Effect of hospital volume of thyroidectomies on outcomes following substernal thyroidectomy.

BACKGROUND: Substernal thyroidectomy (ST), as compared to conventional, cervical thyroidectomy, is a technically demanding procedure that is associated with increased morbidity and mortality. We tested the hypothesis that outcomes following ST are improved at centers that perform a high volume of thyroidectomies.
METHODS: Patients who underwent ST from 1998 to 2004 were extracted from the New York State Statewide Planning and Research Cooperative System database. Hospital volume of thyroidectomies was divided into low (<33 per year), middle (33-99 per year), and high (>or=100 per year) volumes. Outcome variables included hospital length of stay (LOS), recurrent laryngeal nerve (RLN) injury, hypoparathyroidism, postoperative bleeding, respiratory failure, blood transfusion, and mortality.
RESULTS: A total of 1153 STs were analyzed; 372 (32.2%) were performed at low-volume centers, 388 (33.7%) at middle-volume centers, and 393 (34.0%) at high-volume centers. Linear associations were observed between increasing hospital volume of thyroidectomies and decreasing age (p=0.003), increasing co-morbidity (p<0.0001), increased likelihood of total versus subtotal thyroidectomy (p<0.0001), and increased likelihood of thyroid malignancy (p<0.0001). Despite this, increasing hospital volume of thyroidectomies predicted a decreased likelihood of overall complications (p=0.005), postoperative bleeding (p=0.01), blood transfusion (p=0.04), respiratory failure (p=0.04) and mortality (p=0.004), as well as a trend toward a decreased LOS (p=0.06). The overall complication rate and the mortality rate remained significantly associated with volume group by multivariate analysis.
CONCLUSION: Despite more extensive surgery on patients with greater co-morbidity, LOS, morbidity, and mortality were all decreased when ST occurred at hospitals that perform a high volume of thyroidectomies.