Size matters: Large copy number losses in Hirschsprung disease patients reveal genes involved in enteric nervous system development.

Hirschsprung disease (HSCR) is a complex genetic disease characterized by absence of ganglia in the intestine. HSCR etiology can be explained by a unique combination of genetic alterations: rare coding variants, predisposing haplotypes and Copy Number Variation (CNV). Approximately 18% of patients have additional anatomical malformations or neurological symptoms (HSCR-AAM). Pinpointing the responsible culprits within a CNV is challenging as often many genes are affected. Therefore, we selected candidate genes based on gene enrichment strategies using mouse enteric nervous system transcriptomes and constraint metrics. Next, we used a zebrafish model to investigate whether loss of these genes affects enteric neuron development in vivo. This study included three groups of patients, two groups without coding variants in disease associated genes: HSCR-AAM and HSCR patients without associated anomalies (HSCR-isolated). The third group consisted of all HSCR patients in which a confirmed pathogenic rare coding variant was identified. We compared these patient groups to unaffected controls. Predisposing haplotypes were determined, confirming that every HSCR subgroup had increased contributions of predisposing haplotypes, but their contribution was highest in isolated HSCR patients without RET coding variants. CNV profiling proved that specifically HSCR-AAM patients had larger Copy Number (CN) losses. Gene enrichment strategies using mouse enteric nervous system transcriptomes and constraint metrics were used to determine plausible candidate genes located within CN losses. Validation in zebrafish using CRISPR/Cas9 targeting confirmed the contribution of UFD1L, TBX2, SLC8A1, and MAPK8 to ENS development. In addition, we revealed epistasis between reduced Ret and Gnl1 expression and between reduced Ret and Tubb5 expression in vivo. Rare large CN losses-often de novo-contribute to HSCR in HSCR-AAM patients. We proved the involvement of six genes in enteric nervous system development and Hirschsprung disease.

Implementation of a Quality Control System for Laparoscopic Pyloromyotomy in Hypertrophic Pyloric Stenosis: Hurdles and Pitfalls.

BACKGROUND: In 2011, we implemented a new video-based system for quality control of laparoscopic pyloromyotomy. More than 3 years later, we evaluated how the implementation had gone and assessed its usability in predicting postoperative outcomes. MATERIALS AND METHODS: Four key point images or short video-segments were to be recorded perioperatively: prepyloromyotomy, parallel-mobility testing, perforation testing, and postpyloromyotomy. Data of all 134 patients undergoing laparoscopic pyloromyotomy from September 2011 to December 2014 were analyzed retrospectively. Five pediatric surgeons independently assessed the anonymized operative images for predicting reoperation and time to full-enteral feeding. RESULTS: The percentage of operations during which images were recorded increased from 45% in 2012 to 75% in 2014. Over the study period, one or more images were recorded in 89 of the 134 (66%) patients. In only 17 of 89 patients (19%), all four images were documented. The key point images or videos were made for prepyloromyotomy in 49%, parallel-mobility testing in 85%, perforation testing in 42%, and postpyloromyotomy in 94% of 89 patients. Five patients (3.7%) were reoperated for incomplete pyloromyotomy (N = 4) or mucosal perforation (N = 1). Images were recorded during the first operation in four of the five reoperated patients. The need of reoperation was correctly predicted for two of the four patients. Full-enteral feeding within 24 hours was correctly predicted for 67% of the patients (range: 47-88%). CONCLUSION: The increase in recorded images over the years is promising. The implementation of the quality control system did not contribute to a significant decrease in the complication rate, which was already very low. Still, reoperation or a protracted postoperative course could only be predicted with moderate accuracy from the operative images, therefore, for now the use of perioperative images in a medicolegal setting should be advised against. Improved compliance with image recording and better instructions for evaluating the images might improve the usefulness of perioperative images in, e.g., telementoring, education, and medicolegal practice.

Taurolidine in Pediatric Home Parenteral Nutrition Patients.

To reduce the incidence of catheter-related bloodstream infections in home parenteral nutrition patients, the use of taurolidine was introduced in the Sophia Children's Hospital in 2011. This introduction led to a reduction in catheter-related bloodstream infections: 12.7/1000 catheter days before the use of taurolidine, compared with 4.3/1000 catheter days afterwards (n = 7) [relative risk = 0.36, 95% confidence interval: 0.20-0.65 (P = 0.018)].

Effectiveness of Rectal Suction Biopsy in Diagnosing Hirschsprung Disease.

