Minimal Access Aortic Valve Replacement: Is It Worth It?

Minimally invasive surgical aortic valve replacement

Minimally invasive aortic valve replacement (MIAVR) is defined as a surgical aortic valve replacement which involves smaller chest incisions as opposed to full sternotomy. It is performed using cardiopulmonary bypass with cardiac arrest. It benefits from potential advantages of a less invasive procedure. To date, over 14 000 MIAVR have been reported in the literature. Due to heterogeneity of the studies, different surgical techniques and mainly the non-randomised nature of these studies comparing MIAVR with conventional aortic valve replacement, it is difficult to draw definitive conclusions. The two main techniques of MIAVR are mini-sternotomy and right anterior mini-thoracotomy. Both techniques with other less common forms of MIAVR will be discussed in this review. The advantages, disadvantages and surgical pitfalls will be discussed. Some of the advantages include shorter intensive care and hospital stay, reduced perioperative blood loss, less pain, improved respiratory function and cosmesis. The possible disadvantage of longer bypass and cross-clamp times may be counter balanced by the recent sutureless and rapid deployment valves. Despite some of the benefits, MIAVR has not been adopted by a significant proportion of the surgeons possibly related to the learning curve and requirements for re-training. As MIAVR becomes more common, randomised trials comparing this technique with transcatheter aortic valve implantation is warranted. In addition, assessing quality of life including return to work and functional capacity is needed.

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.

Full Sternotomy, Hemisternotomy, and Minithoracotomy for Aortic Valve Surgery: Is There a Difference?

BACKGROUND

This study compared perioperative results and mortality rates of different approaches to perform aortic valve replacement (AVR), describing predictors favoring one approach over the others.

METHODS

All patients who underwent AVR were enrolled. The choice of the approach was left to surgeon's preference. Data were retrospectively collected, and the major baseline characteristics (including age, sex, body mass index, creatinine clearance, preoperative condition, cardiovascular risk factors, functional status, and left ventricular ejection fraction, etc.) and intraoperative variables were recorded. To adjust for differences in baseline characteristics between the study groups, a propensity score matching was performed. Linear and logistic regression analyses were performed.

RESULTS

Partial upper hemisternotomy was performed in 820 patients (43%), right anterior minithoracotomy in 488 (26%), and median sternotomy in 599 (31%). After propensity score matching, three groups of 377 patients were obtained. Cardiopulmonary bypass and cross-clamp times were shorter in the right anterior minithoracotomy group than in the median sternotomy and partial upper hemisternotomy groups (p < 0.001). No significant differences in in-hospital mortality were observed (p = 0.9). Renal failure (odds ratio, 5.4; 95% confidence interval, 2.3 to 11.4; p < 0.0001), extracardiac arteriopathy (odds ratio, 2.9; 95% confidence interval, 1.1 to 6.7; p = 0.017), and left ventricular ejection fraction (odds ratio, 0.96; 95% confidence interval, 0.93 to 0.99; p = 0.009) emerged as independent predictors of in-hospital mortality.

CONCLUSIONS

Minimal-access isolated aortic valve surgery is a reproducible, safe, and effective procedure with similar outcomes and operating times compared with conventional sternotomy.

Sutureless aortic valves: who is the right patient?

PURPOSE OF REVIEW

Sutureless aortic valve replacement (AVR) has emerged as an alternative to traditional AVR for patients with aortic stenosis who present a higher surgical risk, such as the elderly, or those with small or highly calcified aortic roots. With transcatheter aortic valve implantation - the other major AVR alternative - being used in increasingly lower-risk patients, the place of sutureless valves in the AVR landscape needs to be defined. In this review, we discuss recent data and expert opinion as it pertains to the subject of sutureless AVR.

RECENT FINDINGS

Several recent studies have evaluated the performance of sutureless valves in a variety of clinical contexts, including minimally invasive operations and high-risk surgical procedures. The optimal surgical technique for sutureless AVR has been refined through the publication of several reports addressing technical considerations. Reduction in operative times represents the main advantage of sutureless valves over conventional surgical prostheses, and the possibility of complete annular decalcification - and hence a reduced incidence of paravalvular leak - is the primary advantage over TAVI.

SUMMARY

Sutureless valves have emerged as an attractive option for high-risk patients or for complex surgeries where a minimization of bypass time is critical. However, there is limited data regarding long-term outcomes, durability or reoperation.

Ten-year experience with the Perceval S sutureless prosthesis: lessons learned and future perspectives

Aortic stenosis has traditionally been addressed with surgical aortic valve replacement (AVR). In recent years, several technologies have emerged as alternative treatment methods for aortic valve disease. Among them, the Perceval (LivaNova, London, UK) is a sutureless valve that has been used in clinical practice for over 10 years. It has been implanted in over 20,000 patients worldwide. With nearly 600 Perceval implants since 2011, the Montreal Heart Institute has developed a worldwide expertise with this technology. In this article, we provide an overview of the clinical data currently available in the literature and discuss the lessons we have learned from our experience with the Perceval prosthesis.

