A Rare Case of Cholecystoduodenal Fistula with Rapid Distal Gallstone Migration

Background

Obstruction of the gastrointestinal (GI) tract is a rare but serious and potentially fatal complication of gallstone disease. Gastric outlet obstruction (GOO) is any process that causes impaired or blocked emptying of the stomach. Furthermore, GOO due to a gallstone that has passed into the GI tract is known as Bouveret’s syndrome. Patients with acute GOO classically present with early satiety, abdominal pain, and postprandial vomiting. Patients with Bouveret’s syndrome occasionally present with Mirizzi syndrome, wherein an impacted stone in the cystic duct or neck of the gallbladder obstructs the hepatic duct [1]. As in our case described here, stones blocking the gastric outlet can become dislodged, either spontaneously or iatrogenically, and transit through the intestines, potentially causing damage or obstruction further along the GI tract. Our patient presented to a community hospital for management. The aim of the present work, which meets the Surgical Case Report criteria, is to describe surgery used to manage this complex presentation with the goal of preventing further complications associated with the disease process [2].

Case Report

PATHOLOGY:

Because additional images and illustrations were unavailable, detailed descriptions of the operative specimen, based on the information in the gross and microscopic pathology reports, are provided here.

GROSS DESCRIPTION:

The specimen was from a gallbladder gallstone and portion of the duodenum. It consisted of multiple ragged, disrupted fragments of gallbladder that could not be oriented; a separate, barrel-shaped calculus and a portion of possible bowel were loose in the container. The fragments of gallbladder were tan-brown, dusky, and rubbery and measured 6×5×2.0 cm in aggregate. The fragments contained multiple areas of defect, ranging from 0.2 cm up to 2 cm in the largest dimension. Definitive orientation could not be determined because the specimen was disrupted and ragged. No definitive cystic duct margin was identified on gross examination. The external surfaces of the fragments were cauterized, tan-brown, and disrupted; all had exposed tan-brown, dusky mucosa with a velvety appearance. Further sectioning of the larger fragment showed a wall thickness up to 0.4 cm. The calculus loose in the container, which was tan-brown to yellow, measured 3.5 cm long and 2.5 cm in diameter. The separate fragment of possible bowel in the container, which had exposed tan-brown, ragged, dusky mucosa, measured 2.5×1.2×1 cm.

MICROSCOPIC DESCRIPTION:

The gallbladder wall was thickened and fibrotic, with areas of transmural xanthogranulomatous inflammation. Fibrosis of the mucosa was variable, as was the degree of acute and chronic inflammation. Much of the xanthogranulomatous inflammation involved the wall of the gallbladder and serosa. There were also fragments of duodenal tissue, including mucosa, submucosa, and muscularis propria. There were areas of mucosal ulceration, with associated reactive epithelial changes, hemorrhage, edema, and submucosal and muscularis propria fibrosis. In some areas, there was a transmural infiltrate of neutrophils and eosinophils.

Discussion

Abnormal communicating channels or fistulas between the gallbladder, main bile duct, or intestines are rare, but they can result in serious complications [3]. The prevalence of internal biliary fistula is less than 0.3% in patients with gallstone disease; 70% to 90% are cholecystoduodenal fistulas, making them the most common type [4]. Patients with a cholecystoduodenal fistula may also present with Mirizzi syndrome, which has been described, in rare cases, in specific rural Chilean populations [1]. Most stones that pass through a cholecystoduodenal fistula do so uneventfully through the ileum or cause gallstone ileus, and just 2% to 4% of all gallstone-related obstructions result in Bouveret’s syndrome. Thanks to improved detection and surgical techniques, the mortality rate for Bouveret’s syndrome has dropped to <12% [5]. Endoscopic lithotripsy and stone retrieval is often the first-choice treatment in patients with symptomatic Bouveret’s syndrome, followed by surgical lithotomy and simple enterotomy only when attempts at stone retrieval fail [6]. Endoscopic lithotripsy, however, often results in fragmentation of the gallstone into smaller pieces that are capable of causing distal obstruction in the ileum, intestinal hemorrhage, or intestinal perforation [5]. Regardless of where the primary obstructing stone is located, the remaining portion of the bowel should be examined to exclude other stones. In our case, the obstructing stone had migrated to the mid-jejunum within hours of patient presentation and administration of oral contrast, underscoring the necessity of examining the entire bowel. A single study previously described another unique case of stone migration within a few days of the onset of GOO symptoms [5]. Again, our patient had even faster transit in stone migration, which led to high clinical suspicion and a need for immediate intervention to prevent morbidity and mortality.

In our case, the patient presented with the classic symptoms of nausea, non-bilious vomiting, and abdominal pain. However, she did not meet the “emergent” criteria of obstruction, given her continued ability to pass flatus and a produce bowel movement earlier in the day. When a CT scan revealed a gallstone that measured approximately 3 cm in the first portion of the duodenum, surgery was warranted to prevent distal migration and resolve the patient’s symptoms. During the procedure, which was performed within hours of her presentation and CT imaging, it was evident that the gallstone had migrated a significant distance distally to the mid-jejunum. This rapid migration was unexpected but did not create significant complications, such as perforation, distal obstruction, or intestinal hemorrhage. Had the distally migrated gallstone been recognized earlier in the surgery during initial inspection, a simple enterolithotomy could have been completed. This would have eliminated the need to disrupt the cholecystoenteric fistula and perform a cholecystectomy, thereby avoiding the potential for increased patient morbidity. Further, this type of approach would have allowed for expectant management following surgery, given the high probability of biliary-enteric fistula closure or spontaneous shrinkage. The standard of care for gallstone ileus management is highly controversial, ranging from enterolithotomy to cholecystectomy and fistula closure. For patients with gallstone ileus, however, the standard of care and most widely accepted and appropriate choice is simple enterolithotomy [7].

Conclusions

The presentations and complexities of GOO are multiple and varied in individuals who have complaints of early satiety, abdominal pain, and postprandial vomiting. Whether to manage medically and what type of surgery to perform must be decided early on in a patient’s course to decrease the overall risk of future complications. One potentially serious cause of GOO is a gallstone that has passed through an aberrant tract or fistula from the gallbladder or bile duct into the lumen of the GI tract, such as a cholecystoduodenal fistula. Various imaging modalities can be used for early diagnosis of GOO, ranging from CT to magnetic resonance (MR) and MR cholangiopancreatography [8].

Current surgical management of symptomatic Bouveret’s syndrome often begins with endoscopic lithotripsy and stone retrieval. Surgical lithotomy and simple enterotomy can only be used once stone fragment retrieval fails; that, in turn, can pre-dispose the patient to future and more devastating complications [9]. Furthermore, these types of gallstones have the potential for spontaneous displacement distally within the bowel, rather than secondary to lithotripsy or other iatrogenic causes. For these reasons, we recommend that clinicians have a high index of clinical suspicion for Bouveret’s syndrome during the diagnosis and evaluation of patients with GOO caused by passage of a gallstone through a cholecystoduodenal fistula. In such cases, the threshold for surgical intervention should be low to reduce patient morbidity and mortality.