Hernias Flashcards
What is a hernia?
Protrusion of an organ through a defect or opening in the wall of the anatomic cavity which it is normally contained
Hernias can be traumatic/Acquired or congenital where is the defect in those two creating the hernia?
Traumatic/Acquired:
- abdominal
- incisional
- diaphragmatic
-> defect created at origin/insertion of body wall muscles
Congenital:
- umbilical
- inguinal
- scrotal
- femoral
- peritoneal-pericardial diaphragmatic
- hiatal
-> defect in normal anatomic opening of the abdominal wall
What are the 3 parts of a hernia?
- The ring - defect in the wall
- The sac - peritoneum lining the hernia contents
- Contents - organs or tissue that has moved into the hernia ring
What is a true hernia and what is a false hernia?
True hernia: with peritoneal lining
False hernia: no peritoneal lining
Reducible or non-reducible contents - what do both of these mean?
Reducible: abdominal contents can be pushed back into abdominal cavity
Non-reducible:
-> Incarcerated - adhesions have formed which prevents reduction
-> Strangulated - blood supply to a herniated organ is compromised (size of ring plays a role)
What are the signs of an uncomplicated and a complicated hernia?
Uncomplicated hernia:
- Non painful
- Reducible vs. non-reducible
Complicated hernia:
- Congenital: painful
- Traumatic: local tissue swelling and inflammation, may not be evident immediately after trauma (no contents yet)
What are the muscles that “make” the abdominal wall?
External abdominal oblique
Internal abdominal oblique
Transverse abdominal
Rectus abdominis
Which 3 muscles/structures make up the internal inguinal ring?
internal abdominal oblique
inguinal ligament
rectus abdominis
What makes up the external inguinal ring?
The longitudinal slit in aponeurosis of the external abdominal oblique muscle
Which structures go through the inguinal canal?
- Genital branch of genitofemoral a. v. n.
- External pudendal vessel
- Spermatic cord (males)
- Round ligament (females)
When doing surgery have to leave some space open for these structures to come out.
What is a very common congenital hernia?
Umbilical hernia
-> through umbilical ring (umbilical vessels, vitelline duct, stalk of allantois
-> Flaw in embryogenesis - heritable
What are the signs of an umbilical hernia?
- unnoticed
- soft ventral abdominal masses at umbilical scar
- ring may close as late as 6 months
- rarely intestine may herniate (size dependant)
What are the key points for a surgical repair of an umbilical hernia?
- Incision avoiding hernia contents
- amputate hernia sac (peritoneal lining)
- reduce contents
- do at the same time as spay/castrate
- close external rectus sheath
What is the differentiation between a direct and an indirect scrotal/inguinal hernia?
Indirect (scrotal) -> content comes out of inguinal canal and down the vaginal process into the scrotal sac
Direct (inguinal) -> comes outside of that inguinal ring and sits directly underneath the skin (doesn’t go down vaginal process)
Where should the incision be made if we are performing surgery on an inguinal hernia? which suture material and suture pattern should be used to close?
Midline incision - next to hernia (not straight over hernia!)
best to use non-absorbable suture such as prolene, horizontal mattress suture for tension relief! remember to leave enough room for artery and vein when making inguinal ring smaller.
Is a scrotal hernia a direct or indirect inguinal hernia?
Indirect inguinal hernia
Pre-pubic tendon rupture, paracostal and dorsolateral abdomen hernias are most commonly which type of abdominal wall hernias?
traumatic through either blunt trauma or bite wounds
How do we diagnose traumatic abdominal wall hernias?
-> Abdominal radiographs
- free intra-abdominal gas (penetrating wound vs perforated GI tract)
- Discontinuous abdominal wall
-> Ultrasound
- Evaluate soft tissue swelling
Important to evaluate other concurrent injuries (traumatic hernias) - CT scan!
What is most important in the treatment of traumatic abdominal wall hernias?
Life threatening conditions take priority -> Stabilise before surgery!
Delay surgery 3-5 days, wait for inflammation to reside and for tissue to strengthen = better repair!
Emergency surgery is indicated if the animal cannot be adequately stabilised due to hernia, if the herniated organs are progressively turgid or incarcerated, or penetrating wounds explored after emergency resuscitation
How do we treat acute hernias?
- Ventral midline celiotomy
- Full abdominal exploration
- Intra-abdominal repair
Herniorrhaphy
1. Ensure viability of entrapped hernia contents
2. Reduce and return viable hernia contents
3. Obliterate redundant hernia sac/space (drain)
4. Provide tension free and secure primary closure using strong healthy tissue
Which suture material and pattern do we use when closing a herniorrhaphy?
Monofilament non-absorbable or absorbable
- simple continuous +/- tension relieving sutures (horizontal mattress)
Which complications can occur with a herniorrhaphy?
-> Related to the amount and type of tissue traumatised
- Seromas, haematomas, infection (wound drainage, culture)
- Skin dehiscence is common with bite wounds (hernia failure not common)
- Recurrence (uncommon provided appropriate technique is used and proper post operative care given)
- Prognosis is excellent - depending on concurrent injuries
Which is the most common thoracic traumatic hernia?
Traumatic diaphragmatic hernia
- blunt force, car accidents
- mechanism of injury through sudden increase in intra-abdominal pressure with the glottis open
How do we diagnose a traumatic diaphragmatic hernia?
Thoracic radiographs!
- partial loss of the normal line of the diaphragm 97% of cases (not diagnostic alone)
- obscured or displaced cardiac shadow
- abdominal viscera within the thoracic cavity
- cranial displacement of pylorus or duodenum
Ultrasound
- pleural effusion, may not detect rent in diaphragm
CT
