Third Prize: Comparison of radical nephrectomy, laparoscopic microwave thermotherapy, cryotherapy, and radiofrequency ablation for destruction of experimental VX-2 renal tumors in rabbits.

BACKGROUND AND PURPOSE: Currently available minimally invasive renal tumor-ablation procedures include cryotherapy, radiofrequency ablation, and microwave thermotherapy. In this study, we investigated the ability of these three approaches to destroy experimental renal tumors in rabbits. The mechanism of potential tumor metastasis was also explored. MATERIALS AND METHODS: The VX-2 tumor line is an aggressive rabbit epidermoid tumor with a high metastatic potential. An initial experiment comparing cooled-tip microwave thermotherapy with cryotherapy and radical nephrectomy for treatment of small VX-2 tumors revealed that all microwave-treated rabbits had local recurrence and that several also had diffuse intraperitoneal carcinomatosis. In view of these results, a second experiment was performed in which 45 New Zealand White rabbits were implanted laparoscopically with VX-2 xenografts underneath the kidney capsule and divided into five groups of 9 each. The test groups were microwave thermotherapy with a 3.5-mm cooled-tip probe, microwave thermotherapy with a 3.5-mm noncooled- tip probe, radiofrequency ablation with a 1.5-mm cooled-tip probe, radiofrequency ablation with a 1.5- mm non-cooled tip probe, and cryotherapy with a 2.3-mm cryoprobe. The control groups were five rabbits that were not treated, five rabbits with tumors that had the tumor pierced with a probe but were untreated, and five rabbits that underwent nephrectomy after piercing of the tumor. Treatment was initiated 5 days after tumor implantation. One month later, all animals were euthanized and autopsied. RESULTS: At 5 days after tumor implantation, laparoscopic inspection revealed no visible peritoneal metastases. At 1 month, in the cooled and non-cooled microwave-thermotherapy groups, carcinomatosis occurred in five and six of nine animals, respectively. In comparison, carcinomatosis was detected in two of nine animals in the cryotherapy group at autopsy. With respect to cooled and non-cooled radiofrequency ablation, carcinomatosis was observed in four of nine rabbits in each group. In the control groups, none of the animals with unpierced tumors exhibited carcinomatosis, while carcinomatosis was seen in two of the five rabbits with tumor violated by piercing and in three of the five rabbits that underwent immediate nephrectomy after piercing of the tumor. CONCLUSION: Carcinomatosis occurred most frequently in animals treated with microwave thermotherapy, followed by radiofrequency ablation, and lastly cryoablation. The simple act of piercing a highly aggressive tumor can result in local spread. More disconcerting, and less well understood, is why certain ablative modalities appear to increase the rate of intraperitoneal spread.

What happens to hemostatic agents in contact with urine? An in vitro study.

