vascular variation

Question 1

how does development of the heart and vascular system begin?

Answer 1

begins early in development in the mesoderm w/in (embryonic) and outside (extra embryonic, yolk sac and placental) the embryo

Question 2

in early development how many aorta are there?

Answer 2

4:

2 dorsal aortae
2 ventral aortae

Question 3

explain development of the venous system

Answer 3

embryological development of the venous system is complex

early in development vitalise veins (which drain the yolk sac) and umbilical veins form

Question 4

what are the veins above the heart called?

Answer 4

pre cardinal veins (bilateral anterior veins)

• lee et al 2010

Question 5

what are the veins below the heart called?

Answer 5

post cardinal veins (bilateral posterior veins)

• lee et al 2010

Question 6

explain the developmental process of many veins that are singular in the adult

Answer 6

many veins that are singular in an adult go through a developmental process that involves the development of bilateral vessels first and then one regresses to leave the adult for

Question 7

explain the development of the superior vena cava

Answer 7

the right cardinal veins form the superior vena cava

the left anterior cardinal vein should regress

Question 8

what happens if the left anterior cardinal vein does not regress?

Answer 8

then there are 2 SVCs (duplication of the SVC)

Question 9

what is the incidence of duplicated SVC?

Answer 9

very rare

Question 10

explain the implication of a duplicated SVC

Answer 10

usually asymptomatic

venous variations are often asymptomatic because as long as the area is being drained and into the correct vessel then there are no blood flow issues and so no symptoms

Question 11

explain the role of the 2 dorsal aortae in development

Answer 11

they communicate w/ the developing aortic sac and trunkus arterioles via 6 embryonic arches before the most posterior parts of the dorsal aortae fuse together to form one descending aorta

Question 12

what doe the 4th embryonic arch from the dorsal aorta form?

Answer 12

the adult arch of the aorta on the left side

the right subclavian on the right side

Question 13

what is chromosome 22q11 deletion assoc w/ and what is the reference?

Answer 13

chromosome 22q11 deletion is assoc w/ congenital heart disease but also w/ isolated conotrunchal anomalies

momma et al 1999

Question 14

what were the findings of momma et al 1999?

Answer 14

that there is lots of variant anatomy possible when chromosome 22q11 is deleted but the heart retains normal textbook anatomy

Question 15

where does the brachiocephalic artery form?

Answer 15

from the right horn of the aortic arch

Question 16

what is the incidence of brachiocephalic artery variation?

Answer 16

it is rare

Question 17

explain the study carried out by Iterezote et al (2009) on the branchiocephalic artery

Answer 17

study on 110 cadavers found 1 anomaly in the brachiocephalic trunk (0.9%)

the anomaly was brachiocephalic trunk 3.4cm long and 1.9cm in diameter lying infront of the trachea

Question 18

explain the study carried out by Cromer et al (2004) on the brachiocephalic artery

Answer 18

highlighting the same variant as Iterezote et al (2009) but to the left of the aorta

lead to serious haemorrhage during percutaneous tracheotomy

67y/o female cadaver

Question 19

what study discussed anomalous vessel compression and what were the findings?

Answer 19

De-Giogio et al (2011)

40y/o male, sudden death

anomalous origin of the right coronary artery lead to massive aneurysm that eventually burst and caused the death of the pt

Question 20

where is the right coronary artery meant to originate from?

Answer 20

from the R aortic sinus

Question 21

where did the right coronary artery arise from in the 40y/o male who died suddenly in De-Giorgio et al (2011)?

Answer 21

from the L aortic sinus and passed between the aortic and pulmonary valves

Question 22

why did the origin of the right coronary artery cause the death of the 40y/o man in De-Giorgio et al (2011)?

Answer 22

because it passed between the aortic and pulmonary valves meaning it was compressed by the expansion of the valves and altered the haemodynamics leading to the formation of an aneurysm

Question 23

why are variations of the IVC more common than variations of the SVC?

Answer 23

because the developmental process of the IVC is more complex than that of the SVC

Question 24

what is the most common variation of the IVC?

Answer 24

duplication

Question 25

what are the 3 types of IVC duplication?

Answer 25

type 1: same caliber trunks and pre aortic trunk type 2: same caliber trunk but larger pre aortic trunk type 3: asymmetric trunk, R IVC is the largest

Question 26

what is the normal IVC anatomy?

Answer 26

1 IVC to the R of the aorta

Question 27

what are the symptoms of IVC duplication and why?

Answer 27

asymptomatic because blood flow is not restricted

Question 28

what are the findings of Hardwick et al (2011)?

Answer 28

interrupted IVC - blood was draining into a grossly swollen azygous vein

Question 29

what is the prevalence of interruption of the IVC?

Answer 29

1:5000

Question 30

what are the symptoms of IVC interruptions?

Answer 30

normally asymptomatic - the more extensive the interruption the more likely symptoms will be to manifest early

Question 31

what are the findings of Kondo et al (2009)?

