Minimally invasive management of renal cancer

In the last two decades, the diagnosis and treatment of renal cancer were influenced by new technologies and surgical techniques. The new radiologic methods had a major impact in detecting smaller and asymptomatic tumors, while the minimally invasive options have offered a low-morbidity and high-efficacy individualized treatments to the patients, based on tumor characteristics and associated comorbidities. Herein we present a contemporary review of the minimally invasive approaches to the renal cancer, supported by the large experience with these therapeutic methods at the Cleveland Clinic.

Involvement of endothelial thromboxane A2 in the vasoconstrictor response induced by 15-E2t-isoprostane in isolated human umbilical vein

The present study was undertaken to evaluate the contractile response of several E- and F-ring isoprostanes (IsoP) in human umbilical vein (HUV) and to investigate the role of the endothelium on the effect of 15-E2t-IsoP, the most potent vasoconstrictor isoprostane, in human vessels. HUV rings with or without endothelium were suspended in an organ bath for recording the isometric tension in response to different agonists. The inhibitors to be evaluated were applied 30 min before the addition of the agonist. All of the compounds tested produced concentration-dependent contractions when tested on HUV rings with endothelium. Although these compounds were equieffective, significant differences were observed in their potency, with U46619 being the most potent followed by 15-E2t-IsoP > 15-E1t-IsoP = 15-F2t-IsoP > 15-F1t-IsoP = 9-epi-15-F2t-IsoP in descending rank order of potency. 15-E2t-IsoP was the most potent of the isoprostanes evaluated and, therefore, the one employed in the present study. When intact endothelium HUV rings were used, 15-E2t-IsoP-induced contraction was unaffected by the endothelin-converting enzyme inhibitor, phosphoramidon (10 microM), suggesting that short-term endothelin-1 release is not involved in this response. However, the non-selective cyclooxygenase (COX) inhibitor, indomethacin (10 and 30 microM), and the COX-2 selective inhibitor, NS-398 (3, 10 and 30 microM) produced inhibitory effects on 15-E2t-IsoP-induced contraction of HUV rings with endothelium. These results indicate that COX-derived contractile prostanoids are involved in this effect. Furthermore, the apparent pKb values estimated for indomethacin (5.5) and NS-398 (5.4) suggest that the prostanoids involved are derived from the COX-2 isoenzyme pathway. On HUV rings with endothelium, the phospholipase A2 inhibitor, oleyloxyethyl phosphorylcholine (30 and 100 microM), induced an inhibitory effect on 15-E2t-IsoP-induced contraction, suggesting that the phospholipase A2 pathway is also involved in this effect. In addition, the thromboxane A2 synthase inhibitor furegrelate (10 and 30 microM) also inhibited 15-E2t-IsoP-induced contraction of HUV rings with endothelium, indicating that thromboxane A2 is one of the contractile prostanoids involved in this response. Endothelium denudation clearly diminished the vasoconstrictor potency of 15-E2t-IsoP, demonstrating that the endothelium releases a vasoconstrictor factor in response to 15-E2t-IsoP. The absence of an inhibitory effect at the highest concentration of furegrelate (30 microM) on 15-E2t-IsoP-induced contraction of HUV rings without endothelium suggested that endothelium is the source of thromboxane A2. We conclude that prostanoids derived from the COX-2 isoenzyme pathway participate in 15-E2t-IsoP-induced vasoconstriction of isolated HUV rings. Our results also indicate that endothelial thromboxane A2 is one of the prostanoids involved in this effect.

Nefrectomía parcial laparoscópica: Técnica y resultados

The indication of laparoscopic partial nephrectomy (LPN) has evolved considerably, and the technique is approaching established status at our institution. Over the past 5 years, the senior author has performed more than 450 laparoscopic partial nephrectomies at the Cleveland Clinic. Herein we present our current technique, review contemporary data and oncological outcomes of LPN.

Laparoscopic treatment of retroperitoneal fibrosis: report of two cases and review of the literature

OBJECTIVES

We present the results of treatment by laparoscopy of two patients with retroperitoneal fibrosis and review the literature since 1992, when the first case of this disease that was treated using laparoscopy was published. We also discuss the contemporary alternatives of clinical treatment with corticosteroids and tamoxifen.

CASE REPORT

Two female patients, one with idiopathic retroperitoneal fibrosis, and other with retroperitoneal fibrosis associated with Riedel's thyroiditis, were treated using laparoscopic surgery. Both cases had bilateral pelvic ureteral obstruction and were treated using the same technique: transperitoneal laparoscopy, medial mobilization of both colons, liberation of both ureters from the fibrosis, and intraperitonealisation of the ureters. Double-J catheters were inserted before the operations and removed 3 weeks after the procedures. The first patient underwent intraperitonealisation of both ureters in a single procedure. The other had 2 different surgical procedures because of technical difficulties during the first operation. Both patients were followed for more than 1 year and recovered completely from the renal insufficiency. One of them still has occasional vague lumbar pain. There were no abnormalities in the intravenous pyelography in either case.

CONCLUSIONS

Surgical correction of retroperitoneal fibrosis, when indicated, should be attempted using laparoscopy. If possible, bilateral ureterolysis and intraperitonealisation of both ureters should be performed in the same operation.