BACKGROUND AND PURPOSE: As the indications for topical hemostatic agents increase in urology, the question arises: what happens to these agents when they enter the urinary collecting system? To answer this question, we performed a series of in-vitro experiments mixing three hemostatic agents with normal and sanguineous urine. MATERIALS AND METHODS: Four commercially available topical hemostatic products: oxidized regenerated cellulose (Surgicel; Ethicon, Somerville, NJ), fibrin sealant (Tisseel VH Kit; Baxter Health Care Corporation, Irvine, CA), gelatin matrix hemostatic sealant (FloSeal; Baxter Health Care), and polyethylene glycol (CoSeal; Cohesion Technologies, Palo Alto, CA) were studied. Human urine (10 mL) was added to samples of each substance; this was done in triplicate. The 12 sample tubes were then capped and placed on a tube shaker at slow speed and 37 degrees C. Observations regarding consistency of the material were made at 6, 12, 24, 48, 72, 96, and 120 hours (5 days). Gelatin matrix hemostatic sealant was further tested in urine with various amounts of blood or blood clot; observations were again recorded out to 5 days. RESULTS: Surgicel maintained its solid form when it initially came in contact with urine, but over a period of 5 days, it transformed into a mucoid substance with visible free-floating fibers. It did not dissolve completely in urine within 5 days. Gelatin matrix was immediately transformed by urine into a fine colloidal suspension that did not change over the 5 days of the study. Fibrin glue, after mixing of the two components (fibrinogen and thrombin) directly in the urine, and polyethylene glycol immediately formed a solid clot at the bottom of the test tube on contact with the urine. When the mixture of fibrin sealant was allowed to form for 15 minutes and then added to urine, it again maintained a solid form. After 72 hours, the fibrin glue became a semisolid gelatinous plug. On analysis at 5 days, the fibrin sealant clot had transformed into a cohesive mucoid gel, and the polyethylene glycol clot had not changed. The gelatin matrix hemostatic sealant, when in contact with blood or blood clot, appeared to either become part of a clot or to remain in a colloidal suspension. At 5 days, all clots had dissolved to fine particulate suspensions, and the gelatin matrix appeared as a fine suspension. CONCLUSION: Fibrin glue and oxidized regenerated cellulose maintain a solid form when initially placed in direct contact with urine and then assume a semisolid gelatinous state, which is still present at 5 days. Polyethylene glycol forms a solid clot initially and does not change after 5 days. Only hemostatic gelatin matrix remained as a fine particulate suspension in both normal and sanguineous urine. The implications of these findings with regard to sealing the renal parenchyma or small violations of the collecting system after percutaneous or laparoscopic surgery await in-vivo testing.

Current trends in urologic laparoscopic surgery.

PURPOSE: We examined the status of laparoscopy in urology and the impact of residency and fellowship training on the performance of laparoscopy as primary surgeon. We also examined whether performing nonsurgical tasks requiring two-handed dexterity had any link to the adoption of laparoscopic techniques by urologists. MATERIALS AND METHODS: A total of 8760 laparoscopy questionnaires containing 135 queries were mailed to urologists listed on the American Urological Association practicing urologists mailing list. The questions sought information on area of practice, time in practice, fellowship training, ambidexterity, laparoscopic experience, and experience with robotics. The response rate was 1.8% (155 of 8760). RESULTS: There appeared to be no significant correlation between the performance of laparoscopic surgery and participation in activities requiring bimanual dexterity. However, a correlation of strong statistical significance did exist between laparoscopic residency training and performance of laparoscopy after residency (p=0.003. There also was a correlation between fellowship training in laparoscopy/endourology and doing laparoscopy as primary surgeon. CONCLUSIONS: Participation in laparoscopic surgery during residency training is a major determining factor in performance of laparoscopy as a primary surgeon in practice. Younger surgeons trained in laparoscopy during residency are performing more laparoscopy post residency than those without laparoscopic training during residency. At present, there is a need to train more urologists in laparoscopy at the postgraduate level.

Ureteroscopes: flexible, rigid, and semirigid.

Since its introduction, the ureteroscope has undergone significant improvements. Using the currently available rigid, semirigid, and flexible ureteroscopes and working instruments, urologists can diagnose and treat lesions throughout the upper urinary tract. Over the past 25 years, the ureteroscope in combination with shock wave lithotripsy has transformed the diagnosis and treatment of more than 90% of upper urinary tract pathology from an open to an endourologic procedure. With endoscope manufacturers continually incorporating new technology into their ureteroscopes, future models will undoubtedly provide better optics, increased durability, and improved capabilities, resulting in greater success when urologists perform endoscopic forays into the upper urinary tract.

One-knot pyeloplasty.

Laparoscopic pyeloplasty represents one of the more advanced reconstructive procedures for the urologist. While early reports were replete with long operative times, there have been several changes that have added to the efficiency of the procedure. In our practice, we have found three changes to be of greatest value: (1) an upper-midline port placement; (2) use of a continuous suture for the anastomosis with a double-armed, knotted suture; and (3) antegrade stent placement.

Intraoperative catheter management during laparoscopic excision of a giant bladder diverticulum.

