurethral incision of the prostate: Can prostate size predict the long-term outcome?

    PubMed Central

    Elkoushy, Mohamed A.; Elshal, Ahmed M.; Elhilali, Mostafa M.

    2015-01-01

    Introduction: We determine the impact of prostate size on the long-term outcome of holmium laser transurethral incision of the prostate (Ho-TUIP) for bladder outlet obstruction (BOO) secondary to benign prostate enlargement (BPE). Methods: A retrospective review of prospectively collected data was performed for patients undergoing Ho-TUIP by a single surgeon for patients presenting with lower urinary tract symptoms (LUTS) secondary to BOO. Patients were stratified into 2 groups: Group 1 included patients with prostate ≤30 cc and Group 2 included patients with prostate >30 cc. Demographic, operative and follow-up data were recorded and analyzed. In addition, intraoperative and long-term adverse events were included. Results: In total, 82 patients underwent surgery between March 1998 and March 2013, including 9 (11%) reoperated patients. Only prostate size independently predicted reoperation after Ho-TUIP (adjusted odds ratio [aOR], 95% confidence interval [CI] 7.12 [2.92–9.14], p = 0.01). The receiver operating characteristic (ROC) analysis showed an optimal cutoff value of prostate volume of 29 cc to characterize long-term reoperation after TUIP, with area under the curve (AUC) of 0.96, sensitivity of 89.7 and specificity of 88.9. Group 1 included 51 patients and Group 2 included 31 patients. The international prostate symptoms score (IPSS) and peak flow rate (Qmax) significantly improved in both groups at different follow-up points. At the 12-month follow-up, the percent change in IPSS and Qmax were comparable between both groups. However, after 12 months, the degree of improvement in all voiding parameters was significantly higher in Group 1 (p < 0.001 at all points of follow-up). After a median follow-up of 5.3 years (range: 1–13), both groups had comparable early and late adverse events with significantly higher reoperation rate in Group 2 (3.9% vs. 22.6%, p = 0.02). Overall retrograde ejaculation was detected in 25.6% of sexually active men and it was

  1. Enucleation Procedure Manual.

    ERIC Educational Resources Information Center

    Davis, Kevin; Poston, George

    This manual provides information on the enucleation procedure (removal of the eyes for organ banks). An introductory section focuses on the anatomy of the eye and defines each of the parts. Diagrams of the eye are provided. A list of enucleation materials follows. Other sections present outlines of (1) a sterile procedure; (2) preparation for eye…

  2. Holmium:YAG laser lithotripsy for the management of urolithiasis in small ruminants and pot-bellied pigs

    NASA Astrophysics Data System (ADS)

    Halland, Spring K.; House, John K.; George, Lisle

    2001-05-01

    Obstructive urolithiasis is a common problem in small ruminants and pot-bellied pigs. The most common site of urinary tract obstruction in these species is the urethra. Surgical procedures developed to relieve obstructions, in our experience have been effective in approximately 75% of cases. Urethral stricture is a common complication if the mucosa of the urethra is disrupted. The objective of this project was to evaluate endoscopy guided laser lithotripsy as a therapeutic modality to relieve urethral obstructions in small ruminants and pot-bellied pigs. The study population consisted of patients presented to the Veterinary Medical Teaching Hospital at the University of California Davis with obstructive urolithiasis. Lithotripsy was performed using a Holmium:YAG laser via a 200-micron low water quartz fiber passed through a flexible mini-endoscope. Two types of urinary calculi were managed with this technique, calcium carbonate and calcium hydroxyphosphate. Laser lithotripsy was effective at relieving obstructions caused by both types of calculi when conventional methods had failed. Laser lithotripsy performed via urethral endoscopy is a safe and effective therapeutic modality for management of obstructive urolithiasis in small ruminants and pot-bellied pigs and reduces the risk of post procedural urethral stricture.

  3. Severe postoperative dyspnea caused by neglected massive intraperitoneal fluid collection during laser enucleation and morcellation of the prostate: a case report

    PubMed Central

    Kim, Sung-Hoon; Son, Hyo-Jung; Kim, Jae-Won; Kong, Yu-Gyeong; Hwang, Jai-Hyun

    2016-01-01

    Laser enucleation and morcellation of the prostate is an increasingly used surgical management of benign prostatic hyperplasia. However, it can cause several complications including capsular perforation, ureteral orifice injury, and bladder mucosal morcellation injury. Herein, we report a case of severe postoperative dyspnea caused by neglected massive intraperitoneal fluid collection during laser surgery of the prostate. The patient experienced massive abdominal distension and severe respiratory difficulty after the procedure. Although immediate postoperative cystogram showed no leakage of contrast dye, the computed tomography scan of the abdomen and pelvis showed massive fluid collection in the abdominal pelvic cavity suggesting bladder wall injury. After percutaneous drainage of intraperitoneal fluid, abdominal distention and dyspnea were relieved. PMID:27066210

  4. Critical review of lasers in benign prostatic hyperplasia (BPH).

    PubMed

    Gravas, Stavros; Bachmann, Alexander; Reich, Oliver; Roehrborn, Claus G; Gilling, Peter J; De La Rosette, Jean

    2011-04-01

    Laser treatment of benign prostatic hyperplasia has challenged transurethral resection of the prostate (TURP) due to advances in laser technology, better understanding of tissue-laser interactions and growing clinical experience. • Various lasers have been introduced including neodymium: yttrium aluminium garnet (YAG), holmium (Ho):YAG, potassium titanyl phosphate:YAG, thulium(Tm) and diode laser. Based on the different wave-length dependent laser-prostatic tissue interactions, the main techniques are coagulation, vaporization, resection and enucleation. • The present review aims to help urologists to distinguish and to critically evaluate the role of different laser methods in the treatment by using an evidence-based approach. It also details further evidence for use in specific patient groups (in retention, on anticoagulation) and addresses the issues of cost and learning curve. • Coagulation-based techniques have been abandoned; holmium ablation/resection of the prostate has been superseded by the enucleation technique Ho-laser enucleation of the prostate (HoLEP). The short-term efficacy of the emerging laser treatments such as diode and Tm prostatectomy has been suggested by low quality studies. HoLEP and photoselective vaporization of the prostate (PVP) represent valid clinical alternatives to TURP. HoLEP is the most rigorously analysed laser technique with durable efficacy for any prostate size and low early and late morbidity. PVP has grown in acceptance and popularity but long-term results from high quality studies are pending. PMID:21438974

  5. Sialoendoscopy with and without holmium:YAG laser-assisted lithotripsy in the management of obstructive sialadenitis of major salivary glands.

    PubMed

    Sionis, S; Caria, R A; Trucas, M; Brennan, P A; Puxeddu, R

    2014-01-01

    Obstructive sialadenitis is a major cause of dysfunction of the salivary glands, and increasingly sialoendoscopy is used in both diagnosis and treatment. At present the limit of the endoscopic approach is the size of the stone as only stones of less than 4mm can be removed. Endoscopic laser lithotripsy has the potential to treat many stones larger than this with minimal complications and preservation of a functional salivary gland. The holmium:YAG laser has been widely and safely used in urology, and its use has been recently proposed in salivary lithotripsy for the removal of bigger stones. We describe our experience with sialoendoscopy for stones in the parotid and submandibular glands and assess the feasibility and the efficacy of holmium:YAG laser lithotripsy. We have used the procedure 50 times for 43 patients with obstructive sialadenitis; 31 patients had sialolithiasis, 15 of whom (48%) had stones with diameters between 4 and 15mm (mean 7). Total extraction after fragmentation was possible in 14 of the 15 patients without complications. Intraductal holmium:YAG laser lithotripsy is effective and safe, and allows the treatment of large stones in Stensen's and Wharton's ducts. PMID:24280118

  6. Comparison of holmium:YAG and thulium fiber laser lithotripsy: ablation thresholds, ablation rates, and retropulsion effects

    NASA Astrophysics Data System (ADS)

    Blackmon, Richard L.; Irby, Pierce B.; Fried, Nathaniel M.

    2011-07-01

    The holmium:YAG (Ho:YAG) laser lithotriptor is capable of operating at high pulse energies, but efficient operation is limited to low pulse rates (~10 Hz) during lithotripsy. On the contrary, the thulium fiber laser (TFL) is limited to low pulse energies, but can operate efficiently at high pulse rates (up to 1000 Hz). This study compares stone ablation threshold, ablation rate, and retropulsion for the two different Ho:YAG and TFL operation modes. The TFL (λ = 1908 nm) was operated with pulse energies of 5 to 35 mJ, 500-μs pulse duration, and pulse rates of 10 to 400 Hz. The Ho:YAG laser (λ = 2120 nm) was operated with pulse energies of 30 to 550 mJ, 350-μs pulse duration, and a pulse rate of 10 Hz. Laser energy was delivered through 200- and 270-μm-core optical fibers in contact mode with human calcium oxalate monohydrate (COM) stones for ablation studies and plaster-of-Paris stone phantoms for retropulsion studies. The COM stone ablation threshold for Ho:YAG and TFL measured 82.6 and 20.8 J/cm2, respectively. Stone retropulsion with the Ho:YAG laser linearly increased with pulse energy. Retropulsion with TFL was minimal at pulse rates less than 150 Hz, then rapidly increased at higher pulse rates. For minimal stone retropulsion, Ho:YAG operation at pulse energies less than 175 mJ at 10 Hz and TFL operation at 35 mJ at 100 Hz is recommended, with both lasers producing comparable ablation rates. Further development of a TFL operating with both high pulse energies of 100 to 200 mJ and high pulse rates of 100 to 150 Hz may also provide an alternative to the Ho:YAG laser for higher ablation rates, when retropulsion is not a primary concern.

  7. Comparison of holmium:YAG and thulium fiber laser lithotripsy: ablation thresholds, ablation rates, and retropulsion effects.

    PubMed

    Blackmon, Richard L; Irby, Pierce B; Fried, Nathaniel M

    2011-07-01

    The holmium:YAG (Ho:YAG) laser lithotriptor is capable of operating at high pulse energies, but efficient operation is limited to low pulse rates (∼10 Hz) during lithotripsy. On the contrary, the thulium fiber laser (TFL) is limited to low pulse energies, but can operate efficiently at high pulse rates (up to 1000 Hz). This study compares stone ablation threshold, ablation rate, and retropulsion for the two different Ho:YAG and TFL operation modes. The TFL (λ = 1908 nm) was operated with pulse energies of 5 to 35 mJ, 500-μs pulse duration, and pulse rates of 10 to 400 Hz. The Ho:YAG laser (λ = 2120 nm) was operated with pulse energies of 30 to 550 mJ, 350-μs pulse duration, and a pulse rate of 10 Hz. Laser energy was delivered through 200- and 270-μm-core optical fibers in contact mode with human calcium oxalate monohydrate (COM) stones for ablation studies and plaster-of-Paris stone phantoms for retropulsion studies. The COM stone ablation threshold for Ho:YAG and TFL measured 82.6 and 20.8 J∕cm(2), respectively. Stone retropulsion with the Ho:YAG laser linearly increased with pulse energy. Retropulsion with TFL was minimal at pulse rates less than 150 Hz, then rapidly increased at higher pulse rates. For minimal stone retropulsion, Ho:YAG operation at pulse energies less than 175 mJ at 10 Hz and TFL operation at 35 mJ at 100 Hz is recommended, with both lasers producing comparable ablation rates. Further development of a TFL operating with both high pulse energies of 100 to 200 mJ and high pulse rates of 100 to 150 Hz may also provide an alternative to the Ho:YAG laser for higher ablation rates, when retropulsion is not a primary concern. PMID:21806249

  8. Difficulty in the intravesical morcellation procedure for leiomyoma of the prostate enucleated by HoLEP.

    PubMed

    Shinojima, Toshiaki; Yoshimine, Shunsuke

    2013-01-01

    Leiomyoma of prostate are rare benign neoplasms that are usually diagnosed incidentally through postoperative pathological examination. A 70-year-old man is presented with severe symptoms of lower urinary tract obstruction. Although a digital rectal examination and the prostate-specific antigen level did not suggest malignancy, transrectal ultrasonography showed an unusual homogenous echoic mass measuring 45×37 mm in size in the prostate. A needle biopsy was performed and pathological diagnosis was prostatic leiomyoma. Holmium laser enucleation of prostate (HoLEP) was chosen and performed to resect the tumour. Although the enucleation step presented no problems, the morcellation procedure using a conventional transurethral mechanical morcellator was very difficult owing to the firmness of the tissue. By using a bipolar erectrosurgical loop, fragmentation and removal of tissue was accomplished. This is the first case reported of these rare neoplasms in which HoLEP was offered as a less invasive surgical approach. We emphasise the firmness of the leiomyomatous tissue, which would lead to morcellation failure. PMID:23966460

  9. Difficulty in the intravesical morcellation procedure for leiomyoma of the prostate enucleated by HoLEP

    PubMed Central

    Shinojima, Toshiaki; Yoshimine, Shunsuke

    2013-01-01

    Leiomyoma of prostate are rare benign neoplasms that are usually diagnosed incidentally through postoperative pathological examination. A 70-year-old man is presented with severe symptoms of lower urinary tract obstruction. Although a digital rectal examination and the prostate-specific antigen level did not suggest malignancy, transrectal ultrasonography showed an unusual homogenous echoic mass measuring 45×37 mm in size in the prostate. A needle biopsy was performed and pathological diagnosis was prostatic leiomyoma. Holmium laser enucleation of prostate (HoLEP) was chosen and performed to resect the tumour. Although the enucleation step presented no problems, the morcellation procedure using a conventional transurethral mechanical morcellator was very difficult owing to the firmness of the tissue. By using a bipolar erectrosurgical loop, fragmentation and removal of tissue was accomplished. This is the first case reported of these rare neoplasms in which HoLEP was offered as a less invasive surgical approach. We emphasise the firmness of the leiomyomatous tissue, which would lead to morcellation failure. PMID:23966460

  10. Laser treatment of benign prostate enlargement--which laser for which prostate?

    PubMed

    Rieken, Malte; Bachmann, Alexander

    2014-03-01

    Laser-based prostatectomy for benign prostatic obstruction has emerged over the past decade as a treatment alternative to transurethral resection of the prostate (TURP) and open prostatectomy. These techniques set new standards in minimally invasive surgery and aim to obviate the complications of open surgery while ensuring durability of outcomes. Enucleation, which mimics open prostatectomy in that the whole prostate adenoma is removed, and vaporization, which involves ultra-rapid heating of superficial tissue layers and subsequent ablation, are the most often used surgical techniques in laser prostatectomy. The wavelength and the power output of the laser influence the tissue-laser interactions, which determine the physical properties and the safety profile of the technique. Holmium laser enucleation of the prostate (HoLEP) and GreenLight(™) laser vaporization of the prostate are the two reference techniques for laser prostatectomy, both of which have been shown to be as effective as TURP, while offering advantages in the safety profile in various randomized trials. Thulium laser enucleation of the prostate (ThuLEP) shares similarities with HoLEP and has shown encouraging results. However, more controlled trials with longer follow-up assessment are needed. Diode lasers come in various wavelengths and fibre designs and have been used for vaporization and enucleation, but require high-quality data to support their clinical use. PMID:24595121

  11. Impact of holmium fibre laser radiation (λ = 2.1 μm) on the spinal cord dura mater and adipose tissue

    NASA Astrophysics Data System (ADS)

    Filatova, S. A.; Kamynin, V. A.; Ryabova, A. V.; Loshchenov, V. B.; Zelenkov, P. V.; Zolotovskii, I. O.; Tsvetkov, V. B.; Kurkov, A. S.

