Minimally Invasive Aortic Valve Replacement

Innovations in Aortic Valve Replacement: A Comprehensive Overview of the Intuity Rapid Deployment Valve

Rapid deployment/sutureless (RDS) valves have recently emerged as an innovative surgical solution, providing an alternative to traditional methods of surgical aortic valve replacement (SAVR) by eliminating the need for suture placement and tying. This innovation leads to a reduction in aortic crossclamp and cardiopulmonary bypass times, enhancing the efficiency of the procedure. Among the 2 available RDS valves, the Edwards Intuity valve in particular has been demonstrated to be a particularly promising substitute in the field of SAVR. The Intuity valve distinguishes itself from other RDS and conventional valves by yielding superior outcomes, such as a significant reduction in mortality, increase in the longevity of the valve, and a marked decrease in both mean and peak transvalvular pressure gradients. These benefits collectively contribute to its appeal as a favorable new solution. However, further investigation is needed to conclusively determine the long-term outcomes and safety of RDS valves. Nevertheless, the utilization of the Intuity valve presents an exciting solution to the existing limitations of conventional and minimally invasive SAVR, especially for patients afflicted with severe aortic stenosis.

Right Anterior versus Right Transaxillary Access for Minimally Invasive Aortic Valve Replacement: A Propensity Matched Competitive Analysis

(1) Background: Right anterior thoracotomy (RAT-AVR) has been the sole established sternum-sparing technique for minimally invasive aortic valve replacement (MICS-AVR) thus far. Nevertheless, transaxillary access, known as Minimally Invasive Cardiac LATeral Surgery (MICLATS-AVR), represents the latest and innovative advancement in sternum-sparing MICS-AVR access routes. In this study, procedural and clinical outcomes of a substantial transaxillary MICS-AVR cohort are compared to those of a RAT-AVR control group; (2) Patients and Methods: This retrospective study included 918 consecutive patients who underwent MICS-AVR at our facility between 2014 and 2022. This cohort was divided into two surgical access-related groups: RAT-AVR (n = 492) and MICLATS-AVR (n = 426). Procedural data, operative morbidity, and mortality were compared between groups. Further analysis was performed using propensity score matching; (3) Results: After matching, 359 pairs of patients were included and analyzed. There were no notable differences observed between the two groups regarding major adverse cardio-cerebral events. Despite longer cardiopulmonary bypass time in the MICLATS-AVR group (63.1 ± 20.4 min vs. 66.4 ± 18.2 min; p ≤ 0.001) the skin-to-skin time (129.4 ± 35.9 min. vs. 126.5 ± 29.8 min.; p = 0.790) and the aortic cross-clamp time was comparable between both groups (41.9 ± 13.3 min. vs. 43.5 ± 14.4 min.; p = 0.182). The overall hospital stay was significantly shorter in the MICLATS-AVR cohort (9.7 ± 5.2 days vs. 9.2 ± 4.5 days; p = 0.01). Both groups were comparable in terms of postoperative morbidities. However, significantly lower rates of postoperative impaired wound healing were noted in the MICLATS-AVR group (11.7% vs. 3.9%, p < 0.001); (4) Conclusions: In comparing MICLATS-AVR and RAT-AVR, our study found MICLATS-AVR to be at least as safe and time-efficient as RAT-AVR, with no significant differences in MACCE. MICLATS-AVR showed a shorter hospital stay and lower postoperative wound issues, indicating its feasibility and safety as an alternative. Notably, MICLATS-AVR is sternum- and bone-sparing, preserving the right mammary artery, and facilitates combined procedures like multiple valve surgeries.

Novel concept of less invasive concomitant surgical aortic valve replacement and coronary artery bypass grafting avoiding full median sternotomy

