The Prediction and Prevention of Dysphagia After Occipitospinal Fusion by Use of the S-line (Swallowing Line)

Relationship between intervertebral disc height and post operative dysphagia secondary to single-level anterior cervical discectomy and fusion- a retrospective study

BACKGROUND

One goal of Anterior Cervical Discectomy and Fusion (ACDF) is to restore the loss of intervertebral disc height (IDH) results from the degenerative process. However, the effects of IDH on postoperative dysphagia after ACDF remain unclear.

METHODS

Based on the results of a one-year telephone follow-up, A total of 217 consecutive patients after single-level ACDF were enrolled. They were divided into dysphagia and non-dysphagia groups. The age, BMI, operation time and blood loss of all patients were collected from the medical record system and compared between patients with and without dysphagia. Radiologically, IDH, spinous process distance (SP) of the operated segment, and C2-7 angle (C2-7 A) were measured preoperatively and postoperatively. The relationship between changes in these radiological parameters and the development of dysphagia was analyzed.

RESULTS

Sixty-three (29%) cases exhibited postoperative dysphagia. The mean changes in IDH, SP, and C2-7 A were 2.84 mm, -1.54 mm, and 4.82 degrees, respectively. Changes in IDH (P = 0.001) and changes in C2-7 A (P = 0.000) showed significant differences between dysphagia and non-dysphagia patients. Increased IDH and increased C2-7 A (P = 0.037 and 0.003, respectively) significantly and independently influenced the incidence of postoperative dysphagia. When the change in IDH was ≥ 3 mm, the chance of developing postoperative dysphagia for this patient was significantly greater. No significant relationship was observed between the change in spinous process distance (SP) and the incidence of dysphagia. The age, BMI, operation time and blood loss did not significantly influence the incidence of postoperative dysphagia.

CONCLUSION

The change in IDH could be regarded as a predictive factor for postoperative dysphagia after single-level ACDF.

A case of delayed dyspnea after corrective posterior fusion of the middle and lower cervical spine for dropped head syndrome

Dyspnea has been reported to occur following posterior occipitocervical fusion. However, there are no documented cases of dyspnea following posterior fixation of the middle and lower cervical spine without posterior occipitocervical fusion. An 80-year-old woman underwent corrective fusion from T4 to the ilium for kyphoscoliosis. Sixteen months later, the patient developed cervical kyphosis (dropped head syndrome) with proximal junctional kyphosis, leading to a pedicle subtraction osteotomy at T4 and an extended fixation to C2. On the sixth postoperative day, the patient experienced respiratory arrest, prompting a reoperation to reduce cervical lordosis, ultimately resolving the respiratory dysfunction. Excessive correction of cervical kyphosis should be avoided to prevent the occurrence of postoperative dyspnea, even in cases where posterior occipitocervical fusion has not been performed.

Surgical outcomes of intraoperative O-arm versus C-arm fluoroscopy in occipitocervical fixation: a retrospective analysis

PURPOSE

This study aims to compare the effect of using O-arm and C-arm fluoroscopy on the surgical outcomes of occipitocervical fixation.

METHODS

The study included patients who underwent occipitocervical fixation using O-arm or C-arm between 2005 and 2021. Of 56 patients, 34 underwent O-arm-assisted surgery (O-group) and 22 underwent C-arm-assisted surgery (C-group). We assessed surgical outcomes, including operative time, intraoperative blood loss, perioperative complications, and bone union.

RESULTS

Almost half of the patients had rheumatoid arthritis-related disorders in both groups. Sixteen cases (47.1%) in the O-group and 12 cases (54.5%) in the C-group were fixed from occipito (Oc) to C3, 12 cases (38.2%) in the O-group and 7 cases (31.8%) in the C-group from Oc to C4-7, 5 cases (14.7%) in the O-group, and 3 cases (13.6%) in the C-group from Oc to T2 (p = 0.929). There was no significant difference in operative time (p = 0.239) and intraoperative blood loss (p = 0.595) between the two groups. Dysphagia was the most common complication in both groups (O-group vs. C-group, 11.7% vs. 9.1%). Regarding implant-related complications, occipital plate dislodgement was observed in four cases (18.2%) in the C-group (p = 0.02). The bone union rate was 96.3% in the O-group and 93.3% in the C-group (P = 1).

CONCLUSIONS

O-arm use is associated with a reduced rate of occipital plate dislodgment and has a similar complication incidence compared with C-arm-assisted surgery and does not prolong operative time despite the time needed for setting and scanning. Accordingly, an O-arm is safe and useful for occipitocervical fixation surgery.

Effects of Head and Neck Alignment and Pharyngeal Anatomy on Epiglottic Inversion During Swallowing in Dysphagic Patients

The effects of head and neck alignment and pharyngeal anatomy on epiglottic inversion remain unclear. This study investigated the factors involved in epiglottic inversion, including head and neck alignment and pharyngeal anatomy, in patients with dysphagia. Patients with a chief complaint of dysphagia and who underwent videofluoroscopic swallowing study at our hospital from January to July 2022 were enrolled. They were divided into three groups based on the degree of epiglottic inversion as the complete-inversion (CI), partial-inversion (PI), and non-inversion group (NI) groups. Data were compared among the three groups; a total of 113 patients were analyzed. The median age was 72.0 (IQR: 62.0-76.0) years; 41 (36.3%) and 72 (63.7%) were women and men, respectively. There were in 45 (39.8%) patients in the CI, 39 (34.5%) in the PI, and 29 (25.7%) in the NI groups, respectively. Single-variable analysis revealed significant relation to epiglottic inversion of Food Intake LEVEL Scale score, penetration-aspiration score with 3-mL thin liquid bolus, epiglottic vallecula and pyriform sinus residue, hyoid position and displacement during swallowing, pharyngeal inlet angle (PIA), epiglottis to posterior pharyngeal wall distance, and body mass index. Logistic regression analysis with complete epiglottic inversion as the dependent variable revealed the X coordinate at maximum hyoid elevation position during swallowing and PIA as significant explanatory variables. These results suggest that epiglottic inversion is constrained in patients with dysphagia who have poor head and neck alignment or posture and a narrow pharyngeal cavity just before swallowing.

