Minimally Invasive Versus Conventional Aortic Valve Replacement: A Propensity-Matched Study From the UK National Data

Closing the care gap: combining enhanced recovery with minimally invasive valve surgery

PURPOSE OF REVIEW

Patients with advanced age and frailty require interventions for structural heart disease at an increasing rate. These patients typically experience higher rates of postoperative morbidity, mortality and prolonged hospital length of stay, loss of independence as well as associated increased costs to the healthcare system. Therefore, it is becoming critically important to raise awareness and develop strategies to improve clinical outcomes in the contemporary, high-risk patient population undergoing cardiacprocedures.

RECENT FINDINGS

Percutaneous options for structural heart disease have dramatically improved the therapeutic options for some older, frail, high-risk patients; however, others may still require cardiac surgery. Minimally invasive techniques can reduce some of the physiologic burden experienced by patients undergoing surgery and improve recovery. Enhanced Recovery After Cardiac Surgery (ERAS Cardiac) is a comprehensive, interdisciplinary, evidence-based approach to perioperative care. It has been shown to improve recovery and patient satisfaction while reducing complications and length of stay.

SUMMARY

Combining minimally invasive cardiac surgery with enhanced recovery protocols may result in improved patient outcomes for a patient population at high risk of morbidity and mortality following cardiac surgery.

Early Outcomes of Minimally Invasive Right Anterior Thoracotomy vs. Median Full Sternotomy in Isolated Aortic Valve Replacement: A Propensity Score Analysis

INTRODUCTION

This study aimed to compare the early postoperative outcomes of right anterior thoracotomy minimally invasive aortic valve replacement (RAT-MIAVR) surgery with those of median full sternotomy aortic valve replacement (MFS-AVR) approach with the goal of identifying potential benefits or drawbacks of each technique.

METHODS

This retrospective, observational, cohort study included 476 patients who underwent RAT-MIAVR or MFS-AVR in our hospital from January 2015 to January 2023. Of these, 107 patients (22.5%) underwent RAT-MIAVR, and 369 patients (77.5%) underwent MFS-AVR. Propensity score matching was used to minimize selection bias, resulting in 95 patients per group for analysis.

RESULTS

After propensity matching, two groups were comparable in preoperative characteristics. RAT-MIAVR group showed longer cardiopulmonary bypass time (130.24 ± 31.15 vs. 117.75 ± 36.29 minutes, P=0.012), aortic cross-clamping time (76.44 ± 18.00 vs. 68.49 ± 19.64 minutes, P=0.004), and longer operative time than MFS-AVR group (358.47 ± 67.11 minutes vs. 322.42 ± 63.84 minutes, P=0.000). RAT-MIAVR was associated with decreased hospitalization time after surgery, lower postoperative blood loss and drainage fluid, a reduced incidence of mediastinitis, increased left ventricular ejection fraction, and lower pacemaker use compared to MFS-AVR. However, there was no significant difference in the incidence of major complications and in-hospital mortality between the two groups.

CONCLUSION

RAT-MIAVR is a feasible and safe alternative procedure to MFS-AVR, with comparable in-hospital mortality and early follow-up. This minimally invasive approach may be a suitable option for patients requiring isolated aortic valve replacement.

The Learning Curve of Total Arch Replacement via Single Upper Hemisternotomy Approach in Aortic Dissection

Purpose

Upper hemisternotomy (UHS) has benefits over conventional full sternotomy because it ameliorates trauma during cardiac surgery. Owing to its challenging and technically demanding nature, this incision in acute type A aortic dissection (ATAAD) has rarely been reported. This study aimed to analyze the learning curve of total arch replacement (TAR) with moderate hypothermic circulatory arrest via a single UHS approach, which is necessary to guide the training of surgeons in adopting minimally invasive procedures.

Patients and Methods

A total of 202 consecutive patients who were definitively diagnosed with ATAAD between July 2016 and June 2021 were enrolled in this retrospective analysis. Patients were divided into three groups based on cumulative sum plots for circulatory arrest time in chronological order. Perioperative characteristics were compared between the groups.

Results

There was significant difference in the circulatory arrest time and cross-clamp time respectively among three groups (39.0 min vs 28.0 min vs 15.0 min, P < 0.001; 104.5 min vs 106.2 min vs 84.1 min, P < 0.001). The ventilation time and first 24-h chest tube drainage were statistically different among groups (35.5 h vs 24.0 h vs 19.0 h, P = 0.031; 220.0 mL vs 192.5 mL vs 125.5 mL, P = 0.043). No other clinical outcome was observed as significant difference.

