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.

Relaxation of rabbit corpus cavernosum smooth muscle and aortic vascular endothelium induced by new nitric oxide donor substances of the nitrosyl-ruthenium complex

INTRODUCTION: Endothelial dysfunction characterized by endogenous nitric oxide (NO) deficiency made 56 percent of patients affected with erectile dysfunction decline treatment with PDE-5 inhibitors. New forms of treatment are currently being developed for this group of patients. MATERIALS AND METHODS: The study compared the effect of sodium nitroprusside (SNP) and two substances of the nitrosyl-ruthenium complex, cis-[Ru(bpy)2(SO3)(NO)]PF-6-9 ("FONO1”) and trans-[Ru(NH3)4(caffeine)(NO)]C13 ("LLNO1”) on relaxation of rabbit corpus cavernosum smooth muscle and aortic vascular endothelium. The samples were immersed in isolated baths and precontracted with 0.1 µM phenylephrine (PE) and the corresponding relaxation concentration/response curves were plotted. In order to investigate the relaxation mechanisms involved, 100 µM ODQ (a soluble guanylate cyclase-specific inhibitor), 3 µM or 10 µM oxyhemoglobin (an extracellular NO scavenger) or 1 mM L-cysteine (a nitrosyl anion-specific scavenger) was added to the samples. RESULTS: All the NO donors tested produced a significant level of relaxation in the vascular endothelium. In corpus cavernosum samples, FONO1 produced no significant effect, but LLNO1 and SNP induced dose-dependent relaxation with comparable potency (pEC50 = 6.14 ± 0.08 and 6.4 ± 0.14, respectively) and maximum effect (Emax = 82 percent vs. 100 percent, respectively). All NO donors were found to activate soluble guanylate cyclase, since the addition of the corresponding inhibitor (100 µM ODQ) completely neutralized the relaxation effect observed. The addition of oxyhemoglobin reduced the relaxation effect, but did not inhibit it completely. In aortic vascular endothelium 3 µM oxyhemoglobin decreased the relaxation effect by 26 percent on the average, while 10 µM oxyhemoglobin reduced it by over 52 percent. The addition of 100 µM L-cysteine produced no significant inhibiting effect. CONCLUSIONS: These results suggest that LLNO1...

Complications in laparoscopic radical cystectomy: The South American experience with 59 cases

OBJECTIVE: In this study, we have gathered the second largest series yet published on laparoscopic radical cystectomy in order to evaluate the incidence and cause of intra and postoperative complication, conversion to open surgery, and patient mortality. MATERIALS AND METHODS: From 1997 to 2005, 59 laparoscopic radical cystectomies were performed for the management of bladder cancer at 3 institutions in South America. Twenty nine patients received continent urinary diversion, including 25 orthotopic ileal neobladders and 4 Indiana pouches. Only one case of continent urinary diversion was performed completely intracorporeally. RESULTS: Mean operative time was 337 minutes (150-600). Estimated intraoperative blood loss was 488 mL (50-1500) and 12 patients (20 percent) required blood transfusion. All 7 (12 percent) intraoperative complications were vascular in nature, that is, 1 epigastric vessel injury, 2 injuries to the iliac vessels (1 artery and 1 vein), and 4 bleedings that occurred during the bladder pedicles control. Eighteen (30 percent) postoperative complications (not counting mortalities) occurred, including 3 urinary tract infections, 1 pneumonia, 1 wound infection, 5 ileus, 2 persistent chylous drainage, 3 urinary fistulas, and 3 (5 percent) postoperative complications that required surgical intervention (2 hernias - one in the port site and one in the extraction incision, and 1 bowel obstruction). One case (1.7 percent) was electively converted to open surgery due to a larger tumor that precluded proper posterior dissection. Two mortalities (3.3 percent) occurred in this series, one early mortality due to uncontrolled upper gastrointestinal bleeding and one late mortality following massive pulmonary embolism. CONCLUSIONS: Laparoscopic radical cystectomy is a safe operation with morbidity and mortality rates comparable to the open surgery.

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.