Minimally Invasive Surgery for Valve Disease

New approach to the mitral valve through the left anterior minithoracotomy for combined valve and coronary surgical procedures

Objective

We have developed a new technique for accessing the mitral valve through the left anterior minithoracotomy. This approach has been used in patients requiring both mitral valve surgery and coronary artery bypass grafting.

Methods

From October 2020 to September 2022, we performed 24 concomitant mitral valve procedures and coronary artery bypass grafting through the left anterior minithoracotomy. The average age of the patients was 65.5 years, and the mean left ventricular ejection fraction was 44.5%. Computed tomography angiography was routinely performed preoperatively. The surgical technique included a left anterior minithoracotomy in the fourth intercostal space, peripheral cardiopulmonary bypass, aortic crossclamping using a transthoracic clamp through the additional port in the left second intercostal space, the administration of cold blood cardioplegia, a right atrial transseptal approach to the mitral valve, and special surgical exposure maneuvers. These maneuvers were designed to displace the heart into the left pleural space by pulling the inferior vena cava tape and the ascending aorta tape to the left. Conventional mitral valve surgical techniques were used. The mitral valve repair or replacement was performed after the distal anastomoses to the right and circumflex coronary system were completed. Subsequently, after the mitral valve procedure, coronary anastomosis to the left anterior descending artery was performed.

Results

The mitral valve was effectively visualized, and a planned procedure was successfully completed in all patients. There was no need for conversion to a sternotomy. mitral valve repair was performed in 22 patients (91.7%), and mitral valve replacement was performed in 2 patients (8.3%). Conventional surgical instruments were used in 10 cases (41%), and long-shafted instruments were used in 14 cases (59%). A knot-pusher was required in 9 cases (37.5%). A computed tomography distance from the skin level to the mitral valve posterior annulus of more than 14 cm was identified as a technical difficulty marker, necessitating the use of long-shafted instruments. Concomitant complete revascularization was achieved in all cases. The mean number of distal anastomoses was 2.54 ± 0.7 (1; 4). Total operation time was 341 ± 41 (285; 420) minutes, cardiopulmonary bypass time was 231 ± 38 (172; 316) minutes, and the crossclamp time was 127 ± 23 (80; 169) minutes. Patients had a mean intensive care unit stay of 1.87 ± 0.69 (1; 4) days, and their total hospital stay averaged 6.54 ± 1.86 (4; 10) days. There were no reoperations due to bleeding, no occurrences of strokes, and no other major complications. There were no instances of hospital mortality or mortality within 30 days after the procedures.

Conclusions

Mitral valve repair or replacement through the left anterior thoracotomy and transseptal approach is a valuable and effective technique that can be used for concomitant procedures performed through a single minithoracotomy incision in selected patients.

New approach for combined aortic valve and coronary procedures through the left anterior minithoracotomy

OBJECTIVES

We have developed a novel technique for accessing the aortic valve (AoV) through the left anterior minithoracotomy (LAmT). This approach has been used in patients requiring both AoV surgery and coronary artery bypass grafting (CABG).

METHODS

From April 2023 to July 2023, we performed 6 concomitant AoV procedures and CABG through the LAmT. The mean age was 71.5 [standard deviation (SD): 5.8; 64; 82] years, and the mean left ventricular ejection fraction was 53% (SD: 12.1; 30; 60). Surgical technique includes LAmT in the fourth intercostal space, peripheral cardiopulmonary bypass, aortic cross-clamping using transthoracic clamp, cold blood cardioplegia, conventional oblique aortotomy and special surgical exposure manoeuvres, aimed to position the ascending aorta and AoV close to the surgical incision.

RESULTS

AoV was effectively visualized and the procedure was performed as planned in all 6 patients. No conversion to sternotomy was required. AoV replacement with biological prosthesis was performed in 6 (100%) patients. Conventional surgical instruments were used in all cases. The long-shafted instruments were not required. Knot-pusher was used in 4 (67%)cases. Concomitant complete revascularization was achieved in all cases. The mean number of distal anastomosis was 2.0 (SD: 0.6; 1; 3). Total operation time was 371 (SD: 43; 300; 420) min, cardiopulmonary bypass time was 253 (SD: 36; 193; 284) min and cross-clamp time was - 162 (SD: 29; 128; 214) min. intensive care unit stay was-1.5 (SD: 0.55; 1; 2) days, total hospital stay was-7.3 (SD: 1; 6; 9) days. There were no revisions for bleeding, no strokes or other major complications, and no hospital or 30-days mortality.

