Experimental model of human corpus cavernosum smooth muscle relaxation

PURPOSE: To describe a technique for en bloc harvesting of the corpus cavernosum, cavernous artery and urethra from transplant organ donors and contraction-relaxation experiments with corpus cavernosum smooth muscle. MATERIALS AND METHODS: The corpus cavernosum was dissected to the point of attachment with the crus penis. A 3 cm segment (corpus cavernosum and urethra) was isolated and placed in ice-cold sterile transportation buffer. Under magnification, the cavernous artery was dissected. Thus, 2 cm fragments of cavernous artery and corpus cavernosum were obtained. Strips measuring 3 x 3 x 8 mm3 were then mounted vertically in an isolated organ bath device. Contractions were measured isometrically with a Narco-Biosystems force displacement transducer (model F-60, Narco-Biosystems, Houston, TX, USA) and recorded on a 4-channel Narco-Biosystems desk model polygraph. RESULTS: Phenylephrine (1µM) was used to induce tonic contractions in the corpus cavernosum (3 - 5 g tension) and cavernous artery (0.5 - 1g tension) until reaching a plateau. After precontraction, smooth muscle relaxants were used to produce relaxation-response curves (10-12M to 10-4 M). Sodium nitroprusside was used as a relaxation control. CONCLUSION: The harvesting technique and the smooth muscle contraction-relaxation model described in this study were shown to be useful instruments in the search for new drugs for the treatment of human erectile dysfunction.

Stapleless laparoscopic assisted radical cystectomy with ileal neobladder in a male and with ileal loop in a female: initial report from Brazil

INTRODUCTION: Here, we report our initial experience with laparoscopic assisted radical cystectomy without the use of surgical staples. CASES REPORT: A 70 year old male and a 55 year old female were diagnosed to have T2G3 transitional cell carcinoma of the bladder with negative metastatic work-out. both patients were scheduled and agreed to a laparoscopic assisted radical cystectomy. In both cases, urinary diversion (orthotopic ileal Studer neobladder in the male and ileal conduit in the female) was performed extracorporeally following radical cystectomy. In both cases control of the bladder vascular pediclewas accomplished with a combination of metallic and hem-o-lock clips. The total surgical time was 6.5 hours in both cases. Estimated intra-operative blood loss was 500 cc and 350 cc respectively, however both patients required postoperative blood transfusions. No intraoperative complications occurred. In both cases, pathology revealed negative surgical margins. CONCLUSIONS: Extracorporeal creation of urinary diversion decrease the overall operative time. Laparoscopic pelvic lymphadenectomy can be performed following the extended template. The use of surgical clips instead of vascular Endo-GIA titanium staples to control the bladder vascular pedicles is feasible and safe in selected patients, thus reducing intraoperative surgical costs. Considerable experience with laparoscopic radical prostatectomy is necessary before one attempts laparoscopic radical cystectomy.