miscellaneous pediatric gi · : esophageal hiatus • hiatus: a break or interruption. therefore,...

Common Pediatric GI Pathologies:A General Pediatrician’s Perspective

Erin Kreml, M.D.LaNeece Marley, M.D.

Mark Sicilio, M.D.

Wednesday, October 9, 20198:00 a.m.

Topics

• Acute surgical abdomen• Esophageal atresia (EA)• Tracheoesophageal fistula (TEF)• Congenital diaphragmatic hernia• Pyloric stenosis• Duodenal atresia• Malrotation/volvulus• Necrotizing enterocolitis (NEC)• Short bowel syndrome• Meckel’s diverticulum• Intussusception• Appendicitis • Hirschsprung disease

Acute Abdominal Symptoms: Etiologies of Acute Surgical Abdomen

Neonate• Gastroschisis• Omphalocoele• Duplication• Obstruction• Necrotizing enterocolitis• Hirschsprung disease

Infant• Intussusception• Malrotation/volvulus• Incarcerated hernia• Appendicitis

Preschool• Intussusception• Postoperative adhesions• Appendicitis• Primary peritonitis

School age• Appendicitis• Intussusception• Meckel’s diverticulum• Pancreatitis• Cholecystitis

Mimickers of Acute Surgical Abdomen• Pharyngitis• Lower lobe pneumonia• Constipation• Abdominal wall injury/infection• Gastroenteritis• Urinary tract infection/stones• Inflammatory bowel disease• Diabetic ketoacidosis• Hepatitis

• Cystic fibrosis• Sickle cell pain crisis• Porphyria• Henoch-Schöenlein

purpura • Nephrotic syndrome• Collagen vascular disease• Poisoning• Psychiatric disorders

Esophageal Atresia (EA)

• Most frequent congenital anomaly of the esophagus • Blind pouch of proximal esophagus ends at T2-T4• EA has no communication between proximal and distal

portions of the esophagus

Esophageal Atresia (EA)/ Tracheoesophageal Fistula (TEF)• Often associated with other congenital anomalies─VACTERL anomalies: vertebral, anorectal, cardiac,

tracheal, esophageal, renal, limb─More than 90% of EA are associated with TEF─Next most common associations are cardiac defects

EA/TEF: Presentation• In utero: polyhydramnios

– Polyhydramnios is present in many conditions, but it is present in ~95% of EA

• Neonatal course– Symptoms within first few hours of life– Frothing/bubbling at mouth and nose– Regurgitation of food– Coughing, cyanosis, and respiratory distress

(exacerbated with feedings)• TEF allows for aspiration and pneumonitis

– Pneumonitis in TEF is worse with gastric secretions (from distal connection) than with pharyngeal secretions (from proximal connection)

Types of EA/TEF

EA/TEF: Types

EA/TEF:Types

• H-type TEF (without EA) can present later in life: in infancy, the feeding tube can advance so there is little suspicion of the presence of an anomaly (unlike with other EA/TEF combinations or complete EA)

EA/TEF: Diagnosis

• Diagnosis– Primarily is made through the inability to pass a

NG/OG tube, then by – Plain films

• Coiled tube in the esophageal pouch• Airless abdomen in pure EA• Air-filled, distended abdomen in most with EA/TEF

EA/TEF: Treatment

• Treatment – Esophageal suctioning– Ligation of the fistula– May temporarily place a G-tube (gastrostomy-tube

[feeding tube]) in preemies or complicated patients– Definitive is surgical anastomosis

• Primary with an end-to-end attachment of the atretic ends

• If the gap is too large, the gastric, jejunal or colonic segments can be used

EA/TEF: Complications

• Anastomotic leak (~15-20%)– Can cause mediastinitis– Often small and appear after first 48 hours. Treated with

total parenteral nutrition (TPN) and antibiotics Spontaneously heal

– Leaks appearing earlier should be re-explored• Stricture (40%)

