Advantages of intraoperative semiquantitative evaluation of myenteric nervous plexuses in patients with Hirschsprung disease

Approach to Constipation in Children: Recommendations for Evaluation and Management

Constipation is common in childhood, and most patients can be successfully managed by their primary care provider. However, some patients will require more specialized management either due to an underlying congenital colorectal disorder such as Hirschsprung disease or anorectal malformation or due to severe functional constipation that is refractory to medical management.

Histopathology of Ganglion Cells in the Proximal Resected Bowel Correlates With the Clinical Outcome in Hirschsprung Disease: A Pilot Study

INTRODUCTION

Intraoperative leveling biopsy by identifying ganglion cells is crucial to determine surgical margin during surgery for Hirschsprung disease (HSCR). The anastomosis should be performed at least 5 cm proximal to the ganglionic segment to prevent transition zone pull-through. However, the length of the transition zone could be much longer than expected and the histological evaluation of the entire circumference of the proximal margin is recommended, which is time-consuming and not applicable for leveling biopsy. We found that the histopathologic features of ganglion cells varied in the examined bowel specimens and demonstrated a pattern similar to immature and degenerated neuron cells. We assumed that the histopathologic features of ganglion cells in the proximal resected bowel were associated with the clinical outcome and might guide the leveling biopsy. In this study, we described a histopathologic grade of ganglion cells based on the degree of maturity and degeneration. We assessed the correlation between the histopathological grade of ganglion cells in the proximal surgical margin and clinical outcome.

METHODS

Three hundred fifty seven patients with HSCR treated between 2013 and 2020 were included. The ganglion cells were divided into six grades based on the histopathologic features in frozen sections. Medical records and detailed histopathologic results of intraoperative frozen sections were reviewed. Follow-up data were collected to evaluate clinical outcomes. The pediatric incontinence and constipation scoring system was used to predict bowel function.

RESULTS

The histopathologic results of proximal resected bowel from 357 HSCR patients were presented as follows: Grade I in 52 patients (14.6%), Grade II in 186 patients (52.1%), Grade III in 107 patients (30.0%), and Grade IV in 12 patients (3.4%). The median follow-up time was 46.8 mo (13.0-97.6 mo). The histopathologic grade of ganglion cells from the proximal resected margin was significantly related to postoperative constipation problems and the incidence of Hirschsprung-associated enterocolitis. The results from the pediatric incontinence and constipation scoring system indicated a positive correlation between better postoperative bowel function and lower histopathologic grade of ganglion cells.

CONCLUSIONS

This pilot study showed an association between the histopathologic features of ganglion cells in the proximal surgical margin and the clinical outcome. It may provide additional information for intraoperative pathologic consultation in leveling biopsy to prevent insufficient resection of the affected colon. A prospective study is warranted to validate these findings before clinical application.

Long-term outcomes in children with Hirschsprung's disease and transition zone bowel pull-through: impact of surgical techniques and role for conservative approach

PURPOSE

Presence of transition zone (TZ) in the pulled colon can impact the outcome of surgery in children with Hirschsprung's disease. There is a wide variation in terminology used to define TZ and its management. We present our series of managing 11 such children with considerations for conservative management.

METHODS

Eleven of 114 children operated for Hirschsprung's disease had features of TZ on the 4-quadrant doughnut assessment of proximal anastomosing margin. They were followed up for development of obstructive symptoms, failure of pull-through procedure or bowel-related complications. Intervention done were observation with laxatives, dilatation, Botox injection and redo pull-through.

RESULTS

Of the 11 children, 6 underwent Duhamel's procedure and 5, transanal endorectal pull-through (TERP). Features identified on HPE were presence of hypertrophic nerve bundles involving 2 or 3 quadrants in the circumferential doughnut biopsy of proximal anastomosing margin. Observed symptoms included constipation, enterocolitis, increased bowel frequency and soiling. Intervention done were use of laxatives with bowel management program in six and Botox injections in four. Only one child with TZ in 3 quadrants required redo surgery. Mean follow-up was 5.2 years with resolution of symptoms in most.