    2015-08-01

    The impact of holmium fibre laser radiation on the samples of biologic tissues (dura mater of spinal cord and adipose tissue with interlayers of muscle) is studied. The experimental results are evaluated by the size of carbonisation and coagulation necrosis zones. The experiment shows that in the case of irradiation of the spinal cord dura mater samples the size of carbonisation and coagulation necrosis zones is insignificant. In the adipose tissue the carbonisation zone is also insignificant, but the region of cellular structure disturbance is large. In the muscle tissue the situation is opposite. The cw laser operation provides clinically acceptable degree of destruction in tissue samples with a minimal carbonisation zone.

  12. Different lasers in the treatment of benign prostatic hyperplasia: a network meta-analysis.

    PubMed

    Zhang, Xingming; Shen, Pengfei; He, Qiying; Yin, Xiaoxue; Chen, Zhibin; Gui, Haojun; Shu, Kunpeng; Tang, Qidun; Yang, Yaojing; Pan, Xiuyi; Wang, Jia; Chen, Ni; Zeng, Hao

    2016-01-01

    All available surgical treatments for benign prostatic hyperplasia (BPH) have their individual advantages or disadvantages. However, the lack of head-to-head studies comparing different surgeries makes it unavailable to conduct direct analysis. To compare the efficacy and safety among different lasers and transurethral resection of prostate (TURP) for BPH, randomized controlled trials were searched in MEDLINE, EMBASE, Cochrane library, WHO International Clinical Trial Registration Platform, and Clinical Trial.gov by 2015.5; and the effectiveness-, perioperation- and complication-related outcomes were assessed by network meta-analysis. 36 studies involving 3831 patients were included. Holmium laser through resection and enucleation had the best efficacy in maximum flow rate. Thulium laser through vapo-resection was superior in improving international prostate symptom score and holmium laser through enucleation was the best for post-voiding residual volume improvement. Diode laser through vaporization was the rapidest in removing postoperative indwelling catheter, while TURP was the longest. TURP required the longest hospitalization and thulium laser through vapo-resection was relatively shorter. Holmium and thulium lasers seem to be relatively better in surgical efficacy and safety, so that these two lasers might be preferred in selection of optimal laser surgery. Actually, more large-scale and high quality head-to-head RCTs are suggested to validate the conclusions. PMID:27009501

  13. Different lasers in the treatment of benign prostatic hyperplasia: a network meta-analysis

    PubMed Central

    Zhang, Xingming; Shen, Pengfei; He, Qiying; Yin, Xiaoxue; Chen, Zhibin; Gui, Haojun; Shu, Kunpeng; Tang, Qidun; Yang, Yaojing; Pan, Xiuyi; Wang, Jia; Chen, Ni; Zeng, Hao

    2016-01-01

    All available surgical treatments for benign prostatic hyperplasia (BPH) have their individual advantages or disadvantages. However, the lack of head-to-head studies comparing different surgeries makes it unavailable to conduct direct analysis. To compare the efficacy and safety among different lasers and transurethral resection of prostate (TURP) for BPH, randomized controlled trials were searched in MEDLINE, EMBASE, Cochrane library, WHO International Clinical Trial Registration Platform, and Clinical Trial.gov by 2015.5; and the effectiveness-, perioperation- and complication-related outcomes were assessed by network meta-analysis. 36 studies involving 3831 patients were included. Holmium laser through resection and enucleation had the best efficacy in maximum flow rate. Thulium laser through vapo-resection was superior in improving international prostate symptom score and holmium laser through enucleation was the best for post-voiding residual volume improvement. Diode laser through vaporization was the rapidest in removing postoperative indwelling catheter, while TURP was the longest. TURP required the longest hospitalization and thulium laser through vapo-resection was relatively shorter. Holmium and thulium lasers seem to be relatively better in surgical efficacy and safety, so that these two lasers might be preferred in selection of optimal laser surgery. Actually, more large-scale and high quality head-to-head RCTs are suggested to validate the conclusions. PMID:27009501

  14. A comparison of efficacies of holmium YAG laser, and pneumatic lithotripsy in the endoscopic treatment of ureteral stones

    PubMed Central

    Akdeniz, Ekrem; İrkılata, Lokman; Demirel, Hüseyin Cihan; Saylık, Acun; Bolat, Mustafa Suat; Şahinkaya, Necmettin; Zengin, Mehmet; Atilla, Mustafa Kemal

    2014-01-01

    Objective: We aimed to compare the effectiveness of holmium YAG laser and pneumatic lithotripsy in the treatment of ureteral stones. Material and methods: A total of 216 patients who had established indications of ureteroscopy between November 2011 and June 2012 were included in this study. Patients’ files were retrospectively reviewed by dividing cases as groups that underwent pneumatic (PL) or laser lithotripsy (LL) procedures. Age, sex, stone burden and localization, duration of follow-up, operative times were evaluated. Stone-free rates were evaluated by ureteroscopical examination, postoperative scout films and ultrasonography. Results: Group PL consisted of 109 and group LL of 107 patients. Median age was 43.93±15.94 years in Group PL and 46.15±14.54 years in Group LL. Male to female ratio, stone burden and localization were similar for both groups. Overall success rate was 89.9% in Group PL and 87.9% in Group LL, respectively (p<0.791). With the aid of additional procedures, success rate was 100% for both groups at the end of the first month. Groups were not different as for operative time, rate of insertion of an ureteral catheter and its removal time. Hospitalization period was apparently somewhat shorter in Group LL (p=0.00). Conclusion: Pneumatic lithotripsy can be as efficacious as laser lithotripsy and be used safely in the endoscopic management of ureteral stone. In comparison of both methods, we detected no differences as to operative time, success of operation and the time to removal of the catheter, however, hospitalization period was shorter in Group LL. PMID:26328167

  15. Sialendoscopy with holmium:YAG laser treatment for multiple large sialolithiases of the Wharton duct: a case report and literature review.

    PubMed

    Sun, Yu-Ting; Lee, Kuo-Sheng; Hung, Shih-Han; Su, Chin-Hui

    2014-12-01

    Sialolithiasis is defined as calcified stone(s) in the salivary duct or glands. Submandibular gland sialolithiasis is the most common (80 to 90%), followed by parotid gland sialolithiasis (5 to 15%). The typical clinical presentation is salivary gland swelling after eating. As the swelling persists, symptoms owing to local inflammation, such as pain and trismus, emerge. In severe cases, cellulitis and even abscess formation occur and subsequently lead to salivary gland atrophy or fistula formation if the sialolithiasis remains untreated. The most common treatment is complete excision of the affected gland together with the stone(s). In some cases, intraoral sialolithotomy is performed when the stone is solitary and easily palpable through the oral cavity. Sialendoscopy is increasingly performed because of its minimal invasiveness. The major limitation of endoscopic laser lithotripsy of the salivary glands is the size of the stone. Often, for a stone larger than 4 mm, multiple fragmentations of the stone into small pieces is necessary before the pieces can be removed by wire basket or grasping forceps. Recently, the holmium:YAG laser has been reported as quite effective in removing larger salivary gland stones. However, sialoendoscopic laser lithotripsy is a very time-consuming procedure and in most cases, when there are multiple large stones in a single gland, entire gland excision is recommended. This report describes a male patient diagnosed with multiple large stones in his left submandibular gland who was successfully treated under sialendoscopy with holmium:YAG laser lithotripsy. PMID:25216563

  16. Widely tunable short-infrared thulium and holmium doped fluorozirconate waveguide chip lasers.

    PubMed

    Lancaster, D G; Gross, S; Withford, M J; Monro, T M

    2014-10-20

    We report widely tunable (≈ 260 nm) Tm(3+) and Ho(3+) doped fluorozirconate (ZBLAN) glass waveguide extended cavity lasers with close to diffraction limited beam quality (M(2) ≈ 1.3). The waveguides are based on ultrafast laser inscribed depressed claddings. A Ti:sapphire laser pumped Tm(3+)-doped chip laser continuously tunes from 1725 nm to 1975 nm, and a Tm(3+)-sensitized Tm(3+):Ho(3+) chip laser displays tuning across both ions evidenced by a red enhanced tuning range of 1810 to 2053 nm. We also demonstrate a compact 790 nm diode laser pumped Tm(3+)-doped chip laser which tunes from 1750 nm to 1998 nm at a 14% incident slope efficiency, and a beam quality of M(2) ≈ 1.2 for a large mode-area waveguide with 70 µm core diameter. PMID:25401562

  17. Management of impacted proximal ureteral stone: Extracorporeal shock wave lithotripsy versus ureteroscopy with holmium: YAG laser lithotripsy

    PubMed Central

    Khalil, Mostafa

    2013-01-01

    Objective: Prospective evaluation of the efficacy and safety of the extracorporeal shock wave lithotripsy (SWL) and ureteroscopy with Holmium: YAG laser lithotripsy (URSL) as a primary treatment for impacted stone in the proximal ureter. Patients and Methods: A total of 82 patients with a single impacted stone in the proximal ureter were included in the study. Patients were allocated into two groups according to patient preference for either procedure. The first group included 37 patients who were treated by SWL and the second group included 45 patients treated by URSL. The preoperative data and treatment outcomes of both procedures were compared and analyzed. Results: There was no difference as regards to patient and stone characters between the two groups. There was significantly higher mean session number and re-treatment rate in the SWL group in comparison to URSL group (1.5 ± 0.8 vs. 1.02 ± 0.15 session, and 43.2% vs. 2.2%, respectively). At one month, the stone-free rate of the URSL group was statistically significantly higher than that of the SWL group (80% vs. 67.6%, respectively). The stone-free rate at three months was still higher in the URSL group, but without statistically significant difference (80.2% vs. 78.4%, respectively). There was no statistically significant difference in the rate of complications between the SWL and URSL (24.3% vs. 15.6%, respectively). Conclusion: Both procedures can be used effectively and safely as a primary treatment for impacted stone in the proximal ureter; however, the URSL has a significantly higher initial stone-free rate and lower re-treatment rate. PMID:23798864

  18. Transcranial excision of massive pituitary tumor with low-energy holmium laser

    NASA Astrophysics Data System (ADS)

    Xiong, Wen-Hao; Luo, Qi-Zhong; Li, Shan-Quan; Li, Xiao-Xiong; Dai, Jun; Zhu, Jing; Zhang, Mei-Jue

    1998-11-01

    From May, 1994 to September, 1996 we have operated on 64 cases of brain tumor with Homium Laser, 18 cases of massive pituitary tumor with low energy laser were included. The result are satisfying. Now, we report it to the congress.

  19. Against the motion: Lasers are superfluous for the surgical management of benign prostatic hyperplasia in the developing world.

    PubMed

    Varshney, Anil; Agarwal, Anshuman

    2009-07-01

    Lasers have arrived in a big way for the management of benign prostatic hyperplasia. The most common ones in use are holmium, potassium titanyl phosphate (KTP) and thulium.They remove the prostatic adenoma either by way of enucleation or ablation. Backed by numerous studies that prove their safety, efficacy and durability, lasers score over TURP in several ways. Their use is associated with less blood loss, shorter catheter time and decreased hospital stay. The fluid absorption during laser prostatectomy is negligible and thus makes it safer for use in cardiac patients. Also there is no chance of a transurethral resection syndrome, the incidence of which is approximately 2% with TURP. Due to superior hemostatic capabilities and non interference lasers can be used in patients on anti coagulants, cardiac pacemaker. Another advantage of laser over TURP is its ability to deal with prostates that are larger in size especially holmium laser which has been used to enucleate glands more than 300 g in size thus completely avoiding the need for open prostatectomy. The amount of tissue removed with enucleation is more thus retreatment rates are less than that of TURP. The initial cost of laser is higher but its capability to treat stones, its use in high risk situations, less morbidity, short hospital stay, and durable results make it an attractive option to treat BPH even in the developing world. PMID:19881144

  20. Electron-impact excitation of holmium atoms

    SciTech Connect

    Smirnov, Yu M

    2000-06-30

    The electron-impact excitation of holmium atoms was studied by the method of extended crossing beams. The cross sections and the optical excitation functions were obtained for odd levels of Ho I, including the 22014 cm{sup -1} laser level. Over 99% of the atoms were shown to reside in the ground level prior to collisions with electrons. Also measured were the excitation cross sections for six even levels, which presumably participate in the formation of inversion population in a gas-discharge holmium vapour laser. (laser applications and other topics in quantum electronics)

  1. Holmium laser core through internal urethrotomy with explantation of UroLume stent. An ideal approach for a complicated posterior urethral stricture.

