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Q: Why is there more flow with a smart canula ® as compared to a standard cannula or a percutaneous canula?

Q: Is there more haemolysis with the smart canula ®?

Q: For how much time can the smart canula ® be used?

Q: Can the smart canula ® be resterilized?

Q: How can the self-expanding smart canula ® be removed?

Q: How is the smart canula ® inserted?

Q: What can I do, if a feel some resistance during removal of the guide wire?

Q: How can I check the position of the guide wire and/or the smart canula ®?

Q: Why is there only one smart canula ® diameter (15 F expanding to 36 F) for perfusion of adults?

Q: Is kinetic augmention of the venous return recommended with the smart canula ®?

Q: Is one femoral venous smart canula ® sufficient to achieve full flow?

Q: Is one jugular venous smart canula ® sufficient to achieve full flow?

Q: Is one subclavian venous smart canula ® sufficient to achieve full flow?

Q: For trans-subclavian smart cannulation of the right atrium: What to do if the guide wire cannot be identified with echocardiography?

Q: For trans-subclavian smart cannulation of the right atrium: What to do, if the guide wire is in the right atrium/inferior vena cava, but there is a resistance during insertion of the smart canula ®?

Q: What are the various venous smart canula ® lengths good for?

Q: What is direct cannulation of the inferior vena cava through the right atrium with a smart canula ® good for?

Q: What are the indications for smart central cannulation (right atrium/inferior vena cava) cannulation)?

Q: What can be done in a patient who is perfused with a smart canula ® crossing the right atrium and the latter has to be opened?

Q: What are the indications for smart cannulation?

Q: Is it true, that open intra-cardiac surgery is feasible without snare around the vena cava cannulated with a smart canula ®?

Q: How far should the smart canula ® be inserted?

Q: How should the smart canula ® be attached once it is inserted?

Q: How to resolve poor drainage after smart cannulation?