INTRODUCTION: Rectal suction biopsy (RSB) is performed on clinical and radiological suspicion of Hirschsprung disease (HD). Positive histochemical staining for acetylcholinesterase in the lamina propria mucosa and muscularis mucosa together with the absence of ganglion cells in the submucosa confirms HD. A second RSB or a full-thickness biopsy is done in case of doubt. The primary aim of the study was to evaluate the effectiveness of RSB in diagnosing HD. In addition, the results of RSB in preterm born infants were analyzed. METHODS: This retrospective study included all infants younger than 1 year who had RSB for HD suspicion from January 2004 to April 2014. All histopathological results were reviewed. Sensitivity, specificity, positive, and negative predictive values of the first RSB were calculated. RESULTS: In total, 183 patients (99 boys, mean age 11 weeks) were included. HD was diagnosed in 55 patients (30%). A second biopsy was performed in 12/55 patients (22%), which confirmed HD in 9 patients. One patient did not undergo a second biopsy, but HD was excluded based on clinical follow-up. Thus, HD was eventually excluded in 4 of the 55 patients with a positive first RSB. HD was excluded in the first biopsy in 128 patients (70%). In 19 of those (15%), a second biopsy was done, which led to the diagnosis of HD in 10 patients. Two patients with negative biopsy results were still operated on because of the high clinical suspicion for HD, and the histopathological analysis on the operative specimen confirmed HD. Thus, HD was eventually diagnosed in 12 out of 128 patients. Thus, the sensitivity of the first RSB was 81% and the specificity was 97%. The positive predictive value was 93% and the negative predictive value was 91%. A subanalysis for the 38 preterm born infants was done, with a mean conceptional age at the time of biopsy of 44 weeks (range 34-82). Sensitivity and specificity of RSB were 83 and 97%, respectively, with one false-positive and one false-negative results. CONCLUSION: The overall sensitivity of the RSB was 81%, with 12 false-negative results, in which cases extra biopsies had been necessary. The specificity was 97%, with four false-positive findings. We found that RSB can also be reliably and safely performed in preterm born infants, which implies there is no reason to postpone a RSB in those infants. New methods, such as calretinin staining, must be considered to achieve better effectiveness of the RSB for diagnosing HD.

High resolution MRI for preoperative work-up of neonates with an anorectal malformation: a direct comparison with distal pressure colostography/fistulography.

OBJECTIVE: To compare MRI and colostography/fistulography in neonates with anorectal malformations (ARM), using surgery as reference standard. METHODS: Thirty-three neonates (22 boys) with ARM were included. All patients underwent both preoperative high-resolution MRI (without sedation or contrast instillation) and colostography/fistulography. The Krickenbeck classification was used to classify anorectal malformations, and the level of the rectal ending in relation to the levator muscle was evaluated. RESULTS: Subjects included nine patients with a bulbar recto-urethral fistula, six with a prostatic recto-urethral fistula, five with a vestibular fistula, five with a cloacal malformation, four without fistula, one with a H-type fistula, one with anal stenosis, one with a rectoperineal fistula and one with a bladderneck fistula. MRI and colostography/fistulography predicted anatomy in 88 % (29/33) and 61 % (20/33) of cases, respectively (p = 0.012). The distal end of the rectal pouch was correctly predicted in 88 % (29/33) and 67 % (22/33) of cases, respectively (p = 0.065). The length of the common channel in cloacal malformation was predicted with MRI in all (100 %, 5/5) and in 80 % of cases (4/5) with colostography/fistulography. Two bowel perforations occurred during colostography/fistulography. CONCLUSIONS: MRI provides the most accurate evaluation of ARM and should be considered a serious alternative to colostography/fistulography during preoperative work-up. KEY POINTS: • High-resolution MRI is feasible without the use of sedation or anaesthesia. • MRI is more accurate than colostography/fistulography in visualising the type of ARM. • MRI is as reliable as colostography/fistulography in predicting the level of the rectal pouch. • Colostography/fistulography can be complicated by bowel perforation.

To split or not to split: colostomy complications for anorectal malformations or hirschsprung disease: a single center experience and a systematic review of the literature.

INTRODUCTION: The aim of this article is to identify the ideal type and location of colostomy in children with colorectal disease. PATIENTS AND METHODS: A retrospective case study of children with an anorectal malformation who received a colostomy, born between January 1990 and July 2012. Furthermore, a systematic literature search on colostomies in neonates with an anorectal malformation or Hirschsprung disease. Colostomies were classified as loop or split colostomies in the transverse or sigmoid colon. Outcome measures were mortality and complications such as prolapse, technical difficulties with the reconstruction, urinary tract infections, and others. RESULTS: The mortality rate in the 180 children with anorectal malformation was 6%, and none of them were directly related to stoma formation or closure. The overall complication rate was 23% and the specific rates for the two types of procedures and the two locations of the colostomy did not differ (p = 0.389 and p = 0.667, respectively). All prolapses (n = 22) occurred in loop colostomies in the transverse colon. One colostomy required revision because of insufficient length for the reconstruction. Urinary tract infections were not documented. A total of eight studies were included in the systematic review (1982-2011; 2,954 patients). Mortality ranged between 0.1 and 11%. Loop colostomies had more complications than split colostomies (63 vs. 45%; p = 0.007), mainly prolapse (18 vs. 6%; p < 0.001). Overall complication rate differed between transverse en sigmoid colostomies (62 vs. 51%, p = 0.006), and prolapse occurred more often in the transverse colon (23 vs. 7%; p < 0.001). Revision because of insufficient length during the reconstruction was needed in 0 to 6%. Two studies reported on urinary tract infections which are as follows: One showed no difference between loop or split colostomies, whereas the other showed frequent episodes of urinary tract infections in 64% of the loop colostomies. CONCLUSIONS: The complication to be avoided in transverse colostomies is prolapse and the surgical technique should be modified accordingly. The procedure of split sigmoid colostomy is meticulous, and the risk of insufficient length for the reconstruction remains.

