Spontaneous cholecystocutaneous fistula: empirically treated for a missed diagnosis, managed by laparoscopy

Abstract

A 70-year-old woman was referred to our hospital from primary health centre with complaints of pain in the abdomen, swelling and discharging sinus in the right hypochondrium since 2 years. She had received anti-tubercular treatment for 18 months as the wedge biopsy of the sinus tract suggested granulomatous lesion. As the symptoms did not subside she was referred to our hospital. Her blood investigation reports at our hospital were normal. Ultrasound of the abdomen suggested cholelithiasis with normal common bile duct. CT fistulogram findings were diagnostic of cholecystocutaneous fistula (CCCF). She underwent laparoscopic cholecystectomy and excision of the sinus tract. Postoperative recovery was uneventful. Indiscriminate usage of anti-tubercular drugs should be discouraged and possibility of CCCF should be considered in patients presenting with discharging sinus in the anterior abdominal wall. CT fistulogram is helpful in making diagnosis of CCCF. Cholecystectomy with excision of the sinus tract is the treatment of choice.

Background

Biliary fistulas are usually a complication of acute calculous cholecystitis and can be either internal or external.¹ Internal fistulae are more common than external fistulae. External biliary fistulas can be spontaneous, postoperative or post-traumatic. A significant proportion of patients are elderly women with non-specific symptoms.² Irrational and indiscriminate practices on anti-tuberculosis treatment (ATT) are still widespread in India, as even unqualified doctors with a limited understanding who erroneously diagnose and treat tuberculosis would prescribe ATT in India.³ Several physicians in India often give more importance to certain diagnostic tests like erythrocyte sedimentation rate, tuberculin skin test and serological tests. However, these tests have low sensitivity, specificity and positive predictive value for tuberculosis. Such erroneous diagnosis of tuberculosis deprives patients from getting necessary treatment as the actual underlying condition remains undetected. With appropriate clinical evaluation and investigations including microbiology tests, imaging studies, histopathological tests and gene X-pert Mycobacterium tuberculosis/Rifampicin (MTB/RIF) it is possible to make a correct diagnosis of tuberculosis in majority of patients.

Case presentation

A 70-year-old woman presented with a discharging sinus in the right hypochondriac region since 2 years. It began with pain and swelling in the right hypochondriac region. Swelling increased in size over 2 months and ruptured spontaneously leading to seropurulent discharge. Wedge biopsy of the sinus tract in the primary health centre was reported as granulomatous inflammation with no evidence of atypia or malignancy. She was treated with ATT for 18 months (isoniazid (INH), rifampicin, pyrazinamide, and ethambutol for 2 months and INH and rifampicin for 16 months). She was taking oral hypoglycaemic agents as she was suffering from diabetes mellitus. Despite ATT, her symptoms did not subside and she had persistence of discharge; therefore, she was referred to our hospital for further treatment. On arrival at our hospital, her general physical examination and systemic examination were within normal limits. Local abdominal examination showed a scar and a discharging fistula in the right hypochondriac region (figure 1).

Figure 1.

Arrow showing an external opening of 0.5×0.5 cm size present in the right hypochondrium with active seropurulent discharge. The surrounding skin showed scar tissue.

Investigations

Patient’s complete blood count, renal function test and liver function test was within normal limits. Ultrasonography (USG) of the abdomen suggested cholelithiasis with normal common bile duct. CT scan of the abdomen showed a low density mass measuring 8.1×2.6×5.1 cm in the right lateral wall of the abdomen. There was a track of abnormal density that appeared to extend either from the biliary tree or the second part of the duodenum to the abdominal wall. The gall bladder could not be identified and the common bile duct measured 1 cm in diameter; there was no intrahepatic biliary radicle dilatation. CT fistulogram showed a track of fluid that ran from the lateral abdominal wall through the gall bladder into the common bile duct (figure 2); thus, leading to a diagnosis of cholecystocutaneous fistula (CCCF).

Figure 2.

Arrow showing a track of contrast fluid extending from the lateral abdominal wall through the gall bladder into the common bile duct.

Differential diagnosis

Chronic granulomatous lesion, discharging tuberculoma, enterocutaneous fistula, chronic osteomyelitis of ribs with sequestrum and metastatic carcinoma.

Treatment

Laparoscopic cholecystectomy and excision of the tract was performed. Gall bladder was adherent to the anterior abdominal wall. Dense adhesions between liver, gall bladder and omentum were released using harmonic shear. Fistulous tract was identified with injection of methylene blue dye through a feeding tube inserted through the cutaneous opening of the fistula. A large impacted stone in the neck of gall bladder and frozen calot’s triangle made dissection difficult. Calot’s triangle was carefully dissected. Cystic duct and artery was clipped and cut separately. Gall bladder was dissected using diathermy. Laparoscopic cholecystectomy and excision of the tract was performed. Drain tube was placed. Gall bladder specimen was sent for histopathological examination.

