BACKGROUND AND OBJECTIVE:Although the popularity of visual laser ablation of the prostate (VLAP) as a treatment for symptomatic, benign prostatic hyperplasia (BPH) is increasing, the perceived advantages of VLAP over conventional transurethral electroresection of the prostate (TURP) is being debated because optimal technique and dosimetry for surgical lasers are still being refined. At this time, the 1.06 neodymium:yttrium-aluminum-garnet (Nd:YAG) laser and a laterally deflecting delivery system is the hardware combination most widely used for VLAP. STUDY DESIGN/MATERIALS AND METHODS:Reported here is a study of an alternate system, a 805-nm diode laser (Diomed 25 Diomedics, The Woodlands, TX) with a cylindrically diffusing fiber (Surgimedics Inc., The Woodlands, TX). Eight mongrel dogs were prostatectomized by transurethral irradiation of the prostate with 15,000 J of diode laser energy delivered via a fiber that diffuses the energy in a 1.5-cm-long cylindrical pattern. The dogs were sacrificed and prostates harvested at 3 hours and 1,4,7,14,21,35, and 49 days after the procedure, fixed with 10% buffered formalin, and examined histologically. RESULTS/CONCLUSIONS:It was found that this laser/fiber combination created volumes of tissue coagulation similar to those encountered in our previous work with the Nd:YAG laser in combination with both laterally deflecting and diffuser fibers, while offering the distinct advantages of simplified technique, lower cost hardware, and fewer postoperative complications in the dog model.

Conventional radical prostatectomy in the dog has historically been attended by unacceptably high incidence of urinary incontinence (80 - 100%). Ablation of the prostate can be accomplished in the dog by transurethral irradiation of the prostate with the Nd:YAG laser and a laterally deflecting fiber. Exposure has ranged between 40 and 60 watts for 60 seconds at 4 fixed locations. Although prostatectomies performed with the above described technique offers significant advantage over conventional prostatectomies, the high power density at each location can result in small submucosal explosions (`popcorn effect') that increase the potential for bleeding and rupture of the prostatic capsule. We describe a new technique in which the energy is applied continuously by a laser fiber rotating around a central point. Delivering 40 watts of Nd:YAG energy for 4 minutes using a new angle-delivery device (Urotek TM ), we produced results comparable to those of other previously reported techniques in the canine model with two added advantages: (1) a more even application of heat resulting in no `popcorn' effect and (2) a more reliably predictable area of coagulative necrosis within a given axial plane. This technique should provide additional safety for the veterinary surgeon performing visual laser ablation of the prostate in the dog.

We investigated the use of the 805 nm diode laser (Diomed 25 Diomedics, The Woodlands, Texas) in combination with a cylindrically diffusing fiber (Surgimedics, The Woodlands, Texas) to perform visual laser ablation of the prostate in 8 mongrel dogs. Each dog received 15,000 J of laser energy delivered to the prostate in one continuous dose of 25 W for 10 minutes. Gross and histopathologic examinations of serial sections of the prostate were performed at intervals from 3 hours to 7 weeks postoperatively. All dogs did well postoperatively with only one episode of urine retention 5 days after the surgery. Grossly, an ellipsoid zone of destruction with an average maximum diameter of 2.1 cm was present in all dogs. Histopathological changes in the prostate were similar to changes consistently reported for prostatectomies performed with similar dosimetry utilizing the 1.06 Nd:YAG laser. We believe this wavelength laser in combination with the diffusing fiber compared favorably with the Nd:YAG/sidefire fiber studies previously done in this laboratory with the added advantage of simplified operator technique, less postoperative complications and increased margin of safety.

This is the first North American report describing the use of the holmium:YAG (Ho:YAG) laser to treat patients with superficial bladder carcinoma. Fifteen patients, with a total of 52 recurrent superficial bladder tumors, underwent endoscopic laser photoablation of their lesions. No intraoperative or delayed complications occurred. At follow‐up cystoscopy performed 3 months after lasing, four patients (27%) were without disease; eight patients (53%) had out‐of‐field recurrences; and three patients (20%) were classified as having in‐field recurrences. We conclude that using the Ho:YAG for endoscopic treatment of patients with superficial bladder tumors is both feasible and clinically useful and that the lack of perceived pain or discomfort during lasing, as well as the lack of need for an in‐dwelling urethral catheter, makes it advantageous for selected patients over conventional electroresection techniques. © 1994 Wiley‐Liss, Inc.

