BACKGROUND: Transition zone pull-through (TZPT) is incomplete removal of the aganglionic bowel/transition zone (TZ) in patients with Hirschsprung disease (HD). Evidence on which treatment generates the best long-term outcomes is lacking. The aim of this study was to compare the long-term occurrence of Hirschsprung associated enterocolitis (HAEC), requirement of interventions, functional outcomes and quality of life between patients with TZPT treated conservatively to patients with TZPT treated with redo surgery to non-TZPT patients.
METHODS: We retrospectively studied patients with TZPT operated between 2000 and 2021. TZPT patients were matched to two control patients with complete removal of the aganglionic/hypoganglionic bowel. Functional outcomes and quality of life was assessed using Hirschsprung/Anorectal Malformation Quality of Life questionnaire and items of Groningen Defecation & Continence together with occurrence of Hirschsprung associated enterocolitis (HAEC) and requirement of interventions. Scores between the groups were compared using One-Way ANOVA. The follow-up duration lasted from time at operation until follow-up.
RESULTS: Fifteen TZPT-patients (six treated conservatively, nine receiving redo surgery) were matched with 30 control-patients. Median duration of follow-up was 76 months (range 12-260). No significant differences between groups were found in the occurrence of HAEC (p = 0.65), laxatives use (p = 0.33), rectal irrigation use (p = 0.11), botulinum toxin injections (p = 0.06), functional outcomes (p = 0.67) and quality of life (p = 0.63).
CONCLUSIONS: Our findings suggest that there are no differences in the long-term occurrence of HAEC, requirement of interventions, functional outcomes and quality of life between patients with TZPT treated conservatively or with redo surgery and non-TZPT patients. Therefore, we suggest to consider conservative treatment in case of TZPT.

OBJECTIVE: 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.
CONCLUSIONS: 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.

Surgical pathology for Hirschsprung disease (HSCR) occasionally is difficult, especially for those who encounter the disorder infrequently. This article reviews pathologic features of HSCR, considers various specimens the pathologist is required to evaluate, and discusses useful ancillary tests. Potential diagnostic pitfalls are highlighted, and helpful hints are provided to successfully navigate challenging situations. Finally, the article looks forward to new ancillary tests on the horizon and future topics for HSCR research.

Although most children with Hirschsprung disease ultimately do well, many experience a variety of ongoing problems after pull-through surgery. The most common include obstructive symptoms, soiling, enterocolitis and failure to thrive. The purpose of this guideline is to present a rational approach to the management of postoperative obstructive symptoms in children with Hirschsprung disease. The American Pediatric Surgical Association Board of Governors established a Hirschsprung Disease Interest Group. Group discussions, literature review and expert consensus were then used to summarize the current state of knowledge regarding causes, methods of diagnosis, and treatment approaches to children with obstructive symptoms following pull-through for Hirschsprung disease. Causes of obstructive symptoms post-pull-through include mechanical obstruction; persistent or acquired aganglionosis, hypoganglionosis, or transition zone pull-through; internal sphincter achalasia; disordered motility in the proximal intestine that contains ganglion cells; or functional megacolon caused by stool-holding behavior. An algorithm for the diagnosis and management of obstructive symptoms after a pull-through for Hirschsprung disease is presented. A stepwise, logical approach to the diagnosis and management of patients experiencing obstructive symptoms following pull-through for Hirschsprung disease can facilitate treatment. Level of evidence V.