Postoperative compressive spinal epidural hematomas: 15 cases and a reviewof the literature

Purpose of the study In the literature, the frequency of postoperative compressive spinal epidur al hematomas (SEH) appearing very low, we conducted the present study to de termine the frequency of this complication in their unit and look for causa tive and predisposing factors. Material and methods Among the 1,487 spinal operations performed in our unit between September 1 997 and August 1998, fifteen patients had postoperative compressive SEH; th eir files were retrospectively analyzed regarding the initial intervention, postoperative period, revision operation and neurologic follow-up. Results Five women and ten men were involved ranging in age from 47 to 70 years (av erage, 59.5 years). The primary intervention concerned the cervical spine i n one case, the thoracic spine in seven and the lumbar spine in seven. Ten of the fifteen cases including all seven of the thoracic SEH (performed for compressive metastatic epiduritis) involved a laminectomy. A stenotic cana l was the indication for the primary intervention in six of the seven lumba r cases. The average delay before onset of symptoms was 1.5 hours, 3.7 hour s, and 5.3 hours after the cervical, thoracic, and lumbar interventions, re spectively. The clinical pattern began with segmental pain rapidly followed first by bilateral radicular sensory deficit, then unilateral or bilateral motor deficit, except in the patients with thoracic SEH in whom segmental pain was followed by signs of cord impingement. Excluding the four cases in which diagnosis was retarded by work-up examinations (3 cases) or a mislea ding picture (1 case), revision surgery was performed from 1.25 to 4 hours after onset of symptoms (average, 2.75 hours). In the patients for whom reo peration was delayed, SEH resulted in permanent complete paralysis or sphin cter dysfunction, In contrast, eight of the ten patients who were reoperate d within four hours of the onset of symptoms either recovered completely or recovered their former neurologic status. Discussion Compressive SEH after spinal surgery is rare, only 41 cases having been rep orted aside from the series of Deburge et al. In the literature, the freque ncy is around 1 to 2 for 1000 operations for some authors, as opposed to 3 p. 100 and 6 p. 100 found by two other groups. The 1 p. 100 of the present series is close to the latter values. Nonetheless, it is probably important to take the type of surgery into account, as shown by the current series i n which SEH occurred after 5.9 p. 100 of the operations for metastasis, but only once out of 304 anterior cervical interventions. To reduce the risk a s much as possible, it is important to be aware of the factors that may con tribute to this complication. Several recommendations concerning prevention of SEH are thus discussed. Once SEH has occurred, the only modifiable prog nostic factor appears to be the delay before reintervention. Conclusion Although postoperative SEH is relatively rare, it may have dramatic consequ ences. In our opinion, reintervention must be performed as soon as possible after the onset of neurologic deficit, the work-up investigations only pro longing the critical surgical delay, which is probably the only alterable p rognostic factor.