## 5 Treatment of Deep Neck Infections Associated with Descending Necrotizing Mediastinitis
### Surgical Treatment  
Deep neck infection (cervicomediastinal suppuration) remains a frequent condition that can be life-threatening. Knowledge of the complex spaces of the neck and how they communicate is necessary for proper surgical management. The location of the infection can provide information regarding the source of the infection and the likely microorganisms that need to be covered when empiric therapy is instituted [46]. Infections of the deep cervical spaces of the neck, in the case of their extension and propagation to several spaces along the cervical fascia, require aggressive surgical treatment through the drainage and debridement of the tissues involved [65]. Knowledge of the anatomy of and relationships between the deep spaces of the neck is necessary for the adequate drainage of the neck during incision and debridement [58]. The drainage of these spaces, which is visualized in CT examination, is performed through incisions on the edge of the bilateral sternocleidomastoid muscle and the vascular bed, and the internal face of the sternocleidomastoid muscle is approached. If the peripharyngeal or perilaryngeal muscles are involved, the spaces are drained with gentle, sometimes digital, removal in this area. There is a debate in the literature regarding non-surgical management or minimally invasive intervention (aspiration and drainage by radiological guidance). Percutaneous echo-guided drainage has been concluded to be an effective treatment for well-defined unilocular abscesses [47]. In recent studies, in the case of well-defined unilocular abscesses, in patients who do not require securing of the airway, minimally invasive techniques have been practiced. The drainage of percutaneously accessible abscesses is conducted via ultrasound guidance, and the approach to deep abscesses is conducted through CT guidance and needle aspiration. Needle aspiration and catheter placement offer the advantages of a small entry point, rapid healing time, no scarring, and a lower risk of contamination of surrounding deep spaces while draining pus [66]. Conservative management of a deep neck abscess with intravenous antibiotics, with or without needle aspiration, is used more often in the pediatric population. In a recent study by [PERSON] et al., adult patients had a significantly higher risk of morbidity and mortality if surgery was delayed, with a 2.4-fold increase in risk if surgery occurred after day 2 of hospitalization [58]. The external cervical approach is the most frequently used for DNI drainage, especially when several cervical spaces are involved, with the most important and difficult to access space being the retropharyngeal space. In the case of DNI with DNM, wide detachment and the total debridement of the necrotic tissue are necessary for a favorable evolution [35; 39]. Surgery remains the main treatment for more complicated or severe cases of cervical suppuration. Indications for surgery include airway compromise, critical condition, septicmia, complications, downstream infection, diabetes mellitus, or situations in which no clinical improvement is noted within 48 h of the initiation of parenteral antibiotics [6; 36; 37; 55]. For abscesses greater than 3 cm in diameter involving the prevertebral and carotid spaces or involving more than two spaces, surgical drainage is recommended [33]. The decision to perform a tracheotomy is made at the time of establishing the management of the case of cervical suppuration. Affected areas requiring extensive debridement should be kept open with antimicrobial dressings to allow frequent inspection and debridement. In cases where the infections extend downward, it is observed whether the infection spreads below the carina; at that moment, transthoracic drainage is necessary, involving a mixed team with a thoracic surgeon [54]. After the wound and tissues have been debrided and thoroughly examined, the region is irrigated with copious amounts of sterile saline until purulent discharge is no longer observed.