CONCLUSIONS

The simultaneous performance of AoV replacement and multivessel CABG through a single left anterior thoracotomy is technically feasible and can be carried out by experienced surgeons. However, a larger number of cases are required to fully comprehend the potential limitations of this procedure.

Limited versus full sternotomy for aortic valve replacement

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Minimal Access Aortic Valve Surgery

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

Decision support system for the planning of minimally invasive aortic valve replacement surgery

PURPOSE

Minimally invasive aortic valve replacement (MIAVR) procedures remain more complex and technically challenging compared to conventional full sternotomy surgery. This technique involves a restricted surgical field and a limited workspace, which is, at present, strictly reserved for the most experienced surgeons. The MIAVR clinical outcomes are strongly dependent on the appropriate choice of the thoracic incision. This work presents a decision support system to optimize, through an interactive visualization interface, the exposure of the target structure in a limited field of view.

METHODS

Our approach is based on the computation of relevant anatomical measurements from preoperative CT images, and it takes into account the surgical guidelines in order to propose the surgical access that best fits the patient's morphology.

RESULTS

The proposed planning system was applied and tested on 30 datasets from patients affected by severe aortic stenosis for validation purposes. We evaluated the accuracy of the automatic detections and the measurements calculated by the system with those chosen manually by the expert.

CONCLUSIONS

In 87% of thirty cases, the surgical strategy proposed by the decision support system was correct. For the remaining cases, the graphical user interface (GUI) allowed the user to manually adjust the anatomical features.

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.

Myocardial protection during minimally invasive cardiac surgery through right mini-thoracotomy

BACKGROUND

Myocardial damage is an independent predictor of adverse outcome following cardiac surgery and myocardial protection is one of the key factors to achieve successful outcomes. Cardioplegia with Custodiol is currently the most used cardioplegia during minimally invasive cardiac surgery (MICS). Different randomized controlled trials compared blood and Custodiol cardioplegia in the context of traditional cardiac surgery. No data are available for MICS.

AIM

The aim of this study was to compare the efficacy of cold blood versus Custodiol cardioplegia during MICS.

METHOD

We retrospectively evaluated 90 patients undergoing MICS through a right mini-thoracotomy in a three-year period. Myocardial protection was performed using cold blood (44 patients, CBC group) or Custodiol (46 patients, Custodiol group) cardioplegia, based on surgeon preference and complexity of surgery.

RESULTS

The primary outcomes were post-operative cardiac troponin I (cTnI) and creatine kinase MB (CKMB) serum release and the incidence of Low Cardiac Output Syndrome (LCOS). Aortic cross-clamp and cardiopulmonary bypass times were higher in the Custodiol group. No difference was observed in myocardial injury enzyme release (peak cTnI value was 18±46 ng/ml in CBC and 21±37 ng/ml in Custodiol; p=0.245). No differences were observed for mortality, LCOS, atrial or ventricular arrhythmias onset, transfusions, mechanical ventilation time duration, intensive care unit and total hospital stay.

CONCLUSIONS

Custodiol and cold blood cardioplegic solutions seem to assure similar myocardial protection in patients undergoing cardiac surgery through a right mini-thoracotomy approach.

Anterior Mitral Leaflet Augmentation for Ischemic Mitral Regurgitation Performed Via a Right Thoracotomy Approach

Ischemic mitral regurgitation (MR) after myocardial infarction is associated with poor long-term survival, and the optimal treatment strategy remains debated. The most common repair technique used is a restrictive annuloplasty. However, up to 15% to 30% of patients experience recurrent MR owing to progressive left ventricular remodeling and geometric distortion of the mitral valve apparatus. Anterior mitral leaflet augmentation using a pericardial patch, in combination with a true-sized mitral annuloplasty, has been proposed as an adjunctive technique to increase the durability of valve repair for ischemic MR. Herein, we describe 2 cases of anterior mitral leaflet augmentation with annuloplasty repair for severe ischemic MR via a minimally invasive right thoracotomy, and review the literature regarding patient selection and clinical outcomes of this technique.

Minimally Invasive Aortic Valve Replacement

With the advent of transcatheter aortic valve replacement and the emergence of rapid deployment aortic valves, there is a resurgent interest in minimizing the trauma of surgical aortic valve replacement (AVR). The present review summarizes the history of minimal access AVR and attempts to collate the existing evidence regarding minimal access AVR.

Conventional versus minimally invasive aortic valve replacement: pooled analysis of propensity-matched data

BACKGROUND

Minimally invasive aortic valve replacement (mAVR) is increasingly preferred over conventional AVR (cAVR). However, data comparing these procedures present conflicting results. Hence, we conducted a systematic review and meta-analysis comparing clinical results in these cohorts.

