Superficial Parotidectomy: Impact of Postoperative Drainage.

Background: Use of suction drain after superficial parotidectomy (SP) is based on national consensus considered best practice, but there is no evidence on the effect of the treatment. The aim of the present study is to evaluate the effectiveness of drainage after SP by evaluating the rate of complications after SP in relation to the (ie, duration) of drainage and tumor size.
Methods: Retrospective analysis was performed involving data from all consecutive patients undergoing SP at the Ear, Nose, and Throat department, Regional Hospital West Jutland, Denmark, between January 1, 2011, and December 31, 2017. Demographics including comorbidity, medication, tumor size, postoperative secretion through the drainage, as well as complications (hematoma, seroma, infection, fistulas, Frey syndrome, facial nerve palsy) were registered. Patients with secretion below 25 mL were compared to patients with secretion above 25 mL, that is, drainage less than 24 hours versus longer than 24 hours. Results : Two hundred five consecutive patients undergoing SP were enrolled. The overall risk of postoperative infection was 16.2%. Ten of 33 patients with infection were also diagnosed with an hematoma or seroma. The risk of infection increased with secretion above 25 mL (27.2%) compared to patients with less than 25 mL (13.1%; P = .0318). The same accounts for the risk of seromas/hematomas ( P = .0055). We found no evidence that demographics or comorbidity correlated to the secretion in the drainage, but there is a tendency toward male gender having a higher risk off secretion above 25 mL (odds ratio 1.39).
Conclusion: Overall, the risk of complications after SP increased with secretion beyond 25 mL (ie, drainage for more than 24 hours). This applied in particular to infections and seromas/hematomas demanding treatment. The use of routine drainage after SP is questionable, and a randomized trial is warranted to unravel the necessity of postoperative drainage.