Reducing Left Ventricular Wall Stress through Aortic Valve Enlargement via Transcatheter Aortic Valve Implantation in Severe Aortic Stenosis.

Background: In aortic stenosis, the left ventricle exerts additional force to pump blood through the narrowed aortic valve into the downstream arterial vasculature. Adaptive hypertrophy helps to maintain wall stress homeostasis but at the expense of impaired compliance. Advanced ventricular deformation impacts the extent of functional recovery benefits achieved through transcatheter aortic valve implantation. Methods and Results: Subgroups were stratified based on output, with low-flow severe aortic stenosis defined as stroke volume index <35 mL· m-2. Before intervention, the low-flow subgroup exhibited worse effective orifice area index and arterial and global impedance, along with thinner wall thickness and larger chamber volume marginally. LV performance, including stroke volume index, ventricular elastance, and ventricular-arterial coupling, were notably inferior, consistent with worse adverse remodeling. Although the effective orifice area index was similarly augmented after TAVI, inferior recovery benefits were noted. Persistently higher wall stress and energy consumption were observed, along with poorer ventricular-arterial coupling. These changes in wall stress showed an inverse relationship with alterations in wall thickness and were proportional to changes in dimension and volume. Additionally, they were proportional to changes in left ventricular end-systolic pressure, pressure-volume area, and ventricular-arterial coupling but inversely related to ventricular end-systolic elastance. Conclusions: The study revealed that aortic valve enlargement through transcatheter aortic valve implantation reduces left ventricular wall stress in severe aortic stenosis. The reduced recovery benefits in the low-flow subgroup were evident. Wall stress could serve as a marker of mechanical benefit after the intervention.

Acute Effect in Mechanical Efficiency by Pressure-Volume Loop Analysis after Transcatheter Aortic Valve Implantation.

Background: This study aimed to evaluate the immediate effect of transcatheter aortic valve implantation (TAVI) on mechanical efficiency. Methods: A total of 46 patients (25 females) with an average age of 83 ± 6.4 years underwent TAVI using the CoreValve system. During the same hospitalization, we conducted a comprehensive comparison of the patients before and after TAVI without inotropic support using echocardiography. The parameters encompassed left ventricular (LV) geometry, valvular load, global LV afterload and ventricular hemodynamics. The analysis using pressure-volume loops enabled the determination of load-independent contractility (Ees) and afterload, in addition to assessing potential energy, stroke work, and mechanical efficiency. Results: The immediate effect was an augmented aortic valve area accompanied by a reduction in the transvalvular pressure gradient. We observed reductions in left ventricular end-systolic volume and end-diastolic volume, and also reductions in global afterload and end-systolic meridional wall stress. The Ea index decreased, while the Ees index remained relatively stable. We noted increases in stroke volume and systemic arterial compliance, indicating more efficient blood transfer from the ventricle to aorta. These changes contributed to the normalization of ventricular-arterial coupling. In terms of mechanical work of the chamber, we observed significant decreases in potential energy, stroke work, and pressure-volume area. There was an increase in the mechanical efficiency of the chamber. Conclusions: The TAVI procedure immediately reduced global afterload and improved diastolic compliance of the chamber, resulting in enhanced ventricular function and mechanical efficiency.

Impact of Recurrent Mitral Regurgitation on Left Ventricular Mass Regression and Cardiac Events following Mitral Valve Repair.

BACKGROUND: Mitral valve regurgitation results in volume overload, followed by left ventricular remodeling. Variation of reverse remodeling following mitral repair influences the clinical outcomes. We aimed to evaluate the association between recurrent mitral regurgitation and mass regression following mitral valve repair and the impact on major adverse cardiovascular events. METHODS: A retrospective cohort study was conducted on 164 consecutive patients with severe mitral regurgitation who underwent elective mitral valve repair. Subgroups were classified based on the presence of recurrent mitral regurgitation exceeding moderate severity. The hemodynamic parameters were evaluated according to geometry, mass, and function with Doppler echocardiography before and after surgery. Cox regression analysis was performed to evaluate the association between hemodynamics and mass regression and clinical outcomes. RESULTS: The results for MR indicated 110 cases with non-recurrent MR and 54 with recurrent MR, along with 31 major adverse cardiovascular events. The tracked echocardiographic results revealed less reduction in dimension and volume, along with less mass regression in the recurrent MR subgroup. Significant differences were revealed in the relative change of the LV end-diastolic volume index and relative mass regression between subgroups. The relative change in the LVEDVI was proportionally correlated with relative mass regression. Cox regression analysis identified correlations with major adverse cardiovascular events, including suture annuloplasty, recurrent mitral regurgitation, tracked LV mass, relative LV mass regression, and systolic dysfunction. CONCLUSION: LV mass regression and relative change of the LV end-diastolic volume could be risk predictors of recurrent mitral regurgitation. The extent of LV mass regression is correlated with adverse cardiac events.

