Postoperative epidural analgesia and possible transient anterior spinal artery syndrome. (HaEmek Medical Center, Afula, Israel) Reg Anesth Pain Med 2001;26:274–277.
Authors: Crystal Zeev , Katz Yeshayahu 
Published: March 2003

An unusual complication of epidural analgesia used to facilitate postoperative pain relief while mobilizing a patient is presented in this case report. A 65‐year‐old woman with a history of chronic obstructive pulmonary disease, atherosclerotic cardiovascular disease, chronic renal failure, and degenerative vertebral anatomy underwent resection of the left ureter due to an obstructing tumor. The day following the surgery, mobilization to an armchair was started, followed by a decrease in blood pressure. Soon after, flaccid paralysis was sparing of sensory functions, consistent with anterior spinal artery syndrome, was diagnosed. This complication should be taken into account, especially in patients at risk, when considering epidural analgesia techniques in the postoperative period.

Comment by Pedro F. Bejarano, M.D. Fortunately infrequent, the Anterior Spinal Artery Syndrome (ASAS) has been described in the early postoperative period in association with surgery involving the retroperitoneum (specially on the left side), as well as unexpectedly with regional anesthesia procedures (Spinal, Epidural and Celiac Plexus Blocks) in the vicinity of the T6 to L2 “critical zone” of medulary arterial blood flow.1,2 This case highlights the importance of a proper evaluation and prevention when feasible, of combining risk factors (besides type of surgery and anesthetic technique) that may potentiate otherwise subclinical—but certainly prevalent—vascular, circulatory or spinal anatomy aging derangements leading to ASAS.

As the authors state in the discussion of this case, it is remarkable the aethiological association with an apparently uncomplicated and retrospectively “preventable” hypotensive episode, whether it be a consequence of a relative hypovolemia, a pharmacological (postanesthetic or not) impairment of baropressor responses, or to an excessive local anesthetic sympathetic blockade.

Learning from unexpected negative outcomes in anesthesia makes us more sensible to risk factors that are not specially highlighted in daily practice. In this sense, a case with so multiple patient's risk factors including the diagnosis of spinal stenosis, may had lead to other postop analgesia choices, namely systemic or even sole epidural opioid analgesia (that maybe was not considered here due to the COPD) as has been suggested before.3 Moreover, in the scope of an obstructive coronary disease high‐risk patient, a more aggressive treatment to the hypotensive episode including quick return to the recumbent or trendelemburg position limiting the isquemia could have favored this neurological adverse outcome.

1. Hong DK, Lawrence HM: Anterior Spinal Artery Syndrome following total Hip Artroplasty. Anesth Intensive Care. 2001;29:62–66.

2. Hachisuka K, Ogata H, Kohshi K: Postoperative Paraplegia with spinal myoclonus possibly caused by epidural anaesthesia: case report. Paraplegia. 1991 Feb;29(2):131–136.

3. Linz SM, Charbonnet C, Mikhail MS, et al.: Spinal artery syndrome masked by postoperative epidural analgesia. Can J Anaesth. 1997;44(11):1178–1181.