Retroperitoneal Robotic Partial Nephrectomy

Abstract

The ability to perform reconstructive surgery with the robotic surgical platform has recently led to the application of robotics to nephron sparing surgery. Because of space limitations and the size of the robot at the patient side, the standard approach to robotic partial nephrectomy (RPN) has been transperitoneal. However, posterior located tumors are difficult to approach transperitoneally, and require the kidney to be completely mobilized and flipped medially. Laparoscopic partial nephrectomy (LPN) has been performed using a retroperitoneal approach and affords the advantages of direct access to the renal hilum, no need for bowel mobilization, and excellent visualization of posteriorly located tumors.

Retroperitoneal robotic partial nephrectomy is performed with the patient in the full flank position with the table flexed to increase the space between the 12th rib and iliac crest. Access to the retroperitoneal space is performed using a balloon dilating device and pneumoretroperitoneum is maintained using a 12-mm Hasson balloon trocar. Three robotic trocars are used with one 12-mm assistant trocar placed in the anterior axillary line. A 0° robotic laparoscopic is routinely used but on occasion the 30° up lens is necessary due to conflict with the iliac crest. The robot is brought in over the patient’s head parallel to the spine. The renal artery is exposed to allow a bulldog clamp on the artery. The renal vein is rarely clamped. The renal mass is exposed with the assistance of laparoscopic ultrasound and a 5 mm margin is scored circumferentially around the tumor. The tumor is excised under warm ischemic conditions and care was taken to maintain a clear operative field to allow identification of tumor if encountered. Entrance into the collecting system is easily identified with the 3-D robotic visualization and closed with suture. The renal defect is reconstructed in two layers using the sliding locking clip technique on both the deep layer and the cortical layer.

Retroperitoneal robotic partial nephrectomy was performed successfully in the vast majority of patients. One procedure was converted to LPN due to conflict between the robotic arm and the psoas muscle. Posterior and lateral tumors are ideally suited for the retroperitoneal approach, while anterior and medial tumors are better excised using the transperitoneal technique. The psoas muscle and Gerota’s fascia are the major landmarks used to maintain orientation during dissection. Inadvertent entrance into the peritoneal cavity was seen in two cases, but this did not prevent the completion of the procedure by the retroperitoneal approach.

Retroperitoneal robotic partial nephrectomy is a safe and reproducible approach to minimally invasive partial nephrectomy. The retroperitoneal approach is ideally suited to posterior and lateral tumors, eliminating the need to rotate the kidney. The limitations of the retroperitoneal space do not prohibit the use of the robot.