Distensibility of the anal canal in patients with systemic sclerosis: a study with the functional lumen imaging probe.

AIM: Systemic sclerosis (SSc) is a generalized connective tissue disease that affects smooth muscle cells. Patients with SSc often have faecal incontinence caused by fibrotic degeneration of the internal anal sphincter (IAS). The functional lumen imaging probe (FLIP) is a novel method that allows the segmental biomechanical properties of the anal canal to be dynamically evaluated. The aim of the present study was to compare the segmental biomechanical properties of the anal canal in incontinent SSc patients and healthy controls. We hypothesized that the FLIP would reveal weaknesses of the IAS in the SSc patients. METHOD: We performed FLIP distensions, endoanal ultrasonography and standard anal manometry on 14 incontinent SSc patients [11 women, median age 60 years (range 35-80)] and 15 healthy volunteers [12 women, median age 54 years (range 33-67)]. The anal canal was divided into three parts for the biomechanical analysis: upper (surrounded by the IAS and the puborectalis), middle (IAS and external anal sphincter) and lower (external sphincter only). RESULTS: The middle anal canal was the segment most resistant to distension in all of the subjects, but it was less resistant in the SSc patients than in the controls (P < 0.01). Correspondingly, the endoanal ultrasonography showed that the IAS of the SSc patients was thinner than normal (P < 0.05), and the anal resting and squeeze pressures were lower (P < 0.05). Only minor distensibility differences were found in the upper anal canal. No changes were found in the lower anal canal. CONCLUSION: Faecal incontinence in SSc patients is associated with poor IAS function, causing increased distensibility of the middle anal canal.

Patients with esophageal motility disorders show distinct patterns based on axial force measurements.

BACKGROUND: Using manometry, the classification of motility-related disorders in the esophagus is vague and overlapping. We present a new method, which combines manometry and axial force measurements in a single catheter. AIM: The aim was to examine the manometric and axial force recordings during swallows. METHODS: Recordings from 20 patients suffering from diffuse esophageal spasms (DES) (8), achalasia (5) and other diseases including gastro-oesophageal reflux (7) were compared to recordings made in ten healthy subjects. The probe was capable of measuring axial force 6.5-cm proximal to the lower esophageal sphincter (LES) and pressures 8-, 10- and 12-cm proximal to the LES. After insertion, five dry and five wet swallows were made. Swallows were repeated with 0, 2, 4 and 6 ml of water in a bag mounted distal to the axial force recording site. Each contraction was analysed for duration and amplitude, and was categorised according to its configuration. RESULTS: The number of failed contractions measured with axial force was lower for the achalasia (P < 0.001) and DES groups (P < 0.001) compared to the healthy volunteers. The number of multi-peaked contractions was unchanged for the achalasia and DES groups while it increased for the group of healthy volunteers. On several occasions a negative traction force was encountered though the manometric pattern appeared normal. CONCLUSIONS: Measurements of axial force generated by primary peristalsis provide additional information about esophageal neuromuscular function in different diseases that is not demonstrable with manometry alone.

Functional luminal imaging probe: a new technique for dynamic evaluation of mechanical properties of the anal canal.

BACKGROUND: The muscle structures surrounding the anal canal are of major importance in maintaining continence but their anatomy and function vary along its length. Standard manometry does not provide detailed information about mechanical properties of the anal canal. A new functional luminal imaging probe (FLIP) has been developed for this purpose. The aim of our study was to investigate whether FLIP allows detailed evaluation of dynamic biomechanical properties along the length of the anal canal. METHODS: The in vitro validity and reproducibility of the FLIP system were tested. Fifteen healthy volunteers (age 32-65 years, mean 51 years), of whom 12 were females, were investigated. The integrity and dimensions of the anal sphincter apparatus were evaluated with endoanal ultrasonography and standard anal manometry. During standardized distensions with the FLIP, 16 cross-sectional areas of the anal canal were measured at 5-mm intervals. Distensibility of the following three segments was evaluated: upper anal canal (surrounded by the internal anal sphincter and the puborectalis muscle), mid-anal canal (surrounded by the internal anal sphincter and the external anal sphincter) and lower anal canal (surrounded by the external anal sphincter). Color contour plots were generated from the FLIP-based dynamic recordings of serial cross-sections. RESULTS: In vitro tests confirmed the validity and reproducibility of the FLIP system. The luminal geometry during distension and the biomechanical properties of the anal canal differed at the three levels. Both at rest and during squeeze the mid-anal canal was significantly less distensible than the upper (p < 0.01) and the lower (p < 0.05) anal canal. CONCLUSIONS: FLIP is a promising method for evaluation of the nonhomogeneous biomechanical properties along the length of the anal canal.