Bouveret’s syndrome treated with endoscopic electrohydraulic lithotripsy

Abstract

Bouveret’s syndrome is a rare form of small bowel obstruction caused by a large biliary stone entering the lumen of the duodenum or the stomach through a bilioenteric fistula. Treatment options include various surgical techniques. However, recent advances in endoscopy also allow non-surgical endoscopic treatment options. We report a 68-year-old man, with a disseminated small intestinal neuroendocrine tumour, presenting with Bouveret’s syndrome without any previously reported biliary disease. He experienced a number of symptoms 1 month prior to his admittance, which were difficult to differentiate from other infectious diseases and complications due to his neuroendocrine tumour. Abdominal CT showed a biliary stone impacted in the duodenal bulb, small bowel obstruction, pneumobilia and a bilioenteric fistula. The patient was treated with endoscopic electrohydraulic lithotripsy to fragment the large gallstone in smaller retractable pieces. The patient avoided major surgery and was discharged the following day.

Background

Bouveret’s syndrome, first published by Léon Bouveret in 1896, is a rare cause of mechanical bowel obstruction initiated by the passage of a large biliary stone through a cholecystoduodenal or choledochoduodenal fistula.^1–6 In case of Bouveret’s syndrome, the biliary stone is impacted in the duodenum or stomach, but a more common location of the impaction is the terminal ileum (60%–85%), which is commonly called gallstone ileus.^{4 5} The enterobiliary fistulas, leading to Bouveret’s syndrome and mechanical bowel obstruction in general, are rare complications to chronic long-standing cholecystitis. They occur as a result of inflammation and obstruction of the cystic duct, which can cause adhesions of the gallbladder to adjacent tissue such as duodenum, stomach or colon.^{1 2} Less than 1% of all patients, with a known biliary stone disease, develop intestinal obstruction.^{2 4 5}

Bouveret’s syndrome can be managed by surgery or endoscopically if the size allows it.⁶ Recent improvements in endoscopy allow the stone to be fractured into smaller pieces and thereby making it retractable. One of these techniques is called endoscopic electrohydraulic lithotripsy (EHL).¹ We report a rare case of Bouveret’s syndrome in a 68-year-old man, with a disseminated small intestinal neuroendocrine tumour (NET), successfully treated with endoscopic EHL and discharged the following day.

Case presentation

A 68-year-old male patient presented with a 2-week history of postprandial periumbilical pain (verbal rating scale 5 out of 10) and vomiting. Additionally, a 1-month history of malaise, loss of appetite, cough, fever, rashes on both thighs and a weight loss of 8 kg. After the diagnosis was made, the patient revealed that he had classic symptoms related to biliary colic for at least 2–3 months, which included intermittent upper abdominal pain (approximately 8–9 days apart). He had a medical history with a disseminated small intestinal NET located in the proximal ileum. He was treated with antibiotics, several times prior to his admittance, due to fever and slightly elevated C reactive peptide (CRP), which probably was an undetected cholecystitis. He was finally referred to the hospital by his general practitioner as he presented with worsening of his abdominal pain (verbal rating scale 10) and early signs of high bowel obstruction.

Investigations

Abdominal examination and vital signs were normal. Laboratory results were as follows: CRP: 15 mg/L; leukocytes: 14.2×10⁹/L; alanine aminotransferase: 95 U/L; alkaline phosphatase: 113 U/L; and amylase: 46 U/L. Electrolytes and bilirubin levels were normal. A following abdominal CT scan revealed pneumobilia, a cholecystoduodenal fistula and a 3 cm biliary stone located in the duodenum causing small bowel obstruction (figure 1).

Figure 1.

Abdominal CT scan. The arrow showing the biliary stone in the duodenum.

Treatment

The patient was treated with intravenous fluids and a nasogastric tube. An esophagogastroduodenosocopy showed an obstructing biliary stone located in the duodenal bulb, and the initial attempt to retract or shatter the biliary stone was unsuccessful due to the hard consistency of the stone (figure 2). A subsequent attempt with endoscopic EHL was initiated under general anaesthesia. The biliary stone was successfully fragmented into several pieces and retrieved. A visible fistula was noted in the duodenal bulb, and several biliary stone fragments were detected and removed from the fundus region of the ventricle. The patient had an uneventful recovery and was discharged the following day.

Figure 2.

Endoscopic view of the biliary stone impacted in the duodenum.

Outcome and follow-up

At 2-month follow-up, the patient had no complaints and fully recovered.

Discussion

We presented a rare case of Bouveret’s syndrome successfully treated with endoscopic EHL. In this case, the patient had a disseminated small intestinal NET. A minimally invasive treatment was a high priority due to this comorbidity.

The clinical picture of Bouveret’s syndrome can be non-specific. The CT scan showed Rigler’s triad (small bowel obstruction, pneumobilia and an ectopic biliary stone), which is a classic radiological sign of intestinal gallstone obstruction.³ However, a concomitant visualisation of all three findings is seen in less than 50% of any abdominal imaging.⁵

The treatment for Bouveret’s syndrome remains to be controversial,^{4 5} and different surgical treatment options are possible.^1–5 However, the morbidity and mortality rates after surgery are reported to be around 60% and 20%–30%, respectively.^{2 4 6} Although laparoscopic treatment is a minimally invasive surgical option, the management of Bouveret’s syndrome seems challenging with a laparoscopic approach only, which leaves the patient with much more extensive surgery. In a previously reported case of Bouveret’s syndrome, the initial laparoscopic procedure was converted to open surgery with a partial gastrectomy and Billroth II gastrojejunostomy.⁷ In case of an elderly patient with many comorbidities, a much less extensive endoscopic management as the EHL technique is preferred compared with the scenario mentioned above with the extensive surgery.

One possible risk associated with the EHL technique is the distal migration of smaller fragments, which may result in a distal obstruction.² Another disadvantage to the EHL technique is the risk of bleeding and perforation, which is believed to be related to the shock wave dispersion. This risk can be reduced with sufficient water immersion.⁸ Most EHL complications such as the above mentioned and sepsis, cholangitis or pancreatitis are seen when performing endoscopic retrograde cholangiopancreatography or transhepatic biliary drainage. The reported complication rate is 7%–9% for the treatment of common bile duct stones with EHL,⁹ but this may not be comparable with the complication rate when using EHL to treat an impacted gallstone in the duodenum.

In the presented case, we did not perform a fistula repair, and this is also the case in the majority of the examples in the literature.^{7 10} Recurrent gallstone ileus is a possible risk,¹¹ but the benefit of minimal surgical stress outweigh this risk in the high-risk surgical patient.

In conclusion, a patient with Bouveret’s syndrome avoided major surgery due to successful treatment with endoscopic EHL. This was followed by a fast recovery and discharge the following day. In general, an initial endoscopic approach should be considered in duodenal biliary stone obstruction, especially in high-risk patients.

Learning points.

• The enterobiliary fistulas, leading to Bouveret’s syndrome and mechanical bowel obstruction in general, are rare complications to cholecystitis.

• An initial endoscopic approach with electrohydraulic lithotripsy should be considered in duodenal biliary stone obstruction, especially in high-risk patients.

• Avoiding major surgery when minimal invasive treatment options are available.