Device Embolization in Structural Heart InterventionsIncidence, Outcomes, and Retrieval Techniques
Author + information
- Mohamad Alkhouli, MDa,∗ (Mohamad.Alkhouli{at}wvumedicine.org),
- Horst Sievert, MDb and
- Charanjit S. Rihal, MDc
- aDivision of Cardiology, West Virginia University, Morgantown, West Virginia
- bCardiovascular Center Frankfurt, Frankfurt, Germany; Anglia Ruskin University, Chelmsford, United Kingdom
- cDepartment of Cardiology, Mayo Clinic School of Medicine, Rochester, Minnesota
- ↵∗Address for correspondence:
Dr. Mohamad Alkhouli, West Virginia University Heart & Vascular Institute, 1 Medical Drive, Morgantown, West Virginia 26505.
Central Illustration
Abstract
Device embolization is a rare complication of transcatheter structural heart interventions. Although the majority of device embolizations can be treated in a semielective manner, some are life threatening and require prompt intervention. Awareness of this potential complication, and knowledge of retrieval tools and techniques are essential to the structural interventionalist. This paper offers a succinct review of the incidence, and outcomes of device embolization during common structural heart interventions. It also provides an overview of the essential component of the “percutaneous retrieval toolbox” and suggests a systematic algorithmic approach for the management of device embolization.
Device embolization (DE) is an uncommon, but potentially life-threatening, complication of transcatheter structural heart disease (SHD) interventions. Clinical manifestations of DE range from an incidental finding on cardiac or body imaging to cardiogenic shock or sudden cardiac arrest (1,2). In many cases, embolizations result from miss-sizing or suboptimal deployment of the device, but they often occur despite meticulous planning and execution of the procedure (1,3). Management strategies of DE vary according to the type, the size, and the location of the embolized device, the timing of diagnosis, and the clinical profile of the patient. Familiarity with the available tools and understanding of the role and limitations of percutaneous retrieval techniques are paramount for successful management of DE.
The aims of this paper are to: 1) provide a contemporary review on the incidence and outcomes of DE in the most common SHD interventions; 2) suggest a systematic algorithmic approach to manage DE; and 3) summarize the available necessary tools for percutaneous retrieval of embolized devices.
Incidence and Outcomes of DE
The incidence of DE is difficult to assess with accuracy due to underreporting bias. However, data from randomized clinical trials and prospective registries provide important insights into the incidence, causes, and outcomes of DE.
Transcatheter heart valve embolization
The majority of DEs of transcatheter heart valves (THVs) are reported with transcatheter aortic valve replacement (TAVR), although embolization of THVs implanted in the mitral or tricuspid positions have been described.
In the PARTNER (Placement of AoRTic TraNscathetER Valve) trial, DE were reported in 26 of 2,554 patients (1%), occurring immediately, within 1 h, and beyond 1 h in 77%, 19%, and 4% of cases, respectively (1,4). One-half of the valves embolized to the left ventricle (LV), and one-half to the aorta. Twelve patients (46%) required conversion to open heart surgery, and those patients experienced higher mortality than patients treated with percutaneous techniques (33% vs. 14%; p = 0.36). Underlying causes were technical in 50% of cases and included: valve malpositioning, pacing failure, displacement during attempted valve-in-valve (VinV), poor fluoroscopic angle for implantation, incorrect crimping of the valve on the balloon catheter, and incomplete or delayed device balloon inflation. Anatomic factors such as complex valve anatomy (small sinotubular junction, large annulus, paucity of aortic valve calcification) and need for cardiopulmonary resuscitation were implicated in 15% of cases. At 1-year follow up; DE was independently associated with an increased mortality (hazard ratio: 2.68; 95% confidence interval: 1.34 to 5.36; p = 0.006) (1). The incidence of DE decreased with newer generation THVs likely due to the improved designs but also the increasing experience with the TAVR procedure. In the PARTNER II trial, which used the second-generation Sapien XT valve (Edwards Lifesciences, Irvine, California), the incidence of DE was only 0.1% (10 of 994). Of these 10 patients, 4 had a second valve implanted, the procedure was aborted in 2, conversion to open surgery was undertaken in 3, and 1 died (5). Similarly, only 2 DEs were reported in the 1,661 patients (0.1%), who received the third-generation Sapien S3 valve in the PARTNER II SAPIEN 3 trial (6), and 1 DE was reported in 583 patients (0.17%) enrolled the nested registry of this trial (7).
