Laser ablation for preventing coronary obstruction and maintaining coronary access in redo-TAVR: A proof of concept.

BACKGROUND: Redo-transcatheter aortic valve replacement (TAVR) is a promising treatment for transcatheter aortic valve degeneration, becoming increasingly relevant with an aging population. In redo-TAVR, the leaflets of the initial (index) transcatheter aortic valve (TAV) are displaced vertically when the second TAV is implanted, creating a cylindrical cage that can impair coronary cannulation and flow. Preventing coronary obstruction and maintaining coronary access is essential, especially in young and low-risk patients undergoing TAVR. This study aimed to develop a new leaflet modification strategy using laser ablation to prevent coronary obstruction and facilitate coronary access after repeat TAVR. METHODS: To evaluate the feasibility of the leaflet modification technique using laser ablation, the initial phase of this study involved applying a medical-grade ultraviolet laser for ablation through pericardial tissue. Following this intervention, computational fluid dynamics simulations were utilized to assess the efficacy of the resulting perforations in promoting coronary flow. These simulations played a crucial role in understanding the impact of the modifications on blood flow patterns, ensuring these changes would facilitate the restoration of coronary circulation. RESULTS: Laser ablation of pericardium leaflets was successful, demonstrating the feasibility of creating openings in the TAV leaflets. Flow simulation results show that ablation of index valve leaflets can effectively mitigate the flow obstruction caused by sinus sequestration in redo-TAVR, with the extent of restoration dependent on the number and location of the ablated openings. CONCLUSIONS: Laser ablation could be a viable method for leaflet modification in redo-TAVR, serving as a new tool in interventional procedures.

Aortic Valve-in-Valve Procedures: Challenges and Future Directions.

Aortic valve-in-valve (ViV) procedures are increasingly performed for the treatment of surgical bioprosthetic valve failure in patients at intermediate to high surgical risk. Although ViV procedures offer indisputable benefits in terms of procedural time, in-hospital length of stay, and avoidance of surgical complications, they also present unique challenges. Growing awareness of the technical difficulties and potential threats associated with ViV procedures mandates careful preprocedural planning. This review article offers an overview of the current state-of-the-art ViV procedures, with focus on patient and device selection, procedural planning, potential complications, and long-term outcomes. Finally, it discusses current research efforts and future directions aimed at improving ViV procedural success and patient outcomes.

Modeling of valve-in-valve transcatheter aortic valve implantation after aortic root replacement using a 3-dimensional artificial intelligence algorithm.

OBJECTIVE: Aortic root replacement requires construction of a composite valve-graft and reimplantation of coronary arteries. This study assessed the feasibility of valve-in-valve transcatheter aortic valve implantation after aortic root replacement. METHODS: A retrospective review was conducted on 74 consecutive patients who received a composite valve-graft at a single institution from 2019 to 2021. Forty patients had bioprosthetic valves with adequate postoperative gated computed tomographic angiography scans. Computational simulations of balloon and self-expanding transcatheter valve deployments were performed. The modeled coronary distances were compared with traditional, manually measured valve-to-coronary distances. RESULTS: There was a statistically significant difference in the modeled versus manual measurements of valve to coronary distances for all patients regardless of valve type or coronary artery analyzed (P < .05). Most patients are low risk for coronary obstruction per 3-dimensional modeling, including those with a valve-to-coronary distance <4 mm. Only 1 patient (2.5%) was at risk for coronary obstruction for the left coronary artery using a balloon valve. No other valve combination was considered high risk of coronary obstruction. Five patients (12.5%) were at risk for possible valve stent deformation at the outflow, due to angulation at the graft anastomosis. CONCLUSIONS: Following aortic root replacement, all patients were candidates for valve-in-valve procedure using 1 or both types of transcatheter heart valves. Self-expanding valves may be at higher risk for stent frame deformation at graft anastomotic lines and balloon-expandable valves may be at higher risk of coronary obstruction.

Transcatheter Aortic Valve Replacement and Coronary Protection Guided by Deep Learning and 3-Dimensional Printing.

OBJECTIVE: In this case report, the auxiliary role of deep learning and 3-dimensional printing technology in the perioperative period was discussed to guide transcatheter aortic valve replacement and coronary stent implantation simultaneously. CASE PRESENTATION: A 68-year-old man had shortness of breath and chest tightness, accompanied by paroxysmal nocturnal dyspnea, 2 weeks before presenting at our hospital. Echocardiography results obtained in the outpatient department showed severe aortic stenosis combined with regurgitation and pleural effusion. The patient was first treated with closed thoracic drainage. After 800 mL of pleural effusion was collected, the patient's symptoms were relieved and he was admitted to the hospital. Preoperative transthoracic echocardiography showed severe bicuspid aortic valve stenosis combined with calcification and aortic regurgitation (mean pressure gradient, 42 mmHg). Preoperative computed tomography results showed a type I bicuspid aortic valve with severe eccentric calcification. The leaflet could be seen from the left coronary artery plane, which indicated an extremely high possibility of coronary obstruction. After preoperative imaging assessment, deep learning and 3-dimensional printing technology were used for evaluation and simulation. Guided transcatheter aortic valve replacement and a coronary stent implant were completed successfully. Postoperative digital subtraction angiography showed that the bioprosthesis and the chimney coronary stent were in ideal positions. Transesophageal echocardiography showed normal morphology without paravalvular regurgitation. CONCLUSION: The perioperative guidance of deep learning and 3-dimensional printing are of great help for surgical strategy formulation in patients with severe bicuspid aortic valve stenosis with calcification and high-risk coronary obstruction.

