NOTE: The following protocol follows our internal guidelines and standard operation procedures approved by the chair of our department. The same protocol was approved by our institutional review board and was used for studies published in a previous paper8.
1. Pre-ultrasound Scan Preparation
<ol>
	<li>Place the patient in a supine position with an optional elevated head of bed or stretcher for comfort if the patient is awake.</li>
	<li>Position the ultrasound machine in a line with operator&#180;s position and the puncture site to prevent operator&#180;s head or body twisting to see the display. Turn on the ultrasound machine and connect the micro-convex ultrasound probe.</li>
	<li>Choose a pre-set that allows deep tissue penetration, e.g., set probe to 8 MHz or lower. Use alcoholic disinfection on skin for acoustic coupling of the ultrasound probe.</li>
</ol>
2. Ultrasound Scan of the CVC Insertion Site and Superior Vena Cava
<ol>
	<li>Place the micro-convex ultrasound probe on the puncture site. 
	NOTE: A B(rightness)-mode short axis view and out of plane puncture technique is preferred. Adjust gain, depth and focus position for an optimal image.</li>
	<li>Confirm vein by applying pressure to test for compressibility and to exclude thrombus at puncture site. Use color flow doppler if there is uncertainty. Move ultrasound probe centrally to detect potential thrombus.</li>
</ol>
3. Supraclavicular Fossa Ultrasound View
<ol>
	<li>Place the ultrasound probe in the right supraclavicular fossa to obtain a view of the confluence of the internal jugular vein and subclavian vein to detect a potential thrombus. Change gain, depth and focus using knobs of the ultrasound machine. 
	NOTE: Set gain high enough to differentiate between hyperechoic vessel walls and hypoechoic vessel lumen. Set depth (10-12 cm) to have a full view of the SVC and right pulmonary artery (RPA). Set the Focus to the level of the RPA.</li>
	<li>Increase depth (4-6 cm) using the knob of the ultrasound machine to obtain a view of the confluence of the brachiocephalic veins. This will also correspond to the beginning of the upper superior vena cava. Adjust depth (10-12 cm) and angulation of the ultrasound probe to obtain a full longitudinal view of the superior vena cava, adjacent ascending aorta and right pulmonary artery. 
	NOTE: Probe frequency will be adjusted by the ultrasound machine depending on depth of imaging.</li>
	<li>Evaluate the brachiocephalic veins and the superior vena cava for intravenous thrombus. Turn the ultrasound probe 90&#176; clockwise to obtain a sagittal view of the superior vena cava. Observe the right pulmonary artery in short axis dorsal of the lower superior vena cava. Additionally, observe a short axis view of the pulmonary veins distal of the right pulmonary artery. Use optional Doppler to confirm superior vena cava.</li>
</ol>
4. Ultrasound Guided Venipuncture
<ol>
	<li>Prepare CVC kit and dress with sterile gown and gloves. Disinfect skin with alcohol wipes and apply sterile drapes. Insert ultrasound probe into a sterile cover. Ultrasound guided venipuncture can be performed in non-sedated as well as in anesthetized patients. 
	NOTE: For non-sedated patients a local infiltration anesthesia before venipuncture is highly recommended.</li>
	<li>Obtain an ultrasound view of the vein to be punctured. Right-handed operators use the needle attached to a syringe in the right hand and the ultrasound probe in the left hand.</li>
	<li>Perform a venipuncture under ultrasound guidance. 
	NOTE: Out of plane and in plane techniques are both appropriate.</li>
	<li>Following venipuncture, insert the guidewire through the needle. At this point, a long axis view of the vein can confirm the guidewire within the vein.</li>
</ol>
5. Ultrasound Guided Guidewire Advancement
<ol>
	<li>Switch ultrasound probe to the right hand. Obtain a view of the superior vena cava by adjusting depth and focus position of the ultrasound image (Figure 3A and supplemental video loop). 
	NOTE: This has to be done by an assisting person or by the operator himself if the ultrasound machine is operated with a sterile cover. Angulation of the ultrasound probe needs to be in a small angle in relation to neck.</li>
	<li>Advance the guidewire with the left hand. Do not introduce the guidewire too far into the superior vena cava because this will make it difficult to identify the guidewire tip. Visualize the guidewire J-tip during advancement and crossing of the upper wall of the right pulmonary artery (Figure 3B).</li>
	<li>If the ultrasound beam cannot be aligned with the J-tip and the right pulmonary artery, use the ascending aorta as a landmark. Turn the ultrasound probe 90&#176; clockwise to obtain a sagittal view of the superior vena cava. With this view, confirm the guidewire position relative to the right pulmonary artery observed in the short axis.</li>
</ol>
6. Measurement of Insertion Depth
<ol>
	<li>Use the central venous catheter to measure the insertion depth of the guidewire. In order to do so, align the 20 cm markings of the CVC and the guidewire and read the cm marking at the venipuncture site. 
	NOTE: The guidewire has markings at 10, 20 cm and at the position indicating that the J-tip leaves the distal lumen. These markings may be different depending on the manufacturer. Be careful not to move the guidewire. 
	NOTE: From this point on, complete placement according to standard hospital protocol, including dilation of skin and vein, insertion of the CVC over guidewire, aspiration and flushing and suture.</li>
</ol>
7. Lung Ultrasound
<ol>
	<li>In the perioperative setting, perform a lung ultrasound examination in the patient to exclude pneumothorax following CVC placement. 
	NOTE: This procedure has been described by Lichtenstein et al.11.</li>
	<li>Place the ultrasound probe in all four quadrants of the anterior chest bilaterally to obtain view in B-mode for lung sliding and M-mode for seashore sign. Preferably use a linear ultrasound probe. For obese patients, use an ultrasound probe with higher penetration, e.g., curved array or micro-convex probes.</li>
</ol>
8. Central Venous Catheter Change Over Guidewire
NOTE: CVC change over guidewire is a single contributor to catheter-related blood stream infection and should be avoided. In patients with a high risk of mechanical complication related to CVC insertion or limited venous access, CVC change over guidewire still can be considered12.
<ol>
	<li>In case of a misplaced central venous catheter (not using the ultrasound guided tip position method), obtain a supraclavicular view to advance the guidewire into the correct position. Under sterile conditions, introduce a guidewire into the distal lumen of the misplaced central venous catheter. Change of a CVC over a guidewire with ultrasound guidance works in non-sedated patients as well as in anesthetized patients.
	<ol>
		<li>Pull back the central venous catheter. Visualize the guidewire from thesupraclavicular fossa view.</li>
		<li>Advance the guidewire into the correct position in the superior vena cava. Introduce the new central venous catheter over the guidewire.</li>
		<li>From this point on, complete procedure according to standard hospital protocol.</li>
	</ol>
	</li>
</ol>

