Intestinal atresia and stenosis

Congenital intestinal obstruction occurs in approximately 1:2000 live births and is a common cause of admission to a neonatal surgical unit Morphologically, Congenital defects in the continuity of the intestine are divided into either atrasia or stenosis and constitute one of the most common causes of the neonatal intestinal obstruction.

Pyloric atrasia In this case pyloric canal is completely obliterated by either a diaphragm or a solid core of tissue. nonbilious vomiting and upper abdominal distention single gas bubble or air /fluid level with gasless abdomen. Treatment.

Duodenal atrasia and stenosis Etiology : intrinsic or exstrinsic lesion. The intrinsic lesion is most commonly occurs due to failure of recanalization of the fetal doudenum. The extrinsic causes occur due to defects in the development of neighboring structures such as the pancreas, a predoudenal portal vein or malrotation and ladd`s bands.

Pathology: 1- the site of obstruction is either pre or postampullary (mostly 85% it is post) 2- the stomach and proximal duodenum dilates to several times but perforation is rare 3-distal bowel are collapsed

Diagnosis Prenatal diagnosis: Postnatal diagnosis Investigation double bubble sign with no distal bowel gas. Treatment: resuscitation then surgical correction in form of duodenodoudenostomy.

Post operative complications(early and late ):

Jejunoileal atrasia and stenosis Etiology it is generally accepted that jejunoileal atresia occurs as a result of an intrauterine ischemic insult to the midgut, affecting single or multiple segments of the already developed intestine with ischemic necrosis of the sterile bowel and subsequent resorption of the affected segment or segments.

Morphological classification

Type I: Mucosal atresia with intact bowel and mesenetery TypeII: Blind ends separated by a fibrous cord Type III(a): Blind ends separated by a V-shape mesenteric defect Type III(b): Apple-peel atresia Type IV: Multiple atresias (string of sausages)

Diagnosis Prenatal diagnosis: Postnatal diagnosis Investigation Treatment: resuscitation then surgical correction.

Colonic atrasia Diagnosis: Prenatal : by antenatal U/S shows colonic diameter larger than expected for gestational age. Postnatal: erect abdominal radiograph:distal bowel obst. Contrast enema :confirm colonic atrasia Treatment : resuscitation then surgical correction.

Infantile hypertrophic pyloric stenosis It is the most common surgical cause of vomiting in infancy. Incidence: its incidence is increasing, male affected 4 times than female and the 1 st born male baby is a risk factor. Etiology : the true etiology is unknown; possible theories includes: congenital redundancy of pyloric mucosa. Abnormalities of local enteric innervation. Prenatal exposure to erythromycin.

Presentation patient is 2-8 wks of age. has postprandial,forceful, nonbilious vomiting commonly refer to as Projectile.and the baby is typically hungery after vomiting eager to eat, only to vomit once again.

Diagnosis: Clinical exam. Investigations :US upper GI contrast. Treatment : preoperative preparation Serum electrolytes should always be determined.the most common abnormalities is hyponatremic hypochloremic hypokalemic metabolic alkalosis with paradoxical acidurea.

Preoperative placement of NG tube is controversy. Surgical operation is by Ramstedt`s operation since 1912 which is extramucosal muscle-splitting pyloromyotomy operation.

Postoperative complications : Mucosal perforation. persistant vomiting beyond 48hrs mostly due to gastric atony. Duodenal injury Incomplete pyloromyotomy. wound infection and dehiscence 1%

Imperforated anus and cloacal malformation It is congenital malformation that affect the more distal part of the GI tract.

Classification: Male defects female defects Rectoperineal fistula Rectourethral bulbar fistula Rectovestibular fistula Rectourethral prostatic fistula Cloaca Rectobladder neck fistula Complex malformations Imperforated anus without fistula Rectal atrasia Rectal atresia

Recto perianal fistula : which is previously called low type in such a case: the rectum located within the sphincter but its lowest part is anteriorly mislocated. Diagnosis is clinical by inspection, there is a fistula. Treatment by anoplasty without protective colostomy in the 1 st 48 hrs of life.

Rectourethral fistula: 1-it is the most frequent defect in the male patients. 2- the fistula may be located at the lower (bulbar) or the higher (prostatic) part of urethra. The bulbar type associated with good functional prognosis because there is good muscle quality, well developed sacrum,and prominent midline groove. the prostatic type associated with poor functional prognosis.

Diagnosis : clinical and radiological Treatment Resuscitation divided descending colostomy (PSARP) posterior sagital anorectoplasty

rectovestibular fistula : it is the most common female defect with excellent functional prognosis. Diagnosis is clinical one by inspection. Treatment by doing protective colostomy then definite procedure. Cloaca: it is a defect in which the rectum, vagina, and urinary tract meet and fuse, creating a single common perineal channel, the diagnosis is clinical by inspection.