Minimally invasive aortic valve surgery in the elderly: a case-control study

Minimally Invasive and Full Sternotomy Aortic Valve Replacements Lead to Comparable Long-Term Outcomes in Elderly Higher-Risk Patients: A Propensity-Matched Comparison

BACKGROUND

Minimally invasive aortic valve replacement (AVR) via upper ministernotomy (MiniAVR) is a standard alternative to full sternotomy access. Minimally invasive cardiac surgery has been proven to provide a number of benefits to patients. The aim of this study was to compare the short- and long-term outcomes after MiniAVR versus conventional AVR via full sternotomy (FS) using a biological prosthesis in an elderly higher-risk population.

METHODS

Between January 2006 and July 2009, 918 consecutive patients received AVR ± additional procedures with different prostheses at our center. Amongst them, 441 received isolated AVR using a biological prosthesis (median age of 74.5; range: 52-93 years; 50% females) and formed the study population (EuroSCORE II: 3.62 ± 5.5, range: 0.7-42). In total, 137 (31.1%) of the operations were carried out through FS, and 304 (68.9%) were carried out via MiniAVR. Follow-up was complete in 96% of the cases (median of 7.6 years, 6610 patient-years). Propensity score matching (PSM) resulted in two groups of 68 patients with very similar baseline profiles. The primary endpoints were long-term survival, freedom from reoperation, and endocarditis, and the secondary endpoints were early major adverse cardiac and cerebrovascular events (MACCEs).

RESULTS

FS led to shorter cardio-pulmonary bypass and aortic cross-clamp durations: 90 (47-194) vs. 100 (46-246) min (p = 0.039) and 57 (33-156) vs. 69 (32-118) min (p = 0.006), respectively. Perioperative stroke occurred in three patients (4.4%; FS) vs. one patient (1.5%; MiniAVR) (p = 0.506). The 30-day mortality was similar in both groups (2.9%, p = 1.000). Survival at 1, 5, and 10 years was 94.1 ± 3% (FS and MiniAVR), 80.3 ± 5% vs. 75.7 ± 5%, and 45.3 ± 6% vs. 43.8 ± 6%, respectively (p = 0.767). There were two (2.9%) reoperations in each group and two thrombo-embolic events (2.9%) vs. one (1.5%) thrombo-embolic event in the MiniAVR and FS groups, respectively (p = 0.596).

CONCLUSIONS

In comparison to FS, MiniAVR provided similar short- and long-term outcomes in a higher-risk elderly population receiving biological prostheses. In particular, long-term survival, freedom from reoperation, and the incidence of endocarditis were comparable. These results clearly advocate for the routine use of MiniAVR as a standard procedure for AVR, even in a high-risk population.

Quality of life in patients undergoing minimally invasive cardiac surgery: a systematic review

Objective

Minimally invasive procedures have been developed to reduce surgical trauma after cardiac surgery. Clinical recovery is the main focus of most research. Still, patient-centred outcomes, such as the quality of life, can provide a more comprehensive understanding of the impact of the surgery on the patient's life. This systematic review aims to deliver a detailed summary of all available research investigating the quality of recovery, assessed with quality of life instruments, in adults undergoing minimally invasive cardiac surgery.

Methods

All randomised trials, cohort studies, and cross-sectional studies assessing the quality of recovery in patients undergoing minimally invasive cardiac surgery compared to conventional cardiac surgery within the last 20 years were included, and a summary was prepared.

Results

The randomised trial observed an overall improved quality of life after both minimally invasive and conventional surgery. The quality of life improvement in the minimally invasive group showed a faster course and evolved to a higher level than the conventional surgery group. These findings align with the results of prospective cohort studies. In the cross-sectional studies, no significant difference in the quality of life was seen except for one that observed a significantly higher quality of life in the minimally invasive group.

Conclusions

This systematic review indicates that patients may benefit from minimally invasive and conventional cardiac surgery, but patients undergoing minimally invasive cardiac surgery may recover sooner and to a greater extent. However, no firm conclusion could be drawn due to the limited available studies. Therefore, randomised controlled trials are needed.

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.

