Postoperative mediastinitis in open heart surgery patients. Treatment with unilateral or bilateral pectoralis major muscle flap?

Aim: the treatment of mediastinitis, after median sternotomy, in open heart surgery operated patients, remains an important and challenging problem in cardiac surgery. The management of this severe complication by means of surgical debridement of the sternum followed by mediastinal closure with pectoralis major muscle flaps, represents one of the best effective and most common modalities of treatment. The aim of the present publication is to demonstrate the good and comparable result in the mediastinal closure by using a single pectoralis muscle flap instead of two pectoralis muscle flaps.
Methods: in our hospital, between July 1998 and December 2004, 32 patients with mediastinitis were treated after adult open heart surgery with sternal debridement and pectoralis major muscle flaps. In 19 cases the sternal closure was performed with a single pectoralis muscle (group U) and in 13 cases with both pectoralis muscles (Group B).
Results: comparing the group U and group B, we did not found statistical differences in the variables of age, sex, associated diseases, previous myocardial infarction, kind of cardiac surgery undertaken, quality of the sternum, type of germen, number of previous sternal debridement performed and time of hospitalization. Patients in group U showed a statistically significant (P=0.001) shorted plastic reconstructive surgery time, an earlier extubation time (non statistically significant) and less need of blood transfusion (non statistically significant). The morbidity and hospital mortality in group U and B did not show any statistical differences. There were three cases of flap related complications in group B and two in group U. One death was recorded in group U (7.69%) and another in group B (5.26%).
Conclusion: mediastinal infection after cardiac surgery can be effectively managed by surgical debridement followed by plastic coverage with a single pectoralis muscle flap. In our experience, this unilateral pectoralis muscle flap technique showed similar results to the classic closure with both pectoralis muscle flaps. The unilateral technique represents a relative low aggressive operation and preserves intact the contralateral pectoralis muscle. Comparing the single pectoralis muscle flap technique with the bilateral pectoralis musle technique, the former is faster, the extubation is earlier and there is less need of postoperative blood transfusions.