The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation

This video demonstrates a procedure for implanting the Watchman left atrial appendage closure device for prevention of atrial fibrillation associated thromboembolic stroke. A transseptal cannula is inserted through the femoral artery and under fluoroscopic guidance, the inter atrial septum is crossed. Once access to the left atrium has been achieved, a guide wire is placed in the upper pulmon vein and the watchman access sheath and dilator are advanced over the wire into the left atrium, the guide wire is removed.

Then the access sheath is carefully advanced into the distal portion of the left atrial appendage over a pigtail catheter. The Watchman delivery system is prepped, inserted into the access sheath and slowly advanced the Watchman device is then deployed into the left atrial appendage. The device release criteria are confirmed by a fluoroscopy and transoral echocardiography and the device is released.

Preclinical studies completed on the Watchman implant indicate that an endothelial layer covers the device in about 45 days. The Watchman left atrial appendage closures device is a proven alternative for patients with atrial fibrillation and risk of stroke. Today, warfarin is the standard therapy for stroke prevention and THM embolism in those patients.

Warfarin has a lot of side effects. One major side effect is the bleeding risk. Therefore, only 50%of the patient that should take warfarin actually take it.

Interventional closure of the left atrial appendage is a complex procedure for unexperienced physicians. It is hard to learn this procedure and therefore this video can help you by doing step by step. The implantation.

The watchman device frame is constructed of tonal a nickel titanium alloy and is composed of 10 fixation anchors around the device perimeter that are designed to secure the device in the left atrial appendage. A fabric cap constructed outta fabric Polyether Terra Phthalate serves as a 160 micron filter and prevents harmful emboli from exiting during the healing process. The device comes in five different sizes, 21, 24, 27 30, and 33 millimeters, and the contoured shape of the device accommodates most left atrial appendage anatomy.

The Watchman Transseptal access system is available in double or single curve styles and a 75 centimeter working length. The device is preloaded within the 12 F delivery catheter. Note that the Watchman delivery system is compatible with all five device sizes.

Prior to starting the procedure, a transesophageal echocardiogram is performed to document the absence of thrombi within the left atrial appendage and to determine the appropriate sized watchman device to be implanted. The recommended international normalized ratio should be 1.5 or less to perform the implantation procedure with the patient under conscious sedation, pass the ultrasound probe into the esophagus. Confirm the absence of a left atrial or left atrial appendage thrombus, assess the following left atrial appendage features osteum size and shape, number of lobes location, working length in the left atrial appendage and pectinate features the maximum left atrial appendage.

Osteum size should be greater than 17 millimeters or less than 31 millimeters to accommodate available watchman device sizes. To do this, measure the appendage osteum in at least four transesophageal echocardio graft views. First, measure the osteum at zero degrees from the left coronary artery to a point about 1.5 centimeters from the tip of the left upper pole mony vein limbus.

Then measure it at 45 90 and 135 degrees from the top of the mitral valve annulus to a point about 1.5 centimeters from the tip of the left upper pole miney vein limbus measure the approximate left atrial appendage, usable length from thete line to the apex of the appendage. The full usable length should be equal to or greater than this distance to aid in planning the approach categorize the left atrial appendage type most can be categorized as wind sock, chicken wing, or broccoli. By categorizing the left atrial appendage forms, the difficulty of the implantation procedure can be estimated.

The wind sock type appendage shown here is an anatomy in which one dominant lobe of sufficient length is the primary structure. The implantation procedure in most of these cases is relatively easy to perform.Perform. The chicken wing type appendage is an anatomy whose main feature is a sharp bend in the dominant lobe of the appendage anatomy at some distance from the perceived appendage osteum.

If the proximal part of the left atrial appendage is longer than its widest diameter, then the implant procedure is straightforward. However, if the proximal part is shorter than the maximum width of the appendage orifice, the procedure may be complicated. The main of the broccoli type anatomy is a left atrial appendage that has limited overall length with more complex internal characteristics.

When this anatomy is present, the device is often difficult to implant since there are several lobes to cover and the length of the appendage is limited. The watchman left atrial appendage closure device placement procedure should be performed under local or general anesthesia in an examination room in a hospital or clinic with diagnostic imaging equipment used to support the catheterization procedure begin by preparing the catheterization lab for the procedure. The following equipment should be placed in the room.

A Venus introducer, a standard TRANSSEPTAL access system, an exchange length 0.035 inch G wire with extra support, two pigtail catheters, a flushing syringe and a mandatory pressurized saline bag with a drip chamber and sterile line. It is recommended that a five French arterial excess sheath be available for pressure measurement, marking the aortic root during transseptal puncture and managing complications if necessary. Also available should be the appropriate watchman access sheath with corresponding dilator, single or double the watchman delivery system and the optional watchman obturator, which is helpful in left atrial appendage anatomies with an acute bend.