Prospective long-term follow up of children with anorectal malformation: growth and development until 5years of age.

BACKGROUND/PURPOSE: To evaluate growth and development in children with anorectal malformations and to analyze effects of type of malformation and comorbidities. METHODS: Non-syndromal children with anorectal malformations were prospectively evaluated at 0.5, 1, 2, and 5 years. Biometrics were obtained at all visits. Mental and psychomotor function development was determined. RESULTS: 108 children (59% male) were included. 49% had a high malformation, and 46% had ≥ 1 additional major comorbidity. All growth parameters were below the norm at all ages (p<0.01), irrespective of type of malformation. Children with ≥ 1 additional major anomaly had lower height at all ages; at 5 years, mean (95% CI) height was -1.83 (-2.7 to -1.1) and -0.70 (-1.3 to -0.1) in children with and without comorbidities, respectively (p=0.019). Mental development was normal, irrespective of the type of malformation or comorbidities. Motor development was delayed at all ages. At 5 years, motor development (n=30) was normal in 70%, borderline in 23%, and 7% had definitive motor problems (p=0.043). CONCLUSION: Non-syndromal children with anorectal malformations are at risk for growth impairment, especially those with additional major comorbidity. Mental development is normal. Motor development is slightly impaired. Supportive care should focus on growth, dietary management, and motor development besides defecation problems.

Respiratory morbidity and growth after open thoracotomy or thoracoscopic repair of esophageal atresia.

BACKGROUND: Respiratory morbidity has been described in patients who underwent repair of esophageal atresia as a neonate. We compared the influence of open thoracotomy or thoracoscopy on lung function, respiratory symptoms, and growth. METHODS: Functional residual capacity (FRC(p)), indicative of lung volume, and maximal expiratory flow at functional residual capacity (V'max(FRC)), indicative of airway patency, of 37 infants operated for esophageal atresia were measured with Masterscreen Babybody at 6 and 12 months. SD scores were calculated for V'max(FRC). RESULTS: Repair was by thoracotomy in 21 cases (57%) and by thoracoscopy in 16 cases (43%). Lung function parameters did not differ between the types of surgery (FRC(p); P = .384 and V'max(FRC); P = .241). FRC(p) values were in the upper normal range and increased from 6 to 12 months (22.5 and 25.4 mL/kg respectively, P = .010). Mean (SD) V'max(FRC) was below the norm without significant change in SD scores from 6 to 12 months (-1.9 and -2.3, respectively, P = .248). Neither lung function nor type of repair was associated with clinical evolution up to 2 years. CONCLUSION: Lung function during the first year was similar in EA infants repaired by thoracotomy or thoracoscopy. Ongoing follow-up including pulmonary function testing is needed to determine whether differences occur at a later age in this cohort.

Late vs early ostomy closure for necrotizing enterocolitis: analysis of adhesion formation, resource consumption, and costs.

BACKGROUND: Surgeons prefer to close ostomies at least 6 weeks after the primary operation because of the anticipated postoperative abdominal adhesions. Limited data support this habit. Our aim was to evaluate adhesion formation-together with an analysis of resource consumption and costs-in patients with necrotizing enterocolitis who underwent early closure (EC), compared with a group of patients who underwent late closure (LC). METHODS: Chart reviews and cost analyses were performed on all patients with necrotizing enterocolitis undergoing ostomy closure from 1997 to 2009. Operative reports were independently scored for adhesions by 2 surgeons. RESULTS: Thirteen patients underwent EC (median, 39 days; range, 32-40), whereas 62 patients underwent LC (median, 94 days; range, 54-150). Adhesion formation in the EC group (10/13 patients, or 77%) was not significantly different (P = 1.000) from the LC group (47/59 patients, or 80%). No differences were found in the costs of hospital stay, surgical interventions, and outpatient clinic visits. CONCLUSIONS: Ostomy closure within 6 weeks of the initial procedure was not associated with more adhesions or with changes in direct medical costs. Therefore, after stabilization of the patient, ostomy closure can be considered within 6 weeks during the same admission as the initial laparotomy.