In the last decades, minimally invasive procedures have been developed in the therapy of aortic valve disorders. Recently, a novel concept of minimally invasive coronary revascularization in multivessel disease via left anterior mini-thoracotomy demonstrated promising results. Full median sternotomy, as a very invasive procedure, is the standard approach in concomitant surgical aortic valve replacement (sAVR) and coronary bypass grafting (CABG). The aim of our study was to show that the combination of minimal invasive aortic valve replacement via upper mini-sternotomy and coronary artery bypass grafting via left anterior mini-thoracotomy is feasible to avoid full median sternotomy. From 07/2022 to 09/2022, concomitant sAVR via upper partial sternotomy and CABG via left anterior mini-thoractomy on cardiopulmonary bypass and cardioplegic arrest was successfully performed in six consecutive patients (6 males; 69.8 ± 7.4 [60-79] years). All patients had severe aortic stenosis (MPG 45.5 ± 17.3 mmHg) and a significant coronary artery disease (three-vessel: 33%, two-vessel: 33%, one-vessel: 33%) with indication to cardiac surgery. Mean EuroScore2 was 3.2. All patients underwent successful less invasive concomitant biological sAVR and CABG. 67% of patients received a 25 mm, 33% received a 23 mm biological aortic valve replacement (Edwards Lifesciences Perimount). A total of 11 distal anastomoses (1.8 ± 1.0 [1-3] per patient) were performed by using left internal artery mammary (50%), radial artery (17%) and saphenous venous graft (67%) for grafting the left anterior descending (83%), circumflex (67%) and right (33%) coronary artery. Hospital mortality was 0%, stroke rate was 0%, myocardial infarction was 0% and repeat revascularization rate was 0%, ICU stay was 1 day in 83% of all patients and 50% left hospital within 8 days after surgery. Less invasive concomitant surgical aortic valve replacement and coronary artery bypass grafting using upper mini-sternotomy and left anterior mini-thoracotomy is feasible without compromises in surgical principles and complete coronary revascularization while maintaining thoracic stability by avoiding full median sternotomy.

Safety and Efficacy of the Transaxillary Access for Minimally Invasive Aortic Valve Surgery

Background and Objectives: Transaxillary access is one of the latest innovations for minimally invasive aortic valve replacement (MICS-AVR). This study compares clinical performance in a large transaxillary MICS-AVR group to a propensity-matched sternotomy control group. Materials and Methods: This study enrolled 908 patients undergoing isolated AVR with a mean age of 69.4 ± 18.0 years, logistic EuroSCORE of 4.0 ± 3.9%, and body mass index (BMI) of 27.3 ± 6.1 kg/m2. The treatment group comprised 454 consecutive transaxillary MICS-AVR patients. The control group was 1:1 propensity-matched out of 3115 consecutive sternotomy aortic valve surgeries. Endocarditis, redo, and combined procedures were excluded. The multivariate matching model included age, left ventricular ejection fraction, logistic EuroSCORE, pulmonary hypertension, coronary artery disease, chronic lung disease, and BMI. Results: Propensity-matching was successful with subsequent comparable clinical baselines in both groups. MICS-AVR had longer skin-to-skin time (120.0 ± 31.5 min vs. 114.2 ± 28.7 min; p < 0.001) and more frequent bleeding requiring chest reopening (5.0% vs. 2.4%; p < 0.010), but significantly less packed red blood cell transfusions (0.57 ± 1.6 vs. 0.82 ± 1.6; p = 0.040). In addition, MICS-AVR patients had fewer access site wound abnormalities (1.5% vs. 3.7%; p = 0.038), shorter intensive care unit stays (p < 0.001), shorter ventilation times (p < 0.001), and shorter hospital stays (7.0 ± 5.1 days vs. 11.1 ± 6.5; p < 0.001). No significant differences were observed in stroke > Rankin 2 (0.9% vs. 1.1%; p = 0.791), renal replacement therapy (1.5% vs. 2.4%; p = 0.4762), and hospital mortality (0.9% vs. 1.5%; p = 0.546). Conclusions: Transaxillary MICS-AVR is at least as safe as AVR by sternotomy and can be performed in the same time frame. Its advantages are fewer transfusions and quicker postoperative recovery with a significantly shorter hospital stay. The cosmetic result and unrestricted physical abilities due to the untouched sternum and ribs are unique advantages of transaxillary access.

Upper Hemi-Sternotomy Provides Benefit for Patients with Isolated or Combined Mitral Valve Surgery