Advances in surgical treatment for atlantoaxial instability focusing on rheumatoid arthritis: Analysis of a series of 67 patients

AIM

An estimated 88% of rheumatoid arthritis (RA) patients experience various degrees of cervical spine involvement. The excessive movement of the atlantoaxial joint, which connects the occiput to the upper cervical spine, results in atlantoaxial instability (AAI). AAI stabilization is usually achieved by C1 lateral mass-to-C2 pedicle screw-rod fixation (LC1-PC2 fixation), which is technically challenging in RA patients who often show destructive changes in anatomical structures. This study aimed to analyze the clinical results and operative experiences of C1-C2 surgery, with emphasis on the advancement of image-guided surgery and augmented reality (AR) assisted navigation.

METHODS

We presented our two decades of experience in the surgical management of AAI from April 2004 to November 2022.

RESULTS

We have performed surgery on 67 patients with AAI, including 21 traumatic odontoid fractures, 20 degenerative osteoarthritis, 11 inflammatory diseases of RA, 5 congenital anomalies of the os odontoideum, 2 unknown etiologies, 2 movement disorders, 2 previous implant failures, 2 osteomyelitis, 1 ankylosing spondylitis, and 1 tumor. Beginning in 2007, we performed LC1-PC2 fixation under C-arm fluoroscopy. As part of the progress in spinal surgery, since 2011 we used surgical navigation from presurgical planning to intraoperative navigation, using the preoperative computed tomography (CT) -based image-guided BrainLab navigation system. In 2021, we began using intraoperative CT scan and microscope-based AR navigation.

CONCLUSION

The technical complexities of C1-C2 surgery can be mitigated by CT-based image-guided surgery and microscope-based AR navigation, to improve accuracy in screw placement and overall clinical outcomes, particularly in RA patients with AAI.

Postoperative Dysphagia Subsequent to Posterior Fixation of an Axis Fracture Without Cranial Fixation: A Case Report

The incidence of dysphagia following cervical fusion, which involves the occipital bone, is well established. However, dysphagia occurring after cervical fusion not involving the occipital bone is exceedingly rare. We present a case report of a 54-year-old male who developed unexplained dysphagia subsequent to posterior fusion up to C1-3 for an axis fracture.

Radiographic measurements for the prediction of dysphagia after occipitocervical fusion: a systematic review

BACKGROUND

Occipitocervical fusion (OCF) is a procedure performed for multiple upper cervical pathologies. A common postprocedural complication of OCF is dysphagia, which has been linked to the narrowing of the pharyngeal space due to fixation in a hyper-flexed angle. Postoperative dysphagia is linked to reduced quality of life, prolonged hospital stay, aspiration pneumonia, and increased mortality. This has led to investigations of the association between sagittal radiographic angles and dysphagia following OCF.

METHODS

A systematic review of the literature was performed to explore the current evidence regarding cervical sagittal radiographic measurements and dysphagia following OCF. A search strategy was carried out using the PubMed, Embase, and Web of Science databases from their dates of inception until August 2022. Only original English-language studies were considered. Moreover, studies had to include the correlation between dysphagia and at least one radiographic measurement in the sagittal plane.

RESULTS

The search and subsequent selection process yielded eight studies that were included in the final review, totaling 329 patients in whom dysphagia had been assessed and graded. The dysphagia score by Bazaz et al. (Spine 27, 22:2453-2458, 2002) was used most often. The pooled incidence of dysphagia, in the early postoperative period, was estimated at 26.4%. At long-term follow-up (range: 17-72 months), about one-third of patients experienced resolution of symptoms, which resulted in a long-term post-OCF dysphagia incidence of 16.5%. Across the studies included, six different radiographic parameters were used to derive several measures which were repeatedly and significantly associated with the occurrence of dysphagia.

CONCLUSIONS

The high incidence of postoperative dysphagia following OCF warrants close monitoring of patients, especially in the short-term postoperative period. These patients may be assessed through standardized tools where the one by Bazaz et al. was the most commonly used. Moreover, there are several radiographic measurements that can be used to predict the occurrence of dysphagia. These findings may serve as a basis for strategies to prevent the occurrence of dysphagia after OCF.

Analysis of risk factors for postoperative dysphagia after C1-2 fusion

Objective

This study aimed to analyze the risk factors for dysphagia after C1-2 fusion in patients with C1-2 junction diseases.

Summary of the background data

Dysphagia is a common postoperative complication of posterior C1-2 junction surgery. The incidence is 9.5% to 26.3%. However, the etiopathogenisis of postoperative dysphagia remains controversial.

