Abdomen Flashcards
Level of obstruction can be either proximal or distal, in relation to what structure
Ampulla of Vater
Most common cause of congenital esophageal obstruction
Esophageal atresia
It is the result of abnormal development of the foregut early in gestation, which leads to discontinuity of the esophagus and frequently an associated fistulous connection between the esophagus and the trachea
Esophageal atresia
Most common subtype of esophageal atresia/TEF
Complete esophageal atresia with a blind-ending esophageal pouch and distal fistulous connection between the lower portion of the trachea and distal segment of esophagus
Occurs due to failure of the normal sequence of rotation of the bowel and mesentery during development
Malrotation
Ligament of treitz is normally fixed on what side
Left of midline, at similar level of duodenal bulb
Condition in which the base of the mesentery is relatively short and is thus prone to twisting (volvulus)
Malrotation
If volvulus occurs, the resulting obstruction is typicaly seen in the
3rd portion of duodenum
Midgut volvulus can be catastrophic as it involves the
Mesenteric vessels which can result to venous and arterial ischemia of bowel
Normally, the 3rd portion of duodenum in the AP view is seen on _______, and on the lateral view it is seen on ______
Cross midline to the left on AP view, located posteriorly just in front of the spine on the lateral view
In malrotation, the 3rd portion of duodenum appears
It does not cross the midline and extend anteriorly in the lateral view
In malrotation, the ligament of Treitz is located where
Right of midline or may be abnormally low
In malrotation, cecum is located where
Either in midline or high in the right upper quadrant
On ct/mri or ultrasound, the 3rd portion of duodenum in malrotation appears
Not passing between the SMA and aorta
Small bowel loops and colon in malrotation appears where
Small bowel loops primarily appear on the right side and colon on the left side
In malrotation, SMA appears where, and SMV is located where
SMA is in the right
SMV to the left
Normally, SMA and SMV are located where
Mimics position of aorta and IVC, SMA on the left and IVC on the right
The 3rd portion of duodenum in malrotation with volvulus appears as
Corkscrew appearance or beaking
Corrective procedure in malrotation with midgut volvulus
Ladd procedure
Etiology of duodenal atresia
During embryologic development, duodenal lumen undergoes occlusion due to normal cellular proliferation and subsequent recanalization. Failure to recanalize is results in duodenal atresia
Duodenal atresia most commonly occurs on what part of the duodenum
Second
Treatment for duodenal atresia
Duodenoduodenostomy bypassing the atretic segment
Cause of obstruction of the 2nd portion of duodenum when there is abnormal rotation and fusion of the dorsal and ventral bud of pancreas, causing circumferential narrowing of duodenum due to extrinsic compression
Annular pancreas
Treatment for annular pancreas
Surgical bypass of the narrowed segment of duodenum
Caused by redundancy of the duodenal mucosa which may result in a circumferential area of relative narrowing or a pouch-like structure (windsock deformity) that can cause partial duodenal obstruction
Duodenal web
Treatment for duodenal web
Resection of redundant tissue, bypass of involved segment, or endoscopic balloon dilation
Appears as a wedge shaped mesenteric defect associated with the atretic segment of small bowel
Small bowel atresia
This finding indicates that there has been an in utero bowel perforation, with spillage of meconium into the peritoneal cavity, resulting in inflammation and resultant calcification (meconium peritonitis). Occasionally, a discrete peripherally calcified cystic mass called a meconium pseudocyst may be present
Peritoneal calcifications
In distal ileal atresia, colon appears
Small in caliber “microcolon” due to lack of contiguity of the GI tract in utero which prevents normal colonic development by obstructing the normal flow of intestinal secretions into the colon
If small bowel atresia is present in the more proximal jenunal or ileal segment, the appearance of the colon is
Normal
Treatment for bowel atresia
Surgical bypass or resection of the affected segment
Neonatal obstruction of the distal ileum by retained meconium is termed
Meconium ileus
Meconium ileus is strongly associated with
Cystic fibrosis
Meconium ileus is likely secondary to what pathophysiology
Abnormally viscous intestinal secretions and meconium, resulting in obstruction at the ileocecal valve
In contrast enema, it demonstrate diffuse microcolon, with contrast refluxing into a dilated terminal/distal ileum containing multiple filling defects representing the retained meconium
Meconium ileus
Why a hyperosmotic water-soluble contrast is the contrast of choice in the enema for suspected meconium ileus
It causes shift of water into the bowel lumen, loosening up the tenacious meconium and allowing it to pass through the colon
This condition, which is also called “functional immaturity of the colon” and “meconium plug syndrome” occurs in infants of diabetic mothers and in infants whose mothers received tocolytics during pregnancy
Small left colon
Treatment of small left colon
Contrast enema is both diagnostic and therapeutic
Why is colonic atresia less common than small bowel atresia
Due to redundant blood supply of colon
Atretic segment in colonic atresia is usually located where
Junction of the descending and sigmoid colon
Treatment of choice for colonic atresia
Surgical bypass or resection
Occurs due to lack of normal ganglion cells innervating the colon which leads to abnormal colonic peristalsis and varying degrees of obstruction. Rectum is always involved and extend of proximal involvement varies
Hirschsprung disease
Common symptom of Hirschsprung disease
Chronic refractory constipation
Diagnostic measure for Hirschsprung disease
Rectosigmoid ratio
In normal colon, rectum is smaller or larger in diameter than the more proximal colon?