In this study, visual laser ablation of the prostate (VLAP) was performed on eight mongrel dogs utilizing a cylindrically diffusing fiber attached to a 1.06 neodymium:YAG (Nd:YAG) laser. All dogs received one continuous dose totaling 15,000 J (25 W for 10 min) applied from the vesical neck to the colliculus seminalis. There was no visible hemorrhage from the lasing intraoperatively in any dog. Postoperative recovery was uneventful with no dog experiencing urinary incontinence and only one incident of dysuria with urinary retention during their observation period. Gross and histopathologic examinations of serial sections of the prostate were performed from 2 hours to 7 weeks postoperatively and demonstrated a consistent spherical zone of destruction 2.9 cm (average) in diameter. We believe the simplified fiber placement and complete lack of postoperative complications in this small group of dogs suggest that the cylindrically diffusing fiber offers significant advantage over laterally deflecting fibers for transurethral prostatectomies in the dog.

Objective. The scarcity of reports evaluating the effect of current treatment strategies for male urethral carcinoma has prompted a review of our recent experience. Since our last report (1980), we have seen 23 patients with this disease. Methods. We performed a retrospective chart review of 23 patients seen in our institution between 1979 and 1990 with this type of cancer.Results. Fifty-two percent of our patients are alive without evidence of disease, after a mean follow-up of fifty months (range, 5 to 156 months). Treatment analysis indicates that distal urethrectomy and partial penectomy are adequate in controlling local disease for tumors arising in the fossa navicularis and penile urethra, respectively, and that en bloc excision of the penis, scrotum, prostate, and bladder together with resection of the inferior pubic rami, using myocutaneous flaps to cover the surgical defect, can provide long-term disease-free survival for patients whose tumor originates in the bulbomembranous urethra. Use of cisplatin-based chemotherapy resulted in a prolonged survival for patients who presented with metastatic disease.Conclusions. We conclude that the prognosis for patients with urethral carcinoma has improved, and some of the patients are having a prolonged disease-free survival due, in part, to more effective local and regional control and improved chemotherapy.

Visual laser ablation of the prostate was performed on 8 mongrel dogs employing a cylindrically diffusing fiber delivery system and a 1.06 neodymium:YAG laser. Each dog received 15,000 J of laser energy delivered to the prostate in one continuous dose of 25 W for 10 min. Gross and histopathologic examination of serial sections of the prostate was performed at intervals from 2 hours to 7 weeks postoperatively. Grossly, a spherical zone of destruction averaging 2.8 cm in diameter was present in all dogs. Histopathologic changes in the prostate consisted of acute coagulative necrosis with interstitial edema at 2 hours, becoming hemorrhagic at 24 hours. A prominent circular area of acute coagulative necrosis with extensive areas of liquefaction and hemorrhage was presented at 4 days. Early re- epithelialization of the resulting cavity was present at 3 weeks with nearly complete resolution 7 weeks postoperatively. We believe that, because of the simplified fiber placement and complete lack of postoperative complications in this small group of dogs, the cylindrically diffusing fiber could offer significant advantage over side fire-style fibers for transurethral prostatectomies.

We report preliminary potato dosimetry and canine studies evaluating a new 1,000-(mu) optical fiber whose distal tip has been bent to 45 degree(s), allowing for endoscopic delivery of neodymium:YAG laser energy at an angle of 60 degree(s). Our results suggest that this fiber is comparable with other more complex angled delivery systems; has several advantages: it can deliver greater power over longer time intervals, producing larger volumes of coagulative necrosis, and it may be operated in a contact mode within a fluid medium without fiber `burnout.' This fiber should prove useful for transurethral laser ablation of the prostate.

Serial gross and histopathologic examinations of the prostate following interstitial laser prostatectomy in the canine model demonstrated distinct zonal thermal changes around the entire active area of the interstitial thermal therapy (ITT) fiber. A large, well‐demarcated area of acute coagulative necrosis immediately surrounded each fiber tract; beyond that were a prominent narrow peripheral zone of marked tissue disruption and an outer zone of hemorrhage. Liquefaction within these coagulative areas was evident within 24 hours, and by 4 days, each lobe of the prostate contained an irregular cavity that became lined by normal‐appearing transitional epithelium and that, by 5 weeks, communicated with the prostatic urethra. These postmortem pathologic observations, similar to findings previously reported following transurethral laser prostatectomy, suggest that interstitial laser thermal therapy may provide an additional means for treating benign prostatic hyperplasia in men. © 1994 Wiley‐Liss, inc.

