Zero ischemia laparoscopic microwave ablation assisted enucleation vs. laparoscopic partial nephrectomy in clinical T1a renal tumor: a randomized clinical trial

BACKGROUND: The study aims to evaluate efficiency, safety and the functional outcomes of zero ischemia laparoscopic microwave ablation assisted tumor enucleation (LMWATE) in comparison with laparoscopic partial nephrectomy (LPN) for cT1a renal tumors. METHODS: A prospective randomized controlled trial on cT1a renal tumor patients treated by laparoscopic nephron sparing surgeries between October 2014 to September 2017 was conducted. Tumor enucleation was performed in the LMWATE group after microwave ablation (MWA) without hilar clamping. The endpoint was the affected kidney’s change of GFR measured by renal scintigraphy at the 3rd month and 12th month postoperatively. All the patients were followed up for at least 12 months. The Student t-test, Wilcoxon rank sum tests and Pearson Chi-square or Fisher exact were applied to analyse data. RESULTS: The number of patients enrolled in the LMWATE group and LPN group were 90 and 93 respectively. Patients in the LPN group showed much more decline of effect kidney glomerular filtration rate at 3 months (10.3 vs. 17.4, P<0.001) and 12 months postoperatively (8.8 vs. 10.2, P=0.023) when compared to the LMWATE group. Additionally, in the LMWATE group, considerably shorter median operation duration (91 vs. 112 minutes, P<0.001), lower median estimated blood loss (82.5 vs. 117.5 mL, P<0.001) and shorter hospital stay (5.5 vs. 6 days, P=0.013) were observed but with similar postoperative complications in both groups. There was no positive margin or local recurrence in both groups. CONCLUSIONS: Zero ischemia LMWATE may provide better preservation of renal function, decrease operative time and blood loss compared to LPN with similar complication rates.