1. Vascular Access & Cannulation
Dr Osama Bawazir
Assistant Professor , Consultant Pediatric surgeon
FRCSI, FRCS(Ed), FRCS (glas), FRCSC,
FAAP,FACS.

2. ECMO is a supportive measure, which can be instituted as an urgent, semi elective or elective procedure
Time in relation to the event is the limiting factor when going through the assessment cascade in order to accomplish a successful result

3. Introduction PRE-ECMO ASSESSMENT CANNULATION
INITIATION AND MAINTENANCE OF ECMO
EVALUATION

4. CANNULATION
The establishment and maintenance of adequate vascular access is essential for ECMO

5. CANNULATION Patient age and size Underlying disease & condition
Cause of the cardiorespiratory compromise
Type of support:
Veno-venous (VV) ECMO
Veno-arterial (VA) ECMO
Time of the event in relation to the peri-operative period
Location

6. CANNULATION
For each modality, there are different kinds and sizes of cannulae that can be used
Target activated clotting time (ACT) should be accomplished first before ECMO (heparin 100 units/kg) 3 minutes before cannulation.
Consent GA

7. Guidelines for Cannula size
Weight (Kg)
Venous cannula
arterial cannula
2-4
8-14
8-10
5-15
15-19
12-15
16-20
19-21
15-17
21-35
21-23
17-19
35-60 23
>60 21

8. Poiseuille’s Law
Poiseuille's law: In an artificial system, flow through a cylindrical tube or any segment of a tube is directly proportional to ΔP, the driving pressure along the tube, and the fourth power of the radius, r. Flow is inversely proportional to L the length of the segment and to η, the viscosity of the liquid. The proportionality constant is π/8.

9. Cannula Consideration
Venous cannula should be with the largest lumen and shortest length possible (gravity).
Venous cannula should have side holes.
M-number
Resist kinking
The smallest double lumen cannula is size 12 F ( for V V ecmo in neonate)

10. CANNULATION Veno-Venous (V-V) ECMO
Mainly used for respiratory support (ARDS & Congenital Diaphragmatic Hernia)
V-V ECMO provides adequate oxygenation and CO2 removal
The venous access can be established by using the system in one site, or two different sites

11. CANNULATION Veno-Arterial (VA) ECMO
provides cardiac as well as respiratory support and is mainly used for post op cardiac case

13. (V-V) ECMO Advantage offer (V-A) ECMO
Eliminate the potential for arterial embolization and ischemia
Arterial ligation or repair is unnecessary
Improve the blood flow and oxygenation to pulmonary circulation.
No hemodynamic effects

14. CANNULATION TECHNIQUE
Open
Semi-open
Percutaneous

15. CANNULATION
Internal jugular vein

16. Subclavian vein & Right atrium
CANNULATION
Subclavian vein & Right atrium

17. CANNULATION
Femoral vein

18. CANNULATION
One site
A double lumen cannula is inserted into the internal jugular vein
Only one site for venous access

19. CANNULATION
Two different sites

20. CANNULATION Veno-Arterial (VA) ECMO
provides cardiac as well as respiratory support and is mainly used for post op cardiac case

21. Internal jugular vein and the common carotid artery
CANNULATION
Internal jugular vein and the common carotid artery

22. Right atrium and ascending aorta
CANNULATION
Right atrium and ascending aorta

23. Femoral vein and artery
CANNULATION
Femoral vein and artery

24. A Left atrial pressure line can be utilized to monitor the LA pressure
CANNULATION
A Left atrial pressure line can be utilized to monitor the LA pressure

25. In situations where ECMO support is anticipated
CANNULATION
In situations where ECMO support is anticipated
Chest will be left open and covered by a Silastic patch
Purse-string sutures will be left snared in place
Standby preprimed pump will be kept in ICU

26. CANNULATION PROBLEMS Threading the venous catheter Vein division
Proximal vein lost in mediastinum
Lack of venous return
Intrathoracic vein perforation

27. Complication Vascular injury( tear, intimal dissection, perforation).
Obstruction (kinking, positional).
Misplacement( AI, afterload LV failure).
Bleeding.
Recirculation.

28. Thank You