– May develop from natural healing and fibrosis• Gastroesophageal reflux disease (GERD) is seen in ~40-

70% of patients due primarily to intrinsic defects in esophageal function

• Esophageal replacement has own set of complications

Congenital Diaphragmatic Hernia

• Communication between abdominal and thoracic cavities– Communication can be with or

without abdominal contents in thorax

• Often diagnosed in utero• ~50% associated with other

congenital anomalies– When include stillbirths, ~95% are

associated with other anomalies. The most common are neural tube defects, followed by cardiac abnormalities. Many have chromosomal abnormalities


Bochdalek hernia Morgagni hernia and Central herniaother anterior hernias


• Four types of hernias– Bochdalek: posterolateral

• 90% Bochdalek (B=back). Most are left-sided and varied in size

– Morgagni: anterior (retrosternal)• Morgagni (M=midline)

– Central: central diaphragm– Hiatal: esophageal hiatus

• Hiatus: a break or interruption. Therefore, the esophageal hiatus is a break in the diaphragm that allows the esophagus to pass inferiorly into the abdominal cavity. A sliding hiatal hernia occurs when a portion of the stomach intermittently prolapses superiorly through this hiatus into the thoracic cavity


• Physical exam– Barrel-shaped chest– Scaphoid abdomen

• Loss of abdominal contents into chest– ↓ or absent breath sounds (typically unilateral)

• Decreased or absent breath sounds are primarily on the left since most CDHs occur on the left; they are uncommon on the right due to the presence of the liver

– Heart sounds almost always displaced to right


• Physical exam– Bowel sounds in chest– Respiratory distress

• Tachypnea• Grunting• Use of accessory muscles of respiration• Cyanosis

– Late presentation includes vomiting due to bowel obstruction and/or respiratory distress


• Diagnosis– CXR

• Left chest filled with bowel with mediastinal shift to right

• Associated findings̶ Hypoxemia̶ Acidosis̶ Hypotension


• Initial management– Immediate intubation without antecedent Ambu

bagging (as the Ambu bag covers mouth and nose) with subsequent adequate ventilation; the goal is immediate ventilation without associated air-entry into the GI tract with subsequent further airway compression/compromise

– NG (nasogastric) tube placement to continuous suction for decompression of the stomach and intestine

• Definitive treatment: surgical repair– Generally after 48 hours post stabilization and

improvement of pulmonary hypertension– Repair is primary or with a patch


• A primary initial goal is to avoid barotrauma and abdominal distention (which can lead to lung compression). Again, DONOT USE AN AMBU BAG which covers the mouth and nose of these infants as such results in aggressive pushing of air into both the trachea and esophagus (and therefore into the abdomen)

• Pulmonary hypertension is problematic because increased pulmonary pressures shunts blood away from the lungs, exacerbating hypoxemia and acidosis


• Patch may have more long-term complications as it may not easily accommodate growth of the child

• Fetal surgery is still investigational, may increase the risk of premature delivery and is geographically limited


• Long-term prognosis– Pulmonary function abnormalities/chronic respiratory

disease– GER (often requiring fundoplication)– Failure to thrive (FTT)– Neurodevelopmental delay

Meckel Diverticulum

• Most frequent GI anomaly (~2-3% of population)

• Due to incomplete regression of vitelline duct─ Vitelline duct provides nutrition

from the intestines to the yolk sac ─ The vitelline duct and umbilical

blood vessels join to form the umbilical cord

─ The allantois (later called the urachus) connects to the top part of the bladder

• True diverticulum─ Contains all layers of the wall

Meckel Diverticulum

• 106,248 at Kyle Field at the 2016 A&M vs. Tennessee game

• ~2,125 at the game with Meckel’s diverticulum

• ~ 40 were/are symptomatic

• I.e., the most common cause of abdominal pain in Aggie fans is not Meckel’s diverticulum…

