Changzhou KangXin Medical Instruments Co., Ltd.

Specialized medical devices are crucial for improving the outcomes for patients in cardiovascular and critical care medicine. One such innovation is the dual stage venous cannula, a device formulated to maximize venous drainage during complex surgeries. This article explores dual stage venous cannula structure, mechanism, clinical applications, and advantages over traditional single stage cannulas.

What is a Dual Stage Venous Cannula?

A dual stage venous cannula is a medical device used to withdraw deoxygenated blood from a patient’s venous system during procedures such as cardiopulmonary bypass (CPB) or extracorporeal membrane oxygenation (ECMO). Unlike single-stage cannulas, which feature a single drainage port, dual stage cannulas incorporate two distinct openings positioned at different levels, enabling more efficient blood extraction from multiple venous sites simultaneously.

Structure and Design 

The design of the Dual Stage Venous Cannula is crucial to its function:

Proximal Stage: A group of side holes closely connected to the cannula’s tip, placed in the right atrium or vena cava to extract blood from major veins.

Distal Stage: Another set of 10–20 cm proximal openings from the tip, in the inferior vena cava (IVC) or femoral vein to retrieve blood from the peripheral veins.

Material: The most common material for the Dual Stage Venous Cannula is a flexible biocompatible polymer (like polyurethane) reinforced with a rigid polymer to resist collapse under suction.

This bifurcated design enables concurrent drainage from both central and peripheral venous compartments, optimizing blood flow and minimizing blood stasis to thereby significantly decrease risk of thrombus production.

Mechanism of Action

The Dual Stage Venous Cannula uses pressure gradients and anatomical placement for improved drainage:

Central Drainage: The proximal phase actively siphons from the right atrium or superior vena cava.

Peripheral Drainage: The bottom stage brings blood in from more central (e.g., IVC or iliac veins) venous systems.

Synergistic Flow: The Dual Stage Venous Cannula creates higher flow rates at lower suction pressure through access to multiple venous pools, eliminating vascular wall trauma and the risk of hemolysis.

Clinical Applications

Cardiac Surgery:

Efficient venous drainage is essential for a bloodless surgical field during open-heart operations. By enhancing CPB efficiency, Dual Stage Venous Cannula may also decrease surgery time and reduce postoperative complications including systemic inflammatory response.

ECMO Support:

In venovenous ECMO, Dual Stage Venous Cannula reduce “recirculation” (when oxygenated blood is immediately sucked back into the circuit) and improve oxygen delivery. This is especially crucial in ICU settings for patients with severe respiratory failure.

Less Invasive Practices:

Their flexibility makes them perfect for robotic or endoscopic surgeries requiring exact access to the veins through small insertions.

Benefits Compared to Single Stage Cannulas

Decreased Complications: Lower suction pressure results in less endothelial damage and thrombus formation. Studies also report up to 30% less thrombotic events vs single stage designs.

Higher Flow Rates: A dual drainage site can achieve flow rates greater than 6–7 L/min, ideal for adult CPB.

Flexibility in Anatomy: Successful in cases of abnormal anatomy (eg, obesity, congenital defects).

Better Aeration on ECMO: 15–20% decrease in recirculation/external recirculation rate = increased circuit efficiency

Challenges and Considerations

Dual Stage Venous Cannula offer great utility but require a bit of a learning curve in their use. If improperly placed, it can lead to failure to drain entirely, or perforation of a vessel. Moreover, they are more expensive than traditional cannulas, requiring careful patient selection.

Future Directions

Innovations include heparin-coated surfaces to reduce thrombosis and ultrasound-guided insertion systems for accurate positioning. Hybrid designs are also being investigated for pediatric use, where venous access presents a unique set of challenges.

Conclusion

The dual stage venous cannula demonstrates how engineering ingenuity meets clinical needs. By optimizing venous drainage, it enhances safety and efficiency in life-saving procedures, underscoring its value in modern medicine. As technology evolves, its role is poised to expand, benefiting both surgeons and critically ill patients.

As a leading Dual Stage Venous Cannulas manufacturer, Kangxin Medical delivers precision engineered solutions for cardiopulmonary bypass (CPB) and ECMO. Featuring patented dual drainage ports, anti-collapse design, and ISO 13485 quality compliance, our cannulas ensure superior flow rates (6-8 L/min) and reduced thrombosis risk. Explore OEM/ODM services today!