Overview

Definition:
-Intussusception is a pediatric surgical emergency where one segment of the intestine, known as the intussusceptum, telescopes into another segment, the intussuscipiens
-This leads to obstruction, edema, and potential vascular compromise
-Laparoscopic reduction aims to resolve this telescoping minimally invasively.
Epidemiology:
-It is the most common cause of intestinal obstruction in infants and young children, typically occurring between 3 months and 3 years of age
-The peak incidence is between 6 and 12 months
-Idiopathic intussusception is more common in younger infants, while a lead point (e.g., Meckel's diverticulum, lymphoid hyperplasia, polyp) is found in a higher percentage of older children
-The ileocolic region is the most common site (75-90%), followed by ileoileal and colocolic.
Clinical Significance:
-Prompt diagnosis and management are crucial to prevent complications such as bowel ischemia, perforation, peritonitis, and even mortality
-Laparoscopic techniques offer potential benefits of reduced pain, shorter hospital stays, and faster recovery compared to open surgery, making it a preferred approach for suitable candidates.

Clinical Presentation

Symptoms:
-Sudden onset of intermittent, severe, colicky abdominal pain
-Child appears well between episodes
-Vomiting, which may become bilious if obstruction is significant
-Passage of currant-jelly stool (mucus and blood) is a classic sign, but often occurs late or not at all
-Lethargy or irritability may be present
-Abdominal distension can occur in later stages.
Signs:
-Palpable, sausage-shaped abdominal mass, often in the right upper quadrant or epigastrium
-Tenderness on abdominal examination, which may be localized or generalized depending on the duration and severity
-Peritoneal signs (rebound tenderness, guarding) indicate complications like perforation or ischemia
-Signs of dehydration and shock may be present in severe cases
-Digital rectal examination may reveal blood-stained mucus or the intussusceptum.
Diagnostic Criteria:
-Diagnosis is primarily clinical, supported by imaging
-While no formal diagnostic criteria exist, the combination of colicky abdominal pain, palpable mass, and currant-jelly stool in a child within the typical age range is highly suggestive
-Ultrasound findings (target sign, pseudokidney sign) are considered the gold standard for diagnosis.

Diagnostic Approach

History Taking:
-Detailed history of the onset, frequency, and duration of abdominal pain
-Any preceding viral illness or vaccination should be noted
-Character of emesis (non-bilious initially, then bilious)
-Bowel movements (frequency, consistency, presence of blood or mucus)
-Any history of prior abdominal surgery or known gastrointestinal anomalies
-Red flags include persistent, severe pain, signs of peritonitis, or prolonged symptoms suggesting ischemia.
Physical Examination:
-A thorough abdominal examination is paramount
-Inspect for distension or surgical scars
-Palpate for masses and tenderness, noting their location and consistency
-Auscultate bowel sounds, which may be hyperactive early on and diminished with obstruction
-Perform a digital rectal examination to assess for blood or the intussusceptum
-Assess hydration status and vital signs.
Investigations:
-Abdominal Ultrasound: High sensitivity and specificity for diagnosing intussusception
-Findings include a target or pseudokidney appearance of the telescoped bowel loops, absence of peristalsis at the lead point, and presence of free fluid
-Plain abdominal X-rays: May show signs of bowel obstruction (dilated loops, air-fluid levels) and a paucity of gas in the right lower quadrant (if ileocolic)
-Can also help rule out perforation (free air)
-Laboratory tests: Complete blood count (CBC) to assess for leukocytosis and anemia
-electrolytes and renal function tests to assess hydration status and electrolyte balance
-Contrast enema (radiographic or air): Historically used for diagnosis and therapeutic reduction, but less common now with ultrasound
-It can confirm intussusception and potentially reduce it if performed under fluoroscopic guidance.
Differential Diagnosis:
-Gastroenteritis: Common in infants and young children, but typically associated with diarrhea rather than severe colicky pain
-Mesenteric adenitis: Often follows a viral illness and causes abdominal pain, but a mass is usually absent
-Appendicitis: Pain is typically migratory and associated with fever and localized tenderness
-Volvulus: Can cause obstruction, but pain is usually constant and severe
-Pyloric stenosis: Presents with projectile vomiting in younger infants, typically around 4-6 weeks of age.

