A 68-year-old man comes for outpatient follow-up after recent coronary artery bypass grafting surgery. He describes anterior chest "clicking" and "shifting" when he bends or moves his upper extremities. The patient has no chest pain, dyspnea, fever, chills, or abdominal pain. He underwent uncomplicated surgery with internal thoracic artery harvesting 6 days ago for severe coronary artery disease. The patient is afebrile, and vital signs are within normal limits. Medical history includes diabetes mellitus, obesity, and chronic obstructive pulmonary disease. Examination reveals a midsternal wound that is clean with well-approximated sutures and minimal serous discharge at the lower edge but without erythema. On palpation the sternum appears to be rocking and clicking with patient coughing. Which of the following is the best management for this patient?
This patient's presentation is concerning for sternal dehiscence, a complication of cardiac surgery that occurs when the 2 approximated edges of the bony sternum separate, typically due to loosening or fracture of the suture wire. It can occur with or without the involvement of superficial soft tissues (ie, superficial dehiscence) or concurrent deep wound infection (ie, mediastinitis). Patients may have mild pain or sensation of chest wall instability and "clicking" with chest movement. The diagnosis can be made radiographically (eg, displaced sternal wires) or clinically; palpable rocking or clicking of the sternum confirms the diagnosis.
Risk factors are related to impaired wound healing. Obesity, macromastia (large breasts), and the sequelae of chronic obstructive pulmonary disease (eg, barrel chest deformity, chronic cough) increase tensile forces on the wound closure, predisposing patients to sternal separation. Internal thoracic artery harvesting can result in sternal ischemia, whereas patients with diabetes or who smoke are at risk for poor wound healing and infection.
Sternal dehiscence is a surgical emergency and requires urgent surgical exploration, debridement, and sternal fixation to prevent cardiac damage from loose wire or bone fragments. Patients without evidence of underlying infection can undergo rewiring or sternal plate placement to stabilize the sternum.
(Choice A) Sternal dehiscence is a surgical emergency and clinical observation without surgical intervention risks increases in patient morbidity and mortality.
(Choices B and C) Compressive sternal dressings and negative pressure wound therapy are frequently used in patients with sternal wound failure to protect the wound and speed its healing. However, this patient has palpable rocking of the sternum consistent with sternal dehiscence and therefore requires surgical intervention and sternal fixation to prevent cardiac injury.
(Choice D) Blood and wound cultures and broad-spectrum intravenous antibiotics are indicated if there is concern for infection; however, empiric oral antibiotics should be avoided due to the high mortality risk associated with deep sternal wound infection. In addition, this patient does not have signs of infection (ie, fever, chills, erythema on examination), and fixation of the mobile sternum is more appropriate.
Educational objective:
Sternal dehiscence is a complication of cardiac surgery characterized by separation of the bony edges of the sternum. Patients may report mild pain or sensation of chest wall instability and "clicking" with chest movement. The diagnosis can be made radiographically (eg, displaced sternal wire) or clinically; palpable rocking or clicking of the sternum confirms the diagnosis. Management involves urgent surgical exploration and repair.