Diagnosis Of HSCR Research Articles

Advances in Hirschsprung Disease Genetics and Treatment Strategies

Hirschsprung disease (HSCR) is a multigenic condition with variable presentation. Most commonly, it presents in the neonatal period as a functional intestinal obstruction secondary to failure of caudal migration of the enteric nervous system. Classically, this manifests as dilated proximal bowel and constricted distal bowel with absent ganglia and hypertrophic nerve trunks. When recognized early, medical and surgical therapies can be instituted to minimize associated morbidity and mortality. This article reviews current understanding of the etiology of HSCR, its multigenic associations, the historical evolution of HSCR diagnosis and treatment, and current HSCR therapies.

In vivo detection of Hirschsprung's disease by optical coherence tomography in rats

Hirschsprung's disease (HSCR) is a developmental intestinal obstruction, which is often diagnosed with a repeated biopsy. Optical coherence tomography (OCT) is a noninvasive, real-time imaging modality. This study aims to investigate the feasibility of diagnosis of HSCR, the targeted biopsies of suspicious tissues and the location of operative treatment using OCT. An HSCR Sprague–Dawley (SD) rat model (benzalkonium chloride-treated (BAC-treated)) was used. Colon tissues with BAC-treated and without BAC-treated were imaged using OCT. To establish OCT criteria for identification of HSCR, OCT images were compared with corresponding histology images and muscle layer thickness was measured. Furthermore, attenuation coefficients of OCT signals were calculated to illustrate the differences between tissues with BAC-treated and without BAC-treated. Our results show that OCT images of colon tissues with HSCR are well correlated with histology images. In comparison with a muscle layer without HSCR, the thickness of muscle layer with HSCR is increased significantly. The muscle layer in colon tissues with HSCR for 6 weeks had a higher attenuation coefficient than those without HSCR. However, the attenuation coefficient of those with HSCR for 3 weeks had no obvious change. In conclusion, the study demonstrates for the first time that OCT has the potential for diagnosis, biopsy and location of HSCR in vivo.

Screening of the RET gene of Vietnamese Hirschsprung patients identifies 2 novel missense mutations

Background/PurposeHirschsprung disease (HSCR; megacolon, congenital aganglionosis) is a congenital disorder characterized by the absence of ganglion cells along variable segments of the gut. Both rare (RV) and common variants of the RET gene are associated with HSCR. The aim of this study is to assess, for the first time, the variation in the RET gene of Vietnamese HSCR patients. MethodsWe used Sanger sequencing to screen the coding sequence of the RET gene of 97 Vietnamese HSCR patients of Southern Chinese ancestry. The healthy population consisted of 250 Southern Chinese individuals with no diagnosis of HSCR. ResultsWe detected 8 heterozygous RVs distributed among 13 patients (13.40%) and that were not present in healthy individuals. Among those variants, there were 2 novel and deleterious (R133C [c.397 C>T]; R144C [c.430 C>T]) missense amino acid substitutions, 2 novel silent variants (P667P [c.2001 A>T]; Y809Y [c.2427 C>T]), and 4 previously described missense substitutions (R114H [c.341 G>A]; V292M [c.874 G>A]; G533S [c.1597 G>A]; R982C [c.2944 C>T]). As expected, the common RET coding sequence variants rs1800858 (A45A [c.135 G>A]) and rs1800861 (L769L [c.2307 T>G]) were highly associated with the disease. ConclusionsThe identification of novel deleterious variants together with the fact RET RVs are virtually unique to HSCR patients indicates that the RET gene is a target for mutations among Hirschsprung patients of any population.

PP-230. Management and outcome of Hirschsprung's disease diagnosed in neonatal period

Hirschsprung-associated enterocolitis (HAEC) represents the primary cause of high morbidity and mortality in Hirschsprung disease (HSCR) patients. The most common surgical methods for HSCR are the Soave and Duhamel procedures. Therefore, we aimed to compare the HAEC frequency following the Soave and Duhamel procedures.Medical records were retrospectively analyzed for patients who underwent the Soave and Duhamel pull-through at Dr. Sardjito Hospital, Indonesia from 2010 to 2015. The diagnosis of HAEC was determined using a HAEC scoring system.One hundred patients were involved (Soave: 52 males and 19 females vs. Duhamel: 23 males and 6 females, p = 0.62). There was significant difference in mean age at pull-through (Soave: 29.9 ± 45.2 vs. Duhamel: 50.8 ± 47.5 months, p = 0.04), whereas mean age of HSCR diagnosis and pre-operative enterocolitis frequency did not differ significantly between groups (Soave: 25.4 ± 41.0 vs. Duhamel: 43.7 ± 48.1 months, p = 0.06, and Soave: 7% vs. Duhamel: 14%, p = 0.44, respectively). The HAEC frequency after pull-through was significantly higher in the Duhamel than the Soave group (28% vs. 10%, respectively, p = 0.03). Furthermore, pre-operative enterocolitis showed a significant association with HAEC following pull-through (p = 2.0 × 10–4) and the risk of HAEC after Soave pull-through was increased in long-segment aganglionosis compared to short-segment HSCR (p = 0.015).The frequency of HAEC was significantly higher after the Duhamel than the Soave procedure. Moreover, patients with pre-operative enterocolitis are prone to have HAEC following pull-through.III