<ol>
	<li>Troianos, C. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Special+articles:+guidelines+for+performing+ultrasound+guided+vascular+cannulation:+recommendations+of+the+American+Society+of+Echocardiography+and+the+Society+Of+Cardiovascular+Anesthesiologists.">Special articles: guidelines for performing ultrasound guided vascular cannulation: recommendations of the American Society of Echocardiography and the Society Of Cardiovascular Anesthesiologists.</a> Anesth Analg. 114 (1), 46-72 (2012).</li><li>Cavanna, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasound-guided+central+venous+catheterization+in+cancer+patients+improves+the+success+rate+of+cannulation+and+reduces+mechanical+complications:+a+prospective+observational+study+of+1,978+consecutive+catheterizations.">Ultrasound-guided central venous catheterization in cancer patients improves the success rate of cannulation and reduces mechanical complications: a prospective observational study of 1,978 consecutive catheterizations.</a> World J Surg Oncol. 8 (91), (2010).</li><li>Wirsing, M., Schummer, C., Neumann, R., Steenbeck, J., Schmidt, P., Schummer, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Is+traditional+reading+of+the+bedside+chest+radiograph+appropriate+to+detect+intraatrial+central+venous+catheter+position.">Is traditional reading of the bedside chest radiograph appropriate to detect intraatrial central venous catheter position.</a> Chest. 134 (3), 527-533 (2008).</li><li>Ender, J., Erdoes, G., Krohmer, E., Olthoff, D., Mukherjee, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transesophageal+echocardiography+for+verification+of+the+position+of+the+electrocardiographically-placed+central+venous+catheter.">Transesophageal echocardiography for verification of the position of the electrocardiographically-placed central venous catheter.</a> J Cardiothorac Vasc Anesth. 23 (4), 457-461 (2009).</li><li>Pittiruti, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+intracavitary+ECG+method+for+positioning+the+tip+of+central+venous+catheters:+results+of+an+Italian+multicenter+study.">The intracavitary ECG method for positioning the tip of central venous catheters: results of an Italian multicenter study.</a> J Vasc Access. 13 (3), 357-365 (2012).</li><li>Matsushima, K., Frankel, H. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bedside+ultrasound+can+safely+eliminate+the+need+for+chest+radiographs+after+central+venous+catheter+placement:+CVC+sono+in+the+surgical+ICU+(SICU).">Bedside ultrasound can safely eliminate the need for chest radiographs after central venous catheter placement: CVC sono in the surgical ICU (SICU).</a> J Surg Res. 163 (1), 155-161 (2010).</li><li>Matsushima, K., Frankel, H. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+central+venous+catheter+insertion-related+complication+using+bedside+ultrasound:+the+CVC+sono.">Detection of central venous catheter insertion-related complication using bedside ultrasound: the CVC sono.</a> J Trauma. 70 (6), 1561-1563 (2011).</li><li>Kim, S. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasound+confirmation+of+central+venous+catheter+position+via+a+right+supraclavicular+fossa+view+using+a+microconvex+probe:+A+observational+pilot+study.">Ultrasound confirmation of central venous catheter position via a right supraclavicular fossa view using a microconvex probe: A observational pilot study.</a> Eur J Anaesthesiol. , (2013).</li><li>Lanspa, M. J., Fair, J., Hirshberg, E. L., Grissom, C. K., Brown, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasound-guided+Subclavian+Vein+Cannulation+Using+a+Micro-Convex+Ultrasound+Probe.">Ultrasound-guided Subclavian Vein Cannulation Using a Micro-Convex Ultrasound Probe.</a> Ann Am Thorac Soc. 11 (4), 583-586 (2014).</li><li>Weber, S. U., Kim, S. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+right+supraclavicular+ultrasound+view+for+real-time+ultrasound-guided+definite+placement+of+a+central+venous+catheter+with+a+microconvex+transducer.">The right supraclavicular ultrasound view for real-time ultrasound-guided definite placement of a central venous catheter with a microconvex transducer.</a> Eur J Anaesthesiol. 31 (3), 173-174 (2014).</li><li>Lichtenstein, D. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasound+diagnosis+of+occult+pneumothorax.">Ultrasound diagnosis of occult pneumothorax.</a> Crit Care Med. 33 (6), 1231-1238 (2005).</li><li>Garnacho-Montero, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Risk+factors+and+prognosis+of+catheter-related+bloodstream+infection+in+critically+ill+patients:+a+multicenter+study.">Risk factors and prognosis of catheter-related bloodstream infection in critically ill patients: a multicenter study.</a> Intensive Care Med. 34 (12), 2185-2193 (2008).</li><li>Schummer, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intra-atrial+ECG+is+not+a+reliable+method+for+positioning+left+internal+jugular+vein+catheters.">Intra-atrial ECG is not a reliable method for positioning left internal jugular vein catheters.</a> Br J Anaesth. 91 (4), 481-486 (2003).</li></ol>