In the early commercial TAVR experience in the United States (2012 to 2014), DE were reported in 158 of 26,414 patients (0.6%), with an even share (50%) of aortic and ventricular embolization (8). Surgical conversion was required in all patients with DE to the LV, whereas most aortic DEs were managed percutaneously. Patients in this study had a mix of balloon and self-expandable valves implanted (Sapien/Sapien XT, Edwards Lifesciences; and CoreValve, Medtronic, Minneapolis, Minneapolis). Similarly low rates of DE were reported in European TAVR registries. In the GARY registry (German Aortic Valve Registry), DE occurred in 55 of 15,964 patients (0.3%) who underwent TAVR in Germany between 2011 and 2013 (9). In the ITER registry (Italian Transcatheter Balloon-Expandable Valve Implantation Registry), DE occurred in 12 of 1,904 patients (0.6%) who had TAVR with balloon-expandable valves in Italy (10). In the WIN-TAVI (Women's INternational Transcatheter Aortic Valve Implantation) registry, among 1,1019 women who underwent TAVR with a mixture of balloon and self-expandable valves, 11 (1.1%) had DE (11).
Observed embolization rates of self-expandable prostheses were very low with no DEs reported in the pivotal CoreValve and SURTAVI (Safety and Efficacy Study of the Medtronic CoreValve System in the Treatment of Severe, Symptomatic Aortic Stenosis in Intermediate Risk Subjects Who Need Aortic Valve Replacement) trials (12,13). In other single-institution reports, DE of the CoreValve occurred in 1.7% to 4% (14,15). However, these rates included ventricular device migration, and not a true embolization manifested by complete departure of the THV from the annulus. Ventricular migration was not uncommon with the first-generation CoreValve, and is usually treated with a second valve implantation (VinV) or snare-facilitated pulling of the valve into a higher position (16). Experience with mechanically expandable valves (e.g., Lotus, Boston Scientific, Marlborough, Massachusetts) is limited. However, only 1 case of DE of this valve is reported (17). This occurred in the setting of severe ventricular hypertrophy and sigmoid septum and was managed percutaneously. No other DE was observed in the pivotal clinical trial and other large registries of the Lotus valve (18–20).
Embolizations of THVs have also been reported during transcatheter mitral VinV and valve-in-ring (VinR) implantation procedures, and with THV implantation in severely calcified mitral annulus (21–24). In a multicenter global registry of transcatheter mitral valve replacement in patients with native mitral disease and severe mitral annular calcification, DE occurred in 4 of 64 patients (6.25%), all of which embolized to the left atrium during the index procedure. Of these, 3 were retrieved surgically and 1 was stabilized/trapped in the intra-atrial septum percutaneously with a 30-mm Amplatzer Septal Occluder device (24). In a systematic review of 245 patients who underwent transcatheter mitral VinV or VinR implantations, DE occurred during the procedure in 8 patients (3.1%). Of note, no embolizations were reported in cases where the main mode of valve or ring failure was stenosis rather than regurgitation. Data on DE during tricuspid VinV and VinR are limited. In a multicenter international registry that included 156 patients who underwent tricuspid VinV implantations, 2 (1.3%) had acute DE (1 to the right atrium, and 1 to the right ventricle). Both valves were retrieved with endovascular techniques and deployed in the inferior vena cava without further complications (25). In a smaller series of 20 patients who underwent transcatheter tricuspid VinR implantation, DE occurred in 1 patient (5%) with an incomplete tricuspid annuloplasty ring. This patient underwent surgical retrieval of the embolized valve and had a surgical valve implanted without sequelae. In this series, another patient had partial distal migration of the THV, which was successfully treated with a second THV implantation (26).