A technique of minimally invasive aortic valve replacement: an alternative to transcatheter aortic valve replacement (TAVR)

Minimally invasive aortic valve replacement (AVR) is increasingly being adopted worldwide, in which a right mini-thoracotomy (RT) approach plays an important role. Here we reported a novel technique of AVR via RT using sutureless prosthesis, without rib division or groin incision. Surgical access was performed through an anterior right thoracotomy with 5-cm skin incision placed in the third intercostal space. Percutaneous femoral-femoral cardio-pulmonary bypass (CPB) was applied under fluoroscopy guidance to avoid groin incision. A 5-mm stab incision was made in the right chest wall for aortic cross-clamping. A sutureless bioprosthetic valve was utilized in the limited operative field, which reduced the cross-clamp and CPB time. The patient was discharged on post-operative day 2, without obvious cross-valvar gradient, and with no pain or other complication. This report offers a more minimally invasive approach to AVR with proven durable valves, which can benefit high-risk patients.

Technique and Patient Selection Criteria of Right Anterior Mini-Thoracotomy for Minimal Access Aortic Valve Replacement

Aortic valve stenosis has become the most prevalent valvular heart disease in developed countries, and is due to the aging of these populations. The incidence of the pathology increases with growing age after 65 years. Conventional surgical aortic valve replacement through median sternotomy has been the gold standard of patient care for symptomatic aortic valve stenosis. However, as the risk profile of patients worsens, other therapeutic strategies have been introduced in an attempt to maintain the excellent results obtained by the established surgical treatment. One of these approaches is represented by transcatheter aortic valve implantation. Although the outcomes of high-risk patients undergoing treatment for symptomatic aortic valve stenosis have improved with transcatheter aortic valve replacement, many patients with this condition remain candidates for surgical aortic valve replacement. In order to reduce the surgical trauma in patients who are candidates for surgical aortic valve replacement, minimally invasive approaches have garnered interest during the past decade. Since the introduction of right anterior thoracotomy for aortic valve replacement in 1993, right anterior mini-thoracotomy and upper hemi-sternotomy have become the predominant incisional approaches among cardiac surgeons performing minimal access aortic valve replacement. Beside the location of the incision, the arterial cannulation site represents the second major landmark of minimal access techniques for aortic valve replacement. The two most frequently used arterial cannulation sites include central aortic and peripheral femoral approaches. With the purpose of reducing surgical trauma in these patients, we have opted for a right anterior mini-thoracotomy approach with a central aortic cannulation site. This protocol describes in detail a technique for minimally invasive aortic valve replacement and provides recommendations for patient selection criteria, including cardiac computer tomography measurements. The indications and limitations of this technique, as well as its alternatives, are discussed.

Right anterior mini-thoracotomy vs. conventional sternotomy for aortic valve replacement: a propensity-matched comparison

Background

Right anterior mini-thoracotomy (MIAVR) is a promising technique for aortic valve replacement. We aimed at comparing its outcomes with those obtained in a propensity-matched group of patients undergoing sternotomy at our two high-volume centers.

Methods

Main clinical and operative data of patients undergoing aortic valve replacement between January 2010 and May 2016 were retrospectively collected. A total of 678 patients were treated with a standard full sternotomy approach, while MIAVR was performed in 502. Propensity score matching identified 363 patients per each group.

Results

In-hospital mortality was not significantly different between the propensity-matched groups (1.7% in MIAVR patients vs. 2.2% in conventional sternotomy patients; P=0.79). No significant difference in the incidence of major post-operative complications was observed. Post-operative ventilation times (median 7, range 5-12 hours in MIAVR patients vs. median 7, range 5-12 in conventional sternotomy patients; P=0.72) were not significantly different between the two groups. Cardiopulmonary bypass time (61.0±21.0 vs. 65.9±24.7 min in conventional sternotomy group; P<0.01) and aortic cross-clamping time (48.3±16.7 vs. 53.2±19.6 min in full sternotomy group; P<0.01) were shorter in MIAVR group. EuroSCORE (OR 1.52, 95% CI, 1.12-2.06; P<0.01) was found to be the only independent predictor of intra-hospital mortality in the whole propensity-matched population.

Conclusions

Our experience shows that mini-access isolated aortic valve surgery is a reproducible, safe and effective procedure with similar outcomes and no longer operative times compared to conventional sternotomy.

