Non-Imaging Venous Testing/ Venous Treatment

Question 1

describe the venous filling index

Answer 1

calculated using venous volume and venous filling time

normal - number should be low (slow filling via the capillaries)

Question 2

describe ejection fraction

Answer 2

measures the calf muscle pump function: calculated using the ejection volume (EV) and the functional venous volume (VV)

normal should be a high percentage >60% - good calf pump function will eject a lot of blood with one contraction

Question 3

describe residual volume fraction (RVF)

Answer 3

% of blood left following activation of calf pump

calculated as the percentage of VV remaining after 10 toe raises

normal - this should be a low percentage - most of the blood should be ejected

Question 4

name the two types of venous photo plethysmography

Answer 4

alternating current and direct current

Question 5

describe AC coupling

Answer 5

used for arterial studies

alternating current

current flows in both directions

electric voltage reverses polarity (positive to negative) at 60 Hz (60 times per second)

Wall current = 120 volts of AC

detects FAST changes in blood content

Question 6

describe DC coupling

Answer 6

used of venous studies

direct current

current flows in only one direction

electric voltage is either positive or negative

batteries use DC current

detects slower changes in blood content

Question 7

describe normal and abnormal venous refill (recovery) time (VRT)

Answer 7

normal >20 seconds
abnormal <20 seconds

Question 8

name the types of anticoagulations

Answer 8

apixaban (Eliquis), dabigatran (Pradaxa), rivaroxaban (Xarelto), edoxaban (Savaysa)

interferes with the formation of thrombus

DOES NOT lyse existing thrombus

Question 9

name the treatments for acute DVT and/or Pulmonary Embolus

Answer 9

Heparin - IV infusion of unfractionated heparin or daily injections of low molecular weight heparin for a few days
coumadin - nearing the end of heparinization, oral anticoagulation is started and maintained for 3-6 months

Question 10

when is surgical/endovascular treatment considered for deep venous obstruction

Answer 10

a patient with extensive acute DVT and/or PE

Question 11

describe vena caval interruption devices

Answer 11

used in patient who cannot be safely anti coagulated

may be used prophylactically in high risk patients

under fluoroscopy, a filter is placed in the IVC below the renal veins via a jugular and femoral vein access

rarely, a external clip may also be placed around the IVC during abdominal surgery to decrease the risk of PE

Question 12

describe IVC filter

Answer 12

a filter or net to catch and hold thrombus emboli to prevent pulmonary embolus

there are many types and designs

often placed in high risk patients or those that cannot be safely anti coagulated

appears as a bright echogenic structure in the IVC just below the level of the renal veins

Question 13

describe thrombectomy

Answer 13

surgical or catheter based technique for removal of thrombus from the vein segment(s)

Question 14

describe catheter directed thrombolysis

Answer 14

the thrombolytic agents are delivered directly into the thrombus

tempered by the potential for serious bleeding, including intracranial bleed

potential benefits include the prevention of PE and a decreased incidence of post phlebitic syndrome

Question 15

describe mechanical therapy

Answer 15

a variety of catheter based devices are available that can accomplish embolectomy or thrombus fragmentation

may be used alone or in conjunction with thrombolytic therapy

relieve the central obstruction to flow, which is the basis for a hemodynamic collapse in PE

as with thrombolytic therapy, this form of therapy is generally reserved for patients with acute massive PE and evidence of hemodynamic collapse or compromise

Question 16

what are treatment options for CVI

Answer 16

lifestyle modifications
medical graduated compression garments are very important
multiple layers of medicated compression dressing ex. Anna boot
compression is perhaps the most important factor
traditional treatment called vein stripping and/or ligation (isolating and tying off the vein)
valvular reconstruction or valve transplantation is infrequent
most treatment involves ablation or removal of the incompetent veins

Question 17

what is the goal of all treatments for CVI

Answer 17

to decrease venous hypertension

Question 18

what is compression therapy

Answer 18

mainstay of treatment for CVI

properly fitted graduated compression stockings that provide a pressure gradient ex. 20-30mmHg which provides 30mmHg pressure at foot then gradually decreases to 20 mmHg at the top of the sock

Question 19

benefits of compression therapy

Answer 19

aids in preventing venous stasis, venous pooling
improves calf muscle pump
minimizes venous hypertension
decreased patient symptoms

Question 20

what is venous ablation

Answer 20

destruction of vein - most often employed to treat superficial trunks (GSV, SSV, accessory saphenous veins)

Question 21

what is endovenous thermal ablation (EVTA)

Answer 21

uses heat to scar and ultimately shrink and destroy veins

methods to deliver heat
- radio frequency
- laser

Question 22

where should the tip of catheter be placed during a endovenous thermal ablation

Answer 22

catheter must be at a precise specified distance from any junction with the deep system to avoid damage to the deep veins. this may vary with the specified device, but consensus specifies at least 2.5cm distal to the junction

Question 23

how does chemical ablation work

Answer 23

chemical sclerosants can be injected into the vein, which scars and ultimately destroys the vein

most widely used to treat smaller varicosities (spider and reticular veins

Question 24

describe visual slcerotherapy

Answer 24

visible surface veins are directly injected

Question 25

describe ultrasound guided sclerotherapy

Answer 25

the volume of sclerosant users demands precise delivery

subcutaneous veins are identified with ultrasound

needle is directed into the vein under US guidance and then injected

sclerosant can often be milked into the incompetent segment with US guidance

excellent for treatment of venous malformations

Question 26

describe micro phlebectomy

Answer 26

bulging varicosities may be marked on the skin and then extracted using a unique hook through a small skin incision. these incisions are typically closed with a steri-strip