Better post-op pain outcomes seen with robotic radical prostatectomy

June 1, 2011

A prospective, randomized, double-blind study comparing postoperative pain between robot-assisted laparoscopic radical prostatectomy and laparoscopic radical prostatectomy appears to favor the robotic technique.

Vienna, Austria-A prospective, randomized, double-blind study comparing postoperative pain between robot-assisted laparoscopic radical prostatectomy (RALP) and laparoscopic radical prostatectomy (LRP) appears to favor the robotic technique.

Italian researchers, who randomized 100 patients requiring prostatectomy to receive RALP or LRP, also found that patients undergoing the robotic procedure required fewer pain medications.

"Our preliminary study suggests that RALP causes less postoperative pain than LRP, with lower requirement of analgesic drugs in the postoperative period," said co-author Cristian Fiori, MD, of the division of urology, department of clinical and biological sciences, University of Turin, Turin, Italy.

Postoperative pain was measured using the Visual Analog Scale diffused (VAS D), incident pain (pain on light compression of surgical wound, VAS I), and referred pain (shoulder pain, VAS R) scores. Consumption of opioid analgesics (buprenorphine [Buprenex, Butrans, Subutex]), and the amount of rescue drugs (acetaminophen) after surgery were also compared between the study groups.

Patients in the RALP group had statistically significantly lower pain on the VAS D and VAS I scales than patients undergoing LRP, Dr. Fiori reported at the European Association Urology annual congress in Vienna, Austria. Measurements were recorded at 1, 3, 6, and 24 hours after surgery. VAS R measures did not show statistically significant differences in the study groups.

Robotic group requires less medication

The RALP group also required fewer opioid analgesics compared to the LRP group (345±53 µg vs. 451±103 µg, p<.001). The number of patients requiring rescue drugs was also lower in the RALP group than in the LRP group, both at 24 hours and 48 hours after surgery.

The findings by Dr. Fiori and his colleagues prompted several questions during the study's presentation at the EAU congress.

"Intervention in RALP and LRP are similar. The diameter of the port is similar: 5 or 10 mm in RALP and 8 mm in LRP. So what could your observed difference in postoperative pain be due to?" asked session co-moderator Alexandre Mottrie, MD, urologist at the OLV Clinic, Aalst, Belgium.

"We can only speculate that the difference is due to the fact that the robotic procedure may alter the perception of pain in the patient (due to steep Trendelenburg position), or that the action of the arm of the robot is less aggressive," Dr. Fiori responded.

The second session moderator, John W. Davis, MD, raised questions about how the study data were obtained.

"Was there enough of a sample size to draw your conclusions? Is this study hypothesis-driven?" asked Dr. Davis, assistant professor of urology at the University of Texas MD Anderson Cancer Center, Houston.

"The power in this study is on a larger trial comparing RALP and LRP, in which the primary endpoint was the difference in terms of early continence" answered Dr. Fiori. "So this study was not hypthotesis driven. We merely observed the two groups of patients to evaluate differences in terms of pain. This difference was statistically significant so we think that the results are reliable, even if larger studies are needed to confirm and explain our data."

Attendee James Michael Adshead, MD, noted that he presented a similar study with similar results at a urologic conference in South Africa last year. In that study, 50 patients in each group underwent either RALP or LRP, and postoperative pain was registered.

"Only 13% of the patients required opium after RALP compared to 50% of patients after LRP," said Dr. Adshead, consultant urological surgeon at Lister Hospital, London. "This must have to do with the pivot point of the robot where the instrument does not move at all, while if you do LRP, you can shift those ports and cause bruising.