Bouveret syndrome: a clinicoradiological perspective

Abstract

An 87-year-old woman presented to us with a 5-day history of worsening epigastric pain and vomiting. Her medical history included known gallstones and a previous episode of acute cholecystitis complicated by a perforated gallbladder for which she had declined surgery 5 years prior. Radiological imaging confirmed a large gallstone impacted in the first part of the duodenum with gross gastric outlet obstruction and pneumobilia, confirming the diagnosis of Bouveret syndrome, an often overlooked and rare variant of gallstone ileus. Following an unsuccessful oesophagogastroduodenoscopy for stone retrieval, she underwent a laparotomy and gastrotomy with a successful outcome and discharged from hospital 4 weeks following the procedure.

Background

Bouveret syndrome is a rare variant of gallstone ileus, first characterised preoperatively by Leon Bouveret in 1896. Gallstone ileus is a rare complication of cholelithiasis (0.3%–0.5%)¹ in which the gallstone passes via a fistula into the gastrointestinal tract causing bowel obstruction, most commonly at the ileocaecal junction.² In Bouveret syndrome, the gallstone lodges in the duodenum via a cholecystoduodenal or choledochoduodenal fistula and represents 1%–3% of cases of gallstone ileus.¹

This syndrome typically manifests in the comorbid elderly patient population, and results in further significant morbidity and mortality, 60% and 30%, respectively.³ Therefore, timely recognition, diagnosis and treatment is of paramount importance. Radiological investigations are essential to both diagnose and inform management strategy. In this report, we present a case of Bouveret syndrome with classical radiological findings and discuss the subsequent management in a high-risk patient.

Case presentation

An 87-year-old woman presented to us with a 5-day history of worsening epigastric pain and vomiting on a background of 3 weeks of weight loss, loss of appetite, indigestion and abdominal distension. Her medical history included a previous hospital admission 5 years prior for a perforated gallbladder for which she had declined surgery and opted for conservative treatment. Her other previous medical history included hypertension, gastro-oesophageal reflux, heart failure and diverticular disease.

On examination of the abdomen, there was mild distention with minor epigastric tenderness. There were no signs of peritonism. The bowel sounds were normal and there was no evidence of hernia. A per-rectal examination was not performed due to the patient’s wishes.

Investigations

An abdominal ultrasound scan was performed which showed a grossly distended stomach, pylorus and a large echogenic focus with posterior shadowing in the first part of the duodenum suggestive of gallstone (figure 1).

Figure 1.

(A) Static ultrasound image showing a distended stomach filled with fluid and gastric contents. (B) Static ultrasound image showing a large reflective echogenic focus with posterior acoustic shadowing (red arrow) consistent with a gallstone in the first part of the duodenum.

A subsequent abdominal CT scan showed a 2.5 cm gallstone impacted in the first part of the duodenum with resultant gastric outlet obstruction and pneumobilia (figure 2), thus confirming the diagnosis of Bouveret syndrome.

Figure 2.

CT scan showing a 2.5 cm gallstone impacted in the first part of the duodenum (D1) with resultant gastric outlet obstruction and pneumobilia (distended stomach, yellow arrow; pneumobilia, green arrow; gallstone impacted in D1, red arrow) in (A) axial, (B) coronal and (C) sagittal planes.

Treatment

The patient initially declined surgical intervention and therefore, following discussion in the appropriate multidisciplinary team meeting, oesophagogastroduodenoscopy (OGD) with stone retrieval was attempted but was unsuccessful. Following further consultation with the family, the patient consented to surgical treatment. The following day she underwent a laparotomy and gastrotomy. The gallstone was found impacted at the first part of the duodenum as shown on the CT and ultrasound scans. Examination of the gallbladder confirmed a cholecystoduodenal fistula with associated dense adhesions. The stone was extracted via the stomach, and examination of the entire small bowel revealed no further fragments or stones. The patient’s age, comorbidities and the generally poor condition of local tissues indicated simple stone retrieval⁴ rather than simultaneous cholecystectomy with fistula repair. She was scheduled for follow-up in clinic at 6 weeks.

Outcome and follow-up

The plan was to follow-up the patient in 6 weeks following discharge. However, due to the recent COVID-19 pandemic, the outpatient appointment was delayed and a phone consultation was arranged. The patient otherwise remains well and has not re-presented to due to similar symptoms.

