Overview
Definition:
Gallstone ileus is a mechanical bowel obstruction caused by a gallstone eroding through the gallbladder wall and entering the intestinal lumen, most commonly the ileum, leading to impaction and obstruction
enterolithotomy is a surgical procedure to remove such impacted stones through a small incision in the intestine.
Epidemiology:
It is a rare complication of cholelithiasis, accounting for less than 1% of all intestinal obstructions, but the incidence increases significantly with age, particularly in patients over 65 years old
it is more common in women and associated with comorbidities like diabetes and cardiovascular disease.
Clinical Significance:
Gallstone ileus presents as a surgical emergency with high morbidity and mortality if not promptly diagnosed and treated
understanding its pathophysiology, presentation, and management is crucial for surgical residents preparing for DNB and NEET SS examinations to ensure appropriate patient care.
Clinical Presentation
Symptoms:
Abdominal pain, typically colicky and epigastric
Nausea and vomiting, often feculent with complete obstruction
Abdominal distension
Constipation or obstipation
Passage of small amounts of flatus or stool may occur initially
Fever may indicate associated cholecystitis or perforation.
Signs:
Abdominal tenderness, often localized to the site of impaction
Distended abdomen with tympanic percussion
Visible peristaltic waves in some cases
Palpable abdominal mass, particularly in the right iliac fossa
Signs of dehydration and electrolyte imbalance
Fever may be present.
Diagnostic Criteria:
No formal diagnostic criteria exist
diagnosis is primarily clinical, supported by imaging findings
Characteristic findings on imaging include Rigler's triad: 1) bowel obstruction, 2) an abnormal gas shadow in the biliary tree (pneumobilia), and 3) a gallstone within the small bowel
Absence of all three does not exclude the diagnosis.
Diagnostic Approach
History Taking:
Detailed history of gallstone disease, prior cholecystitis episodes, and previous abdominal surgeries
Duration and character of abdominal pain
Pattern of bowel movements and emesis
Presence of comorbidities
Red flags include intractable pain, signs of sepsis, or hemodynamic instability.
Physical Examination:
Thorough abdominal examination, assessing for distension, tenderness, guarding, rebound tenderness, and palpable masses
Digital rectal examination may reveal impacted stool or a palpable stone
Assess for signs of dehydration and shock.
Investigations:
Plain abdominal X-rays can show signs of obstruction and sometimes reveal calcified gallstones or pneumobilia
CT scan of the abdomen is the investigation of choice, demonstrating gallstone impaction, bowel obstruction, pneumobilia, and potentially the cholecystoenteric fistula
Ultrasound may show dilated bile ducts and stones but is less sensitive for fistula detection
Laboratory tests: CBC to assess for leukocytosis, electrolytes, renal function, and liver function tests to evaluate for cholangitis or other complications.
Differential Diagnosis:
Other causes of small bowel obstruction: adhesions, hernias, malignancy, intussusception, Crohn's disease
Inflammatory conditions: appendicitis, diverticulitis
Biliary tract pathology: cholangitis, cholecystitis.
Management
Initial Management:
Immediate resuscitation with intravenous fluids, electrolyte correction, and nasogastric tube decompression
Broad-spectrum antibiotics if infection is suspected
Pain management with analgesics.
Surgical Management:
Surgical intervention is indicated for definitive treatment
The primary goal is to relieve the obstruction and remove the offending stone
Surgical options include: 1
Enterolithotomy: The preferred method, involving a small enterotomy distal to the impacted stone, milking the stone, and removing it
the enterotomy is then repaired
2
Resection and anastomosis: Considered for friable bowel, significant ischemia, or multiple stones
3
Cholecystectomy and fistula repair: May be performed concurrently or as a second-stage procedure if the patient is stable and the fistula is identified, but often delayed due to increased morbidity.
Surgical Technique:
Enterolithotomy is performed through a linear or transverse enterotomy made in the antimesenteric border of the ileum distal to the stone
The stone is milked proximally towards the enterotomy and removed
The enterotomy is then closed with a two-layer anastomosis
Careful attention is paid to bowel viability and meticulous closure to prevent leakage.
Supportive Care:
Postoperative monitoring for fluid balance, pain control, bowel function return, and wound healing
Nutritional support may be required in prolonged ileus or if resection was performed
Early mobilization is encouraged.
Complications
Early Complications:
Bowel perforation, leakage from enterotomy site, wound infection, intra-abdominal abscess, anastomotic leak, sepsis, prolonged ileus, intraoperative injury to adjacent structures.
Late Complications:
Recurrence of gallstone ileus if the fistula is not addressed and other stones remain in the gallbladder
Stricture formation at the enterotomy site
Adhesions leading to further obstruction.
Prevention Strategies:
Prophylactic cholecystectomy in asymptomatic patients with gallstones is a debated topic but may prevent future complications
Prompt surgical intervention for symptomatic gallstone disease can prevent the development of a cholecystoenteric fistula.
Prognosis
Factors Affecting Prognosis:
Patient's age and comorbidities, delay in diagnosis, presence of perforation or sepsis, extent of bowel compromise, and surgical technique employed significantly impact prognosis.
Outcomes:
With prompt diagnosis and surgical management, the mortality rate for uncomplicated gallstone ileus is around 5-10%
However, it can be as high as 30% in elderly patients or those with delayed presentation and complications.
Follow Up:
Postoperative follow-up typically involves monitoring for resolution of symptoms, wound healing, and return of bowel function
Long-term follow-up may be necessary to assess for recurrence, especially if the fistula was not surgically addressed
Imaging studies may be performed if symptoms recur.
Key Points
Exam Focus:
Gallstone ileus is a complication of chronic cholelithiasis
Rigler's triad (bowel obstruction, pneumobilia, gallstone in small bowel) is pathognomonic but not always present
Enterolithotomy is the primary surgical treatment for removing the impacted stone
Delay in diagnosis and treatment increases morbidity and mortality.
Clinical Pearls:
Always consider gallstone ileus in elderly patients with acute small bowel obstruction, especially those with a history of gallstone disease
CT scan is crucial for diagnosis
Aim to relieve obstruction with enterolithotomy
definitive fistula repair can often be staged.
Common Mistakes:
Misdiagnosing gallstone ileus as other forms of small bowel obstruction
Delaying surgical intervention due to patient's comorbidities
Undertaking extensive bowel resection when simple enterolithotomy suffices
Failing to consider staged management for fistula repair.