Caval-aortic access to allow transcatheter aortic valve replacement in otherwise ineligible patients: initial human experience

Transcatheter Electrosurgery: JACC State-of-the-Art Review

Transcatheter electrosurgery refers to a family of procedures using radiofrequency energy to vaporize and traverse or lacerate tissue despite flowing blood. The authors review theory, simulations, and benchtop demonstrations of how guidewires, insulation, adjunctive catheters, and dielectric medium interact. For tissue traversal, all but the tip of traversing guidewires is insulated to concentrate current. For leaflet laceration, the "Flying V" configuration concentrates current at the inner lacerating surface of a kinked guidewire. Flooding the field with non-ionic dextrose eliminates alternative current paths. Clinical applications include traversing occlusions (pulmonary atresia, arterial and venous occlusion, and iatrogenic graft occlusion), traversing tissue planes (atrial and ventricular septal puncture, radiofrequency valve repair, transcaval access, Potts and Glenn shunts), and leaflet laceration (BASILICA, LAMPOON, ELASTA-Clip, and others). Tips are provided for optimizing these techniques. Transcatheter electrosurgery already enables a range of novel therapeutic procedures for structural heart disease, and represents a promising advance toward transcatheter surgery.

Transfemoral transcatheter puncture of interventricular septum in a swine model: A novel transfemoral-venous access to left ventricle with the assistance of arterio-venous circuit

OBJECTIVE

Via subclavian/jugular vein, successful puncture of interventricular septum (IVS) has been achieved transvenously. However, the approach was limited by acute entry-angle. The study was conducted to investigate a novel transcatheter puncture of IVS via femoral access and transfemoral-venous access to left ventricle (LV) through IVS.

METHODS

Via femoral artery, transcatheter puncture of mid-IVS was performed with a custom-made nickel-titanium needle and 6F-sheath in 16 healthy mini-swine. Then femoral arterio-venous circuit was established through IVS. After pre-dilation of IVS, a 20F-sheath was introduced into LV transvenously over-the-guidewire in 15 swine. Furthermore, transfemoral-venous TAVR was attempted with the approach in another swine. IVS was evaluated postoperatively and was further confirmed pathologically 2 months later.

RESULTS

All transcatheter puncture of IVS was performed successfully in LV and the mid-IVS thickness was 7.67 ± 0.98 mm. In all swine, femoral arterio-venous circuit was established via IVS, and a 20F-sheath was introduced into LV and aorta transfemoral-venously (entry-angle: 145.3 ± 12.2° in front view). After the procedure, there was one swine with moderate tricuspid-regurgitation and five swine with mild residual-shunt (2.6 ± 0.7 mm). Two months later, residual-shunt was still detected in three swine and the communication was confirmed pathologically. In other swine, no defect occurred and replacement-scar was identified along puncture-tract. In the swine underwent transfemoral-venous TAVR, prosthetic valve was deployed successfully with good function.

CONCLUSIONS

Transfemoral transcatheter puncture of IVS is feasible and safe in a swine model, and large sheath can be introduced into LV transfemoral-venously using the novel access with the aid of vessel circuit.

Imaging of transcatheter aortic valve replacement complications

Aortic stenosis is increasing in incidence and is now commonly managed with transcatheter aortic valve replacement (TAVR) in intermediate and high-risk patients. Radiologists are likely to encounter patients undergoing this procedure both pre- and postoperatively, and therefore, an understanding of procedural complications is essential. Complications may relate to the access site or approach, or the valve itself. This article will review the most common complications described in literature and focuses on the role of multidetector computed tomography (CT) in their evaluation either exclusively, or complementary to other imaging methods.

Transcatheter Aortic Valve Replacement: Procedure and Outcomes

Initially, transcatheter aortic valve replacement (TAVR) was only used in patients with severe symptomatic aortic stenosis and prohibitive risk for surgical aortic valve replacement. Subsequently, TAVR was extended to patients with high and intermediate surgical risk. Recently, the results of randomized trials in low-surgical-risk patients showed superiority or noninferiority of TAVR versus surgical aortic valve replacement in this population. Procedural outcomes have been improved. Long-term durability of transcatheter heart valves remains to be confirmed. This article presents the evolution and current status of TAVR, with respect to the different types of devices and procedures as well as its outcomes.

