Endometrial laser ablation in rabbits: a comparative study of three laser types

Endometrial laser ablation is one of the alternatives to hysterectomy in cases of intractable uterine bleeding. It is currently performed using the Nd:YAG laser at 1.06 microns. The aim of this study was to compare the tissue effect of three types of laser irradiation (Nd:YAG laser at 1.06 and 1.32 microns and holmium laser at 2.12 microns) on the rabbit endometrium. Crater formation, coagulation necrosis, and muscle necrosis were evaluated at the time of ablation, as well as at 1 week and 4 weeks postablation. The results were assessed by determining the depth and width of the affected portion in the uterine wall (lumen to serosa). It was shown that Nd:YAG laser at 1.32 microns caused more generalized and extended effects as compared with the other laser types examined. Endometrial regeneration was faster after ablation by the Nd:YAG laser at 1.06 microns and the holmium laser than by the Nd:YAG laser at 1.32 microns. The widest range of "ablation energy" (defined as that causing ablation without muscle damage) was achieved by applying the holmium laser. Further evaluation of the holmium laser for this indication is recommended.     

980 nm半导体激光与钬激光在中央气道消融治疗中的临床效果

目的：比较980 nm半导体激光与钬激光在中央气道内消融治疗中的应用效果。方法：连续选取2020年9月1日—2022年9月30日在天津市南开医院胸外科行气道内激光消融的58例患者，随机均分为两组，分别使用980 nm半导体激光与钬激光进行消融治疗，比较两组在烟雾大小、视野亮度可见、出血情况、止血效果、术后创面肉芽增生、消融时间及安全性方面的差异。结果：980 nm半导体激光组视野亮度对治疗操作影响较大（P <0.01），两组在烟雾大小（P=0.81）、出血（P=0.46）、止血效果（P=0.41）、术后创面肉芽增生（P=1.00）、消融时间（P=0.621）及安全性方面无显著差异。结论：980 nm半导体激光与钬激光具有相似的治疗效果，并具有体积小、经济性好、不受电源限制的优点，可作为钬激光的替代选择。     

The Holmium Laser for the Treatment of Benign Prostatic Hyperplasia: A Brief Review

At a wavelength of 2140 nm, the holmium:YAG (Ho:YAG) laser can be used for incision, ablation and resection of prostatic tissue. This laser has revolutionised the surgical management of benign prostatic hyperplasia (BPH) in our institution. Five different techniques have been utilised in evolving the current techniques using the Ho:YAG laser either alone or in combination with neodymium:YAG (Nd:YAG laser for the surgical management of BPH. The clinical outcome of 664 patients undergoing these procedures is presented. Enucleation of the prostatic adenoma using the holmium laser energy is the most common procedure presently performed at our institution for the surgical management of BPH. A mechanical tissue morcellator appears to be the most efficient way to remove prostatic tissue, once enucleated, from within the bladder. Paper received 24 February 1998; accepted after revision 30 June 1998.     

Holmium laser for benign prostatic hyperplasia

PURPOSE OF REVIEW: The following review provides an overview of the current status, while focusing on the surgical techniques associated with the holmium laser for the treatment of benign prostatic hyperplasia. RECENT FINDINGS: A systematic Medline database search, with a focus on articles about surgical treatment with holmium laser for benign prostatic hyperplasia, provided some new data concerning holmium laser enucleation of the prostate. On the other hand, new interesting data concerning both resection and ablation techniques using the holmium laser have only been sparsely reported during this review period. SUMMARY: Holmium laser enucleation of the prostate is a safe procedure for treating not only patients without co-morbidities but also patients with urinary retention or who are on anticoagulants. Holmium laser enucleation of the prostate can be performed on prostates of all sizes with significantly less morbidity. Although holmium laser enucleation of the prostate represents a state-of-the-art procedure, a prolonged learning curve has still prevented the widespread adoption of this device in the urological community.     

