Minimally invasive approach for redo mitral valve surgery

Innovative balloon-inflatable venous cannula for enhanced cardiopulmonary bypass in minimally invasive cardiac surgery

OBJECTIVES

Minimally invasive cardiac surgery (MICS) struggles with effective caval isolation and cannulation for cardiopulmonary bypass (CPB). We aimed to develop a novel MICS venous cannula, eliminating external manipulations. The goal of this study is to thoroughly evaluate both the safety and the efficacy of a newly developed venous cannula.

METHODS

The study presents the Aulus venous cannula for MICS, designed with internal balloons to block caval blood flow. Preclinical bench tests with a cardiac biosimulator and large animal studies per ISO10993-2016, evaluated performance and safety.

RESULTS

The heparin-coated Aulus cannula had a post-sterilization comparable density of ∼0.200 μg/cm2. In ex vivo tests, using porcine heart models, the cannula enabled full caval occlusion, with endoscopic views confirming precise positioning. The pressure drop remained below the haemolytic threshold of 100 mmHg, indicated lower values compared to BioMedicus. A non-Good Laboratory Practice (GLP) large animal study included eight ovine models, divided into short- and long-term follow-up groups. Clinical pathology values were consistent CPB procedures, and histopathology indicated favourable tolerance despite short-term vessel injuries and long-term stenosis with fibrosis.

CONCLUSIONS

The Aulus cannula showed effective anticoagulant activity, strong integrity, and good tolerance in vitro and in vivo, highlighting its clinical potential.

Mini-thoracotomy in redo mitral valve surgery: safety and efficacy of a standardized procedure

Background

Re-operative mitral valve surgery is sometimes burdened by a greater technical difficulty and a higher complications rate than the first operation. Minimally invasive cardiac surgery has become routine, and it could significantly reduce the surgical risk in redo surgery. The objective of our retrospective observational study is to assess the results of cardiac reoperations in patients with mitral valve disease approached trough a 5–7 cm right mini-thoracotomy.

Methods

From February 2017 to December 2019, 65 patients underwent re-operative mitral valve surgery in our institution. Cardiopulmonary bypass (CPB) was started by cannulation of the femoral and jugular vein and femoral artery or alternatively right axillary artery. Patients enrolled had a mean age of 66.6±11.5 years. Patients were divided into three groups based on the procedure adopted: external aortic cross-clamp (EAC), EndoAortic balloon occlusion (EABO) and ventricular fibrillation (VF). Major complications were evaluated and compared with a propensity matched population of patients undergoing elective isolated mitral valve surgery via right minithoracotomy (MVS).

Results

The average time between last operation and reoperation was 7.1±3.4 years. Fourteen patients (21%) underwent mitral valve repair and 51 patients (78%) underwent mitral valve replacement; 9 patients (14%) received tricuspid valve surgery. There was no statistically significant difference in CPB time between the groups. Seven patients (11%) had a postoperative renal failure, 5 patients (8%) underwent surgical reopening for bleeding; incidence of post-operative stroke and pace-maker implantation was 3% for both. No deaths were registered during in-hospital stay and at 30-days echocardiographic control all patients respect the criterions of device success according with MVARC. Propensity matched patients of group redo had a longer CPB time (100.8±42.7 versus 72.8±16.7 min, P<0.001) and cross-clamp time (71.9±30.7 versus 59±10.7 min, P<0.001) respect to first operation mitral valve surgery patients.

Conclusions

Minimally invasive mitral valve redo surgery is a safe procedure. Less invasive techniques in redo surgery could minimize morbidity and mortality without prolonging the duration of CPB.

