Airway obstruction caused by cerebrospinal fluid leakage after anterior cervical spine surgery. A report of two cases

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.

Airway Complications After Anterior Cervical Spine Surgery: Etiology and Risk Factors

STUDY DESIGN

Narrative Review.

OBJECTIVE

To provide an overview of etiology and risk factors of airway complications after anterior cervical spine surgery (ACSS).

METHODS

A search was performed in PubMed and adapted for use in other databases, including Embase, Cochrane Library, Cochrane Register of Controlled Trials, Health Technology Assessment database, and NHS Economic Evaluation Database.

RESULTS

81 full-text studies were reviewed. A total of 53 papers were included were included in the review and an additional four references were extracted from other references. 39 papers were categorized as etiology and 42 as risk factors.

CONCLUSIONS

Most of the literature on airway compromise after ACSS is level III or IV evidence. Currently, there are no systems in place to risk-stratify patients undergoing ACSS regarding airway compromise or guidelines on how to manage patients when these complications do occur. This review focused on theory, primarily etiology and risk factors.

Complication Avoidance in Spine Surgery

The outcomes of spine surgery are closely related to postoperative morbidity. Therefore, an experienced surgeon must be aware of various complications and should apply all necessary preventive measures to avoid them. It is widely considered that complications of spine surgery are underreported and that their real incidence is much higher than expected. This review highlights methods to prevent various types of morbidity that may be encountered during different spinal procedures, considering general complications, approach-related complications, fusion- and implant-related complications, and systemic complications.

Comparative Study between Caspar Cervical Retractor System and Traditional S Retractor in Application on Anterior Cervical Decompression and Fixation

OBJECTIVE

Although Caspar cervical retractor system (CCRS) is commonly utilized in anterior cervical decompression and fixation (ACDF), most urban hospitals still use both traditional S retractor and CCRS in conventional anterior cervical surgeries. Related data to evaluate the effect are required to be reported. The aim of this study is to compare the efficacy between using the traditional cervical S retractor and CCRS in anterior cervical decompression and fixation ACDF.

METHODS

The retrospective study that total 360 patients received ACDF using different retractors (traditional S retractor or CCRS) were enrolled in this study from January 2010 to January 2020. Width change rate of cervical prevertebral soft tissue, throat symptoms, and subjective experiences of the operating surgeons were evaluated by t-test or analysis of variance (ANOVA) respectively.

RESULTS

The width change rate of prevertebral soft tissue was significantly higher in the S retractor group than that of the CCRS group both in single segment group (40.9% vs 20.8%, P < 0.05) and double segments group (45.8% vs 25.2%; p < 0.05). In the three segments group, the width change rate of prevertebral soft tissue was higher in the S retractor group than that of the CCRS group, but with no statistical significance (27.3% vs 23.6%; P > 0.05). The incidence rates of dysphagia, dyspnea, and throat discomfort in the traditional S retractor group were significantly higher compared to the CCRS group (P < 0.05), while satisfactory rate of surgeon was higher in the CCRS group (P < 0.05). However, there was no correlation between anterior soft tissue rate and operative time (P > 0.05), as well as the width change rate of anterior soft tissue and the DNRS score (P > 0.05).

CONCLUSION

CCRS was superior compared to the traditional S retractor in reducing the postoperative complications and the postoperative fatigue of surgeon. Meanwhile, the width change rate of prevertebral soft tissue was not related to operative time and DNRS score.

Space-Occupying Lesions of the Retropharyngeal Space: An Anatomical Study With Application to Postoperative Retropharyngeal Hematomas

STUDY DESIGN

Cadaver study.

OBJECTIVE

The retropharyngeal space's (RPS's) clinical relevance is apparent in anterior cervical spine surgery with respect to postoperative hematoma, which can cause life-threatening airway obstruction. This cadaver study aims to establish guidance toward a better understanding of the tolerance of the RPS to accommodate fluid accumulation.

METHODS

Five fresh-frozen cadavers were dissected in the supine position. A digital manometer and a 20 Fr Foley catheter were inserted into the RPS via an anterolateral approach. While inflating the Foley catheter, the position of the esophagus/trachea was documented using fluoroscopy, and the retropharyngeal pressure was measured. We quantified the volume required to deviate the esophagus/trachea >1 cm from its original position using fluoroscopy. We also recorded the volume required to cause a visible change to the normal neck contour.

