What is the approach to primary endorectal pull-through surgery in children with Hirschsprung's disease?

Primary Endorectal Pull-Through Surgery in Children with Hirschsprung's Disease

Primary transanal endorectal pull-through (TEPT) is the preferred surgical approach for children with rectosigmoid Hirschsprung's disease, offering excellent outcomes without the need for preliminary colostomy, with shorter hospital stays and lower morbidity compared to traditional staged procedures.

Surgical Approach Selection

The modern approach to Hirschsprung's disease has evolved toward single-stage procedures that avoid colostomy:

• Primary transanal endorectal pull-through is the optimal technique for rectosigmoid disease, which represents the majority of cases, as it avoids transabdominal exploration while achieving excellent functional outcomes 1, 2
• Laparoscopic-assisted endorectal pull-through is an effective alternative, particularly useful for mobilizing higher transition zones or when retroperitoneal fixation of the descending colon requires dissection beyond what the transanal route can achieve 1, 3
• The choice between purely transanal versus laparoscopic-assisted approach depends on the level of the transition zone—transanal alone is limited when the aganglionic segment extends significantly beyond the rectosigmoid region 2

Optimal Timing and Patient Selection

Age is not a contraindication to primary pull-through, and the procedure can be performed safely from the neonatal period through childhood:

• Younger patients at the time of surgery have better long-term functional outcomes, with faster recovery of normal stooling patterns and fewer complications 4
• Primary pull-through can be performed in patients ranging from a few days old to 6 years, though operating earlier (ideally before 2 years) is associated with superior results 1, 4
• Patients with aganglionic segments less than 30 cm have significantly better outcomes compared to those with longer segments (P < .05), with lower rates of postoperative stooling disorders 4

Preoperative Preparation

The extent of preoperative bowel preparation varies based on patient age and degree of colonic dilation:

• Infants and young children (under 2 years) require minimal preparation—typically 3 days of bowel preparation similar to standard colorectal surgery 2, 5
• Older children with substantial fecal impaction require more extensive preparation, potentially up to 2 weeks of preoperative saline enemas to evacuate the dilated colon 2
• Some centers have successfully eliminated preoperative colon preparation entirely in their modified TEPT protocols without increased complications 5

Technical Execution

The procedure follows a standardized sequence with specific technical considerations:

Transanal Approach

• Full-thickness rectal biopsy at 1-2 cm above the dentate line is obtained for frozen section confirmation of ganglion cells 2
• Rectal mucosectomy begins 0.5 cm proximal to the dentate line and extends into the intraperitoneal rectum 2
• The muscular sleeve is divided circumferentially at 3-4 cm proximal to the dentate line, exposing the intraperitoneal rectum and allowing full-thickness mobilization 2
• The aganglionic segment is resected and normal colon is pulled through to anastomose with the distal anorectal mucosa 5-10 mm above the pectinate line 3

Laparoscopic-Assisted Technique

• Three 5-mm abdominal ports provide adequate access for laparoscopic mobilization of the sigmoid colon and proximal rectum 3
• Laparoscopic visualization clearly delineates pelvic structures even in small infants, facilitating safe dissection 3
• A submucosal sleeve is developed transanally to meet the laparoscopic dissection from above 3

Technical Refinements

• General anesthesia combined with regional sacral anesthesia improves operative conditions 5
• Use of only one purse-string suture in the rectal mucosa before submucosal dissection simplifies the procedure 5
• Avoid retractors and electrocautery during submucosal dissection to minimize tissue trauma and thermal injury 5

Expected Operative Times and Hospital Stay

• Operative time ranges from 90 minutes to 3.5 hours, with laparoscopic procedures averaging just over 2 hours—comparable to open procedures 1, 2, 3
• Hospital stay is significantly shorter with primary pull-through: 3.5-7 days for infants and young children, though older children with significant fecal impaction may require 10-28 days 1, 2
• Oral feeding typically begins within 24-48 hours postoperatively, earlier than with traditional staged approaches 5

Postoperative Outcomes and Complications

Early Complications

• Perineal dermatitis is the most common early complication (occurring in approximately 23% of patients), managed conservatively with barrier creams 5
• Anastomotic strictures occur in approximately 8-9% of cases, typically managed with dilation 5
• Wound infection rates are lower with TEPT compared to traditional transabdominal approaches 5
• Early postoperative enterocolitis can occur, particularly in older children, requiring urgent treatment with rectal tube decompression 2

Long-Term Functional Outcomes

• Most patients (79-80%) achieve satisfactory results without complications at 6-24 months follow-up 4
• Normal stooling patterns develop within 3 weeks postoperatively in the majority of patients, with mean stool frequency of 1-2 times per day 2, 4
• Postoperative soiling occurs in approximately 15% of patients, constipation in 9%, and enterocolitis in 5% 4
• No cases of fecal incontinence, cuff infection, or anastomotic leak were reported in major series 4
• Long-term continence rates are comparable to traditional Duhamel procedures, with no significant difference in complete continence or total incontinence 5

Critical Success Factors

The following factors predict optimal outcomes:

• Shorter aganglionic segment length (< 30 cm) is associated with significantly fewer stooling disorders and faster functional recovery 4
• Younger age at operation correlates with better long-term stooling patterns 4
• Absence of preoperative enterocolitis improves postoperative course 5
• Adequate mobilization of the colon to ensure a tension-free anastomosis prevents complications 2

Common Pitfalls to Avoid

• Do not delay surgery in older children with significant fecal impaction—these patients require more extensive preoperative preparation and have higher rates of early postoperative complications including enterocolitis 2
• Do not attempt purely transanal pull-through when the transition zone extends significantly beyond the rectosigmoid—retroperitoneal fixation of the descending colon cannot be adequately dissected transanally and requires laparoscopic assistance 2
• Do not use electrocautery during transanal submucosal dissection—this increases the risk of thermal injury and complications 5
• Do not assume all patients require colostomy—primary pull-through avoids the morbidity, inconvenience, and additional procedures associated with staged approaches 1, 3