Introduction

Sigmoid gallstone ileus represents a rare complication of cholelithiasis, accounting for 1–4% of all cases of large-bowel obstruction [1]. Most commonly it is due to the transit of gallstones through a cholecysto-colonic fistula. This is a highly morbid, and often fatal, condition due to its challenging diagnosis and late presentation [2,3,4]. Primary symptoms include abdominal distension, pain and vomiting, the latter can easily be mistaken for other causes of intestinal obstruction. There are three characteristic radiographic signs known as “the Rigler triad” in gallstone ileus: intestinal obstruction, pneumobilia, and the presence of an aberrant gallstone [5, 6]. Abdominal contrast-enhanced computed tomography represents the optimal imaging tool for a detailed visualization of both the site of obstruction and the cholecysto-colic fistula.

We describe a rare case of sigmoid gallstone ileus in an elderly female patient followed by a comprehensive review of the available literature on therapeutic management.

Case Report

A 90-year-old woman was admitted to the Emergency Department with severe abdominal pain, nausea and constipation lasting five days. The patient had recently been hospitalized for obstructive jaundice caused by metastatic pancreatic head cancer, palliated with biliary stenting. She had a history of diverticular disease. Physical examination revealed abdominal distension, diffuse abdominal pain, with no signs of peritonitis. Laboratory tests showed elevated inflammatory markers and normal liver function tests. An abdominal multiphase computerised tomographic scan revealed a collapsed empty gallbladder with pneumobilia, a cholecystocolonic fistula connecting the gallbladder to the right colic flexure (Fig. 1), and a 6 × 3 cm gallstone lodged in the proximal sigmoid colon (Fig. 2a, b). After discussion with endoscopists, a colonoscopy deferred due to the large gallstone that increased the likelihood of procedural failure and complications. Accordingly, the patient underwent urgent laparotomy with a colotomy performed to remove the gallstone (Fig. 3). The radiographic and actual appearance of the gallstone was most consistent with a pigment stone.

Fig. 1
figure 1

Abdominal CT-scan: a coronal view and b sagittal view showing the cholecysto-colonic fistula connecting the gallbladder to the hepatic flexure (white circle)

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Fig. 2
figure 2

Abdominal CT-scan: a axial view (white arrow), and b sagittal view (white star) showing a gallbladder stone impacted in the proximal sigmoid colon with narrowing of the lumen due to diverticular disease

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Fig. 3
figure 3

Giant gallstone retrieved from the sigmoid colon

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The colotomy was then closed with a continuous transverse monofilament suture. Due to tenacious adhesions in the supra-mesocolic compartment, the presence of significant neoplastic lymphadenopathy at the root of the mesentery, and the patient's overall clinical condition, the cholecysto-colonic fistula was left untreated. In the post-operative follow-up, the patient experienced a rapid recovery of normal bowel function; she was discharged on day six in stable condition.

Discussion

Gallstone ileus is caused by the migration of gallstones from the gallbladder to the bowel through a cholecystoenteric fistula [1, 2]. Acute inflammation of the gallbladder, along with obstruction of the cystic duct promotes ulceration and ischemia of the gallbladder wall with subsequent adherence of the gallbladder to adjacent organs, creating an abnormal communication between them. The sigmoid colon represents the most common colonic location for the lodged gallstone in the case of cholecysto-colonic fistula, accounting for over 85% of cases, since it is the narrowest part of the colon with a diameter of just 2.5 cm [2,3,4]. Furthermore, it is the most frequent location for diverticular disease, which can further reduce the lumen size. The right colon is the least frequent location for gallstone impaction due to its larger diameter.

Treatment options for large-bowel gallstone ileus include endoscopic extraction of the gallstone (although this is rarely successful for gallstones > 2.5 cm), endoscopic lithotripsy, decompression tube placement, and surgery, which can be performed as a one-stage or two-stage operation [2,3,4]. Among surgical procedures, the simple cololithotomy is the most appropriate treatment option for the majority of patients. Furthermore, spontaneous closure of the fistula without any treatment of the biliary tract can occur in 61.5% of cases after cololithotomy [2,3,4]. Such a result was observed in a recent follow-up study after cololithotomy, where follow-up colonoscopy revealed spontaneous closure of the fistulous connection [7].

