Biliary fistulas: causes, symptoms, diagnosis, treatment

External biliary fistulas

External biliary fistulas usually develop after biliary procedures such as cholecystotomy, transhepatic biliary drainage, and T-tube drainage of the common bile duct. Very rarely, fistulas may develop as a complication of cholelithiasis, gallbladder cancer, or biliary trauma.

Due to sodium and bicarbonate losses in bile, patients with external biliary fistulas may develop severe hyponatremic acidosis and hyperammonemia. Biliary obstruction distal to the fistula prevents its healing. In such cases, endoscopic or percutaneous stent placement allows fistula closure without complex reoperation.

Internalbiliaryfistulas

In 80% of cases, the cause of internal biliary fistulas is the long-term existence of calculous cholecystitis. After the inflamed gallbladder fuses with a section of the intestine (usually the duodenum, less often the colon) and a fistula is formed, the stones enter the intestinal lumen and can completely block it (cholelith intestinal obstruction). This usually occurs in the terminal ileum.

Postoperative biliary strictures, especially after multiple attempts to eliminate them, can be complicated by the formation of fistulas, most often hepatoduodenal or hepatogastric. Such fistulas are narrow, short, and easily blocked.

A biliary fistula may develop as a result of penetration into the gallbladder or common bile duct of a chronic duodenal ulcer, a colon ulcer in nonspecific ulcerative colitis or Crohn's disease, especially if the patient has received corticosteroids.

In rare cases, the stone can lead to the formation of a fistula between the hepatic duct and the portal vein with massive hemobilia, shock and death of the patient.

Symptoms of biliary fistulas

The disease is preceded by a long history of cholelithiasis. Fistulas can be asymptomatic and close on their own after the stone passes into the intestine. In such cases, they are diagnosed during cholecystectomy.

Approximately one third of patients have jaundice in their medical history or on admission to hospital. Pain may be absent, but sometimes it is severe and resembles biliary colic in intensity. Symptoms of cholangitis may be present. In cholecystocolic fistulas, the common bile duct is filled with stones, putrefactive and fecal matter, which leads to severe cholangitis. The entry of bile salts into the intestine causes profuse diarrhea and significant weight loss.

Diagnosis of biliary fistulas

Radiographic signs include gas in the bile ducts and unusual placement of stones. The bile ducts may be contrasted after oral barium intake (in cholecystoduodenal fistulas) or after a barium enema (in cholecystocolic fistulas). In some cases, a distended small intestine is detected.

Usually the fistula is visualized by ERCP.

Treatment of biliary fistulas

Fistulas that develop as a result of gallbladder disease require surgical treatment. After separating the involved organs and closing the defects in their wall, cholecystectomy and drainage of the common bile duct are performed. Surgical mortality is high and amounts to about 13%.

Closure of cholecystocolic and bronchobiliary fistulas may occur after endoscopic removal of common bile duct stones. Intestinal obstruction caused by gallstones.

A gallstone larger than 2.5 cm in diameter that enters the intestine causes obstruction, usually at the ileum, less commonly at the duodenojejunal junction, duodenal bulb, pyloric region, or even the colon. As a result of the stone becoming trapped, an inflammatory reaction of the intestinal wall or intussusception develops.

Intestinal obstruction caused by gallstones is very rare, but in patients over 65 years of age, gallstones are the cause of obstructive intestinal obstruction in 25% of cases.

The complication is usually observed in elderly women with a history of chronic cholecystitis. Intestinal obstruction develops gradually. It is accompanied by nausea, sometimes vomiting, and cramping abdominal pain. When palpated, the abdomen is swollen and soft. Body temperature is normal. Complete obstruction of the intestine by a stone leads to a rapid deterioration in the condition.

Plain abdominal radiographs may show distended bowel loops with fluid levels, sometimes a stone causing the obstruction. Gas in the bile ducts and gallbladder indicates a biliary fistula.

Plain radiography on admission allows the diagnosis to be established in 50% of patients, and in another 25% of patients the diagnosis is established using ultrasound, CT, or radiographic examination after taking a barium suspension. In the absence of cholangitis and fever, leukocytosis is usually not observed.

Before laparotomy, gallstone intestinal obstruction can be diagnosed in 70% of cases.

The prognosis for the disease is poor and worsens with age.

After correction of water-electrolyte imbalances, intestinal obstruction is eliminated surgically. The stone is pushed into the lower sections of the intestine or removed by enterotomy. If the patient's condition and the nature of the bile duct lesion allow, cholecystectomy and fistula closure are performed. Mortality is about 20%.