Spinal subdural hematoma after lumbar discectomy without dural injury - Is it possible? A case report and literature review.

BACKGROUND: Spinal subdural hematoma (SSDH) is a rare complication of lumbar discectomy. Here, the authors reviewed 10 articles concerning the etiology, clinical, diagnostic, and surgical management of SSDH. CASE DESCRIPTION: A postoperative SSDH occurred following a lumbar microdiscectomy in an 80-year-old patient in the absence of a dural injury.
CONCLUSION: SSDH is a rare complication of lumbar discectomy and may even occur without a dural fistula. Notably, magnetic resonance is the diagnostic study of choice to identify this pathology that may then be appropriately managed.

INTRODUCTION

Spinal subdural hematomas (SSDHs) are rare following lumbar diskectomy; they account for just 4.1% of all spinal hematomas, and in 5% of cases, there is no evidence of any clear-cut cause.[3,9]

SSDH may occur due to multiple factors; vascular malformation, tumors, bleeding disorders, anticoagulant therapy, trauma, and infection but has only rarely been described after diagnostic lumbar punctures and/or spinal anesthesia.[4]

Here, we report a case of SSDH following a lumbar microdiscectomy without accompanying dural injury.

CASE DESCRIPTION

An 80-year-old male complaining of the left lumbar pain underwent a magnetic resonance (MR) scan that documented a herniated lumbar disc on the left at the L4–L5 level. He underwent an L4–L5 hemilaminectomy/microdiscectomy, without a dural fistula. Notably, he had stopped acetylsalicylic acid (ASA) utilized for an aortic valve prosthesis, 4 days before surgery.

Immediately postoperatively, he complained of bilateral lower extremity numbness. The lumbar MR scan revealed an acute SSDH extending from L1 to S1 [Figures 1 and 2]. Due to the absence of a motor deficit or sphincter dysfunction, the patient was managed conservatively without surgery; the pain gradually improved over the next 72 h. The 7th day follow-up MR showed partial resorption of the hematoma [Figures 3 and 4]. Of interest, ASA was reintroduced on the 6th postoperative day. The patient was asymptomatic 2 months later.

Figure 1:

Sagittal T2-weighted magnetic resonance showing spinal subdural hematoma in its hyperacute phase (green arrows).

Figure 2:

Axial T2-weighted magnetic resonance showing spinal subdural hematoma in its hyperacute phase (green arrow).

Figure 3:

Control sagittal T2-weighted magnetic resonance showing partial resorption of the hematoma.

Figure 4:

Control axial T2-weighted magnetic resonance showing partial resorption of the hematoma.

DISCUSSION

Gehri et al. first described SSDH as a complication of spinal surgery in 2000. They highlighted these lesions typically resulted from a dural tear during microdiscectomy.[4]

Chang et al. reported a 59-year-old female who following an L3–L5 laminectomy with instrumentation and fusion developed an acute MR documented SSDH at the L2 level proximal to the laminectomy.[1]

Lykissas et al. published two cases of acute SSDH after lumbar decompressive surgery, one of whom had an incidental durotomy.[5]

A prospective study at the Twin Cities Spine Center, Minneapolis, MN, USA, (2008) showed that lumbar decompression surgery results in a 58% incidence of asymptomatic compressive postoperative epidural hematoma (POEH). Adjacent level compression by POEH occurs in 28% of patients. Advanced age (>60), multilevel procedures, and preoperative international normalized ratio were independently associated with POEH.[10]

A recent study involved a retrospective analysis of the MR images of 410 patients who underwent lumbar decompression surgery with or without instrumented fusion to assess the prevalence and risk factors for spinal subdural lesions (SSDLs). They identified SSDLs in 30% of the 410 cases of lumbar spine surgery.[7]

Mattei et al. reported a case of acute SSDH after vertebroplasty.[6]

de Beer et al. showed that spontaneous SSDHs were predominantly located in the thoracic spine and correlated with acute paraparesis/paraplegia; over 40% was caused by a coagulation defect, most frequently due to Coumadin.[2]

On study (2015) documented a mortality rate of approximately 1.3% and a morbidity rate (permanent neurological deficits) of 28% for patients with SSDH.[8]

Two risk factors may also contribute to SSDH in the case reported here: age >60 years and the prior use of ASA.

Surgical recommendation

Emergency evacuation through durotomy is the treatment of choice to treat SSDH with neurologic impairment. Conservative management may be indicated in selected cases with clinical improvement and without significant motor/sensory deficits.

CONCLUSION

SSDH is a rare complication of lumbar discectomy. For patients acutely presenting with pain and/or other new postoperative deficits may have SSDH best documented with MR studies. Conservative care may be warranted for minimally symptomatic patients, while decompressive surgery may be required for those with significant neurological findings.