Deep neck infection with mediastinitis of iatrogenic etiology – a case report

Summary

Hluboké krční infekce jsou zánětlivá postižení fasciemi jasně definovaných oblastí krku ve formě flegmóny či abscesu. Etiologie je nejčastěji odontogenní, méně často na základě faryngeálních zánětů. Jednou ze vzácných příčin vzniku hluboké krční infekce je poškození iatrogenní, kterému se věnuje tato kazuistika. Je prezentován případ poranění krční části jícnu při endoskopickém výkonu s následným rozvojem hluboké krční infekce s akutní mediastinitidou. Cílem tohoto sdělení je zdůraznit nutnost komplexní multidisciplinární péče o tyto pacienty a poukázat i na možné navazující komplikace po zvládnutí akutní fáze infekce.

Keywords:

hluboký krční zánět – akutní mediastinitida – iatrogenní perforace jícnu

Introduction

Deep neck infections are a group of serious bacterial diseases of various etiology that affect the spaces of the neck delineated by the fascia. Phlegmons or already formed abscesses can spread from the skull base to the mediastinum and cause life-threatening complications [1]. Diagnosis requires a detailed medical history, clinical examination, laboratory tests, and imaging. Treatment is based on these findings, and a correct interpretation of the results is essential.

Case report

The 68-year-old female patient was closely monitored for a long time by a surgeon and a gastroenterologist for an 8-mm cyst of the pancreas. During follow-up, she underwent repeated endoscopic ultrasound (EUS) examinations under the guidance of a gastroenterologist. During the most recent procedure, the sonographic probe could not be successfully advanced and the examination had to be aborted. The patient was discharged without any apparent complications.

Two days later, the patient attended the ENT outpatient department. She presented with a sore throat, dysphagia, and fever. An ENT examination was performed, revealed saliva stasis in the hypopharynx, crepitus and circumferential tenderness of the neck upon palpation as well as flexed head posture.

An emergency contrast-enhanced CT scan of the neck and mediastinum revealed extensive soft tissue emphysema, which extended from the skull base to the level of the tracheal carina through the mediastinum. The largest concentration of gas was present in the pre -⁠ and perivisceral spaces on the right at the level of the thyroid gland and then on the right along the external surface of the esophagus (Fig. 1). Therefore, esophageal perforation was suspected, and the patient was referred to a surgeon for evaluation.

She was admitted to the surgical ICU. Initial lab results showed no leukocytosis, a C-reactive protein (CRP) level of 275 mg/L, and a procalcitonin level of 2.2 μg/L. Conservative therapy was started with piperacillin/tazobactam and fluconazole. However, due to her deteriorating condition, cervico-mediastino-thoracic drainage was performed the following day by a thoracic surgeon, yielding slightly cloudy secretion. Cultures of smears and thoracic effusion were negative. The patient remained on mechanical ventilation.

A follow-up CT scan was performed after 72 hours, revealing a large abscess-like cavity in the retropharyngeal and right parapharyngeal regions, extending into the retropharyngeal space, with suspected infiltration of the right thyroid lobe. There was also significant left-sided pleural effusion. Immediate reoperation was performed in collaboration with an ENT surgeon and a thoracic surgeon. During the operation, a large amount of purulent secretion was found in the areas described, including the mediastinum. Complete drainage of the cervical space and mediastinum was performed. A wound culture revealed the presence of Staphylococcus coagulase-negative, Enterococcus faecium, and multidrug-resistant Pseudomonas aeruginosa (producing NDM-type metallo-beta-lactamase). An isolation protocol was initiated in the intensive care unit of the surgery department, and the targeted antimicrobial therapy was adjusted to cefiderocol in combination with colistin, according to the results of the susceptibility testing. The patient required mechanical ventilation for eight days, during which regular wound care was performed. Purulent drainage gradually subsided, accompanied by a decline in inflammatory markers. A nasogastric tube was inserted to exclude oral intake. However, a salivary fistula developed on the right side of the neck. Follow-up CT imaging showed the abscess had regressed, and the patient was subsequently extubated and regained full consciousness. Antibiotic therapy was continued, the cervical wounds showed progressive secondary healing, and oral feeding was gradually reintroduced. The fistula closed spontaneously. The patient was discharged home in good general condition and followed up by a surgeon on an outpatient basis. She remained asymptomatic for four months.

After this symptom-free interval, the patient returned to the ENT outpatient department with recurrent complaints, including progressive dysphagia, febrile episodes, and a palpable right-sided cervical mass. Contrast-enhanced CT scans of the neck and mediastinum revealed an abscess-forming infection involving the soft tissues of the neck and mediastinum on the right side, adjacent to the esophagus (Fig. 2). The patient was readmitted to the ICU. Urgent surgical drainage of both the cervical and mediastinal abscesses was performed. Microbiological cultures once again identified multidrug-resistant Pseudomonas aeruginosa together with Streptococcus anginosus. Intravenous antibiotic therapy with cefiderocol, metronidazole, and penicillin G was initiated. Over the subsequent days, there was a steady decline in inflammatory parameters, accompanied by an improvement in local findings and radiological evidence of abscess regression on follow-up CT scans.