Novel Utility of Amplatzer Septal Occlusion Device to Treat Persistent Aortocaval Fistula following Ruptured Endovascular Aortic Aneurysm Repair (rEVAR)

Aortocaval fistulas following endovascular repair of ruptured abdominal aortic aneurysms (rAAA) are rare. We herein describe repair using an Amplatzer Septal Occluder in a 68-year-old male who presented to the emergency department 6 months after ruptured endovascular aneurysm repair (rEVAR) with right heart failure. With the assistance of diagnostic angiography and intravascular ultrasound, the patient was found to have a 1.2 cm diameter aortocaval fistula and a type-II endoleak. His aortocaval fistula was successfully closed using an Amplatzer septal occluder device after failure of attempted closure with an Amplatzer plug and coiling of the aneurysm sac. His symptoms of heart failure improved, and he was discharged to an acute rehabilitation unit. Follow-up at 3 months demonstrated continued improvement in heart failure symptoms, and a small persistent type II endoleak. Aortocaval fistulae are a potentially fatal complication of rAAA. We discuss the sequelae and treatment strategies of aortocaval fistulas following rEVAR including the use of the Amplatzer Septal Occluder.

Transcaval Access for Large Bore Devices

PURPOSE OF REVIEW

Examine the latest data and techniques regarding transcaval access and closure.

RECENT FINDINGS

Transcaval access was proven to be a feasible and a translatable skill in a 100 patient open-label prospective study. No late complications from fistulas occurred and of all patients alive at 1 year, one fistula remained open. Transcaval is a viable access route for large bore devices. With adequate planning, bleeding and vascular complications are minimal. It should be integrated into the rubric of transcatheter large bore access.

Advances in transcatheter aortic valve replacement

Evidence in transcatheter aortic valve replacement (TAVR) has accumulated rapidly over the last few years and its application to clinical decision making are becoming more important. In this review, we discuss the advances in TAVR for patient selection, expanding indications, complications, and emerging technologies.

TAVI and the future of aortic valve replacement

Aortic valve stenosis (AS) is the most common valvular pathology and has traditionally been managed using surgical aortic valve replacement (SAVR). A large proportion of affected patient demographics, however, are unfit to undergo major surgery given underlying comorbidities. Since its introduction in 2002, transcatheter aortic valve implantation (TAVI) has gained popularity and transformed the care available to different-risk group patients with severe symptomatic AS. Specific qualifying criteria and refinement of TAVI techniques are fundamental in determining successful outcomes for intervention. Given the successful applicability in high-risk patients, TAVI has been further developed and trialed in intermediate and low-risk patients. Within intermediate-risk patient groups, TAVI was shown to be noninferior to SAVR evaluating 30-d mortality and secondary endpoints such as the risk of bleeding, development of acute kidney injury, and length of admission. The feasibility of expanding TAVI procedures into low-risk patients is still a controversial topic in the literature. A number of trials have recently been published which demonstrate TAVI as noninferior and even superior over SAVR for primary study endpoints.

Transcatheter electrosurgery in bipolar or monopolar modes

Transcatheter electrosurgery has emerging value in a range of other new procedures that require traversing tissue (transcaval access, transcatheter Glenn Shunt) or slicing tissue (LAMPOON slicing of the mitral valve and BASILICA slicing of the aortic valve). This is the first report of bipolar radiofrequency wires used to cross lesions in humans, reported here in seven re-entry CTO cases. The bipolar configuration may provide directionality to charge without need for wire alignment and advancement, but is theoretically disadvantageous for tissue "cutting" because of problems with charge concentration.

