Emergent lumbar drain placement resulting in reversal of paraplegia after total aortic arch replacement and stent grafting of descending thoracic aorta

IntroductionOpen surgery on the aortic arch and thoracic aorta is complex and carries high morbidity and mortality. Indications for open surgery on the thoracic aorta include type A dissection, bicuspid aortic valve and... [ view full abstract ]

Introduction

Open surgery on the aortic arch and thoracic aorta is complex and carries high morbidity and mortality. Indications for open surgery on the thoracic aorta include type A dissection, bicuspid aortic valve and specific ascending aortic diameter/expansion criteria. Integral to these procedures are surgical and anesthetic techniques that minimize ischemia to sensitive CNS tissues.  Placement of a lumbar drain can be used preemptively or as a rescue measure in patients that develop cord ischemia. Various studies have demonstrated that lumbar drains can minimize paraplegia.  Few authors have demonstrated examples of emergent lumbar drain placement as a rescue measure that reversed paraplegia.  
Case
This patient is a 52 year old male with a bicuspid aortic valve and 4.9cm aortic arch presenting for total arch replacement. After induction, arterial line, central line and swan ganz catheter were placed.  After sternotomy and cannulation the patient went on cardiopulmonary bypass (CPB).  He was cooled to 20 C and antegrade cerebral cannulas were placed bilaterally. Intraoperative findings indicated a stent to the descending aorta was necessary. A 3.5x10cm stent graft was deployed in descending thoracic aorta under circulatory arrest. The total circulatory arrest time was 35 minutes and CPB time was 240 min.  At the end of the case patient was found to have good biventricular function and transported to ICU.  Upon extubation 6 hours after arrival, patient was following commands but unable to move bilateral lower extremities.  Emergent lumbar drain was placed at L2-3. Systolic goals were increased to 140-160 and patient was given mannitol.  Three hours after lumbar drain placement and drainage <15cc/hr he was able to flex at the knee bilaterally.  After an additional 3 hours he was able to lift lower extremities. Spinal drain was removed on post operative day 3. Remainder of hospital course was uncomplicated. On followup patient denies neurologic deficit.
Discussion
One major complication of aortic surgery is ischemia resulting in paraplegia secondary to compromised distal perfusion pressure, hypoperfusion and thrombosis of segmental arteries. The distal cord near the level of T8-L1, supplied by the artery of adamkiewicz, is susceptible during cross clamping.  The rate of paraplegia following this procedure ranges 8-30%.  Techniques for preventing ischemia include reducing spinal cord metabolism, increasing distal aortic pressure, or controlling neuraxial outflow pressure via lumbar drain.  The risks of lumbar drain placement are nerve injury, hematoma, intracranial hemorrhage and infection.  Intracranial hypotension occurs due to excessive drainage >15 ml/hour.  Post operative draining should be limited to 48-72 hours to avoid infection. A major randomized study on use of lumbar drain showed 80% reduction of paraplegia in those that received preoperative CSF drain vs those that did not. There is growing evidence for the placement of lumbar drain for spinal cord protection in aortic repair in patients at high risk for ischemic spinal cord. Case studies of prompt post-op placement of lumbar drain with newly developing deficits have shown that this technique can be used to rapidly reverse them.