Posttraumatic bronchobiliary fistulae due to foreign body remnants after a road traffic injury: a case report

Background Bronchobiliary fistula is an extremely rare disease that involves abnormal communication between a hepatic segment and bronchial tree. It is mostly caused by untreated hydatid cyst, liver abscess, iatrogenic stenosis, and, rarely, trauma. Case presentation We experienced an extremely rare case of bronchobiliary fistula after motor vehicle accident. A 15-year-old Persian boy visited our clinic with chief complaints of persistent pleuritic chest pain, productive cough, weight loss, and fever for 2 months. Coronavirus disease 2019 reverse transcription polymerase chain reaction test was negative. Chest X-ray revealed hazy opacification of right lower lobe. Bronchoalveolar lavage for acid-fast bacillus came back negative. Thoracoabdominal computed tomography scan revealed a collection in segment VIII of the liver communicating with another 13 × 5 cm multiloculated collection in the lower lobe of the right lung, with air foci within the collection. Right posterolateral thoracotomy was performed with the impression of bronchobiliary fistula. Drainage of hepatic collection with debridement, diaphragmatic repair, and open decortication of lung followed by resection of the involved segment of the right lung was performed. Histopathologic evaluations revealed abscess formation in pulmonary tissue, and many multinucleated giant cells were seen that appear to be due to foreign body remnants after previous laparotomy surgery. The foreign body seemed to be the remnants of Surgicel absorbable hemostat. Conclusions Herein, we report an extremely rare case of a posttraumatic bronchobiliary fistula caused by remnants of Surgicel hemostatic agent. Bronchobiliary fistula is mainly caused by untreated hydatid cyst, liver abscess, iatrogenic stenosis, and, rarely, trauma. Migration and erosion of oxidized regenerated cellulose through the diaphragm seems to be the causative factor of bronchobiliary fistula in this patient.


Introduction
Bronchobiliary fistula (BBF) is an extremely rare disease first introduced by Peacock in 1850 [1]. BBF is an abnormal communication between a hepatic segment and bronchial tree. It is mostly caused by untreated hydatid cyst, liver abscess, iatrogenic stenosis, and, rarely, trauma [2]. Herein, we describe a rare case of BBF after motor vehicle accident (MVA) and blunt abdominal trauma. Our patient differs in that the BBF seems to be caused by remnants of nonabsorbed Surgicel (an absorbable hemostatic agent) particles in the abdominal cavity after laparotomy surgery.

Open Access
*Correspondence: shekouhi.ramin@gmail.com 2 Colorectal Research Center, Department of Surgery, Shiraz University of Medical Sciences, Zand Avenue, P.O. Box 71345-1744, Shiraz, Iran Full list of author information is available at the end of the article A 15-year-old Persian boy was involved in a car accident 3 months prior. He underwent chest tube insertion owing to massive right-sided pneumothorax. The patient was taken to operation room (OR) for exploratory laparotomy for blunt trauma of abdomen. Surgery revealed a grade 3 liver laceration in segments VI-VII with massive hemoperitoneum. Pringle maneuver was performed to reduce bleeding from the liver. Furthermore, the laceration in segment VI was repaired with deep mattress sutures. However, the surgical team used an absorbable hemostatic agent (Surgicel) in the liver VII segment owing to severe liver contusion caused by blunt trauma to the abdomen. The Surgicel was placed in the anterior part of the liver VII segment, definitive hepatic repair was performed, and he was discharged 10 days later. However, the patient was referred to the clinic with complaints of persistent pleuritic chest pain, productive cough, weight loss, and fever for the last 2 months.
Upon arrival, the patient was hemodynamically stable without signs of respiratory distress. Past medical history was unremarkable except for the recent surgery due to MVA. Family history was unremarkable. Physical examination revealed mild right upper quadrant (RUQ) tenderness at site of previous surgery. Lung auscultation showed decreased breath sounds at the base of right lung. Laboratory data showed leukocytosis (WBC count 14,000) with marked elevation in the neutrophil count, and high C-reactive protein (CRP) levels. Coronavirus disease 2019 (COVID-19) reverse transcription polymerase chain reaction (RT-PCR) test was negative. Chest X-ray revealed hazy opacification of the right lower lobe. Bronchoalveolar lavage (BAL) for acid-fast bacillus (AFB) came back negative. Thoracoabdominal computed tomography (CT) scan revealed a collection in segment VIII of the liver communicating with another 13 × 5 cm multiloculated collection in the lower lobe of the right lung, with air foci within the collection (Fig. 1). After thoracoabdominal CT scan, sputum analysis was performed with suspicion of BBF. However, there was no sign of bile in the sputum.