The authors declare that they have no competing financial interests.

This procedure allows for visualization of ultrasound guided venipuncture and central venous catheter tip position in real time via the right supraclaviculare fossa view. In combination with a lung ultrasound scan, this approach could replace chest radiograph for confirmation of catheter tip position and exclusion of a pneumothorax.
It is critical for ultrasound trained operators to become familiar with the ultrasound anatomy provided by the supraclavicular fossa view and correctly identify th...

Central venous catheter (CVC) tip position has to be confirmed since misplaced catheters can lead to trauma and erosion of endothelium and vessel walls with subsequent potentially fatal pericardial tamponade1. Furthermore, CVC in the upper superior vena cava (SVC) can provoke thrombotic events, especially in cancer patients. The same is true for misplaced CVC in opposite brachiocephalic vein or internal jugular vein (IJV)2.
Several methods have been established to confirm CVC tip position in the lower SVC. Chest radiograph has been performed traditionally as a bedside method to visualize the CVC tip and exclude pneumothorax. However, additionally to exposure to radiation and costs, the accuracy of chest radiograph for tip position and sensitivity for pneumothorax have been questioned, specifically for the patient in a supine position3. Computer tomography is highly accurate and sensitive for both CVC tip position and pneumothorax, respectively. However, the costs and exposure to radiation do not justify this method for the sole indication of CVC tip confirmation. Transesophageal echocardiography (TEE) is highly accurate for tip position, but indication for TEE is limited to patients with cardiac pathology4. Intra-cardiac electrocardiography (ECG) is an accurate method but depends on a p-wave cardiac rhythm5.
Parasternal and subcostal ultrasound view were suggested to verify the CVC tip position, but success depends on deep insertion of the guidewire into the right atrium. A negative result does not exclude misplaced catheters6,7. The right supraclavicular fossa ultrasound view has been solely described for diagnostic purposes in cardiac failure. In a pilot study, we have demonstrated that this view can also be safely used for venipuncture of the right IJV and accurate positioning of the CVC guidewire with subsequent CVC placement in real-time8. The right supraclavicular fossa ultrasound view can be established with a microconvex probe which has the advantage of a small footprint, deep pentetration and, yet a sufficient resolution for venipuncture when compared to a linear probe8-10.
The proposed procedure has the advantage of visualizing venipuncture and guidewire advancement with a single ultrasound probe within the sterile field in real-time. CVCs insertion length does not have to be corrected afterwards and extra manipulations and potential sources of contamination are prevented. In conjunction with lung ultrasound for exclusion of a pneumothorax, the proposed procedure has the potential to replace chest radiograph for CVC tip position confirmation and exclusion of pneumothorax, reducing costs and exposure to radiation and increasing patient comfort in any hospital setting where an ultrasound machine equipped with a microconvex ultrasound probe is available.