Minimally Invasive Aortic Valve Surgery in Octogenarians: Reliable Option or Fallback Solution?

OBJECTIVE

Aortic valve disease is more and more common in western countries. While percutaneous approaches should be preferred in older adults, previous reports have shown good outcomes after surgery. Moreover, advantages of minimally invasive approaches may be valuable for octogenarians. We sought to compare outcomes of conventional aortic valve replacement (CAVR) versus minimally invasive aortic valve replacement (MIAVR) in octogenarians.

METHODS

We retrospectively collected data of 75 consecutive octogenarians who underwent primary, elective, isolated aortic valve surgery through conventional approach (41 patients, group CAVR) or partial upper sternotomy (34 patients, group MIAVR).

RESULTS

Mean age was 81.9 ± 0.9 and 82.3 ± 1.1 years in CAVR and MIAVR patients, respectively (P = 0.09). MIAVR patients had lower 24-hour chest drain output (353.4 ± 207.1 vs 501.7 ± 229.9 mL, P < 0.01), shorter mechanical ventilation (9.6 ± 2.4 vs 11.3 ± 2.3 hours, P < 0.01), lower need for blood transfusions (35.3% vs 63.4%, P = 0.02), and shorter hospital stay (6.8 ± 1.6 vs 8.3 ± 4.3 days, P < 0.01). Thirty-day mortality was zero in both groups. Survival at 1, 3, and 5 years was 89.9%, 80%, and 47%, respectively, in the CAVR group, and 93.2%, 82.4%, and 61.8% in the MIAVR group, with no statistically significant differences (log-rank test, P = 0.35).

CONCLUSIONS

Aortic valve surgery in older patients provided excellent results, as long as appropriate candidates were selected. MIAVR was associated with shorter mechanical ventilation, reduced blood transfusions, and reduced hospitalization length, without affecting perioperative complications or mid-term survival.

Benefits of rapid deployment aortic valve replacement with a mini upper sternotomy

BACKGROUND

Surgical aortic valve replacement (AVR) is currently deemed the gold standard of care for patients with severe aortic stenosis. Currently, most AVRs are safely performed through a full median sternotomy approach. With an increasingly elderly and high-risk patient population, major advances in valve technology and surgical technique have been introduced to reduce perioperative risk and post-operative complications associated with the full sternotomy approach, in order to ensure surgical AVR remains the gold standard. For example, minimally invasive approaches (most commonly via mini sternotomy) have been developed to improve patient outcomes. The advent of rapid deployment valve technology has also been shown to improve morbidity and mortality by reducing cardiopulmonary bypass and aortic cross-clamp times, as well as facilitating the use of minimal access approaches. Rapid deployment valves were introduced into our department at the Royal Infirmary of Edinburgh in 2014. The aim of this study is to investigate if utilising the combination of rapid deployment valves and a mini sternotomy minimally invasive approach resulted in improved outcomes in various patient subgroups.

METHODS

Over a 3-year period, we identified 714 patients who underwent isolated AVR in our centre. They were divided into two groups: 61 patients (8.5%) were identified who received rapid deployment AVR via J-shaped mini upper sternotomy (MIRDAVR group), whilst 653 patients (91.5%) were identified who received either a full sternotomy (using a conventional prosthesis or rapid deployment valve) or minimally invasive approach using a conventional valve (CONVAVR group). We retrospectively analysed data from our cardiac surgery database, including pre-operative demographics, intraoperative times and postoperative outcomes. Outcomes were also compared in two different subgroups: octogenarians and high-risk patients.

RESULTS

Pre-operative demographics showed that there were significantly more female and elderly patients in the MIRDAVR group. The MIRDAVR group had significantly reduced cardiopulmonary bypass (63.7 min vs. 104 min, p = 0.0001) and aortic cross-clamp times (47.3 min vs. 80.1 min, p = 0.0001) compared to the CONVAVR group. These results were particularly significant in the octogenarian population, who also had a reduced length of ICU stay (30.9 h vs. 65.6 h, p = 0.049). In high-risk patients (i.e. logistic EuroSCORE I > 10%), minimally invasive-rapid deployment aortic valve replacement is still beneficial and is also characterized by significantly shorter cardiopulmonary bypass time (69.1 min vs. 96.1 min, p = 0.03). However, post-operative correlations, such as length of ICU stay, become no more significant, likely due to serious co-morbidities in this patient group.

