Elective Repair of Type IV Thoraco-abdominal Aortic Aneurysms; Experience of a Subcostal (Transabdominal) Approach

Objective preoperative pulmonary function has been shown by univariate analysis to be an independent predictor of outcome following Crawford Type IV thoraco-abdominal aortic aneurysm repair. The aim of this study was to determine if outcome had been improved by the introduction of a subcostal approach for the elective repair of these aneurysms. Methods 39 patients studied (19 subcostal, 20 thoracolaparotomy) all operated on between 1993 and 1998 by a single surgeon using a standard technique. No significant difference in median age (69 years) or weight (64 kg vs. 69 kg) between the two groups. Results preoperative co-morbidities, pulmonary function and predictors of respiratory failure did not vary significantly between the two groups, despite a trend towards greater respiratory, cardiac and renal disease in the subcostal group. Preoperative median pulmonary function in both groups was 80% of that predicted for age, sex and height. The subcostal approach did not significantly reduce blood loss (3500 ml vs. 4500 ml) or anaesthetic time (255 min vs. 253 min). Overall 30 day mortality was 10.2%. The rate of re-operation was significantly higher in the subcostal group (21% vs. 0%, p =0.05). No differences were observed in intensive care unit stay, total hospital stay or respiratory complications, despite earlier extubation of the subcostal group (47% vs. 10% extubated at 12 h, p =0.01). Conclusion the introduction of a subcostal approach for type IV thoraco-abdominal aneurysm repair in selected "high risk" patients has been associated with an unacceptably high rate of complications requiring early re-operation. We feel that this relates to the problems inherent in the introduction of a new technique and reduced exposure in patients of inappropriate body habitus. The predicted benefit to pulmonary function is realised in shorter intubation times, but has not translated into earlier recovery or improved outcome. Operation duration and blood loss have not been significantly reduced. Based on these outcomes, we do not currently recommend the general adoption of this approach in all type IV repairs. We will continue to evaluate this approach in patients with poor pulmonary function and a suitable body habitus.