Also in case of complications, the following material should be available, a pericardiocentesis tray and a 14 to 16 French sheath for device retrieval. Coronary guiding catheters, a thrombectomy device, a coronary guide wire, and supplementary airway. Devices such as LMA ET tube and laryngoscopes should also be available for emergencies.

In addition, the procedure requires a BP monitor, EKG, and a pulse oximeter as a minimum for conscious sedation, the use of echocardiographic imaging is required and transesophageal echo echocardiography is recommended. Furthermore, by a plain fluoroscopy should be used if it is available. Once the room is ready, have the patient lie down flat on his or her back, have the patient place his arms behind his head.

Then strap the patient's arms and legs into place, taking care to avoid injury to the plexus of the arms. Finally, immediately before the procedure begins, administered 20 milliliters of 1%lidocaine as a local anesthetic in the groin region. Once the area has been cleaned and prepped, locate the femoral artery and then introduce arterial and venous sheaths.

Once these are in place, insert the 0.035 inch guide wire and vessel dilator into the femoral vein to access the heart. For an algo sedation administer five milligram midazolam and propofol according to the patient's body weight. Then administer a bolus of propofol of 0.1 milligram per kilogram, followed by continuous infusion of 0.5 to one milligram per kilogram body weight intravenously.

Then introduce an eight French transseptal sheath into the femoral artery. For the transseptal puncture, insert a johnson needle, advance the transseptal sheath and the needle into the upper vena caver. Monitor the central venous pressure.

Place a pigtail catheter in the aortic root as a landmark and for pressure monitoring ring, then pull back the sheath with the needle until a tenting of the needle on the atrial septum is seen in the transesophageal echocardiogram. Using the transesophageal echocardiogram, identify the mid to lower part of the posterior septum. This is the optimal place for transseptal crossing.

Advance the needle and observe the pressure change to a left atrial pressure curve. Next, advance the sheath over the needle into the left atrium. Then advance the sheath into the upper pole mony vein.

Connect the sheath with a line for pressure measurement to monitor left atrial pressure and ensure it is in the high normal range. This helps to avoid air embolism and is necessary for appropriate measurement of the left atrial appendage diameter. Then administer heparin to obtain an activated clotting timing between 200 and 300 seconds.

Monitor the a CT every 30 minutes as needed. Next, under sterile conditions, remove the Watchman access system and dilator from the packaging and inspect the entire system for damage. Insert a syringe with saline into the side port of the watchman access sheath.

Flush the unit with saline. Then insert the dilator into the sheath and close the hemostatic valve. Remove the syringe from the side port.

Insert it into the end of the dilator and again, flush with the remaining saline. Maintain an a CT of 200 to 250 seconds during the procedure. Next advance a 0.035 inch stiff guide wire into the left upper pole mony vein and remove the transseptal access system leaving the guide wire in place.

Next, advance the Watchman access sheath and dilator over the guide wire into the left atrium. Remove the dilator while maintaining sheath position in the left upper pulmonary vein, the LUPV to minimize the potential for introducing air within the sheath. Allow bleed back and then tighten the valve on the access sheath.

Flush the pigtail catheter and advance it over the wire and through the watchman access sheath. Then remove the G wire and connect a syringe with contrast eye to the pigtail catheter under echocardiographic control. Pull the sheath with the pigtail catheter back from the LUPV and turn it counterclockwise until it reaches the lateral atrial appendage.

Note that counterclockwise torque on the axis system aligns the sheath More anterior clockwise. Torque on the access system align the sheath more posterior. Once the pigtail catheter has reached the appendage, obtain cine angiography at an RAO of 20 to 30 degrees.

Cordal 20 to 30 degrees. Carefully manipulate the catheter and sheath into the most superior lobe. This lobe appears around two o'clock in the angiogram and is the ripe most lobe in the 135 degree transesophageal echocardiogram.

Advance the pigtail catheter into the distal portion of the appendage. Under fluoroscopy guidance, carefully advance the access sheath over the pigtail catheter using the marker bands on the access sheath as a guide. Next to confirm appendage dimensions, use transesophageal echocardiography to measure the maximum left atrial appendage dimensions in four views at 0 45 90 and 135 degrees as before.

Further confirm these measurements using angiography. Then choose the appropriate size of the watchman device according to the device instructions. Navigate the sheath as deep into the appendages necessary to implant the watchman device of the chosen size.

The markers on the sheath can be used to help decide whether the sheath is deep enough. The second most distal band marks the length of the 21 millimeter device, the middle band, the length of the 27 millimeter device, and the most proximal band the length of the 33 millimeter device. Ideally, the marker band corresponding to the chosen device size should align with the orifice of the left atrial appendage.

