Soft tissue surgery (hernias) Flashcards
what is a hernia?
full thickness defect in an anatomical structure allowing protrusion of viscera
what are the 2 components of a hernia?
ring (border of defect)
sac (mesothelial layer coating hernia)
what are the types of hernias?
internal/external
true/false
spontaneous/acquired
reducible/incarcerated/strangulating
what is a true hernia?
hernia through an existing anatomical opening
what is a false hernia?
hernia through a rupture/trauma (opening that should be there)
what is an incarcerated hernia?
one that isn’t reducible through the ring
what are some pathophysiological consequences of hernias?
loss of domain
incarceration
strangulation
what does loss of domain mean when describing a hernia?
the cavity adapts to lower its volume to having less contents in it so it makes repair harder and increased pressure when put back in (compartment syndrome)
what is the main problem of incarceration?
lumen of the herniated structure can become obstructed
what is strangulation of a hernia?
loss of blood supply to the herniated structure leading to necrosis and possibly rupture (release of the contents can worsen the condition)
what can cause a delayed strangulating hernia?
traumatic hernia ring healing and fibrosis causing constriction to the contents
what should be done to hernia contents of strangulating hernias?
resect them if they aren’t viable to prevent the release of toxins
what causes umbilical hernias?
an incomplete fusion of the ventral abdominal wall
what are the two types of inguinal hernias?
direct and indirect
what is a direct inguinal hernia?
herniation through the inguinal ring adjacent to the vaginal process into subcutaneous tissue
what is an indirect hernia?
herniation through the inguinal ring into the cavity of the vaginal process
what are some possible causes of weakened/enlarged inguinal rings?
oestrogen
malnutrition
obesity (increased intrabdominal pressure)
what type of hernia is a scrotal hernias?
indirect inguinal hernia (of male dogs)
are scrotal hernias usually reducible?
tend to be incarcerated or strangulated
why are traumatic hernias more prone to adhesions/incarceration?
lack a hernia sac due to peritoneal being torn during trauma (ring constricts during healing leading to strangulation)
what causes an incisional hernia?
dehiscence of a surgical abdominal wound
what may cause dehiscence of a surgical wound leading to herniation?
excessive force on inaction (obesity, effusions, straining…)
poor holding strength (delayed healing, poor suturing…)
what is a diaphragmatic hernia due to?
failure of fusion of transverse septum resulting in midline communication between abdomen and pericardium
blunt force trauma
what are possible clinical signs of an umbilical hernia?
can be asymptomatic
respiratory - dyspnoea, tachypnoea, cough…
GI signs - anorexia, polyphagia, vomiting…
right sided heart failure (tamponade)
how do traumatic diaphragmatic hernias occur?
blunt force trauma with the glottis open - increased pleuroperitoneal pressure gradient causing tearing of muscle of diaphragm
what is perineal hernias due to?
weakness/separation of pelvic diaphragm
what is the aetiology of perineal hernias?
inherited (certain breeds predisposed)
androgens (more common in older intact males)
relaxin secreted by prostate
tenesmus
neurogenic myopathy
what are the clinical signs of perineal hernias/
erythema or oedema
constipation
faecal tenesmus/pain on defaecation
flatulence
faecal incontinence
altered ail carriage
dysuria
what are the indications for hernia repair?
symptomatic (pain, inflammation…)
significant protrusion affecting quality of life
significant risk of incarceration/strangulation
what are the goals of hernia repair?
ensure entrapped content is viable
released and return viable content
obliterate redundant sac
tension free closure
what hernias is a ventral midline coeliotomy indicated for?
bilateral hernias
internal abdominal hernias
traumatic hernias
strangulating hernia
can can complications associated with hernias be prevented?
prepare/stabilise patient
correct predisposing factors
correct surgical technique
good post operative care
rapid treatment/recognition of complications
what needs to be checked for in cases of umbilical hernias?
other congenital defects (frequently coexist with other defects)
how are umbilical hernias treated?
small hernia (<3mm) in very young (<6 month old) animals often close spontaneously
neuter animals (inherited)
surgery if risk of incarceration/strangulation
how are inguinal hernias treated?
ASAP after diagnosis - midline if complicated and over hernia if uncomplicated
what should be caught in the suture of an inguinal hernia repair?
inguinal ligament, rectus fascia and internal oblique fascia
what are some common complications of inguinal hernia repair?
infection
haematoma/seroma (because of high movement area)
pain/reluctance to walk
nerve/vessel compression
what is the prognosis for inguinal hernia surgery?
tend to be good with limited reoccurrence
how are traumatic hernias treated?
stabilise patient (other injuries are probable)
support hernia with bandage and delay surgery for a few days
why is surgery of traumatic hernias delayed a few days?
improve blood supply
reduced haemorrhage
resolve oedema
(don’t leave too long as you risk of fibrosis/incarceration)
what are the indications for carrying out immediate surgery on a traumatic hernia?
if patient can’t be stabilised
if patient deterioration is due to hernia
if hernia is associated with penetrating wound
what is the best way to surgically repair an acute traumatic hernia?
ventral midline coeliotomy (able to inspect abdominal contents for other injury)
how are acute incisional hernias treated?
support wound with bandage
(determine cause)
open - reopen original suture if uncomplicated
deride fat/tissue then close again
how are chronic incisional hernias treated?
conservative - asymptomatic and no incarceration
surgical repair if needed
if evisceration occurs due to an incisional hernia, what is the treatment?
protect viscera (dressing and collar)
stabilise and repair (may need a drain to be placed)
what is the best way to diagnose a peritoneal-pericardium diaphragmatic hernia?
thoracic radiography (enlarged/rounded cardiac output and abnormal soft tissue in thorax)
how are peritoneal-pericardium diaphragmatic hernias treated?
best to do surgery - ventral midline coeliotomy, reduce viscera, close defect and drain air from pericardial sac
how do traumatic diaphragmatic hernias often present?
tucked up abdomen
reduced heart sounds
borborygmi in thorax
displaced apex beat
how long should you wait to repair a traumatic diaphragmatic hernia?
until the patent is stable enough for anaesthesia
what post operative care do traumatic diaphragmatic hernias need?
ICU (complex surgery and often need referral)
what is a very good way to diagnose perineal hernias?
rectal examination (gap in the muscle) - check for other lesions whilst doing this
how are perineal hernias fixed by surgery?
internal obturator transposition