<table border="0" cellpadding="0" cellspacing="0" width="1058">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Name of Material/ Equipment</td>
			<td style="width:93px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:631px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">skin desinfection</td>
			<td style="width:93px;">Ecolab</td>
			<td align="right" style="width:119px;">2686556</td>
			<td>Skinsept G</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">8C-RS microconvex probe</td>
			<td style="width:93px;">GE Healthcare</td>
			<td style="width:119px;">8C-RS</td>
			<td>Any ultrasound machine equipped with a microconvex ultrasound probe should be suitable for this method</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Logiq e ultrasound machine</td>
			<td style="width:93px;">GE Healthcare</td>
			<td style="width:119px;">Logiq e</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">CVC Kit</td>
			<td style="width:93px;">Teleflex Medical</td>
			<td style="width:119px;">OW-15802-E</td>
			<td>8 Fr. 2 Lumen Blue-Flex tip catheter</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Sterile gloves</td>
			<td style="width:93px;">Protexix</td>
			<td style="width:119px;">2D72NT70X</td>
			<td>LatexMicro</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Sterile gown</td>
			<td style="width:93px;">Medline</td>
			<td style="width:119px;">OP9512CE</td>
			<td>OPS Advanced</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">sterile ultrasound probe cover</td>
			<td style="width:93px;">CIVCO</td>
			<td style="width:119px;">610-637</td>
			<td>CIV-Fle Transducer Cover; sterile 8.9 x 91.5 cm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">suture</td>
			<td style="width:93px;">Ethicon</td>
			<td style="width:119px;">EH7723</td>
			<td>Ethibond</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">12L-RS linear ultrasound probe</td>
			<td style="width:93px;">GE Healthcare</td>
			<td style="width:119px;"></td>
			<td>any linear ultrasound probe is suitable for lung ultrasound</td>
		</tr>
	</tbody>
</table>

the supraclavicular fossa ultrasound view for central venous catheter placement and catheter change over guidewire

The supraclavicular fossa ultrasound view can be useful for central venous catheter (CVC) placement. Venipuncture of the internal jugular veins (IJV) or subclavian veins is performed with a micro-convex ultrasound probe, using a neonatal abdominal preset with a probe frequency of 10 Mhz at a depth of 10-12 cm. Following insertion of the guidewire into the vein, the probe is shifted to the right supraclavicular fossa to obtain a view of the superior vena cava (SVC), right pulmonary artery and ascending aorta. Under real-time ultrasound view, the guidewire and its J-tip is visualized and pushed forward to the lower SVC. Insertion depth is read from guidewire marks using central venous catheter. CVC is then inserted following skin and venous dilation. The supraclavicular fossa view is most suitable for right IJV CVC insertion. If other insertion sites are chosen the right supraclavicular fossa should be within the sterile field. Scanning of the IJVs, brachiocephalic veins and SVC can reveal significant thrombosis before venipuncture. Misplaced CVCs can be corrected with a change over guidewire technique under real-time ultrasound guidance. In conjunction with a diagnostic lung ultrasound scan, this technique has a potential to replace chest radiograph for confirmation of CVC tip position and exclusion of pneumothorax. Moreover, this view is of advantage in patients with a non-p-wave cardiac rhythm were an intra-cardiac electrocardiography (ECG) is not feasible for CVC tip position confirmation. Limitations of the method are lack of availability of a micro-convex probe and the need for training.