Reflectance during pulsed holmium laser irradiation of tissue

Although generally ignored in considerations of laser ablation of tissue, reflectance of laser light from tissue during laser-induced ablation is a potentially important factor in determining ablation efficiency because it determines the amount of laser light coupled into the target. To determine the significance of reflectance changes induced by laser irradiation, we examined the reflectance of liver samples during pulsed holmium laser ablation by placing the target at one focus of an ellipsoidal reflector and a detector at the other focus. The temporal behavior, total reflectance, and effect of multiple pulses were examined. Tissue reflectance as large as 50% was observed during holmium laser irradiation but depended upon laser radiant exposure and number of laser pulses. These measurements suggest that changes in the optical properties of the target during ablation are important and should be considered in detailed modeling of the ablation process.     

Design and evaluation of a fiberoptic fluorescence guided laser recanalization system

Current angioplasty techniques for recanalization of totally occluded arteries are limited by the inability to cross the occlusion and by the risk of perforation. A fiberoptic fluorescence guided laser recanalization system was developed and evaluated in vitro for recanalization of 17 human femoral or tibial totally occluded arterial segments (length 1.9-6.8 cm, diameter 2.5-6.0 mm). A 400 or 600 micron silica fiber was coupled to a helium-cadmium laser (lambda = 325 nm) for fluorescence excitation and to a holmium: YAG laser (lambda = 2.1 micron) for tissue ablation. Fluorescence was recorded during recanalization after every other holmium laser pulse. During recanalization, each arterial segment was bent 30-90 degrees with respect to the fiber to simulate arterial tortuosity. Ablation continued with fiber advancement as long as the fluorescence confirmed that the target tissue was atherosclerotic. Arterial spectra were classified as normal or atherosclerotic by an on-line computerized fluorescence classification algorithm (sensitivity 93%, specificity 95%). Normal fluorescence necessitated redirection of the fiber greater than 30 times per segment to continue recanalization. Fifteen of 17 totally occluded arteries had multiple recanalization channels created following total energy delivery of 40-1,016 Joules per segment with no angiographic or histologic evidence of laser perforation. Two heavily calcified arterial occlusions were not recanalized due to inhibition of holmium: YAG laser ablation by the recording of normal fluorescence spectra. Therefore, this fluorescence guided laser recanalization system appears safe and effective for recanalization of totally occluded arteries and merits in vivo evaluation. However, the lower sensitivity of fluorescence detection of heavily calcified plaques may limit the efficacy (but not safety) of fluorescence guided recanalization of heavily calcified occlusions.     

In vitro comparison of stone retropulsion and fragmentation of the frequency doubled, double pulse nd:yag laser and the holmium:yag laser

