Laparoscopic renal tumor cryoablation: appropriate application of real-time ultrasonographic monitoring.

BACKGROUND AND PURPOSE: Many authors who report outcomes of laparoscopic cryoablation for renal tumors comment that real-time intracorporeal ultrasonographic monitoring of the ice-ball formation is imperative. In our experience, ultrasonographic monitoring of the ice-ball formation necessitates significantly more mobilization of the kidney, and the images are difficult to interpret because of artifact and the cryoablation effect on the tissue. We report our intermediate outcomes for laparoscopic cryoablation without real-time ultrasonographic monitoring of the ice ball. PATIENTS AND METHODS: Between December 2002 and May 2007, 27 patients underwent laparoscopic renal cryoablation. The cryoablation approach was based on tumor location and surgeon preference. Lesions were identified and overlying fat was excised, without further mobilization. Real-time ultrasonographic measurement and mapping of the renal lesion were performed. All lesions were biopsied before cryoablation. A double 10-minute freeze-thaw cycle was performed. Postoperative follow-up comprised serial imaging at months 1, 3, 6, and 12 and yearly thereafter. RESULTS: Mean patient age was 70.1 years with a mean renal tumor size of 2.2 cm. Sixteen (59.3%) patients had more than three comorbidities and six (22.2%) patients had two comorbidities with at least 1 previous intra-abdominal surgery. An average of four cryoablation probes were used per lesion. The serum creatinine level was 1.3 mg preoperatively and 1.4 mg at last follow-up. At follow-up of 22 months, there were no local recurrences and 1 (3%) metastatic lesion. CONCLUSION: Laparoscopic cryoablation of small renal masses continues to be a safe and effective technique, even without the use of real-time ultrasonographic monitoring of the ice ball.

Hurdles to helium gas laparoscopy and a readily available alternative.

BACKGROUND AND PURPOSE: Although multiple series of helium insufflation-assisted laparoscopic surgery are reported, we encountered difficulty at many levels when arranging a laparoscopic nephrectomy with helium insufflation. We present our experience with attempting to use helium gas as an insufflant and our successful use of argon gas as an adjunct to CO(2) insufflation with a case report as illustration. MATERIALS AND METHODS: The patient is a 66-year-old man with a progressively enlarging 3.1-cm right renal mass. His history is significant for severe chronic obstructive pulmonary disease, necessitating home oxygen and frequent cycles of steroids. In line with the patient's desire for a minimally invasive procedure, we scheduled a laparoscopic nephrectomy with helium gas. Helium tanks need specialized adapters (yoke) to connect to laparoscopic insufflators; once the yoke was located, we were informed that helium is not approved by the Food and Drug Administration for use as an insufflant and we could not proceed with its use without a full hospital institutional review board review. We elected to use low-pressure CO(2) insufflation augmented by argon gas insufflation via the argon beam coagulator. RESULTS: The patient tolerated the low-pressure CO(2) /argon gas pneumoperitoneum without difficulty. There were no significant changes in the hemodynamic variables throughout the procedure. This patient was extubated at the completion of the procedure, and there were no intraoperative or postoperative complications. CONCLUSIONS: Although numerous reports and case series exist regarding the use of helium as an alternate insufflation agent to CO(2), the logistics of obtaining the correct helium yoke and hospital approval are cumbersome for this rarely indicated agent. A far simpler alternative, with similar physiologic effects, is the use of argon gas as an adjunct to CO(2) insufflation, or in lieu of CO(2) insufflation.

Robot-assisted laparoscopic excision and ureteroureterostomy for congenital midureteral stricture.

Congenital ureteral strictures most commonly occur at the proximal and distal segments of the ureter. Congenital midureteral stricture is a rare entity that is usually detected by prenatal ultrasonography and repaired in infants. We present the case and video of a congenital midureteral stricture in a 20-year-old woman who presented with a severe episode of pyelonephritis. The congenital midureteral stricture was successfully managed with robot-assisted laparoscopic excision and ureteroureterostomy.

Robotically assisted excision of ovarian vein for intermittent ureteral obstruction.

With the increasing popularity of robotically assisted procedures, new indications for robotically assisted surgery are being examined. Although open and laparoscopic surgical management of intermittent ureteral obstruction from ovarian vein syndrome has been reported previously, we report the first use of robotic assistance for ureterolysis and ovarian vein excision.

Missed diagnoses by urologists resulting in malpractice payment.

