Vascular Shunts Flashcards
(26 cards)
T/F: A portosystemic shunt is a good example of an arterio-venous malformation.
False, portosystemic shunts are abnormal communications between 2 venous systems [venovenous shunts].
Arteriovenous malformations lead to ________ ________.
Tissue hypoxia [this is because most arterial blood is bypassing the capillary bed and going directly into the draining vein.]
The most common site for an AV fistula is the ______.
Liver
These types of shunts have the most severe consequences.
Central A-V shunts
Pain, swelling, edema, palpable bruit/thrill [the feeling of machinery buzz if you put your hand over the skin], are all signs of what?
Local consequences of a peripheral A-V shunt.
____ to _____ of aortic blood flow may be diverted into the ductus with PDAs.
1/2 to 1/3
In PDAs, the ductus connects the aorta to the ______ ______. Blood then travels back to the lungs, down to the left atrium and then the left ventricle again. Over time this leads to left ventricular hypertrophy and left sided heart failure.
Pulmonary artery
What is Elsenmenger Syndrome?
Condition associated with some high flow shunts [VSDs and PDAs].
With high flow shunts the flow is typically from ______ to ______, except over time it becomes ______ to ______ which leads to cyanosis and is typically an irreversible change.
Left to right.
Right to left.
With portosystemic shunts, blood bypasses the liver and enters systemic circulation via the ______ _______ _______.
Caudal vena cava
Congenital extrahepatic shunts are mostly associated with ______ ______ ______, these are also the most common type of shunts.
Small breed dogs [like Yorkshire terriers.]
Congenital intrahepatic shunts are mostly associated with ______ _______ ______.
Large breed dogs [like Labs and Siberian huskies].
Acquired multiple extra hepatic shunts are caused when we do what?
Try to treat a portosystemic shunt and we end up causing portosystemic hypertension. (changing the blood flow somehow).
The most common shunt for is the ______ ________ ______ _______ ______.
Single extrahepatic portal systemic shunt
Extrahepatic shunts occur when you have different types of veins (like the portal vein or splanchnic vein) dumping blood into the _______ ______.
Vena cava
Intrahepatic shunts is where a branch of the portal vein communicates direclty with hepatic vein within the ________ _______.
Hepatic parenchyma
PDV (Patent ductus venosus) is where the ______ _____ connects with the ______ _____.
Umbilical vein connects with the Vena Cava [thus bypassing the liver].
The 2 different forms of portal vein hypoplasia are what?
- Idiopathic noncirrhotic portal hypertension
- Portal Vein Hypoplasia-Microvascular Dysplasia
Multiple extrahepatic shunts develop in response to what?
Response to prolonged sublethal portal hypertension.
The problem with multiple acquired shunts when performing surgery is that what?
Many of the branches are present in the falciform fat and can be easily nicked during surgery.
Hepatic arteriovenous malformation is where you have multiple aberrant shunting vessels resulting in communication between ______ _______ and ______ _______. This results in severe portal hypertension and multiple acquired shunt formation to relieve pressure in portal vasculature.
Hepatic artery and Portal vein
Hypoglycemia, hypoalbuminemia, hypocholesterolemia, hypokalemia, microcytosis, clotting factor deficiencies and stunted growth are all consequences of _______ _______ _______.
Portal systemic shunts [PSS].
A dog that has a known PSS presents with head pressing, what is the most likely cause?
Hepatic encephalopathy
The most common type of crystals associated with PSS are ________ ________ crystals.
Ammonium Biurate