Extent of Left Ventricular Mass Regression and Impact of Global Left Ventricular Afterload on Cardiac Events and Mortality after Aortic Valve Replacement.

Patient-prosthesis mismatch (PPM) causes a high transvalvular pressure gradient and residual left ventricular (LV) hypertrophy, consequently influencing long-term results. This study aimed to find the relationships between hemodynamic parameters and LV mass regression and determine the risk predictors of major adverse cardiovascular and cerebral events (MACCE) after aortic valve replacement (AVR) for aortic stenosis. Methods and Results: Preoperative and postoperative Doppler echocardiography data were evaluated for 120 patients after AVR. The patients' mean age was 67.7 years; 55% of the patients were male. Forty-four (37%) patients suffered from MACCE during a mean follow-up period of 3.6 ± 2 years. The following hemodynamic parameters at follow-up were associated with lower relative indexed LV mass (LVMI) regression: lower postoperative indexed effective orifice area, greater mean transvalvular pressure gradient (MPG), greater stroke work loss (SWL), and concentric or eccentric LV remodeling mode. The following hemodynamic parameters at follow-up were associated with a higher risk of MACCE: higher valvuloarterial impedance (ZVA), greater SWL, greater MPG, greater relative wall thickness, greater LVMI, and hypertrophic LV remodeling mode. Lower relative LVMI regression was associated with a higher risk of MACCE (hazard ratio, 1.01: 95% confidence interval, 1.003-1.03). The corresponding cutoff of relative LVMI regression was -14%. Conclusions: Changes in hemodynamic parameters were independently associated with relative LVMI regression. Impaired reverse remodeling and persistent residual LV hypertrophy were independent risk predictors of MACCE. An LVMI regression lower than 14% indicated higher MACCE. A postoperative ZVA greater than 3.5 mmHg/mL/m2 was an independent risk predictor of cardiac events and mortality after AVR. Preventive strategies should be used at the time of the operation to avoid PPM.

Endovascular Aortic Arch Reconstruction with Parallel Grafts: A Dilemma of Excessive Endograft Oversizing.

BACKGROUND: Preservation of supra-aortic branches in thoracic endovascular aortic repair plays a role in associated neurological outcomes, and the strategy varies. OBJECTIVES: This study aimed to evaluate the safety and efficacy of a parallel graft technique to reconstruct the aortic arch. METHODS: From August 2014 to July 2018, a total of 25 patients with thoracic aortic pathologies requiring arch reconstruction were included. All patients underwent thoracic aortic endovascular repair (TEVAR) with a zone 1 landing aortic stent graft, a chimney graft to preserve the left common carotid artery, and a periscope graft to preserve the left subclavian artery. The associated outcomes and complications were reported. RESULTS: Eighteen patients presented with aortic dissection, 4 with a thoracic aortic aneurysm, 1 with a penetrating aortic ulcer, 1 with a traumatic aortic injury, and 1 case of re-TEVAR. The technical success rate was 96% (24/25), but the case of immediate failure died of retrograde type A dissection. Over a mean follow-up of 32.33 months, another retrograde type A aortic dissection was detected in 1 month, and a case of early failure (< 1 year) and 3 cases of late failure (> 1 year) whose primary aortic problems recurred were detected. CONCLUSIONS: This study demonstrates a total endovascular approach to preserve supra-aortic branches with a parallel graft technique. However, the dilemma of excessive graft oversizing was disclosed due to the risk of retrograde type A dissections and an unsatisfactory durability in this small series.

Handmade fenestrated stent grafts to preserve all supra-aortic branches in thoracic endovascular aortic repair.

