The incidence of infantile hypertrophic pyloric stenosis and its association with folic acid supplementation during pregnancy: A nested case–control study

Background and Rationale

Several studies have suggested that the incidence of infantile hypertrophic pyloric stenosis (IHPS) has decreased in recent decades. This decrement is controversial and not fully explained. Concurrently, there has been a major increase in folic acid consumption by pregnant women to prevent neural tube defects. We aimed to describe IHPS incidence in Israel in recent years and to assess its potential association with folic acid consumption.

Surgical technique of laparoscopic pyloromyotomy for infantile hypertrophic pyloric stenosis

We report herein a new method of performing laparoscopic pyloromyotomy for infantile hypertrophic pyloric stenosis, using refined surgical techniques. The pyloric tumor was immobilized by grasping the first portion of the duodenum and the anterior wall of the stomach, and electrocoagulation was used prior to incising the pyloric tumor to minimize bleeding during the procedure. Although this technique has been applied in only two patients so far, we present the details herein. We believe that with technical and instrumental refinements, the speed and safety of laparoscopic pyloromyotomy will improve and it will become an alternative to open surgery in pediatric patients.     

Seromuscular laceration of the stomach associated with infantile hypertrophic pyloric stenosis in the newborn

Two cases of seromuscular laceration of the stomach associated with infantile hypertrophic pyloric stenosis are reported. The diagnosis and treatment of this lesion is uncertain due to a paucity of clinical experience. The first patient was treated by mucosal resection. Early decompression therapy of the stomach is essential for the neonate with upper gastrointetinal obstruction or stenosis.     

Early developmental outcome of infants with infantile hypertrophic pyloric stenosis

Purpose

The study aimed to compare the developmental outcome of infants with infantile hypertrophic pyloric stenosis (IHPS) who underwent pyloromyotomy with healthy control infants in New South Wales (NSW), Australia.

Methods

Infants diagnosed with IHPS requiring surgical intervention were enrolled prospectively between August 1, 2006, and July 31, 2008. Healthy control infants were enrolled in the same period. The children underwent a developmental assessment at 1 year of age (corrected) using the Bayley Scales of Infant and Toddler Development (Version III).

Results

Of 52 infants with IHPS who were enrolled, 43 had developmental assessments. Most (90.6%) were term infants (>36 weeks gestation) with a median birth weight of 3237.8 g. Two infants (8%) had an associated birth defect, and survival was 100%. Developmental assessments were also performed on 211 control infants. Infants with IHPS scored significantly lower on the cognitive, receptive language, fine motor, and gross motor subscales compared to the control infants.

Conclusions

This unique study found lower than expected developmental scores for infants after surgery for IHPS than for healthy control infants. These findings raise concerns over the potential impact of IHPS and its surgical treatment. Further studies, including continuing developmental review to determine whether these differences persist and their functional importance, should be performed.     

Adenomyoma of the stomach mimicking infantile hypertrophic pyloric stenosis

We report a case of gastric adenomyoma in a 1-month-old girl. This patient presented with gastric outlet obstruction simulating infantile hypertrophic pyloric stenosis. Histologic examination of the excised specimen showed irregularly arranged glands and interlacing smooth muscle bundles surrounding the glandular elements. We suggest that this lesion is not just heterotopia, but hamartoma composed of abnormal mixture of endoderm-derived epithelial component and mesoderm-derived smooth muscle.     

Absence of motilin gene mutations in infantile hypertrophic pyloric stenosis

Background

Erythromycin treatment before 2 weeks of age has been shown to increase the risk of infantile hypertrophic pyloric stenosis (IHPS) up to 10 times. Erythromycin is a motilin agonist, a hormone that induces gastrointestinal contractions. The purpose of this study was to investigate if mutations in the motilin gene (MLN) cause IHPS or if the V15A polymorphism in MLN is associated with the disease.

Methods

The MLN was screened for mutations, and the V15A polymorphism was determined in a total of 57 patients with IHPS using polymerase chain reaction and DNA sequencing. The polymorphism genotype and allele frequencies among the patients were compared with 184 controls.

