Neodymium-YAG laser core through urethrotomy in obliterative posttraumatic urethral strictures after failed initial urethroplasty

OBJECTIVE: To assess the feasibility, problems and results of Nd-YAG laser core through urethrotomy in the management of failed urethroplasty for posttraumatic bulbomembranous urethral strictures. MATERIAL AND METHODS: 61 patients with obliterative posttraumatic urethral strictures were treated by Nd-YAG laser core through urethrotomy between May 1997 to April 2000. Of these, 5 patients had failed end-to-end urethroplasty done as an initial procedure at various periods of time. The procedure was performed as day care and patients were discharged within 6 h of procedure. RESULTS: At 24-30 months of follow-up, all patients are voiding well and are continent. Auxiliary procedures were required in 2 cases. CONCLUSION: Nd-YAG laser core through urethrotomy is a feasible day care option for patients of obliterative urethral strictures following failed initial urethroplasty with successful outcome.     

Treatment of benign urethral strictures using a sapphire tipped neodymium:YAG laser

Sapphire tips increase the energy density and cutting effect of a neodymium:YAG laser. Sapphire tipped neodymium:YAG laser fibers were used to perform urethrotomy in 24 men with benign urethral strictures. The cutting effect was inadequate in 10 patients. Of the 24 patients 16 (67%) had a recurrent stricture within 1 year. Sapphire tipped neodymium:YAG laser fibers offer no apparent advantage over cold knife urethrotomy for treatment of benign urethral strictures.     

Low-power holmium:YAG laser urethrotomy for treatment of urethral strictures: functional outcome and quality of life

PURPOSE: To evaluate the efficacy of endourethrotomy with the holmium:YAG laser as a minimally invasive treatment for urethral stricture. PATIENTS AND METHODS: Between January 2002 and January 2004, 32 male patients with symptomatic urethral strictures (8 bulbar, 9 penile, 9 combined) were treated with Ho:YAG-laser urethrotomy in our department. The stricture was iatrogenic in 60% (N = 18), inflammatory in 16.6% (N = 5), traumatic in 13.3% (N = 4), and idiopathic in 7% (N = 3). The stricture was incised under vision at the 12 o'clock location or the site of maximum scar tissue or narrowing in asymmetric strictures. Laser energy was set on 1200 to 1400 mJ with a frequency of 10 to 13 Hz. Postoperatively, drainage of the bladder was performed for 4 days using a 18F silicone catheter. Triamcinolone was instilled intraurethrally after removal of the catheter in all patients. Patients were followed up by mailed questionnaire, including International Prostate Symptom Score and quality of life. RESULTS: Retrograde endoscopic Ho:YAG laser urethrotomy could be performed in all 32 patients. Most patients (22; 68.7%) did not need any reintervention. Ten patients developed recurrent strictures that were treated by another laser urethrotomy in 4 patients (12.5%), while 6 patients (18.7%) needed open urethroplasty with buccal mucosa. Including 2 patients treated with repeat laser urethrotomy, 24 patients (75%) were considered successful after a mean follow-up of 27 months (range 13-38 months). No intraoperative complications were encountered, although in 5% of patients, a urinary-tract infection was diagnosed postoperatively. No gross hematuria occurred. CONCLUSIONS: The Ho:YAG laser urethrotomy is a safe and effective minimally invasive therapeutic modality for urethral stricture with results comparable to those of conventional urethrotomy. Further data from long-time follow-up are necessary to compare the success rate with that of conventional urethrotomy and urethroplasty. Nevertheless, the Ho:YAG laser urethrotomy might at least be an alternative to urethroplasty in patients with high comorbidity who are not suitable for open reconstruction.     

