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

The Postoperative Airway Compromise Score-First Steps to Developing a Postoperative Tool for the Assessment of Upper Airway-Related Complications Following Anterior Cervical Spine Surgery

BACKGROUND

Acute upper airway compromise is a rare but catastrophic complication after anterior cervical discectomy and fusion. This study aims to develop a score to identify patients at risk of acute postoperative airway compromise (PAC).

METHODS

Potential risk factors for acute PAC were selected by a modified Delphi process. Ten patients with acute PAC were identified of 1466 patients who underwent elective anterior cervical discectomy and fusion between July 2014 and May 2019. A comparison group was created by a randomized selection process (non-PAC group). Factors associated with PAC and a P value of < 0.10 were entered into a logistic regression model and coefficients contributed to each risk factor's overall score. Calibration of the model was evaluated using the Hosmer-Lemeshow goodness-of-fit test. Quantitative discrimination was calculated, and the final model was internally validated with bootstrap sampling.

RESULTS

We identified 18 potential risk factors from our Delphi process, of which 6 factors demonstrated a significant association with airway compromise: age >65 years, current smoking status, American Society of Anesthesiologists class >2, history of a bleeding disorder, surgery of upper subaxial cervical spine (above C4), and duration of surgery >179 minutes. The final prediction model included 5 predictors with very strong performance characteristics. These 5 factors formed the PAC score, with a range from 0 to 100. A score of 20 yielded the greatest balance of sensitivity (80%) and specificity (88%).

CONCLUSIONS

The acute PAC score demonstrates strong performance characteristics. The PAC score might help identify patients at risk of upper airway compromise caused by surgical site abnormalities.

An anatomical study of the pharyngeal plexus: Application to avoiding postoperative dysphagia following anterior approaches to the cervical spine

We aimed to localize the pharyngeal branches of the pharyngeal plexus to preclude postoperative complications such as dysphagia resulting from injury to those branches. Cranial nerves IX and X and the sympathetic trunk were dissected on 10 sides in the necks of embalmed adult cadavers of European descent to identify the pharyngeal branches so that anatomical landmarks could be identified and injury thereby avoided. In all sides, the pharyngeal branches originated from the glossopharyngeal and vagus nerves and the superior cervical ganglion and entered the posterior pharyngeal wall at the C2-C4 levels within 10 mm medial to the greater horn of the hyoid bone. All pharyngeal branches were anterior to the alar fascia. Based on our anatomical study, vagus nerve branches to the pharyngeal muscles enter at the C3/C4 vertebral levels. Such knowledge might help decrease or allow surgeons to predict which patients are more likely to develop dysphagia after cervical spine surgery.