Biliary complication is regarded as the Achilles’ heel of living donor liver transplantation (LDLT). This diagnosis is usually straightforward, based on abnormalities of liver function tests and the appearance of bile in the drainage tubes. We report a bronchobiliary fistula (BBF) which became evident 3 months after LDLT. In 1850 Peacock et al. [1] reported the first BBF case in a young woman with a ruptured hydatid cyst. Both the acquired and the congenital varieties of BBF are very rare complications in children [2-5]. Acquired BBF usually occurs as a complication of a rupture of a hydatid cyst or subphrenic abscess. It could also occur following hepatic trauma, tumor, or hepatobiliary surgery [2,6-8]. The condition is universally characterized by the presence of yellow bile in the sputum (bilioptysis), which is pathognomonic of the condition [7,8]. A high index of suspicion and early diagnosis are crucial to prevent progressive corrosion of pulmonary and bronchial tissues. In the context of liver transplantation (LT), only a few cases have been reported in adults [4,5]. However, no such data exist in the pediatric LT setting to the best of our knowledge. Herein, we report a 7-year-old female child with Wilson disease, who developed BBF post-LT.

In our institution, a case report does not require Institutional Review Board approval. We have obtained informed consent from the patient’s guardian.

A 7-year-old female child presented to our center with decompensated chronic liver disease and portal hypertension. On evaluation, she was diagnosed with hepatic Wilson disease. She underwent ABO-compatible LDLT with the mother as the donor. The child received a 430-g left lobe graft with middle hepatic vein, with a graft-to-recipient weight ratio of 2.5. The grafted left hepatic duct was anastomosed to the recipient’s common hepatic duct. The immediate postoperative period was uneventful, and she was extubated after completion of the surgery on the operation table. She was started on triple immunosuppressive therapy (steroids, tacrolimus, and mycophenolate mofetil) and other supportive medicines as per our institution’s standard protocol [9,10]. The right and left abdominal drains were removed on postoperative day (POD) 3 and POD 11, respectively. On POD 14, she developed fever with a nonproductive cough, and on clinical examination, although there was no tachypnoea, the right subscapular region showed decreased air entry. Subsequent computed tomography (CT) imaging was suggestive of right pleural effusion with basal atelectasis, without any perihepatic fluid collection. The diagnostic pleural fluid aspiration suggested empyema (turbid fluid, total pleural fluid cells 2,760, neutrophils 90%, sterile culture), which was managed with pleural fluid drainage and antibiotics. Her graft function was excellent, and she was discharged on POD 24.

She was readmitted on POD 75 with a productive cough, respiratory difficulty, and intermittent fever spikes for 3 days. On examination, she had tachycardia, tachypnoea, and reduced air entry on the right infrascapular region; oxygen saturation on room air was 88%, which improved on supplemental oxygen and supportive measures. Chest imaging revealed heterogeneous opacity of the right lower lobe with mild pleural effusion (Fig. 1). Bronchoscopy for the unexplained pulmonary issues revealed enteric/bilious content in the right bronchus, which was interpreted as aspiration pneumonitis. She responded to antibiotics, chest physiotherapy, and nebulization. The liver graft function was persistently normal. She was discharged on POD 85 in a hemodynamically stable condition with mild respiratory symptoms.

Figure 1. (A) Chest X-ray, posteroanterior view, showing confluent nonhomogeneous opacities in the right lower zone obscuring the diaphragm and right cardiac border with mild right-hand pleural effusion. (B) Computed tomography showing consolidation of the right lung.

During outpatient follow-up on POD 90, the patient’s sputum was noticed to be bilious (bilioptysis) (Fig. 2), which suggested a clinical diagnosis of BBF. She was admitted immediately and subjected to endoscopic retrograde cholangiopancreaticography (ERCP), which failed. She was then scheduled for exploratory laparotomy and surgical correction of the suspected communication. On laparotomy, a fistula was noticed from the strictured biliary anastomotic site to the right thoracic cavity, as shown in Fig. 3. The fistula was excised, and Roux-en-Y hepaticojejunostomy was performed. A drain was inserted in the right subphrenic space. The child’s symptoms improved, the drain was removed, and she was discharged with normal graft functions on POD 102. She was doing well on follow-up as per the last visit on POD 185.

Figure 2. Bilioptysis: yellow-colored bilious sputum. (A) Cup containing yellow colored sputum (bilioptysis), shown by parents in the outpatient clinic. (B) Tray showing yellow sputum after the admission to the intensive care unit

Figure 3. Bronchobiliary fistula: communication from the strictured duct-duct anastomotic site to the right-hand thoracic cavity. (A) Before and (B) after examination of fistula tract by metallic probe (indicated by arrows).