    PubMed

    Gupta, N P; Ansari, M S

    2004-05-01

    Although the UroLume wallstent has been proven effective in the treatment of recurrent urethral stricture, obstruction may recur in some cases. A likely cause of obstruction is hyperplastic tissue reaction, which may necessitate the removal of the stent. The hyperplastic tissue reaction may be severe, resulting in a completely obliterative stricture. Stent removal with a completely obliterative stricture and the stent in situ is a tedious job, as there is no lumen in which to place the laser fiber to cut the stent wires. We report on a patient in whom a UroLume urethral stent was placed one year ago for post-traumatic recurrent bulbomembranous urethral stricture. The stricture recurred in spite of the stent in place and the lumen was finally completely obliterated. A holmium laser was used for core through internal urethrotomy and the explantation of the stent. PMID:15147555

  2. Holmium laser ablation of cartilage: effects of delivery fiber angle of incidence

    NASA Astrophysics Data System (ADS)

    Asshauer, Thomas; Oberthur, Thorsten; Jansen, Thomas; Gerber, Bruno E.; Delacretaz, Guy P.

    1996-01-01

    The effects of 2.12 micrometers Cr:Tm:Ho:YAG laser pulses delivered in isotonic saline solution via an optical fiber system on fresh porcine femur patellar groove cartilage were studied in vitro. Various irradiation geometry, corresponding to angles of 0 - 90 degree(s) of the delivering fiber with respect to the cartilage surface, have been investigated. A laser pulse energies of 1.0 J with a pulse duration of 250 microsecond(s) (FWHM) was used. The dynamics of the induced transient vapor bubbles and the ablation process were monitored by time resolved flash videography techniques. Acoustic transients of up to 200 bars induced by bubble collapses were measured by a calibrated piezoelectric needle probe hydrophone. Histological assessment of the irradiated cartilage samples was performed using azan and Safranin-O stains. The extent of the area of altered cartilage cells is larger than the zone of tissue matrix damage. The predominant mechanism of tissue damage is thermal rather than acousto-mechanical. Cartilage treatment at an angle of incidence of 30 degree(s) reduces significantly the overall damage as compared to 60 degree(s) or 90 degree(s) irradiation.

  3. Evidence of the efficacy and safety of the thulium laser in the treatment of men with benign prostatic obstruction

    PubMed Central

    Barbalat, Yana; Velez, Marissa C.; Sayegh, Christopher I.; Chung, Doreen E.

    2016-01-01

    In 2005, the high power thulium laser was introduced for the surgical treatment of benign prostatic obstruction. It has several properties that confer theoretical advantages over other lasers used for the same indication, such as technical versatility and a relatively small zone of thermal damage. Studies using the 70–150 W thulium laser systems demonstrate good efficacy of these procedures with low morbidity and few complications even in higher risk patients. Different techniques have been employed to treat the prostate with this technology, including enucleation, vapoenucleation, vaporization and resection. Comparative studies have been published comparing thulium laser prostatectomy to monopolar transurethral resection of prostate (TURP), bipolar TURP and holmium laser enucleation of prostate (HoLEP). In this review we discuss the current literature on the safety and efficacy of various thulium techniques for the treatment of benign prostatic hyperplasia and examine comparative studies. PMID:27247628

  4. Evidence of the efficacy and safety of the thulium laser in the treatment of men with benign prostatic obstruction.

    PubMed

    Barbalat, Yana; Velez, Marissa C; Sayegh, Christopher I; Chung, Doreen E

    2016-06-01

    In 2005, the high power thulium laser was introduced for the surgical treatment of benign prostatic obstruction. It has several properties that confer theoretical advantages over other lasers used for the same indication, such as technical versatility and a relatively small zone of thermal damage. Studies using the 70-150 W thulium laser systems demonstrate good efficacy of these procedures with low morbidity and few complications even in higher risk patients. Different techniques have been employed to treat the prostate with this technology, including enucleation, vapoenucleation, vaporization and resection. Comparative studies have been published comparing thulium laser prostatectomy to monopolar transurethral resection of prostate (TURP), bipolar TURP and holmium laser enucleation of prostate (HoLEP). In this review we discuss the current literature on the safety and efficacy of various thulium techniques for the treatment of benign prostatic hyperplasia and examine comparative studies. PMID:27247628

  5. Modular flexible ureteroscopy and holmium laser lithotripsy for the treatment of renal and proximal ureteral calculi: A single-surgeon experience of 382 cases

    PubMed Central

    YAN, ZEJUN; XIE, GUOHAI; YUAN, HESHENG; CHENG, YUE

    2015-01-01

    To determine the safety and efficacy of modular flexible ureteroscopy and holmium laser lithotripsy for the treatment of renal and proximal ureteral calculi, a retrospective chart review of a single surgeon's 3-year modular flexible ureteroscopy experience was performed. All of the patients were treated with modular flexible ureteroscopy and holmium laser lithotripsy by a single surgeon. Stone-free status was defined as no fragments or a single fragment ≤4 mm in diameter at the 3-month follow-up. The procedure number, operative time, stone-free rates, repeat usage of the multilumen catheter, and perioperative complications were documented. The present study included 215 male patients and 167 female patients, with an average age of 48.5±13.7 years (range, 17–84 years). The mean stone size was 11.5±4.1 mm (range, 4–28 mm), and the mean total stone burden was 17.5±5.7 mm (range 15–46 mm). A total of 305 patients (79.8%) had a stone burden ≤20 mm, and 77 patients (20.2%) had a stone burden >20 mm. The mean number of primary procedures was 1.3±0.2 (range, 1–3). The stone-free rate following the first and the second procedure was 73.4 and 86.9%, respectively. The mean postoperative hospital stay was 3.1±1.2 days (range, 2–6 days). The highest clearance rates were observed for proximal ureteral stones (100%) and renal pelvic stones (88.7%), whereas the lowest clearance rates were observed for lower calyx stones (76.7%) and multiple calyx stones (77.8%). The higher the initial stone burden, the lower the postoperative stone-free rate (≤20 vs. >20 mm; 89.8 vs. 75.3%). The overall complication rate was 8.1%. The results of the present study suggest that modular flexible ureteroscopy with holmium laser lithotripsy may be considered the primary method for the treatment of renal and proximal ureteral calculi in select patients, due to its acceptable efficacy, low morbidity, and relatively low maintenance costs. PMID:26622508

  6. AB178. Holmium laser resection of the distal ureter and bladder cuff during radical nephroureterectomy for patients with pelvis or ureteral cancer

    PubMed Central

    Ge, Yongchao

    2016-01-01

    Objective To explore the feasibility of transurethral resection for the distal ureter and bladder cuff in radical nephroureterectomy for the treatment of upper urinary tract urothelial carcinoma (UUT-UC). Methods A total of 76 patients with renal pelvic carcinoma or upper tract urothelial carcinoma during July 2003 to December 2011 were retrospective analyzed. All patients were divided into two groups according to doctor’s suggestion and their wishes. Thirty-six patients of them received excision of the distal ureter and bladder cuff by transurethral Holmium laser (cystoscopy group) combined with open nephroureterectomy, and 40 patients of them underwent open surgery (open surgery group).The operation time, postoperative activity time, and postoperative hospital stay in the two groups were compared. Results All operations were completed successfully in both groups. Compared with Open Surgery Group, the operation time [(177.2±36.9) vs. (229.6±28.1) min, t=−7.004, P=0.000], postoperative activity time [(2.7±0.7) vs. (4.1±1.0) d, t=−6.802, P=0.000] and hospital stay [(6.9±1.0) vs. (8.6±1.5) d, t=−5.448, P=0.000] of cystoscopy group were shorter. No recurrence or metastasis was observed from a follow-up of 6–120 months (median=32 months) in the two groups. Conclusions Transurethral surgery is superior to traditional open surgery in trauma degree and postoperative recovery time. Transurethral Holmium laser resection of the distal ureter and bladder cuff is a minimally invasive and safety technique in the nephroureterectomy for the treatment of UTUC.

  7. [History of laser in BPH therapy].

    PubMed

    Grande, Marco; Facchini, Francesco; Moretti, Matteo; Larosa, Michelangelo; Leone, Marco; Ziglioli, Francesco; Pozzoli, Gian Luigi; Frattini, Antonio

    2014-01-01

    Laser technology has been used in the treatment of BPH for more than 15-20 years in order to challenge transurethral resection of the prostate. The aim of this review article is to analyze the evolution of laser in BPH therapy, from early coagulative techniques - progressively abandoned for their elevated postoperative morbidity and unfavorable outcomes - to the newer techniques of vaporization, resection and enucleation of the prostate. A better comprehension of tissue-laser interactions, the improvement of laser technology and a growing clinical experience have lead to the development of different laser systems (Holmium, KTP, Thulium laser) that challenge TURP. Today, HoLEP and, secondarily, PVP are the laser techniques supported by more clinical evidences and represent valid alternatives to TURP. PMID:24665033

  8. Impressive Performance: New Disposable Digital Ureteroscope Allows for Extreme Lower Pole Access and Use of 365 μm Holmium Laser Fiber

    PubMed Central

    Kelly, Emily Fell

    2016-01-01

    Abstract Background: Since the development of the first flexible ureteroscope, in 1964, technological advances in image quality, flexibility, and deflection have led to the development of the first single-use digital flexible ureteroscope, LithoVue™ (Boston Scientific, Marlborough, MA). With respect to reusable fiber-optic and now digital ureteroscopes, there is an initial capital cost of several thousand dollars (USD) as well as, controversy regarding durability, the cost of repairs and the burdensome reprocessing steps of ureteroscopy. The single-use LithoVue eliminates the need for costly repairs, the occurrence of unpredictable performance, and procedural delays. Renal stones located in the lower pole of the kidney can be extremely challenging as extreme deflections of greater than 160° are difficult to maintain and are often further compromised when using stone treatment tools, such as laser fibers and baskets. This case describes an initial use of the LithoVue digital disposable ureteroscope in the effective treatment of lower pole calculi using a 365 μm holmium laser fiber. Case Report: A 35-year-old female, with a medical history significant for chronic bacteriuria, and recurrent symptomatic culture proven urinary tract infections, underwent localization studies. Retrograde ureteropyelography demonstrated two calcifications adjoining, measuring a total of 1.4 cm, overlying the left renal shadow. Urine aspirated yielded clinically significant, >100,000, Escherichia coli and Streptococcus anginosus bacteriuria, which was felt to be originating from the left lower calix. This case used the newly FDA-approved LithoVue flexible disposable ureteroscope. The two stones were seen using the ureteroscope passed through an ureteral access sheath in the lower pole calix. A 365 μm holmium laser fiber was inserted into the ureteroscope and advanced toward the stones. There was no loss of deflection as the ureteroscope performed reproducibly. The laser was used

  9. Holmium:YAG (λ=2120nm) vs. Thulium fiber laser (λ=1908nm) ablation of kidney stones: thresholds, rates, and retropulsion

    NASA Astrophysics Data System (ADS)

    Blackmon, Richard L.; Irby, Pierce B.; Fried, Nathaniel M.

    2011-03-01

    The Holmium:YAG (Ho:YAG) laser lithotriptor is capable of operating at high pulse energies, but its efficient operation is limited to relatively low pulse rates (~10 Hz) during lithotripsy. On the contrary, the Thulium Fiber Laser (TFL) is limited to low pulse energies, but can operate at very high pulse rates (up to 1000 Hz). This study compares stone ablation threshold, ablation rate, and retropulsion effects for different Ho:YAG and TFL operation modes. The TFL (λ=1908 nm) was operated with pulse energies of 5-35 mJ, 500-μs pulse duration, and pulse rates of 10-400 Hz. The Ho:YAG laser (λ=2120 nm) was operated with pulse energies of 30-550 mJ, 350-μs pulse duration, and pulse rate of 10 Hz. Laser energy was delivered through small-core (200-270-μm) optical fibers in contact mode with human calcium oxalate monohydrate (COM) stones for ablation studies and plaster-of-Paris stone phantoms for retropulsion studies. The COM stone ablation threshold for Ho:YAG and TFL measured 82.6 J/cm2and 20.8 J/cm2, respectively. Stone retropulsion with Ho:YAG laser increased linearly with pulse energy. Retropulsion with TFL was minimal at pulse rates < 150 Hz, then rapidly increased at higher pulse rates. For minimal stone retropulsion, Ho:YAG operation at pulse energies < 175 mJ at 10 Hz, and TFL operation at 35 mJ at 100 Hz is recommended, with both lasers producing comparable ablation rates. Further development of a TFL operating with both high pulse energies (e.g. 100-200 mJ) and high pulse rates (100-150 Hz) may also provide higher ablation rates, when retropulsion is not the primary concern.

  10. Low-power holmium:YAG laser urethrotomy for urethral stricture disease: comparison of outcomes with the cold-knife technique.

    PubMed

    Atak, Mustafa; Tokgöz, Hüsnü; Akduman, Bülent; Erol, Bülent; Dönmez, Ibrahim; Hancı, Volkan; Türksoy, Ozlem; Mungan, Necmettin Aydın

    2011-11-01

    In this prospective randomized clinical trial, we aimed to evaluate the safety and efficacy of endourethrotomy with holmium:yttrium-aluminium-garnet (HO:YAG) laser and compare the outcomes with the conventional cold-knife urethrotomy. Fifty-one male patients with single, iatrogenic, annular strictures of the urethra were randomly divided into two groups; 21 patients who underwent direct-vision endoscopic urethrotomy with Ho:YAG laser (15 W; 1,200-1,400 mJ; 8-12 Hz) at 12 o'clock position (laser group) and 30 patients who underwent direct-vision endoscopic urethrotomy with cold-knife incision at 12 o'clock position (cold-knife group). The results obtained were analyzed and compared at 3 months, 6 months, 9 months, and 12 months postoperatively by clinical evaluation, uroflowmetry, and retrograde urethrographies. Variables were compared among groups using Fisher's exact and Mann Whitney U tests. There were no differences between two groups in terms of patient age, preoperative Qmax value, stricture location, and length. Operative time was shorter in laser group (16.4 ± 8.04 minutes) when compared with cold-knife group (23.8 ± 5.47 minutes) (p<0.001). Recurrence-free rate at 3 months was similar between two groups (p=0.122). However, recurrence-free rates at 6 months, 9 months, and 12 months were significantly higher in laser group when compared with cold-knife group (p values were 0.045, 0.027, and 0.04, respectively). No intra- or postoperative complications were encountered. Use of Ho:YAG laser in the management of urethral stricture disease is a safe and effective method. In addition, it provides shorter operative time and lower recurrence rate when compared with the conventional technique. PMID:22005159

  11. Efficacy and safety profile of a novel technique, ThuLEP (Thulium laser enucleation of the prostate) for the treatment of benign prostate hypertrophy. Our experience on 148 patients

    PubMed Central

    2012-01-01

    Background Over the past years laser technology has played a predominant role in prostate surgery, for the treatment of benign prostate hypertrophy (BPH). Various laser devices have been introduced in clinical practice, showing good results in terms of complications and urodynamic outcomes efficacy compared with TURP and Open Prostatectomy. In this study we describe the efficacy and the safety profile of a novel laser technique, ThuLEP (Thulium Laser Enucleation of Prostate) that permits a complete anatomical endoscopic enucleation of prostatic adenoma independently to prostate size. Methods 148 patients with a mean age of 68.2 years were enrolled between September 2009 and March 2012 (36 months), and treated for BPH with ThuLEP. Every patient was evaluated at base line according to: Digital Rectal Examination (DRE), prostate volume, Post-Voided volume (PVR), International Prostate Symptoms Score (I-PSS), International Index of Erectile Function-5 (IIEF-5), Quality of Life (QoL), PSA values, urine analysis and urine culture, uroflowmetry. The same evaluation was conducted after a 12 month follow-up. ThuLEP was performed by 2 expert surgeons. Results Our data showed a better post-operative outcome in terms of catheter removal, blood loss, TURP syndrome, clot retention and residual tissue compared to large series of TURP and OP. Only 1.3% of patients had bladder wall injury during morcellation. I-PSS, Qmax, Prostate Volume, QoL and PVR showed a highly significant improvement at 12 month follow-up in comparison to preoperative assessment. Conclusion ThuLEP represent an innovative option in patients with BPH. It is a size independent surgical endoscopic technique and it can be considered the real alternative, at this time, to TURP and even more to Open Prostatectomy for large prostate, with a complete removal of adenoma and with a low complication rate. PMID:23173611

  12. New techniques for laser prostatectomy: an update

    PubMed Central

    Chung, Doreen E.; Te, Alexis E.

