Surgical vs transcatheter aortic valve replacement in bicuspid aortic valve stenosis: A systematic review and meta-analysis

This systematic review and meta-analysis aim to provide a comprehensive analysis of the literature directly comparing the outcomes of surgical aortic valve replacement (SAVR) and TAVR in patients with BAV stenosis. Medline, PubMed, and Scopus were systematically searched for articles published between 2000 and 2023, 1862 studies were screened, and 6 retrospective studies met the inclusion criteria. We included 6550 patients in the final analyses: 3,292 and 3,258 in the SAVR and TAVR groups, respectively. Both groups have similar rates of in-hospital mortality (odds ratio (OR) 1.11; 95% CI 0.59-2.10; p = 0.75) and stroke (OR 1.25; 95% CI 0.85-1.86; p = 0.26. Patients who underwent SAVR experienced lower rates of permanent pacemaker implantation (OR 0.54; 95% CI 0.35-0.83; p = 0.005) and paravalvular leak (OR 0.47; 95% CI 0.26-0.86; p = 0.02). On the other hand, patients who underwent TAVR displayed lower rates of acute kidney injury (OR 1.81; 95% CI 1.15-2.84; p = 0.010), major bleeding (OR 3.76; 95% CI 2.18-6.49; p < 0.00001), and pulmonary complications (OR 7.68; 95% CI 1.21-48.84; p = 0.03). Despite the early mortality data suggesting that TAVR may be a reasonable strategy for patients with bicuspid AS with low to intermediate surgical risk, the increased risk of PPI and PVL is concerning. A prospective, randomized, controlled trial reporting long-term outcomes with pre-defined subgroup analyses based on BAV morphology is paramount. In the interim, caution should be exercised in the widespread adoption of TAVR in lower surgical-risk patients.

Minimal Learning Curve for Minimally Invasive Aortic Valve Replacement

BACKGROUND

 Minimally invasive aortic valve replacement (MiAVR) is an established technique for surgical aortic valve replacement (AVR). Although MiAVR was first described in 1993 and has shown good results compared with full sternotomy AVR (FSAVR) only a minority of patients undergo MiAVR. We recently started using MiAVR via an upper hemisternotomy. We aimed to examine the early results of our initial experience with this technique.

METHODS

 We compared 55 MiAVR patients with a historical cohort of 142 isolated FSAVR patients (December 2016-December 2022). The primary outcome was in-hospital mortality. Secondary outcomes included cardiopulmonary bypass (CPB) and cross-clamp times, blood product intake, in-hospital morbidity, and length of intensive care unit and hospital stay.

RESULTS

 There was no significant difference in preoperative characteristics, including age, laboratory values, and comorbidities. There was no significant difference between the groups regarding in-hospital mortality (FSAVR 3.52 vs. MiAVR 1.82%). There was no significant difference in CPB time (FSAVR 103.5 [interquartile range: 82-119.5] vs. MiAVR 107 min [92.5-120]), aortic cross-clamp time (FSAVR 81 [66-92] vs. MiAVR 90 min [73-99]), and valve size (FSAVR 23 [21-25] vs. MiAVR 23 [21-25]). The incidence of intraoperative blood products transfusion was significantly lower in the MiAVR group (10.91%) compared with the FSAVR group (25.35%, p = 0.03).

CONCLUSION

 Our findings further establish the possibility of reducing invasiveness of AVR without compromising patient safety and clinical outcomes. This is true even in the learning curve period and without requiring any significant change in the operative technique and dedicated equipment.

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.

Limited versus full sternotomy for aortic valve replacement

BACKGROUND

Aortic valve disease is a common condition easily treatable with cardiac surgery. This is conventionally performed by opening the sternum ('median sternotomy') and replacing the valve under cardiopulmonary bypass. Median sternotomy is well tolerated, but as less invasive options become available, the efficacy of limited incisions has been called into question. In particular, the effects of reducing the visibility and surgical access have raised safety concerns with regard to the placement of cannulae, venting of the heart, epicardial wire placement, and de-airing of the heart at the end of the procedure. These difficulties may increase operating times, affecting outcome. The benefits of smaller incisions are thought to include decreased pain; improved respiratory mechanics; reductions in wound infections, bleeding, and need for transfusion; shorter intensive care stay; better cosmesis; and a quicker return to normal activity. This is an update of a Cochrane review first published in 2017, with seven new studies.

OBJECTIVES

To assess the effects of minimally invasive aortic valve replacement via a limited sternotomy versus conventional aortic valve replacement via median sternotomy in people with aortic valve disease requiring surgical replacement.

SEARCH METHODS

We performed searches of CENTRAL, MEDLINE and Embase from inception to August 2021, with no language limitations. We also searched two clinical trials registries and manufacturers' websites. We reviewed references of primary studies to identify any further studies of relevance.