CONCLUSION

We have demonstrated that minimally invasive rapid deployment aortic valve replacement is associated with significantly reduced cardiopulmonary bypass and aortic cross-clamp times. This correlation is much stronger in the octogenarian population, who were also found to have significantly reduced length of ICU stay. Our study raises the suggestion that this approach should be utilised more frequently in clinical practice, particularly in octogenarian patients.

Does minimal invasive cardiac surgery reduce the incidence of post-operative atrial fibrillation?

Atrial fibrillation (AF) is the most common post-operative complication and tends to be the most common arrhythmia after cardiac surgery. The etiology and risk factors for post-operative AF are poorly understood, but older age, large left atrium, diffuse coronary artery disease, a history of AF paroxysms and in general, pre-existing cardiac conditions that cause restricting and susceptibility towards inflammation have been consistently linked with post-operative atrial fibrillation (POAF). It has been traditionally thought that post-operative AF is transient, well-tolerated, benign to the patient and self-limiting complication of cardiac surgery that was temporary and easily treated. However, recent evidence suggests that POAF may be more "malignant" than previously thought, associated with follow-up mortality and morbidity. Several minimally invasive approaches, including the right parasternal approach, upper and lower mini-sternotomy (MS), V-shaped, Z-shaped, inverse-T, J-, reverse-C and reverse-L partial MS, transverse sternotomy and right mini-thoracotomy, have been developed for cardiac surgery operations since 1993 and have been associated with better outcomes and lower perioperative morbidity compared to full sternotomy (FS). The common goal of several minimally invasive approaches is to reduce invasiveness and surgical trauma. According to a statement from the American Heart Association (AHA), the term "minimally invasive" refers to a small chest wall incision that does not include a FS. This review is aimed to evaluate the use of minimally invasive techniques like mini-sternotomy, mini-thoracotomy and hybrid techniques versus conventional techniques which are used in cardiac surgery and to compare the frequency of post-operative AF and its effect on post-operative complications, morbidity and mortality, after cardiac surgery operations with FS versus cardiac surgery operations with the use of minimally invasive techniques.

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.

Efficacy of Aortic Valve Replacement through Full Sternotomy and Minimal Invasion (Ministernotomy)

Background: new minimally invasive sternotomy (mini-sternotomy) procedures have improved the treatment outcome and reduced the incidence of perioperative complications leading to improved patient satisfaction and a reduced cost of aortic valve replacement in comparison to the conventional median sternotomy (full sternotomy). The aim of this study is to compare and gain new insights into operative and early postoperative outcomes, long-term postoperative results, and 5-year survival rates after aortic valve replacement through a ministernotomy and full sternotomy. Methods: This is a retrospective study of patients who underwent an isolated replacement of the aortic valve via a full sternotomy or ministernotomy from 2011 to 2016. From 2011 to 2016, 426 cardiac interventions were performed, 70 of which (16.4%) were of the ministernotomy and 356 (83.6%) of the full sternotomy. Through propensity score matching, 70 patients who underwent the ministernotomy (ministernotomy group) were compared with 70 patients who underwent the full sternotomy (control group). Results: in the propensity matching cohort, no statistical difference in operative time was noted (p = 0.856). The ministernotomy had longer cross clamp (88.7 ± 20.7 vs. 80.3 ± 24.6 min, p = 0.007) and bypass (144.0 ± 29.9 vs. 132.9 ± 44.9 min, p = 0.049) times, less ventilation time (9.7 ± 1.7 vs. 11.7 ± 1.4 h, p < 0.001), shorter hospital stay (18.3 ± 1.9 vs. 21.9 ± 1.9 days, p = 0.012), less 24-h chest tube drainage (256.2 ± 28.6 vs. 407.3 ± 40.37 mL, p < 0.001), fewer corrections of coagulopathy (p < 0.001), fewer patients receiving catecholamine (5.71 vs. 30.0%, p < 0.001) and better cosmetic results (p < 0.001). Moreover, the number of patients without complaints at 1 year after the operation was significantly greater in the ministernotomy group (p = 0.002), and no significant differences in the 5-year survival between the groups were observed. In the overall cohort, the ministernotomy had longer cross clamp times (88.7 ± 20.7 vs. 79.9 ± 24.8 min, p < 0.001), longer operative times (263.5 ± 62.0 vs. 246.7 ± 74.2 min, p = 0.037) and bypass times (144.0 ± 29.9 vs. 132.7 ± 44.5 min, p = 0.026), lower incidence of 30-day mortality (1(1.4) vs. 13(3.7), p = 0.022), shorter hospital stays post-surgery p = 0.025, less 24-h chest tube drainage, p < 0.001, and fewer corrections of coagulopathy (p < 0.001). Conclusions: the ministernotomy has a number of advantages compared with the full sternotomy and thus could be a better approach for aortic valve replacement.

