Hemodynamic assesment of centripetal flow originating during the muscle pump contraction phase

1. Systolic Shunts
Significance and diagnosis method
Stefano Ermini

2. What is a Systolic Shunt?
It is a centripetal NON physiologic flow whose
origin passes from a deeper network to a
superficial one during muscle systole.
Note: only the gradient created by a muscle
contraction can evoke a centripetal systolic
flow. This means that these situations are
not visible using the squeezing test.

3. N1N2 N1N3

4. This flow originates as a result of an increased
resistance in the deep vein system
This increased resistance can be
due to :
1. A functional stenosis (e.g small
caliber of the superficial femoral
vein or muscular compression
during contraction)
2. A post-thrombotic syndrome
GSV
SSV
Giacomini
Deep Veins
Thrombosis

5. How to distinguish these 2 different situations
1. By shunt and DUS analysis of superficial and deep
vein flow at the thigh level
2. By analysis of the popliteal flow during muscle
contraction and relaxation
3. By shunt manual maneuvers

6. Systolic Vicarious shunt
(Compensative circle)
 Its function is to by-pass a deep anatomical
stenosis/obstruction
 It originates from a calf perforator, at the popliteal vein
area, or at the thigh level.
 The flow through this perforator reaches a superficial
trunk, gives origin to a centripetal flow and re-enters
into the deep system above the occlusion.
 In the perforator the flow moves in a non physiologic
way (reflux).

8. Hemodynamic characteristics of a Systolic Vicarious
Shunt :
 At the perforator level, the flow also originates
during a small movement and continues after the
muscle contraction is finished.
 The flow during diastole can persist or not in
relation to the gravity of venous hypertension.
 DUS assessment of the deep system above the
refluxing perforator shows the absence of flow or a
stenosis

9. Systolic Vicarious shunt
(Compensative circle)
The manual compression of the superficial
trunk involved in this vicious recirculation
stops the flow in the deep vein below the
shunt origin
Thrombosis
Thrombosis
Compression
STOP FLOW

10. Systolic derivative shunt
This shunt often appears in the popliteal fossa
where a centripeal flow originates in the
Giacomini Vein through the SPJ or a popliteal
perforator

11. Systolic derivative shunt
2 situations are possible:
• The flow from the Giacomini Vein re-enters into
the deep system through a Giacomini perforator or
through the SFJ
• The flow also feeds a varicose vein whose re-entry
perforator is placed below the escape point.
Re-entry point
Escape point
Re-entry point
Escape point

12. Systolic derivative shunt
Systolic flow:
It only appears during the muscle contraction and stops
when the muscle relaxes
The manual compression of the superficial trunk does not
stop the deep vein flow below the shunt origin.
Note: the systolic flow only has a centripetal direction
>Resistance
Compression
PERSISTING FLOW
>Resistance

13. Systolic derivative shunt
Diastolic flow
It only appears when the Giacomini Vein feeds a
varicose vein whose re-entry point is placed
below the escape point.
This flow is due to the pseudo-siphon effect
Re-entry point
Escape point

14. The siphon effect explains the presence of a relaxation centripetal flow in the Giacomini v.
The siphon effect occurs when a tube in an inverted U shape causes a liquid to flow
upwards first and pass above the surface level of the reservoir and continuously flow
down without pumps , powered by the fall of the liquid as it flows down the tube under
the pull of gravity, and discharges at a level lower than the surface of the reservoir it
comes from ( http://en.wikipedia.org/wiki/Siphon ) .
The real siphon effect works in a open circuit. In the venous system the circuit is closed
and the effect of gravity’s potential energy is charged by muscle pump activity.
Tank A
Tank B
The Siphon Effect
Tank A
Tank B

15. Systolic derivative shunt
The manual compression of the varicose vein
origin stops the diastolic flow in the
Giacomini Vein
Re-entry point
Escape point
Compression
STOP FLOW

16. Therapeutic considerations
Systolic vicarious shunt:
This situation must be correctly diagnosed and the
role of the visible varicose veins clarified (absence of
diastolic centrifugal flow)
The role of the refluxing perforator is not pathogenic,
as it is the origin of a compensative circle and must
not be treated even if the flow has a non-physiological
direction.
Foto di lella cartella clinica e schema vene

17. The GSV trunk has a
fundamental function in a
systolic vicarious shunt even if
incompetent, because the flow
has a centripetal direction
thanks to a pressure gradient,
and is independent from the
valve function.
This fact must be considered
every time GSV trunk avulsion
is planned.

18. Therapeutic considerations
Systolic derivative shunts:
A systolic derivative shunt is fed by an escape point that
refluxes during muscle systole.
This means that the outward flow is pushed by the
muscle systolic pressure.
Note that a diastolic escape point refluxes thanks to a
gravitational aspirative gradient.

19. The high pressure in a systolic escape point is
responsible for a high frequency of recurrences if
treated.
The treatment strategy of systolic derivative shunts
gives better results preserving the systolic flow
without interrupting the escape point and treating
the diastolic shunt alone.
Therapeutic considerations
Systolic derivative shunts: