Aortic Debranching Can Aid Endovascular Repair of TAA

BY MARK S. LESNEY

Hybrid open and endoluminal approaches to complex thoracic aortic aneurysm repair can provide an alternative to open TAA repair when significant limitations to a fully endovascular approach are present, according to Dr. Karthikeshwar Kasirajan of the division of vascular surgery at Emory University, Atlanta.

Endovascular techniques can provide a significant reduction in surgical trauma and can provide decreased cardiac stress. This is especially beneficial to patients, including the elderly, who may have multiple comorbid conditions. But such techniques are not always useable for every patient. For an endograft to be successful in excluding the pathology, it must be fixed both proximal and distal to the lesion (in a "nondiseased" segment of the aorta), which can be especially challenging in the thoracic aorta with its multiple branches to other critical vessels.

"Open TAA repair continues to carry a high mortality and morbidity. But at the same time, there are situations where endovascular approaches are not an easy alternative. Landing zones can be in close proximity to, or involve, critical branch vessels. And branched endograft and fenestrated grafts have not yet passed clinical trials," Dr. Kasirajan reported.

Extraanatomic bypass procedures, however, may help create an adequate landing zone in patients to allow for an endovascular TAA repair with acceptable morbidity, according to results that Dr. Kasirajan first presented at the 16th annual winter meeting of the Peripheral Vascular Surgery Society.

In a study conducted over 5 years, Dr. Kasirajan and his colleagues, Dr Ross Milner and Dr. Elliot Chaikof of the division of vascular surgery at Emory University, performed 22 extraanatomic bypasses in patients to facilitate endograft placement. All but one patient had their endografts placed concomitantly with the bypass.

The 22 bypasses comprised:

• Ascending aorta to innominate/left common carotid (four patients).
• Left carotid to subclavian (six patients).
• Left axillary to celiac/superior mesenteric artery (SMA) (one patient).
• Splenic to renal (two patients).
• Hepatic to right renal (one patient).
• Iliac to renal (two patients).
• Common-iliac to bilateral renal (one patient).
• Iliac to SMA (two patients).
• Iliac to renal/SMA (three patients).

All of the patients (mean age 77 years) had cardiac risk factors that prohibited open surgery, with 11 patients also having chronic obstructive pulmonary disease. End-stage renal disease was present in two patients. Their mean aneurysm diameter was 6.7 cm. Their vascular anatomy was such that they were not suitable for standard endograft procedures.

A variety of endografts were used: the Gore thoracic excluder in 13 patients, the Talent thoracic stent graft in 7 patients, a custom device in 1 patient, and a Zenith graft in another. The mean operative time was roughly 5.7 hours and the average length of hospital stay was 12 days.

After surgery, three patients had a type I endoleak. Perioperative complications included stroke in one patient, and upper gastrointestinal bleeding that required operative intervention in another. Perioperative mortality was seen in two patients, one who developed a perforation of an aortic dissection which resulted in paraplegia and death secondary to an MI, and another patient who died secondary to a pulmonary embolism 12 days post surgery.

During a mean follow-up of 17 months, two patients required reintervention for a type I and a type III endoleak, and four patients died secondary to underlying medical comorbidities, according to the researchers.

These results indicated that patients who are not ideal candidates for open repair or endografts could be offered hybrid open/endograft procedures as a treatment option with acceptable early and late morbidity, Dr. Kasirajan and his colleagues concluded.