SELECTION CRITERIA

We included randomised controlled trials comparing aortic valve replacement via a median sternotomy versus aortic valve replacement via a limited sternotomy. We excluded trials that performed other minimally invasive incisions such as mini-thoracotomies, port access, transapical, transfemoral or robotic procedures. Although some well-conducted prospective and retrospective case-control and cohort studies exist, these were not included in this review.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial papers to extract data, assess quality, and identify risk of bias. A third review author provided arbitration where required. We determined the certainty of evidence using the GRADE methodology and summarised results of patient-relevant outcomes in a summary of findings table.

MAIN RESULTS

The review included 14 trials with 1395 participants. Most studies had at least two domains at high risk of bias. We analysed 14 outcomes investigating the effects of minimally invasive limited upper hemi-sternotomy on aortic valve replacement as compared to surgery performed via full median sternotomy. Upper hemi-sternotomy may have little to no effect on mortality versus full median sternotomy (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.45 to 1.94; 10 studies, 985 participants; low-certainty evidence). Upper hemi-sternotomy for aortic valve replacement may increase cardiopulmonary bypass time slightly, although the evidence is very uncertain (mean difference (MD) 10.63 minutes, 95% CI 3.39 to 17.88; 10 studies, 1043 participants; very low-certainty evidence) and may increase aortic cross-clamp time slightly (MD 6.07 minutes, 95% CI 0.79 to 11.35; 12 studies, 1235 participants; very low-certainty evidence), although the evidence is very uncertain. Most studies had at least two domains at high risk of bias. Postoperative blood loss was probably lower in the upper hemi-sternotomy group (MD -153 mL, 95% CI -246 to -60; 8 studies, 767 participants; moderate-certainty evidence). Low-certainty evidence suggested that there may be no change in pain scores by upper hemi-sternotomy (standardised mean difference (SMD) -0.19, 95% CI -0.43 to 0.04; 5 studies, 649 participants). Upper hemi-sternotomy may result in little to no difference in quality of life (MD 0.03 higher, 95% CI 0 to 0.06 higher; 4 studies, 624 participants; low-certainty evidence). Two studies reporting index admission costs concluded that limited sternotomy may be more costly at index admission in the UK National Health Service (MD 1190 GBP more, 95% CI 420 GBP to 1970 GBP, 2 studies, 492 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

The evidence was of very low to moderate certainty. Sample sizes were small and underpowered to demonstrate differences in some outcomes. Clinical heterogeneity was also noted. Considering these limitations, there may be little to no effect on mortality. Differences in extracorporeal support times are uncertain, comparing upper hemi-sternotomy to full sternotomy for aortic valve replacement. Before widespread adoption of the minimally invasive approach can be recommended, there is a need for a well-designed and adequately powered prospective randomised controlled trial. Such a study would benefit from also performing a robust cost analysis. Growing patient preference for minimally invasive techniques merits thorough quality of life analyses to be included as end points, as well as quantitative measures of physiological reserve.

Is There a Future for Minimal Access and Robots in Cardiac Surgery?

Minimally invasive techniques in cardiac surgery have found increasing use in recent years. Both patients and physicians often associate smaller incisions with improved outcomes (i.e., less risk, shorter hospital stay, and a faster recovery). Videoscopic and robotic assistance has been introduced, but their routine use requires specialized training and is associated with potentially longer operating times and higher costs. Randomized evidence is scarce and transcatheter treatment alternatives are increasing rapidly. As a result, the concept of minimally invasive cardiac surgery may be viewed with skepticism. In this review, we examine the current status and potential future perspectives of minimally invasive and robotic cardiac surgery.

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.

Economic Justification Analysis of Minimally Invasive versus Conventional Aortic Valve Replacement

There is no definitive consensus about the cost-effectiveness of minimally invasive aortic valve replacement (AVR) (MI-AVR) compared to conventional AVR (C-AVR). The aim of this study was to compare the rate of postoperative complications and total hospital costs of MI-AVR versus C-AVR overall and by the type of aortic prosthesis (biological or mechanical). Our single-center retrospective study included 324 patients over 18 years old who underwent elective isolated primary AVR with standard stented AV prosthesis at the Institute for Cardiovascular Diseases "Dedinje" between January 2019 and December 2019. Reintervention, emergencies, combined surgical interventions, and patients with sutureless valves were excluded. In both MI-AVR and C-AVR, mechanical valve implantation contributed to overall reduction of hospital costs with equal efficacy. The cost-effectiveness ratio indicated that C-AVR is cheaper and yielded a better clinical outcome with mechanical valve implantation (67.17 vs. 69.5). In biological valve implantation, MI-AVR was superior. MI-AVR patients had statistically significantly higher LVEF and a lower Euro SCORE than C-AVR patients (Mann-Whitney U-test, p = 0.002 and p = 0.002, respectively). There is a slight advantage to MI-AVR vs. C-AVR, since it costs EUR 9.44 more to address complications that may arise. Complications (mortality, early reoperation, cerebrovascular insult, pacemaker implantation, atrial fibrillation, AV block, systemic inflammatory response syndrome, wound infection) were less frequent in the MI-AVR, making MI-AVR more economically justified than C-AVR (18% vs. 22.1%).

