Preoperative multidetector computed tomograpy angiography for planning of minimally invasive robotic mitral valve surgery: Impact on decision making

Preoperative Nonselective Chest Computed Tomography Prior to Primary Cardiac Surgery Results in Meaningful Change to Surgical Management: Systematic Review and Pooled Prevalence Meta-Analysis

BACKGROUND

Routine screening chest computed tomography (CT) prior to primary cardiac surgery is advocated by some surgeons due to the purported benefits of identifying significant aortic calcification that impacts ongoing management, such as performing anaortic off-pump surgery or adjusting cannulation strategy. Additionally, axial imaging can identify incidental findings that may require concomitant or staged procedures such as ascending aortic dilatation or pulmonary lesions. The objective of this study was to quantify the impact that nonselective chest CT prior to primary cardiac surgery had on subsequent management.

METHOD

A systematic review and pooled prevalence meta-analyses were performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Included studies performed non-selective chest CT prior to primary cardiac surgery.

RESULTS

A total of eight studies, including 2,250 patients were included. The rate of mortality and stroke was low (1% and 2%, respectively). Calcification of the ascending aorta was identified in 15% of patients (95% confidence interval [CI] 5.0-26.0). A significant change to the surgical plan such as cannulation strategy, off-pump surgery, cancellation, or an additional procedure was required in 7% (95% CI 2.0-12.0). Clinically relevant incidental findings requiring in-patient management or follow-up were identified in 10% (95% CI 6.0-14.0).

CONCLUSIONS

Nonselective CT chest prior to primary cardiac surgery identifies clinically relevant findings that result in a modification of the surgical plan in a significant population of patients to address the risk of stroke associated with aortic calcification as well as the identification of important incidental findings such as pulmonary lesions.

Antegrade axillary arterial perfusion in 3D endoscopic minimally-invasive mitral valve surgery

Background

Minimally-invasive (MIS) mitral valve (MV) surgery has become standard therapy in many cardiac surgery centers. While femoral arterial perfusion is the preferred cannulation strategy in MIS mitral valve surgery, retrograde arterial perfusion is known to be associated with an increased risk for cerebral atheroembolism, particularly in atherosclerosis patients. Therefore, antegrade perfusion may be beneficial in such cases. This analysis aimed to compare outcomes of antegrade axillary vs. retrograde femoral perfusion in the MIS mitral valve surgery.

Methods

This analysis includes 50 consecutive patients who underwent MIS between 2016 and 2020 using arterial cannulation of right axillary artery (Group A) due to severe aortic arteriosclerosis. Perioperative outcomes of the study group were compared with a historical control group of retrograde femoral perfusion (Group F) which was adjusted for age and gender (n = 50). Primary endpoint of the study was in-hospital mortality and perioperative cerebrovascular events.

Results

Patients in group A had a significantly higher perioperative risk as compared to Group F (EuroSCORE II: 3.9 ± 2.5 vs. 1.6 ± 1.5; p = 0.001; STS-Score: 2.1 ± 1.4 vs. 1.3 ± 0.6; p = 0.023). Cardiopulmonary bypass time (group A: 172 ± 46; group F: 178 ± 51 min; p = 0.627) and duration of surgery (group A: 260 ± 65; group F: 257 ± 69 min; p = 0.870) were similar. However, aortic cross clamp time was significantly shorter in group A as compared to group F (86 ± 20 vs. 111 ± 29 min, p < 0.001). There was no perioperative stroke in either groups. In-hospital mortality was similar in both groups (group A: 1 patient; group F: 0 patients; p = 0.289). In group A, one patient required central aortic repair due to intraoperative aortic dissection. No further cardiovascular events occurred in Group A patients.

Conclusion

Selective use of antegrade axillary artery perfusion in patients with systemic atherosclerosis shows similar in-hospital outcomes as compared to lower risk patients undergoing retrograde femoral perfusion. Patients with higher perioperative risk and severe atherosclerosis can be safely treated via the minimally invasive approach with antegrade axillary perfusion.

