Novel Chest Wall Reconstruction Following Excision of an Xiphisternal Chondrosarcoma

DISCUSSION

Chondrosarcomas represent 0.5%-1% of all neoplasms and 20% of chest wall neoplasms, the most common primary malignant tumor of the chest wall.¹ Researchers at the Memorial Sloan-Kettering Cancer Center reviewed 40 years of patient history and reported primary location occurrence incidence rates of 5% in the clavicles, 16% in the sternum, 36% in the scapula, and 43% in the ribs.¹ In reported xiphoid cases, the tumors grew inferiorly. Because our patient presented for the first time to the ED with a full-sized tumor, evolution of his chondrosarcoma can be hypothesized as radial based on location, size, and erosion into the pericardium; however, this hypothesis cannot be confirmed as the evolution of the tumor is unknown.

The treatment of choice for thoracic wall chondrosarcoma is radical en bloc excision with wide margins because chondrosarcomas are usually resistant to chemotherapy.³ One of the major challenges after tumor resection is reconstruction of the chest wall. The goal is to create an adequate or rigid thoracic cage for chest wall stability, good pulmonary function, and protection of thoracic organs. Various materials have been used in an attempt to achieve adequate stability. Often a rigid repair material, such as methyl methacrylate cement, muscular flaps, titanium rib and sternal plates, or cryopreserved bone graft, are used to mimic the original chest wall stability.^4-6 The drawbacks of methyl methacrylate include wound complications, tilting, excursion of the plate if it is not properly fixed, and failure to create an adequate scaffold for new bone.³ In our case, we had concerns about the exothermic properties of the methyl methacrylate and migration of the plate through the omentum and into the exposed right ventricle; thus, we chose to avoid this method of repair. Cryopreserved bone grafts are easily manipulated and tailored to a site but can be hard to access and are time consuming to fixate.⁴ Our hospital did not have access to cryopreserved bone graft at the time of the operation. Titanium has been used to help create rigid support across anterior chest wall dissections and can be imaged with CT scan and magnetic resonance imaging, allowing safe postoperative surveillance.⁷ However, the available titanium plates were not long enough to span our patient's defect.

Combined with rigid support, other materials are often used as barriers or added support layers, such as omentum, polypropylene mesh, and polytetrafluoroethylene patches. The omentum is vascularized, which can help carry antibiotics to the defect site, and angiogenic, amorphous in shape, and bulky.⁸ The omentum is often used to cover rigid chest wall replacements, such as methyl methacrylate cement, to prevent infection and create a bed for skin grafting.⁹ Omental flaps are a particularly excellent option for filling large inferior sternal defects.¹⁰ A pectoralis turnover flap could also provide coverage to this area, but this approach was not an option for our patient because of ligation of the internal mammary arteries during dissection. Complications such as herniation, spread of abdominal infection, and omental pedicle necrosis are rare.⁹ Polypropylene is often used to repair hernia-like defects but can be a nidus for infection and may wrinkle during placement.¹¹ In our patient, we used omentum as an allogenic covering for the heart and exposed lungs, creating a bulky cushioned barrier to fill the defect, and covering it with a tightly placed polypropylene mesh that created a semirigid barrier for containing the thoracic organs.

To our knowledge, our case is the first report of a chest wall reconstruction of a large defect using a combination of polypropylene and omentum without a rigid support or muscular flap. This repair option could be used as a treatment option for patients in whom rigid chest wall reconstruction for large defects is not possible or available.