Robotic-assisted anorectal pull-through for anorectal malformations

Background/purpose

Many reports have addressed the feasibility and safety of using robotic surgery in children. To our knowledge, no published report has described the use of a surgical robot in the repair of anorectal malformations (ARMs).

Methods

Included children underwent robotic-assisted repair of ARMs with rectourethral fistula between April 2006 and March 2010 at King Khalid University Hospital, Riyadh, Saudi Arabia, using the da Vinci Surgical System. Their medical records were reviewed with respect to demographic data, associated anomalies, techniques and operative procedures, complications, outcomes, and follow-up.

Results

Five male infants (mean age, 6.6 months) underwent robotic-assisted repair of ARMs with rectourethral fistula using the Georgeson technique. The fistulae were divided and ligated in 4 patients and was left open in 1. All procedures were successfully completed without conversion to an open technique. One patient developed left-sided epididymo-orchitis postoperatively. All the patients had their colostomy closed. The follow-up ranged from 6 to 36 months. Fecal continence was difficult to assess in 2 patients. Two patients have voluntary bowel movements without soiling. One infant has fecal soiling and is on a laxative/enema for constipation.

Conclusions

Robotically assisted repair of ARMs with rectourethral fistula is feasible and safe. It offers a good alternative to the criterion standard, posterior sagittal anorectoplasty (PSARP), for repair of ARMs with rectourethral fistula. More patients and a longer follow-up period are needed for further evaluation of this novel approach.     

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.     

Social quality of life for adult patients with anorectal malformations

Background/Purpose

Pediatric surgeons who performed the initial surgery on anorectal malformations (ARM) lose contact with the patients as they become adults. In the present study, we examined 20- to 40-year-old adult patients with a history of surgery for ARM and analyzed them from the points of social quality of life.

Patients and Methods

Twenty-nine patients with ARM, aged 20 to 40, were surveyed by questionnaire or personal interview. Thirteen with high-type and 9 with intermediate-type anomalies underwent abdominoperineal rectoplasty, and 7 with low-type anomalies underwent perineoplasty between 1965 and 1985. Responses were analyzed from the perspectives of bowel, urinary, and sexual functions and social activity.

Results

One third of patients with high- or intermediate-type anomalies occasionally complained of fecal soiling. However, the other patients gained good bowel function and enjoyed occupational or student life without problems. Fecal soiling was the key factor disturbing occupational life, although the problem remained within a socially manageable level. All of the patients with ARM had normal urinary function. Three of the 18 male patients had sexual problems such as erectile or ejaculatory dysfunction because of associated genitourinary anomalies. Nine of the 11 female patients had regular menstruation and the other 2 had irregular menstrual periods. Five female patients were married and 4 of the 5 had children (1-5 children). Modes of delivery were normal vaginal delivery in 8 and cesarean section in 1. Only one of the 5 had a slight sacral anomaly. However, she had no apparent abnormality of bladder function and got through pregnancy and delivery without difficulty.

Conclusion

One third of adult patients with high- or intermediate-type anomalies after abdominoperineal rectoplasty had some problems in bowel function. Fecal soiling was the key factor that disturbed their occupational life. Most of the patients had normal urinary and sexual functions if they did not have associated genitourinary anomalies and enjoyed social activities.     

Loop colostomies are safe in anorectal malformations

Aim of the study

Divided colostomy (DC) has been recommended in anorectal malformations (ARMs) with previously reported advantages of decreasing overflow into the distal limb and urinary tract infections (UTIs). Skin bridge loop colostomy (LC) is a technically easier alternative without an increase in these complications. We report our institutional experience of LC in ARM.

Comparison of clinical outcomes and anorectal manometry in patients with congenital anorectal malformations treated with posterior sagittal anorectoplasty and laparoscopically assisted anorectal pull through

Purpose

The objective of this study is to analyze the clinical outcomes and anorectal manometry (AM) in infants with congenital high anorectal malformations treated with posterior sagittal anorectoplasty (PSARP) and laparoscopically assisted anorectal pull through (LAARP).

Materials and Methods

From August 2005 to December 2008, 23 patients with congenital high anorectal malformations were randomly distributed into PSARP and LAARP groups. All of them underwent LAARP (11 cases) or PSARP (12 cases) at 2 or 3 months old. Clinical outcomes and results of anorectal manometry were compared between patients at the age of 17.4 ± 4.9 and 19.3 ± 6.2 months (P = .4270), respectively.

