Hernias and Ruptures Flashcards
Define hernia
Protrusion of an organ through a naturally occurring orifice in the structure that usually contains it.
What is the correct term for a traumatic hernia?
Rupture
Define rupture
protrusion of an organ through a traumatically induced opening (i.e. a tear) in the wall of a structure that usually contains it.
What is a true vs false hernia?
True - Congenital
False - Rupture
What is an internal vs external hernia?
inside body - internal
outside body - external
What are congenital hernias lined with that traumatic are not?
Peritoneal sac
Ruptures have no sac present initially but over time a peritoneal lining may form through a process known as..?
Peritonealisation
What is the huge risk of ruptures with the abscence of a hernial sac?
Adhesions form and restrict movement
What is incarceration?
when the organ/tissue within a hernia or rupture has formed adhesions and cannot be reduced.
Define strangulated
If the blood supply to that tissue is obstructed the herniated structure
What does the umbilical aperture allow to pass through the umbilcial ring in the fetus? (2)
Vitelline duct
The stalk of the allantois
What develops improperly to cause a PPDH?
Septum transversum
What causes incisional hernias? (3)
- Surgeon error
- Incorrect suture
- Poor Post op care
Type of cause of rupture of cranial pubic ligament
Traumatic
Type of cause of PPDH?
Congenital
Define PPDH
Peritoneopericardial diaphragmatic hernia
Type of cause for incisional hernia?
Iatrogenic
Type of cause of umbilical hernia
Congenital
Mechanism of hernias cause the following adverse effect?
- Space occupying effect
The herniated organs may compromise function of other organs by simply occupying space within the adjacent body cavity.
Mechanism of hernias cause the following adverse effect?
- Loss of domain
The walls of the body cavity may become accustomed to having a smaller volume because of organ displacement outside the body cavity. This can make it difficult to return the herniated organs back to their correct location such that closure of the body cavity can be difficult and have an associated risk of accompanying compartment syndrome*.
Mechanism of hernias cause the following adverse effect?
- Incarceration
The herniated contents become trapped at their abnormal location and can no longer be reduced back to their correct anatomical location. This can be due to the formation of adhesions
Mechanism of hernias cause the following adverse effect?
- Strangulation
The blood supply to the herniated organs becomes compressed due to abnormal positioning (stretching, compression or kinking) with subsequent devitalisation of these organs.
Mechanism of hernias cause the following adverse effect?
- Los of normal function of organ
Kinking or compressing on the herniated structure may prevent normal function.
What organ can be obstructed 2ry to prepubic tendon rupture?
Urethra
Mechanism of hernias cause the following adverse effect?
- Presence of visible mass
If the hernia or rupture is in a location that allows herniated structures to move outside of a body cavity (i.e. an external hernia) then a mass/swelling may be seen.
Name external hernias (3)
Umbilical
Scrotal
Inguinal
How does a diaphragmatic hernia cause adverse effects - “wasp waist”
The “wasp waist” appearance of the abdomen is because of contraction of the abdominal wall (loss of domain) associated with herniation of a large volume of abdominal organs into the thorax with compression of the thoracic structures (space occupying effects).
Following a diaphragmatic hernia, how can the chance of compartment syndrome be reduced?
bilateral releasing incisions should be made in the aponeurosis of the external abdominal oblique muscle parallel to and several centimetres from the ventral midline and/or inclusion of a prosthetic mesh to allow tension free closure of the abdominal wall
What is the main issue of using plain radiograph to diagnose hernias?
is not always definitive for diagnosing a hernia or rupture because when soft tissues and fluid are in contact these cannot specifically be differentiated.
Positive contrast radiographic studies are particularly useful to allow identification of the location and integrity of what hernia/rupture? (2)
Bladder
Urethra
What imagine is a definitive to diagnose hernia?
CT
Traumtic rupture - what must be done and for for lon?
Stabilisation over 24-72 hours is recommended so that the patient is cardiovascularly stable and pulmonary contusions, etc are resolving before the patient is anaesthetised.
2 approaches to repair hernias
- Incision over hernia
- Midline celiotomy
Examples for hernia to be repaired directly over hernia?
- Umbilical hernia
- Uncomplicated inguinal hernia
Main steps in a hernia repair? (5)
- Ensure viability
- Release contents to correct cavity
- Resect non viable contents
- Resect redundant hernia sac tissue
- Tension free closure
Suture pattern for acute diaphragm hernia? (2)
- Simple continuous
- Simple interrupted
What sutures if there is a chronic tear where fibrosis and scarring of the diaphragm cause some mild tension on the wound edges?
