The impact of obesity on perioperative outcomes in laparoscopic radical nephrectomy: a systematic review and meta-analysis

Objective: Controversy exists regarding the safety and efficiency of laparoscopic radical nephrectomy (LRN) on morbidly obese patients and the difference of perioperative outcomes between obese and non-obese patients. This study aims to assess the association of obesity with perioperative outcomes of LRN. Materials and methods: We conducted a systemic review and meta-analysis to clarify this relationship. Relevant studies were searched in nine databases, PubMed, Web of Science, Embase, Cochrane Library, Wiley Online Library, SpringerLink, Elsevier, EBSCO, and Ovid. Database searching was updated until June 2019. Mesh search headings with combining keywords were searched about obese and non-obese patients who had undergone LRN. References in all the inclusions were also searched. Data extraction and study quality assessment were conducted by canonical methods. Results: Nine retrospective studies were included with a total of 1039 patients. The results demonstrated that: (1) obese groups were compared with non-obese groups with a longer operation duration (American P<0.00001, WMD: 49.21 min, 95% CI: 35.97 to 62.45; Asian P<0.00001, WMD: 26.94 min, 95% CI: 19.04 to 34.85; overall WMD: 32.80 min, 95% CI: 26.01 to 39.58, P<0.00001) and a larger estimated blood loss (American P=0.03, WMD: 34.02 ml, 95% CI: 3.95 to 64.09; Asian P<0.00001, WMD: 49.61 ml, 95% CI: 42.32 to 56.91; overall WMD: 48.75 ml, 95% CI: 41.66 to 55.83, P<0.00001), with significant statistical difference; (2) the two groups showed no significant statistical difference in blood transfusion rate (American P=0.27, Asian P=0.27), length of stay (American P=0.37, Asian P=0.87), conversion to open operation rate (American P=0.27, Asian P=0.11), total complication rates (American P=0.89, Asian P=0.07), major and minor complication rates (major complication rates P=0.97, minor complication rates P=0.54), time until oral intake resumption (American P=0.94, Asia P=0.72), and time to ambulation (American P=0.14, Asian P=0.42). Conclusions: LRN can be performed for obese patients safely and efficiently. However, the perioperative outcomes of obese patients who had undergo laparoscopic radical nephrectomy demonstrated larger EBL and longer OD in comparison of those of non-obese groups, without increasing complication and conversion to open operation rates.