    2009-01-01

    Traditionally, the gold standard for treatment of BPH has been the electrocautery-based TransUrethral Resection of the Prostate (TURP). However, the number of laser techniques being performed is rapidly increasing. Potential advantages of laser therapy over traditional TURP include decreased morbidity and shorter hospital stay. There are several techniques for laser prostatectomy that continue to evolve. The main competing techniques are currently the Holmium Laser Enucleation of the Prostate (HoLEP) and the 80W 532nm laser prostatectomy. The HoLEP, using the Holmium:YAG laser, has been shown to have clinical results similar to TURP and is suitable for patients on anticoagulation as well as those with large prostates. Disadvantages of this technique are the high learning curve and requirement of a morcellator. When used to treat BPH, studies have demonstrated that, like the HoLEP, the 80W KTP laser is safe and effective in patients with large prostates and in those taking oral anticoagulation. Several studies have compared these two techniques to TURP. Frequently reported advantages of the HoLEP over the 80W laser prostatectomy are the availability after the procedure of a pathology specimen and ability to remove a higher percentage of prostate tissue during resection. However, the transurethral laser enucleation of the prostate addresses these concerns and has shown to have durable outcomes at 2-year follow-up. Two new laser systems and techniques, the thulium laser and the 980nm laser, have emerged recently. However, clinical data from these procedures are in their infancy and large long-term studies are required. PMID:21789057

  13. Inductively coupled plasma-emission spectroscopy and atomic absorption for the use of elemental analysis of a root canal after lasing with a holmium:YAG laser.

    PubMed

    Deutsch, Allan S; Cohen, Brett I; Musikant, Barry Lee

    2003-06-01

    It has been reported in the literature that after lasing dentin the dentin surface has a glassy or globular appearance. Many authors believe this to be recrystallized hydroxyapatite. The purpose of this elemental analysis was to see if any of the silica fiber optic was melted and deposited as these globular structures on the canal wall. Two teeth were used. One was hand-instrumented with files and used as the control, the other was lased with a holmium:YAG laser. A 245-micro low OH- fiber was used with a power setting of 0.75 W, 5 Hz, 94.2 J, and 1134 V to lase the root. The roots were microanalyzed for oxygen, phosphorus, silicon, nitrogen, hydrogen, calcium, and carbon. The percentages for all elements tested were the same for both teeth. Therefore, there was no silicon deposited onto the canal wall of the tooth that was lased. It is concluded that the low OH- silica fiber optic was not melted and deposited onto the dentinal canal wall. PMID:12814225

  14. A prospective, randomized comparison of a 1940 nm and a 2013 nm thulium: yttrium–aluminum–garnet laser device for Thulium VapoEnucleation of the prostate (ThuVEP): First results

    PubMed Central

    Tiburtius, Christian; Gross, Andreas J.; Netsch, Christopher

    2015-01-01

    Introduction: We report the early postoperative results of the first prospective, randomized comparison of two commercially available thulium lasers with different wavelengths for the treatment of benign prostatic obstruction (BPO). Materials and Methods: From January to June 2013, 80 consecutive patients were randomized for Thulium VapoEnucleation of the prostate (ThuVEP) with a 2013 nm (RevoLix®) (n = 39) or a 1940 nm (Vela®XL) (n = 41) thulium laser. Preoperative status, surgical details and the immediate outcome were recorded for each patient. The perioperative complications were assessed and classified according to the modified Clavien classification system. Results: Median operation time, resected tissue, percentage of resected tissue, catheter time, overall operation efficiency and Hb loss differed nonsignificantly between both devices (P > 0.05). At discharge, the median maximum urinary flow rate and postvoiding residual (PVR) urine improved significantly in both groups (P < 0.001). The PVR was lower in the 1940 nm ThuVEP group (P ≤ 0.034). Perioperative complications occurred in 18 (22.5%) patients (Clavien 1: 12.5%; Clavien 2: 5%, Clavien 3b: 2.5%, Clavien 4a: 2.5%), with no differences between the groups (P = 0.5). Conclusions: The 1940 nm and the 2013 nm thulium lasers are both safe and effective for the treatment of BPO with ThuVEP. Both lasers give equivalent and satisfactory immediate micturition improvement with low perioperative morbidity. PMID:25624576

  15. A comparative study of diode laser and plasmakinetic in transurethral enucleation of the prostate for treating large volume benign prostatic hyperplasia: a randomized clinical trial with 12-month follow-up.

    PubMed

    Wu, Gang; Hong, Zhe; Li, Chao; Bian, Cuidong; Huang, Shengsong; Wu, Denglong

    2016-05-01

    The objective of this study is to compare the efficacy and safety of diode laser enucleation of the prostate (DiLEP) with plasmakinetic enucleation of the prostate (PKEP) for symptomatic benign prostatic hyperplasia (BPH) patients with large prostate (volume > 80 ml). From January 2013 to June 2014, 80 consecutive patients were randomized treated with DiLEP (n = 40) or PKEP (n = 40). Perioperative and postoperative outcome data were assessed during a 1-year follow-up. There were no significant preoperative differences between the two surgical groups. The mean prostate volumes in the DiLEP and PKEP groups were 98.6 and 93.3 ml, respectively. DiLEP was equivalent to PKEP in improvement in International Prostate Symptom Score (IPSS), quality of life scores, and maximum flow rate. Compared with PKEP, patients treated with DiLEP showed a lower risk of blood loss (P < 0.01), shorter bladder irrigation and catheterization times (P < 0.01), as well as shorter hospital stays (P < 0.01). Moreover, the DiLEP group was significantly superior to bipolar plasmakinetic group in the irritative symptoms. However, the operation time of the DiLEP group was longer than that of PKEP group (P = 0.02). Both DiLEP and PKEP are safe and effective methods for the treatment of BPH in large prostates (volume > 80 ml). Compared with PKEP, DiLEP provides a decreased risk of hemorrhage, reduced bladder irrigation, and catheterization times, as well as shorter hospital stays. PMID:26822403

  16. Efficacy of holmium laser urethrotomy and intralesional injection of Santosh PGI tetra-inject (Triamcinolone, Mitomycin C, Hyaluronidase and N-acetyl cysteine) on the outcome of urethral strictures

    PubMed Central

    Kishore, Lalit; Sharma, Aditya Prakash; Garg, Nitin; Singh, Shrawan Kumar

    2015-01-01

    Introduction To study the efficacy of holmium laser urethrotomy with intralesional injection of Santosh PGI tetra-inject (Triamcinolone, Mitomycin C, Hyaluronidase and N-acetyl cysteine) in the treatment of urethral strictures. Material and methods A total of 50 patients with symptomatic urethral stricture were evaluated by clinical history, physical examination, uroflowmetry and retrograde urethrogram preoperatively. All patients were treated with holmium laser urethrotomy, followed by injection of tetra-inject at the urethrotomy site. Tetra-inject was prepared by diluting acombination of 40 mg Triamcinolone, 2 mg Mitomycin, 3000 UHyaluronidase and 600 mg N-acetyl cysteine in 5–10 ml of saline, according to the stricture length. An indwelling 18 Fr silicone catheter was left in place for 7–10 days.All patients were followed-up for 6-18 months postoperatively by history, uroflowmetry, and if required, retrograde urethrogram and micturating urethrogram every 3 months. Results 41 (82%) patients had asuccessful outcome,whereas 9 (18%) had recurrences during a follow-up ranging from 6–18 months. In <1 cm length strictures, the success rate was 100%, while in 1–3 cm and >3 cm lengthsthe success rates were 81.2% and 66.7% respectively. This modality, thus, has an encouraging success rate, especially in those with short segment urethral strictures (<3 cm). Conclusions Holmium laser urethrotomy with intralesional injection ofSantosh PGI tetra-inject (Triamcinolone, Mitomycin C, Hyaluronidase, N-acetyl cysteine) is a safe and effective minimally-invasive therapeutic modality for short segment urethral strictures. PMID:26855803

  17. Effect of power settings versus temperature change at the root surface when using multiple fiber sizes with a Holmium YAG laser while enlarging a root canal.

    PubMed

    Cohen, B I; Deutsch, A S; Musikant, B L; Pagnillo, M K

    1998-12-01

    The aim of this study was to determine if there is an increase in temperature at the root surface as the canal is enlarged when using a Holmium:YAG laser. An increase might be expected because, as the canal is enlarged, there is less dentin between the canal walls and the outer cementum surface of the root to absorb the heat. Sixty single-rooted human teeth were randomly assigned to 1 of 3 groups according to laser power settings: 0.50, 0.75, and 1.00 W. Each tooth in each power group was subjected to lasing using fiber sizes of 140, 245, 355, and 410 microns. The dependent variables in these analyses included: (a) change in temperature, measured with T-type thermocouples placed 2 mm from the coronal and apical ends of the root; (b) depth of laser in the tooth; (c) depth that a conventional fiber could be inserted after lasing; and (d) tooth physical dimensions. ANOVA for coronal temperature showed no interaction between fibers and power settings. Repeated-measures ANOVA for apical temperature showed a significant difference between fibers, but not between power settings. No interaction between fibers and power settings was observed. For the depth of tooth during lasing (how far the fiberoptic guide penetrated into the tooth), no interaction between fibers and power settings was observed. Pairwise contrasts revealed that all fibers were different from one another, with depth decreasing as fiber size increased. Depth files could be inserted that showed the depth significantly decreased as file size increased from 50 through 70. ANOVAs illustrated that there were no significant differences between power settings for any of the five tooth physical dimensions. All temperature differences observed apically and coronally were between 0 degree to 10 degrees C, with the majority (> 98%) being between 0 degree to 5 degrees C. After lasing with the 410-micron fiber, the root canals were widened to at least 45 or 50 K-files (450 or 500 microns). However, by using a 410-micron

  18. A comparative study to analyze the efficacy and safety of flexible ureteroscopy combined with holmium laser lithotripsy for residual calculi after percutaneous nephrolithotripsy

    PubMed Central

    Xu, Gang; Wen, Jiaming; Li, Zhongyi; Zhang, Zhewei; Gong, Xiuqing; Chen, Jimin; Du, Chuanjun

    2015-01-01

    A certain proportion of patients with initial Percutaneous nephrolithotripsy (PCNL) management require ancillary procedures to increase the stone-free rate. In this study, we aim to analyze the efficacy and safety of flexible ureteroscopy combined with holmium laser lithotripsy (F-UL) for treatment of residual calculi after PCNL by comparison with extracorporeal shockwave lithotripsy (SWL). Total of 96 patients with residual renal calculi (4 mm to 20 mm) after PCNL was enrolled from May 2010 to March 2013. They were randomly divided into two groups: US Group: patients were treated with F-UL; SWL Group: patients were treated with SWL. Follow-up was made one month and three months after treatment. The mean residual stone size after PCNL was 12.4 ± 4.3 mm in US group compared with 11.9 ± 4.5 in SWL group. The stone-free rate was 84.7% one month after surgical procedure in US group, this rate increased to 91.3% in the third months, while the stone-free rate in SWL group is 64.6% one month after treatment and 72.9% in the third month. For residual stone in lower calyx, the stone-free rate three month after treatment was 90.4% in US group compared to 65.2% in SWL group (P < 0.05). The overall complication rate was low in both groups, no severe complication was found. Both F-UL and SWL are safe and effective methods for residual calculi after PCNL, without severe complications. F-UL provided significantly higher stone-free rate compared with SWL, especially for low-pole calculi. PMID:26064375

  19. Electronically tunable thulium-holmium mode-locked fiber laser for the 1700-1800 nm wavelength band.

    PubMed

    Noronen, Teppo; Okhotnikov, Oleg; Gumenyuk, Regina

    2016-06-27

    We demonstrate a widely tunable, mode-locked fiber laser capable of producing sub-picosecond pulses between 1705 and 1805 nm. The 100 nm tuning range is achieved by using intracavity acousto-optic tunable filter. The laser delivers highly stable pulses via self-starting hybrid mode-locking triggered by frequency-shifting and nonlinear polarization evolution. PMID:27410623

  20. Holmium laser use in debridement of stable labral lesions: two-year experience in initial 50 patients

    NASA Astrophysics Data System (ADS)

    Dew, Douglas K.; Risch, E. David

    1994-09-01

    The purpose of this study is to determine the laser related complication rate for shoulder arthroscopy in the initial clinical experience of 50 patients, and to identify potential advantages of laser use in shoulder arthroscopy. Fifty patients spanning ages 25 to 87 were treated. Surgical debridement was selective and conservative creating a smooth post resection rim. In those that included rotator cuff tears, in addition to arthroscopic debridement, a mini arthrotomy and open acromioplasty were performed. Changes in arthroscopic technique due to laser use included no arthroscopic pump use and use of the shaver only when the fiber could not be easily seen with severe synovitis. We found that the hyper-vascular synovium did not need to be resected last, it could be resected at any point during the procedure. Four hundred and 600 micron fiberoptics were used as well as 20 watts average power. Technical advantage of the laser was felt to be the size of the instrument probe and the availability of excellent hemostasis. Complications include one case of arthroscope damage and one case with a broken fiber tip which was removed with a grasper. Long term follow up of these patients is now underway.

