Postoperative pain in Sprague Dawley rats after liver biopsy by laparotomy versus laparoscopy.

Laparoscopic surgery offers advantages for both animal welfare and quality of experimental data. Compared with laparotomy, laparoscopy is associated with less postoperative pain and faster recuperation in humans and is also associated with less postoperative pain in dogs. Postoperative pain associated with laparotomy and laparoscopy has not been compared in rodents, however. The authors used a validated pain grimace scale to evaluate postoperative pain in male Sprague Dawley rats after liver biopsy by laparotomy or laparoscopy. Rats that underwent laparoscopy showed fewer recognized signs of pain than did rats that underwent laparotomy. The authors suggest that laparoscopy could be used for repeated biopsies in rats, minimizing the number of animals used in pharmacological and toxicological studies.