CONCLUSION

This study highlights the role of conservative management with good outcomes in children with TZ bowel pull-through having hypertrophic nerve fibers and normal ganglion pattern. Children who underwent Duhamel's procedure had little impact with the presence of TZ at anastomotic margin and majority of those undergoing TERP benefitted from Botox injection. Conservative management can be attempted successfully to prevent redo surgical interventions as they can lead to poorer outcomes. Only those children not responding to conservative measures need to be planned for revision surgery.

Clinical predictors of readmission after surgery for Hirschsprung disease

The reasons for readmission of children with Hirschsprung disease (HD) are multiple. The study aims to predict the relevant factors for the readmission of children with HD by collecting and analyzing the relevant data of the child's admission to the hospital at the time of surgery.A retrospective review was performed including all patients with surgical treatment of HD at our institution between the years of 2011 to 2020. Univariate and multivariate Logistic regression analysis were performed to obtain the independent risk factor for this study. The receiver operating characteristic curve (ROC) were used to assess the performance of derived models.A total of 162 patients were identified. The average presurgery weights were 6.93 ± 1.78 kg in the readmission group and 8.38 ± 3.17 kg in the non-readmission group. Six children were classified as a low-weight in the readmission group, and 11 children classified as low-weight in the non-readmission group. The length of the intestinal tube after resection was 25.25 ± 15.21 cm in the readmission group, and 16.23 ± 4.10 cm in the non-readmission group. The ROC for the prediction model of readmission after HD surgery (AUC = 0.811).In children undergoing the HD surgery, we showed preoperative low body weight and long intra-operative bowel resection significantly increase the probability of readmission due to complications.

Postoperative Pullthrough Obstruction in Hirschsprung Disease: Etiologies and Diagnosis

Some patients continue to have obstructive symptoms and/or incontinence after pullthrough surgery for Hirschsprung disease. Incontinence can be due to injury to the anal sphincter and/or dentate line, abnormal colonic motility (nonretentive), or a chronic large stool burden (retentive). A diagnostic algorithm based on clinical and pathological evaluations can be applied to distinguish potential etiologies for obstructive symptoms, which segregate into anatomic (mechanical or histopathological) or physiologic subgroups. Valuable clinical information may be obtained by anorectal examination under anesthesia, radiographic studies, and anorectal or colonic manometry. In addition, histopathological review of a patient's original resection specimen(s) as well as postoperative biopsies of the neorectum usually are an important component of the diagnostic workup. Goals for the surgical pathologist are to exclude incomplete resection of the aganglionic segment or transition zone and to identify other neuromuscular pathology that might explain the patient's dysmotility. Diagnoses established from a combination of clinical and pathological data dramatically alter management strategies. In rare instances, reoperative pullthrough surgery is required, in which case the pathologist must be aware of histopathological features specific to redo pullthrough resection specimens.

Variability of the transition zone length in Hirschsprung disease

BACKGROUND

Surgical management of Hirschsprung disease (HD) involves fully excising the transition zone (TZ). The literature suggests that resection of ≥5 cm of ganglionic bowel proximal to the aganglionic segment is sufficient. Our primary aim was to evaluate the lengths of the TZ in a cohort of consecutive patients with HD. We reviewed the impact this had on the need for revision surgery. We hypothesized that the TZ can be highly variable and may lead to a TZ pull-through when the proximal donut is not reviewed intraoperatively.

METHODS

A retrospective review was conducted for all patients undergoing primary pull-through surgery between January 2012 and September 2018. Data was collected on demographics, need for staged surgery, and complications following surgery.

RESULTS

Forty-eight patients were eligible for inclusion. 11/48 (23%) patients presented late (>6 months). 27/48 (56%) patients needed a stoma prior to definitive surgery. The median age at pull-through was 6 months (1-84 months). The median TZ length was 1.7 cm (0.3-22.9 cm). 11/48 (23%) had a TZ >5 cm. 36/48 (75%) patients did not have intraoperative review of the donut resulting in three TZ pull-throughs.

CONCLUSIONS

We would advocate circumferential intraoperative frozen section review of the proximal donut to minimize the risk of a TZ pull-through.

LEVEL OF EVIDENCE

Level III.

Hirschsprung Disease - Current Diagnosis and Management

Hirschsprung disease is a common cause of neonatal and infantile large gut obstruction. It is characterised by varying extent of contiguous aganglionosis extending from the anorectum proximally. Since its recognition, the diagnosis and management has continuously evolved with advances in histological evaluation and surgical techniques. This article summarizes the current modalities of investigation and optimal surgical management of Hirschsprung disease and concludes with a reference to the Indian scenario.

