Rectal Manometric Findings and Associated Clinical Changes in Myelopathy from Extradural Spine Pathology

Studies of rectal manometric findings in patients with extradural spine diseases are lacking. The objective of this study was to determine the changes in anorectal physiology caused by myelopathy from extradural spine diseases and to correlate these with other clinical features of myelopathy and improvement after surgery.

Twenty-eight patients with myelopathy caused by extradural spine diseases were prospectively enrolled and underwent clinical evaluation. Laboratory evaluation included rectal manometry and balloon expulsion tests in each of these patients, as well as pulmonary function tests and uroflowmetry. Follow-up data at 6 weeks were noted. Using the Kruskal-Wallis/Mann-Whitney U test and bivariate correlation, an association of manometric parameters with clinical variables and improvement in bowel function after surgery was identified.

Squeeze pressure (mean, 92.3 mm Hg) was lower and basal pressures (mean, 76.5 mm Hg) and sphincter pressures at defecation (mean, 92.3 mm Hg) and first sensation (mean, 48.2 mL) were found to be higher than normal. A significant correlation of pulmonary function test (P = 0.01)/uroflowmetry (P = 0.01) parameters and the duration of symptoms (P = 0.02) with manometric parameters was found. Improvement in constipation (P = 0.04) and myelopathy (P = 0.007) were also found to be associated with manometric parameters.

The findings of manometry help explain the cause of constipation in this subset of patients. There was a definite association of manometric parameters with clinical and pulmonary function test/uroflowmetry variables. Few manometric variables were found to be associated with improvement in myelopathy and bowel function.