RESULTS

A mean volume of 12.5 mL (mean pressure 1.50 mm Hg) was needed to cause >1 cm of esophageal deviation. Tracheal deviation was encountered at a mean volume of 20.0 mL (mean pressure of 2.39 mm Hg). External visible clinical neck contour changes were apparent at a mean volume of 39 mL.

CONCLUSION

A relatively small volume of fluid in the RPS can cause the esophagus/trachea to radiographically deviate. The esophagus is the structure in the RPS to be most influenced by mass effect. The mean volume of fluid required to cause clinically identifiable changes to the normal neck contour was nearly double the volume required to cause 1 cm of esophageal/tracheal deviation in a cadaver model.

Evaluation of Benefit and Cost Utility of Immediate Postanesthesia Care Unit Radiographs to Predict Airway Compromise After Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective review.

OBJECTIVE

Anterior cervical discectomy and fusion (ACDF) is a commonly performed procedure that may be complicated by airway compromise postoperatively. This life-threatening complication may necessitate reintubation and reoperation. We evaluated the cost utility of conventional postoperative x-ray.

SUMMARY OF BACKGROUND DATA

Studies have demonstrated minimal benefit in obtaining an x-ray on postoperative day 1, but there is some utility of postanesthesia care unit (PACU) x-rays for predicting the likelihood of reoperation.

METHODS

We retrospectively reviewed the records of consecutive patients who underwent ACDF between September 2013 and February 2017. Patients were dichotomized into those who received PACU x-rays and those who did not (control group). Primary outcomes were reoperation, reintubation, mortality, and health care costs.

RESULTS

Eight-hundred and fifteen patients were included in our analysis: 558 had PACU x-rays; 257 did not. In those who received PACU x-rays, mean age was 53.7 ± 11.3 years, mean levels operated on were 2.0 ± 0.79, and mean body mass index (BMI) was 30.3 ± 6.9. In those who did not, mean age was 51.8 ± 10.9 years, mean levels operated on were 1.48 ± 0.65, and mean BMI was 29.9 ± 6.3. Complications in the PACU x-ray group were reintubation-0.4%, reoperation-0.7%, and death-0.3% (due to prevertebral swelling causing airway compromise). Complications in the control group were reintubation-0.4%, reoperation-0.8%, and death-0. There were no differences between groups with respect to reoperation (P = 0.92), reintubation (P = 0.94), or mortality (P = 0.49). The mean per-patient cost was significantly higher (P = 0.009) in those who received PACU x-rays, $1031.76 ± 948.67, versus those in the control group, $700.26 ± 634.48. Mean length of stay was significantly longer in those who had PACU x-rays (P = 0.01).

CONCLUSION

Although there were no differences in reoperation, reintubation, or mortality, there was a significantly higher cost for care and hospitalization in those who received PACU x-rays. Further studies are warranted to validate the results of the presented study.Level of Evidence: 3.

Acute post-operative airway complications following anterior cervical spine surgery and the role for cricothyrotomy

Anterior cervical spine surgery (ACSS) is a common procedure, but not without its own risks and complications. Complications that can cause airway compromise occur infrequently, but can rapidly lead to respiratory arrest, leading to severe morbidity or death. Knowing emergent post-operative airway management including surgical airway placement is critical. We aim to review the different etiologies of post-operative airway compromise following ACSS, the predictable timeline in which they occur, and the most appropriate treatment and management for each. We place special emphasis on the timing and proper surgical technique for an emergent cricothyrotomy. Angioedema is seen the earliest as a cause of post-operative airway compromise, typically within 6-12 hours. Retropharyngeal hematomas can be seen between 6-24 hours, most commonly within 12 hours. Pharyngolaryngeal edema is seen within 24-72 hours. After 72 hours, retropharyngeal abscess is the most likely etiology. Several studies have utilized delayed extubation protocols following ACSS based on patient risk factors and found reduced postoperative airway complications and reintubation rates. The administration of perioperative corticosteroids continues to be controversial with high-level studies recommending both for and against their use. Animal studies showed that after cardiac arrest, the brain can recover if oxygenation is restored within 5 minutes, but this time is likely shorter with asphyxia prior to cardiac arrest. Experience and training are essential to reduce the time for successful cricothyrotomy placement. Physicians must be prepared to diagnose and treat acute postoperative airway complications following ACSS to prevent anoxic brain injury or death. If emergent intubation cannot be accomplished on the first attempt, physicians should not delay placement of a surgical airway such as cricothyrotomy.