Left atrial appendage occluder embolization
Transcatheter left atrial appendage (LAA) occlusion is an increasingly adopted therapy for stroke prevention in patients with atrial fibrillation who are not suitable for long-term anticoagulation (27). Due to anatomical variability in LAA anatomy and limited shapes and sizes of the LAA occluders, the potential risk of DE has been a concern especially due to the elective preventative indication of the procedure (28). The incidence of LAA occluder embolization varies with reported rates between 0 and 2% (Online Table 1). The Amplatzer family of devices (ACP and Amulet, St. Jude Medical, St. Paul, Minnesota) appears to carry a higher risk of DE compared with the Watchman device (Boston Scientific) (29 of 3,585 [0.78%] vs. 19 of 7,236 [0.26%]; p < 0.001) (Online Table 1). However, DE with the newer generation Amplatzer device (Amulet) was rare (0.2%) in a large multicenter registry of the 1,088 Amulet implantations (29,30).
The vast majority of DE occur during the procedure, but delayed embolization has been discovered up to 12-months after the procedure (Online Table 1). This led to the recognition that embolization of these devices (especially with small device sizes <25 mm) can be completely asymptomatic or associated with atypical symptoms (ectopy, transient rhythm disturbances, and so on) (31). The location of the embolized device determined the retrieval route; in most cases, devices that embolized to the aorta were retrieved with percutaneous techniques, and devices that remained in the LV were removed surgically. However, percutaneous and surgical retrieval have been reported in both locations (28,31). Limited data are available on the secondary adverse events related to DE of LAA occluders. Nonetheless, cases of mitral and aortic valve damage, LV outflow obstruction, cardiogenic shock, and death as a result of LAA occluder embolization have been described (2,3,30) (Online Table 1).
Septal occluders and vascular plugs embolization
Percutaneous closure of atrial septal defects (28) and patent foramen ovale (PFO) has essentially replaced surgical repair in the majority of patients (32). Although these procedures are performed with excellent safety and efficacy in contemporary practice, DEs have not been completely eliminated (33). Early experience with the Amplatzer Septal Occluder (St. Jude Medical) (3,824 implants up to 2003) was associated with a 0.55% embolization rate. The majority of these were retrieved surgically (71.4%), and 2 were fatal (34). A similar rate was found in a query of the MAUDE (Manufacturer and User Facility Device Experience) database, in which embolization of an Amplatzer ASD or PFO Occluder was reported in 233 of 18,333 patients (0.62%) between January 2002 and June 2007 (35). Nonetheless, the rate of DE appears to have decreased substantially overtime. In the Closure of Atrial Septal Defects with the AMPLATZER Septal Occluder Post-Approval Study, DE occurred only in 1 of 1,000 patients (0.1%) (36). The clinical presentation of these and other reported DEs varied from incidental finding to ventricular fibrillation and hemodynamic collapse (33,37–42). Embolization of PFO occluders is uncommon and rarely present in a life-threatening manner (43,44). In the REDUCE (GORE Septal Occluder Device for Patent Foramen Ovale (PFO) Closure in Stroke Patients) trial, of the 441 patients who underwent PFO closure with GORE occluders (W. L. Gore & Associates, Newark, Delaware), 2 (0.5%) experienced DE, but both were retrieved percutaneously (45). No DEs were specifically reported in the other major PFO trials (45–47). Similarly, several large institutional registries reported low rates of DE in patients undergoing PFO closure (0% to 0.7%) (48–52).
4 Other less common DE
Embolization of Amplatzer Vascular Plugs and/or other occluders is a rare complication of transcatheter closure of non-ASD congenital or acquired defects (paravalvular leaks, pseudoaneurysms, fistula, and so on). For example, embolization of Amplatzer Vascular Plugs occurred in 1% to 3.5% of cases in the largest series of transcatheter paravalvular leak closure, but those embolizations were managed percutaneously in the vast majority of patients (53–55).
Partial (single leaflet) detachment of the MitraClip mitral valve repair system (Abbott Vascular, Abbott Park, Illinois) is not uncommon, but complete embolization of the clip has been reported in 5 cases: 4 embolized to the peripheral vasculature, the LV, and the non-coronary sinus presenting with severe mitral regurgitation, and 1 embolized to the right coronary artery and presented with ST-segment elevation myocardial infarction (56–59). In addition, embolization of the radiopaque tip of the clip delivery system to the left atrium during retraction of the clip delivery system into the guiding catheter has been reported in 3 cases (60). Two of these cases required surgical rescue, whereas percutaneous retrieval of the embolized tip was successfully performed in the third case.