Results

We detected 3 different, not previously reported, MLN sequence variants in 4 patients. One of these variants results in an amino acid exchange in the motilin signal peptide (A25G). All 3 detected sequence variants were also found in controls or were not inherited with the disease. We found no significant association between the V15A polymorphism and the disease.

Conclusions

We have excluded the MLN coding region as a major cause of IHPS. Future studies will evaluate the importance of this metabolic pathway in the pathogenesis of IHPS.     

Lack of association between nNOS −84G>A polymorphism and risk of infantile hypertrophic pyloric stenosis in a Chinese population

Background

Infantile hypertrophic pyloric stenosis (IHPS) is one of the most common gastrointestinal obstructions in the infancy requiring surgery. Reduced expression of neuronal nitric oxide synthase (nNOS), which plays an important role in the regulation of the human pyloric muscle, is thought to underlie IHPS. The role of nNOS in IHPS has been supported by the genetic association of a functional regulatory nNOS polymorphism (−84G>A) with IHPS in whites. We reasoned that the corroboration of this association in a population of different ethnic origin would prompt follow-up studies and further investigation of the IHPS pathology at molecular level. Thus, we attempted to reproduce the original findings in a Chinese population of comparable size in what would be the first genetic study on IHPS conducted in Chinese.

Methods

nNOS −84G>A genotypes were analyzed in 56 patients and 86 controls by polymerase chain reaction and DNA sequencing. Logistic regression was used to compute odds ratios.

Results

Our study could not corroborate the association previously reported. Although the frequency of the IHPS-associated allele (−84A) in controls (0.205) was similar to that reported for white controls, there was a dramatic difference in −84A frequencies between white and Chinese patients (0.198). Similarly, there was no difference in the nNOS −84G>A genotype distribution between patients and controls, even when the GA and AA genotypes were combined to compare GG genotype (odds ratio, 1.01; 95% confidence interval, 0.47-2.19).

Conclusions

Failure to replicate the initial finding does not detract from its validity, because genetic effects may differ across populations. Differences across populations in linkage disequilibrium and/or allele frequencies may contribute to this lack of replication. The role nNOS in IHPS awaits further investigation.     

Maternal risk factors and perinatal characteristics of anorectal malformations

Purpose

The aim of this study was to assess maternal risk factors and perinatal characteristics of patients with anorectal malformations (ARM) in Sweden.

Treatment of infantile hypertrophic pyloric stenosis in a district general hospital: a review of 160 cases

Background: Ramstedt’s pyloromyotomy has long been the standard operation for the treatment of infantile hypertrophic pyloric stenosis. Controversy exists over whether this procedure can be performed safely in the district general hospital setting or whether it should be restricted to specialist pediatric units only.Methods: Retrospective analysis was performed on the medical records of a series of 160 infants treated by Ramstedt’s pyloromyotomy by 2 surgeons in a district general hospital over 16 years.Results: There was no perioperative mortality. Oral feeding was achieved by 24 hours in 76% of infants, and there was persistent vomiting in only 3.8%. Wound discharge was encountered in 4.4% and confirmed wound infection in 1.3%. Wound dehiscence occurred in 1.9% of infants. Inadvertent mucosal perforation occurred in 19% of cases, although all cases were recognized and repaired at once with no apparent ill effects. These results are comparable with those reported from specialist pediatric units and from pediatric surgeons working within general surgical units.Conclusions: Infantile hypertrophic pyloric stenosis can be treated safely in a district general hospital when care is provided by appropriately trained surgical, anesthetic, and pediatric staff.     

A review of postoperative feeding regimens in infantile hypertrophic pyloric stenosis

Infantile hypertrophic pyloric stenosis is a condition well known to pediatric surgeons. Postoperative length of hospital stay is a financial concern and remains a potential target for reduction in hospital costs. Ultimately, these costs are directly affected by the ability to effectively advance postoperative enteral nutrition. This review will serve to: 1) identify clinically relevant postoperative feeding patterns following pyloromyotomy, 2) review the relevant literature to determine an optimal feeding pattern, and 3) identify possible preoperative predictors that may determine the success of postoperative feeding regiments.     

