Histopathological perspective of the pulled-through colon in Hirschsprung disease: Impact on clinical outcome

Is It Safe to Operate without Frozen Section Biopsies in Short-Segment Hirschsprung's Disease? An Overview of 60 Cases

Background: Advancements in surgical management in a single-stage procedure made intraoperative frozen section biopsies critical for determining of level of resection to avoid the potential risk of leaving a retained aganglionic segment. However, in most low-income countries, due to the lack of this facility, the surgeon's intraoperative judgment is used for the determination of the resection level. Objective: This study aims to evaluate the accuracy of determining the level of bowel resection in short-segment Hirschsprung's disease based on macroscopic changes. Materials and methods: Intraoperative macroscopic evaluations were assessed using postoperative microscopic findings to determine whether the surgeons' intraoperative judgments were accurate in determining the level of bowel resection in 60 cases of operated short-segment Hirschsprung's disease. In addition, Pearson's correlation coefficient was used to determine whether the sensitivity and specificity of both methods were significantly correlated. Results: The microscopic results showed that the level of resection based on the macroscopic evaluation was performed in normally ganglionated segment in cases of short-segment Hirschsprung's disease. Conclusions: Macroscopic intraoperative assessment by an experienced surgeon is highly accurate method of determining the level of bowel resection in short-segment HSCR.

Does Length of Extended Resection Beyond Transition Zone Change Clinical Outcome for Hirschsprung Pull-Through?

INTRODUCTION

A proximal resection margin greater than 5 cm from the intra-operative histologically determined transition zone has been deemed necessary to minimize the risk of transition zone pull-through. This extended resection may require the sacrifice of vascular supply and even further bowel resection. The impact of extended proximal resection margin on post-operative complications and functional outcomes is unclear.

METHODS

A retrospective chart review of patients who underwent primary pull-through for Hirschsprung disease at a single institution between January 2008 and December 2022 was performed. An adequate proximal margin was defined by a circumferential normally ganglionated ring and absence of hypertrophic nerves. The extended margin was defined as the total length of proximal colon with normal ganglion cells and without hypertrophic nerves. Fecal incontinence severity was assessed with the Pediatric Fecal Incontinence Severity Score (PFISS).

RESULTS

Eighty seven patients met criteria for inclusion. Median age at primary pull-through was 17 days (IQR 10-92 days), 55% (n = 48) of patients had an extended proximal margin (EPM) ≤ 5 cm, and 45% (n = 39) had an EPM > 5 cm. An EPM ≤5 cm was not associated with increased rates of Hirschsprung associated enterocolitis (≤5 cm 43%, >5 cm 39%, P = 0.701), diversion post pull-through (≤5 cm 10%, >5 cm 5%, P = 0.367) or reoperation for transition zone pull-through (≤5 cm 3%, >5 cm 0%, P = 0.112). EPM ≤5 cm had more frequent involuntary daytime bowel movements (P = 0.041) and more frequent voluntary bowel movements (P = 0.035). There were no differences in other measures of fecal incontinence severity.

CONCLUSIONS

Shorter proximal extended margins beyond the adequate ganglionated margin do not significantly impact post-operative complication rates and have an unclear effect on fecal incontinence.

TYPE OF STUDY

Case Control.

LEVEL OF EVIDENCE

Level III.

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.

Bowel function at preschool and early childhood age in children with long-segment Hirschsprung disease