Background and objectives: Certain clinical and anatomical conditions are absolute or relative contraindications for safe mitral valve surgery via the right mini-thoracotomy access. It is uncertain whether patients with these contraindications may benefit from the less invasive approach via upper hemi-sternotomy compared to standard full sternotomy. Materials and methods: Out of 2052 mitral valve surgery patients, operated from 6/04 through 2/19, 1535 were excluded due to the different criteria for eligibility to both approaches. Out of these, 350 received full sternotomy and 167 upper hemi-sternotomy. After propensity score matching, 164 pairs were analyzed for operative variables, postoperative complications and 30-day and one-year survival. Results: Upper hemi-sternotomy was associated with a survival benefit of 30 days (99.4% vs. 82.1%; p < 0.001) and one-year (93.9% vs. 79.9% p < 0.001, HR 0.26, 95% CI 0.14–0.49). Cardiopulmonary bypass and aortic cross-clamp times were comparable in both groups. Upper hemi-sternotomy resulted in less low cardiac output syndrome (18.9% vs. 31.1%; p = 0.011); ventilation time (8 vs. 13 h; p < 0.001), length of intensive care stay (1 vs. 2 days; p < 0.001) and total hospital stay (8 vs. 9 days; p < 0.001) were shorter in the upper hemi-sternotomy group. Conclusion: In patients undergoing mitral valve surgery, upper hemi-sternotomy is associated with short- and mid-term survival benefits as well as lower postoperative complication rates compared to full sternotomy. Hence, the less invasive upper hemi-sternotomy can be a valid approach in patients with contraindications for right mini-thoracotomy.

Post-operative Quality of Life after Full-sternotomy and Mini-sternotomy Aortic Valve Replacement

BACKGROUND

Few longitudinal data exist comparing quality of life (QoL) after full sternotomy aortic valve replacement (fsAVR) vs mini-sternotomy AVR (msAVR) METHODS: 1844 consecutive AVR prospectively enrolled in a European multicentre Registry were dichotomized according to surgical access. A non-parsimonious propensity-score matching selected 187 pairs of fsAVR or msAVR with comparable baseline characteristics. Hospital outcome was compared in the two groups. QoL was assessed with Short Form-36, further detailed in its Physical Component Score (PCS) and Mental Component Score (MCS). QoL was investigated at hospital admission, discharge, 1 month, 6 months and 1 year thereafter.

RESULTS

There were 1654 fsAVR and 190 msAVR in the entire population. fsAVR showed a worse preoperative risk-profile, a longer ICU length of stay (59.7 hours vs 38.8, p=0.002), and a higher life-threatening/disabling bleeding (4.1% vs. 0%; p=0.011); msAVR reported a higher early reintervention for failed index intervention (2.1% vs. 0.5%, p=0.001). QoL showed better PCS and MCS at 1 month after fsAVR, but no temporal-trend differences (PCS group-time p=0.202; MCS group-time p=0.141). Propensity-matched pairs showed comparable baseline characteristics and hospital outcome (p=NS for all endpoints), and comparable improvements of PCS and MCS over time, but no between-group differences over time (PCS group-time p=0.834; MCS group-time p=0.737).

CONCLUSIONS

Patients with similar baseline profiles report comparable hospital outcome and comparable improvement of physical and mental health, up to 1 year after surgery, with both fsAVR and msAVR. As for QoL, mini-sternotomy does not seem to offer any advantage compared to the traditional approach.

Anesthesia for minimally invasive cardiac surgery

Due to its potential benefits and increased patient satisfaction minimal invasive cardiac surgery (MICS) is rapidly gaining in popularity. These procedures are not without challenges and require careful planning, pre-operative patient assessment and excellent intraoperative communication. Assessment of patient suitability for MICS by a multi-disciplinary team during pre-operative workup is desirable. MICS requires additional skills that many might not consider to be part of the standard cardiac anesthetic toolkit. Anesthetists involved in MICS need not only be highly skilled in performing transesophageal echocardiography (TEE) but need to be proficient in multimodal analgesia, including locoregional or neuroaxial techniques. MICS procedures tend to cause more postoperative pain than standard median sternotomies do, and patients need analgesic management more in keeping with thoracic operations. Ultrasound guided peripheral regional anesthesia techniques like serratus anterior block can offer an advantage over neuroaxial techniques in patients on anti-platelet therapy or anticoagulation with low molecular weight or unfractionated heparin The article reviews the salient points pertaining to pre-operative assessment and suitability, intraoperative process and postoperative management of minimally invasive cardiac procedures in the operating theatre as well as the catheterization lab. Special emphasis is given to anesthetic management and analgesia techniques.

Clinical study of minimally invasive aortic valve replacement through a right parasternal second intercostal transverse incision: The first Chinese experience

BACKGROUND

There is an increasing demand for minimally invasive aortic valve replacement. This study aimed to investigate the safety and feasibility of minimally invasive aortic valve replacement through a right parasternal second intercostal transverse incision.

METHODS

This was a retrospective study, and we collected information from 111 patients who underwent isolated aortic valve replacement surgery performed by the same surgeon from January 2018 to December 2019. According to the operative approach, the patients were divided into a sternotomy aortic valve replacement (SAVR) group (n = 62) and a minimally invasive aortic valve replacement (Mini-AVR) group (n = 49). We compared the intraoperative and postoperative data between the two groups.

