Device discordancy: Lost cords, quick-fix seekers, quality, and ethics

Abstract

doi:10.1016/j.jtcvs.2005.10.031 Our modern world is so accustomed to instant gratification and efficiency with the accompanying expectations of little effort or pain that people will often choose the easy path at the cost of a poorer outcome over the long term. There are many examples of these choices by both consumers and patients, particularly when they are not fully informed, including use of catheter-based devices rather than open procedures. In this issue of the Journal, Flores and colleagues present their experience with combined open aortic arch repair and descending thoracic aortic stenting in the hopes of avoiding a second procedure, either open or endovascular, to treat patients more speedily. The results are sobering. First, their circulatory arrest times must have been prolonged, thus risking greater brain injury to the patients. Second, postoperative spinal cord injury occurred at an unacceptably high percentage of 24%. The finding of an increased complication rate of spinal cord injury is not new. For example, acute aortic dissection repair with replacement of the entire aortic arch (a questionable procedure except in rare cases) and stenting of the descending aorta has resulted in a similarly high rate of lost spinal cord function. Furthermore, in our early experience with the modified inverted elephant trunk insertion method in 84 patients, we noted that too long of an elephant trunk graft in the descending aorta resulted in complete paraplegia in 1 patient and paraparesis in 2 patients. This led to our recommendation that an elephant trunk graft should be no longer than 10 to 15 cm. Why then is stenting or a long elephant trunk graft a problem? The obvious answer is that the intercostal arteries are occluded by the graft material, and the cord becomes dependent on collateral circulation. Second, it is likely that pump-related nonpulsatile hypotension and perioperative hypotension are inadequate for sufficient perfusion of the spinal cord in many patients who are dependent on their collateral arteries. In addition, it is worth noting that the squeezing of atheroma, somewhat akin to the texture of toothpaste, into intercostal arteries by stents could likely cause embolic obstruction of the blood supply. Whether these factors completely explain the high risk of paralysis when stenting is combined with cardiopulmonary bypass cannot be determined from this study. In our review of 832 descending aortic open repairs, paralysis occurred mostly in those patients who underwent replacement of either the entire descending aorta or the distal third or in those patients who had previously undergone abdominal aortic replacements. In 132 patients with descending aortic repairs, Borst and colleagues found paralysis was higher in patients with replacement below T8. Similarly, others noted a higher paralysis rate with distal descending aorta replacements. It appears that these hard lessons are now being relearned for descending aortic stenting. The Stanford group reported in 2004 that the risk of paralysis increased with either distal descending aortic stents or combined descending aortic stents in patients with previous aortic abdominal replacements. In our experience with descending aortic