Video assisted right mini-thoracotomy for aortic valve replacement

Aortic valve replacement through minimally invasive access is increasing. These procedures have several advantages over conventional sternotomy including decreased intensive care unit and hospital length of stay and decreased ventilation time. The right anterior mini-thoracotomy (RAM) approach is potentially attractive in that it completely spares the sternum leading to improved cosmesis, reduced blood loss, and improved patient satisfaction. However, this approach is underutilized due to anticipated technical challenges including difficulty with visualization and annular suture placement. We employ a camera and automated suturing technology for supra-annular valve implant. A RAM is performed via a 5 cm incision in the right second intercostal space with a camera port placed lateral to the incision. Peripheral venous cannulation is performed along with central arterial cannulation. Aortic cross clamp is placed through a 5 mm incision in the third interspace anterior to mid axillary line. Histidine tryptophan ketoglutarate (HTK) cardioplegia is administered. After aortic leaflet removal, annular and prosthetic sutures are placed with shafted instruments or with automated suturing technology. Aortic valve replacement can be performed safely through a RAM. The use of a camera and automated suturing technology facilitates this procedure, potentially enabling more surgeons to offer this less invasive approach to patients.

Sutureless Perceval Aortic Valve Versus Conventional Stented Bioprostheses: Meta-Analysis of Postoperative and Midterm Results in Isolated Aortic Valve Replacement

Background

Aortic stenosis is the most common valvular disease and has a dismal prognosis without surgical treatment. The aim of this meta‐analysis was to quantitatively assess the comparative effectiveness of the Perceval (LivaNova) valve versus conventional aortic bioprostheses.

Methods and Results

A total of 6 comparative studies were identified, including 639 and 760 patients who underwent, respectively, aortic valve replacement with the Perceval sutureless valve (P group) and with a conventional bioprosthesis (C group). Aortic cross‐clamping and cardiopulmonary bypass duration were significantly lower in the P group. No difference in postoperative mortality was shown for the P and C groups (2.8% versus 2.7%, respectively; odds ratio [OR]: 0.99 [95% confidence interval (CI), 0.52–1.88]; P=0.98). Incidence of postoperative renal failure was lower in the P group compared with the C group (2.7% versus 5.5%; OR: 0.45 [95% CI, 0.25–0.80]; P=0.007). Incidence of stroke (2.3% versus 1.7%; OR: 1.34 [95% CI, 0.56–3.21]; P=0.51) and paravalvular leak (3.1% versus 1.6%; OR: 2.52 [95% CI, 0.60–1.06]; P=0.21) was similar, whereas P group patients received fewer blood transfusions than C group patients (1.16±1.2 versus 2.13±2.2; mean difference: 0.99 [95% CI, −1.22 to −0.75]; P=0.001). The incidence of pacemaker implantation was higher in the P than the C group (7.9% versus 3.1%; OR: 2.45 [95% CI, 1.44–4.17]; P=0.001), whereas hemodynamic Perceval performance was better (transvalvular gradient 23.42±1.73 versus 22.8±1.86; mean difference: 0.90 [95% CI, 0.62–1.18]; P=0.001), even during follow‐up (10.98±5.7 versus 13.06±6.2; mean difference: −2.08 [95% CI, −3.96 to −0.21]; P=0.030). We found no difference in 1‐year mortality.

Conclusions

The Perceval bioprosthesis improves the postoperative course compared with conventional bioprostheses and is an option for high‐risk patients.

Comparison of Automated Titanium Fasteners to Hand-Tied Knots in Open Aortic Valve Replacement

Objective

Aortic cross-clamp and cardiopulmonary bypass times are independent predictors of postoperative morbidity and mortality. Reducing ischemic times with automated titanium fasteners may improve surgical outcomes. This study compared operative times and costs of titanium fasteners versus hand-tied knots for prosthesis securement in open aortic valve replacement.

Methods

A randomized control trial was conducted during a 16-month period at a single university medical center. Patients undergoing elective aortic valve replacement were randomized to the titanium fastener (n = 37) or hand-tied groups (n = 36). Knotting, aortic cross-clamp, cardiopulmonary bypass, and total operating room times were recorded. Hospital charges were also calculated for these procedures.

Results

Baseline characteristics, concomitant procedures, prosthetic valve size, and sutures were similar between groups. The titanium fastener group had significantly reduced knotting (7.4 vs. 13.0 minutes, P < 0.001), aortic cross-clamp (69 vs. 90 minutes, P < 0.05), cardiopulmonary bypass (86 vs. 114 minutes, P < 0.05), and total operating room times (234 vs. 266 minutes, P < 0.05). Intraoperative complications occurred more frequently in the hand-tied group compared with the titanium fastener group. Postoperative complications were similar between groups. Operating room costs were significantly higher in the titanium fastener group (US $10,428 vs. US $9671, P = 0.01). Hospitalization costs did not differ significantly between the titanium fastener and hand-tied group (US $23,987 vs. US $21,068, P = 0.12).

Conclusions

Titanium fastener use was associated with shorter knotting, aortic cross-clamp, cardiopulmonary bypass, and operating room times and fewer intraoperative complications in open aortic valve replacement, without significantly increasing hospitalization cost.