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.

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.

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.

Minimally Invasive Aortic Valve Replacement in Left Ventricular Dysfunction

The safety and benefit of minimally invasive aortic valve replacement in patients with left ventricular dysfunction has not been well investigated. We conducted a retrospective review of 140 patients with ejection fraction ≤ 40% who underwent isolated aortic valve replacement between July 1996 and March 2005. Aortic valve replacement was performed via an upper hemisternotomy in 73 patients and via a full sternotomy in 67. Two matched cohorts of 41 patients each were constructed using propensity score analysis, and the outcomes were compared. There was no significant difference in operative mortality (hemisternotomy, 2.4% vs 4.8% for full sternotomy), incidence of postoperative complications, blood transfusion requirement, length of hospital stay, or discharge to home rates. Aortic valve replacement via an upper hemisternotomy can be performed safely, even in patients with left ventricular dysfunction, with morbidity and mortality outcomes similar to those of a full sternotomy.

Upper ministernotomy

During the past 50 years, median sternotomy has been the gold standard approach in cardiac surgery with excellent long-term outcomes. However, since the 1990 s, minimally invasive cardiac surgery (MICS) has gained wide acceptance due to patient and economic demand. The advantages include less surgical trauma, less bleeding, less wound infections, less pain and faster recovery of the patients. One of these MICS approaches is the J-shaped upper ministernotomy which results in favourable long-term outcomes even in elderly and redo patients when compared with conventional sternotomy. Owing to its similarity to a full midline sternotomy, it has become the most popular MICS approach besides a mini-thoracotomy. It is a safe and feasible access, but certain recognized principles are mandatory to minimize complications. After identification of the landmarks, the 5-cm skin incision is performed in the midline between the second and fourth rib. The third or fourth right intercostal space is located and dissected laterally off the sternum. After osteotomy, the pericardium is pulled up with stay sutures which allow excellent exposure. The surgical procedures are performed in a standard fashion with central cannulation. Continuous CO2 insufflation is used to minimize the risk of air embolism. Epicardial pacing wires are placed before the removal of the aortic cross-clamp and one chest tube is used. Sternal closure is achieved with three to five stainless steel wires. The pectoral muscle, subcutaneous tissue and skin are adapted with resorbable running sutures. When performed properly, complications are rare (conversion, bleeding and wound infection) and well manageable.

Minimally invasive aortic valve replacement - pros and cons of keyhole aortic surgery

Over the last twenty years, minimally invasive aortic valve replacement (MIAVR) has evolved into a safe, well-tolerated and efficient surgical treatment option for aortic valve disease. It has been shown to reduce postoperative morbidity, providing faster recovery and rehabilitation, shorter hospital stay and better cosmetic results compared with conventional surgery. A variety of minimally invasive accesses have been developed and utilized to date. This concise review demonstrates and discusses surgical techniques used in contemporary approaches to MIAVR and presents the most important results of MIAVR procedures.

Minimally invasive aortic valve replacement: 12-year single center experience

BACKGROUND

This study reports the single center experience on minimally invasive aortic valve replacement (MIAVR), performed through a right anterior minithoracotomy or ministernotomy (MS).