Methods

This retrospective study included patients who underwent C1-2 fusion from January 2016 to January 2020. The patients were divided into dysphagia group and control group in accordance with the Bazaz R dysphagia scoring system. The patients' age, gender, BMI(body mass index), cause of disease, and changes in the C01cobb, C02cobb, C12cobb, C27cobb, dC02cobb, dC01cobb, dC12cobb, d C27cobb angles before and after operation, were recorded. The parameters and changes were compared to analyze the risk factors for dysphagia after C1-2 fusion.

Results

65 cases (15, with dysphagia; 50, without dysphagia) were included. The incidence of postoperative dysphagia was 23%. The differences in age, gender ratio, and BMI between the two groups were not significant (P > 0.05). The differences among postoperative C12 (29.8° ± 11.24° vs. 20.46° ± 13.39°), postoperative C27cobb (10.56° ± 8.53° vs. 20.21° ± 13.21°), and dC12cobb (9.49° ± 5.16° vs. 1.07° ± 12.44°) between the two groups were significant (P < 0.05). Multiple logistic regression analyses revealed that dC12cobb > 5° was a significant independent risk factor for postoperative dysphagia, And preoperative C27cobb was a preventive factor of postoperative dysphagia.

Conclusions

Dysphagia after the C1-2 fusion was common. dC02cobb and dC12cobb were the significant independent risk factors for postoperative dysphagia. Preoperative c27cobb was a preventive factor of dysphagia.

Impact of Radiation Therapy on Outcomes After Spinal Instrumentation for Craniocervical Junction Malignancies

Objective

Spinal reconstruction after resection of invasive craniocervical junction malignancies is fraught with technical and management considerations as well as a paucity of data in the existing literature. In this study, we describe our experience with craniocervical junction malignancies, especially the influence of radiation on the need for revision spinal instrumentation.

Methods

We performed a retrospective chart review of all patients who underwent occipitocervical fixation between 2011 and 2019 at The University of Texas MD Anderson Cancer Center.

Results

Twenty-five patients had primary malignancies and 12 (30%) had metastatic tumors. Thirteen (33%) underwent a staged resection in multiple operations during their hospital stay. Tumor resection was performed in 19 patients (48%), while only stabilization was performed in 21 patients (52%). Nine patients (23%) underwent expanded endoscopic transclival approaches for tumor resection, 10 patients (25%) an extreme lateral approach, and 2 patients (5%) an anterior open approach. Eleven patients underwent early postoperative radiation therapy (within 3 months) and 8 underwent delayed radiation therapy (between 3 months and 1 year in 7 patients). The revision rate was 8%, with a median time to revision surgery of 42 months. The administration and timing of adjuvant radiation therapy relative to surgery had no significant effect on the need for instrumentation revision on log-rank and Cox regression analyses (p < 0.05).

Conclusion

Revision surgery was needed infrequently in our patients. Postoperative radiation therapy was not associated with hardware failure, indicating that the timing of radiation therapy should be dictated by the diagnosis and can be initiated postoperatively without delay.

Dysphagia after occipital cervical fusion for retro-odontoid pseudotumor with ossification of the anterior longitudinal ligament

Background:

Ossification of the anterior longitudinal ligament (OALL) of the cervical spine is a relatively rare disease. If patients present with dysphagia, hoarseness, and/or dyspnea, they may require surgery.

Case Description:

Over a 7-month period, a 55-year-old female with a history of cerebral palsy developed a progressive quadriparesis accompanied by diffuse sensory loss (i.e., clumsiness of the hand/legs and gait disturbance). The cervical spine X-rays showed atlanto-axial subluxation with instability, while the cervical MRI demonstrated “pseudotumor in the retro-odontoid” region. Following an occipital cervical fusion (C0-C2) surgery, her quadriparesis resolved. Nevertheless, she had persistent dysphagia that worsened over 6 months. Video fluoroscopy revealed severe mechanical stenosis of the pharynx, which was attributed to OALL extending from the C3-C6 levels. Following OALL resection through a right anterior approach utilizing diamond burrs and an ultrasonic bone curette, the dysphagia rapidly resolved.

Conclusion:

We report a rare case of retro-odontoid pseudotumor successfully treated with a posterior C0-C2 cervical fusion. Additional symptomatic C3-C6 OALL, responsible for progressive dysphagia, was later managed with focal anterior OALL resection.

The predictive ability of occipital to C3 angle for dysphagia after occipitocervical fusion in patients with combined C2-3 Klippel-Feil syndrome

Background

Improper occipitocervical alignment after occipitocervical fusion (OCF) may lead to devastating complications, such as dysphagia and/or dyspnea. The occipital to C2 angle (O-C2a), occipital and external acoustic meatus to axis angle (O-EAa) have been used to evaluate occipitospinal alignment. However, it may be difficult to identify the inferior endplate of the C2 vertebra in patients with C2–3 Klippel-Feil syndrome (KFS). The purpose of this study aimed to compare four different parameters for predicting dysphagia after OCF in patients with C2–3 KFS.

Methods

There were 40 patients with C2–3 KFS undergoing OCF between 2010 and 2019. Radiographs of these patients were collected to measure the occipital to C3 angle (O-C3a), O-C2a, occipito-odontoid angle (O-Da), occipital to axial angle (Oc-Axa), and narrowest oropharyngeal airway space (nPAS). The presence of dysphagia was defined as the patient complaining of difficulty or excess endeavor to swallow. Patients were divided into two groups according to whether they had postoperative dysphagia. We evaluated the relationship between each of the angle parameters and nPAS and analyzed their influence to the postoperative dysphagia.