Access and closure management of large bore femoral arterial access

Femoral and radial artery access continue to be the standard of care for percutaneous coronary interventions. Cardiac catheterization has progressed to encompass a wide range of diagnostic and interventional procedures including coronary, peripheral, endovascular, and structural heart disease interventions. Despite advanced technology to make these procedures safe, bleeding, and vascular complications continue to be a substantial source of morbidity, especially in patients undergoing large-bore access procedures. New variations of percutaneous devices have reduced complications associated with these procedures. However, safe vascular access with effective hemostasis requires special techniques which have not been well described in the literature. Large-bore femoral artery access is feasible, safe, and associated with low complication rates when a protocol is implemented. Wayne State University, Detroit Medical Center Heart Hospital is a tertiary care, high-volume center for endovascular, structural heart and complex high risk indicated procedures with more 150 procedures involving mechanical circulatory support (MCS) devices per year. In this manuscript, we describe our approach to femoral artery large-bore sheath insertion and management. Our protocol includes proper identification of the puncture site, device selection, insertion, assessment of limb perfusion while on prolong MCS support, and hemostasis techniques after sheath removal.

Percutaneous or surgical access for transfemoral transcatheter aortic valve implantation

Transcatheter aortic valve implantation is an important therapeutic option for patients with symptomatic, severe aortic stenosis at increased risk for open surgical aortic valve replacement. Although a number of alternative vascular access sites have been developed, transfemoral access is overwhelmingly the dominant access strategy for this procedure. Access was achieved in the initial clinical experience primarily via surgical cutdown, but more recently, there has been increasing use of a fully percutaneous approach. This is likely driven by improvements in technology, more experience with large bore vascular closure devices (VCDs), and pressures to reduce hospital length of stay. This review will describe temporal trends of percutaneous versus surgical transfemoral access, identify the advantages and disadvantages of each approach, and describe the best practices for achieving safe transfemoral percutaneous access.

Chest Radiographic Appearance of Minimally Invasive Cardiac Implants and Support Devices: What the Radiologist Needs to Know

Minimally invasive implantable cardiac devices used in valve repair and replacement, cardiovascular support, and partial chamber and appendageal occlusion represent a burgeoning area of both bioengineering and clinical innovation. In addition to familiarizing the reader with the radiographic appearance of the most commonly utilized and encountered newer devices, this review will also address the relevant clinical and pathophysiological indications for usage and deployment as well as potentially encountered complications.

Access Sites for TAVI: Patient Selection Criteria, Technical Aspects, and Outcomes

During the last ten years, transcatheter aortic valve implantation (TAVI) has become a reliable and valid alternative treatment for elderly patients with severe symptomatic aortic valve stenosis requiring valve replacement and being at high or intermediate surgical risk. While common femoral arteries are the access site of choice in the vast majority of TAVI patients, in up to 15–20% of TAVI candidates this route might be precluded due to the presence of diffuse atherosclerotic disease, tortuosity or small vessel diameter. Therefore, in order to achieve an antegrade or retrograde implant, several alterative access routes have been described, namely trans-axillary, trans-aortic, trans-apical, trans-carotid, trans-septal, and trans-caval. The aim of this paper is to give a concise overview on vascular access sites for TAVI, with a particular focus on patient's selection criteria, imaging, technical aspects, and clinical outcome.

A Review of Alternative Access for Transcatheter Aortic Valve Replacement

With the advent of transcatheter aortic valve replacement (TAVR), appropriately selected intermediate-, high-, and extreme-risk patients with severe aortic stenosis (AS) are now offered a less invasive option compared to conventional surgery. In contemporary practice, TAVR is performed predominantly via a transfemoral arterial approach, whereby a transcatheter heart valve (THV) is delivered in a retrograde fashion through the iliofemoral arterial system and thoraco-abdominal aorta, into the native aortic valve annulus. While the majority of patients possess suitable anatomy for transfemoral arterial access, there is a subset of patients with extensive peripheral vascular disease that precludes this traditional approach to TAVR. Fortunately, innovation in the field of structural heart disease has led to the refinement of alternative access options for THV delivery. Selection of the most appropriate route of therapy mandates a careful consideration of multiple factors, including patient anatomy, technical feasibility, and equipment specifications. Furthermore, understanding the risks conferred by each access site for valve delivery-notably stroke, vascular injury, and major bleeding-is of paramount importance when selecting the approach that will best optimize the outcome for an individual. In this review, we provide a comprehensive summary of alternative approaches to transfemoral arterial TAVR as well as the available outcome data supporting each of these various techniques.