We searched for articles published from 2003 to 2023 in Medline/PubMed using the following keywords: “sigmoid gallstone ileus”, “colonic gallstone ileus”, “large bowel gallstones ileus”, “colonic gallstones ileus” “cholecystocolonic fistula” to identify relevant articles published in English, French, German, Spanish or Italian. Reference lists from the articles were reviewed to identify additional pertinent articles. Retrieved manuscripts (case reports, reviews, and abstracts) were reviewed by the authors, with the data were extracted using a standardized collection tool.

From the literature data analysis, the mean age of patients was 76.8 years-old (ranging from 44 to 93 years), with a male-to-female ratio of 9/26, and the average gallstone diameter was 4.2 cm (2–7 cm). The most common location for lodged gallstones in case of cholecysto-colonic fistula was the sigmoid colon (83.3%), followed by the descending colon, recto-sigmoidal junction, proximal transverse colon, and cæcum-ascending colon. In more than half of all cases, the fistulous connection was situated at the right hepatic flexure. The leading cause of colonic obstruction was diverticular disease. Endoscopic lithotripsy and stone extraction were successfully performed in 13.9% of patients, whereas enterolithotomies, one-stage operations with enterolithotomy, cholecystectomy and fistula closure, Hartmann's procedures, sigmoidectomies, loop colostomies were carried out in the remainder. The average hospital stay was 9.1 days, with a mortality rate of 5.5%. A summary of all the retrieved articles [7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40] is provided in Table 1. Currently, there are no robust data on whether primary or delayed cholecystectomy is mandatory in cholecysto-colonic management since long-term follow-up is missing [3, 4]. In most cases, the repair and closure of cholecysto-colonic fistula was delayed [9, 13, 34].

Table 1 Summary of studies reporting the diagnosis of colonic gallstone ileus
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If available, the first option should be colonoscopic removal via mechanical or laser lithotripsy. Gastroenterologists and surgeons should take into account endoscopic management of colonic gallstone ileus in high-risk surgical patients without contraindications to endoscopy. The first successful colonoscopic stone extraction was performed in 1977 by Zaretzky et al. using a two-stage approach [41]; first the tip of the colonoscope was used to push the mucosa over the surface of the stone, the polypectomy snare was then applied to the protruding tip, and the stone was pulled using multiple repetitions of this sequence. After about 2 h, the stone was dislodged. Twenty-four hours later, the stone became lodged in the anal canal and was removed manually. Sigmon et al. [19] reported a successful attempt to remove a colonic gallstone measuring approximately 4.5 × 3 cm by using an adult therapeutic gastroscope in a patient with ulcerative colitis. O'Brien et al. in 2017 [22] described a novel method in a patient who was successfully managed with on-table endoscopy and, under local anesthetic, the formation of a left iliac fossa loop colostomy, facilitating stone delivery via enterolithotomy. The author advocated this technique in patients not able to tolerate a general anesthesia. A Spanish experience in 2022 [35] reported a successful resolution of sigmoid biliary obstruction by endoscopic pneumatic dilatation and subsequent removal of small impacted gallstones with biopsy forceps in high-risk patients with sigmoid stricture. In other cases, an endoscopically placed decompression tube may suffice [34].Though with very large stones, the endoscopic approach is generally unsuccessful, with a high risk of iatrogenic colonic perforation needing subsequent surgical treatment, with appropriate expertise and available equipment in selected cases, endoscopy and lithotripsy are useful tools. Moreover, in fragile, frail, and elderly patients, large-bowel obstruction may to lead colonic perforation and segmental ischemia with subsequent acute peritonitis, requiring emergency surgical treatment. From the literature data analysis, a colonic perforation was encountered in three patients [12, 26, 38]. In a recent systematic review, Augustin et al. [3] also found that acute presentation is more likely to be treated surgically than chronic/subacute presentation, regardless of stone size.

Conclusion

The primary goal in cases of colonic gallstone ileus is to promptly resolve intestinal obstruction and, if feasible, to prevent any involvement of the gallbladder area. Though endoscopic treatment is generally suggested for first-line treatment, depending on stone diameter and clinical condition of the patients, a multidisciplinary discussion between endoscopists and surgeons is often needed to choose the optimal therapeutic option, especially in high-risk patients.

Key Messages

  • Sigmoid gallstone ileus represents a rare complication of cholelithiasis, accounting for 1–4% of all cases of large-bowel obstruction.

  • If available and feasible, the first option in selected patients should be colonoscopic removal, colonoscopic mechanical or laser lithotripsy.

  • In cases where the endoscopic approach is unsuccessful, subsequent surgery is mandatory.

  • A multidisciplinary discussion between endoscopists and surgeons is often needed to choose the optimal therapeutic option, especially in high-risk patients.