Conclusion

A cardiac surgeon can convert a conventional full sternotomy to a single UHS for TAR after experiencing a learning curve, to ensure patient safety. The mastery of this minimally invasive surgical technique may be beneficial for the prognosis of patients with ATAAD.

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.

Network Meta-Analysis Comparing Transcatheter, Minimally Invasive, and Conventional Surgical Aortic Valve Replacement

The landscape of aortic valve replacement (AVR) has evolved dramatically over the years, but time-varying outcomes have yet to be comprehensively explored. This study aimed to compare the all-cause mortality among 3 AVR techniques: transcatheter (TAVI), minimally invasive (MIAVR), and conventional AVR (CAVR). An electronic literature search was performed for randomized controlled trials (RCTs) comparing TAVI with CAVR and RCTs or propensity score-matched (PSM) studies comparing MIAVR with CAVR or MIAVR to TAVI. Individual patient data for all-cause mortality were derived from graphical reconstruction of Kaplan-Meier curves. Pairwise comparisons and network meta-analysis were conducted. Sensitivity analyses were performed in the TAVI arm for high risk and low/intermediate risk, as well as patients who underwent transfemoral (TF) TAVI. A total of 27 studies with 16,554 patients were included. In the pairwise comparisons, TAVI showed superior mortality to CAVR until 37.5 months, beyond which there was no significant difference. When restricted to TF TAVI versus CAVR, a consistent mortality benefit favoring TF TAVI was seen (shared frailty hazard ratio [HR] = 0.86, 95% confidence interval [CI] = 0.76 to 0.98, p = 0.024). In the network meta-analysis involving majority PSM data, MIAVR demonstrated significantly lower mortality than TAVI (HR = 0.70, 95% CI = 0.59 to 0.82) and CAVR (HR = 0.69, 95% CI = 0.59 to 0.80); this association remained compared with TF TAVI but with a lower extent of benefit (HR = 0.80, 95% CI = 0.65 to 0.99). In conclusion, the initial short- to medium-term mortality benefit for TAVI over CAVR was attenuated over the longer term. In the subset of patients who underwent TF TAVI, a consistent benefit was found. Among majority PSM data, MIAVR showed improved mortality compared with TAVI and CAVR but less than the TF TAVI subset, which requires validation by robust RCTs.

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.

Comparing mini-sternotomy to full median sternotomy for aortic valve replacement with propensity-matching methods

Objective

This study aims to compare clinical outcomes between mini-sternotomy and full median sternotomy for aortic valve replacement using propensity-matching methods.

Methods

From August 2014 to July 2021, a total of 1,445 patients underwent isolated aortic valve surgery, 1,247 via full median sternotomy and 198 via mini-sternotomy. To reduce the impact of potential confounding factors, a propensity score based on 18 variables is used to obtain 198 well-matched case pairs, which include 231 aortic valve regurgitations and 165 aortic stenosis cases.

Result

Occurrences of in-hospital mortality (P = 0.499), stroke (P > 0.999), renal failure (P = 0.760), and paravalvular leakage (P = 0.224) are similar between the two groups. No significant difference in operation, cardiopulmonary bypass, and aortic cross-clamp times are found between the two groups. However, compared with the full sternotomy group, the mini-sternotomy group has less postoperative 24-hour drainage (131.7 ± 82.8 ml, P < 0.001) and total drainage (459.3 ± 306.3 ml, P < 0.001). The median mechanical ventilation times are 9.4 [interquartile range (IQR) 5.4-15.6] and 9.8 (IQR 6.1-14.4) in mini-sternotomy and full sternotomy groups (P = 0.284), respectively. There are no significant differences in intensive care unit stay and postoperative stay between the two groups. For either aortic valve regurgitations or aortic stenosis patients, significantly less postoperative 24-h and total drainage are still found in the mini-sternotomy group compared with the full sternotomy group.

Conclusions

Mini-sternotomy for aortic valve replacement is a safe procedure, with not only cosmetic advantages but less postoperative drainage compared with full sternotomy. Mini-sternotomy should be considered for most aortic valve operations.

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.

Hybrid Aortic Arch Repair Using a Ministernotomy

Hybrid thoracic endovascular aortic repair with surgical arch debranching is an accepted method for total arch reconstruction. Although off-pump arch debranching is increasingly used as a prophylactic adjunct to endovascular arch repair extending into landing zone 0, this technique is seldom performed with a ministernotomy due to a steep learning curve among surgeons. Herein, we report our standard technique for off-pump hybrid total aortic arch repair using a ministernotomy.

