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Published on: March 12, 2019
Clinical Significance of 2 Deep Posterior Perianal Spaces to Complex Cryptoglandular Fistulas
Heng Zhang1, Zhi-Yang Zhou, Bang Hu
11 Department of Colorectal Surgery, Sixth Affiliated Hospital of Sun Yat-sen University (Gastrointestinal and Anal Hospital), Guangzhou, People's Republic of China 2 Department of Radiology, Sixth Affiliated Hospital of Sun Yat-sen University (Gastrointestinal and Anal Hospital), Guangzhou, People's Republic of China.
Background:
Confusion exists regarding the clinical significance of the deep posterior intersphincteric space and deep postanal space to complex perianal fistulas.
Objective:
The purpose of this study was to assess the clinical significance of the 2 deep posterior perianal spaces and to describe in detail the courses of posterior complex cryptoglandular fistula extensions.
Design:
This was a retrospective study. MRI-based characteristics of selected perianal fistulas were independently evaluated by examiners who focused on lesions in these 2 spaces and were blinded to each other's findings.
Settings:
This study was conducted in the colorectal surgery and radiology departments of a large university teaching hospital in China.
Patients:
Included in the study were patients who underwent pelvic MRI for posterior perianal fistula between October 2012 and December 2014.
Main Outcome Measures:
The occurrence rates of these 2 deep perianal space lesions in posterior cryptoglandular fistulas were determined.
Results:
A total of 513 primary posterior cryptoglandular fistulas were identified in 508 patients, including 167 deep posterior intersphincteric space lesions (32.6%) and 23 deep postanal space lesions (4.5%). Of those, 173 fistulas (33.7%) were evaluated as complex. The former and latter spaces were involved in 79.2% (137/173) and 13.3% (23/173) of posterior complex fistulas. Compared with deep postanal space lesions, deep posterior intersphincteric space lesions were more common in cases with high transsphincteric or suprasphincteric fistulas (80.1% vs 15.8%), synchronous multiple transsphincteric fistulas (82.4% vs 20.6%), horseshoe-like fistulas (85.5% vs 14.5%), and supralevator fistulas (93.5% vs 16.1%). Similar incidences were also seen in cases with ischioanal-involved horseshoe-like fistulas (75.0% vs 25.0%).
Limitations:
This study was limited by its retrospective nature.
Conclusions:
The deep posterior intersphincteric space is more likely than the deep postanal space to be involved in complex cryptoglandular fistulas and is likely to play a more important role in the management of complex cryptoglandular fistulas.
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