Preoperative carotid ultrasound in degenerative cervical myelopathy: from routine screening to selective use

To determine the prevalence and clinical relevance of carotid atherosclerosis in patients undergoing surgery for degenerative cervical myelopathy (DCM). Specifically, to identify clinical and radiographic predictors of carotid plaque, to develop and internal-temporal validate a nomogram to guide selective preoperative carotid ultrasound screening, and to explore the association between carotid disease and both neurological recovery and global patient-reported outcome.

We conducted a single-center retrospective prognostic cohort study of 160 consecutive patients who underwent cervical decompression for DCM between January 2017 and February 2023, all with ≥ 2 years of follow-up. Patients treated from 2017 to 2021 (n = 104) formed the development cohort, and those treated from 2021 to 2023 (n = 56) constituted a temporally distinct internal-temporal validation cohort from the same institution. Preoperative carotid ultrasonography classified patients by (1) presence of carotid plaque and (2) carotid stenosis severity (none/mild vs. moderate/severe, ≥ 50%). Clinical, biochemical, radiographic, and outcome measures-including mJOA recovery rate and modified Macnab criteria (excellent/good vs. fair/poor)-were compared between groups. In the development cohort, variables with p < 0.05 in univariable analyses entered multivariable logistic regression to identify independent predictors of carotid plaque and construct a nomogram. Model performance was assessed by the area under the receiver operating characteristic curve (AUC), calibration plots, and decision curve analysis (DCA) in both cohorts. Bootstrap-based internal validation with 1,000 resamples was additionally performed for the final prediction model in the development cohort.

Overall, 94 of 160 patients (58.8%) had carotid plaque and 39 (24.4%) had moderate/severe carotid stenosis. In the development cohort, the plaque group was older, had higher body mass index (BMI), more vertigo and hypertension, greater C2-C7 Cobb angle (CL), more moderate/severe stenosis, and a lower proportion of excellent/good outcomes by modified Macnab criteria than the normal group (p < 0.05). Multivariable analysis identified age, BMI, vertigo, and CL as independent predictors of carotid plaque; each 1-year increase in age increased the odds of plaque by 13.7% (odds ratio 1.137, p < 0.001). These four variables were incorporated into a nomogram. The model showed good discrimination in the development cohort (apparent AUC 0.863; optimism-corrected AUC 0.838) and internal-temporal validation cohort (AUC 0.892), with acceptable calibration. DCA in both cohorts demonstrated greater net benefit for nomogram-guided selective screening than for "screen-all" or "screen-none" strategies across a clinically relevant range of threshold probabilities.

Carotid atherosclerotic plaque is common in patients undergoing surgery for DCM and is independently associated with age, BMI, vertigo, and increased cervical lordosis. These findings do not support mandatory preoperative carotid ultrasound screening for all DCM patients. A nomogram-based selective screening strategy using these four readily available variables may provide a practical framework for risk stratification, but its clinical utility should be interpreted cautiously pending stronger outcome-based evidence and external validation.