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SA Sx - Hernias (Diaphragmatic)

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drraythe's version from 2017-10-10 14:15

Intro & Diaphragmatic Hernia

Question Answer
What is his big soapbox issue w/ D. hernias?Not true hernia bc no perineal lining
In a D. hernia, where does the diaphragm usually break?On VENTRAL aspect usu
Definition of a Diaphragmatic HerniaContinuity of the diaphragm is disrupted leading to protrusion of the abdominal viscera through the diaphragm into the thoracic cavity
2 types of etiology of a D. hernia?Congenital, or Acquired (traumatic) (**more commonly traumatic)
The cupula of the diaphragm can extend to what ICS?8th (the cupula is the reflection of the plura against the diaphragm back up the sides of the walls (red line)
What are the 3 different kinds of D. hernias (based on how the tears are) how common is each?Radial, Circumferential, Combined
*Radial is most common* > Combined > Circumferential
Where does a radial D. hernia happen?Costal insertion up to center tendinosis. Most common
Where does a circumferential hernia happen?Parallel up to ribs.
What are the 3 types of congenital hernias?(1) Pleuroperitoneal
(2) Peritoneo-pericardial
(3) Hiatal
Which congenital hernia is sometimes associated w/ ventral hernias?Peritoneo-pericardial
What is more common - congenital or traumatic hernias?Traumatic hernias are 93% of the hernias!
Which side of the body do pleuroperitoneal hernias usually happen? (Why?)Left (Bc liver abutting on right I think he said?)
CSs of a traumatic D. herniaDyspnea (if more severe, resp. sounds)
Tachypnea
Cyanosis
Orthopnea (short of breath when laying down)
Muffled heart sounds
Borborygmus
Careful w’ thin PTxs (can be GI that's just up high near diaphragm)
Vomiting
Chronic cough
Exercise intolerance
Tucked-up abdomen
Postprandial respiratory difficulty
Anorexia
What are 2 general things you should know about using CSs to Dx a D. hernia?*Signs may be intermittent or absent *Signs are not pathognomonic
If stomach passes through herniation, what might happen?True ER - when stomach passes through diaphragmatic hole - dies
Coughing - may aspirate
If small intestine passes through herniation, what might happen?Small bowel often passes through - doesnt tend to cz adherence w/ other organs
If liver passes through herniation, what might happen?Capsule can extrude fibrin & cz adhesions
What are some things he mentioned of how the thorax is affected by the herniation? Ex of when it might be best to NOT operate?Hepatization of lungs due to being squished. Electric axis of heart is shifted (bc heart pushed out of place). Other lung that's not squished tries to compensate. Sometimes not best to operate if disturbing quiet organs or abd isnt big enough to replace viscera
When might you wanna use fluoroscopy?To try to Dx hiatal hernia
2 types (locations) of contrast studies you can use to Dx D. hernias?GI transit, intra-peritoneal
4 radiographic signs of a traumatic D. hernia?(1) Interruption of diaphragmatic outline
(2) Soft tissue density in thorax
(3) Gas-filled viscera in thorax
(4) Loss of cardiac silhouette
3 auscultation oddities/ abnormalities which might indicate a D. hernia(1) Muffled heart & respiratory sounds - indicates fluid or viscera in pleural space
(2) Borborygmus - intestines in pleural space
(3) Tympany on left side of thorax - stomach in pleural space
Sx repair of hernias - in what situations is mortality higher? (Timing) What is the highest mortality situation?Mortality is higher when hernias are repaired < 24 hours, or > 1 yr after occurrence. Repairs carried out w/in the 1st 24 hrs May have the highest mortality rate, if not adequately stabilized
Seeing bowels beyond the _________ ICS is something to note8th (esp if ventral)
How might the thorax change radiographically if there is fluid in it?Lung lobes more distinguished, heart silhouette shadowed
memorize