The Management of Cerebrospinal Fluid Leak After Anterior Cervical Decompression Surgery

Cerebrospinal fluid (CSF) leak is a rare but potentially troublesome and occasionally catastrophic complication after anterior cervical decompression surgery. There is limited literature describing this complication, and the management of CSF leak varies. The aim of this study was to retrospectively review the treatment of cases with CSF leak and develop a management algorithm. A series of 14 patients with CSF leak from January 2011 to May 2016 were included in this study. Their characteristics, management of CSF leak, and outcomes were documented. There were 5 male and 9 female patients. Mean age at surgery was 57.1±9.9 years (range, 37-76 years). All instances of CSF leak, except 1 noted postoperatively, were indirectly repaired intraoperatively. A closed straight wound drain was placed for all patients. A lumbar subarachnoid drain was placed immediately after surgery in 4 patients and postoperatively in 7 patients. In 1 patient, lumbar drain placement was unsuccessful. In 2 additional patients, the surgeon decided not to place a lumbar drain. One patient developed meningitis and recovered after antibiotic therapy with meropenem and vancomycin. Another patient had a deep wound infection and required a revision surgery. Wound drains and lumbar drains should be immediately considered when CSF leak is identified. Antibiotics also should be considered to prevent intradural infection. [Orthopedics. 2018; 41(2):e283-e288.].

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.

A Multicenter Study of the Presentation, Treatment, and Outcomes of Cervical Dural Tears

STUDY DESIGN

Retrospective multicenter case series study.

OBJECTIVE

Because cervical dural tears are rare, most surgeons have limited experience with this complication. A multicenter study was performed to better understand the presentation, treatment, and outcomes following cervical dural tears.

METHODS

Multiple surgeons from 23 institutions retrospectively identified 21 rare complications that occurred between 2005 and 2011, including unintentional cervical dural tears. Demographic data and surgical history were obtained. Clinical outcomes following surgery were assessed, and any reoperations were recorded. Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA), Nurick classification (NuC), and Short-Form 36 (SF36) scores were recorded at baseline and final follow-up at certain centers. All data were collected, collated, and analyzed by a private research organization.

RESULTS

There were 109 cases of cervical dural tears among 18 463 surgeries performed. In 101 cases (93%) there was no clinical sequelae following successful dural tear repair. There were statistical improvements (P < .05) in mJOA and NuC scores, but not NDI or SF36 scores. No specific baseline or operative factors were found to be associated with the occurrence of dural tears. In most cases, no further postoperative treatments of the dural tear were required, while there were 13 patients (12%) that required subsequent treatment of cerebrospinal fluid drainage. Analysis of those requiring further treatments did not identify an optimum treatment strategy for cervical dural tears.

CONCLUSIONS

In this multicenter study, we report our findings on the largest reported series (n = 109) of cervical dural tears. In a vast majority of cases, no subsequent interventions were required and no clinical sequelae were observed.

Noninfectious prevertebral soft-tissue inflammation and hematoma eliciting swelling after anterior cervical discectomy and fusion

OBJECTIVE

Anterior cervical discectomy and fusion (ACDF) procedures are performed to treat patients with cervical myelopathy or radiculopathy. Dysphagia is a post-ACDF complication. When it coincides with prevertebral space enlargement and inflammation, surgical site infection and pharyngoesophageal perforation must be considered. The association between dysphagia and prevertebral inflammation has not been reported. The authors investigated factors eliciting severe dysphagia and its relationship with prevertebral inflammation in patients who had undergone ACDF.

MATERIALS

The clinical data of 299 patients who underwent 307 ACDF procedures for cervical radiculopathy or myelopathy at Kushiro Kojinkai Memorial Hospital and Kushiro Neurosurgical Hospital between December 2007 and August 2014 were reviewed.

RESULTS

After 7 ACDF procedures (2.3%), 7 patients suffered severe prolonged and/or delayed dysphagia and odynophagia that prevented ingestion. In all 7 patients the prevertebral space was enlarged. In 5 (1.6%) the symptom was thought to be associated with prevertebral soft-tissue edema; in all 5 an inflammatory response, hyperthermia, and an increase in the white blood cell count and in C-reactive protein level was observed. After 2 procedures (0.7%), we noted prevertebral hematoma without an inflammatory response. None of the patients who had undergone 307 ACDF procedures manifested pharyngoesophageal perforation or surgical site infection.

CONCLUSIONS

Severe dysphagia and odynophagia are post-ACDF complications. In most instances they are attributable to prevertebral soft-tissue edema accompanied by inflammatory responses such as fever and an increase in the white blood cell count and in C-reactive protein. In other cases these anomalies are elicited by hematoma not associated with inflammation.

