A review of risk factors and timing for postoperative hematoma after thyroidectomy: is outpatient thyroidectomy really safe?
BACKGROUND
Although postoperative hematoma after thyroidectomy is uncommon, patients traditionally have been advised to stay overnight in the hospital for monitoring. With the growing demand for outpatient thyroidectomy, we assessed its safety and feasibility by evaluating the potential risk factors and timing of postoperative hematoma after thyroidectomy.


METHODS
From 1995-2011, 3,086 consecutive patients underwent thyroidectomy at our institution; of these, 22 (0.7 %) developed a postoperative hematoma that required surgical reexploration (group I). Potential risk factors were compared between group I and those without hematoma (n = 3,045) or with hematoma but not requiring reexploration (n = 19; group II). Variables that were significant in the univariate analysis were entered into multivariate analysis by binary logistic regression analysis.


RESULTS
Group I was significantly more likely to have undergone previous thyroid operation than group II (27.3 vs. 8.2 %, p = 0.007). The median weight of excised thyroid gland (71.8 vs. 40 g, p = 0.018) and the median size of the dominant nodule (4.1 vs. 3 cm, p = 0.004) were significantly greater in group I than group II. Previous thyroid operation (odds ratio (OR) = 4.084; 95 % confidence interval (CI), 1.105-15.098; p = 0.035) and size of dominant nodule (OR = 1.315; 95 % CI, 1.024-1.687; p = 0.032) were independent factors for hematoma. Sixteen (72.7 %) had hematoma within 6 h, whereas the other 6 (27.3 %) had hematoma at 6-24 h.


CONCLUSIONS
Previous thyroid operation and large dominant nodule were independent risk factors for hematoma requiring surgical reexploration. Given that a quarter of hematoma occurred between 6 to 24 h after surgery, routine outpatient thyroidectomy could not be recommended.
Department of Surgery, The University of Hong Kong, Hong Kong SAR, China. blang@hkucc.hku.hk
Brian Hung-Hin
BH
Lang
Patricia Chun-Ling
PC
Yih
Chung-Yau
CY
Lo
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000556:Ambulatory Surgical Procedures / Q000009:adverse effects*; D002648:Child; D005240:Feasibility Studies; D005260:Female; D006406:Hematoma / Q000453:epidemiology* / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D013965:Thyroidectomy / Q000009:adverse effects*; D013997:Time Factors; D055815:Young Adult