Transcaval transcatheter aortic valve replacement: a visual case review

Transcatheter aortic valve replacement (TAVR) has emerged as a viable, minimally-invasive and widely adopted approach for the treatment of severe symptomatic aortic stenosis in patients who are intermediate-risk or greater for surgical aortic valve replacement. Numerous studies have demonstrated favorable outcomes with TAVR in this population, particularly with transfemoral access TAVR. Transfemoral TAVR has been shown to be safer and associated less morbidity, shorter lengths of hospital stay and more rapid recovery as compared with traditional thoracic alternative-access TAVR (transapical or transaortic). Despite iterative advancements in transcatheter heart valve technology and delivery system, there remain a portion of patients with iliofemoral arterial vessel sizes that are too small for safe transfemoral TAVR. Paradoxically, these patients are generally higher risk and are thus less favorable candidates for open surgery or traditional alternative-access TAVR. With these considerations in mind, transcaval TAVR was developed as a fully percutaneous, non-surgical approach for aortic valve replacement in patients who are poor candidates for traditional alternative-access TAVR. In this manuscript we describe the principles on which transcaval TAVR was developed, the outcomes from the largest trial completed evaluating this technique as well as describing the technique used to perform this procedure in a case-based format.

Non-transfemoral access sites for transcatheter aortic valve replacement

Transfemoral access is currently the standard and preferred access site for transcatheter aortic valve replacement (TAVR), though novel approaches are emerging to expand treatment options for the increasing numbers of patients with a contraindication for the traditional route. Previous publications have provided comparisons between two TAVR access sites, primarily transfemoral versus one of the novel approaches, while others have compared three or four novel approaches. The aim of this report is to provide a comprehensive summary of publications that analyse and compare the six non-transfemoral access sites currently described in the literature. These include the transapical, transaortic, axillary/subclavian, brachiocephalic, transcarotid, and transcaval approaches. Though there remains little consensus as to the superiority or non-inferiority of TAVR approaches, and there has yet to be randomized clinical trials to support published findings, with careful patient and procedural selection, outcomes for novel approaches have been reported to be comparable to standard transfemoral access when performed by skilled physicians. As such, choice of procedure is primarily based on registry data and the judgement of surgical teams as to which approach is best in each individual case. As TAVR continues to be an increasingly widespread treatment, search for the optimal access site will grow, and focus should be placed on the importance of educating surgeons as to all possible approaches so they may review and chose the most appropriate technique for a given patient.

Percutaneous access planning, techniques and considerations for endovascular aortic repair (EVAR)

Percutaneous endovascular aortic repair (EVAR) has transformed the field of aortic repair. As techniques and devices improve, interventionalists continue to expand the boundaries of what is possible, enabling these life-saving procedures to be performed on a wider range of more technically challenging cases. This article discusses endovascular access considerations for EVAR including; ultrasound guidance, preclose technique, access vessel options, innovative devices, and bailout strategies that interventionalists should be familiar with to optimize patient outcomes.

Temporal trends in patient referral for Transcatheter aortic valve replacement and reasons for exclusion at a high-volume Center in the United States

BACKGROUND

Clinical indications for transcatheter aortic valve replacement (TAVR) and elements of the implantation procedure, including delivery system miniaturization and novel access options, have evolved over time. The reasons patients are excluded from TAVR also have changed. The impact of these changes on patient referral for and exclusion from TAVR is unknown.

METHODS

We retrospectively analyzed patients referred to our center for TAVR from January 2010 to August 2016 to evaluate reasons for patient exclusion. Patients were divided into three groups based on initial screening date for trends in demographics and exclusion: Group 1, 2010-2012; Group 2, 2012-2014; Group 3, 2014 to August 1, 2016. Annual trends for patient exclusion from TAVR were assessed.