Meckel Diverticulum: Rule of 2s

• Occurs in ~2% of population• Only ~2% symptomatic• Most commonly present at ~2 years old • Males ~2x as likely to be affected • ~2’ from ileocecal valve• ~2” in length• 2 types of mucosa

– Native – Ectopic

• 2 types of ectopic tissue– Gastric (most common)– Pancreatic (or colonic) also reported

Meckel Diverticulum• Presentation─Typically intermittent, painless rectal bleeding

• Maroon-colored stools (Gig ‘em! [again, again…])─Most symptomatic diverticula have ectopic, acid-

producing mucosa and may present with features of acute appendicitis, particularly when the appendix has already been removed

─Anemia─Bowel obstruction

• Intraperitoneal bands• Volvulus around duct remnants • Can act as lead point for intussusception─With inflammation (diverticulitis)

Meckel Diverticulum

• Diagnosis– Meckel scan is a nuclear medicine

study with technetium-99m pertechnetate

– Ectopic gastric mucosa has an affinity for pertechnetate, which is detected by scintigraphy

– A Meckel scan will identify only those diverticula that contain ectopic gastric mucosa, which occurs in <25% of cases

• Treatment: surgical excision

Meckel Diverticulum

Necrotizing Enterocolitis (NEC)

• NEC presents with various degrees of mucosal or transmural intestinal necrosis

• NEC is most commonly seen in the distal ileum and proximal colon

• Gut necrosis potentially progresses to perforation, peritonitis, sepsis and death

• Fatal in up to 50% of cases• Most common GI medical/surgical neonatal emergency


• Risk factors– Any prematurity itself is a primary risk to fatality

• Decreases with increasing birth weight• Increases with decreasing birth weight─Most severe disease if birth weight <1000 grams ─Risk decreases significantly if birth weight >1500 grams

– Presence of patent ductus arteriosus (PDA)• Potentially decreases gut perfusion


• Multifactorial etiologies– Abnormal intestinal flora– Intestinal ischemia/reperfusion– Intestinal mucosal immaturity/dysfunction


• Multifactorial etiologies– Abnormal intestinal flora

• Normal gut has bifidobacteria. Colonization enhanced by oligofructose (present in breastmilk)

• Infants fed formula without oligofructose have many clostridial organisms which may contribute to the development of NEC

• Breast milk is protective for several reasons: contains secretory IgA, inflammatory mediators, oligofructose(enhances bifidobacteria)

• Exposure to broad-spectrum antibiotics alters flora


─ Intestinal ischemia/reperfusion• Ischemia/reperfusion seems to induce local

inflammatory response─Decreased placental blood flow can result from

many maternal causes including chronic disease (i.e., diabetes, HTN), drugs (i.e., cocaine), etc.

─Decreased systemic blood flow can also be secondary to many causes

─One of the most common is cyanotic heart disease and/or PDA leading to decreased gut perfusion


─ Intestinal mucosa immaturity/dysfunction• Cellular immaturity and absence of mature

antioxidative mechanisms• Human milk appears to be protective


• Presentation─Younger gestational age patients often have later onset─ Significant preemies (<30 weeks) often don’t present for

3-4 weeks postnatally ─Earlier presentation is often associated with

comorbidities, regardless of gestational age ─Rare term infants who develop NEC generally present

within 1-3 days of birth─NEC often presents while advancing to full enteral feeds


• Signs and symptoms– Initial: feeding intolerance, gastric retention,

abdominal distention and/or tenderness, ↓ bowel sounds, ileus, hematochezia, bilious drainage from enteral feeding tubes, abdominal wall erythema (later sign)

– Systemic: apnea, respiratory failure, lethargy, temperature instability, bacteremia (20-30%), sepsis


• Laboratory findings– Hyponatremia– Metabolic acidosis– Leukocytopenia or

leukocytosis with left shift– Disseminated intravascular

coagulation (DIC)