双窥镜法联合钬激光内切开术治疗严重尿道狭窄疗效观察

目的观察双窥镜法联合钬激光内切开术治疗严重尿道狭窄的初期疗效。方法2005年5月至2009年4月,应用双窥镜法联合钬激光内切开术治疗8例尿道狭窄或尿道闭锁,狭窄段长度0.8-2.5cm。结果8例患者均尝试逆行内切开术均无法通过狭窄段,应用双窥镜法联合钬激光内切开术治疗均获成功,术后留置尿管4-6周,拔管后均排尿通畅,无尿失禁。8例患者中7例获随访6.24个月（平均18个月）,其中2例患者无需任何后续治疗,3例需行6-16次尿道扩张（平均11次）以维持正常排尿;2例术后3及4个月再次因尿道狭窄行开放手术治疗。结论双窥镜法联合钬激光内切开术治疗尿道狭窄提高了一期腔内手术的成功率,可作为严重尿道狭窄、尿道闭锁患者的可选微创治疗术式。该术式早期疗效良好,但远期效果不尽满意尚待长期观察。     

Laser lithotripsy with the neodymium YAG laser

Laser-induced shock wave lithotripsy (LISL) with a Q-switched neodymium-YAG laser depends on the generation of a laser-induced breakdown in the fluid surrounding the stone. An oscillating plasma bubble is created, directing shock waves towards the stone. These cavitational effects fragment the calculus into small particles. A new bifunctional laser is introduced: this allows both nanosecond pulses for shock wave generation and disintegration of urinary calculi and millisecond pulses for biliary stones and tissue coagulation. It can be supplied with 320-, 400-, and 600-micron fibers. We have treated 189 ureteric stones in 185 patients with laser lithotripsy utilizing flexible ureteroscopes (n = 26) or rigid ureteroscopes (n = 159). It proved possible to fragment 179 stones into small pieces. In eight patients LISL was not successful. A rigid cystoscope that can be dismantled into an upper and lower hemisheath for the introduction of flexible endoscopes into the ureter without prior dilatation of the ureteral orifice was used in 15 patients.     

Intraocular lens design for the neodymium:YAG laser

Phacoemulsification was performed on both lenses of 24 rabbits. One eye received a lens implant with a convex-plano optic; the fellow eye received an implant with a convex-concave optic which separated the posterior surface of the implant from the posterior capsule by 0.2 mm, 0.3 mm, or 0.4 mm. A YAG laser capsulotomy was performed on all eyes immediately following surgery and an assessment of both microscopic and macroscopic YAG-induced lens damage was made. The meniscus optics with their capsule-implant separation showed significantly less YAG-induced damage than their convex-plano counterparts without this separation. Increasing the amount of capsule-implant separation beyond 0.2 mm did not enhance the degree of protection from YAG-induced damage.     

Urologic neodymium: YAG laser surgery

The advantages of each of the laser types used in urologic surgery are discussed and evaluated. Use of the Nd:YAG laser in urologic surgery is a recent advancement.     

Treatment of urethral diseases with neodymium:YAG laser

Over a thirty-month period, a wide variety of common urethral problems were treated on an ambulatory basis, with the neodymium:yttrium-aluminum garnet (Nd:YAG) laser. When used discriminately, laser treatment appears to be an effective modality for the management of selected urethral strictures. Thus far, excellent results have been obtained in 30 of 31 cases of short strictures where laser urethrotomy was performed as the first stricture procedure (average follow-up 10 months). Furthermore, in a series of 36 cases of secondary bladder neck contractures, all of the evaluated patients responded well (average follow-up 7 months). Good results were obtained in only 11 of 48 complicated strictures (average follow-up 14 months). However, while most of these extensive strictures were not eradicated, laser therapy generally produced a documented clinical improvement, comparable to urethrotomy or dilatation, in 15 of these cases. A series of 24 condylomata involving the urethra were treated satisfactorily, with no recurrences (average follow-up 13 months). Laser treatment also has been used successfully for the management of several urethral caruncles, urethral polyps, two meatal hemangiomas, one urethral carcinoma, and a distal duplicated urethra. Recently, the Nd:YAG laser has been applied to the prostatic urethra with vaporization of obstructing median bar hyperplasia. Favorable results have been achieved in 5 of 6 cases treated with a newly developed technique that utilizes direct laser contact. Retrograde ejaculation has not been encountered in these patients (average follow-up 6 months). All of these procedures have been accomplished in the office, largely without urethral catheterization. Lidocaine jelly occasionally supplemented with intravenous sedation provided satisfactory anesthesia.     