RESULTS

One thousand nine hundred fifty-three patients were referred and underwent screening for TAVR. The rates at which patients were referred for TAVR were 23.8, 25.9, and 24.5 per month in groups 1, 2, and 3, respectively. Rate of patient exclusion from TAVR decreased from 68% in Group 1 to 38% in Group 3 (P < .001). The largest percentage of patients (29.4%) were initially excluded from TAVR for cardiac reasons, but this trend has decreased over time. Twenty-five percent are excluded for lack of procedural indication. Exclusion from TAVR for vascular access reasons decreased from 7.9% in 2010 to 1.0% in 2016 (P = .017).

CONCLUSIONS

Referral numbers have been robust since TAVR became available. The percentage of patients excluded from TAVR has decreased over time. Patients are most commonly excluded from TAVR for concomitant coronary artery disease (CAD), asymptomatic severe AS, moderate AS, or non-cardiac critical illness. Patients with CAD and those with asymptomatic severe AS or moderate AS should be a focus for continued research in TAVR.

Alternate Access for TAVI: Stay Clear of the Chest

Transcatheter aortic valve implantation (TAVI) is currently performed through an alternative access in 15% of patients. The transapical access is progressively being abandoned as a result of its invasiveness and poor outcomes. Existing data does not allow TAVI operators to favour one access over another - between transcarotid, trans-subclavian and transaortic - because all have specific strengths and weaknesses. The percutaneous trans-subclavian access might become the main surgery-free alternative access, although further research is needed regarding its safety. Moreover, the difficult learning curve might compromise its adoption. The transcaval access is at an experimental stage and requires the development of dedicated cavo-aortic crossing techniques and closure devices.

Thirty-Day Readmissions After Transcatheter Aortic Valve Replacement in the United States: Insights From the Nationwide Readmissions Database

BACKGROUND

Readmissions after cardiac procedures are common and contribute to increased healthcare utilization and costs. Data on 30-day readmissions after transcatheter aortic valve replacement (TAVR) are limited.

METHODS AND RESULTS

Patients undergoing TAVR (International Classification of Diseases-Ninth Revision-CM codes 35.05 and 35.06) between January and November 2013 who survived the index hospitalization were identified in the Nationwide Readmissions Database. Incidence, predictors, causes, and costs of 30-day readmissions were analyzed. Of 12 221 TAVR patients, 2188 (17.9%) were readmitted within 30 days. Length of stay >5 days during index hospitalization (hazard ratio [HR], 1.47; 95% confidence interval [CI], 1.24-1.73), acute kidney injury (HR, 1.23; 95% CI, 1.05-1.44), >4 Elixhauser comorbidities (HR, 1.22; 95% CI, 1.03-1.46), transapical TAVR (HR, 1.21; 95% CI, 1.05-1.39), chronic kidney disease (HR, 1.20; 95% CI, 1.04-1.39), chronic lung disease (HR, 1.16; 95% CI, 1.01-1.34), and discharge to skilled nursing facility (HR, 1.16; 95% CI, 1.01-1.34) were independent predictors of 30-day readmission. Readmissions were because of noncardiac causes in 61.8% of cases and because of cardiac causes in 38.2% of cases. Respiratory (14.7%), infections (12.8%), bleeding (7.6%), and peripheral vascular disease (4.3%) were the most common noncardiac causes, whereas heart failure (22.5%) and arrhythmias (6.6%) were the most common cardiac causes of readmission. Median length of stay and cost of readmissions were 4 days (interquartile range, 2-7 days) and $8302 (interquartile range, $5229-16 021), respectively.

CONCLUSIONS

Thirty-day readmissions after TAVR are frequent and are related to baseline comorbidities, TAVR access site, and post-procedure complications. Awareness of these predictors can help identify and target high-risk patients for interventions to reduce readmissions and costs.