Pneumoperitoneum

http://radiology.rsna.org/content/231/1/81/F1.large.jpg


• Laboratory findings─DIC

• Thrombocytopenia or signs of consumptive coagulopathy ─Prolonged PT/PTT─↓ fibrinogen ─↑ fibrin degradation

products (FDPs)─↑ D-dimer

Pneumoperitoneum



• Radiologic findings– Pneumatosis intestinalis– Dilated loops of small

bowel– Sentinel loops– Pneumoperitoneum:

may see “football sign”

Pneumoperitoneum



• Pneumatosis intestinalis: gas accumulation in the submucosa of bowel wall

Pneumatosisintestinalis



• Sentinel loop: loop of bowel that remains in a fixed position suggesting necrotic bowel and/or perforation

Pneumoperitoneum



• “Football sign”: a large ovalradiolucency demarcated by the parietal peritoneum of the abdominal wall (curved arrows). The falciformligament (straight arrows) is outlined by air

Pneumoperitoneum



Do you see it now?


Necrotizing Enterocolitis (NEC)• Management─ Supportive therapy: bowel rest, TPN, correction of

metabolic abnormalities, CV/respiratory support as needed

─Antibiotics: ampicillin and gentamicin for 10-14 days to cover those 20-30% with documented bacteremia

─ Surgery• Indications: perforation, mass, abdominal wall

erythema, failure of medical management• If needed, surgery (often laparotomy with resection) is

ideally performed after observation (“watchful waiting”) has failed and patient deteriorates, suggesting necrosis occurred, but before perforation and peritonitis


• Complications– Immediate

• Infection• Metabolic abnormalities• DIC• CV/respiratory collapse

– Longer-term• Stricture formation

– Unrelated to severity of necrosis– Often develop within 2-3 months– May have multiple sites, often in colon

• Short bowel syndrome


• Prevention– Breast milk when possible– Avoid unnecessary use of broad-spectrum antibiotics– Increase enteral feeds slowly often starting with

administration of trophic feeds: small volume of nutrients given enterally to “prime the gut” for later feeds. These are not designed to be a significant source of calories or volume

– Probiotics (typically include bifidobacteria and lactobacilli)

Short Bowel Syndrome

• Clinically defined by malabsorption, diarrhea, steatorrhea, fluid/electrolyte imbalances and malnutrition– Loss of >50% of small bowel can produce malabsorptive

symptoms• Can be congenital or after resection

– Resection has a better prognosis at younger ages• Symptoms vary with portion lost

– Jejunum does primary nutrient absorption– Ileum responsible for absorption of B12 and bile salts– Need only 15 cm with ileocecal valve or 20 cm without

valve to have realistic goal of weaning off TPN

Short Bowel Syndrome

• Symptoms vary with portion lost– Jejunum

• Primary nutrient absorption– Ileum can adapt to nutrient absorption

• Jejunal resection tolerated better than ileal resection– Ileum

• Extensive absorption of water, electrolytes• Terminal ileum responsible for absorption of B12, bile salts• Resection here has profound effect on fluid/electrolyte

balance almost always producing diarrhea– Ileocecal valve

• Important to prolong intestinal transit time • Often associated with weight loss, malaise, fatigue, lethargy

Bowel Obstruction

• Pyloric stenosis• Duodenal atresia• Malrotation/volvulus• Intussusception• Hirschsprung disease

Bowel Obstruction: Hypertrophic Pyloric Stenosis (HPS)

• More commonly in males – 4:1• More likely in first-born males• Multifactorial etiologies• Environmental factors

– Maternal smoking– Bottle feeding

• Familial incidence– Genetic loci identified

• Infrequently associated with other congenital defects– Hypoplasia/agenesis of inferior labial frenulum, TEF

• Macrolide (erythromycin and azithromycin) administration (both to mother [pregnant and/or breastfeeding] and infant) implicated


