Poststernotomy mediastinitis: a review of conventional surgical treatments, vacuum-assisted closure therapy and presentation of the Lund University Hospital mediastinitis algorithm

Abstract

Poststernotomy mediastinitis, also commonly called deep sternal wound infection, is one of the most feared complications in patients undergoing cardiac surgery. The overall incidence of poststernotomy mediastinitis is relatively low, between 1% and 3%, however, this complication is associated with a significant mortality, usually reported to vary between 10% and 25%. At the present time, there is no general consensus regarding the appropriate surgical approach to mediastinitis following open-heart surgery and a wide range of wound-healing strategies have been established for the treatment of poststernotomy mediastinitis during the era of modern cardiac surgery. Conventional forms of treatment usually involve surgical revision with open dressings or closed irrigation, or reconstruction with vascularized soft tissue flaps such as omentum or pectoral muscle. Unfortunately, procedure-related morbidity is relatively frequent when using conventional treatments and the long-term clinical outcome has been unsatisfying. Vacuum-assisted closure is a novel treatment with an ingenious mechanism. This wound-healing technique is based on the application of local negative pressure to a wound. During the application of negative pressure to a sternal wound several advantageous features from conventional surgical treatment are combined. Recent publications have demonstrated encouraging clinical results, however, observations are still rather limited and the underlying mechanisms are largely unknown. This review provides an overview of the etiology and common risk factors for deep sternal wound infections and presents the historical development of conventional therapies. We also discuss the current experiences with VAC therapy in poststernotomy mediastinitis and summarize the current knowledge on the mechanisms by which VAC therapy promotes wound healing. Finally, we suggest a structured algorithm for using VAC therapy for treatment of poststernotomy mediastinitis in clinical practice.

Mediastinitis: mortality rate comparing single-stage surgical approach and preconditioning of wound

“…Its elimination during the preoperative period should have top priority, in addition to strengthened care by the surgical team during the intraoperative period. Brazilian studies indicate Staphylococcus aureus as the most predominant causal agent in mediastinitis, whereas international reports demonstrate a predominance of Staphylococcus epidermis [9,10,24,25].…”

“…Its elimination during the preoperative period should have top priority, in addition to strengthened care by the surgical team during the intraoperative period. Brazilian studies indicate Staphylococcus aureus as the most predominant causal agent in mediastinitis, whereas international reports demonstrate a predominance of Staphylococcus epidermis [9,10,24,25].Using the preconditioning wound can reduce mortality by approximately 22% compared to the procedures of time only. This improvement in survival seems mainly related best clinical conditions of the patient and the wound at the time of final closure of the chest.…”

“…Surgical management of postoperative mediastinitis counts on several techniques described in the literature [5,[10][11][12][13][14][15][16][17]. Treatment may include single-or multiple-stage procedures, with or without the use of muscle or omental flap [11,12,18].…”

“…Moreover, there are several series exhibiting poor long-term results with these techniques. Moreschi et al [18] reported 81 consecutive mediastinitis cases treated with different modalities, early intervention with the use of flaps being a good treatment option with low mortality rates.Therapy failure in mediastinitis leading to infection recurrence aggravates significantly an already difficult situation, resulting in an even higher mortality rate [3,10].In an attempt to reduce high recurrence and treatment failure rates associated with primary resuture, several alternatives and technical refinements have been suggested over the past decades. Among them, we point out plastic reconstruction procedures using pectoralis muscle or omental flap [11,12].…”

“…However, mortality associated with such surgical complications, even after appropriate treatment, is extremely high, ranging between 14% and 47% [1,6,7]. Several studies have identified risk factors such as obesity, diabetes, reoperation, smoking, prolonged operative time, bilateral use of the internal thoracic artery, and postoperative bleeding [4,5,8,9].Surgical management of postoperative mediastinitis counts on several techniques described in the literature [5,[10][11][12][13][14][15][16][17]. Treatment may include single-or multiple-stage procedures, with or without the use of muscle or omental flap [11,12,18].…”