Cruciate mattress
For large defects that cannot be closed using local tissues then the following options are available. (2)
Use of a muscular or fascial flap (autogenous tissue)
Use of a prosthetic implant such as polypropylene mesh
What is the exception to this statement:
“The use of autogenous or prosthetic grafts is only very rarely require”
perineal hernias where muscle/fascial flap
When are Autogenous and prosthetic grafts are more likely to be required? type (1), details (2)
Body wall ruptures:
- severe trauma with contraction of local tissues,
- large tissue defects
T or F
If infection is suspected, then prosthetic meshes ideally should not be used.
True (Nidus for infect)
For the majority of uncomplicated hernia repairs there will be no or minimal inflammation of the tissues undergoing surgery, and the respiratory, digestive and urogenital tracts will not be entered.
Class this surgery
Clean
Abx in routine hernia repair?
No
It is essential to reduce tension/pressure of the hernia repair post operatively. How can this be achieved? (2)
Strict rest for 4 weeks (whilst fibrous tissue heals, and the repair starts to regain strength)
Avoidance of increased abdominal pressure that could occur during barking, coughing, straining to urinate or defaecate.
Main intra-op hernia problems? (4)
- GA
- Hemorrhage
- Difficulty reducing
- Loss of domain
Those patients with chronic diaphragmatic ruptures with reduced lung volume will also have respiratory compromise due to compression of the lungs by herniated abdominal contents. What can happen to these patients after anaesthetized?
Decompensate
What organs in particular may bleed during repair? (2)
Reduction of vascular organs such as the liver or spleen
Reduction of abdominal contents through a chronic hernia can result in overcrowding of the abdomen with increased intra-abdominal pressure so that circulation through the abdominal organs and hindlegs is compromised
What is this termed?
Compartment syndrome
How to reduce compartment syndrome when reducing abdo organs?
releasing incisions must be made parallel to the coeliotomy incision through the tendon of insertion of the external abdominal oblique muscle. These incisions should be made on both sides of the midline at a location several centimetres from the coeliotomy incision
In rare cases where a defect cannot be closed - use,,?
polypropylene mesh of incision
Post op complications? (5)
Pain
Infect
Dehiscence
Seroma
Failure of repair
In the early postoperative recovery period following repair of a chronic diaphragmatic hernia/rupture there is a risk of…?
Re-expansion pulmonary oedema
Why doe re-expansion pulmonary oedema occur?
This is believed to occur when re-expansion of chronically compressed lungs causes tissue trauma with resulting pulmonary oedema and respiratory compromise.
How to reduce re-expansion pulmonary oedema?
To avoid this, gradual re-expansion of the lungs over 24-72 hours is recommended by incomplete removal or air and fluid from the pleural cavity postoperatively.
What might happen if the inguinal ring is reduced too much during the repair of an inguinal hernia?
The genitofemoral vessels and nerve can be compressed causing hind limb swelling and pain.
The main late complication of hernia repair is?
Failure and recurrence of hernia/rupture
Late complication risk specific to use of prosthetic mesh?
Chronic surgical site infect
Name differentails for :
Soft, non-painful “mass” approximately 2.5 cm in diameter palpable in left inguinal region
3mo FE Lhasa Apso (6)
- Inguinal hernia
- Granuloma
- Abscess
- Cyst
- Haematoma
- Neoplasia
Are inguinal hernias commonly bilateral?
Yes
Suspected inguinal hernia - how to examine?
The mass and inguinal ring should be palpated carefully to gauge the consistency of the mass, to palpate the inguinal ring and to attempt reduction of the mass;
The patient should be placed in dorsal recumbency with their hind quarters elevated to reduce caudal abdominal pressure, this may aid reduction of abdominal contents that have herniated through the inguinal ring;
T or F
Many congenital inguinal hernias resolve spontaneously without treatment
True
As the dog grows the hernial ring remains the same size and therefore becomes relatively smaller compared to the size of the dog.
Whilst monitoring inguinal hernias as a dog grows; what clinical signs to watch for? (4)
- Enlargement of the mass: due to herniation of more abdominal structures;
- Urinary signs: dysuria due to herniation of the bladder and kinking of the urethra;
- Gastrointestinal signs: vomiting and diarrhoea associated with partial or complete obstruction of the jejunum or ileum;
- Pain and/or inflammation of the hernia.
Why would you neuter (and in particular spay) a dog with inguinal hernia?
- Hereditary
- Pregnancy; increase intra abso pressure
Options for an inguinal hernia which does not resolve? (2)
- Cont to monitor
- Surgical reapair
Pros of midline approach to inguinal hernia? (2)
- One incision
- Assess and repair through one incision
When is this approach for inguinal hernia adequate?
Via an incision made directly over the left inguinal hernia with sutures placed extra-abdominally
This approach would be adequate in the case of an uncomplicated hernia (i.e. no incarceration and/or strangulation of herniated contents).
How common are congenital inguinal hernia?
Rare
Which sex are predisposed to inguinal hernia? Why?
Male - This is believed to be delayed narrowing of the inguinal ring in the male to allow descent of the testicles from the abdomen to the scrotum.
