Innovations: Technology and Techniques in Cardiothoracic and Vascular Surgery

Transcatheter aortic valve replacement (TAVR), previously reserved for patients of intermediate to prohibitive surgical risk, has now been expanded to patients of any surgical risk with severe aortic stenosis. Bioprostheses are prone to structural valve degeneration (SVD), a progressive and multifactorial process that limits valve durability. As the population undergoing TAVR shifts toward a lower-risk and younger profile, long-term durability is a crucial determinant for patient outcomes. Our objective was to determine the incidence and risk factors of SVD at midterm follow-up in a veteran TAVR population.

Patients undergoing TAVR at our federal facility were retrospectively evaluated for SVD and other endpoints with standardized consensus criteria. Multivariable Cox proportional hazards analysis was performed to evaluate risk factors for mortality and SVD.

From 2013 to 2020, 344 patients (median age, 78 years) underwent TAVR. Survival from all-cause mortality was 91.3% at 1 year, 75.1% at 3 years, and 61.7% at 5 years. Cumulative freedom from SVD was 98.2% at 1 year, 96.5% at 3 years, and 93.7% at 5 years. All 13 patients with SVD met hemodynamic criteria, and 1 required intervention. Median time to hemodynamic SVD was 1.04 years. Independent risk factors for SVD included age (hazard ratio [HR] = 0.92, 95% confidence interval [CI]: 0.86 to 0.99) and valve size (HR = 0.19, 95% CI: 0.04 to 0.89).

SVD was evident at a low but detectable rate at 5-year follow-up. Further understanding of TAVR biomechanics as well as continued longer-term follow-up will be essential for informing patient-specific risk of SVD.

This subgroup analysis aimed to evaluate the effect of comorbidities on infrapopliteal angioplasty outcomes in patients with chronic limb-threatening ischemia (CLTI).

This was an observational study evaluating eligible CLTI patients aged >18 years who underwent infrapopliteal angioplasty between April 2014 and May 2017 at a tertiary care center. Subgroup analyses were based on (1) baseline glycated hemoglobin (HbA1c ≤6.5% vs >6.5%), (2) presence/absence of chronic kidney disease (CKD), and (3) control of lipid parameters.

A total of 231 patients with 332 infrapopliteal vessels were treated. While diabetes was prevalent in all participants, hypertension, coronary artery disease, and CKD were reported in 76.6%, 46.3%, and 25.5% of patients at baseline, respectively. The overall technical success rate was 84.4%, and the patency rate at 6 months was 82.04%. Patency at 6 months, wound healing, in-line flow, and complete plantar arch formation were numerically higher in patients with HbA1c ≤6.5% versus >6.5%, but all comparisons were nonsignificant. According to multivariable analysis, the odds of wounds not healing was 2.38 times higher (odds ratio [OR] = 2.4, 95% confidence interval [CI]: 1.2 to 4.5) and developing plantar arch was 5.88 times higher (OR = 5.9, 95% CI: 1.3 to 25) among patients with CKD compared with patients without CKD.

The 6-month outcomes of infrapopliteal angioplasty may be better in patients with controlled versus uncontrolled glycemic levels. Control of lipid parameters may not have a significant influence on outcomes, especially in patients on statin therapy. The short-term outcomes may be similar in patients with and without CKD.

Monitored anesthesia care (MAC) has been increasingly used in lieu of general anesthesia (GA) for transcatheter aortic valve replacement (TAVR). We sought to compare outcomes and in-hospital costs between MAC and GA for TAVR at a Veterans Affairs Medical Center.

A single-center retrospective review was performed of 349 patients who underwent transfemoral TAVR (MAC, n = 244 vs GA, n = 105) from January 2014 to December 2019. Baseline patient characteristics, operating room (OR) time, intensive care unit (ICU) length of stay (LOS), and cost, total LOS, hospital cost, total cost, and complication rates were collected. Propensity matching was performed and resulted in 83 matched pairs.

In the unmatched TAVR cohort, MAC TAVR was associated with reduced OR time (146 vs 198 min, P < 0.001), ICU LOS (1.4 vs 1.8 days, P < 0.001), total hospital LOS (3.4 vs 5.4 days, P < 0.001), and lower index total cost ($81,300 vs $85,400, P = 0.010). After propensity matching, MAC TAVR patients had reduced OR time (146 vs 196 min, P < 0.05), ICU LOS (1.2 vs 1.7 days, P = 0.006), total LOS (3.5 vs 5.1 days, P = 0.001), and 180-day mortality (2.4% vs 12%, P < 0.03). There was no difference in total hospitalization cost or total cost.

In propensity-matched groups, TAVR utilizing MAC is associated with improved OR time efficiency, decreased LOS, and a reduction in 180-day mortality but no significant difference in cost.

Expert consensus guidelines recommend surgical ablation (SA) for patients with symptomatic atrial fibrillation (AF), but less than half of patients with AF undergoing cardiac procedures receive concomitant SA. Complete isolation of the left atrial posterior wall (LAPW) has been shown to be the most critical part of the Cox maze procedure. The purpose of this study was to investigate the performance of a novel radiofrequency (RF) bipolar device, EnCompass™ (AtriCure, Inc., Mason, OH, USA), designed to isolate the LAPW in a single application.

