Simulator Practice Can Improve Catheter Use

BOSTON -- The use of a simulator during endovascular training greatly improved residents' ability to perform a catheter-based procedure, Dr. K. Craig Kent reported at the annual meeting of the American Surgical Association.

Increasingly, simulators are being used to train surgeons before they get to the operating room. Better endovascular training is needed because more percutaneous procedures are being performed, said Dr. Kent, chief of vascular surgery at New York- Presbyterian Hospital. According to the National Hospital Discharge Survey, the number of catheter-based vascular operations increased from 5 per 100,000 in 1995 to 80 per 100,000 in 2003, he said.

When Dr. Kent and his colleagues studied the simulator some years ago, they found that it greatly improved novices' skills, but not those of more experienced interventionalists (J. Vasc. Surg. 2004;40:1112-7). And there was no way to gauge whether improved performance on a simulator translated to better operating skills on a live patient.

As a result, they decided to conduct a randomized study. They enrolled 20 residents, none of whom had prior experience with a catheter-based intervention. The residents were asked about skills that might improve their ability to work with a catheter, such as exposure to video games and their ability to work on a computer or to type. They also were given a visual-spatial test to gauge their understanding of working in a three-dimensional format. All were assigned to read eight chapters in a textbook and given a 30-minute lecture. Ten were randomized to no simulation and 10 to a simulator--the ProcedicusVIST made by Mentice. The simulator group had 2 hours of one-on-one instruction in conducting an iliac artery angioplasty.

All 20 residents then took part in two consecutive interventions on live patients, either large artery angioplasty or stent placement. Attending physicians graded performance on the basis of an endovascular checklist--which measured steps such as ability to walk a stent over a wire--and a global rating scale.

At baseline, the groups were similar in terms of demographics, video and computer exposure, and visual-spatial performance.

For the first case, the simulator group scored 50 out of 77 points on the checklist, compared with 30 for the nonsimulator group. The global rating score was 30 (out of a total of 40) for the simulator group and 19 for the nonsimulator arm.

There was not a marked improvement on the second case, but simulator residents still performed better than did nonsimulator trainees. Checklist scores were 53 and 36 for the simulator and nonsimulator groups, respectively. The simulator group earned a global rating score of 33 compared with 21 for the nonsimulator arm.

"So both for the first and the second intervention there was a substantial advantage for residents who were subjected to simulation," said Dr. Kent. "Our results would suggest that simulation actually is a very valuable tool in training residents for catheter intervention."

There are some unknowns, including whether the simulator provides a durable advantage, he said. At $250,000 per machine, simulation does not appear to be cost-effective, and there are no data yet on whether the device will improve experienced interventionalists' performance, he added.

The results do show that performance was "significantly better among those taught with the simulator," said Dr. Carlos Pellegrini, ASA president and Henry N. Harkins Professor and Chair of the Department of Surgery at the University of Washington Medical Center, Seattle.

Dr. Richard Shemin, chairman of cardiothoracic surgery at Boston University Medical Center, said that simulators also are needed for cardiac applications. He asked Dr. Kent if he envisioned simulators being used eventually for procedure planning. "If so, that would greatly increase the value of these machines," he said.

Simulators already are being used experimentally for planning purposes, and most likely will be employed more often in the future, Dr. Kent said. "Once that happens, the cost issues will fade very rapidly," he predicted.