Minimally invasive surgical aortic valve replacement: The RALT approach

Omniparticle Contrast Agent for Multimodal Imaging: Synthesis and Characterization in an Animal Model

PURPOSE

Individual imaging modalities have certain advantages, but each suffers from drawbacks that other modalities may overcome. The goal of this study was to create a novel contrast agent suitable for various imaging modalities that after a single administration can bridge and strengthen the collaboration between the research fields as well as enrich the information obtained from any one modality.

PROCEDURES

The contrast agent platform is based on dextran-coated iron oxide nanoparticles (for MRI and MPI) and synthesized using a modified co-precipitation method, followed by a series of conjugation steps with a fluorophore (for fluorescence and photoacoustic imaging), thyroxine (for CT imaging), and chelators for radioisotope labeling (for PET imaging). The fully conjugated agent was then tested in vitro in cell uptake, viability, and phantom studies and in vivo in a model of intraductal injection and in a tumor model.

RESULTS

The agent was synthesized, characterized, and tested in vitro where it showed the ability to produce a signal on MRI/MPI/FL/PA/CT and PET images. Studies in cells showed the expected concentration-dependent uptake of the agent without noticeable toxicity. In vivo studies demonstrated localization of the agent to the ductal tree in mice after intraductal injection with different degrees of resolution, with CT being the best for this particular application. In a model of injected labeled tumor cells, the agent produced a signal with all modalities and showed persistence in tumor cells confirmed by histology.

CONCLUSIONS

A fully functional omniparticle contrast agent was synthesized and tested in vitro and in vivo in two animal models. Results shown here point to the generation of a potent signal in all modalities tested without detrimental toxicity. Future use of this agent includes its exploration in various models of human disease including image-guided diagnostic and therapeutic applications.

Totally endoscopic aortic valve replacement: Techniques and early results

Objective

To demonstrate the technical details of total endoscopic aortic valve replacement using a standard prosthesis, compare the clinical effect and safety of endoscopic aortic valve replacement and traditional aortic valve replacement.

Methods

From 2020 to 2021, 60 consecutive patients underwent elective isolated aortic valve replacement (AVR). They were divided into two groups: the total endoscopic AVR group (TE-AVR group, 29 patients, nine women, aged 51.65 ± 11.79 years), and the traditional full-sternotomy group (AVR group, 31 patients, 13 women, aged 54.23 ± 12.06 years). Three working ports were adopted in the TE-AVR procedure.

Results

No patient died in either group. The cardiopulmonary bypass (CPB) time and aortic cross-clamp (ACC) time in the TE-AVR group were longer than those in the AVR group (CPB time: 177.6 ± 43.2 vs. 112.1 ± 18.1 min, p < 0.001; ACC time: 118.3 ± 29.7 vs. 67.0 ± 13.2 min, p < 0.001). However, the mechanical ventilation duration (14.2 ± 9.3 vs. 24.0 ± 18.9 h, p = 0.015) and postoperative hospital stay (6.0 ± 1.7 vs. 8.0 ± 4.5 days, p = 0.025) were shorter in patients of TE-AVR group than those of AVR group. Although the ICU stay (55.1 ± 26.9 vs. 61.5 ± 44.8 h, p = 0.509) and post-operative chest drainage of the first 24 h (229.8 ± 125.0 vs. 273.2 ± 103.2 ml, p = 0.146) revealed no statistical difference, there was a decreasing trend in the TE-AVR group. Among the patients of the TE-AVR group, two patients were converted to thoracotomy because of mild to moderate paravalvular leakage identified by intraoperative transesophageal echocardiography.

Conclusion

Total endoscopic aortic valve replacement is safe and feasible, with less trauma and quicker recovery.

