review with 100% complete solution
what are 2 reasons why PV arterialization would be done (rare) - ANS 1. salvage operation
2. rescue procedure
what is a rescue procedure - ANS for revascularization in totally de-arterialized livers after HPB
(hepatopancreatobiliary)- procedures
what is a savage procedure - ANS in some transplant or surgery patients where the hepatic
artery is thrombosed or damaged beyond reconstruction
an acute occlusion of the HA is a high risk of - ANS biliary ischemia or necrosis and liver
necrosis with hepatic failure
what are some complications of PV arterialization - ANS Portal vein arterialization is associated
with substantial morbidity and mortality in the early postoperative period
what are the 2 types of dialysis - ANS 1. hemodialysis: requires vascular access
2. peritoneal dialysis: uses a peritoneal catheter
what are some examples of vascular access in hemodialysis - ANS central venous catheter,
loop graft, AVF
why are autogenous/native AV hemodialysis access recommended over prosthetic grafts - ANS
they tend to function longer with fewer complications
what improves long term results of autogenous AV hemodialysis access - ANS increased use of
preoperative imaging
what is the first choice for creation of dialysis access - ANS The nondominant extremity is
always the first choice for creation of dialysis access, but if there are problems with that arm's
vessels (or an associated central vein stenosis), the contralateral extremity may be chosen
why are distal locations preferred over proximal anastomoses - ANS because they are less
likely to cause certain complications, and this also preserves the integrity of proximal
vasculature for any required revisions in the future
what are the 3 common types of AVF anastomoses - ANS 1. radiocephalic
,2. brachiocephalic
3. brachiobasilic
where is the radiocephalic vein taken - ANS at the snuffbox
what is a principal indication for use of a lower extremity for AV access - ANS central venous
stenosis or obstruction
what are the primary options for thigh AVF - ANS Saphenous and superficial femoral vein
transposition
why is the mid thigh now preferred over the groin - ANS to avoid lymphatic tissue and to
preserve another more proximal option in case of conduit failure or the need for graft revision
how long may it take for a fistula to mature - ANS several weeks to 3 months
what characteristics of the fistula give signs of the source of maturation problems - ANS bruit
and thrill
what g needles are used during hemodialysis - ANS 15g
what is bruit - ANS a rumbling soud
what is thrill - ANS a vibration or buzzing sensation
what does a fistula with a weak or no thrill suggest - ANS a stenosis at or near the
anastomoses
what does a pulsatile thrill at palpation suggest - ANS outflow obstruction
what does a strong thrill at the anastomosis only indicate - ANS accessory draining veins that
are stealing flow from the body of the fistula
what happens when the outflow vein is compressed - ANS should become pulsatile
what happens if it doesnt become pulsatile - ANS you can be sure it is drained by multiple veins
what is the second choice for long-term vascular access in hemodialysis patients - ANS A
prosthetic arteriovenous (AV) graft
what are major complications of AV graft - ANS thrombosis and infection
what is more common with AV grafts than native fistula - ANS infection
, when would a graft use be indicated - ANS when a native fistula cannot be created due to
inadequacy of native veins/arteries (old age is a factor), a primary AV fistula failure, or
inadequate maturation of a native conduit
what location is preferred for different alignments and anatomical locations - ANS more distal
upper extremity grafts
what are some examples of xenografts - ANS the ovine (Omniflow) and bovine ureter graft
(SynerGraft); or cow carotid arteries or mesenteric veins, human cryopreserved femoral or
saphenous veins have also been used
what are the rule of 6s (indicating maturation) - ANS vein diameter of >6mm, depth of less than
6mm from surface, at least 6cm in length, blood flow rate of >600ml/min, by 6 weeks post op
what are some complications of early iterations of AV grafts - ANS rapid aneurysmal
degradation and did not completely mitigate infectious complications as suspected
what are some new graft construction techniques - ANS tissue-engineered vessels and
three-dimensional (3D) printing
what can using hemodialysis as a bridge to kidney transplants lead to - ANS concerns over
induction of the immune response and overall antigenic properties of various graft materials
what is the min diameter of grafts required - ANS min 3.5mm, 4mm is ideal
what is the preferred locations for AVF - ANS upper limb preferably non dominant arm, more
distally
T or F:
autogenous AVF < AV graft - ANS false: Autogenous AVF > AV graft
autogenous AVF must mature before use, is this the case for synthetic grafts? - ANS may be
used almost immediately (around 2 weeks+ post-op to allow for adequate wound healing)
why would we do an US for already created hemodialysis vascular accesses - ANS
assessment of maturation
causes of dysfunction
pathologies: hematoma, infiltration, aneurysm, pseudoaneurysm, stenosis or thrombosis
what is known as a afferent vessel - ANS inflow
what is known as an efferent vessel - ANS outflow