Risk factors for dural tears in the cervical spine

STUDY DESIGN

Retrospective review of prospective database.

OBJECTIVE

To investigate the incidence of cervical dural tears (DTs), risk factors for occurrence and failure of treatment, and the effect on clinical outcomes.

SUMMARY OF BACKGROUND DATA

Only 1 study has specifically investigated the impact of cervical DTs.

METHODS

Cervical spine surgical procedures performed by the senior author (K.D.R.) at Washington University from 1995-2012 were evaluated. Demographic data, surgical history, operative data, and complications were recorded prospectively, and retrospectively reviewed. Intraoperative treatment of DTs was noted. Treatment failure was defined by reoperation or delayed lumbar drain placement. Patients who sustained a dural tear (DT group) were compared with those who did not sustain a dural tear (No-DT group) to identify risk factors. Comparison between successful and failed treatments was used to identify risk factors for treatment failure.

RESULTS

A total of 3848 cervical surgical procedures were performed, with 38 occurrences (1.0%) of DT. Risk factors for DT were: older age (P < 0.01), rheumatoid arthritis (relative risk [RR] = 3.1, 95% confidence interval [CI] = 1.0-9.8), ossification of the posterior longitudinal ligament (RR = 19.2, 95% CI = 10.4-35.6), cervical deformity (RR = 3.3, 95% CI = 1.6-6.6), longer operative time (P = 0.01), greater number of surgical levels (P < 0.01), worse preoperative neurological status (P < 0.01), and performance of a corpectomy (RR = 2.1, 95% CI = 1.1-4.0) or revision laminectomy (RR = 20.0, 95% CI = 8.4-47.4). Initial treatments failed in 12 cases (32%) and hospital readmission was required for 5 patients (13%). Older age and ossification of the posterior longitudinal ligament were found to be risk factors for failure of the DT treatment. With an average follow-up of 18 months, there were no clinical sequelae from the DTs.

CONCLUSION

In the largest series of cervical DTs reported, the incidence of DTs was found to be 1% and several risk factors were identified. Initial treatment failures occurred more often than previously reported. No significant clinical impact was found after successful DT treatment.

LEVEL OF EVIDENCE

4.

Endotracheal tube intubation with the aid of a laryngeal mask airway, a fiberoptic bronchoscope, and a tube exchanger in a difficult airway patient: a case report

A 28-year-old male patient with occipito-atlanto-axial instability underwent a cervical fusion with posterior technique. Post-operatively, the endotracheal tube (ETT) was removed, and the patient was transferred to the intensive care unit. After transfer, an upper airway obstruction developed and reintubations with a laryngoscope were attempted but failed. We inserted a #4 proseal laryngeal mask airway (LMA) and passed a 5.0 mm ETT through the LMA with the aid of a fiberoptic bronchoscope. We passed a tube exchanger through the 5.0 mm ETT and exchanged it with a 7.5 mm ETT. This method may be a useful alternative for difficult tracheal intubations.

Acute respiratory failure from Surgifoam expansion after anterior cervical surgery

A 65-year-old woman underwent an uneventful C3–4 anterior cervical discectomy and fusion for a large, symptomatic disc herniation. On postoperative Day 1 the patient suffered a sudden, acute respiratory compromise. Emergency fiberoptic intubation revealed significant anterior neck swelling with concern for physical obstruction of the airway. Computed tomography of the neck did not demonstrate an expanding hematoma. The patient was managed with surgical wound exploration and washout. Examination of the anterior neck after incision of the prior surgical site revealed a large volume of Surgifoam under high pressure, which was greater than the amount used during the initial surgery. Thorough washout of the surgical site did not reveal any swelling of the prevertebral soft tissues or hematoma, and the Hemovac drain did not appear to be occluded. The patient was extubated on the 2nd postoperative day and is symptom free 12 months after surgery. To the authors' knowledge, this report represents the first reported complication of acute respiratory failure from Surgifoam overexpansion after anterior cervical surgery.

Management of cerebrospinal fluid leaks after anterior decompression for ossification of the posterior longitudinal ligament: a review of the literature

Object

Anterior decompression is an effective way to treat cervical myelopathy associated with ossification of the posterior longitudinal ligament (OPLL); however, this approach is associated with an increased risk of a dural tear and resultant CSF leak because fusion of the dura with the ossified PLL is common in these cases. The authors review the literature and present an algorithm for treatment of CSF leaks in these patients.