Prevention and Management of DE
The majority of DE can be avoided with meticulous planning, sound techniques, and adequate knowledge of the factors that have been shown to increase the risk of DE. Table 1 summarizes the most common causes of DE during various structural heart interventional procedures and suggests best practices for their avoidance.
Mechanisms of DE During Structural Heart Interventions
Once embolization occurs, however, its successful management depends on 2 key elements; 1) the availability of percutaneous retrieval tools and adequate knowledge of their abilities and limitations; and 2) an algorithmic approach that integrates both percutaneous and surgical options and accounts for the experience of the operator and the clinical condition of the patient. Also, a multidisciplinary collaboration is invaluable in achieving safe retrieval. In many centers, specialties other than the structural cardiologist have more experience in retrieving foreign objects, and calling for their input often enhances the safety and success of the retrieval procedure. The importance of multimodality and multiplanar imaging in the management of DE cannot be overemphasized. Biplane fluoroscopy can provide an incremental value over single-plane fluoroscopy in guiding snaring attempts, but it is still used in the minority of SHD interventions (61). Three-dimensional echocardiography, a widely used modality in contemporary SHD interventional suites, not only facilitates the snaring of embolized devices but also allows real-time survey of the surrounding structures (valves, aorta, pericardium, etc.) during device retrieval.
The percutaneous retrieval toolbox
Retrieval techniques vary according to the type and size embolized device, site of embolization, and clinical stability. However, the following tools are used in retrieval attempts in most scenarios:
1. Snares: The first snaring tool used to retrieve embolized devices was a manually constructed snare using a 0.014-inch coronary wire and a 5-F diagnostic catheter (62). Due the rapid evolution of endovascular procedures in the last 2 decades, dedicated snares are now readily accessible in most catheterization laboratories. Snare systems are available in a single or multiple overlapping loops configurations (Figure 1). Due to the variable introducer sizes, working lengths and diameters, and wire compatibilities, operators should familiarize themselves with 1 or 2 snare systems that are kept routinely updated in their catheterization laboratory inventory. The choice of snare type and size largely depend on the type and the location of the embolized devices, and the planned retrieval technique. For example, retrieving an embolized septal occluder by hooking its pin requires a small-diameter single-loop snare, whereas encircling the same device requires a much larger snare. A summary of commercially available snare systems, their sheath compatibility, features, and their working lengths and diameters is provided in Online Table 2.
2. Other retrieval tools: Various non–snare-based devices can be used successfully to manage embolization in SHD interventions. Those devices are usually used for myocardial biopsies (e.g., bioptome/forceps devices), electrophysiological applications (e.g., adjustable electrical mapping catheters, large lead removal systems) and interventional radiology procedures (e.g., basket-based ureteral stone extractors) (Figure 2, Online Table 3) (63,64). Steerable sheaths and pigtail catheters can also be invaluable in reaching and disimpacting embolized devices and should be included in the retrieval tool kit. Some of these devices are not designed for use in vascular beds and hence caution should be exercised with their use.
Commonly Used Snare Catheters
(A) Goose Neck snare. (B) Multi-snare. (C) Ensnare.
Non–Snare-Based Retrieval Systems*
(A) Biopsy forceps (grey = soft cardiac biopsy forceps, white = rigid bronchoscope biopsy forceps). (B) Needle’s Eye Retrieval System. (C) NGage Nitinol Stone Extractor. (D) Adjustable lasso catheters. (E) Captura Three-Prong Graspers. (F) Indy Retriever. *Intravascular use of some of these devices is considered off-label.
Algorithmic approach to device embolizations
The goal of DE management strategies is to remove or reposition the embolized device in a safe manner. This can be achieved with a variety of techniques:
Embolization of THV
When DE of a balloon-expandable valve occurs to the aorta, the key first step is to maintain a coaxial wire position to avoid flow obstruction from an inverted valve (Figure 3). Next, a valvuloplasty balloon can then be inflated distal to the valve, and the valve can be pulled to a secure a position in a more distal branch-free aortic segment (Figure 4, Online Video 1). Other retrieval tools can also be used to retract the valve (bioptome, a looped wire through the struts of the valve frame, and so on) to a more desirable location. Concerns of aortic injury/dissection, occlusion of side branches and valve thrombosis have been allayed in large series of embolized Sapien THVs (1,16,65). Exclusion of the embolized valve leaflets with a covered or uncovered stent has been suggested, but may not be necessary, because the addition of a second valve does not appear to have any hemodynamic consequences at mid-term follow-up (16,65). If the embolization occurs to the LV, surgical removal is required. Nonetheless, repositioning and annular deployment of a Sapien valve embolized to the LV has been reported (Online Video 2) (66,67). If surgical retrieval is planned, implanting a second valve in the proper annular position, if feasible, might make the patient more tolerant of the surgical procedure.