Minimally invasive mitral valve surgery

There is considerable interest and demand in the application of minimally invasive techniques in cardiac surgery driven by multiple factors including patient cosmesis and satisfaction, reduction of surgical trauma and the development of specialized instrumentation that allows these procedures to be performed safely. Minimally invasive mitral valve surgery (MIMVS) has been conducted for more than 25 years and has been shown to offer multiple benefits including better cosmetic results, enhanced post-operative recovery, improved patient satisfaction and most importantly, equivalent clinical outcomes with regards to quality and safety when compared to the standard sternotomy approach. MIMVS may be particularly beneficial in certain subgroups of patients, for example patients undergoing redo mitral valve surgery. In this article, we discuss patient selection criteria for MIMVS, the merits and drawbacks of MIMVS relative to conventional sternotomy approaches, and detail procedural aspects including anaesthetic management, intraoperative technique, and important considerations in myocardial protection and cardiopulmonary bypass (CPB). When considering developing a MIMVS programme, as for any new technique, a team approach to the introduction of the programme is essential. Although it is clear that patient selection is important, particularly early in a surgical programme, with experience complex repairs can be performed through a minimally invasive approach with excellent outcomes.

Minimally invasive beating heart technique for mitral valve surgery in patients with previous sternotomy and giant left ventricle

PURPOSE

To analyze the efficacy of minimally invasive beating heart technique for mitral valve surgery in the cardiac patients with previous sternotomy and giant left ventricle.

METHODS

Eighty cardiac patients with previous sternotomy and giant left ventricle according to the diagnostic criteria that left ventricular end diastolic diameter (LVEDD) was ≥70 mm, who underwent mitral valve surgery at our center from January 2006 to January 2019 were analyzed. We divided all patients into minimally invasive beating heart technique group (n = 30) and conventional median resternotomy arrested heart technique group (n = 50) according to the surgical methods. Preoperative, intraoperative, and postoperative variables were compared between two groups.

RESULTS

Minimally invasive beating heart technique compared to the conventional median resternotomy arrested heart technique for mitral valve surgery in the cardiac patients with previous sternotomy and giant left ventricle had significant differences in operation time(P = 0.002), cardiopulmonary bypass (CPB) time(P < 0.001), intraoperative blood loss(P < 0.001), postoperative transfusion ratio(P = 0.01), postoperative transfusion amount(P < 0.001), postoperative drainage volume(P = 0.001), extubation time(P = 0.04), intensive care unit (ICU) stay time(P = 0.04) and postoperative hospital stay time(P < 0.001), but no significant differences in re-exploration for bleeding, postoperative 30-day mortality, postoperative complications and 6 months postoperative echocardiographic parameters.

CONCLUSIONS

Using the method of minimally invasive beating heart technique for mitral valve surgery in the cardiac patients with previous sternotomy and giant left ventricle is effective and reliable, meanwhile reduce the operation time and CPB time, decrease the transfusion ratio and transfusion amount, shorten postoperative ICU stay and hospital stay time, promote the early extubation so that accelerate the patients' early recovery. All of these show a benefit of minimally invasive beating heart technique compared to conventional median resternotomy arrested heart technique.

Right mini-thoracotomy approach reduces hospital stay and transfusion of mitral or tricuspid valve reoperation with non-inferior efficacy: evidence from propensity-matched study

Background

There is limited evidence about the efficacy and cost difference between minimally invasive and conventional valve reoperation. This study intended to compare the short-term efficacy and cost between right mini-thoracotomy approach and median sternotomy approach in valve reoperation.

Methods

From Feb 2011 to Sep 2017, 156 patients underwent valve reoperation including 68 cases of minimally invasive approach and 88 cases of traditional median sternotomy approach in our hospital. A propensity scoring was used to match patients with similar demographic characteristics. A total of 42 pairs of patients were left and divided into the conventional sternotomy group (CS group) and the right mini-thoracotomy group (RT group). A retrospective study of efficacy and cost was conducted between two groups.

Results

There was no statistical difference between two groups in demographical characteristics after propensity-scoring match (P>0.05). In-hospital mortality was 11.9% (5/42) for CS group and 7.1% (3/42) for the RT group (P=0.687). No significant disparity was found in the incidence of complications between two groups (P>0.05). CPB time (P=0.012), bypass time (P=0.006) and operation time (P=0.003) of CS group were significantly higher than RT group. Blood loss (P=0.014) and transfusion volume (P=0.003) of RT group was less than CS group. Shorter ICU and hospital stay was seen in RT group compared with CS group (P<0.001). Though the materials cost of RT group was higher than CS group (P<0.001), no significant disparity was found in total cost between CS group and RT group (P=0.790).

