Surgical management of esophageal-respiratory fistula from pulmonary Mycobacterium avium complex: case report

Introduction

Background

An esophageal-respiratory fistula (ERF), which encompasses tracheoesophageal fistula and bronchoesophageal fistula, denotes an abnormal connection between the esophagus and the airway. While malignancy is the most common cause of acquired ERF, traumatic and post-surgical injuries, and infections such as tuberculosis, histoplasmosis, syphilis, actinomycosis, cytomegalovirus (CMV), and Candida account for a smaller proportion of these instances (1-3).

Rationale and knowledge gap

Although infections account for a small proportion of ERF cases, the management of ERF caused by treatment-resistant infections, particularly Mycobacterium avium complex (MAC), is not well-documented. Existing literature primarily focuses on more common etiologies, leaving a gap in knowledge regarding the best approach for managing ERFs complicated by resistant mycobacterial infections.

Objective

This case report aims to describe the management of an ERF and intrabronchial mycetoma caused by treatment-resistant MAC infection, providing insights into potential strategies for dealing with similarly complex cases. We present this article in accordance with the CARE reporting checklist (available at https://shc.amegroups.com/article/view/10.21037/shc-24-20/rc).

Case presentation

An 82-year-old male with a medical history of stage 3 chronic kidney disease, type 2 diabetes mellitus, coronary artery disease, and extensive lung damage due to silicosis/pneumoconiosis, stemming from a lifetime of work in a foundry, developed an extensive pulmonary infection caused by MAC. Due to the extent of the disease spread, the patient developed an intrabronchial MAC mycetoma in the bronchus intermedius (Figure 1). Lung biopsy showed anthracosis lung parenchyma with numerous granulomas and multinucleated giant cells in a background of extensive hyalinization and necrosis, associated with lymphoplasmacytic infiltrate with foamy macrophages, histiocytes and abundant polarizable material. The esophagus had intestinal metaplasia and was negative for dysplasia or cancer. Culture of the lesion confirmed the presence of non-necrotizing granulomas with acid-fast bacilli consistent with MAC infection, with no other microorganisms detected. Over the course of years, the patient experienced multiple hospitalizations due to post-obstructive pneumonia and adverse reactions to antimycobacterial. The patient was initially treated with Rifampin, ethambutol, and azithromycin for 3 months, but the treatment was withdrawn due to recurrent maculopapular rash and subsequent hospitalizations. Subsequently, the patient received doxycycline for 4 months until worsening shortness of breath for several weeks. Then, the patient was started on amikacin and ethambutol for 1 month but was readmitted to the hospital for community-acquired pneumonia (CAP) and maculopapular rash, so MAC antimicrobial therapy was discontinued. After treating for CAP, the patient was started on inhaled amikacin but underwent another hospital admission due to recurrent CAP, hypoxemic respiratory failure, and diffuse rash. He had then been on maintenance ethambutol and clofazimine, but had multiple hospital admissions due to bacterial pneumonia iso silicosis, MAC infection, and ERF, so MAC therapy was held, at which point we opted for surgical treatment.

Figure 1 CT chest with contrast showing intrabronchial MAC mycetoma. Dotted lines measure the length and width of the lesion size. Bilateral nodular lesions in the lung parenchyma are considered to be due to silicosis. CT, computed tomography; MAC, Mycobacterium avium complex.

After presenting with two weeks of postprandial coughing, decreased per-oral tolerance, and worsening weight loss, an esophagram was performed, which raised concern for an ERF (Figure 2). Esophagogastroduodenoscopy (EGD) and bronchoscopy confirmed an ERF approximately 26 cm from the incisors at the anterolateral wall of the esophagus and adjacent to the intrabronchial mycetoma in the bronchus intermedius. Despite an esophageal stent, the patient continued to experience clinical deterioration due to recurrent pneumonia. The patient’s preoperative lung ventilation/perfusion study revealed limited ventilation in the right middle lobes (RML 19%) and right lower lobes (RLL 4%). To address the ongoing medical challenges and prevent further morbidity, surgical management was offered to the patient, given his independent functional status and very limited treatment options otherwise. On day 1 of a staged procedure for ERF repair, the patient underwent resection of the right middle and lower lobes (bilobectomy) (Figure 3), placement of an intercostal muscle flap, and esophagectomy. On day 2, the patient returned to the operating room (OR) for cervical esophagostomy, laparoscopic hiatal closure, and the placement of a feeding gastrostomy tube (G-tube). The patient had an excellent initial post-operative recovery. The patient was weaned to 2 L of nasal cannula oxygen on postoperative day 1, started tube feeding on postoperative day 2, and was ambulating independently. However, on post-operative day 6, he began requiring higher oxygen support with worsening bilateral lung opacities. He was found to have contracted coronavirus disease 2019 (COVID-19). Despite treatment with dexamethasone and remdesivir, along with other supportive measures, the patient deteriorated clinically, ultimately requiring intubation due to acute respiratory distress syndrome, vasopressor support, and a brief period of cardiopulmonary resuscitation. Ultimately, the patient was transitioned to comfort measures only before passing away on the eighteenth postoperative day. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration and its subsequent amendments. Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Figure 2 Pre-operative barium swallow showing contrast within the right-sided airways, concerning for esophageal-respiratory fistula.