Rectum is larger
In Hirschsprung, rectum is smaller or larger in caliber than the more proximal, unaffected colon?
Smaller or contracted
Additional finding in Hirschsprung that may also be helpful; it is caused by abnormal peristalsis and spasm
Irregular “sawtooth” appearance of the rectal wall on the lateral view
Rare form of Hirschsprung disease that involves the entire colon
Total colonic aganglionosis
Definitive diagnosis of Hirscsprung
Rectal suction biopsy
Caused by failure of normal development of the hindgut, resulting in a distal colonic obstruction
Imperforate anus/anorectal malformation
Associated with imperforate anus or anorectal malformations
Rectovesical or rectourethral fistula in boys and cloaca in girls
High or low anorectal malformations are related to what line
Pubococcygeal line
Skeletal abnormalities related to imperforate anus/anorectal malformation
Dysplasia/hypoplasia of sacrum
It is an allergic inflammatory condition that occurs in susceptible patients, often in patients with asthma and other forms of atopy. The resultant inflammatory response can cause esophageal dysmotility, focal strictures or diffuse esophageal narrowing
Eosinophilic esophagitis
Esophagram findings in eosinophilic esophagitis
Focal strictures which are typically located relatively high in the esophagus
Caused by abnormal hypertrophy of the pyloric muscle, resulting in gastric outlet obstruction
Hypertrophic pyloric stenosis
Exact etiology of hypertrophic pyloric stenosis is not known, but may be related to
Abnormal innervation or nitric oxide synthase activity leading to prolonged pylorospasm and ultimately hypertrophy of the muscle and gastric outlet obstruction
Imaging test of choice for HPS
Ultrasound
Diagnostic cut off measurements to diagnose HPS
Pyloric wall thickness of greater than 3mm, pyloric channel length of greater than 14 mm
True or false, diagnosis of HPS depends on the peristent abnormal morphology of the pylorus, not whether contents pass through the pylorus
True
Treatment of HPS
Pyloromyotomy
Commonly acquired cause of small bowel obstruction in children
AAIIMM
Adhesions, appendicitis, inguinal hernia, intussusception, midgut volvulus, meckel diverticulum
Aside from prior intra-abdominal infections or other inflammatory processes as a cause for having adhesions, what else can cause this condition
Those with omphalomesenteric duct remnant
Decreased mural enhancement, bowel wall thickening, pneumatosis, and extensive mesenteric edema/ascites are signs of
Bowel ischemia
One of the most common causes of bowel obstruction in a previously healthy older child
Perforated appendicitis
Relatively common cause of obstruction in infants under 6 months of age and are common in boys
Incarcerated inguinal hernia
This is caused by failure of the normal closure of processus vaginalis, resulting in persistent communication between peritoneal cavity and the scrotum
Indirect hernias
Common cause of obstruction after 6 months of age
Ileocolic intussusception
Why is the ileocolic segment prone to intussusceptions
Idiopathic, but likely related to reactive lymph nodes
Pathologic lead points of intussusceptions
Tumor, polyps, diverticula, inflammatory bowel wall thickening (henoch-schonlein purpura)