Next, under sterile conditions, remove the appropriate sized watchman device from the packaging and inspect it for damage. Open the hemostatic valve and retract the device about one centimeter. To confirm the device is attached to the core wire, align the distal tip of the device with the corresponding marker band, and then push the device until the distal tip is aligned with the most distal marker on the delivery catheter.

Making sure that the watchman device does not protrude. Attach a large 60 cc syringe and flush the system with saline. First flush backwards, then close the valve and flush forward several times to remove all air from the system.

Submerge the tip of the delivery catheter in saline and tap it in order to remove bubbles. Once the device is prepared, recheck the position of the access sheath by angiography. Loosen the access sheath valve and slowly remove the pigtail catheter from the sheath.

Ntroduce the Watchman device system to avoid introducing air. Submerge the access sheath hub in saline or allow the sheath to back bleeded. Then inject saline through the flush port so that it drips from the delivery catheter during introduction into the access sheath.

Under fluoroscopic guidance, slowly advance the delivery catheter into the access sheath until the most distal marker band on the access sheath lines up with the marker band on the delivery catheter. Then stabilize the delivery catheter, retract the excess sheath and snap it onto the delivery catheter. Do not advance the excess sheath.

Once the delivery system has been snapped into it, loosen the valve on the Watchman delivery catheter to deploy the device. Observe the distal end of the device to ensure that no forward advancement or repositioning relative to osteum occurs. Holding the deployment knob stationary slowly retract the access sheath delivery catheter assembly with a slow stable motion.

Then leaving the core wire attached. Withdraw the access sheath delivery catheter assembly a few centimeters from the device to align it with the left atrial appendage. Once the device has been use fluoroscopy and transesophageal echocardiography to confirm that the device release criteria have been met.

These are position, anchor, size and seal or pass. First to confirm that the device was properly positioned, ensure that the plane of maximum diameter of the device is at or just distal to the orifice of the left atrial appendage and that it spans the entire appendage osteum. Next to confirm the device is anchored in place, withdraw the access sheath delivery catheter assembly one to two centimeters from the face of the device, gently retract and release the deployment knob.

The device and appendage should move in unison. To confirm the device size, measure the plane of the maximum diameter of the device using transesophageal echocardiography in the standard four views, 0 45 90 and 135 degrees. Ensuring that the threaded insert is visible, the device should be 80 to 92%of the original size.

Finally, using color doppler, ensure that all of the lobes distal to the device are sealed. Ideally, no color flow should be detected near the device. If a small gap is visible between the wall of the appendage and the device, it may be possible to reposition the device.

If the patient is in sinus rhythm, the synchronized movement of the delivery cable with the pulse when the valve is open is an indirect sign that the device is anchored. If all of the release criteria are met, move the access sheath delivery catheter up to the face of the device and rotate the deployment knob three to five turns counterclockwise to release it After release, perform angiography with contrast eye to document that the device is still in place. Remove the sheath assembly from the left atrium.

Then using echocardiography, recheck the size and seal. If the device is too distal in the left atrial appendage, advance the tip of the access sheath delivery catheter assembly up to the device. Do not unsnap holding the deployment knob with the right hand.

Gently advance the assembly over the shoulders of the device. Then position the right thumb against the delivery catheter hub for stability. Continue to advance the assembly up to, but not beyond the fixation anchors.

Resistance will be felt as the device shoulders collapse when resistance is felt. A second time indicating anchor contact, stop and tighten the hemostasis valve. After this partial recapture, pull back the sheath and device together as far as needed.

Under fluoroscopic and echocardiographic guidance. Pull back a few millimeters and then redeploy the device. Check to see if the release criteria have now been met.

Then release the device. The procedure for full recapture of the device as well as post-procedural care of the patient can be found in the accompanying document. The Protect AF clinical trial was performed to compare the safety and effectiveness of the implantation of the Watchman device to that of Warfarin treatment.

707 Eligible patients were randomly assigned in a two to one ratio to either percutaneous closure of the left atrial appendage with subsequent discontinuation of warfarin or to warfarin Treatment as seen here, the primary efficacy of event rate as assessed by primary composite endpoint of stroke, cardiovascular death, and systemic embolism was compared in patients undergoing left atrial appendage closure with the Watchman device, the intervention group, and patients undergoing Warfarin therapy. The control group, the primary efficacy event rate was three per 100 patient years in the intervention group and 4.9 per 100 patient years in the control group. The overall stroke rate was 2.3 in the intervention group and 3.2 in the control group taken together.

This reflects a 38%decrease in cardiovascular adverse events demonstrating that left atrial appendage closure is not inferior to Warfarin therapy. After watching this video, you should have a better understanding how the implantation procedure will be done during the Watchman implantation procedure, two major complications can happen, pericardial effusion and air embolism. By watching this video and following the Implantation Pro procedure step by step, most of these complications can be avoided.

Within the ProTech AF trial, we were able to show that the Watchman device is as effective as Warfarin therapy in preventing stroke and drum embolism.