SS09 - A report of the safety of spinal fluid drainage in 1445 open and endovascular thoracic and thoracoabdominal aortic aneurysm patients treated at a single institution from 1987 to 2023

Objectives: Spinal cord injury (SCI) is a complication of open and endovascular thoracic (TAA) and thoracoabdominal aortic aneurysm (TAAA) repair. Spinal fluid drainage (SFD) is used to reduce SCI risk in open surgery; however, many question the safety of SFD in endovascular repair. We present our experience with 1445 patients undergoing open and endovascular TAA and TAAA repair and the safety of SFD.

Methods: Spinal drains were placed in open TAAA repairs and endovascular repairs planning >12cm aortic coverage. Cardiac anesthesiologists placed and managed all drains. From 1987-2000 18g catheters were placed through 16g needles using anatomic landmarks. From 2000-2023 16g catheters through 14g needles were placed using fluoroscopic guidance. Spinal fluid was drained to < 5-8 mmHg depending on SCI risk. If bloody fluid appeared, drainage was stopped and head CT obtained. Drainage was stopped when patient demonstrated normal leg strength; drains were removed at 48 hours if leg strength was normal and coagulation factors acceptable. Post-SFD headache was treated with blood patch. We tracked intraoperative fluid drained, neurologic complications from SFD (any neurologic deficit from intracranial or spinal hematoma), bloody spinal fluid, intracranial blood on head CT without neurologic deficit, headache requiring blood patch, transient SCI (paraparesis/paraplegia), and permanent SCI (paraparesis/paraplegia).

Results: Of the 1445 patients (1029 open, 416 endovascular) undergoing TAA/TAAA repair, 1007 (777 open, 230 endovascular) had SFD. Before 2000, 263 open repairs done with smaller drains had an average of 125mls of fluid drained intraoperatively to achieve pressure goals. From 2000-2023 intraoperative SFD to achieve pressure goals averaged 132mls in open and 81mls in endovascular repairs. Six patients (0.6%) had neurologic complications from SFD; 4 of these (0.77%) occurred in open patients. Only 1 patient having endovascular repair had a neurologic complication from SFD (0.43%). From 2000-2023 other events not resulting in neurologic deficit included bloody spinal fluid (20.7% open; 21.7% endovascular); intracranial blood on CT without neurologic deficit (9.9% open; 6.1% endovascular); and headache requiring blood patch (7.6% open; 11.7% endovascular). From 2000-2023 5.6% of open patients had transient SCI; 4.2% had permanent SCI. 3.6% of endovascular patients had transient SCI; 1.2% had permanent SCI.

Conclusions: SFD can be performed with acceptable risk in both endovascular and open TAAA repair. We advocate that SFD be used to reduce risk of SCI in both endovascular and open TAAA repair.