Pathogenesis of gallstones

What are the clues to gallstone ileus when stones don't show up on scans? A case presentation and literature review

Gallstone ileus is a rare yet significant cause of mechanical bowel obstruction, particularly in elderly patients. This condition arises when gallstones migrate into the gastrointestinal tract through a cholecystoenteric fistula, often due to chronic inflammation. Despite medical advancements, gallstone ileus remains associated with high morbidity and mortality rates due to delayed diagnosis and nonspecific symptoms. The clinical presentation typically includes intermittent nausea, vomiting, abdominal pain, and constipation, which can obscure the diagnosis. Advanced imaging techniques, especially computed tomography (CT), are crucial for identifying key diagnostic features such as pneumobilia, ectopic gallstones, and signs of bowel obstruction. Gallstone ileus should be considered in any case of small bowel obstruction, even if CT imaging is inconclusive, as gallstones can be radiolucent. Indirect clues like pneumobilia and dilated small bowel loops can lead to the diagnosis. Effective management of gallstone ileus requires prompt surgical intervention to remove the obstructing gallstone and restore bowel patency. The primary surgical procedure is enterolithotomy, although additional procedures such as cholecystectomy and fistula repair may be necessary depending on the patient's condition and intraoperative findings. The choice of surgical approach should be individualized, considering the patient's overall health and the specific characteristics of the obstruction. Early recognition and timely surgical management are essential to prevent complications and improve patient outcomes.

Diagnosis of intrahepatic and common duct stones: combined unenhanced and contrast-enhanced helical CT in 1090 patients

BACKGROUND

We determined the accuracy of combined unenhanced and contrast-enhanced helical computed tomography (CT) for diagnosis of bile duct stones.

METHODS

During a 12-month period, 1090 patients who underwent combined CT and endoscopic retrograde cholangiography (ERC) or percutaneous transhepatic cholangioscopy (PTC) were enrolled in this study. The results of prospective CT interpretation regarding the presence of bile duct stones were compared with results of endoscopic stone removal, PTC and with surgical results. In 70 patients, detectability of stones on CT was evaluated depending on stone types.

RESULTS

Of 1090 study patients, 175 and 299 patients were confirmed to have intrahepatic and common duct stones, respectively. The sensitivity and specificity of combined CT were 73% and 98% for diagnosis of intrahepatic stones and 71% and 97% for common duct stones. Of 70 patients 24, 25, and 21 patients had cholesterol, black pigment, and brown pigment stones, respectively. Eleven of 24 cholesterol stones, 21 of 25 black pigment stones, and 15 of 21 brown pigment stones were detected on combined CT.

CONCLUSION

Combined CT is of limited sensitivity for detection of bile duct stones, especially in Western countries where cholesterol stones predominate. It may be of greater value in populations with a higher incidence of pigment stones. Other complementary imaging modalities are needed for patients with negative CT findings who are highly suspected to have biliary stones.

Spectrum of gallstone disease in the veterans population

BACKGROUND

Elderly male patients are thought to have a higher incidence of biliary infections. This demographic is common among veterans, so we analyzed the spectrum of gallstone disease in a large veteran population.

METHODS

A total of 285 patients with gallstone disease were studied. There were 27 women and 258 men, with an average age of 62 years. Gallstones, bile, and blood (as indicated) were cultured. Illness severity was staged as none (no clinical infection), moderate (fever, leukocytosis), or severe (cholangitis, bacteremia, abscess, hypotension, organ failure). Gallstones were grouped by appearance. Three bacterial groups were defined: EK (Escherichia coli or Klebsiella species), N (Enterococcus), or Oth (all other species).

RESULTS

Biliary bacteria were present in 145 (51%) patients. Bacterial presence by patient age was 33% for those less than 50 years, 48% for those 50 to 70 years, and 65% for those more than 70 years (P <.02 vs. others). Bacterial presence by stone type was as follows: cholesterol, 11%; mixed, 51%; pigment, 71% (P <.01 vs. others). Illness severity by stone type was as follows for cholesterol: none, 73%; moderate, 27%; severe, 0%; for mixed: none, 62%; moderate, 25%; severe, 13%; for pigment: none, 41%; moderate, 17%; severe, 41% (P <.0001 vs. others). Illness severity by bacterial group was as follows for sterile: none, 77%; moderate, 23%; severe, 0%; for the Oth group: none, 57%; moderate, 22%; severe, 20%; for the N group: none, 32%; moderate, 16%; severe, 52%; for the EK group: none, 18%; moderate, 22%; severe, 60% (P <.0001 vs. sterile/Oth, P = .126 vs. N).

