Functional anorectal imaging

MR-defecography in obstructed defecation syndrome (ODS): technique, diagnostic criteria and grading

BACKGROUND

The aim of this study was to evaluate the use of a magnetic resonance (MR)-based classification system of obstructive defecation syndrome (ODS) to guide physicians in patient management.

METHODS

The medical records and imaging series of 105 consecutive patients (90 female, 15 male, aged 21-78 years, mean age 46.1 ± 5.1 years) referred to our center between April 2011 and January 2012 for symptoms of ODS were retrospectively examined. After history taking and a complete clinical examination, patients underwent MR imaging according to a standard protocol using a 0.35 T permanent field, horizontally oriented open-configuration magnet. Static and dynamic MR-defecography was performed using recognized parameters and well-established diagnostic criteria.

RESULTS

Sixty-seven out of 105 (64 %) patients found the prone position more comfortable for the evacuation of rectal contrast while 10/105 (9.5 %) were unable to empty their rectum despite repeated attempts. Increased hiatus size, anterior rectocele and focal or extensive defects of the levator ani muscle were the most frequent abnormalities (67.6, 60.0 and 51.4 %, respectively). An MR-based classification was developed based on the combinations of abnormalities found: Grade 1 = functional abnormality, including paradoxical contraction of the puborectalis muscle, without anatomical defect affecting the musculo-fascial structures; Grade 2 = functional defect associated with a minor anatomical defect such as rectocele ≤ 2 cm in size and/or first-degree intussusception; Grade 3 = severe defects confined to the posterior anatomical compartment, including >2 cm rectocele, second- or higher-degree intussusception, full-thickness external rectal prolapse, poor mesorectal posterior fixation, rectal descent >5 cm, levator ani muscle rupture, ballooning of the levator hiatus and focal detachment of the endopelvic fascia; Grade 4 = combined defects of two or three pelvic floor compartments, including cystocele, hysterocele, enlarged urogenital hiatus, fascial tears enterocele or peritoneocele; Grade 5 = changes after failed surgical repair abscess/sinus tracts, rectal pockets, anastomotic strictures, small uncompliant rectum, kinking and/or lateral shift of supra-anastomotic portion and pudendal nerve entrapment.

CONCLUSIONS

According to our classification, Grades 1 and 2 may be amenable to conservative therapy; Grade 3 may require surgical intervention by a coloproctologist; Grade 4 would need a combined urogynecological and coloproctological approach; and Grade 5 may require an even more complex multidisciplinary approach. Validation studies are needed to assess whether this MR-based classification system leads to a better management of patients with ODS.

Use of anorectal manometry for evaluation of postoperative results of patients with anorectal malformation: a study from Kuwait

PURPOSE

The objective of this study is to use anorectal manometry for functional assessment of early postoperative results after corrective surgery for anorectal malformations (ARMs) in children and compare manometric observations with age-matched controls. Parents were counseled and management strategies were planned according to the manometric assessments.

METHODS

From August 2005 to September 2009, 32 patients who underwent surgery for ARM were assessed postoperatively with anorectal manometry using a water-perfused anorectal motility catheter to record anal canal length or high-pressure zone, resting pressure of anal canal (RP), and rectoanal inhibitory reflex (RAIR). These patients were divided in 2 groups (infants, <1 year; children, >1 year) according to the age at the time of performance of anorectal manometry that was done at 6 months or later following stoma closure or anoplasty.

RESULTS

Out of these 32 patients, high anomaly was present in 13, whereas 19 had low type of defect. Manometric anal canal length of the children with high and low ARM was 2.10 ± .44 and 2.25 ± .53 cm, respectively, which was significantly shorter than that of their age-matched controls(P < .05). In patients with high ARM, RP in infants (17 ± 7.7 mm of Hg) and children (21 ± 9.4 mm of Hg) was lower than that of controls (RP in infants = 42.43 ± 8.19 mm of Hg, RP in children = 43.43 ± 8.79 mm of Hg, P < .001). In patients with low ARM, RP in infants (34 ± 8.6 mm of Hg, P = .002) and children (26 ± 9.9 mm of Hg, P = .001) was lower than that in controls. Presence of RAIR was demonstrated in 5 (38.4%) of 13 patients with high ARM and in 11 (57.9%) of 19 cases with low ARM. Parental counseling was done after this early evaluation, and management strategies like bowel management program and biofeedback training were planned according to the results of the tests.

