NEW YORK (Reuters Health) – Robots can be helpful in resecting small renal masses, researchers say – but those same researchers say operating without a robot can be just as good.
“There are two messages we want to convey. First, any surgeon experienced with laparoscopic partial nephrectomy does not need a robot to achieve good outcomes. Second, the robotic platform does allow urologists with robotic/laparoscopic experience to achieve comparable results with a relatively short learning curve.”
Those words come (via email to Reuters Health) from Dr. Alon Z. Weizer at the University of Michigan in Ann Arbor, senior author of a report online May 14 in the Journal of Urology.
Working with data from 2007 to 2010, Dr. Weizer and his coauthors compared 108 partial nephrectomies performed by a single surgeon using a standard laparoscopic technique with 108 cases done by five surgeons using robotic assistance. Patients were matched according to demographics, renal function and tumor characteristics such as size and location.
Robotic patients had longer postoperative hospital stays (by half a day, p=0.02), longer warm ischemia times (by 5.6 min, p=0.006), and longer operative times (by 53 min, p<0.0001).
Dr. Weizer feels that the warm ischemic time and length of stay differences, while statistically significant, are not clinically important.
And there were no differences between groups in the number of blood transfusions, postoperative renal function, margin status on pathology, or complications.
Dr. Alexander Kutikov, a urologic oncologist at the Fox Chase Cancer Center in Philadelphia who did not participate in Dr. Weizer’s research, commented on it for Reuters Health. Warm ischemia time “may not have as critical a role as previously thought in determining long-term renal functional outcomes,” he wrote in an email. “The volume and quality of preserved renal parenchyma appear to be much more important.”
And he pointed out that many confounding variables may contribute to differences in length of stay.
The paper did not address the costs associated with the robot. Dr. Weizer said, “There is some literature suggesting that the costs of the robot are cancelled out by volume, and each of our robots is used for an average of roughly 8-11 cases/week. The disposable costs may actually cancel out between open and robotic cases since each robotic arm can be used 10 times before being disposed of and most laparoscopic energy source equipment is single use.”
Dr. Kutikov agreed. “The additional costs are likely justified, especially given the fact that the costs will certainly decrease in the future,” he said.
“In terms of OR time, it is clear that the robotic cases take longer compared to a very experienced laparoscopic surgeon,” Dr. Weizer said. “But the operative time decreased over time and ultimately we anticipate that the OR times will be similar as we continue to do more robotic partial nephrectomies.”
Regarding the applicability of the procedure, Dr. Kutikov concluded, “Minimally-invasive partial nephrectomy is a safe and oncologically sound treatment of the localized renal mass. In expert hands, laparoscopy and robotics appear equivalent; however, robotics likely flattens the learning curve, and, as such, lowers barriers to minimally-invasive nephron-sparing surgery.”
“The robotic surgeons in this series had extensive prior laparoscopic experience,” Dr. Weizer emphasized, “including laparoscopic partial nephrectomy and extensive experience with robotic prostatectomy and open partial nephrectomy.”
J Urol 2012.