SA commonly occuring hernias

When do incisional hernias usually occur?

Following abdo surgery —> usually due to surgeon error

• Can be acute (within 2 week of surgery) or chronic (weeks to years aftery surgery)

How does an incisional hernia present? How would you diagnose it?

• Swelling/mass at surgical site

• Carefully palpate wound for any defects —> confirm by US, rads, CT or surgical exploration (last resort)

How are acute incisional hernias treated?

• Hospitalise & support w/ bandage until surgery —> risk of evisceration

• Reopen & surgically explore

• Remove ineffectual sutures

• Debride devitalised fat/ tissue between wound edges then close primarily (PDS suitable)

How are chronic incisional hernias treated?

• Less risk of evisceration because skin healed

• Conservative management

  • if asymptomatic, no incarceration, owner can closely monitor

• Surgical repair

  • Approach over original incision

  • Identify ring and excise the edge

  • Close the defect primarily / as for chronic traumatic hernias

How do you manage evisceration?

• Surgical emergency

• Protect viscera using large sterile dressing and place collar

• Stabilise with fluid and AB

• Ex Lap, resect damaged viscera, debride wound edges, lavage and close abdo

• Close wound

How do body wall ruptures (traumatic ruptures) occur?

• As result of significant trauma e.g. RTA, fall, kick

  • multiple inuries & rupture may be overlooked initially —> check body wall ruptures, diaphragmatic ruptures, injuries to urinary tract

What are the most common body wall ruptures (traumatic rupture)

• Paracostal —> avulsion of muscles from last rib

• Rupture / avulsion of pre pubic tendon —> body wall ruptured off caudal attachement

How do acute body wall ruptures present?

• Marked bruising, swelling, pain @ site of rupture

• Patient may have concurrent life threatening injuries

• (Ability to palpate herniated organs subcutaneously is unlikely in acute injury)

^^^ prepubic tendon rupture —> muscle not attached dorsally (follow from ventral m.) —> do cd coeliotomy

intramuscular & intra abdominal haemorrhage —> high risk anaesthesia

local inflam, subcut tissue injury

• Referral!

How are body wall ruptures (acute presentation) diagnosed?

Imaging —> plain (± contrast) rads, U/S, CT

large clip

What should you do for cd abdo ruptures / concern for the urinary tract? (diagnosis)

retrograde urethrogram (RUG) & +ve contrast cystogram to assess integrity of bladder & urethra

How do you treat an acute body wall rupture?

• Delay surgery 1-5 days to stabilise

• Emergency surgery if cannot stabilise, penetrating abdo wound present or strangulation present

Explain the surgical approach to a body wall rupture repair

• Prepare large area

• Debride devascularised / necrotic tissue

• Repair m. layers individually

• Use appositional synthetic monofilament absorbable sutures

• Include strong tissues in repair (fascia / ligament / bone)

Consider referral for multidisciplinary approach (imaging, anesthesia, critical care, surgery)

How would a chronic body wall rupture present?

Patient presents w/ mass/swelling (= herniated tissue, may not be @ location of the hernia)

• Hernial ring may be palpable

• Herniated structures may be felt subcut

• Differentiate from seroma, neoplasia, cyst, abscess etc. (imaging)

How is a chronic body wall rupture treated?

• Surgery once diagnosis is confirmed via imaging

• Incise directly over rupture

• Enlarge hernial ring if needed to reduce herniated structures

• Repair as for acute hernias

Consider referral

Explain how a diaphragmatic rupture happens

• Usually due to blunt trauma w/ glottis open

• Incr pleuroperitoneal pressure gradient (due to air moving out of lungs through open glottis) causes tearing of m. of diaphragm

• Commonly ass. w/ RTAs, kicks, falls

What are the main presenting signs of diaphragmatic rupture?

• Dyspnoea (Incr RR and shallow, decr lung sounds)

• Lethargy

• Reduced appetite

• Borborygmi in thorax due to decr lung sounds

• Reduced/ abnormally positioned heart sounds

  • displaced apex beat due to herniated abdo contents

• Tucked up abdomen

• Can exist w/ other significant injuries e.g. long bone fracture (may be overlooked on initial presentation)

Cats can present weeks/ months after injury

How is diaphragmatic rupture diagnosed?

• Care re-positioning / handling —> risk of decompensation / death

• U/S —> do conscious in sternal recum

• Thoracic rads —> might have to do w/ single DV view

• CT (usually unnecessary)

What is being shown in this radiograph?

Diaphragmatic hernia

How do you treat an acute diaphragmatic rupture?

