Laparoscopic partial nephrectomy in the pig: comparison of three hemostasis techniques

Control of intraoperative bleeding is the main technical difficulty encountered during laparoscopic partial nephrectomy. The objective of this study was to compare the efficacy and morbidity of three renal parenchymal hemostasis techniques: high-frequency bipolar electrical current, high-frequency unipolar spray electrical current, and ultrasound during laparoscopic partial nephrectomy performed in pigs without vascular control.

A standardized laparoscopic transperitoneal right lower-pole partial nephrectomy was performed in 27 pigs with a mean weight of 65 +/- 5 kg. The pigs were divided into three groups according to the technology used: Group 1 = bipolar electrical current, Group 2 = unipolar spray electrical current, and Group 3 = ultrasound. Intravenous urography was performed on the 28th day. The kidneys were then removed for histologic examination, and the pigs were sacrificed. The criteria evaluated were intraoperative and postoperative complications, blood loss, renal function, and thickness of the parenchymal lesions induced. The Kruskal-Wallis nonparametric test for comparison of medians was used for statistical analysis of the data (P < 0.05). Data from pigs that died before the end of the study were excluded from the analysis.

All partial nephrectomies were performed laparoscopically, and all pigs were alive at the end of the operation. The postoperative complication rate was 11% (N = 3): two pigs died before the end of the study, one from hemorrhage on Day 6 (Group 2), and the other from prolonged reflex ileus with sacrifice of the pig on Day 7 (Group 3). One pig developed an asymptomatic urinoma (Group 2). Blood loss was significantly lower when ultrasound was used (P = 0.026). Global renal function was not significantly altered in the various groups. The median thickness of tissue necrosis and fibrosis detected in the scar zone was 6 mm (range 4-10 mm) and was similar in the three groups.

Partial nephrectomy can be performed by laparoscopy without vascular control in the pig. Coagulation by ultrasound appears to present an advantage in terms of limitation of blood loss compared with coagulation by bipolar or unipolar spray electrical currents without presenting any benefit in terms of preservation of the renal parenchyma.