Minimally invasive Ozaki technique

Implantation of a mechanical or biological graft remains the gold standard in treatment of patients with aortic valve pathology. However, the necessity of taking anticoagulants, the problem of graft durability, the risk for thromboembolic and haemorrhagic complications, prosthetic infective endocarditis impel surgeons to search for and develop new technologies. One of such new techniques is prosthetic repair of the aortic valve using autologous pericardium according to the S. Ozaki operation. This procedure makes it possible to form an aortic valve with excellent haemodynamic characteristics and low frequency of re-do operations in both the early and remote periods. Current trends are towards exponential growth of minimally invasive cardiosurgical interventions. Upper partial sternotomy is one of the most commonly used techniques in surgery of the aortic valve. The results of previous studies demonstrated that a minimally invasive approach apart from a good cosmetic effect has a series of advantages over full sternotomy by the in-hospital and remote outcomes. On the other hand, a minimally invasive access is associated with limited surgical exposure and tight operative field and is therefore technically more complicated than the operation via full sternotomy. In our retrospective study we compared the clinical outcomes of the minimally invasive Ozaki technique (Ozaki Mini Group, n=30) and full sternotomy (Ozaki Full Group, n=112). Because of differences between the groups by the clinical and demographic parameters in order to ensure maximum comparability we conducted computer-assisted propensity score matching, resulting in formation of 2 groups consisting of 30 patients each. The primary outcome measures of the study were 30-day all-cause mortality and postoperative major adverse cardiac events (myocardial infarction, stroke). As additional categorical outcomes we examined new-onset atrial fibrillation and renal failure, resternotomy, prolonged (>24 h) assisted artificial pulmonary ventilation, mediastinitis/sternal instability. Secondary outcome measures were as follows: the duration of the operation, duration of myocardial ischaemia and artificial circulation, blood loss, requirement for transfusion of donor blood components.

Outcomes of minimally invasive aortic valve replacement surgery

Minimally invasive aortic valve replacement has been used for more than 20 years, but its uptake has been limited. The volumes have increased steadily over the last 10 years, but it is still not regarded as a mainstream procedure. The issue, to some extent, is due to the lack of perceived evidence that minimal access incisions confer any benefit other than cosmetic appearance. In this article, the current literature on minimally invasive aortic valve replacement is reviewed, and it is concluded that benefits are demonstrable, particularly in higher risk, comorbid settings.

The Opportunities and Limitations of Minimally Invasive Cardiac Surgery

BACKGROUND

Over the past two decades, minimally invasive techniques for classic heart valve surgery and isolated bypass surgery have been developed that enable access to the heart via partial sternotomy for most aortic valve procedures and via sternotomy-free mini-thoracotomy for other procedures.

METHODS

We review the current evidence on minimally invasive cardiac surgery on the basis of pertinent randomized studies and database studies retrieved by a selective search in the MEDLINE and PubMed Central databases, as well as by the Google Scholar search engine.

RESULTS

A PubMed search employing the search term "minimally invasive cardiac surgery" yielded nearly 10 000 hits, among which there were 7 prospective, randomized, controlled trials (RCTs) on aortic valve replacement, with a total of 477 patients, and 3 RCTs on mitral valve surgery, with a total of 340 patients. Only limited reports of specified centers are currently available for multiple valvular procedures and multiple coronary artery bypass procedures. The RCTs reveal that the minimally invasive techniques are associated with fewer wound infections and faster mobilization, without any difference in survival. Minimally invasive procedures are technically demanding and have certain anatomical prerequisites, such as appropriate coronary morphology for multiple bypass operations and the position of the aorta in the chest for sternotomy-free aortic valve procedures. The articles reviewed here were presumably affected by selection bias, in that patients in the published studies were preselected, and there may have been negative studies that were not published at all.

CONCLUSION

Specialized surgeons and centers can now carry out many cardiac valvular and bypass operations via minithoracotomy rather than sternotomy. According to current evidence, these minimally invasive techniques yield results that are at least as good as classic open-heart surgery.

Minimally Invasive Access Aortic Arch Surgery

OBJECTIVE

Median sternotomy is still the standard approach for aortic arch surgery. Minimally invasive techniques promise faster recovery with shorter hospital stay due to thoracic stability, reduced pain, and superior cosmetic results. However, safety is a concern in complex aortic surgery. The aim of our study was to demonstrate that aortic arch surgery via partial upper sternotomy is viable, safe, and equivalent to standard procedure both in terms of its safety and the risk of major adverse cardiac and cerebrovascular events.

METHODS

We interrogated our prospectively collected database and identified a total of 21 nonemergent patients operated on at our center between October 2008 and February 2015. Indication for operation was aneurysmatic disease in 18 and aortic dissection in 3 patients. Data were analyzed for in-hospital mortality, stroke, bleeding complications, and acute kidney injury.