• Try to stabilise prior to surgery & GA

  • intra op risk of decompensation / death

  • induce → GA = short time as poss

• Tilt table so head / thorax slightly elevated

  • Can decompress —> prepare for intra-op manual ventilation

• Perform cr midline coeliotomy

• ID diaphragmatic tear (check for more), reduce herniated organs, assess viability → resect devitalised tissues

• Close tear (simple int / cont / cruciate mattress), drain thorax to resolve intra-op pneumothorax (chest drain?), check abdo organs for concurrent trauma

• Routine closure of abdo

How do you treat a chronic diaphragmatic rupture? How will it differ in acute presentation

• Surgical

  • More likely to be stable for GA (not suffered recent trauma)

  • May be adhesions of herniated structures making surgery more challenging

    • be prepared to extend incision to caudal sternum / abdo if required

  • Post- op greater risk of re-inflation pulmonary oedema (life threatening)

    • lungs squashed into smaller vol for long period of time → correction → more space in pleural cavity → ventilation → overinflated lungs too quickly → fibrotic lesions in lungs tear

    • place chest drain, empty air and fluid q.4-6hrs over a couple days

What causes a peritoneopericardial diaphragmatic hernia (PPDH)?

Congenital —> due to failure of fusion of transverse septum → midline communication between abdo & pericardium

often incidental finding

What does PPDH often commonly coexist with?

Other defects e.g. split caudal sternal, cr abdo wall defect etc.

What are the clinical signs of a PPDH?

• Often asymptomatic and is an incidental finding on thoracic radiographs

• Respiratory signs —> reduced volume of thorax for lungs to expand

  • Elevated respiratory rate, cough, exercise intolerance

• GI signs

  • Various including V+, D+, inapp, polyphagia, etc

• Cardiac signs

  • Sudden collapse

  • R-HF (tamponade)

What is this radiograph showing?

PPDH

• Massive cardiac sil w/ gas filled opacity superimposed and cannot differentiate from diaphragm

  • diaphragm fused with pericardium

• Dorsally displaced trachea

• V. clear silhouette because no movement as heart is just somewhere within sac

How do you treat a PPDH?

• Asymptomatic patients —> conservative management

• Symptomatic patients —> surgical repair

How is PPDH surgically repaired (symptomatic patients)?

• (clip higher up sternum)

• Ventral midline coeliotomy

• Reduce viscera (may need to extend defect)

• Resect any devitalised/strangulated tissues (unusual)

• Close defect with interrupted / cont. monofilament absorbable suture (cruciate mattress if under tension)

• For large defect —> harvest pericardium from attachment to diaphragm & use to close the defect → pneumothorax

• Drain air from pericardial sac (& pleural cavity using needle & syringe if caused pneumothorax)

• Routine closure of abdomen

What causes a perineal hernia?

Weakness of pelvic diaphragm = internal obturator muscles, levator ani & coccygeus muscles (either side of rectum)

dilation of rectum & accumulation of faeces

→ tenesemus & constipation

What is the typical presentation of a perineal hernia?

• Common

• Almost exclusively seen in middle aged/older male entire dogs (/ male dogs castrated in later life)

• Muscles of perineal diaphragm weaken & atrophy

What is being shown in this radiograph?

Perineal hernia can be seen @ same time as enlarged prostrate gland but not causative (cause most likely hormonal)

• distal colon gets squeazed → faecal material in rectum → defecatory tenesemus

What happens due to a perineal hernia?

Loss of muscular support of rectum

• Sacculation (expansion of rectum on one side i.e. unilateral perineal hernia), deviation (into hernia) or dilation of rectum (bilateral perineal hernia)

• Accum of faeces in rectum

• Constipation, straining to defaecate

• Swelling/bulge of perineum on affected side(s)

• Perineal bulge can disappear after defaecation

• Owner may push on bulge to aid defaecation

  • faeces witin descended rectum = bulge

• Bladder can retroflex into the hernia

What is being shown here? What clinical signs are associated with this?

Retroflexion of the bladder → dysuria

How is a perineal hernia diagnosed?

Rectal exam —> palpate laterally and there will not be lateral support muscles (+/- imaging)

feel laterally to feel pelvic diaphragm —> can feel bands of tissue while muscles being lost → finger can be pushed towards skin & seen through subcut tissue = diagnosis of perineal hernia!

What other investigations can be done for perineal hernia?

• Abdo rads & or U/S to assess other potential causes of defaecatory tenesmus

  • often concurrent benign prostatic hypertrophy (concurrent, not causative)

  • CT rarely indicated

• +ve contrast retrograde urethrogram to locate bladder in dysuric patients —> bladder herniation?

How is a perineal hernia treated?

• Conservative = Not reccommended unless GA contraindicaton

  • add fibre, laxative, castration (medical/surgical)

  • muscles cont. to deteriorate (delayed sx may be more challenging) & rectal dilation gets worse

  • risk of bladder herniation → life threatening urethral obstruction

• Surgical (recommended)

  • castration plus hernia repair (concurrent) —> inclusion of adjacent int. obturator m. & / or superficial gluteal muscles

    • consider referral

    • good prog (relatively minor complications but possibility of recurrence)