Comparison of ultrasound and manometric sphincter length and incontinence scores

Functional anal canal length measurement using high-resolution anorectal manometry to investigate anal sphincter dysfunction in patients with fecal incontinence or constipation

BACKGROUND

Using high-resolution anorectal manometry, we aimed to evaluate the: (a) optimal threshold to measure functional anal canal length (FACL) with intra- and inter-observer variability; (b) relationship between abnormal FACL and other phenotypic findings; and (c) utility of FACL measurement to discriminate between healthy volunteers (HV) and patients with fecal incontinence (FI) or chronic constipation (CC).

METHODS

Consecutive patients referred for investigation of FI or CC in isolation were included. FACL was calculated at 5, 10, 20, 30, and 50 mm Hg above rectal pressure. 5th-95th percentile in HV defined limits of normality.

KEY RESULTS

FACL was analyzed in 192 patients with FI (154 females), 204 patients with CC (175 females), and 134 HV (101 females). The optimal threshold for measurement of FACL was 20 mm Hg. Using this threshold, observer reproducibility was very high (ICC 0.99, P < 0.0001). FACL was shorter in females with FI and longer in females with CC compared to HV (2.3 vs 2.9 cm; and 3.4 cm vs 2.9 cm; both P < 0.0001). Twenty percent of females and 13% males with FI had a short FACL, associated with older age, anal hypotonia or hypocontractility, and a atrophic internal anal sphincter. However, abnormal FACL in isolation was only found in 1/190 FI (0.5%) and 2/201 CC (1%) patients; all other patients had other abnormal manometric findings.

CONCLUSIONS AND INFERENCES

Considering overlap with other routinely evaluated manometric parameters, FACL measurement does not provide additional information in the diagnostic assessment of FI or CC.

Does preoperative anal physiology testing or ultrasonography predict clinical outcome with sacral neuromodulation for fecal incontinence?

INTRODUCTION AND HYPOTHESIS

To determine the value of preoperative anal physiology testing and transanal ultrasonography in predicting clinical response to sacral neuromodulation for fecal incontinence.

METHODS

We report a retrospective study of all patients treated with sacral neuromodulation for fecal incontinence in a single practice between 2011 and 2014 was performed. Patient demographics included age, gender, comorbidities, presence of an ultrasound-defined external sphincter defect, and history of prior anal sphincter repair. Cleveland Clinic Florida (CCF) scores were used to assess the severity of fecal incontinence at baseline, and at 3, 6 and 12 months. Pearson's correlation coefficient was used to evaluate the relationship between preoperative physiology testing and ultrasonography and patient outcome.

RESULTS

Sacral neuromodulation was trialed in 60 patients, of whom 31 had anorectal physiology testing and 29 did not. Patients who were tested were younger (60.9 vs. 71.4 years, p = 0.013) and more likely to have had a prior overlapping sphincteroplasty (40.5% vs. 15%, p = 0.043). Among patients who progressed to complete system implantation, CCF scores at 3 and 12 months were similar whether they had physiology testing or not. Likewise, patient outcome did not correlate with the finding of an ultrasound-defined external sphincter defect. Pearson's correlation coefficient was used to evaluate the relationship between the test results and the 3-month CCF scores. CCF scores 3 months after full system implantation did not correlate with the presence or size of an external sphincter defect, resting or squeeze pressure, pudendal nerve terminal motor latency, rectoanal inhibitory reflex, or minimum detectable volume.

CONCLUSIONS

Anal physiology testing and ultrasonography were not predictive of clinical outcomes among patients treated with sacral neuromodulation for fecal incontinence.

Anorectal manometric parameters are influenced by gender and age in subjects with normal bowel function

PURPOSE

Anorectal manometry provides objective information about anorectal function, but its results depend on the examiner's skill, the type of equipment, and subject characteristics like age or gender. This single institution, prospective study was performed to investigate the effect of gender and age on the results of anorectal manometry.

METHODS

All included subjects completed a questionnaire to assess their bowel function. The survey included 13 validated questions (eight on constipation and five on incontinence) and was used to exclude subjects with pathological constipation or incontinence. Subjects with normal bowel function underwent anorectal manometry to measure anal sphincter length (ASL), maximum resting pressure (MRP), and maximum squeeze pressure (MSP), and the results were compared by gender and age.

RESULTS

The mean age of the 154 participants (94 male and 60 female) was 59.1 years. ASL was greater in men (4.23 vs. 3.85 cm, p < 0.001). MRP was not significantly different according to gender (p = 0.93), but MSP was higher in men (190.18 vs. 116.49 mmHg, p < 0.001). ASL did not correlate with age (p = 0.707). MRP was inversely related to age in both men (R (2) = 0.152, p < 0.001) and women (R (2) = 0.282, p < 0.001), and MSP only in women (R (2) = 0.210, p < 0.001).

CONCLUSIONS

Anorectal manometric parameters are influenced by gender and age. This should be taken into consideration when interpreting manometric readings in a clinical setting.

