Comparison of surgical stress between laparoscopy and open surgery in the field of urology by measurement of humoral mediators

Background: Recently, laparoscopic procedures have become more common in urological surgery, and are suggested to be less stressful compared with open surgery; however, little data on objective evaluation of surgical stress after laparoscopic surgery are available. The objective of this study was to compare surgical stress between laparoscopic and open surgery in the field of urology by measurement of humoral mediators. Methods: Blood samples were obtained from 25 patients who underwent laparoscopic surgery (laparoscopic radical prostatectomy, 10; retroperitoneoscopic nephrectomy or nephroureterectomy, seven; laparoscopic adrenalectomy, five; and hand-assisted laparoscopic radical nephrectomy, three) and 10 who underwent open surgery (retropubic radical prostatectomy, four; radical cystectomy, three; and radical nephrectomy, three), 48 h before surgery, during surgery, and 24, 48 and 96 h after surgery. Serum levels of interleukin (IL)-6, IL-10 and granulocytic elastase in these samples were measured, and the results were analyzed with respect to several clinical factors. Results: In both groups, IL-6 and granulocytic elastase levels increased during surgery and reached maximum levels 24 h after surgery; the increase in granulocytic elastase tended to be prolonged compared with that of IL-6. Changes in IL-10 levels in the open surgery group were similar to those of IL-6 and granulocytic elastase levels, whereas IL-10 levels in the laparoscopic surgery group reached a maximum level during surgery and then decreased to the same level as at 48 h before surgery, on the first postoperative day. The maximum levels of these three mediators in the laparoscopic surgery group were significantly lower than those in the open surgery group. IL-6 was closely associated with the interval of fasting and duration of hospitalization after surgery. Conclusion: Although the present study was based on retrospective and non-randomized analysis, the findings suggest that serum levels of IL-6, IL-10 and granulocytic elastase are useful as objective markers of surgical stress, and that laparoscopic surgery is markedly less stressful than open surgery.