Results

The incidence of dysphagia after OCF was 25% in patients with C2–3 KFS. The Oc-Axa, and nPAS were smaller in the dysphagia group compared to non-dysphagia group at the final follow-up (p < 0.05). Receiver-operating characteristic (ROC) curves showed that dO-C3a had the highest accuracy as a predictor of the dysphagia with an area under the curve (AUC) of 0.868. The differences in O-C3a, O-C2a, O-Da, and Oc-Axa were all linearly correlated with nPAS scores preoperatively and at the final follow-up within C2–3 KFS patients, while there was a higher R² value between the dO-C3a and dnPAS. Multiple linear regression analysis showed that the difference of O-C3a was the only significant predictor for dnPAS (β = 0.670, p < 0.001).

Conclusions

The change of O-C3a (dO-C3a) is the most reliable indicator for evaluating occipitocervical alignment and predicting postoperative dysphagia in C2–3 KFS patients. Moreover, dO-C3a should be more than − 2° during OCF to reduce the occurrence of postoperative dysphagia.

Sequential sagittal alignment changes in the cervical spine after occipitocervical fusion

BACKGROUND

There are few studies regarding sequential changes in the sagittal alignment of the upper and lower cervical regions of the spine after occipitocervical fusion (OCF). In addition, no comparisons of cervical sagittal alignment (CSA) between patients with craniocervical junction disorders (CJDs) and normal populations have been reported.

AIM

To compare the CSA of patients with CJDs with that of normal controls and investigate the sequential changes in the CSA of the upper and lower cervical spine after OCF.

METHODS

Eighty-four patients who underwent OCF (OCF group) and 42 asymptomatic volunteers (control group) were included. Radiographic parameters, including the occipital to C2 angle (O-C2a), occipital and external acoustic meatus to axis angle (O-EAa), C2–7 angle (C2-7a), and pharyngeal inlet angle (PIA), were measured and compared pre- and postoperatively. The correlations among the parameters were analyzed using Pearson’s correlation test.

RESULTS

The O-C2a and PIA of the OCF group were smaller than those of the control group, while their O-EAa and C2-7a values were larger than those of the normal controls. There were no significant differences in O-C2a, C2-7a, or PIA in the OCF group at baseline, 1 mo, or the final follow-up after surgery. The Pearson’s correlation results showed that there were significant correlations between the O-C2a and C2Ta, C2-7a, C2-7 sagittal vertical axis (SVA), and PIA at 1 mo after OCF surgery and between O-C2a and O-EAa, C2Ta, C2-7a, C2-7 SVA, and PIA at the final follow-up.

CONCLUSION

Patients with CJDs have a more kyphotic upper CSA and a more lordotic lower CSA than normal controls. The effectiveness of OCF surgery in restoring CSA may be limited by the realignment of the craniocervical junction being neglected. The reduction in O-C2a after OCF surgery may increase C2-7a and decrease PIA.

Occipitocervical fusion and dysphagia. The role of head neck alignment: A case report

Dysphagia is a less reported but serious adverse outcome post occipitocervical fusion. Any patient suffering from dysphagia and or nasal regurgitation post fusion in flexion should be offered early revision. The right position for occipitocervical fusion is neutral alignment.

Predictive value of sagittal craniocervical roentgenographic parameters for HRQOL after craniocervical fusion

PURPOSE

Loss of "physiological" sagittal alignment following craniocervical fusion (CCF) for degenerative disease may be associated with loss of horizontal gaze, dysphagia and poor HRQOL. This study reports on sagittal craniocervical roentgenographic predictors of HRQOL (SF-36) in patients following uncomplicated CCF for fresh upper cervical traumatic (UCT) injuries.

METHODS

Twenty-two consecutive adult patients (group P) aged 50 ± 16 years, who had undergone CCF for fresh unstable C₁ and C₂AO/type UCT injuries, were evaluated 39 ± 12 months postoperatively with upright lateral cervical roentgenograms and SF-36as HRQOL measure. Physiological data for cervical sagittal alignment and SF-36 were taken from an age-matched control group (C) of 30 individuals aged 52 ± 12 years. Several commonly used sagittal cervical roentgenographic parameters were tested as potential predictors of the SF-36 domains in both groups. Roentgenographic predictors for each of the nine SF-domains were calculated using stepwise multilinear regression analysis (MLRA).

RESULTS

The roentgenographic predictors in patients included (1) the angle created by McGregor's line and the inferior surface of the axis (OC₂a) for physical function (PF, P = 0.049), role limitations due to physical health (RLPH, P = 0.004),role limitation due to emotional problems (RLEP, P = 0.004), emotional functioning (EF) (P = 0.012), social functioning (SF) (P = 0.028) and general health (GH, P = 0.041). (2) The angle formed between a horizontal line and the superior endplate of T₁-vertebra (T₁-slope) was predictor for SF (P = 0.017) and pain (P = 0.021), and (3) the angle between McGregor's line and the line that links the center of the C₁ anterior arch and the apex of cervical sagittal curvature (PIA) was predictor for health change (HC, P = 0.002).

CONCLUSIONS

This study showed that postoperative OC₂a, PIA and T1-slope safely predict HRQOL outcomes (SF-36) following CCF for fresh trauma. It seems theoretically that the adequate restoration of the upper cervical alignment including C1-C2 upper cervical lordosis (OC₂a) and PIA, in interaction with T1-slope, is important for postoperative HRQOL scores close to physiological values. The authors speculate that C0-C4 fusion restores horizontal gaze and allows for painful regain of pre-trauma quality of life. Spine surgeons should realign and stabilize the craniocervical junction taking in consideration these roentgenographic predictors.

