Ultrasound-based scoring to predict long-term healing in anal fistula: A practical alternative or complementary to the MRI-based Garg scoring system?

We read with great interest the article by Thakur et al. ¹ The authors must be commended for addressing a clinically relevant and globally important challenge—postoperative assessment of fistula healing in settings where access to magnetic resonance imaging (MRI) is limited.

The study highlights an important gap in current practice. While MRI remains the gold standard for postoperative evaluation owing to its high sensitivity and specificity, its cost and limited availability in some regions limit its routine use. ² In this context, the development of the Jabalpur Transperineal Ultrasonography-Based Scoring System (J-TPUSS) represents a pragmatic attempt to bridge this disparity.

The authors mention the limitation of a relatively small sample size and a single-centre design. Larger, multicentric studies will be essential to establish external validity. The inherent selection bias was also mentioned. This implicates the robustness of comparative accuracy between MRI and J-TPUSS. Finally, the declining sensitivity of J-TPUSS with increasing fistula complexity (notably in Grade 4–5 disease) is noted to be a critical limitation. There remains a risk of underestimation of residual disease by ultrasound. The operator-dependent nature of this methodology obviously introduces greater variability than NMR. Also, a follow-up duration of 40 weeks may not adequately capture late recurrences, which are well-documented in cryptoglandular fistula disease. ¹

J-TPUSS is quite similar to the Garg scoring system, as all the parameters included in J-TPUSS are almost the same as those utilised in the Garg scoring system.^1,3,5 Another important technical point is that the authors assigned a linear weight (0, 1, 2) to all the parameters in J-TPUSS, ¹ despite all the parameters not having have equal clinical weight. In contrast, the Garg scoring system ³ is based on a rigorous statistical exercise done to calculate and assign different weights to different parameters. ³

MRI remains the gold standard, being able best to delineate deep tracts, internal openings, and occult abscesses, which are often not clinically apparent. ⁴ Ultrasound, though obviously very useful, may prove unsatisfactory in complex cases.

In conclusion, J-TPUSS is a promising, low-cost adjunct for postoperative assessment in resource-constrained settings. Further large-scale, multicentric validation with standardised imaging protocols and long-term follow-up is necessary before it can gain widespread acceptance.