Sternal-sparing aortic valve replacement with sutureless valve in bicuspid valve

Over the last decade, sutureless valves (Perceval, LivaNova PLC) were brought to the market as an alternative to stented valves for patients requiring surgical aortic valve replacement (SAVR). However, Perceval demands special steps for implantation, among which we can mention specific training for the surgical team members. Sternal-sparing cardiac procedures are conceived to limit surgical trauma, but the technical requirements and preoperative planning are more challenging than those for conventional sternotomy. SAVR is frequently carried out through an upper hemisternotomy, but the right anterior thoracotomy (RAT) represents an even less traumatic, technical advancement. In the context of SAVR with RAT, Perceval has been considered the "perfect marriage." In patients with bicuspid aortic valve (BAV), some surgeons initially avoided the Perceval valve but, with growing experience, the prosthesis has been used for a wide variety of indications. According to an international consensus statement recently published, there are 3 BAV types: the fused BAV, the 2-sinus BAV and the partial-fusion BAV, each with specific phenotypes. The 2-sinus BAV has 2 cusps, roughly equal in size and shape, each cusp occupying 180° of the annular circumference, with only 2 aortic sinuses, resulting in a 2-sinus/2-cusp valve without raphe and with 180° commissural angles. Since the elliptic aortic annulus in BAV patients poses a challenge for sutureless valves and the RAT approach has been increasingly adopted for minimally invasive SAVR, our description of the surgical technique focuses on the specific procedural details in the scenario of 2-sinus BAV laterolateral phenotype.

At the Crossroads of Minimally Invasive Mitral Valve Surgery—Benching Single Hospital Experience to a National Registry: A Plea for Risk Management Technology

Almost 30 years after the first endoscopic mitral valve repair, Minimally Invasive Mitral Valve Surgery (MIMVS) has become the standard at many institutions due to optimal clinical results and fast recovery. The question that arises is can already good results be further improved by an Institutional Risk Management Performance (IRMP) system in decreasing risks in minimally invasive mitral valve surgery (MIMVS)? As of yet, there are no reports on IRMP and learning systems in the literature. (2) Methods: We described and appraised our five-year single institutional experience with MIMVS in isolated valve surgery included in the Netherlands Heart Registry (NHR) and investigated root causes of high-impact complications. (3) Results: The 120-day and 12-month mortality were 1.1% and 1.9%, respectively, compared to the average of 4.3% and 5.3% reported in the NHR. The regurgitation rate was 1.4% compared to 5.2% nationwide. The few high-impact complications appeared not to be preventable. (4) Discussion: In MIMVS, freedom from major and minor complications is a strong indicator of an effective IRMP but remains concealed from physicians and patients, despite its relevance to shared decision making. Innovation adds to the complexity of MIMVS and challenges surgical competence. An IRMP system may detect and control new risks earlier. (5) Conclusion: An IRMP system contributes to an effective reduction of risks, pain and discomfort; provides relevant input for shared decision making; and warrants the safe introduction of new technology. Crossroads conclusions: investment in machine learning and AI for an effective IRMP system is recommended and the roles for commanding and operating surgeons should be considered.

Eligibility for minithoracotomy aortic valve replacement: from Van Praet classification to complex scanner measurements

Van Praet proposed a classification to predict the ease of minithoracotomy aortic valve replacement (MT-AVR) based on the position of the aorta in the thorax. We have evaluated the relevance of complex computed tomography (CT) scan measurements to predict the ease of performing a MT-AVR. The first 57 patients who underwent MT-AVR from February 2018 to June 2020 were selected prior to surgery using Van Praet's IA and IB classes. We made additional measurements on aorta position related to the chest and the incision on the preoperative CT scan. The main objective was to correlate complex CT measurements with different operating durations. Van Praet criteria were significantly related to the distance from the center of the aorta to the midline (p value < 0.001), the distance from the center of the aortic ring to the midline (p value = 0.013) and aorto-sternal angle (p < 0.001). We did not find a correlation between CT criteria and the different surgical steps durations in patients belonging to Van Praet classes IA and IB. Our cohort of Van Praet class Ia and Ib patients were able to benefit from a MT-AVR without the need for conversion. Complex CT measurements do not provide additional information to predict surgical difficulties. This classification appears to be sufficient to determine a patient's eligibility for MT-AVR, even for a surgeon experienced in sternotomy in his first MT-AVR.

90-Day Patient-Centered Outcomes after Totally Endoscopic Cardiac Surgery: A Prospective Cohort Study

Over the past years, minimally invasive procedures have been developed to reduce surgical trauma after cardiac surgery. The value of patient-centered outcomes, including the quality of recovery after hospital discharge, is increasingly recognized. Identifying meaningful changes in postoperative function that might have a negative impact on patients without noticeable complications can provide a more comprehensive understanding of the impact on the patient’s life. In total, 209 patients were included in this trial. Of these, 193 patients underwent totally endoscopic cardiac surgery, 8 underwent cardiac surgery through a sternotomy, and 8 underwent transcatheter aortic valve implantation. Patients who previously underwent cardiac surgery were excluded. Quality of life was determined through the Short Form 36 and European Quality of Life-5 Dimensions questionnaires before the surgery and 14, 30, and 90 days afterward. In patients who underwent totally endoscopic cardiac surgery, the quality of life improved over the three time periods. The different domains of the questionnaire evolved in a positive manner. However, 14 days postoperatively, a decline in quality of life was noted, followed by a return to baseline at 30 days and an increase at 90 days. In conclusion, totally endoscopic cardiac surgery improves the quality of life 90 days after surgery.