• History– Non-bilious, non-bloody emesis– Occurs immediately after feeding (post prandially)– Infant is hungry and wants to feed again after

vomiting– Progresses in frequency and amount until projectile– Typically presents between 2-4 weeks

• Seldom before 2 weeks• Unusual beyond 2 months


• Physical exam– Palpable “olive”: firm mass at lateral edge of rectus

abdominis in the right upper quadrant, when infant is quiet, while sucking on pacifier dipped in sucrose solution, after vomiting, perhaps from left side, while held prone, and/or with sedation/anesthesia pre-operatively

– Gastric peristaltic waves from left to right may be visible after feeding just pre-emesis

– Other findings vary by degree of dehydration and malnutrition


• Diagnosis– Ultrasound of abdomen– Ward rounds question and answer: What counts as

pyloric hypertrophy? Wall thickness >3-4 mm or length >14 mm

– UGI may also be useful if considering other obstruction (i.e., antral or duodenal web, etc.)


• Laboratory findings– Hypochloremic, hypokalemic, metabolic alkalosis

with paradoxical aciduria• Serum laboratory findings secondary to loss of H+

and Cl- from gastric secretions• Kidneys attempt to retain Na+ and fluid→

accelerated K+ and H+ losses in urine• Loss of H+ in urine contributes to paradoxical

aciduria

Pyloric Stenosis:Radiographs and Ultrasounds

Measurement of Pylorus


• Medical management– Stabilize infant pre-operatively

• Correction of metabolic alkalosis, hypokalemia, hypochloremia

• IVF and correction of fluid deficits (via NS boluses of 20 mL/kg)

• NG decompression


• Surgery: pyloromyotomy– Pyloromyotomy: the

pyloric muscle is opened using an arthroscopy blade and then spread open with a grasping forceps

Bowel Obstruction: Duodenal Atresia

• May be complete (failure to recanalize lumen after solid phase of intestinal development) or incomplete (stenotic)

• Comorbidities– Down syndrome (20-30%)– Malrotation (20%)– Esophageal atresia (10-20%)– Congenital heart disease (10-15%)– Anorectal and renal anomalies (5%)


• Manifestations of duodenal atresia– Bilious vomiting without distended abdomen

(often noted on DOL 1)• Vomiting may be nonbilious if atretic proximal to

ampulla of Vater– Scaphoid abdomen– History of maternal polyhydramnios

• Polyhydramnios: decreased absorption of amniotic fluid (~50%)

– Jaundice in 1/3 cases


• Diagnosis─Plain films show “double-bubble:” gas in the

stomach/separated by pylorus/gas in the proximal duodenum prior to duodenal atresia

─Anything that obstructs duodenum (i.e., annular pancreas) can cause “double-bubble” but most commonly associated with duodenal atresia

─Contrast studies can help rule out malrotation

“Double Bubble”

“Double-bubble:” gas in the stomach/separated by pylorus/gas in the proximal duodenum prior to duodenal atresia

Bowel Obstruction: Duodenal Atresia• Treatment─NG/OG decompression─ Surgery: duodenoduodenostomy─ IVF and/or TPN until feeding PO

• Prognosis– Depends on associated anomalies– Must remember to evaluate for

other congenital anomalies (ECHO, films of chest and spine)

Bowel Obstruction: Malrotation

• Due to non/incomplete rotation in utero– Midgut extends from abdominal cavity and rotates

on reentry – Most common malrotation involves failure of

cecum to move to RLQ• May present at any age

– 50% <1 week– 89% >1 year old

Malrotation:Ladd’s Bands

• Failure to rotate may leave obstructing bands across duodenum (Ladd’s bands)

• Fold of peritoneum attaching cecum to abdominal wall crosses over and obstructs duodenum

• Impaired gut perfused by the superior mesenteric artery (SMA) tethered by narrow stalk and associated with midgut volvulus can result in catastrophic gut loss