Role of preoperative cervical alignment on postoperative dysphagia after occipitocervical fusion

Background:

Dysphagia is one of the most serious complications of occipitocervical fusion (OCF). The previous studies have shown that postoperative cervical alignment, documented with occipito (O)-C2 angles, C2-C6 angles, and pharyngeal inlet angles (PIA), impacted the incidence of postoperative dysphagia in patients undergoing OCF. Here, we investigated the relationship of preoperative versus postoperative cervical alignment on the incidence of postoperative dysphagia after OCF.

Methods:

We retrospectively reviewed the clinical data/medical charts for 22 patients following OCF (2006– 2019). The O-C2 angles, C2-C6 angles, PIA, and narrowest pharyngeal airway spaces (nPAS) were assessed using plain lateral radiographs of the cervical spine before and after the surgery. The severity of dysphagia was assessed with the functional oral intake scale (FOIS) levels as documented in medical charts; based on this, patients were classified into the nondysphagia (FOIS: 7) versus dysphagia (FOIS: 1–6) groups.

Results:

Seven patients (35%) experienced dysphagia after OCF surgery. Preoperative PIA and nPAS were smaller in the dysphagia group. Spearman rank correlation showed a positive correlation between preoperative PIA and FOIS and between preoperative nPAS and FOIS.

Conclusion:

This study suggests that preoperative cervical alignment may best predict the incidence of postoperative dysphagia after OCF.

Risk factors of dysphagia in patients with ossification of the anterior longitudinal ligament

INTRODUCTION

Cervical ossification of the anterior longitudinal ligament (OALL) occasionally leads to dysphagia by the anterior osteophyte. A recent report explained that the dysphagia after an occipito-cervical fusion is caused by the narrowing of pharyngeal space due to the cranio-cervical malalignment. The purpose of this study was to evaluate the cranio-cervical alignment in patients with OALL complaining of the dysphagia.

SUBJECTS AND METHODS

The subjects were 11 cases with complaining of dysphagia due to cervical OALL who underwent anterior cervical OALL resection and as control, age-matched 12 cases without dysphagia who have diffuse idiopathic skeletal hyperostosis in cervical spine. All subjects were male, and the mean age was 59.5 ± 9.1 years. The subjects were divided into two groups according to the symptoms of dysphagia (dysphagia, group A; control, group B). The O-C2 angle, C2-C7 angle, and the maximum thickness of OALL and the cranio-cervical alignment (pharyngeal inlet angle; PIA) and swallowing line (S-line) were measured before and after the operation on the lateral cervical radiogram at the sitting position.

RESULTS

Group A showed significantly large maximum thickness of OALL, small cervical range of motion, small O-C2 angle, large C2-C7 angle, and small PIA. The S-line crossed the anterior apex of cervical osteophyte in group A. After OALL resection, dysphagia had improved, PIA had increased, and the S-line uncrossed the apex of cervical vertebrae in all cases.

CONCLUSION

The prevalence of dysphagia in patients with cervical OALL was influenced by the thickness of osteophyte, cervical mobility, and cranio-cervical alignment.

Considerations in revising occipitocervical fixation for dysphagia

Background:

Dysphagia after occipitocervical fixation (OCF) is a complex phenomenon and revision surgery in this context involves difficult decision-making. The pathogenesis is explored and surgical strategies discussed. A surgical strategy that has not been described before in the management of this condition, is discussed with two illustrative cases.

Methods:

Two cases are presented where dysphagia occurred after OCF for C1/C2 instability. The preoperative imaging was not available to determine whether the optimal craniocervical angle had been achieved. Both had revision surgery with removal of the cranial fixation and fusion to the atlas instead. One of the cases had the revision surgery more than 10 years after the original OCF.

Results:

The dysphagia recovered after the revision surgery in both cases. The patients gained weight and reported more satisfaction with their posture and head movements compared to before the revision surgery. There was no head ptosis and instead, patients reported better forward gaze and head position.

Conclusion:

In cases of C1/C2 instability, it is preferable to perform C1/C2 fusion rather than OCF. If performing an OCF, care must be taken to fix the head at the same O-C2 angle as preoperative. When an OCF done for C1 C2 instability ends up causing dysphagia, it is feasible and effective to shorten the rostral construct by removing the cranial fixation and fusing to C1 instead.

Predictive ability of pharyngeal inlet angle for the occurrence of postoperative dysphagia after occipitocervical fusion

Background

PIA has been proven to be a predictor for postoperative dysphagia in patients who undergo occipitospinal fusion. However, its predictive effect for postoperative dysphagia in patients who undergo OCF is unknown. The aim of this study was to evaluate the predictive ability of the pharyngeal inlet angle (PIA) for the occurrence of postoperative dysphagia in patients who undergo occipitocervical fusion (OCF).

Methods

Between 2010 and 2018, 98 patients who had undergone OCF were enrolled and reviewed. Patients were divided into two groups according to the presence of postoperative dysphagia. Radiographic parameters, including the atlas-dens interval (ADI), O-C2 angle (O-C2a), occipital and external acoustic meatus to axis angle (O-EAa), C2 tilting angle (C2Ta), C2-7 angle (C2-7a), PIA and narrowest oropharyngeal airway space (nPAS), were measured and compared. Simple linear regression and multiple regression analysis were used to evaluate the radiographic predictors for dysphagia. In addition, we used PIA = 90° as a threshold to analyze its effect on predicting dysphagia.

