BOWEL OBSTRUCTION IN NEWBORN
ANATOMY/ EMBROLOGY GIT develops from 4 sections (blind ending tubes)
Pharyngeal gut Fore gut Mid gut Hind gut
Development process of gut
Lateral folding of the fetus Cell Migration ( neural crest cells) Connection/ fusion of guts Proliferative obliteration of gut Recanalization Physiological herniation Rotation Return of gut Mesentery attachments/ fixation 10-1
Level of obstruction
Upper I.O
Involves obstruction prox to ligament of treitz
Lower I.O
Obstruction distal to ligament of treitz
Upper I.O
Duodenal atresias/webs Small bowel atresias Malrotation/midgut volvulus Meconium ileus pyloric stenosis Inguinal hernia
Lower GI obstruction
Colonic atresia Meconium plug Hirschsprungs Small Left Colon Syndrome Magalocystis-Microcolon Intestinal Hypoperistalsis Syndrome Imperforate anus
General Clinical features
Varies with level of obstruction Present in the first 12-24 hrs of life Pyrolic stenosis 3-6 weeks
Vomiting Abdominal distension Failure to pass Meconium Features of dehydration
Look out for associated malformations(VACTERL)
Pyloric stenosis
Due to hypertrophy of the circular muscles in the pylorus Presents 3-6 weeks Late with features of malnutrition (FTT) Non bilious vomiting Hungry infant Abd. X ray- beak sign Rx- pyloromyotomy
Duodenal atresia
It is usually a complete stenosis of the 2nd part of duodenum at the level of ampulla of vater. defective fusion of foregut and midgut with failure of recanalisation Associated with annular pancreas and other congenital abnormalities Also maternal polyhydraminos
Clinical features
Jaundice. Bilious/nonbilious vomiting immediately after birth. Features of GOO Dehydration Growth retardation of new born
Treatment
Duodenoduodenostomy
Intestinal Atresia
Failure in recanalization of gut It is jejunoileal atresia.proximal jejunum,distal ileus intestinal obstruction soon after birth Bilious vomiting is in(jejunal atresia) abdominal distension (ileal atresia). Meconium(pale small amounts) Maternal polyhydraminos(35% J A)
Griesfield Modification of Martins Classification of Intestinal Atresia
Type I Membranous/mucosal with normal mesentery . Type II The lumen is atretic fibrous cord between proximal and distal parts of the segment involved (only one atretic segment) but mesentery is normal 40%. Type III (a) Atresia with complete separation of proximal and distal ends and V-shaped defect of mesentery 35%. Type III (b) Atresia with christmas tree-shaped defect in mesentery with distal bowel being supplied by single artery right colic/ileocolic/superior mesenteric apple peel atresia. Type IV Multiple atresias 5%.
Clinical features
LBW infants Bilious vomiting Features of IO Respiratory distress Jaundice
Treatment
Resection and anastomosis Tapering proximal jejunoplasty
Malrotations
Interference in the process of normal rotation of mid gut in the fetus Different errors Stage 1 Exomphalos major/minor or gastroschisis. Stage 2 Nonrotation Causing small bowel in right side; colon in left side
Incomplete rotation Caecum is located in sub hepatic RHQ _Reverse rotation colon posterior to SMA and duodenum _Hyper rotation Rotation up to 360 or 450causing caecum on left side of the abdomen Stage 3 mobile caecum and ascending colon leading into caecal volvus
treatment
Laparotomy with horizontal incision
Hirschprungs disease
Also called congenital megacolon/aganglionic MC due to an absence of parasympathetic ganglia in the bowel wall ganglia are derived from neural crest cells that migrate from the neural folds to the wall of the bowel mutations in receptors of crest cell migration rectum most 80% the defect extends to the midpoint of the sigmoid. 10 to 20% transverse and right-side colonic segments i and in 3% the entire colon is affected Abd distension, bilious emesis, obstructive enterocolitis
Investigations
Barium Enema
Transition zone
Anorectal Manometry
shows failure of reflexive relaxation not very helpful in infants, young children
Rectal Biopsy
Absence of Ganglion cells and hypertrophy of nerves
Acetyl cholinesterase staining increased staining of neurofibrils
Anal malformations
High malformation Anus is absent May present with a fistula -Vagina in the females -Prostate or bladder in the males
low malformations
Anus present but abnormal
Anal stenosis. Concealed Anus. Covered Anus. Cutaneous Fistula Anterior anus Vestibular anus