Nerve growth factor receptor immunohistochemistry has a limited additional value to diagnose Hirschsprung’s disease

The diagnosis of Hirschsprung's disease (HSCR) is based on the histopathological evaluation of rectal suction biopsies (RSB), using haematoxylin and eosin (H&E) stains and acetylcholinesterase (AChE) histochemistry. The use of different immunohistochemical markers, such as nerve growth factor receptor (NGFR), has been suggested to facilitate the diagnosis of HSCR. The aim of this study was to evaluate the addition of NGFR immunohistochemistry to diagnose HSCR. RSB from 23 HSCR patients and 16 patients investigated for, but not diagnosed with, HSCR were retrospectively reviewed. The histopathology report supported or did not support the diagnosis of HSCR. In patients with HSCR, the primary biopsies confirmed the diagnosis in 21 of 23 cases with H&E staining, in 16 of 23 cases with AChE histochemistry, and in 8 of 23 cases with NGFR immunohistochemistry. Due to inadequate biopsies or equivocal interpretation, the biopsies were repeated in seven of the patients with HSCR and two patients underwent biopsies a third time. In the 16 patients investigated for but not diagnosed with HSCR, the three tests were normal in all cases. We conclude that NGFR immunohistochemistry has limited additional value to diagnose HSCR.

Hirschsprung Disease and Congenital Anomalies of the Kidney and Urinary Tract (CAKUT)

Congenital anomalies of the kidney and urinary tract (CAKUT) can be associated with Hirschsprung disease (HSCR). Based on the common genetic background of enteric nervous system and kidney development, the reported association of CAKUT and HSCR seems underestimated. Therefore, we designed a prospective study aimed at determining the prevalence of CAKUT in HSCR patients and at identifying RET, glial cell line-derived neurotrophic factor (GDNF), and GDNF family receptor alpha1 (GFRalpha1) mutations or haplotypes associated with this subset of HSCR patients. Eighty-four HSCR patients consecutively admitted to our department between July 2006 and July 2007 underwent interviews, notes review, ultrasound screening (further investigation according to detected anomaly), urinalysis, and DNA extraction for molecular genetics study. Another 27 patients with isolated CAKUT were included as a control group for the molecular genetics study. Twenty-one patients (25%) with HSCR had associated CAKUT, with hydronephrosis and hypoplasia being the most frequent diagnoses. Nine of 21 CAKUT were symptomatic. Six additional patients had other non-CAKUT anomalies (for example, stones, Barter syndrome) that were excluded from association and molecular genetics analysis to avoid bias of inclusion criteria. RET mutations were found in 5 patients (4 HSCR, 1 HSCR + CAKUT, 0 CAKUT) and GDNF mutations in 3 (2 HSCR, 1 CAKUT, 0 HSCR + CAKUT). No GFRalpha1 mutations were found. Finally, the HSCR-predisposing T haplotype of RET proto-oncogene was found in 64% of HSCR, 50% of HSCR + CAKUT, and in 24% of CAKUT patients. The incidence of CAKUT in HSCR patients is 4- to 6-fold higher than expected. Therefore, a patient with HSCR has a 3- to 18-fold higher risk of developing a CAKUT, particularly hydronephrosis or hypoplasia. If we consider that the proportion of predisposing haplotype in HSCR + CAKUT patients resembles that of other syndromic HSCR, we can conclude that HSCR + CAKUT has to be considered a novel syndromic association. These results need to be confirmed in a larger series. At present, we strongly suggest considering ultrasound screening of the urinary tract in every patient with a diagnosis of HSCR.

Hirschsprung's Disease, One of the Most Difficult Diagnoses in Pediatric Surgery: A Review of the Problems from Clinical Practice to the Bench

The diagnosis of Hirschsprung's disease (HSCR) should take place early in the neonatal period, because without an effective diagnosis and appropriate treatment, a considerable proportion of infants will go on to develop serious complications such as acute enterocolitis or toxic megacolon. Because no more than 10 % of HSCR cases have a late presentation with classical chronic constipation and megacolon, the clinician has to make a difficult, early diagnosis, which is the crux of the clinical problem. The aim of this review paper is to present all tools currently available to make a clear HSCR diagnosis and to discuss the problems facing the clinician and the pediatric surgeon in the correct identification of HSCR and of other intestinal dysganglionoses. Based on the current state of knowledge and 24 years' personal experience in clinical practice and basic research in this field, I describe an algorithmic approach that enables clinicians and surgeons to rationalize and maximize the clarity of diagnosis through a complementary set of procedures and enzyme-histochemical reactions. Two innovative techniques, added to the protocol in the last four years, are described: the lyophilized HSCR diagnostic kit, and the one-trocar transumbilical laparoscopic intestinal full-thickness biopsy technique (OTTLB). The rational, algorithmic diagnostic pathway proposed in this review paper aims to optimize every diagnosis by the stepwise application of a complementary set of procedures and enzyme-histochemical reactions as they become appropriate. In the interests of simplifying genetic molecular diagnosis, I suggest the following guidelines: 1) only in cases of total colonic aganglionosis (TCA) is it advisable to carry out full RET mutation screening (the mutation rate is up to 70 %); and 2) all HSCR patients should be tested only for standard MEN2A and MTC mutations. If these are present, the patients should be followed up carefully with proper surveillance and biochemical testing of other susceptible family members as they are at risk of developing neuroendocrine tumors.