Treatment
The patient was scheduled for thoracotomy, and preoperative management was considered.
The surgery was conducted under general anesthesia. The patient was scheduled for thoracotomy with the purpose of complete drainage of lung abscess and resection of involved segments. In addition, a transdiaphragmatic approach was carried out for drainage of liver collection (Fig. 2). Diffuse pleural thickening and parenchymal adhesion bands with collection formation were revealed during the operation. Drainage of hepatic collection with debridement and diaphragmatic repair were done. Furthermore, open decortication of lung followed by resection of involved segment of right lung was performed. Intercostal chest drains were placed. Histopathologic evaluation revealed abscess formation in pulmonary tissue with diffuse fibrosis. Many multinucleated giant cells were seen in most parts of inflamed tissues, which appeared to be due to remnants of nonabsorbed Surgicel (an absorbable hemostatic agent) particles used in previous laparotomy surgery (Figs. 3 and 4).

Outcome and follow-up
The postoperative course was uneventful without any signs of short-term complications. He had no episodes of cough, fever, and bilioptysis after the surgery. The patient was discharged 4 days after surgery with the abdominal drain. The abdominal drain had 10 mL output after 1 week. On the second follow-up visit 14 days postoperation, abdominal ultrasound was unremarkable without any collection, and the drain was removed.