  1. Effects of holmium:YAG laser on equine articular cartilage and subchondral bone adjacent to traumatic lesions

    NASA Astrophysics Data System (ADS)

    Collier, Michael A.; Haugland, L. Mark; Bellamy, Janine; Johnson, Lanny L.; Rohrer, Michael D.; Walls, Robert C.; Bartels, Kenneth E.

    1994-09-01

    The effects of Ho:YAG laser energy on articular cartilage and subchondral bone adjacent to traumatically created cartilage lesions in a continuous weight-bearing model were investigated. The 2.1 micrometers wavelength was delivered in hand-controlled contact and near-contact hard tissue arthroscopic surgery in a saline medium. Bilateral arthroscopy was performed on normal antebrachiocarpal and intercarpal joints of four adult horses. One-hundred twenty traumatic lesions were created on three weight-bearing articular surfaces with a knife, curette, or a motorized burr. Depths of the lesions were partial and full thickness. Configurations of the lesions were lacerations, scrapes, and craters. Left limbs were used as controls. Right limb lesions were treated with various intensities of laser energy. Animals were sacrificed at intervals of 1, 3, and 8 weeks. Gross microscopic anatomy was documented, and tissue sections were subjected to blind review by a pathologist. Mankin grading for cellularity and proteoglycan content was used to qualitatively evaluate cartilage response. Cartilage adjacent to all lesions exposed to laser energy had better cellularity and proteoglycan content than corresponding controls by Mankin grading.

  2. Flexible ureterorenoscopy (F-URS) with holmium laser versus extracorporeal shock wave lithotripsy (ESWL) for treatment of renal stone <2 cm: a meta-analysis.

    PubMed

    Mi, Yuanyuan; Ren, Kewei; Pan, Haiyan; Zhu, Lijie; Wu, Sheng; You, Xiaoming; Shao, Hongbao; Dai, Feng; Peng, Tao; Qin, Feng; Wang, Jian; Huang, Yi

    2016-08-01

    The objective of the study was to systematically review the efficacy and safety of flexible ureterorenoscopy (F-URS) with holmium laser versus extracorporeal shock wave lithotripsy (ESWL) for the treatment of renal stone <2 cm. A systematic literature review was performed in April 2015 using the PubMed, Embase, Web of Science and the Chinese Biomedical Literature (CNKI and Wanfang) databases to identify relevant studies. All clinical trials were retrieved and their included references investigated. Two reviewers independently assessed the quality of all included studies, and the eligible studies were included and analyzed using the RevMan 5.3 software. Six prospective randomized comparison trials and eight retrospective comparison trials were included, involving a total of 2348 patients. For renal stone 1-2 cm, F-URS technique provided a significantly higher stone-free rate (SFR) [weighted mean difference (WMD) = 2.35, 95 % confidence interval (CI) 1.65-3.34, P < 0.00001], lower auxiliary procedure rate (APR) [odds ratio (OR) 0.33, 95 % CI 0.22-0.50, P < 0.00001] and lower retreatment rate (RR) (OR 0.07, 95 % CI 0.01-0.37, P = 0.002). Similar results were found in the lower pole stone for 1-2 cm subgroup. For renal stone <1 cm, F-URS technique also showed a significantly higher SFR than ESWL (WMD = 2.13, 95 % CI 1.13-4.00, P = 0.02). F-URS is associated with higher SFR, lower APR and RR than ESWL. F-URS is a safe and effective procedure. It can successfully treat patients with stones for 1-2 cm, especially for lower pole stone, without increasing complications, operative time and hospital stay. F-URS can be used as an alternative treatment to ESWL in selected cases with larger renal stones. However, further randomized trials are needed to confirm these findings. PMID:26530230

  3. Holmium-doped fibre amplifier operating at 2.1 μm

    SciTech Connect

    Kamynin, V A; Antipov, S O; Kurkov, A S; Baranikov, A V

    2014-02-28

    A small-signal holmium-doped fibre amplifier is demonstrated. The seed source is a cw holmium-doped fibre laser whose output power is modulated by an electro-optical modulator. The maximum gain reached (wavelength, 2.1 μm; power, 0.25 mW; pulse duration, 100 ns; pulse repetition rate, 1 μs) is 28.5 dB. (lasers)

  4. Development of high-power holmium-doped fibre amplifiers

    NASA Astrophysics Data System (ADS)

    Hemming, Alexander; Simakov, Nikita; Davidson, Alan; Oermann, Michael; Corena, Len; Stepanov, Dmitrii; Carmody, Neil; Haub, John; Swain, Robert; Carter, Adrian

    2014-03-01

    Resonantly pumped holmium fibre lasers present a range of opportunities for the development of novel fibre laser and amplifier devices due to the availability of mature, efficient high power thulium fibre pump lasers. In this paper we describe the operation of a large mode area holmium-doped fibre amplifier. The master-oscillator is an all-fibre linearly polarised, core pumped single mode laser operating at 27 W at 2.11 μm. This laser was amplified in a large mode area fibre producing up to 265 W of output power. This system is the first demonstration of a resonantly pumped holmiumdoped fibre amplifier. It is also the highest power fibre amplifier that is capable of operating in an atmospheric transmission window <2.05 μm. This monolithic all-fibre system is able to address a wide range of remote sensing, scientific, medical and defence applications.

  5. A Review of Laser Treatment for Symptomatic BPH (Benign Prostatic Hyperplasia).

    PubMed

    Nair, Shiva Madhwan; Pimentel, Marie Adrianne; Gilling, Peter John

    2016-06-01

    Benign prostatic hyperplasia (BPH) is the predominant cause of bladder outflow obstruction and is associated with significant morbidity. Surgical removal of adenoma has been a key treatment principle for alleviation of obstruction. Lasers have been used as an alternative to transurethral resection of the prostate (TURP), due to the higher complications of the latter procedure, since the early 1990s. Early generations of lasers utilized coagulative and ablative techniques to dis-obstruct the bladder. Ablative techniques have remained popular with the resurgence of 532-nm vaporization (commonly known as GreenLight). Enucleation techniques especially with the holmium laser have shown durable efficacy in randomized controlled trials whilst new modalities such as thulium still require long-term data. This review examines the most common types of laser technology used in BPH surgery, with a focus on efficacy and side effect profile. PMID:27053186

  6. Calcium Signaling Is Required for Erythroid Enucleation

    PubMed Central

    Russell, Sarah M.; Humbert, Patrick O.

    2016-01-01

    Although erythroid enucleation, the property of erythroblasts to expel their nucleus, has been known for 7ore than a century, surprisingly little is known regarding the molecular mechanisms governing this unique developmental process. Here we show that similar to cytokinesis, nuclear extrusion requires intracellular calcium signaling and signal transduction through the calmodulin (CaM) pathway. However, in contrast to cytokinesis we found that orthochromatic erythroblasts require uptake of extracellular calcium to enucleate. Together these functional studies highlight a critical role for calcium signaling in the regulation of erythroid enucleation. PMID:26731108

  7. Calcium Signaling Is Required for Erythroid Enucleation.

    PubMed

    Wölwer, Christina B; Pase, Luke B; Russell, Sarah M; Humbert, Patrick O

    2016-01-01

    Although erythroid enucleation, the property of erythroblasts to expel their nucleus, has been known for 7ore than a century, surprisingly little is known regarding the molecular mechanisms governing this unique developmental process. Here we show that similar to cytokinesis, nuclear extrusion requires intracellular calcium signaling and signal transduction through the calmodulin (CaM) pathway. However, in contrast to cytokinesis we found that orthochromatic erythroblasts require uptake of extracellular calcium to enucleate. Together these functional studies highlight a critical role for calcium signaling in the regulation of erythroid enucleation. PMID:26731108

  8. Investigation and visualization of scleral channels created with femtosecond laser in enucleated human eyes using 3D optical coherence tomography images

    NASA Astrophysics Data System (ADS)

    Chaudhary, Gautam; Rao, Bin; Chai, Dongyul; Chen, Zhongping; Juhasz, Tibor

    2007-02-01

    We used optical coherence tomography (OCT) for non-invasive imaging of the anterior segment of the eye for investigating partial-thickness scleral channels created with a femtosecond laser. Glaucoma is associated with elevated intraocular pressure (IOP) due to reduced outflow facility in the eye. A partial-thickness aqueous humor (AH) drainage channel in the sclera was created with 1.7-μm wavelength femtosecond laser pulses to reduce IOP by increasing the outflow facility, as a solution to retard the progression of glaucoma. It is hypothesized that the precise dimensions and predetermined location of the channel would provide a controlled increase of the outflow rate resulting in IOP reduction. Therefore, it is significant to create the channel at the exact location with predefined dimensions. The aim of this research has two aspects. First, as the drainage channel is subsurface, it is a challenging task to determine its precise location, shape and dimensions, and it becomes very important to investigate the channel attributes after the laser treatment without disturbing the internal anterior structures. Second, to provide a non-invasive, image-based verification that extremely accurate and non-scarring AH drainage channel can be created with femtosecond laser. Partial-thickness scleral channels created in five human cadaver eyes were investigated non-invasively with a 1310-nm time-domain OCT imaging system. Three-dimensional (3D) OCT image stacks of the triangular cornea-sclera junction, also known as anterior chamber angle, were acquired for image-based analysis and visualization. The volumetric cutting-plane approach allowed reconstruction of images at any cross-sectional position in the entire 3D volume of tissue, making it a valuable tool for exploring and evaluating the location, shape and dimension of the channel from all directions. As a two-dimensional image-based methodology, an image-processing pipeline was implemented to enhance the channel features to

  9. Best laser for prostatectomy in the year 2013

    PubMed Central

    Maheshwari, Pankaj N; Joshi, Nitin; Maheshwari, Reeta P

    2013-01-01

    Lasers have come a long way in the management of benign prostatic hyperplasia. Over last nearly two decades, various different lasers have been utilized for prostatectomy. Neodymium: yttrium-aluminum-garnet laser that started this journey, is no longer used for prostatectomy. Holmium laser can achieve transurethral enucleation of the prostatic adenoma producing a fossa that can be compared with the fossa after Freyer's prostatectomy. Green light laser has a short learning curve, is nearly blood-less with good immediate results. Thulium laser is a faster cutting laser while diode laser is a portable laser device. Often laser prostatectomy is considered as a replacement for the standard transurethral resection of prostate (TURP). To be comparable, laser should reduce or avoid the immediate and long-term complications of TURP, especially bleeding and need for blood transfusion. It should also be safe in the ever increasing patient population on antiplatelet and anticoagulant drugs. We need to take stock of the situation and identify, which among the present day lasers has stood the test of time. A review of the literature was performed to see if any of these lasers could be called the “best laser for prostatectomy in 2013.” PMID:24082446

  10. Enucleation in psychosis associated with aqueductal stenosis.

    PubMed

    Mancinelli, Iginia; Pompili, Maurizio; Scapati, Francesco; Lazanio, Simone; Kotzalidis, Giorgio D; Tatarelli, Roberto

    2004-03-01

    Reports of self-enucleation are frequent in medical literature, but cases of enucleation towards another are rare. We report the case of a man, 20 years of age, who suffered from psychosis with hydrocephalus and aqueductal stenosis that required a forensic psychiatric investigation to ascertain whether he was of unsound mind when he assaulted and enucleated the right eye of an officer and led to the surgical enucleation of the victim's left eye. Based on his clinical interviews and hospitalization record, we conclude that at the time of the assault, he was suffering from a delusional disorder with religious and demonic content, visual and auditory hallucinations, illusion phenomena, delusional interpretations, imaginative elements, a feeling of terror, and command hallucinations that compelled him to perform the act of aggression. PMID:15027561

  11. The role of lasers in modern urology

    PubMed Central

    Dołowy, Łukasz; Dembowski, Janusz; Zdrojowy, Romuald; Kołodziej, Anna

    2015-01-01

    Introduction The functioning of modern urological departments and the high level of service they provide is possible through, among other things, the use of modern laser techniques. Material and methods Open operations have been replaced by minimally invasive procedures, and classical surgical tools by advanced lasers. The search for new applications with lasers began as technology developed. Among many devices available, holmium, diode and thulium lasers are currently the most popular. Results Depending on the wavelength, the absorption by water and hemoglobin and the depth of penetration, lasers can be used for coagulation, vaporization and enucleation. In many centres, after all the possibilities of pharmacological treatment have been exhausted, lasers are used as the primary treatment for patients with benign prostatic hyperplasia, with therapeutic results that are better than those obtained through open or endoscopic operations. The use of lasers in the treatment of urolithiasis, urinary strictures and bladder tumours has made treatment of older patients with multiple comorbidities safe, without further necessity to modify the anticoagulant drug treatment. Laser procedures are additionally less invasive, reduce hospitalization time and enable a shorter bladder catheterization time, sometimes even eliminating the need for bladder catherterization completely. Such procedures are also characterized by more stable outcomes and a lower number of reoperations. Conclusions There are also indications that with the increased competition among laser manufacturers, decreased purchase and maintenance costs, and increased operational safety, laser equipment will become mandatory and indispensable asset in all urology wards. PMID:26251737

  12. High-power frequency comb in the range of 2-2.15  μm based on a holmium fiber amplifier seeded by wavelength-shifted Raman solitons from an erbium-fiber laser.