Diagnosis and therapy of primary hypertrophic pyloric stenosis in adults: Case report and review of literature

Adult idiopathic hypertrophic pyloric stenosis (AIHPS) is a misleading anatomic and radio-clinical entity of unknown etiology. Only about 200 cases have been reported in the literature. It is a benign disease resulting from hypertrophy of the circular fibers of the pyloric canal. Despite the recent progress in radiography and endoscopy, it is very hard to define hypertrophic stenosis in adults. Differentiation of primary from secondary pyloric stenosis is frequently a task of the pathologist rather than the surgeon. The main therapy is surgical, although endoscopic dilatation has been tried. There remains controversy over the best surgical approach. A case is reported of a 48-year-old male patient with AIHPS who was subjected to distal gastrectomy. This paper discusses the possible causes of the disorder, the recommended diagnostic steps, and the different surgical approaches.     

Late-onset hypertrophic pyloric stenosis: definition of diagnostic criteria and algorithm for the management

Background and Purpose

Gastric outlet obstruction (GOO) may be caused by various congenital and acquired conditions in children. The authors report 11 cases of GOO caused by muscular hypertrophy of the pylorus, which was proven histologically in 7. They describe this entity as “late-onset hypertrophic pyloric stenosis (HPS),” define the diagnostic criteria of the disease, and produce an algorithm for its management.

Materials and Methods

The medical records of patients with GOO treated from 1999 and 2009 were retrospectively reviewed. Patients with infantile HPS and GOO secondary to corrosive ingestion or neoplasm were not included. Age, sex, family history, presenting symptoms and signs, radiologic methods and findings, type of management, histopathologic features, and outcome were noted for each patient.

Results

Eleven patients (4 male, 7 female) ranging in age from 2 to 8 years (mean, 3.6 years) were included in the study. The symptoms were nonbilious vomiting (n = 11), abdominal pain (n = 4), and weight loss (n = 2). Abdominal ultrasound (n = 6) and upper gastrointestinal contrast studies were obtained (n = 11). Gastroscopy revealed complete (n = 6) or partial (n = 5) obstruction of the pylorus. Balloon dilatation of the pylorus was performed in 5 cases and repeated in 3 cases. Conservative treatment was initially attempted in 11 patients. Two patients with chronic gastritis and Helicobacter pylori (n = 2) were treated with amoxicillin-clavulanic acid, clarithromycin, and lansoprazole. A Billroth I procedure was performed in 7 cases. Hypertrophied pyloric muscle was noted in 7 patients and chronic gastritis in 2. The postoperative course was uneventful.

Conclusion

Hypertrophic pyloric stenosis is rarely seen after infancy. Analysis of our results and review of the literature prompted us to redescribe this entity as “late-onset HPS” and define the diagnostic criteria. Late-onset HPS is probably an acquired disease of unknown etiology. The management of late-onset HPS has been summarized in an algorithm, which will also be useful in the treatment of GOO in children caused by etiologies other than classical infantile HPS.     

Surgical practice for infantile hypertrophic pyloric stenosis in the United Kingdom and Ireland--a survey of members of the British Association of Paediatric Surgeons

Purpose

Operative strategy and antibiotic policy in treating infantile hypertrophic pyloric stenosis (IHPS) may vary widely. This study surveys current practice in the United Kingdom and Ireland among members of the British Association of Paediatric Surgeons.

Methods

The study used postal and email survey of consultant pediatric surgeons.

Results

One hundred five questionnaires were distributed, and 94 replies (90% response) were received. Umbilical pyloromyotomy is performed exclusively by 57 surgeons. Fourteen surgeons (15%) use laparoscopy, whereas 5 (randomized trial in progress) use the umbilical or laparoscopic route. Eight reported that the umbilical or classical right upper quadrant (RUQ) incision is undertaken at their institution according to surgeon's preference. Ten surgeons only deploy an RUQ incision. Antibiotic practice showed that 40 (70%) using the umbilical incision prescribe prophylactic therapy, whereas only 6 adopting other operative techniques (RUQ incision or laparoscopy) found this policy beneficial. More than 50% surveyed do not routinely recommend antibiotics.

