A variant pattern of calretinin immunohistochemistry on rectal suction-biopsies is fully specific of short-segment Hirschsprung's disease

Hirschsprung's disease. Management

BACKGROUND

Hirschsprung's disease (HD) is a rare congenital disease that is characterised by the absence of ganglion cells in the myenteric plexus starting in the distal bowel. This results in distal functional obstruction and may lead to complications like enterocolitis. The treatment is surgical and requires the resection of the aganglionic segment, and the pull-through of normal intestine into the anal opening. However, even after successful surgery, patients may continue to have symptoms.

AIM

Discuss current surgical techniques and management strategies for patients with postoperative symptoms after surgical correction of Hirschsprung's disease.

METHODS

A review of the literature was done through PubMed, with a focus on clinical management and approach.

RESULTS

We describe the clinical problems that can occur after surgical correction. These include obstructive symptoms, enterocolitis, or faecal incontinence. A systematic approach for the evaluation of these patients includes the exclusion of anatomic, inflammatory, behavioural or motility related factors. Depending on the severity of the symptoms, the evaluation includes examination under anaesthesia, the performance of contrast studies, endoscopic studies, measurement of anal sphincter function and colonic motility studies. The treatment is focused towards addressing the different pathophysiological mechanisms, and may include medical management, botulinum toxin to the anal sphincter or rarely redo-operation.

CONCLUSIONS

Patients with Hirschsprung's disease need to have surgical correction, and their postoperative long-term management is complex given a variety of associated problems that can occur after surgery. A systematic evaluation is necessary to provide appropriate therapy.

Hirschsprung disease

Hirschsprung disease (HSCR) is a rare congenital intestinal disease that occurs in 1 in 5,000 live births. HSCR is characterized by the absence of ganglion cells in the myenteric and submucosal plexuses of the intestine. Most patients present during the neonatal period with the first meconium passage delayed beyond 24 h, abdominal distension and vomiting. Syndromes associated with HSCR include trisomy 21, Mowat-Wilson syndrome, congenital central hypoventilation syndrome, Shah-Waardenburg syndrome and cartilage-hair hypoplasia. Multiple putative genes are involved in familial and isolated HSCR, of which the most common are the RET proto-oncogene and EDNRB. Diagnosis consists of visualization of a transition zone on contrast enema and confirmation via rectal biopsy. HSCR is typically managed by surgical removal of the aganglionic bowel and reconstruction of the intestinal tract by connecting the normally innervated bowel down to the anus while preserving normal sphincter function. Several procedures, namely Swenson, Soave and Duhamel procedures, can be undertaken and may include a laparoscopically assisted approach. Short-term and long-term comorbidities include persistent obstructive symptoms, enterocolitis and soiling. Continued research and innovation to better understand disease mechanisms holds promise for developing novel techniques for diagnosis and therapy, and improving outcomes in patients.

The transition zone in Hirschsprung's bowel contains abnormal hybrid ganglia with characteristics of extrinsic nerves

The aganglionic bowel in short-segment Hirschsprung's disease is characterized both by the absence of enteric ganglia and the presence of extrinsic thickened nerve bundles (TNBs). The relationship between the TNBs and the loss of enteric ganglia is unknown. Previous studies have described decreasing numbers of ganglia with increasing density of TNBs within the transition zone (TZ) between ganglionic and aganglionic gut, and there is some evidence of spatial contact between them in this region. To determine the cellular interactions involved, we have analysed the expression of perineurial markers of TNBs and enteric ganglionic markers for both neural cells and their ensheathing telocytes across four cranio-caudal segments consisting of most proximal ganglionic to most distal aganglionic from pull-through resected colon. We show that in the TZ, enteric ganglia are abnormal, being surrounded by perineurium cells characteristic of TNBs. Furthermore, short processes of ganglionic neurons extend caudally towards the aganglionic region, where telocytes in the TNB are located between the perineurium and nerve fibres into which they project telopodes. Thus, enteric ganglia within the TZ have abnormal structural characteristics, the cellular relationships of which are shared by the TNBs. These findings will help towards elucidation of the cellular mechanisms involved in the aetiology of Hirschsprung's disease.

PHOX2B Immunostaining: A Simple and Helpful Tool for the Recognition of Ganglionic Cells and Diagnosis of Hirschsprung Disease

Hirschsprung disease (HD) is a congenital disorder of the enteric nervous system that occurs in ∼1 in 5000 live births. It is characterized by the absence of ganglionic cells (GCs) in the distal intestine. The diagnosis relies on the thorough analysis of a rectal suction biopsy (RSB), which must show a complete absence of GCs after careful examination of at least 100 serial sections. Such a negative characteristic explains the difficulty of this diagnosis. Moreover, GCs may be immature in very young or preterm born children, making them hard to recognize. Therefore, ancillary techniques have been developed as diagnostic help, such as acetylcholinesterase histochemistry and calretinin immunostaining. These techniques reveal only indirect clues, focusing mainly on the changes in nerve fibers, but not on GCs themselves. As PHOX2B has been shown to be a very specific transcription factor in GCs and in progenitor enteric nerve cells, we have assessed (i) PHOX2B immunostaining in immature enteric ganglia and (ii) the use of PHOX2B immunostaining for the recognition of GCs on RSBs for suspicion of HD. We have observed PHOX2B expression in all GCs, both mature and immature, and its complete absence in Hirschsprung cases. We suggest that the use of PHOX2B immunostaining is of great help (i) in the recognition of GCs on RSBs regardless of their differentiation and therefore (ii) in the diagnosis of HD.

