Gallstone ileus managed with enterolithotomy

Abstract

Although gallstone disease is classically associated with the inflammatory sequela of cholecystitis, other presentations include gallstone ileus, Mirizzi syndrome, Bouveret syndrome and gallstone ileus. Gallstone ileus occurs when a gallstone passes from a cholecystoduodenal fistula into the gastrointestinal tract and causes obstruction, usually at the ileocaecal valve. It represents an uncommon complication of cholelithiasis, accounting for 1%–4% of all cases of mechanical bowel obstruction and 25% of all cases in individuals aged >65 years. It has a female predilection. Clinical presentation depends on the site of the obstruction. Diagnosis can prove challenging with the diagnosis rendered in 50% of cases intraoperatively. The authors present the case of a 79-year-old woman with a 10-day history of abdominal pain, nausea, vomiting and episodes of loose stools. An abdominal radiograph showed mildly distended right small bowel loops. Further investigation with a CT of the abdomen and pelvis demonstrated small bowel obstruction secondary to a 3.3 cm calculus within the small bowel. She underwent a laparotomy and a 5.0×2.5 cm gallstone was evident, causing complete obstruction. An enterolithotomy was performed. Her postoperative course was complicated by Mobitz type II heart block requiring pacemaker insertion. This paper will provide an overview of the clinical presentation, investigations and management of gallstone ileus. It provides a cautionary reminder of considering gallstone ileus in the differential diagnosis in elderly patients presenting with bowel obstruction and a history of gallstone disease.

Background

Surgical management for gallstone ileus with fistula formation remains controversial. Non-operative strategies to resolve obstruction due to the comorbidities of this patient cohort should be considered. In elderly patients with significant comorbidities, enterolithotomy alone is advised. A one-stage procedure (enterolithotomy, cholecystectomy and fistula repair) should be reserved for low-risk patients.¹

Presentation

A 79-year-old woman presented to the emergency department with a 10- day history of generalised abdominal pain, nausea, vomiting and loose stools. Her medical history included secondary Sjogren syndrome, hypertension, type 2 diabetes mellitus, chronic renal impairment and a right middle coronary artery infarct following percutaneous coronary intervention. In addition, she had microcytic anaemia and an oesophago-gastro-duodenoscopy (OGD) identified a hiatus hernia. She had a previous history of gallstone disease requiring intravenous antimicrobial therapy for acute cholecystitis. An ultrasound scan of her abdomen showed multiple gallstones, one in the infundibula and a dilated common bile duct (10 mm). As her inflammatory markers remained elevated (C reactive protein (CRP) of 200), a CT of the abdomen and pelvis was performed. It confirmed the diagnosis of acute cholecystitis secondary to gallstones with no evidence of a liver abscess. She declined a laparoscopic cholecystectomy. Her medications included clopidogrel, bisoprolol, ramipril, linagliptin, gliclazide, metformin, folic acid and glyceryl trinitrate spray. She was allergic to amlodipine. She had poor exercise tolerance of <100 yards. Physical examination confirmed mild distension and tenderness of her abdomen. Bowel sounds were present on auscultation. Digital rectal examination was unremarkable.

Investigations

Her observations were as follows: HR 93, blood pressure (BP) 133/63 mm Hg, respiratory rate (RR) 14, SpO₂ 100% on air and temperature 36.80°C. Her venous blood gas confirmed a lactate of 1. Haematological investigations showed a low haemoglobin (104 g/L) and an elevated CRP (112 mg/L). Her chest radiograph showed mild pulmonary congestion but no focal consolidation, lobar collapse or pleural effusion. Her abdominal radiograph showed a non-specific bowel gas pattern (figure 1). She had type VII stools. The clinical impression was of gastroenteritis and an acute kidney injury. She was transferred to the gastroenterology ward for further investigation and management of her loose stools. She completed a course of oral metronidazole 400 mg three times a day. Her stool cultures were negative for Clostridium difficile. Her thyroid function tests were normal. A flexible sigmoidoscopy showed diverticulosis. She commenced treatment with cholesytramine 8 g once daily. A repeat abdominal radiograph 24 hours later showed mildly distended right small bowel loops (figure 2). Further investigation with a CT of the abdomen and pelvis with contrast showed aerobilia. A fistula was noted between the duodenum and gallbladder and within the ascending colon. There was small bowel obstruction secondary to a 3.3 cm calculus within the small bowel (figure 3). The distal small bowel and colon were collapsed. Only one calculus was visualised. Minor bibasal atelectasis in the lung bases was observed.

