Overview
Definition:
The Soave pull-through procedure is a surgical technique for treating Hirschsprung disease
It involves removing the aganglionic segment of the colon and rectum while preserving the rectal mucosa and muscularis propria, and then pulling through a healthy, ganglionic segment of colon to create a new rectal anastomosis.
Epidemiology:
Hirschsprung disease affects approximately 1 in 5,000 live births, with a higher incidence in males (4:1 ratio) and individuals with Down syndrome
The aganglionic segment is most commonly found in the rectosigmoid region.
Clinical Significance:
Hirschsprung disease is a critical congenital anomaly causing functional intestinal obstruction due to the absence of ganglion cells in the distal bowel wall
Early diagnosis and definitive surgical management, such as the Soave pull-through, are crucial for preventing severe complications like enterocolitis and ensuring normal bowel function and growth in affected children.
Clinical Presentation
Symptoms:
Failure to pass meconium within the first 48 hours of life
Abdominal distension
Bilious vomiting
Constipation or obstipation
Poor feeding
Intermittent diarrhea
Growth failure
Episodes of explosive watery stools following rectal examination.
Signs:
Abdominal distension with visible bowel loops
Palpable stool in the dilated proximal colon
Empty rectal vault on digital examination
Squirt sign (explosive expulsion of gas and stool upon rectal examination)
Peritonitis in cases of perforation or enterocolitis.
Diagnostic Criteria:
Diagnosis is confirmed by a contrast enema demonstrating a narrow aganglionic segment with a dilated, normally innervated proximal colon, and crucially, by a rectal biopsy demonstrating the absence of ganglion cells in the submucosal (Meissner's) and myenteric (Auerbach's) plexuses.
Diagnostic Approach
History Taking:
Detailed birth history including passage of meconium
Duration and pattern of constipation
Associated symptoms like vomiting or diarrhea
History of any previous interventions or investigations
Family history of Hirschsprung disease or other gastrointestinal anomalies.
Physical Examination:
Assess for abdominal distension, tenderness, and presence of bowel sounds
Palpate for enlarged colon
Perform a digital rectal examination to assess for anal tone, rectal patency, and presence of stool
Observe for the "squirt sign."
Investigations:
Abdominal X-ray: may show distended loops and absence of gas in the rectum
Contrast enema (barium or water-soluble contrast): outlines the aganglionic segment and proximal dilation, showing a transition zone
Rectal biopsy: the gold standard
assessed for absence of ganglion cells using H&E and special stains (e.g., acetylcholinesterase)..
Differential Diagnosis:
Functional constipation
Meconium ileus (especially in cystic fibrosis)
Intestinal malrotation with volvulus
Small left colon syndrome
Idiopathic intestinal pseudo-obstruction
Anorectal malformations.
Management
Initial Management:
For suspected Hirschsprung disease with obstruction or enterocolitis: bowel decompression via rectal tube
Nasogastric tube insertion for gastric decompression
Intravenous fluids for hydration and electrolyte correction
Antibiotics for enterocolitis
Nutritional support.
Medical Management:
Primarily supportive and preparatory
Bowel irrigation to empty the colon
Antibiotics to treat or prevent enterocolitis
Adequate hydration and electrolyte balance.
Surgical Management:
Definitive treatment is surgical resection of the aganglionic segment and pull-through of healthy colon
The Soave procedure (endorectal pull-through) involves mucosectomy of the aganglionic rectum, leaving the muscularis propria, and pulling down ganglionic colon through this sleeve.
Postoperative Care:
Close monitoring of vital signs and fluid balance
Pain management
Gradual reintroduction of oral feeds
Monitoring for signs of enterocolitis, anastomotic leak, or wound infection
Stoma care if a temporary diverting ostomy was performed
Bowel mobilization exercises
Long-term follow-up for bowel function and growth.
Complications
Early Complications:
Anastomotic leak or dehiscence
Enterocolitis (the most serious)
Sepsis
Wound infection
Bleeding
Injury to adjacent structures (e.g., urinary tract).
Late Complications:
Anastomotic stricture
Rectal prolapse
Persistent constipation or fecal incontinence (soiling)
Irritable bowel syndrome-like symptoms
Failure to thrive
Stoma-related complications (if applicable).
Prevention Strategies:
Adequate bowel preparation before surgery
Careful surgical technique to ensure healthy margins and secure anastomosis
Meticulous postoperative care, including prompt recognition and management of enterocolitis
Diligent stoma care and wound management
Regular follow-up to monitor for and manage late complications.
Prognosis
Factors Affecting Prognosis:
Length of the aganglionic segment (shorter segments generally have better outcomes)
Presence and severity of enterocolitis
Early diagnosis and prompt surgical intervention
Quality of surgical technique
Postoperative care and management of complications.
Outcomes:
The majority of children achieve good to excellent long-term bowel function after a successful pull-through procedure
However, some may experience chronic constipation, soiling, or fecal incontinence requiring ongoing management
Early and definitive treatment significantly improves outcomes.
Follow Up:
Regular follow-up appointments are essential, particularly in the first few years post-surgery
This includes monitoring for growth and development, assessing bowel habits, and addressing any issues like constipation, soiling, or signs of enterocolitis
Serial rectal irrigations may be needed in some cases
Long-term evaluation of continence and quality of life is important.
Key Points
Exam Focus:
Soave procedure involves endorectal mucosectomy with preservation of muscularis propria
Gold standard for diagnosis is rectal biopsy showing absence of ganglion cells
Enterocolitis is the most feared complication
Key goal is to restore normal bowel continuity and function.
Clinical Pearls:
Always consider Hirschsprung disease in neonates failing to pass meconium
A contrast enema is helpful for diagnosis but rectal biopsy is definitive
Early recognition and management of enterocolitis are life-saving
Postoperative bowel irrigation may be needed for persistent constipation.
Common Mistakes:
Delayed diagnosis leading to severe enterocolitis or malnutrition
Inadequate biopsy specimen or misinterpretation of histology
Incomplete resection of the aganglionic segment
Failure to recognize and aggressively treat enterocolitis
Overly aggressive mucosectomy leading to devascularization of the pulled-through segment.