In a previously published study, chest radiographs were obtained in all patients following ultrasound guided CVC placement8. The CVC tip position in relation to the carina on chest radiographs was analysed by a radiologist who confirmed a correct position of the CVC in the lower SVC in all investigated patients. In 90% of all cases CVC tip was within 35 mm distance of the carina. In 17% the CVC tip was above, in 19% at the level of and in 64% below the carina. In 4% the CVC tip was more than 55 mm below the ca...

Watch this Scientific Journal Video about The Supraclavicular Fossa Ultrasound View for Central Venous Catheter Placement and Catheter Change Over Guidewire at JoVE.com

The Supraclavicular Fossa Ultrasound View for Central Venous Catheter Placement and Catheter Change Over Guidewire

The overall goal is to enable clinicians to insert a central venous catheter under real-time ultrasound guidance via the right supraclavicular fossa view of the lower part of the superior vena cava. This view is useful for different catheter insertion sites, thrombosis detection before insertion and ultrasound guided correction of misplaced catheters.

The supraclavicular fossa ultrasound view can be useful for central venous catheter (CVC) placement. Venipuncture of the internal jugular veins (IJV) or ...

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18.7K Views.  University Hospital Bonn. The overall goal is to enable clinicians to insert a central venous catheter under real-time ultrasound guidance via the right supraclavicular fossa view of the lower part of the superior vena cava. This view is useful for different catheter insertion sites, thrombosis detection before insertion and ultrasound guided correction of misplaced catheters.

Video: The Supraclavicular Fossa Ultrasound View for Central Venous Catheter Placement and Catheter Change Over Guidewire

Remote Magnetic Navigation for Accurate, Real-time Catheter Positioning and Ablation in Cardiac Electrophysiology Procedures

New remote navigation systems have been developed to improve current limitations of conventional manually guided catheter ablation in complex cardiac substrates such as left atrial flutter. This protocol describes all the clinical and invasive interventional steps performed during a human electrophysiological study and ablation to assess the accuracy, safety and real-time navigation of the Catheter Guidance, Control and Imaging (CGCI) system. Patients who underwent ablation of a right or left atrium flutter substrate were included. Specifically, data from three left atrial flutter and two counterclockwise right atrial flutter procedures are shown in this report. One representative left atrial flutter procedure is shown in the movie. This system is based on eight coil-core electromagnets, which generate a dynamic magnetic field focused on the heart. Remote navigation by rapid changes (msec) in the magnetic field magnitude and a very flexible magnetized catheter allow real-time closed-loop integration and accurate, stable positioning and ablation of the arrhythmogenic substrate.

This report provides a detailed description of a new remote navigation system based on magnetic driven forces, which has been recently introduced as a new robotic tool for human cardiac electrophysiology procedures.

New remote navigation systems have been developed to improve current limitations of conventional manually guided catheter ablation in complex cardiac ...

Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting millions of individuals worldwide 1-3. The rapid, irregular, and disordered electrical activity in the atria gives rise to palpitations, fatigue, dyspnea, chest pain and dizziness with or without syncope 4, 5. Patients with AF have a five-fold higher risk of stroke 6.
Oral anticoagulation (OAC) with warfarin is commonly used for stroke prevention in patients with AF and has been shown to reduce the risk of stroke by 64% 7. Warfarin therapy has several major disadvantages, however, including bleeding, non-tolerance, interactions with other medications and foods, non-compliance and a narrow therapeutic range 8-11. These issues, together with poor appreciation of the risk-benefit ratio, unawareness of guidelines, or absence of an OAC monitoring outpatient clinic may explain why only 30-60% of patients with AF are prescribed this drug 8.
The problems associated with warfarin, combined with the limited efficacy and/or serious side effects associated with other medications used for AF 12,13, highlight the need for effective non-pharmacological approaches to treatment. One such approach is catheter ablation (CA), a procedure in which a radiofrequency electrical current is applied to regions of the heart to create small ablation lesions that electrically isolate potential AF triggers 4. CA is a well-established treatment for AF symptoms 14, 15, that may also decrease the risk of stroke. Recent data showed a significant decrease in the relative risk of stroke and transient ischemic attack events among patients who underwent ablation compared with those undergoing antiarrhythmic drug therapy 16.
Since the left atrial appendage (LAA) is the source of thrombi in more than 90% of patients with non-valvular atrial fibrillation 17, another approach to stroke prevention is to physically block clots from exiting the LAA. One method for occluding the LAA is via percutaneous placement of the WATCHMAN LAA closure device. The WATCHMAN device resembles a small parachute. It consists of a nitinol frame covered by fabric polyethyl terephthalate that prevents emboli, but not blood, from exiting during the healing process. Fixation anchors around the perimeter secure the device in the LAA (Figure 1). To date, the WATCHMAN is the only implanted percutaneous device for which a randomized clinical trial has been reported. In this study, implantation of the WATCHMAN was found to be at least as effective as warfarin in preventing stroke (all-causes) and death (all-causes) 18. This device received the Conformit&eacute; Europ&eacute;enne (CE) mark for use in the European Union for warfarin eligible patients and in those who have a contraindication to anticoagulation therapy 19.
Given the proven effectiveness of CA to alleviate AF symptoms and the promising data with regard to reduction of thromboembolic events with both CA and WATCHMAN implantation, combining the two procedures is hoped to further reduce the incidence of stroke in high-risk patients while simultaneously relieving symptoms. The combined procedure may eventually enable patients to undergo implantation of the WATCHMAN device without subsequent warfarin treatment, since the CA procedure itself reduces thromboembolic events. This would present an avenue of treatment previously unavailable to patients ineligible for warfarin treatment because of recurrent bleeding 20 or other warfarin-associated problems.
The combined procedure is performed under general anesthesia with biplane fluoroscopy and TEE guidance. Catheter ablation is followed by implantation of the WATCHMAN LAA closure device. Data from a non-randomized trial with 10 patients demonstrates that this procedure can be safely performed in patients with a CHADS2 score of greater than 1 21. Further studies to examine the effectiveness of the combined procedure in reducing symptoms from AF and associated stroke are therefore warranted.