Holmium: YAG laser endoureterotomy for ureterointestinal strictures

PURPOSE: The management of ureterointestinal stricture in patients who have undergone urinary diversion can be challenging. Endourological techniques have been increasingly used in recent years for ureteral stricture. While long-term results may not be as reliable or durable as those of traditional open reconstructive surgical techniques, associated morbidity is much less. The holmium (Ho):YAG laser, which has cutting and coagulating properties, has been demonstrated to have many applications in urology. We report our experience with and long-term results of Ho:YAG laser endoureterotomy for ureterointestinal strictures. MATERIALS AND METHODS: We reviewed the charts and followup history of 23 patients in whom the Ho:YAG laser was used to treat ureterointestinal anastomotic stricture. Strictures were treated percutaneously via the antegrade approach with flexible endoscopes and the holmium laser. A reversed 12/6Fr endopyelotomy stent was left indwelling for 6 weeks postoperatively. Success was defined as symptomatic improvement and radiographic resolution of obstruction. RESULTS: Between 1993 and 2000, 23 patients with a mean age of 61 years underwent endo-ureterotomy using the Ho:YAG laser for 24 ureterointestinal stricture. An overall success rate of 71% (17 of 24 cases) was achieved at a mean followup of 22 months. The success rate of holmium laser endoureterotomy for ureterointestinal stricture at 1, 2 and 3 years was 85%, 72% and 56%, respectively. Seven patients had recurrent strictures of which 4 developed 16 months or more postoperatively. No complications were noted. CONCLUSIONS: Ho:YAG laser endoureterotomy for ureterointestinal stricture disease is a minimally invasive endourological procedure that may provide more durable results than other modalities used for endoureterotomy. The Ho:YAG laser with its ability to cut tissue precisely and provide hemostasis combined with its versatility and compatibility with flexible endoscopes is an ideal instrument for safely performing endoureterotomy.     

Renal preservation utilizing neodymium:YAG laser

Six patients with malignancies in a solitary kidney were treated with conservative renal parenchymal-sparing surgery utilizing the Neodymium Yttrium Aluminum Garnet (Nd:YAG) laser. Three patients had transitional cell carcinoma in an upper pole calyx of a solitary kidney. The transitional cell carcinoma was treated definitively by the Nd:YAG laser through a nephroscope prior to partial nephrectomy. The 3 patients have been followed up for twenty-eight, eighteen, and six months, respectively. None of the patients has shown evidence of recurrent cancer on follow-up retrograde ureterograms or on urine cytology obtained from the renal pelves. Three patients with renal cell carcinoma in a solitary kidney had the tumor surgically excised utilizing the Nd:YAG laser in conjunction with standard surgical techniques. All the patients were elderly with compromised renal vasculature that prevented bench surgery with autotransplantation or occlusion of the renal artery. At sixteen, fourteen, and three months, respectively, there is no evidence of recurrent cancer on CAT scans obtained on these patients.     

Transscleral neodymium: YAG laser cyclocoagulation for uncontrolled glaucoma

To determine the efficacy and safety of the procedure, we reviewed the records of 25 eyes of 25 patients who had received noncontact transscleral Nd:YAG laser cyclocoagulation for a variety of uncontrolled glaucomas. Thirteen to 35 pulses (mean, 22.7 pulses) had been placed 1 mm to 2 mm behind the limbus with an energy per pulse of 3.4 J to 8.2 J (mean 4.5 J). Follow-up ranged from 6 months to 23 months, with the exception of one eye, which had to be enucleated. Nine of the 25 eyes (36%) required one or two repeat treatments. Twelve (48%) had intraocular pressures at last follow-up of less than 21 mm Hg but greater than 4 mm Hg. Ten eyes (40%) developed moderate to severe pain transiently, and 10 (40%) developed substantial, but transient, inflammation. Transscleral Nd:YAG laser cyclocoagulation appears to be relatively effective and well tolerated.     

