Robotic surgery expands horizons for urologic surgeons

May 15, 2010

The advent of robot-assisted surgery is allowing more urologists to perform complex procedures-partial nephrectomies, in particular-which in turn contributes to better patient outcomes.

Key Points

That's the assessment of J. Stuart Wolf, Jr, MD, professor of urology at the University of Michigan, Ann Arbor, and a physician who, ironically, has been known to argue against the use of robotic surgical techniques.

"I don't use the robot, so I don't have a dog in this hunt," Dr. Wolf said. "But given the data that are emerging now, I see a significant role for the robot and I encourage its careful and thoughtful use."

Dr. Wolf noted research to be presented at the upcoming AUA annual meeting, where attendees will hear about encouraging comparisons between robotic versus conventional laparoscopic partial nephrectomy.

Those results will help encourage the use of minimally invasive partial nephrectomy, which has been shown in most cases of small renal cancers to be preferable to radical nephrectomy, but tends to be a difficult procedure to master.

"The robot appears to technically simplify the performance of minimally invasive partial nephrectomy," he said. "The hope is that urologists will offer the procedure more frequently if it is easier to do. We need to encourage both partial nephrectomy and minimally invasive surgery. Data suggest that some urologists are sacrificing nephrons just so the procedure can be done minimally invasively. The robot might help address that problem."

Generally speaking, Dr. Wolf said, new surgical techniques must fit one of two criteria in order to become widely adopted: Either they must improve patient outcomes without a significant increase in difficulty for the surgeon, or they must produce equivalent patient outcomes while simplifying the procedure.

"Robotics probably fits both categories, depending on the application," he said. "In the case of radical prostatectomy, it fits the latter category in that it is easier on the surgeon. In the case of partial nephrectomy, it fits both."

Dr. Wolf added that robotic techniques in kidney surgery may allow urologists to address challenging renal masses that otherwise would be difficult to manage in a purely laparosopic fashion. That can be attributed to the robot's three-dimensional visualization and its ability to work through difficult surgical angles.

Also of interest is forthcoming research on the effect of surgeon experience on outcomes in both open surgical and minimally invasive radical prostatectomy.

One group is expected to report that while surgeons who perform large numbers of procedures of both types have better results in terms of incontinence and cancer control, surgical volume does not appear to affect such perioperative outcomes as the number of blood transfusions, length of stay, complications, and anastomotic strictures in the minimally invasive radical prostatectomy group, while it did in the open surgery group.

"This feeds into the idea that robotic radical prostatectomy has a shorter learning curve than other approaches to prostatectomy," said Dr. Wolf.

New data on potential of LESS

Much has been made of the potential of laparo-endoscopic single-site surgery (LESS), and urologic researchers are trying to find its best fit in urology. Data from at least one group will suggest that patient selection is key to success.

"Younger and thinner patients with less challenging pathology-that is, those with benign lesions or smaller tumors-appear to do best with this technique," Dr. Wolf said. "Those are likely the best candidates, because the technical limitations of LESS are profound."

He added that it's still not clear whether LESS offers any benefits in patient convalescence over standard laparoscopy.

As is always the case with minimally invasive surgery, expect new technology to be in the spotlight at this year's AUA meeting.

One example is laparoscopic Doppler ultrasound, which has demonstrated some objective benefits for evaluating vascular strictures during minimally invasive renal surgery. Dr. Wolf is encouraged by its potential, especially in comparison with laparoscopic ultrasound.

"This is a laparoscopic Doppler probe that is introduced through a laparoscopic port and helps identify blood vessels by Doppler signal," he said. "It's much easier to use than a laparoscopic ultrasound probe. With the Doppler, you literally hear the big vessels when the probe is pointed at them."

While that approach is less exact than ultrasonography, he noted, "It's quicker and easier."

Dr. Wolf also singled out irreversible electroporation (IRE) as a promising new method of renal tissue ablation. IRE uses electrical fields to create nano-scale defects in cell membranes, which causes cell death in targeted tissue.

Animal studies suggest that IRE may have some advantages over standard radiofrequency ablation.

"But the problem with ablation in general, even in the best of hands, is that it's probably less effective than simply excising lesions," Dr. Wolf said. "The reasons for that are probably related to targeting, but may also have something to do with the technology itself. If IRE proves to be a better technology, that will be an important advancement. This is very interesting, but still experimental."