Endovascular, noninvasive thoracic aortic aneurysm repair (TEVAR) is safer than open aneurysm repair as it is associated with fewer cardiac, respiratory, and haemorrhagic complications, as well as a shorter hospital stay, according to a study in the May 2009 issue of the Journal of Vascular Surgery.
According to Gilbert Upchurch Jr from the University of Michigan Medical School in Ann Arbor, USA, thoracic aortic aneurysms, while rarer than abdominal aortic aneurysms, remain a lethal disease. “The aneurysms form in the chest cavity and usually go undetected unless found during tests being done for other diseases,” said Upchurch. “Even in the elective setting, surgical repair of these aneurysms has a mortality rate of close to 10% to 20%. This operation also is fraught with complications, including paralysis and renal failure that also approach 20%.”
An endograft to treat thoracic aneurysm was first approved by the US regulator, the FDA, in 2005. During the first three months following approval, Upchurch and fellow researchers performed the first study to compare TEVAR and traditional open aneurysm repair from a large, unselected cohort from the National Inpatient Sample (NIS database) that represents the entire scope of unruptured thoracic aortic aneurysm repairs in the United States.
“We collected and compared data of 267 patients who had TEVAR to 1,030 patients who underwent open repair,” said Upchurch. “Complications, mortality, length of stay, hospital charges, patient disposition, discharge status, and patient demographics were examined.”
The average ages were 66 years for open repair patients and nearly 70 years for TEVAR. Patients who had TEVAR had a higher burden of cardiovascular comorbidities, and were more likely to have hypertension, renal insufficiency, chronic obstructive pulmonary disease, cerebrovascular occlusive disease, and peripheral artery disease. In-hospital mortality was not significantly different between the two repair approaches. Researchers reported that open repair had a higher overall complication rate (33% vs. 20%). The two approaches were equivalent in their rates of iatrogenic cerebrovascular accident; however, haematoma development, postoperative infections, and cardiac, respiratory, and haemorrhagic complications were more likely to occur in open repair patients.
More TEVAR patients were discharged from hospital (more likely to their home rather than an extended care facility) within the first few days of their procedure, and a significant number of open repair patients were hospitalised for more than 10 days.
In contrast to what occurs with the endovascular surgery in abdominal aortic aneurysm, which is uniformly believed to be more expensive than open repair, the current study shows that when treating thoracic aortic aneurysm there were no significant costs or charge differences between the open and endovascular approaches. However, patients who were free of complications after TEVAR were associated with a US$10,000 reduction in costs.
Upchurch pointed to the success of endovascular repair for abdominal aneurysm and believes it is likely that the proportion of thoracic aneurysm repairs performed with an endovascular approach also will increase. He added that past research has shown that stent grafts are designed and simulation-tested to be durable for 10 years, and as more favourable evidence becomes available about the longevity of these grafts, more patients (particularly younger ones) will become TEVAR candidates. He noted that as technology and collective clinical experience with TEVAR increases with individual practitioners, institutional levels’ volume and increased FDA graft approval, the mortality rate associated with endovascular repair for thoracic aneurysm may decrease, just as it has for endovascular abdominal aneurysm repairs.
Researchers cautioned that healthcare policy decisions must be based on hospital stay, as well as long-term health and financial data. “Our NIS data does not report long-term complications of TEVAR – endoleak, stent migration, and stent fracture – which are known to occur frequently after discharge,” explained Upchurch.
“Also, TEVAR patients currently require life-long computer tomography surveillance. Therefore, further long-term studies comparing the post-operative complications, mortality, and economic impact of both approaches using different data sources are warranted.”
“However, studies of mid-term follow-up for TEVAR show that the real concern for death lies in the immediate perioperative period before hospital discharge, suggesting that our mortality rate accurately captures the bulk of repair-related deaths.”