Surgery Flashcards
acute apendicitis
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gastroschisis definition
full thickness abdominal wall defect in which foetal organs protrude outside the abdomen with no protective membrane covering it. Direct intestinal exposure to amniotic fluid in utero leads to chemical reactions, creating a thick inflammatory film or peel over the bowel
prevalence gastroschisis
1-6 per 10000 live births
gastroschisis patho
unknown
possible..compromised vascular supply to anterior abdo wall, defect in primordial umbilical ring, or abdnormal involution of R umbilical vein so weakened point at risk of rupture
risk factors gastroschisis
Maternal smoking (possibly due to placental insufficiency and abnormal development of the vascular system)
Maternal age <20 years old
Environmental exposures e.g. Nitrosamines
Maternal cyclooxygenase inhibitors use e.g. aspirin and ibuprofen
clinical features gastroschisis
can be present visible at birth or detected on prenatal USS at 20 weeks
often found to R of umbilicalcord
organs involed - S and L intestines, liver, stomach
swollen/thickened intestines
abdo cavity may appear smaller
intestinal malrotation sometimes - intestinal atresia
gastroschisis v omphalocoele
omphalocoele - no membrane covering abdo contents
extra intestinal or structural abnormalities
gastroschisis investigations
mainly clinical diagnosis
alpha fetoprotein - elevated
routine USS in 2nd trimester - detected
Ultrasonography - echogenic and dilated loops of bowel freely floating in amniotic fluid
coloured doppler - localise herniation
immediate management gastroschisis
fluid resus
maintain temp
sterile, clear covering over herniated contents
definitive management gastroschisis
surgery - protrude and close abdo wall
may need to be staged if large - nvolve placing the bowel in a clear sac called a silo, which is tightened until there is enough space to reduce the bowel completely
then NG tube and parenteral feeding
complications gastroschisis
Abdominal Compartmental Syndrome
Persistent bowel dysfunction
Wound infection
Necrotizing Enterocolitis
Short gut syndrome
Abdominal Compartmental Syndrome
prognosis gastroschisis
87-100% survival rates
intestinal atresia - poor prognostic factor
hirschsprung’s disease definition
also known as congenital aganglionic megacolon disease, is a congenital disease in which ganglionic cells fail to develop in the large intestine. This commonly presents as delayed or failed passage of meconium around birth.
prevalence hirschsprung’s disease
1 case per 1500-1700
median age 2 days
males 4 times more likley
genes hirschprung’s disease
those that encode the proteins for the RET signaling pathway and endothelin type B receptor pathway. The strongest association with Hirschsprung’s, is the Receptor tyrosine kinase (RET) gene, a proto-oncogene on chromosome 10q11. HD is strongly associated with chromosomal abnormalities, with 10-15% HD cases associated with trisomy 21 (Down Syndrome)
hirschsprung’s disease subtypes
short-segment - most common
long segment - aganglionosis extends past rectosignoid portion of colon to splenic flexture
total colonic aganglionosis disease - entire colon affected
hirschsprung’s disease pathophysiology
ganglionic cells of the myenteric and submucosal plexuses in the bowel aren’t present proximally from the anus to a variable length along the large intestine.
The most common accepted aetiology of this disease is due to the arrest of the neuroblast, derived from neural crest cell migration in fetal development between week 8 to 12.
