Efficacy of Liver Wound Healing by Secondary Intent

Abstract
Nonoperative treatment of liver injury raises questions about liver wound healing (LWH) when the edges are not approximated by primary intent. The efficacy of LWH was studied in 18 dogs and 18 pigs with a total of 108 standard 6-cm injuries. The 36 injuries in six dogs and six pigs were compressed for hemostasis and then allowed to heal by second intent. LWH in these animals was compared to 36 liver wounds in six dogs and six pigs following primary closure (hepatorrhaphy) and 36 liver wounds after omental buttress plus hepatorrhaphy in six dogs and six pigs. Average wound breaking strength (WBS) of liver wounds was studied at 3 weeks (54 wounds) and 6 weeks (54 wounds) with a Chatillon tensiometer and microscopic analysis. The WBS of liver wounds was also compared to normal uninjured liver WBS. The porcine WBS at 3 weeks after healing by second intent (0.31 kg/cm2) was similar to the WBS at 3 weeks after healing by hepatorrhaphy (0.30 kg/cm2) and omental buttress (0.25 kg/cm2). Porcine WBS at 6 week after healing by second intent was significantly greater than WBS at 6 weeks after hepatorrhaphy or omental buttress. The canine WBS at 3 weeks after healing by second intent exceeded WBS at 3 weeks after hepatorrhaphy or omental buttress. Canine WBS at 6 weeks after healing by second intent exceeded WBS at 6 weeks after omental buttress and was similar to WBS at 6 weeks after hepatorrhaphy. WBS in all groups paralleled the extent of fibrosis seen on microscopic analysis. The WBS of uninjured liver in both the canine and porcine subgroups was similar so that the above differences reflect the treatment regimen. WBS at 3 and 6 weeks after healing by second intent was complete and equaled or exceed WBS after primary closure by hepatorrhaphy or omental buttress. The decision to return to normal activities after nonoperative therapy of large liver injury should follow the same guidelines as for primary closure.