Discussion

Bouveret syndrome typically affects females between the ages of 60 and 80.⁵ The common presentations are nausea and vomiting (87%), abdominal pain (71%) or haematemesis (15%).⁶ Given its rarity, it is an often overlooked diagnosis and should be considered, especially in the elderly population, presenting with features of cholelithiasis and gastric outlet obstruction.

The choice of primary investigation is dependent on the clinical presentation. Signs of bowel obstruction warrant a screening abdominal radiograph or a CT scan for a definitive diagnosis, whereas right upper quadrant or epigastric pain should ideally be investigated initially with an abdominal ultrasound to exclude gallbladder pathology. If haematemesis is the initial presenting symptom, then endoscopy is warranted.¹ CT scan is the radiographic modality of choice with a sensitivity and specificity of 93% and 100%, respectively.⁶ The value of CT scan may be limited in the instance of isoattenuating gallstones for which magnetic resonance cholangiopancreatography may offer an alternative.⁵ ultrasound has previously been used in isolation to diagnose Bouveret syndrome⁷ but from our experience it should commonly be used alongside CT scan. Classic findings on radiographic investigation are Rigler’s triad of small bowel obstruction, ectopic gallstone and pneumobilia (figure 2).⁷ OGD may be used in the diagnosis of Bouveret syndrome. However, findings have shown that the stone is only visualised in 69% of cases⁸ and therefore provides suboptimal diagnostic value.

OGD can be further used to retrieve the ectopic gallstone with a net or basket but is only successful in 10% of cases.⁸ Despite this, the minimally invasive nature of OGD leads to significantly lower morbidity and mortality compared with surgical options. This is a pertinent factor in the typical comorbid elderly patient population of Bouveret syndrome,¹ which rationalises its choice as a common first-line therapeutic approach. This patient-centred approach is evidenced in our case and in the existing literature.^{5 7 9} This case further suggests that OGD may be a more amenable first-line approach for these patients. Endoscopic retrieval may be aided by the use of mechanical, electrohydraulic or laser lithotripsy with the latter having a suggested success rate of 60%.⁸ However, the rarity of the condition and the lacking availability of the requisite equipment in a general operating theatre means that the sample size for such analysis is currently insufficient for drawing robust conclusions. Mechanical lithotripsy is more commonly performed with success rates of 25%.⁸

Combined endoscopic and surgical approaches have been attempted in the management of Bouveret syndrome. Khuwaja et al describe a case of successful endoscopic stone displacement distally followed by retrieval through enterotomy.⁵ Similarly, successful cases of laparotomy with distal milking of the stone and retrieval by enterotomy have been outlined.^{3 10} Laparotomy with proximal displacement has proven a less successful method requiring enterolithotomy.^{3 7} The majority of cases require surgical intervention for which the most commonly performed procedures are enterolithotomy and gastrotomy. The success rate of surgical treatment approaches 90%⁸ and is therefore a mainstay of treatment. This may be followed by a cholecystectomy with fistula repair in a one-stage or two-stage procedure.⁷ In elderly patients with multiple comorbidities, a two-stage procedure is recommended where the subsequent cholecystectomy with fistula repair is dependent on potential biliary complications.⁴ A one-stage procedure has a significantly higher mortality than a two-stage approach (16.9% and 11.7%, respectively), rationalising this recommendation.¹¹ Overall, 11% of patients with persistent cholecystoduodenal fistula experience associated cholangitis. Therefore, fistula repair presents preventative benefit. However, natural closure of cholecystoduodenal fistula is reported to occur in 61.5% patients¹² and only 10% patients require further surgical intervention with fistula closure due to persistent biliary symptoms.⁴ These findings provide rational for a watch and wait approach in the comorbid patient population for which a two-stage repair is indicated.

Timely diagnosis and management of Bouveret syndrome are essential for optimal outcome. This case serves to inform the classic presentation, radiological findings and treatment options for patient’s presenting with Bouveret syndrome.

Learning points.

• Bouveret syndrome is a rare condition and is often overlooked given its rarity and non-specific presenting clinical features. It should be suspected in elderly patients presenting with features of gastric outlet obstruction and a previous history of gallstones/gallbladder pathology. If left untreated, it is associated with significant mortality and morbidity, and therefore, timely diagnosis is important.

• CT scan is considered the gold standard in the initial diagnostic work-up. Ultrasound may also be diagnostic if CT scan is contraindicated or unavailable.

• Oesophagogastroduodenoscopy with stone retrieval is a potential treatment option as it is associated with reduced morbidity compared with surgical options, however surgical options have a much higher success rate in retrieving the gallstone and relieving obstruction.