Novel Techniques and Technologies for Surgical Aortic Valve Replacement: A Large Retrospective Cohort Analysis

Background/Objectives: In an era of growing evidence for transaortic valve implantation (TAVI), our research topic was the evaluation of how surgical aortic valve replacements (SAVRs) are performing in terms of short- and long-term outcomes in different risk categories. Methods: This was a single centre, prospective, and observational cohort study of consecutive patients with aortic valve stenosis, undergoing isolated aortic valve replacement using a biological or mechanical prosthesis, Freestyle™ (Medtronic, Minneapolis, MN, USA) graft, homograft, or Ross procedure. The participant data were collected by review of an internal database. The primary endpoints were all-cause operative mortality (in hospital and at 30 days) and late mortality at the follow-up date. The secondary composite endpoint was the incidence of postoperative complications. Results: 1501 patients underwent SAVR; the mean age was 67 years (SD: 12.6). The in-hospital mortality was 1% (n = 16). At a median follow-up of 60 months, the survival rate was 98.7%. The main predictors for mortality were operative urgency and cardiogenic shock. The overall incidence of PPM was 2.3% (n = 34). Patients who underwent Ross procedure were younger (mean age: 20 years (SD: 1.7)), had a lower incidence of postoperative complications, and were all alive at follow-up. Conclusions: SAVR shows an excellent survival rate and a low rate of postoperative complications despite an increasing surgical risk. Recent advancements in technology, like sutureless/rapid deployment prostheses and minimally invasive techniques, are shown to have favourable effects on outcomes.

Aortic valve replacement through right anterior mini-thoracotomy in patients with chronic severe aortic regurgitation: a retrospective single-center study

BACKGROUND

Aortic valve replacement (AVR) has recently been performed at many centers using a minimally invasive approach to reduce postoperative mortality, morbidity, and pain. Most previous reports on minimally invasive AVR (MiAVR) have mainly focused on aortic stenosis, and those exclusively dealing with aortic regurgitation (AR) are few. The purpose of this study was to investigate early surgical results and review our experience with patients with chronic severe AR who underwent AVR via right anterior mini-thoracotomy (RAT).

METHODS

Data were retrospectively collected in this single-center study. Eight patients who underwent RAT AVR between January 2020 and January 2024 were enrolled. Short-term outcomes, including the length of hospital stay, in-hospital mortality, postoperative complications, and echocardiographic data, were analyzed.

RESULTS

No in-hospital mortalities were observed. Postoperative atrial fibrillation occurred temporarily in three patients (37.5%). However, none required permanent pacemaker implantation or renal replacement therapy. The median values of ventilator time, length of intensive care unit stay, and hospital stay were 17 hours, 34.5 hours, and 9 days, respectively. Preoperative and postoperative measurements of left ventricular ejection fraction were similar. However, the left ventricular end systolic and diastolic diameters significantly decreased postoperatively from 42 mm to 35.5 mm (p=0.018) and 63 mm to 51 mm (p=0.012), respectively.

CONCLUSION

MiAVR via RAT is a safe and reproducible procedure with acceptable morbidity and complication rates in patients with chronic severe AR. Despite some limitations such as a narrow surgical field and demanding learning curve, MiAVR is a competent method for AR.

Different approach, similar outcomes: the impact of surgical access routes in minimally invasive cardiac surgery on enhanced recovery after surgery

Objectives

Enhanced recovery after surgery (ERAS) is a growing phenomenon in all surgical disciplines and aims to achieve a faster functional recovery after major operations. Minimally invasive cardiac surgery (MICS) therefore integrates well into core ERAS values. Surgical access routes in MICS include right anterolateral mini-thoracotomy (MT) as well as partial upper mini-sternotomy (PS). We seek to compare outcomes in these two cohorts, both of which were enrolled in an ERAS scheme.

