Early vs. standard unclamping technique in minimal access partial nephrectomy: a meta-analysis of observational cohort studies and the Lister cohort.

To evaluate if early unclamping (EUC) of the renal pedicle compromises perioperative outcomes in minimally invasive partial nephrectomy (PN). The cohort study includes all robot-assisted PN performed between September 2012 and September 2015 by a single surgeon at the Lister Hospital, Stevenage, UK. The systematic review and meta-analysis was performed according to the PRISMA guidelines identifying studies comparing EUC and standard unclamping (SUC) in either laparoscopic or robot-assisted PN. The Lister cohort prospectively reported 84 cases of robot-assisted PN (SUC = 22, EUC = 62) with a mean age of 58 years (SD = 11). The operative time (OT), estimated blood loss (EBL) and warm ischaemia time (WIT) were 186.5 min (SD = 33.8), 125.5 mls (SD = 188.91) and 16.7 min (SD = 5.6), respectively. The data from the Lister cohort were included in the meta-analysis. The systematic review identified four studies, encompassing 666 cases (313 SUC, 353 EUC), for inclusion in the final analysis. There was a statistically significant difference in WIT in favour of the EUC group [-10.59 min (95% CI -16.58, -4.60)]. Specifically, the reduction in WIT was more pronounced in laparoscopic PN (-15.43 min (95% CI -19.05, -11.81)), when compared with the robotic PN [-5.60 min (95% CI -5.70, -5.50)]. There was no statistical difference in OT [-3.97 min (95% CI -14.22, 6.28)]. EBL was found to be increased in the EUC group [71.39 ml (95% CI -0.78, 143.56)]. There was no statistically significant difference in transfusion rates or complications between the two groups. The EUC technique for robot-assisted PN appears to offer a safe limited period of WIT without compromising perioperative outcomes and morbidity.