The BMI Paradox and Robotic Assisted Partial Nephrectomy

Abstract

Introduction: Partial nephrectomy (PN), has become the gold standard for the surgical management of small renal masses, due to excellent oncologic control with concomitant preservation of nephron units. However, data regarding the association of obesity with perioperative outcomes following PN are mixed. Therefore, the association between obesity (using BMI) and post-operative complications (POC) rate following Robotic assisted laparoscopic PN (RPNx) was tested. Methods: Two hundred and fifty-one adult patients who underwent RPNx from 1/2011 to 5/2017 at a single institution, with at least 90 days follow-up were identified and included. No patients were excluded. Electronic medical records were reviewed to record all POC within 90 days of surgery. A piecewise generalized linear model for binary outcomes (logistic) was used to model the proportion of subjects with POC by their BMI. The slope of the line is adjusted to a BMI of 30 Kg/m 2. Results: BMI is significantly associated with POC rate. POC rate decreased with increasing BMI below the inflection point of 30 Kg/m 2 (0.848[0.756, 0.952]) (OR [95% CI], p = 0.005). POC rate was found to increase with increasing BMI above the BMI inflection of 30 Kg/m 2 (1.102 [1.027, 1.182], p = 0.0071). Conclusions: In this cohort study, BMI showed an association with PC. It may be important to take BMI into account in surgical and clinical management considerations of RPNx, since higher rates of POC are associated with patients who are underweight, morbidly obese, and even with normal BMI. Further research is required on larger cohorts of RPNx patients to provide better description of this phenomenon and elucidate the role of BMI in development of POC.

The association of body composition with postoperative complications and length of hospital stay after radical or partial nephrectomy in patients with renal cell cancer: a multicenter population-based cohort study

“…Other studies found no relationship between obesity and any complications ( 19 - 21 ) or major complications ( 22 ). Kott et al found in 251 patients treated with robot-assisted partial nephrectomy that increasing BMI decreased complications rates up till an inflection point of 30 kg/m 2 , while above that point higher BMI was associated with higher complication rates ( 23 ). The precise relationship remains to be investigated.…”

Prediction of Intraoperative Trifecta Achievement during Laparoscopic Partial Nephrectomy

“…Wiens [15] showed that obese patients undergoing LPN are not at significantly increased risk of complication relative to non-obese patients and that comorbidity status and R.E.N.A.L.-score should be the main criteria to take into account to evaluate feasibility for LPN. On the contrary, Kott [16] found that a BMI over 30 kg/m 2 was a significant factor for POC associated with robot assisted LPN. In our analysis there was a relative significant correlation between achievement of intraoperative Trifecta and BMI.…”

Laparoscopic repeat surgery for gastro-oesophageal reflux disease: Results of the analyses of a cohort study of 117 patients from a multicenter experience

“…In this cohort study of 117 patients, the female/male ratio was 1.54 (71/46), the mean age was 60.4 years (range 17-89 years) and the mean body mass index (BMI) was 25.5 (range [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. As detailed in Table 1, patients were mostly ASA (American Society of Anaesthesiologists classification) II at the time of operation.…”

“…Interestingly, a BMI higher than 23 was associated to lower rate of post-operative complications, raising questions on the potential protective role of intra-abdominal fat around the hiatus that may reduce local inflammatory response 25 .…”