Results

Kelly's clinical score for patients in LAARP and PSARP groups was 3.91 ± 1.14 and 3.83 ± 1.40 (P = .8827), respectively. Anal canal resting pressure and high-pressure zone length were 29.4 ± 7.2 vs 23.4 ± 6.5 mm Hg (P = .0479) and 14.9 ± 3.0 vs 13.9 ± 3.1 mm (P = .4414), respectively. Rectal anal inhibitory reflex was observed in 81.8% (9/11) and 83.3% (10/12) patients (P = 1.0000), respectively. The mean length of stay during the second hospitalization was 10.6 ± 0.9 and 14.3 ± 1.4 days (P < .0001), respectively.

Conclusions

Although no significant difference can be noted in clinical scoring between both groups, the results of anorectal manometry indicate that LAARP can significantly improve anal canal resting pressure and reduce the length of stay.     

A new job for an old device: A novel use for nerve stimulators in anorectal malformations

Muscle stimulation of the perineum is a crucial step in the repair of anorectal malformations. This allows the surgeon to assess muscle function and locate precisely the sphincter muscles during a pull-through operation. Presently, the device commonly used is very expensive.     

Validation of the Baylor Continence Scale in children with anorectal malformations

Background

Anorectal malformations (ARMs) often result in lifelong problems with defecation. There have been no studies performed to develop scoring systems in children with fecal incontinence following repair of ARM. This study was designed to develop and validate a tool (Baylor Continence Scale [BCS]) to measure social continence in children after surgical correction of ARMs.

Methods

The BCS is a 23-question survey, was administered to children who have had repair of an ARM, children with enuresis, and normal children.

Results

Children in the ARM group had an average BCS score of 28.0, which was statistically different from an enuresis control group (16.5) and normal controls (11.5) (P < .05). A significantly greater proportion of children in the ARM group had higher Impact on Family Scores (>30) than either the enuresis or normal control group (P < .05).

Conclusions

The BCS tool should be useful in prospective studies of interventions to improve incontinence after repair of an ARM. An important secondary result of this study was to demonstrate the effect on families of caring for a child with imperforate anus, even years after the repair.     

Developmental study of tethered spinal cord in murine embryos with anorectal malformations

Background/Purpose

Tethered spinal cord is frequently associated with anorectal malformations (ARMs). However, it remains unknown how the tethered spinal cord develops and relates to the severity of ARM. We studied the development of the spinal cord in ARM mouse embryos induced by all-trans retinoic acid (ATRA).

Methods

Pregnant ICR-Slc mice were administered 100 mg/kg of ATRA on the ninth embryonic day (E9.0). Embryonic specimens were obtained from the uteri between E11.0 and E18.5. Midsagittal histologic sections focusing on the spinal cord and pelvis were prepared for immuonhistochemistry specific for neurofilament and Protein Gene Product 9.5 molecules.

Results

More than 98% of ATRA-treated embryos demonstrated ARM with rectourethral or rectocloacal fistula. Normal embryos exhibited progressive ascent of the spinal cord from E14.5. However, in ARM embryos, the distal spinal cord ended with meningomyelocelelike or atypical hamartomatous lesions at E11.5 to E13.5, which later caused stretch force that damaged the spinal cord, resulting in tethered cord between E16.0 and E16.5.

Conclusions

In ATRA-induced ARM mouse embryos, tethered spinal cord was mostly established, accompanied by caudal neural maldevelopment, during early fetal development. This experimental model may be useful for researching detailed neuropathologic conditions in ARM children accompanied with tethered spinal cord.     

Acquired posterior urethral diverticulum following surgery for anorectal malformations

Purpose

Despite significant advances in the surgical management of anorectal malformations (ARMs), many children still experience significant debilities from potentially avoidable complications. One complication, the posterior urethral diverticulum, may have untoward consequences if not recognized and treated.

Methods

A retrospective cohort review was undertaken of male patients who presented to us with persistent problems after being operated on elsewhere for ARM. Twenty-nine patients presented with a urethral diverticulum. Their charts were reviewed for the type of malformation, prior repair, presentation, treatment, and postoperative follow-up.

Results

Twenty-nine patients were identified that fit the criteria for this study. To date, 28 patients have been managed with reoperation. Urinary complaints were the most common presenting symptoms. All patients were repaired using a posterior sagittal approach. Pathology of the diverticulum in one patient revealed a well-differentiated mucinous adenocarcinoma.

Conclusion

The incidence of acquired posterior urethral diverticulum has decreased with the popularization of the posterior sagittal incision. There is a theoretical concern that the incidence may increase with the use of laparoscopy for the treatment of ARMs especially those where the fistula is below the peritoneal reflection. Once detected, the diverticulum should be excised.     

