Sunday, October 10, 2004

Co-morbidity Trends in Patients Requiring Sternectomy and Reconstruction

Peter D. Ray, MD, Jorge I. de la Torre, MD, Leonik L. Ahumada, MD, R Jobe Fix, MD, and Luis O Vásconez, MD.

Introduction: The predisposing risk factors for sternal wound dehiscence and/or deep mediastinitis have been well delineated. It is not uncommon for busy cardiac surgery practices to see an increased number of these problems as their clinical volume increases over time. The indications and co-morbidity of patients who require cardiac surgery via the median sternotomy approach have changed over time, however, and have changed the patient population presenting to plastic surgeons for sternal complications. The trends to use bilateral internal mammary arteries, operate on older patient, non-operatively angioplasty and stent simple cases of cardiac ischemia, and aim for early post-operative discharge may require an adjustment of the plastic surgical approach and methods in order to optimize outcomes in the patient population.

Methods: The University Hospital Operating Room Database was searched to identify patients who had undergone sternectomy or sternal debridement followed by flap coverage. A total of 50 cases included radical sternectomy and reconstruction between September 1999 and January 2003. A retrospective electronic chart review was done to collect data about the initial presentation, operative procedure, and post-operative care of each patient. For each patient 15 characteristic data points were collected after being derived from the current literature. The data was then analyzed to identify population characteristics.

Results: A few unexpected findings resulted from this review which had impact on our current management of these patients. First, there was a 22% (n = 11) 30-day mortality in this population undergoing immediate radical sternectomy and reconstruction. Second, 64% (n = 32) were over age 60 (range 18 – 86 years old). Third, 82% (n = 41) of the patients underwent operative debridement and reconstruction greater than 20 days from their original cardiac procedure. Third, 90% (n = 10) of the patients who died within 30 days of their reconstruction had a serum BUN of greater than 20 on admission. Fourth, in the 8 mortalities in which albumin levels were assessed, 7 presented with a serum albumin less than 2.3 (range 1.4 – 3.2). And fifth, in patients with a BUN >20 and a serum albumin <2.3 the mortality was 100% (n = 7).

Conclusions: Though the incidence of sternal wound problems is rare (about 1-5%), and the majority are simple superficial infections or non-unions, there is a significant population of older, renal-insufficient, malnourished patients who present days or weeks after one would normally diagnose and treat a deep sternal wound infection who have a significant mortality rate. Often these patients have been on long term PICC line antibiotic therapy at home.

Indications for the timing and type of cardiac surgery performed on these patients are outside the plastic surgeon’s realm. Our role begins with the presentation of the complication. Given that the two controllable factors relating to mortality in our sample appear to be malnutrition and renal insufficiency, we have prospectively changed our treatment regimen to optimize these factors after an initial debridement, prior to definitive reconstruction. We hope to improve outcomes and reduce overall mortality using this approach. Treatment suggestions for optimal management are presented.