Intestinal obstruction in neonate

Intestinal Obstruction in neonate

Incidence-it is difficult to estimate because of it may result from functional or embryonic anomally.it is the most common neonatal emergency.it is about 1/1000 ---
50% are atresia or stenosis.
Etiology-mostly it is due to intrauterine vascular accident.
The majority of neonate present shortly after birth .
Prenatal diagnosis is possible in selected cases.clinical finding may suggest obstruction like-maternal polyhydraminios ,excessive gastric aspiration ,abdominal distension,bilious vomiting,and obstipation.these finding depend on the level of obstruction .early diagnosis befor respiratory compromise and sepsis are obvios is important in outcome.
1-maternal polyhydraminiosamniotic fluid is ingested and then absorbed within the intestine of the fetus .then through the placenta to the maternal blood .proximal GIT obstruction interrupts this process and lead to accumulation of excess amniotic fluid.distal bowel or colonic obstruction donot result in polyhydraminios.
2-exessive gastric out put-passage of NGtube reveals more than 50cc or bilious then GITobstruction should consider.
3-abdominal distentionmay be not apparent at birth but develops over times as ingested air accumulates proximal to an obstruction .the times of onset the degree and characteristic appearance of the distension may suggest the level of obstruction .gastric distension within afew hours may cause the epigastrium to protrude idicating an obstruction of the stomach or duodenum .gradual over all distension ocuuring 1224hrs suggest a distal GITobstruction.
3-bilious emesisit is normal for healthy new born to spit-up but bilious emesis in aterm infant is abnormal .bilious emesis
In premature infant may occure due immaturity of pyloric sphincter .sepsis with paralytic ileus may cause bilious emesis .early begging of vomiting may be due to proximal or complete obstruction but may be delay in case of distal or incomplete obstruction .
4-failure to pass meconiumanormal new born is expected to pass alarge amount of thick ,dark green.shiny,meconium usually and mostly (95%) in the first day of live.passage of meconium not exclude obstruction.premature may have delay passage even after 48 hrs.
Visible perstalsis ,distended loop of bowel ,may be palpable ,doughy abdomen and multiple masses may felt.rectal tightness and empty rectum lethargy hypotonia may occurs, abdominal wall discoloration and echymosis suggest perforation.

Diagnosis

It is largly on clinical basis ,radiological study also important, swallow air serves as the contrast media to accurately show the level of obstruction air reach the proximal small bowel at 30 minutes .and colon at 3-4 hrs and rectum at 6-8hrs .no air fluid levels should be found in normal newborn. in complete obstruction air pattern may stop abruptly leaving gaseless bowel .bowels loops proximal to obstruction are dilated .air fluid levels are most commonly seen in distal bowel obstruction except in meconium ileus .


Pyloric and duodenal obstruction
Includes obstruction, stenosis, and annular pancreas, .hypertrophic pyloric stenosis and malrotationsuction also present as proximal GIT obstruction.
Incidence;pyloric atresia is rare ,less than 1% of atresia ,duodenal obstruction is 1per 10000 live birth.
Eiology: pyloric atresia usually caused by solid mucosl diaphragm obstruct the pylorus,result from vascular or mechanical injury ,either duodenal narrowing or web to complete obstruction.or may be defect in recanalization of the embryonic duodenum .recanalization complete in the 8 wk of gestation.Annular pancreas and preduedenal portal vein may cause extrinsic duodenal obstruction .3rd portion of duodenum is affected.
Clincal pictures ;
A-Pyloric obstruction ;the newborn with complete pyloric atresia or prepyloric antral web present shortly after birth with persistant nonbilious vomting and possibly epigastric distension ,aspiration may occurs and lead to dyspnea,tachypnea and cyanosis .exessive salivation occurs ,in older children abdominal pain and vomiting or postprandial fullness ,epidermolysis bullosa being the most common.

B-Duedenal obstruction ;50%of them is premature and are low birth wieght maternal polyhydramnios is present up to 75% .bilious vomiting on first day of live is usual presentating features ,but may be nonbilious in preampullary atresia 20%.

