Warm ischemia less than 30 minutes is not necessarily safe during partial nephrectomy: every minute matters.
ABSTRACT At the 11th Annual Meeting of the Society of Urologic Oncology (SUO), an expert panel discussed the importance of warm ischemia time on renal function during partial nephrectomy. The position of this manuscript is that every minute of warm ischemia time has a deleterious effect on renal function outcomes following partial nephrectomy.
The presentation was derived from a review of the published urologic, nephrology, and transplant literature related to warm ischemia time and renal function outcomes.
There exist numerous clinical models to study the effects of warm ischemia on renal function. These include the bilateral kidney, unilateral partial nephrectomy, solitary kidney partial nephrectomy, and transplant kidney model. Each of these models provides evidence for minimizing warm ischemia time to prevent acute renal failure, chronic kidney disease, and end stage renal failure. In the best available model, solitary kidney partial nephrectomy, each minute of warm ischemia was found to be associated with a 6% increased risk of acute renal failure, 7% increased risk of acute-onset end stage renal disease (ESRD), and 4% increased risk of new-onset ESRD while controlling for preoperative renal function, tumor size, and surgical approach.
There is ample evidence, consistent across multiple human kidney models, supporting the potentially deleterious renal effects of warm ischemia during partial nephrectomy. There does not appear to be a known safe threshold of warm ischemia since each minute sequentially contributes to the risk of developing acute kidney injury and renal function decline. Ultimate renal function following PN is dependent on the "3 Qs": quality (renal function prior to surgery), quantity (renal parenchyma preserved during surgery), and quickness (ischemia time).
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ABSTRACT: Introduction Intrarenal tumors pose a unique challenge to surgeons due to the lack of visual cues on the kidney surface. Intraoperative ultrasonography has facilitated the management of these tumors during minimally invasive partial nephrectomy. We sought to evaluate the safety, feasibility, and comparative effectiveness of robotic-assisted partial nephrectomy (RPN) in the management of completely intrarenal tumors. Methods Our institutional database was queried for patients undergoing RPN between 2007 and 2013. Patient demographics, tumor characteristics and perioperative outcomes were compared for patients with intrarenal tumors and tumors with any exophytic component. Patients without available preoperative imaging were excluded from the study. Results A total of 297 patients were identified with 30 having completely intrarenal tumors and 267 having some exophytic component. Patient demographics were similar between the two groups. Median tumor size was smaller for the intrarenal group than the exophytic group (2.3 vs. 2.7cm, p=0.015) and nephrometry score was higher for the intrarenal group (9 vs. 6, p<0.0001). Tumor characteristics were otherwise similar. Perioperative outcomes were similar between the intrarenal and exophytic groups: estimated blood loss (100 vs. 100 mL, p=0.56), operative time (165 vs. 162 min, p=0.86), warm ischemia time (17 vs. 17 min, p=0.54), RCC positive surgical margin (0% vs. 2.4%, p=0.74), intraoperative complications (0% vs. 0.76%, p=0.81) and postoperative complications (6.7% vs. 17.6% p=0.76). Conclusions RPN is feasible, safe, and effective in the treatment of select intrarenal kidney tumors with outcomes similar to those of partially exophytic tumors. This is likely facilitated by intraoperative ultrasonography. Completely intrarenal kidney tumors should not be automatically relegated to radical nephrectomy or open surgery.Journal of Endourology 07/2014; · 2.07 Impact Factor
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ABSTRACT: Although robot-assisted partial nephrectomy (RALPN) has been increasingly adopted, open procedures continue to be the reference nephron-sparing technique. We describe our initial surgical outcomes of RALPN in our single institution robotic program. Between January 2011 and February 2013, 65 consecutive patients underwent a RALPN by 2 surgeons. Preoperative characteristics, including the R.E.N.A.L. nephrometry score, perioperative parameters, and postoperative course, including renal function, were assessed from a retrospective database. The mean follow-up was 12 months. The mean age was 60.2 years and the mean tumour size was 3.9 cm. According to the R.E.N.A.L. nephrometry score, the tumours were classified moderately and highly complex tumours in 51% and 18.5% of cases, respectively. Median warm ischemia time (WIT) was 21 minutes. Factors associated with WIT were R.E.N.A.L. nephrometry score, tumour size, complication rates and surgeon experience. No conversion or grade 4 to 5 complications were reported. The mean hospital stay was 3 days. The overall complication rate was 24.6% (re-admission rate 7.7%), and decreased to 12% after 20 cases. After these initial 20 cases, a trifecta rate (no margins, preserved renal function, no complications) of 64.3% was achieved in moderately and highly complex tumours. The mean change in estimated glomerular filtration rate was 6.7 mL/min without severe postoperative renal failure. RALPN is a safe and feasible procedure with low specific morbidity, even in moderately or highly complex renal masses. The WIT depends on tumour characteristics, mainly determined by the R.E.N.A.L. nephrometry score and is improved by surgeon experience. Longer follow-up is needed to assess the oncologic mid-term safety of the procedure.Canadian Urological Association journal = Journal de l'Association des urologues du Canada 01/2013; 7(9-10):348-354. · 1.66 Impact Factor
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ABSTRACT: To compare renal functional outcomes in robotic partial nephrectomy (RPN) with selective arterial clamping guided by near-infrared fluorescence (NIRF) imaging to a matched cohort of patients who underwent RPN without selective arterial clamping and NIRF imaging.Urology 06/2014; · 2.42 Impact Factor