The aim of this study is to evaluate the three-dimensional anorectal pressure topography of normal healthy adults and patients with paradoxical puborectalis syndrome (PPS) using a novel three-dimensional high-resolution manometry (3D-HRM) of the anorectum.Methods
The 3D-HRM probe has a 6.4 cm long sensing segment that is composed of 256 independent pressure transducers around its circumference. It generates a 3D pressure topographic profile of the anorectum. We evaluated 41 women and 38 men with PPS (median age 52 years), and compared them with 37 women and 34 men who were healthy (median age 51 years). The three-dimensional anorectal pressure topography was evaluated at rest, and during squeeze, stimulated defecation, and balloon inflation.Results
Maximum resting pressure, mean resting pressure, high pressure zone length, and residual anal pressure were significantly higher in patients with PPS compared with healthy adults (P<0.01 each). The rectoanal pressure differential was significantly lower in the PPS patients compared with healthy adults (P<0.05). There was a characteristic purple high-pressure area in the posterior wall of the pressure cylinder of patients with PPS during stimulated defecation that was absent in healthy adults. The longest diameter and widest diameter of this purple high-pressure area were 1.71±0.25 and 1.07±0.14 cm. The maximum, mean, and minimum pressures of the posterior distal pressure zone were significantly higher in patients with PPS (270.1±8.2, 152.7±4.8, and 51.9±2.7 mmHg, respectively) compared with healthy adults (168.5±11.1, 88.0±5.9, and 30.7±2.8 mmHg, respectively) (P<0.01).Conclusion
Using the 3D-HRM technique, the increase in the resting pressure and residual anal pressure and decrease in the rectoanal pressure differential in patients with PPS compared with healthy adults further indicated the mechanism of this disease. Unlike traditional manometry, the 3D-HRM technique could find, locate, and evaluate the scope and the pressure of the paradoxical contraction of puborectalis muscle, which further indicates the value of manometry in terms of diagnosis.