Overview
Definition:
Hirschsprung disease (HSCR) is a congenital anomaly characterized by the absence of ganglion cells (aganglionosis) in the distal bowel, most commonly the rectum and sigmoid colon
This leads to a functional obstruction, as the affected segment cannot relax and propel stool
The laparoscopic pull-through is a minimally invasive surgical technique used to resect the aganglionic segment and pull down the normally innervated bowel to the anus.
Epidemiology:
Hirschsprung disease affects approximately 1 in 5,000 live births
It is more common in males (4:1 male to female ratio)
Approximately 10-20% of cases are associated with other congenital anomalies, including Down syndrome, congenital heart defects, and neurological disorders
Familial cases account for about 12% of HSCR, with a higher recurrence risk.
Clinical Significance:
Hirschsprung disease is a critical diagnosis in pediatric surgery due to the potential for severe complications such as enterocolitis, perforation, and chronic constipation
Early diagnosis and appropriate surgical management are crucial for achieving good long-term outcomes and preventing significant morbidity
Understanding the laparoscopic pull-through technique is essential for residents preparing for DNB and NEET SS examinations.
Clinical Presentation
Symptoms:
Neonates: Delayed passage of meconium (typically >24-48 hours after birth)
Abdominal distension
Bilious vomiting
Constipation
Enterocolitis
Older children: Chronic constipation resistant to laxatives
Stool soiling
Abdominal pain
Poor growth
Recurrent enterocolitis.
Signs:
Abdominal distension and palpable stool in the dilated proximal colon
Empty rectal vault on digital rectal examination
Explosive expulsion of stool and gas after rectal examination
Absence of stool in the rectal vault
Tenderness and signs of peritonitis in cases of enterocolitis.
Diagnostic Criteria:
Diagnosis is primarily confirmed by rectal biopsy demonstrating the absence of ganglion cells in the submucosal (Meissner's) and myenteric (Auerbach's) plexuses
Ancillary investigations like contrast enema and anorectal manometry support the diagnosis but are not definitive
Definitive diagnosis requires histological confirmation of aganglionosis.
Diagnostic Approach
History Taking:
Detailed history of meconium passage time
Pattern and duration of constipation
Stool characteristics
Episodes of vomiting
Fever, or other signs suggestive of enterocolitis
Family history of Hirschsprung disease or similar bowel issues
Associated congenital anomalies.
Physical Examination:
Assess for abdominal distension, tenderness, and bowel sounds
Perform a digital rectal examination to assess rectal tone, the presence of stool, and the calibre of the distal rectum
Look for any signs of dehydration or systemic illness
Assess for associated congenital anomalies.
Investigations:
Contrast enema (barium or water-soluble contrast): May show a narrowed aganglionic distal segment with a dilated proximal segment, a transition zone, and the characteristic 'funnel' shape
Should be performed after bowel preparation to avoid false positives
Anorectal manometry: Assesses the rectoanal inhibitory reflex (RAIR), which is absent in Hirschsprung disease
Rectal biopsy: The gold standard for diagnosis
Can be suction biopsy (less invasive, good for screening) or full-thickness biopsy (more definitive)
Histology confirms absence of ganglion cells and presence of hypertrophied nerve fibers.
Differential Diagnosis:
Functional constipation
Meconium ileus
Intestinal atresia
Malrotation with volvulus
Pelvic mass
Imperforate anus
Congenital hypoganglionosis.
Management
Initial Management:
For neonates with suspected HSCR and signs of obstruction: Bowel decompression with a nasogastric tube
Rectal irrigations to relieve distension
Antibiotics if enterocolitis is suspected
Surgical consultation for definitive management.
Medical Management:
Primarily supportive and adjunctive
Prophylactic antibiotics for patients with a history of enterocolitis
Stool softeners and laxatives can be used for symptomatic relief in milder cases or postoperatively, but are not curative for HSCR itself.
Surgical Management:
The goal is to resect the aganglionic segment and restore intestinal continuity with an endorectal pull-through procedure
Current standard of care is laparoscopic pull-through
Types include: Primary pull-through (Swenson, Soave, Duhamel) performed in one stage
Two-stage procedures involve a diverting colostomy initially, followed by pull-through later
Laparoscopic approach offers advantages such as smaller incisions, reduced pain, and faster recovery compared to open surgery
Key steps involve mobilization of the colon, identification of the aganglionic segment, and pull-through of the normally innervated bowel to the anus, often with an antimesenteric stitch to facilitate mucosal apposition.
Supportive Care:
Postoperative care includes pain management, fluid and electrolyte balance, nutritional support (often TPN initially), and monitoring for complications
Gradual reintroduction of oral feeds
Education for parents regarding long-term bowel management.
Complications
Early Complications:
Anastomotic leak or stricture
Wound infection
Intra-abdominal abscess
Enterocolitis
Bleeding.
Late Complications:
Persistent constipation or soiling
Fecal incontinence
Rectal prolapse
Enterocolitis (can occur years later)
Growth failure
Stricture at the anastomosis.
Prevention Strategies:
Adequate resection of the aganglionic segment
Careful surgical technique to avoid injuring sphincteric structures
Prompt recognition and management of enterocolitis
Meticulous postoperative bowel management including adequate hydration and stool softeners
Genetic counseling for familial cases.
Prognosis
Factors Affecting Prognosis:
Length of the aganglionic segment (shorter segments have better outcomes)
Presence of associated anomalies
Development of postoperative enterocolitis
Quality of surgical technique and postoperative care
Patient compliance with long-term management.
Outcomes:
With successful surgery and appropriate follow-up, most children achieve good bowel control and growth
Long-term continence rates are generally high, but some degree of soiling or constipation may persist in a significant minority of patients
Laparoscopic techniques have improved functional outcomes and reduced hospital stay.
Follow Up:
Regular follow-up is essential, particularly in the first few years post-surgery
This includes assessment of growth, bowel function (frequency, consistency, soiling), and management of any complications
Education and support for families are crucial for long-term success.
Key Points
Exam Focus:
The gold standard for HSCR diagnosis is rectal biopsy
Laparoscopic pull-through is the current preferred surgical technique
Key complications include enterocolitis and chronic constipation/soiling
DNB/NEET SS questions often focus on diagnostic steps, surgical indications, and management of complications.
Clinical Pearls:
Always consider HSCR in neonates with delayed meconium passage
A thorough digital rectal exam can be diagnostic in acute presentations
Postoperative enterocolitis requires aggressive management, often including re-exploration
Early surgical intervention improves long-term functional outcomes.
Common Mistakes:
Mistaking functional constipation for HSCR without adequate investigation
Incomplete resection of the aganglionic segment
Underestimating the risk and severity of enterocolitis
Inadequate postoperative bowel management leading to persistent symptoms.