Despite data, cautery-free RAP approach preferred

December 1, 2006

Cleveland-Although their data show otherwise, a group of researchers at the University of Rochester (NY) Medical Center have faith that using a cautery-free approach with Weck clips to preserve the neurovascular bundle during robot-assisted prostatectomy is a better choice than bipolar cautery.

Cleveland-Although their data show otherwise, a group of researchers at the University of Rochester (NY) Medical Center have faith that using a cautery-free approach with Weck clips to preserve the neurovascular bundle during robot-assisted prostatectomy is a better choice than bipolar cautery.

"With bipolar cautery, we worry about scatter of electricity and heat," said study presenter Seth Capello, MD, a fellow in minimally invasive and laparoscopic surgery at the University of Rochester. "So we've converted from the old bipolar cautery to now using plastic Weck clips."

However, this particular study did not have the results that the authors were expecting for their presentation at the World Congress of Endourology here.

The researchers, led by Jean Joseph, MD, MBA, followed 30 consecutive patients who underwent robot-assisted prostatectomy with 4-month follow-up data available. Fifteen patients had their nerve preservation carried out using bipolar cautery (10 with bilateral nerve bundle preservation and five with unilateral bundle preservation). Weck Hem-O-Lock Clips (Teleflex Medical, Bannockburn, IL) were used to preserve the neurovascular bundle in the other 15 patients; 13 of them had bilateral bundle preservation. All of the patients were sexually active and were potent, with a Sexual Health Inventory in Men (SHIM) score of 20.

Learning curve seen

Among the patients in the bipolar cautery group, the mean SHIM score was 12.2, and 10 (66%) were potent. In the group of patients in whom Weck clips were used, the mean SHIM score was 9.1, and five (33.3%) were potent. There was no difference between the groups in terms of blood loss, intraoperative time, and positive margin rate.

"This was a pilot study to see how the patients we used Weck clips on are doing," Dr. Capello said. "What we saw is that bipolar cautery patients did a little bit better, which is not what we expected. Four months of follow-up is a bit early to draw meaningful conclusions about potency. In addition, there may be a learning curve effect in the placement of the clips. Care must be taken not to include the bundles in the clips."

Despite the weaker numbers using Weck clips in the early results, the urologists have used them to preserve the neurovascular bundle almost exclusively during robotic prostatectomy.

"There is some thermal damage that happens with long application of cautery," said Dr. Joseph, who is head of laparoscopy and robotics in the department of urology at the University of Rochester.

"We're more comfortable knowing that we haven't used any excess electrical energy," Dr. Capello concurred. "Those theoretical benefits outweigh this early data that still needs to mature. I think you'll see that, with more data and longer follow-up, using clips for bundle preservation is a better method."

He admitted that there are slight disadvantages to the Weck clips, but that they are usually attributed to the learning curve.

"The clips are slightly larger than the bipolar forceps, so initially it can be difficult to properly place the clips. The assistant must be trained in the proper application of the clips to avoid clipping the bundles," he explained.

"Adherence to athermal or cautery-free technique is necessary to avoid unintended damage to structures that are vital to the preservation potency," Dr. Joseph said.

The researchers are continuing to gather data on the patients who have undergone robotic prostatectomy with Weck clips to preserve the nerve bundle, and plan to publish the results.