Cerebrospinal fluid leakage during anterior approach cervical spine surgery for severe ossification of the posterior longitudinal ligament: prevention and treatment

A novel computed tomography scoring system for evaluating the risk of dural defects in anterior surgery for cervical ossification of the posterior longitudinal ligament

OBJECTIVE

To develop and validate a computed tomography (CT)-based scoring system for evaluating the risk of dural defects (DDs) in anterior surgery for cervical ossification of the posterior longitudinal ligament (OPLL).

METHODS

We retrospectively analyzed CT imaging features of 114 OPLL patients in our institute who received anterior decompression surgery. Intraoperative DDs were found in 16 patients. A multivariable logistic regression was used to evaluate the predictors. According to the odd ratio of the included risk factors, we developed a CT scoring system for evaluating the risk of DDs in anterior OPLL surgery. The system was further validated in an independent group of 39 OPLL patients.

RESULTS

We developed a CT scoring system as follows: hook sign (2 points), K-line (-) (1 point) and broad base (1 point). Thus, the system comprised 4 total points, and patients were at high risks of dural defects when the score ≥3 points. The operating characteristics of a score ≥3 for predicting DDs in the validation group were: sensitivity of 0.83, specificity of 0.94, LR positive of 13.75, LR negative of 0.18 and AUC of 0.886. The discriminatory ability of the proposed score could be demonstrated in the validation cohort.

CONCLUSIONS

The relatively simple and easy-to-use scoring system we propose integrates the 3 most reliable spinal CT findings observed in patients with OPLL and a DD. The likelihood to identify the underlying risks of spinal CSF leaks may be useful to triage patients who may benefit from indirect decompression techniques.

Management of Cerebrospinal Fluid Leakage by Pump-Regulated Volumetric Continuous Lumbar Drainage Following Anterior Cervical Decompression and Fusion for Ossification of the Posterior Longitudinal Ligament

OBJECTIVE

Cerebrospinal fluid (CSF) leakage is a major concern related to anterior cervical decompression and fusion for ossification of the posterior longitudinal ligament (OPLL). We propose a management algorithm for CSF leakage following anterior cervical decompression and fusion for OPLL involving the use of pump-regulated volumetric continuous lumbar drainage.

METHODS

We retrospectively reviewed patients who underwent anterior cervical decompression and fusion for OPLL and were managed with the proposed algorithm between March 2018 and July 2022. The proposed management algorithm for CSF leakage by pump-regulated volumetric continuous lumbar drainage was as follows. On exposure of the arachnoid membrane with or without CSF leakage, a dural sealant patch was applied to manage the dural defect. In case of persistent CSF leakage despite application of the dural sealant patch, patients underwent pump-regulated volumetric continuous lumbar drainage.

RESULTS

Fifty-one patients were included in the study. CSF leakage occurred in 14 patients. Of these 14 patients, 9 patients underwent lumbar drain insertion according to the proposed management algorithm. Successful resolution of CSF leakage was observed in 8 of the 9 patients who underwent lumbar drainage. All patients were encouraged to ambulate without concern of CSF overdrainage due to gravity, because it could be avoided with pump-regulated volumetric continuous CSF drainage. Therefore, complications associated with absolute bed rest or CSF overdrainage were not observed.

CONCLUSION

The proposed management algorithm with pump-regulated volumetric continuous lumbar drainage showed safety and efficacy for management of CSF leakage following anterior decompression and fusion for OPLL.

Use of tissue sealant patch (TachoSil) in the management of cerebrospinal fluid leaks after anterior cervical spine discectomy and fusion

PURPOSE

The purpose of this study was to evaluate a fast, sutureless technique to repair anterior cervical dural tears. Anterior cervical discectomy and fusion (ACDF) is a commonly performed procedure for the treatment of cervical degenerative diseases. Although uncommon, incidental durotomy with cerebrospinal fluid (CSF) leak during ACDF is a potentially serious complication. Yet, its technical management for the prevention of CSF leak is controversial.

METHODS

Between September 2012 and June 2018 we encountered seven cases (2 female/5 male) presenting with intraoperative CSF leaks secondary to incidental dural tears during ACDF surgery. All the cases were surgically treated using a topical fibrin sealant patch (TachoSil) with high adesive strength and fibrin glue (Tisseel). Intraoperative source of leakage, time to leakage control, quantity of Sealant Sponge used and postoperative complications were evaluated.

