Small intestinal fistula caused by drainage tube removal: A case report
Executive Summary
Small intestinal fistulas resulting from the removal of abdominal drainage tubes are rare but high-morbidity complications, typically occurring in the context of postoperative abdominal surgery. This briefing analyzes a specific clinical case involving an 80-year-old male who developed a small intestinal fistula following radical surgery for sigmoid colon cancer. While drainage tubes are essential for fluid evacuation and infection prevention, their presence and removal carry risks of intestinal adhesion, sinus tract failure, leakage, and perforation.
The following analysis highlights that such complications are often misdiagnosed due to nonspecific symptoms, leading to significant healthcare burdens. The core takeaways for clinical practice include the necessity of judicious drainage tube use, meticulous placement techniques to avoid mechanical pressure on the intestinal wall, and the prioritization of contrast-enhanced imaging for early diagnosis. Prompt surgical intervention—specifically partial resection and end-to-end anastomosis—remains the definitive treatment for successful recovery.
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Patient Profile and Clinical Presentation
The primary subject was an 80-year-old Han Chinese male admitted with a three-day history of abdominal pain and hematochezia.
Initial Diagnosis and Primary Surgery
Preoperative Findings: Enhanced CT showed thickening of the descending and sigmoid colon walls. Colonoscopy confirmed sigmoid colon cancer and polyps.
Primary Procedure: Laparoscopy-assisted radical resection of the colon cancer.
Intraoperative Findings: A 5.0 cm × 5.0 cm tumor was identified in the middle segment of the sigmoid colon.
Pathology: Moderately to poorly differentiated adenocarcinoma (Stage IIIb, T4N1M0) with metastasis in 1 of 15 regional lymph nodes.
Drainage Placement: A drainage tube was placed 20 cm deep in the left pelvic cavity near the anastomosis.
Postoperative Timeline and Complication Onset
Diagnostic Analysis and Surgical Findings
Laboratory and Imaging Results
Initial postoperative laboratory tests showed elevated inflammatory markers:
White Blood Cell (WBC) Count: 12.8 × 10⁹/L
C-reactive Protein (CRP): 53.2 mg/L
Procalcitonin (PCT): 0.517 µg/L
Fistulography: Injecting a contrast agent through the original drainage tract revealed that the small intestines in the middle and lower right abdomen were filled with the agent, definitively indicating a communication between the intestine and the drainage tract.
Exploratory Laparotomy Findings
A second surgery revealed the following:
Anastomosis Status: The original rectal anastomosis was well-healed.
Fistula Location: Two adjacent ruptures (1.5 cm diameter each) were found in the ileum, approximately 1 meter from the ileocecal valve.
Associated Pathology: Significant congestion and edema in the small and large intestines; 500 mL of pale yellow fluid accumulation in the upper abdominal cavity.
Tissue Analysis: Postoperative pathology confirmed chronic inflammation of the intestinal wall with congestion, edema, bleeding, and local necrosis.
Pathophysiology and Causative Factors
The development of the fistula was multifactorial, involving mechanical, physiological, and patient-specific variables:
Mechanical Pressure: Trimming drainage tube side holes too large can create localized pressure points on the small intestinal wall, impairing blood flow and causing ischemic necrosis.
Frictional Erosion: Postoperative intestinal motility and peristalsis cause the intestines to rub against the stationary tube, leading to erosion and eventual perforation.
Tube Migration: While the tube was initially placed in the left pelvic cavity, patient movement and bowel peristalsis may have shifted the tube to the mid-abdominal region, where it came into contact with the ileum.
Negative Pressure Adhesion: Routine maintenance or suction may have drawn the intestinal wall into the tube's side holes, exacerbating tissue damage.
Patient Factors: The patient’s advanced age (80) likely contributed to decreased intestinal perfusion and slower wound healing.
Clinical Recommendations and Prevention
Judicious Use of Drainage
The case study suggests that routine prophylactic drainage in colorectal surgery may be unnecessary in the absence of infection or significant bleeding.
Evidence: Meta-analyses indicate that pelvic drainage does not reduce the incidence of anastomosis leakage but does significantly increase the risk of postoperative small bowel obstruction.
Criteria for Omission: Precise surgical technique, elimination of dead space, and minimal intraoperative blood loss (e.g., 20 mL in this case) may render drainage tubes unnecessary.
Best Practices for Tube Placement and Removal
For cases where drainage is required, the following precautions are recommended:
Hole Preparation: Avoid excessive trimming of the side holes.
Positioning: Ensure the tube tip does not directly contact the omentum or mesentery; avoid sharp angles.
Removal Protocol: Remove tubes promptly once the volume of drainage significantly decreases. If resistance is met during removal, use flexible, standardized nursing approaches to avoid trauma.
Management of Suspected Fistula
If a patient exhibits abdominal pain or peritoneal irritation following tube removal:
Perform immediate abdominal CT and biochemical blood tests.
Utilize fistulography (contrast through the drainage site) to distinguish the fistula from anastomotic leakage or abscesses.
Initiate supportive care (somatostatin, nutritional support) to prepare for potential reoperation.
Prognosis and Long-Term Considerations
While the patient in this case recovered well and was asymptomatic at a three-month follow-up, small intestinal fistulas carry a general mortality rate of 15% to 20%. Long-term monitoring is essential to address potential sequelae:
Nutritional Disturbances: Chronic loss of intestinal fluid can lead to protein-energy deficiency and depletion of electrolytes (Na+, K+, Mg2+) or trace elements (zinc, selenium).
Vitamin Deficiency: Ileal involvement increases the risk of Vitamin B12 deficiency, potentially leading to anemia and neurological symptoms.
Mechanical Complications: Intra-abdominal adhesions or stenosis at the repair site may result in future intestinal obstructions requiring further surgical intervention.