METHOD

Only randomized controlled trials (RCT) and propensity-matched observational studies (POS) (1998-2013) comparing clinical outcome of patients subjected to mAVR or cAVR were pooled. Continuous data was compared using mean/standardized mean difference (MD/SMD) while categorical results were pooled to obtain an odds ratio (OR) with a 95% confidence interval.

RESULTS

A total of 18 studies (6 RCT and 12 POS) (1973 mAVR patients; 2697 cAVR patients) were analyzed. The mean ischemic time was significantly longer with mAVR (MD 9.42 minutes [4.25-14.59]; p < 0.01). However, early mortality (mAVR [1.8%] and cAVR [3%]) was comparable (OR 0.70 [0.46-1.06]; p = 0.09). Postoperative ventilation time was slightly shorter after mAVR (7.5 vs 11.1 hours; p = 0.07), and hospital discharge was earlier after mAVR (MD -1.05 [-1.64 to -0.46]; p < 0.01). However, mAVR failed to reduce transfusion requirement (OR 0.77 [0.51-1.14]; p = 0.19) or pain scores (SMD -0.25 [-0.65 to 0.13]; p = 0.20). Postoperative atrial fibrillation (p = 0.67) and stroke (p = 0.79) rates were comparable. Pooled rate of conversion to full sternotomy was 2.5%. Cosmetic satisfaction could not be pooled due to reporting heterogeneity.

CONCLUSION

Minimally invasive aortic valve replacement can be performed safely despite the longer ischemic time. While minimally invasive surgery does demonstrate some advantages in postoperative recovery, we failed to find any other substantial improvement in outcome over conventional aortic valve replacement.

Minimally invasive approach for redo mitral valve surgery

Redo cardiac surgery represents a clinical challenge due to a higher rate of peri-operative morbidity and mortality. Mitral valve re-operations can be particularly demanding in patients with patent coronary artery bypass grafts, previous aortic valve replacement, calcified aorta or complications following a previous operation (abscesses, perivalvular leaks, or thrombosis). Risk of graft injuries, hemorrhage, the presence of dense adhesions and complex valve exposure can make redo valve operations challenging through a median sternotomy. In this review article we provide an overview of minimally invasive approaches for redo mitral valve surgery discussing indications, techniques, outcomes, concerns and controversies. Scientific literature about minimally invasive approach for redo mitral surgery was reviewed with a MEDLINE search strategy combining "mitral valve" with the following terms: 'minimally invasive', 'reoperation', and 'alternative approach'. The search was limited to the last ten years. A total of 168 papers were found using the reported search. From these, ten papers were identified to provide the best evidence on the subject. Mitral valve reoperations can be safely and effectively performed through a smaller right thoracotomy in the fourth intercostal space termed "mini" thoracotomy or "port access". The greatest potential benefit of a right mini-thoracotomy is the avoidance of sternal re-entry and limited dissection of adhesions, avoiding the risk of injury to cardiac structures or patent grafts. Good percentages of valve repair can be achieved. Mortality is low as well as major complications. Minimally invasive procedures with an unclamped aorta have the potential to combine the benefits of minimally invasive access and continuous myocardial perfusion. Less invasive trans-catheter techniques could be considered as the natural future evolution for management of structural heart disease and mitral reoperations. The safety and efficacy of these procedures has never been compared to open reoperations in a randomized trial, although published case series and comparisons to historical cohorts suggest that they are an effective and feasible alternative. Ongoing follow-up on current series will further define these procedures and provide valuable clinical outcome data.

Aortic valve replacement through a right minithoracotomy

Minimally-invasive operative techniques have many advantages, such as less postoperative pain, lower morbidity and mortality, faster recovery, and shorter duration of operation and hospital stay, associated with lower costs. Minimally invasive cardiac surgery has been developed to offer patients the benefits of open heart operations with decreased pain and limited skin incision. It has been popularized as an alternative to the conventional median sternotomy approach. These techniques require some dedicated skills and experience from surgeons, anesthetists, and perfusionists for a successful result. In this article we demonstrate our surgical approach for aortic valve replacement through a right minithoracotomy.