PURPOSE: The frequency doubled, double pulse Nd:YAG (FREDDY) laser (World of Medicine, Berlin, Germany) functions through the generation of a plasma bubble. Upon bubble collapse a mechanical shock wave is generated, causing stone fragmentation. This mechanism of action is in contrast to the holmium laser, which cause stone destruction by vaporization. Observed clinical stone retropulsion and fragmentation with the FREDDY and holmium lasers has prompted a series of in vitro experiments designed to compare laser induced retropulsion and fragmentation with those of a holmium laser and pneumatic lithotrite. MATERIALS AND METHODS: For retropulsion a hands-off underwater laboratory setup, including a horizontally oriented silicone tube 1.3 cm in diameter and a holder to keep the stone phantom in contact with the quartz laser fiber or pneumatic probe, was used. Previously weighed, cylindrical Bego stone phantoms (Bego USA, Smithfield, Rhode Island) were placed in the apparatus. Stone fragmentation was performed with the FREDDY or holmium laser, or the pneumatic lithotripter. The FREDDY and holmium lasers were tested at similar pulse energy and frequency settings. As a standard for comparison, a pneumatic lithotrite was tested with a semirigid probe and single pulse settings of 100, 200 and 300 kPa. Stone phantoms underwent 30 shocks per setting. Mean net retropulsion, defined as the final resting point of the stone, as determined by direct measurement, was recorded for each setting. For fragmentation plaster of Paris stone phantoms of known weights were used to compare the fragmentation ability of each laser. Stones phantoms were placed in a hands-off underwater setup, consisting of an inverted silicon syringe and holder immersed in tap water. The laser fiber (365 microm for the holmium and 280 microm for the FREDDY) was placed through the tip of the syringe in contact with the stone phantom. A total of 24 stones were divided into 4 groups of 6 per group. Two groups were fragmented with the FREDDY laser at 300 and 400 J total energy. The other 2 groups were fragmented using the holmium laser at 300 and 480 J total energy. Fragmentation efficiency was determined as percent weight loss. RESULTS: For retropulsion at 160 mJ the FREDDY laser caused stone retropulsion to a mean distance of 7.6, 8.1 and 6.8 cm at settings of 5, 10 and 15 Hz, respectively. At 0.8 J the holmium laser retropulsed the stone to a mean distance of 3.3 and 4.9 cm at settings of 5 and 10 Hz, respectively. The pneumatic device caused stone retropulsion a mean distance of 8.5, 9.9 and 13.8 cm at pressure settings of 100, 200 and 300 kPa, respectively. The FREDDY laser generally caused less retropulsion than the pneumatic device, although this difference was only significant at the highest pneumatic lithoclast setting (p <0.05). At clinically relevant settings the FREDDY laser caused significantly more retropulsion than the holmium laser (p <0.05). For fragmentation at total energy settings of 300 and 400 J the FREDDY laser resulted in 44.9% and 86.8% weight loss, respectively (p <0.05). At settings of 300 and 480 J the holmium:YAG laser resulted in 3.3% and 7.1% weight loss, respectively (p <0.05). CONCLUSIONS: At lower frequency settings stone retropulsion was significantly greater with the FREDDY laser compared with the holmium laser. However, retropulsion was significantly less than that caused by the pneumatic lithotripter at all settings. Therefore, we recommend the use of an occlusive device, such as the Stone Cone (Boston Scientific, Natick, Massachusetts) proximal to the calculus during intracorporeal ureteral lithotripsy and in the ureteropelvic junction during percutaneous laser nephrostolithotomy. In vitro stone fragmentation was significantly greater with the FREDDY laser than with the holmium:YAG laser, suggesting that the FREDDY may offer a low cost alternative to the holmium:YAG laser lithotrite in select patients.     

Efficacy of percutaneous treatment of biliary tract calculi using the holmium:YAG laser

Background Few Western studies have focused on percutaneous techniques using percutaneous transhepatic choledochoscopy (PTHC) and holmium:yttrium–aluminum–garnet (YAG) laser to ablate biliary calculi in patients unable or unwilling to undergo endoscopic or surgical removal of the calculi. The authors report the efficacy of the holmium:YAG laser in clearing complex biliary calculi using percutaneous access techniques. Methods This study retrospectively reviewed 13 non-Asian patients with complex secondary biliary calculi treated percutaneously using holmium:YAG laser. Percutaneous access was accomplished via left, right, or bilateral hepatic ducts and upsized for passage of a 7-Fr video choledochoscope. Lithotripsy was performed under choledochoscopic vision using a holmium:YAG laser with 200- or 365-μm fibers generating 0.6 to 1.0 joules at 8 to 15 Hz. Patients underwent treatment until stone clearance was confirmed by PTHC. Downsizing and subsequent removal of percutaneous catheters completed the treatment course. Results Seven men and six women with an average age of 69 years underwent treatment. All the patients had their biliary tract stones cleared successfully. Of the 13 patients, 3 were treated solely as outpatients. The average length of percutaneous access was 108 days. At this writing, one patient still has a catheter in place. The average number of holmium:YAG laser treatments required for stone clearance was 1.6, with no patients requiring more than 3 treatments. Of the 13 patients, 8 underwent a single holmium:YAG laser treatment to clear their calculi. Prior unsuccessful attempts at endoscopic removal of the calculi had been experienced by 7 of the 13 patients. Five patients underwent percutaneous access and subsequent stone removal as their sole therapy for biliary stones. Five patients were cleared of their calculi after percutaneous laser ablation of large stones and percutaneous basket retrieval of the remaining stone fragments. There was one complication of pain requiring admission, and no deaths. Conclusions The use of PTHC with holmium:YAG laser ablation is safe and efficacious, but requires prolonged biliary access and often multiple procedures to ensure clearance of all calculi.     

