[Thoraco-abdominal aneurysms of type IV]

Aims of the study were: 1. to evaluate the results of surgical treatment of type IV thoraco-abdominal aneurysms (TAA), with relationship to other types, 2. to evaluate results obtained with an approach different from the traditional thoraco-phreno laparatomy, with specific attention to postoperative respiratory function.

We have retrospectively compared type IV TAA with all other types of thoraco-abdominal aneurysms electively treated between January 1st, 1994 and May 31st, 2003. Data on perioperative mortality, spinal cord ischemia and renal failure (both temporary and permanent) occurring in the first 30 postoperative days were considered. Protection from spinal cord ischemia was accomplished through liquor drainage and prostaglandin E1 (PGE1) infusion. When the aneurysm extension was limited to the celiac axis an extrapleuric access with removal of XI rib was performed. In this subgroup of patients we have considered postoperative recovery time of respiratory function (intubation time, number of days in intensive care unit, postoperative pulmonary complications) postoperative renal failure, perioperative mortality and morbidity.

Seventy-eight TAA have been treated in the period of time of the study. Twenty cases were type IV TAA (25.6%) of which 2 due to chronic dissection. Cumulative postoperative mortality has been 19.2%. The single perioperative death in the group of type IV TAA (5%) occurred in post-operative day 15 for multiple organ failure. No spinal cord ischemia occurred in this group. Temporary renal failure occurred in 3 cases (15%) with one case requiring dialysis. In 10 cases (50%) an extrapleuric access with removal of XI rib was performed, with adequate control of the proximal aorta. Postoperative respiratory failure requiring and intubation time longer than 12 hours occurred in 2 cases (20%). In the remaining 8 cases the mean intubation time was 5.3 hours (range 4-8 hrs). Tracheostomy was not necessary in any case. Mean time of intensive care unit stay was 3.5 days (range 0-15 days).

The appropriate treatment of type IV TAA leads to low mortality and morbidity with results similar to those of pararenal aneurysms rather than those of other TAA forms. Left extrapleuric access when feasible allows faster recovery of a normal respiratory function.