Anatomic Suitability for Transcaval Access Based on Computed Tomography

Transcaval access has been used successfully for over 200 transcatheter aortic valve replacements, large-bore percutaneous left ventricular assist devices, and thoracic endovascular aortic aneurysm repairs. This review teaches how to plan transcaval access and closure based on computed tomography. The main planning goals are to: 1) identify calcium-free crossing targets in the abdominal aorta along with optimal fluoroscopic projection angles and level with respect to lumbar vertebrae; 2) identify obstacles such as interposed bowel or pedunculated aortic atheroma; 3) plan covered stent bailout; and 4) identify jeopardized vascular branches such as renal arteries that might be obstructed by bailout covered stents if employed. The aorta and inferior vena cava are segmented (sculpted) using an image reconstruction workstation and crossing targets are highlighted. Important measurements such as aortic lumen diameter and target distance from renal arteries, aortoiliac bifurcation, and right femoral vein puncture site are reported to assist the operator. The proposed classification for transcaval feasibility has been revised, making some previously unfavorable candidates now feasible or favorable based on procedural success to date. Transcaval access allows percutaneous introduction of large devices into the aorta despite small or diseased iliofemoral arteries. By following these simplified procedures, both operators and imaging specialists can easily prepare comprehensive treatment plans.

Guidewire electrosurgery-assisted trans-septal puncture

OBJECTIVES

Electrifying a coronary guidewire may be a simple escalation strategy when trans-septal needle puncture is unsuccessful.

BACKGROUND

Radiofrequency energy to facilitate trans-septal puncture through a dedicated device is costly and directly through a trans-septal needle may be less safe. Our technique overcomes these limitations.

METHODS

The technique was used in patients when trans-septal needle penetration failed despite excessive force or tenting of the atrial septum. A coronary guidewire, connected to an electrosurgery pencil, was advanced through the trans-septal needle, dilator, and sheath to perforate the interatrial septum during a short burst of radiofrequency energy. With the guidewire tip no longer "active," the dilator and sheath were advanced safely over the wire into the left atrium. In posthoc validation, radiofrequency assisted Brockenbrough needle and coronary guidewire punctures were made in freshly explanted pig hearts and compared under microscopy.

RESULTS

Eight patients who required trans-septal access for structural intervention were escalated to a guidewire electrosurgery strategy. Six patients had thickened fibrotic septum and two had prior surgical patch repair. Crossing was successful in all patients with no procedure related complications. The size of punctures (1.11 ± 0.40 mm vs 0.37 ± 0.08 mm, P = .009) and blanched penumbra (3.62 ± 1.23 mm vs 0.72 ± 0.29 mm, P = .003) in pig atrial septum were larger with an electrified needle than electrified guidewire. The hole generated by the electrified guidewire was smaller than by the nonelectrified needle.

CONCLUSIONS

When conventional trans-septal puncture fails, a coronary guidewire can be used to deliver brief radiofrequency energy safely and effectively. This technique is inexpensive and accessible to operators.

Vascular complications associated with transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) is now an accepted pathway for aortic valve replacement for patients who are at prohibitive, severe and intermediate risk for traditional aortic valve surgery. However, with this rising uptrend and adaptation of this new technology, vascular complications and their management remain an Achilles heel for percutaneous aortic valve replacement. The vascular complications are an independent predictor of mortality for patients undergoing TAVR. Early recognition of these complications and appropriate management is paramount. In this article, we review the most commonly encountered vascular complications associated with currently approved TAVR devices and their optimal percutaneous management techniques.

TAVI with current CE-marked devices: strategies for optimal sizing and valve delivery

Transcatheter aortic valve implantation (TAVI) has evolved from an exclusive, highly complex and hazardous procedure into a mature, safe and streamlined therapy for patients with severe aortic stenosis (AS). Various successive device iterations and product refinements have created a dynamic and competitive field with a spectrum of different CE-marked transcatheter heart valve (THV) designs. This review provides a practical overview of current CE-marked THVs with a focus on respective sizing algorithms and delivery strategies.

