Beyond tailored sphincterotomy: an endoanal ultrasound-based morphometric study for anal fissure
Alp Ömer Cantürk1, Hakan Demir1, Emine Sena Cunuk2, Emre Gönüllü3, Merve Yeşilsancak2, Fatih Altıntoprak21Department of General Surgery, Sakarya Training and Research Hospital, Sakarya, Türkiye2Department of General Surgery, Sakarya University Faculty of Medicine, Sakarya, Türkiye
3Department of Gastrointestinal Surgery, Sakarya Training and Research Hospital, Sakarya, Türkiye
INTRODUCTION: This study aimed to demonstrate the clinical value of endoanal ultrasonography (EAUS) in patients with chronic and/or recurrent anal fissures, compare sphincter thickness in primary cases with healthy EAUS norms, determine the classification performance of EAUS in differentiating operated from non-operated sphincter anatomy, and quantitatively assess sphincterotomy adequacy.
METHODS: In this single-center observational study, 48 patients were evaluated in two distinct groups: the chronic anal fissure group and the postoperative anal fissure group. Morphometric EAUS findings in patients with chronic anal fissures were compared with normal anal canal anatomy. The detectability of the postoperative sphincterotomy line, adequacy of sphincterotomy, quality of internal and external sphincterotomy, and classification performance for unintended external sphincterotomy were examined.
RESULTS: In the anal fissure group, the detection rates with EAUS were 91.3% for the IAS and 87.0% for the EAS; in the postoperative group, they were 100% for the IAS and 96.0% for the EAS. The specificity for differentiating operated from non-operated sphincter anatomy was 100%, and the sensitivity was 76–80%. In the anal fissure group, the IAS thickness was 3.53±0.89 mm and the EAS thickness was 8.86±1.92 mm, both of which were greater than the healthy EAUS norms reported in the literature. In the postoperative group, unintended external sphincterotomy was detected in nine cases (36.0%).
DISCUSSION AND CONCLUSION: EAUS may serve as a complementary tool to strengthen diagnostic and treatment decisions by providing inexpensive, rapid, reproducible, and quantitative morphometric data on anal fissures. These findings are consistent with internal anal sphincter hypertrophy in primary fissures and may enable the quantification of sphincterotomy adequacy and the identification of unintended external sphincter effects in the postoperative period.
Keywords: Anal fissure, Endoanal ultrasonography (EAUS), Lateral internal sphincterotomy (LIS), sphincter morphometry, tailored sphincterotomy
Manuscript Language: English