Histology of the Transition Zone in Hirschsprung Disease

Surgical management of Hirschsprung disease requires resection of the aganglionic bowel and transition zone, a length of ganglionic bowel, immediately proximal to the aganglionic segment, with neuropathologic features that seem to correlate with dysmotility. Pathologists must be able to recognize histopathologic features of the transition zone in hematoxylin and eosin-stained sections in order to interpret intraoperative frozen sections and ensure adequate resection. The proximal ganglionic portions of colonic resection specimens from 59 patients with distal aganglionosis were analyzed with closely spaced transverse sections to map the distribution of the 3 most commonly referenced features of transition zone (partial circumferential aganglionosis, myenteric hypoganglionosis, and submucosal nerve hypertrophy). Each of these "primary" findings was restricted to a region ≤5 cm proximal to the aganglionic segment in the overwhelming majority of patients. Exceptions were more common with longer aganglionic segments. Three other neuroanatomic phenotypes (gangliosclerosis, ectopic myenteric ganglia, and eosinophilic ganglionitis) of uncertain clinical significance were distributed more irregularly and often over much longer distances. Routine resection of at least 5 cm of ganglionic bowel proximal to the aganglionic segment may reduce the incidence of transition zone pull-through. However, routine intraoperative frozen section examination of the proximal resection margin to exclude the 3 primary forms of hematoxylin and eosin neuropathology described in this study is strongly advised.

Submucosal nerve diameter of greater than 40 μm is not a valid diagnostic index of transition zone pull-through

BACKGROUND

Submucosal nerve hypertrophy is a feature of the transition zone in Hirschsprung disease and has been used as a primary diagnostic feature of transition zone pull-through for patients with persistent obstructive symptoms after their initial surgery. Most published criteria for identification of hypertrophy rely on a nerve diameter of greater than 40μm, based primarily on data from a relatively small number of infants with Hirschsprung disease and controls. The validity of these objective measures has not been validated in appropriate controls for post-pull-through patients.

SCIENTIFIC APPROACH

The primary pull-through specimens and post pull-through biopsies +/- redo pull-through resections from a series of 9 patients with Hirschsprung disease were reviewed to assess the prevalence of submucosal nerves >40μm in diameter and 400× microscopic fields containing two or more such nerves. Similar data from multiple colonic locations were collected from a series of 40 non-Hirschsprung autopsy and surgical controls.

RESULTS

The overwhelming majority of Hirschsprung patients harbored submucosal nerves >40μm in their post-pull-through specimens independent of other features of transition zone pathology, and despite normal innervation at the proximal margins of their initial resections. Measurement of submucosal nerve diameters in autopsy and surgical non-Hirschsprung control samples indicated that nerves >40μm are normal in the distal rectum after 1year of age and are found in more proximal colon at older ages.

CONCLUSIONS

These results suggest that diagnostic criteria currently used to recognize submucosal nerve hypertrophy in the neorectum after a pull-through for Hirschsprung disease are not justified and should not be regarded as definitive evidence for transition zone pull-through.

Clinicopathological significance of STAT4 in hepatocellular carcinoma and its effect on cell growth and apoptosis

Background

Recent studies showed that signal transducer and activator of transcription 4 (STAT4) was downregulated in hepatocellular carcinoma (HCC) tissues. However, the role of STAT4 in HCC is still unknown. The aim of this study is to explore the association between STAT4 expression and other clinicopathological features in HCC and to test the effect of STAT4 on cell growth and apoptosis in vitro.

Methods

STAT4 was evaluated by immunohistochemistry in 171 HCC and corresponding paraneoplastic liver, 37 cirrhosis, and 33 normal liver tissues. Association between STAT4 and clinicopathological parameters was analyzed. Meta-analysis on STAT4 in cancer was performed. The effect of STAT4 small interfering RNA (siRNA) on cell growth and cell apoptosis was also detected.