Conclusions

The right mini-thoracotomy approach can achieve equivalent efficacy with conventional median approach, and doesn't necessarily increase the total cost. Moreover, the minimally invasive approach can decrease the operation time, hospital stay and blood product transfusion.

Previous Sternotomy as a Risk Factor in Minimally Invasive Mitral Valve Surgery

Background

Cardiac redo surgery, especially after a full sternotomy, is considered a high-risk procedure. Minimally invasive mitral valve surgery (MIMVS) is a potential therapeutic approach. However, current developments in interventional cardiology necessitate additional discussion regarding the therapy of choice in high-risk patients. In this context, it is necessary to clarify the perioperative and postoperative risks induced by the factor previous sternotomy in the setting of MIMVS. Thus, we present a comparative study analyzing the outcome of MIMVS after previous sternotomy vs. primary operation.

Methods

We identified 19 patients who received isolated or combined mitral valve (MV) surgery via the MIMVS approach after previous full sternotomy (PS group) and compared the results to those of a group of 357 patients who received primary MIMVS (non-PS group). After a propensity score analysis, groups of n = 15 and n = 131, respectively, were subjected to a comparative evaluation. A 1-year follow-up analysis of functional cardiac parameters and clinical symptoms was performed, accompanied by a Kaplan-Meier analysis.

Results

Except for the rate of realized MV reconstructions (PS group: 53.8% vs. non-PS group: 85.5%; p = 0.011), no significant differences were to be noted within the intraoperative and early postoperative course. However, patients in the PS group experienced an increased intensive care unit stay length (PS group: 2 days, 95% CI, 1-8 vs. non-PS group: 1 day, 95% CI, 1-2; p = 0.072). The follow-up examinations revealed excellent functional and clinical outcomes for both groups. The Kaplan-Meier analysis displayed no significant difference regarding the postoperative mortality (p = 0.929) related to the patients at risk.

Conclusion

A previous sternotomy remains a risk factor for MIMVS and demands special attention in the early postoperative period. Nevertheless, the early- and late-term results concerning the functional and clinical outcomes suggest that the MIMVS procedure is satisfactory, even after a full sternotomy.

Minimally invasive mitral valve surgery through a right mini-thoracotomy

Since its introduction in the mid-1990s, minimally invasive mitral valve surgery (MIMVS) has been shown to be a feasible alternative to a conventional full-sternotomy approach, and several studies have reported excellent clinical outcomes with low perioperative morbidity and mortality. As a result, MIMVS is being increasingly employed as a routine procedure worldwide. On the other hand, several issues have been raised, including complications specific to this technique and its steep learning curve, while there are also concerns regarding the durability of a mitral valve repair through a limited access. In this study, the current status and future perspectives of MIMVS were examined.

Repeated valve replacement surgery: technical tips and pitfalls

For successful repeated valve replacement surgery, it is essential issue that the preoperative evaluation includes an assessment of the previous operation record, computed tomography (CT: including 3D-CT), ultrasound cardiography, coronary artery angiography, and so on. Although it is especially needed for repeated valve replacement surgery, setting up of the external defibrillation pads is the most important preparation just prior to the surgery. In regard to the approach, re-sternotomy is frequently employed as a standard fashion because it allows us to re-entry any part of the heart. As alternative approaches, partial sternotomy, right thoracotomy for minimally invasive cardiac surgery approach have also been highlighted recently. Myocardial protection is another important consideration in repeated valve replacement surgery, especially in post-coronary artery bypass grafting cases with a patent internal thoracic artery. In repeated valve replacement surgery, special and unique techniques are required both for taking the affected prosthetic valve out and for implanting a new valve, which is dependent on the types of the previous prosthetic valve and the condition of the affected prosthetic valve. Therefore, for performing repeated valve replacement surgeries, surgeons should be highly skilled in these special techniques.