Hernias & ruptures Flashcards
What is a hernia
- a protrusion of an organ or part of an organ through a defect in the wall of the anatomical area in which it normally lies
- generally consists of a hernia ring and sac
Hernia vs rupture
Hernia - generally consists of a hernial ring and sac.
Rupture - normally has no ring or sac
What is a prolapse?
- the movement of an organ or tissue out of its normal anatomical location, without passing through a deficit in the body wall, often occurring under the influence of significant force, e.g. uterine prolapse in cattle after calving or rectal prolapse in puppy with tenesmus
Hernial locations
- umbilical
- inguinal
- incisional
- diaphragmatic
- perineal
- pericardio-peritoneal
- hiatal
What hernial location is most common?
- umbilical
Aims of hernial surgery
- return hernia content to normal location
- secure closure of neck of sac
- obliterate redundant tissue in the sac
- try to use the pts own tissues for repair
How to reduce the hernia
- some are non-reducible
- directly incise over site
- ensure adequate exposure
- try to use atraumatic technique
- breakdown adhesions
- check viability of herniated tissues esp if strangulated hernia
- reset non-viable tissue before returning to abdominal cavity
Defect closure - how to
- direct opposition if possible
- use sufficiently strong suture material e.g. polydioxanone, polypropylene
- monofilament to avoid sinus formation
Tensionless closure
- use muscle flap e.g. internal obturator for perineal hernia
- polypropylene mesh if necessary
- well tolerated, allows capillary and granulation tissue in growth
- strict asepsis
- omentum
- eliminate dead space, drains if necessary
Umbilical hernia - signalment, aetiology
- generally young
- usually congenital due to failed embryogenesis
- thought to be inherited
- true hernias lined by peritoneal sac
- can see in association with cryptorchid dogs
Umbilical hernia - CS / presentation
- clinically soft, painless swelling at umbilicus
- may be v+/abdominal pain if strangulation of bowel
- normally reducible
Umbilical hernia - what does it normally contain?
- fat/omentum
- occasionally intestine
Umbilical hernia - where else should you check?
- diaphragm and heart
Umbilical hernia - diagnosis
- radiography not normally necessary
- diagnose on palpation
Umbilical hernia - tx
- can resolve spontaneously, or be correct at neutering
- repair by reducing, incise over hernia, excise sac and repair muscle edges
- don’t deride margins
- close with synthetic, absorbable, monofilament suture e.g. polydioxanone
What is an incisional hernia?
- surgical closure of the body cavity fails
- generally lines alba
- normally within 7d (as this is the weakest time for wound healing)
- can be chronic
Incisional hernia - causes
- incorrect surgical technique
- incorrect suture material/pattern
- entrapped fat between wound edges
- infection
- steroid therapy / cushingoid pt
- poor post op care
Incisional hernia - signs
- oedema, inflammation and serosanguinous fluid often pre-empt
- soft painless swelling
- palpable defect
- exposed viscera
Incisional hernia - investigations
- commonly obvious but in some cases US might be useful
- similar with x-rays and advanced imaging
Incisional hernia - tx
- repair asap
- evisceration is an acute abdominal emergency
- lavage and resect nonviable tissues / anastomose bowel if necessary
- re-open and repair entire wound
- only debride edges if infection or are nonviable
- suture external seats of rectus abdominis (strongest holding layer)
- ensure monofilament suture, long lasting and appropriate size
- chronic hernias often more difficult due to adhesions
Traumatic abdominal rupture - cause? position?
- caused by blunt trauma/bite
- flank
- prepubic
- prepubic tendons can rupture associated with pelvic fracture
Traumatic abdominal rupture - tx
- same hernia repair principles
- contaminated wounds e.g. bites, lots of lavage and avoid mesh
- identify free edge of abdominal wall and reattach to cranial pelvic brim if prepubic tendon rupture
- prognosis relates to organs involved
Inguinal hernia - what is it? aetiology? signalment?
- due to congenital inguinal ring abnormality or trauma
- intestine, bladder or uterus can enter subcutaneous space
- omentum is most common content
- can be associated with obesity/pregnancy
- thought to probably be inherited -> recommend neutering
- scrotal hernia is rare form (can be traumatic) or post castration in small mammals with large inguinal rings and open methods
- non traumatic inguinal hernias mainly seen in intact female middle aged dogs or under 2y/o male dogs
- small breeds e.g. Cairn/WHWT
Inguinal hernia - CS
- non-painful inguinal swelling
- painful if incarcerated contents
Diaphragmatic rupture - cause
- relatively common presentation following RTAs
- can be congenital (hernia)
- results from including abdominal pressure with open glottis
- tear in diaphragm allows abdominal content to move into thorax
Diaphragmatic rupture - which portion of the diaphragm is most commonly affected? why?
