Kyle J. Weld

Comparison of cryoablation, radiofrequency ablation and high-intensity focused ultrasound for treating small renal tumours

For an ablative technology to be considered as a clinically viable alternative for oncological applications, two simple criteria must be met. First, an ablative technology must be able to completely destroy all viable tissue, with no areas of viable tissue left. Second, the surgeon must be able to monitor and precisely target the area to be ablated to assure complete tumour destruction and preservation of surrounding vital structures. Ablative methods that can achieve these two basic requirements while allowing a minimally invasive approach may become the future of surgical management of small renal masses. Herein, we discuss the currently available data on the efficacy and morbidity rates of the most promising ablative technologies, i.e. cryoablation, radiofrequency ablation (RFA) and high-intensity focused ultrasound (HIFU).

Longterm Changes in Creatinine Clearance after Laparoscopic Renal Surgery

BACKGROUNDnControversy exists about the impact of ischemia on renal function. We evaluated the creatinine clearance of patients having undergone laparoscopic renal extirpative and ablative surgery.nnnSTUDY DESIGNnThe records of patients undergoing laparoscopic procedures for renal masses from February 2000 to March 2004 were examined. Creatinine clearance (CrCl) for each patient was determined using the Cockcroft-Gault equation and ideal body weight. We compared CrCl changes of patients undergoing laparoscopic partial nephrectomy (without renal ischemia [LPN-none], with warm ischemia [LPN-warm], and with cold ischemia [LPN-cold]) with patients undergoing laparoscopic radical nephrectomy (LRN) and laparoscopic cryoablation. Patients predisposed to medical renal disease were substratified and evaluated.nnnRESULTSnAll patients who underwent LRN or LPN-warm sustained a significant drop in CrCl on the first postoperative day, compared with patients who had LPN without ischemia or cryoablation (p < 0.01). The CrCl decrease correlated directly with warm ischemia time. Six months postoperatively, CrCl changes were no longer significant. Patients with medical renal disease risk factors were more likely to sustain longterm (1 year postoperatively) renal damage if they had renal ischemia, trending toward statistical significance.nnnCONCLUSIONSnIschemia causes acute renal damage, which is apparently reversible in patients without evidence of medical renal disease. Patients with known medical renal disease have substantial longterm changes in renal function associated with unilateral renal ischemia. Considering the insensitivity of creatinine-based renal function metrics, only eliminating ischemic time will realize the goal of maximal nephron preservation, particularly in patients with preexisting medical renal disease.