Fibrotic Abdominal Tuberculosis Presenting as Acute Small Bowel Obstruction Due to Multiple Bands in a Virgin Abdomen: case report

Technical Summary: Fibrotic Abdominal Tuberculosis Presenting as Acute Small Bowel Obstruction in a Virgin Abdomen

Problem Statement
Small bowel obstruction (SBO) is a prevalent surgical emergency, typically caused by postoperative adhesions. However, in patients with a "virgin abdomen" (no history of prior abdominal surgery, trauma, or radiation), the etiology is less predictable, often raising suspicion for malignancy, internal hernias, or congenital bands. While infectious causes like abdominal tuberculosis (ATB) are recognized in endemic regions, the fibrotic-fixed subtype of ATB remains a rare and diagnostically challenging cause of adhesive SBO in virgin abdomens. This subtype is characterized by dense adhesions and matted bowel loops but often lacks the ascites typical of the wet-ascitic form, leading to nonspecific clinical and radiological findings that can mimic other pathologies, such as intussusception or neoplasms.

Methodology
This study presents a single case report of a 45-year-old Sudanese male with a history of treated pulmonary tuberculosis who presented with a 7-day history of colicky abdominal pain, vomiting, fever, and constipation. The patient had no prior surgical scars.

• Diagnostic Approach: Initial evaluation included physical examination, laboratory tests (revealing anemia and mild renal impairment), abdominal ultrasonography, and contrast-enhanced computed tomography (CT). The CT scan suggested a "bowel-within-bowel" configuration consistent with small bowel intussusception.
• Intervention: Due to the failure of conservative management (bowel rest, decompression, fluids), the patient underwent an exploratory laparotomy.
• Intraoperative Findings: The surgery revealed multiple dense fibrotic adhesions and constricting bands involving the distal ileum in a virgin abdomen, with matted and friable bowel loops. No true intussusception was found. Adhesiolysis was performed, and incidental serosal injuries were repaired. A mesenteric lymph node biopsy was obtained.
• Histopathological Analysis: The biopsy demonstrated caseating granulomatous inflammation, confirming the diagnosis of fibrotic abdominal tuberculosis.
• Post-operative Management: The patient was treated with anti-tubercular therapy (ATT) and monitored for recovery.

Key Results

• Clinical Presentation: The patient presented with classic signs of SBO but lacked the typical risk factor of prior surgery.
• Radiological Discrepancy: Preoperative CT imaging suggested intussusception, a finding that was not confirmed intraoperatively. The "bowel-within-bowel" appearance was attributed to transient telescoping, pseudo-intussusception due to matted loops, or anatomical distortion from dense adhesions.
• Pathological Confirmation: Histopathology was the definitive diagnostic tool, revealing caseating granulomas consistent with tuberculosis.
• Outcome: The patient underwent successful adhesiolysis and repair of serosal injuries without bowel resection. Following the initiation of anti-tubercular therapy, the patient achieved an uneventful recovery with no postoperative complications.

Significance and Claims
The authors assert that this case highlights several critical clinical points:

1. Differential Diagnosis: Fibrotic abdominal tuberculosis must be included in the differential diagnosis for adhesive SBO in patients with a virgin abdomen, particularly in tuberculosis-endemic regions or those with a history of pulmonary TB.
2. Radiological Limitations: The case demonstrates that radiological findings in fibrotic-fixed ATB can be misleading, mimicking intussusception or malignancy. The absence of ascites, a common feature in other forms of ATB, further complicates non-invasive diagnosis.
3. Diagnostic Necessity: Definitive diagnosis often requires histopathological confirmation via surgical exploration when conservative management fails or the diagnosis remains uncertain.
4. Management Strategy: The paper advocates for a combined approach of limited surgical intervention (prioritizing adhesiolysis and bowel preservation over resection due to tissue friability) followed by pharmacological anti-tubercular therapy.
5. Clinical Value: The report contributes to the growing evidence that infectious etiologies can cause adhesive SBO without prior surgery, emphasizing the need for a high index of suspicion to prevent diagnostic delays and inappropriate treatment.

Limitations
The authors acknowledge that as a single case report, the findings have limited generalizability. Preoperative microbiological confirmation (e.g., PCR or culture) was not performed, and the diagnosis relied on intraoperative findings and histopathology.