Point-of-Care Ultrasound-Guided Peripheral Veno-Arterial Extracorporeal Membrane Oxygenation Cannulation in Adult Patients

Summary

This protocol demonstrates the use of point-of-care ultrasound to guide peripheral veno-arterial extracorporeal membrane oxygenation cannulation through pre-procedural assessment, real-time procedural guidance, and post-cannulation verification.

Abstract

Point-of-care ultrasound (POCUS) has become an important imaging modality for guiding peripheral veno-arterial extracorporeal membrane oxygenation (VA-ECMO) cannulation. This protocol describes the integration of POCUS throughout the peripheral VA-ECMO cannulation workflow, including pre-procedural assessment, real-time procedural guidance, and post-cannulation verification. During the pre-procedural assessment, POCUS facilitates differentiation of arteries from veins, measurement of vessel diameter to estimate appropriate cannula size, and identification of vascular pathology, including plaques, thrombosis, and stenosis. During cannulation, combined out-of-plane and in-plane ultrasound techniques enable real-time visualization of the guidewire, confirmation of guidewire placement within the target vessel, and avoidance of posterior wall perforation or injury to adjacent structures. Following cannulation, POCUS is used to verify drainage cannula positioning at the inferior vena cava–right atrium junction and arterial return cannula positioning at the external or common iliac artery level, and to assess for complications such as cardiac tamponade, cannula malposition, and thrombosis. Compared with landmark-based or fluoroscopy-guided techniques, POCUS provides bedside imaging without ionizing radiation and supports continuous procedural guidance without interrupting resuscitation. This protocol provides a practical, evidence-based approach for ultrasound-guided peripheral VA-ECMO cannulation and focuses specifically on vascular access and cannulation rather than broader VA-ECMO management.

Introduction

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is used as salvage therapy for patients with severe cardiogenic shock, refractory cardiac arrest, and profound cardiopulmonary failure^1,2. As the use of VA-ECMO has increased, the need for safe, rapid, and reliable cannulation techniques has also grown. Percutaneous cannulation using the Seldinger technique is commonly used for peripheral VA-ECMO because it avoids the morbidity associated with surgical cutdown and can be performed at the bedside^3,4. This method is intended specifically for ultrasound-guided peripheral VA-ECMO cannulation and does not address the broader use of ultrasound in other ECMO configurations or in comprehensive post-cannulation hemodynamic management.

Peripheral VA-ECMO cannulation has traditionally been guided by anatomical landmarks or fluoroscopy. Landmark-based techniques carry risks of cannula misplacement and vascular complications⁵. Although fluoroscopy provides accurate imaging guidance, it may require transport to a catheterization suite, exposes patients and staff to ionizing radiation, and may involve the use of contrast agents with a risk of nephropathy⁶. Point-of-care ultrasound (POCUS) provides a noninvasive, repeatable, and portable alternative that can be used at the bedside without substantially interrupting ongoing resuscitation efforts⁷. Using phased-array, curvilinear, or linear transducers as appropriate, operators can assess target vessels, visualize the guidewire and cannula in real time, confirm positioning at the inferior vena cava (IVC)-right atrium junction or within the iliac arterial system, and evaluate for complications such as cannula malposition or thrombosis⁸. During low-flow states or ongoing cardiopulmonary resuscitation, pulsatility and compressibility may be less reliable for vessel discrimination; therefore, vessel morphology, wall characteristics, anatomical location, and guidewire position should also be considered.

The overall goal of this protocol is to describe the use of POCUS throughout peripheral VA-ECMO cannulation, including pre-procedural vascular assessment, real-time guidance during needle puncture and guidewire advancement, post-cannulation cannula-position verification, and complication assessment. The protocol is intended for centers performing or developing bedside femoral VA-ECMO cannulation and may be most appropriate when fluoroscopy is unavailable, impractical, or would delay resuscitation. The principal contribution of this protocol is the integration of point-of-care ultrasound throughout the entire peripheral VA-ECMO cannulation workflow, encompassing pre-procedural vascular assessment, real-time procedural guidance, and post-cannulation verification⁶. All practitioners completed the standardized training program for restricted medical technologies in Zhejiang Province and obtained the required certification before performing the procedure. Senior attending physicians supervised the procedures to ensure adherence to institutional protocols and procedural safety.

Protocol

This study was approved by the Ethics Committee of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine (Approval No. 2026-2186). The inclusion criterion was any patient receiving VA-ECMO, and the exclusion criterion was refusal to undergo ultrasound examination. Written informed consent for publication of the case report and accompanying images was obtained from the legally authorized representative. Potential risks associated with this procedure include vascular injury, vessel rupture, cardiac tamponade, cardiac rupture, retroperitoneal hematoma, and other clinically relevant adverse events.

