A New Grading of Epidural Hematoma or Scar Formation after Posterior Cervical Spine Surgery: Evaluation of Perioperative Related Factors, Distributions, and Clinical Outcomes after Surgery

Abstract

Introduction The purpose of this study was to evaluate surgical outcomes using a new grading of postoperative epidural hematoma (EH) or epidural scar formation after posterior cervical spine surgery. Methods Postoperative EH or epidural scar formation after cervical laminoplasty (LP) or posterior decompression and fusion (PDF) were graded into Grades 1-5 by magnetic resonance imaging at 24 hours, 2 weeks, 6 months, and one year after surgery. The patients were divided into the Mild group (Grades 1-3) and the Severe group (Grades 4, 5). Perioperative factors were compared between the two groups at 24 hours after surgery. Distribution of EH or scar formation was investigated according to two surgeries. The recovery rate of Japanese Orthopedic Association (JOA) scores and the improvements of neck disability index (NDI) were compared between the two groups at one year postoperatively. Results Of the postoperative factors, posterior shift of the cervical spinal cord at C4 and C7 significantly differed between the two groups. Patients in the Severe group at 24 hours after surgery (17%) increased to 41% at 2 weeks and subsequently decreased to 16% at 6 months after LP. After PDF, 3% in the Severe group at 24 hours after surgery increased to 15% at 2 weeks and then decreased to 3% at 6 months postoperatively. Only one (3%) patient remained in the Severe group at 1 year after PDF. The recovery rate of JOA score (47.5%) of the patients in the Mild group showed trend larger than that of the Severe group (34.7%) after LP. Preoperative NDI (15.6 points) significantly improved postoperatively to 12.1 points in only the Mild group after LP. Conclusions The patterns of distribution of EH or scar formation did not differ between the two surgical methods. The severity of postoperative scar formation related to surgical outcomes after LP.

Primary Results of Our Protocol for Standardization of Perioperative Antiplatelet Agent Management on the Incidence of Epidural Hematoma and Thrombotic Complications in Posterior Cervical Surgery: A Prospective Cohort Study

“…In line with these observations, Takeuchi et al showed that the number of patients in the severe group at 24 h after surgery (17%) increased to 41% at 2 weeks and decreased to 16% at 6 months after LP. Similarly, following PDF, the percentage of patients in the severe group at 24 h after surgery (3%) increased to 15% at 2 weeks and then decreased to 3% at 6 months postoperatively 3) . Furthermore, there were no significant differences in preoperative factors, including antithrombotic agent intake, between the mild and severe groups by grade 24 h after surgery.…”

“…Perioperative management with anticoagulants and antiplatelets is based on the interplay between the risk of hemorrhage induced by maintenance therapy and the risk of thrombosis if treatment is discontinued. Indeed, the development of an epidural hematoma (EH) after cervical spine surgery may lead to paralysis and severe neck pain 3) . A previous study showed that among 295 consecutive patients aged >50 years who underwent spinal surgery, 15 and 55 patients received anticoagulants and antiplatelets, respectively 4) .…”

Modified K-Line in Neck Extension Is a Prognostic Indicator of the Surgical Outcome at 5 Years After Cervical Laminoplasty for Cervical Spondylotic Myelopathy

“…The scar was diagnosed histologically to be fibrous granulation tissue with foreign-body granuloma characterized by multinucleated giant cells and a marked increase in capillary vessels, fibroblasts, and collagen fibers. Takeuchi et al 4 examined postoperative scar formation in 69 consecutive patients who underwent LP (47 CSM, 22 OPLL) using MRI and reported that the rate of recovery of the JOA score (47.5%) tended to be better in patients with mild scar formation than in those with severe scar formation (34.7%) at 1 year postoperatively. Therefore, postoperative scar formation influences the neurological outcome after LP.…”

“…Formation of a postoperative epidural scar has been reported to be a risk factor for late deterioration after cervical laminoplasty (LP) 1–4 . In one cohort study, the rate of recovery of the Japanese Orthopedic Association (JOA) score tended to be greater in patients with mild scar formation than in those with severe scar formation at 1 year after LP 4 .…”

“…Formation of a postoperative epidural scar has been reported to be a risk factor for late deterioration after cervical laminoplasty (LP) 1–4 . In one cohort study, the rate of recovery of the Japanese Orthopedic Association (JOA) score tended to be greater in patients with mild scar formation than in those with severe scar formation at 1 year after LP 4 . The authors have also frequently encountered patients with any contact between the spinal cord and posterior elements, including the lamina and ligamentum flavum, and scar formation on axial or para/midsagittal magnetic resonance imaging (MRI) after LP (Figure 1).…”