Predictors of morbidity and mortality among patients with cervical spondylotic myelopathy treated surgically

Abstract

Purpose: The aim of this study is to report and quantify the associated factors for morbidity and mortality following surgical management of cervical spondylotic myelopathy (CSM).

Methods: The Nationwide Inpatient Sample (NIS) database was use to retrospectively review all patients over 25 years of age with a diagnosis of CSM who underwent anterior and/or posterior cervical fusion or laminoplasty between 2001 and 2010. The main outcome measures were total procedure-related complications and mortality. Multivariate regression analysis was used to identify demographic, comorbidity, and surgical parameters associated with increased morbidity and mortality risk [reported as: OR (95% CI)].

Results: A total of 54,348 patients underwent surgical intervention for CSM with an overall morbidity rate of 9.83% and mortality rate of 0.43%. Comorbidities found to be associated with an increased complication rate included: pulmonary circulation disorders [6.92 (5.91-8.12)], pathologic weight loss [3.42 (3.00-3.90)], and electrolyte imbalance [2.82 (2.65-3.01)]. Comorbidities found to be associated with an increased mortality rate included: congestive heart failure [4.59 (3.62-5.82)], pulmonary circulation disorders [11.29 (8.24-15.47)], and pathologic weight loss [5.43 (4.07-7.26)]. Alternatively, hypertension [0.56 (0.46-0.67)] and obesity [0.36 (0.22-0.61)] were found to confer a decreased risk of mortality. Increased morbidity and mortality rates were also identified for fusions of 4-8 levels [morbidity: 1.55 (1.48-1.62), mortality: 1.80 (1.48-2.18)] and for age >65 years [morbidity: 1.65 (1.57-1.72), mortality: 2.74 (2.25-3.34)]. An increased morbidity rate was found for posterior-only [1.55 (1.47-1.63)] and combined anterior and posterior fusions [3.20 (2.98-3.43)], and an increased mortality rate was identified for posterior-only fusions [1.87 (1.40-2.49)]. Although revision fusions were associated with an increased morbidity rate [1.81 (1.64-2.00)], they were associated with a decreased rate of mortality [0.24 (0.10-0.59)].

Conclusion: The NIS database was used to provide national estimates of morbidity and mortality following surgical management of CSM in the United States. Several comorbidities, as well as demographic and surgical parameters, were identified as associated factors.

Keywords: Cervical spondylotic myelopathy; Morbidity; Mortality; NIS database.