Malrotation: Ladd’s Bands


• Presentation– Infants: bilious emesis, acute obstruction– Older infants: episodes of intermittent, recurrent

abdominal pain (can be similar to colic)– Recurrent symptoms secondary to intermittent

volvulus or duodenal compression– Can occasionally present with malabsorption – ~25-50% of adolescents are asymptomatic


• Acute bowel obstruction in a patient without previous surgery usually is a volvulus associated with malrotation– Can resemble acute abdomen or sepsis– Life-threatening– Infarction can occur in 6-12 hours

Bowel Obstruction: Malrotation• Diagnosis

– Plain film may be gasless or may show “double-bubble” if duodenal compression present

– Contrast studies• Upper GI shows malposition of

ligament of Treitz (“corkscrew”)• Barium enema shows

malposition of cecum or obstruction at transverse colon

• Treatment: surgical reduction of volvulus

Ligament of TreitzLigament of Treitz

Malrotation/Volvulus

• Corkscrew sign in malrotation/volvulus


• Often associated with other congenital anomalies• Survival related to

– Presence of other congenital anomalies– Younger age increased mortality– Delay in diagnosis– Presence/extent of necrotic bowel– Bowel ischemia can result in increased resection

which can lead to short gut syndrome

Bowel Obstruction: Intussusception

• Telescoping of proximal into distal segment of bowel• Rare in neonates• Most common cause of obstruction in children

between 3 month and 6 years old• ~60% <1 years old, ~80% <2 years old• Most commonly occurs at 3-9 months of age• More common in males – 4:1• Most common site: ileocecal valve

• Upper portion invaginates and pulls mesentery with it• Obstruction of venous return causes engorgement of

invaginated portion• Typically doesn’t strangulate within first 24 hours

Intussusception


• Etiologies– ~90% of cases are idiopathic– But, pathologic lead point more common >2 years

old


• Etiologies─ Lead points (occur in only in ~2-8% of cases) can include

• Peyer patches • Meckel • Polyps• Cystic fibrosis• Henoch-Schönlein purpura• Malignant lymphomas• Neurofibromas• Intestinal duplication• Hemangiomas

─ Postoperative intussusception typically occurs within 5 days of surgery

Bowel Obstruction: Intussusception• Symptoms

– Sudden onset of intermittent, severe, colicky pain– Occurs at frequent intervals and is often asymptomatic

between episodes– Vomiting common in early stages– “Currant-jelly” stool: up to 60% (late finding)– Sausage-shaped mass (often RLQ)– Abdominal distention, tenderness– Often with decreased stool production– Progressive lethargy/obtundation may be only

symptom

Ward Rounds Question

• What is the classic triad in intussusception?1. Colicky pain2. “Sausage” shaped mass (RLQ)3. “Currant-jelly” stool


• What causes “currant-jelly” stool?─Not simply bleeding, but also shedding of bloody

mucosa injured with invagination


• Physical exam– Physical exam varies with time– Abdominal mass may be palpable in RLQ, especially

during pain episode– Heme positive stools– Shock symptoms

• Increases as bowel infarcts

Bowel Obstruction: Intussusception• Diagnosis

– Based primarily on history– Plain films

• May see density in area of intusussception– Gastrograffin/barium/air enema

• Study of choice; may be diagnostic and therapeutic!!!

– Ultrasound– Upper GI with small bowel follow through

“Coiled spring” seen with contrast enemas in intussusception


Bowel Obstruction: Intussusception• Treatment

– May spontaneously reduce– Intravenous access for fluid resuscitation and/or

urgent medication administration is important– Air enema/gastrograffin/barium enema

• May be both diagnostic and therapeutic– Surgery if repetitive or incarcerated

• Manual reduction, or• Resection and anastomosis

Bowel Obstruction: Intussusception • Prognosis

– Often fatal if untreated, but otherwise good– Low recurrence rates

• ~10% recurrence if reduced with enemas• ~2-5% recurrence if surgical reduction• None after resection