Algorithmic Approach for the Management of Embolized Balloon-Expandable THV
*A percutaneous first approach can be attempted in the majority of patients with aortic embolization of THV. Examples of aortic and ventricular embolizations of THV during TAVR are shown in Online Videos 1 and 2, respectively. ECMO = extracorporeal membrane oxygenation; LV = left ventricular; TAVR = transcatheter aortic valve replacement; THV = transcatheter heart valve; Tx = treatment.
TAVR Aortic Embolization
TAVR Ventricular Embolization
Implantation of Embolized Balloon-Expandable Valves
The valves are implanted in the transverse arch (A), the abdominal aorta (B), and the descending thoracic aorta distal to the left subclavian artery (C). White arrows annotate the location of the embolized valve.
Reprinted with permission from Tay et al. (65).
Characteristics of DE and retrieval of self-expandable valves differ from those with balloon-expandable valves: 1) embolization of self-expandable valves is rare, especially with the newer generation valves (e.g., Evolute-R) because of their recapturability (16,68); and 2) the Evolute-R valve has taller frames (45 mm vs. 18 to 22 mm) and larger outflow diameters (32 to 34 mm vs. 20 to 29 mm) compared with the Sapien-S3 valve. Hence, an aortic embolized Evolute-R valve almost always leads to a valve lodged in the ascending aorta, whereas the Sapien-S3 valve may travel further, depending on the size of the aorta. For the same reason, it can often be challenging to withdraw an embolized Evolute-R to the abdominal aorta in some patients. Self-expandable valves usually have releasing tabs at the cephalic most portion of the frame. These tabs can hence be “hooked” with a snare and pulled to a more distal aortic location (16) (Figure 5).
Management of Malpositioned and Embolized CoreValve Valves
(A, B) Snaring of a CoreValve after ventricular migration (white arrow). (C) Computed tomography imaging of an embolized CoreValve implanted in the aortic arch (black arrow). A second CoreValve was then implanted in the native annulus (white arrow).
Reprinted with permission from Gerckens et al. (15) and Latib et al. (16).
Embolization of balloon-expandable valves during mitral or tricuspid VinV or valve in mitral annular calcification procedure requires surgical removal in the majority of cases (15,21,22,26). However, it is often possible to partially stabilize dislocated THVs with a bioptome until a second valve can be implanted overlapping with the first valve in a more suitable position (23). Also, a THV embolized into the inferior vena cava during tricuspid VinV implantation can be safely deployed in the vena cava (25).
Embolization of septal/LAA/vascular occluders
Retrieval techniques differ according to the specific embolized device. However, a universal algorithm can be applied to most non-THV devices (Figure 6). As a general rule, percutaneous retrieval should be attempted as a first-line strategy for devices embolized to large vessels. Percutaneous retrieval of devices embolized to a free cardiac chamber can be considered but extreme caution should be exercised especially with barbed and/or large devices to avoid irreversible valvular injuries. At first, a simple snare (single-loop snares are preferred over multiloop snares for large devices) can be used to capture and retrieve the device (Online Video 3). The snare can be introduced directly via the retrieval sheath or in a curved coronary guiding catheter inserted inside the retrieval sheath. The latter approach allows directionality that may facilitate grasping of the device, especially when non-steerable sheaths are used. Steerable sheaths (e.g., Agilis NxT, St. Jude, Dexterity, Spirus Medical, Stoughton, Massachusetts; and FlexCath, Medtronic) can also be used to retrieve embolized devices, but their available sizes (8.5- to 14-F) may not accommodate large septal occluders or LAA occlusion devices. Regardless of the sheath’s type, the selected sheath has to be 2- to 4-F sizes larger than the required sheath size for device introduction. Beveling of the sheath’s tip has been suggested to increase the tip orifice, but such sheaths should be advanced with caution because the resultant sharp edge increases the chance of perforation (28). The site of snaring differs according to the type of device (nitinol- vs. non–nitinol-based device) and the presence or absence of end screw pins. Caution should be exercised when snaring septal occluders at their waist, because the snare might not be