RESULTS

Mean ± standard deviation age of patients was 69.3 ± 14.4 years, 57.1% were female, and mean ± standard deviation logistic EuroSCORE was 17.0 ± 7.2%. Surgery on the aortic arch comprised proximal arch in 9, hemiarch in 9, and total arch replacement plus frozen elephant trunk in 3 patients. Concomitant procedures included aortic root repair in 10, aortic root replacement in 2, and aortic valve replacement in 3 patients. We lost one patient because of septic shock, no stroke occurred, but a transient neurologic deficit in three and a postoperative delirium in four patients. Re-exploration for bleeding was necessary in two patients, and one patient had acute kidney injury.

CONCLUSIONS

Minimally invasive aortic arch surgery via partial upper sternotomy does not increase the risk of morbidity or mortality. Thus, in experienced hands, it is viable, safe, and therefore favorable and as a result should be offered to more patients.

Minimally invasive aortic valve replacement in high risk patient groups

Minimally invasive aortic valve replacement (AVR) aims to preserve the sternal integrity and improve postoperative outcomes. In low risk patients, this technique can be achieved with comparable mortality to the conventional approach and there is evidence of possible reduction in intensive care and hospital length of stay, transfusion requirement, renal dysfunction, improved respiratory function and increased patient satisfaction. In this review, we aim to asses if these benefits can be transferred to the high risk patient groups. We therefore, discuss the available evidence for the following high risk groups: elderly patients, re-operative surgery, poor lung function, pulmonary hypertension, obesity, concomitant procedures and high risk score cohorts.

Traditional Sternotomy Versus Minimally Invasive Aortic Valve Replacement in Patients Stratified by Ejection Fraction

OBJECTIVE

Low ejection fraction (EF < 40%) portends adverse outcomes in patients undergoing valvular heart surgery. The role of traditional median sternotomy aortic valve replacement (SAVR) compared with minimally invasive aortic valve replacement (MIAVR) in this cohort remains incompletely understood.

METHODS

A multi-institutional retrospective review of 1503 patients who underwent SAVR (n = 815) and MIAVR via right anterior thoracotomy (n = 688) from 2011 to 2014 was performed. Patients were stratified into two groups: EF of less than 40% and EF of 40% or more. In each EF group, SAVR and MIAVR patients were propensity matched by age, sex, body mass index, race, diabetes, hypertension, dyslipidemia, dialysis, cerebrovascular disease, cardiovascular disease, cerebrovascular accident, peripheral vascular disease, last creatinine level, EF, previous MI and cardiogenic shock, and the Society for Thoracic Surgeons (STS) score.

RESULTS

Among patients with an EF of 40% or more (377 pairs), patients who underwent MIAVR compared with SAVR had decreased intensive care unit hours (56.8% vs 84.6%, P < 0.001), postoperative length of stay (7.1 vs 7.9 days, P = 0.04), incidence of atrial fibrillation (18.8% vs 38.7%, P < 0.001), bleeding (0.8% vs 3.2%, P = 0.04), and a trend toward decreased 30-day mortality (0.3% vs 1.3%, P = 0.22). The STS scores were largely equivalent in patients undergoing MIAVR compared with SAVR (2.4% vs 2.6%, P = 0.09). In patients with an EF of less than 40% (35 pairs), there was no difference in intensive care unit hours (69% vs 72.6%, P = 0.80), postoperative length of stay (10.3 vs 7.2 days, P = 0.13), 30-day mortality (3.8% vs 0.8%, P = 0.50), or the STS score (3.3% vs 3.2%, P = 0.68).

CONCLUSIONS

Minimally invasive aortic valve replacement in patients with preserved EF was associated with improved short-term outcomes compared with SAVR. In patients with left ventricular dysfunction, short-term outcomes between MIAVR and SAVR are largely equivalent.

Minimally invasive aortic valve surgery

Aortic valve disease is a prevalent disorder that affects approximately 2% of the general adult population. Surgical aortic valve replacement is the gold standard treatment for symptomatic patients. This treatment has demonstrably proven to be both safe and effective. Over the last few decades, in an attempt to reduce surgical trauma, different minimally invasive approaches for aortic valve replacement have been developed and are now being increasingly utilized. A narrative review of the literature was carried out to describe the surgical techniques for minimally invasive aortic valve surgery and report the results from different experienced centers. Minimally invasive aortic valve replacement is associated with low perioperative morbidity, mortality and a low conversion rate to full sternotomy. Long-term survival appears to be at least comparable to that reported for conventional full sternotomy. Minimally invasive aortic valve surgery, either with a partial upper sternotomy or a right anterior minithoracotomy provides early- and long-term benefits. Given these benefits, it may be considered the standard of care for isolated aortic valve disease.