The evolution of minimally invasive cardiac surgery: from minimal access to transcatheter approaches

The field of minimally invasive cardiac surgery has undergone rapid transformation over recent years. In this review, we provide a summary of the most current evidence supporting the use of minimally invasive aortic and mitral valve replacement techniques, as well as transcatheter approaches for aortic and mitral valve disease. As an adjunct, the use of robotically assisted coronary bypass surgery and hybrid coronary revascularization procedures is discussed. In order to obtain optimal patient outcomes, a collaborative, heart-team approach between cardiac surgeons and interventional cardiologists is necessary.

Advantages of Minimal Access Versus Conventional Aortic Valve Replacement in Elderly or Severely Obese Patients

OBJECTIVE

The aim of our study was to investigate potential clinical advantages of minimal access versus conventional surgical approach in older and severely obese patients undergoing isolated aortic valve replacement (AVR).

METHODS

One hundred thirty-five patients undergoing isolated primary AVR were enrolled. Propensity score matching was used to compare 42 selected patients operated on ministernotomy (MS, group B) with 42 selected patients operated on full sternotomy (FS, group A).

RESULTS

After propensity score matching, the two groups were comparable in terms of preoperative characteristics. Cardiopulmonary bypass time was significantly longer in MS group compared with the FS group [median (95% confidence level or CL), 103 (98.7-106.4) vs 94 (83.6-99) minutes, respectively; P = 0.0019]. No significant difference was observed in aortic cross-clamp time [median (95% CL), 73 (71.1-78.2) vs 69.5 (62.7-83) minutes; P = 0.4]. Significantly shorter ventilation time [median (95% CL), 13 (12-16.4) vs 24 (22-25) hours; P = 0.00018], intensive care unit stay [median (95% CL), 1 vs 2 days; P = 0.00017], and hospital stay [median (95% CL), 8.5 (8-10.8) vs 13.5 (11.1-14) days; P = 0.00030] were shown in the MS group. The age subgroup analysis showed that statistical significance for mechanical ventilation, intensive care unit, and hospital stay was specific for patients older than 75 years. The analysis of body mass index quartile showed that statistical significance for mechanical ventilation was specific for patients in the fourth quartile.

CONCLUSIONS

Minimal access AVR is a reproducible, safe, and effective surgical option in patients candidate for isolated AVR, and our study suggests a faster recovery when used in severely obese or older patients.

Review of minimal access versus transcatheter aortic valve replacement for patients with severe aortic stenosis

Transcatheter aortic valve replacement (TAVR) and minimally invasive aortic valve replacement (miniAVR) have become alternatives to surgical aortic valve replacement via median sternotomy (SAVR) to treat severe aortic stenosis (AS). Despite increased interest and utilization, few studies have directly compared TAVR and miniAVR. A review of the current literature shows TAVR to be an indispensable tool for inoperable, high-risk, and perhaps intermediate-risk patients with severe AS. However, it is associated with a number of deleterious perioperative outcomes, such as valvular regurgitation and vascular complications. MiniAVR is associated with decreased intensive care unit (ICU) and hospital length of stay, a lower incidence of blood transfusions, decreased ventilation time, and improved cosmetic results. MiniAVR maintains potential advantages over SAVR, including the implantation of a durable prosthesis and low rates of perioperative myocardial infarction and paravalvular leak. It is associated with longer aortic cross clamp and cardiopulmonary bypass (CPB) times; however, the use of sutureless valve implants can circumvent this. Studies comparing TAVR and miniAVR demonstrate decreased postoperative mortality, valvular regurgitation, and incidence of stroke in the miniAVR cohorts. Few studies currently exist comparing TAVR and miniAVR, as it is hard to compare the typically low-risk miniAVR versus high-risk TAVR patient populations. It is clear that both strategies will be cornerstones in the modern AVR era, but the situations in which to apply each strategy have not yet been clearly delineated. This highlights the need for surgeons to adopt these minimally invasive techniques. We believe there is a compelling role for miniAVR in low- and intermediate-risk patients, but due to the paucity of data, neither TAVR nor miniAVR should be discounted before a randomized, risk-stratified trial is performed. More studies are needed to compare TAVR and miniAVR in low- and intermediate-risk patients.

Early Hemodynamic Results in Patients with Small Aortic Annulus after Aortic Valve Replacement

Objective

Patients with a small aortic annulus (≤21 mm) have an increased risk of patient-prosthesis mismatch after valve replacement. The aim of this study was to compare the early hemodynamic performance of the balloon-expandable transaortic valve implantation Edwards system (SAPIEN) and the sutureless Perceval prostheses.

Methods

Fifty patients underwent transcatheter aortic valve implantation, and 113 patients underwent sutureless aortic valve replacement. Mean ± SD aortic annulus diameter was 19.7 ± 1 mm, with no significant difference between groups. SAPIEN valve size was 23 mm in 40 patients (80%) and 26 mm in 10 patients (20%). Perceval valve size was small in 45 patients (40%), medium in 62 patients (55%), and large in 6 patients (5%). Transthoracic Doppler echocardiographic images were collected at baseline and before discharge.

