Summary
Descending necrotizing mediastinitis (DNM) is caused by aerobic and anaerobic bacteria as a rare but severe complication of oropharyngeal abscesses developing secondary to odontogenic infections. Patients with hypersensitivity reaction to beta-lactam antibiotics pose challenges in the treatment. To our knowledge, only two cases of postoperative mediastinitis treated with tigecycline have been reported in the English medical literature to date. In this paper, we present a case of descending mediastinitis developing one week after dental extraction. The patient was given tigecycline treatment with the diagnosis of complicated deep neck infection, which progressed to descending mediastinitis because of severe allergic reaction to beta-lactam group antimicrobials. He successfully recovered after early surgical drainage and debridement together with four weeks of tigecycline therapy. Tigecycline may be an alternative option for treatment of odontogenic infections and descending mediastinitis in beta-lactamallergic patients. It may be used effectively and successfully with concurrent standard early surgical intervention in selected patients, especially in those with severe hypersensitivity reaction.
Introduction
Mediastinitis occurs due to perforation of the esophagus or after cardiac surgery, head and neck infections, and dissemination from another focus of infection[1]. Suppurative odontogenic infections may cause life-threatening complications by extending along deep fascial layers of the head and neck[2]. Descending necrotizing mediastinitis (DNM) occurs as a rare but severe complication of oropharyngeal abscesses developing secondary to odontogenic infections[3, 4]. The relevant mortality has been reported to be 40-50% because of rapid dissemination of the infection[5, 6]. Early diagnosis, control of the infective focus and effective long-lasting antibiotic treatment are lifesaving principles in the management of mediastinitis. In this paper, we present a case of descending mediastinitis developing one week after dental extraction.
Case Report
Discussion
In the case series of Boscolo-Rizzo and his coworkers including 167 patients with deep neck infection, only six cases had DNM[10]. In another case series of 10 patients, only three cases developed mediastinitis secondary to odontogenic abscess after dental extraction. Eight of these 10 patients were treated successfully where as two cases (1 patient over 75 years old and the other diabetic) died because of septic shock and multiorgan failure[11]. In a report of 105 cases (aged 18-93 years) with deep cervical infection, older age (> 65 years), accompanying systemic disease, and in appropriate empirical antimicrobial therapy were statistically significant parameters for lifethreatening complications[12].
Pathogens causing mediastinitis include aerobic and anaerobic Gram-positive cocci and bacilli, and Candida albicans[1]. However, prior antibiotic use, just as in our patient, decreases the possibility of microbial isolation from the culture. CT is important in the early diagnosis and surgical management of DNM[13].
The primary treatment of DNM is surgical eradication of the pharyngeal or odontogenic infectious focus and concurrent drainage of the cervical and/or mediastinal collection. Relevant mortality is considerably high despite appropriate therapy[14]. Hsu and his colleagues reported in their DNM series of 29 patients that treatment with early, aggressive transcervical drainage and debridement was equally as successful as combined cervical and thoracic drainage[15]. The decision regarding type of surgical approach is made according to the extent of the infection and the experience of the surgeon[16, 17]. Cervical and mediastinal drainage was performed by transcervical approach in our patient.
Ampicillin-sulbactam, amoxicillin-clavulanate, penicillin G and metronidazole combination, cefoxitin, or cefotetan is recommended in the treatment of odontogenic infections in immunocompetent patients. For beta-lactam-allergic patients, clindamycin or moxifloxacin may be recommended. Broad-spectrum beta-lactam and beta-lactamase combinations and tigecycline are the alternative drugs for immunosuppressed cases[18]. The majority of the patients reported in the medical literature received beta-lactam group antibiotics. Because of severe hypersensitivity to beta-lactam agents, we administered tigecycline to our patient under close monitoring.
Tigecycline, an antibiotic from the glycylcycline class, has a wide antibacterial spectrum with activity against gram-positive and gram-negative aerobic and anaerobic bacteria and good tissue penetration[19]. Although it is a bacteriostatic antibiotic, some in vitro studies revealed its cidal activity against Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria gonorrhoeae[20, 21]. In the literature to date, only two case reports of mediastinitis mentioned its safety and therapeutic success when used together with surgical debridement and drainage. One of them was panresistant Acinetobacter baumannii mediastinitis and the other was multi-drug-resistant Klebsiella pneumoniae mediastinitis[22, 23]. Their characteristic features in comparison to the case presented herein are summarized in Table 1. Despite its bacteriostatic feature, tigecycline has been reported to be used successfully in the treatment of severe infections[24, 25]. It has high penetration into skin and soft tissues[26]. Our patient was treated successfully with tigecycline as he was young, immunocompetent, with no underlying disease and because of the early diagnosis by means of CT and urgent surgical intervention.
In conclusion, tigecycline has the potential to be an alternative option for treatment of odontogenic infections and descending mediastinitis. It may be used effectively and successfully with concurrent standard surgical intervention in selected patients, especially in those with severe hypersensitivity reaction to betalactam antibiotics.
