Postoperative Seroma Formation After Posterior Cervical Fusion with Use of RhBMP-2

Abstract

Case: We present 2 cases of postoperative seroma formation following posterior cervical fusion with the use of recombinant human bone morphogenetic protein-2 (rhBMP-2). Conclusion: Although some who advocate for the off-label use of rhBMP-2 in patients undergoing posterior cervical spine fusion believe it to be safe, relatively little has been published regarding complication rates. We believe that rhBMP-2 carries a risk of seroma formation in patients who undergo posterior cervical fusion, which necessitates the use of a postoperative drain. Surgeons should have a low threshold for obtaining postoperative magnetic resonance imaging in a symptomatic patient.

Compressive Postoperative Seromas Causing Delayed Neurological Deterioration Following Cervical Laminectomy and Instrumented Fusion

“…Seroma formation is a known complication of spinal surgery, which in the literature has been most commonly attributed to the use of rhBMP-2 [7,8]. While the incidence of asymptomatic seromas in the postsurgical field is likely to be under-reported due to postoperative MRI scans not routinely being performed in most cases, the formation of compressive seromas causing neurological compromise in the cervical spine is a much rarer entity, with only eight cases reported in the literature to our knowledge [1][2][3][4][5][6].…”

“…The clinical course is typically one gradual and delayed neurological deterioration that begins several days postoperatively and after the removal of surgical drains, which would have prevented further fluid build-up, given the serous nature of the fluid. Other cases reported in the literature have described neurological deterioration occurring as early as three days and up to six weeks postoperatively [1][2][3][4][5][6]9]. Neurological deterioration in such cases is seldom dramatic and typically follows a more insidious course, making it easy for clinicians to attribute the symptoms to postoperative pain or generalized deconditioning, which may be common in the postoperative state, especially in elderly patients.…”

“…While seromas are not uncommon following posterior spinal surgery, the accumulation of sufficient amounts of fluid to cause mass effect on the spinal cord and neurological deficits and/or myelopathy are much rarer. A large majority of information in the literature on this condition is from case reports that focused on the role of recombinant human bone morphogenetic protein-2 (rhBMP-2) in seroma formation [1][2][3][4], rhBMP-2 being an osteo-inductive agent with increasing use in spine surgery to achieve spinal fusion, although two subsequent case reports [5,6] also noted this complication in the absence of rhBMP-2. Overall, there is a paucity of information about this complication.…”

Postoperative Spinal Hematoma and Seroma

“…The risk of PS is most closely attributed to the use of osteoinductive agents, particularly rhBMP-2. 34,35 RhBMP-2 has been hypothesized to lead to local inflammation that promotes excessive edema and seroma formation while others implicate an immune response by anti-rhBMP-2 antibodies. 33,35,36 The use of rhBMP-2 in anterior cervical surgery is associated with increased incidences of swelling, hematoma, dysphagia, and respiratory failure.…”