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.

Mini-sternotomy versus full sternotomy for isolated aortic valve replacement: A single-center experience

BACKGROUND

Minimally invasive approaches to isolated aortic valve replacement (AVR) are well-described and widely utilized. While there are numerous proposed benefits, there is limited literature describing significant morbidity or mortality benefits for minimally invasive isolated AVR resulting in hesitancy in its universal adoption. In this retrospective study, we compare the 5-year outcomes of patients undergoing isolated AVR via full sternotomy (FS) or mini-sternotomy (MS).

METHODS

756 patients underwent isolated AVR between 2014 and 2019. Propensity matching resulted in 142 matched pairs that received either FS or MS. The primary outcome was mortality during the follow-up period. Secondary outcomes included intraoperative variables and postoperative morbidity.

RESULTS

Intraoperative variables including total operative, cardiopulmonary bypass, and aortic cross-clamp times did not differ significantly between groups. Postoperative mortality was similar between the matched groups with nonsignificant differences at 30 days (2.12% vs. 1.4%, p = .657), 1 year (4.9% vs. 2.1%, p = .0.223), and 5 years (7.5% vs. 3.5%, p = .174). Rates of postoperative morbidity were comparable between groups with no significant differences.

CONCLUSION

This study examined the long-term outcomes of propensity-matched patients undergoing isolated AVR via FS or MS and identified no significant differences in outcomes over a 5-year follow-up period. The decision for surgical approach is multifactorial and should be decided on a case-by-case basis taking into consideration patient anatomy, surgeon experience, and comfort, as well as patient preference.

Low-Risk Surgical Aortic Valve Replacement in the Era of Transcatheter Aortic Valve Implantation

Open surgical aortic valve replacement (SAVR) is a viable alternative to transcatheter implantation in low-risk patients. In this light, we evaluated the safety and effectiveness of SAVR performed through conventional and less invasive surgical approaches in a high-volume center.

We retrospectively reviewed the records of 395 consecutive patients who underwent open SAVR from January 2019 through December 2019 in our center. We evaluated and compared the operative results and postoperative major adverse outcomes of 3 surgical approaches: full median sternotomy (n=267), upper ministernotomy (ministernotomy) (n=106), and right anterior thoracotomy (minithoracotomy) (n=22).

Overall, the 30-day all-cause mortality rate was 0.8% (3 patients). Stroke occurred in 8 patients (2%), disabling stroke in 4 patients (1%), myocardial infarction in 1 (0.2%), and surgical site infection in 13 (3.2%). There was no difference in 30-day mortality rate or incidence of postoperative major adverse events among the 3 surgical groups. Stroke and surgical site infection occurred more frequently, but not significantly so, in the full-sternotomy group. The mean hospital stay was longer after full sternotomy (9.1 ± 5.5 d) than after ministernotomy (7.5 ± 2.9 d) or minithoracotomy (7.4 ± 1.9 d) (P=0.012).

Our findings suggest that open SAVR performed in a high-volume center is associated with a low early mortality rate and that less invasive approaches result in faster postoperative recovery and shorter hospital stays.

Conventional Versus Minimally Invasive Aortic Valve Replacement Surgery: A Systematic Review, Meta-Analysis, and Meta-Regression

Objective: To assess the potential benefits of minimally invasive aortic valve replacement (MIAVR) compared with conventional AVR (CAVR) by examining short-term outcomes. Methods: A systematic search identified randomized trials comparing MIAVR with CAVR. To assess study limitations and quality of evidence, we used the Cochrane Risk of Bias tool and GRADE and performed random-effects meta-analysis. We used meta-regression and sensitivity analysis to explore reasons for diversity. Results: Thirteen studies (1,303 patients) were included. For the comparison of MIAVR and CAVR, the risk of bias was judged low or unclear and the quality of evidence ranged from very low to moderate. No significant difference was observed in mortality, stroke, acute kidney failure, infectious outcomes, cardiac events, intubation time, intensive care unit stay, reoperation for bleeding, and blood transfusions. Blood loss (mean difference [MD] = -130.58 mL, 95% confidence interval [CI] = -216.34 to -44.82, I² = 89%) and hospital stay (MD = -0.93 days, 95% CI = -1.62 to -0.23, I² = 81%) were lower with MIAVR. There were shorter aortic cross-clamp (MD = 5.99 min, 95% CI = 0.99 to 10.98, I² = 93%) and cardiopulmonary bypass (CPB) times (MD = 7.75 min, 95% CI = 0.27 to 15.24, I² = 94%) in the CAVR group. In meta-regression analysis, we found that age was the variable with the greatest influence on heterogeneity. Conclusions: MIAVR seems to be an excellent alternative to CAVR, reducing hospital stay and incidence of hemorrhagic events. Despite significantly greater aortic cross-clamp and CPB times with MIAVR, this did not translate into adverse effects, with no changes in the results found with CAVR.