Results

There were no significant difference in predischarge effective orifice area (SAPIEN: 1.5 ± 0.5 cm2 and Perceval: 1.48 ± 0.34 cm2, P = 0.58) and indexed effective orifice areas (SAPIEN: 0.93 ± 0.32 cm2/m2 and Perceval: 0.88 ± 0.22 cm2/m2, P = 0.42). Predischarge mean ± SD transaortic gradient was lower with the SAPIEN than with Perceval valves (12 ± 6 and 17 ± 6 mm Hg, respectively, P < 0.001). Rates of moderate and severe prosthesis-patient mismatch were similar (SAPIEN: 44% and 10% and Perceval: 50% and 14%, P = 0.53 and 0.75, respectively). There were no moderate-severe paravalvular leaks.

Conclusions

Although indexed effective orifice areas were similar, transcatheter aortic valve implantation with the balloon-expandable SAPIEN system yielded lower predischarge transaortic mean gradients than the surgically implanted Perceval, in patients with a small annulus.

Aortic Valve Surgery: Minimally Invasive Options

Minimally invasive aortic valve surgery has not been adopted by a significant proportion of cardiac surgeons despite proven benefits. This may be related to a high learning curve and technical issues requiring retraining. In this review, we discuss the data for minimally invasive aortic valve surgery and describe our operative technique for both ministernotomy and anterior thoracotomy approaches. We also discuss the advent of novel sutureless valves and how these techniques compare to available transcatheter aortic valve procedures.

First-in-Man Transcervical Surgical Aortic Valve Replacement Using the CoreVista System

OBJECTIVE

This study aimed to evaluate a novel device system for surgical aortic valve replacement (SAVR) using a unique new less invasive access approach. The hypothesis is that SAVR can be performed through a short transverse incision in the neck, similar to that used for transcervical thymectomy avoiding chest disruption.

METHODS

A new device system was developed to provide retraction, step-by-step illumination, and on-screen visualization for the new approach. Preliminary feasibility studies were performed in cadavers. Comprehensive risk analysis was performed, and training was implemented in Thiel preserved cadavers. For the first-in-man clinical case, a 63-year-old woman with symptomatic critical aortic stenosis (The Society of Thoracic Surgeons risk, 11%) and heavily calcified aortic valve was selected. A short transverse incision was made in the neck; the device was introduced, and the sternum was elevated; femorofemoral cardiopulmonary bypass was established; substernal dissection was guided by the sequenced illumination, and high-definition visualization was provided by the device, allowing for optimal exposition of the aorta and aortic valve; and a 23-mm Medtronic ENABLE sutureless valve prosthesis was implanted. Procedure success was evaluated according to the standardized composite end point definition of "device success" proposed by the Valve Academic Research Consortium.

RESULTS

Access, delivery, and deployment of the valve prosthesis were successful. The correct position and intended performance of the valve were demonstrated (mean gradient, 6 mm Hg; aortic valve area, 2.5 cm) with the absence of moderate or severe prosthetic aortic regurgitation. Only one valve prosthesis was used.

CONCLUSIONS

Transcervical SAVR with sutureless valve is feasible using this novel access system. The new approach has potential to offer patients substantially shorter stay and fewer, less serious complications, as has been observed in transcervical thymectomy. Further studies are merited.

Limited versus full sternotomy for aortic valve replacement

BACKGROUND

Aortic valve disease is a common condition that is easily treatable with cardiac surgery. This is conventionally performed by opening the sternum longitudinally down the centre ("median sternotomy") and replacing the valve under cardiopulmonary bypass. Median sternotomy is generally well tolerated, but as less invasive options have become available, the efficacy of limited incisions has been called into question. In particular, the effects of reducing the visibility and surgical access has raised safety concerns with regards 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.

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, Embase, clinical trials registries, and manufacturers' websites from inception to July 2016, with no language limitations. We reviewed references of identified papers to identify any further studies of relevance.

SELECTION CRITERIA

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, trans-apical, trans-femoral 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. The quality of evidence was determined using the GRADE methodology and results of patient-relevant outcomes were summarised in a 'Summary of findings' table.

