Table 4

Factors that may adversely affect spontaneous closure rates^1,^13,^36,³⁸

Anatomical	Other
^aOpinion is divided on the effect of output on spontaneous closure. According to Martineau and colleagues³⁸ and Rubelowsky and Machiedo,¹³ high output is associated with low closure rates; according to Berry and Fischer,¹ output does not prognosticate closure.
• Discontinuity of bowel ends	• Cancer
• Complete disruption	• Chemotherapy
• Distal obstruction (caused by an obstacle downstream or discontinuity between	• Radiation
parts of the gastrointestinal tract)	• Underlying IBD
• Intra-abdominal foreign body	• Uncontrolled sepsis, with or without abscess formation
• Lateral fistula	• Fistula fluid infected
• Complex fistula	• Hypoproteinaemia
• Associated abscess	• Large and early leakage of anastomosis
• Adjacent bowel diseased	• Diabetes patients
• Poor bowel vascularisation	• Corticosteroids
• Fistula tract <2 cm	• Renal failure
• Defect >1 cm	• Output may prognosticate closure^a
• Epithelialisation of mucocutaneous fistula tract
• Drainage through large abdominal wall defect (multiple orifices)
• Internal fistulae
• Fistula site (gastric, lateral duodenal, or ileal)