Hirschsprung Disease for the Practicing Surgical Pathologist

Evaluation and Management of Total Colonic Hirschsprung Disease: A Comprehensive Review From the American Pediatric Surgical Association (APSA) Hirschsprung Disease Interest Group

BACKGROUND

Children with total colonic Hirschsprung disease (TCHD) are a unique group of patients with pre- and postoperative management challenges. This review provides a rational, expert-based approach to diagnosing and managing TCHD.

METHODS

The guidelines were developed by the Hirschsprung Disease Interest Group members established by the American Pediatric Surgical Association (APSA) Board of Governors. Group discussions, literature review, and expert consensus were used to summarize the current knowledge regarding diagnosis, staged approach, the timing of pull-through, and pre-and postoperative management in children with TCHD.

RESULTS

This paper presents recommendations for managing TCHD before and after reconstruction, including diagnostic criteria, surgical approaches, bowel management, diet, antibiotic prophylaxis, colonic irrigations, and post-surgical considerations.

CONCLUSIONS

A clear understanding of the unique challenges posed by TCHD and consensus on its treatment are lacking in the literature. This review standardizes this patient group's pre- and postoperative management.

LEVEL OF EVIDENCE

V.

Can the diameter of nerve fibers be effectively utilized to enhance the accuracy of determining the length of the aganglionic segment compared to intraoperative biopsy in patients with Hirschsprung's disease?

OBJECTIVE

The aim of this study is to investigate the accuracy of utilizing neural fiber trunk diameter in accurately diagnosing the length of the aganglionic segment in patients definitively diagnosed with Hirschsprung's disease.

RESULTS

In this study, 40 patients (19 males, 21 females; mean age 2.5 ± 2.2646 years) were assessed for Hirschsprung's disease. Constipation was the main symptom (75%), followed by abdominal issues. All underwent contrast enema and rectal suction biopsy for diagnosis, followed by surgery (predominantly Soave and Swensen techniques). Majority (85%) had rectosigmoid involvement. Neural fiber diameter was measured, with 52.5% ≤40 μm and 47.5% >40 μm. Statistical analysis showed 40% sensitivity(CI:95%) and 47% specificity(CI:95%) with a cutoff of 40.5 μm. Cohen's kappa index for aganglionic segment size was 0.7.

The Pathologist's Role in the Diagnosis of Hirschsprung's Disease

INTRODUCTION

 The possibilities, recent advances, and pitfalls in the histopathologic workup of specimens submitted for the diagnosis of Hirschsprung's disease (HSCR) are presented.

MATERIALS AND METHODS

 A literature research was performed in the database PubMed including the years 2000 to 2024.

RESULTS

 The pathologist is involved in the diagnosis of HSCR in three scenarios: (1) the primary diagnosis in a child with the typical clinical symptoms, (2) the intra-operative guidance of surgery in a case where the diagnosis is already established, and (3) the confirmation of the diagnosis and the documentation of the extent of the disease in the resected specimen. Identification of ganglion cells in the enteric neural plexuses excludes HSCR, and the histological confirmation of a complete absence of these ganglion cells is the gold standard for its diagnosis. However, difficulties in the detection of ganglion cells with standard stains and/or a limited amount of tissue in the specimen submitted for diagnosis make supportive histologic stains and techniques, e.g., calretinin immunohistochemistry or acetylcholinesterase histochemistry necessary for an unequivocal diagnosis of HSCR.

CONCLUSIONS

 Improving the diagnostic accuracy of this life-threating disease is an interdisciplinary task. A good communication between pathologist and clinician, as well as mutual knowledge of skills and challenges of the other discipline, is necessary for a successful diagnostic teamwork.

Enhancing diagnosis of Hirschsprung's disease using deep learning from histological sections of post pull-through specimens: preliminary results

PURPOSE

Accurate histological diagnosis in Hirschsprung disease (HD) is challenging, due to its complexity and potential for errors. In this study, we present an artificial intelligence (AI)-based method designed to identify ganglionic cells and hypertrophic nerves in HD histology.

METHODS

Formalin-fixed samples were used and an expert pathologist and a surgeon annotated these slides on a web-based platform, identifying ganglionic cells and nerves. Images were partitioned into square sections, augmented through data manipulation techniques and used to develop two distinct U-net models: one for detecting ganglionic cells and normal nerves; the other to recognise hypertrophic nerves.

RESULTS

The study included 108 annotated samples, resulting in 19,600 images after data augmentation and manually segmentation. Subsequently, 17,655 slides without target elements were excluded. The algorithm was trained using 1945 slides (930 for model 1 and 1015 for model 2) with 1556 slides used for training the supervised network and 389 for validation. The accuracy of model 1 was found to be 92.32%, while model 2 achieved an accuracy of 91.5%.

CONCLUSION

The AI-based U-net technique demonstrates robustness in detecting ganglion cells and nerves in HD. The deep learning approach has the potential to standardise and streamline HD diagnosis, benefiting patients and aiding in training of pathologists.

