Bursting strength with various methods of renal artery ligation and potential mechanisms of failure.

BACKGROUND AND PURPOSE: Vascular control is crucial during laparoscopic ligation of the renal vessels. Intracorporeal suture ligation has been replaced by easier methods, such as specialized clip appliers and automatic stapling devices; nevertheless, the optimal application and margin of safety of such devices have yet to be determined. We sought to address this question by measuring the bursting strength of arteries ligated with several standard devices. MATERIALS AND METHODS: One end of an adult porcine artery (3-7-mm diameter) was occluded with a titanium clip, self-locking polymer clip, or laparoscopic linear cutting stapler. Comparisons were made with one or two clips and with different distal cuff lengths (i.e., flush or 2 mm). The open end was secured to a pulsatile infusion pump. Leak/failure pressures were measured using a digital barometer. RESULTS: The mean bursting pressures for the clips were above physiologic arterial pressures (1220-1500 mm Hg). However, the vessels closed with the stapler leaked at a lower mean pressure (262 mm Hg). Failure of titanium or self-locking polymer clips was the result of vessel retraction into and behind the clip, while staple- line leakage occurred between individual staples. Bursting pressures with the titanium and self-locking polymer clips was unaffected by the number of clips or length of vascular cuff. CONCLUSIONS: All tested methods of vascular control performed well at physiologic pressures, suggesting that safety is not increased with traditional maneuvers such as additional clips or longer cuff length.

Novel everting urologic access sheath: decreased axial forces during insertion.

BACKGROUND: Advancement of urologic instruments through the genitourinary tract is associated with significant axial forces that likely contribute to patient discomfort, even after injection of a local anesthetic, and may lead to mucosal trauma, postprocedural dysuria and hematuria, and increased susceptibility to infection and strictures. Placing an everting urethral sheath prior to instrumentation may decrease these problems. MATERIALS AND METHODS: Two 7-cm-long, 5-mm diameter urethral luminal models were created, one with and one without an artificial stricture. We measured the forces generated during advancement of a novel everting access sheath (Cystoglide; Percutaneous Systems, Mountain View, CA) through the models in comparison with a representative cystoscope and a urologic dilator simulating a traditional access sheath. RESULTS: The mean force generated during advancement of the everting sheath was significantly less than that of both the representative cystoscope (P<0.01) and the traditional access sheath (P<0.01). This held true for the urethral models both with and without an artificial stricture (P<0.01) and with and without lubrication (P<0.01). CONCLUSIONS: This novel introduction sheath markedly decreased the axial forces applied to an artificial urethral luminal wall. It is possible that the clinical use of this technology will decrease the discomfort and potential complications associated with lower urinary-tract endoscopy.

Laparoscopic appreciation of the adrenal artery: fact or fiction?

BACKGROUND: It is well accepted that identification and control of the adrenal vein is a critical step in laparoscopic adrenalectomy. The surgical and anatomic literature propagates the notion of a dominant or multiple dominant adrenal arteries that should likewise be controlled during surgical extirpation. MATERIALS AND METHODS: We assessed the frequency of adrenal-artery identification and the need for formal ligation in an extensive series of laparoscopic adrenalectomies. RESULTS: In our experience, even using a magnified laparoscopic view, we found it possible to identify and necessary to formally ligate an adrenal artery in only 3 of 265 cases (1.1%). Further, in this series, only the inferior adrenal artery was ever seen definitively to require formal clip ligation, while a discrete middle or superior adrenal artery was almost never seen, and the vasculature in these areas could be controlled with electrocautery or ultrasonic energy alone during routine dissection. CONCLUSIONS: The need to search for and ligate the arterial supply during laparoscopic adrenalectomy is not as clinically significant as once thought, and formal control appears unnecessary unless the vessels are serendipitously encountered during the routine dissection.

Sexual, irritative, and voiding outcomes, following stereotactic body radiation therapy for prostate cancer.

BACKGROUND: Urinary symptoms and sexual dysfunction are the two most common complaints following prostate radiotherapy. The impact of hypofractionated treatment on sexual function, irritative symptoms, and voiding symptoms has not been determined within the same patient population. Here we present our institutional data on sexual function, voiding function, irritative symptoms, and treatment response following SBRT. METHODS: This retrospective analysis includes 102 non-metastatic patients treated with SBRT at a single institution between May 2008 and September 2014. The course of radiotherapy consisted of 36.25 Gy (range 35-40) over five daily fractions. International Prostate Symptom Score (IPSS), Sexual Health Inventory for Men (SHIM), and PSA were recorded at baseline, 1, 3, 6, 9, 12, 18, 24, and 36 months after treatment. RESULTS: Median patient age was 72 years old with a median follow-up of 4.3 years. Pretreatment IPSS-I score was 5.21, increasing to 6.97 (p < .001) after 1 month. The mean IPSS-I score returned close to baseline after 3 months to 5.86 and decreased to below baseline after 2 years to 5.09. At 3 months, 9 months, and 2 years, 47.5, 76.2, and 91.1% of patients had reached IPSS-I resolution. The mean IPSS-O score prior to treatment was 5.31 and there was an increase in the score to 6.45 (p = 0.344) at 1 month. The score remained close to baseline and decreased to 4.00 at 2 years and significantly decreased to 3.74 (p = 0.035) at 3 years. 64.4, 82.1, and 96.0% of patients had IPSS-O resolution by 3 months, 9 months, and 2 years. The mean SHIM score prior to treatment was 13.52 and continually decreased to below baseline a year after treatment to 10.56 (p < .001). SHIM score began to improve at 18 months, but was still significantly less than baseline at 12.12 (p = .01). CONCLUSIONS: While an increase in AUA/IPSS score initially occurred, all patients resume normal activities immediately following treatment and the AUA/IPSS symptoms improved from baseline. Irittative symptoms take longer to resolve when compared to obstructive voiding symptoms in patients treated with SBRT. Three year PSA response, reported toxicity, erectile function preservation, and urinary function improvement, shows favorable results.

Failed percutaneous balloon dilation for renal access: incidence and risk factors.

OBJECTIVES: To present our experience using balloon dilation and discuss secondary techniques to establish a percutaneous tract when balloon dilation fails. Balloon dilation is a safe and effective method to achieve percutaneous renal access, but it is not uniformly successful. Also, the failure rate and risk factors have not been well documented. METHODS: We retrospectively reviewed our last 99 consecutive percutaneous renal procedures using a balloon system as our initial dilation modality. In all cases, the urologist achieved needle access. We determined the balloon failure rate, relationship to prior renal surgery and other patient-related factors, and success rate using secondary techniques of tract dilation. RESULTS: The balloon did not adequately dilate a tract in 17 (17% failure rate) of 99 cases. The risk factors for failure included a history of prior ipsilateral renal surgery (25% failure rate versus 8% without surgery) and subcostal compared with supracostal puncture (18% versus 9% failure rate). The failure rate was not increased when stratified by laterality, stone composition, stone size and location, or history of ipsilateral renal infection. Amplatz dilators were used in 16 refractory cases and were successful in 15. Metal Alken dilators were successfully used in 2 patients. CONCLUSIONS: The balloon dilation system is commonly used as the primary modality to establish percutaneous renal access. Although safe and effective (83%), the success rate drops dramatically in patients with prior ipsilateral renal surgery. Knowledge and skill with alternative dilation systems, such as Amplatz or metal Alken dilators, are necessary to successfully gain entry into all renal collecting systems.