BACKGROUND: Massive bladder diverticula present a technical challenge to the laparoscopic surgeon. We describe a laparoscopic approach to transperitoneal diverticulectomy, using a specific catheter arrangement to allow excellent control of the various portions of the procedure. METHODS: A 49-year-old male with longstanding frequency was diagnosed with a 1000 cc bladder diverticulum and bladder neck outlet obstruction. Laparoscopic transperitoneal diverticulectomy was performed using a triple catheter arrangement: endoscopic placement of a Councill catheter in the diverticulum, fluoroscopic positioning of an occlusion balloon catheter in the renal pelvis, and placement of a Cope loop suprapubic tube. Additionally, a transurethral incision of the prostate was performed. RESULTS: The procedure was completed laparoscopically using a four port transperitoneal approach. During the procedure, the diverticulum could be filled and emptied as needed; the catheter across the diverticular neck facilitated subsequent closure of the bladder wall defect. The diverticulum was completely excised. The remaining defect in the bladder was then closed in 2 layers. The patient was discharged on postoperative day 3. CONCLUSION: Careful planning and arrangement of catheters in the bladder, ureter, and diverticulum facilitates laparoscopic transperitoneal diverticulectomy of even a very large volume diverticulum.

Seed implant retention score predicts the risk of prolonged urinary retention after prostate brachytherapy.

PURPOSE: To risk-stratify patients for urinary retention after prostate brachytherapy according to a novel seed implant retention score (SIRS). PATIENTS AND METHODS: A total of 835 patients underwent transperineal prostate seed implant from March 1993 to January 2007; 197 patients had (125)I and 638 patients had (103)Pd brachytherapy. Four hundred ninety-four patients had supplemental external-beam radiation. The final downsized prostate volume was used for the 424 patients who had neoadjuvant hormone therapy. Retention was defined as reinsertion of a Foley catheter after the implant. RESULTS: Retention developed in 7.4% of patients, with an average duration of 6.7 weeks. On univariate analysis, implant without supplemental external-beam radiation (10% vs. 5.6%; p = 0.02), neoadjuvant hormone therapy (9.4% vs. 5.4%; p = 0.02), baseline alpha-blocker use (12.5% vs. 6.3%; p = 0.008), and increased prostate volume (13.4% vs. 6.9% vs. 2.9%, >45 cm(3), 25-45 cm(3), <25 cm(3); p = 0.0008) were significantly correlated with increased rates of retention. On multivariate analysis, implant without supplemental external-beam radiation, neoadjuvant hormone therapy, baseline alpha-blocker use, and increased prostate volume were correlated with retention. A novel SIRS was modeled as the combined score of these factors, ranging from 0 to 5. There was a significant correlation between the SIRS and retention (p < 0.0001). The rates of retention were 0, 4%, 5.6%, 9%, 20.9%, and 36.4% for SIRS of 0 to 5, respectively. CONCLUSIONS: The SIRS may identify patients who are at high risk for prolonged retention after prostate brachytherapy. A prospective validation study of the SIRS is planned.

Comparison of flexible ureteroscopes: deflection, irrigant flow and optical characteristics.

PURPOSE: We measured and compared the deflection, irrigation flow rates, distortion, resolution and light transmission of new generation flexible ureteroscopes. MATERIALS AND METHODS: Multiple characteristics of 5 flexible ureteroscopes (ACMI DUR-8 Elite, Olympus URF-P3, Storz 11278AU1 [Flex-X], Wolf 7330.072 and Wolf 7325.172) commonly available in the market were measured and compared. Measured data included active deflection, irrigation flow rates and optical characteristics. Each ureteroscope was evaluated with an empty working channel and with various accessories. Optical characteristics, specifically resolution and distortion, were measured using test targets (Edmund Optics, Barrington, New Jersey). Light transmission was also measured from the ureteroscope tip at 50% and 100% intensity. All 5 flexible ureteroscopes were tested in a laboratory setting using a Storz OR 1 system to capture the images. RESULTS: For all 5 ureteroscopes the angle of deflection was most impaired by a 365 microm laser fiber probe and least impaired by a 2.2Fr nitinol basket. Among all 5 ureteroscopes irrigation flow rate was most impaired with a 3.0Fr basket and least impaired with 200 microm laser fiber. The Wolf 7325.172 had the highest observed resolution of 25.39 lines per mm and the Wolf 7330.072 had the lowest distortion at 11.9%. The Karl Storz Flex-X and the ACMI DUR-8 Elite had the highest light output at 374 and 364 mV, respectively. CONCLUSIONS: The various flexible ureteroscopes differ with regard to flow rates as well as degree of deflection with either an empty or an occupied working channel. The Wolf flexible ureteroscope with a slightly larger working channel and a fused quartz bundle provided for superior flow and better optical performance. However, the greatest amount of tip deflection and highest light output were found in the ACMI and Karl Storz flexible ureteroscopes.