Functional external anal sphincter reconstruction for treatment of anal incontinence using muscle progenitor cell auto grafting

PURPOSE

This study aimed to investigate the feasibility of autologous muscle progenitor cell transplantation for anal sphincter regeneration in a rabbit model of anal incontinence. We examined the serial changes in structure, with particular emphasis on histology and functional properties of the anal sphincter.

METHODS

External anal sphincterotomy was performed in 21 rabbits; these rabbits were randomly assigned to 2 groups. In group I (n = 9), autologous muscle progenitor cells were isolated from quadriceps myofiber explants, labeled with PKH-26, and injected into sphincter 3 weeks after sphincterotomy. In group II (n = 12), saline buffer was injected at the site of damage. Sphincter electromyography and manometry were performed immediately before sphincterotomy and 14, 28, and 60 days after injection in 3 animals in each group at every interval and the findings were correlated with histomorphological studies. In addition, electromyography and manometry were performed in the remaining 3 rabbits in group II after 6 months.

RESULTS

In group II, a flaccid sphincter persisted during the 6 months of follow-up. In group I, muscle progenitor autografting accelerated sphincter myofiber repair and improvement in functional capacity of the damaged sphincter. Fluorescently labeled cells were detected in all of the grafted sphincters; regenerated myotubes were detectable at the injection site as evidenced by the presence of desmin. We also observed a significant decrease in interstitial fibrosis in the 4th week and strikingly higher amounts of Ki-67-positive cells in group I. Manometry and electromyography showed a significant improvement in the mean resting anal canal pressure and sphincteric electrical activity 4 weeks after cell injection, respectively.

CONCLUSION

Transplanting muscle progenitor cells showed the potential for recapitulation of a myogenic program when injected into deficient rabbit anal sphincter. Objective anal measures of resting and stimulated pressures and electromyographic profile improved. Stem cell-mediated anal myoplasty warrants additional investigation as a new method to treat anal incontinence before attempting this modality in the clinical setting.

Anal physiology testing in fecal incontinence: is it of any value?

INTRODUCTION

The prognostic value of postoperative manometry in fecal incontinence is still controversial. The aims of this study were to establish if Fecal Incontinence Severity Index (FISI) and Fecal Incontinence Quality of Life Scale (FIQL) scores correlate with anal manometry and endoanal ultrasound findings and to define if there is any prognostic value in performing anal manometry after patients are surgically treated for fecal incontinence.

METHODS

Fifty-three patients, all women, were identified. All patients underwent a surgical procedure and were analyzed pre- and postoperatively. Fecal incontinence was assessed using the FISI and FIQL. Patients who did not have these score were excluded. Manometry and ultrasound findings before treatment and manometry findings after treatment were compared with surgical patient's incontinence scores. Anal canal length was noted, and its association with the pre- and postoperative manometry finding and incontinence scores were compared.

RESULTS

No correlation of pre- and postoperative resting and squeeze pressures with incontinence scores was found. Ultrasound findings had no correlation with manometry results and incontinence scores. Anal canal length correlated with both pre- and postoperative manometry findings but not with incontinence scores.

CONCLUSION

Preoperative anal manometry and endoanal ultrasound help in guiding treatment options in patients with fecal incontinence. A decrease in FISI and increase in FIQL scores after a sphincter repair quantifies improvement after incontinence surgery, while changes in anal manometry pressures readings do not.

Assessment of sonographic quality of anal sphincter muscles in patients with faecal incontinence

OBJECTIVE

The main application of endoanal ultrasonography (US) in evaluation of faecal incontinence is to identify surgically correctable sphincter defects. The aim of our study was to determine whether qualitative changes in echogenicity and in uniformity of internal (IAS) and external (EAS) anal sphincter muscles detected on endoanal US correlate with other anal laboratory tests and modified Wexner faecal incontinence functional score.

METHOD

Records on 99 patients having complete information on anorectal manometry, faecal incontinence scoring and available endoanal US imaging of the anal sphincters were included in statistical analysis. Anatomic appearance and changes in echogenicity of the anal sphincter muscles were recorded according to the proposed scoring system. Endoanal US defect and quality component scores for IAS and EAS as well as the total score were correlated with anal laboratory tests and incontinence score using Spearman's correlations test.

RESULTS

There was a trend for correlation between IAS quality score and incontinence score (P = 0.06), but no correlation for IAS defect score. EAS defect score had a significant negative correlation with maximum squeeze pressure (MSP) (P = 0.031). Distal EAS quality score had a significant correlation with incontinence score (P = 0.002). EAS total score correlated with MSP (P = 0.02) and incontinence score (P = 0.006). Endoanal US total score was significantly correlated with incontinence score (P = 0.006), maximal resting (MRP) (P = 0.035) and MSP (P = 0.045) and high pressure anal canal zone length (P = 0.03).

CONCLUSION

Sonographic morphology of anal sphincter muscles correlates with anal laboratory tests and functional incontinence score. Qualitative ultrasound scoring instrument may improve evaluation of patients with faecal incontinence.