Outcome and follow-up

On postoperative day (POD)−1, the patient was haemodynamically stable and accepting diet orally. Drain output was 50 mL serosanguinous. Drain tube was removed on POD-2 and the patient was discharged on POD-3. Fistulous tract healed completely at the end of 21 days. Histopathology of specimen was suggestive of chronic cholecystitis with no dysplasia or malignancy. At the end of 4 years after the surgery, there was no recurrence of symptoms and the patient is comfortable with improved quality of life.

Discussion

Anomalous communication of gall bladder to skin is known as external fistulae and to the mucous membrane is known as internal fistulae. Internal fistulae are more common than external fistulae.⁴ Biliary fistula is rare and only a few such cases have been reported in the medical literatures in the past 50 years.⁵ Incidence of spontaneous external biliary fistula is rare owing to early diagnosis and prompt treatment.⁵ External biliary fistulas can be spontaneous, postoperative or post-traumatic. Spontaneous CCCF generally occur as a result of neglected calculous cholecystitis; however, it can occur in acalculous cholecystitis, carcinoma of gall bladder and cholangiocarcinoma.^6–8 The external opening of a CCCF is generally in the right hypochondrium; moreover, alternative locations such as left hypochondrium, umbilicus, right iliac fossa, groin, anterior chest wall, gluteal region, bronchial tree, stomach and urinary tract have also been reported.

The pathophysiology of CCCF begins following obstruction of the cystic duct leading to increase in intraluminal pressure. Progressive distension of gall bladder leads to impairment of the blood supply resulting in mural necrosis and perforation of gall bladder. Once perforated, it may drain into the peritoneal cavity (acute), adjacent viscera (sub-acute) or less commonly to the abdominal wall to form an external fistula (chronic). A significant proportion of elderly patients have non-specific symptoms that are often complicated by co-existent disease. The clinical presentation of a cutaneous biliary fistula is variable and depends on the anatomical course. Patients usually present with a swelling that progresses gradually to form an abscess that ruptures and manifests as chronic draining sinus. The discharge can be bilious, mucoid or purulent. There may be history of passage of stones. Jaundice is uncommon, even in the presence of choledocholithiasis.⁸ There is usually a history of chronic biliary colic; however, patients generally may not report a previous distinct episode of acute cholecystitis. Necrotising fasciitis of the anterior abdominal wall due to sepsis and malignant transformation of the tract has been reported.^{9 10} A high level of suspicion and a low threshold for referral needs to be maintained in patients with discharging sinus located in the anterior abdominal wall. Major risk factors for the development of a spontaneous CCCF include elderly females (>50 years), steroid treatment, history of typhoid, bacterial dissemination, trauma, immunocompromised states, etc. The imaging techniques that can guide diagnosis are USG and CT fistulogram.^{11 12}

The management of an external biliary fistula clearly depends on the underlying aetiology. The acute phase requires treatment with adequate antibiotics, analgesia and resuscitation. In a proportion of patients, the external biliary fistula will heal spontaneously, and therefore operation may be avoided if the patient is elderly or debilitated.¹³ Following control of the acute inflammatory process in the abdominal wall, an elective cholecystectomy is advisable in these patients. Possible surgical options include cholecystostomy with excision of fistulous tract and repair of abdominal wall defect. Laparoscopic cholecystectomy and excision of the fistula confers the advantages of shorter hospital stay and shorter convalescence. An open approach is usually favoured, although a laparoscopic technique has been described by Malik et al.¹⁴

This case is unique because:

1. This case highlights about indiscriminate usage of ATT. All that is granuloma is not tuberculosis. Indiscriminate usage of ATT is one of the major causes of acquired multidrug-resistance tuberculosis and complications such as drug resistance, hepatotoxicity, etc.

2. CT fistulography generally helps in arriving at diagnosis in most cases of chronic sinus presenting in the anterior abdominal wall.

3. An open approach is generally preferred over laparoscopic treatment of CCCF. However, this patient underwent laparoscopic cholecystectomy and excision of tract.

Learning points.

• Indiscriminate usage of anti-tuberculosis treatment should be discouraged as all that is granuloma is not tuberculosis.

• Cholecystocutaneous fistula (CCCF) is rare; however, possibility of diagnosis should be considered in patients presenting with discharging sinus located in anterior abdominal wall.

• CT fistulogram is helpful in arriving at diagnosis.

• Cholecystectomy and excision of fistulous tract is the treatment of choice for CCCF. An open approach is usually favoured, although a laparoscopic technique can be attempted for CCCF.