- muscular portion of diaphragm as weakest point
– diaphragm: tendinous centre and muscular rim - radial or circumferential tears
– radial = tear straight up through the muscle
– circumferential: muscle comes right off the chest wall
Diaphragmatic rupture - CS
- normally present shortly after trauma shocked
- pale/cyanotic
- tachypneoic/dyspnoeic
- tachycardia
- occasional cardiac arryhthmias
- hydrothorax
Can be chronic injury with resp/GI signs
- exercise intolerance
- dyspnoea
- v+
- weight loss
Occasional incidental finding
Diaphragmatic rupture - investigations
Radigraphy
- loss of diaphragmatic line
- loss of cardiac silhouette
- present of gas filled structure in thorax
- atelectasis
- displaced abdominal organs
Water soluble contrast into abdomen
US, esp in chronic cases
Diaphragmatic rupture - tx
- oxygen
- IVFT & warm up
- higher mortality of surgery performed less than 24h following injury (also greater than 1y/o)
- acute gastric distension, need to operate asap
- prophylactic antibiotics due to toxin release from organ strangulation
- ECG
Perineal hernia - prevalence, CS, signalment
- not uncommon
- can be spectacular
- bulging perineal area
- faecal tenesmus/dysuria
- normally entire older male
- occasionally bitch/cat
Perineal hernia - cause
- progressive weakening of pelvic diaphragm
- hormonal influence
- tenesmus
- congeital/acquired weakness
- colitis/prostatomegaly
Relevance of pelvic diaphragm re perineal hernia
- levator ani, coccygeus and external anal sphincter muscles provide lateral support to the anus
- disruption to this causes rectal enlargement, faecal impaction and tenesmus
- can be bilateral
- pelvic fat, peritoneal fat, prostate and bladder can herniate
Perineal hernia - diagnosis
- reducible perineal swelling
- on rectal, absence of pelvic diaphragm
- always check for bilateral dz
- assess sphincter tone: chronic case can remain incontinent
- US hernia/contrast urethrography will highlight bladder
Perineal hernia - bladder retroflexion
- emergency
- stranguria
- hyperkalaemia
- azotaemia
- avascular necrosis
Perineal hernia - tx
- cystocentesis through perineum if bladder retroflexed and can’t pass urethral catheter
- IVFT (check K levels if urinary obstruction)
- herniorrhapy
Perineal hernia - complications
- faecal incontinence
– suture placement
– duration of problem - urinary problems
- infection
- rectal prolapse
- sciatic nerve entrapment
- recurrence
Hiatal hernia - breed predisposition
- brachycephalic breeds
- shar pei
Hiatal hernia - what is it?
- congenital defect
- the hiatus where the oesophagus runs through from thorax to abdomen is wider than it should be and so can see signs of oesophagi’s & regurgitation
Hiatal hernia - CS
Clinically v similar to oesophagitis
- regurgitation
- hypersalivation
- visceral discomfort
Normally thin
Hiatal hernia - diagnosis
Radiography
- soft tissue opacity in dorso-caudal thorax adjacent to diaphragm
Fluoroscopy
Endoscopy
Hiatal hernia - tx
Treat oesophagitis
- antacid
- sucralfate
- prokinetic
- antibiotic (if aspiration)
Surgery
- ventral midline coeliotomy
- reduce hernia at oesophageal hiatus and close
- pexy oesophagus to diaphragm
- pexy stomach to body wall
Peritoneopericardial diaphragmatic hernia (PPDH) - what is it?
- congenital communication between pericardial sac and abdomen
- faulty development of septum transversum
- often cardiac/sternal deformity in association
Peritoneopericardial diaphragmatic hernia (PPDH) - CS
- can be asymptomatic
- GI or resp signs e.g. v+/d+, anorexia, weight loss, wheezing, dyspnoea
Peritoneopericardial diaphragmatic hernia (PPDH) - breed predispositions
- Weimaraner
- cocker spaniel
Peritoneopericardial diaphragmatic hernia (PPDH) - investigation
Radiography
- enlarged cardiac silhouette
- dorsally displaced trachea
- gas opacities in pericardial sac
US
Contrast radiography
Peritoneopericardial diaphragmatic hernia (PPDH) - surgery
- ventral midline coeliotomy
- incise sternum if necessary
- reduce viscera
- suture diaphragm
– no need to separately close pericardium
