Totally minimally invasive robot-assisted unstented pyeloplasty using the Zeus Microwrist Surgical System: an animal study.

BACKGROUND

Minimally invasive pyeloplasty is a difficult procedure even for an expert laparoscopic surgeon. The major difficulty is associated with the limitations of intracorporeal suturing and knot tying. Surgical robots, which hold minimally invasive surgical instruments, have wrists and provide tremor filtration and motion scaling that might be expected to facilitate complex procedures in newborns.

METHODS

Seven survival piglets (4.0-7.5 kg) underwent a totally minimally invasive robot-assisted unstented pyeloplasty employing the Zeus Robotic Microwrist System. The ureter was transected at the level of the ureteropelvic junction and 8 mm was resected. The unstented anastomosis was fashioned with running suture and intracorporeal knot tying. The animals were recovered and intravenous urography was performed at 1 month. After sacrifice, the anastomosis and the kidney were evaluated grossly and histologically for leak, caliber, and healing.

RESULTS

All animals survived the procedure without postoperative complications. The mean robotic setup time was 19 minutes (range, 10-30 min), mean anastomosis time 51 minutes (range, 39-63 min), and mean total operation time 76 minutes (range, 57-87 min). The urography showed hydronephrosis in the first animal. The other 6 animals had no abnormalities. Histopathology demonstrated severe hydronephrosis in the first pig and moderate hydronephrosis in the sixth and seventh. All other animals had no sign of hydronephrosis. All anastomoses were well healed and intact.

CONCLUSIONS

Robot-assisted laparoscopic pyeloplasty is a technically feasible procedure with acceptable morbidity in an animal model. The robotic technology enhances surgical dexterity and precision. Robotic assistance can increase the applicability of minimally invasive surgery to complex procedures in children.