Minimally invasive mitral valve procedures: the current state

Since its early days, cardiac surgery has typically involved large incisions with complete access to the heart and the great vessels. After the popularization of the minimally invasive techniques in general surgery, cardiac surgeons began to experiment with minimal access techniques in the early 1990s. Although the goals of minimally invasive cardiac surgery (MICS) are fairly well established as decreased pain, shorter hospital stay, accelerated recuperation, improved cosmesis, and cost effectiveness, a strict definition of minimally invasive cardiac surgery has been more elusive. Minimally invasive cardiac surgery started with mitral valve procedures and then gradually expanded towards other valve procedures, coronary artery bypass grafting, and various types of simple congenital heart procedures. In this paper, the authors attempt to focus on the evolution, techniques, results, and the future perspective of minimally invasive mitral valve surgery (MIMVS).

Polymeric trileaflet prosthetic heart valves: evolution and path to clinical reality

Present prosthetic heart valves, while hemodynamically effective, remain limited by progressive structural deterioration of tissue valves or the burden of chronic anticoagulation for mechanical valves. An idealized valve prosthesis would eliminate these limitations. Polymeric heart valves (PHVs), fabricated from advanced polymeric materials, offer the potential of durability and hemocompatibility. Unfortunately, the clinical realization of PHVs to date has been hampered by findings of in vivo calcification, degradation and thrombosis. Here, the authors review the evolution of PHVs, evaluate the state of the art of this technology and propose a pathway towards clinical reality. In particular, the authors discuss the development of a novel aortic PHV that may be deployed via transcatheter implantation, as well as its optimization via device thrombogenicity emulation.

Outcomes of minimally invasive mitral valve surgery in patients with an ejection fraction of 35% or less

OBJECTIVE

We evaluated the outcomes of minimally invasive mitral valve surgery via a right anterior thoracotomy approach in patients with isolated severe mitral regurgitation and severely reduced left ventricular systolic function.

METHODS

We retrospectively reviewed all minimally invasive mitral valve surgeries for mitral regurgitation in patients with an ejection fraction of 35% or less performed at our institution between December 2008 and June 2011. The operative times, lengths of stay, postoperative complications, and mortality were analyzed.

RESULTS

We identified a total of 71 patients with severe mitral regurgitation and an ejection fraction of 35% or less who underwent minimally invasive mitral valve surgery. The mean ± SD age was 67 ± 10 years, and 44 of the patients were men (62%). The mean ± SD left ventricular ejection fraction was 27% ± 6%, and 28 patients (39%) had previous heart surgery. The median aortic cross-clamp and cardiopulmonary bypass times were 62 [interquartile range (IQR), 50-80) and 98 minutes (IQR, 92-124), respectively. There was no mitral regurgitation noted in any patient on postoperative transesophageal echocardiogram. The median intensive care unit length of stay was 51 hours (IQR, 42-86), and the median postoperative length of stay was 6 days (IQR, 5-9).

CONCLUSIONS

Minimally invasive mitral valve surgery for severe functional mitral regurgitation in patients with severe left ventricular dysfunction can be performed with a low morbidity and mortality.

Aortic stenosis in high-risk patients. Surgical therapy

Conventional aortic valve replacement is the standard approach for treating aortic stenosis, it is performed via a full or partial sternotomy, and is associated with low risks for patients and with excellent long-term outcomes. This also holds true for octogenarians, if they present without relevant comorbidities. After resection of the calcified native leaflets, biological prostheses with good functionality and durability are implanted. Elderly patients with an increasing risk profile, however, should be treated by a heart team using transcatheter approaches including cardiac surgery.

Clinical results of minimally invasive mitral valve surgery: endoaortic clamp versus external aortic clamp techniques

OBJECTIVE

: This study was carried out with the aim of presenting our experience with minimally invasive mitral surgery and compare the endoaortic clamp with the external aortic clamp (EAC) techniques.

METHODS

: Between December 2002 and May 2009, 139 patients (75 men, aged 63 ± 11 years) underwent video-assisted mitral valve surgery through right thoracotomy. Twelve (9%) patients were operated without clamping the aorta, 32 (23%) patients (group A) were operated on by using the endoaortic clamp, and 95 (68%) patients were operated on by using the EAC (group B). There was no significant difference between groups A and B regarding preoperative variables.

RESULTS

: Intraoperative procedure-associated problems were experienced in three group A patients (9.3%, two aortic dissections with conversion to sternotomy; one conversion due to bad exposure) and in two group B patients (2%, one conversion to sternotomy for bleeding and one for ascending aorta hematoma). At a mean follow-up of 32 months, 121 patients (97%) were in New York Heart Association class I-II, with satisfactory echocardiographic results. There was one in-hospital and six late deaths (three noncardiac, two cardiac, and one valve related). Five-year actuarial survival was 88% ± 8%. There were three reoperations, one early (<30 days) after complex mitral valve repair, with a 5-year freedom from reoperation of 97% ± 2%. Postoperative levels of myocardial cytonecrosis enzymes as well as the extracorporeal circulation time were significantly lower in group B patients (P < 0.05).