Transcatheter Aortic Valve Replacement for Failed Surgical or Transcatheter Bioprosthetic Valves: A Comprehensive Review.

Transcatheter aortic valve replacement (TAVR) has proven to be a safe, effective, and less invasive approach to aortic valve replacement in patients with aortic stenosis. In patients who underwent prior aortic valve replacement, transcatheter and surgical bioprosthetic valve dysfunction may occur as a result of structural deterioration or nonstructural causes such as prosthesis-patient mismatch (PPM) and paravalvular regurgitation. Valve-in-Valve (ViV) TAVR is a procedure that is being increasingly utilized for the replacement of failed transcatheter or surgical bioprosthetic aortic valves. Data regarding long-term outcomes are limited due to the recency of the procedure's approval, but available data regarding the short- and long-term outcomes of ViV TAVR are promising. Studies have shown a reduction in perioperative and 30-day mortality with ViV TAVR procedures compared to redo surgical repair of failed bioprosthetic aortic valves, but 1-year and 5-year mortality rates are more controversial and lack sufficient data. Despite the reduction in 30-day mortality, PPM and rates of coronary obstruction are higher in ViV TAVR as compared to both redo surgical valve repair and native TAVR procedures. New transcatheter heart valve designs and new procedural techniques have been developed to reduce the risk of PPM and coronary obstruction. Newer generation valves, new procedural techniques, and increased operator experience with ViV TAVR may improve patient outcomes; however, further studies are needed to better understand the safety, efficacy, and durability of ViV TAVR.

Chimney Stenting vs BASILICA for Prevention of Acute Coronary Obstruction During Transcatheter Aortic Valve Replacement.

BACKGROUND: Coronary obstruction (CO) is a potentially life-threatening complication of transcatheter aortic valve replacement (TAVR). Chimney stenting or leaflet laceration with transcatheter electrosurgery (Bioprosthetic or Native Aortic Scallop Intentional Laceration to Prevent Iatrogenic Coronary Artery Obstruction [BASILICA]) are 2 techniques developed to prevent CO. OBJECTIVES: The aim of the present study was to compare periprocedural and 1-year outcomes of chimney and BASILICA in TAVR patients at high risk of CO. METHODS: This multicenter observational registry enrolled consecutive TAVR patients at high risk of CO, undergoing either preventive chimney stenting or BASILICA. Clinical success was defined as successful performance of the chimney or BASILICA technique without clinically relevant ostial CO. The primary endpoint was major adverse cardiovascular events, a composite of death, myocardial infarction, stroke, or unplanned target lesion coronary revascularization at 1 year. RESULTS: A total of 168 patients were included: 71 (42.3%) received chimney stenting, and 97 (57.7%) underwent BASILICA. Patients undergoing BASILICA had higher preprocedural risk of CO, as indicated by lower sinotubular junction height (18.2 ± 4.8 mm vs 14.8 ± 3.4 mm; P < 0.001) and diameter (28.2 ± 4.5 vs 26.8 ± 3.4; P = 0.029). Rates of periprocedural complications were similar between the 2 groups. Clinical success was 97.2% and 96.9% in chimney and BASILICA, respectively (P = 0.92). At 1-year follow-up, the cumulative incidence of major adverse cardiovascular events was 18.7% (95% CI: 11%-30.6%) in the chimney group and 19.9% (95% CI: 12.1%-31.5%) in the BASILICA group (log-rank P = 0.848), whereas chimney was associated with a numerically higher cardiovascular mortality than BASILICA (6.7% vs 1.3%; log-rank P = 0.168). CONCLUSIONS: Chimney stenting and BASILICA effectively prevent TAVR-induced acute CO. Both techniques seem to have comparable acceptable periprocedural and 1-year outcomes.

Clinical considerations and challenges in TAV-in-TAV procedures.

Transcatheter aortic valve replacement (TAVR) has emerged as a viable treatment for aortic valve disease, including low-risk patients. However, as TAVR usage increases, concerns about long-term durability and the potential for addition interventions have arisen. Transcatheter aortic valve (TAV)-in-TAV procedures have shown promise in selected patients in numerous registries, offering a less morbid alternative to TAVR explantation. In this review, the authors aimed to comprehensively review the experience surrounding TAV-in-TAV, summarize available data, discuss pre-procedural planning, highlight associated challenges, emphasize the importance of coronary obstruction assessment and provide insights into the future of this technique.

Thick endothelialization of the self-expandable valve causes delayed coronary obstruction.

