# APBA Kısa Özet

This systematic review and meta-analysis of 11 primary studies (6,142 patients) quantifies the burden of difficult airway (9.4%), surgical morbidity (21.3%), tracheal invasion (28.7% in locally advanced cases), and mediastinal extension (18.3% in retrosternal cases) in thyroid cancer. CT imaging shows pooled sensitivity of 61.4% and specificity of 90.8% for tracheal invasion. The authors emphasize the need for multidisciplinary preoperative assessment, advanced airway planning, and intraoperative neuromonitoring in high-risk cases.

# Çalışma neyi araştırdı?

This systematic review and meta-analysis aimed to quantitatively synthesize evidence on diagnostic performance, perioperative airway management, surgical outcomes, and mediastinal extension in thyroid cancer, with emphasis on locally advanced and complex disease reported between January 2021 and January 2026. A systematic review and meta-analysis were conducted in accordance with PRISMA 2020 guidelines and the MOOSE framework. PubMed/MEDLINE, Scopus, Web of Science, Cochrane Library, and Embase were searched. Studies reporting original data on diagnostic test accuracy, airway management, surgical outcomes, or mediastinal involvement in thyroid cancer patients were included. Studies were excluded if they were reviews, comments, or lacked quantitative data. A total of 11 primary studies encompassing 6,142 patients were eligible for final synthesis.

# Yöntem

The methodological approach followed established guidelines for systematic reviews and meta-analyses. The search strategy encompassed five major databases (PubMed/MEDLINE, Scopus, Web of Science, Cochrane Library, and Embase) from inception until January 2026, using a combination of MeSH terms and free-text keywords related to thyroid cancer, airway management, surgical strategies, and mediastinal extension. Study selection was performed independently by two reviewers, with discrepancies resolved through consensus. Data extraction focused on study characteristics, patient demographics, diagnostic test results (sensitivity/specificity of CT for tracheal invasion), airway events (incidence of difficult airway), surgical morbidity rates, and mediastinal extension rates. Statistical synthesis was performed using random-effects models to account for expected heterogeneity. Pooled odds ratios with 95% confidence intervals were calculated for dichotomous outcomes. Heterogeneity was quantified using the I² statistic, and subgroup analyses were explored based on study design, geographic region, and tumor stage. Risk of bias was assessed using the Cochrane Risk of Bias tool for randomized trials and the ROBINS-I tool for non-randomized studies. The review adhered to the PRISMA 2020 statement and the MOOSE (Meta-analysis Of Observational Studies in Epidemiology) guidelines throughout.

# Temel bulgular

  • Difficult Airway Incidence: The pooled incidence of difficult airway in thyroid cancer patients was 9.4% (95% CI: 6.1-14.2%; I² = 61.3%).
  • Overall Surgical Morbidity: Overall surgical morbidity in included thyroid cancer studies was 21.3% (95% CI: 16.8-26.5%; I² = 72.6%).
  • Tracheal Invasion in Locally Advanced Cases: Tracheal invasion was present in 28.7% (95% CI: 21.4-37.3%) of locally advanced thyroid cancer cases.
  • Mediastinal Extension in Retrosternal Cases: Mediastinal extension requiring thoracic surgical access occurred in 18.3% (95% CI: 12.7-25.7%) of retrosternal thyroid cancer cases.
  • CT Diagnostic Performance: Computed tomography demonstrated a pooled sensitivity of 61.4% and specificity of 90.8% for tracheal invasion detection.
  • Heterogeneity Assessment: Significant heterogeneity was observed across studies, with I² values reaching up to 72.6% for surgical morbidity and 61.3% for difficult airway, indicating variability in patient populations, diagnostic criteria, and surgical techniques.

# Bulgular ne anlama geliyor?

The quantified outcomes underscore the clinical complexity of managing thyroid cancer, particularly in locally advanced and retrosternal presentations. A difficult airway incidence of 9.4% suggests that a subset of patients will require specialized anesthetic techniques, prompting the recommendation for preoperative airway assessment and the availability of advanced airway equipment (e.g., fiberoptic intubation, video laryngoscopy) in all thyroidectomy cases. The 21.3% surgical morbidity rate highlights that complications remain a significant concern, advocating for continuous refinement of surgical techniques and perioperative care pathways. A tracheal invasion rate of 28.7% in locally advanced disease emphasizes the critical role of imaging in tumor staging and the potential need for combined surgical approaches. Furthermore, the 18.3% rate of mediastinal extension in retrosternal cases suggests that thoracic surgical teams should be prepared for potential intraoperative collaboration. Finally, the CT performance data (61.4% sensitivity, 90.8% specificity) indicates that while CT is a valuable non-invasive tool for detecting tracheal invasion, it is not infallible, and histopathologic confirmation or adjunctive imaging may be necessary in equivocal cases.

# Klinik önem

The clinical implications of these findings are multifaceted. First, the identification of a non-trivial difficult airway incidence mandates that anesthesiologists incorporate thorough preoperative airway assessment into the standard thyroid cancer workup, particularly for patients with large goiters, retrosternal extension, or prior neck radiation. Second, the substantial surgical morbidity rate calls for a multidisciplinary tumor board approach preoperatively to optimize surgical planning, potentially involving otolaryngologists, thoracic surgeons, and radiologists. Third, the high prevalence of tracheal invasion in locally advanced cases supports the use of CT with contrast as a routine staging modality, although the moderate sensitivity warrants correlation with clinical examination and, when necessary, direct laryngoscopy or bronchoscopy. Fourth, the significant rate of mediastinal extension argues for the inclusion of thoracic surgeons in the care algorithm for retrosternal thyroid cancers, ensuring that airway and vascular structures are adequately addressed. Overall, these data support the implementation of a standardized, multidisciplinary care pathway for thyroid cancer patients, particularly those with advanced disease, to improve perioperative safety and long-term oncologic outcomes.

# Sınırlılıklar

The authors acknowledge several limitations that temper the interpretation of the results. Primary among these is the heterogeneity across the included studies, as evidenced by high I² values, which may reflect differences in patient demographics, definitions of difficult airway, surgical techniques, and reporting standards. The relatively small number of primary studies (n=11) limits the generalizability of the findings and reduces the statistical power for subgroup analyses. Most of the included primary studies were retrospective in design, introducing potential selection bias and information bias. Additionally, potential publication bias was not explicitly assessed using funnel plots or statistical tests. Finally, variability in diagnostic criteria for tracheal invasion and variability in surgical techniques across different medical centers may have influenced the pooled estimates, necessitating cautious interpretation of the synthesized data and highlighting the need for future prospective, multicenter studies with standardized protocols.