Holmium laser incision technique for ureteral stricture using a small-caliber ureteroscope.

BACKGROUND AND OBJECTIVES: The holmium laser has a short absorption depth in tissue and possesses excellent properties both in ablation and hemostasis. We have performed endoscopic incision for ureteral stricture using the holmium laser through a small-caliber ureteroscope. METHODS: This method was used on five patients and seven ureters. The etiology of the stricture was stone scar in two patients, ureteroenteroanastomosis of Indiana urinary pouch in two, and primary in one. We used an 8F semi-rigid or 6.9F flexible ureteroscope. No prior procedures, such as balloon dilation, were necessary in any of the cases. The stricture was incised with the holmium laser using a 365-microm fiber through the working channel of the ureteroscope. The holmium laser operated at a wavelength of 2100 nm, with an output of 1.0 J/pulse at a rate of 10 Hz. After completion of the incision, a 12F Double-J catheter was left in for six weeks. RESULTS: The mean operative time was 89 minutes. The stricture resolved completely in all cases at an average follow-up of 8.6 months. CONCLUSIONS: The holmium laser incision for ureteral stricture using a small-caliber ureteroscope is an easy-to-perform, safe and effective procedure.     

Laser prostatic surgery: An update

This review presents an overview of the current state of the art of laser prostatic surgery. Several types of lasers have been used in the treatment of benign prostatic hyperplasia (BPH) over the past 15 years. Vaporization techniques have recently gained popularity and have been widely accepted by many urologists. Short-term results show that vaporization of a prostatic adenoma with higher-power potassium titanyl phosphate and holmium lasers is safe and effective in the treatment of symptomatic BPH. However, well designed randomized comparative trials with long-term follow-up are still needed. Holmium laser is a multi-purpose surgical tool and has multiple applications in urology. In the treatment of symptomatic BPH, holmium laser can be used in ablation, resection and enucleation of the prostate. Holmium laser enucleation of the prostate (HoLEP) is the most investigated laser procedure used in the treatment of symptomatic BPH. Several randomized controlled trails confirmed the safety, efficacy, and durability of HoLEP regardless of the prostate size.     

High-powered holmium-laser ablation: comparison of setting effectiveness using tissue-surrogate model

BACKGROUND AND PURPOSE: The 100-W holmium laser, in conjunction with a sidefiring 550-microm fiber, can ablate prostate glands as large as 40 g to relieve lower urinary-tract symptoms. We evaluated the effect of various setting combinations on ablation efficiency using beef kidney as a tissue-surrogate model. MATERIALS AND METHODS: Beef kidney specimens (mean weight 44.8 +/- 3.1 g) were secured in a cylinder, which was submerged in a water-filled tank through which a 27F resectoscope and 550-microm sidefiring fiber were positioned. Four energy/frequency combinations were tested, with each used to treat 10 kidney specimens. The difference between the mean pretreatment and post-treatment weights of each treatment group were compared statistically with Student's t-test. RESULTS: The largest mean weight difference after treatment (8.94 +/- 2.38 g) was achieved using 3.2 J and 25 Hz. This mass reduction was significantly greater than that of all other combinations except 2.5 J and 40 Hz. CONCLUSIONS: Use of the 3.2 J and 25 Hz setting combination resulted in the greatest amount of ablation in this tissue-surrogate model, suggesting that maximal energy settings may provide an advantage in tissue vaporization using the 100-W holmium laser. Clinical assessment must be performed to substantiate these findings.     