Unusual variants of congenital pouch colon with anorectal malformations

Anorectal malformations are common worldwide. Several classifications were used to describe the different types, but in spite of this, there are rare variants. This report describes 2 unusual cases of congenital pouch colon and anorectal malformations.     

Establishment of a rescue program for anorectal malformations induced by retinoic acid in mice

Aims of Study

Retinoid-mediated signal transduction plays a crucial role in the embryogenesis of various organs. We previously reported the successful induction of anorectal malformations in mice using retinoic acid (RA). Retinoic acid controls the expression of essential target genes for cell differentiation, morphogenesis, and apoptosis through a complicated interaction in which RA receptors form heterodimers with retinoid X receptors. In the present study, we investigated whether the retinoid antagonist, LE135, could prevent the induction of anorectal malformations (ARMs) in mice.

Methods

Retinoic acid was intraperitoneally administered as 100 mg/kg of all-trans RA on E9; and then the retinoid antagonist, LE135, was intraperitoneally administered to pregnant ICR strain mice on the eighth gestational day (E8), 1 day before administration of RA (group B) or on E9, simultaneously (group C) with RA administration. All of the embryos were obtained from the uteri on E18. Frozen sections were evaluated for concentric layers around the endodermal epithelium by hematoxylin and eosin staining.

Results

In group A, all of the embryos demonstrated ARM with rectoprostatic urethral fistula, or rectocloacal fistula, and all of the embryos showed the absence of a tail. In group B, 36% of the embryos could be rescued from ARM. However, all of the rescued embryos had a short tail that was shorter than their hind limb. The ARM rescue rates in group B were significantly improved compared to those in group A (P < .01). In group C, 45% of the embryos were rescued from ARM, but all of the rescued embryos had short tail. The ARM rescue rate in group C was significantly improved compared to that in group A (P < .01). However, there was no significant difference in the ARM rescue rate between group B and Group C.

Conclusion

The present study provides evidence that in the hindgut region, RAR selective retinoid antagonist, LE135, could rescue embryos from ARM. However, the disturbance of all-trans RA acid was limited to the caudal region. Further study to establish an appropriate rescue program for ARM in a mouse model might suggest a step toward protection against human ARM in the future.     

Anal mucosal electric sensation in postoperative patients with anorectal malformations

Background

No previous report has, to our knowledge, been made on anal mucosal electric sensation in postoperative patients with anorectal malformations (ARMs). We studied the anal mucosal electric sensory threshold (AMEST) in comparison with clinical manifestation.

Methods

The study included 25 patients with ARMs who underwent anorectoplasty (ARMs group) and 10 subjects (control group). Based on the type of ARMs, patients were divided into 3 subgroups: high type, n = 14; intermediate type, n = 6; low type, n = 5. The AMEST was measured at 3 positions, at the anal skin margin and 1 and 2 cm from the anal skin margin. The AMEST was analyzed compared with the type of ARMs and clinical manifestation.

Results

The AMEST clearly increased at the 3 sites in patients with ARMs, especially those with high and intermediate types, compared with control subjects. The sensitivity threshold in the lower anal canal in the low-type subgroup was about the same as that in the control group. An analysis of clinical manifestations showed significantly increased thresholds in the upper and middle anal canal in the group of patients with difficulty in discriminating between gas and defecation and with fecal incontinence (P < .01 and P < .05).

Conclusions

The AMEST for the high-type and intermediate-type subgroups in the ARMs group was worse than that in the low-type subgroup and control group. The AMEST in the upper and middle anal canal was important for gas and defecation distinction and fecal maintenance.     

Impaired expression of myogenic regulatory molecules in the pelvic floor muscles of murine embryos with anorectal malformations

Background/Purpose

Recent biological studies have elucidated the molecular mechanism of muscle development, in which various regulatory factors (myogenic regulatory factors [MRFs]) play key roles during embryogenesis. To investigate the development of anorectal malformations (ARMs), we studied MRF expressions in myogenic cells in the pelvic floor using murine embryos affected with ARM.

Methods

Anorectal malformation embryos were obtained from the 10.5th embryonal day (E10.5) to the 7.0th postnatal day (D7.0) in a natural mutant strain (Sd/+, RSV/Le). Serial frozen sections were prepared for immunohistochemistry using specific antibodies to M-cadherin, myoD, Myogenin, myosin heavy chain, and alfa-actin molecule.

Results

In normal mice, embryonal caudal somites differentiated into myogenic stem cells and migrated to the pelvic floor between E11.0 and E14.0. In the ARM mice, however, caudal somites were irregularly arranged and MRF expressions in myogenic cells were markedly decreased in the dorsocaudal region at E11.5 to E13.0, leading to hypoplastic pelvic floor muscles.