Rectal suction biopsy with calretinin immunohistochemistry in patients suspected with residual aganglionosis after operation for Hirschsprung disease

INTRODUCTION

This study investigates the use of rectal suction biopsy (RSB) with calretinin immunohistochemical staining (CIS) in patients suspected of having abnormally innervated bowel after pull through operation for Hirschsprung disease (HD).

METHOD

This study was conducted in Children's Hospital 2, Ho Chi Minh City from January 2015 through June 2016. Patients suspected with abnormally innervated bowel after pull through operation for HD were submitted for a RSB with CIS. Following histological results, the patients underwent an appropriate treatment (redo pull through operation or non-operative medical management) and followed up at least 6 months to evaluate their outcomes.

RESULTS

Ten patients were enrolled in our study. The median age was 5.6 (range 1.4-20) years. The diagnosis of normally innervated bowel was made in five patients by showing positive reactivity of CIS on RSB, whereas five others were diagnosed with abnormally innervated bowel. Final diagnosis of the five latter patients was confirmed by analyses of the resected bowel after a redo pull through operation (including 4 cases with residual aganglionosis and one case with transition zone bowel).

CONCLUSIONS

RSB with CIS is a reliable and simple method for diagnosis of abnormally innervated bowel after pull through operation for HD.

LEVEL OF EVIDENCE

III TYPE OF STUDY: Study of diagnostic test (evaluate the effectiveness of a diagnostic test or outcome assessment).

The utility of the hematoxylin and eosin staining in patients with suspected Hirschsprung disease

Background

While immunohistochemistry (IHC) methods have been widely conducted for the diagnosis of Hirschsprung disease (HSCR) in developed countries, there are very few studies on their use in developing countries where hematoxylin and eosin (HE) staining is a key element of the diagnosis of HSCR. We aimed to determine the accuracy of HE staining in the diagnosis of HSCR using S100 IHC as the reference standard in Indonesia.

Methods

All histopathology performed for the suspicion of HSCR patients from January 2013 to August 2015 in Dr. Sardjito Hospital, Yogyakarta, Indonesia, were retrospectively reviewed.

Results

Our study included 23 HSCR patients: 9 males and 14 females. The HE staining revealed 14 negative (absence of ganglion cells) cases (61%) and 9 positive (presence of ganglion cells) cases (39%). In S100 IHC, out of the 9 positive cases by HE staining, 6 (67%) were confirmed for having ganglion cells; and out of the 14 negative cases by HE staining, 12 (86%) were reported negative and 2 (14%) were positive by S100 IHC staining. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy rates of the HE staining were 80% (95% CI: 0.51–0.95), 75% (95% CI: 0.36–0.96), 85.7% (95% CI: 0.56–0.98), 66.7% (95% CI: 0.31–0.91), and 78.3% (95% CI: 0.58–0.90), respectively.

Conclusions

Our study showed that HE staining has relatively moderate accuracy for the diagnosis of HSCR. The use of HE staining is still recommended for the diagnosis of HSCR given the limitation of resource allocation for more expensive IHC technologies in developing countries.

Diagnostic value of rectal suction biopsies using calretinin immunohistochemical staining in Hirschsprung's disease

BACKGROUND

The study investigates the diagnostic value of calretinin immunohistochemical staining (CIS) on rectal suction biopsies (RSB) in Hirschsprung's disease (HD).

METHODS

A prospective study was conducted at Children's Hospital 2 in Ho Chi Minh City, Vietnam, from January through December 2015. Patients suspected of HD during this period underwent RSB and were followed in order to assess the accuracy of the diagnostic test with CIS compared with conventional histology (H&E).

RESULTS

A total of 188 children with RSB were investigated. Median age was 7.1 (range 0.2-159) months with 65.4% boys. HD was confirmed in 80 (42.6%) children. There were 1 false positive and no false-negative cases. The sensitivity and specificity were 100% (80/80) and 99.1% (107/108) for CIS and 100% and 85.2% for H&E, respectively. Cohen's kappa coefficient was 0.9891 with a diagnostic accuracy of 99.5% for CIS, compared with 0.8303 and 91.5% for H&E, respectively. There were no serious complications related to the RSB.

CONCLUSION

RSB with CIS is a useful diagnostic method for HD, with easy interpretation and no need for cryostat. CIS has a high diagnostic accuracy and should be considered as the primary method for the diagnosis of HD by RSB.

LEVEL OF EVIDENCE

Diagnostic Studies - Level I.