What size dogs do Congenital and acquired inguinal hernias occur more commonly in?
Small
Breeds predisposed to inguinal hernias? (9)
Basenji
Cairn terrier
CKCS
Cocker spaniel
Chihuahua
Dachsund
Pomeranian
Maltese terrier
WHWT
Which sex are acquired hernias more commonly seen in?
Female (entire)
Acquired inguinal hernias are __________ common than congenital inguinal hernias. Why
More - As female more likely -the pathophysiology of the condition is unknown but oestrogen is likely to have a role in the development of acquired inguinal hernias given the predominance of intact bitches that are diagnosed with this condition.
Discuss the anatomy of PPDH:
A) What is abnormally developed?
B) Where is the gap?
C) Which cavity and position does the heart end up in?
A) transverse septum (which forms part of the diaphragm)
B) ventral aspect of the diaphragm.
C) The tendinous portion of the diaphragm around the defect is continuous with the pericardial sac so that in fact the heart, whilst in a normal location within the thorax, is located within the peritoneal cavity.
Most common abdo structures to herniate with PPDH? (4)
- Liver
- Omentum
- Spleen
- SI
Clincial sings of PPDH? (4)
(relate to GI signs)
- V+
- D+
- Weight loss
- Anorexia
How common is resp compromise with PPDG?
Rare
PPDH: Do organs enter pleural cavity?
No
What causes resp signs with PPDH?
Organs do not enter the pleural cavity occasionally indirect pulmonary compression can occur in which case the patient will show respiratory signs
What causes these clinical signs with PPDH: (2)
- Tamponade
- R heart failure signs
Compression of R side of heart or Vena cava
What cavities will effusions develop in with PPDH? (occasionally) (2)
- Pericardial
- Peritoneal
On clinical examination of a patient with a PPDH the heart sounds are (2)
- Muffled+/- displaced
What Other congenital abnormalities can be found in cats and dogs with PPDH (4)
- Sternal defect
- Cranial midline abdo wall hernia
- Umbilical hernia
- Intracardiac defect
What do xrays show with PPDH? (4)
- Enlarged rounded or ovoid cardiac silhouette
- Dorsal displacement of the trachea
- Overlapping of the cardiac silhouette and diaphragm (best detected on a lateral view)
- Identification of gas filled intestines superimposed over the cardiac silhouette makes a definitive diagnosis if present.
What approach is made for PPDH correction?
A cranial ventral midline coeliotomy.
Why should The clip, surgical prep and draping should be extended cranially to the level of the mid sternum?
In the rare event that extension via a caudal sternotomy is required to reduce the herniated organs.
How to replace/repair PPDH? Include suturing.
- Organs reduced back into the abdomen. Often this can be done without incising through the pericardial sac or its diaphragmatic attachment. The defect in the diaphragm is then closed by apposition of the edges of the defect using a non-absorbable or slowly absorbable monofilament suture material placed in a simple continuous, simple interrupted or cruciate mattress pattern.
PPDH repair:
If the pericardial sac and/or diaphragmatic attachment have not been cut the pleural cavity is not entered so the patient does not develop a
Pneumothorax
If there is no pneumothorax - what does NOT need to be placed after surgery?
Chest drain
True or false:
Replacing a PPDH: This cannot be done without incising through the pericardial sac or its diaphragmatic attachment.
FALSE
If the pericardium/diaphragmatic attachment has to be incised; what must happen?
A chest drain must be placed once the hernia is repaired to allow evacuation of the pleural cavity of air.
Congenital PPDH - is caused by?
It is caused by incomplete development or failure of fusion of the pleuroperitoneal membrane across the pleuroperitoneal canal during diaphragmatic development
Why is surgical repair of a congenital PPDH more difficult?
Most had an absence of the left crus of the diaphragm.
2 dog breeds identified to have had a congenital PPDH?
French bulldog
CKCS
Herniation of the stomach through a diaphragmatic rupture or hernia is how common?
Unusual
Effects of stomach herniating and filling with gas? (3)
Rapidly fatal - prevents inflation of the lungs, compresses the heart, and prevents venous return and obstructs circulation to the stomach.
Old name for rupture of the cranial pubic ligament
Rupture of prepubic tendon
How would we confirm the integrity and location of the lower urinary tract in a dog?
Positive contrast retrograde vaginourethrogram
Why would a vaginourethrogram (+ve) be used over +ve cystogram to ssess lower urinary tract integrity?
A cystogram alone would give us information on the bladder but would give us no information on the urethra
Why +ve not -ve contrast to assess urethra integrity?
could miss a small urethral or bladder injury because there is a lot of soft tissue swelling in the area and this may obscure superimposition of a small amount of gas on the tissues.
Surgical approach to rupture of cranial pubic ligament?
Anchoring the caudal body wall/cranial pubic ligament to the pubis by passing sutures between the muscle/ligament and small holes drilled through the pubis using K-wires.
