Follow-Up on Thoracic Stent-Grafts Encouraging

BY SHERRY BOSCHERT

SEATTLE -- Follow-up data on 190 patients who underwent endovascular treatment for thoracic aortic disease between 1997 and 2006 showed generally good results, Dr. John F. Reidy said at the annual meeting of the Society for Interventional Radiology.

The procedure was technically successful in all but one case. The mortality 30 days after the procedure was 8%, and later mortality was 9%, rates which "would compare very favorably with surgery in such patients, " said Dr. Reidy of Guy's and St. Thomas' Hospital Trust, London.

Many of the patients were very sick and were poor candidates for surgery, he added. Patients were treated acutely in 62 cases and had an elective procedure for chronic disease in 128 cases.

The most feared complication, paraplegia, developed in 4% (seven patients). After cerebrospinal fluid [CSF] drainage, four recovered fully, one recovered partially, and one had permanent paraplegia. One of the seven died. Strokes occurred in 4% of patients, all during the endovascular procedure. Three of these patients recovered fully, and one partially recovered. Two died, and one showed no recovery.

The predominant indication for treatment was degenerative aneurysm in 106 patients. Other indications included acute or chronic dissection, mycotic aneurysm, trauma, coarctation, or Takayasu's arteritis.

"All in all, this is very encouraging and shows that the endografts are here to stay," Dr. David M. Williams of the University of Michigan, Ann Arbor, said in formal commentary after Dr. Reidy's presentation. "About the only conditions in which it's really uncertain what role [endografts will] play would be the patient with marginal anatomy and in patients with acute uncomplicated dissection."

The single-institution results from Dr. Reidy's series fairly closely match results from a multicenter, controlled study of 142 patients treated with thoracic stent-grafts, Dr. Williams noted (J. Vasc. Surg. 2005;41:1-9). The study admitted only patients with degenerative aneurysm who had 2-cm landing zones on either side of the aneurysm, and did not include patients with active leaks, acute or chronic dissections, or mycotic aneurysms. "In general, the patients in Dr. Reidy's group are much sicker," he said.

The technical success rate in that series was 98%. Procedure times were 150 minutes in the multicenter study and 113 minutes in the single-center series. Patients lost 506 cc and 500 cc of blood in the multicenter and single-center cohorts, respectively. Hospital stays were 7.6 days and 7.4 days, respectively.

As in Dr. Reidy's series, the stroke rate was 4% in the multicenter study. Paraplegia occurred in 3%, compared with 4% in Dr. Reidy's series. The 30-day mortality was lower (2%) in the multicenter study than in the single-center series (8%), probably because the former did not include patients with acute disease, Dr. Williams suggested. The similarity in results "point out that this is going to be a very durable procedure worldwide," he added.

Early in the series, they used general anesthesia, "but our routine now is to do regional and an epidural anesthetic," Dr. Reidy said. "We think this has advantages in detecting paraplegia earlier" so that CSF drainage can begin.

The surgeons did not routinely transpose the subclavian artery. "If there are concerns about the landing zone where we're going to cover the subclavian, and we're not going to be in an ideal position, we would do a right-to-left carotid-to-carotid bypass 1 week earlier," he said.

Carotid-to-carotid bypass was the most common additional procedure required; it was done in 16 patients. Seven patients with severe arterial disease needed repair of an access artery. Other additional procedures included embolectomy, stent-grafts for abdominal aortic aneurysm, aorto-iliac conduit, and dissection of bare stents.

"This very favorable report on thoracic stent grafting is consistent with several others that have recently appeared, suggesting that the procedure has arrived as a better treatment method," said Dr. Frank J. Veith when asked to comment on this article.

"Yet, there continue to be problems, complications and poor results in some patients. This suggests that we are early in the phase of evaluation of this new form of therapy, and that it is likely that better endografts will be developed, especially for certain lesions," he added.

"These improved grafts and better patient selection will almost certainly render the results of thoracic aortic endografting better than they already are," he concluded. Dr. Veith is professor of surgery and Liebig Chair of vascular surgery at the Cleveland Clinic, and professor of surgery at New York University Medical Center.