    PubMed

    Coluccelli, Nicola; Cassinerio, Marco; Gambetta, Alessio; Laporta, Paolo; Galzerano, Gianluca

    2014-03-15

    We demonstrate a room-temperature high-power frequency comb source covering the spectral region from 2 to 2.15 μm. The source is based on a femtosecond erbium-fiber laser operating at 1.55 μm with a repetition rate of 250 MHz, wavelength-shifted up to 2.06 μm by the solitonic Raman effect, seeding a large-mode-area holmium (Ho) fiber amplifier pumped by a thulium (Tm) fiber laser emitting at 1.94 μm. The frequency comb has an integrated power of 2 W, with overall power fluctuations as low as 0.3%. The beatnote between the comb and a high-spectral-purity, single-frequency Tm-Ho laser has a linewidth of 32 kHz over 1 ms observation time, with a signal-to-noise ratio in excess of 30 dB. PMID:24690863

  13. Resonance ionization of holmium for ion implantation in microcalorimeters

    NASA Astrophysics Data System (ADS)

    Schneider, F.; Chrysalidis, K.; Dorrer, H.; Düllmann, Ch. E.; Eberhardt, K.; Haas, R.; Kieck, T.; Mokry, C.; Naubereit, P.; Schmidt, S.; Wendt, K.

    2016-06-01

    The determination of the electron neutrino mass by calorimetric measurement of the 163 Ho electron capture spectrum requires ultra-pure samples. Several collaborations, like ECHo or HOLMES, intend to employ microcalorimeters into which 163 Ho is implanted as an ion beam. This makes a selective and additionally very efficient ion source for holmium mandatory. For this purpose, laser resonance ionization of stable holmium 165 Ho was studied, using a three step excitation scheme driven by pulsed Ti:sapphire lasers. Five measurements with sample sizes of 1014 and 1015 atoms were performed for the efficiency investigation. In average, an excellent ionization efficiency of 32(5) % could be shown, demonstrating the suitability for ion beam implantation.

  14. Magnetic structure of holmium

    NASA Astrophysics Data System (ADS)

    Pechan, M. J.; Stassis, C.

    1984-03-01

    The magnetic structure of high purity single crystals of holmium has been studied by neutron diffraction techniques. Although the general characteristics of the magnetic structure have been found to agree with earlier measurements, some discrepancies have been resolved and new features have been observed. The magnetic form factor has been measured and compared with relativistic atomic calculations. The low temperature structure (T<20 K) is that of a conical ferromagnet with wave vector (1/6)(2π/c) along the c axis. The basal plane moment is 9.7 μB and the c-axis ferromagnetic component is 1.6 μB at T=6 K. Bunching of the basal plane moments around the easy hexagonal direction has been observed below T=50 K. Evidence for asphericity in the magnetization density is presented and discussed. The wave vector of the basal plane modulation decreases monotonically with temperature in general accordance with the Elliott-Wedgewood theory. Several inflection points were observed, however, which correspond to commensurability with the chemical lattice. The measured temperature dependence of the c- and a-axis lattice constants shows significant magnetostriction. The possibility of a c-axis modulated moment is discussed.

  15. Enucleation versus plaque irradiation for choroidal melanoma

    SciTech Connect

    Straatsma, B.R.; Fine, S.L.; Earle, J.D.; Hawkins, B.S.; Diener-West, M.; McLaughlin, J.A.

    1988-07-01

    The Collaborative Ocular Melanoma Study (COMS) is an international, multicenter-controlled study. The organization includes an Executive Committee, Steering Committee, 6 Central Units, 32 Clinical Centers, and a Data and Safety Monitoring Committee. Scientifically, the COMS consists of (1) a randomized trial of patients with medium choroidal melanoma treated with enucleation versus iodine-125 plaque irradiation, (2) a randomized trial of patients with large choroidal melanoma treated with enucleation versus preenucleation external beam irradiation and enucleation, and (3) a prospective observational study of patients with small choroidal melanoma to determine whether a randomized trial of treatment is appropriate. In design and conduct of the COMS, special consideration is given to biostatistics and sample size considerations, iodine-125 plaque irradiation of choroidal melanoma, and coordinated ocular melanoma research. Recruitment is in progress. However, the pool of eligible patients is limited and the COMS needs the continued support and cooperation of ophthalmologists throughout the United States and Canada.

  16. Magneto-optical trapping of holmium atoms

    NASA Astrophysics Data System (ADS)

    Miao, J.; Hostetter, J.; Stratis, G.; Saffman, M.

    2014-04-01

    We demonstrate sub-Doppler laser cooling and magneto-optical trapping of the rare-earth element holmium. Atoms are loaded from an atomic beam source and captured in six-beam σ+-σ- molasses using a strong J =15/2↔J=17/2 cycling transition at λ =410.5 nm. Due to the small difference in hyperfine splittings and Landé g factors in the lower and upper levels of the cooling transition the MOT is self-repumped without additional repump light, and deep sub-Doppler cooling is achieved with the magnetic trap turned on. We measure the leakage out of the cycling transition to metastable states and find a branching ratio <10-5, which is adequate for state-resolved measurements on hyperfine encoded qubits.

  17. Enucleation for Treating Rodent Ocular Disease

    PubMed Central

    Wilding, Laura A; Uchihashi, Mayu; Bergin, Ingrid L; Nowland, Megan H

    2015-01-01

    Our standard of care for rodent corneal lesions previously included treatment of the primary lesion, application of topical NSAIDs, and systemic NSAIDs in severe cases. When intensive medical management was unsuccessful, animals were euthanized, leading to premature loss of valuable genetically modified animals and those on long-term studies. We investigated enucleation surgery as a treatment for 15 cases of rodent corneal disease that did not respond to medical management. Enucleation was performed under isoflurane anesthesia and involved removal of the globe, extensive hemostasis, and packing the orbital space with absorbable gelatin sponge. The lid margins were closed by tarsorrhaphy and tissue glue. Analgesia was provided by using buprenorphine preoperatively and carprofen chew tabs postoperatively. To date, we have a 100% success rate with this procedure (n = 20; 15 clinically affected rodents [2 rats, 13 mice], 5 healthy controls), which included a 60-d follow-up period. The single complication involved dehiscence of the tarsorrhaphy site and was repaired by trimming the lid margins to provide fresh tissue for closure. Histologic examination at both 1 and 3 mo after surgery revealed no evidence of infection of the enucleation site. Enucleation in rodents is a straightforward procedure that represents a refinement to our current standard of care for rodents, does not cause significant inflammation of remaining periocular structures, and has reduced the number of animals euthanized prior to study endpoint because of severe ocular lesions. PMID:26045460

  18. Current Laser Treatments for Benign Prostatic Hyperplasia

    PubMed Central

    Son, Hwancheol; Song, Sang Hoon

    2010-01-01

    The latest technical improvements in the surgical armamentarium are remarkable. In particular, advancements in the urologic field are so exceptional that we could observe the flare-up of robot-assisted laparoscopic radical prostatectomy for prostate cancer and laser prostatectomy for benign prostatic hyperplasia (BPH). Photoselective vaporization of the prostate (PVP) and holmium laser prostatectomy are the most generalized options for laser surgery of BPH, and both modalities have shown good postoperative results. In comparison to transurethral prostatectomy (TURP), they showed similar efficacy and a much lower complication rate in randomized prospective clinical trials. Even in cases of large prostates, laser prostatectomy showed comparable efficacy and safety profiles compared to open prostatectomy. From a technical point of view, PVP is considered to be an easier technique for the urologist to master. Furthermore, patients can be safely followed up in an outpatient clinic. Holmium laser enucleation of the prostate (HoLEP) mimics open prostatectomy because the adenomatous tissue is peeled off the surgical capsule in both procedures. Therefore, HoLEP shows notable volume reduction of the prostate similar to open prostatectomy with fewer blood transfusions, shorter hospital stay, and cost reduction regardless of prostate size. Outcomes of laser prostatectomy for BPH are encouraging but sometimes are unbalanced because safety and feasibility studies were reported mainly for PVP, whereas long-term data are mostly available for HoLEP. We need longer-term randomized clinical data to identify the reoperation rate of PVP and to determine which procedure is the ideal alternative to TURP and open prostatectomy for each patient. PMID:21165192

  19. Special optical fibers doped with nanocrystalline holmium-yttrium titanates (HoxY1-x)2Ti2O7 for fiber-lasers

    NASA Astrophysics Data System (ADS)

    Mrázek, Jan; Kašík, Ivan; Boháček, Jan; Proboštová, Jana; Aubrecht, Jan; Podrazký, Ondřej; Cajzl, Jakub; Honzátko, Pavel

    2015-05-01

    The paper deals with the preparation and characterization of the silica optical fibers doped with nanocrystalline holmium-yttrium titanates (HoxY1-x)2Ti2O7 with optimized luminescence properties. The sol-gel approach was employed to prepare colloidal solution of (HoxY1-x)2Ti2O7 precursors. The concentration of Ho3+ ions in the compounds was varied up to x=0.4. Prepared sols were calcined at 1000 °C forming xerogels which were characterized by X-ray diffraction to confirm their structure. The xerogels were analyzed by the mean of steady-state luminescence technique to optimize the concentration of Ho3+ ions in the compound. The most intensive emission at 2050 nm was observed for the compound (Ho5Y95)2Ti2O7. Sol of the corresponding composition was soaked into the porous silica frit deposed inside the silica substrate tube which was collapsed into preform and drawn into optical fiber. Single mode optical fiber with the core diameter 12 μm and outer diameter 125 μm was prepared. Numerical aperture of prepared fiber was 0.16. The concentration of Ho3+ ions in the fiber core was 0.03 at %. Background attenuation of prepared fiber at 850 nm was smaller than 0.5 dBṡm-1.

  20. High-power and highly efficient diode-cladding-pumped holmium-doped fluoride fiber laser operating at 2.94 microm.

    PubMed

    Jackson, Stuart D

    2009-08-01

    A high-power diode-cladding-pumped Ho(3+), Pr(3+)-doped fluoride glass fiber laser is demonstrated. The laser produced a maximum output power of 2.5 W at a slope efficiency of 32% using diode lasers emitting at 1,150 nm. The long-emission wavelength of 2.94 microm measured at maximum pump power, which is particularly suited to medical applications, indicates that tailoring of the proportion of Pr(3+) ions can provide specific emission wavelengths while providing sufficient de-excitation of the lower laser level. PMID:19649086

  1. Relaxation oscillations of the radiation from a 2-{mu}m holmium laser with a Cr,Tm,Ho : YSGG crystal

    SciTech Connect

    Alpat'ev, A N; Smirnov, Valerii A; Shcherbakov, Ivan A

    1998-02-28

    Analytic expressions for the parameters of relaxation oscillations in a cw 2-{mu}m, Cr,Tm,Ho : YSGG crystal laser are derived and analysed. They are compared quantitatively with the corresponding parameters of a 2-{mu}m Cr,Tm : YSGG crystal laser. Significant differences are found between the damping decrements. The experimental and theoretical results are compared and the different operational dynamics of the Ho{sup 3+} and Tm{sup 3+} ion lasers explained. (control of laser radiation parameters)

  2. Suppression of optical damage at 532 nm in Holmium doped congruent lithium niobate.

    PubMed

    Barnes, Eftihia; O'Connell, Nathan H; Balli, Nicolas R; Pokhrel, Madhab; Movsesyan, Anush; Kokanyan, Edvard; Sardar, Dhiraj K

    2014-10-20

    Optical damage experiments were carried out in a series of Holmium doped congruent lithium niobate (Ho:cLN) crystals as a function of dopant concentration and laser intensity. The light induced beam distortion was recorded with a camera and a detector under the pseudo-Z-scan configuration. At 532 nm, strong suppression of the optical damage was observed for the 0.94 mol. % doped crystal. Increased resistance to optical damage was also observed at 488 nm. The suppression of the optical damage is predominantly attributed to the reduction of the Nb antisites due to the holmium doping. PMID:25401654

  3. Gain and energy storage in holmium YLF

    NASA Technical Reports Server (NTRS)

    Storm, Mark E.; Deyst, John P.

    1991-01-01

    It is demonstrated that Q-switched holmium lasers are capable of high-gain and high-energy operation at 300 K. Small-signal gain coefficients of 0.50 and 0.12/cm have been measured in YLF and YAG, respectively. Small-signal gains of 0.50/cm are comparable to those achievable in Nd:YAG and are not typical of low-gain materials. This large gain in the Ho:YLF material is made possible by operating the amplifier in the ground state depletion mode. The amplifier performance data and associated analysis presented demonstrate that efficient energy storage is possible with very high excited state ion densities of the Ho 5I7 upper laser level. This is an important result since upconversion can limit the 5I7 population. Although upconversion was still present in this experiment, it was possible to achieve efficient energy storage, demonstrating that the problem is manageable even at high excitation densities in YLF.

  4. Efficient holmium-doped fluoride fiber laser emitting 2.1 µm and blue upconversion fluorescence upon excitation at 2 µm.

    PubMed

    Guhur, A; Jackson, S D

    2010-09-13

    We demonstrate a highly efficient and high power Ho(3+)-doped fluoride glass fiber laser that is resonantly pumped with a Tm(3+)-doped silicate glass fiber laser operating at 2.051 µm. The laser operates at 2080 nm and generated 6.66 W at a slope efficiency of 72%. We observe strong visible upconversion fluorescence centered at a variety of wavelengths including 491 nm which results from three sequential energy transfer upconversion processes; the fluorescence to pump energy ratio for this emission is one the largest reported to date. PMID:20940907

  5. Effects of simultaneously fiber transmitted erbium and holmium radiation on the interaction with highly absorbing media

    NASA Astrophysics Data System (ADS)

    Frenz, Martin; Pratisto, Hans S.; Ith, Michael; Koenz, Flurin; Weber, Heinz P.

    1995-05-01

    Erbium and Holmium lasers have both been shown to be suitable for orthopedic surgery performed under water. Erbium lasers emitting in the 3 micrometers wavelength region corresponding to the maximum water absorption peak effectively ablated biological tissues with high precision and minimal thermal damage. Holmium laser radiation at 2 micrometers , due to a lower absorption coefficient, is characterized by a greater extent of thermal damage leading to hemostasis. To combine the special advantages of each system we simultaneously coupled their radiation into a zirconium fluoride fiber (ZrF4) which was protected with a quartz fiber tip. Pressure measurements performed in the liquid using a piezo electrical transducer, transmission measurements and video flash lamp schlieren imaging of the laser induced vapor bubble were used in order to determine optimum laser parameters. The cutting efficiency of the Erbium laser is drastically improved when a low energy Holmium laser pulse is additionally used which is just able to open a vapor channel through which the Erbium laser pulse can be transmitted. The dynamics of the channel formation, geometry and life time are measured as a function of the delay time between the two different laser pulses and the pulse energy applied. The combination of 2 micrometers and 3 micrometers radiation seems to be an ideal instrument for tissue treatment.