CONCLUSIONS

Bacterial biliary tree colonization is prevalent in the veterans' population, it increases with age, and is more common with pigment stones. But not all bacterial species cause infectious manifestations. Patients with E coli and/or Klebsiella species commonly showed infectious manifestations, patients with Enterococcus were in an intermediate range, and those with other species had few infectious manifestations.

Hepatolithiasis and biliary parasites

Hepatolithiasis, or the presence of intrahepatic stones, is prevalent in East Asia and is characterized by the finding of stones within the intrahepatic bile ducts proximal to the confluence of the right and left hepatic ducts. Bile stasis and bacterial infection have been incriminated as the major aetiopathogenic factors. Clinical features include recurrent pyogenic cholangitis, multiple liver abscesses, secondary biliary cirrhosis and cholangiocarcinoma. The goals of management include accurate localization of pathologies, control of biliary sepsis and the elimination of stones and stasis. Ultrasonography, computed tomography and direct cholangiography complement each other in defining the stones, strictures and degree of liver damage. Non-operative biliary decompression by endoscopy and interventional radiology is effective in controlling the infection, but surgery remains the mainstay for the treatment of stones and strictures. Intra-operative ultrasound and flexible choledochoscopy, combined with percutaneous transhepatic cholangioscopy and intraductal lithotripsy, facilitate stone removal. Balloon dilatation and biliary stenting serve to open the bile duct strictures. The creation of a hepaticocutaneous jejunostomy after conventional surgery allows atraumatic access to the biliary system for the removal of recurrent stones. The management of biliary parasites begins with conservative measures, including analgesics and anti-helminthic therapy. In refractory cases or patients with acute cholangitis, endoscopic biliary drainage and the extraction of worms may be necessary. Improvement in sanitation plays a crucial role in the epidemiological control of these biliary diseases.

Ultrastructural aspects of human gallbladder epithelial cells in cholelithiasis: production of anionic mucus

The surface epithelium of 28 gallbladders removed during elective cholecystectomies and pathology collection was studied ultrastructurally. Focusing on 10 of the 28 cases that were diagnosed as cholecystitis, we found that the epithelium displayed numerous apical mucous granules and bulging apical apices. Mucous granule changes included 1) hyperproduction of secretory granules of neutral type containing an electron-dense proteinaceous spherule, similar to that described in other mucus-producing glands of the digestive system, and 2) production of anionic, osmiophilic secretory mucus. Other alterations of the surface epithelial cells included the production of bizarre surface appendages resembling primitive cilia without axoneme and epithelial excrescences.

Structure and composition of primary intrahepatic stones in Korean patients

We have analyzed the chemical composition of primary intrahepatic stones from 72 Korean patients. Two types of concretions have been identified: brown pigment (calcium bilirubinate) stones and black-colored mixed stones. Brown pigment stones were found in 68% of all cases and the remainder (32%) consisted of mixed stones. Intrahepatic mixed stones had mean cholesterol and bilirubin contents of 46.6% and 25.9%, respectively, whereas calcium bilirubinate stones had mean cholesterol and bilirubin contents of 14.1% and 43.6%, respectively. Intrahepatic mixed stones had a smooth black-colored surface and on cross section, exhibited a distinct outer shell surrounding an inner yellow, cholesterol-rich body. The finding of intrahepatic mixed stones with high cholesterol content suggests that primary hepatolithiasis may result from at least two different conditions or disorders and points to different approaches to their treatment.

Adaptation and renewal of the gastrointestinal surgeon to meet the continuous challenge of modern gastroenterology

The treatment of gastrointestinal diseases has entered into a period of rapid evolution. Gastroenterology has in the last 50 years evolved into a major specialty, covering not only complex clinical and diagnostic areas, but inclusive of sophisticated investigative work and major therapeutic endoscopic technology. Unfortunately, the evolution of gastrointestinal surgery has lagged behind. The scope of the gastrointestinal surgeon has become more limited, as potent pharmacotherapeutic probes, invasive radiological techniques and diagnostic and therapeutic endoscopic advances have been implemented. The development of minimally invasive surgical techniques has introduced a new era in surgical management. However, the establishment of new training programs and the acquisition of skills requiring the acquisition of costly equipment are major issues which surgical departments need to address. A novel training and programmatic configuration for the group of physicians involved in the management of gastrointestinal disease is required to meet this challenge. In particular, internists and surgeons must focus on the development of cost and time effective strategies for the management of clinical gastrointestinal disease. It seems likely, however, that adequate resources and management of these undertakings will only be forthcoming if corporate establishments, venture capital groups, medical health insurance institutions and national research agencies develop a consortium approach with medical schools to address these issues.