Postoperative Hirschsprung's associated enterocolitis (HAEC): transition zone as putative histopathological predictive factor

AIMS

Hirschsprung's-associated enterocolitis (HAEC) is the most severe complication of Hirschsprung disease (HD), and its pathogenesis is still unknown. Length of transition zone (TZ) interposed between aganglionic and normal bowel has been poorly explored as predictor for postoperative HAEC (post-HAEC). This study aimed to identify potential predictive factors for post-HAEC, with a particular focus on histopathological findings.

METHODS

Data from Hirschsprung patients treated in a single Italian centre between 2010 and 2022 with a follow-up >6 months were collected. Thorough histopathological examination of the resected bowel was conducted, focusing on length of TZ and aganglionic bowel.The degree of inflammatory changes in ganglionic resected bowel was further obtained. Ultra-long HD, total colonic aganglionosis and ultra-short HD were excluded. Bivariate and multivariate regression analysis were performed.

RESULTS

Thirty-one patients were included; 5 experienced preoperative HAEC (pre-HAEC) and later post-HAEC (16.1%), further 10 patients developed post-HAEC (total post-HAEC 48.38%). Pre-HAEC-history and a TZ<2.25 cm correlated with an early development of post-HAEC. Multivariate analysis identified a TZ<2.25 cm as an independent post-HAEC predictive factor (p=0.0096). Inflammation within the ganglionic zone and a TZ<2.25 cm correlated with higher risk of post-HAEC (p=0.0074, 0.001, respectively). Severe post-HAEC more frequently occurred in patients with pre-HAEC (p=0.011), histological inflammation (p=0.0009) and short TZ (p=0.0015).

CONCLUSIONS

This study suggests that TZ<2.25 cm predicts the risk of post-HAEC. Preoperative clinical and histopathology inflammation may predispose to worst post-HAEC. Readily available histopathological findings might help identifying patients at higher risk for HAEC and implementing prevention strategies.

Comparison of the efficacy and safety of different surgical procedures for patients with hemorrhoids: a network meta-analysis

PURPOSE

This study used a network meta-analysis to evaluate the efficacy and safety of different surgical approaches in patients with hemorrhoids.

METHODS

PubMed, Embase, Web of science, and Cochrane Library were searched for randomized controlled trials on patients with hemorrhoids treated by different surgical procedures. The search was conducted until January 15, 2023. Two investigators independently screened the resulting literature, extracted information, evaluated the risk of bias of the included studies, and performed a network meta-analysis.

RESULT

A total of 23 randomized controlled studies were included and involved 3573 patients and 10 interventions, namely L (Ligasure), M-M (Milligan-Morgan), F (Ferguson), H (Harmonic), OH (open Harmonic), CH (closed Harmonic), PPH (procedure for prolapse and hemorrhoids), TST (tissue selecting technique), T-S (TST STARE+; tissue selection therapy stapled transanal rectal resection plus), and STARR (stapled transanal rectal resection). Network meta-analysis results showed that L has the shortest mean operating time and STARR has the longest mean operating time, F and H have the longest length of hospitalization and T-S has the shortest length of hospitalization, PPH has the most intraoperative blood loss and L has the least intraoperative blood loss, TST has the shortest time to first defecation and M-M has the longest time to first defecation, STARR had the least recurrence and PPH had the most recurrence, PPH had the least anal stenosis and L had the most anal stenosis, and F had the least postoperative pain after 24 h and PPH had the most postoperative pain after 24 h.

CONCLUSION

Current evidence suggests that L is best at reducing mean operative time and intraoperative bleeding, T-S is best at reducing mean length of stay, TST has the shortest time to first defecation, STARR is best at reducing recurrence rates, PPH is best at reducing postoperative anal stricture, and F is best at reducing postoperative pain after 24 h.

Full-Thickness Rectal Biopsy in Children Suspected of Having Hirschsprung's Disease: The Inconclusive Biopsy

The diagnosis of Hirschsprung's disease relies on histologically proven aganglionosis and nerve trunk hypertrophy in rectal biopsies. Although the frequency of inconclusive biopsies is relatively low, it is a relevant clinical problem. The aim of the present study was to investigate whether a re-evaluation of archived full-thickness biopsies (FTBs) stained with hematoxylin and eosin (HE), together with immune histochemical (IHC) staining, would be diagnostic in biopsies otherwise deemed inconclusive at initial examination with HE only. A total of 34 inconclusive biopsies in 31 patients were identified. From each tissue block, three slices were cut and stained with HE, S100 and calretinin. A blinded pathologist examined the tissue samples. At re-evaluation, one patient was found positive for HD and 11 negative for HD with both HE and IHC staining, respectively. In all 12 cases, the result was confirmed by the final diagnosis at a 5-year follow-up. The rest of the cases were deemed inconclusive. A re-evaluation of the remaining tissue from the biobank might have saved one third of the children from a re-biopsy. The value of adding IHC to conventional HE staining is dubious.