Catheter ablation is combined with placement of the WATCHMAN Left Atrial Appendage Closure Device to prevent ischemic stroke in a patient with non-valvular atrial fibrillation.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting millions of individuals worldwide 1-3. The rapid, irregular, and ...

Non-fluoroscopic Catheter Tracking for Fluoroscopy Reduction in Interventional Electrophysiology

A technological platform (MediGuide) has been recently introduced for non-fluoroscopic catheter tracking. In several studies, we have demonstrated that the application of this non-fluoroscopic catheter visualization system (NFCV) reduces fluoroscopy time and dose by 90-95% in a variety of electrophysiology (EP) procedures. This can be of relevance not only to the patients, but also to the nurses and physicians working in the EP lab. Furthermore, in a subset of indications such as supraventricular tachycardias, NFCV enables a fully non-fluoroscopic procedure and allows the lab staff to work without wearing lead aprons. With this protocol, we demonstrate that even complex procedures such as ablations of atrial fibrillation, that are typically associated with fluoroscopy times of &#62;30 min in conventional settings, can safely be performed with a reduction of &#62;90% in fluoroscopy exposure by the additional use of NFCV.

Radiation exposure is an underestimated risk in complex ablation procedures. Here, we describe a protocol to significantly decrease fluoroscopy time and dosage for both the patient and the lab staff by using a novel non-fluoroscopic catheter visualization system.

A technological platform (MediGuide) has been recently introduced for non-fluoroscopic catheter tracking. In several studies, we have demonstrated that ...

Murine Model of Central Venous Stenosis using Aortocaval Fistula with an Outflow Stenosis

Central venous stenosis is an important entity contributing to arteriovenous fistula (AVF) failure. A murine AVF model was modified to create a partial ligation of the inferior vena cava (IVC) in the outflow of the fistula, mimicking central venous stenosis. Technical aspects of this model are introduced. The aorta and IVC are exposed, following an abdominal incision. The infra-renal aorta and IVC are dissected for proximal clamping, and the distal aorta is exposed for puncture. The IVC at the midpoint between the left renal vein and the aortic bifurcation is carefully dissected to place an 8-0 suture beneath the IVC. After clamping the aorta and IVC, an AVF is created by puncturing the infra-renal aorta through both walls into the IVC with a 25 G needle, followed by ligating a 22 G intra-venous (IV) catheter and IVC together. The catheter is then removed, creating a reproducible venous stenosis without occlusion. The aorta and IVC are unclamped after confirming primary hemostasis. This novel model of central vein stenosis is easy to perform, reproducible, and will facilitate studies on AVF failure.

An aortocaval fistula was created by puncturing the murine infra-renal aorta through both walls into the inferior vena cava and was followed by creation of a stenosis in its outflow via partial ligation of the inferior vena cava. This reproducible model can be used to study central venous stenosis.

Central venous stenosis is an important entity contributing to arteriovenous fistula (AVF) failure. A murine AVF model was modified to create a partial ...

