Deep neck infection (DNI) is associated with morbidity and mortality. Surgical incision and drainage (I&D) of DNI abscesses are essential. Refractory abscesses require repeat I&D. Few studies have assessed the risk factors associated with repeat I&D; here, we investigated such factors. In total, 605 patients with DNI were enrolled between July 2016 and February 2022. Of these patients, 107 underwent repeat I&D. Clinical variables were assessed. On univariate analysis, a high blood sugar level (odds ratio (OR) = 1.006, p < 0.001), the involvement of at least four neck spaces (OR = 15.44, p < 0.001), and mediastinitis (OR = 1.787, p = 0.040) were significant risk factors for repeat I&D. On multivariate analysis, a high blood sugar level (OR = 1.005, p < 0.001) and the involvement of at least four neck spaces (OR = 14.79, p < 0.001) were significant independent risk factors for repeat I&D. Patients who required repeat I&D had longer hospital stays and a higher tracheostomy rate than did other patients (both p < 0.05). The pathogens did not differ between patients who did and did not require repeat surgical I&D (all p > 0.05), but the rates of pathogen non-growth from blood cultures were 19.47% (97/498) in the group without a need for repeat I&D and 0.93% (1/107) in the group with such a need (p < 0.001). DNI can be fatal; a higher blood sugar level and the involvement of at least four neck spaces were independent risk factors for repeat surgical I&D. If at least four neck spaces are involved, we recommend controlling the blood sugar level after admission. We found significant differences in the length of hospital stay and the need for tracheostomy between groups who did and did not require repeat surgical I&D. Although the pathogens did not differ between the groups, pathogen non-growth from blood cultures was less common in the group with for repeat surgical I&D than in the group without such a need.
Keywords: blood sugar; deep neck infection; incision and drainage; multiple space involvement; re-operation.