A Propensity Score Analysis of Early and Long-Term Outcomes of Retrograde Arterial Perfusion for Endoscopic and Minimally Invasive Heart Valve Surgery in Both Young and Elderly Patients

(1) Background: Minimal invasive cardiac surgery via right anterolateral thoracotomy for heart valve surgery and other intracardiac procedures proven to have lower postoperative complications. We aim to compare the neurological complications and post-operative outcomes in two cohort groups as well as survival rates up to 5 years postoperatively; (2) Methodology: Retrospective observational study for patients who had minimally invasive cardiac valve surgery with retrograde femoral arterial perfusion between 2007 and 2021 (n = 596) and the categorized patients into two groups based on their age (≥70 years old and below 70). Propensity match analysis was conducted. The primary endpoint consisted of major postoperative complications and the secondary endpoint was the long-term survival rate. (3) Results: There was no difference between the two groups in terms of postoperative outcomes. Patients ≥ 70 years old had no increased risk for neurological complications (p = 0.75) compared with those below 70 years old. The mortality rate was also not significant between the two groups (p = 0.37) as well as the crude survival rates. (4) Conclusions: The use of retrograde femoral arterial perfusion in elderly patients is not associated with increased risk compared to the younger patients’ group for a spectrum of primary cardiac valve procedures. Hence, minimally invasive approaches could be offered to elderly patients who might benefit from it.

Impact of standardized computed tomographic angiography for minimally invasive mitral and tricuspid valve surgery

Background

Femoral cannulation for extracorporeal circulation (ECC) is a standard procedure for minimally invasive cardiac surgery (MICS) of the atrio-ventricular valves. Vascular pathologies may cause serious complications. Preoperative computed tomography-angiography (CT-A) of the aorta, axillary and iliac arteries was implemented at our department.

Methods

Between July 2017 and December 2018 all MICS were retrospectively reviewed (n = 143), and divided into 3 groups.

Results

In patients without CT (n = 45, 31.5%) ECC was applied via femoral arteries (91.1% right, 8.9% left). Vascular related complications (dissection, stroke, coronary and visceral ischemia, related in-hospital death) occurred in 3 patients (6.7%). In patients with non-contrast CT (n = 35, 24.5%) only femoral cannulation was applied (94.3% right) with complications in 4 patients (11.4%). CT-angiography (n = 63, 44.1%) identified 12 patients (19.0%) with vulnerable plaques, 7 patients (11.1%) with kinking of iliac vessels, 41 patients (65.1%) with multiple calcified plaques and 5 patients (7.9%) with small femoral artery diameter (d ≤ 6 mm). In 7 patients (11.1%) pathologic findings led to alternative cannulation via right axillary artery, additional 4 patients (6.3%) were cannulated via left femoral artery. Only 2 patients (3.2%) suffered from complications.

Conclusions

CT-A identifies vascular pathologies otherwise undetectable in routine preoperative preparation. A standardized imaging protocol may help to customize the operative strategy.

Utility of Cardiac CT for Preoperative Evaluation of Mitral Regurgitation: Morphological Evaluation of Mitral Valve and Prediction of Valve Replacement

OBJECTIVE

We aimed to investigate the diagnostic accuracy of cardiac computed tomography (CT) for the detection of mitral valve (MV) prolapse in mitral regurgitation (MR) with surgical findings as the standard reference, and to assess the predictability of MV replacement based on morphologic CT findings.

MATERIALS AND METHODS

A total of 156 patients who had undergone preoperative cardiac CT and subsequently received MV surgery due to severe MR were retrospectively enrolled. Non-repairable MV was defined when at least one of the following conditions was met: 1) anterior leaflet prolapse, 2) bi-leaflet prolapse, or 3) valve morphology (leaflet thickening, calcification, or mitral annular calcification [MAC]). Diagnostic performance of CT for the detection of the prolapsed segment was assessed with surgical findings as the standard reference. Logistic regression analysis was performed to evaluate the value of CT findings to predict actual valve replacement.