Conclusions

The maldevelopment of pelvic floor muscles in ARM is derived from a deficient supply of myogenic stem cells, with impaired MRF expression. These results suggest that myogenic stem cells, available from bone marrow contents, may be used for postnatal muscle regeneration to reinforce the pelvic floor muscle function in children with ARM.     

Functional outcome and quality of life in anorectal malformations

Background/Purpose

The aim of this study was to assess the early functional outcome and quality of life (QOL) in children with anorectal malformations.

Methods

Children treated for anorectal malformations (ARMs) from 1994 to 2000 were evaluated if 4 years or older. Primary outcome measures were bowel function score, assessed by functional outcome questionnaire, and QOL using the Pediatric Quality of Life Inventory (PedsQL 4). The secondary outcome measure was age at potty training. Twenty healthy children were used as controls for functional outcome and age at potty training. Data are reported as mean (SD) unless otherwise stated.

Results

Eighty children were evaluated during the study period. The mean age at follow-up was 82 months (18.7). The response rate was 76.3% (58/76) for bowel function and 77.5% (62/80) for QOL questionnaires. Functional outcome score (maximum 20) decreased significantly with increasing severity of the ARM (male perineal fistula, 16 [3]; female perineal fistula, 15 [3]; rectourethral fistula, 12 [4]; vestibular fistula, 13 [3.5]; bladder neck fistula, 6 [2]; analysis of variance, P = .001). However, there was no difference in QOL between patients with ARM and controls. There was no correlation between age and either bowel function score (Pearson r² = 0.06) or QOL (Pearson r² = 0.12). Affected children took significantly longer to achieve potty training for bladder (35 [13.8] months vs 26 [8.7] months for controls [t test, P = .005]) and bowels (38 [16] months vs 25 [7] months [t test, P = .001]).

Conclusion

Children with ARMs have significantly worse bowel function than their peers, depending on the type of lesion. Despite these findings, QOL was not significantly impaired. No correlation was demonstrated between age and either functional outcome or QOL.     

Anomalies associated with anorectal malformations according to the Krickenbeck anatomic classification

Purpose

We evaluated the incidence of congenital anomalies associated with anorectal malformations (ARMs) in relation to the anatomic type of ARM as defined by the Krickenbeck classification.

Methods

We reviewed 99 children with ARM in our institution from 2002 to 2011. Data were collected on patient demographics, type of ARM, and associated congenital anomalies, which were categorized according to organ systems. Statistical analysis was performed for comparison between groups using ‘perineal fistula’ as the base group.

Results

There were 62 (63%) male patients. The majority had perineal fistulas (35, 35%). Seventy-seven (78%) had at least one associated malformation. The most frequent malformations seen were genitourinary (28, 28%) and spinal anomalies (26, 26%). Those with rectovesical fistula had the highest proportion of genitourinary malformations (Odds Ratio [OR], 41.3; 95% confidence interval [CI], 4.7–363.4). Those with cloaca (OR, 49.5; 95% CI, 3.4–718.9) and those with rectovestibular fistula (OR, 12.4; 95% CI, 2.3–65.6) were most likely to have major spinal abnormalities, with tethered cord seen in all groups. The rectovestibular group was also most likely to have other associated malformations (OR, 8.6; 95% CI, 2.2–32.8).

Conclusion

More than 75% of children with anorectal malformation have other associated malformations. Genitourinary anomalies are the most common. Major spinal anomalies are seen in all groups, affecting nearly half of those with rectovestibular fistula and those without fistula. The incidence of associated malformations in the rectovestibular group is higher than described in the literature. Thorough systematic evaluation of all infants with ARM should be done regardless of type of ARM.     

Aberrations of the intrinsic innervation of the anorectum in fetal rats with anorectal malformations

Background

Fecal accumulation, constipation, soiling, and incontinence are common sequelae after repair of anorectal malformations (ARMs) in children. It is believed that besides the abnormalities of sacral roots, certain inherent abnormalities of the myenteric plexuses may play an important role in the final outcome after definitive repair.

Methods

This study was conducted to investigate the distribution of neuron-specific enolase (NSE), vasoactive intestinal peptide (VIP), and substance P (SP)-100 neurotransmitters in the rectosigmoid and fistulous tract of the ethylenethiourea-treated rat with ARMs.

Results

ARMs were induced by administering 1% ethylenethiourea (125 mg/kg) on gestational day 10, and the litter was harvested on gestational day 21 by cesarean section. Forty-eight controls and 63 with ARMs (46 high-type and 17 low-type) were recovered. Whole-mount preparations of each rectosigmoid and fistulous communication between the rectum and genitourinary tract were stained with fluorescent antibodies against NSE, VIP, and SP-100. The tissues were counterstained with Eriochrome black-T and methyl green dyes to improve the visualization of the myenteric plexuses.