OBJECTIVE: To evaluate the efficacy and safety of a zone 0 landing aortic stent graft with handmade fenestrations for the preservation of all supra-aortic branches in thoracic endovascular aortic repair (TEVAR). METHODS: This study included 13 consecutive patients who underwent TEVAR using zone 0 landing handmade fenestrated stent grafts to preserve all supra-aortic branches from July 2016 to April 2017. Technical success was defined as the resolution of the primary aortic pathology as well as the preservation of all supra-aortic branches through the accurate alignment of the fenestration. Outcomes including technical success, perioperative morbidity and mortality, requirement of secondary interventions, and graft patency were analyzed. RESULTS: In this study, 11 patients presented with aortic dissection, 1 presented with thoracic aortic aneurysm with impending rupture, and 1 presented with penetrating aortic ulcer of the thoracic aorta. The technical success rate of the primary procedure was 100%. Over a mean follow-up of 20 months, secondary endovascular procedures were performed in 6 patients to resolve 3 cases of stent graft-induced new entry, 2 cases of type Ib endoleak, and 1 case of new false lumen formation. During the study period, no complication resulting from proximal landing and fenestration occurred. CONCLUSIONS: Our experience of using handmade fenestrated stent grafts revealed preliminary results of using the grafts to preserve all supra-aortic branches in TEVAR, and results demonstrated the feasibility of this technique for achieving total arch replacement endovascularly in selective patients. Further technical advancement is anticipated, and larger studies with long-term follow-up are required.

Handmade stent graft fenestration to preserve left subclavian artery in thoracic endovascular aortic repair†.

OBJECTIVES: This study aimed to evaluate the efficacy and safety of a handmade fenestrated stent graft over an aortic stent graft for preserving the left subclavian artery (LSA) in thoracic endovascular aortic repair (TEVAR). METHODS: From July 2015 to October 2018, a total of 32 consecutive patients with various thoracic aortic pathologies who underwent TEVAR in which handmade fenestration over a thoracic aortic stent graft was used for LSA were included. Outcomes including technical success, procedure-related complications, perioperative mortality and morbidity and graft patency were analysed. RESULTS: Twenty-four patients (75.00%) presented with aortic dissection, 5 patients (15.63%) with thoracic aortic aneurysm and 2 patients (6.25%) with penetrating aortic ulcer; 1 patient (3.13%) required re-TEVAR due to endoleak and sac expansion from previous TEVAR for thoraco-abdominal aneurysm. TEVAR was performed in a zone 2 landing with single fenestration for LSA (26 patients, 81.25%), zone 1 landing with double fenestration for both LSA and left common carotid artery (5 patients, 15.63%) or zone 1 landing with single fenestration for LSA and a chimney graft for left common carotid artery (1 patient, 3.13%). The technical success rate, defined as the successful alignment of fenestration to LSA, was 93.75%. At a mean follow-up of 17.3 months, 4 cases of endoleak and 2 cases of stent graft-induced new entry were noted, 3 of which were treated endovascularly. CONCLUSIONS: Our preliminary results demonstrate the viability of preserving LSA blood flow in TEVAR using a handmade stent graft fenestration to treat various aortic pathologies in various clinical situations and the technical feasibility and short-term results that may justify the use of this method in emergency cases.

The Sandwich Technique with Body Flossing Wire to Revascularize Left Subclavian Artery in Thoracic Endovascular Aortic Repair.

BACKGROUND: To evaluate the safety and efficacy of the sandwich technique with the body flossing wire to revascularize the left subclavian artery (LSA) in thoracic endovascular aortic repair (TEVAR). METHODS: From April 2014 to April 2015, 20 consecutive patients with a variety of thoracic aortic pathologies who underwent LSA revascularization with the sandwich technique and body flossing wire during TEVAR were included. Outcomes including technical success, endoleaks, perioperative mortality and morbidity, and graft patency were analyzed. RESULTS: There were 13 patients (65.0%) who presented with aortic dissection, 3 (15.0%) with thoracic aortic aneurysm, 3 (15.0%) with penetrating aortic ulcer, and 1 (5.0%) with traumatic aortic disruption. Technical success rate was 100%. But one type Ia endoleak (5.0%) was noted and treated with extended endografting. One sandwiched gutter leak (5.0%) resolved spontaneously at 6 months. One sandwiched graft (5.0%) was occluded but not treated because no related complications were found. At a mean follow-up of 9.7 months (range 4-17), all the patients with aortic aneurysm, penetrating aortic ulcer, or traumatic aortic disruption had complete thrombosis of the aortic pathologies. Patients with aortic dissection had thrombosed false lumen down to the distal aortic endograft edge (12/13, 92.3%) or the celiac artery level (8/13, 61.5%). There was no neurological deficit but 2 non-procedure-related late deaths during the study period. CONCLUSIONS: Our early experience showed that the sandwich technique with the body flossing wire to maintain blood flow to the LSA is a safe and effective method. This technique can be applied in various clinical situations with a high technique success rate. However, outcomes are preliminary and larger studies are required.