A Protocol to Set Up Needle-Free Connector with Positive Displacement on Central Venous Catheter in Intensive Care Unit

Needle-free connectors were initially designed and promoted to avoid blood exposure for healthcare workers. Some recent data suggest that the latest generation of connectors (with positive displacement) may be of interest for reducing central venous line infections. We have been using needle-free connectors for several years in our intensive care unit and here we present a protocol for installing these connectors on central venous catheters. After insertion of the catheter and control of the permeability of the lines, the connectors must be purged with 0.9% NaCl before being connected. The connectors replace all disposable caps used on infusion stopcocks and manifolds. All the connectors are changed every 7 days as recommended by the manufacturer (except when there is macroscopic contamination, which requires an immediate change of the connector). Before each injection, the connector must be disinfected for at least 3 seconds with 70% isopropyl alcohol. The connectors must not be disconnected (unless changed), as the injection is done through the device. Setting up the connectors slightly increases the total time required to place the catheter and there is no formal evidence that these connectors reduce the incidence of infectious or thrombotic complications. However, these devices simplify the management of central venous lines and prevent the catheter circuit from &#34;opening&#34; once it has been sterilely installed.

We present a protocol to show the installation of a needle-free connector with positive displacement on a central venous catheter.

Needle-free connectors were initially designed and promoted to avoid blood exposure for healthcare workers. Some recent data suggest that the latest ...

A Retrograde Implantation Approach for Peritoneal Dialysis Catheter Placement in Mice

Murine models are employed to probe various aspects of peritoneal dialysis (PD), such as peritoneal inflammation and fibrosis. These events drive peritoneal membrane failure in humans, which remains an area of intense investigation due to its profound clinical implications in managing patients with end-stage kidney disease (ESKD). Despite the clinical importance of PD and its related complications, current experimental murine models suffer from key technical challenges that compromise the models&#39; performance. These include PD catheter migration and kinking and usually warrant earlier catheter removal. These limitations also drive the need for a greater number of animals to complete a study. Addressing these drawbacks, this study introduces technical improvements and surgical nuances to prevent commonly observed PD catheter complications in a murine model. Moreover, this modified model is validated by inducing peritoneal inflammation and fibrosis using lipopolysaccharide injections. In essence, this paper describes an improved method to create an experimental model of PD.

This article describes modifications of a procedure to implant a peritoneal dialysis catheter in a murine model to avoid major technical issues observed with the conventional techniques.

Murine models are employed to probe various aspects of peritoneal dialysis (PD), such as peritoneal inflammation and fibrosis. These events drive ...

Drug Treatment by Central Venous Catheter in a Mouse Model of Angiotensin II Induced Abdominal Aortic Aneurysm and Monitoring by 3D Ultrasound

Since pharmaceutical treatment options are lacking in the clinical management of abdominal aortic aneurysm (AAA), animal models, in particular mouse models, are applied to advance the understanding of the disease pathogenesis and to identify potential therapeutic targets. Testing novel drug candidates to block AAA growth in these models generally requires repeated drug administration during the time course of the experiment. Here, we describe a compiled protocol for AAA induction, insertion of an intravenous catheter to facilitate prolonged therapy, and serial AAA monitoring by 3D ultrasound. Aneurysms are induced in apolipoprotein E (ApoE) deficient mice by angiotensin II release over 28 days from osmotic mini-pumps implanted subcutaneously into the mouse back. Subsequently, the surgical procedure for external jugular vein catheterization is conducted to allow for daily intravenous drug treatment or repeated blood sampling via a subcutaneous vascular access button. Despite the two dorsal implants, the monitoring of AAA development is readily facilitated by sequential semi-automated 3D ultrasound analysis, which yields comprehensive information on the expansion of aortic diameter and volume and on aneurysm morphology, as illustrated by experimental examples.

This protocol describes the consecutive implantation of an osmotic pump to induce abdominal aortic aneurysm by angiotensin II release in apolipoprotein E (ApoE) deficient mice and of a vascular access port with a jugular vein catheter for repeated drug treatment. Monitoring of aneurysm development by 3D ultrasound is effectively conducted despite dorsal implants.

Since pharmaceutical treatment options are lacking in the clinical management of abdominal aortic aneurysm (AAA), animal models, in particular mouse ...

