URR Other Types of Lower Extrem Arterial Eval

Question 1

what is transutaneous oximetry?

Answer 1

-determines capability of healing of a wound or specific site for amputation
-evals O2 suplly and consumption of healing of a wound or specific site for amputation
-measures the O2 partial pressure in adjacent areas of a wound
-cannot eval the wound itself, only surrounding tissues

Question 2

how to do transcutaneous oximetry?

Answer 2

-electrodes heat skin to 45 degrees celsius and O2 escapes from the tissue to be measured by the sensor
-takes about 15-20 mins to obtain reading
-obtain reading on the chest as a baseline
-obtain readings of the toes, lower leg and thigh

Question 3

normal and abnormal for trancutaneous oximetry? how do they know where to amputate?

Answer 3

-norm TcPO2 levels 70-80 mmHg; < 40 mmHg indicates tissue hypoxia
-amputation must be done at an area of tissue that has normal healing capabilities
-abnorm ankle reading, normal reading in upper calf = below the knee ampution
-abnormal ankle and abnormal calf readings, but normal distal thigh readings = above the knee amputation

Question 4

limitations to transutaneous oximetry?

Answer 4

-inability to keep electrode in contact with skin surface
-cannot be applied to ulceration or open skin

Question 5

what is intravascular US?

Answer 5

-allows 360 degree imaging of the artery lumen
-used to locate the most narrow segment that would benefit from stent placement, used during and after angiography to evaluate proper stent placement, used to evaluate coronary artery disease from within the coronary arteries
-ONLY 2D imaging, NO doppler
-10-30 MHz transducer

Question 6

what is the corpus cavernosa of the Penis?

Answer 6

(CC)
-two main erectile structures of the penis
-sinusoids fill with blood during erection
-covered by tunica albuginea
-the right and left cavernosal arteries course through the right and left CC
-glans penis extends over ends of corpora cavernosa

Question 7

urethra and urethral arteries travel through this portion, covered by tunica albuginea

Answer 7

corpus spongiosum

Question 8

indications for penile doppler?

Answer 8

-inability to obtain an erection
-inability to maintain an erection
-priapism

Question 9

what is priapism?

Answer 9

-painful, prolonged erection that occurs without sexual stimuli, lasts more than 4 hours
-can be caused by venocclusive disease in the pelvic veins or an AV fistula in the pelvic region
-can be spontaneous or caused by medications
-excessive arterial inflow with inadequate venous outflow
-PW doppler for diagnosis
-requires immediate treatment to reduce penile blood flow

Question 10

the internal iliac artery supplies blood to the penis with blood through the what?

Answer 10

internal pudenal artery
-internal pudendal artery branches into the penile artery

Question 11

the penile artery branches into the dorsal artery and then to the what?

Answer 11

dorsal vein
-dorsal artery courses along the dorsal side of the penis lateral to the midline dorsal vein; supplies blood to the glans penis and the corpus spongiosum
-cavernosal artery courses through the corpus cavernosum and supplies blood to the cavernosal sinusoids via the helicline arteries

Question 12

what provides primary venous flow to the penis?

Answer 12

-superficial dorsal vein and deep dorsal vein provide the primary venous otflow routes

Question 13

during erection what happens to flow?

Answer 13

in the cavernosal arteries increases and venous outflow decreases

Question 14

in order to become erect, the penis resistance must what?

Answer 14

decrease
-stenosis can inhibit the increase in arterial inflow and limit the ability to have a erection

Question 15

aortoiliac disease can cause what to the penis?

Answer 15

blood flow disturbance to the internal artery affecting the penis

Question 16

how to do penile exam?

Answer 16

-7-10 MHz transducer (CW and Duplex)
-obtain CFA and tibial artery waveforms with bilateral ABIs, poor arterial inflow may affect penile flow
-penile blood pressure is obtained on the flaccid penis and compared to the systolic BP; <60 mmHg usually indicates impotence due to inflow disease
-the 2.5 cm cuff is used to obtain penile pressures
-doppler or PPG sensor can be used with the cuff to take penile pressures
-If PBI is normal, papaverine can be injected at the base
-if PBI drops, vasculogenic impotence should be suspected
-if venous outfow increases post injection, this can be another cause of impotence in cases with normal arterial inflow

Question 17

penile brachial index?

