Aryeh Keehn

Virtual surgical planning: a novel aid to robot-assisted laparoscopic partial nephrectomy.

BACKGROUND AND PURPOSE Incidental detection of small renal masses has significantly increased over the last two decades with the advent of cross-sectional imaging. The shift in stage has been met with a shift in treatment modality because the preservation of renal parenchyma can prevent adverse outcomes. Robot-assisted laparoscopic partial nephrectomy (RALPN) needs significant surgeon expertise, and preoperative planning is imperative. PATIENTS AND METHODS Between December 2010 and September 2011, virtual surgical planning (VSP) was used in consecutive patients with renal tumors that were suspicious for renal-cell carcinoma who were undergoing RALPN by a single surgeon. Three-dimensional (3D) reconstructions were examined and manipulated preoperatively, and an operative plan formulated. Intraoperative anatomy and preoperative 3D reconstructions were compared in real time. RESULTS A total of 10 patients underwent RALPN with preoperative VSP. Average patient age at intervention was 54.6 years and average tumor size was 4.3 cm (range 1.7-7.5 cm). Tumor laterality was evenly distributed. Nephrometry score ranged from 5A to 10P, and final tumor pathology results revealed malignancy in 80%. No complications occurred intraoperatively, and an excellent correlation was noted between preoperative 3D reconstruction and intraoperative anatomy. All patients underwent a successful partial nephrectomy with no positive margins on final pathology results. Mean length of surgery was 232.9 minutes (range 156-435 min), and mean estimated blood loss was 370 mL (range 75-1800 mL). Warm ischemia time ranged from 20 to 50 minutes (mean 33.9 min). Data regarding postoperative renal function were available for six patients with an average loss of function of 9.5% (range 2%-17%). CONCLUSIONS The implementation of this novel technology has significantly improved our ability to plan RALPN preoperatively. Tumor depth and complexity of tumor resection are assessed and the appropriate operative intervention and approach planned. Tumor proximity to vascular structures and collecting system were reliably predicted and therefore anticipated. Overall, these advantages created a safer surgical endeavor.

The Relationship Between Visceral Obesity and the Clinicopathologic Features of Patients with Small Renal Masses

INTRODUCTION AND OBJECTIVES It is well known that adipose tissue plays a key role in the metabolic syndrome. We investigated whether visceral fat (VFA) and or subcutaneous fat (SQF) levels are associated with the tumor phenotype of small renal masses. Additionally, we sought to investigate the relationship between VFA and baseline renal function as measured by glomerular filtration rate. MATERIALS AND METHODS From 2002 through 2011, 144 patients undergoing minimally invasive partial nephrectomy were retrospectively reviewed by a radiologist for VFA and SQF fat measurements, using standard software. A third parameter, visceral adipose tissue percent (VAT%), was also calculated using the formula: (VAT%=[VFA/VFA+SQF]×100%). We used tertiles of VFA and SQF content to compare demographic and clinical characteristics. We also looked at VFA as a continuous variable. Associations between covariables were analyzed using multivariate logistic regression analysis and odds ratios with 95% confidence intervals. RESULTS Eighty-one patients had renal-cell carcinoma (RCC) and 30 patients had non-RCC pathology. On multivariate analysis, increasing BMI (p=0.023), VFA (p=0.048), VAT% (p=0.028), and Charlson comorbidity score (p=0.047) were significantly associated with worse preoperative Modification of Diet in Renal Disease (MDRD). In a subset multivariate analysis of the 81 patients with RCC, increasing VFA was statistically associated with worsening Fuhrman grade (p=0.017). CONCLUSIONS VFA may be linked to the pathophysiology of renal function in patients evaluated for renal masses. Additionally, VFA may be associated with worsening tumor grades in patients with small-volume RCC. Interestingly, SQF did not play such a role. This small study proposes an interesting physiologic link between VFA and the biology of both kidney function and tumor histology. Larger studies are needed to corroborate our findings.

Outcomes and Management Considerations in Patients on Dialysis Undergoing Laparoscopic Radical Nephrectomy for Renal-Cell Carcinoma

PURPOSE To analyze the perioperative outcomes and management considerations in patients with dialysis-dependent end-stage renal disease (ESRD) undergoing laparoscopic radical nephrectomy for renal-cell carcinoma (RCC). METHODS There were 224 consecutive laparoscopic radical nephrectomies reviewed. Of those, 37 patients with ESRD were identified and compared with 187 patients with sporadic RCC. Evaluable parameters included age, sex, race, side of surgery, medical comorbidities, body mass index, American Society of Anesthesiologist (ASA) scoring, and age adjusted Charlson Comorbidity Index. All complications occurring intraoperatively and within the first 30 days were classified as per the Clavien classification system. Presurgical workup and transplant considerations were evaluated. Demographic and clinical characteristics were compared using Student t tests and chi-square tests for categoric variables. RESULTS Compared with non-ESRD patients, those with ESRD were younger and had smaller tumors. ASA was significantly higher in the ESRD group (P<0.001). Mean blood loss was similar between ESRD patients and non-ESRD patients. Overall complication rates were higher in patients with ESRD. Pathologic characteristics of ESRD renal masses included a higher proportion of papillary RCC. CONCLUSION Patients with RCC associated with ESRD tend to have a higher ASA class and lower grade tumors. In addition, this population is at increased risk of surgical complications and more likely to need transfusions. Careful preoperative preparation and intraoperative anesthetic management are crucial to minimize patient morbidity and improve outcomes.

V9-04 PARTIAL NEPHRECTOMY IN PATIENTS WITH MULTIPLE RENAL LESIONS AMENABLE TO NEPHRON SPARING SURGERY

with cold scissors, the tumor pseudocapsule is identified (white asterisk) and separated from normal renal parenchyma (black plus sign). C) As the tumor pseudocapsule (white asterisk) is freed from renal parenchyma, the tumor can be rolled out of the tumor bed (black plus sign). d) Once the tumor is removed, hemostatic agents are applied to the tumor bed and manual pressure is held with the robot for five minutes. Renorraphy may be performed, but not necessary if bleeding is controlled. RESULTS: All 42 RALER procedures were completed robotically. The mean patient age was 60 years (standard deviation (SD) 12), with a mean BMI of 34.3 (SD 6.7). Radiographic mass size was 0.05). Limitations include small sample size and short follow up. CONCLUSIONS: RALER is a safe and oncologically sound approach to small renal mass excision. This technique is maximally renal sparing as there is no resection of normal renal parenchyma and can be performed off clamp.