Results

Positive rate of STAT4 was 29.2% (50/171) in HCC tissues, 53.2% (91/171) in paraneoplastic liver tissues, 64.9% (24/37) in cirrhosis tissues, and 72.7% (24/33) in normal liver tissues. STAT4 was upregulated in younger patients who were female, with single tumor node, early TNM stage, without portal vein tumor embolus, and α-fetoprotein (AFP)-positive tumors compared with the groups comprising older patients, males, and those with multiple tumor nodes, advanced TNM stage, with portal vein tumor embolus, and AFP negative tumors. Meta-analysis showed STAT4 was correlated with TNM stage (OR =0.50, 95% CI =0.30, 0.83, P=0.008) and age (OR =0.58, 95% CI =0.38, 0.95, P=0.032) in malignant tissues, and with AFP level (OR =1.76, 95% CI =1.06, 2.94, P=0.03) in HCC. STAT4 siRNA promoted growth and suppressed apoptosis of HepG2 cells.

Conclusion

STAT4 might play a vital role in development of HCC, via influencing cell growth and apoptosis, as a tumor suppressor.

Calretinin, β-tubulin immunohistochemistry, and submucosal nerve trunks morphology in Hirschsprung disease: possible applications in clinical practice

OBJECTIVES

The aim of this study was to investigate calretinin and β-tubulin immunohistochemical expression together with submucosal nerve trunks morphology in differently innervated segments of Hirschsprung disease (HD) and total colonic aganglionosis (TCA).

METHODS

A total of 25 cases (22 HD, 3 TCA) and 18 controls were processed for calretinin and β-tubulin immunohistochemistry. Sections representative of distal aganglionic, transition, and proximal ganglionic segments were evaluated by a visual grading score; β-tubulin was evaluated also by image analysis. Submucosal nerve trunks hypertrophy and hyperplasia were measured by citomorphology. The length of proximal segment was correlated to postoperative bowel function.

RESULTS

Controls showed intense calretinin and β-tubulin staining. In HD and TCA, calretinin staining was related to the presence of ganglion cells: negative in distal, faint in transition, intense in proximal segment. β-Tubulin staining was weak in all of the segments of HD and negative in TCA. Hypertrophic and hyperplastic nerve trunks characterized aganglionic segment, and progressively decreasing nerve size was observed in transition and ganglionic segments. Transient postoperative constipation, soiling, or enterocolitis was present in 59% of patients with HD without clear relation to proximal segment length or presence of hypertrophic nerve trunks.

CONCLUSIONS

Calretinin is a reliable marker of the presence of ganglion cells, and, together with nerve hypertrophy, it helps to identify the transition zone. Length and nerve size of proximal segment in resected specimen did not affect the postsurgical intestinal function. Reduced β-tubulin expression along the entire colonic tract, included proximal ganglionic segments, may represent a potential impairing factor for the enteric neural transmission.

Histopathologic delineation of the transition zone in short-segment Hirschsprung disease

Failure to completely resect the transition zone (TZ) between aganglionic and neuroanatomically normal bowel ("TZ pull-through") is considered one reason for postoperative obstructive symptoms in Hirschsprung disease (HD). Despite years of study, the proximal boundary of the TZ remains nebulous, complicated by discordant, often subjective, histopathologic definitions. In order to objectively delineate the TZ, transverse sections at 1 cm intervals from the rectums of 9 non-HD autopsy subjects and resections from 15 infants with short-segment HD were immunostained with Hu (ganglion cell bodies) and glucose transporter 1 (Glut1) (perineurium of extrinsic nerves), and 6 putative features of TZ were examined: (1) aganglionosis of ≥1/8th circumference; (2) myenteric or submucosal hypoganglionosis; (3) hypertrophic submucosal nerves; (4) Glut1+ submucosal innervation; (5) submucosal hyperganglionosis; and (6) "ectopic" ganglia in lamina propria, muscularis propria, or serosa. In non-HD controls, Glut1+ submucosal innervation, hypertrophic nerves, partial circumferential aganglionosis, and hypoganglionosis were absent or restricted to the distal 2 cm. In contrast, all 6 neuropathologic features of TZ were identified proximal to the aganglionic segment in the majority of HD resections, but the length of the TZ ranged from 0 to 12 cm, depending on which neuropathologic feature was considered. Excluding submucosal hyperganglionosis and ectopic ganglia, the TZ was generally ≤5 cm. Many features of TZ cannot be excluded intraoperatively with a biopsy or a full-circumference frozen section. However, partial circumferential aganglionosis, severe myenteric hypoganglionosis, and hypertrophic submucosal nerves can, and probably should, be assessed in full-circumference frozen sections of the proximal resection margin, to reduce the likelihood of TZ pull-through.

