Clear Margins With Laparoscopic Prostatectomy

NEW ORLEANS—Transperitoneal laparoscopic radical prostatectomy achieves negative surgical margins comparable to those achieved with the open retropubic approach, according to a study from University of Massachusetts Medical School investigators. They reported their results at the American College of Surgeons 87th Clinical Congress.

The reproducibility of laparoscopic prostatectomy has already been demonstrated in several large series, and a number of theoretical advantages have been suggested: improved surgical visualization, decreased operative morbidity, and increased cosmesis.

However, to justify the adoption of this new technique as a cancer operation, it is important to show that adequate surgical margins can be achieved in a reproducible manner, said Vernon Pais, Jr., MD, of the Division of Urology, Department of Surgery.

"There have been several major obstacles to more widespread acceptance," he said. "One is the so-called steep learning curve. Many have questioned the utility of developing a technically challenging alternative to what is a well-tested, established, and reproducible procedure at which most urologic surgeons are quite well trained." Another issue is that the procedure remains unproven. "There is very limited experience and no long-term follow-up," he said.

Dr. Pais shared the experience at his institution, where about 70 laparoscopic prostatectomies have been performed to date. The research team compared the surgical margins of 37 consecutive patients undergoing laparoscopy with those of the most recent 37 patients undergoing open procedures. The same surgeons performed all the procedures.

Any specimen in which tumor extended to the margin was considered to represent a positive surgical margin.

Dr. Pais reported there was no evidence of cancer at the surgical margins in 33 of the 37 laparoscopic patients (89%), and in 29 of the 37 patients undergoing the open approach (78%). Overall, the positive surgical margin rate, therefore, was 11% in the laparoscopic group and 22% in the open prostatectomy group.

The rate of positive margins with laparoscopic prostatectomy actually seems improved over the open prostatectomy procedure, although the reasons for this are unclear, Dr. Pais said. "It may be partially attributed to the improved visualization afforded by the laparoscope, allowing a precise and magnified dissection," he noted.

The researchers then looked at patients with extracapsular extension—one patient in the laparoscopic group and four in the open group—because these represented cases where positive tumor margins could potentially be attributed to tumor characteristics and not technique. When these patients were excluded from the analysis, the difference between the groups in positive margins decreased, to 8% with the laparoscopic approach and 12% with open prostatectomy.

The study confirmed that laparoscopic prostatectomy is technically feasible and reproducible. It allows for complete resection of the tumor with negative surgical margins in the majority of patients, Dr. Pais concluded. "Achieving adequate margins does not appear to be compromised by the learning curve, but we must await long-term follow-up to assess cancer control," he added.

Robert D. Blute, Jr., MD, chief of the Division of Urology, performed these procedures at the University of Massachusetts in conjunction with Douglas Dahl, MD, and Demetrius Litwin, MD, chief of minimally invasive surgery.

Dr. Blute said that "laparoscopic prostatectomy remains an investigational procedure, but we are very encouraged by our preliminary results. Innovations in instrumentation and technique may decrease the learning curve to the point that this procedure can become more competitive with the standard open radical prostatectomy."

Operative Time

Dr. Pais said the operative time in the initial cases was about 8 hours. The mean operative time of the full 70 patients now is 274 minutes (4.5 hours), and most recently the procedure has been performed in only 180 minutes. "About 3 hours is what it may come down to," he commented. "So we have cut the time in half over the course of our series."

The investigators have no data on continence, he said. Hospital stay and catheter duration is the same for both approaches (2.3 days and 1 week, respectively), and there have been few complications.