  6. Holmium-doped Lu2O3, Y2O3, and Sc2O3 for lasers above 2.1 μm.

    PubMed

    Koopmann, Philipp; Lamrini, Samir; Scholle, Karsten; Schäfer, Michael; Fuhrberg, Peter; Huber, Günter

    2013-02-11

    Efficient room-temperature laser operation was obtained in the wavelength range from 2117 nm to 2134 nm with Ho:Lu(2)O(3) and Ho:Y(2)O(3) as the active materials. With an FBG-stabilized Tm-doped fiber laser as the pump source, the maximum slope efficiency and output power of the Ho:Y(2)O(3) laser were 63% and 18.8 W, respectively. With Ho:Lu(2)O(3) the respective values were 76% and 25.2 W. With Ho:Sc(2)O(3) as the active material the accessible wavelength range could be expanded to 2158 nm in a diode-pumped setup. PMID:23481849

  7. [Testicular epidermoid cyst: orchiectomy or enucleation resection?].

    PubMed

    Heidenreich, A; Zumbé, J; Vorreuther, R; Klotz, T; Vietsch, H; Engelmann, U H

    1996-01-01

    Our experience with 18 patients with simple epidermoid cysts of the testis is reported. In each patient the tumour was enucleated completely and two biopsies of the adjacent parenchyma were obtained for exclusion of associated germ cell cancer, scars or carcinoma in situ. There was no evidence of malignancy in any of the biopsy specimens. Preoperative evaluation included physical examination, testicular sonography, and determination of AFP and hCG serum levels. Although epidermoid cyst can be strongly suspected on sonography the ultrasound appearance is not specific, and inguinal testicular exploration was required in these patients. In 1 patient multiple epidermoid cysts of the right testis were associated with an adult teratoma containing embryonal carcinoma and choriocarcinoma of the left testis; no similar case has been described in the literature. On the basis of our results and experience we consider tumour enucleation and biopsy of the adjacent parenchyma to be adequate treatment for benign epidermoid cyst. The world literature concerning organ-sparing surgery in testicular epidermoid cyst is reviewed. PMID:8851841

  8. Comparison of the clinical efficacy and safety of retroperitoneal laparoscopic ureterolithotomy and ureteroscopic holmium laser lithotripsy in the treatment of obstructive upper ureteral calculi with concurrent urinary tract infections.

    PubMed

    Jiang, Jun-Tao; Li, Wei-Guo; Zhu, Yi-Ping; Sun, Wen-Lan; Zhao, Wei; Ruan, Yuan; Zhong, Chen; Wood, Kristofer; Wei, Hai-Bin; Xia, Shu-Jie; Sun, Xiao-Wen

    2016-07-01

    The aim of this study is to compare the clinical efficacy and safety of retroperitoneal laparoscopic ureterolithotomy (RPLU) and ureteroscopic holmium laser lithotripsy (UHLL) as two minimally invasive procedures in managing obstructive upper ureteral calculi with concurrent urinary tract infections (UTI). The retrospective study included 189 patients who underwent unilateral obstructive upper ureteral stones with concurrent UTI from January 2007 to November 2014 at our institution. Patients received RPLU (81 cases) or UHLL (108 cases). All patients received preoperative anti-infection treatment (indwelling ureteral stent and/or preoperative antibiotics). Collected data, including sex, age, stone size, success rate, operation duration, post-operation hospitalization time, and post-operation complications, were compared. All patients were followed up for more than 6 months after surgeries, and no ureterostenosis occurred. The study included 189 patients, 41 (21.7 %) females and 148 (78.3 %) males with a medium age of 52 years (range 22-81 years). All surgeries were successfully performed without conversion to open surgery. Stone size in the RPLU group was larger than that of the UHLL group (16.1 ± 1.4 vs. 10.4 ± 1.6 mm, P = 0.012). Operative duration (P = 0.009) and hospitalization time (P < 0.001) in the UHLL group were significantly shorter than those in the RPLU group, whereas stone clearance rate was significantly higher in the RPLU group (100 vs. 88.9 %, P = 0.002). Of note, postoperative fever was more common in patients treated with UHLL (15 cases) versus RPLU (4 cases) (13.9 vs. 4.9 %, P = 0.043). Moreover, in the UHLL group, three patients without a preoperative indwelling ureteral stent were complicated with sepsis, which was not seen in RPLU group. In our study, the safety and stone clearance rate of RPLU are better than those of UHLL in the treatment of unilateral upper ureteric calculi with concurrent UTI

  9. Erythroblast enucleation is a dynein-dependent process.

    PubMed

    Kobayashi, Isuzu; Ubukawa, Kumi; Sugawara, Kotomi; Asanuma, Ken; Guo, Yong-Mei; Yamashita, Junsuke; Takahashi, Naoto; Sawada, Kenichi; Nunomura, Wataru

    2016-04-01

    Mammalian erythroblasts undergo enucleation through a process thought to be similar to cytokinesis. Microtubule-organizing centers (MTOCs) mediate organization of the mitotic spindle apparatus that separates the chromosomes during mitosis and are known to be crucial for proper cytokinesis. However, the role of MTOCs in erythroblast enucleation remains unknown. We therefore investigated the effect of various MTOC inhibitors on cytokinesis and enucleation using human colony-forming units-erythroid (CFU-Es) and mature erythroblasts generated from purified CD34(+) cells. We found that erythro-9-[3-(2-hydroxynonyl)]adenine (EHNA), a dynein inhibitor, and monastrol, a kinesin Eg5 inhibitor, as well as various inhibitors of MTOC regulators, including ON-01910 (Plk-1), MLN8237 (aurora A), hesperadin (aurora B), and LY294002 (PI3K), all inhibited CFU-E cytokinesis. Among these inhibitors, however, only EHNA blocked enucleation. Moreover, terminally differentiated erythroblasts expressed only dynein; little or none of the other tested proteins was detected. Over the course of the terminal differentiation of human erythroblasts, the fraction of cells with nuclei at the cell center declined, whereas the fraction of polarized cells, with nuclei shifted to a position near the plasma membrane, increased. Dynein inhibition impaired nuclear polarization, thereby blocking enucleation. These data indicate that dynein plays an essential role not only in cytokinesis but also in enucleation. We therefore conclude that human erythroblast enucleation is a process largely independent of MTOCs, but dependent on dynein. PMID:26724640

  10. Energy upconversion in holmium doped lead-germano-tellurite glass

    SciTech Connect

    Kamma, Indumathi; Reddy, B. Rami

    2010-06-15

    Holmium doped lead-germano-tellurite glass was prepared by the melt quenching technique. The Judd-Ofelt intensity parameters were estimated as {Omega}{sub 2}=7.6x10{sup -20}, {Omega}{sub 4}=12.9x10{sup -20}, and {Omega}{sub 6}=2.5x10{sup -20} cm{sup 2}. Radiative transition probabilities and lifetimes were also determined for some of the levels. Room temperature upconversion emissions have been observed from Ho{sup 3+} at 497 nm under 532 nm laser excitation, and at 557 and 668 nm under 762 nm laser excitation. The upconversion emission mechanisms were found to be due to a step wise excitation process. Upconversion emission intensity enhanced in a heat treated glass.

  11. Unsuccessful Self-Enucleation in a Schizophrenic Patient

    PubMed Central

    Noy Achiron, Romi; Paul, Michael; Achiron, Asaf

    2014-01-01

    Self-enucleation is a very unusual form of self-mutilation directly linked to mental illness. In this case we present a 26-year-old schizophrenic patient who attempted to enucleate his eye with a rollerball pen. Antipsychotic therapy and emergency surgery saved the patient eye and emphasize the importance of quick response and good collaboration between psychiatric and ophthalmic teams. PMID:25328735

  12. Space-resolved density diagnostic of a highly ionized holmium ([ital Z]=67) laser-produced plasma from 3[ital d][sup 10]4[ital l]-3[ital d][sup 10]4[ital l][prime] Cu I--like lines

    SciTech Connect

    Mandelbaum, P.; Behar, E. ); Seely, J.F.; Feldman, U.; Brown, C.M. ); Hammel, B.A.; Back, C.A.; Lee, R.W.; Kania, D.R. ); Bar-Shalom, A. )

    1994-06-01

    A space-resolved electron density diagnostic of a holmium laser-produced plasma has been performed using the intensity ratios of Cu I--like 3[ital d][sup 10]4[ital l]-3[ital d][sup 10]4[ital l][prime] lines. The atomic theoretical model of the Cu I--like ion included the 3[ital d][sup 10][ital nl] levels with [ital n]=4,5 and [ital l]=[ital s],[ital p],[ital d],[ital f]. The effect of line absorption at high electron densities is discussed and the atomic data obtained with the HULLAC computer code are compared with previously published data.

  13. On-chip enucleation of an oocyte by untethered microrobots

    NASA Astrophysics Data System (ADS)

    Ichikawa, Akihiko; Sakuma, Shinya; Sugita, Masakuni; Shoda, Tatsuro; Tamakoshi, Takahiro; Akagi, Satoshi; Arai, Fumihito

    2014-09-01

    We propose a novel on-chip enucleation of an oocyte with zona pellucida by using a combination of untethered microrobots. To achieve enucleation within the closed space of a microfluidic chip, two microrobots, a microknife and a microgripper were integrated into the microfluidic chip. These microrobots were actuated by an external magnetic force produced by permanent magnets placed on the robotic stage. The tip of the microknife was designed by considering the biological geometric feature of an oocyte, i.e. the oocyte has a polar body in maturation stage II. Moreover, the microknife was fabricated by using grayscale lithography, which allows fabrication of three-dimensional microstructures. The microgripper has a gripping function that is independent of the driving mechanism. On-chip enucleation was demonstrated, and the enucleated oocytes are spherical, indicating that the cell membrane of the oocytes remained intact. To confirm successful enucleation using this method, we investigated the viability of oocytes after enucleation. The results show that the production rate, i.e. the ratio between the number of oocytes that reach the blastocyst stage and the number of bovine oocytes after nucleus transfer, is 100%. The technique will contribute to complex cell manipulation such as cell surgery in lab-on-a-chip devices.

  14. Prostate resection - minimally invasive

    MedlinePlus

    Laser prostatectomy; Transurethral needle ablation; TUNA; Transurethral incision; TUIP; Holmium laser enucleation of the prostate; HoLep; Interstitial laser coagulation; ILC; Photoselective vaporization of the prostate; PVP; Transurethral ...

  15. Spectrum of the holmium atom arising from bombardment of a tantalum surface by holmium ions

    SciTech Connect

    Vasileva, E.K.; Morozov, S.N.

    1986-12-01

    The ion--photon emission spectrum of holmium has been recorded and investigated. It is shown that the appearance of so-called continuous radiation (CR) is due to excitation of the lower triplet system of terms.

  16. Obliterated urethra: holmium:yttrium-aluminum-garnet cut-to-light with urolume stenting.

    PubMed

    Monga, M; Gordon, Z; Alexandrescu, B

    2001-12-01

    Antegrade-retrograde urethrotomy, or the cut-to-light procedure, performed for obliterated urethra is associated with a high rate of recurrence of urethra] stricture. With the goal of reducing the stricture recurrence rate, we performed a modified cut-to-light procedure using a holmium:yttrium-aluminum-garnet laser and UroLume stenting in a 76-year-old man with urethral obliteration. PMID:11763485

  17. New, efficient, room temperature mid-infrared laser at 3.9 mu m in holmium:barium yttrium fluoride and visible praseodymium:lithium yttrium fluoride laser for holography

    NASA Astrophysics Data System (ADS)

    Tabirian, Anna Murazian

    This dissertation describes a series of experiments and theoretical studies, which led to the development of two new solid state laser systems: efficient, room temperature mid-infrared solid state laser at 3.9 μm in Ho 3+ doped BaY2F8 and visible Pr:LiYF4 laser at 640 mn for holography. The 3.9 μm laser wavelength matches the peak of mid-IR atmospheric transmission window, which makes it very important for multiple applications such as remote sensing, imaging, IR countermeasures, eye-safe lidars and environmental agent detection. We present the results of spectroscopic evaluations and numerical modeling of energy transfer processes between rare earth ions of Ho3+ doped in two host laser materials: BaY2F8 and LiYF 4. The 3.9 μm laser is based on transition with upper laser lifetime considerably shorter than lower level lifetime, which in general leads to self-terminating laser action in the cw mode or at high repetition rates. Therefore, three different pumping and lasing schemes, that could allow overcoming these limitations have been suggested and studied. First, cascade laser action at 1.4 μm and 3.9 μm was achieved with low thresholds and near-theoretical quantum efficiency in Ho3+ doped BaY2F8 pumped at 532 nm by a Q- switched frequency doubled Nd:YAG laser. Next, the feasibility of achieving 3.9 μm laser with cw resonant cascade pumping at 750 mn by a Ti:Sapphire laser was studied. New energy transfer process, such as upconversion from terminal level of the 3.9 μm laser was observed in high concentration Ho3+ doped BaY2F 8. Finally, we proposed to use high-energy flashlamp pumped tunable Cr:LiSAF laser operating in long pulse regime for the direct pumping of the upper level of the 3.9 μm laser. Pulsed laser oscillation at 3.9 μm is demonstrated in Ho3+ doped BaY2F8 with low threshold of 3 mJ and a slope efficiency of 14.5% with maximal energy of 30 mJ. The second part of the thesis describes the design and the development of the visible Pr:LiYF4 laser