Figure 1.

The patient’s abdominal radiograph showing a non-specific bowel gas pattern.

Figure 2.

A repeat abdominal radiograph 24 hours later showed mildly distended right small bowel loops.

Figure 3.

Further investigation with a CT of the abdomen and pelvis with contrast showed aerobilia and small bowel obstruction secondary to a 3.3 cm calculus within the small bowel.

Differential diagnosis

The working diagnosis was of gallstone ileus and emergency surgery was scheduled.

Treatment

The patient was resuscitated with intravenous fluids. A nasogastric tube was inserted for decompression and a urinary catheter was inserted. She underwent an exploratory laparotomy via an upper midline incision. The proximal bowel was dilated to the mid ileum. A 5.0×2.5 cm gallstone was observed causing complete obstruction (figure 4). An enterotomy was performed and the gallstone was extracted between the bowel clamps. Manual inspection of the entire small and large bowels revealed no other stones. The bowel mucosa was healthy with no evidence of contamination. The fascia was closed with polydioxanone (PDS) and skin clips. 40 mL of 0.25% bupivicaine with epinephrine was infiltrated in to the wound.

Figure 4.

The calculus was observed in the small bowel.

Outcome and follow-up

Her nasogastric tube was left on free drainage. Four days postoperatively, she became bradycardic (HR 42) and hypotensive (BP 85/55 mm Hg). A 12-lead ECG showed Mobitz type II heart block. She underwent pacemaker insertion. She was discharged home unremarkably.

Discussion

In 1654, Dr Erasmus Bartholin, a Danish physician and mathematician, first described gallstone ileus following an autopsy examination.² Interestingly, the term ‘gallstone ileus’ is a misnomer as it is a mechanical obstruction of the gut and is not a true ileus. It occurs in 0.3%–0.5% of patients with cholelithiasis and has a female predilection (3.5, 6:1).³ Adhesions form between the inflamed gallbladder and an adjacent part of the gastrointestinal tract. As a consequence of pressure necrosis from large stones within the gallbladder, a cholecystoenteric fistula is subsequently formed, thus allowing gallstones direct access to the gut.⁴ Most fistulas involve the duodenum, but fistulas to the stomach and colon have been described. A bilioenteric fistula between the gallbladder and the transverse colon represents a rare event.⁵ This results in its impaction in the bowel, most commonly the terminal ileum or the ileocaecal valve, if its diameter is at least 2.0–2.5 cm.⁶ Smaller gallstones may pass spontaneously through a normal gastrointestinal tract and will be excreted uneventfully in the stool. It accounts for 1%–4% of all hospital presentations with small bowel obstruction, and 25% of cases occur in individuals aged >65 years.¹ The multiple comorbidities in this patient cohort contributes to the high morbidity and mortality. The first large series of gallstone ileus was published by Courvoisier in 1890 and it described a mortality of 44%.⁶ Cases have also been reported after endoscopic retrograde cholangiopancreatography and endoscopic sphincterotomy. Spillage of gallstones during a laparoscopic cholecystectomy may cause an intra-abdominal abscess, ulcerate the intestinal wall and gain entrance to the bowel lumen, causing gallstone ileus. Individuals present with non-specific symptoms resulting in a diagnostic delay. It may be preceded by a history of prior biliary symptoms or acute cholecystitis. However, symptoms of intestinal obstruction may be described, such as nausea, vomiting, abdominal pain and failure of the bowels to open. Only 50% present with a history of biliary disease. The average time between symptom onset and presentation is 4–8 days. Physical examination may be non-specific. Patients are often acutely unwell with abdominal tenderness and high-pitched bowel sounds on auscultation. Signs of obstructive jaundice may be present. Ischaemia may develop at the site of gallstone impaction, resulting in necrosis, perforation and peritonitis. Bouveret syndrome is a variant of gallstone ileus where the gallstone lodges in the duodenum or pylorus, causing a gastric outlet obstruction; hence, a dilated stomach is evident on plain abdominal radiograph. There is an intimate relationship between Mirizzi syndrome and biliary enteric fistulas. Marcelo’s study showed that 90% of patients who had biliary enteric fistula had concomitant Mirizzi syndrome.^{7 8}