The patient was extubated and a CT scan of the neck was performed after ingestion of an iodine contrast agent, which revealed a defect in the posterior right wall of the hypopharynx extending into the parapharyngeal space.

An external neck revision was performed, and sutures were placed at the site of the suspected perforation, followed by the application of tissue adhesive. The patient was then transferred to the ENT department. Inflammatory parameters normalized, and daily wound dressings were applied to the right side of the neck. However, a salivary fistula persisted. A follow-up CT scan with contrast swallowing was performed, in addition to the standard supine position, patient was also positioned on her right side. This showed persistence of the hypopharyngeal perforation (Fig. 3).

A gastrostomy (minilaparatomy technique, using percutaneous gastrostomy set) was performed and, after consultating with the Department of Otorhinolaryngology and Head and Neck Surgery at Motol University Hospital, the patient was transferred for hypopharyngeal reconstruction. During the external incision, a suspicious fistula opening was identified. Reconstructive surgery was carried out using the sternocleidomastoideus (SCM) muscle flap, with the additional application of tissue adhesive.

Eight days after surgery, a contrast swallow study revealed a small, persistent perforation in the posterior wall of the esophagus with a prevertebral pouch. Conservative monitoring was chosen. Subsequent CT scan again confirmed the perforation‘s persistence, so a second operation was performed in collaboration with a plastic surgeon. Plastic surgery of the swallowing tract was performed using a radial forearm free flap (RFFF). Swallowing rehabilitation continued. A follow-up CT scan three months after surgery, revealed no further signs of perforation. The patient reported gradual subjective improvement in swallowing and no loss of weight, therefore the gastrostomy was discontinued almost exactly one year after its placement. The latest fibroscopic findings illustrate the condition of the swallowing tract 5 months following the last, successful surgery (Fig. 4).

Discussion

In our case report, we present a patient diagnosed with deep neck infection and acute mediastinitis of iatrogenic etiology after undergoing an endoscopic diagnostic procedure performed by a gastroenterologist. Although some authors have noted a declining trend in the incidence of deep neck infections [2], the condition remains clinically relevant due to its high morbidity and mortality rates. Despite advances in medical care, the mortality rate from deep neck infections is estimated at 1–3% [3, 4], and increases to 20–40% in cases complicated by acute descending mediastinitis [5, 6].

Deep neck infections most commonly arise as complications of dental infections or tonsillopharyngitis spreading. Other causes, including iatrogenic ones, are rare [7]. In our patient, perforation occurred at the hypopharynx-esophagus junction following an endoscopic ultrasound (EUS) examination, leading to the development of deep neck infection and acute mediastinitis. Esophageal perforation is most commonly reported cause of acute mediastinitis, and in the majority of cases (60–70%), the etiology is iatrogenic [8, 9]. Given the increasing number of semi-invasive gastrointestinal procedures being performed, a significant reduction in incidence is unlikely. Microbiological cultures most often reveal a polymicrobial spectrum of pathogens, including both aerobic bacteria (most commonly Streptococcus and Staphylococcus) and anaerobes (Prevotella, Fusobacterium, and Peptostreptococcus), or a combination of these [10]. In our case report, the pathogen was a multidrug-resistant strain of Pseudomonas aeruginosa producing NDM-type metallo-beta-lactamase, which, as reported in a similar study complicates both treatment and wound healing [11].

After the acute phase of the infection has been managed, the difficult process of reconstructing the swallowing tract begins. This difficulty is primarily due to previous repeated surgical procedures and scarring of wounds, which significantly obscure the surgical field. Numerous techniques for hypopharyngeal and esophageal reconstruction have been described in the literature [12]. These include regional flaps such as the sternocleidomastoideus (SCM) or supraclavicular artery flap, and free tissue transfers such as the radial forearm free flap (RFFF), anterolateral thigh flap, and free jejunal flap [13–16]. We used the aforementioned reconstructive approaches in our case, with the free flap proving more effective.

Conclusion

Esophageal perforation is one of the most common causes of acute mediastinitis. Iatrogenic injury during flexible endoscopy of the swallowing tract is one possible cause. This case report illustrates the prolonged and complex treatment required for such conditions, emphasizing the crucial role of multidisciplinary collaboration among the involved specialties.

Abbreviations

EUS         endoscopic ultrasonography

 

Conflict of interest statement

The author of this paper declares that he has no conflict of interest in relation to the topic, development, and publication of this paper and that the development and publication of this paper was not supported by any pharmaceutical company. This declaration also applies to all co-authors.

 

Funding

This work was supported by the Cooperatio Program, research area SURG.

Supported by the Ministry of Health, Czech Republic –⁠ conceptual development of research organization (University Hospital in Pilsen (FNPl), 00669806)).