Representation of Women in Randomized Trials in Cardiac Surgery: A Meta-Analysis

Background

Women have traditionally been underrepresented in randomized clinical trials (RCTs). We performed a systematic evaluation of the inclusion of women in cardiac surgery RCTs published in the past 2 decades.

Methods and Results

MEDLINE, EMBASE, and the Cochrane Library were searched (2000 to July 2020) for RCTs written in English, comparing ≥2 adult cardiac surgical procedures. The percentage of women enrolled and its association with year of publication, sample size, mean age, funding source, geographic location, number of sites involved, and interventions tested were analyzed using a meta‐analytic approach. Fifty‐one trials were included. Of 25 425 total patients, 5029 were women (20.8%; 95% CI, 17.6–24.4; range, 0.5%–57.9%). The proportion of women dropped significantly during the study period (29.6% in 2000 versus 13.1% in 2019, P<0.001). Women were significantly more represented in European trials (26.2%; 95% CI, 21.2–31.9), and less represented in trials of coronary bypass surgery versus other interventions (16.8%; 95% CI, 12.3–22.7 versus 33.6%; 95% CI, 27.4–40.5; P=0.0002) and in trials enrolling younger patients (P=0.009); the percentage of women was higher in industry‐sponsored versus non‐industry sponsored trials (31.7%; 95% CI, 27.2–36.6 versus 15.5%; 95% CI, 10.0–23.2; P=0.0004) and was not associated with trial sample size (P=0.52) or study design (multicenter versus monocenter: P=0.22). After exclusion of trials conducted at Veteran Affairs centers, women representation was 24.4% (95% CI, 21.1–28.0; range, 10.4%–57.9%), with no significant changes during the study period.

Conclusions

The proportion of women in cardiac surgery trials is low and likely inadequate to provide meaningful estimates of the treatment effect.

Mini-sternotomy versus conventional sternotomy for aortic valve replacement: a randomised controlled trial

OBJECTIVE

To compare clinical and health economic outcomes after manubrium-limited mini-sternotomy (intervention) and conventional median sternotomy (usual care).

DESIGN

A single-blind, randomised controlled trial.

SETTING

Single centre UK National Health Service tertiary hospital.

PARTICIPANTS

Adult patients undergoing aortic valve replacement (AVR) surgery.

INTERVENTIONS

Intervention was manubrium-limited mini-sternotomy performed using a 5-7 cm midline incision. Usual care was median sternotomy performed using a midline incision from the sternal notch to the xiphisternum.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the proportion of patients who received a red cell transfusion postoperatively and within 7 days of index surgery. Secondary outcomes included proportion of patients receiving a non-red cell blood component transfusion and number of units transfused within 7 days and during index hospital stay, quality of life and cost-effectiveness analyses.

RESULTS

270 patients were randomised, received surgery and contributed to the intention to treat analysis. No difference between mini and conventional sternotomy in red-cell transfusion within 7 days was found; 23/135 patients in each arm received a transfusion, OR 1.0 (95% CI 0.5 to 2.0) and risk difference 0.0 (95% CI -0.1 to 0.1). Mini-sternotomy reduced chest drain losses (mean 181.6 mL (SD 138.7) vs conventional, mean 306·9 mL (SD 348.6)); this did not reduce red-cell transfusions. Mean valve size and postoperative valve function were comparable between mini-sternotomy and conventional groups; 23 mm vs 24 mm and 6/134 moderate or severe aortic regurgitation vs 3/130, respectively. Mini-sternotomy resulted in longer bypass (82.7 min (SD 23.5) vs 59.6 min (SD 15.1)) and cross-clamp times (64.1 min (SD 17.1) vs 46·3 min (SD 10.7)). Conventional sternotomy was more cost-effective with only a 5.8% probability of mini-sternotomy being cost-effective at a willingness to pay of £20 000/QALY (Quality Adjusted Life Years).

CONCLUSIONS

AVR via mini-sternotomy did not reduce red blood cell transfusion within 7 days following surgery when compared with conventional sternotomy.

TRIAL REGISTRATION NUMBER

ISRCTN29567910; Results.