Five adult pigs underwent SA in a beating heart model. After a single ablation, the heart was arrested, explanted, and stained with triphenyl-tetrazolium-chloride for histological assessment. Each lesion was sectioned, and the ablation depth, muscle, and fat thickness were determined. The lesion width, energy delivery, and ablation times were compared with those from a reference RF clamp (Synergy™, AtriCure).

Transmurality was documented in 100% of lesions (5 of 5) and cross sections (160 of 160). Electrical isolation was documented in every instance. There was no evidence of clot, charring, or pulmonary vein stenosis. Compared with the reference clamp, the lesions created by the EnCompass™ clamp were 1.5 times wider on average. The average energy delivered was 5 times higher over a duration that was 4.5 times longer due to the increased volume of tissue ablated.

The EnCompass™ clamp reproducibly created transmural isolation of the LAPW with a single application. This may allow for simplification of the SA strategy and increased adoption of AF treatment during concomitant surgery.

The need for concomitant tricuspid surgery during mitral valve surgery is associated with higher operative risk. We hypothesized that concomitant tricuspid surgery through a minimally invasive thoracotomy (MICS) is associated with noninferior risk compared with a sternotomy.

All patients undergoing mitral valve surgery at a single institution (2010 to 2020) were evaluated. After excluding endocarditis, emergent operations, and concomitant aortic valve or coronary artery bypass grafting procedures, patients were stratified by MICS versus sternotomy. Multivariable logistic regression assessed the risk-adjusted association between concomitant tricuspid valve procedure and Society of Thoracic Surgeons major morbidity or mortality. An interaction term evaluated the impact of approach on concomitant tricuspid surgery.

A total of 772 patients underwent mitral valve surgery, including 138 (17.9%) with concomitant tricuspid valve operation. Of the total cohort, 243 patients (31.5%) underwent the MICS approach. Concomitant tricuspid operation was performed in 104 sternotomy patients (19.7%) compared with 34 MICS patients (14.0%, P = 0.056). After risk adjustment, patients who underwent concomitant tricuspid valve surgery via sternotomy had nearly 2 times greater odds of morbidity and mortality relative to those undergoing isolated mitral surgery via sternotomy (adjOR = 1.86, P = 0.049), while patients who underwent concomitant tricuspid surgery via the MICS approach had no increased risk of the composite outcome (adjOR = 0.66, P = 0.543), relative to isolated mitral surgery via MICS approach.

Concomitant tricuspid surgery at the time of mitral valve surgery carries additional risk in a broad patient population. A minimally invasive approach appears to be safe for selected patients requiring concomitant tricuspid valve surgery.

The aim of this study was to evaluate the anatomic topography of the circumflex artery (Cx) and left atrial appendage (LAA) and to determine the safety zones for epicardial LAA closure and LAA occlusion procedures.

The left coronary artery was segmented and visualized from 116 computed tomography angiography scans. Four points were located on the Cx portion periappendicularly, starting from the entry point. The landing zone plane was defined as parallel to the LAA orifice at the level of the beginning of the periappendicular course of the Cx, and the plane of the neck bend was located at the end of the LAA neck. A distance smaller than 2 mm was considered a dangerous distance.

The distance between the Cx and the LAA landing zone was 4.3 ± 2 mm. The distance between the Cx and the LAA neck bend was 5.1 ± 2.2 mm. The distance between the Cx and the LAA bottom surface was 5.8 ± 2.9 mm. In 38.8% of patients, at least 1 distance between Cx and LAA was smaller than 2 mm in at least 1 dimension. These distances occurred in 30.2% of the LAA landing zone dimensions, 19.8% of LAA neck bend dimensions, and 11.2% of the LAA bottom surface distances.

The study showed that most dangerous distances (30.2%) occurred in the LAA landing zone dimension. The data showed that landing zones more distal from the orifice of the LAA are safer in terms of Cx damage. Therefore, LAA closure should always be performed with caution, to avoid iatrogenic complications.

Virtual reality can be applied preoperatively by surgeons to gain precise insights into a patient’s anatomy for planning minimally invasive coronary artery bypass grafting (CABG) with in situ arterial grafts. This study aimed to examine virtual reality simulation for minimally invasive CABG with in situ arterial grafts.

Preoperative stereolithographic files in 35 in situ arterial grafts were converted using 320-slice computed tomography and workstation. The accurate length and direction of each graft were confirmed through virtual reality glasses. The simulation of graft designs was performed by using an immersive virtual reality platform.

The mean harvested lengths of in situ left internal thoracic artery (n = 17), right internal thoracic artery (n = 12), and gastroepiploic artery (n = 6) grafts predicted by virtual reality simulation were 21.4 ± 3.4 cm, 21.2 ± 3.6 cm, and 22.8 ± 4.8 cm. The required lengths of these grafts predicted by virtual reality simulation were 15.8 ± 2.3 cm, 16.4 ± 2.1 cm, and 14.5 ± 4.4 cm. Minimally invasive CABG using virtual reality simulation was completed in 17 patients, of whom 16 patients underwent aortic no-touch total arterial CABG. The surgical strategy was adjusted in 11.8% of the cases due to the 3-dimensional virtual reality–based anatomy evaluation. The early mortality and morbidity were 0%, and the patency of the graft was 100%. The median time to return to full physical activity was 7.1 days.

This study demonstrated the successful development and clinical application of the first dedicated virtual reality platform for planning aortic no-touch total arterial minimally invasive CABG. Virtual reality simulation can allow the accurate preoperative understanding of anatomy and appropriate planning of the graft design with acceptable postoperative outcomes.