BBFs can be divided broadly into congenital and acquired types. Congenital BBF usually presents early in infancy with poor feeding, bilioptysis, and respiratory difficulty. Acquired BBF can develop from pathology in the lung, diaphragm, or biliary tract [4]. Subphrenic abscesses, hydatid cysts, malignancies, and trauma are the leading causes of BBF. Table 1 shows a compilation of relevant case reports of acquired BBF in children. Patients with acquired BBF usually present with fever spikes, persistent productive cough, and respiratory difficulty. Bilioptysis remains the pathognomonic and most common clinical feature of BBF. Clinical features suggestive of biliary obstruction are often present. BBF is associated with a high risk of morbidity and mortality (12%) [7,16]. ERCP with or without surgical correction is the mainstay of management. A systematic review of 68 adult cases of BBF showed bilioptysis in all patients, 41% of which required surgical correction [7].

Table 1. Case reports of acquired BBF in children

Study	Subject		Primary diagnosis	Fistulous communication	Interval between primary diagnosis and BBF (mo)	Clinical feature	Imaging/diagnostic modality	Treatment	Outcome on last follow-up
	Age (yr)	Sex
Kumar et al. (2015) [2]	3.5	Female	Ruptured liver abscess	Right hepatic duct to a branch of right main bronchus	7	Bilioptysis	MRCP showed fistulous communication	Right lateral thoracotomy and right lower lobectomy with surgical excision of sinus tract	Alive and healthy
Yang et al. (2017) [3]	10	Male	Traumatic liver rupture	Unknown	36	Bilioptysis	CT could not identify the fistula	Orthotopic liver transplantation (persistent BBF and chronic HVOTO)	Alive and healthy
Rahimi et al. (2023) [11]	17	Female	Liver hydatid cyst	Unknown	10	Bilioptysis	CT chest and abdomen	Right thoracotomy, adhesiolysis, and fistula tract excision	Alive and healthy

BBF, bronchobiliary fistula; MRCP, magnetic resonance cholangiopancreaticography; CT, computed tomography; HVOTO, hepatic venous outflow tract obstruction.

To the best of our knowledge there are only two case reports of BBF in post-LT patients and a few after hepatectomy, as shown in Table 2. Chaing et al. [4] reported a BBF in a 40-year-old post-LT woman from Taiwan. She developed biliary stricture and right subphrenic bile collection leading to BBF, for which she underwent percutaneous transhepatic biliary drainage (PTBD) [4]. A similar case was reported by Yeatman et al. [5]. The likely mechanism of the development of BBF in a post-LT setting is hypothesized to be because of the biliary stricture and bile leak in the subphrenic space, where bile acts as a tissue-corrosive agent, leading to the erosion of the diaphragm and subsequent communication with the right-hand bronchial tract. There was no rise in bilirubin level despite the biliary stricture. This can be explained by diversion of bile from the biliary system into the bronchi instead of the duodenum.