1. Safety Procedures

1. Wear nitrile or latex-free gloves.
   NOTE: If the patient has surgical wounds in active stages of healing, use sterile, individually packaged ultrasound gel.
2. Apply non-sterile ultrasound gel to the transducer and cover the transducer with a sterile sheath to maintain asepsis during the procedure. Apply sterile normal saline or povidone-iodine solution to the puncture site as the acoustic coupling medium.

2. Probe Selection

1. Use a phased-array transducer (1.0–5.0 MHz) to evaluate the heart and IVC.
2. Use a high-frequency linear transducer (5.0–10.0 MHz) to evaluate the femoral artery and vein and to guide vascular access during cannulation.
3. Use a curvilinear-array transducer (2.5–5.0 MHz) to evaluate the iliac artery and IVC.

3. Patient Positioning

1. Place the patient in the supine position.
   NOTE: If supine positioning is not possible, maintain the patient in the most favorable position to avoid displacement of the VA-ECMO cannulas.

4. Ultrasound-Guided Procedure for VA-ECMO Cannulation

1. Perform the pre-cannulation ultrasound assessment.
   1. Identify the arteries and veins.
      1. Identify the artery by confirming a round short-axis appearance, a thick vessel wall with a visible intimal line, pulsatility during the cardiac cycle, and a pulsatile Doppler waveform.
      2. Identify the vein by confirming an irregular short-axis appearance, a thin vessel wall with visible venous valves, non-pulsatility, and a continuous low-velocity Doppler waveform.
      3. Apply gentle probe pressure to assess vessel compressibility. Confirm that veins progressively collapse whereas arteries remain unchanged.
      4. During extracorporeal cardiopulmonary resuscitation (ECPR), distinguish arteries from veins according to vascular morphology, wall thickness, and anatomical location. Alternatively, after guidewire insertion, confirm that the guidewire is located within the IVC or the abdominal aorta.
   2. Select the appropriate ECMO cannula size. Measure the short-axis inner diameter (D) of the target vessel using two-dimensional ultrasound. Estimate the maximum cannula size as: French (Fr) = D (mm) × 3.
      NOTE: Assess for arterial plaques, venous thrombosis, luminal stenosis, dissecting aneurysm, arteriovenous fistula, and other vascular abnormalities. Avoid selecting vessels with significant pathology for cannulation.
2. Provide real-time ultrasound guidance during cannulation.
   1. Localize the target vessel with ultrasound. Perform vessel puncture using combined in-plane and out-of-plane approaches.
   2. Perform vascular puncture using the Seldinger technique and advance the guidewire.
   3. Measure and mark the target guidewire insertion depth before cannula advancement (e.g., using the xiphoid-to-puncture distance). After guidewire insertion, perform bedside ultrasound to confirm that the guidewire tip is positioned at the junction of the inferior vena cava and the right atrium before advancing the cannula.
   4. Make a 0.5-cm skin incision with a scalpel. Sequentially dilate the subcutaneous tissue and vessel using dilators.
   5. Advance the arterial or venous cannula over the guidewire.
   6. Continuously track the guidewire and cannula tip throughout puncture and cannulation under ultrasound guidance.
   7. After confirming correct cannula position, secure the cannula with sutures and protect the insertion site with a sterile dressing.
      NOTE: Combine out-of-plane and in-plane approaches. Use short-axis views to confirm that the needle tip is within the vessel lumen and to avoid injury to adjacent vessels. Use long-axis views to confirm alignment of the needle with the target vessel and to avoid posterior wall perforation. Adjust the needle angle, direction, and depth according to vessel anatomy and patient body habitus. Perform arterial puncture below the inferior epigastric artery and above the common femoral artery bifurcation. Perform venous puncture above the common femoral vein bifurcation.
3. Perform the post-cannulation assessment.
   1. Perform cardiac ultrasound after successful cannulation to assess for complications such as cardiac tamponade.
   2. Confirm the position of the cannula tip.
      1. Position the drainage cannula tip at the junction of the IVC and the right atrium.
      2. Position the femoral arterial return cannula tip at the level of the external iliac artery.
   3. Place a distal perfusion catheter in the superficial femoral artery to reduce the risk of lower-limb ischemia associated with peripheral femoral arterial VA-ECMO cannulation.
      NOTE: For patients with femoral artery atherosclerosis, stenosis, or prior cardiopulmonary resuscitation, consider prophylactic placement of a distal perfusion catheter. Place the catheter in the superficial femoral artery. If vessel stenosis or reduced blood flow makes placement difficult, use ultrasound guidance to direct puncture and cannulation according to the vessel course.

