Published online Apr 27, 2021. doi: 10.4240/wjgs.v13.i4.355
Peer-review started: January 12, 2021
First decision: February 11, 2021
Revised: February 11, 2021
Accepted: April 14, 2021
Article in press: April 14, 2021
Published online: April 27, 2021
Processing time: 97 Days and 23.9 Hours
The association of tuberculosis (TB) with anal fistulas can make its treatment quite difficult. The main challenge is timely detection of TB in anal fistulas and its proper management. There is little data available on diagnosis and management of TB in anal fistulas.
To detect TB in fistula-in-ano patients were analyzed in different methods utilized.
A retrospective analysis of different methods, polymerase chain-reaction (PCR), GeneXpert and histopathology (HPE), utilized to detect tuberculosis in fistula-in-ano patients, treated between 2014-2020, was performed. The sampling was done for tissue (fistula tract lining) and pus (when available). The detection rate of various tests to detect TB and prevalence rate of TB in simple vs complex fistulae were studied.
In 1336 samples (776 patients) tested, TB was detected in 133 samples (122 patients). TB was detected in 52/703 (7.4%) samples tested by PCR-tissue, in 77/331 (23.2%) samples tested by PCR-pus, 3/197 (1.5%) samples tested with HPE-tissue and 1/105 (0.9%) samples tested by GeneXpert. To detect TB, PCR-tissue was significantly better than HPE-tissue (52/703 vs 3/197 respectively) (P = 0.0012, significant, Fisher’s exact test) and PCR-pus was significantly better than PCR-tissue (77/331 vs 52/703 respectively) (P < 0.00001, significant, Fisher’s exact test). TB fistulas were more complex than non-tuberculous fistulas [78/113 (69%) vs 278/727 (44.3%) respectively] (P < 0.00001, significant, Fisher’s exact test) but the overall healing rate was similar in tuberculous and non-tuberculous fistula groups [90/102 (88.2%) vs 518/556 (93.2%) respectively] (P = 0.10, not significant, Fisher’s exact test).
This is the largest study of anorectal TB to be published. The detection of TB by polymerase chain-reaction was significantly higher than by histopathology and GeneXpert. Amongst polymerase chain-reaction, pus had a higher detection rate than tissue. TB fistulas were more complex than non-tuberculous fistulas but aggressive diagnosis and meticulous treatment led to comparable overall success rates in both groups.
Core Tip: This is the largest study of anorectal tuberculosis (TB) to be reported. A total of 1336 tissue and pus samples were tested in 776 patients over 6 years. Polymerase chain-reaction, GeneXpert and histopathology were utilized to detect TB in these samples. Polymerase chain-reaction was more sensitive than histopathology and GeneXpert to detect TB in anal fistulas. This is the first study in which these three methods have been compared in the same cohort. Pus was more sensitive than tissue samples to detect TB. TB fistula had a significantly higher proportion of complex fistulas but timely diagnosis and treatment led to a high success rate in these fistulas.