MAIN RESULTS

The review included seven trials with 511 participants. These included adults from centres in Austria, Spain, Italy, Germany, France, and Egypt. We performed 12 comparisons investigating the effects of minimally invasive limited upper hemi-sternotomy on aortic valve replacement as compared to surgery performed via full median sternotomy.There was no evidence of any effect of upper hemi-sternotomy on mortality versus full median sternotomy (risk ratio (RR) 1.01, 95% confidence interval (CI) 0.36 to 2.82; participants = 511; studies = 7; moderate quality). There was no evidence of an increase in cardiopulmonary bypass time with aortic valve replacement performed via an upper hemi-sternotomy (mean difference (MD) 3.02 minutes, 95% CI -4.10 to 10.14; participants = 311; studies = 5; low quality). There was no evidence of an increase in aortic cross-clamp time (MD 0.95 minutes, 95% CI -3.45 to 5.35; participants = 391; studies = 6; low quality). None of the included studies reported major adverse cardiac and cerebrovascular events as a composite end point.There was no evidence of an effect on length of hospital stay through limited hemi-sternotomy (MD -1.31 days, 95% CI -2.63 to 0.01; participants = 297; studies = 5; I2 = 89%; very low quality). Postoperative blood loss was lower in the upper hemi-sternotomy group (MD -158.00 mL, 95% CI -303.24 to -12.76; participants = 297; studies = 5; moderate quality). The evidence did not support a reduction in deep sternal wound infections (RR 0.71, 95% CI 0.22 to 2.30; participants = 511; studies = 7; moderate quality) or re-exploration (RR 1.01, 95% CI 0.48 to 2.13; participants = 511; studies = 7; moderate quality). There was no change in pain scores by upper hemi-sternotomy (standardised mean difference (SMD) -0.33, 95% CI -0.85 to 0.20; participants = 197; studies = 3; I2 = 70%; very low quality), but there was a small increase in postoperative pulmonary function tests with minimally invasive limited sternotomy (MD 1.98 % predicted FEV1, 95% CI 0.62 to 3.33; participants = 257; studies = 4; I2 = 28%; low quality). There was a small reduction in length of intensive care unit stays as a result of the minimally invasive upper hemi-sternotomy (MD -0.57 days, 95% CI -0.93 to -0.20; participants = 297; studies = 5; low quality). Postoperative atrial fibrillation was not reduced with minimally invasive aortic valve replacement through limited compared to full sternotomy (RR 0.60, 95% CI 0.07 to 4.89; participants = 240; studies = 3; moderate quality), neither were postoperative ventilation times (MD -1.12 hours, 95% CI -3.43 to 1.19; participants = 297; studies = 5; low quality). None of the included studies reported cost analyses.

AUTHORS' CONCLUSIONS

The evidence in this review was assessed as generally low to moderate quality. The study sample sizes were small and underpowered to demonstrate differences in outcomes with low event rates. Clinical heterogeneity both between and within studies is a relatively fixed feature of surgical trials, and this also contributed to the need for caution in interpreting results.Considering these limitations, there was uncertainty of the effect on mortality or extracorporeal support times with upper hemi-sternotomy for aortic valve replacement compared to full median sternotomy. The evidence to support a reduction in total hospital length of stay or intensive care stay was low in quality. There was also uncertainty of any difference in the rates of other, secondary outcome measures or adverse events with minimally invasive limited sternotomy approaches to aortic valve replacement.There appears to be uncertainty between minimally invasive aortic valve replacement via upper hemi-sternotomy and conventional aortic valve replacement via a full median sternotomy. 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 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.

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.

Respiratory System Function in Patients after Minimally Invasive Aortic Valve Replacement Surgery

Objective

The aim of the study was to comparatively analyze respiratory system function after minimally invasive, through right minithoracotomy aortic valve replacement (RT-AVR) to conventional AVR.

Methods

Analysis of 201 patients scheduled for RT-AVR and 316 for AVR between January 2010 and November 2013. Complications of the respiratory system and pulmonary functional status are presented.

Results

Complications of the respiratory system occurred in 16.8% of AVR and 11.0% of RT-AVR patients ( P = 0.067). The rate of pleural effusions, thoracenteses, pneumonias, or phrenic nerve dysfunctions was not significantly different between groups. Perioperative mortality was 1.9% in AVR and 1.0% in RT-AVR ( P = 0.417). Mechanical ventilation time after surgery was 9.7 ± 5.9 hours for AVR and 7.2 ±3.2 hours for RT-AVR patients ( P < 0.001). Stroke (odds ratio [OR] = 13.4, P = 0.008), increased postoperative blood loss (OR = 9.6, P <0.001), and chronic obstructive pulmonary disease (OR = 7.7, P < 0.001) were risk factors of prolonged mechanical lung ventilation. A week after surgery, the results of most pulmonary function tests were lower in the AVR than in the RT-AVR group ( P < 0.001 was seen for forced expiratory volume in the first second, vital capacity, total lung capacity, maximum inspiratory pressure and maximum expiratory pressure, P = 0.377 was seen for residual volume).

Conclusions

Right anterior aortic valve replacement minithoracotomy surgery with single-lung ventilation did not result in increased rate of respiratory system complications. Spirometry examinations revealed that pulmonary functional status was more impaired after AVR in comparison with RT-AVR surgery.