  18. Management of large prostatic adenoma: Lasers versus bipolar transurethral resection of prostate.

    PubMed

    Gupta, Narmada P; Nayyar, Rishi

    2013-07-01

    Transurethral resection of prostate (TURP) has long been the most commonly performed surgical procedure for the management of benign prostate enlargement (BPE), but has several associated limitations. Over the years, laser techniques have developed as major contenders as alternative therapies for BPE. However, simultaneously, TURP has also flourished and with relatively recent development of resection in saline (bipolar TURP), the tussle between laser techniques and TURP has further gained momentum. A systematic search was performed on Medline using the various Medical subject headings related to the surgical management of BPE including TURP, bipolar, lasers, holmium laser enucleation of prostate (HoLEP), photo-selective vaporization of prostate (PVP), etc., All articles types including meta-analysis randomized controlled trials, review articles, guidelines from various urological associations, single center studies from 2002 onward were considered for review. Bipolar TURP, HoLEP, and PVP provide equivalent outcomes for large prostate adenoma (<60 g). For extremely large glands (<150 g), HoLEP is a very efficacious endoscopic alternative to open prostatectomy and has proven long-term results over more than a decade. Bipolar TURP and PVP are attractive with a minimal learning curves and equivalent short term durability. Surgical management of large prostate should be individualized based upon patient's comorbidities and surgeon's expertise. PMID:24082445

  19. Management of large prostatic adenoma: Lasers versus bipolar transurethral resection of prostate

    PubMed Central

    Gupta, Narmada P; Nayyar, Rishi

    2013-01-01

    Transurethral resection of prostate (TURP) has long been the most commonly performed surgical procedure for the management of benign prostate enlargement (BPE), but has several associated limitations. Over the years, laser techniques have developed as major contenders as alternative therapies for BPE. However, simultaneously, TURP has also flourished and with relatively recent development of resection in saline (bipolar TURP), the tussle between laser techniques and TURP has further gained momentum. A systematic search was performed on Medline using the various Medical subject headings related to the surgical management of BPE including TURP, bipolar, lasers, holmium laser enucleation of prostate (HoLEP), photo-selective vaporization of prostate (PVP), etc., All articles types including meta-analysis randomized controlled trials, review articles, guidelines from various urological associations, single center studies from 2002 onward were considered for review. Bipolar TURP, HoLEP, and PVP provide equivalent outcomes for large prostate adenoma (<60 g). For extremely large glands (<150 g), HoLEP is a very efficacious endoscopic alternative to open prostatectomy and has proven long-term results over more than a decade. Bipolar TURP and PVP are attractive with a minimal learning curves and equivalent short term durability. Surgical management of large prostate should be individualized based upon patient's comorbidities and surgeon's expertise. PMID:24082445

  20. Risk factors for endophthalmitis requiring evisceration or enucleation

    PubMed Central

    Lu, Xuehui; Ng, Danny Siu-Chun; Zheng, Kangkeng; Peng, Kun; Jin, Chuang; Xia, Honghe; Chen, Weiqi; Chen, Haoyu

    2016-01-01

    Endophthalmitis has devastating sequelae resulting in blindness and even loss of eyeball. Although the prognosis of endophthalmitis has much improved with the advances of antibiotics and vitreoretinal surgery, of the number of patients that required evisceration or enucleation is still significant. We retrospectively reviewed the charts of 210 eyes of 210 patients with endophthalmitis andcompared the group that required evisceration or enucleation with those that received salvaging therapies. Regression analysis was used to identify the risk factors for evisceration or enucleation. Thirty eyes (14.3%) underwent enucleation or evisceration. The group of eviscerated or enucleated eyes were older (58.7 vs. 42.2 years, p < 0.001), had more women (56.7% vs. 22.2%, p = 0.003), had poorer initial visual acuity (2.79 vs. 2.10 LogMAR, p < 0.001), and had longer duration before intervention (18.03 vs. 5.74 days, p = 0.031). The most common primary indications for endophthalmitis were infections from corneal ulcer (50.0% vs. 4.4%, p < 0.001) andfrom endogenous source (23.3% vs. 5.6%, p < 0.001). Less common indications were trauma (26.7% vs. 67.8%, p < 0.001) and postoperative (6.7% vs. 22.2%, p = 0.049) endophthalmitis. After adjusting for confounding factors, corneal ulcer-related endophthalmitis, endogenous endophthalmitis and initial visual acuity were the independent risk factors for evisceration or enucleation. PMID:27302573

  1. Psychological Reactions and Persistent Facial Pain following Enucleation

    PubMed Central

    2014-01-01

    Background. Enucleation is a psychologically and physically traumatic event associated with chronic pain. It would be desirable to better predict which patients will have pain after surgery. Methods. A cross-sectional postal questionnaire study of adults undergoing enucleation captured the demographic details, Pain Quality Assessment Scale (PQAS), Pain Catastrophizing Scale (PCS), and the Facial Pain Assessment questionnaire. Patients were classified as suffering from chronic pain if they reported a pain score of >1 out of 10 on the numerical pain score (NRS). Results. Seventeen of 60 adults participated in the study. 47% of patients reported chronic pain (mean pain score = 1.4 ± 0.7, n = 17); 25% experienced pain daily. No difference in age, surgical side, reason for surgery, or the duration of time since the surgery was noted. All patients had low PQAS scores and 50% of individuals with persistent pain were concerned about their facial appearance. There was no significant difference in the level of catastrophization noted in patients with or without pain or between the subgroups (rumination, magnification, or helplessness). Conclusions. Although persistent pain following enucleation affected a significant number of patients, the pain intensity was mild. Enucleation influenced the physical perception some individuals had of themselves. PMID:24864208

  2. The risk of enucleation after proton beam irradiation of uveal melanoma

    SciTech Connect

    Egan, K.M.; Gragoudas, E.S.; Seddon, J.M.; Glynn, R.J.; Munzenreider, J.E.; Goitein, M.; Verhey, L.; Urie, M.; Koehler, A. )

    1989-09-01

    Enucleation after proton beam irradiation of uveal melanomas occurred in 64 (6.4%) of 994 eyes with a median follow-up time of 2.7 years. The median time between irradiation and enucleation in the 64 enucleated eyes was 13 months. The probability of retaining the eye was 95 and 90%, 2 and 5 years postirradiation, respectively. Three percent of eyes were enucleated during posttreatment year 1, and the yearly rate was 1% by the fourth year. No patient had enucleation later than 5 1/2 years posttreatment. The complication most likely to result in enucleation was neovascular glaucoma although this was frequently managed without enucleation. Other common reasons for enucleation were documented or suspected tumor growth and complete retinal detachment with associated loss of vision. The leading risk factors for enucleation were anterior tumor margin involving the ciliary body, tumor height greater than 8 mm, and proximity of the tumor to the fovea. Based on the presence or absence of these factors, 5-year eye retention rates were 99, 92, and 76% for low-, moderate-, and high-risk groups, respectively. Thus, the probability of eye retention after proton beam irradiation is high even among those at greatest risk of enucleation.

  3. Sequential transurethral enucleation of the prostate and laparoscopic bladder diverticulectomy.

    PubMed

    Yu, Yang; Guan, Sheng; Shen, Chen; Yang, Bo

    2016-08-01

    Transurethral endoscopic technique and standard laparoscopic technique are surgical options for the management of benign prostatic hyperplasia (BPH) associated with urinary bladder diverticuli (UBD). In this article, we report laparoscopic diverticulectomy (LD) and transurethral plasmakinetic enucleation of the prostate (TUEP) in the same patient sequentially. To the best of our knowledge, this is the first case report of LD combined with TUEP. An 82-year-old patient with benign prostatic hyperplasia and two secondary large bladder diverticuli underwent sequential TUEP and LD. After completion of the TUEP procedure, the detached adenoma was pushed into the bladder as a whole. Then laparoscopic transperitoneal extravesical diverticulectomy assisted by cystoscopic transillumination was performed immediately, and the enucleated prostate was removed via the neck of the diverticulum. The enucleation time and diverticulectomy time was 18 minutes and 108 minutes, respectively. The catheter was removed on the tenth postoperative day. Transurethral endoscopic surgery combined with LD is a good choice in treating BPH and UBD in one session. But the combined procedure is time-consuming, especially for fragmentation of the prostate. TUEP can greatly reduce the operative time of the combined procedure. PMID:27249185

  4. Cobalt-60 plaque radiotherapy vs enucleation for posterior uveal melanoma

    SciTech Connect

    Augsburger, J.J.; Gamel, J.W.; Lauritzen, K.; Brady, L.W. )

    1990-05-15

    We compared the survival of 302 patients with a primary choroidal or ciliary body melanoma treated by cobalt-60 plaque radiotherapy between 1976 and 1982 with the survival of 134 patients treated by enucleation during the same period. Tumor size, location of the anterior margin of the tumor, and patient age at the time of treatment were identified as simultaneous significant clinical variables for predicting melanoma-specific mortality by multivariate Cox proportional hazards modeling. We computed a prognostic index for each patient based on this model and found that patients in the enucleation group had slightly higher values of this index than did patients in the cobalt-60 plaque radiotherapy group. Risk ratios for the treatment effect computed from a Cox model incorporating prognostic index and the treatment variable were found to be approximately equal to 1, both for analysis of melanoma-specific mortality and total mortality. These results indicate that when one controls for differences in prognostic index between the groups, cobalt-60 plaque therapy and enucleation are essentially equivalent in their effect on survival.

  5. Phylogenic insights into the enucleation of erythroblasts in human.

    PubMed

    Nunomura, Wataru

    2016-07-01

    Two key questions remain unanswered in the erythropoiesis field: Why and how do erythroblasts enucleate in mammalian species? Recent studies have unveiled the roles of various molecules, cytoskeletal proteins, motor proteins, vesicle transport, signaling pathways, lipid rafts and actomyosin ring contraction in the enucleation process. However, few reports provide insights into the fitness benefit for mammalian species of having anucleate erythrocytes. Herein, we discuss the biological significance of enucleation of human erythroblasts based on our recent results and on evolutionary considerations related to the biology of hemoglobin and the comparative biochemistry of erythrocyte membrane cytoskeletal proteins, such as protein 4.1R. We specifically focus on the Mesozoic era, a geological period during which dinosaurs and the ancestors of mammalian species coexisted. Approximately 200 million years ago, at the beginning of this era, the earth's atmosphere was hypoxic. Interestingly, animals adopted different respiration systems to adapt to this hypoxic environment. Recent studies using state-of-the-art technologies have shown that dinosaurs might have had nucleated erythrocytes. After dinosaurs became extinct about 65.5 million years ago, their respiration system was maintained by birds. We propose a new adaptive theory that establishes a correlation between evolution towards nucleated or anucleate erythrocytes depending on organism respiration systems during the Mesozoic era. PMID:27498741

  6. Enucleation: a possible mechanism of cancer cell death

    PubMed Central

    Paunescu, Virgil; Bojin, Florina M; Gavriliuc, Oana I; Taculescu, Elena A; Ianos, Robert; Ordodi, Valentin L; Iman, Vlad F; Tatu, Calin A

    2014-01-01

    There are few major morphologies of cell death that have been described so far: apoptosis (type I), cell death associated with autophagy (type II), necrosis (type III) and anchorage-dependent mechanisms—anoikis. Here, we show for the first time a possibly novel mechanism inducing tumour cell death under in vitro conditions—enucleation. We pursued the influence of colloidal suspensions of Fe3O4 nanoparticles on tumour cell lines (SK-BR-3 and MCF-7 breast cancer cell lines) grown according to standard cell culture protocols. Magnetite nanoparticles were prepared by combustion synthesis and double layer coated with oleic acid. Scanning and transmission electron microscopy revealed that tumour cells developed a network of intracytoplasmic stress fibres, which induce extrusion of nuclei, and enucleated cells die. Normal adult mesenchymal stem cells, used as control, did not exhibit the same behaviour. Intact nuclei were found in culture supernatant of tumour cells, and were visualized by immunofluorescence. Enucleation as a potential mechanism of tumour cell death might open new horizons in cancer biology research and development of therapeutic agents capable of exploiting this behaviour. PMID:24629135

  7. Self-enucleation: forget Freud and Oedipus, it's all about untreated psychosis.

    PubMed

    Large, Matthew Michael; Nielssen, Olav B

    2012-08-01

    Self-enucleation is a rare but serious ophthalmological and psychiatric emergency. It has traditionally been considered to be the result of psycho-sexual conflicts, including those arising from Freud's Oedipal complex and Christian religious teaching. However, an analysis of published case reports suggests that self-enucleation is a result of psychotic illnesses such as schizophrenia. Early treatment with antipsychotic medication in the case of unilateral or threatened self-enucleation might prevent some cases of blindness. PMID:22373824

  8. Histologic comparison of needle, holmium:YAG, and erbium:YAG endoscopic goniotomy

    NASA Astrophysics Data System (ADS)

    Joos, Karen M.; Shen, Jin-Hui; Rivera, Brian K.; Hernandez, Eleut; Shetlar, Debra J.

    1995-05-01

    An endoscope allows visualization of the anterior chamber angle in porcine eyes despite the presence of cloudy corneas. The pectinate ligaments in the anterior chamber angle are a surgical model for primary infantile glaucoma. This study investigated the histologic results, one month after treating the anterior chamber angle with a goniotomy needle, the holmium:YAG laser, or the erbium:YAG laser coupled to a small endoscope. The anterior chambers were deepened with a viscoelastic material in one-month-old anesthetized pigs. An Olympus 0.8 mm diameter flexible endoscope was externally coupled to a 23 gauge needle or a 300 micron diameter fiber. The angle was treated for 120 degrees by one of the three methods, and the probe was removed. During the acute study, all three methods cut the pectinate ligaments. The histologic findings one month after healing demonstrated minimal surrounding tissue damage following goniotomy with a needle and the most surrounding tissue damage following treatment with the holmium:YAG laser.

  9. The laser in urology

    NASA Astrophysics Data System (ADS)

    Hofstetter, Alfons G.

    2002-10-01

    Laser is an acronym for a physical principle and means: Light Amplification by stimulated Emission of Radiation. This principle offers a lot of tissue/light effects caused by the parameters: power density/time and the special qualities of the laser light. Nowadays for diagnosis and therapy following lasers are used in urology: Krypton- and Dye-lasers as well as the Neodymium-YAG- (nd:YAG-), Holmium-YAG (Ho:YAG-), Diode-, Argon- and the CO2-lasers.

  10. Soliton Thulium-Doped Fiber Laser With Carbon Nanotube Saturable Absorber.

    PubMed

    Kieu, K; Wise, F W

    2009-02-01

    We report stabilization of a thulium-holmium codoped fiber soliton laser with a saturable absorber based on carbon nanotubes. The laser generates transform-limited 750-fs pulses with 0.5-nJ energy. PMID:21731403