Continuous Venous-Arterial Doppler Ultrasound During a Preload Challenge

A preload challenge (PC) is a clinical maneuver that, first, increases the cardiac filling (i.e., preload) and, second, calculates the change in cardiac output. Fundamentally, a PC is a bedside approach for testing the Frank-Starling-Sarnoff (i.e., "cardiac function") curve. Normally, this curve has a steep slope such that a small change in the cardiac preload generates a large change in the stroke volume (SV) or cardiac output. However, in various disease states, the slope of this relationship flattens such that increasing the volume into the heart leads to little rise in the SV. In this pathological scenario, additional cardiac preload (e.g., intravenous fluid) is unlikely to be physiologically effective and could lead to harm if organ congestion evolves. Therefore, inferring both the cardiac preload and output is clinically useful as it may guide intravenous (IV) fluid resuscitation. Accordingly, the goal of this protocol is to describe a method for contemporaneously tracking the surrogates of cardiac preload and output using a novel, wireless, wearable ultrasound during a well-validated preload challenge.

The Frank-Starling-Sarnoff curve is clinically important and describes the relationship between cardiac preload and output. This report illustrates a novel method of simultaneous jugular venous and carotid arterial Doppler velocimetry as transient surrogates of cardiac preload and output, respectively; this approach is enabled by wireless, wearable Doppler ultrasound.

A preload challenge (PC) is a clinical maneuver that, first, increases the cardiac filling (i.e., preload) and, second, calculates the change in cardiac ...

Point-Of-Care Ultrasound Screening for Proximal Lower Extremity Deep Venous Thrombosis

Acute lower extremity deep venous thrombosis (DVT) is a serious vascular disorder that requires accurate and early diagnosis to prevent life-threatening sequelae. While whole leg compression ultrasound with color and spectral Doppler is commonly performed in radiology and vascular labs, point-of-care ultrasound (POCUS) is becoming more common in the acute care setting. Providers appropriately trained in focused POCUS can perform a rapid bedside examination with high sensitivity and specificity in critically ill patients. This paper describes a simplified yet validated approach to POCUS by describing a three-zone protocol for lower extremity DVT POCUS image acquisition. The protocol explains the steps in obtaining vascular images at six compression points in the lower extremity. Beginning at the level of the proximal thigh and moving distally to the popliteal space, the protocol guides the user through each of the compression points in a stepwise manner: from the common femoral vein to the femoral and deep femoral vein bifurcation, and, finally, to the popliteal vein. Further, a visual aid is provided that may assist providers during real-time image acquisition. The goal in presenting this protocol is to help make proximal lower extremity DVT exams more accessible and efficient for POCUS users at the patient&#39;s bedside.

Traditionally, lower extremity deep venous thrombosis (DVT) is diagnosed by radiology-performed venous duplex ultrasound. Providers appropriately trained in focused point-of-care ultrasound (POCUS) can perform a rapid bedside examination with high sensitivity and specificity in critically ill patients. We describe the scanning technique for focused POCUS DVT lower extremity examination.

Acute lower extremity deep venous thrombosis (DVT) is a serious vascular disorder that requires accurate and early diagnosis to prevent life-threatening ...

Hickman Catheter for Long-Term Vascular Access in Swine

Hickman Catheter Use for Long-Term Vascular Access in a Preclinical Swine Model

Central venous catheters (CVCs) are invaluable devices in large animal research as they facilitate a wide range of medical applications, including blood monitoring and reliable intravenous fluid and drug administration. Specifically, the tunneled multi-lumen Hickman catheter (HC) is commonly used in swine models due to its lower extrication and complication rates. Despite fewer complications relative to other CVCs, HC-related morbidity presents a significant challenge, as it can significantly delay or otherwise negatively impact ongoing studies. The proper insertion and maintenance of HCs is paramount in preventing these complications, but there is no consensus on best practices. The purpose of this protocol is to comprehensively describe an approach for the insertion and maintenance of a tunneled HC in swine that mitigates HC-related complications and morbidity. The use of these techniques in &gt;100 swine has resulted in complication-free patent lines up to 8 months and no catheter-related mortality or infection of the ventral surgical site. This protocol offers a method to optimize the lifespan of the HC and guidance for approaching issues during use.

Author Spotlight: Hickman Catheter Use for Long-Term Vascular Access in a Preclinical Swine Model  

A reliable and reproducible approach for the insertion and maintenance of a tunneled Hickman catheter for long-term vascular access in swine is described. Placement of a central venous catheter allows for convenient daily sampling of whole blood from awake animals and intravenous administration of medication and fluids.

Central venous catheters (CVCs) are invaluable devices in large animal research as they facilitate a wide range of medical applications, including blood ...