Even cold ischemia results in renal damage 29% to 40% of the time. Dr. Libertino has used 3D imaging and modifications in surgical techniques to perform partial nephrectomies without clamping the renal artery.
Dr. Kavoussi discussed what constitutes a complex renal mass. There are 3 nephrometry scoring systems. The one from Dr. Uzzo combines tumor sizes, exo- or endophytic status and degree, nearness to the collecting system, anterior/posterior descriptor and whether it is located above or below the renal pelvis. A score up to 12 defines the complexity of the tumor. All three scoring systems correlate with post-operative outcomes, such as change in creatinine.
Dr. Libertino discussed a case with a lower pole tumor in a solitary kidney with a nephrometry score of 12. Intraoperative ultrasound is used to delineate the tumor and its boundary. Vessels are cauterized with bipolar or tied if larger in diameter. Margins are inked to ensure no tumor involvement. Weck laproscopic clips are used to close the defect and minimize the risks of bleeding and urine leak.
Dr. Gill discussed the concept of “zero-ischemia” using super-selective control of clamping very small arterial branches to the tumor, and avoiding clamping the main renal artery. They do this using neurosurgical aneurysm micro-bulldogs. They identify the pre-terminal branch via a radial nephrotomy incision to place the bulldog. After the bulldog is placed, they use ultrasound to confirm that there is selective vascular ischemia. This renovascular anatomy must be defined using 5mm CT imaging to appreciate the relationship between the vessels and tumor. In their first 100 cases, they have not had a vascular injury.
Dr. Kavoussi discussed results of partial nephrectomy. OR time ranges from 2.3 to 4.5 hours. Estimated blood loss ranges from 205 to 550cc. It is lowest with Dr. Gill’s technique. The average nephrotomy score in Dr. Gill’s series was 7 and average tumor size was 3.2cm. There was a complication rate of 25%, but only 3% were high-grade. Neither complications nor severity of complications differed between on-clamp and off-clamp. In solitary kidneys, there is no statistical decrease in GFR in non-clamped cases from pre-op to post-op, but there is a 23% drop in the clamped patients. Cancer control was comparable.
Panelists: Inderbir Singh Gill MD, MCh, and Kavoussi Louis Raphael, MD
Moderated by John A. Libertino, MD at the American Urological Association (AUA) Annual Meeting - May 14 - 19, 2011 - Walter E. Washington Convention Center, Washington, DC USA
Reported for UroToday by Christopher P. Evans, MD, FACS, Professor and Chairman, Department of Urology, University of California, Davis, School of Medicine.
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