Thirty Years of Experience with the “Elephant Trunk” Technique

Dr. Coselli Publishes Largest-ever Series of Aortic Aneurysm Repairs with the “Elephant Trunk” Technique

Aortic aneurysm—a weakening of the wall of the aorta that causes it to expand beyond its normal diameter—can become life-threatening if the expansion is too great. Aneurysms that arise in the thoracic aorta may span both the proximal and distal thoracic aorta; such repairs are typically too complex to treat surgically with a single repair. Aneurysms may also develop after the aorta tears, especially if the tear affects the entire length of the aorta. Further, because these repairs often involve important vessels that branch off to supply blood to the brain and spinal cord, they can increase the patient’s operative risk of stroke or spinal cord deficit.

In the 1980s, a 2-stage procedure called the “elephant trunk” operation was devised to treat these aneurysms. In the first stage, through a median sternotomy, the aortic arch is replaced with a graft. The downstream end of the graft is allowed to float free in the descending thoracic aorta—hanging like the trunk of an elephant. After the patient recovers from the first operation, the second-stage procedure is performed: Through a thoracotomy or a thoracoabdominal incision, a second graft is sewn end-to-end to the first to replace the descending thoracic aorta; the graft is anchored beyond the aneurysmal part of the aorta, so that blood flow will pass through the grafts instead of through the aneurysmal aorta itself.

Recently, Dr. Joseph Coselli—program director of Texas Heart Institute/Baylor College of Medicine Thoracic Surgery Residency Program and one of the world’s leading experts in treating disease of the thoracic aorta—published the largest-ever series of elephant trunk procedures. Between 1990 and 2021, Dr. Coselli’s group performed 363 stage-1 elephant trunk operations and 203 stage-2 completion procedures. The operative mortality rate was 12.4% for the stage-1 repairs and 10.3% for the stage-2 repairs, which is fairly typical for such procedures.

Rates of permanent spinal cord deficit (ie, long-term paraplegia) were low: 0.3% after stage-1 operations and 2.0% after stage-2 procedures. This is noteworthy because the traditional elephant trunk procedure is being used less often now; these days, the preferred procedure is the “frozen elephant trunk,” in which a wire-mesh stent is either included in the elephant-trunk graft or expanded inside it to hold the graft in place, so that the entire operation can be done in a single stage in select patients. However, these stented grafts can block arteries that supply blood to the spinal cord, thereby posing a greater risk of paraplegia than traditional stage-1 elephant trunk repair.

“Our findings from this extensive series suggest that the traditional elephant trunk operation still has a role to play in treating disease of the thoracic aorta, particularly for patients with aneurysms complicated by extensive tearing and those with heritable thoracic aortic disease that makes repair with a stent prone to failure,” says Dr. Coselli.

News Story By Stephen N. Palmer, PhD, ELS