easily released after its attachment to the device’s waist. Nitinol-based devices (e.g., the Amplatzer family of devices) can be folded and engulfed in the sheath without affecting their integrity, whereas non–nitinol-based devices (e.g., Watchman device, Gore Cardioform Septal Occluder, and so on) may require significant deformation to pull through the sheath (69). The availability of “hookable” pins affords an opportunity to recover the device in a seemingly reversal fashion to its deployment, although maintaining a stable tug after snaring the pins can often be challenging. The number of end screw pins varies from 0 for the Watchman device, to 1 for the Amulet device, to 2 for the ACP device and the Amplatzer septal occluders. If complete recapture is achieved, the device is pulled through the sheath and reimplantation may be considered if an avoidable cause is promptly identified. If complete recapture fails, escalation to more advanced percutaneous retrieval techniques may be warranted. These techniques include:
1. Disimpacting of an embolized device: If a snare cannot be advanced around a device lodged in a large vessel, partially disimpacting the device from the vascular wall is necessary and can be achieved with: 1) grasping of the device with a bioptome (Online Video 4); 2) retrograde pulling of the device via an upper extremity access for devices lodged in abdominal aorta or iliac arteries (70); and 3) balloon-assisted traction in which a 0.014-inch wire and a coronary balloon are advanced through the device, the balloon is inflated distally, and then the wire and the balloon are pulled together (71). Large embolized septal or LAA occluders may lodge in the mitral apparatus, the LV outflow tract, or in the aortic valve, and lead to significant hemodynamic compromise. In such cases, jiggling of the device with simple catheters (e.g., pigtail) or partially unseating it with a bioptome can be life-saving (Figure 7, Online Video 5).
2. Double tool retrieval techniques: A single tool (bioptome, snare, and so on) often does not provide adequate grasp of the embolized device, which may result in escaping of the device (re-embolization) or inability to pull it through the sheath. Hence, 2 retrieval tools can be used simultaneously to stabilize or elongate the device with 1 tool and pull it back with the other (Figure 8, Online Video 6). This technique has been used in the retrieval of embolized septal occluders, LAA occluders using mixed combinations of tools (2 snares, snare + bioptome, snare + forceps, snare + adjustable mapping catheter) (63,70,72–77) (Online Video 7). In addition, a third tool (a pigtail or a mapping catheter for example) can also be placed beyond the captured device to prevent it from migrating (63).
3. Stent exclusion techniques: Retrieval of embolized devices can be time consuming and often unsuccessful. For smaller devices (vascular occluders, device fragments, and so on), deployment of a large stent in the iliac arteries or vein can effectively trap and exclude them from the vasculature. However, experience with this technique for larger devices and long-term outcomes are limited (78).
Algorithmic Approach for the Management of Embolized Septal/LAA and Vascular Occluders
An example of an embolized Amplatzer Vascular Plug to the abdominal aorta is shown in Online Video 3. An example of disimpacting a cardiofrom device lodged in the pulmonary artery is shown in Online Video 4. LAA = left atrial appendage.
AVP2 Embolization
Hybrid Management of an Embolized Watchman Device
A 27-mm Watchman device was implanted uneventfully but needed recapturing for optimal positioning. During recapturing, the device embolized and lodged in the mitral valve apparatus (A, B) leading to severe mitral regurgitation and shock (C). A 6-F pigtail catheter was used to unseat the device from the mitral apparatus. However, the device lodged into the LV outflow tract and led to cardiac arrest (D, E). Attempts to push the device through the aortic valve with the pigtail were unsuccessful. Hence, a 6-F pigtail catheter was advanced in a retrograde fashion to dislodge the device from the LV outflow tract. The device was successfully held between the 2 pigtail catheters, stabilizing LV and valve functions (F), peripheral bypass was instituted, and the device was removed surgically without further complications (Online Video 5). Yellow arrows annotate the 2 pigtail catheters (single-antegrade, double-retrograde). AV = aortic valve; LV = left ventricle.