Low-power holmium laser for the management of urinary tract calculi, structures, and tumors

BACKGROUND AND PURPOSE: Introduction of the holmium laser has provided an indispensable tool for the management of urinary tract stones, strictures, and superficial urothelial tumors. While full-power holmium lasers are required for laser resection of the prostate, lower-power devices can be utilized for all cases of stone fragmentation and stricture incision and most cases of superficial urothelial tumors. Herein, we report our initial experience in utilizing a low-power holmium laser in our endourologic practice. PATIENTS AND METHODS: Over a 6-month period, we have utilized both low-power (25 W) and full-power (80 W) holmium lasers to fragment urinary tract stones, incise ureteral or urethral strictures, and ablate superficial urothelial tumors. A series of 80 consecutive patients were assessed prospectively. Laser fibers with a diameter of 200 microm and 365 microm were employed with power settings of 6.4 to 10 W. Laser fiber size and power settings were similar for the low- and full-power devices. RESULTS: Overall, 95% of the stones were completely fragmented, with a stone-free rate at 3 months of 92%. All strictures were incised, with a 91% patency rate at 3 months. Complete tumor ablation was attained in 70%, with a tumor-free rate of 60% at 3 months. Results were equivalent for the low- and full-power lasers. The 200-microm laser fiber allowed adequate access throughout the upper urinary tract during flexible ureteroscopy and flexible nephroscopy. The 365-microm laser fiber was employed via rigid and semirigid endoscopes. CONCLUSIONS: A low-power holmium laser supplies adequate fragmentation and incision power for virtually all endourologic cases. It also provides ablative power in most situations. The only current urologic application that cannot be performed with the low-power device is laser prostatic resection, which requires 60 to 80 W of power. The reduced-power holmium laser should be considered as a low-cost alternative for the management of urinary tract stones, strictures, and urothelial tumors, especially in centers where laser prostatic resection is not performed.     

The effect of frequency doubled double pulse Nd:YAG laser fiber proximity to the target stone on transient cavitation and acoustic emission

PURPOSE: Scant information has been published describing the effect of laser fiber distance from the stone target on the mechanism of calculus fragmentation. Using high speed photography and acoustic emission measurements we characterized the impact of laser fiber proximity on stone comminution. We evaluated the effect of laser fiber distance from the stone target on resultant cavitation bubble formation and shock wave generation. MATERIALS AND METHODS: Stone fragmentation was assessed using a FREDDY (frequency doubled double pulse Nd:YAG) (World of Medicine, Orlando, Florida) laser and a holmium laser. The FREDDY laser was operated using a 420 microm fiber at an output energy of 120 and 160 mJ in single and double pulse settings, and a pulse repetition rate of 1 Hz. The holmium laser was operated using a 200 microm fiber at an output energy of 1 to 3 J and a pulse repetition rate of 1 Hz. The surface of a 1 cm square BegoStone (Bego, Bremen, Germany) attached to an X-Y-Z translational stage was aligned perpendicular to the laser fiber, which was immersed in a Lucite tank filled with water at room temperature. An Imacon 200 high speed camera was used to capture transient cavitation bubbles at a framing rate of up to 1,000,000 frames per second. Acoustic emission signals associated with shock waves generated during the rapid expansion and collapse of the cavitation bubble were measured using a 1 MHz focused ultrasound transducer. RESULTS: At laser fiber distances of 3.0 mm or less cavitation bubbles and shock waves were observed with the FREDDY laser. In contrast to the holmium laser, the bubble size and shock wave intensity of the FREDDY laser was inversely related to the fiber-to-stone distance over the range tested (0.5 to 3.0 mm). CONCLUSIONS: While bubble size was noted to increase with a larger stone-to-fiber distance using the holmium laser, to consistently generate cavitation bubbles and shock waves using the FREDDY laser the laser fiber should be operated within 3.0 mm of the target stone. These findings have significant implications during clinical laser stone fragmentation.     