Q: Why is there more flow with a smart canula ® as compared to a standard cannula or a percutaneous canula?
A: There are three main factors that contribute to the superior performance of the smart canula ®:
a) the self-expanding mechanism allows for a larger smart canula ® diameter wherever the vessel lumen is wide
b) the wall thickness of the smart canula ® is far less than in any other cannula allowing for superior effective luminal width
c) the uncovered "open wall" design of the smart canula ® allows for direct drainage of the blood coming from collaterals.
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Q: Is there more haemolysis with the smart canula ®?
A: No, there is not more haemolysis with the smart canula ® as compared to other cannulae because there is not only a larger mean effective luminal width but also the total orifice area is at least one order of magnitude higher. Both factors contribute to lower velocities and less stress (see also literature for experimental and clinical data).
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Q: For how much time can the smart canula ® be used?
A: Typical use of the smart canula ® is two hours and maximal use is six (6) hours.
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Q: Can the smart canula ® be resterilized?
A: No, the smart canula ® is designed for single use. It cannot be resterilized.
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Q: How can the self-expanding smart canula ® be removed?
A: smart canula ® removal is easy, because simple traction reduces its diameter.
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Q: How is the smart canula ® inserted?
A: Each smart canula ® comes with its specific mandrel in the same blister. Insertion of the smart canula ® requires a guide wire, which is positioned in the target vessel area (e.g. vena cava superior for femoral cannulation). Correct positioning of the guide wire has to be checked with echocardiography or other suitable means. The smart canula ® is collapsed by extension with its mandrel and inserted over the guide wire previously positioned as described above. Once the smart canula ® is in place, it is important to remove the guide wire before the mandrel in order to avoid dislodgement of smart canula ® tip. For the patients safety, it is mandatory to read the instructions for use.
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Q: What can I do, if a feel some resistance during removal of the guide wire?
A: Some resistance during guide wire removal can occur if the guide wire is kinked. For this reason, the guide wire should be removed before the mandrel in order to maintain the position of the tip of the smart canula ®. If this is not successful, the guide wire, the smart canula ®, and the mandrel have to be removed "en bloc" (together) by gentle traction.
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Q: How can I check the position of the guide wire and/or the smart canula ®?
A: Suitable means to check the guide wire and/or the smart canula ® position include echocardiography (transesophageal (TEE), intracardiac (ICE), epicardial, transthoracic ), intravascular ultrasound (IVUS), fluoroscopy, digital exploration, etc.
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Q: Why is there only one smart canula ® diameter (15 F expanding to 36 F) for perfusion of adults?
A: It has been shown in the experimental and in the clinical setting that the venous smart canula ® expanding to 36 F has sufficient drainage capacity (6 l/min) with gravity drainage alone. Hence, augmentation of venous return with a centrifugal pump or vacuum can be avoided.
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Q: Is kinetic augmention of the venous return recommended with the smart canula ®?
A: With a well positioned smart canula ® in the right atrium (femoral, jugular or subclavian accessis possible), gravity drainage is sufficient for achieving the target flow.
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Q: Is one femoral venous smart canula ® sufficient to achieve full flow?
A: Yes, one femoral venous smart canula ®, well positioned in the superior vena cava/right atrium is sufficient to achieve the target flow with gravity drainage alone.
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Q: Is one jugular venous smart canula ® sufficient to achieve full flow?
A: Yes, one jugular venous smart canula ®, well positioned in the inferior vena cava/right atrium is sufficient to achieve the target flow with gravity drainage alone.
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Q: Is one subclavian venous smart canula ® sufficient to achieve full flow?
A: Yes, one subclavian venous smart canula ®, well positioned in the inferior vena cava/right atrium is sufficient to achieve the target flow with gravity drainage alone. Trans-subclavian insertion of the smart canula ® may require curved catheters, as well as soft and stiff guide wires.
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Q: For trans-subclavian smart cannulation of the right atrium: What to do if the guide wire cannot be identified with echocardiography?
A: One possibility is that the guide wire progresses cranially. A curved catheter pointing caudally may allow for exploration of the superior vena cava with a J-type guide wire.
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Q: For trans-subclavian smart cannulation of the right atrium: What to do, if the guide wire is in the right atrium/inferior vena cava, but there is a resistance during insertion of the smart canula ®?
A: One possibility is that the curve from the subclavian vein towards the superior vena cava is to narrow for the guide wire selected. This type of problem can often be overcome with a stiffer guide wire. For the purpose, an exchange catheter (e.g. a pig tail catheter) has to be sled over the guide wire which is in place. Once the catheter can be identified in the right atrium, the guide wire can be replaced with a super stiff guide wire, which in turn may allow to insert the smart canula ®. Alternatively, a jugular (straighter) approach may be considered.
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Q: What are the various venous smart canula ® lengths good for?
A: For adults, the long venous smart canula ® (63 cm, 53 cm) is designed for single femoral cannulation of the right atrium/superior vena cava. The medium venous smart canula ® (43 cm) is designed for femoral cannulation of the inferior vena cava (tip position at the level of the hepatic veins). The very short smart canula ® (26cm) is designed for jugular cannulation of the superior vena cava. The main indication for the medium and very short smart canula ® is dual cannulation for open heart surgery with open right atrium. There is also a short smart canula ® (34 cm) which is suitable for either single trans-subclavian or trans-jugular cannulation of the right atrium or direct cannulation of the inferior vena cava through the right atrium.
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Q: What is direct cannulation of the inferior vena cava through the right atrium with a smart canula ® good for?
A: Full flow can usually be achieved with gravity drainage alone, provided an access orifice of 24 F to 28 F is made available for the smart canula ® as compared to up to 51 F for standard two stage venous cannulae.
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Q: What are the indications for smart central cannulation (right atrium/inferior vena cava) cannulation)?
A: The main indications for central venous (= right atrial) smart cannulation include lack of space for various reasons and/or a small/crowded right atrium from previous procedures. Smart cannulation of the right atrium/inferior vena cava may also be indicated for assisted beating heart procedures, where the ventricles have to be lifted and/or stabilized.
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Q: What can be done in a patient who is perfused with a smart canula ® crossing the right atrium and the latter has to be opened?
A: Several options are available here. The vena cava and smart canula ® can be snared down together on the side of insertion and a solution has to be found for drainage of the second vena cava. For a short period, this may be handled with the cardiotomy suction. Alternatively, a second venous cannula may be necessary. Opening of the right atrium will reveal the snared smart canula ®, which will re-expand once the snare is released.
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Q: What are the indications for smart cannulation?
A: We distinguish six main groups of indications for smart cannulation:
a) small access surgery with remote cannulation. This is the original indication for which the smart canula ® has been developed. As a matter of fact, it is very difficult to achieve full flow with traditional percutaneous cannulae despite augmentation of venous return with centrifugal pumps or vacuum whereas gravity drainage is sufficient after smart cannulation.
b) remote smart cannulation for (redo-) procedures with increased risk of cardiac injury allows for achieving full flow and decompression of the heart before entering the chest.
c) remote smart cannulation for aortic surgery allows for superior flow which in turn results in faster cooling respectively rewarming of the patient.
d) remote cannulation for open intra-caval procedures without snare.
e) central smart cannulation of the right atrium/inferior vena cava for patients with small or crowded right atrium (smaller access) or assisted beating heart procedures (requiring lifting and/or stabilizing of the ventricles).
f) other
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Q: Is it true, that open intra-cardiac surgery is feasible without snare around the vena cava cannulated with a smart canula ®?
A: Yes, open intra-cardiac surgery without snare around one vena cava is possible with the smart canula ® . This is due to the fact that the drainage of the vena cava after remote smart cannulation occurs close to the access orifice and not close to the heart as with traditional cannulae. Although special attention to the venous return during open right atrial surgery without snare around the vena cave with the smart canula ® is necessary in order to prevent/recognize a potential airlock, only little perfusionist intervention is usually required.
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Q: How far should the smart canula ® be inserted?
A: At least 10 mm of the covered part of the smart canula ® have to be inserted into the vessel to be drained.
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Q: How should the smart canula ® be attached once it is inserted?
A: If a suture is used, it should be placed onto the silastic sleeve, preferably in the section where the latter is supported with wires. If a tape is to be used, the silastic sleeve is again the preferred location.
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Q: How to resolve poor drainage after smart cannulation?
A: There are a number of reasons that can explain poor drainage (corrective measures). These include a) malposition (check position and reposition if necessary), b) narrowing by a purse string or a suture (release suture), c) kincked cannula or tubing (reposition) d) unexpected anatomic constriction (add additional cannula), e) other (add additional cannula)
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Patents: US 6626859, WO 015273, AU770989, JP5059305, EP1248571, US8679053, EP1651121, HK1091109, US7967776, CN02149340, US8992455, US8679053
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