Methods

358 consecutive patients underwent MICS and perioperative ERAS at our institution between 01/2021 and 03/2023. Patients age >80 years, with BMI > 35 kg/m², LVEF ≤ 35%, endocarditis or stroke with residuum were excluded. Retrospective cohort analysis and statistical testing was performed on the remaining 291 patients. The primary endpoint was successful ERAS, secondary endpoints were the occurrence of major bleeding, ERAS-associated complications (reintubation, return to ICU) as well as access-related complications (wound infection, pleural and pericardial effusions).

Results

170 (59%) patients received MT for mitral and/or tricuspid valve surgery (n = 162), closure of atrial septal defect (n = 4) or resection of left atrial tumor (n = 4). The remaining 121 (41%) patients had PS for aortic valve repair/replacement (n = 83) or aortic root/ascending surgery (n = 22) or both (n = 16). MT patients' median age was 63 years (IQR 56-71) and 65% were male, PS patients' median age was 63 years (IQR 51-69) and 74% were male. 251 (MT 88%, PS 83%, p = 0.73) patients passed through the ERAS program successfully. There were three instances of reintubation (2 MT, 1 PS), and three instances of readmission to ICU (2 MT, 1 PS). Bleeding requiring reexploration occurred six times (3 MT, 3 PS). There was one death (PS), one stroke (MT), and one myocardial infarction requiring revascularization (MT). There were no significant differences in any of the post-operative outcomes recorded, except for the incidence of pericardial effusions (MT 0%, PS 3%, p = 0.03).

Conclusions

Despite different surgical access routes and underlying pathologies, results in both the MT and the PS cohort were generally comparable for the recorded outcomes. ERAS remains safe and feasible in these patient groups.

Minimally invasive approaches versus conventional sternotomy for aortic valve replacement in patients with aortic valve disease: a systematic review and meta-analysis of 17 269 patients

Background

Aortic valve replacement (AVR) is a common procedure for aortic valve pathologies, particularly in the elderly. While traditional open AVR is established, minimally invasive techniques aim to reduce morbidity and enhance treatment outcomes. The authors' meta-analysis compares these approaches with conventional sternotomy, offering insights into short and long-term mortality and postoperative results. This study provides valuable evidence for informed decision-making between conventional and minimally invasive approaches for AVR.

Materials and methods

Till August 2023, PubMed, Embase, and MEDLINE databases were searched for randomized controlled trials (RCT) and propensity score matched (PSM) studies comparing minimally invasive approaches [mini-sternotomy (MS) and right mini-thoracotomy (RMT)] with full sternotomy (FS) for AVR. Various outcomes were analyzed, including mortality rates, bypass and clamp times, length of hospital stay, and complications. Risk ratios (RR) and the weighted mean differences (WMD) with corresponding 95% CIs were calculated using Review Manager.

Results

Forty-eight studies were included having 17 269 patients in total. When compared to FS, there was no statistically significant difference in in-hospital mortality in MS (RR:0.80; 95% CI:0.50-1.27; I2=1%; P=0.42) and RMT (RR:0.70; 95% CI:0.36-1.35; I2=0%; P=0.29). FS was also linked with considerably longer cardiopulmonary bypass duration than MS (MD:8.68; 95% CI:5.81-11.56; I2=92%; P=0.00001). The hospital length of stay was determined to be shorter in MS (MD:-0.58; 95% CI:-1.08 to -0.09; I2=89%; P=0.02) with no statistically significant difference in RMT (MD:-0.67; 95% CI:-1.42 to 0.08; I2=84%; P=0.08) when compared to FS.

Conclusions

While mortality rates were comparable in minimally invasive approaches and FS, analysis shows that MS, due to fewer respiratory and renal insufficiencies, as well as shorter hospital and ICU stay, may be a safer approach than both RMT and FS.

