Vascular Access

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

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Introduction

• PRE-ECMO ASSESSMENT
• CANNULATION
• INITIATION AND MAINTENANCE OF ECMO
• EVALUATION

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CANNULATION

• The establishment and maintenance of adequate
  vascular access is essential for ECMO

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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

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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

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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 19-21
gt60 23 21
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Poiseuilles Law

• Poiseuille's law In an artificial system, flow
  through a cylindrical tube or any segment of a
  tube is directly proportional to ?P, 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 ?, the
  viscosity of the liquid. The proportionality
  constant is p/8.

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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)

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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

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CANNULATION

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

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(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

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CANNULATION TECHNIQUE

• Open
• Semi-open
• Percutaneous

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CANNULATION

• Internal jugular vein

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CANNULATION

• Subclavian vein Right atrium

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CANNULATION

• Femoral vein

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CANNULATION

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

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CANNULATION

• Two different sites

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CANNULATION

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

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CANNULATION

• Internal jugular vein and the common carotid
  artery

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CANNULATION

• Right atrium and ascending aorta

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CANNULATION

• Femoral vein and artery

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CANNULATION

• A Left atrial pressure line can be utilized to
  monitor the LA pressure

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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

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CANNULATION PROBLEMS

• Threading the venous catheter
• Vein division
• Proximal vein lost in mediastinum
• Lack of venous return
• Intrathoracic vein perforation

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Complication

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

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Thank You