Bowel dysfunction has been proven to be the most typical complication of long-segment Hirschsprung disease (LSHD). Additionally, bowel dysfunction in preschool and early childhood should be properly assessed, because it may result in persistent bowel dysfunction, social issues, and depression in adolescence and adulthood. This study evaluated bowel function during preschool and early childhood in patients with LSHD. A cross-sectional bowel function score (BFS) questionnaire survey was conducted on 270 infants with short-segment Hirschsprung disease (SSHD) and LSHD who underwent pull-through (PT) between January 2014 and December 2019 at the Children's Hospital of Nanjing Medical University. One hundred ninety patients who consented to the survey were asked to complete the questionnaire and were divided into two groups: the LSHD group (n = 42) and the SSHD group (n = 148). Bowel function outcomes were assessed by using a questionnaire. The total BFS score in the LSHD group was significantly lower than that in the SSHD group (15.0 [14.0, 17.0] vs. 18.0 [16.0, 19.0], p < 0.05) and did not improve with age (p > 0.05). Independent BFS items with lower scores were discovered in LSHD than in SSHD, including the capacity to hold back defecation, feeling/reporting the urge to defecate, frequency, soiling, and accidents (all p < 0.05). After subgroup analysis of follow-up age (3-5 years, 5 ~ 7 years, and > 7 years), there was no difference between the score of ability to hold back defecation over 7 years old and feeling/reporting the urge to defecate over 5 years old (all p > 0.05). The frequency and soiling scores were lower in the LSHD group than in the SSHD group over 5 years of age (all p < 0.05). Fortunately, there was no difference in constipation scores and social problems between the LSHD and SSHD groups in every sub-follow-up group (all p > 0.05).  Conclusion: Overall, bowel function at preschool and early childhood age was poorer in LSHD than in SSHD and did not improve with age. However, the ability to hold back defecation and feeling/reporting the urge to defecate with age in LSHD may be similar to those in SSHD. Simultaneously, the frequency, soiling, and number of accidents were consistently worse in the LSHD group.  Trial registration: This study was retrospectively registered in the ClinicalTrials database.gov (NCT05461924) in August 2022. What is Known: • Bowel function in SSHD is satisfactory or near-normal, and the general consensus is that the longer the aganglionic segment, the worse the bowel function after surgery. • Bowel functional outcomes of LSHD were not defined, and the limited reports of bowel functional outcomes compared with SSHD were extensively varied. Bowel dysfunction at preschool and early childhood may lead to persistent bowel dysfunction, social problems, and depression in adolescence or adulthood. What is New: • Bowel function in preschool and early childhood in patients with LSHD has not been defined and should be thoroughly assessed in a larger group of patients with precise definitions of incontinence or soiling. • The present study was primarily designed to evaluate bowel function at preschool and early childhood age in LSHD compared with SSHD in a relatively large number of HD cases using BFS.

Pediatric colorectal robotic surgery

Robotic colorectal surgery allows adult and pediatric surgeons to overcome the technical limitations of laparoscopic surgery. It also provides improved ergonomics in the field of surgery. Robotic surgery has several advantages in colorectal operations that require complex minimally invasive skills including anorectal malformations, Hirschsprung disease, and inflammatory bowel disease. In this section, we discuss the key aspects of colorectal surgery where robotic instrumentation seems ideal.

Reoperation for Hirschsprung Disease: Two cases of Vanishing Ganglion Cells and Review of the Literature

Hirschsprung disease (HD) is characterized by circumferential aganglionosis of the rectum with variable proximal bowel involvement. The underlying pathogenesis is due to failure of caudal migration of neural crest cells during pre-natal development, causing functional bowel obstruction. Definitive therapy is surgical resection; however, a subset of patients will require reoperation. An important cause of reoperation is the rare but distinct entity described as the ganglion cell "vanishing" phenomenon. In this phenomenon, affected patients have normal circumferential ganglion cells present at the proximal margin during primary resection. They undergo a variable asymptomatic period post-primary resection but ultimately develop recurrent symptoms. Upon reoperation, ganglion cells seemingly vanish and are no longer present in the previously functioning and ganglionated bowel proximal to the initial anastomotic site. To further characterize and investigate this poorly understood pathology, here we present 2 cases of HD patients who required reoperation. Our small series implicates that an immune component may contribute as patient 2 had a brisk neurotrophic eosinophilic infiltrate only present in the reoperation specimen. However, this was not observed in patient 1. Other possible etiologies include post-operative ischemia/hypoxia, visceral neuropathy, or signaling abnormalities within the residual ganglion cells themselves.