Deep chest wall infections, including subpectoral abscesses and necrotizing soft tissue infections, require immediate surgical exploration alongside empiric broad-spectrum antibiotics. Medical literature documents complex presentations involving mycobacteria and mixed aerobic-anaerobic pathogens, where delayed recognition significantly increases patient mortality rates.
Anatomical Challenges and Deep Chest Wall Abscesses
The thorax accounts for one-fifth of the total body surface area and thus can be afflicted with many common, nonspecific soft tissue infections. Furuncles and boils common to any hair-bearing surface frequently occur, and superficial infections often develop in minor injuries and burns of the chest, as they do elsewhere in the body. Soft tissue abscesses may occur anywhere on the chest wall. They are characterized by the usual signs and symptoms of an abscess anywhere on the body and are rarely associated with an abnormal chest radiograph. Two potentially serious infections specific to the chest wall and involving large potential spaces are subpectoral and subscapular abscesses. These occasionally present as primary infections but more often are secondary to a chronically infected thoracotomy incision. They are characterized by local pain, with or without swelling, combined with fever and leukocytosis.
Computed tomography easily identifies and localizes the problem. Prompt drainage and appropriate antibiotic therapy usually lead to successful resolution. Suction catheters are rarely required because these spaces are obliterated once drained. Occasionally, when the abscess is large, several counterincisions are made to debride and pack the space more completely.
Complex Etiologies: Tubercular and Fungal Infections
With the worldwide increase in tuberculosis and immigration of people from the third world to North America, pulmonary tuberculosis may be seen in any thoracic surgical practice. Like tuberculous infections of the skin on the neck, called scrofula, mycobacteria can cause a soft tissue infection of the chest wall. Hsu and colleagues reviewed its management in 1995. Even bacillus Calmette-Guérin spread from immunization has caused chest wall infection, as documented by Bellet and Prose. Patients present with a slowly enlarging, sometimes painful, sometimes painless mass on the chest wall. A CT scan is helpful to determine the extent of involvement, demonstrating that the surface involvement may be the simplest part of the abscess. Diagnosis can be made with a diagnostic aspiration of the abscess. Treatment should begin preoperatively with combination antituberculous therapy and continue for 6 to 9 months. Although Hsu advocated that surgical debridement should be reserved for failures, Kim and colleagues showed in 2008 that they could lower the recurrence rate of abscesses from 40% to 9.2%. Also, Cho and associates showed that the use of adequate preoperative antibiotic therapy markedly decreased the need for a second surgical debridement. Fungal infections of the chest wall should also receive long-term antibiotic therapy, but radical debridement is a mandatory part of the therapy.
Surgical Management and Intensive Antibiotic Protocols
Treatment of early necrotizing soft-tissue infections including clostridial myonecrosis is primarily surgical, which should not be delayed by diagnostic studies, combined with empiric broad-spectrum antibiotics and intensive supportive care. Immediate surgical exploration and debridement are done when there is evidence of bullae, ecchymosis, fluctuance, crepitus, and systemic spread of infection. The initial incision should be extended until an instrument or finger can no longer separate the skin and subcutaneous tissue from the deep fascia. The most common error is insufficient surgical intervention; serial debridement every 1 to 2 days, with further incision and debridement as needed, should be carried out routinely. Negative-pressure wound therapy, also called vacuum-assisted closure, applies suction to the wound and has been used as an adjunct for care between debridements.
Because serial debridements should be continued until no further necrosis is identified, amputation of an extremity may sometimes be necessary. Intravenous antibiotics are typically initiated immediately after diagnosis, usually including 2 or more medications. An empiric regimen should include antibiotics effective against aerobic and anaerobic organisms. The Infectious Diseases Society of America recommends vancomycin, linezolid, or daptomycin combined with piperacillin/tazobactam, a carbapenem, ceftriaxone plus metronidazole, or a fluoroquinolone plus metronidazole. Clindamycin and linezolid are also often administered to inhibit toxin production. Antibiotic coverage should be narrowed based on blood and tissue culture results once they become available.
Supportive care includes intravenous fluids, which may be needed in large volumes before and after surgery. Intravenous immune globulin has been suggested as adjunctive therapy for streptococcal toxic shock syndrome with necrotizing soft-tissue infections, but robust clinical data are lacking.
