The vast majority of CEF results in patients with
previous cholecystitis or chronic cholecystitis. Most cases occur in women
around the age of 60, the female-to-male ratio varies from 1.9 to 2.5:1 [1,3].
The incidence is estimated to affect between 3-5% of patients with
cholelithiasis and 0.15-4.8% of all who undergo surgery of the biliary tract
[4,5]. The three most common types of CEF are cholecystoduodenal (75-80% of all
CEF), cholecystocolic, and cholecystogastric [1-7]. Historically, CEF was
always an incidental finding during surgical procedures [8], Bartholin was the
first to record a case of CEF with the entrance of a gallstone into the
intestinal tract in a patient examined at autopsy in 1654. Later, in 1890,
Courvoisier published an article in which he reported 131 cases of gallstone
ileus [9]. CEF was considered a contraindication for laparoscopic
cholecystectomy (LC) at the beginning of the laparoscopic era, but since the
late 1980s, LC has been a widely accepted method for treating gallbladder
disease [5-8]. Most internal biliary fistulas develop spontaneously. About 91%
to 94% of spontaneous internal biliary fistulas are caused by stones in the
biliary tract [10]. There are two possible explanations for the CEF, the first
theory is based on the erosion of stones through the injured wall of the
gallbladder into the duodenum, colon, or stomach. The second theory involves
acute inflammation with obstruction of the cystic duct, causing the gallbladder
to stretch and swell, sometimes rubbing the gastrointestinal tract and forming
adhesions between two organs with subsequent gangrenous changes with eventual
erosion, thereby establishing a lasting anomalous communication [4-11]. The
fistula allows gallstones to migrate into the digestive tract, being
responsible for 1-4% of all mechanical intestinal obstructions [3].
The clinical presentation of CEF is highly variable,
in its chronic presentation it is indistinguishable from the dyspeptic symptoms
of uncomplicated cholelithiasis, such as abdominal weight and bloating,
belching, nausea, pain in the right upper quadrant of the abdomen, or back pain
[5,10]. In cases of acute presentation, they present with signs compatible with
gastric outlet obstruction. Physical examination is frequently nonspecific.
Common findings include dry mucous membranes, abdominal distension, abdominal
tenderness, and high-pitched bowel sounds. Occasionally, there may be features
consistent with gastrointestinal bleeding, often because of a marginal ulcer at
the site of the fistula or erosion into surrounding vascular structures [1]. A
long history of cholecystolithiasis, especially >5 years, should raise
suspicion about the presence of CEF [8]. The diagnosis of CEF is usually an
incidental finding, most studies report that the fistulas are revealed
incidentally by other radiologic studies to investigate biliary conditions,
pancreatic diseases, or intestinal obstructions [4]. An accurate preoperative
diagnosis is difficult due to its non-specific presentation. Nevertheless,
advances in imaging diagnosis coupled with the development of endoscopic
techniques have markedly improved preoperative diagnostic accuracy [2,3].
Computed tomography (CT) has proven to be very useful in the diagnosis, though
in some cases, advanced imaging techniques, such as magnetic resonance imaging
(MRI), and even invasive techniques, such as endoscopic ultrasound or
endoscopic retrograde cholangiopancreatography (ERCP) must be employed [2].
Intestinal obstructions are easily detected by CT, which is also useful for
excluding neoplastic lesions located in the hepatic hilum or in the liver.
Pneumobilia may be evident on CT and is highly suggestive of a biliary-enteric
fistula. Magnetic resonance cholangiopancreatography (MRCP) has superior
diagnostic accuracy in about 50% of cases, thus providing better information
about the structure and contents of the biliary tree4. The predictive value of
ultrasound for detecting CEF remains low, but signs such as thick-walled
gallbladder, gallbladder atrophy, and pneumobilia are valuable clues of CEF
[3,8]. In addition, when CEF is suspected, upper gastrointestinal imaging and
gastroscopy/colonoscopy should be considered, which can observe the fistula or
communication between the gastrointestinal tract and the gallbladder [3].
Laboratory studies are typically nonspecific but may show evidence of
hyperbilirubinemia, leukocytosis, electrolyte abnormalities, acid-base
alterations, and renal failure [1].
Failure to diagnose CEF preoperatively may result in
challenges for the surgeon, who may be required to perform unanticipated
complex and extensive procedures. This circumstance may cause catastrophic
damage to the patients, most of whom are aged and have comorbidities.
Therefore, a preoperative diagnosis, although difficult, is essential to ensure
appropriate management [8]. Since most CEF arise due to underlying chronic
cholecystitis, cholecystectomy is frequently part of the management strategy
[2]. The standard treatment of CEF consists of cholecystectomy and repair of
the fistulous opening either by a laparoscopic, or an open approach, depending
on the condition of the patient and the experience of the surgeon [4].
Traditionally, most scholars advise CEF should be managed in an open manner
because of the dense adhesion and the obscured Calot's triangle [3]. However, open
surgery in this patient population is fraught with increased morbidity and
mortality (up to 12–27%) because up to 80% of patients with CEF have multiple
comorbidities [1]. LC has many advantages over open cholecystectomy, including
marked pain relief and a shorter recovery time. In addition, LC is not
associated with increased mortality or morbidity [8]. Nevertheless, other
studies show that the rate of conversion to open surgery is still high. The
need for conversion is most likely related to bleeding, difficulty in
intestinal suturing, and inflammation around the gallbladder [3,8]. Whenever a
difficult dissection or significant bleeding is found in a laparoscopic
approach, intestinal suturing can increase the risk of injury to the biliary
tree [4]. An alternative to intracorporeal or extracorporeal sutures for
fistula closure is the use of an endoloop or stapler [5]. Finally, endoscopic
therapy (mechanical, laser, or extracorporeal shock wave lithotripsy with stone
removal) may be considered in those with a large enteric gallstone obstructing
the gastric outlet or proximal duodenum [1].