The metabolic and immune response to laparoscopic versus open liver resection

Laparoscopic liver surgery is a field in its infancy, and scientific evidence of its benefits over those of traditional open techniques has not been shown. Various applications from wedge resections to formal segmental resections have been reported, but the technical ability does not necessarily translate into improved patient outcomes. There is an abundance of evidence reflecting the benefits of laparoscopic cholecystectomy [9, 12, 23], and some of these benefits have been linked to the decreased metabolic and immune responses involved [24, 27]. There is also accumulating evidence that tumor growth may be slower after laparoscopic surgery than after comparable open surgery, and that this is a result of less immune suppression [1]. It is not known whether laparoscopic liver surgery will convey similar benefits.

In this study, 14 pigs were assigned randomly to undergo a liver resection either by a laparoscopic or an open approach. Operative stress was assessed via cortisol, tumor necrosis factor, interleukin-6, C-reactive protein. The immune response was evaluated through delayed-type hypersensitivity skin antigen testing. Adhesion formation also was assessed at 6 weeks.

Immune response as measured by delayed-type hypersensitivity is better preserved after laparoscopic than after open liver resection. The average diameter of induration was 46% greater in the laparoscopic group (20.71 +/- 2.7 mm versus 14.14 +/- 1.5 mm). Interleukin-6 and tumor necrosis factor levels showed a significantly greater rise after open surgery. No difference was observed in the levels of C-reactive protein or cortisol. Adhesion formation was considerably less after laparoscopic resection.

Laparoscopic liver resection results in a diminished stress response, as compared with that of open resection, which translates into greater preservation of immune function. This finding may well have a beneficial effect on infection and tumor growth.