RESULTS

Dural tears were tipically the result of dissection of adherent posterior longitudinal ligament and/or calcified disc from the cervical dural sac to allow full decompression of the spinal cord. Effective repair of dural tear defined as cessation of CSF leak after topical sealant agents application was achieved no later than one minute in all cases. Evident clinical and/or radiological postoperative CSF leak was used to determine the patient's postoperative result. Postoperative CSF leak was not evident during a minimum 6 months follow up.

CONCLUSIONS

In the present study, we have reported our experience with a new sealing technique to manage CSF leaks from iatrogenic cervical dural lacerations. Tachosil tissue sealant patch is a rapid sutureless technique that may help in repairing introperatively incidental dural tears, thus reducing the risk of postoperative CSF leaks. To our knowledge, this is the first series to report the use of Tachosil adhesive sealant patch for the treatment of incidental dural tears during anterior cervical discectomy.

Repair of cerebrospinal fluid leak during posterior thoracolumbar surgery using paraspinal muscle flap combined with fat graft

Objective

This study aimed to propose a novel surgical method via combination of fat graft and paraspinal muscle flap, in order to treat cerebrospinal fluid (CSF) leak during posterior thoracolumbar surgery. The clinical outcomes were also evaluated.

Methods

Data of a total of 71 patients who were diagnosed with intraoperative incidental durotomy and CSF leak after posterior thoracolumbar surgery in our hospital form January 2019 to January 2021 were retrospectively collected and analyzed. Among them, 34 and 37 patients were assigned into conventional suturing (CS) group and fat graft and paraspinal muscle flap (FPM) group, respectively. Patients’ demographic and clinical data were compared between the two groups.

Results

The average drainage tube time in the FPM group was 3.89 ± 1.17 days, which was shorter than that in the CS group (5.12 ± 1.56, P < 0.001). The drainage volume in the FPM group (281.08 ± 284.76 ml) was also smaller than that in the CS group (859.70 ± 553.11 ml, P < 0.001). Besides, 15 (44.11%) patients in the CS group complained of postural headache, which was more than that in the FPM group (7 patients, 18.91%). There was a statistically significant difference in postoperative visual analogue scale (VAS) score between the two groups (P = 0.013). Two patients underwent revision surgery resulting from incision nonunion and delayed meningeal cyst.

Conclusion

Fat graft combined with paraspinal muscle flap showed to be an effective method to repair CSF leak during posterior thoracolumbar surgery. The proposed method significantly reduced postoperative drainage tube time and postoperative drainage volume. It also decreased the incidence and the degree of postural headache. The proposed method showed satisfactory clinical outcomes, and it is worthy of promotion.

Comparison of Anterior and Posterior Approaches for Acute Traumatic Central Spinal Cord Syndrome with Multilevel Cervical Canal Stenosis without Cervical Fracture or Dislocation

INTRODUCTION

This is a retrospective comparative study that aims to compare the benefits of different surgical approaches for patients with multilevel cervical canal stenosis (CCS) without cervical fracture or dislocation of acute traumatic central cord syndrome (ATCCS).

METHODS

From January 2015 to December 2018, 59 patients were included in the study. Among them, 35 patients (Group A) received anterior surgery and 24 patients (Group B) received posterior surgery. Primary outcome measures were American Spinal Cord Injury Association (Asia) grade, Japanese Orthopaedic Association (JOA) score, and recovery rate (RR). Secondary outcome measures included operation time, intraoperative blood loss, visual analogue scale (VAS) score, cervical sagittal parameters, and complications. Multivariate linear regression was used to analyze prognostic determinants.

RESULTS

Compared with Group B, Group A had longer operation time and more intraoperative blood loss (P < 0.05). However, the VAS score of Group B was higher than that of Group A at discharge (P < 0.05). There was no significant difference in cervical sagittal plane parameters between the two groups (P > 0.05). Postoperative complications were different in the two groups. During follow-up, the Asia grade, the JOA score, and RR of both groups improved (P < 0.05), but there were no significant differences between the two groups (P > 0.05). Younger age, earlier surgery, and better preoperative Asia grade were correlated with better prognosis.

CONCLUSIONS

For patients with multilevel CCS without cervical fracture or dislocation of ATCCS, both surgical approaches had good outcomes. Although no significant differences were found in the primary outcome measures between the two groups, there were different recommendations for the secondary outcome measures. Younger age, earlier surgery, and better preoperative Asia grade were protective factors for better prognosis.