Abominal distesion may not occurs .Meconiumo is usually passed in the first day then constipation occurs.The obstruction are associated with ,downs syndrome 30%,malrotation ,congenital heart disease,T.E.F ,urinary and anorectal anomalies,and vertebral anomalies and VACTREL SYNDROM {vertebral-anorectal-congenital heart disease-TEF-radial anomally- limb anomalies}
DDX;malrotation ,pyloric web,pyloric stenosis,duodenal atresia ,annular pancreas ,preduedenal portal vein.
Diagnosis;erect abdominal x-ray ,demonstrate the gas in the stomach duodenum and gasless of the other parts
-pyloric web----single gas bubble sign .
-duedenal atresia---dilated stomach and duodenum giving double bubble sign. Some gas may found in other parts if the obstruction is not complete .ultra sound may identify the double bubble sign.
Duedenal obstruction can be secondary to internsic or extrinsic lesion ,iternsic may be cause duodenal atresia ,diaphragme,with or without perforation[wind-sock}or usually there is stenosis or web in side.

Treatment
NG tube ,intravenous hydration ,to correct metabolic alkalosis and electrolyte correction .pyloroplasty is the treatment of choice and NG tube pass distally to ensure there is no other atresia .Web resected if found,.in duodenal obstruction {double diamond} duedenoduedenoplasty.

MALROTATION AND VOLVOLUS

It occure in 1per 6000 live birth ,it clear that it occur through out live with out any problem .The growth rate of GIT in early gestation is faster than that of the body there for ,intestinal development occur through umbilical ring within physiological hernia {4th wk},of gestation and return in the 10th wk of gestation .This includes counter clouckwise rotation of two intestinal segment the duedenojujenal segment and cecolic segment ,the rotation 270* on the superior mesenteric artery axis .
It may become with congenital diaphragmatic hernia or omphalocele or gastroschisis,it classify in to nonrotation ,abnormal rotation ,and revers rotation .
c/F symptoms may be mild and itermitent or sever or catastrophic with complete obstruction .mostly 95% is vomiting abilious or even bloody necrosis .child look severly ill with abdominal pain ,lethargy ,grunting,dehydration ,peritonitis and shock.


Diagnosis; the diagnosis usually on radiographic confirmation .it may show obstruction and distension ,gaseless abdomen occur contrast study may show the malrotation abrupt cut of barium {bird beak}.enema may show the abnormal position of caecum ,but it highly variable 15% of malrotation have normally place caecum.ultrasound show the superior mesenteric vein to the right of superior mesenteric artery if change suggest malrotation .

Treatment ;after correction of fluid and electrolyte ladd procedure is done it include;

1-evisceration supra umbilical transverse incision is made .ascitis {chylous from obstruction ,bloody from necrosis }is drained.
2-untwisted the volvolus ;in counterclockwise
3-division of ladd band ;it cross the malposision 2nd and 3rd part of duodenum
4-widening of the mesenteric base ;to free the caecum .
5-releif of obstruction ;lysis of the band and straighten the duodenum and check any luminal obstruction.
6-incidental appendicictomy ;to remove any confusion because of abnormal position of cecum we put the cecum on the left side .
Out come ;recurrent in 10%,5% adhesion ,short bowel syndrome.

Atresia and stenosis

Jujenal atresia is the most common GIT atresia one per 2000 live birth it have many types;
1-type 1 {20%} continuity of the bowel wall is preserve {wind sock}
2-type 2 {35%}============================= by fibrous cord
3-type 3A part of mesentry is abscent with two blind end .
Type 3B extesive loss of bowel and large mesenteric defect the blood supply is retrograde by iliocolic artery and spirals of bowel {apple peel}
Type 4-multiple atresia
C-F: the infant usually refered to pediatric surgery center within 24-48hr
With bilious vomiting abdominal distension and failure to pass meconium {7%}.
Diagnosis:abdominal film show dilated loop of bowel with air fluid level .if perforation has occur free air or peritoneal calcification may be present .
Treatment: NG tube ,incubator ,correction of fluid and electrolyte and surgery.by supra umbilical transvers incision resection or tapering of dilated part and primary anastomosis done.
Survival:about 90% .


