Multidisciplinary Management of Sternal Osteomyelitis Due to Klebsiella aerogenes after Open Heart Surgery in a Patient with Multiple Myeloma: A Case Report and Discussion of the Literature

Abstract

Sternal wound complications following cardiac surgery, including sternal dehiscence, mediastinitis, and osteomyelitis, pose significant challenges in terms of management and patient outcomes. We present a case report highlighting the complex management of a patient who underwent open heart surgery for severe aortic valve stenosis, followed by sternal wound dehiscence and sternum osteomyelitis due to extended spectrum beta lactamase (ESBL) producing Klebsiella aerogenes. A multiple myeloma diagnosis was also suspected at the positron emission tomography (PET) scan and confirmed with bone marrow biopsy. Multidisciplinary evaluation of the case led to a comprehensive treatment plan. To control the sternal osteomyelitis, total sternectomy was performed followed by immediate reconstruction with a bone (tibia) graft from the tissue bank and fixation with the minimal hardware possible. A microsurgical latissimus dorsi free flap was required to reconstruct the soft tissue defect. After 6 weeks of antibiotic treatment with ertapenem and fosfomycin based on a culture of intraoperative material, no clinical, imaging, or laboratory signs of infection were seen. Multiple myeloma treatment was then started. At 1 year of follow up, no recurrence of infection occurred, and the reconstruction was stable and closed. Multiple myeloma is under chronic treatment with novel agent combination, with an excellent haematological response.

Keywords: chest reconstruction; microsurgical flap; multiple myeloma; open heart surgery; sternal osteomyelitis.

Figure 1

Preoperative 3D CT scan—outcomes of sternotomy and sternal wiring from the previous surgery are visible.

Figure 2

Sternal wound dehiscence.

Figure 3

Osteomyelitis diagnosis—CT PET images documenting sternal osteomyelitis at various sections of sternum (proximally and distally).

Figure 4

Multiple myeloma—CT PET image shows multiple focal areas of vertebral bone marrow with increased metabolic activity at T6 (above), T10 (middle), L1 (below).

Figure 5

Sternum reconstruction—intraoperative photo of the bone allograft used to reconstruct the sternum and fixed to the costal stumps with titanium plates.

Figure 6

Latissimus dorsi flap—intraoperative photo of the LD flap to cover the allogenic bone graft and costal plates. A skin paddle of size 20 cm × 8 cm was harvested and the lateral areas were then grafted with meshed split-thickness skin grafts from the patient’s thigh.

Figure 7

Postoperative follow up—(left) at 3 months, wounds are healed. (center) At 6 months, the flap is stable. (right) At 12 months, LD muscle hypotrophism is observed, but no hardware exposure or infection relapse occurred.