Table 2. Case reports of acquired BBF in post-liver surgery patients

Study	Subject		Primary diagnosis	Type of fistula	Interval between primary diagnosis and BBF	Clinical feature	Imaging/diagnostic modality	Treatment	Outcome on last follow-up
	Age (yr)	Sex
Post-liver transplantation
Yeatman et al. (2004) [5]	40	Female	Ruptured hepatic adenoma	Right subphrenic biloma to right lower bronchus	4 mo	Bilioptysis	Bronchoscopy showed bile in the bronchi	External biliary stent	Alive and healthy
Chaing et al. (2020) [4]	40	Female	Autoimmune hepatitis	Right subphrenic biloma to right lower bronchus	1 yr	Bilioptysis	MRCP showed fistulous communication	Subphrenic drainage tube and PTBD with internalization	Alive and healthy
Current study (2023)	7	Female	Wilson disease	Strictured biliary anastomotic site to the right thoracic cavity	3 mo	Bilioptysis	Bronchoscopy showed bilious content in the bronchi	Laparotomy, fistula tract excision, Roux-en-Y hepaticojejunostomy, and subphrenic drain	Alive and healthy
Post-hepatectomy
Eryigit et al. (2007) [6]	35	Male	Liver hydatid cyst	Unknown	2 mo	Bilioptysis	MRCP showed mild IHBRD; right thoracotomy showed fistula	Right thoracotomy, adhesiolysis, and fistula tract excision	Alive and healthy
	20	Male	Gunshot injury to liver and diaphragm	Unknown	15 day	Bilioptysis	None	Right inferior thoracotomy and lower lobectomy with postoperative chest and abdominal drains	Alive and healthy
	38	Male	Liver hydatid cyst	Unknown	4 mo	Bilioptysis, jaundice	Percutaneous cholangiography	Right inferior thoracotomy and lower lobectomy with postoperative subcostal drain	Alive and healthy
Kuo et al. (2014) [12]	68	Male	Hepatocellular carcinoma	Unknown	2 yr	Reduced right-hand air entry	Flexible bronchoscopy	Video-assisted thoracoscopic surgery, adhesiolysis	Alive and healthy
Hai et al. (2016) [13]	70	Male	Recurrent hepatocellular carcinoma	Common bile duct to right lower lung bronchus	2 wk	Bilioptysis	CT abdomen followed by fistulogram	Residual right bisectionectomy without resection of the fistulous tract and involved lung	Alive and healthy
Miranda García et al. (2018) [14]	57	Male	Sigmoid adenocarcinoma with metastatic liver disease	Subphrenic space to right lower lung	8 mo	Bilioptysis, fever	CT chest and abdomen; MRCP	Percutaneous transhepatic biliary drainage	Alive and healthy
Lazarou et al. (2019) [15]	64	Male	Metastatic colon cancer	Intrahepatic collection to inferior lobular bronchus	3 mo	Bilioptysis, fever, jaundice	CT chest and abdomen	ERCP with stenting and transhiatal fistula tract excision	Alive and healthy

BBF, broncho-biliary fistula; MRCP, magnetic resonance cholangiopancreaticography; PTBD, percutaneous transhepatic biliary drainage; IHBRD, intrahepatic biliary radicle dilatation; CT, computed tomography; ERCP, endoscopic retrograde cholangiopancreaticography.

The diagnosis is based on demonstrating the abnormal communication between the biliary tree and the bronchial tract, which is usually done by cholangiography via magnetic resonance cholangiopancreaticography or ERCP. CT and hepatobiliary iminodiacetic acid scans are other modalities for diagnosis. Chest imaging usually shows right lower lung heterogenous opacities with reactionary pleural effusion, and bronchoscopy shows the bilious content in the bronchi [7]. In our case, bronchoscopy showed bilious content, which was initially misinterpreted as the aspiration of the content of the stomach and was treated as aspiration pneumonitis. Later, the child presented with frank bilioptysis, which raised the possibility of BBF; exploratory laparotomy confirmed the diagnosis.

Management focused on correcting the primary hepatobiliary insult. The first step was to ensure adequate drainage of bile from the biliary tract to the duodenum without any obstruction in the path. The commonly used modalities are ERCP with sphincterotomy and biliary stenting [17] and PTBD (especially in postsurgical cases) [18]. Surgical closure by excision of the BBF remains the treatment of choice for complicated cases. Interventional radiological procedures, such as endobronchial embolization with silicone spigots and transhepatic microcoil embolization, have also been mentioned in the literature [19]. From the largest series on hydatid cyst BBF by Tocchi et al. [20], the thoracoabdominal incision approach was found to be better for post-surgical outcomes than abdominal- or thoracic-only incision. Refractory cases need thoracotomy and lung resection, which is the last resort when all other conservative modalities fail.

The pediatric literature is limited. From the Indian subcontinent, one case of BBF was reported in a 3-year-old child with ruptured liver abscess, where it was managed with right lateral thoracotomy, right lower lobectomy, and excision of the communicating tract [2]. Yang et al. [3] published a case report of a 10-year-old child who experienced liver rupture following a road traffic accident, for which he underwent repeated operations. He subsequently developed obstruction of the iatrogenic hepatic venous outflow tract and BBF and had to undergo LT [3].

In our case, the child was suspected to have BBF based on bilioptysis. On failure of the ERCP, exploratory laparotomy and successful surgical closure were undertaken with a postoperative right subphrenic drain. The child did well after the procedure and was discharged in hemodynamically stable condition with normal graft functions. This is the first case report of BBF in a child following LDLT. BBF is extremely rare in children, and it requires a high index of suspicion for the timely intervention and prevention of subsequent complications.

Conflict of Interest

No potential conflict of interest relevant to this article was reported.

Author Contributions

Conceptualization: all authors. Project administration: SG. Writing–original draft: VG, VK. Writing–review & editing: SA, SG. All authors read and approved the final manuscript.