Aortic valve replacement via right anterolateral minithoracotomy: preventing adverse events during the initial learning curve

BACKGROUND

Despite excellent outcomes and reduced invasiveness, the right anterolateral thoracotomy approach for aortic valve replacement (RALT-AVR) has not been broadly adopted. This study provides results regarding the initial experience and learning curve of a single surgeon performing this procedure.

METHODS

Periprocedural details and postoperative outcomes of the first 100 consecutive patients who underwent RALT-AVR at our institution were retrospectively analyzed. We conducted a cumulative sum analysis of surgical failure, defined as occurrence of 30-day-mortality, surgical revision for bleeding, conversion to sternotomy, 3^rd degree heart block, paravalvular leakage, postoperative stroke or mean transvalvular gradient >20 mmHg.

RESULTS

The cohort was of low surgical risk (mean EuroSCORE II 1.31%±0.85, mean STS PROM 1.45%±0.97), 58% were males. Median cross-clamp time was 67.5 (57.8-76) min, median CPB time 105 (91.8-119) min, and median operation time 164.5 (144.5-183.2) min. There were no conversions to full sternotomy, 4 cases of revision for bleeding and 2 pacemaker implantations for 3^rd degree heart block. Prosthesis function was good (median ΔPmean 10.9 [7.4-13.6] mmHg). Thirty-day-mortality was 0%. The log-likelihood graph never crossed the upper boundary, and after a steady decrease, crossed the lower boundary at 93 patients.

CONCLUSIONS

RALT-AVR can be performed with acceptable procedural times and satisfactory outcomes. For a well-trained surgeon, adapting to this new procedure does not expose patients to an increased risk, when patient selection and procedural planning are applied appropriately. Cumulative sum failure analysis is an appropriate tool to monitor the transition from standard AVR to the technically more demanding RALT-AVR.

Updates on the Latest Surgical Approach of the Aortic Stenosis

Over the last twenty years, we marked significant progresses in the field of tissue engineering and the development of new aortic valve structural and delivery systems. These continuous iterations on the field, have completely changed the surgical indications and approaches for AVR. Nowadays, therapeutic decisions are endorsed by international guidelines; however, new technical advances need a new integrated approach. The clinical scenarios issued from the interaction between the Guidelines and the newest approaches and technologies are regularly on debate by the Heart Team. We will present some of our most encountered situations and the pattern of our therapeutic decisions. To easily navigate through Guidelines and clinical scenarios, we reported in this review a simplified and easy to use Clinical decision-making algorithm that may be a valuable tool in our daily practice.

Lifetime management of aortic valve disease: Aligning surgical and transcatheter armamentarium to set the tone for the present and the future

Transcatheter aortic valve replacement (TAVR) has already received the green light for high-, intermediate- and low-risk profiles and is an alternative for all patients regardless of age. It is clear that there has been a push towards the use of TAVR in younger and younger patients (<65 years), which has never been formally tested in randomized controlled trials but seems inevitable as TAVR technology makes steady progress. Lifetime management as a concept will set the tone in the field of the structural heart. Some subjects in this scenario arise, including the importance of optimized prosthetic hemodynamics for lifetime care; surgical procedures in the aortic root; management of structural valve degeneration with valve-in-valve procedures (TAVR-in-surgical aortic valve replacement [SAVR] and TAVR-in-TAVR) and redo SAVR; commissural alignment and cusp overlap for TAVR; the rise in the number of surgical procedures for TAVR explantation; and the renewed interest in the Ross procedure. This article reviews all these issues which will become commonplace during heart team meetings and preoperative conversations with patients in the coming years.