RESULTS

During surgery, MV prolapse was identified in 72.1%. The sensitivity, specificity, and diagnostic accuracy for the detection of MV prolapse were 99.1%, 81.4%, and 94.2%, respectively, per patient. One-hundred eighteen patients (75.6%) underwent MV repair and the remaining 38 patients received MV replacement. Bi-leaflet prolapse and valve morphology were independent predictors of valve replacement after adjusting for clinical variables (adjusted odds ratio, [OR] 8.63 for bi-leaflet prolapse; OR, 4.14 for leaflet thickening; and OR, 5.37 for leaflet calcium score > 5.6; p < 0.05).

CONCLUSION

Cardiac CT can have high diagnostic performance for detecting the prolapsed segment of the MV and predictability of valve replacement before surgery. Bi-leaflet prolapse and valve morphology, such as leaflet thickening, or calcification or MAC, are the most important predictors of valve replacement.

Incidence and Distribution of Cerebral Embolism After Cardiac Surgery According to the Systemic Perfusion Strategy - A Diffusion-Weighted Magnetic Resonance Imaging Study

BACKGROUND

Stroke is a major concern in minimally invasive cardiac surgery, so we investigated the incidence and risk factors of cerebral embolism according to the systemic perfusion strategy under thorough imaging assessment.Methods and Results:Between November 2011 and May 2015, 315 cardiac surgery patients who underwent preoperative computed tomography angiography (CTA) as a routine evaluation were enrolled. The incidence and distribution of cerebral embolism were analyzed with routine postoperative brain diffusion-weighted magnetic resonance imaging (DW-MRI) examination. Anterograde perfusion was used in 103 patients (group A), and retrograde perfusion was performed in 212 patients (group R). Operative deaths, incidence of clinical stroke (group A: 0%, group R: 0.5%, P=0.77), and rate of cerebral embolism (group A: 35.9%, group R: 26.4%, P=0.08) were comparable. The median number of new embolic lesions detected by MRI per patient (group A: 2, group R: 2, P=0.16), maximal diameter of the lesion (group A: 6.5 mm, group R: 6.0 mm, P=0.97), and anatomic distribution of the lesion were similar between groups. In the multivariate analysis, hypertension, emergency status, atherosclerosis grade 3 or 4 (intimal thickening >4 mm), and cardiopulmonary bypass time were independent risk factors for postoperative cerebral embolism, but retrograde perfusion was not.

CONCLUSIONS

According to the results of postoperative DW-MRI, retrograde perfusion itself might not increase the incidence of postoperative cerebral embolism in properly selected cardiac surgery patients undergoing routine preoperative CTA examination.

Systematic preoperative CT scan is associated with reduced risk of stroke in minimally invasive mitral valve surgery: A meta-analysis

BACKGROUND

Minimally invasive mitral valve surgery (MIMVS) is performed with increasing frequency. However, patients undergoing MIMVS might be at increased risk of perioperative stroke, mainly due to retrograde aortic embolization during femoral cardio-pulmonary bypass. Pre-operative computed tomography (CT) screening allows visualization of the aorta and femoro-iliac vessels and individualization of the surgical approach. In this meta-analysis, we aim to determine if systematic pre-operative CT screening is associated with decreased incidence of post-operative stroke and other complications following MIMVS.

METHODS

A comprehensive review was performed in PubMed (inception-May 2018). Eligible studies included those which reported on MIMVS (mini-thoracotomy, port access or robotic approach) with retrograde arterial perfusion. Studies were separated into two subgroups: systematic pre-operative CT screening (CT-group) and no CT screening (Non-CT). Pooled event rates (PER) for operative mortality, post-operative stroke, perioperative myocardial infarction (MI), and new onset renal failure requiring dialysis were estimated and inter-group comparisons were performed.

RESULTS

Data from 57 studies (13,731 patients) were analyzed (19 CT-group, 38 Non-CT). PER for post-operative stroke was 2.0% with a statistically significant difference between the groups (CT-group: 1.5% versus Non-CT: 2.2%, P = 0.03). PER for new dialysis was 1.9%, significantly lower in the CT-group (0.8% versus 2.3% in the Non-CT group, P = 0.02). PER for operative mortality was 1.4% with a trend towards better outcomes in the CT-group (0.8% versus 1.6% in the Non-CT group, P = 0.05).

CONCLUSIONS

Systematic pre-operative CT screening is associated with lower risk of post-operative stroke and need for dialysis and a trend toward lower operative mortality after MIMVS.

