Perioperative Outcomes of Laparoscopic Partial Nephrectomy Stratified by Body Mass Index

Laparoscopic Partial Nephrectomy

Renal cell carcinoma has historically been managed by radical nephrectomy, but as knowledge of the disease has advanced, nephron sparing surgery has become the norm in appropriately selected tumors. Laparoscopic partial nephrectomy (LPN) has been shown to have comparable oncologic outcomes and a shorter convalescence period compared to the traditional open partial nephrectomy. Dissemination of techniques has led to significantly increased use of minimally invasive nephron sparing surgery, and LPN remains a cost-effective and efficacious method for approaching small renal masses.

Metabolic Syndrome Predicts Worse Perioperative Outcomes in Patients Treated With Partial Nephrectomy for Renal Cell Carcinoma

OBJECTIVE

To test the association between metabolic syndrome (MetS) and its components (high blood pressure, body mass index [BMI]  ≥ 30, altered fasting glucose, low high-density lipoprotein cholesterol and high triglycerides) on perioperative outcomes after partial nephrectomy (PN).

METHODS

Within the National Inpatient Sample database (2000-2015) we identified all PN patients. First, temporal trends of MetS were reported. Second, the effect of MetS components was tested in multivariable logistic regression models predicting overall and specific perioperative complications. Third, we tested for dose-response from the concomitant effect of multiple MetS components. All models were weighted and adjusted for clustering, as well as all available patient and hospital characteristics.

RESULTS

Of 25,875 patients: (1) 59.3% had high blood pressure, (2) 14.7% had BMI  ≥ 30, (3) 21.7% had altered fasting glucose, (4) 20.2% had high triglycerides, and (5) <0.01% had low high-density lipoprotein cholesterol. One vs 2 vs 3 vs 4 MetS components were recorded in 34.9% vs 22.9% vs 8.9% vs 2.2% patients. Of all, 11.1% exhibited  ≥ 3 components and qualified for MetS. The rates of MetS increased over time (estimated annual percentage changes: +12.0%;P <.001). The 4 tested MetS components (high blood pressure, BMI  ≥ 30, altered fasting glucose, and high triglycerides) achieved independent predictor status in multivariable models predicting overall, cardiac, miscellaneous medical, vascular, and respiratory complications, as well as transfusions. Moreover, a statistically significant dose-response was confirmed for the same endpoints.

CONCLUSION

MetS and its components consistently and strongly predict perioperative complications after PN. Moreover, the strength of the effect was directly proportional to the number of MetS components exhibited by each individual patient, even if formal MetS diagnosis of  ≥ 3 components has not been met.

High BMI and male sex as risk factor for increased short-term renal impairment in living kidney donors - Retrospective analysis of 289 consecutive cases

BACKGROUND

Kidney transplantation represents the treatment of choice for end-stage renal disease (ESRD). However, nephrectomy bears certain short- as well as long-term risks for the healthy, voluntary donor. As obesity is increasing and is a known risk factor for surgical complications, we wanted to assess the impact of BMI on perioperative complication rates and renal function.

MATERIALS AND METHODS

We retrospectively assessed patients undergoing living donor kidney nephrectomy at our institution. We identified 289 donors that underwent unilateral nephrectomy between January 2006 and December 2015. Donors were categorized according to their BMI (BMI <25 kg/m², BMI ≥25/<30 kg/m², BMI ≥30 kg/m²). Where indicated, analysis of variance (ANOVA) was used to compare groups, a stepwise linear regression model was used to assess impact of BMI on the change of eGFR.

RESULTS

126 donors (43.6%) had a BMI <25 while 120 (41.5%) had a BMI ≥25/<30 and 43 (14.9%) were obese with a BMI ≥30. BMI had no statistically significant influence on the percentage of laparoscopic approach (86.5% vs. 83.3% vs. 88.4%, p = 0.6564), on conversion rates (0% vs. 2.0% vs. 2.6%, p = 0.2879) or postoperative complication rates defined as Clavien Dindo ≥ II (8.7% vs. 13.3% vs. 14.0%, respectively; p = 0.4474). Notably, there were no Grade III or higher complications in any group. There was no difference in pre-operative kidney function, postoperative surgical site infection or systemic infection. BMI and male sex had a statistically significant influence on short-term decline of eGFR.

CONCLUSION

Obese donors do not suffer from an increased risk of intraoperative or perioperative complication rates. However, male sex and high BMI are associated with a more pronounced short-term decline in renal function. The impact of BMI on long-term consequences for kidney donors needs to be defined in larger prospective cohorts.

Feasibility of laparoscopic partial nephrectomy in the obese patient and assessment of predictors of perioperative outcomes

Introduction:

Partial nephrectomy is the gold standard for treatment of small renal masses. Our study compares outcomes for obese (body mass index [BMI] ≥30) and healthy (BMI <30) patients undergoing laparoscopic partial nephrectomy (LPN) with the intention of defining preoperative risk factors for complications and renal insufficiency in the obese.

Materials and Methods:

We conducted a retrospective review of 187 consecutive patients who underwent LPN. We examined the association between BMI and postoperative complication, estimated blood loss (EBL), hospital length of stay, warm ischemic time (WIT), and postoperative renal function. We did similar analyses using the RENAL nephrometry score and the comorbidity status of the patients.

Results:

We found no statistically significant increase in complications in obese (BMI ≥30) individuals relative to healthy (BMI <30) patients. The obese experienced approximately 100 cc more EBL (P = 0.0111). Patients experienced more complications if they had a Charlson comorbidity score ≥3 (P = 0.0065), an American Association of Anesthesiologists score ≥3 (P = 0.0042), or a history of diabetes mellitus (P = 0.0196). There was no association between RENAL nephrometry score and complication. However, patients with a score ≥8 experienced higher WIT (P = 0.0022), a greater decline in estimated glomerular filtration rate postoperatively (P = 0.0488), and an increased risk of developing chronic kidney disease ≥3 (P = 0.0065).

Conclusions:

Obese patients undergoing LPN are not at significantly increased risk of complication relative to nonobese patients. Comorbidity status and RENAL nephrometry score, independent of BMI, should be the main considerations of a patient's suitability for LPN.