Transitional zone pull through: surgical pathology considerations

Incomplete resection of the transitional zone (TZ) between histologically normal and aganglionic bowel in Hirschsprung disease is a putative cause of postoperative dysmotility. A review of literature indicates that diverse histopathological indexes have been used to define the TZ, and validated and reproducible diagnostic criteria have not been established. As a consequence, the proximal margin of the TZ is difficult to delimit, and the length of the TZ in a given patient depends on the diagnostic criteria used. Seromuscular biopsies are inadequate to exclude TZ, as diagnostic indexes may involve only a portion of the bowel circumference or the submucosa. Most published investigations of postoperative outcome after a TZ pull through (TZPT) conclude that the latter can cause persistent obstructive symptoms, which necessitate reoperation. However, the results of these studies are difficult to translate into clinical practice because most lack appropriate controls, and the overwhelming majority provide inadequate histopathological descriptions for reference at the time of intraoperative frozen section analysis. At present, a conservative approach based on frozen section examination of the entire proximal margin of the resection to exclude obvious subcircumferential aganglionosis (contiguous gap between ganglia of more than one-eighth of the circumference), hypoganglionosis (continuous string of myenteric ganglia comprised of 1 or 2 ganglion cells without surrounding neuropil), or hypertrophic submucosal nerves (>2 nerves with widths ≥40 μm per high-power field) seems prudent. Well-controlled studies to correlate proximal margin histology, especially subtle anatomic or immunohistochemical changes, with postoperative outcome are needed.

Reoperation for Hirschsprung disease: pathology of the resected problematic distal pull-through

Hirschsprung disease, which consists of aganglionosis of the rectum and sometimes more proximal bowel, requires surgical removal of the aganglionic bowel and creation of ganglionated neorectum using proximal normally innervated bowel. The border between aganglionic and ganglionic bowel is irregular; the transition zone features variable quantities of ganglion cells and numerous large nerves. We report the histopathology of pull-through bowel segments resected because of poor postoperative outcome from 30 patients (22 boys, 8 girls). The most common indication for reoperation was severe constipation/obstruction. Transition zone (bowel with at least two nerves ≥40 µm diameter per 400× high-power field, and ganglion cells) or aganglionic bowel (bowel with at least two nerves ≥40 µm per high-power field diameter, but without ganglion cells) was found in 19/30 (63%) resections. In colons resected because of familial adenomatous polyposis, rare high-power fields showed two enlarged nerves; the mean age of those patients (135 ± 49.4 months) was significantly higher than that of the patients undergoing redo pull-through surgery (67.9 ± 42.8 months). Additional pathology included stricture and enterocolitis. Although there are multiple causes for poor outcomes following surgical therapy for Hirschsprung disease, abnormal innervation of the bowel used for pull-through is common. We recommend that intraoperative consultation at primary pull-through procedure include frozen section evaluation of the circumference of the bowel to be used for pull-through to confirm histologically the presence of both ganglion cells and normal-caliber nerves. The criteria used in this study are most suitable for infants and young children.

Pathology of Intestinal Motor Disorders in Children

Varied intestinal neuromuscular pathologies are responsible for Hirschsprung disease and other forms of chronic pseudo-obstruction that are encountered in pediatrics. Pathologically distinct subtypes discussed in this review include aganglionosis, hypoganglionosis, neuronal intranuclear inclusion disease, ganglionitis, degenerative neuropathy, diffuse ganglioneuromatosis, neuronal dysplasia, malformations of the muscularis propria, degenerative leiomyopathy, leiomyositis, and mitochondriopathies. Emphasis is given to the histopathologic features that distinguish these conditions and their differential diagnoses.

The distal level of normally innervated bowel in long segment colonic Hirschsprung's disease

PURPOSE

The definitive surgical management of Hirschsprung's disease (HD) depends on an unambiguous histological diagnosis of bowel aganglionosis, as well as an accurate assessment of its proximal extent from the rectum or 'leveling'. This study aimed to evaluate and compare the transition zone in rectosigmoid and long segment colonic forms of HD.