Methods

A MEDLINE review was performed to identify papers related to CSF leak after anterior decompression for OPLL, and data were summarized to identify treatment options for various situations. A treatment algorithm was identified based on these findings and the experience of the authors.

Results

Eleven studies were identified that presented data on intra- and postoperative management of a CSF leak during ventral surgery for OPLL. The incidence of cervical dural tears and CSF leaks after anterior decompression procedures for OPLL ranged from 4.3% to 32%. Techniques including preventative measures, intraoperative dural repair with various materials, and postoperative drainage or shunt placement have all been used.

Conclusions

Although direct dural repair is the preferred treatment for CSF leak, this technique is not always technically possible. In these cases, intraoperative adjuncts in combination with postoperative measures can be used to decrease the pressure gradient across the dural tear.

Upper airway obstruction associated with flexed cervical position after posterior occipitocervical fusion

Upper airway obstruction resulting from overflexion fixation of the cervical spine is a rare but life-threatening complication after cervical spine surgery. There are few reports of dyspnea after a posterior cervical fusion. We present the case of a 63-year-old woman with rheumatoid arthritis who developed an upper airway obstruction immediately after an O-C4 fusion. She was reintubated with a fiberoptic scope. Revision surgery allowing the angle to return to the neutral position was performed to ameliorate the overflexion of the cervical spine fixation and the consequent upper airway obstruction. After revision surgery, the upper airway obstruction disappeared. Our experience suggests that intraoperative use of fluoroscopy and extubation with a tube exchanger are recommended to avoid this complication, especially in patients at high risk of upper airway obstruction.

Airway compromise secondary to upper cervical spine injury

BACKGROUND

Airway compromise secondary to isolated injury at the atlas (C1) and axis (C2) without an associated spinal cord injury is a rare, but recognized phenomenon that results in significant morbidity and mortality. No previous study in the literature has reported the incidence of this potentially lethal complication of these relatively common fractures.

METHODS

The medical records for 625 consecutive patients who presented to a Level I trauma center with C1 and C2 fractures during the years from 1996 to 2005 were reviewed retrospectively. Strict inclusion and exclusion criteria were applied to identify adult patients with isolated fractures and no other injuries. All patients that developed significant airway compromise were identified and correlations were made with the patient's demographic features, clinical presentation, and radiologic findings, to determine potential risk factors.

RESULTS

During the 10 years studied, 343 patients with isolated C1 and C2 fractures were identified. Of these, 17 patients developed significant airway compromise. This represents a 4.9% incidence of this potentially life-threatening complication. Older age and male gender were found to be risk factors with a statistically significant association (p value <0.05). The majority of patients also exhibited prevertebral swelling, the presence of significant degenerative changes, and significant fracture displacement. Twelve patients required intubation and admission to Intensive Care Unit (ICU). There were four deaths.

CONCLUSIONS

Approximately 5% of patients with isolated C1 and C2 fractures developed airway compromise. All patients with these injuries should be assessed for the risk of developing this complication and some will require close monitoring to detect this problem at an early stage.

Upper airway obstruction after cervical spine fusion surgery: role of cervical fixation angle

Upper airway obstruction is one of the life-threatening events in cervical spine surgery. The risk is particularly great during the period immediately after operation. We present the case of a 56-year-old female with breast cancer and metastasis to the cervical spine. The surgical procedure involved C2-C3 laminectomy, posterior fixation (C0-C5), and C2 neurectomy. Tracheal extubation was carried out in the intensive care unit, and upper airway obstruction immediately followed. Emergency cricothyrotomy was performed under well-managed ventilation with a laryngeal mask after several failed intubation attempts. Over-flexion of the cervical spine fixation and severe prevertebral soft tissue swelling were the most probable causes of upper airway obstruction. With a well-adjusted angle for fixation of the cervical spine under fluoroscopic guidance before the procedure, such a surgical mishap could be avoided. Reintubation with a fiberscope might be considered first, and sustaining intubation for 2-3 days postoperatively could be safer in such high risk patients.