两种不同能量钬激光在治疗输尿管上段结石中的临床效果对比

目的：探讨两种不同能量钬激光在治疗输尿管上段结石中的临床效果。方法：本研究于2010年1月~2012年5月分别采用60瓦钬激光和40瓦钬激光碎石术治疗输尿管上段结石,并比较两种不同能量钬激光碎石术在治疗输尿管上段结石的临床疗效。结果：40瓦钬激光组患者的结石清除率明显高于60瓦钬激光组,且差异具有统计学意义（x2 =5.24,P<0.05）。而两组患者的手术时间及平均住院时间比较则无明显差异（t=0.76、0.65,P>0.05）。结论：对于输尿管上段结石,使用经皮肾镜碎石术治疗时,使用能量较小的激光,碎石成功率更高,可以有效提高碎石率,减少患者术后再次处理的风险。     

Fragmentation of uric acid calculi with the holmium: YAG laser produces cyanide

BACKGROUND AND OBJECTIVES: To independently test previously reported findings of cyanide evolution under holmium:yttrium aluminum garnet (Ho:YAG) (holmium) lithotripsy of uric acid calculi, determine if this occurs with other forms of intracorporeal lithotripsy, and establish if this occurs due to a photothermal, photochemical, or photoacoustic reaction. STUDY DESIGN/MATERIALS AND METHODS: Human uric acid calculi were fragmented in vitro through exposure to holmium, ultrasound, and electrohydraulic (EHL) energy sources. The following parameters were varied: total laser energy, individual laser pulse energy, ultrasonic energies, and EHL energies. Uric acid powder was suspended in solution and exposed to holmium laser energy in vitro. Serum and irrigant samples from a human patient were collected following intrarenal holmium lithotripsy of a uric acid calculus. All samples were analyzed for hydrogen cyanide (HCN) content. RESULTS: Holmium lithotripsy of solid uric acid calculi produces cyanide. The yield is linearly dependent upon total laser energy delivered. Pulse energy does not affect cyanide yield. Photothermal mechanisms coupling laser energy to the solid crystal lattice are responsible for the production of cyanide. Ultrasound and EHL lithotripsy do not produce cyanide. A clinically insignificant level of cyanide was detected in the blood of a single patient following laser lithotripsy of a uric acid calculus. CONCLUSIONS: Our study confirms that cyanide is produced by a photothermal mechanism during holmium laser lithotripsy of uric acid calculi, and that the amount produced is clinically insignificant.     

Free-beam and contact laser soft-tissue ablation in urology

The ablation of tissue by laser has several applications in urology. Most of the published research has been concerned with the treatment of benign prostatic hyperplasia (BPH). Other applications studied include superficial upper- and lower-tract transitional-cell carcinoma, urethral and ureteral strictures, ureteropelvic junction stenosis, and posterior urethral valves. The attraction of laser ablation for the treatment of BPH lies with the decreased morbidity in comparison with standard transurethral electrocautery resection of the prostate and the ability to remove tissue immediately and therefore allow a more rapid progression to catheter removal and early voiding. The three main laser wavelengths used in urology for tissue ablation are the neodymium:yttrium-aluminum-garnet when used with contact tips or high-density power settings, the potassium-titanyl-phosphate, and the holmium:YAG. This article reviews the published literature on the use of these laser wavelengths in soft-tissue ablation, focusing on the treatment of BPH.     

Intracorporeal Lithotripsy With the Holmium:YAG Laser

Purpose

Preliminary evaluations of the holmium:YAG laser have demonstrated a variety of potential urological applications, including ablation of soft tissue lesions as well as stone fragmentation. We present our experience with the holmium:YAG laser for intracorporeal lithotripsy of urinary calculi.

Materials and Methods

During a 24-month period 75 patients underwent 79 laser procedures, including retrograde ureteroscopy for ureteral calculi (71) and fragmentation of caliceal stones remote from the nephrostomy tract during percutaneous nephrolithotripsy (8).