Transurethral laser prostatectomy was performed on eight mongrel dogs employing a cylindrically diffusing fiber delivery system and a 1.06 mu Nd:YAG laser. Each dog received 15,000 joules of laser energy delivered to the prostate in one continuous dose of 25 watts for 10 minutes. Gross and histopathologic examinations of serial sections of the prostate were performed postoperatively after intervals of 2 hours to 7 weeks. Grossly, a spherical zone of destruction averaging 2.8 cm in diameter was present in dogs except one. Histopathologic changes in the prostate consisted of acute coagulative necrosis with interstitial edema at 2 hours, becoming hemorrhagic by 24 hours. A prominent circular area of acute coagulative necrosis with progressively larger areas of liquefaction and hemorrhage was present in prostates harvested from 4 days to 1 week after lasing. Initial re-epithelization of the resulting cavity was observed at 3 weeks with nearly complete epithelialization 7 weeks after laser treatment. The simplified fiber placement and lack of postoperative complications in this small group of dogs suggest that the cylindrically diffusing fiber could offer significant advantages over laterally deflecting fibers for transurethral prostatectomies in the dog model. (C) 1994 Wiley-Liss Inc.

Laser photoirradiation has been delivered endoscopically for the treatment of both benign prostatic hyperplasia and early localized prostatic carcinoma. In treating carcinoma, aggressive transurethral resection of the prostate has been followed with laser irradiation to the remnants of malignant capsular disease. No attempt has been made heretofore to completely destroy the glandular prostate using laser irradiation alone. We performed a two-stage endoscopic laser prostatectomy in 6 adult mongrel dogs in an attempt to completely destroy the glandular prostate. Although no complications developed, histologic evaluation of the prostate revealed viable glandular elements in the midst of necrosis and atrophy. We conclude that in order to accomplish total ablation of the glandular prostate using laser photoirradiation, more precise thermal telemetry is needed.

We used the holmium:YAG (Ho:YAG) laser successfully to fragment human urinary calculi of various sizes and compositions. At an energy level of 0.5 J/pulse and a frequency of 5 Hz, lithotripsy resulted in minimal ureteral-wall injury that was limited to superficial coagulative necrosis of the submucosa. Increasing the amount of energy or the frequency level, however, often resulted in significant damage to deeper ureteral tissue. When performed at low power settings with care to avoid direct ureteral-wall contact, Ho:YAG laser lithotripsy is safe and effective.

Lymphoepithelioma of the bladder is rare and has only recently been described at this site. Based upon the reported sensitivity to chemotherapy of lymphoepitheliomas at more common sites, we treated 3 cases of muscle invasive lymphoepithelioma of the bladder with primary chemotherapy to salvage bladder function.

The tissue effects of a holmium:YAG (Ho:YAG) laser operating at a wavelength of 2.1-mu with a maximum power of 15 watts (W) and 10 different energy-pulse settings was systematically evaluated on kidney, bladder, prostate, ureteral, and vasal tissue in the dog. In addition, various urologic surgical procedures (partial nephrectomy, transurethral laser incision of the prostate, and laser-assisted vasovasostomy) were performed in the dog, and a laparoscopic pelvic lymph node dissection was carried out in a pig. Although the Ho:YAG laser has a strong affinity for water, precise tissue ablation was achieved in both the contact and noncontact mode when used endoscopically in a fluid medium to ablate prostatic and vesical tissue. Using the usual parameters for tissue destruction (blanching without charring), the depth of thermal injury in the bladder and ureter was kept superficial. In performing partial nephrectomies, a 2-fold reduction in the zone of coagulative necrosis was demonstrated compared to the use of the continuous wave Neodymium:YAG laser (Nd:YAG). When used through the laparoscope, the Ho:YAG laser provided precise cutting and, combined with electrocautery, allowed the dissection to proceed quickly and smoothly. Hemostatic control was adequate in all surgical procedures. Although the results of these investigations are preliminary, our initial experience with the Ho:YAG laser has been favorable and warrants further investigations.

Sarcomatoid carcinoma of the prostate is a rare tumor that can be difficult to distinguish from a true sarcoma. The authors report 12 patients in whom the typical light microscopic appearance of prostatic adenocarcinoma was accompanied by the appearance of spindled or pleomorphic sarcomatoid areas within the same specimen or in subsequent accessions. Immunostaining or electron microscopic study demonstrated epithelial differentiation within the sarcomatoid area(s) in 6 of the 11 patients in whom special studies were performed. All nine patients for whom follow-up data were available died of disease within 3 to 48 months (median time until death, 12.0 months) after the appearance of the sarcomatoid carcinoma, and the clinical course in each instance was characterized by aggressive local recurrence. Our experience confirms that sarcomatoid carcinoma of the prostate is an aggressive variant of prostatic adenocarcinoma.