Answer 17

NL > .75
marginal reduction .65-.75
ABNL <.65 (vasculogenic impotence)

Question 18

-development of scar tissue and fibrous plaque formation that usually involves the tunica albuginea
-causes restriction and curvature of the affected side of the penis during erection
-can be very painful
-2D shows hyperechoic areas along margins of the corpus cavernosa
-US used to assess plaque size and extent of formation
-penile doppler with an intracavernosal injection is recommended prior to consideration of plaque excision

Answer 18

peyronie disease

Question 19

doppler evaluation of penis>

Answer 19

-includes assessment of the carvernous arteries and dorsal veins with doppler pre and post medication injection
-priot to medication, measure velocities in cavernous arteries
-pressure cuff on penis
-injection performed in prox shaft, lateral puncture
-norm PSV and EDV will increase post injection, but dorsal venous flow will remain unchanged
-PSV > 30 cm/s considered normal
-> 15 cm/ s difference in PSV in right and left cavernosal arteries suggests arterial disease
-report should have characteristics of the CFA, PTA, and ATA, ABI values, penile pressure and PBI value

Question 20

arteriography

Answer 20

invasive procedure that uses iodinated contrast to demonstrate vessel patency during fluoroscopic techniques
-CFA most common catheter insertion point in lower extrem
-axillary and brachial arteries can also be used
-gold standard for stenosis/occlusion/collateral eval of native arteries
-not used much anymroe due to improved 3D capabilities of CT and MRI

Question 21

seldinger technique in arteriography refers to the what?

Answer 21

puncture of an artery adn insertion of a small catheter

Question 22

how does arteriography work?

Answer 22

contrast opacifies the vessel lumen; areas of absent contrast indicate obtstuction
-can also detect aneurysm as bulbous area in vessel that fills with contrast

Question 23

limitations to arteriogarphy?

Answer 23

dye allergies, kidney failure, single plane eval technique can lead to over or underestimation of the stenosis

Question 24

complications of arteriography?

Answer 24

hematoma, nerve damage, pseudoaneurysm, AV fistula (bruit), distal embolization (blue toes), and acute occlusion from the puncture

Question 25

post procedure for arteriography?

Answer 25

-must stay in the supine position for 6-8 hours to avoid pulling on the puncture wound
-sandbag is placed on the puncture site to prevent formation of pseudoaneurysm
-some facilities use closure devices such as the starclose, proglide, angiseal, which usually greatly reduce the recovery time

Question 26

disadvantages of arteriography?

Answer 26

-radiation exposure
-contrast allergies
-cannot be performed on patients with renal failure
-only demonstrates images in a single place, which can lead to over - or underestimation of stenosis
-provides anatomic data, but no functional data

Question 26

follow up exam for puncture site in symptomatic patients

Answer 26

-eval of the groin for a bruit (psuedoaneurysm)
-eval of the toes for blue discoloration (embolism)
-eval of the leg for signs of pallor (acute occlusion)

Question 27

-exam that requires iodinated contrast for optimal vascular eval
-provides very accurate info on AAA size and location
-also very helpful in the diagnosis arterial dissection
-disadvantages include degraded images due to metalic prosthetics or clips, risk of contrast reaction and cost
-patients that have iodine (seafood) allergies or kidney failure cannot have contrast

Answer 27

CT

Question 28

-uses a varied strong magnetic field to eval changes in the tissues
-phased contrast MRA can distinguish blood flow from tissues without contrast; useful for patients with renal failure or contrast allergies
-commonly used with IV contrast material injected to better vis arterial flow in patients without renal failure or contrast allergies
-most common used to eval the arteries of the calf and foot
-disadvantages include patient claustrophobia, reaction to contrast, cost, artifact from surgical clips, usually overestimates stenosis

Answer 28

MRI