METHODS

Eight hundred and fifty-three patients, who underwent MIAVR from 2002 to 2014, were retrospectively analyzed. Survival was evaluated using the Kaplan-Meier method. The Cox multivariable proportional hazards regression model was developed to identify independent predictors of follow-up mortality.

RESULTS

Median age was 73.8, and 405 (47.5%) of patients were female. The overall 30-day mortality was 1.9%. Four hundred and forty-three (51.9%) and 368 (43.1%) patients received biological and sutureless prostheses, respectively. Median cardiopulmonary bypass time and aortic cross-clamping time were 108 and 75 minutes, respectively. Nineteen (2.2%) cases required conversion to full median sternotomy. Thirty-seven (4.3%) patients required re-exploration for bleeding. Perioperative stroke occurred in 15 (1.8%) patients, while transient ischemic attack occurred postoperative in 11 (1.3%). New onset atrial fibrillation was reported for 243 (28.5%) patients. After a median follow-up of 29.1 months (2,676.0 patient-years), survival rates at 1 and 5 years were 96%±1% and 80%±3%, respectively. Cox multivariable analysis showed that advanced age, history of cardiac arrhythmia, preoperative chronic renal failure, MS approach, prolonged mechanical ventilation and hospital stay as well as wound revision were associated with higher mortality.

CONCLUSIONS

MIAVR via both approaches is safe and feasible with excellent outcomes, and is associated with low conversion rate and low perioperative morbidity. Long term survival is at least comparable to that reported for conventional sternotomy AVR.

Minimally invasive aortic valve replacement versus aortic valve replacement through full sternotomy: the Brigham and Women's Hospital experience

BACKGROUND

Minimally invasive aortic valve surgery (mini AVR) is a safe and effective treatment option at many hospital centers, but there has not been widespread adoption of the procedure. Critics of mini AVR have called for additional evidence with direct comparison to aortic valve replacement (AVR) via full sternotomy (FS).

METHODS

Our mini AVR approach is through a hemi-sternotomy (HS). We performed a propensity-score matched analysis of all patients undergoing isolated AVR via FS or HS at our institution since 2002, resulting in 552 matched pairs. Baseline characteristics were similar. Operative characteristics, transfusion rates, in-hospital outcomes as well as short and long term survival were compared between groups.

RESULTS

Median cardiopulmonary bypass and cross clamp times were shorter in the HS group: 106 minutes [inter-quartile ranges (IQR) 87-135] vs. 124 minutes (IQR 90-169), P≤0.001, and 76 minutes (IQR 63-97) vs. 80 minutes (IQR 62-114), P≤0.005, respectively. HS patients had shorter ventilation times (median 5.7 hours, IQR 3.5-10.3 vs. 6.3 hours, IQR 3.9-11.2, P≤0.022), shorter intensive care unit stay (median 42 hours, IQR 24-71 vs. 45 hours, IQR 24-87, P≤0.039), and shorter hospital length of stay (median 6 days, IQR 5-8 vs. 7 days, IQR 5-10, P≤0.001) compared with the FS group. Intraoperative transfusions were more common in FS group: 27.9% vs. 20.0%, P≤0.003. No differences were seen in short or long term survival, or time to aortic valve re-intervention.

CONCLUSIONS

Our study confirms the clinical benefits of minimally invasive AVR via HS, which includes decreased transfusion requirements, ventilation times, intensive care unit and hospital length of stay without compromising short and long term survival compared to conventional AVR via FS.

Minimally invasive valve surgery

Cardiac valve surgery is life saving for many patients. The advent of minimally invasive surgical techniques has historically allowed for improvement in both postoperative convalescence and important clinical outcomes. The development of minimally invasive cardiac valve repair and replacement surgery over the past decade is poised to revolutionize the care of cardiac valve patients. Here, we present a review of the history and current trends in minimally invasive aortic and mitral valve repair and replacement, including the development of sutureless bioprosthetic valves.