Cervical Transdural Discectomy with Laminoplasty for the Treatment of Multi-segment Cervical Spinal Stenosis Accompanied with Cervical Disc Herniation: Technical Note and Clinical Outcome

Objective

To describe the surgical technique of cervical transdural discectomy with laminoplasty (CTDL) for the treatment of multi‐segment cervical spinal stenosis (CSS) accompanied with cervical disc herniation (CDH) and investigate its surgical outcomes and complications.

Methods

This was a clinical study. Between 2012 and 2018, 31 patients (13 males and 18 females) with multi‐segment CSS (over two cervical segments) accompanied with huge CDH and underwent CTDL were enrolled in this study. The details of CTDL technique with general anesthesia was described by the authors. The average follow‐up period of patients was 65.03 months (range from 24 to 126 months). Perioperative parameters such as age, sex, operative level, operative time, estimated blood loss, ambulation time, and operative complications were recorded. The results of clinical metrics such as the visual analog scale (VAS) and Japanese Orthopaedic Association (JOA) scores in the preoperative and during the follow‐up period were obtained and used to evaluate clinical outcomes. Radiographic improvement was evaluated by the compression ratio, sagittal maximum spinal cord compression (SMSCC), and cervical range of motion (ROM). The preoperative and postoperative follow‐up parameters (VAS, JOA, Compression ratio, SMSCC, and ROM) were assessed with paired t test. A P‐value <0.05 was considered statistically significant.

Results

In the study, the mean age of the 31 patients was 55.23 ± 10.97 years. The mean operative time was 192.45 ± 24.17 min (ranging from 150 to 245 min), and intraoperative blood loss was 322.58 ± 129.00 mL (ranging from 150 to 600 mL). The VAS neck pain was improved significantly over the follow‐up period (P < 0.05, respectively). The VAS arm pain improved significantly from 6.26 ± 0.93 preoperatively to 1.74 ± 0.63 at 24 months postoperatively (P < 0.001). There was no significant difference in improvement of VAS arm pain between 24 months postoperatively and final follow‐up (P = 0.180). Compared with preoperative JOA score, JOA score was significantly improved at 24 months postoperatively (14.79 ± 1.84 vs 9.66 ± 2.81, P < 0.001). Meanwhile, there were no statistically significant differences between the final follow‐up and the postoperative JOA scores (15.08 ± 1.71 vs 14.79 ± 1.84, P = 0.051). Postoperative patients showed significantly higher index of compression ratio (58.30 ± 8.51 vs 27.17 ± 3.89, P < 0.001) and lower SMSCC (25.12 ± 5.67 vs 33.66 ± 5.38, P < 0.001). In addition, there was no significant difference between preoperative and postoperative cervical ROM (P = 0.740). One patient observed postoperative symptom of C₆ nerve root injury, which was resolved within 24 months after the surgery; meanwhile, the neurological monitoring also reflected the intraoperative stretching of the C₆ nerve root. Two cases involved postoperative cerebrospinal fluid (CSF) leakage which may have been related to laceration of dura mater.

Conclusions

This study suggested that CTDL technique could acquire satisfactory surgical outcomes for patients with multi‐segment CSS accompanied with CDH, but the surgical indications of the patients need to be selected strictly.

Anatomical Evaluation of Spinal Nerve and Cervical Intervertebral Foramina in Anterior Controllable Antedisplacement and Fusion Surgery: A Cadaveric and Radiologic Study

Objective

To achieve the anatomical evaluation of spinal nerve and cervical intervertebral foramina in anterior controllable antedisplacement and fusion (ACAF) surgery, a novel surgical technique with the wider decompression, through a cadaveric and radiologic study.

Methods

Radiographic data of consecutive 47 patients (21 by ACAF and 26 by anterior cervical corpectomy and fusion [ACCF]) who have accepted surgery for treatment of cervical ossification of the posterior longitudinal ligament(OPLL) and stenosis from March 2017 to March 2018 were retrospectively reviewed and compared between an ACAF group and ACCF group. Three postoperative radiographic parameters were evaluated: the decompression width and the satisfaction rate of decompression at the entrance zone of intervertebral foramina on computed tomography (CT), and the transverse diameter of spinal cord in the decompression levels on magnetic resonance imaging (MRI). In the anatomic study, three fresh cadaveric spines (death within 3 months) undergoing ACAF surgery were also studied. Four anatomic parameters were evaluated: the width of groove, the distance between the bilateral origins of ventral rootlets, the length of ventral rootlet from their origin to the intervertebral foramina, the descending angle of ventral rootlet.