Results

Complete stone fragmentation without need for additional procedures or lithotripsy was achieved in 85 percent of the cases. Treatment failures included 1 case of stone migration, 7 incomplete fragmentation requiring other lithotripsy devices and 3 laser malfunction. One ureteral perforation occurred when the laser was activated without direct visual guidance.

Conclusions

The holmium: YAG laser has demonstrated its efficacy as a method of intracorporeal lithotripsy. Advantages include ability to fragment stones of all composition, and the multipurpose, multispecialty applications of the holmium wavelength. This laser has potential soft tissue effects, and careful attention to technique during lithotripsy is required to avoid ureteral wall injury.     

Measurement of Acoustic Transients During Pulsed Holmium:YAG Laser Ablation of Cadaveric Human Temporal Bone

Pulsed infrared (IR) and ultraviolet (UV) lasers have been suggested for use in middle ear surgery due to potential fiberoptic delivery, decreased thermal trauma and precise ablation characteristics. Although attention has been focused on the thermal and photoacoustic events that occur during pulsed laser ablation of hard tissue, there are few studies which evaluate the acoustic energy generated from these devices from an audiological standpoint. In this study, the mastoid cavities of cadaveric human temporal bones were irradiated with a holmium: yttrium aluminium garnet (Ho:YAG) laser (λ=2.12 μm) using the following parameters: 5, 10, and 15 Hz pulse repetition rate and 1, 2, 4, 6, 8, and 10 W average power. During ablation, acoustic measurements were made using a sound level meter positioned 5 cm away from the target site. With each set of laser parameters, the sound intensity exceeded 85 dB (dBA scale). Peak intensities of 125 dB were measured, and a saturation effect noted above 4 W or 500 mJ/pulse. The clinical significance of these findings is discussed and the acoustical aspects of middle ear function and noise trauma are reviewed. Paper received 24 August 1998;accepted after revision 20 June 1999.     

钬激光腔内碎石术治疗输尿管、膀胱结石

目的 探讨经输尿管肾镜或膀胱镜下钬激光碎石术治疗输尿管、膀胱结石的疗效。方法 我科2002年12月～2004年11月，经输尿管肾镜或膀胱镜下钬激光治疗输尿管、膀胱结石322例。直接经尿道插入F8/9.8输尿管镜或F22膀胱镜，直达结石位置，自镜身操作腔道插入光纤，激发激光粉碎结石至3mm以下，合并息肉或狭窄者汽化切割或切开，术毕常规留置导尿管1～3d，留置双J管2～6周拔除。行钬激光前列腺剜除术（holmium laser enucleation of the prostate，HoLEP），或经尿道前列腺电切术（transurethral resection of the prostate，TURP），或经尿道前列腺汽化电切术（transurethral vaporization of the prostate，TUVP）的病例，留置三腔气囊导尿管压迫前列腺窝，1周后拔除。结果11例膀胱结石一次性碎石成功；311例输尿管结石，单次碎石成功率97．1％（302／311）。手术时间10～150min，平均38min。术中输尿管黏膜出血22例，无输尿管穿孔、撕裂等并发症。术后6例发热（1．9％）。肉眼血尿时间1～3d。术后住院1～5d，平均3．2d；术后结石排净时间14～35d，平均28d。结论 通过腔道钬激光碎石术治疗泌尿系结石安全、高效。     

钬激光在泌尿系腔道模型中热效应的实验研究

目的:观察钬激光在泌尿系腔道模型中的局部热效应。方法:本研究于2019年3—12月进行。建立静态介质模型：在常压、25℃恒温、50%湿度的环境下,将内径为1 cm、装有1 ml工作介质的玻璃试管置入300 ml 37℃恒温水浴烧杯中,将550 μm激光光纤置入试管内工作介质中,连续激发激光60 s。利用电子温度测定仪连...