Canine model of surgical stress response comparing standard laparoscopic, microlaparoscopic, and hand-assisted laparoscopic nephrectomy.

OBJECTIVES: To compare the postoperative stress induced by standard laparoscopic, microlaparoscopic, and hand-assisted laparoscopic (HALS) nephrectomy in an animal model.
METHODS: A total of 39 dogs underwent standard laparoscopic (n = 19), microlaparoscopic (n = 11), or HALS (n = 9) left nephrectomy. The serum cortisol levels were measured preoperatively, at skin closure, and 2, 4, and 6 hours postoperatively.
RESULTS: Compared with the preoperative level, a sharp rise was noted in the serum cortisol taken at skin closure that correlated with both operative time (P = 0.003) and method (P = 0.009 for HALS versus microlaparoscopy and P = 0.02 for HALS versus standard). HALS had the lowest cortisol increase and shortest operative time, and microlaparoscopy had the greatest cortisol increase and longest operative time (P = 0.03 for cortisol increase, HALS versus microlaparoscopy). Two hours postoperatively, HALS was the only method associated with a continuing increase in cortisol levels (P = 0.01 and P = 0.02 compared with the other methods) and had the greatest cortisol level relative to baseline. The cortisol level decreased at all postoperative points in the other groups. By 4 hours, all methods were associated with similar and falling cortisol levels.
CONCLUSIONS: HALS nephrectomy was associated with a greater operative stress response in the first 2 postoperative hours in dogs compared with standard laparoscopic and microlaparoscopic nephrectomy that was partially ameliorated by the lower intraoperative cortisol production in the more rapid HALS procedure. Microlaparoscopy provided no benefit in terms of reduced surgical stress. The stress differences among the techniques were insignificant by 4 hours postoperatively.