hirschsprung’s enterocolitis
Increased intraluminal pressure can lead to decreased blood flow and deterioration in the mucosal layer. This stasis can lead to bacterial proliferation and the subsequent complication of Hirschsprung’s enterocolitis, which has a mortality rate of 25-30%. If not recognised early this can lead to sepsis and death
risk factors hirschsprung’s disease
males
chromsomal abnormalities - down’s
family hx - mutations
25% have classic triad in hirscsprung’s
failure to pass (within 48 hrs) meconium
abdo distention
billous vomiting
examination hirschsprung’s diease
faecal mass palpated in left lower abdomen
tympanic abdomen
empty rectal vault…forceful discharge of gas and faecal material
ddx hirschprung’s disease
meconium plug syndrome
meconium ileus
intestinal atresia
hirschsprung’s disease investigations
gold standard: rectal suction biopsy to confirm aganglionosis using acetylcholinesterase
contrast enema - short transition between proximal end of colon and narrow distal end of colon plus rectal diameter equal to sigmoid colon
laparatomy - if perfortation present as enema contraindicatedr
rectal suction biopsy guidelines
clinical features indicated, otherwise avoided:
Delayed passage of meconium (more than 48 hours after birth in term babies)
Constipation since first few weeks of life
Chronic abdominal distension plus vomiting
Family history of Hirschsprung’s disease
Faltering growth in addition to any of the previous features
management hirschsprung’s
IV abx
NG
bowel decompression
definitive - surgery - resecting aganglionic section and connecting unaffected bowel to dentate line
complications hirschsprung’s
Hirschsprung associated enterocolitis (HAEC) - c.diff, s.aureus
complications of surgery - constipation, enterocolitis, perianal abscess, faecal soiling, adhesions
risk factors inguinal heria
prematurity
male
fhx
management inguinal hernia
surgical repair - herniotomy on ful term male infants with asx reduciable hernias
emergency surgery if irreducible…testicular ischaemia
intussusception definition
the movement or ‘telescoping’ of one part of the bowel into another. The proximal bowel segment is referred to as the intussuceptum whilst the distal segment as intussucipiens
epidemiology intussception
5-7 mths of age
boys twice as more likely
pathophysiology intussception
leads to intestinal obstruction
up to 90% are ileo colic type -distal ileum passes into caecum through ileo-caecal valve
risk factors intessuscption
most are idiopathic
rotaviruses increase risk
pathological causes include Meckel diverticulum (most common)
Polyps
Henoch-Schönlein purpura
Lymphoma and other tumors
Post-operative
when pathological cause suspected in intussception
if child older
high recurrence rate
hx intrussception
sudden onset inconsolable crying episodes
pallor
draw up kneeds
normal inbetween episodes
lethargic
anorexic
red current consistency - blood and mucus stooll
older - obstruction features
examination intussecption
Distention
A palpable ‘sausage-shaped’ abdominal mass which can be found in the right upper quadrant (ileo-ceceal type)
Signs of peritonism
Presence of bowel sounds
dehydration and shock
ddx intessception
colic
testicular torsion
appendicitis
diagnosis intussception
abdo USS - dougnut/target sign on transverse plane and pseudokidney sign on longitudinal plane
AXR - distented small bowel loops, outline intussuception, rigler’s sign
contrast enema
management intussception
fluid resus
NG tube
non op reduction - air or contrast enema. c/i if perforation or peritonitis
surgical reduction - manually reduce and resection of necrotic bowel
complications intussception
obstruction -surgical emergency
perforation - venous congestion and oedema within bowel wall..necrosis and perforation
dehydration and shock
omphalocoele definition
a congenital, abdominal wall defect at the insertion of the umbilical cord. Abdominal contents herniates outside the abdomen within a membranous sac consisting of the peritoneum and amnion
prevalence omphalocele
1 in 5000 live births
pathophysiology
During normal development of the intestines, the midgut begins to elongate at around 6 weeks gestation. However, at this time the liver and stomach are also growing, meaning there is not enough room in the abdomen to accommodate the midgut. In order to continue developing, the midgut herniates through the umbilical ring out of the abdomen into the umbilical cord (called physiological umbilical herniation). During the 10th week, the abdomen has enlarged enough for the midgut to return (3).
The exact cause of omphalocele is unknown (4), however the main theory is failure of this normal intestinal migration back into the abdominal cavity, and persistence of the physiological umbilical herniatio
risk factors omphalocele
maternal smoking
maternal age >40 yrs
chromosomal abnormalities - triosomy,turners, klinefelters
clinical features omphalocele
4-12cm abdo wall defects located centrally within umbilical cord
protective membranes surroudning
healthy intestines
ddx omphalocele
gastroschisis
cloacal exstrophy
physiological gut herniation
omphalocele investigations
clinical diagnosis
prenatal USS or birth
alpha fetoprotein elevated
chromosomal abnormalities - chronic villus sampling or amniocentesis