Results

Our institution is a 2,000-bed tertiary-care hospital. Bedside peripheral VA-ECMO cannulation is performed by attending physicians in emergency medicine and critical care medicine, with an annual procedural volume of approximately 30–40 cases. Ultrasound-guided bedside cannulation is the standard first-line approach at our institution. The representative ultrasound images were acquired during peripheral VA-ECMO cannulation procedures performed by critical care physicians in the Emergency Intensive Care Unit (EICU) of Sir...

Discussion

POCUS has emerged as an indispensable imaging modality throughout the entire workflow of peripheral VA-ECMO cannulation. Our protocol details a systematic approach encompassing pre-procedural vessel assessment, real-time intra-procedural guidance, and post-cannulation verification. Pre-procedural vascular assessment begins with selection of the optimal puncture site, followed by POCUS evaluation to differentiate the artery from the vein. Measurement of the vessel diameter to estimate the maximum cannula size (French [Fr]...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Curvilinear ultrasound transducer (2.5–5.0 MHz)	Shenzhen Mindray Bio-Medical Electronics Co., Ltd.	120-018844-00	Specification: C5-1s
Curvilinear ultrasound transducer (2.5–5.0 MHz)	Shenzhen Mindray Bio-Medical Electronics Co., Ltd.	120-018844-00	Specification: C5-1s
Guidewire	Terumo Corporation	20153032566	Specification: RF*GA35153M
Guidewire	Terumo Corporation	20153032566	Specification: RF*GA35153M
High-frequency linear ultrasound transducer (5.0–10.0 MHz)	Shenzhen Mindray Bio-Medical Electronics Co., Ltd.	120-018844-00	Specification: L12-4s
High-frequency linear ultrasound transducer (5.0–10.0 MHz)	Shenzhen Mindray Bio-Medical Electronics Co., Ltd.	120-018844-00	Specification: L12-4s
Latex-free gloves	ARMEDICOM (M) SDN. BHD.	20190299	Alternative to nitrile gloves for safety procedures
Latex-free gloves	ARMEDICOM (M) SDN. BHD.	20190299	Alternative to nitrile gloves for safety procedures
Nitrile gloves	Shandong Blue Sail Innovation Co., Ltd.	20160003	Required for safety procedures
Nitrile gloves	Shandong Blue Sail Innovation Co., Ltd.	20160003	Required for safety procedures
Peripheral extracorporeal membrane oxygenation cannula and puncture accessories	Maquet Cardiopulmonary GmbH	20183101652	Specification: BE-PAL1723
Peripheral extracorporeal membrane oxygenation cannula and puncture accessories	Maquet Cardiopulmonary GmbH	20183101652	Specification: BE-PAL1723
Phased-array ultrasound transducer (1.0–5.0 MHz)	Shenzhen Mindray Bio-Medical Electronics Co., Ltd.	120-018844-00	Specification: SP5-1S
Phased-array ultrasound transducer (1.0–5.0 MHz)	Shenzhen Mindray Bio-Medical Electronics Co., Ltd.	120-018844-00	Specification: SP5-1S
Scalpel	Hangzhou Huawei Pharmaceutical Co., Ltd.	20152020713	Used to make a 0.5-cm skin incision
Scalpel	Hangzhou Huawei Pharmaceutical Co., Ltd.	20152020713	Used to make a 0.5-cm skin incision
Sterile dressing	Shaoxing Fuqing Health Products Co., Ltd.	20172140349	Used to protect the cannulation site
Sterile dressing	Shaoxing Fuqing Health Products Co., Ltd.	20172140349	Used to protect the cannulation site
Suture material	Ethicon, LLC	XJ8720.O31	Used to secure the cannula
Suture material	Ethicon, LLC	XJ8720.O31	Used to secure the cannula
Ultrasound gel	Hangzhou Kaipule Medical Devices Co., Ltd.	20150031	Specification: KL-250 Type II
Ultrasound gel	Hangzhou Kaipule Medical Devices Co., Ltd.	20150031	Specification: KL-250 Type II
Ultrasound imaging system	Shenzhen Mindray Bio-Medical Electronics Co., Ltd.	20193061691	Specification: M9
Ultrasound imaging system	Shenzhen Mindray Bio-Medical Electronics Co., Ltd.	20193061691	Specification: M9
Vascular sheath	Terumo Corporation	20193031784	Specification: RS*A60K10SQ
Vascular sheath	Terumo Corporation	20193031784	Specification: RS*A60K10SQ
Vessel dilator set	Maquet Cardiopulmonary GmbH	20183101652	Used for sequential tissue and vessel dilation
Vessel dilator set	Maquet Cardiopulmonary GmbH	20183101652	Used for sequential tissue and vessel dilation