Minimally invasive surgery of mitral valve (MIS-MV)

Following the revision of the therapeutic guideline of ACC/AHA in (Circulation 114:450-527, 2006), the incidence of mitral valve repair in asymptomatic patients with moderate or severe mitral valve regurgitation has increased. For mitral valve repair, the quality and outcomes as well as lower invasive procedure are important to obtain the confidence of cardiologists and ensure request of early phase operation from cardiologists. With recent innovations of technologies and the development of revolutionary techniques, minimally invasive surgery of the mitral valve (MIS-MV) has become a widespread surgical option of mitral valve repair. It is vital, however, that careful preoperative assessment, and planning of the approach and perfusion strategy are put in place to perform MIS-MV safely.

Experience with a minimally invasive approach to combined valve surgery and coronary artery bypass grafting through bilateral thoracotomies

BACKGROUND

Minimally invasive coronary artery bypass grafting (MICS-CABG) and minimally invasive valve surgery (MIVS) have been used independently to manage occlusive coronary artery disease and valvular diseases, respectively. We present 12 patients who underwent combined MICS-CABG and MIVS via bilateral mini-thoracotomies.

METHODS

We retrospectively reviewed 116 consecutive valve/CABG operations by a single surgeon and compared the outcomes obtained via sternotomy with those obtained via bilateral minithoracotomies.

RESULTS

Six patients in the MIVS group underwent aortic valve replacement (sternotomy group, n = 70), 3 patients underwent mitral valve repair (sternotomy group, n = 9), and 3 underwent mitral valve replacement (sternotomy group, n = 25). The minimally invasive valve surgeries were combined with MICS-CABG for single- (n = 2), double- (n = 9), and triple-vessel (n = 1) coronary artery disease in a single operation. The mean SD duration of cardiopulmonary bypass was 164 ± 44.6 minutes (mean time via sternotomy, 152 ± 50.5 minutes; P = .4146), and the mean aortic cross-clamp time was 87.8 ± 22.1 minutes (mean time via sternotomy, 105 ± 39.8 minutes; P = .1455). The use of perioperative blood transfusions averaged to 2.3 ± 5.6 units (mean usage via sternotomy, 2.7 ± 4.9 units; P = .8326). There were no conversions to sternotomy in the minimally invasive group. Patients in the minimally invasive group were extubated earlier (24 ± 11 hours; sternotomy group, 40 ± 61 hours; P = .3684) and discharged earlier (7 ± 4 days) than patients who underwent median sternotomy (9 ± 10 days; P = .4027).

CONCLUSION

MICS-CABG combined with MIVS via bilateral minithoracotomies yielded short-term results comparable to those for CABG and valve repair via median sternotomy. There were no operative mortalities or reoperations. The possible advantages of the minimally invasive approach included earlier extubation and earlier discharge from the hospital. Combined CABG and valve surgery can be safely performed via bilateral thoracotomies.

Functional adaptation of venous smooth muscle response to vasoconstriction in proximal, distal, and varix segments of varicose veins

BACKGROUND

Varicose veins (VarVs) are a common disorder of venous dilation and tortuosity with unclear mechanism. The functional integrity and the ability of various regions of the VarVs to constrict is unclear. This study tested the hypothesis that the different degrees of venodilation in different VarV regions reflect segmental differences in the responsiveness to receptor-dependent vasoconstrictive stimuli and/or in the postreceptor signaling mechanisms of vasoconstriction.

METHODS

Varix segments and adjacent proximal and distal segments were obtained from patients undergoing VarV stripping. Control great saphenous vein specimens were obtained from patients undergoing lower extremity arterial bypass and coronary artery bypass grafting. Circular vein segments were equilibrated under 2 g of tension in a tissue bath, and changes in isometric constriction in response to angiotensin II (AngII, 10(-11)-10(-7) M), phenylephrine (PHE, 10(-9)-10(-4) M), and KCl (96 mM) were recorded. The amount of angiotensin type 1 receptor (AT(1)R) was measured in vein tissue homogenate.

