Distinguishing Pseudomeningocele, Epidural Hematoma, and Postoperative Infection on Postoperative MRI

Imaging of the postoperative spine

There has been a significant increase in the number of spinal surgical procedures performed over the last few decades, resulting in a proportionate increase in the number of postoperative imaging studies.An exhaustive literature search was performed along with consideration of various guidelines and expert opinions regarding postoperative spine imaging. Complications are divided into early (in the first few weeks) and delayed, depending on the time of onset. Some complications occurring in the early postoperative period are common for both the instrumented and non-instrumented spine. Delayed complications are specific to the type of surgery performed and have been described as such. This review discusses the normal postoperative appearance and the various early and delayed complications.An understanding of the normal postoperative appearance is pertinent to distinguish normal from abnormal. A plain radiograph is the primary imaging modality for immediate postoperative assessment and long-term follow-up after spinal instrumentation. MRI with or without contrast is the imaging modality of choice for the evaluation of the postoperative spine. CT is the best modality for the assessment of the instrumented spine and status of bony fusion. Imaging assessment of the postoperative spine is complex and requires knowledge of key factors for interpretation like indications for the initial surgical procedure, type and approach of the surgical procedure, instrumentation used, time elapsed since surgery, and clinical complaints. · For proper interpretation of the postoperative spine, it is very important to understand the indication and type of spinal procedure involved. · Baseline postoperative radiographs are important to detect any change in the position of metalwork and implant integration.. · Computed tomography is the modality of choice to evaluate bony fusion and metalwork-specific complications. · Postoperative fluid collection is the most common early complication and MRI is the imaging modality of choice for the identification of the same.. · Intravenous gadolinium is helpful to differentiate between scar/vascularized granulation tissue and recurrent or residual disc.. · Kaur S, Lalam R, Trivedi R. Imaging of the postoperative spine. Rofo 2025; DOI 10.1055/a-2507-8347.

Ultrasound-guided needle aspiration of immediate postoperative symptomatic spinal epidural hematoma after lumbar stenosis surgical decompression in the elderly: a proof-of-concept case

BACKGROUND

Symptomatic spinal epidural hematoma (SSEH) is one of the most feared complications and source of litigation in spine surgery. Its occurrence rises up to 2% in minimally invasive spine surgery. In parts of the world where the population is aging, more fragile patients are expected to undergo degenerative spine surgery. Management of the SSEH includes emergent spine MRI, though some experts advocate for direct second-look surgery without imaging. Then, an urgent revision surgery under general anesthesia for hematoma evacuation is warranted. We report the case of a threatening SSEH in an 88-year-old patient after lumbar spine stenosis surgery. In order to spare a second general anesthesia for this fragile patient, we opted for a percutaneous ultra-sound guided drainage of the hematoma under local anesthesia as a first line treatment. The procedure was successful, we report an instant relief of his neurological deficit while performing the procedure.

CONCLUSION

Ultra-sound guided percutaneous drainage of hyperacute SSEH successfully avoided a revision surgery. It spared a second general anesthesia in a fragile patient. This procedure could be an alternative first-line treatment of SSEH for fragile patients.

Value of [18F]FDG PET/CT in Diagnosis and Management of Spondylodiscitis

Vertebral osteomyelitis is the third most common form of osteomyelitis in patients over 50 years of age.Whereas prompt (pathogen-directed) therapy is crucially associated with better outcomes, the heterogeneous clinical presentation of disease with unspecific symptoms often delays adequate treatment initiation. Diagnosis requires a careful investigation of medical history, clinical findings and diagnostic imaging, including magnetic resonance imaging and nuclear medicine techniques.Due to its high sensitivity, [18F]FDG PET/CT is becoming increasingly important in diagnosis and management of spondylodiscitis, especially in the postoperative setting with presence of spinal hardware or other implantable devices in which MRI is limited.

Postoperative Spinal Hematoma and Seroma

Fluid collections after spine surgery are rare complications, although potentially grave, and may be broadly grouped into two major categories. Symptomatic postoperative epidural hematomas have some known risk factors and can present with a widely variable profile of signs and symptoms. Treatment involves emergent surgical evacuation to reduce the risk of permanent neurologic deficit. Postoperative seroma may lead to disruption of wound healing and deep infection and has been associated with the use of recombinant human bone mineral protein. These diagnoses may present diagnostic challenges; thorough understanding of the involved pathophysiology, meticulous clinical evaluation, and radiographic interpretation are critical to appropriate management and optimal outcome.