Aortic Valve Replacement: Is Minimally Invasive Really Better? A Contemporary Systematic Review and Meta-Analysis

In recent years, minimally invasive cardiac surgery has increased in prevalence. There has been significant debate regarding the optimal approach to isolated aortic valve replacement between conventional midline sternotomy and minimally invasive approaches. We performed a systematic review of the contemporary literature comparing minimally invasive to full sternotomy aortic valve replacement. PubMed and Embase were systematically searched for articles published from 2010-2021. A total of 1215 studies were screened and 45 studies (148,606 patients total) met the inclusion criteria. This study found rates of in-hospital mortality were higher with full sternotomy than ministernotomy ( P = 0.02). 30-day mortality was higher with full sternotomy compared to right anterior thoracotomy ( P = 0.006). Renal complications were more common with full sternotomy versus ministernotomy ( P < 0.00001) and right anterior thoracotomy ( P < 0.0001). Rates of wound infections were greater with full sternotomy than ministernotomy ( P = 0.02) and right anterior thoracotomy ( P < 0.00001). Intensive care unit length of stay ( P = 0.0001) and hospital length of stay ( P < 0.0001) were shorter with ministernotomy compared to full sternotomy. This review found that minimally invasive approaches to isolated aortic valve replacement result in reduced early mortality and select measures of postoperative morbidity; however, long-term mortality is not significantly different based on surgical approach. An analysis of mortality alone is not sufficient for the selection of the optimal approach to isolated aortic valve replacement. Surgeon experience, individual patient characteristics, and preference require thorough consideration, and additional studies investigating quality of life measures will be imperative in identifying the optimal approach to isolated aortic valve replacement.

Minimally invasive, surgical, and transcatheter aortic valve replacement: A network meta-analysis

BACKGROUND

Transcatheter aortic valve replacement (TAVR) has evolved as an alternative to surgical aortic valve replacement (SAVR). In addition to full-sternotomy (FS), recent reports have shown successful minimally-invasive SAVR approaches, including mini-sternotomy (MS) and mini-thoracotomy (MT). This network-meta-analysis (NMA) seeks to provide an outcomes comparison based on these different modalities (MS, MT, TAVR) compared with FS as a reference arm for the management of aortic valve disease.

METHODS

A comprehensive literature search was performed to identify studies that compared minimally-invasive SAVR (MS/MT) to conventional FS-SAVR, and/or TAVR. Bayesian NMA was performed using the random effects model. Outcomes were pooled as risk ratios (RR) with their 95 % confidence intervals (CIs). Our primary outcomes included 30-day mortality, stroke, acute kidney injury (AKI), major bleeding, new permanent pacemaker (PPM), and paravalvular leak (PVL). We also assessed long-term mortality at the latest follow-up.

RESULTS

A total of 27,117 patients (56 studies) were included; 10,397 patients had FS SAVR, 9523 had MS, 5487 had MT, and 1710 had TAVR. Compared to FS, MS was associated with statistically-significantly lower rates of 30-day mortality (RR, 0.76, 95%CI 0.59-0.98), stroke (RR, 0.84, 95%CI 0.72-0.97), AKI (RR, 0.76, 95%CI 0.61-0.94), and long-term mortality (RR 0.84, 95%CI 0.72-0.97) at a weighted mean follow-up duration of 10.4 years, while MT showed statistically-significantly higher rates of 30-day PVL (RR, 3.76, 95%CI 1.31-10.85) and major bleeding (RR 1.45; 95%CI 1.08-1.94). TAVR had statistically significant lower rates of 30-day AKI (RR 0.49, 95%CI 0.31-0.77), but showed statistically-significantly higher PPM (RR 2.50; 95%CI 1.60-3.91) and 30-day PVL (RR 12.85, 95%CI 5.05-32.68) compared to FS.

CONCLUSIONS

MS was protective against 30-day mortality, stroke, AKI, and long-term mortality compared to FS; TAVR showed higher rates of 30-day PVL and PPM but was protective against AKI. Conversely, MT showed higher rates of 30-day PVL and major bleeding. With the emergence of TAVR, the appropriate benchmarks for SAVR comparison in future trials should be the minimally-invasive SAVR approaches to provide clinical equipoise.

