Spontaneous intestinal perforation vs NEC:What is the difference??

Dr Varsha Atul Shah

Spontaneous intestinal perforation Isolated perforation of newborn Typically at terminal ileum Separate clinical entity from NEC* Differentiation is important as there are

management considerations

*J Am Coll Surg. 2002 Dec;195(6):796-803. Spontaneous localized intestinal perforation in very-low-birth weight infants: a distinct clinical entity different from necrotizing

enterocolitis

epidemiology

Commonly found in VLBW, ELBW Risk~2-3 % in VLBW, 5% in ELBW Median gestational age 25-27 weeks Median BW 670-973g More frequent in male infants

Risk factors

Prematurity Antenatal1. Severe placental chorioamnionitis*2. ? Glucocorticoids/NSAIDS Postnatal1. Early postnatal glucocorticoids@2. ? Indocid

* Maternal factors in extremely low birth weight infants who develop spontaneous intestinal perforation. Ragouilliaux CJ; Keeney SE; Hawkins HK; Rowen JL Pediatrics 2007. @Focal small bowel perforation: an adverse effect of early postnatal dexamethasone therapy in extremely low birthweight infants. Gordon PV; Young ML; Marshall DD J Perinatol. 2001 Apr-May;21(3)New insights into spontaneous intestinal perforation using a national data setAttridge JT; Clark R; Gordon PV J Perinatol. 2006 Nov;26(11):667-70. Epub 2006 Oct 5.

Pathology and pathogenesis

Single isolated perforation Typically in terminal iluem, but also reported

in jejunum, colon Focal hemorrhagic necrosis with well defined

margins seen(in contrast to ischemic, coagulative necrosis in NEC)

Bowel proximal and distal to perforation normal

Clinical presentation

SIP NEC

First week of life, median age 7(0-15)

After first week,

Median age 15

Abdominal distension, bluish discoloration(groin, scrotum)

Hypotension

Abdominal distension

Abdominal erythema

Crepitus, induration

Pneumoperitoneum, gasless abdomen

Pneumatosis intestinalis, portal venous gas, transient thickening of intestinal wall, fixed dilated SB loops, pneumoperitoneum

Associated sepsis due to CONS, fungemia

Leukocytosis, raised ALP, bilirubin, decreased platelet, hct

Clinical diagnosis based upon: Clinical presentation Physical examination Abdominal radiographs support diagnosis

Definitive diagnosis :

Direct visualization of intestinal perforation in setting of otherwise healthy appearing small bowel

Management

NBM, drip and suck Fluid resuscitation Intravenous antibiotics Surgical treatment1. Definitive treatment2. Exploratory laparotomy with bowel

resection3. Primary peritoneal drainage

Primary peritoneal drainage

Avoids laparotomy, need for GA and transport Many do recover without any further surgical

intervention Laparotomy indicated if:1. Reaccumulation of free air after drain removed,

indicating perforated bowel did not seal2. Fistula with intestinal drainage that fails to close3. Bowel obstruction secondary to adhesions or

stricture at site of perforation

Long term outcome

Survival rates of 64-90% Neurodevelopmental outcome better than those with

NEC* Increased risk to develop ROP and PVL compared

to controls

*Intestinal perforation in very low birth weight infants: growth and neurodevelopment at 1 year of age.

Adesanya OA; O'Shea TM; Turner CS; Amoroso RM; Morgan TM; Aschner JL J Perinatol. 2005 Sep;25(9):583-9.

NEC

Ischaemic necrosis of intestinal mucosa, associated with inflammation, invasion of enteric gas forming organisms and dissection of gas into muscularis and portal venous system.

NEC

1-3 per 1000 live births Predominently in prems, up to 6-7% in VLBW Incidence decreases with increasing GA, BW Males and females equally affected Sometimes occurs in clusters, associated with

epidermics Reported mortality of 15-30% 13% occur in term infants

Pathogenesis

Terminal ileum and colon Entire GIT in severe cases Pathogenesis remains unknown Heterogeneous disease results from multiple factors that result in mucosal injury in

susceptible host1. Prematurity2. Microbial bowel overgrowth3. Milk feeding4. Impaired mucosal defense5. Circulatory instability of intestinal tract6. Medications7. CHD, perinatal asphyxia, polycythemia, sepsis, respiratory

disease8. Inflammation

Clinical presentation

Timing of onset of symptoms varies, inversely related to GA

Systemic signs

1. Nonspecific (apnea, resp failure, lethargy, poor feeding, temp instability)

2. Hypotension Abdominal signs

- distension, gastric retention, tenderness, vomiting, diarrhoea, rectal bleeding, bilious aspirates

Bells staging

Classifies severity of NEC based on severity of systemic, intestinal, radiographic findings

Treatment directed at clinical signs rather than particular stage of NEC

Bells staging

Diagnosis

Clinical Radiologic findings

Clinical

Abdominal distension Rectal bleeding

Radiological

AXR/lateral decubitus (left side down) Confirm diagnosis/follow progression of disease Abnormal gas patterns, dilated loops of bowel(ileus) Pneumatosis intestinalis(hallmark of NEC) Pneumoperitoneum (football sign) Sentinel loops(necrotic/perforation) Portal venous gas

Abdominal Ultrasound

Bowel wall with central echogenic focus, hypoechoic rim(pseudo-kidney)-necrotic bowel and imminent perforation

Intermittent gas bubbles in liver parenchyma, portal venous system

Free gas, focal fluid collection

Supportive investigations

FBC(neutropenia, thrombocytopenia) Coagulation studies(evidence of DIC) Electrolytes (hyponatraemia, hyperglycaemia,

metabolic acidosis) CRP Septic workup Stool c/s, CD toxin Stool occult blood

Differential diagnosis

Pneumatosis coli Infectious enterocolitis Intestinal obstruction secondary to hirschsprung,

ileal atresia, volvulus, meconium ileus, intussusception

SIP Anal fissures Neonatal appendicitis Cow’s milk protein allergy

Management

Depends on severity of illness Medical management Surgical management

Medical management

Supportive care-NBM, drip and suck, TPN, fluid replacement, correction of hematological and metabolic abnormalities, cardiorespiratory support

Antibiotic therapy Close monitering and radiologic monitering(6-

8 hrly)

Surgical intervention

Perforation/severe peritonitis unremitting clinical deterioration despite

medical management suggesting extensive necrosis

presence of abdo mass, ascites or intestinal obstruction

Primary peritoneal drainage Laparotomy with bowel excision

Complications

Acute: cardioresp, metabolic complications, DIC Late: GIT complications (short bowel syndrome,

intestinal strictures, increased frequency of bowel movements)

Rare: enterocele, enterocolic fistula, intra-abd abscess

Mortality Impaired Growth and neurodevelopmental outcome

Clinical presentation

SIP NEC

First week of life, median age 7(0-15) After first week,

Median age 15

Abdominal distension, bluish discoloration (groin, scrotum)

Hypotension

Abdominal distension

Abdominal erythema

Crepitus, induration

Pneumoperitoneum, gasless abdomen Pneumatosis intestinalis, portal venous gas, transient thickening of intestinal wall, fixed dilated SB loops, pneumoperitoneum

Associated sepsis due to CONS, fungemia

Concomitant bacteremia

Leukocytosis, raised ALP, bilirubin, decreased platelet, hct

Thrombocytopenia,neutropenia, hypoNa, hyperglycaemia, metabolic acidosis