Value of [18F]FDG PET/CT in diagnosis and management of spondylodiscitis

Vertebral osteomyelitis is the third most common form of osteomyelitis in patients over 50 years of age.Whereas prompt (pathogen-directed) therapy is crucially associated with better outcomes, the heterogeneous clinical presentation of disease with unspecific symptoms often delays adequate treatment initiation. Diagnosis requires a careful investigation of medical history, clinical findings and diagnostic imaging, including magnetic resonance imaging and nuclear medicine techniques.Due to its high sensitivity, [¹⁸F]FDG PET/CT is becoming increasingly important in diagnosis and management of spondylodiscitis, especially in the postoperative setting with presence of spinal hardware or other implantable devices in which MRI is limited.

Postoperative Epidural Hematoma

Symptomatic postoperative epidural hematomas are rare, with an incidence of 0.10% to 0.69%. Risk factors have varied in the literature, but multiple studies have reported advanced age, preoperative or postoperative coagulopathy, and multilevel laminectomy as risk factors for hematoma. The role of pharmacologic anticoagulation after spine surgery remains unclear, but multiple studies suggest it can be done safely with a low risk of epidural hematoma. Prophylactic suction drains have not been found to lower hematoma incidence. Most symptomatic postoperative epidural hematomas present within the first 24 to 48 hours after surgery but can present later. Diagnosis of a symptomatic hematoma requires correlation of clinical signs and symptoms with a compressive hematoma on MRI. Patients will usually first complain of a marked increase in axial pain, followed by radicular symptoms in the extremities, followed by motor weakness and sphincter dysfunction. An MRI should be obtained emergently, and if it confirms a compressive hematoma, surgical evacuation should be carried out as quickly as possible. The prognosis for neurologic improvement after evacuation depends on the time delay and the degree of neurologic impairment before evacuation.

ACR Appropriateness Criteria® Suspected Spine Infection

Spine infection is both a clinical and diagnostic imaging challenge due to its relatively indolent and nonspecific clinical presentation. The diagnosis of spine infection is based upon a combination of clinical suspicion, imaging evaluation and, when possible, microbiologic confirmation performed from blood cultures or image-guided percutaneous or open spine biopsy. With respect to the imaging evaluation of suspected spine infection, MRI without and with contrast of the affected spine segment is the initial diagnostic test of choice. As noncontrast MRI of the spine is often used in the evaluation of back or neck pain not responding to conservative medical management, it may show findings that are suggestive of infection, hence this procedure may also be considered in the evaluation of suspected spine infection. Nuclear medicine studies, including skeletal scintigraphy, gallium scan, and FDG-PET/CT, may be helpful in equivocal or select cases. Similarly, radiography and CT may be appropriate for assessing overall spinal stability, spine alignment, osseous integrity and, when present, the status of spine instrumentation or spine implants. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Acute neurological deficit caused by thoracic pseudomeningocele after spinal surgery

Postoperative pseudomeningocele usually has a benign course. We report a rare presentation of postoperative acute neurological deficit caused by compressive thoracic pseudomeningocele. This patient had posterior spinal fusion and decompression surgery for thoracic ossification of posterior longitudinal ligament and ligamentum flavum. Intraoperative incidental durotomy was covered with hydrogel dural sealant. She developed acute neurological deterioration 1 week after index surgery. Emergency decompression surgery was performed. One year after the surgery, she showed good neurological recovery.

Evaluation of craniocervical pseudomeningoceles with three-dimensional T2-SPACE sequence at 3T

BACKGROUND

Pseudomingocele is a postoperative fluid collection adjacent to the dural membrane. The distinction of pseudomeningocele from other postoperative collections is very important.

PURPOSE

To show the efficacy of three-dimensional (3D) T2-weighted sampling perfection with application-optimized contrasts using a different flip-angle evolution (SPACE) magnetic resonance imaging (MRI) sequence in the diagnosis of pseudomeningocele in which conventional MRI sequences may be insufficient.

MATERIAL AND METHODS

A total of 10 patients were included in the study. All of these patients also had 3D T2-SPACE high-resolution volumetric MR image in addition to conventional cervical and cerebral MR sequences. All MR examinations were reviewed by two neuroradiologists.

RESULTS

Pseudomeningocele neck was shown in six patients by both conventional sequences and SPACE sequence. In two patients, the neck was only shown in the SPACE sequence. Four pseudomeningocele necks were shown to have flow void with both conventional sequences and SPACE sequence. Flow void could only be demonstrated by SPACE sequence in two patients.

CONCLUSION

A T2-SPACE sequence can show the presence of pseudomeningocele neck and flow void even in cases where conventional MRI cannot show, thus contributing to the diagnosis of pseudomeningocele. Therefore, especially in postoperative imaging, the T2-SPACE sequence may be included in routine sequences to make the differential diagnosis correctly.