Conclusions

The immunoreactivity of NSE, VIP, and SP-100 was markedly reduced in the rectum and fistulous tract of high-type ARMs and slightly reduced in low-type ARMs compared with controls. Intramural nerves stained by VIP and SP-100 antisera were decreased in both types of ARM, indicating that both inhibitory and excitatory motor neural elements were affected, and this may explain the distal colonic dysmotility seen postoperatively in both high and low ARMs.     

Embryonic development of the internal anal sphincter in rats with anorectal malformations

Background/Purpose

The embryogenesis of the internal anal sphincter (IAS) in anorectal malformations (ARMs) remains unclear. This study aimed to investigate the development of the smooth muscle in the terminus of the digestive tract in normal and abnormal rats.

Methods

Rat embryos with ARMs were generated by administration of ethylenethiourea to pregnant rats. The normal rat embryos and embryos with ARMs from E13.5 to E21 were serially sectioned in the sagittal plane and stained immunohistochemically using specific antibody to α-smooth muscle actin (SMA). Temporospatial study was carried out on circular muscle of the distal portion of the hindgut.

Results

α-Smooth muscle actin immunolabeling cells could not be observed in the hindgut on E13.5, E14, and E14.5. On E15, there were α-SMA immunolabeling circular muscle cells in the hindgut; and the distal portion of the circular muscle was not thickened in the normal and ARMs rats. From E16 onward, the smooth muscle with slight dilated terminus, which was characterized by the features of IAS, could be noted in the primitive anorectum. In the normal group, the circular muscle in the distal portion of the hindgut thickened slightly and became the musculature with shutter-like bundles. In the ARMs group, the α-SMA immunolabeling myogenic precursors of the smooth muscle could be observed in the primitive anorectum as well. The musculature was similar to that in the normal group. On E15 and E16, there was no significant difference in the development of the circular muscle in the 2 groups. Moreover, the terminus of the circular muscle in the hindgut did not reach the orificium fistulae in ARMs rats. From E17 onward, in ARMs rats, the funnel-shaped distal hindgut communicated the genitourinary tract with a narrow fistula; the dilated musculature at this portion thinned gradually and formed an acute angled extremity in the ARMs group rather than formed blunt extremity in the normal group; the terminus circular muscle in the dorsal hindgut reached the orificium fistulae. During the following gestational days, the circular muscle of the hindgut in both normal and ARMs rats continued its own tendency.

Conclusion

The IAS primordium started to appear at the terminus of the hindgut on E15 in the 2 groups. The IAS in the ARMs group failed to develop as well as that in the normal group. The IAS dysplasia occurred in the late embryonic development (E17-E21).     

Association of endothelin-beta receptor (EDNRB) gene variants in anorectal malformations

Animal models have demonstrated the role of genetic influences in anorectal malformations (ARM), although the pathogenetic mechanism remains uncertain. A body of collateral evidence points to possible connection with the endothelin-β receptor (EDNRB) gene and the endothelin system. This study investigates the EDNRB gene in patients with ARM.Resected surgical specimens of terminal colonic tissue were obtained from 14 children (6 males and 8 females) undergoing surgery for ARM correction with ethical permission. DNA samples were screened for mutations in EDNRB. Polymerase chain reaction amplification of 7 exons of EDNRB was followed by heteroduplex single-strand conformation polymorphism analysis. Heteroduplex single-strand conformation polymorphism variants were validated with automated sequencing techniques on polymerase chain reaction products showing conformational variants in acrylamide gel.All investigated patients with ARM showed mobility shift aberrations and polymorphisms in the EDNRB gene. These included one previously described polymorphism in exon 4 (831G/A) seen in association with Hirschsprung disease and 6 novel polymorphisms identified in exons 1 (178G/A), 2 (552C/T and 561C/T), and 3 (702C/T). No aberrant banding patterns were observed. The exon 1 (178 G/A) variation was identified in 2 (50%) of 4 low lesions compared with 1 (1%) of 84 control samples. The exon 3 (702C/T) single nucleotide polymorphism was present in 3 (60%) of 5 of the supralevator lesions being associated with exon 4 (831G/A). The patient with VATER associations including cardiac and limb anomalies had the 831G/A variation only.Analysis revealed statistically significant differences for the polymorphism 178G/A (P < .01, χ² with Yates correction = 8.24) compared to controls.Potential disease-related mutations were identified in South African patients with ARM, raising the question of its potential role in the pathogenesis of this condition.