J. R. Imbus1, Y. Shan1, N. Brys1, G. Leverson1, J. Havlena1, N. Zaborek1, S. Pitt1, D. F. Schneider1 1University Of Wisconsin,Surgery,Madison, WI, USA
Introduction:
Following thyroid lobectomy, patients may require a completion thyroidectomy (CT) to remove the remaining thyroid tissue. To avoid the possibility of CT, patients may prefer or be advised to undergo total thyroidectomy (TT) instead. The frequency of CT and associated risks are not well established, but potentially influenced by patient- and hospital-level factors. The purpose of this study is to determine the incidence, factors, and complications associated with CT.
Methods:
We identified adult patients who underwent thyroidectomy for benign disease using the Healthcare Cost and Utilization Project State Inpatient Databases and State Ambulatory Surgery and Services Databases for Florida and New York from 2011-2013. We defined the CT cohort as patients undergoing two thyroid operations within 133 days (85th percentile). Multilevel logistic regression identified hospital and patient-level factors associated with undergoing CT (vs definitive lobectomy or TT), as well as factors associated with complications occurring within 30 days post-operatively.
Results:
Of all 37,282 patients (definitive lobectomy, CT, and TT), 4.6% (n = 1,713) underwent CT. Compared to urban hospitals, CT frequency was higher in rural hospitals (7.3% vs 4.5%, p < 0.001) whereas TT was less frequent (21.4% vs 39.9%, p<0.001). CTs were less common in black patients (3.1% vs 4.7%, p <0.001) compared to white patients. Black patients underwent more TTs (47% vs 37%, p < 0.01) compared to white patients. After adjustment for patient and hospital-level factors, rural hospitals (vs urban hospitals) were associated with CT (OR 1.77, 95% CI 1.16-2.71, p < 0.01). Compared to whites, blacks were less likely to undergo CT (OR 0.66, 95% CI 0.56-0.79, p < 0.001).
¶ Rates of hematoma (0.8% vs 1.3%, p=0.1) and RLN injury (0.8% vs 0.8%, p=0.99) in CT did not differ from TT, but hypocalcemia was less frequent (5.6% vs 7.9%, p<.001). Additional multilevel modeling revealed that post-operative complications (hypocalcemia, RLN injury, or hematoma) were associated with Charlerson co-morbidity index greater than 1 (p<0.001) for patients undergoing CT or TT. In this cohort, complications were nearly 70% less likely for outpatient operations (OR 0.28, 95% CI 0.24-0.33, p<0.001,). Age over 45 years was associated with decreased odds of complications (p<0.001), and patients undergoing CT were less likely to have a complication compared to patients undergoing TT (OR 0.79, 95% CI 0.63-0.98). Black patients undergoing either CT or TT were twice as likely to suffer a RLN injury compared to white patients (OR 2.03, 95% CI 1.32-3.13, p<0.01).
Conclusion:
In two large states, the rates of CT are expected based on thyroid cancer incidence and treatment guidelines. Higher rates of CT in rural hospitals appears related to less extensive use of initial TT. More frequent index TT may explain lower rates of CT in black patients, as well as their vulnerability to RLN injury.