A new contact neodymium:YAG laser for cyclophotocoagulation

A newly developed compact (40 kg), self-contained contact Neodymium:YAG laser produces high-peak, high-energy (800 mJ/pulse), short (1.0 millisecond) pulses with 1 to 3 pulses/exposure. Energy is delivered via a 320-microns cleaved quartz fiber optic probe. Cyclophotocoagulation was performed in five eyes of three medium-sized Dutch-pigmented rabbits. The eyes received exposures of 1 to 3 pulses/exposure. Energy delivered ranged from 100 to 800 mJ/pulse. Histopathology revealed ciliary body disruption and hemorrhage with no damage to overlying sclera. When used for transscleral cyclodiathermy in the rabbit, the laser created significant ciliary body disruption with minimal scleral injury.     

Carcinoma of penis treated with neodymium YAG laser

Sixteen men with squamous cell carcinoma of the penis were treated primarily with the Neodymium Yttrium Aluminum Garnet (Nd:YAG) laser. Five patients had TIS, 9 had T1 tumors, and 2 had T2 carcinoma. All patients had refused traditional therapy of partial penectomy and gave informed consent as to the investigational nature of the Nd:YAG laser photoradiation therapy. Circumcisions and deep tissue biopsies were performed on all patients prior to tumoricidal neodymium photoradiation treatment. The patients were followed from twelve to thirty-six months. At follow-up, 5 patients with TIS had no evidence of recurrent cancer. Of the 9 patients with T1 squamous cell carcinoma of the penis, 6 (67%) were tumor-free at a mean follow-up of twenty-six months. The 2 men with T2 carcinoma of the penis had reduction of the tumor mass but were not cured. The obvious advantage of the Nd:YAG laser in treating carcinoma of the penis is preservation of the penis eliminating disfiguring amputation.     

The treatment of closed injuries and posttraumatic strictures of the urethra

Immediate and long-term results of treatment were evaluated for 211 males who had pelvic and urethral injuries. Most common were the methods: primary epicystostomy followed by urethroplasty, healing on a permanent catheter from the bladder, the primary suture. The material of 12 autopsies was investigated to characterize morphohistological features of pelvic and urethral traumas with consequent pathomorphological substantiation of the ways to recover urethral patency. It is revealed that urethral injuries especially in hip bone fractures should be considered as severe. An individual surgical approach in the condition is to allow for its severity, presence of combined injuries, diagnostic evidence on urethral involvement.     

Anterior capsulotomy with the neodymium: YAG laser: results and opinions

Three series and a control group of patients have been analyzed to study the early and long-term complications of neodymium: YAG laser anterior capsulotomy. In the author's opinion, the results have been favorable, and the procedure is recommended. It is important that a limited number of punctures be made, especially if there is any delay in surgery.     

Safety of high-energy neodymium:YAG laser pulses in YAG sclerostomy

YAG sclerostomy was performed in 15 eyes of nine cynomolgus monkeys. Individual pulse energies ranged between 10 and 135 millijoules. Total pulse energy ranged between 2,000 and 36,000 millijoules in order to test the extreme range of energy that might be required. Both acute effects and chronic effects were studied in the corneal endothelium, the lens capsule, the iris, the ciliary body, the retina, and the sclera. Techniques included flat preparations of the corneal endothelium, paraffin sections for light microscopy, and scanning and transmission electron microscopy. Our conclusion is that individual pulse energies of up to 135 millijoules with a total of up to 36 joules of energy are safe in monkey eyes when performing YAG sclerostomy.