Laparoscopic assisted radical cystectomy with ileal neobladder: a comparison with the open approach.

PURPOSE: To date, there have been only a few reports regarding the feasibility of the laparoscopic approach to radical cystectomy. In none of these cases has the laparoscopic approach been contrasted with a contemporary cohort of open cystectomy and diversion. Recently, we initiated laparoscopic assisted radical cystoprostatectomy and ileal neobladder (LACINB) wherein the cystoprostatectomy and pelvic lymph node dissections are performed laparoscopically and the reconstructive portion is performed via a 15 cm Pfannenstiel incision. We present and compare our initial series of LACINB with radical cystectomy performed by the open approach (OCINB) during the same period. MATERIALS AND METHODS: Between September 2001 and February 2003, 13 men underwent LACINB and 11 underwent OCINB at our institution. RESULTS: There was no statistically significant difference in operative time, blood loss or complication rates between the LACINB and OCINB groups. However, postoperative analgesic use was significantly less in the LACINB group. Time to start of a liquid diet, solid diet and length of hospitalization were also significantly less in the LACINB group vs the OCINB group. All margins in both groups were negative for bladder cancer, although 1 patient in the LACINB group had an incidentally found prostate cancer with a positive apical margin. CONCLUSIONS: LACINB is a feasible and reproducible procedure, which results in decreased postoperative pain and quicker recovery without a significant increase in operative time. However, longer followup is needed to assess long-term oncological and functional outcomes.

Influence of prostate volume in the detection of prostate cancer.

OBJECTIVES: To assess the influence of prostate volume on prostate cancer (CaP) detection in men who underwent repeated sextant transrectal ultrasound biopsy of the prostate. METHODS: Between September 1991 and September 2000, 4376 men underwent sextant transrectal ultrasound-guided biopsy of the prostate. Of the 4376 men, 556 underwent repeat biopsy because of persistent prostate-specific antigen elevation (greater than 4 ng/mL) and/or an abnormal digital rectal examination or suspicious pathologic findings. The percentage of CaP missed on the initial biopsy and detected on the repeat biopsy between arbitrary prostate volumes of less than 50 and 50 cm3 or greater and between less than 37.5 and 37.5 cm3 or greater, the median prostate volumes of men with CaP, were compared. Patient age, prostate-specific antigen level, digital rectal examination findings, and Gleason score in each volumetric cutoff group were also compared. RESULTS: CaP was detected in 22% of men who underwent a repeat biopsy. The percentage of CaP missed on the initial biopsy but subsequently detected on the repeat biopsy consistently increased as the volume increased. A statistically significant difference in the percentage of CaP not detected on the initial biopsy was found between prostate volumes of less than 50 and 50 cm3 or greater and between less than 37.5 and 37.5 cm3 or greater (P <0.05). No statistically significant difference in prostate-specific antigen, age, digital rectal examination, or Gleason score was found between each volumetric cutoff group. CONCLUSIONS: A significant percentage of men are diagnosed with CaP after a repeat biopsy. We have demonstrated that the percentage of CaP missed on the initial biopsy and detected on the repeat biopsy increases as the prostate volume increases. The results of our study suggest that in men with large prostates, traditional sextant biopsies may not be adequate to detect CaP.

The effect of finasteride on the expression of vascular endothelial growth factor and microvessel density: a possible mechanism for decreased prostatic bleeding in treated patients.