Conclusion

Umbilical pyloromyotomy is used by most pediatric surgeons in the United Kingdom and Ireland. Laparoscopy is increasingly popular in minimally invasive centers. The RUQ incision is used by a minority of surgeons. Antibiotic prophylaxis was common with the umbilical incision only. The superior cosmetic results offered by umbilical pyloromyotomy and laparoscopy are a benchmark for surgeons currently providing contemporary care for babies with IHPS.     

Association between IL-6 -174G/C polymorphism and acute rejection of renal allograft: evidence from a meta-analysis

Background

Results from published studies on the association of donor or recipient IL-6 -174G/C (rs1800795) polymorphism with acute rejection (AR) of renal allograft are conflicting. We performed a meta-analysis to estimate the possible association.

Methods

Studies were identified by searching PUBMED and EMBASE until July 1, 2011. Meta-analysis was performed in a fixed/random effects model using Revman 5.0.25 and STATA10.0.

Results

Seven studies addressing the association between donor high producer genotype (G/G and G/C) of IL-6 -174G/C polymorphism and acute rejection of renal allograft were identified. Pooled OR based on 341 cases (whose recipient developed acute rejection) and 702 controls (whose recipient did not develop acute rejection) was 0.59 (95% CI, 0.26-1.33; p = 0.20), with a strong between-study heterogeneity. No association was observed in the subgroup analysis based on ethnicity. 13 studies evaluating the association between recipient IL-6 -174G/C polymorphism and acute rejection were identified. Pooled OR based on 451 cases (patients did not develop acute rejection) and 848 controls was 1.00 (95% CI = 0.72-1.37; p = 0.98), with a weak between-study heterogeneity.

Conclusions

Donor high producer genotype (G/G and G/C) of IL-6 -174G/C polymorphism had a tendency of decreased risk for acute rejection, although it was not statistically significant. Recipient high producer genotype was not associated with acute rejection of renal allograft. Additional well designed studies with larger sample size are needed to support our findings, especially for the association between donor high producer genotype (G/G and G/C) of IL-6 -174G/C polymorphism and acute renal allograft rejection.     

Genomic variants in the coding region of neuronal nitric oxide synthase (NOS1) in infantile hypertrophic pyloric stenosis

Background

Infantile hypertrophic pyloric stenosis (IHPS) is a common childhood pathology affecting 1 to 5:1000 newborns, with a genetic background suggested by familial occurrence. Neuronal nitric oxide synthase (NOS1) is a candidate gene owing to its role in the relaxation of smooth musculature and the association of the −84g>a variant of NOS1 with IHPS.

Methods

We investigated NOS1 through sequencing of the complete NOS1 coding region in DNA from 43 patients with IHPS compared the genotype frequencies to 47 controls using the Cochran-Armitage trend or Fisher exact tests.

Results

We found 19 polymorphisms in the coding region of NOS1. The variants c.3827-42_3827-43 del_insTA and c.+276 c>t were more frequent in IHPS with statistically significant exact P values (P = .010 and P = .039, respectively) yet failed to show significance after Bonferroni adjustment for multiple testing. We have also found a marginally significant occurrence of the variants c.−460A (P = .065) and c.2823+15G (P = .076). There was a significant correlation between the variants c.2706C>T ? c.2823+15A>G, (r² = 1.00) and c.3258 C>T ? c.3235+31A>G (r² = 1.00).

Conclusions

We conclude that NOS1 variants are present in patients with IHPS yet show no significant statistical association with the IHPS phenotype, suggesting at best an adjuvant role for NOS1 in IHPS.     

Concomitant ablation for atrial fibrillation during septal myectomy in patients with hypertrophic obstructive cardiomyopathy

Objective

The appearance of atrial fibrillation is associated with significant clinical deterioration in patients with obstructive hypertrophic cardiomyopathy; therefore, maintenance of sinus rhythm is desirable. Guidelines and most articles have reported the results of catheter ablation and pharmacologic atrial fibrillation treatment; nevertheless, data regarding concomitant procedures during septal myectomy are limited. The aim of this study was to assess the outcomes of concomitant atrial fibrillation treatment in patients with obstructive hypertrophic cardiomyopathy.