The Provisional Extension To Induce Complete Attachment (PETTICOAT) technique to promote distal aortic remodelling in repair of acute DeBakey type I aortic dissection: preliminary results.

OBJECTIVES: To report our preliminary results of an aggressive technique, the Provisional Extension To Induce Complete Attachment (PETTICOAT), in repair of acute DeBakey type I aortic dissection. METHODS: From April 2014 to November 2014, 18 patients with acute DeBakey type I aortic dissection were reviewed retrospectively. Nine patients underwent open repair combined with proximal stent grafting and distal bare stenting (PETTICOAT group). For comparison, another 9 patients underwent open repair combined with proximal stent grafting (NON-PETTICOAT group) were included. Open repair entailed ascending aorta plus total arch replacement under circulatory arrest, with variable aortic root work. Mortality and morbidity were recorded, and computed tomography was performed to evaluate the aortic remodelling at 6 months postoperatively. RESULTS: Preoperative parameters were similar. In the PETTICOAT group, one early mortality was noted. One complication of cardiac tamponade and sternal wound infection led to reopen surgeries. In the NON-PETTICOAT group, one case of transient ischaemic attack took place. Compared with the NON-PETTICOAT group, a significant increase in diameter of true lumen (median, 0.6 vs 0.1 mm, P < 0.01) and a decrease in diameter of false lumen (FL; median, -0.9 vs 0.0 mm, P < 0.01) at the level of lowest renal artery were noted in the PETTICOAT group. Moreover, significant FL volume regression (median, -102.0 vs -42.2 mm(3), P = 0.03) was observed in the PETTICOAT group. More cases of total thrombosis or regression of FL down to the level of renal artery were also noted in the PETTICOAT group (5/8 vs 0/9, P < 0.01). Two patients of the NON-PETTICOAT group received endovascular distal aortic reintervention at 6 months. CONCLUSIONS: The PETTICOAT technique in the management of acute DeBakey type I dissection is a feasible and promising method to promote distal aortic remodelling. However, outcomes are preliminary and further follow-up is required.

Intraoperative Measurement of Fractional Flow Reserve in Off-Pump Coronary Artery Bypass: A Pilot Study.

BACKGROUNDS: Fractional flow reserve of myocardium (FFRmyo) is a functional study of significant coronary artery stenosis, defined as the ratio of the pressure distal to the stenosis (poststenosis) divided by the pressure of aortic root (prestenosis). Instead of cath laboratory, we could measure it in operating room for off-pump coronary artery bypass (OPCAB) surgery and here shared our methods in the pilot study. METHODS AND RESULTS: We used needles, catheters, and pressure tracing but without guidewires or fluoroscopy to measure FFRmyo during OPCAB. In February 2010, we conducted the pilot study and collected 32 anastomosis data from 10 patients. Without revising the anastomosis plans based on coronary angiographies, 24 FFRmyo of the 32 anastomoses (75%) were less than 0.75, which represented significant functional stenosis. The FFRmyo measurements did not lead to any adverse events. CONCLUSION: The measurement of fractional flow reserve in OPCAB is safe and feasible. It can serve as a functional assessment of coronary artery stenosis in adjuvant to conventional coronary angiography.

Cardioplegia delivery by transcutaneous pigtail catheter in minimally invasive mitral valve operations.

For cardioplegia delivery and removing air from the aorta in minimally invasive mitral valve operations, we would like to propose a cost-effective pigtail method. The 8F pigtail punctures the aorta, delivers cardioplegia, and stays in place for removing air from the aorta. We then slide its tip out of the aorta as an accessory drain. With more than 100 successes, we are using it in every case and would like to share it with peer surgeons.