Percutaneous thoracic aortic aneurysm repair through transcaval aortic access

Transcaval aortic access has been used for deployment of transcatheter aortic valves in patients in whom conventional arterial approaches are not feasible. This access can be vital in other situation when large bore access is needed. We described a case of 65-year-old man who had large thoracic descending aortic aneurysm with diffuse bilateral iliac disease precluding the arterial access required for the procedure. The patient underwent successful transcaval access with placement of 22-Fr balloon expandable sheath followed with successful deployments of 32 mm × 32 mm × 150 mm Valiant stent graft (Medtronic, Minneapolis, MN). The aorto-vena cava tract was closed successfully using 12 × 10 PDA occluder device with no residual flow at the end of the case, which was confirmed on repeated CT next day.

Biventricular Impella placement via complete venous access

Impella (Abiomed, Danvers, MA) is an effective option for emergent treatment of critical refractory cardiogenic shock. However, in patients who have inadequate peripheral arterial access, Impella for left ventricular support sometimes requires surgical access, leading to disadvantages for emergent procedures or invasiveness for very sick patients. In addition, Impella for right ventricular support was recently reported to contribute to the management of severe biventricular dysfunction. In this report, we describe a case of refractory cardiogenic shock in a patient with inadequate vascular access who was treated with biventricular Impella via venous and caval-aortic access under conscious sedation. This technique can be used as a bridge to surgical ventricular assist device or heart transplantation. © 2017 Wiley Periodicals, Inc.

Vascular approaches for transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is a rapidly evolving therapeutic modality currently available for patients with severe aortic stenosis (AS) that are unsuitable for surgery because of technical/anatomical issues or high-estimated surgical risk. Transfemoral approach is the preferred TAVI delivery route when possible. Alternative non-transfemoral access options include transaortic, trans-subclavian and transapical access. Other approaches are also feasible (transcarotid, transcaval, and antegrade aortic) but are restricted to operators and hospitals with experience. The peculiarities of each of the vascular approaches designed for TAVI delivery make it necessary to carefully assess patient's atherosclerotic load and location, arterial size and tortuosity, and presence of mural thrombus. Several clinical trials are currently ongoing and in the near future the indications for these approaches will likely be better defined and extended to a broader spectrum of TAVI candidates.

Intentional Percutaneous Laceration of the Anterior Mitral Leaflet to Prevent Outflow Obstruction During Transcatheter Mitral Valve Replacement: First-in-Human Experience

OBJECTIVES

This study sought to use a new catheter technique to split the anterior mitral valve leaflet (AML) and prevent iatrogenic left ventricular outflow tract (LVOT) obstruction immediately before transcatheter mitral valve replacement (TMVR).

BACKGROUND

LVOT obstruction is a life-threatening complication of TMVR, caused by septal displacement of the AML.

METHODS

The procedure was used in patients with severe mitral valve disease and prohibitive surgical risk. Patients either had prior surgical mitral valve ring (n = 3) or band annuloplasty (n = 1) or mitral annular calcification with stenosis (n = 1). Iatrogenic LVOT obstruction or transcatheter heart valve dysfunction was predicted in all based on echocardiography and computed tomography. Transfemoral coronary guiding catheters directed an electrified guidewire across the center and base of the AML toward a snare in the left atrium. The externalized guidewire loop was then electrified to lacerate the AML along the centerline from base to tip, sparing chordae, immediately before transseptal TMVR.

RESULTS

Five patients with prohibitive risk of LVOT obstruction or transcatheter heart valve dysfunction from TMVR successfully underwent LAMPOON, with longitudinal splitting of the A2 scallop of the AML, before valve implantation. Multiplane computed tomography modeling predicted hemodynamic collapse from TMVR assuming an intact AML. However, critical LVOT gradients were not seen following LAMPOON and TMVR. Doppler blood flow was seen across transcatheter heart valve struts that encroached the LVOT, because the AML was split. Transcatheter heart valve function was unimpeded.

CONCLUSIONS

This novel catheter technique, which resembles surgical chord-sparing AML resection, may enable TMVR in patients with prohibitive risk of LVOT obstruction or transcatheter heart valve dysfunction.