Discussion
Classically, BBF can be divided into congenital and acquired. Congenital BBF (CBBF) mostly presents early in life with poor feeding, bilioptysis, and respiratory distress. It mainly coexists with other biliary tract anomalies [3]. Acquired BBF can be a result of damage to the bronchioles, diaphragm, or biliary tracts [4]. Hydatid cysts have been known to be the main cause of BBF. However, thanks to use of broad-spectrum antibiotics and early detection, incidence has decreased tremendously. Other causes of BBF include subphrenic abscess formation, malignancy, iatrogenic factors, and trauma. Posttraumatic BBF is extremely rare, with few cases reported worldwide [5]. To the best of our knowledge, there are only 20 cases (including this patient) of published posttraumatic BBF in English literature (Table 1). Among a total of 20 patients, 17 (85%) patients were males and the rest were females, with a mean age of 25.0 years. Penetrating injures, mostly by gunshot, were the most common cause of posttraumatic BBF (60%). Postural intractable cough, bilioptysis (bile in the sputum), fever, and pleuritic chest pain are the usual presentation of BBF [6]. Bilioptysis ranges from mild bile-streak sputum to expectoration of extensive amounts of bile [7].
BBF can be initially misdiagnosed as acquired pneumonia, making the diagnosis of BBF difficult. In terms of diagnosis, chest X-ray may reveal pleural effusion and lung collapse. CT scan shows any fluid collection, including subphrenic abscess, damage to inferior lobes, and obstructed biliary tracts. Pleural fluid and sputum analysis should be assessed for elevated bilirubin levels; however, it requires a high index of suspicion [8]. Santra et al. [9] recommended hepatobiliary iminodiacetic acid (HIDA) scan as a precise noninvasive diagnostic tool for BBF. However, Nigro et al. [10] stated that, owing to reversal of transdiaphragmatic pressure gradient in patients on mechanical ventilation, HIDA scan falls short of confirming the diagnosis.
Magnetic resonance cholangiography (MRCP), ERCP, or percutaneous transhepatic cholangiography (PTCD) are the safest, most precise nonsurgical interventions that can be successfully operated [8]. ERCP is more practical than MRCP because of its capacity to identify the BBF precisely, and it also has potential for therapeutic interventions [11]. ERCP is considered the first-line treatment in BBF. Traditionally, surgery was the keystone of treatment. However, recently, more conservative, noninvasive treatment methods are preferred initially. Accordingly, among the reports of 20 patients with BBF published in English literature, ERCP was performed in 12 (60%) patients with the goal of complete drainage of hepatic collection. ERCP-guided biliary decompression and stent insertion facilitate bilious drainage into the gastrointestinal tract and successful resolution of BBF. Despite its noninvasive nature, complications including bleeding, cholangitis, pancreatitis, duodenal perforation, and stent occlusion occur. Although ERCP showed success in treatment of BBF, the failure rate of conservative methods alone without surgical interventions was estimated at nearly 38% [12]. According to previous case reports, death associated with posttraumatic BBF has not been reported.
Open surgery is indicated if conservative techniques fail. Multiple surgical approaches have been recommended for treatment of BBF, including thoracotomy, thoracoabdominal approach, and laparotomy. Most studies preferred the thoracoabdominal approach as the definite surgical method. According to our results, 15 (75%) patients, underwent thoracotomy for resection of involved lung segment, and fistulectomy (Table 1). It provides accessibility to perform decortication, complete excision of fistulae tract, wedge resection of lung parenchyma, lobectomy, and diaphragmatic closure [13,14]. We considered surgical intervention as the first-line therapy because of the subphrenic abscess and better management of biliary leakage to the abdominal cavity. Our case differs in that the BBF seems to be caused by remnants of nonabsorbed Surgicel particles in the abdominal cavity after laparotomy surgery.
Surgicel, which is a bioabsorbable hemostatic agent, consists of oxidized regenerated cellulose. It is a thrombogenic material mainly used to control bleeding. Once the Surgicel is placed in the surgical bed, it forms a gelatinous mass that helps control the bleeding and clot formation [15]. Macrophage processing seems to play a role in the absorption mechanism of Surgicel in the body; however, the exact mechanism is not well understood. The absorption process of Surgicel by the body begins after 18 hours, and will usually be absorbed within 6 weeks [16]. However, in our case, Surgicel was not completely absorbed after 3 months of insertion, as we noticed remnants of Surgicel on histological evaluation.
Although oxidized cellulose is a safe hemostat, complications including delayed absorption, granuloma formation, and compression effect to surrounding organs still occur. There have been multiple reports of paraplegia following thoracotomy due to compressive effects of oxidized cellulose. Swelling and migration of oxidized cellulose through intervertebral foramen into the spinal canal were the main cause of paraplegia following Surgicel insertion after thoracotomy. The pressure gradient between the spinal canal and pleural space seems to be the causative factor for postthoracotomy Surgicel migration [17][18][19][20].
In addition, Dokumcu et al. [21] reported a patient of esophageal atresia (EA) with distal tracheoesophageal fistula (TEF) who underwent thoracotomy for surgical management of esophagus and tracheal defects. However, 1 month after thoracotomy, the patient developed symptoms indicative of TEF. Esophagoscopy revealed patent TEF with the nonabsorbed Surgicel in the TEF lumen, which was not removed to prevent fistulae enlargement. Three weeks later, the Surgicel hemostat disappeared and the patient underwent another thoracotomy for closure of TEF. Dokumcu et al. concluded that postoperative Surgicel migration and expansion were the cause of TEF recurrence.
In our case, the major cause of Surgicel migration, and erosion through the diaphragm, seems to be the increased thoracoabdominal pressure gradient (TAPG), which caused the migration of Surgicel to reach the diaphragm, especially in the setting of increased intraabdominal pressure following blunt trauma and laparotomy surgery. That said, our second hypothesis is that the delayed absorption of Surgicel material could have caused an abscess within the involved liver segment, which later on the abscess fistulized to the adjustment diaphragm and lung tissue, causing BBF. Regardless, delayed absorption of Surgicel hemostatic agent seems to be the main cause in the formation of BBF. However, due to rarity of the disease, there is not enough evidence to support any of these hypotheses. To the best of our knowledge, this is the first case of posttraumatic BBF due to remnants of nonabsorbed Surgicel hemostatic agent.

Conclusion
Herein, we reported an extremely rare case of posttraumatic bronchobiliary fistula (BBF) caused by remnants of Surgicel hemostatic agent. BBF is mainly caused by untreated hydatid cyst, liver abscess, iatrogenic stenosis, and, rarely, trauma. The patient was a 15-year-old boy who developed BBF following laparotomy surgery, in which Surgicel hemostatic agent was inserted to control bleeding due to liver laceration. Migration and erosion of oxidized regenerated cellulose through the diaphragm seems to be the causative factor of BBF in this patient. We reviewed the early signs and symptoms of BBF, the gold standard diagnostic method, and emphasized the importance of surgical management in the treatment of BBF.

Patient perspective
Five months ago, I had an accident and I was rushed to a nearby hospital. I had an operation and was admitted for two weeks. 2 days after I discharged from the hospital, I developed with persistent cough, fever and malaise. First, I thought I was infected with covid- 19 4. Histologic evaluation of the specimen; fistulation of BBF into the lung parenchyma (×4) (a); diffuse fibrosis in pulmonary tissue (×10) (b); giant cell within the involved lung segment with, interestingly, bile staining in the alveoli (black arrow) (×40) (c); many multinucleated giant cells in most parts of involved liver tissue that appear to be due to foreign body remnants (Surgicel) after previous surgery (×40) (d)