CONCLUSION

Our anorectal manometric results suggest that patients with ARM had short anal canal with lower RP and impaired RAIR, which could affect the ultimate functional outcome in these patients. Thus, postoperative anorectal manometric evaluation of the patients with ARM can give more realistic information about future continence and might help in planning future treatment strategies like bowel management program or biofeedback training.

Radiologic evaluation of pelvic floor disorders

Several imaging modalities are available ranging from fluoroscopic techniques to ultrasonography and MRI for the evaluation of patients with pelvic floors disorders. High-resolution ultrasonography and MRI not only provide superior delineation of the pelvic floor anatomy but also reveal pathology and functional changes. This article focuses on standard imaging procedures including defecography, ultrasonography, and MRI and discusses its use in clinical practice by illustrating both normal and abnormal patterns.

Obstetric anal sphincter injury: incidence, risk factors, and management

BACKGROUND AND AIMS

Obstetric sphincter damage is the most common cause of fecal incontinence in women. This review aimed to survey the literature, and reach a consensus, on its incidence, risk factors, and management.

METHOD

This systematic review identified relevant studies from the following sources: Medline, Cochrane database, cross referencing from identified articles, conference abstracts and proceedings, and guidelines published by the National Institute of Clinical Excellence (United Kingdom), Royal College of Obstetricians and Gynaecologists (United Kingdom), and American College of Obstetricians and Gynecologists.

RESULTS

A total of 451 articles and abstracts were reviewed. There was a wide variation in the reported incidence of anal sphincter muscle injury from childbirth, with the true incidence likely to be approximately 11% of postpartum women. Risk factors for injury included instrumental delivery, prolonged second stage of labor, birth weight greater than 4 kg, fetal occipitoposterior presentation, and episiotomy. First vaginal delivery, induction of labor, epidural anesthesia, early pushing, and active restraint of the fetal head during delivery may be associated with an increased risk of sphincter trauma. The majority of sphincter tears can be identified clinically by a suitably trained clinician. In those with recognized tears at the time of delivery repair should be performed using long-term absorbable sutures. Patients presenting later with fecal incontinence may be managed successfully using antidiarrheal drugs and biofeedback. In those who fail conservative treatment, and who have a substantial sphincter disruption, elective repair may be attempted. The results of primary and elective repair may deteriorate with time. Sacral nerve stimulation may be an appropriate alternative treatment modality.

CONCLUSIONS

Obstetric anal sphincter damage, and related fecal incontinence, are common. Risk factors for such trauma are well recognized, and should allow for reduction of injury by proactive management. Improved classification, recognition, and follow-up of at-risk patients should facilitate improved outcome. Further studies are required to determine optimal long-term management.

Anal endosonography is useful for postoperative assessment of anorectal malformations

AIM

This study aimed to develop and evaluate a scoring system for anal endosonography to assess anal canal structures after repair of anorectal malformations (ARM).

METHODS

Forty patients with ARM aged 16 years (range, 1-22 years) and 20 controls aged 17 years (range, 0.5-20 years) were examined. Anal function was assessed clinically and by anal canal manometry. The anal canal structures were imaged by anal endosonography using a 7.5-MHz transducer. A scoring system was developed to assess the anal sphincters as visualized on the endosonographic images.

RESULTS

Continence was significantly correlated to anal canal pressures. The estimated extent of muscle defect (measured in quadrants) and the number of disruptions in the internal and external anal sphincters correlated significantly to the rest and squeeze pressures, respectively. Thus, patients (>4 years) with squeeze pressure of less than 80 cm H2O were characterized by more than 1 disruption in the external anal sphincter ring and 2 or more quadrants with scar tissue.

CONCLUSION

The extent of scar tissue and the number of disruptions in the anal sphincters correlate with anal canal pressures and continence after ARM repair. Anal endosonography may be used to study the results after different surgical techniques and for prognosis on continence in patients with ARM.