From the Research
Hilton's line is a crucial anatomical landmark in anal fistula surgery, serving as a guide to determine the type of fistula and the appropriate surgical approach to prevent fecal incontinence and promote healing. The line marks the junction between the columnar epithelium and the squamous epithelium, occurring at the level of the dentate line 1. During anal fistula surgery, identifying Hilton's line helps surgeons determine whether a fistula is intersphincteric, transsphincteric, suprasphincteric, or extrasphincteric, which directly influences the surgical approach and potential complications.
Clinical Significance of Hilton's Line
- Hilton's line is essential in preserving sphincter function and preventing fecal incontinence during anal fistula surgery
- The line helps surgeons determine the type of fistula and the appropriate surgical approach
- Fistulas that traverse above Hilton's line involve the internal sphincter and require more careful management to prevent fecal incontinence, while those below it typically involve only the external sphincter and can be treated more aggressively
Surgical Approaches and Hilton's Line
- Surgeons must carefully identify Hilton's line during procedures like fistulotomy or advancement flap repairs to preserve sphincter function while adequately addressing the fistulous tract
- Failure to recognize Hilton's line may lead to inappropriate surgical decisions, resulting in either incomplete fistula treatment or unnecessary sphincter damage with subsequent continence issues
- Recent studies have shown that minimally invasive procedures, such as the Fat GRAFT technique 2 and laser closure (FiLaC™) 3, can be effective in treating anal fistulas while preserving sphincter function
Recent Evidence and Recommendations
- A 2019 study found that the Surgisis anal fistula plug was associated with similar quality of life scores to surgeon's preference at 12-month follow-up, but with higher costs and uncertain gains in quality-adjusted life-years 4
- A 2017 study demonstrated the effectiveness of the Fat GRAFT technique in treating trans-sphincteric anal fistulas with a low risk of anal incontinence 2
- The most recent and highest quality study, published in 2019, suggests that a surgeon's preference for sphincter-saving procedures, such as fistulotomy or advancement flap repairs, may be the most effective approach in treating anal fistulas while preserving sphincter function and promoting healing 4