Management

Initial Management:
-NPO (nil per os) status
-Intravenous fluid resuscitation to correct dehydration and electrolyte imbalances
-Nasogastric tube insertion for gastric decompression if vomiting is significant or obstruction is evident
-Pain management with analgesics
-Close monitoring of vital signs and abdominal status.
Medical Management:
-Not applicable for definitive treatment of intussusception
-Antibiotics are indicated if perforation or peritonitis is suspected.
Surgical Management:
-Indications for surgery include: failure of non-operative reduction, signs of perforation or peritonitis, suspicion of a lead point that cannot be reduced laparoscopically (e.g., tumor), strangulation, or prolonged duration of symptoms leading to bowel compromise
-Laparoscopic reduction is the preferred surgical approach
-It involves diagnostic laparoscopy to confirm the intussusception
-Reduction is then performed gently, manually or with laparoscopic graspers, by milking the intussusceptum out of the intussuscipiens
-Careful assessment of bowel viability is crucial
-If irreducible or if signs of non-viability are present, conversion to open surgery and resection of compromised bowel with or without anastomosis may be necessary
-If a clear lead point is identified and easily removable (e.g., small polyp), it may be resected laparoscopically
-For extensive lead points or non-viability, bowel resection and anastomosis (ileocolic anastomosis, or ileo-rectal anastomosis for certain cases) is performed
-The use of a laparoscopic linear stapler can facilitate resection and anastomosis.
Supportive Care:
-Postoperative care includes continued NPO status until bowel sounds return and flatus is passed, followed by gradual advancement of diet
-Intravenous fluids and analgesia are continued as needed
-Antibiotics are usually continued postoperatively if given preoperatively
-Close monitoring for signs of complications such as leak, ileus, or wound infection
-Early mobilization is encouraged.

Complications

Early Complications:
-Recurrent intussusception (especially if a lead point is present and not addressed)
-Bowel perforation
-Peritonitis
-Intra-abdominal abscess
-Wound infection (in laparoscopic or open surgery)
-Anastomotic leak (if resection performed)..
Late Complications:
-Bowel obstruction due to adhesions
-Chronic abdominal pain
-Short bowel syndrome (rare, following extensive resection).
Prevention Strategies:
-Prompt diagnosis and timely reduction (operative or non-operative) are key to prevent ischemia and perforation
-Careful assessment of bowel viability during surgery
-Meticulous surgical technique to minimize adhesions
-Addressing identifiable lead points during surgery, when feasible.

Prognosis

Factors Affecting Prognosis:
-Timeliness of diagnosis and treatment
-Presence of complications such as perforation or ischemia
-Age of the child
-Underlying cause (lead point)
-Successful reduction (non-operative or operative).
Outcomes:
-With prompt diagnosis and treatment, the prognosis is generally excellent
-Recurrence rates vary but are typically around 2-10%
-Laparoscopic reduction is associated with shorter hospital stays and quicker recovery compared to open surgery
-Outcomes after resection and anastomosis are generally good, with recurrence rates influenced by the nature of the lead point.
Follow Up:
-Follow-up is typically recommended to monitor for recurrence, especially in children with identified lead points
-This may involve clinical assessment and potentially imaging if symptoms recur
-For children who have undergone bowel resection, long-term follow-up may be necessary to assess for growth and potential nutritional deficiencies.

Key Points

Exam Focus:
-The most common site is ileocolic
-Peak incidence is 6-12 months
-Ultrasound is diagnostic (target sign)
-Laparoscopic reduction is preferred for suitable cases
-Indications for surgery include failed reduction, peritonitis, or non-viability
-Recurrence is a known complication.
Clinical Pearls:
-Always consider intussusception in an infant with colicky abdominal pain, even without currant-jelly stool
-The palpable mass is often mobile and may be mistaken for constipation
-Be prepared to convert to open surgery if laparoscopic reduction is not feasible or if bowel viability is questionable.
Common Mistakes:
-Delayed diagnosis due to misinterpretation of symptoms as simple gastroenteritis
-Failure to adequately assess bowel viability during surgery
-Inadequate fluid resuscitation in critically ill children
-Aggressive non-operative reduction attempts in the presence of peritoneal signs.