Results

Of the 98 patients, 26 exhibited postoperative dysphagia. Preoperatively, PIA in the dysphagia group was significantly higher than that in the nondysphagia group. We detected that O-C2a, O-EAa, PIA and nPAS all decreased sharply in the dysphagia group but increased slightly in the nondysphagia group. The changes were all significant. Through regression analyses, we found that PIA had a similar predictive effect as O-EAa for postoperative dysphagia and changes in nPAS. Additionally, patients with an increasing PIA exhibited no dysphagia, and the sensitivity of PIA <90° in predicting dysphagia reached 88.5%.

Conclusions

PIA could be used as a predictor for postoperative dysphagia in patients undergoing OCF. Adjusting a PIA level higher than the preoperative PIA level could avoid dysphagia. For those who inevitably had decreasing PIA, preserving intraoperative PIA over 90° would help avert postoperative dysphagia.

Trial registration

This trial has been registered in the Medical Ethics Committee of West China Hospital, Sichuan University. The registration number is 762 and the date of registration is Sep. 9 th, 2019.

Sarcopenic Dysphagia After Occipito-Cervical Fusion Surgery in an Elderly Patient With High-Cervical Myelopathy Caused by Retro-Odontoid Pseudotumor: A Case Report

Occipito-cervical fusion surgery may cause dysphagia due to inadequate occipito-cervical alignment. However, little is known about any other mechanisms behind postoperative dysphagia. We present a rare case of severe sarcopenic dysphagia despite appropriate occipito-cervical alignment after occipito-cervical fusion surgery. An 85-year-old man who presented with high-cervical myelopathy due to a retro-odontoid pseudotumor underwent occipito-cervical fusion surgery and developed severe dysphagia immediately after the surgery. Swallowing videoendoscopy revealed stagnation of thick fluid at the larynx. Oral intake was prohibited and swallowing rehabilitation was performed. Subsequently, he showed a gradual improvement in swallowing function. He was allowed to start oral intake in the fourth week after surgery and was able to swallow solid foods in the sixth week after surgery. In this case, several parameters of occipito-cervical alignment such as the occipito-C2 angle (O-C2 angle), swallowing line (S-line), C2-C7 angle, and pharyngeal inlet angle, which are recognized as predictors of postoperative dysphagia after occipito-cervical fusion surgery, were adequate to prevent postoperative dysphagia. However, the patient had sarcopenia and cervical hyperlordosis to compensate for thoracic hyperkyphosis, which induces the hypertonicity of hyoid muscles. These findings led to a diagnosis of sarcopenic dysphagia after surgical invasion. Sarcopenic dysphagia is considered to be associated with skeletal and swallowing muscle weakness, apart from thinness, malnutrition, and surgical invasion. Elderly patients with sarcopenia may present with sarcopenic dysphagia because of surgical invasion after occipito-cervical fusion surgery. In such cases, it is important not only to control intraoperative occipito-cervical alignment but also to evaluate preoperative swallowing function.

Recurrent dysphagia after lower posterior cervical fusion

Background:

Although dysphagia following posterior craniocervical fixation is well known, the incidence after mid-lower posterior cervical fixation is not well described. Here, we presented a case of recurrent dysphagia in a 72-year-old male following C3–T3 posterior cervical fixation and discussed its etiology.

Case Description:

A 72-year-old male sustained a cervical fracture in a fall; he was neurologically intact. The cervical/thoracic MR and CT studies documented ankylosing spondylitic changes in the cervicothoracic spine, a C5/6 disc herniation, and a C7 vertebral fracture. He underwent posterior cervical C3 to T3 fusion without decompression. For the 1^st postoperative day, he complained of dysphagia without hoarseness, and fiberoptic endoscopy revealed poor esophageal mobility. For the next 6 postoperative years, he continued to require repeated attempts at the dilation of the esophageal entrance but remained reliant on a feeding tube.

Conclusion:

Posterior cervical fixation restricts cervical motion and may restrict expansion of the esophageal duct leading to permanent postoperative dysphagia requiring continued feeding tube utilization.

Predictive abilities of O-C2a and O-EAa for the development of postoperative dysphagia in patients undergoing occipitocervical fusion

BACKGROUND CONTEXT

Dysphagia is a common postoperative complication in patients undergoing occipitocervical fusion (OCF). Previous studies had proposed the use of two measures-the occipital to C2 angle (O-C2a) and the occipital and external acoustic meatus to axis angle (O-EAa)-to predict postoperative dysphagia after OCF. However, these studies had small sample sizes and the predictive abilities of both measures are still not clear.

PURPOSE

To evaluate the predictive ability of O-EAa and O-C2a for dysphagia after OCF.

STUDY DESIGN

A retrospective clinical study.

PATIENT SAMPLE

A total of 109 consecutive patients who had undergone OCF.

OUTCOME MEASURES

Presence of postoperative dysphagia, O-C2a, C2 tilting angle (C2Ta), O-EAa, and the narrowest oropharyngeal airway space (nPAS).

