Advances in the Management of the Neonate Born with an Anorectal Malformation

Intra-amniotic delivery of tropomodulin 3 rescues cell apoptosis induced by miR-200b-3p upregulation via non-canonical nuclear factor kappa B pathways in ethylene thiourea induced anorectal malformations fetal rat

Ethylene thiourea (ETU), a metabolite of the fungicide ethylene bisdithiocarbamate (EBDC), has received great concern because of its harmful effects. ETU-induced anorectal malformations (ARMs) in rat models have been reported and widely used in the study of ARMs embryogenesis. Dysplasia of the lumbosacral spinal cord (LSSC), pelvic floor muscles (PFMs), and hindgut (HG) during intrauterine life affects postoperative defecation in patients with ARMs. However, the underlying toxic effects of ETU and pathological mechanisms in the three defecation-related tissues of fetuses with ARMs have not been reported. Thus, this study aimed to elucidate the molecular mechanisms involved in ARMs, with a focus on the dysregulation of miR-200b-3p and its downstream target tropomodulin 3 (TMOD3). The mRNA and protein levels of miR-200b-3p and TMOD3 in LSSC, PFMs, and HG of fetal rats with ARMs were evaluated by reverse transcription quantitative polymerase chain reaction and Western blotting (WB) on embryonic day 17 (E17). Further, a dual-luciferase reporter assay confirmed their targeting relationship. Gene silencing and overexpression of miR-200b-3p and TMOD3 were performed to verify their functions in HEK-293 T cells. Fetal rats with ARMs also received intra-amniotic microinjection of Ad-TMOD3 on E15, and key molecules in nuclear factor kappa (NF-κB) signaling and apoptosis were evaluated by WB on E21. Abnormally high levels of miR-200b-3p inhibited TMOD3 expression by binding with its 3'-untranslated region, leading to the activation of the non-canonical NF-κB signaling pathway, which is critical in the maldevelopment of LSSC, PFMs, and HG in ARMs rats. Furthermore, miR-200b-3p triggered apoptosis by directly targeting TMOD3. Notably, intra-amniotic Ad-TMOD3 microinjection revealed that the upregulation of TMOD3 expression mitigates the effects of miR-200b-3p on the activation of non-canonical NF-κB signaling and apoptosis in fetal rat model of ARMs. A novel miR-200b-3p/TMOD3/non-canonical NF-κB signaling axis triggered the massive apoptosis in LSSC, PFMs, and HG of ARMs, which was restored by the intra-amniotic injection of Ad-TMOD3 during embryogenesis. Our results indicate the potential of TMOD3 as a treatment target to restore defecation.

Medical management of anorectal malformations

BACKGROUND

Anorectal malformations (ARMs) are congenital anomalies of the anorectum and the genitourinary system that result in a broad spectrum of hindgut anomalies. Despite surgical correction patients continue to have late postoperative genitourinary and colorectal dysfunction that have significant impact on quality of life.

AIM

This paper will review the current evidence and discuss the evaluation and management of postoperative patients with ARMs who present with persistent defecation disorder.

METHODS

A literature search was conducted using PubMed/MEDLINE/EMBASE databases applying the following terms: ARMs, imperforate anus, constipation, faecal incontinence, neurogenic bowel, posterior sagittal anorectoplasty.

RESULTS

Patients who present with postoperative defecation disorders require timely diagnostic and surgical evaluation for anatomic abnormalities prior to initiation of bowel management. Goals of management are to avoid constipation in young children, achieve faecal continence in early childhood and facilitate independence in older children and adolescents. Treatment options vary from high dose stimulant laxatives to high-volume retrograde and antegrade enemas that facilitate mechanical colonic emptying.

CONCLUSIONS

Appropriate diagnostic work-up and implementation of treatment can decrease long-term morbidity and improve quality of life in postoperative patients with ARMs who presents with defecation disorders.

Long-term (> 10 years) bowel function of anorectal malformations: a retrospective single-center study

PURPOSE

To describe the long-term bowel function of anorectal malformation (ARM) patients and explore the potential influence factors.

METHODS

ARM patients with follow-up data > 10 years were included. Cases of cloaca, Currarino syndrome, and VACTERL syndrome were excluded. Rintala score and PedsQL 4.0 were used to assess bowel function score (BFS) and quality of life (QoL). Based on the results, patients were divided into satisfactory group with BFS ≥ 17 and unsatisfactory group with it < 17. Comparisons between the groups were made.

RESULTS

Among the 81 patients were 44 males and 37 females. Follow-up time was 138 (126,151) months. 16 (19.75%) patients had associated anomalies. 23 (28.40%) patients had reoperations, and fistula recurrence was the most common reason. BFS of the patients was 20 (18,20). QoL score was 100 (100,100), which correlated positively with BFS (r = 0.648, P < 0.001). The satisfactory and the unsatisfactory groups had 69 and 12 cases, and their BFS were 20 (20,20) and 11 (8,15) respectively, which had statistical difference (P < 0.001). Total QoL score and psycho-social health score of the unsatisfactory group were lower (P < 0.001). Only reoperations were statistically different between the groups (P < 0.001).

CONCLUSIONS

Long-term (> 10 years) bowel function of ARM patients is good in this study. Defecation problems have negative impacts on QoL and mainly affects their psycho-social health. Primary anorectoplasty is extremely important. Reoperations, which are most commonly seen in recto-urethral fistula recurrence, adversely affect the outcome.

Transurachal Catheter for Management of Difficult Catheterization in Anorectal Malformations: A Novel Technique

BACKGROUND

Urinary tract drainage is necessary to facilitate the maneuver in laparoscopic-assisted anorectoplasty (LAARP). Male patients with Anorectal malformations (ARM) are often encounter difficult catheterization during surgery.

OBJECTIVE

We pioneered the urinary catheterization through the urachus in ARM patients and evaluated the efficacy.

METHOD

Fourteen ARM patients undergoing urinary catheterization through urachus between September 2015 and September 2023 were reviewed.

RESULTS

The median age at the time of surgery was 0.06 months. Nine neonatal patients underwent the one-stage LAARP, while five patients underwent staged procedure. Four ARM patients with rectoprostatic fistula, while ten with rectobulbar fistula. All patients successfully underwent transurachal catheterization. No incidents of catheter blockage, accidental removal, or urinary tract infection symptoms were detected during hospitalization.

CONCLUSIONS

Transurachal catheterization is a safe, effective, and cosmetic procedure for ARM patients with difficulty urethral catheterization.

LEVEL OF EVIDENCE

IV.