PURPOSE: Several studies have confirmed the benefit of finasteride in limiting hematuria from benign prostatic hyperplasia. Vascular endothelial growth factor (VEGF), a potent stimulator of angiogenesis, and microvessel density have been independently evaluated in the mechanism of decreased bleeding observed in patients treated with finasteride. We evaluated the expression of VEGF and suburethral prostatic microvessel density in patients with benign prostatic hyperplasia treated with finasteride. MATERIALS AND METHODS: The study included 24 patients undergoing prostatic surgery for benign disease, of whom 12 were given finasteride for a minimum of 6 weeks before surgery and the remaining 12 served as controls. Sections from the prostatic urothelium and hyperplastic prostate were individually stained for CD34 specific for nascent blood vessels and VEGF. Analysis of each specimen was performed in a blinded fashion. Microvessel density was calculated by counting the number of positively stained blood vessels on 10 consecutive, nonoverlapping, high power fields within the suburethral and hyperplastic prostate compartments. VEGF expression was examined by immunohistochemistry. Statistical analysis of the results was performed using Student's t test. RESULTS: Prostatic suburethral VEGF expression and microvessel density were significantly lower in the finasteride group compared to controls (p <0.05). Differences in VEGF expression and microvessel density at the level of the hyperplastic prostate were not found to be significantly different between the 2 groups. CONCLUSIONS Decreased expression of VEGF by finasteride inhibits angiogenesis and significantly decreases microvessel density in prostatic suburethral tissue. This sequential relationship provides histochemical insight into the mechanism by which finasteride reduces prostatic urethral bleeding.

Decreased suburethral prostatic microvessel density in finasteride treated prostates: a possible mechanism for reduced bleeding in benign prostatic hyperplasia.

PURPOSE: We evaluated the influence of finasteride on prostatic microvessel density to elucidate a mechanism of decreased bleeding in finasteride treated patients with hematuria secondary to benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: A total of 22 patients with clinical BPH and gross hematuria who underwent prostate reductive surgery between 1998 and 2000 were prospectively evaluated. The prostate from 10 finasteride treated and 12 untreated patients was immunohistochemically stained for CD-34. Microvessel density analysis was performed by quantifying positive stained blood vessels located within the stroma of hyperplastic nodules as well as in the suburethral portion of the prostate. RESULTS: Mean microvessel density plus or minus standard deviation in finasteride treated patients was significantly lower in the suburethral portion of the prostate versus untreated controls (14.0 +/- 2.8 versus 20.2 +/- 5.3 vessels per high power field, p <0.05). In the nodular hyperplasia there was no statistically significant difference in the treatment and control groups (mean 17.5 +/- 2.8 and 16.7 +/- 4.6 vessels per high power field, respectively). CONCLUSIONS: Finasteride significantly decreases suburethral prostatic microvessel density in patients with BPH, which may explain its efficacy for decreasing BPH associated bleeding.

Sealing percutaneous nephrolithotomy tracts with gelatin matrix hemostatic sealant: initial clinical use.

PURPOSE: Tubeless percutaneous nephrolithotomy (PCNL) has been performed at several centers with good success. However, these cases have been carefully selected with regard to short duration and smaller stone burden to prevent complications associated with the loss of access to the collecting system. We describe the use of gelatin matrix hemostatic sealant (FloSeal Baxter Medical, Fremont, California) as an adjunct to tubeless percutaneous nephrolithotomy to help preclude bleeding complications. MATERIALS AND METHODS: Two patients were treated with PCNL through a single nephrostomy tract. At the satisfactory conclusion of the cases the tract was occluded retrograde with an occlusion balloon catheter and gelatin matrix hemostatic sealant was injected down the nephrostomy tract. An indwelling stent and bladder catheter were placed following which all guidewires were removed and skin sutures were placed. RESULTS: The operative times were 75 and 180 minutes, respectively. Both patients had stable postoperative hemoglobin and no evidence of bleeding or obstruction on postoperative computerized tomography. CONCLUSIONS: Injection of gelatin matrix hemostatic sealant into the nephrostomy tract may be of value in preventing bleeding after PCNL. In this pilot experience it provided immediate and effective hemostasis.