S024

Malignancy but not lymph node dissection or thyroid size predict inadvertent parathyroidectomy during thyroid surgery

Ioannis Christakis, Vasileios Constantinides, Neil Tolley, Fausto Palazzo

Background

Inadvertent parathyroidectomy (IP) during thyroidectomy is common. The purpose of this study was to seek to identify the preventable risk factors and outcomes.

Methods

This is a retrospective review using prospectively collected data on thyroidectomies performed in a single UK hospital from January 2006 to January 2011. The clinical records and operative reports were accessed for patient demographic data, diagnosis, operative details, and total duration of hospital stay.

Results

A total of 260 patients met the inclusion criteria. The M/F ratio was 1:41 with a mean age of 49.4 years. The pre-operative diagnosis was benign pathology in 89.2% of cases and malignant in 10.8% (Figure 1). In 11.5% a parathyroid gland was identified in the thyroid specimen. In an additional 6.5% some microscopic parathyroid tissue was identifiable. The true intrathyroidal PG incidence was 0.77%.  In the Multivariate analysis only malignancy was found to be a risk factor for IP (p=0.023). In the Univariate analysis, lymph node dissection (L.N.D) was significant (p=0.001) and thyroid weight was also seen to approach significance (p=0.062) for IP. In the IP group, temporary hypocalcemia occurred in 14.89% and permanent hypoparathyroidism in 3.33%.Average length of stay for the IP group was 2 days.

Conclusion

A pre-operative diagnosis of malignancy but not lymph node dissection or thyroid size is a statistically significant predictor of IP.