Patch aortoplasty and anatomical lung resection in a patient with aortobronchial fistula due to aortic psuedo-aneurysm

Abstract

Aortobronchial fistula (ABF) is a rare and devastating complication, if left untreated. Its main clinical manifestation is hemoptysis, and there are no defined guidelines for its treatment yet. Herein, we present the case of a 74-year-old male who complained of back pain and hemoptysis. The patient was diagnosed with pseudo-aneurysm and ABF, and he underwent hybrid thoracic endovascular aortic repair. However, hemoptysis recurred. With patch aortoplasty and anatomical lung resection, successful management of ABF was achieved, with no relapse for 5 years.

Introduction

Aortobronchial fistula (ABF) is a devastating complication, and it results in catastrophic consequences without treatment. The main symptom of ABF is hemoptysis, and it can be fatal to patients depending on the amount of hemoptysis. Most patients with ABF are ill; however, definite treatment has not been clearly established.

Case report

A 74-year-old male patient who complained of back pain was admitted. Initial computed tomography (CT) revealed concealed ruptures of a large aortic pseudo-aneurysm from the eighth thoracic spine level to the first lumbar spine level and multiple consolidations with haziness in the left lower lung field (Fig. 1a, b). The patient experienced sudden-onset hemoptysis after admission; however, his vital signs were stable. We suspected that expansion of the pseudo-aneurysm caused tracheobronchial compression, leading to ABF. Hybrid thoracic endovascular aortic repair (TEVAR) was performed because of the miniscule amount of hemoptysis and dangers of paraplegia. As the distal end of the stent graft should be located directly above the left renal artery orifice, we planned to bypass the celiac, superior mesenteric, and right renal arteries using a prosthesis (Fig. 1c, d). A trifurcated graft was prepared by unioning a 7-mm ringed polytetrafluoroethylene graft with a 14 × 7 × 400-mm bifurcated graft, and the inflow artery was determined by the left common iliac artery. Subsequently, the prepared prosthesis was anastomosed, and an S&G SEAL thoracic stent graft (30 × 26 × 150 mm; S&G Biotech, Seongnam, Korea) was advanced to the level of the left renal artery. Ten days after discharge, the patient visited our medical center for recurrent hemoptysis. His vital signs were stable, and the amount of hemoptysis was low. CT showed well-maintained patency of the artificial bypass, and there was no evidence of endoleak of the stent graft (Fig. 2a). Focal mass-like consolidation suspicious of inflammation was noted, and interstitial infiltration worsened in the left lower lung field (Fig. 2b, c). No bacteria were identified in sputum cultures and blood cultures, and broad-spectrum antibiotics were administered. We thought that the patient’s ABF should be addressed.

Fig. 1.

a Initial chest computed tomography scan shows multiple consolidations with haziness and atelectasis in the left lower lung field (white arrow). b There is a large (about 9 cm) aortic pseudo-aneurysm with concealed rupture (11th thoracic spine level) (black arrow). c Aortic pseudo-aneurysm invades a portion of the celiac artery (white arrow). d The distal end of the stent graft should be located at the level of the left renal artery. CA celiac artery, SMA superior mesenteric artery, RRA right renal artery, LRA left renal artery

Fig. 2.

a Follow-up chest computed tomography angiography demonstrates well-maintained patency of the artificial bypass from the left common iliac artery (white arrow) to the celiac artery, superior mesenteric artery, and right renal artery. b Focal mass-like consolidation suspicious of inflammation is noted in the left lower lung field (white arrow). c The pseudo-aneurysm remains and caused extrinsic compression of the left lower lung (11th thoracic spine level) (white arrow)

Under general anesthesia, left posterolateral thoracotomy was performed through the sixth intercostal space. There was tight and diffuse adhesion between the left lower lobe and pseudo-aneurysm. There was extensive pulmonary parenchymal hemorrhage and necrosis with severe inflammation in the left lower lobe. Left lower lobectomy was performed first to remove all necrotic lung lesions. As we aimed to resect the residual fistula and hemoptysis could not be resolved by resecting only necrotic lung lesions, we performed lobectomy. After left lower lobectomy, a 1.5-cm ABF was found in the lesion. The pseudo-aneurysm was relatively healthy in a chronic state, and the amount of blood to be infiltrated was so scant that only the involved aortic lesion was removed. Dark hematoma and inflammatory tissues within the pseudo-aneurysm were removed, and the fistula was sutured by patch closure using a Hemashield graft. The postoperative course was uneventful, and sputum cultures and operative tissue cultures identified no any organisms. The patient is on a routine outpatient follow-up schedule, and he has not complained of hemoptysis for 5 years (Fig. 3a, b).

