Dynamic magnetic resonance imaging of the pelvic floor in children and adolescents with vesical and anorectal malformations

Internal fat prolapse from ischiorectal fossa masquerading as currarino syndrome

Pelvic magnetic resonance imaging (MRI) is the latest addition to already existing tools for evaluation of anorectal malformation (ARM). It provides detailed information about pelvic floor musculature as well as position of rectal pouch. However, lack of knowledge about normal pelvic floor anatomy can lead to misinterpretation of pelvic MRI which can create confusion and change in approach for surgery. A 14-month-old male child with diagnosis of ARM was evaluated with pelvic MRI. There was finding of abnormal protrusion of fat through the ischiorectal fossa which was misinterpreted as Currarino syndrome which created confusion immediately before posterior sagittal anorectoplasty. Pelvic MRI is highly informative while evaluating a case of ARM. However, a detailed knowledge of pelvic floor anatomy is mandatory to avoid wrong interpretation and misdiagnosis.

Pelvic Floor Muscles Contribution in Surgical Outcome of Children with High-type Anorectal Malformations

As a consequence of high-type anorectal malformations (ARMs) pathogenesis, the pelvic floor muscles remain severely underdeveloped or hypoplastic, the rectal pouch is located at the level or above the puborectalis sling, and the bowel terminates outside the sphincter muscle complex support. For children with high-type ARMs the ultimate objective of therapy is mainly to grow up having bowel continence function that is compatible with a good quality of life, and the final prognosis depends significantly on the grade of development of pelvic floor muscles and the successful entering of the anorectum fully within the support of the external anal sphincter due to intraoperative conservation of the puborectalis sling. Pelvic magnetic resonance imaging (MRI) has recently become the preferred imaging study for prediction of functional outcomes, since it can define the anatomy and evaluate the development of the sphincteric muscles before and after surgical correction. Based on recent literature and our clinical experience, we will discuss the relevance of pelvic floor muscles MRI to the clinical outcome of children with high type ARMs.

Revision Surgery in the Management of Anorectal Malformations: Experience from a Tertiary Center of India

Aim and Objectives:

Despite the significant advancements in the management of anorectal malformations (ARMs), there are various surgical and functional complications reported. Complications are closely related with the surgical techniques adopted and the types of malformations. In this article, we present our experiences with ARM patients who required reoperation after unsuccessful previous surgeries or who had developed complications related to the previous surgical techniques.

Materials and Methods:

We retrospectively reviewed clinical and electronic records of all the patients with ARM who were operated for ARMs in our institute from June 2010 to May 2016. All ARM patients who needed reoperation were included in the study. These patients were previously operated outside our institute and referred to us with ongoing problems of constipation, stool impaction with overflow incontinence, perineal soiling, and difficult urination.

Results:

There were 31 patients (M:F = 2.1:1) of ARM, reoperated for 38 indications during the above-mentioned period. Five patients had more than one problem. Presentation included neoanal stenosis (11), complete obliteration of neoanus (2), malpositioned neoanus (2), persistent/recurrent rectourethral fistula (3), iatrogenic rectovaginal fistula (4), rectal prolapse (5), large widened neoanus with soiling (2), and urethral stricture (2), which required revision interventions. Six patients had megarectum. All patients showed improvement in their symptoms after revision surgery, but 10 (41.7%) patients required further regular bowel management program (BMP) to avoid the soiling and constipation. Fourteen (58.3%) patients stayed clean without regular BMP.

Conclusion:

All these complications had clear explanations and are well described in the literature. Revision surgery in such patients had fair outcome, but some sort of BMP was required. Both posterior sagittal anorectoplasty and anterior sagittal anorectoplasty are excellent techniques for revision surgery with few simple modifications.

Childhood incontinence and pelvic floor muscle function: Can we learn from adult research?

Little research has been undertaken regarding pelvic floor muscle function and dysfunction in children. Apart from dysfunctional voiding, whether specific dysfunction of these muscles contributes to different types of childhood incontinence is not documented. The two areas of practice, that is adult and paediatric incontinence, are quite different; nevertheless, there may be lessons to be learned from the extensive work done in pelvic floor dysfunction and rehabilitation in adults. In this paper key points regarding pelvic floor muscle function and dysfunction in adults, and lessons that can be learned from how studies are reported and how muscle function is measured are presented. The aim is to prompt deeper thought regarding the direction in which further research in children may proceed. There are challenges in first validating muscle measurement standards and making the work relevant to children across different age groups with differing cognitive and motor abilities.

MRI findings in patients with defecatory dysfunction after surgical correction of anorectal malformation

BACKGROUND

Postoperative anorectal malformation patients frequently have defecatory dysfunction. MRI may be useful in the management of these patients.

OBJECTIVE

To analyze static and dynamic MRI findings in patients with defecatory dysfunction after correction of anorectal malformation (ARM), and compare differences between patients with constipation and fecal incontinence.

MATERIALS AND METHODS

Pelvic MRI studies of 20 constipated and 32 incontinent postoperative ARM patients were analyzed retrospectively to determine the location and morphology of the neorectum, presence of peritoneal fat herniation, presence of scarring, development of the striated muscle complex (SMC) and any other abnormalities. The two groups were then compared using χ(2)-test. Eighteen patients also underwent MRI defecography to evaluate pelvic floor function and abnormalities are reported.