Answer 31

27 y/o man w/ 1 month history of painful swelling in both legs (DVT) MRI found that there was an absence of the intra-hepatic IVC and the collateral circulation that communicates between the ascending lumber veins and the azygous system was attempting to compensate and becoming v enlarged in doing so

Question 32

what is agenesis of the IVC?

Answer 32

the IVC does not form at all

Question 33

what happens in agenesis of the IVC?

Answer 33

blood will find alternative routes back to the heart and so there will be enlargement of vessels

Question 34

what are the findings of Gil et al (2006)?

Answer 34

14 y/o boy w/ mass in abdo and L leg DVT found to have IVC agenesis and enlarged azygous and hemiazygous veins

Question 35

what is the prevalence of agenesis of IVC?

Answer 35

up to 1% in the general population up to 5% of young pts w/ DVT

Question 36

what is the standard anatomy of the ascending lumbar vein?

Answer 36

it passes between the lumbar transverse process and psoas

Question 37

what are the findings of Karcaaltincaba and Akata (2004)?

Answer 37

46 y/o man R lumbar vein passed through the foramen in the pedicle of L3 and mimicked the appearance of a lesion in the bone the L lumbar vein was normal and the pt was asymptomatic

Question 38

what is the standard anatomy of the renal arteries?

Answer 38

1 renal artery entering each kidney at the hilum

Question 39

what is the incidence of people who have accessory / supernumerary renal arteries?

Answer 39

25% of people have 2-4 renal arteries

Question 40

where do accessory / supernumerary renal arteries enter the kidney?

Answer 40

usually not at the hilum usually at the poles

Question 41

what is the importance of accessory / supernumerary arteries?

Answer 41

they are end arteries meaning that if they get blocked the area they supply will become ischaemic

Question 42

how can accessory renal arteries cause hydronephrosis?

Answer 42

if they cross over the ureter they can obstruct it causing hydronephrosis

Question 43

which paper reported the highly variable nature of the renal arteries and why is this a robust paper?

Answer 43

Ozkan et al (2006) robust because of the large sample size (855 patients) and so likely to have found many of the variations present in the population

Question 44

what are the issues regarding transplant and accessory renal arteries?

Answer 44

you must connect the donor and recipient vessels to successfully plumb in the kidney transplant very anomalous and very short vessels are difficult to connect

Question 45

2what were the findings of Yoo et al (2003)?

Answer 45

embryological vessel - persistent vitelline artery in 74 y/o woman was silent until a loop of intestine became twisted around it and surgery was needed

Question 46

why can vein patterns be used in biometrics?

Answer 46

because veins are formed during individual environment in developing tissue and therefore venous patterns are unique to each individual and so can reused for biometric authentication

Question 47

what is the classic textbook description of the branching pattern of the common carotid arteries?

Answer 47

classic textbook description is that the only branches of the common carotid arteries are the terminal branches of the internal and external carotid arteries

Question 48

how does the branching pattern of the common carotid arteries vary in real life compared to the classic textbook description?

Answer 48

several branches that normally arise form the external carotid artery may branch from the common carotid instead

Question 49

which 5 arteries have been reported as branches from the common carotid artery?

Answer 49

lingual artery superior thyroid artery occipital artery thyroid IMA artery right vertebral artery

Question 50

what are the findings of Anangwe et al (2008) in their study of the bifurcation of the common carotid artery?

Answer 50

they found that C3 is the most common vertebral level for bifurcation of the common carotid into the internal and external carotid (C3-4 is the textbook bifurcation level) bifurcation levels ranged from C2 to C6/7

Question 51

how does agenesis of the internal carotid artery occur?

Answer 51

compression of the internal carotid artery during development leads to regression and agenesis of the internal carotid artery

Question 52

what are the findings of Naeini et al (2005) in their report on agenesis of the internal carotid artery?

Answer 52

38y/o woman presented w/ right sided headaches but no neurological deficit cerebral angiography revealed no R internal carotid artery which caused anomalous supply to the circle of wills on that side

Question 53

what is the estimated prevalence of internal carotid artery agenesis?

Answer 53

<0.01%

Question 54

agenesis of the internal carotid artery alters the origin of which artery?

Answer 54

the ophthalmic artery

Question 55

what are the findings of Nathal et al (1992) in their circle of wills study?

Answer 55

intraoperative findings of 134 patients found that the circle of willis was the most frequent site of cerebral aneurysms there was an assoc between anomalies and cerebrovascular disease

Question 56

what are the findings of Bugricourt et al (2009) in their circle of willis and migraine study?

Answer 56

investigated whether incomplete circle of willis is assoc w/ migraine 27 pts who had migraine w/out air 77 control pts incomplete circle of willis in 49% of migraine pts and 18% of control pts

Question 57

how common is duplication of the internal jugular vein?

Answer 57

very rare Padres et al (2002) found 4 / 1000 unilateral neck dissections

Question 58

when there is a duplicated internal jugular vein what finding is commonly seen?

Answer 58

an accessory nerve passing between the 2 sides of the vein

Question 59

why may changes to the pathway of the internal jugular vein alter cause issues during lymph node clearance in the neck?

Answer 59

because the deep nodes cluster around the internal jugular vein