Extra-anatomical revascularization of the Adamkiewicz artery using the internal mammary artery: preliminary...

Ischemic spinal cord injury remains a major complication of both open and endovascular repairs of extensive lesions of the thoracic or thoracoabdominal aorta. Patients undergoing endovascular treatment cannot benefit from direct revascularization of the Adamkiewicz artery (AA). Primary revascularization of the intercostal artery (ICA) giving rise to the AA using the internal mammary artery (IMA) could ensure uninterrupted flow in the AA even if the origin of the feeding ICA was obstructed. The purpose of this study was to assess the anatomical feasibility of revascularization of the ICA giving rise to the AA using the IMA. Twenty-four dissections were carried out on 12 cadavers (eight men, four women) with a mean age of 76 at the time of death. Preparation consisted of intra-arterial injection of polymethylsiloxane (Rhodorsil, Rhodia, France). For each IMA, the following parameters were determined: diameter in relation to the ICA in the paravertebral region before division, length, and level of the intercostal space in which direct anastomosis was possible. Dissection showed that the mean diameter at the end of the IMA was 1.8mm (range 1.2-2.4). The mean diameter of the ICA in the paravertebral region was compatible with that of the IMA, i.e., 1.6mm (range 0.9-2.5). The mean length of the IMA was 185 mm (range 165-230). The lowest intercostal space available in the paravertebral region for direct anastomosis between the IMA and ICA was the seventh space in one case, the eighth in 12, the ninth in eight, and the tenth in three. The findings of this preliminary study document the feasibility of using the IMA to revascularize the ICA in the paravertebral region. This technique could provide a means of preserving spinal cord vascularization during endovascular treatment of thoracic or thoracoabdominal aortic lesions.