Effects of local anesthetics on healing of abdominal wounds in rabbits

The influence of lidocaine and bupivacaine on the breaking strength and histopathologic appearance of wounds in the ventral abdominal midline (linea alba) of rabbits was studied. In control rabbits, group 1 (n = 24), skin and subcutaneous tissues were incised, permitting direct infiltration of the linea alba with normal saline solution. The linea alba was then incised, and wound margins were apposed in layers, using absorbable suture material. Group 2 rabbits (n = 24) were given 0.5% lidocaine, group 3 rabbits (n = 24) were given 2% lidocaine, and group 4 rabbits (n = 24) were given 0.5% bupivacaine, rather than saline solution. Eight rabbits from each group were killed 6, 12, and 18 days after wounding. Eight 1.0-cm wide transverse strips were removed from the abdominal wall of each rabbit. Two strips were used for histopathologic evaluation and 6 were tested for failure, using a mechanical testing device. Breaking strengths in group 1 averaged 0.66 kg, 1.35 kg, and 1.57 kg at 6, 12, and 18 days, respectively. None of the test groups had significantly different (P greater than 0.05) breaking strength results as compared with that in controls. The histopathologic appearance of tissues infiltrated with local anesthetics did not vary consistently from that of tissues infiltrated with normal saline solution. Local infiltration of lidocaine and bupivacaine does not alter substantially the healing of midline abdominal incisions in rabbits.