METHODS

Between April 2010 and June 2018, 109 consecutive patients who had undergone OCF were reviewed. Patients were divided into two groups according to the presence of postoperative dysphagia. Radiographic measurements, including O-C2a, C2Ta, O-EAa, and nPAS, were evaluated at preoperative and 1 month postoperative and the findings were compared. Simple linear regression was used to measure the correlations between the parameters and the presence of dysphagia, and the correlations within the parameters. Multiple regression analysis was used to examine the variables that affected the change of nPAS (dnPAS%). Sensitivity and specificity analyses were used to evaluate the effectiveness of the previously proposed measures ("O-C2a change≤-5°" and "postoperative O-EAa<100°") for prediction of post-OCF dysphagia.

RESULTS

The incidence of dysphagia after OCF was 26.6% (29/109). Preoperative values for the radiographic parameters were similar between patients with and without dysphagia. In the dysphagia group, both O-C2a and O-EAa values showed a dramatic decrease after surgery, which was accompanied by a decrease in nPAS. Postoperative O-C2a, O-EAa, and nPAS in the dysphagia group were significantly smaller than those in the nondysphagia group (p<.05). The changes in O-EAa, O-C2a, and nPAS showed a linear correlation with the presence of dysphagia (p<.05). In addition, linear correlations were found between two of the three parameters. Multiple regression showed the change of O-C2a and O-EAa were significant predictors for dnPAS% (β=0.200, p=.022 and β=0.549, p=.000). The sensitivity and specificity of "O-C2a change≤-5°" in predicting dysphagia were 75.9% and 80.0% respectively, and those of "postoperative O-EAa<100°" were 75.9% and 62.5%, respectively. However, the sensitivity of the combination of these two values in predicting postoperative dysphagia was as high as 96.6%.

CONCLUSION

Both O-EAa and O-C2a could be critical predictors for postoperative dysphagia. During surgery, ensuring that the O-EAa exceeds 100° and simultaneously avoiding an O-C2a reduction greater than 5° could effectively avert postoperative dysphagia.

Role of O-C2 angle in the development of dysphagia in patients with halo-vest fixation

Background

Dysphagia is one of the most serious complications in patients treated with a halo-vest brace. However, the cause of dysphagia development by halo-vest fixation is not yet clear. We therefore investigated the incidence of dysphagia and cervical alignment as well as clinical data from medical charts in patients treated with a halo-vest brace.

Methods

We retrospectively reviewed clinical data from the medical charts of 49 patients who had undergone halo-vest fixation. Occipito (O)-C2 angle, C2-C6 angle, and pharyngeal inlet angle were assessed by lateral plain X-rays of the cervical spine. The impacts of these parameters on incidence and severity of dysphagia were analyzed.

Results

Thirteen patients (32%) suffered from dysphagia during halo-vest fixation, and age and length of intensive care unit (ICU) stay were greater in the dysphagia group (p = 0.044 and 0.013, respectively) than in those who did not develop dysphagia. O-C2 angle was smaller in the dysphagia group (p = 0.016). After multivariate logistic analysis, body mass index, ICU stay, and O-C2 angle remained as independent risk factors related to incidence of dysphagia. Spearman rank correlation showed a negative correlation between ICU stay and Food Intake Level Scale (FILS) (p = 0.026), and a positive correlation between O-C2 angle and FILS (p = 0.008).

Conclusion

This study suggested that O-C2 angle is related to both incidence and severity of dysphagia due to halo-vest fixation.

Impact of the occiput and external acoustic meatus to axis angle on dysphagia in patients suffering from anterior atlantoaxial subluxation after occipitocervical fusion

BACKGROUND CONTEXT

Dysphagia is a complication that sometimes occurs after occipitocervical fusion (OCF). An appropriate O-C2 angle (O-C2a) is recognized as a critical factor for preventing dysphagia. The occiput and external acoustic meatus to axis angle (O-EAa) has some advantages over the O-C2a and is now recognized to outperform O-C2a in predicting dysphagia. However, there are no data on this topic from patients with anterior atlantoaxial subluxation (AAS).

PURPOSE

To evaluate the relationship between the O-EAa and dysphagia in patients suffering from AAS after OCF surgery.

STUDY DESIGN

A retrospective clinical study.

PATIENT SAMPLE

Data from 22 consecutive AAS patients who had undergone OCF were reviewed retrospectively.

OUTCOME MEASURES

The outcome measures included the O-EAa, O-C2a, the narrowest oropharyngeal airway space (nPAS), and the morbidity of dysphagia after OCF.

METHODS

Between September 2011 and September 2017, data from 22 consecutive AAS patients who had undergone OCF were reviewed retrospectively. The patients were divided into two groups according to whether they had suffered postoperative dysphagia by face-to-face questioning or telephone interview. Lateral radiographs were analyzed to determine the pre- and postoperative O-EAa, O-C2a, angle formed by the inferior endplate of C2 and the EA-line (C2Ta), and smallest anteroposterior diameter of the oropharynx between the levels of the uvula and the tip of the epiglottis (nPAS).

RESULTS

The incidence of dysphagia after OCF was 18.18% (4/22). The pre- and postoperative mean nPAS values were significantly different between the groups (p<.05). The postoperative mean O-EAa of the group with dysphagia was significantly smaller than that of the group without dysphagia (p<.05). The mean change in nPAS was significantly larger in the group with dysphagia than that in the group without dysphagia (p<.05). The changes in the O-EAa, O-C2a, and nPAS were linearly correlated within patients. The marginal R² values for the patients were 0.452 and 0.202 for the O-EAa and O-C2a, respectively.

