Advancing Education, Research, and Quality of Care for the Head and Neck oncology patient.
Introduction: Thyroidectomy is one of the most common open neck surgeries performed by head & neck surgeons, general otolaryngologists and endocrine surgeons. While risks of thyroidectomy are well-documented, it is unclear how prior neck interventions might affect the rates of certain common or important complications. These pre-thyroidectomy interventions may include prior neck soft tissue surgeries, cervical spine surgery and neck irradiation. Understanding how these previous treatments influence outcomes is important for managing patient expectations and guiding clinical decision making when planning thyroid surgery. This study sought to compare postoperative outcomes between patients with and without prior neck interventions.
Methods: A retrospective cohort study was conducted using the TrinetX Research database. All patients in the study underwent total thyroidectomy. Cases were stratified based on additional pre-thyroidectomy interventions including tracheotomy, neck dissection, anterior cervical discectomy and fusion (ACDF), and neck radiotherapy. Cohorts were first propensity matched for patient age and gender. Risk ratios (RR) with 95% confidence intervals (CI) were calculated for postoperative hypoparathyroidism, recurrent laryngeal nerve injury, wound infection, hematoma and readmission.
Results: The analysis identified 102,848 patients who underwent total thyroidectomy and 913 patients who had undergone prior tracheotomy, neck dissection, ACDF or neck radiation. Patients with any neck intervention prior to thyroidectomy had a significantly higher risk of recurrent laryngeal nerve injury (RR: 1.512, 95% CI: 1.031-2.218, p = 0.0329) and hypoparathyroidism (RR: 1.804, 95% CI: 1.274-2.555, p = 0.0007) compared to controls. The risk of hypoparathyroidism was significant higher in patients who had previously undergone tracheotomy (RR: 2.167, 95% CI: 1.27-3.695, p = 0.0034) and neck dissection (RR: 1.824, 95% CI: 1.027-3.237, p = 0.0367). Patients with prior neck dissection also experienced a higher rate of recurrent laryngeal nerve injury after thyroidectomy (RR: 1.824, 95% CI: 1.027-3.237, p = 0.0367). Prior ACDF and prior radiotherapy did not have a significant impact on any of the risk factors evaluated. Similarly, no prior neck interventions were found to have a significant influence on rates of hematoma, wound infection or readmission rates.
Discussion: Our findings demonstrated that risk of hypoparathyroidism and recurrent laryngeal nerve injury were most significantly affected after thyroidectomy in patients who had previously undergone neck intervention. In particular, prior neck dissection and prior tracheotomy were shown to increase the risk of hypoparathyroidism. Recurrent laryngeal nerve injury rates were uniquely influenced by prior neck dissection. It is possible that rates of wound infection, hematoma and readmission were not affected by prior intervention because these occurred at quite low numbers in general. Similarly, the lack of impact on complication rates by prior radiotherapy and ACDF may have been biased by low sample sizes in our cohort.