Hernias Flashcards
What is a hernia? What is the difference between an external and internal hernia?
protrusion of a tissue or organ through a defect in the wall of the anatomical cavity in which it normally lies
- EXTERNAL = defect in external wall of the abdomen allows protrusion of abdominal contents
- INTERNAL = through a ring of tissue confined within the abdomen or thorax
What is the difference between true and false hernias? How do traumatic hernias commonly start?
- TRUE = anatomical hernia with a peritoneal sac
- FALSE = lack of hernial sac with protrusion of organs outside of normal abdominal opening
initially false hernias that tear through the body wall and eventually develop a sac
What are the 3 most common internal locations of hernias?
- diaphragmatic
- hiatal
- intercostal
What are the 8 most common external anatomical locations of hernias?
- paracostal
- dorsal lateral
- inguinal
- cranial pubic ligament rupture (prepubic)
- femoral
- umbilical
- ventral
- scrotal
(+ intercostal)
What is omphalocele?
large neonatal defect of the abdominal wall resulting in the intestines, liver, and other organs (covered in amniotic tissue) sticking outside through the umbilicus
- grave prognosis - outside during fetal development and compartment syndrome makes it hard to place organs in their normal positiongs
How are hernias diagnosed?
- Hx: usually just swelling, unless strangulation is present
- PE and palpation
- radiograph shows organs within the SQ
- ultrasound - intestine vs. fat vs. lipoma
- advanced imaging - CT
What is an incarcerated hernia? What do they commonly lead to?
contents are irreducible and trapped
strangulation - ischemia, tissue death
What is a strangulated hernia?
blood supply of the organs stuck in the hernia becomes compromised, leading to ischemia and necrosis —> requires emergency surgical correction
What sized hernias are the most dangerous?
small - more likely to strangulate organs that make it through
(large hernias allow free movement of organs in and out)
What is loss of domain?
chronic hernias result in compartment syndrome due to constricted abdominal muscles making the normal location too small to accomodate reduced contents
What is compartment syndrome? What does it commonly result in?
increase in pressure within a compartment that results in a restriction of the blood flow to the area
tissue death due to ischemia and free radical formation
What are the 4 principles of herniorrhaphy?
- return contents to the normal location
- secure ring closure
- tension-free closure
- utilize patient tissues
What suture material is preferred for herniorrhaphy? What can also be used?
non-absorbable nylon - lasts longer
absorbable PDS
How is an open herniorrhaphy performed?
- hernial sac is incised and removed
- edges are freshened by removing the hernial ring
How is a closed herniorrhaphy performed?
- invert sac and contents without opening the hernial sac
- freshening edges by removing the hernial ring is NOT necessary and avoided if possible
What is an umbilical hernia? When is strangulation or obstruction suspected?
true hernia due to the failure of fusion of rectus abdominus muscle at the umbilicus that may close spontaneously around 6 months
if the umbilical sac is irreducible and warm/painful
What breeds have a predisposition for umbilical hernias? What other defects should be looked for?
- Airedales
- Pekingese
- Basenjis
- Pointers
- Weimeraners
cleft palate, cryptorchidism, cardiac
What treatment options are available for umbilical hernias?
- monitor initially, if young
- primary reconstruction
- repair when neuters or other surgeries
How is a herniorrhaphy performed for umbilical hernias? What should be done if strangulation or obstruction is present?
- reduce contents if possible
- incise directly over hernia or around base if irreducible
- open hernial sac
- excise the sac (no trimming of hernial ring)
- suture with non-absorbable or absorbable sutures
extend the defect on midline
What is the difference between congenital and acquired inguinal hernias?
CONGENITAL = younger dogs < 2 y/o, male dogs
ACQUIRED = non-traumatic, middle-aged and intact males
What are the most common inguinal hernia? What can this be mistaken as?
left unilateral —> neuter animals with it!
caudal abdominal fat pads in obese cats
What are the 4 multifactoral pathogeneses of inguinal hernias?
- genetic
- obesity
- trauma
- estrogen influence - estrogen, pregnancy
What is the difference between direct and indirect inguinal hernias?
DIRECT - outpouching of peritoneum and abdominal contents adjacent to the inguinal canal
INDIRECT - outpouching of peritoneum (vaginal process) and abdominal contentd through the inguinal canal (young males and mature females; + scrotum and intestines)
What is present in the internal and external ring of the inguinal canal?
INTERNAL - internal abdominal oblique muscle, rectus abdominus muscle, inguinal ligament
EXTERNAL - slit in the external abdominal oblique muscle
What are the 3 contents of the inguinal canal?
- spermatic cord
- genitofemoral artery, vein, nerve
- external pudendal artery and vein