Results

The groove created in ACAF surgery included the bilateral origins of ventral rootlets. The rootlets tended to be vertical from the rostral to the caudal direction as their takeoff points from the central thecal sac became higher and farther away from their corresponding intervertebral foramina gradually. No differences were identified between left and right in terms of the length of ventral rootlet from the origin to the intervertebral foramina and the descending angle of ventral rootlet. The decompression width was significantly greater in ACAF group (19.2 ± 1.2 vs 14.7 ± 1.2, 21.3 ± 2.2 vs 15.4 ± 0.9, 21.5 ± 2.1 vs 15.7 ± 1.0, 21.9 ± 1.6 vs 15.9 ± 0.8, from C₃ to C₆). The satisfactory rate of decompression at the entrance zone of intervertebral foramina tended to be better in the left side in ACAF group (significant differences were identified in the left side at C_3/4, C_4/5, C_6/7 level, and in the right side at C_4/5 level when compared with ACCF). And decompression width was significantly greater than the transverse diameter of spinal cord in ACAF group. Comparatively, there existed no significant difference in the ACCF group besides the C₅ level.

Conclusion

ACAF can decompress the entrance zone of intervertebral foramina effectively and its decompression width includes the origins and massive running part of bilateral ventral rootlets. Due to its wider decompression range, ACAF can be used as a revision strategy for the patients with failed ACCF.

Can the Risk of Postoperative Cerebrospinal Fluid Leakage Be Predicted for Patients Undergoing Cervical Spine Surgery? Development and Evaluation of a New Predictive Nomogram

OBJECTIVE

Previous studies have retrospectively analyzed the likely causes of cerebrospinal fluid leakage (CSFL) during cervical spine surgery and the management of CSFL after its occurrence. In the present study, we aimed to develop and validate a nomogram for the risk of CSFL in Chinese patients who had undergone cervical decompression and internal fixation (CDIF) surgery.

METHODS

We performed a retrospective analysis of patients who had undergone CDIF surgery. Of the 1286 included patients, 54 were in the CSFL group and 1232 were in the normal group. The patients were randomly divided into training and validation tests. The risk assessment for CSFL included 21 characteristics. The feature selection for the CSFL model was optimized using the least absolute shrinkage and selection operator regression model in the training test. Multivariate logistic regression analysis was performed to construct the model according to the selected characteristics. The clinical usefulness of the predictive model was assessed using the C-index, calibration curve, and decision curve analysis with identification and calibration.

RESULTS

The risk prediction nomogram included the diagnosis, revision surgery, ossification of the posterior longitudinal ligament, cervical instability, and a history of malignancy in the training test. The model demonstrated high predictive power, with a C-index of 0.914 (95% confidence interval, 0.876-0.951) and an area under the curve of 0.914. The results of the decision curve analysis demonstrated the clinical usefulness of the CSFL risk nomogram when the probability threshold for CSFL was 1%-62%.

CONCLUSIONS

Our proposed nomogram for CSFL risk includes the diagnosis, revision surgery, ossification of the posterior longitudinal ligament, cervical instability, and a history of malignancy. The nomogram can be used to evaluate the risk of CSFL for patients undergoing CDIF surgery.

A Systematic Review of Classification Systems for Cervical Ossification of the Posterior Longitudinal Ligament

DESIGN

Systematic review.

OBJECTIVE

To conduct a systematic review to (1) summarize various classification systems used to describe cervical ossification of the posterior longitudinal ligament (OPLL) and (2) evaluate the diagnostic accuracy of various imaging modalities and the reliability of these classification systems.

METHODS

A search was performed to identify studies that used a classification system to categorize patients with OPLL. Furthermore, studies were included if they reported the diagnostic accuracy of various imaging modalities or the reliability of a classification system.