Delayed coronary obstruction is a rare complication occurring after transcatheter aortic valve replacement (TAVR). Although TAVR has become popular, in some cases, the therapeutic strategy should be carefully selected depending on the patient's anatomical and/or functional restrictions. We report a rare case of delayed coronary obstruction in which coronary obstruction was caused by thick endothelialization of the nitinol frame of the prosthetic valve. A 79-year-old female who had undergone TAVR 4 months before presented with mild chest pain and was admitted to our institution. Computed tomography and coronary angiography revealed that the space from the sinus of Valsalva to the nitinol frame was narrow and separated from the inside of the nitinol frame because of critical endothelialization. Therefore, an emergency surgical aortic valve replacement was performed. The patient had an uneventful postoperative course and was discharged 20 days postoperatively without any complications.

Risk of Sinus Sequestration During Redo Transcatheter Aortic Valve Implantation: The Prevalence, Predictors, and Risk Stratification.

The number of patients who underwent transcatheter aortic valve implantation (TAVI) with the potential for reintervention is steadily increasing; however, there is a risk of sinus sequestration (SS) during a redo TAVI. The prevalence, predictors, and risk stratification of the risk for SS remain uncertain. We analyzed computed tomography acquired from 263 patients who underwent TAVI between 2021 and 2022: balloon-expandable valve (BEV) (71%) and self-expandable valve (SEV) (29%). Patients were considered at risk for SS if they met the following: (1) BEV frame > sinotubular junction (STJ) or SEV neocommissure greater than the STJ and (2) valve-to-STJ <2 mm. The risk of left, right, and any SS in 51%, 50%, and 65%, respectively, did not differ between BEV and SEV. The predictors of any SS were the height of the left and right coronary cusp (odds ratio [OR] 0.81 and 0.71, cutoff 18.6 and 19.2 mm, respectively) and STJ minus the annulus diameter (OR 0.65, cutoff 3.7 mm) in BEV, and STJ diameter (OR 0.47, cutoff 27.6 mm) in SEV. The number of predictors stratified the risk of any SS: low risk with BEV at 0 predictors (14% at risk of SS), intermediate risk at 1 predictor (65%), high risk at 2 or 3 predictors (81% and 95%), and low risk with SEV at 0 predictors (33%) versus high risk at 1 predictor (91%). In conclusion, 2/3 of patients who underwent TAVI were at risk of SS. The height of the coronary cusp and the STJ diameter were associated with and adequately stratified the risk of SS.

Very Late Sinus of Valsalva Sequestration After Transcatheter Aortic Valve Implantation in Native Aortic Annuli.

Coronary artery obstruction caused by sinus sequestration is well described after transcatheter aortic valve implantation in failed bioprosthetic valves, which usually occurs during or shortly after the transcatheter aortic valve implantation procedure. We report the presentation, management, and outcomes of 2 cases of very late sinus sequestration in native aortic annuli, which has not been described before to our knowledge. (Level of Difficulty: Advanced.).

Transcatheter aortic valve implantation in patients with anomalous origin of a coronary artery.

Transcatheter aortic valve implantation (TAVI) has become a well-established treatment option for elderly patients with symptomatic severe aortic stenosis. Coronary artery anomalies are an infrequent finding and there have only been few anecdotal reports of patients with coronary anomalies treated with TAVI. We here present a comprehensive overview of existing reports in addition to an own case series to facilitate better understanding of this potentially challenging clinical scenario.

Predicted vs Observed Valve to Coronary Distance in Valve-in-Valve TAVR: A Computed Tomography Study.

BACKGROUND: Preprocedural computed tomography (CT) workup with assessment of virtual transcatheter heart valve-to-coronary ostia (VTC) distance and transcatheter heart valve-to-sinus (VTS) distances is recommended to assess the risk of coronary obstruction following valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR). OBJECTIVES: The authors sought to investigate the agreement of predicted VTC and VTS distances and observed post-TAVR anatomy on CT and their relationship with transcatheter heart valve (THV) expansion and deployment conditions. METHODS: Fifty-one patients who underwent a balloon-expandable ViV procedure were included in this study. The expansion of the THV stent frame was evaluated at 4 levels: THV inflow, surgical heart valve (SHV) sewing ring, SHV outflow, and THV outflow. Assessment of the VTC/VTS distances was performed on the pre-TAVR CT, and THV-to-coronary ostia and THV-to-sinus distances were assessed on the post-TAVR CT. RESULTS: Following the ViV procedure, the THV stent frame flared toward the outflow but was generally underexpanded at all levels, particularly at the SHV sewing ring level. Postdilatation impacted the extent of THV expansion, resulting in greater expansion than nominal balloon filling at all 4 THV levels (P < 0.001). Observed THV-to-coronary ostia distances were systematically larger than predicted by the VTC distance (mean difference 1.25 ±1.28 mm) in patients with nominal balloon filling but systematically smaller in case of postdilatation (mean difference -0.45 ± 0.52 mm). A similar relationship was observed between VTS and THV-to-sinus distance measurements. CONCLUSIONS: With nominal balloon filling, VTC and VTS distances underestimate postprocedural distances due to THV frame underexpansion. However, postdilatation may lead to distances smaller than predicted due to THV overexpansion at the outflow level.