Watchman in LV
Illustration of Double-Tool Retrieval Techniques
(A) A 33-mm Watchman device embolized into the left atrium after release. The device was successfully recaptured and retrieved with 2 alligator cups biopsy forceps. (B) A 20-mm Amulet LAA occluder embolized to the abdominal aorta. An EnSnare could not be advanced retrograde around the device. A smaller EnSnare was then used to capture the pin of the device and dislodge it from the aorta. The larger EnSnare was then advanced from the femoral artery and captured the device. Both snares were pulled simultaneously, elongating the device and allowing its retraction into the sheath (Online Video 6). (C) A 30-mm Gore Cardioform device was retrieved into iliac inferior vena cava but could not be retrieved inside the sheath. Therefore, a 2-device technique (gooseneck snare and a grasping forceps) was used to successfully remove the device (Online Video 7). (D) A-26-mm Amplatzer Septal occluder embolized into the right ventricle. The device was successfully retrieved with a combination of a bioptome forceps and a 20-pole adjustable circular Lasso catheter. Reprinted with permission from Li et al. (72) and Padala et al. (63). B = bioptome forceps; F = forceps; LAA = left atrial appendage; LS = Lasso catheter; S = snare.
Amulet Retrieval
To maximize the safety of these maneuvers, however, it is crucial for the operator to: 1) ensure adequate anticoagulation; 2) be comfortable with retrieval techniques and/or solicit assistance from experienced colleagues; 3) involve the appropriate surgical specialist (cardiac, vascular) early on; and 4) set a finite time to abort percutaneous attempts and convert to surgery.
Embolization avoidance strategies include comprehensive pre-procedural planning, and consistent application of the recommended safety checks before device deployment and release. However, DE may still occur despite optimal planning. Hence, familiarity with the incidence and predictors of DE, and their optimal management approach are paramount to modern SHD programs (Central Illustration). Nonetheless, current training schemes, unfortunately, do not include specific instructions on the handling of this potentially life-threatening complication. Given the rarity of DEs, it is unlikely that a SHD fellow will attain enough experience in their management during training. Yet, alternative venues may afford trainees with the opportunity to gain familiarity with basic retrieval tools and techniques. This can be acquired during certain SHD procedures that require elective snaring (e.g., arteriovenous loops in paravalvular leak closure), by cross training with vascular specialists routinely performing snare removal of temporarily implanted devices (e.g. vena cava filters), and by bench retrieval experiments using in vitro models. Time has come for a collaborative effort between structural interventionalists and device manufacturers to develop simulator models that can be integrated into fellowship and new users training programs to minimize the risk of DE and optimize its management.
DEs in SHD Interventions
DE = device embolization; ECMO = extracorporeal membrane oxygenation; SHD = structural heart disease; TAVR = transcatheter aortic valve replacement.
Conclusions
Device embolizations during SHD interventions are rare but can lead to catastrophic consequences. Careful planning and knowledge of the risk factors for DEs in specific structural procedure can mitigate the majority of embolizations. Once they occur, DEs are best managed with an integrated algorithmic approach the incorporate both percutaneous techniques and surgical modalities.
Appendix
Footnotes
Dr. Sievert has received study honoraria, travel expenses, and consulting fees from 4Tech Cardio, Abbott, Ablative Solutions, Ancora Heart, Bavaria Medizin Technologie, Bioventrix, Boston Scientific, Carag, Cardiac Dimensions, Celonova, Cibiem, CGuard, Comed B.V., Contego, CVRx, Edwards Lifesciences, Endologix, Hemoteq, InspireMD, Lifetech, Maquet Getinge Group, Medtronic, Mitralign, Nuomao Medtech, Occlutech, pfm Medical, Recor, Renal Guard, Rox Medical, Terumo, Vascular Dynamics, and Vivasure Medical.
- Abbreviations and Acronyms
- DE
- device embolization
- LAA
- left atrial appendage
- LV
- left ventricle/ventricular
- PFO
- patent foramen ovale
- SHD
- structural heart disease
- TAVR
- transcatheter aortic valve replacement
- THV
- transcatheter heart valve
- VinR
- valve-in-ring
- VinV
- valve-in-valve
- Received May 21, 2018.
- Revision received July 16, 2018.
- Accepted August 21, 2018.
- 2019 American College of Cardiology Foundation
