The Breast Musculocutaneous Flap for Complete Coverage of the Median Sternotomy Wound

Even though the rate of sternal dehiscence, infection, and other complications following median sternotomy is extremely low, the sheer volume of cardiothoracic procedures for coronary artery disease in our society has made these sequelae not uncommon. The potentially devastating complications of systemic sepsis, graft thrombosis or hemorrhage, disruption or bacterial seeding of prosthetic grafts, and even death are realistic concerns.1,2 The appropriate treatment is multifactorial and depends on wound severity, the physiological status of the patient, and any restrictions imposed by the type of bypass conduit utilized or scars from prior surgical interventions. The most severe sternal wounds, as categorized by Arnold and Pairolero,3,4 usually require a vascularized muscle flap to obliterate dead space and to enhance the immunological milieu.1 The pectoralis major muscle has played a pivotal role in this regard,3,5–7 but if it is unavailable, the latissimus dorsi muscle,8,9 the omentum,2,9,10 or even a free flap11 may be acceptable alternatives. Occasionally, a single or even bilateral pectoralis muscle flaps are inadequate for closing the chest wound in its entirety, particularly the lower third or xiphoid region.5,7,12,13 This deficiency must then be remedied by complementary flaps (e.g., often the rectus abdominis muscle)5,7,9,13,14 or, rarely, by a segmental split pectoralis major muscle,5,13 a bipedicled pectoralis-rectus abdominis fascia flap,12,15 a vertical rectus abdominis musculocutaneous flap,16 or adjacent cutaneous flaps alone if no bone is exposed.17 Yet these usually compromised hosts tolerate any treatment protocol poorly, and they are the worst candidates for the additional time necessary to perform these adjunctive maneuvers.3,7 The unilateral breast musculocutaneous flap can be a simpler and total solution that is independent of the type of bypass conduit. It can be elevated very rapidly, and it will cover the entire mediastinal defect, with surgical morbidity limited to a single donor site. Successful closure of the complicated and/or infected median sternotomy incision must consider the severity of the wound, restrictions on flap options imposed by any type of prior cardiac bypass or other surgical interventions, and the physiological status of the patient. The morbidly obese female patient with multiple comorbid problems adds additional unique challenges. A single flap for expeditious and complete sternal wound closure with minimal donor-site morbidity would be the ideal solution. In these usually largebreasted women, these prerequisites can sometimes all be met by using a breast musculocutaneous flap, in which this appendage is kept intact with the underlying pectoralis major muscle to ensure total and reliable vascularization after transfer. This option clinically proved feasible in extraordinary circumstances on three occasions. Aesthetic shortcomings due to medial displacement of the breast mound or skin grafting of the lateral chest donor site are the major detriments.