METHODS

One hundred and fifteen cases of rectosigmoid Hirschsprung's disease (RSHD) and 20 cases of long segment colonic Hirschsprung's disease (LScHD) managed from 1998 to 2008 with a consensus prospective protocol were included in this clinicopathological analysis.

RESULTS

In RSHD, the radiologic transition zone (rTZ)/gross appearance at laparotomy correlated with the histological 'leveling' in the majority (96%); the histologic transition zone was also short and predictable. In contrast, the rTZ in LScHD was conclusive in only 53%; overall the radiologic and histological transition zones concurred in only 26%. The histologic transition zone extended proximally for an unpredictable length before normal circumferential innervation was noted.

CONCLUSIONS

A stringent intraoperative histological evaluation of the colon as outlined is more helpful than radiology to establish the distal level of normally innervated bowel in LScHD and achieve an accurate leveling during a colostomy/pull through.

Practical pathology and genetics of Hirschsprung's disease

Diagnosis and management of Hirschsprung's disease (HSCR) requires understanding of the malformation's anatomic features and multigenic nature. Rectal biopsies, intraoperative frozen sections, and resection specimens provide invaluable information. Extraction of these data requires thoughtful biopsy technique, adequate histologic sections, histochemistry, and collaboration of surgeon and pathologist. Critical consideration of transition zone anatomy and published studies of "transition zone pull through" indicate that more research is needed to determine how much ganglionic bowel should be resected from HSCR patients. Many HSCR-susceptibility genes have been identified, but mutational analysis has limited practical value unless family history or clinical findings suggest syndromic HSCR.

Gastrointestinal neuromuscular pathology: guidelines for histological techniques and reporting on behalf of the Gastro 2009 International Working Group

The term gastrointestinal neuromuscular disease describes a clinically heterogeneous group of disorders of children and adults in which symptoms are presumed or proven to arise as a result of neuromuscular, including interstitial cell of Cajal, dysfunction. Such disorders commonly have impaired motor activity, i.e. slowed or obstructed transit with radiological evidence of transient or persistent visceral dilatation. Whilst sensorimotor abnormalities have been demonstrated by a variety of methods in these conditions, standards for histopathological reporting remain relatively neglected. Significant differences in methodologies and expertise continue to confound the reliable delineation of normality and specificity of particular pathological changes for disease. Such issues require urgent clarification to standardize acquisition and handling of tissue specimens, interpretation of findings and make informed decisions on risk-benefit of full-thickness tissue biopsy of bowel or other diagnostic procedures. Such information will also allow increased certainty of diagnosis, facilitating factual discussion between patients and caregivers, as well as giving prognostic and therapeutic information. The following report, produced by an international working group, using established consensus methodology, presents proposed guidelines on histological techniques and reporting for adult and paediatric gastrointestinal neuromuscular pathology. The report addresses the main areas of histopathological practice as confronted by the pathologist, including suction rectal biopsy and full-thickness tissue obtained with diagnostic or therapeutic intent. For each, indications, safe acquisition of tissue, histological techniques, reporting and referral recommendations are presented.

Quantitative evaluation of myenteric ganglion cells in normal human left colon: implications for histopathological analysis

The analysis of myenteric neurons is becoming increasingly important for the assessment of enteric nervous system injury and degeneration occurring in motor disorders of the gut. Limited information is presently available on the quantitative estimation of myenteric neurons and glial cells in paraffin-embedded colonic sections; additional data would be useful for diagnostic purposes. In this morphometric study, we performed immunohistochemistry to count myenteric neurons and glial cells in paraffin sections of human colon. Serial cross sections of formalin-fixed paraffin-embedded full-thickness normal human left colon (n = 10, age-range: 50-72 years) were examined. HuC/D and S100beta antigens were found to be the best markers for the detection of neurons and glial cells, respectively. Significant correlations were noted between the numbers of neurons/glial cells and the respective myenteric ganglion areas. These findings suggest that HuC/D-S100beta-immunostained paraffin cross sections of human colon can be regarded as valuable tools for the quantitative estimation of myenteric neurons and glial cells. Based on the present method, only a limited number of paraffin sections are needed for reliable quantitative assessments of myenteric ganglion cells, thus allowing fast and simple approaches in the settings of the histopathological diagnosis of colonic motility disorders and retrospective evaluations of pathological archival tissue specimens.