Minimal Access Aortic Valve Surgery

Minimally invasive approaches to the aortic valve have been described since 1993, with great hopes that they would become universal and facilitate day-case cardiac surgery. The literature has shown that these procedures can be undertaken with equivalent mortality rates, similar operative times, comparable costs, and some benefits regarding hospital length of stay. The competing efforts of transcatheter aortic valve implantation for these same outcomes have provided an excellent range of treatment options for patients from cardiology teams. We describe the current state of the art, including technical considerations, caveats, and complications of minimal access aortic surgery and predict future directions in this space.

Propensity matched analysis of minimally invasive versus conventional isolated aortic valve replacement

OBJECTIVE

To analyse the early and mid-term outcome of patients undergoing conventional aortic valve replacement (AVR) versus minimally invasive via hemi-sternotomy aortic valve replacement (MIAVR).

METHODS

A single centre retrospective study involving 653 patients who underwent isolated aortic valve replacement (AVR) either via conventional AVR (n = 516) or MIAVR (n = 137) between August 2015 and March 2020. Using pre-operative characteristics, patients were propensity matched (PM) to produce 114 matched pairs. Assessment of peri-operative outcomes, early and mid-term survival and echocardiographic parameters was performed.

RESULTS

The mean age of the PM conventional AVR group was 71.5 (±8.9) years and the number of male (n = 57) and female (n = 57) patients were equal. PM MIAVR group mean age was 71.1 (±9.5) years, and 47% of patients were female (n = 54) and 53% male (n = 60). Median follow-up for PM conventional AVR and MIAVR patients was 3.4 years (minimum 0, maximum 4.8 years) and 3.4 years (minimum 0, maximum 4.8 years), respectively. Larger sized aortic valve prostheses were inserted in the MIAVR group (median 23, IQR = 4) versus conventional AVR group (median 21, IQR = 2; p = 0.02, SMD = 0.34). Cardiopulmonary bypass (CPB) time was longer with MIAVR (94.4 ± 19.5 minutes) compared to conventional AVR (83.1 ± 33.3; p = 0.0001, SMD = 0.41). Aortic cross-clamp (AoX) time was also longer in MIAVR (71.6 ± 16.5 minutes) compared to conventional AVR (65.0 ± 52.8; p = 0.0001, SMD = 0.17). There were no differences in the early post-operative complications and mortality between the two groups. Follow-up echocardiographic data showed significant difference in mean aortic valve gradients between conventional AVR and MIAVR groups (17.3 ± 8.2 mmHg vs 13.0 ± 5.1 mmHg, respectively; p = 0.01, SMD = -0.65). There was no significant difference between conventional AVR and MIAVR in mid-term survival at 3 years (88.6% vs 92.1%; log-rank test p = 0.31).

CONCLUSION

Despite the longer CPB and AoX times in the MIAVR group, there was no significant difference in early complications, mortality and mid-term survival between MIAVR and conventional AVR.

Consensus statement on aortic valve replacement via an anterior right minithoracotomy in the UK healthcare setting

The wide uptake of anterior right thoracotomy (ART) as an approach for aortic valve replacement (AVR) has been limited despite initial reports of its use in 1993. Compared with median sternotomy, and even ministernotomy, ART is considered to be less traumatic to the chest wall and to help facilitate quicker patient recovery. In this statement, a consensus agreement is outlined that describes the potential benefits of the ART AVR. The technical considerations that require specific attention are described and the initiation of an ART programme at a UK centre is recommended through simulation and/or use of specialist instruments in conventional cases. The use of soft tissue retractors, peripheral cannulation, modified aortic clamping and the use of intraoperative adjuncts, such as sutureless valves and/or automated knot fasteners, are important to consider in order to circumvent the challenges of minimal the altered exposure via an ART.A coordinated team-based approach that encourages ownership of the programme by team members is critical. A designated proctor/mentor is also recommended. The organisation of structured training and simulation, as well as planning the initial cases are important steps to consider.

Minimally invasive versus conventional aortic valve replacement: The network meta-analysis

BACKGROUND

Outcome comparisons after surgical aortic valve replacement (SAVR) with minimally invasive approaches including mini-sternotomy (MS) and right mini-thoracotomy (RMT) and full sternotomy (FS) have been conflicting. Furthermore, the synthesis of mid-term mortality has not been performed.

