Soft Tissue Surgery

Question 1

Peritoneal-pericardial hernias
• Etiology
• Five most commonly herniated organs
• Two most common complications responsible for clinical morbidity

Answer 1

• Abnormal development of septum transversum (forms ventral portion of the diaphragm) ± pleuroperitoneal folds (form dorsolateral diaphragm), resulting in joined peritoneal and pericardial cavities
• A congenital abnormality, not acquired
• Allows herniation of cranial abdominal organs and omentum into the pericardial space (from most to least common: liver, gallbladder, small intestine, spleen, stomach).
• Can result in vascular compromise or obstruction of herniated organs and cardiac tamponade

Question 2

Are peritoneal-pericardial hernias more common in dogs or cats? At what age are these hernias typically diagnosed?

Answer 2

• Uncommon defect; prevalence in cats > dogs
• Age at diagnosis variable (30% diagnosed at > 4 years of age)

Question 3

List three feline and one canine breed predisposed to peritoneal-pericardial hernias

Answer 3

• Predisposed cat breeds: domestic long-haired cat, Maine coon, Persian, Himalayan
• Predisposed dog breed: Weimaraner

Question 4

List 5 of the most common congenital disorders observed concomitantly with peritoneal-pericardial hernias

Answer 4

• Cranioventral abdominal hernia
• Caudal sternal abnormalities (pectus excavatum, malformed/absent sternebrae)
• Ventricular or atrial septal defect, pulmonic stenosis, pericardial cyst
• Portosystemic shunt
• Chylothorax

Question 5

What are the prognosis and outcome for patients treated surgically Vs medically for peritoneal-pericardial hernias?
Include in your answer the reported success rate of surgical treatment as well as post-op mortality rates.

Answer 5

• Excellent prognosis with effective surgical correction; resolution of clinical signs in 85% of cases
• Postoperative mortality rates of 5%-14%
• Left uncorrected, the patient may remain free of clinical signs, but the risk of complications persists.

Question 6

What are some of the complications a patient medically-managed for pericardial-peritoneal hernia may experience? What complications can you anticipate should you decide to pursue surgery?

Answer 6

• Left uncorrected, the risk of hepatic or splenic incarceration, bowel obstruction, or cardiac tamponade and right-heart failure persists.
• Surgical complication rate is low but may include difficulty ventilating, hypotension, re-expansion pulmonary edema, and pleural effusion. Postoperative pericardial cyst and constrictive pericarditis have each been reported in one cat.

Question 7

What are the most likely causes of pericardial-peritoneal Vs pleural-peritoneal hernias?

Answer 7

• Pericardial-peritoneal diaphragmatic hernia (PPDH) is a congenital defect, in contrast to a pleuroperitoneal diaphragmatic hernia, which may be congenital or the result of trauma.

Question 8

Pectus Excavatum - Inheritable? Breed predisposition?

Answer 8

Littermates are often affected, suggesting heritability; 37% of individuals with pectus excavatum have a first-degree family member with the disorder. Autosomal recessive pectus excavatum has been reported in a litter of setter-cross puppies. Burmese cats and brachycephalic dogs are predisposed.

Question 9

What clinical signs may be observed in a case of Pectus Excavatum? Do clinical signs correlate with severity of deformity?

Answer 9

• Defect of the caudal sternum with dorsal concavity (by definition)
• Tachypnea with inspiratory or paradoxical effort may be appreciated.
• Cardiovascular auscultation sometimes reveals
○ Muffled heart sounds
○ Heart murmur
• Severely affected animals may demonstrate failure to thrive compared with unaffected littermates.
• Severity of anatomic abnormalities and severity of clinical signs are not well correlated.

Question 10

Based on the paper by Matthiesen et al (JAAHA 1983): Accuracy of assessing the stomach for loss of viability in a GDV case based on color, thickness, peristalsis and bleeding?

Answer 10

85%

Question 11

Mackenzie et al (JAAHA 2010) studied the factors affecting survival following surgery for GDV. What was the effect of delaying surgery for the sake of stabilizing a critical GDV patient?

Answer 11

Increased duration of time between presentation and surgery decreased mortality rate, purportedly as a result of greater efforts to stabilize the patients prior to general anesthesia.

Question 12

Buber et al (JAVMA 2007) - What was the effect of lidocaine administered to GDV patients as a protective agent against ischemic reperfusion injury?

Answer 12

No effect on mortality rate
Longer hospitalization

Question 14

What is the absorptive capacity of the peritoneum and omentum?

Answer 14

“peritoneal membrane and omentum are capable of absorbing fluid at a rate of 3% to 5% of the animal’s body weight per hour,”

Excerpt From
Veterinary Surgery: Small Animal Expert Consult
Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS
https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401
This material may be protected by copyright.

Question 15

List five possible causes of chylothorax

Answer 15

Cardiac disease
Thromboembolism
Thoracic masses
Trauma
Congenital abnormalities
Infection
Foreign objects

Question 16

Define second intention healing, third intention healing and delayed primary closure

Answer 16

Second intention healing: a wound allowed to heal without sutures, typically by contraction and epithelialization
Third intention healing: a wound closed by sutures after the development of granulation tissue
Delayed primary closure: a wound closed with sutures within 2 to 5 days, post wound creation, but before the development of granulation tissue.