RESULTS

A total of 167 studies were deemed relevant. Five classification systems were developed based on X-ray: the 9-classification system (0.60%); continuous, segmental, mixed, localized or focal, circumscribed and others (92.81%); hook, staple, bridge, and total types (2.40%); distribution of OPLL (2.40%); and K-line classification (4.19%). Six methods were based on computed tomography scans: free-type, contiguous-type, and broken sign (0.60%); hill-, plateau-, square-, mushroom-, irregular-, or round-shaped (5.99%); rectangular, oval, triangular, or pedunculate (1.20%); centralized or laterally deviated (1.80%); plank-, spindle-, or rod-shaped (0.60%); and rule of nine (0.60%). Classification systems based on 3-dimensional computed tomography were bridging and nonbridging (1.20%) and flat, irregular, and localized (0.60%). A single classification system was based on magnetic resonance imaging: triangular, teardrop, or boomerang. Finally, a variation of methods was used to classify OPLL associated with the dura mater (4.19%).

CONCLUSIONS

The most common method of classification was that proposed by the Japanese Ministry of Health, Labour and Welfare. Other important methods include K-line (+/-), signs of dural ossification, and patterns of distribution.

Risk Factors and Management of Dural Defects in Anterior Surgery for Cervical Ossification of the Posterior Longitudinal Ligament

OBJECTIVE

To investigate risk factors and outcomes and to develop a cogent perioperative management algorithm for dural defects (DDs) in anterior surgery for cervical ossification of the posterior longitudinal ligament (OPLL).

METHODS

Ninety OPLL patients who had undergone anterior cervical decompression between January 2014 and December 2016 were reviewed. DDs occurred in 12 patients. Demographic, clinical, and radiologic data; intraoperative and postoperative management; and complications were analyzed. Risk factors for DDs were assessed with multivariate analysis. A treatment algorithm was identified based on these findings and our experience.

RESULTS

The prevalence of DDs was 13.3% (12/90). Univariate and multivariate analyses showed that the ratio of OPLL base to spinal canal (odds ratio [OR] 1.09, P = 0.012), kyphotic cervical alignment with thick OPLL masses (OR 9.44, P = 0.026), and lateral, curved, and irregular OPLL masses (OR 8.28, P = 0.037) could be risk factors for DDs. DDs were repaired intraoperatively with onlay grafts, and lumbar drains were placed in all DD patients. The treatment was successful in all DD patients, and outcome measures did not differ between the DD and no DD groups. No patient had experienced complications associated with DDs and CSF leaks at the final follow-up visit.

CONCLUSIONS

Patients with broad-based OPLL, kyphotic cervical alignment with thick OPLL masses, and lateral, curved, and irregular OPLL masses have a higher risk of DD in anterior surgery for OPLL. Intraoperative primary repair with onlay grafts combined with early lumbar drains is a simple, safe, and effective strategy for DDs. The outlook for the long-term sequelae of DDs is optimistic if they are managed adequately.

What you need to know about ossification of the posterior longitudinal ligament to optimize cervical spine surgery: A review

What are the risks, benefits, alternatives, and pitfalls for operating on cervical ossification of the posterior longitudinal ligament (OPLL)? To successfully diagnose OPLL, it is important to obtain Magnetic Resonance Images (MR). These studies, particularly the T2 weighted images, provide the best soft-tissue documentation of cord/root compression and intrinsic cord abnormalities (e.g. edema vs. myelomalacia) on sagittal, axial, and coronal views. Obtaining Computed Tomographic (CT) scans is also critical as they best demonstrate early OPLL, or hypertrophied posterior longitudinal ligament (HPLL: hypo-isodense with punctate ossification) or classic (frankly ossified) OPLL (hyperdense). Furthermore, CT scans reveal the "single layer" and "double layer" signs indicative of OPLL penetrating the dura. Documenting the full extent of OPLL with both MR and CT dictates whether anterior, posterior, or circumferential surgery is warranted. An adequate cervical lordosis allows for posterior cervical approaches (e.g. lamionplasty, laminectomy/fusion), which may facilitate addressing multiple levels while avoiding the risks of anterior procedures. However, without lordosis and with significant kyphosis, anterior surgery may be indicated. Rarely, this requires single/multilevel anterior cervical diskectomy/fusion (ACDF), as this approach typically fails to address retrovertebral OPLL; single or multilevel corpectomies are usually warranted. In short, successful OPLL surgery relies on careful patient selection (e.g. assess comorbidities), accurate MR/CT documentation of OPLL, and limiting the pros, cons, and complications of these complex procedures by choosing the optimal surgical approach. Performing OPLL surgery requires stringent anesthetic (awake intubation/positioning) and also the following intraoperative monitoring protocols: Somatosensory evoked potentials (SSEP), motor evoked potentials (MEP), and electromyography (EMG).