METHODS

MEDLINE and EMBASE were searched through April 2022 to identify propensity score matched (PSM) studies or randomized controlled trial (RCT) which compared outcomes following SAVR among three incisional approaches: FS, MS, or RMT. The network analysis was performed to compare these approaches with random effects model. Mid-term mortality was defined as 1-year mortality.

RESULTS

A total of 42 studies met the inclusion criteria enrolling 14,925 patients. RCT and PSM were performed in 13 and 29 studies, respectively. The operative mortality was significantly lower with MS compared to FS (risk ratio [RR]: 0.60, 95% confidence interval [CI]: 0.41-0.90, p = .01, I²  = 25.8%) or RMT (RR: 0.51, 95% CI: 0.27-0.97, p = .03, I²  = 25.8%). RMT had significantly higher risk of reoperation for bleeding compared to MS (RR: 1.65, 95% CI: 1.18-2.30, p = .003, I²  = 0%). Hospital length of stay was significantly shorter with MS compared to FS (mean difference: -0.89 days, 95% CI: -1.58 to -0.2, p = .01, I²  = 95.5%) while it was equivocal between FS and RMT. The mid-term mortality was similar among the three approaches.

CONCLUSIONS

While mid-term mortality was comparable among approaches, MS may be a safe and potentially more effective approach than FS and RMT for SAVR in the short term.

Aortic valve replacement through minithoracotomy. Results from the Peruvian experience

Objectives

To assess mortality, major valve-related events (MAVRE), and other complications in the perioperative period and follow up in patients with aortic valve replacement (AVR) through mini-thoracotomy (MT).

Methods

We retrospectively analyzed patients aged <80 who underwent AVR through MT between January 2017 and December 2021 in a national reference center in Lima, Peru. Patients undergoing other surgical approaches (mini-sternotomy, etc.), other concomitant cardiac procedures, redo, and emergency surgeries were excluded. We measured the variables (MAVRE, mortality, and other clinical variables) at 30 days and a mean follow-up of 12 months.

Results

Fifty-four patients were studied, the median age was 69.5 years, and 65% were women. Aortic valve (AV) stenosis was the main indication for surgery (65%), and bicuspid AV represented 55.6% of cases. At 30-days, MAVRE occurred in two patients (3.7%), with no in-hospital mortality. One patient had an intraoperative ischemic stroke, and one required a permanent pacemaker. No patient underwent reoperation due to prosthesis dysfunction or endocarditis. In a mean follow-up of one year, MAVRE occurrence did not show variations with the perioperative period, most patients remained in NYHA I (90.7%) or II (7.4%) compared to the preoperative period (p<0.001).

Conclusions

AV replacement through MT is a safe procedure in our center for patients under 80 years.

Robotic Aortic Valve Replacement: First 50 Cases

BACKGROUND

Existing management challenges in selecting transcatheter versus surgical aortic valve replacement (SAVR) include bicuspid stenosis, low clinical risk, horizontal valve position, aortic insufficiency (AI), and need for concomitant procedures or mechanical valves. To address these gaps, we present our early experience with fully robotic-assisted aortic valve replacement (RAVR).

METHODS

Between January 2020 and February 2021, 50 consecutive RAVR operations were performed utilizing a 3-4 cm lateral mini-thoracotomy three-port technique with transthoracic aortic clamping, similar to our robotic mitral platform. Conventional SAVR prostheses were implanted with interrupted braided sutures in all cases.

RESULTS

Median age was 67.5 years, BMI was 29, calcified bicuspid disease was present in 28/50 (56%), and severe AI in 8/50 (16%). Ejection fraction was 54.8±8.4% (mean±SD), and STS PROM was 1.54±0.7%. Mechanical prostheses were used in 16/50 (32%), and 7 required concomitant procedures including Cox-Maze (3), left atrial appendage clipping (1), aortic root enlargement (2), mitral repair (1), and left atrial myxoma excision (1). Median times for cardiopulmonary bypass, cross-clamp, valvectomy, annular sutures, and aortotomy closure were 166, 117, 4, 20, and 31 minutes, respectively. All times plateaued after the initial five cases. Most patients (42/50, 84%) were extubated in the operating room, and the remainder (8/50, 16%) within 4 hours. There was no 30-day operative mortality or stroke. All had 30-day echocardiography demonstrating no valvular or perivalvular abnormalities.

