Diagnostic performance of transcutaneous laryngeal ultrasound for vocal cord paralysis after esophagectomy: a systematic review and meta-analysis.

Vocal cord paralysis (VCP) caused by recurrent laryngeal nerve injury is a common complication following esophagectomy, particularly in patients undergoing minimally invasive esophagectomy (MIE). It may lead to dysphonia, aspiration, and pneumonia, significantly impacting recovery and prognosis. Transcutaneous laryngeal ultrasound (TLUSG) has emerged as a non-invasive tool for evaluating vocal cord function; however, its diagnostic performance relative to endoscopy remains unclear. Following PRISMA 2020 guidelines, we conducted a systematic search of PubMed, Embase, and Web of Science through January 2025. Studies comparing TLUSG with endoscopy in patients after esophagectomy were included. Two independent reviewers screened articles, extracted data (e.g., patient demographics and diagnostic measures), and assessed study quality using the QUADAS-2 tool. Pooled diagnostic metrics including sensitivity, specificity, diagnostic odds ratio (DOR), and area under the curve (AUC) were calculated using RevMan and Stata. Subgroup analyses were performed to explore the impact of inspection timing, reference standard, gender ratio, and age. Five studies involving 286 patients were included. The pooled sensitivity and specificity of TLUSG were 0.79 (95% CI: 0.55-0.92) and 0.95 (95% CI: 0.79-0.99), respectively. The DOR was 65.53 (95% CI: 17.41-246.75), and the AUC was 0.95, indicating excellent diagnostic accuracy. The overall vocal cord visualization rate was 92.3%, and the pooled incidence of VCP was 29%. Subgroup analysis showed that inspection timing, reference standard, and gender ratio influenced diagnostic accuracy, while age had no significant effect. Deeks' funnel plot revealed no evidence of publication bias, though the small number of studies limits definitive conclusions. TLUSG demonstrates relatively good diagnostic performance in detecting postoperative VCP. However, a non-negligible false-negative rate (approximately 20%) remains, warranting cautious interpretation in clinical settings, especially for high-risk patients. Further prospective multicenter studies are needed to standardize TLUSG protocols and improve visualization, particularly in elderly patients.