Coverage of visible intercostal and lumbar segmental arteries can predict the volume of cerebrospinal fluid drainage in elective endovascular repair of descending thoracic and thoracoabdominal aortic disease: a pilot study

OBJECTIVES: Our goal was to identify anatomical and physiological factors that could predict the amount of cerebrospinal fluid (CSF) drainage in patients undergoing elective endovascular repair of descending thoracic and thoracoabdominal aortic disease. METHODS: All consecutive elective endovascular procedures performed for descending thoracic or thoracoabdominal aortic disease between January 2015 and December 2017 were included in the study. Routine use of CSF drainage was established in all patients. The goal of drainage was to reach a spinal fluid pressure of 10-12 mmHg by draining in 5-15-ml aliquots. The number of visible intercostal and lumbar segmental arteries (SAs) was evaluated before and after endovascular repair. The covering ratio of SAs was calculated as covered preoperative SAs/total preoperative SAs. RESULTS: Twenty-four consecutive patients were included in the final analysis. The indication for the intervention was a descending thoracic aneurysm in 13 cases, a thoracoabdominal aneurysm in 4 cases and a chronic type B dissection in 7 cases. The procedure performed was thoracic endovascular aortic repair in 20 cases and fenestrated endovascular aneurysm repair in 4 cases. None of the patients developed spinal cord ischaemia. The mean volume of CSF drained was 46 ml. The mean length of aortic coverage was 231 mm. The mean number of total preoperative SAs and of covered preoperative SAs was, respectively, 22 and 9. The volume of CSF drained was significantly correlated with all these variables (length of aortic coverage, total visible SAs and covered SAs), but the most powerful correlation was individuated with the covering ratio of SAs. CONCLUSIONS: Our findings suggest that the percentage of intercostal and lumbar SAs covered by placement of a stent graft can predict the volume of CSF drained in patients undergoing elective endovascular repair of descending thoracic and thoracoabdominal aortic disease.