In 2 cases epididymo-orchitis, indistinguishable from a testicular tumor, developed as a late (15 and 34 months, respectively) complication following use of Tice strain bacillus Calmette-Guerin for treatment of superficial bladder carcinoma. In each instance the lesion was asymptomatic and ultrasonography demonstrated a complex scrotal mass. Inguinal orchiectomy was performed for diagnosis and therapy. The importance of obtaining a mycobacterial culture for further therapy planning is stressed.

This is the first report on the use of endoscopic argon photoirradiation to treat patients with low-grade ureteral tumors involving the distal ureter. Using a rigid ureteropyeloscope, a 300 mu or 600 mu quartz fiber, and 5 watts (W) of power in a continuous-wave mode, the lesions were ablated without complication. Patients remain free of ureteral recurrence after 5, 7, and 22 months. We conclude that the shallow (1 mm) depth of penetration and the ability to use the fiber in either a contact or noncontact mode provide the surgeon a large margin of safety and low risk of ureteral perforation.

Serial changes occurring in the canine prostate were studied at 1 and 3 hours; 1, 2, 4, and 7 days; and 2, 3, 5, 7, and 20 weeks following transurethral laser prostatectomy using the Neodymium:YAG (Nd:YAG) laser which delivered 60 watts (W) of power for 60 seconds at 4 positions (2, 5,8, and 11 o'clock) through a Lateralase' 2.5-mmfiber. A well-demarcated sphere of thermal necrosis measuring 2.7 cm in diameter was present immediately which, within 24 hours, had begun liquefaction and was showing multiple areas of cavitation. At 1 week, the area of cavitation had coalesced to form a central cavity and within 5weeks, the ectatic cavity had been lined by transitional epithelium. These observations confirm our previous surgical and clinical impression of being able to satisfactorily perform an effective transurethral laser prostatectomy with reproducible and consistent results without using sophisticated monitoring devices.

Seventy-one patients with pathologic Stage B (P2/3a/N0) transitional cell carcinoma (TCC) of the bladder underwent radical cystectomy alone without preoperative radiotherapy or perioperative chemotherapy between 1983 and 1987 and have been followed a median of fifty months. The five-year actuarial survival and disease-free survival rates were 82 percent and 77 percent, respectively, and only 13 patients (18 %) have relapsed. Histologic parameters were evaluated as to prognostic impact; none correlated with disease-free survival rates although the presence of vessel involvement portended a worse disease-free survival rate (68 % versus 80 %). During this same period, an additional 15 patients underwent radical cystectomy for pathologic Stage B disease but received adjuvant chemotherapy on the basis of vessel invasion. Their disease-free survival rate at five years was 80 percent, comparable to the disease-free survival rate for patients with vessel invasion treated by surgery alone (68 %). Although the role of systemic chemotherapy in the management of invasive bladder cancer remains under investigation, it would appear that patients with Stage B TCC are best treated with radical cystectomy alone. Continued analysis of modern surgical results grouped by current pathologic staging criteria is needed to identify patients who have a relatively low risk of relapse and thus little need for additional therapeutic intervention. These results demonstrate that Stage P2/3a/N0 TCC of the bladder is highly curable by surgery.

Transurethral incisions of the prostate were made endoscopically in 5 dogs under a fluid medium using a holmium:YAG (Ho:YAG) laser operating at a wavelength of 2.1 microns and with delivery of 1.0 J/pulse in 15 Hz (15 W). Histopathologic examination of tissues collected immediately after surgery revealed irregular crevices outlined by a narrow zone of coagulative necrosis. Ulcerated fissures persisted at 5 and 7 days with the initial stages of epithelial regeneration partially re-epithelializing the ulcerated surfaces. A modest inflammatory response characterized by edema, hemorrhage, and a mixed inflammatory cell infiltrate was also associated with the laser incision sites at 5 and 7 days. Three weeks postlasing, the ulcerated surfaces of the fissures were completely re-epithelialized. At 5 weeks only a slight indentation persisted at the incision sites with minimal changes in the subjacent submucosa and prostatic glandular architecture. Although the results of these investigations are preliminary, we believe that the Ho:YAG laser warrants further clinical evaluation for treating patients with benign prostatic hyperplasia (BPH), urethral strictures, bladder neck contractures, and constrictions of the upper urinary tracts.