2. To be US detected, there must be an increase in speed
of the venous flow
To increase the venous flow speed we must create a
pressure gradient.
Pressure Gradient = Force directed from high to low
pressure. The change in pressure measured across a
given distance is called a "pressure gradient".
3. Considerations about applying a pressure gradient to the
venous system
A flow originates in a competent system only if
the pressure gradient has the same valve
direction
If there is no valve competence, the flow has the
same direction as the pressure gradient.
When the patient is standing , a force is also
represented by the hydrostatic pressure
4. A pressure Gradient may be Propulsive and/or Aspirative
B
A
B
A
Propulsive Aspirative
Force of the
gradient
Muscle Pump
Systole
(contraction)
Muscle Pump Dyastole
(relaxation)
or Manual
Compression/release
Force of the
gradient
Increasing Decreasing
B
A
Force of the
gradient
Valsalva
Manouvre
Increasing
6. Resting Valsalva
( Clamp effect)
The residual Venous Pressure
creates an increase in pressure
and venous diameter
Valsalva Manouvre in a Normal Subject
7. Valsalva Manouvre in SFJ incompetence
Situation A
( Without Femoro-Iliac valve)
Situation B
( With Femoro-Iliac valve)
8. Manual Calf Compression ( Squeezing) - Systolic Phase
LSV Incompetence
Compression
Area of Blood
Mobilization
10. Active Muscle pump activity - Systolic Phase
LSV Incompetence
Area of Blood
Mobilization
11. Active Muscle pump activity - Dyastolic Phase
LSV Incompetence
Emptied Zone
12. Point A
Point B
Gradient Line
Squeezing Test : The Gradient only involves
superficial veins
Gradient Line
13. Point A
Point B
Dynamic Tests : The Gradient involves superficial veins,
perforators and deep veins
Gradient Line
Time duration of
centrifugal flow
=
Time of gradient
exaustion
14. Dynamic tests are still not accepted by the international community
The most well-known dynamic test is the Paranà Manouvre,
described by Claude Franceschi in 1998.
To check its validity, I have compared this manouvre with the
squeezing test in the following patient series/situations :
A. Popliteal vein in healthy subject - 20 patients
B. Incompetent SFJ , with incompetent terminal v., in varicose veins
- 13 patients
C. Incompetent saphenous axis 15 cm below the groin in cases with
an incompetent terminal valve - 13 patients
D. Re-entry perforators in varicose veins subjects - 11 patients
15. Both the Paranà Manouvre and the Squeezing Test are not
mechanical tests but their results depend on a series of
variables:
For the Squeezing Test:
Manual compression strength
Muscle contraction / relaxation level while the patient is
standing
Leg volume
For the Paranà Manouvre
Pushing force
Muscle contraction / relaxation level while the patient is
standing
A support point for the patient
17. The force applied, produces a flow movement , that in an arc
of time reaches the maximum speed that decreases later.
The increase of speed in an arc of time is called
“ acceleration” .
18. Paranà and Squeezing test in a healthy Popliteal Vein
Area= (Speed xTime A /2) + (Speed x Time B/2)
Acceleration = Max Speed/Time A
Max Speed
Time A Time B
Time A Time B
Max Speed
19. Squeezing and Paranà in an incompetent Saphenous Trunk
Speed A
Time B
Time A
Speed B
Area A = ( Speed A x Time A )/2
Area B =( Speed B x Time B)/2
Time A
Time B
Max Speed A
Max Speed B
20. To determine if the average variation is similar in the squeezing test and the Paranà
manouvre group we have calculated the acceleration and its “Standard Deviation”.
Standard Deviation shows how much variation from the average exists.
A. The Paranà manouvre and Squeezing test have some variables that change the
final result
B. The energy applied to the venous system gives origin to a flow acceleration that
is detected by the US.
We have said that:
The higher the standard deviation, the lower the test accuracy
21. Examinations done
Vein examined Number of cases Total measurements
done
Popliteal vein in healty subjects 20 patients 120 measurements
Incompetent SFJ 13 patients 156 measurements
Incompetent LSV axis 13 patients 156 measurements
Re-entry perforators 11 patients 143 measurements
TOTAL 57 patients 575 measurements
One of the Excel spread sheet
22. Mean ( μ )
Coefficient of
variation C V
Standard Deviation ( 𝞂 )
Squeezing Acceleration Paranà Acceleration
Healthy Popliteal Vein
23. Average
Squeezing
Average
Paranà
𝞂 Squeezing 𝞂 Paranà
Healthy Poplitea 0,19 0,13
0,06 0,07
Incompetent SFJ 0,06 0,11
0,02 0,14
Incompetent GSV 0,06 0,04
0,04 0,02
Re-Entry Perforator 0,07 0,03
0,04 0,01
In the Paranà group standard deviation is similar or lower
than in the squeezing group. This means that the Paranà
manouvre is more accurate than the squeezing test.
Standard deviation (𝞂 )
24. Popliteal Vein in Healthy subjects ( 20 cases)
Squeezing Paranà
Tempo A (ms) 379 593
Tempo B 349 546
Max Speed cm/sec 68 72
Area 25033 41657
Area :
In 3 cases the squeezing test moves 10% more than the Paranà
In 17 cases the squeezing test moves 40% less than the Paranà
Area measurement
25. Incompetent Saphenous Axis
Squeezing Paranà
Time A 501 571
Speed A 45 26
Area A 12683 9695
Time B 4332 7881
Speed B 35 40
Area B 66533 144392
SystolicEventsDiastolicEvents
The centrifugal relaxation ( diastolic) flow is more than double in the
Paranà compared to the squeezing test
26. Incompetent SFJ
Squeezing Paranà
Time A 751 1078
Speed A 45 34
Area A 16100 18502
Time B 2269 5808
Speed B 43 71
Area B 48597 185478
SystolicEventsDiastolicEvents
The centrifugal relaxation ( diastolic) flow is more than triple in the Paranà
compared to the squeezing test
27. Re-entry perforator
Squeezing Paranà
Time A 468 764
Speed A 28,35 26,08
Area A 6605 10722
Time B 1488 4861
Speed B 22,76 45,96
Area B 19057 92476
SystolicEventsDiastolicEvents
The centrifugal relaxation ( diastolic) flow is more than four times greater in the
Paranà.
28. Conclusions
Standard deviation acceleration shows that the
Parana manouvre is more accurate than the
squeezing test.
In healthy subjects the Paranà manouvre moves
40% more blood than in the squeezing test.
In incompetent systems, the diastolic phase of
the Paranà manouvre’s flow lasts 3 times longer
than the squeezing test.
The Parana manouvre is more accurate and more
effective than the squeezing test.
31. Paranà Test versus Toe Standing Test in the
Popliteal Vein in Healthy subjects ( 20 cases)
Toe standing Paranà
Tempo A (ms) 343 561
Tempo B 332 549
Max Speed cm/sec 109 70
Area 36155 39172
Accelerazione 0,34 0,13
32. Valsalva Manouvre in deep vein incompetence
Situation A
( Without VV Shunt)
Situation B
( With VV Shunt)
33. Corso di Flebologia Emodinamica e Linfologia
Con sessioni teorico-pratiche
Università di Camerino
direttore e vicedirettore : Amenta-Bernardini
docenti: Bernardini-Cappelli-Ermini- Castagnoli-Moretti