Step-by-Step Minimally Invasive Aortic Valve Replacement: the RAT Approach

In the growing era of transcatheter aortic valve implantation, it is crucial to develop minimally invasive surgical techniques. These methods enable easier recovery from surgical trauma, especially in elderly and frail patients. Minimally invasive aortic valve replacement (MIAVR) is frequently performed via upper hemisternotomy. We describe MIAVR via right anterior thoracotomy, which is associated with less trauma, rapid mobilization, lower blood transfusion rates, and lower risk of postoperative wound infections. As minimally invasive procedures tend to take longer operative times, we suggest using rapid-deployment valve prostheses to overcome this limitation. This description focuses on the technical aspects and preoperative assessment.

SLL-PEEP Ventilation to Improve Exposure in Minimally Invasive Right Anterolateral Minithoracotomy Aortic Valve Replacement

OBJECTIVE

An accepted landmark to assess feasibility of surgical aortic valve replacement (SAVR) via right anterolateral minithoracotomy (RALT) is the aortic-midpoint to right-sternal-edge distance. We aimed to evaluate single left lung positive-end-expiratory-pressure (SLL-PEEP) ventilation inducing an intraoperative rightward shift of the ascending aorta to improve exposure.

METHODS

Nineteen patients with aortic stenosis undergoing SAVR via RALT were prospectively analyzed. SLL-PEEP ventilation (20,395 cmH₂O) via a double-lumen endotracheal tube was applied immediately before transthoracic aortic cross-clamping, thereby inducing rightward shift of the ascending aorta to enhance exposure. We analyzed preoperative computed tomography (CT) reconstructions and intraoperative video recordings. Primary endpoint was extent of rightward shift induced by SLL-PEEP ventilation; secondary endpoints were procedure times and safety events.

RESULTS

Mean age was 61 ± 14.8 years and 6 of 19 (31.6%) were female. Mean EuroSCORE II was 0.81% ± 0.04%, STS-PROM was 1.13% ± 0.74%, and mean aortic rightward shift induced by SLL-PEEP ventilation was 10.32 ± 4.14 mm (4 to 17 mm; P = 0.003). Median shift in the group considered suitable for the RALT approach by preoperative CT-scan evaluation was 14.2 mm (IQR 11) and in the less suitable group 11.5 mm (IQR 5). Mean procedure time was 167 ± 28.9 min, CPB time was 105.7 ± 18.4 min, and cross-clamp time was 64.5 ± 13 min. Fifteen patients (79%) received SAVR via RALT with implantation of a bioprosthesis, whereas a rapid-deployment-prosthesis was used in 4 patients (21%). Ten of 19 (53%) patients who were classified as less suitable preoperatively received SAVR via RALT after SLL-PEEP ventilation. No strokes were observed.

CONCLUSIONS

The SLL-PEEP ventilation maneuver during SAVR via RALT significantly enhances aortic exposure. There were no safety events associated with this maneuver and we were able to demonstrate significant rightward aortic shift in every single patient.

Minithoracotomy versus full sternotomy for isolated aortic valve replacement: Propensity matched data from two centers

BACKGROUND

Minimally invasive approaches to isolated aortic valve replacement (AVR) continue to gain popularity. This study compares outcomes of AVR through right anterolateral thoracotomy (RALT) to those of AVR through full median sternotomy (MS).

METHODS

Outcomes of two propensity-matched groups of 85 each, out of 250 patients that underwent isolated AVR through RALT or MS at our two institutions, were compared in a retrospective study.

RESULTS

Propensity score matching resulted in 85 matched pairs with balanced preoperative characteristics. Procedure times were significantly shorter in the RALT group (median difference: 13 min [-25 to -0.5]; p = .039), cardiopulmonary bypass times were longer (median difference: 17 min [10-23.5]; p = < .001) and ventilation times shorter (median difference: 259 min [-390 to -122.5]; p = < .001). There was no significant difference in aortic cross-clamp times (median difference: 1.5 min [-3.5 to 6.5]; p = .573). The RALT group had lower rates of perioperative platelet transfusions (odds ratio [OR] = 0.00 [0.00-0.59]; p = .0078) and postoperative pneumonia (OR = 0.10 [0.00-0.70]; p = .012), as well as shorter hospitalization times (median difference: 2.5 days [-4.5 to -1]; p = .005). There were no significant differences regarding paravalvular leakage (p = .25), postoperative stroke (p = 1), postoperative atrial fibrillation (p = .12) or 1-year-mortality (p = 1).

CONCLUSIONS

This study found RALT to be an equally safe approach to surgical AVR as MS. Furthermore, RALT showed advantages regarding important aspects of postoperative recovery, especially concerning pulmonary function.