Overview
Definition:
Necrotizing enterocolitis (NEC) is a serious gastrointestinal emergency in neonates characterized by inflammation and necrosis of the intestinal wall
Laparotomy is indicated for suspected or confirmed intestinal perforation, intractable sepsis, or portal venous gas
Stoma creation, typically an ileostomy or colostomy, is often a necessary component of surgical management to divert fecal stream and allow bowel rest.
Epidemiology:
NEC primarily affects premature infants, with incidence increasing with decreasing gestational age and birth weight
Overall incidence ranges from 1-8% in NICU admissions, with surgical NEC occurring in about 10-30% of NEC cases
Mortality rates for surgical NEC can be as high as 30-50%.
Clinical Significance:
NEC represents a critical surgical emergency in neonates, demanding prompt diagnosis and intervention
Understanding the indications for laparotomy, surgical techniques, and post-operative stoma care is vital for surgical residents preparing for DNB and NEET SS examinations, as well as for managing critically ill infants and improving outcomes.
Clinical Presentation
Symptoms:
Abdominal distension
Bloody stools
Vomiting (bilious or non-bilious)
Lethargy and irritability
Apnea and bradycardia
Poor feeding tolerance
Abdominal tenderness and erythema.
Signs:
Vital sign instability (hypotension, hypothermia, tachycardia)
Palpable abdominal mass or rigidity
Pneumoperitoneum on imaging
Dilated bowel loops
Portal venous gas on imaging
Ascites.
Diagnostic Criteria:
Modified Bell staging criteria are commonly used: Stage I (suspected NEC) - vague symptoms
Stage II (definite NEC) - intestinal symptoms with focal findings
Stage III (advanced NEC) - intestinal perforation or systemic instability
Surgical intervention is typically reserved for Stage IIB and Stage III disease.
Diagnostic Approach
History Taking:
Gestational age
Birth weight
Feeding history (prematurity, breast milk vs
formula)
Previous episodes of NEC or abdominal surgery
Use of antenatal steroids
Presence of congenital anomalies.
Physical Examination:
Thorough abdominal examination focusing on distension, tenderness, erythema, masses, and signs of peritonitis (rigidity, guarding)
Assess for signs of systemic compromise (respiratory distress, cardiovascular instability).
Investigations:
Abdominal X-ray (supine and cross-table lateral views): Dilated bowel loops, intramural gas (pneumatosis intestinalis), portal venous gas, free air (pneumoperitoneum)
Complete blood count (CBC): Leukocytosis or leukopenia, thrombocytopenia
Electrolytes, blood gas analysis: Metabolic acidosis
Blood cultures: Sepsis workup
Ultrasound: Can detect free air and assess bowel wall thickness.
Differential Diagnosis:
Intestinal obstruction (malrotation, atresia)
Sepsis
Colitis
Hirschsprung disease
Intussusception
Congenital abdominal anomalies.
Surgical Management
Indications:
Confirmed intestinal perforation (pneumoperitoneum on imaging)
Intractable abdominal distension and tenderness refractory to medical management
Clinical deterioration despite maximal medical therapy
Portal venous gas with systemic instability
Fixed, dilated bowel loop on imaging suggesting ischemia or perforation.
Procedure Steps:
The goal is to resect necrotic or perforated bowel and, if necessary, create a stoma
A midline or paramedian laparotomy is performed
The extent of resection is determined by the viability of the bowel
minimal resection of non-viable bowel is preferred initially
If resection involves a significant portion of the small bowel or the colon, a stoma (ileostomy or colostomy) is typically created
The stoma can be end or loop, depending on the bowel ends and the planned reconstruction
If diffuse NEC is present without a clear perforation, but with severe intestinal compromise, a "second look" laparotomy may be planned.
Stoma Considerations:
Ileostomy is more common in NEC due to the involvement of the ileocecal region
The stoma should be well-constructed, with adequate length and caliber
Parental education on stoma care is crucial
Stoma sites should be carefully selected to avoid pressure points and facilitate appliance adherence.
Intestinal Resection:
Resection of necrotic or perforated segments
Preservation of as much viable bowel as possible
Ligation of mesenteric vessels to control bleeding
Primary anastomosis is rarely performed in the acute setting of NEC due to high risk of dehiscence.
Postoperative Care
Supportive Care:
Intensive care unit (ICU) monitoring
Mechanical ventilation
Fluid and electrolyte management
Blood product support
Aggressive antibiotic therapy
Nutritional support (parenteral nutrition initially).
Stoma Care:
Regular stoma output monitoring
Skin barrier protection
Adequate hydration and electrolyte replacement
Management of potential stoma complications (retraction, prolapse, stenosis).
Pain Management:
Adequate analgesia to ensure comfort and facilitate recovery
Opioids are often required initially, transitioned to non-opioid analgesics as tolerated.
Monitoring For Complications:
Close observation for signs of sepsis, wound infection, intra-abdominal abscess, and further bowel compromise.
Complications
Early Complications:
Sepsis
Wound dehiscence
Intra-abdominal abscess
Further bowel necrosis
Stoma complications (necrosis, retraction, prolapse)
Short bowel syndrome.
Late Complications:
Stricture formation at the anastomosis site (if primary anastomosis attempted later) or stoma site
Adhesions leading to bowel obstruction
Failure to thrive
Malabsorption syndromes
Cholestasis associated with long-term parenteral nutrition.
Prevention Strategies:
Early recognition and medical management of NEC
Timely surgical intervention when indicated
Careful surgical technique to minimize bowel resection and preserve length
Meticulous stoma construction and post-operative stoma care
Prompt initiation of parenteral nutrition.
Prognosis
Factors Affecting Prognosis:
Gestational age and birth weight
Extent of bowel involved
Presence of perforation and associated sepsis
Need for extensive bowel resection (leading to short bowel syndrome)
Post-operative complications.
Outcomes:
Survival rates vary significantly based on the severity of NEC and extent of surgery, ranging from 50-80% for surgically treated infants
Infants surviving NEC often face long-term gastrointestinal issues, requiring multidisciplinary management.
Follow Up:
Regular growth monitoring
Nutritional assessment
Gastroenterology follow-up for malabsorption or feeding issues
Surgical follow-up for stoma reversal (if planned) or management of adhesions
Developmental assessments.
Key Points
Exam Focus:
Indications for emergent laparotomy in NEC are clear: pneumoperitoneum, severe clinical deterioration, or fixed dilated loop
Stoma creation is essential for fecal diversion and bowel rest
Differentiate medical vs
surgical NEC
Bell staging criteria are high-yield.
Clinical Pearls:
When in doubt about bowel viability, err on the side of caution and resect only frankly necrotic bowel, planning a "second look" if necessary
Optimal stoma siting is critical for infant well-being and ease of care
Early parenteral nutrition is key for intestinal rest and healing.
Common Mistakes:
Delaying surgical intervention when indicated
Resecting too much bowel unnecessarily
Inadequate stoma construction or post-operative stoma care
Underestimating the risk of sepsis or intra-abdominal abscess.