Appendicitis

• Not uncommon surgical condition in children• Rare in children <5 years old• Peak incidence 12-18 years old• Primary focus is to avoid sepsis and minimize

infectious complications• Complications tend to arise after perforation

Appendicitis

• Presentation– “Classic”: less than ~50%

• General malaise; anorexia is a very common symptom

• Initially colicky periumbilical pain• Progression of pain to RLQ over 12-24 hours

(as inflammation increasingly involves parietal surfaces)

• Nausea/vomiting several hours after onset of pain• Symptoms can vary depending on location of

appendix and age of patient

Appendicitis

• Physical exam– Still child with tentative movements– Guarding, rigidity– Rebound tenderness– Localized abdominal tenderness

is the single most reliable finding in diagnosis

– McBurney point– Positive Rovsing, obturator and/or

psoas signs

Appendicitis

─After perforation• Often initial relief of pain• Then rapidly increasing abdominal pain, diarrhea,

dehydration and signs of sepsis (hypotension, oliguria, acidosis, high-grade fever)

• May have signs/symptoms similar to developing small bowel obstruction


• What does rebound tenderness imply?─Peritoneal irritation

• Start with soft, gentle percussion, as testing for rebound tenderness may be very painful

Ward Rounds Questions

• Where is McBurney point?─2/3 of the distance from the umbilicus to the

anterior superior iliac spine (ASIS)─Maximal tenderness here is not as common with

retrocecal appendicitis• Thus, where is the appendicitis if those cases where

there’s no pain at McBurney point?– Likely it’s retrocecal

Appendicitis

• Physical exam– Rovsing sign: pain in the RLQ on palpation of the

left side– Obturator sign: pain on flexion and internal

rotation of the right hip (seen when inflamed appendix lies in the pelvis, irritating obturator internus muscle)

– Iliopsoas sign: pain on extension of the right hip, (secondary stretching of psoas muscle), found in retrocecal appendicitis

Appendicitis

• Laboratory findings– WBCs often elevated, but not often >20,000– Other labs often normal– Urinalysis obtained to rule out UTI or stone

• May note WBCs/RBCs in urine (secondary to inflammation), but should not have bacturia in isolated appendicitis

Appendicitis

• Radiologic studies– CT: historically “gold standard” in adults, but in children

and adolescents obtain US to avoid irradiation• Distended appendix with thickened walls, fat

stranding, abscess, focal thickening of ileum, cecum • Appendicolith/fecalith (seen in ~25% of patients)• Negative CT DOES NOT always rule out appendicitis

– MRI: may be helpful in pregnant adolescents; a normal appendix is a tubular structure <6 mm in diameter and filled with air and/or oral contrast material; 6-7 mm is inconclusive; and >7 mm is considered abnormal

Appendicitis

Perforated acute appendicitis. Axial CT scan shows extensive fat stranding and fluid collection (arrows) surrounding enhanced and dilated appendix (A). Adjacent small bowel (sb) shows wall thickening

Appendicitis

• Ultrasound– Infants to young adults should have an ultrasound

rather than CT (thus avoiding needless ionizing radiation) to evaluate for appendicitis

–Suggestive findings: increased thickness of appendiceal wall, abscess formation, free peritoneal fluid, tissue edema

–May be difficult to visualize appendix –Negative ultrasound does not always rule out

appendicitis

Appendicitis

• Management– Analgesia and hydration

• Analgesia typically does not mask significant findings on physical exam

– Surgery consultation

Appendicitis• Definitive treatment is appendectomy

– Ideally performed within a few hours after diagnosis, if not perforated

– But, attempt to stabilize before surgery– Antibiotic prophylaxis

• Antibiotic prophylaxis for wound infection and abscess formation. Infection is most common complication. Prophylaxis is usually piperacillin/tazobactam (Zosyn) or cefoxitin

