Hernia

Question 1

what is a hernia?

Answer 1

full-thickness defect in an anatomical structure allowing protrusion of viscera

Question 2

what are the two components of hernias?

Answer 2

ring (border of defect)
sac (mesothelial layer covering the herniated contents)

Question 3

what are the types of hernia?

Answer 3

internal/external
true/false
spontaneous/acquired
reducible/incarcerated/strangulating

Question 4

what is an internal hernia?

Answer 4

within the body

Question 5

what is an external hernia?

Answer 5

herniation through the body wall into the subcutaneous space

Question 6

what is a true hernia?

Answer 6

herniation through a preexisting anatomical structure (such as inguinal ring)

Question 7

what are some negative impacts of hernia?

Answer 7

loss of domain
incarceration (entrapment of organ, obstructing perfusion or lumen)
strangulation

Question 8

what is loss of domain in relation to hernias?

Answer 8

large hernias (such as abdominal) can lead to the wall getting used to having less content in it making reducing them very difficult, reducing them can increase pressure leading to perfusion issues

Question 9

why are strangulating hernias an issue?

Answer 9

decreased perfusion leading to necrosis and rupture
releasing contents can worsen the condition

Question 10

which are effected first by strangulating hernias, venous or arterial vessels?

Answer 10

venous (thinner walled and lower pressure)

Question 11

what causes umbilical hernias?

Answer 11

incomplete fusion of ventral abdominal wall

Question 12

can animals with umbilical hernias be bred from?

Answer 12

should be as it is often an inherited condition

Question 13

what are the two types of inguinal hernias?

Answer 13

direct and indirect

Question 14

what is a direct inguinal hernia?

Answer 14

herniation through the inguinal ring into the subcutaneous space adjacent to the vaginal process

Question 15

what is an indirect inguinal hernia?

Answer 15

herniation through the inguinal ring into the cavity of the vaginal process

Question 16

what dogs are inguinal hernias usually seen in?

Answer 16

intact middle aged female dogs

Question 17

what are some aetiologies of inguinal hernias?

Answer 17

short inguinal canal of females
weakening/enlargement of inguinal rings - oestrogen, malnutrition, catabolic disease, obesity

Question 18

what type of hernias are scrotal hernias?

Answer 18

indirect inguinal hernias

Question 19

why do traumatic hernias often strangulate?

Answer 19

the ring constricts as the hernia heals

Question 20

why are traumatic hernias often prone to incarceration?

Answer 20

usually lack a sac so are more prone to adhesions

Question 21

what is an incisional hernia?

Answer 21

dehiscence of a surgical abdominal wound

Question 22

what can cause an incisional hernia?

Answer 22

excessive force on incision - obesity, effusions/ascites, activity/straining
poor holding strength of wound - delayed healing (infection/medication), incorrect suture/knot

Question 23

what are some clinical signs of incisional hernias?

Answer 23

inflammation/oedema
swelling around wound
evisceration (content through skin)

Question 24

what causes congenital peritoneopericardial diaphragmatic hernias?

Answer 24

failing of fusion of transverse septum of the diaphragm on the midline

Question 25

what are the clinical signs of congenital peritoneopericardial diaphragmatic hernias?

Answer 25

asymptomatic
respiratory signs - dyspnoea, cough, wheeze
GI signs - anorexia, polyphagia, vomiting
right heart failure due to tamponade

Question 26

why can congenital peritoneopericardial diaphragmatic hernias cause right sided heart failure?

Answer 26

due to tamponade

Question 27

what causes traumatic diaphragmatic hernias?

Answer 27

blunt force trauma whilst glottis is open (no counter pressure exerted on the diaphragm from the chest)

Question 28

what are the main clinical signs associated with traumatic diaphragmatic hernias?

Answer 28

respiratory - lung compression, pleural effusion, chest wall dysfunction

Question 29

what causes perineal hernias?

Answer 29

weakness/separation of pelvic diaphragm

Question 30

what forms the pelvic diaphragm?

Answer 30

external anal sphincter
elevator ani
coccygeus muscles

Question 31

what are possible aetiologies of perineal hernias?

Answer 31

inherited predisposition
androgens (testosterone) - common in older intact males

Question 32

what can reduce the risk of perineal hernias in males?

Answer 32

castration (reduces androgen)

Question 33

what are the clinical signs of perineal hernias?

Answer 33

unilateral/bilateral perineal swelling
erythema/oedema
faecal tenesmus
constipation
flatulence
faecal incontinence
altered tail carriage

Question 34

what are the indications for repairing hernias?

Answer 34

pain, inflammation, incarceration/strangulation
effecting animals quality of life
risk of hollow organ incarceration/strangulation

Question 35

what are the goals of hernia repair?

Answer 35

ensure entrapped organs remain viable
release viable contents to their original location
obliterate redundant sac
tension-free closure

Question 36

what are some possible complication of hernia repair?

Answer 36

surgical - anaesthetic, haemorrhage, contamination, inability to close, loss of domain, poor tissue strength
early post-operative - serum, haematoma, infection, dehiscence, pain
late post-operative - recurrence, infection