RESULTS

The children with incontinence were more likely to have abnormal location of the neorectum (P = 0.031), increased anorectal angle (ARA) (P = 0.031) and peritoneal fat herniation (P = 0.032), and less likely to have dilation of the neorectum (P = 0.027), than the children with constipation. There were no significant differences between the two groups in incidence of focal stenosis of the neorectum (P = 0.797), presence of extensive scarring (P = 0.591) and developmental agenesis of the SMC (P > 0.05). MRI defecography showed 6 anterior rectoceles, 6 cystoceles and 18 pelvic floor descents.

CONCLUSIONS

MRI is a helpful imaging modality in postoperative ARM patients with defecatory dysfunction, and it shows distinct differences between the children with constipation and incontinence and provides individualized information to guide further treatment.

Dynamic MRI (dMRI) as a guide to therapy in children and adolescents with persistent full thickness rectal prolapse: a single centre review

INTRODUCTION

Full thickness rectal prolapse (FTRP) tends to be self-limiting in children and is usually managed expectantly. However, it may persist and therefore requires surgical correction. There is no consensus upon operative management, and no one procedure has uniformly good outcomes. The aim of this study was to determine whether pre-operative diagnostic dMRI findings might help identify the operative approach best suited to the anatomical abnormality of the individual child.

METHODS

A retrospective review of ten children with persistent FTRP who had been evaluated pre-operatively with dMRI between 2002 and 2010 was performed. In this preliminary work, MRI findings were not used to direct surgical management. Data collected included: age at presentation, underlying medical conditions, timing and findings of dMRI (specifically, descent of rectum from pubococcygeal (PC) line on straining), timing and type of surgery, surgical outcomes, and length of follow-up.

RESULTS

Ten children (two female) with a median age of 11 years 2 months (range 8-15 years) with FTRP refractory to conservative treatment underwent diagnostic pre-operative dMRI. Median perineal descent from PC line on straining during dMRI was 3.5 cm (range 1-4 cm). Three of the seven children with severe descent initially underwent a Delorme's procedure, and all required surgical revision. Five with severe descent and one with moderate descent achieved a cure following rectopexy. Two patients with mild descent underwent a Delorme's procedure. One achieved a cure, and the other developed recurrence. Of the ten patients, seven had no prolapse at the last clinic review, and three have persisting symptoms. Median follow-up was 3.5 years (range 1-6).

CONCLUSION

The findings from this small study favour rectal suspension techniques for surgical management of moderate to severe perineal descent on dMRI. Delorme's procedure should only be applied to those with mild descent. Pre-operative dMRI assessment may have a potential role in guiding surgical intervention for children. However, future prospective studies will be required to confirm this assertion.

Apoptosis during the development of pelvic floor muscle in anorectal malformation rats

PURPOSE

Fecal incontinence and constipation still remain as major postoperative complications after procedures for anorectal malformations (ARM). The striated muscle complex (SMC) is one of the most important factors that influence defecation. Previous studies have demonstrated different degrees of the muscle complex dysplasia dependent on the complexity of ARM. To explore the mechanisms of maldevelopment of SMC in ARM, apoptosis was investigated during pelvic floor muscle development in rat embryos with ARM.

METHODS

Anorectal malformations in rat embryos were induced by treating pregnant rats with ethylenethiourea on the 10th embryonic day (E10). Normal and ARM rat embryos from E16 to E21 were serial-sectioned transversely or sagittally, and SMCs were dissected and snap frozen. TdT mediated dUTP Nick Ending Labeling (TUNEL) staining and DNA ladder analysis were performed to identify apoptosis and expression of Bax/Bcl-2 were confirmed with immunohistochemical staining and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) analysis.

RESULTS

Hypoplastic and disordered SMC sling shifted cephalad, ventrally, and converged inferior to the rectourethral fistula and infiltrated connective tissue in ARM embryos. In the normal group, TUNEL-positive cells became evident on E17; sporadic positive staining was mainly localized in 2 areas as follows: the junction area between SMC and bulbocarvernosus muscle and posterior to the rectum where bilateral SMC converged. In the ARM group, massive positive staining of nuclei was observed from E16 to E21 and was mainly distributed in the dorsal part of the SMC. Electrophoresis of DNA samples yielded a "ladder" pattern of migration both in normal and the ARM group from E17 to E21, the ladders were stronger in the ARM group. In both groups, the expression of Bax/Bcl-2 was detectable on E17, the immunoreactivity increased on E19 and E21. Compared with the normal group, the expression of Bax was increased, whereas Bcl-2 was declined in the ARM group. Significant upregulation of Bax messenger RNA (mRNA) levels and downregulation of Bcl-2 mRNA levels were observed in ARM embryos.

CONCLUSIONS

In the current study, abnormal apoptosis and disturbed expression of Bax/Bcl-2 were identified during SMC development in ARM embryos. It is suggested that precocious, excessive, and dislocated apoptosis might be a fundamental pathogenesis for the maldeveloped SMC in ARM rats. The temporospatial expressions of Bax/Bcl-2 indicate they may have an important role in the regulation of apoptosis of SMC.