Early results of the Sorin® Perceval S sutureless valve: systematic review and meta-analysis

BACKGROUND

Minimally invasive aortic valve replacement (MAVR) has demonstrated a benefit with respect to increased patient satisfaction due to minimised pain and earlier recovery. Sutureless valves may benefit MAVR and conventional aortic valve replacement (AVR) by reducing operative times and blood transfusion requirements. The Perceval valve (Sorin, Salluggia, Italy) is a self-expanding prosthesis made from bovine pericardium mounted in a nitinol stent, designed to simplify the implantation of an aortic valve. This meta-analysis evaluates the clinical, haemodynamic, and survival outcomes of the Perceval sutureless valve.

METHODS

An electronic search of 4 databases was performed from January 2000 to December 2016. Primary outcomes included mortality and stroke. Secondary outcomes included minimally invasive access, paravalvular leak, overall long-term survival, postoperative echocardiographic findings, and functional class improvement.

RESULTS

After the application of inclusion and exclusion criteria, 14 of 66 relevant articles were selected for assessment. Of these 14 studies, a total number of 2,505 patients were included. The current evidence on the Perceval valve for aortic valve disease is limited to observational studies only. Minimally invasive surgery was performed in 976 patients, of which 336 were via the right anterior thoracotomy approach. The Perceval M and L sutureless valves were the most frequently used, 782 and 770 respectively. The incidence of major adverse events included 30-day mortality (0 to 4.9%), cerebrovascular accident (0 to 3%), permanent pacemaker insertion (0 to 17%), moderate to severe paravalvular leak (0 to 8.6%), and re-operation (0 to 4.8%). Post-operative mean aortic valve gradient ranged from 9 to 15.9 mmHg and post-operative New York Heart Association (NYHA) Class I or II ranged from 82% to 96%. The 1-year survival ranged from 86% to 100%; and 5-year survival was 71.3% to 85.5% in two studies.

CONCLUSIONS

The Perceval valve is associated with excellent post-operative results in MAVR and in conventional AVR. Larger randomised controlled studies are required to evaluate the long-term efficacy of the prosthesis.

Minimally Invasive Aortic Valve Replacement via Right Anterior Minithoracotomy and Central Aortic Cannulation

Objective

This study reports the evolution of a minimally invasive aortic valve replacement (mini-AVR) technique that uses a right anterior minithoracotomy approach with central cannulation, for a 13-year period. This technique has become our standard approach for isolated primary AVR in nearly all patients.

Methods

This observational study evaluated perioperative clinical outcomes of patients 18 years or older who underwent mini-AVR from November 2003 to June 2015.

Results

The mini-AVR technique was used in 202 patients during two periods of 2003 to 2009 (n = 65, “early”) and 2010 to 2015 (n = 137, “late”). The mean ± SD age was 72.5 ± 12.9 years and 60% were male. Demographic parameters were statistically similar between the study periods, except for increased body weight in the later period (75.3 ± 14.7 vs 80.9 ± 20.8 kg, P = 0.03). The mean cardiopulmonary bypass and aortic cross-clamp times were significantly different by each year and Bonferroni adjustment, with significant decreases in cardiopulmonary bypass and aortic cross-clamp times beginning 2006. Compared with the early study period, late study period patients were more often extubated intraoperatively (52% vs 12%, P < 0.001), had less frequent prolonged ventilator use postoperatively (6% vs 16%, P = 0.018), required fewer blood transfusions (mean, 2.0 ± 2.3 U vs 3.6 ± 3.0 U; P = 0.011), and had shorter postoperative stay (6.3 ± 4.5 days vs 8.0 ± 5.9 days, P = 0.026). Numerically, fewer postoperative strokes (1% vs 6%, P = 0.09) and fewer reoperations for bleeding (3% vs 6%, P = 0.3) occurred in the late period. In-hospital mortality did not differ (1/65 early vs 3/137 late).

Conclusions

Overall mini-AVR intraoperative and postoperative clinical outcomes improved for this 13-year experience.

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

Minimally invasive aortic valve replacement (MIAVR) has been demonstrated as a safe and effective option but remains underused. We aimed to evaluate outcomes of isolated MIAVR compared with conventional aortic valve replacement (CAVR).

Sutureless Aortic Valves: Combining the Best or the Worst?

Aortic valve replacement is a life saving intervention. Significant progress has been made toward reducing surgical trauma through minimally invasive surgery and transcatheter techniques. Each of these approaches has its advantages and limitations. Sutureless aortic valves have been proposed to overcome these limitations and have been in use in Europe. It is however less than clear whether these valves will prove advantageous and whether they will have a role in the future. We review the published literature for sutureless aortic valves and their performance against standard and transcatheter aortic valve replacements.

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.

Mini-aortic surgery with percutaneous cannulation and rapid-deployment valve

Background

We aimed to evaluate the results of the combined use of rapid-deployment valves, percutaneous cardioplegia delivery and left heart venting during minimally invasive aortic valve replacement surgery.

