33875

Descending thoracic aorta graft, with or without bypass

CPT code 33875 represents an open surgical procedure for the replacement or repair of the descending thoracic aorta utilizing a synthetic graft, which may or may not involve cardiopulmonary bypass such as left heart bypass or full bypass. The descending thoracic aorta begins anatomically at the level of the left subclavian artery and extends inferiorly to the diaphragm. This exhaustive open intervention is typically indicated for patients suffering from severe cardiovascular pathologies including descending thoracic aortic aneurysms (DTAA), acute or chronic Type B aortic dissections, aortic rupture, or traumatic aortic injury, particularly in cases where thoracic endovascular aortic repair (TEVAR) is contraindicated or the patient's anatomy is unsuitable for endovascular techniques. During the procedure, the patient is placed under general anesthesia with double-lumen endotracheal intubation to allow for single-lung ventilation, optimizing surgical exposure. The patient is positioned in a right lateral decubitus position, and a substantial left posterolateral thoracotomy is performed to adequately access the descending thoracic aorta. Depending on the extent of the aortic disease, the expected duration of cross-clamping, and the surgeon's clinical judgment, partial or full cardiopulmonary bypass, or a temporary mechanical shunt, may be employed. This is critical to maintain distal organ perfusion and protect the spinal cord and visceral organs from devastating ischemic injury. The aorta is meticulously mobilized, and cross-clamps are applied proximally and distally to the diseased segment. The pathological portion of the aorta is then longitudinally incised or excised, and a synthetic tube graft, frequently made of Dacron, is anatomically anastomosed end-to-end to the healthy aorta proximally and distally. Furthermore, critical intercostal arteries may need to be re-implanted directly into the synthetic graft to preserve the crucial blood supply to the anterior spinal artery and mitigate the risk of postoperative paraplegia. Once the vascular anastomoses are secure and absolute hemostasis is achieved, the aortic clamps are removed to sequentially restore blood flow. If a bypass was utilized, the patient is successfully weaned off the circuit, and the cannulae are removed. The extensive thoracotomy incision is then meticulously closed in anatomical layers after the appropriate placement of pleural chest tubes for drainage.

Clinical Indications

  • Descending thoracic aortic aneurysm (DTAA) greater than 5.5 to 6.0 cm in diameter or demonstrating rapid expansion.
  • Acute or chronic Type B aortic dissection presenting with complications such as malperfusion syndrome, rapid expansion, or impending rupture.
  • Traumatic transection or blunt injury of the descending thoracic aorta.
  • Formation of an aortic pseudoaneurysm requiring urgent or elective surgical intervention.
  • Complex adult aortic coarctation not amenable to endovascular stenting.
  • Mycotic aneurysm or severe infection of the descending thoracic aorta.

Procedure Steps

  1. Administration of general anesthesia and placement of a double-lumen endotracheal tube for isolated single-lung ventilation.
  2. Positioning the patient in the right lateral decubitus position and performing a comprehensive left posterolateral thoracotomy.
  3. Establishing cardiopulmonary bypass (e.g., left heart bypass or femorofemoral bypass) if deemed necessary to maintain distal perfusion.
  4. Careful mobilization and isolation of the descending thoracic aorta, identifying and preserving critical structures such as the vagus, phrenic, and recurrent laryngeal nerves.
  5. Administering systemic heparinization and placing secure proximal and distal aortic cross-clamps to isolate the diseased aortic segment.
  6. Incising the aneurysmal or diseased aorta longitudinally and evacuating any mural thrombus or atherosclerotic debris.
  7. Sizing, trimming, and preparing a synthetic tube graft (such as a Dacron graft) for the reconstruction.
  8. Constructing the proximal anastomosis between the synthetic graft and the healthy aorta using continuous non-absorbable monofilament sutures.
  9. Re-implanting critical intercostal arteries directly into the synthetic graft as needed to prevent spinal cord ischemia.
  10. Constructing the distal anastomosis to the healthy descending thoracic aorta, subsequently flushing the graft, and carefully removing the cross-clamps to restore systemic blood flow.
  11. Weaning the patient from cardiopulmonary bypass, decannulating the vessels, and reversing heparin with protamine.
  12. Achieving meticulous surgical hemostasis, placing pleural chest tubes, and closing the thoracotomy incision in standard anatomical layers.

Coding Guidelines

  • Note: CPT code 33875 is a historical code that was deleted and replaced in recent CPT updates (e.g., by code 33873). Coders must verify the active status of the code based on the specific date of service.
  • Cardiopulmonary bypass is considered an inherent component of this procedure when performed by the primary operating surgeon; do not report bypass codes separately unless performed by a distinctly separate team.
  • Do not report open surgical code 33875 in conjunction with endovascular repair (TEVAR) codes for the descending thoracic aorta.
  • The re-implantation of intercostal arteries into the graft is typically included in the primary open repair procedure and should not be unbundled.
  • Modifier 22 may be appropriately appended if the procedural complexity, surgical time, or patient anatomy requires work that is substantially greater than typically required.
  • If the procedure is converted from a planned endovascular approach to an open approach, typically only the successful open procedure (33875) is reported.

Associated ICD-10 Codes