CONCLUSIONS

: Intraoperative procedure-associated complications with endoclamping combined with an apparently better myocardial protection forced us to change our practice to the more simple and economic EAC technique.

Mitral Re-Repair and Right Coronary Fistula Closure Advantage of Minimally Invasive Approach

A 51-year-old man developed severe mitral regurgitation 10 years after previous mitral valve repair; the echocardiographic images showed a remarkable eccentric jet toward posterior wall of left atrium associated with a high degree of pulmonary vein retrograde flow. The coronary arteriography pointed out no pathologic lesions but a coronary fistula from the proximal right coronary to the right atrium. The standard approach was avoided, and a right anterolateral minithoracotomy was chosen, providing an excellent view. Under cardiopulmonary bypass and mild hypothermia, the mitral valve was re-repaired, and a new ring was implanted. After aortic cross-clamp release, the right coronary fistula was closed through the right atrium. The postoperative course was uneventful, and the patient was discharged on the fourth postoperative day. In such a high-risk reintervention and concomitant procedure, we think that this different approach may represent a feasible and reliable alternative.

Towards a new image guidance system for assisting transapical minimally invasive aortic valve implantation

We propose a new image guidance system for assisting transapical minimally invasive aortic valve implantation. The goal is to define the exact positioning of aortic valve prosthesis, preventing the misplacement of the valve. The proposed system consists of two stand-alone modules. First, preoperative planning software uses DynaCT images with manual anatomical landmarks to calculate the size and optimal position of the prosthesis. Second, an intraoperative system is developed for tracking of the prosthesis and the coronary ostia in 2-D fluoroscopic images. Then the safe area of implantation is defined. The preliminary experimental results of preoperative planning and intraoperative tracking system are promising.

Minimally invasive mitral valve surgery: a systematic review and meta-analysis

The mitral valve has been traditionally approached through a median sternotomy. However, significant advances in surgical optics, instrumentation, tissue telemanipulation, and perfusion technology have allowed for mitral valve surgery to be performed using progressively smaller incisions including the minithoracotomy and hemisternotomy. Due to reports of excellent results, minimally invasive mitral valve surgery has become a standard of care at certain specialized centers worldwide. This meta-analysis quantifies the effects of minimally invasive mitral valve surgery on morbidity and mortality compared with conventional mitral surgery and demonstrates equivalent perioperative mortality (1641 patients, odds ratio (OR) 0.46, 95% confidence interval 0.15-1.42, p=0.18), reduced need for reoperation for bleeding (1553 patients, OR 0.56, 95% CI 0.35-0.90, p=0.02) and a trend towards shorter hospital stays (350 patients, weighted mean difference (WMD) -0.73, 95% CI -1.52 to 0.05, p=0.07). These benefits were evident despite longer cardiopulmonary bypass (WMD 25.81, 95% CI 13.13-38.50, p<0.0001) and cross-clamp times (WMD 20.91, 95% CI 8.79-33.04, p=0.0007) in the minimally invasive group. Case-control studies show consistently less pain and faster recovery compared to those having a conventional approach. Data for minimally invasive mitral valve surgery after previous cardiac surgery are limited but consistently demonstrate reduced blood loss, fewer transfusions and faster recovery compared to reoperative sternotomy. Long-term follow-up data from multiple cohort studies are also examined revealing equivalent survival and freedom from reoperation. Thus, current clinical data suggest that minimally invasive mitral valve surgery is a safe and a durable alternative to a conventional approach and is associated with less morbidity.

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.

Partial Median “I” Sternotomy: Minimally Invasive Alternate Approach for Aortic Valve Replacement

Minimally invasive aortic valve replacement using the inversed L-like partial upper sternotomy has evolved during the last 10 years. It is performed with excellent results with regard to sternal stability and cosmesis. However, the lateral incision may result in sternal overriding, instability, or fracture. We present an alternate minimally invasive approach to aortic valve replacement. We performed a partial median "I" sternotomy in 30 consecutive patients: After a 6- to 8-cm skin incision, the sternum was incised from the jugulum downward to the corpus, ending at the level of the fourth or fifth intercostal space. No lateral incision of the sternum was performed. The access to the heart and aorta was excellent. During the postoperative course and during follow-up, clinical examination revealed sternal stability and normal wound healing in all patients. These results show that the partial median I sternotomy can be performed safely and provides excellent clinical and cosmetic results.