Methods

We identified 2 propensity-matched cohorts of patients who underwent primary elective isolated minimally invasive aortic valve surgery at our center over a 3-years period: 30 patients in group A had a conventional valve prosthesis and 30 patients in group B received a rapid-deployment valve using percutaneous cardioplegia delivery and percutaneous left heart venting. Skin incision length, intraoperative times, postoperative hospital outcomes, and 30-day echocardiographic results were compared between the 2 groups.

Results

Patients in group B had significantly shorter operative times and shorter skin incisions compared to group A (total operative time 196.0 ± 40.6 vs. 225.1 ± 30.8 min, respectively, p < 0.003; cardiopulmonary bypass time 79.9 ± 10.6 vs. 92.9 ± 17.2 min respectively, p < 0.001; crossclamp time 52.3 ± 9.6 vs. 74.9 ± 10.2 min, respectively, p < 0.001; incision length 3.6 ± 0.5 vs. 6.0 ± 0.6 cm, respectively, p < 0.001). Postoperative hospital outcomes and echocardiographic evaluation showed no significant differences.

Conclusions

The combined use of rapid-deployment valves, percutaneous cardioplegia, and left heart venting is safe and effective and allows a significant reduction of the skin incision together with a significant reduction of intraoperative times without affecting hospital outcomes or hemodynamic performance of the prosthetic valves.

Exploring the learning curve for minimally invasive sutureless aortic valve replacement

OBJECTIVE

The study objective was to assess the learning process and quality of care of right minithoracotomy aortic valve replacement with a sutureless bioprosthesis at a single institution.

METHODS

We performed an analysis of the first 300 consecutive patients (aged 76 ± 6 years; logistic European System for Cardiac Operative Risk Evaluation 9 ± 6) who underwent sutureless valve implantation via a right minithoracotomy by 6 surgeons at the G. Pasquinucci Heart Hospital between 2011 and 2015. The learning curve was analyzed by dividing the study population into tertiles of 100 patients each. Departmental and individual learning curves were calculated using sequential probability cumulative sum failure analysis. Quality indicators were 2 composite end points reflecting the technical success and 30-day complications.

RESULTS

The overall mortality was 0.7% (2 patients). No significant differences were noted in terms of mortality and complications between tertiles. The sutureless valve was implanted successfully in 99% of patients (298/300). Cumulative sum analysis failed to identify any significant learning effects for technical success. Nevertheless, surgeons A, B, and C had a small initial learning curve, and surgeons D, E, and F did not, reflecting a trend toward a positive effect of cumulative institutional experience on the individual learning curve. The 30-day complications analysis revealed a cluster of failures at the beginning of the experience. This cluster prompted an internal audit and modification of the patients' selection process. Consecutively, the procedure returned in control.

CONCLUSIONS

Right minithoracotomy sutureless valve implantation can be performed safely without learning curve effects. Cumulative sum analysis is a valuable tool to describe and monitor the learning process. The analysis can identify periods of less than expected performance and alert the team to react.

Influence of body mass index on outcomes after minimal-access aortic valve replacement through a J-shaped partial upper sternotomy

Background

Minimal-access aortic valve replacement (MAAVR) may reduce post-operative blood loss and transfusion requirements, decrease post-operative pain, shorten length stay and enhance cosmesis. This may be particularly advantageous in overweight/obese patients, who are at increased risk of post-operative complications. Obese patients are however often denied MAAVR due to the perceived technical procedural difficulty. This retrospective analysis sought to determine the effect of BMI on post-operative outcomes in patients undergoing MAAVR.

Methods

Ninety isolated elective MAAVR procedures performed between May 2006–October 2013 were included. Intra- and post-operative data were prospectively collected. Ordinary least squares univariate linear regression analysis was performed to determine the effect of BMI as a continuous variable on post-operative outcomes. One-way ANOVA and Chi-squared testing was used to assess differences in outcomes between patients with BMI <25 (n = 36) and BMI ≥25 (n = 54) as appropriate.

Results

There was no peri-operative mortality, myocardial infarction or stroke. Univariate regression demonstrated longer cross-clamp times (p = 0.0218) and a trend towards increased bypass times (p = 0.0615) in patients with higher BMI. BMI ≥25 was associated with an increased incidence of hospital-acquired pneumonia (p = 0.020) and new-onset atrial fibrillation (p = 0.036) compared to BMI <25. However, raised BMI did not extend ICU (p = 0.3310) or overall hospital stay (p = 0.2614). Similar rates of sternal wound complications, inotrope requirements and renal dysfunction were observed in both normal- and overweight/obese-BMI groups. Furthermore, increasing BMI correlated with reduced mechanical ventilation time (p = 0.039) and early post-operative blood loss (p = 0.004).

Conclusions

Our results demonstrate that within the range of this study, MAAVR is a safe, reproducible and effective procedure, affording equivalent clinical outcomes in both overweight/obese and normal-weight patients considered for an isolated first-time AVR, with low post-operative morbidity and mortality. MAAVR should therefore be considered as an alternative surgical strategy to reduce obesity-related complications in patients requiring aortic valve replacement.