Figure 3 Robotic video-assisted-thoracoscopic bi-lobectomy of right middle and lower lobes in extensively fibrotic lung due to silicosis and MAC infection. MAC, Mycobacterium avium complex.

Discussion

Key findings

Prior to the 1960s, granulomatous infections, particularly tuberculosis, were the primary causes of benign acquired ERFs. However, with the availability of antimycobacterial medications and the success of antiretroviral therapy for human immunodeficiency virus (HIV), infectious causes of ERF have become much less prevalent. Even rarer are ERFs that result from MAC, with only one other documented case in the medical literature (4). Management of MAC ERF lacks widely accepted management strategies and should be tailored to the patient’s individual clinical presentation. Although studies have reported successful ERF closure/resolution through stent placement and anti-mycobacterial therapy in the case of tuberculosis, there is no known instance of MAC-induced ERF being successfully managed through conservative management. This is the first reported case of a MAC infection complicated by an intrabronchial mycetoma and subsequent ERF. Our case highlights the feasibility of surgical approaches in managing medically refractory advanced pulmonary mycobacterial disease.

Strengths and limitations

A key strength of this case report is that it documents a surgical approach in the management of a rare and complicated MAC infection with ERF, adding valuable insights to the limited existing literature on this topic. However, the discussion is limited by the rarity of such cases, which restricts the generalizability of the findings. Additionally, the absence of widely accepted management strategies for MAC-induced ERF further underscores the need for more research and clinical guidelines.

Comparison with similar research

Pulmonary mycobacterial infections can trigger chronic granulomatous inflammation, resulting in damage to the respiratory system and, in some instances, the formation of fistulas. To date, there has been only one documented case of an ERF arising from a MAC infection (4). The previous case report details the experience of a previously healthy 30-year-old woman with anti-interferon-gamma autoantibodies who presented with a 2-month history of symptoms and was ultimately diagnosed with pulmonary MAC complicated by ERF. The treatment approach for this patient’s condition involved the use of an esophageal stent, a feeding jejunostomy, and a combination of multiple antimicrobial medications. Unfortunately, the patient failed the medical treatment, and upon a 9-month follow-up, she continued to rely on tube feeding without any improvement in the ERF.

Explanations of findings

MACs are opportunistic pathogens ubiquitously encountered in the environment, and they generally do not pose a risk to immunocompetent individuals. Here, we describe a case involving a patient with extensive pulmonary silicosis who developed a complicated pulmonary MAC infection. Silicosis is recognized for its potential to weaken the pulmonary immune system, likely stemming from compromised macrophage phagocytic activity attributed to the presence of intracellular silica, and has been linked to increased susceptibility to tuberculosis infection (5,6).

The usual treatment for pulmonary MAC infections involves a combination of antimycobacterial medications prescribed for an extended period, often spanning several months to more than 1 year. Current society guidelines for addressing fibro-cavitary MAC disease recommend a prolonged antibiotic regimen comprised of medications such as clarithromycin, azithromycin, rifampin, ethambutol, streptomycin, or amikacin (7). Although occurrences of endobronchial lesions from non-tuberculous mycobacteria are extremely rare, a few documented cases have demonstrated the successful application of conservative management, such as debulking bronchoscopy with cryotherapy of the masses, to prevent post-obstructive pneumonia (8). However, in specific patient groups with extensive disease and comorbidities, conservative approaches may not be feasible, particularly when there are issues with medication tolerance.

The development of ERF in this patient can be attributed to the chronic granulomatous inflammation caused by the pulmonary MAC infection, which was likely exacerbated by the patient’s compromised local pulmonary immune function due to silicosis. The failure of conservative management, such as antimicrobial therapy and stenting, in this context underscores the challenges of treating such complex cases. Given the extent of the disease and the patient’s comorbidities, surgical intervention was deemed necessary and ultimately proved to be a feasible approach.

Implications and actions needed

This case suggests that in certain patient populations, particularly those with advanced pulmonary disease and comorbidities, conservative management may not be viable, highlighting the importance of individualized treatment plans. Surgery should be considered as a potential option when other treatments fail. Moving forward, further research is needed to develop widely accepted management strategies for MAC-induced ERF and better understand the role of surgical intervention in similar cases.

Conclusions

This case suggests that surgical intervention may be a potential option for managing ERF resulting from antibiotic-resistant MAC infection when conservative antimicrobial treatments are ineffective; however, further studies are necessary to establish its efficacy and long-term outcomes, as the patient unfortunately passed away shortly after surgery. Our case demonstrates the complexity of managing MAC-related complications and the importance of individualized treatment strategies. Further research and documentation are necessary to establish standardized protocols for managing similar cases of MAC-induced ERF.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the CARE reporting checklist. Available at https://shc.amegroups.com/article/view/10.21037/shc-24-20/rc

Peer Review File: Available at https://shc.amegroups.com/article/view/10.21037/shc-24-20/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://shc.amegroups.com/article/view/10.21037/shc-24-20/coif). J.D.L. serves as an unpaid editorial board member of Shanghai Chest from December 2023 to November 2025. The other authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration and its subsequent amendments. Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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