Plain abdominal radiographs have a low sensitivity for detecting gallstone ileus. Features of gallstone ileus include pneumobilia, the presence of an aberrant gallstone and enteric obstruction (Rigler’s triad).⁹ Balthazar and Schechter described another sign, consisting of two air fluid levels in the right upper quadrant on abdominal radiograph.¹⁰ The medial air fluid level corresponds to the duodenum and is lateral to the gallbladder. Ultrasound is more sensitive at detecting pneumobilia and ectopic gallstones. CT is the investigation of choice with a high sensitivity of 93%.¹¹ However, the diagnosis is often rendered at laparotomy in a patient undergoing an operation for unexplained small bowel obstruction. The management of gallstone ileus remains controversial with no clearly defined guidelines in the literature. Enterolithotomy and stone extraction will resolve the intestinal obstruction as in our case but will leave the patient at risk of acute cholecystitis, cholangitis, Mirizzi syndrome and a further episode of gallstone ileus. It involves identification of the stone within the gastrointestinal tract and making a longitudinal incision into the bowel at a healthy segment proximal to the impaction site. The stone is extracted through the incision site. Attempts to crush the gallstone in situ should be avoided. This approach has a 4.9% mortality rate, and there is a risk of repeated impaction from further stones (5%–33%).¹² Gallbladder cancer is a potential complication of biliary enteric fistula.¹³ Spontaneous closure of the fistulous tract is observed in >50%.¹⁴ Attempts at laparoscopic enterolithotomy have also been described. Alternative approaches include enterolithotomy, cholecystectomy and fistula repair as a one-step procedure, or an enterolithotomy and interval cholecystectomy with fistula repair when patients have recovered from their acute episode. The reported rate of recurrent gallstone ileus is between 5% and 9% in those patients treated by enterolithotomy alone.¹⁵ The most common postoperative complications include acute renal failure, urinary tract infection, ileus, anastomotic leak, intra-abdominal abscess, enteric fistula and wound infection. Gallstone ileus represents <1% of gastrointestinal obstruction cases and occurs more frequently in the elderly. Concomitant comorbidities, such as hypertension, diabetes, heart failure and chronic obstructive pulmonary disease in this patient cohort, contribute to the high morbidity and mortality. Diagnosis is often delayed due to its non-specific clinical presentation, and a mean delay of 4 days from symptom onset to hospital admission has been described. CT is the imaging modality of choice. Surgical management of the obstruction with enterolithotomy remains the cornerstone of management.

Learning points.

• Gallstone ileus occurs when a gallstone passes from a cholecystoduodenal fistula into the gastrointestinal tract and causes obstruction, usually at the ileocaecal valve.

• It is a rare disease and should be suspected in patients with intermittent intestinal obstruction, advanced age, cholelithiasis and previous episodes of cholecystitis. Its diagnosis is challenging and Rigler’s triad is pathognomonic.

• The mainstay of management is surgical relief of the gastrointestinal obstruction. The current surgical procedures include¹ enterolithotomy,² enterolithotomy, cholecystectomy and fistula closure as a one-stage procedure and³ enterolithotomy with cholecystectomy performed later as a two-stage procedure.