Comparative analysis of conventional vs high-resolution anorectal manometry methods

Area of Science:

• Gastroenterology
• Colorectal Surgery
• Diagnostic Imaging

Background:

• High-resolution anorectal manometry (HR-ARM) is increasingly adopted, often replacing conventional anorectal manometry (C-ARM).
• Existing studies report strong correlations in pressure measurements, but significant variations in normative values across devices exist.
• This discrepancy highlights the need to directly compare manometric parameters obtained from both C-ARM and HR-ARM in the same patient cohort.

Purpose of the Study:

• To compare manometric parameters between C-ARM and HR-ARM.
• To assess the agreement of quantitative pressure measurements and diagnostic classifications between the two manometry techniques.
• To evaluate the clinical implications of using existing normative values with HR-ARM.

Main Methods:

• Fifty consecutive patients underwent both C-ARM and HR-ARM by the same examiner.
• Intraclass correlation coefficients were used for continuous variables (e.g., resting and squeeze pressures).
• Kappa coefficients assessed agreement for categorical variables (e.g., functional anal canal length, diagnostic categories).

Main Results:

• Excellent agreement was observed for resting and squeeze pressures between C-ARM and HR-ARM.
• Agreement was poor for functional anal canal length.
• Diagnostic agreement was fair to moderate for anal tone and dyssynergia markers, but poor for rectal relaxation and intra-rectal propulsion when using current normative values.

Conclusions:

• C-ARM and HR-ARM demonstrate excellent agreement in quantifying resting and squeeze pressures.
• The diagnostic agreement significantly decreases when applying current normative values, indicating poor concordance for clinical interpretation.
• Establishing unique, device-specific reference ranges for HR-ARM is crucial for accurate diagnosis and patient management.