RESULT

There was no difference in preoperative data between the Mini-AVR and SAVR. The postoperative ventilator-assisted time, CSICU time and postoperative hospital stay of the Mini-AVR were shorter than those of the SAVR [(15.45 ± 5.75) VS (18.51 ± 6.71) h; (1.77 ± 0.31) VS (2.04 ± 0.63) d; (8.69 ± 2.75) VS (10.77 ± 2.94) d], and the difference was statistically significant (P < 0.05). Mini-AVR had lower postoperative drainage and blood transfusion rates in the first 24 h than SAVR [(109.86 ± 125.98) VS (508.84 ± 311.70) ml; 22.4% VS 46.8%], and the differences were statistically significant (P < 0.05). The incidence of postoperative AF in the Mini-AVR group was also lower than that in the SAVR group (10.2% VS 30.6%), and the differences were statistically significant (P < 0.05).

CONCLUSION

Mini-AVR has the advantages of less ventilator time, a reduced need for blood transfusion, less AF and a faster recovery. Mini-AVR is a safe and feasible surgical technique that is worthy of clinical application.

Left Anterior Thoracotomy Minimally Invasive Aortic Valve Replacement Following Left Pneumonectomy

We report the case of a 59-year-old man referred for aortic valve replacement for severe, symptomatic aortic insufficiency who underwent a minimally invasive left anterior thoracotomy aortic valve replacement. This approach was facilitated by his history of a left pneumonectomy for lung cancer 7 years prior to presentation, which resulted in a significant left mediastinal shift. The cannulation strategy and exposure were analogous to what would be expected from a standard right anterior thoracotomy minimally invasive aortic valve replacement. The minimally invasive approach allowed for early extubation and mobilization in a patient with moderate baseline pulmonary dysfunction.

Computed Tomography-based evaluation of porcine cardiac dimensions to assist in pre-study planning and optimized model selection for pre-clinical research

The pig (Sus Scrofa Domestica) is an accepted model for preclinical evaluation of prosthetic heart valves and trans-catheter implantation techniques. Understanding porcine cardiac dimensions through three-dimensional computed tomography (CT), increases preclinical study success, leading to higher cost efficiency and to the observance of the obligation to the 3 R principles. Cardiac CT images of twenty-four Swiss large white pigs were segmented; aortic root, mitral valve, pulmonary trunk, tricuspid valve, as well as the aorto-mitral angle and left atrial height were analyzed. Correlation coefficient (r) was calculated in relation to body weight. In Swiss large white pigs, valvular dimensions, length of the pulmonary artery and ascending aorta as well as left atrial height correlate with body weight. Coronary ostia heights and aorto-mitral angle size can be neglected in animal size selection; no changes were found for either of the two parameters with increasing body weight.

Assessment of exercise-induced changes in von Willebrand factor as a marker of severity of aortic stenosis

Background

Loss of high-molecular-weight multimers (HMWMs) of von Willebrand factor (vWF) occurs due to high shear stress in patients with aortic stenosis. As symptoms of aortic stenosis occur during exercise, measurement of vWF during exercise might identify patients with aortic stenosis of clinical importance. The aim of this pilot study is to evaluate whether vWF changes over time as a result of exercise in patients with asymptomatic moderate or severe aortic stenosis.

Methods

Ten subjects were analysed for changes in vWF by measuring HMWMs and closure time with adenosine diphosphate (CT-ADP). All subjects underwent a full stress test on a bicycle ergometer. At rest and at peak exercise, a transthoracic echocardiogram was performed. HMWMs and CT-ADP were assessed at baseline, during and after exercise.

Results

HMWMs and CT-ADP did not change significantly during exercise, p=0.45 and p=0.65, respectively. HMWMs and CT-ADP correlated well, Spearman’s rho −0.621, p<0.001. HMWMs during peak exercise did not correlate with maximal velocity measured, p=0.21. CT-ADP during exercise correlated well with the maximal echocardiographic velocity over the aortic valve (AV), rho 0.82, p=0.04.

Conclusions

In a cohort of 10 patients with moderate or severe aortic stenosis, we observed no significant change in vWF biomarkers during exercise. Peak CT-ADP during exercise showed a good correlation with peak AV velocity measured with echo. Although CT-ADP is an easy test to perform and could be an alternative for peak AV velocity measured during exercise, our results suggest that it can only detect large changes in shear stress.