Meconium ileus
It is one of the most common cause of GIT obstruction caused by inspissatend meconium in 80% -90% of them have cystic fibrosis .and when complicated it lead to meconium peritonitis ,and it occur in 10-20% of patient with cystic fibrosis .95% of patient with cystic fibrosis have abnormal pancreatic secretion and enzymes deficiency and-or meconium composition .which lead to thick meconium adherent to distal ileal mucsa lead to obstruction by pellets of meconium which have high protein and low water and high bilirubin ,the ileum proximal to obstruction is dilated and microcolon and this may lead to volvolus.
Classification :
1-simple or uncomplicated
2- complicated :may result from volvulus and perforation may occur
C-F: generalize abdominal distension develop within 24-48hr
Bilious vomiting but start as non bilious .failure to pass meconium maternal polyhydramnios occur in about 20% of cases presentation as sever abdominal distension .bilious vomiting and respiratory distress ,hypovolemia .palpable meconium impacted bowel (doughy) abdomen .meconium may be seen in vagina or scrotum in complicated cases .in meconium plug syndrome is atranseint neonatal colonic obstruction (diabetes hirsch-cystic fibrosis) should consider.

Diagnosis: plain film in simple may show just dilated loop of bowel and no air fluid level .aground glass or soap bubble appearance is often clear in right lower abdominen due to thick meconium mixed with air but in complicated cases may see
a-calcification b-massive bowel dilatation c-air fluid level d-ascitis.

Barium enema show microcolon and inspissated pellets chloride sweat test {pilocarpine iontophoresis }is simple test for diagnosis of cystic fibrosis.

Treatment:

Initially as with all types of resuscitation and NG tube and antibiotics .simple type can be managed non operatively with gastrograffin enemas in fluoroscopic guidance oral N-acetylcystein also given to help clearance of bowel .surgery is idicated when there is complication or if 3 trial failure of gastrograffin enema .
Treatment by multiple enterotomy irrigation specially at the appendiccular stump ,or by irrigation at the site of obstruction when enterotomy done and then primsry suturing but when complicated by atresia ,volvolus ,perforation ,iliostomy is better (bishop-koop or mikulics-or santulli)procedure .
Out come :one year survival in simple one 90% and in complicated type 75%-90%.

Hirschsprung disease

Congenital megacolon is adevelopmental anomaly caused by failure of migration of neural crest cells, and not take apposition in the submucosa and itermyentric plexi of the bowel from the lips to the anus ,motility disturbance result that present as constipation and GIT obstruction in newborn.
Incidence;1/5000 with males 4 times affected more than female .
Aetiology; unknown familiar incidence in 3-30%.
C-F; 98% of babies pass meconium within 24-48hrs of birth in baby with Hirsch. 90%fail to pass meconium in the first 24hr of live .then progress to abdominal distension ,bilious vomiting and obstructive enerocolitis .if the neonate leave the hospital without diagnosis it will appear with constipation within 2yr .
The most common physical finding are abdominal distension ,visible bowel loops with perstalsis and poor muscle development .
Rectal examination reveal spastic rectum with little or no stool since the stool bolus is high and beyond the examining finger we should look for downs syndrome.
Diagnosis; history and physical examination ,but barium enema reveal spastic ,poorly compliant rectum with eventual passage through acone shaped transition zone in to dilated colon.


These are found in older children ,delay film often reveals slow clearance of contrast and may reveal the cone segment shape transition zone .in normal person distension of rectum produce relaxation of internal sphincter which diagnosis by manometry .failure suggest hirschsprung
Disease.
Rectal biopsy punch biopsy demonstrate absence of ganglionic cells and nerve hypertrophy .special stain acetylcholinestrase activity may be used in 20-40% enterocolitis develop by fever ,vomiting ,diarrhea ,shock ,sepsis.

Treatment ; by leveling colostomy and pullthrow technique or laproscopic pullthrow.

Pyloric and duodenal

ا