Multiple-Layer Lumbosacral Pseudomeningocele Repair with Bilateral Paraspinous Muscle Flaps and Literature Review

BACKGROUND

Pseudomeningocele is an uncommon but widely recognized complication of spinal surgery that can be challenging to correct. When conservative measures fail, patients frequently require reoperation to attempt primary closure of the durotomy, yet attempts at true watertight closures of the dura or fascia sometimes fall short. We describe a technique of lumbosacral pseudomeningocele repair involving a 2-layer pants-over-vest closure of the pseudomeningocele coupled with mobilization of bilateral paraspinal musculature to create a Z-plasty, or a Z-shaped flap. We have demonstrated a high success rate with our small series.

METHODS

The technique used meticulous manipulation of the pseudomeningocele to make a 2-layer pants-over-vest closure. This closure coupled with wide mobilization and importation of paraspinous muscle into the wound effectively obliterated dead space with simultaneous tamponade of the dural tear. The lateral row perforators were left intact, providing excellent vascularity with adequate mobility to the patient.

RESULTS

This technique was incorporated into the care of 10 patients between 2004 and July 2019. All wounds were closed in a single stage after careful flap section based on the wound's needs. We demonstrated successful pseudomeningocele resolution in all 10 patients with no observed clinical recurrence of symptomatic pseudomeningocele after at least 6 months of follow-up.

CONCLUSIONS

This technique provides a straightforward option for the spine surgeon to manage these challenging spinal wounds with minimal, if any, need for further laminectomy as well as a high fistula control rate with minimal morbidity.

Nerve root entrapment with pseudomeningocele after percutaneous endoscopic lumbar discectomy: A case report

Context: Pseudomeningocele is a relatively uncommon postoperative complication of spine surgery. Although the condition tends to be asymptomatic and self-limiting, it may cause radicular pain and neurological defect due to herniation of the nerve root or the spinal cord. Its pathophysiology remains unclear. Only few cases with intraoperative photos have been reported. Finding: We present a case of pseudomeningocele with nerve root entrapment after percutaneous endoscopic lumbar discectomy (PELD). A 52-year-old man had undergone PELD for sciatic pain and showed good postoperative recovery. Unfortunately, he was readmitted for progressive right leg pain at six weeks after the surgery. After the failure of conservative therapy, he received PELD again to explore the surgical site. Intraoperatively, a pseudomeningocele-containing nerve root, herniating through a small defect in the dural sac, was identified. During the dissection process, the pseudomeningocele was broken, which led to entrapment of the nerve root. Thereafter, the microsurgical technique was adopted to relocate the nerve root into the thecae sac and to repair the dural tear by non-resorbable suture. Conclusion: To our knowledge, this case report is the first documented instance of identification of a pseudomeningocele under an endoscope, and provides insights into the transformation of a pseudomeningocele into a cerebrospinal fluid fistula with nerve root entrapment. For neurological deficit caused by pseudomeningocele following PELD, operative revision by the microsurgery technique is the appropriate strategy.

Operative Field Debris Often Rises to the Level of the Surgeon's Face Shield During Spine Surgery: Are Orthopedic Space Suits a Reasonable Solution?

Background

The present study intended to identify debris in the spine surgical field that frequently rises to the level of the surgeon's face during several different elective spine procedures. Unlike other areas of orthopedic surgery where infection risk is of high concern, in spine surgery the surgical team usually uses a nonsterile face mask instead of a protective space suit with a sterile face shield. It is possible that blood or bone burr particles striking the surgeon's face mask represent a potential source of infection if they ricochet back into the operative field.

Methods

We reviewed 46 consecutive, elective spine surgeries between May 2015 and August 2015 from a single-surgeon practice. For each surgery, every member of the surgical team wore sterile (space suit) personal protective equipment. After each procedure, the face shield was carefully inspected by 2 members of the surgical team to identify patient blood, tissue, or bone burr dust present on the face shield.

Results

The rate of surgeon face shield debris inspected for each case overall was 38/46 (83%). The rate of first assistant face shield debris inspected per case was 16/46 (35%). The scrub technician had a 0% rate of face mask debris on inspection. The highest debris exposure rates occurred with transforaminal lumbar interbody fusions (100%), open laminectomy and fusions (100%), and anterior cervical discectomy and fusions 43/46 (93%).

Conclusions

There is a high rate of blood and tissue debris contact that occurs during spine surgery, and it is procedure dependent. Spine surgeons may consider using sterile shields particularly in high-risk cases to protect themselves and their patients.

Level of Evidence

4.