PURPOSE: Missed diagnoses are a patient safety concern and they can result in malpractice allegation. The specialist physician may be liable for missed or delayed diagnoses even if an abnormality in the physician area of expertise is ruled out. We approached this largely unstudied area of medical malpractice in an effort to increase physician awareness and identify opportunities for prevention. MATERIALS AND METHODS: Working with the Medical Liability Mutual Insurance Company of New York State, we evaluated malpractice claims in urology that were closed with indemnity payment between 1985 and 2004. We identified all such claims resulting from alleged missed or delayed diagnoses by urologists. Claims were divided into 2 main categories based on whether the missed diagnosis was primarily urological, ie testis torsion, or not urological, ie appendicitis. RESULTS: A total of 75 missed diagnosis claims were identified, representing 15% of claims overall. The total indemnity payment for missed diagnosis claims was $32,591,013, which represented 27% of all indemnity payments for the study period. They were divided into 58 missed urological diagnoses and 17 missed nonurological diagnoses. Cancer represented 71% of missed urological diagnoses and 41% of missed nonurological diagnoses. Urological cancer missed diagnosis claims were associated with the highest average indemnity payment of $526,460. The average indemnity payment for missed diagnosis claims was 92% greater than the average indemnity payment for all other claims ($434,546 vs $226,133). An increase in the frequency of missed diagnosis claims closed with indemnity payment and in the amount of payment for missed diagnosis claims were observed during the 20-year study period. CONCLUSIONS: Indemnity payments resulting from missed diagnosis claims represent a disproportionately high percent of total indemnity payments (27%) due to a high average payment for such claims. Liability for the urologist resulted from missed diagnoses not only of urological conditions, but also of nonurological conditions.

Does laparoscopy beget underuse of partial nephrectomy for T(1) renal masses? Competing treatment decision pathways may influence utilization.

BACKGROUND AND PURPOSE: It has been suggested that renal laparoscopy has resulted in an underuse of partial nephrectomy (PN) for small renal masses in the U.S. In the absence of evidence-based medicine (EBM) guide-lines, multiple-perspective reasoning is required where complete v partial nephrectomy and the laparoscopic v the open surgical approach must be considered. We report on the PN rate in a contemporary laparoscopicera series of patients with T(1) renal masses and examine the potential influence of the management decision tree on the PN rate. PATIENTS AND METHODS: An actively managed database of referred patients with T(1) renal masses was utilized retrospectively. All patients were evaluated by a single fellowship-trained urologic oncologist with formal laparoscopic training. Patients were presented with a management decision tree in which PN v total nephrectomy (TN) was the first decision node, laparoscopy v open surgery was the second decision node, and the actual PN rate was reported. We then constructed a hypothetical decision tree in which the first and second decision nodes were reversed and the criteria for performing laparoscopic nephrectomy remained constant. RESULTS: Seventy consecutive patients were entered during a 36-month period (July 2002-June 2005). The actual PN rate was 60%: 91% for lesions <2.0 cm, 68% for lesions 2.1 to 4.0 cm, and 33% for lesions 4.1 to 7.0 cm; and 62% of patients were treated laparoscopically. When the first and second decision nodes were reversed and this hypothetical model was applied to the study cohort, the projected PN rate was 23%, and 96% of the patients were treated laparoscopically. In the hypothetical model, the PN rate fell when patients who chose laparoscopy at the first decision node were excluded from PN at the second decision node if the criteria for laparoscopic PN were not met. CONCLUSION: Laparoscopy did not appear to result in underuse of PN. We explain this by suggesting that the PN rate may be influenced by variation in the decision tree itself. Such variation is inherent in complex clinical decision making where EBM guidelines are lacking.

The immediate effect of castration on female rabbit bladder blood flow and tissue oxygenation.

BACKGROUND: The female urinary bladder is a target organ for estrogen. Reductions in circulating estrogen have been associated with urothelial and vaginal atrophy and bladder disorders including incontinence and increased incidence of bladder infections. We determined the effect of short-term ovariectomy on sex hormones, bladder blood flow, and tissue oxygenation in the rabbit model. MATERIALS AND METHODS: Female New Zealand White rabbits were ovariectomized and evaluated on 1, 3, and 7 days after ovariectomy. Tissue oxygenation (pO2) and blood flow were measured with oxylab system of real time measurements. Serum estrogen and progesterone were determined at sacrifice. Tissue hypoxia was localized histologically using Hypoxyprobe-1 immunohistochemistry. RESULTS: Short-term ovariectomy caused rapid decreases in serum estrogen and progesterone, significant decreases in urothelial oxygenation and blood flow. No significant decreases in blood flow or oxygenation were noted for the detrusor smooth muscle. Immunohistochemistry confirmed the presence of urothelial hypoxia at all times after ovariectomy. Bladder muscle did not demonstrate significant levels of hypoxia. CONCLUSION: The bladder urothelium is extremely sensitive to short-term ovariectomy, with significant urothelial hypoxia seen by post-ovariectomy day 1. Urothelial hypoxia may play a significant role in pelvic pain syndromes, incontinence, and increased susceptibility to bladder infection.