Repairing D. hernia

Question Answer
*How can you really inc the success rate of repairing D. hernia? Why?Delaying Sx 1-2 weeks → success rate 90%!!!! Bc stabilization of PTx & edges of rib into diaphragm will be partially healed & stronger tissue to place bites
*When is it an emergency & you absolutely can't wait to fix the D. hernia?If the stomach has herniated into the thoracic cavity, Sx must be done immediately. This is bc A dilating stomach will cz complete & rapid collapse of the lungs
What things should ANx be mindful of/do when inducing/maintaining during D. hernia Sx?Pre-oxygenate PTx
Minimize stress & rapid induction
Avoid drugs that depress respiration!!
Controlled respiration - mechanical or manual, avoid over-inflation of lungs
For repair of D. hernia, which approach is generally better/preferred?Do ABDOMINAL approach
NOT thoracic!
Pros & cons of abdominal approach to repair of hernia?PROS: More familiarized, provides bilateral access, can be extended by sternotomy or paracostal incision
CONS: Requires ventilatory support of PTx
Pros & cons of thoracic approach to repair of hernia?PROS: good visualization, suture over convex surface. CONS: only 1 side / accurate Dx! need experience w/ thoracic Sx
Describe the Sx technique for repairing a D. herniaGently retract herniated viscera into abdomen → If viscera are adhered in thorax, extend incision cranially & break up adhesions by sharp & blunt dissection under direct visualization → Begin suturing radial tear at most dorsal margin/ Anchor circumferential tears by suturing around ribs
Where (directionally) do you want to start suturing if it is a radial tear?Most dorsal margin
How can you anchor/suture down a circumferential tear which pulled away from the ribs?Anchor circumferential tears by suturing around ribs
If the liver/liver lobes have gone through hernia, what structure should you be esp. careful of when trying to replace?Phrenic nerves, bc you often need to enlarge opening to replace it
If you are fixing a D. hernia & you see this white stuff on the liver, what do you think is going on? This is fibrin that is excreted from the liver capsule & can cz adhesions
When repairing the D. hernia, be careful not to pierce through what blood vessel?Vena cava!
If you accidentally break liver when trying to replace it, what can happen?Chemical peritonitis
Once you have finished replacing things & you are ready to expand the lungs, in what manner should you expand them?SLOWLY - to prevent pulmonary edema due to reperfusion injury
In what direction should you close the hernia & what stitch does he prefer? What can you do w/ your suture to make your life easier?From distal to proximal - place 1st stitch close to vena cava - dont pierce it. He like cruciate - leave long tag - helps to bring edges of diaphragm up in order to assist stitching better. Can place lap sponge btwn liver & diaphragm!
What type of suture material can you use to close the D. hernia?Non-absorbable suture, can also use nylon or Prolene
What suture patterns can you use to close?Simple continuous or simple interrupted (he said he liked cruciate too)
If a 1° closure if not possible (say the diaphragm is blown out & there is no way to oppose the edges) what can you do?(2)(1) Use autogenous or synthetic graft. Examples incld fascia lata (he didn't like this), Muscular pedicle graft from abdominal wall (can create a mm flap from traverses abd mm. can also use liver if hole not too big.), Omental pedicle flap (omentum if defect not too big), Teflon or Silastic sheeting
(2) Advance diaphragm - can displace diaphragm cranial - suture it around ribs like said before - if have to get rid of big section of diaphragm or last ribs. Ok for resp capacity
Mm pedicle graft technique of patching if can't do 1° closure... (pic)
What is the last ditch salvage procedure if the diaphragm can't be fixed & what is the downside to this?Get rid of diaphragm & turn into a celomic cavity - this is not so awesome though bc if you need to open the abdomen the PTx will have to be on a ventilator
How does the Prolene mesh repair kinda work?Works like a scaffold (infiltrated by RBCs & fibroblasts) - & once fleshed out, will work like the diaphragm
What mistake do people often make when trying to restore neg pressure to thoracic cavity?W/ last stitch introduce cath to remove air.... before last stitch tied...then ask anesthetist to inflate lungs but already closed ...he says alveoli will explode.
After Sx what kinda tubes should you place?Thoracostomy tube
With chronic hernia or herniated liver, what else will you have to do after the Sx?Drainage may be required for several days
During postop, you will need Careful constant monitoring of PTx bc of what 4 things?(1) Risk of reperfusion injury
(2) Risk of re-expansion pulmonary edema
(3) Risk of hemorrhage/bleeders
(4) Risk of pneumothorax
When is the prog of the Sx guarded & when is it excellent?GUARDED: Until PTx has survived 24 hours following Sx
EXCELLENT: If PTx survives 1st 24 hours following Sx (reported survival rate is 60-90%)
Most deaths related to D. hernia occur when? What has the highest impact on mortality rate?Pre-operatively. Many also occur during induction. Pre & post-operative management have greatest impact on mortality rate
memorize

Not D. hernias

Question Answer
How does the Paracostal hernia appear radiographically?
Which stitch does he like to use to repair Paracostal hernia?Cruciate
What is the etiology of the Peritoneo-pericardial hernia?In dogs & cats, always congenital!!
The Peritoneo-pericardial hernia is Often associated w/ what other problems?Cardiac abnormalities & sternal deformities
In a Peritoneo-pericardial hernia, where are the abdominal organs displaced to?Abdominal organs inside *pericardial cavity
What are the CSs of a PP hernia?PTxs are often asymptomatic! (Signs may be variable & intermittent)
Cardiac murmur<brRight heart insufficiency<br>Muffled heart sounds
Which part of the heart is often insufficient w/ a PP hernia?Right heart
How will the ECG be affected w/ a PP hernia?Low voltage
Congenital associated defects w/ the PP hernia?(3)(1) Ventral / umbilical hernia
(2) Cardiac defects
(3) Lack of union of the last sternebra (*associated w/ ventral hernia in 4/13 dogs)
Some ancillary Dx techniques for PP hernia?survey radiograph, contrast radiograph (GI transit/Celiography), US
5 radiographic signs of Peritoneao-pericardia hernia?(1) Enlarged cardiac silhouette
(2) Discontinued ventral diaphragm
(3) Structures w/ gas in pericardial sac
(4) Sternum defects
(5) Tracheal elevation
How do you Sx repair a PP hernia?Abdominal approach to diaphragm → Relocate abdominal viscera → Debride edges of defect & close from dorsal to ventral
In what direction do you close a PP hernia?From dorsal to ventral
For a PP hernia, which approach to the diaphragm do you wanna do?Abd
****What should you NOT DO when repairing a PP hernia?Do not close pericardial sac
In order to fix PPH, you must increase the defect size to allow reduction. What is the sequelae to this (so what must you do?)Communication w/ pleural cavity.
This means you will need assisted ventilation, thoracic drainage, intensive care for 24-48 hrs
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