• If perforated, may treat with piperacillin/tazobactam (Zosyn), cefoxitin or ceftriaxone (Rocephin). May also use combination of metronizadole and ceftriaxone. Traditional antibiotic regimen is ampicillin, gentamicin, and clindamycin or metronizadole (Flagyl)

Bowel Obstruction: Hirschsprung Disease

• Also know as (AKA) congenital aganglionic megacolon• Aganglionisis of distal bowel

– May occur at internal anal sphincter, extending proximally– Generally limited to rectosigmoid (~80%)– Rarely affects the entire colon (~5%), with resultant

poorer prognosis • Most common cause of lower intestinal obstruction in

neonates• More common in males 4:1 if limited to rectosigmoid• Migration failure of neural crest cells

– Defect in craniocaudal migration of neuroblasts– Aganglionic segment is nonfunctional

Yet Another Step 1/MII Year High Yield Question• What is derived from neural crest cells?─Melanocytes ─Dorsal root ganglia─ Sympathetic neurons─ Schwann cells─Adrenomedullary cells

Bowel Obstruction: Hirschsprung Disease

• Presentation– Failure to pass meconium within 48 hours of birth

Some pass meconium normally and then present with constipation or obstipation

▪ Rectal exam generally shows normal tone and no stool in the vault

– Enterocolitis▪ Secondary to colonic stasis and bacterial overgrowth▪ Fever▪ Bilious emesis▪ Abdominal distention▪ Requires IV fluids, antibiotics (including coverage for

anerobes), and even emergency colostomy

Bowel Obstruction:Hirschsprung Disease

─ Late signs in some patients ▪ ~10% are diagnosed after 3 years of age

• Constipation or obstipation• Failure to thrive

Yet Another Ward Rounds Question • What’s the difference between constipation and

obstipation?─Constipation occurs with hard feces that is difficult

to pass; gas still goes through. (We’ve all been constipated!)

─Obstipation is failure of passage of stool and gas. (Not many of us have been obstipated)

Significant abdominal distention prompts emergency evaluations and treatment

Concerning Physical Findings

Bowel Obstruction: Hirschsprung Disease• Diagnosis

– Plain films• May show dilated bowel loops proximal to the aganglionic

region, with decreased or absent air in the rectum• May also be normal

– Anorectal manometry• Manometry is accurate in older children and adults, but is

difficult to perform in infants <1 month of age– Gastrograffin or barium enema (BE)

• In the diagnostic workup, enemas may document a clear transition zone between normal and aganglionic bowel, thus guiding the operative approach; still, the diagnosis is confirmed by rectal biopsy

Dilated loops of small bowel proximal to the distal obstruction are often seen in Hirschsprung disease

Dilated Loops of Small Bowel

– Rectal biopsy• Suction rectal biopsy is more sensitive and specific

than contrast enema and anorectal manometry for diagnosis

• May be performed at bedside without general anesthesia

• Must be 2 cm past dentate line to prevent sampling of the 1-2 cm zone of physiologic hypoganglionic normally present

• A second biopsy should be taken proximal to the first one

• Diagnosis is confirmed if ganglion cells are absent, provided tissue sample is adequate

Hirschsprung Disease:Rectal Biopsy

Hirschsprung Disease:“Pull Through” with Resection

• Treatment– Supportive care

• NG or rectal decompression• IVF• Broad-spectrum antibiotics

– Surgery: definitive treatment• Temporary colostomy until >~10 kg• Definitive repair

– “Pull through” with aganglionic segment resected

– Remaining bowel anastomosed

Our Motivation:Healthy Children

References

• American Academy of Pediatrics• Anne Geddes• Harriet Lane Handbook, 21st Edition, 2018• Nelson Textbook of Pediatrics, 20th Edition, 2017• UpToDate, 2019

miscellaneous pediatric gi · : esophageal hiatus • hiatus: a break or interruption. therefore,...

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