Patients and methods
After obtaining approval from the Institutional Review Board of our institution, retrospective chart reviews were undertaken for patients with DNI between March 2006 and June 2019. Among these patients, those who had shown downward involvement of necrotizing mediastinitis on chest CT were selected. Patients with mediastinitis resulting from an iatrogenic esophageal perforation and cervical spine fracture were excluded. Data including personal demographics, image studies, laryngoscopy findings, anesthesia records, operation records, and hospital courses were carefully collected. Initial status of upper airway was evaluated with a flexible laryngoscope (Machida Instruments, Tokyo, Japan) on an emergency basis. Details of difficult airway and orotracheal intubations were graded based on the anesthesiologist’s report, estimating difficulty of laryngeal exposure and intubation time.
All patients initially received empirical broad-spectrum intra-venous antibiotics such as ceftriaxone and clindamycin after neck infection was identified on CT. Once the causative pathogen was cultured, antibiotics were adjusted according to results of sensitivity tests.
Patients were evaluated according to Endo and colleagues’ classification about the degree of diffusion of DNM based on chest CT findings. For type I, the infection was localized in the upper mediastinum above the carina. For type IIA, the infection extended to the lower anterior mediastinum. For type IIB, the infection extended to lower anterior and posterior portions of the mediastinum.3 Involved cervical spaces were opened, drained, and debrided of necrotic tissues. Various types of mediastinal drainage including transcervical, lateral thoracotomy approach, and video-assisted thoracic surgery (VATS) were selected according to Endo classification.