Surgical time and severity of postoperative pain in dogs undergoing laparoscopic ovariectomy with one, two, or three instrument cannulas

Objective-To determine whether number of instrument cannulas is associated with surgical time or severity of postoperative pain in dogs undergoing laparoscopic ovariectomy. Design-Randomized clinical trial. Animals-18 healthy dogs. Procedures-Dogs were randomly assigned to undergo laparoscopic ovariectomy with 1, 2, or 3 instrument cannulas. Surgical time and intraoperative and postoperative complications were recorded. Severity of pain was monitored 2, 4, 8, 12, and 24 hours after surgery by means of pain scoring with a modified Melbourne Pain Scale and palpation of surgical sites with variably sized von Frey filaments. Owner-assessed postoperative comfort was also evaluated. Results-Surgical time was significantly longer with 1 cannula (mean +/- SD, 29.7 +/- 5.6 minutes) than with 2 cannulas (18.2 +/- 4.4 minutes) or 3 cannulas (19.3 +/- 3.4 minutes). Intraoperative complications included splenic puncture (2 dogs), pedicle hemorrhage (1 dog), and SC emphysema (1 dog); complication rates were not significantly different among groups. Total pain score was significantly lower for dogs with 2 cannulas than for dogs with 3 cannulas; total pain score for dogs with 1 cannula did not differ significantly from scores for dogs with 2 cannulas or 3 cannulas. Owner assessments of postoperative comfort and number of days pain medications were administered did not differ among groups. Conclusions and Clinical Relevance-Results suggested that laparoscopic ovariectomy with 2 instrument cannulas, rather than with 1, resulted in shorter surgical times without increasing severity of postoperative pain. (J Am Vet Med Assoc 2011;239:203-208)