Transient Paraplegia after Stent Grafting of a Descending Thoracic Aortic Aneurysm Treated with Cerebrospinal Fluid Drainage
Ralph J. Fuchs, M.D., W. Anthony Lee, M.D., and Christoph N.
Seubert, M.D., Ph.D.
Department of Anesthesiology (RJF, CNS) and Division of Vascular
Surgery (WAL), University of Florida, Gainesville, FL
Case Report
IMPLICATIONS. We present a case of descending thoracic aortic
aneurysm repair by endovascular stent graft, complicated by
postoperative paraplegia, which was successfully treated by
placement of a spinal drain. The case highlights the importance
of collateral flow to the spinal cord and of choosing an
anesthetic technique that allows immediate postoperative
evaluation of lower extremity neurologic function.
CASE REPORT. A 66-yr-old, 74 kg patient presented for
endovascular repair of a 6.1 cm descending thoracic aortic
aneurysm beginning 7 cm distal to the left subclavian artery and
extending inferiorly to 3.5 cm above the diaphragm. He was
enrolled in Phase II of the W. L. Gore (Sunnyvale, CA) thoracic
aortic endograft trial. The patient had undergone an
aorto-biiliac reconstruction for an abdominal aortic aneurysm
ten years ago.
Intraoperative monitoring included electrocardiogram, invasive
arterial blood pressure, central venous pressure, end-tidal CO2,
pulse oximetry, esophageal temperature and an indwelling
urethral catheter. Anesthesia was induced with thiopental, and
fentanyl. Succhinylcholine was given to facilitate endotracheal
intubation. Anesthesia was maintained with isoflurane (0.4-1.2%
end-tidal concentration), in air and oxygen supplemented with
fentanyl and rocuronium. After uneventful placement of the
endovascular stent graft the patient was awakened. He was able
to move all extremities to command. Because the left leg was
found to be pulseless, general anesthesia was re-induced. A
focal dissection of the left external iliac artery was repaired,
restoring perfusion to the leg.
Postoperatively, the patient was again responsive, but unable to
move his lower extremities despite normal distal pulses. A
spinal drain was placed at the L4/L5 interspace and set to 5
cmH2O. After drainage of 50 ml cerebrospinal fluid, the patient
was able to move his left leg and sense light touch in his right
leg. The spinal drain was kept in place for four days resulting
in complete resolution of the neurologic deficits.
DISCUSSION. Risk factors for postoperative paraplegia during
open repairs of the descending thoracic aorta are dissection,
rupture, long clamp time, Crawford type I, postoperative
hypotension, and sacrifice of spinal collateral vessels.
Although some advocate routine use of CSF drainage, a recent
meta-analysis illustrates the difficulties in documenting a
protective effect.
There is evidence to suggest that endovascular repair of
descending thoracic aortic aneurysms decreases the incidence of
spinal cord injury compared to open surgical repair by limiting
the extent of aorta replaced and by avoiding the hemodynamic
instability and ischemia/reperfusion associated with open
repairs. Our patient with his history of a previous infrarenal
aortic aneurysm repair and an acute paraplegia that resolved
with cerebrospinal fluid drainage underscores the importance of
collateral flow to the spinal cord and adequate spinal cord
perfusion pressure.
The anesthetic plan for patients, who undergo endovascular
repair of thoracic aortic aneurysms, should consider the risk of
spinal cord ischemia. This consideration is becoming more
important, because endovascular repair, in the setting of
clinical trials, is increasingly offered to anatomically
eligible patients as first-line treatment for descending
thoracic aneurysms. Our case suggests that the anesthetic
technique should enable early postoperative assessment of
neurologic function of the lower extremities.