Adverse events associated with anterior cervical spine surgery

Anterior cervical procedures for neurologic decompression and fusion, including cervical diskectomy and cervical corpectomy, are commonly performed by orthopaedic surgeons and spinal neurosurgeons. These procedures are highly successful in treating most patients with persistent pain and neurologic symptoms that have not responded to nonsurgical methods. Adverse events occur infrequently, but several have been described, including esophageal injury, vertebral artery injury, dural tear, postoperative airway compromise, spinal cord injury, hematoma, dysphagia, dysphonia, and graft dislodgement. Newer procedures, such as cervical total disk replacement and the use of bone morphogenetic protein as a supplement to fusion, have raised unique concerns. Appropriate strategies must be utilized to avoid these adverse events, and the treating surgeon should have an understanding of how to detect and manage such events when they do arise.

Pseudomeningocele: an unusual cause of intraoperative tracheal compression and expiratory obstruction

Cerebrospinal fluid leak resulting from spine surgery has been associated with postoperative upper airway obstruction and the need for emergent airway management. We report a case of a known pseudomeningocele resulting in acute intraoperative compression of the intrathoracic trachea and an unexpected variable expiratory obstruction.

Anterior corpectomy and fusion for severe ossification of posterior longitudinal ligament in the cervical spine

Between May 2002 and October 2006, 19 patients (17 men and 2 women; average age 57.2; range 47-71 years) received anterior corpectomy and fusion for severe ossification of the posterior longitudinal ligament (OPLL) in our department. Preoperative radiological evaluation showed the narrowing by the OPLL exceeded 50% in all cases, and OPLL extended from one to three vertebrae. We followed-up all patients for 12-36 months (mean 18 months). The Japanese Orthopaedic Association (JOA) score before surgery was 9.3 +/- 1.8 (range 5-12) which significantly increased to 14.2 +/- 1.3 (range 11-16) points at the last follow-up (P < 0.01). The improvement rate (IR) of neurological function ranged from 22.2-87.5%, with a mean of 63.2% +/- 15.2%. The operation also provided a significant increase in the cervical lordosis and the cord flatting rate (P < 0.01). No severe neurological complication developed. We therefore concluded that anterior decompression and fusion was effective and safe in the treatment of the selected patients, although OPLL exceeded 50% diameter of the spinal canal.

Management of the Airway in Patients Undergoing Cervical Spine Surgery

The perioperative management of the airway in patients with cervical spine disease requires careful consideration. In an observational prospective cohort study, we assessed the preoperative factors that may have influenced the anesthesiologists' choice for the technique of intubation and the incidence of postoperative airway complications. We recorded information from 327 patients: mean (+/-SD) age 51+/-15 year, 138 females and 189 males, for anterior surgical approach (n=195) and posterior (n=132). The technique of intubation used was awake fiberoptic bronchoscopy (FOB) in 39% (n=128), asleep FOB 32% (n=103), asleep laryngoscopy 22% (n=72), and other asleep 7% (n=24). Awake FOB was predominately chosen for intubating patients with myelopathy (45%), unstable/fractured spine (73%), and spinal stenosis (55%) but patients with radiculopathy had more asleep FOB (49%) (P<0.001). There was no association between method of intubation and postoperative airway complications. Acute postoperative airway obstruction occurred in 4 (1.2%) patients requiring reintubation. The technique of management of the airway for cervical spine surgery varied considerably among the anesthesiologists, although the choice was not associated with postoperative airway complications.

Prevertebral soft tissue swelling after anterior cervical discectomy and fusion with plate fixation

Airway complications after anterior cervical surgery are rare but potentially lethal. The purpose of this study was to identify the natural course of prevertebral soft tissue swelling after one- or two-level anterior cervical discectomy and fusion (ACDF) in order to prevent lethal airway obstruction after ACDF. Eighty-seven patients scheduled for one- or two-level ACDF were studied prospectively. Lateral radiographs of the cervical spine were taken preoperatively, postoperatively on the day of surgery and on the first, second, third, fourth, and fifth days after operation. Prevertebral soft tissue was measured from C2 to C6 on cervical spine lateral radiographs. The anteroposterior (AP) thickness of the prevertebral soft tissue was measured at each cervical level from C2 to C6. Prevertebral soft tissue swelling occurred postoperatively and increased markedly on the second day after operation. The maximum swelling was found on the second and third days. In fusions above C5 swelling was most prominent at C2, 3. Gradual decrease in swelling was observed after the fourth postoperative day. Prominent swelling was noted at the second, third, and fourth cervical levels. There was no significant difference in swelling when comparing one-level and two-level ACDF. Only one patient required reintubation (1.1%). In conclusion, in this prospective study of 87 patients fused at one or two levels in the cervical spine peak prevertebral soft tissue swelling was observed on the second and third days after the surgery.