Endoanal Ultrasonographic Assessment After Lateral Internal Sphincterotomy for Chronic Anal Fissure: Protocol for a Prospective Longitudinal Cohort Study
Trial Snapshot
- Phase
- Not Applicable
- Status
- Recruiting
- Sponsor
- Enrollment
- 66
- Locations
- 1
- Primary Endpoint
- Fissure Healing Without Persistence or Recurrence
Study Overview
Brief Summary
Chronic anal fissure is a painful tear in the lining of the anal canal that may not heal with medication or other non-surgical treatments. Lateral internal sphincterotomy (LIS) is a commonly used surgical treatment. However, the amount of internal anal sphincter muscle divided during surgery may affect both fissure healing and the risk of impaired bowel control.
The purpose of this prospective observational study is to assess whether the extent of internal anal sphincter division, measured using three-dimensional endoanal ultrasound, is associated with fissure healing and changes in anal continence during the first year after surgery.
The study will include 66 adults with chronic anal fissure undergoing open or closed lateral internal sphincterotomy as part of their usual clinical care. The surgical technique will be selected by the treating clinical team and will not be assigned by the researchers.
Participants will be assessed before surgery and at 3, 6, and 12 months after surgery. At the 3-month visit, they will undergo two-dimensional and three-dimensional endoanal ultrasound. Two independent observers will separately review the stored ultrasound images. Follow-up assessments will evaluate fissure healing or recurrence, bowel control, faecal soiling, pain, bleeding, postoperative complications, and quality of life.
The findings may help identify the extent of sphincter division that provides effective fissure healing while limiting the risk of postoperative anal incontinence.
Detailed Description
BACKGROUND AND RATIONALE
Chronic anal fissure is a persistent, longitudinal tear in the anoderm that commonly causes severe pain during or after defecation, rectal bleeding, and a substantial reduction in quality of life. Increased resting pressure and persistent hypertonia of the internal anal sphincter, reduced local blood flow, and repeated mechanical trauma during defecation contribute to persistence of the fissure. Initial management generally consists of measures intended to improve stool consistency, reduce trauma, and promote chemical relaxation of the internal anal sphincter. However, some patients continue to experience symptoms despite an adequate course of conservative treatment.
Lateral internal sphincterotomy is an established surgical treatment for chronic anal fissure that has not responded to conservative management. The procedure reduces internal anal sphincter pressure by dividing part of the distal internal sphincter. Although lateral internal sphincterotomy achieves high healing rates, the optimal extent of sphincter division remains uncertain. Division of an insufficient amount of muscle may fail to relieve sphincter hypertonia and may contribute to persistence or recurrence of the fissure. Conversely, excessive sphincter division may impair continence and lead to postoperative leakage of gas, liquid stool, or solid stool, or to faecal soiling.
The anatomical extent of sphincter division cannot always be accurately determined from the operative description alone. Endoanal ultrasonography permits direct postoperative assessment of the internal and external anal sphincters. Three-dimensional endoanal ultrasonography additionally enables longitudinal reconstruction of the anal canal and measurement of both the total length of the internal anal sphincter and the length of the postoperative sphincterotomy defect. The proportion of the internal sphincter divided can therefore be calculated for each participant and related to subsequent clinical outcomes.
The central hypothesis of this study is that there is a measurable range of internal anal sphincter division that is sufficient to promote fissure healing while limiting deterioration in anal continence. Identification of this relationship could contribute to a more anatomically tailored surgical approach rather than relying on a uniform division length for patients with different sphincter anatomy.
Study Design
- Study Type
- Observational
- Observational Model
- Cohort
- Time Perspective
- Prospective
Eligibility Criteria
- Ages
- 18 Years to — (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Age 18 years or older.
- •Primary chronic anal fissure, defined as symptoms lasting more than 6-8 weeks and failure of complete conservative treatment, irrespective of the presence of anatomical signs of chronicity.
- •Clinical indication for open or closed LIS.
- •Capacity to understand the study, complete the questionnaires and provide written informed consent.
Exclusion Criteria
- •Acute anal fissure of less than 6-8 weeks' duration.
- •Secondary anal fissure associated with Crohn's disease, ulcerative colitis, tuberculosis, HIV infection, anal malignancy or another identified secondary cause.
- •Neurological or neuromuscular disease that may affect continence.
- •Moderate or severe anal incontinence at baseline.
- •Concomitant anorectal disease requiring another procedure, including symptomatic haemorrhoids or anal fistula.
- •Previous or current circumstances that prevent reliable completion of patient-reported measures.
- •Anticipated inability to attend postoperative follow-up.
- •Incomplete conservative treatment before the decision for surgery.
- •Participants may withdraw consent at any time without affecting their care. Investigators may discontinue study follow-up if eligibility was incorrectly assigned or if a clinical event prevents completion of study procedures. Data collected before withdrawal will be handled in accordance with the consent form and applicable legislation.
Outcomes
Primary Outcomes
Fissure Healing Without Persistence or Recurrence
Time Frame: From surgery to 12 months after surgery
Fissure status will be assessed clinically and classified as healed without recurrence or as persistent or recurrent. Healing is defined as complete epithelialisation with no visible residual fissure and resolution of fissure-related pain and bleeding. Persistence is defined as failure to achieve healing by 3 months. Recurrence is defined as the reappearance of a symptomatic fissure after documented healing and an intervening symptom-free period.
Change in Anal Continence Assessed Using the Jorge-Wexner Score
Time Frame: 12 months
Change from baseline to 12 months in the Jorge-Wexner score. The score ranges from 0 to 20, with higher scores indicating worse anal incontinence. The analysis will assess postoperative deterioration in continence. The threshold used to define clinically relevant deterioration will be prespecified in the statistical analysis plan before database lock.
Secondary Outcomes
- Health-Related Quality of Life Assessed Using the SF-36(Baseline and 3, 6, and 12 months after surgery)
- Fissure Recurrence After Lateral Internal Sphincterotomy(From documented healing to 12 months after surgery)
- Early Change in Anal Continence Assessed Using the Jorge-Wexner Score(Baseline to 3, 6 and 12 months after surgery)
- Extent of Anal Sphincter Injury Assessed Using Three-Dimensional Endoanal Ultrasonography(3 months after surgery)
Investigators
Francisco Castillejos Ibáñez
Medicine
Hospital Clínico Universitario de Valencia