Harvesting the Omentum for Poststernotomy Mediastinitis

Abstract

Sir: The eloquently written and beautifully illustrated article by Vyas and colleagues1 presents some strong arguments for limiting the abdominal access to harvest the omentum in the management of poststernotomy mediastinitis. We concur with this principle. It is with a similar intent that some advocate harvesting the omentum laparoscopically.2,3 Indeed, it is true that more equipment is required for the latter—not more personnel (one surgeon, one assistant, and one scrub nurse). The other points advanced in the penultimate paragraph in their article1 against laparoscopic harvest of an omental flap also warrant closer scrutiny. First, yes, laparoscopy does require additional stab wounds (all <10 mm); however, bear in mind that in at least 15 percent of their cases1 additional abdominal incisions were necessary to release the adhered omentum. Second, the percentage of ventral hernias was more than doubled by converting the transdiaphragmatic approach to a laparotomy. The incisional hernia rate is distinctively higher when compared with the 1.5 to 1.8 percent rate reported following laparoscopy.4 Third, the mean blood loss (Table 3) following laparotomy was significantly higher compared with not only the transdiaphragmatic approach but also with laparoscopy. The latter offers a clear and complete view during dissection, avoids blunt adhesiolysis, and reduces bleeding to an absolute minimum. Finally, during laparoscopic harvest of an omental flap, the loss of any amount of pneumoperitoneum only occurs once the flap has been safely dissected, prepared, and at the end of the abdominal surgical procedure. Obviously, creating a wrist/lower arm–sized transdiaphragmatic opening at the beginning of the procedure limits the possibility of laparoscopic harvest of an omental flap. This opens the door to a pertinent question. In the study by Vyas et al.,1 a steady increase in the number of laparotomies since 2002 can be observed (Fig. 3). Was this because of the failure of intention-to-treat by technique (transdiaphragmatic harvesting) or were the laparotomies planned preoperatively? If planned, it would be of interest to know which selection criteria the authors developed for either of the procedures. It may be fair to seek an alternative to the transdiaphragmatic approach to the omentum in patients who have undergone previous, perhaps extensive, abdominal surgery. This does not have to be a laparotomy. Laparoscopic harvest of an omental flap has been shown to be feasible and not a contraindication in these cases. Most of the patients in the four largest case series of laparoscopic harvest of an omental flap for reconstruction in poststernotomy mediastinitis had a history of previous, major abdominal surgery.2,3 In each, the outcome following laparoscopic harvest of an omental flap was good. A recently published meta-analysis for a systematic review comparing patient-based outcome with muscle flaps or an omental flap indicated a slight survival advantage for reconstruction with an omental flap (overall relative risk, 1.29; 95 percent CI, 0.58 to 2.88).5 In addition, the results of our systematic review5 suggest that muscle flaps are associated with more, and more frequent, complications compared with omental flaps. Vyas et al.1 do not compare their results with a similar cohort of patients in whom muscle flaps were harvested. However, their good results lend further support to lowering the threshold in preferentially choosing the omentum in the treatment of poststernotomy mediastinitis when a flap is indicated. DISCLOSURE The authors have no financial interest to declare in relation to the content of this communciation. No outside funding was received. Jan J. van Wingerden, F.C.S.(S.A.)., M.Med.(Plast.Chir.) Oren Lapid, M.D. Department of Plastic, Reconstructive, and Hand Surgery Academic Medical Center University of Amsterdam Amsterdam, The Netherlands Erik R. Totté, M.D., Ph.D. Leeuwarden Institute for Minimal Invasive Surgery Medical Center Leeuwarden Leeuwarden, The Netherlands