Fig. 3.

a Postoperative chest radiography. The white arrow indicates the thoracic aortic stent graft. b Postoperative computed tomography shows that the function of the stent graft in the descending thoracic aorta is good, and there is no evidence of endoleak. Patchy closure of the thoracic abdominal aorta is observed and the patch (white arrow) is patent

Discussion

ABF is a rare condition characterized by the development of a communication between the aorta and a branch of the bronchial tree, and the ABF incidence ranges from 0.56 to 1.7% [1, 2] Its main clinical symptom is hemoptysis, which depends on the characteristics of the fistula [3, 4]. Diagnosis of ABF is primarily carried out by CT [3]. Signs of ABF on CT include air entrapment within the thrombosed aneurysm, peri-aortic fluid collection, bronchial wall thickening, and lung consolidation with atelectasis; however, the exact fistulous tracts are rarely detected [3]. Regarding lethal ABFs, primary aortic pathology initiated fistulas most often involve aneurysms associated with various etiological causes [5]. As aneurysms expand, they exert pressure on the adjacent tracheobronchial tree, causing tissue necrosis and allowing direct communication between the circulation and lumen of the upper airways.

When ABF occurs, the patient’s prognosis is determined according to the amount of hemoptysis and the presence of infection. Infection is a major threat because operative mortality can reach about 50% [2]. Once infection occurs within the vessel, it can readily extend to the bronchial wall and lung parenchyma, which can ultimately lead to sepsis. When infection of the ABF is suspected, repair by open surgery is mostly required [6]. Although surgical principles dictate control of infection, removal of the entire infected aorta, and reconstruction in a clean field, these are not always achievable because they place a huge demand on an already ill patient [6].

Conservative nonsurgical therapy with antibiotic treatment is used in patients who do not want invasive treatment because of the minimal hemoptysis or in patients with multiple comorbidities. However, conservative nonsurgical therapy can result in a fatal outcome, which may leave massive hemoptysis or chronic mediastinitis [7]. Endovascular treatment, which is a less invasive and safer alternative to open surgery, may be used to treat ABF. However, it is uncertain whether endovascular repair alone provides a complete and durable cure for an ABF because endovascular repair leaves the patients at risk for recurrence or infection [7–9].

Reduction of infection and elimination of repeated hemoptysis are the most important aspects of patient’s prognosis, and open ABF repair is the most effective strategy. The conventional approach involves combined replacement or bypass of the thoracic aorta with concomitant resection or repair of involved pulmonary segments. Despite significant improvement in surgical techniques, the operative mortality of open ABF repair ranges from 15 to 41% [10]. The high mortality is related to the need for thoracotomy, thoracic aortic cross clamping, and surgical replacement or repair of the thoracic aorta with concomitant resection of the pulmonary segments involved [7].

The mechanism in the presented ABF case might be associated with mechanical compression and secondary erosion with increased local inflammatory response by progression of the pseudo-aneurysm. The patient was old, and because of the miniscule amount of hemoptysis and the danger of paraplegia, the authors postulated that hybrid TEVAR would be better than active open repair. Stent-graft insertion was performed, but the patient’s symptoms did not improve. To reduce patient morbidity by decreasing the length of the operation and the risk of cardiopulmonary bypass, patch aortoplasty of the involved aortic lesion was performed. This was possible because the pseudo-aneurysm was relatively healthy despite its chronic state and the true lumen of the aneurysm after hematoma and thrombus evacuation was well preserved without injury.

In conclusion, ABF is a serious complication and can be fatal to patients. A surgical approach to resolve the ABF is beneficial for removal of the lesion that could be a focus of infection. Herein, we suggested that patch aortoplasty with concomitant lung resection is an alternative treatment for ABF to reduce repeated hemoptysis and chance of infection.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no competing interests.

Ethics Committee approval

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Informed consent

All authors declare that written informed consent was obtained from the patient for publication of this case report and accompanying images.

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Human and animal rights statement

This article does not contain any studies with human participants performed by any of the authors.