CONCLUSIONS

The O-EAa impacts dysphagia in patients with AAS after OCF. Measuring this angle intraoperatively may be a simple and effective procedure. The O-EAa may be used as a practical index to avoid postoperative dysphagia in patients with AAS after OCF.

Cervical Alignment of Anterior Cervical Hyperostosis Causing Dysphagia

STUDY DESIGN

Retrospective case control study.

OBJECTIVE

To investigate whether cervical alignment is related to dysphagia in patients with cervical diffuse idiopathic skeletal hyperostosis (DISH).

SUMMARY OF BACKGROUND DATA

DISH involves a wide range of ligamentous ossifications, which can cause dysphagia. However, even patients with a high degree of ossification can have only mild dysphagia. Dysphagia results from esophageal compression due to ossification; however, the exact cause of dysphagia is unknown.

METHODS

We reviewed five patients with advanced dysphagia due to anterior cervical hyperostosis who underwent resection (S group), and five patients with mild symptoms who were only monitored (NS group). The patients were evaluated using the Eating Assessment Tool-10 (EAT-10) and plain kinetic radiographs of the cervical spine. The O-C2 angle, M-C angle, C2-7 angle, and C2-6a angle were measured in the flexion, neutral, and extension positions. We compared these parameters in the S group versus the NS group, and compared the pre- and postoperative values in the S group.

RESULTS

The EAT-10 score indicated a high degree of dysphagia in the S group preoperatively (25 [22-27]) compared with the NS group (1 [1-6]). In the S group, the EAT-10 score significantly decreased postoperatively to 1 (0-1), and improvement of dysphagia was observed. There was a significant difference between the S and NS groups in the ΔC2-7 and ΔC2-6a, and between pre- and postoperative values in the S group. There were no significant changes in O-C2 angle and M-C angle, which are parameters of the superior cervical vertebrae.

CONCLUSION

The present results suggest that the restriction of flexion due to cervical spine ankylosis may be one of the reasons for dysphagia in patients with DISH.

LEVEL OF EVIDENCE

4.

The impact of the difference in O-C2 angle in the development of dysphagia after occipitocervical fusion: a simulation study in normal volunteers combined with a case-control study

BACKGROUND CONTEXT

Dysphagia has been recognized as one of the most serious complications after occipitocervical fusion (OCF), and the difference between postoperative and preoperative O-C2 angle (dO-C2A) was proposed to be an indicator in predicting and preventing dysphagia. Therefore, to prevent postoperative dysphagia, previous studies recommend that surgeons should correct the O-C2 angle (O-C2A) during surgery if the occipitocervical alignment was in an excessively flexed position. However, until now, there was no explicit indicator of the condition in which surgeons should adjust the patient's O-C2A during surgery.

PURPOSE

One of the purposes of this study was to explore the threshold of dO-C2A between dysphagia and normal swallowing by a simulation study. The other aim was to evaluate the validity of the threshold of dO-C2A in predicting dysphagia after OCF via a case-control study.

STUDY DESIGN

This is a simulation study combined with a retrospective case-control study.

PATIENT SAMPLE

Thirty volunteers were enrolled in the simulation study. Thirty-four consecutive patients who underwent OCF between September 2011 and September 2016 were included in the case-control study.

OUTCOME MEASURES

The outcome measures included O-C2A, C2-7 angle (C2-7A), atlantodental interval (ADI), the narrowest oropharyngeal airway space (nPAS), the rate of change in dnPAS (%dnPAS), and the prevalence of postoperative dysphagia.

MATERIALS AND METHODS

In the simulation study, each volunteer received two lateral x-rays of their cervical spine in neutral position and dysphagia position, respectively. We compared the radiographic parameters in neutral and dysphagia positions. The cumulative frequency diagram of dO-C2A in the dysphagia position was analyzed to identify the threshold of dO-C2A in the development of dysphagia. In the case-control study, these 34 patients were divided into two groups according to the threshold of dO-C2A identified in the simulation study. The impact of radiographic parameters on nPAS was analyzed. The prevalence of postoperative dysphagia between the two groups was compared to evaluate the validity of the threshold of dO-C2A in predicting dysphagia after OCF.

RESULTS

In the simulation study, the mean O-C2A and nPAS in the dysphagia position were significantly smaller than in the neutral position (p<.05). There was no significant difference between the mean C2-7A in the neutral and dysphagia positions (p>.05). There was a significant positive correlation between dO-C2A and dnPAS (p<.05). A dO-C2A of -5° delineated the threshold between normal swallowing and dysphagia. In the case-control study, multiple regression analysis showed that dO-C2A was the only significant variable correlated with dnPAS (β=0.769, p<.001). Among the reviewed 34 patients, the incidence of dysphagia was 17.6% (6/34) at 2 weeks after surgery and decreased over time to 11.8% (4 of 34) at the last follow-up. There was also a significant positive correlation between the dO-C2A and dnPAS (p<.05). The prevalence of dysphagia after OCF in patients with dO-C2A<-5° was as high as 66.7% (6/9). However, there was no patient suffering from dysphagia in patients with dO-C2A≥-5°.

CONCLUSION

The present study showed that the dO-C2A should be a key factor in the development of postoperative dysphagia after OCF. A dO-C2A of -5° could be the threshold between dysphagia and normal swallowing. Furthermore, to avoid dysphagia, surgeons should correct the O-C2A just before the final occipitocervical fixation if the checked dO-C2A during surgery is less than -5°.