RESULTS

AngII caused concentration-dependent constriction in control vein (max 35.3 +/- 9.6 mg/mg tissue, pED(50) 8.48 +/- 0.34). AngII caused less contraction and was less potent in proximal (max 7.9 +/- 2.5, pED(50) 6.85 +/- 0.61), distal (max 5.7 +/- 1.2, pED(50) 6.74 +/- 0.68), and varix segments of VarV (max 7.2 +/- 2.0, pED(50) 7.11 +/- 0.50), suggesting reduced AT(1)R-mediated contractile mechanisms. VarVs and control veins had similar amounts of AT(1)R. alpha-adrenergic receptor stimulation with PHE caused concentration-dependent constriction in control veins (max 73.0 +/- 13.9 mg/mg tissue, pED(50) 5.48 +/- 0.12) exceeding that of AngII. PHE produced similar constriction and was equally potent in varix and distal segments but produced less constriction and was less potent in proximal segments of VarVs (max 32.1 +/- 6.4 mg/mg tissue, pED(50) 4.89 +/- 0.13) vs control veins. Membrane depolarization by 96 mM KCl, a receptor-independent Ca(2+)-dependent response, produced significant constriction in control veins and similar contractile response in proximal, distal, and varix VarV segments, indicating tissue viability and intact Ca(2+)-dependent contraction mechanisms.

CONCLUSIONS

Compared with control veins, different regions of VarV display reduced AngII-mediated venoconstriction, which may be involved in the progressive dilation in VarVs. Postreceptor Ca(2+)-dependent contraction mechanisms remain functional in VarVs. The maintained alpha-adrenergic responses in distal and varix segments, and the reduced constriction in the upstream proximal segments, may represent a compensatory adaptation of human venous smooth muscle to facilitate venous return from the dilated varix segments of VarV.

Percutaneous and Minimally Invasive Valve Procedures

The incidence of valvular heart disease is expected to increase over the next several decades as a large proportion of the US demographic advances into the later decades of life. At the same time, the next several years can be anticipated to bring a broad transition of surgical therapy to minimally invasive (minithoracotomy and small port) access and the more gradual introduction of percutaneous approaches for the correction of valvular heart disease. Broad acceptance of these technologies will require careful and sometimes perplexing comparisons of the outcomes of these new technologies with existing standards of care. The validation of percutaneous techniques, in particular, will require the collaboration of cardiologists and cardiac surgeons in centers with excellent surgical and catheter experience and a commitment to trial participation. For the near term, percutaneous techniques will likely remain investigational and will be limited in use to patients considered to be high risk or to inoperable surgical candidates. Although current-generation devices and techniques require significant modification before widespread clinical use can be adopted, it must be expected that less invasive and even percutaneous valve therapies will likely have a major impact on the management of patients with valvular heart disease over the next several years.

Robotic Resection of an Aortic Valve Papillary Fibroelastoma

Robotic technology has been applied to multiple cardiac surgical procedures. Purported benefits include decreased tissue trauma, reduced postoperative bleeding, fewer blood product transfusions, and shorter lengths of stay. We describe the case of a 50-year-old man with an incidentally discovered 1-cm mobile mass on the edge of the aortic valve noncoronary leaflet. The patient underwent robotic minimally invasive resection. The pathologic examination revealed papillary fibroelastoma.

One thousand minimally invasive valve operations: early and late results

OBJECTIVE

We sought to evaluate the potential benefits of minimally invasive approaches for treatment of isolated aortic and mitral valve disease.

METHODS

From 7/96 to 04/03, we performed 1000 minimally invasive valve operations: 526 aortic (AV) procedures (64 years; mean, 25-95) and 474 mitral (MV) procedures (58 years; mean, 17-90).

RESULTS

In the AV group, an upper ministernotomy was used in 492/526 patients (93%) and a right parasternal approach in 34 (7%). Sixty-three patients had reoperative aortic valve replacements. In the MV group lower sternotomy was used in 260/474 (55%), right parasternal in 200/474 (42%), and a right thoracotomy in 14 patients. MV repair was performed in 416 and MV replacement in 58 patients. Operative mortality was 12/526 (2%) in the AV and 1/474 (0.2%) in the MV group. Freedom from reoperation at 6 years was 99% and 95% in the AV and MV group, respectively. Late mortality was 5% in the AV and 3% in the MV group, respectively.

CONCLUSIONS

Minimally invasive valve surgery can be performed at very low levels of morbidity and mortality, with results equal to or better than conventional techniques. All forms of valve repair and replacement operations can be performed. Long-term survival and freedom from reoperation are excellent.