CONCLUSIONS

RAVR appears to have procedural safety and short-term outcomes to rival alternatives. Incremental experience may facilitate the safe performance of concomitant procedures as deemed necessary.

Right anterior mini thoracotomy approach for isolated aortic valve replacement: Early outcomes at a Canadian center

OBJECTIVE

The goal of this manuscript was to report the clinical outcomes of the initial series of 100 consecutive Right Anterior Mini Thoracotomy (RAMT) aortic valve replacement (AVR) implantations at a Canadian Center.

METHODS

This retrospective study reported the clinical outcomes of the first 100 patients who underwent the RAMT approach for isolated surgical AVR in Calgary, Canada, between 2016 and 2020. Primary outcomes were death within 30 days of surgery and disabling stroke. Secondary outcomes included surgical times, the need for permanent pacemaker (PPM), incidence of postoperative blood transfusion in the intensive care unit (ICU), postsurgical atrial fibrillation (AF), length of ICU/hospital stay, postsurgical AF, residual paravalvular leak (PVL), postoperative transvalvular gradient, need for postsurgical intravenous opioids, duration of invasive ventilation in the ICU, and chest tube output in the first 12 h postsurgery.

RESULTS

In this study, 54 patients were male, and the average age of the cohort was 72 years. Mortality within 30 days of surgery was 1% with no disabling postoperative strokes. Mean cardiopulmonary bypass and cross clamp was 84 and 55 min, respectively. PPM rate was 3%, incidence of blood transfusion in the ICU was 4%, and the rate of postoperative AF was 23%. Median length of ICU and hospital stay was 1 and 5 days, respectively. Rate of mild or greater residual PVL was 3%, while the average residual transvalvular mean gradient was 8.5 mmHg.

CONCLUSION

The sternum-sparing RAMT approach can be safely integrated into surgical practice as a minimally invasive alternative for isolated AVR, and can reduce postoperative bleeding and narcotic requirements.

Minimally invasive aortic valve replacement with sutureless bioprosthesis through right minithoracotomy with completely central cannulation-Early results in 203 patients

OBJECTIVES

Minimally invasive aortic valve replacement (mini-AVR) might improve clinical outcomes, particularly in high-risk and elderly patients. Sutureless/rapid deployment bioprosthesis can offer advantage of decreasing the cross-clamp time (XCT) and easing the procedure. Our aim was to evaluate the safety and perioperative outcomes of mini-AVR using sutureless bioprothesis via the right minithoracotomy approach with our modified technique of central cannulation.

METHODS

We performed a single-center retrospective analysis of 203 patients consecutively undergoing isolated AVR between March 2016 and June 2018 with the right minithoracotomy approach and our modified technique of central cannulation. Aortic valve diseases were stenosis (89.9%), regurgitation (1.6%), and mixed valve disease (8.5%). Patients with concomitant procedures were excluded. Primary endpoints were 30-day and 4-month mortality.

RESULTS

Mean age was 76 ± 6.2 years, 63 (31%) patients were 80 years or older. Cardiopulmonary bypass and XCT were 60.5 (39-153) and 35 (24-76) min, respectively. Thirty-day and 4-month mortality were 1% (two patients). We have observed minor paravalvular leak (PVL) which occurred in seven patients (3.4%), and no moderate/severe PVL was found perioperatively. One patient developed moderate/severe PVL during the 4-month follow-up. There was no structural valve degeneration. Two (1%) patients needed conversion to full sternotomy, and two (1%) patients to ministernotomy.

CONCLUSIONS

Mini-AVR via the right minithoracotomy approach with central cannulation is an effective and safe procedure and demonstrates excellent early clinical outcomes. This approach can be particularly valuable in higher risk and elderly patients.