Integrate imaging approach for minimally invasive and robotic procedures

Over the past two decades, robotic and minimally invasive cardiac surgery has been continuously refined and is currently an alternative to traditional open-heart surgery for some patients. The parallel evolution of imaging modalities has made robotic surgery safer and more efficient. Here, we review the pre- and post-operative use of computed tomography (CT) in minimally invasive and robotic cardiac procedures.

Preprocedural Computed Tomography Evaluation for Minimally Invasive Mitral Valve Surgery: What the Surgeon Needs to Know

The proven success of endoscopic and videoscopic surgery combined with recent advancements in telemanipulation has made the performance of minimally invasive cardiac surgery a clinical reality during the past decade. A complete understanding of the basic concepts of minimally invasive surgery and the recent advancements in peripheral cardiopulmonary bypass techniques help the cardiac imager to provide a clinically meaningful interpretation for the surgical team. In this article we present an overview of minimally invasive mitral valve surgery and the fundamentals of preprocedural computed tomography angiography imaging and highlight the usefulness of cardiac computed tomography as a supplementary tool to echocardiography.

Imaging Techniques for Diagnosis of Thoracic Aortic Atherosclerosis

The most severe complications after cardiac surgery are neurological complications including stroke which is often caused by emboli merging from atherosclerosis in the ascending aorta to the brain. Information about the thoracic aorta is crucial in reducing the embolization risk for both surgical open and closed chest procedures such as transaortic heart valve implantation. Several techniques are available to screen the ascending aorta, for example, transesophageal echocardiography (TEE), epiaortic ultrasound, TEE A-view method, manual palpation, computed tomography, and magnetic resonance imaging. This paper provides a description of the advantages and disadvantages of these imaging techniques.

Cardiac CT angiography beyond the coronary arteries: what radiologists need to know and why they need to know it

OBJECTIVE

With current state-of-the-art CT combining fast scanning times and high spatial resolution, anatomy beyond the coronary arteries is well visualized and may lead to discovery of abnormalities. The purpose of this article is to provide a strategy for radiologists to recognize important extracoronary cardiac CT angiography (CTA) findings.

CONCLUSION

A systemic approach to cardiac CTA by anatomic location and attention to key CT features are critical to identify and properly characterize important extracoronary cardiac abnormalities.

Videoscope-assisted cardiac surgery

Videoscope-assisted cardiac surgery (VACS) offers a minimally invasive platform for most cardiac operations such as coronary and valve procedures. It includes robotic and thoracoscopic approaches and each has strengths and weaknesses. The success depends on appropriate hardware setup, staff training, and troubleshooting efficiency. In our institution, we often use VACS for robotic left-internal-mammary-artery takedown, mitral valve repair, and various intra-cardiac operations such as tricuspid valve repair, combined Maze procedure, atrial septal defect repair, ventricular septal defect repair, etc. Hands-on reminders and updated references are provided for reader's further understanding of the topic.

Robotically assisted minimally invasive mitral valve surgery

Increased recognition of advantages, over the last decade, of minimizing surgical trauma by operating through smaller incisions and its direct impact on reduced postoperative pain, quicker recovery, improved cosmesis and earlier return to work has spurred the minimally invasive cardiac surgical revolution. This transition began in the early 1990s with advancements in endoscopic instruments, video & fiberoptic technology and improvements in perfusion systems for establishing cardiopulmonary bypass (CPB) via peripheral cannulation. Society of Thoracic Surgeons data documents that 20% of all mitral valve surgeries are performed using minimally invasive techniques, with half being robotically assisted. This article reviews the current status of robotically assisted mitral valve surgery, its advantages and technical modifications for optimizing clinical outcomes.

Advances in Perfusion Techniques: Minimally Invasive Procedures

There is a growing demand from patients and referring physicians for minimally invasive cardiac surgery. Minimally invasive cardiac procedures are technically unique from conventional cardiac procedures and require a thorough understanding of the surgical, anesthetic, and perfusion strategies. Strategies include routine use of augmented venous drainage, alternative arterial and venous cannulation sites, and special cannulas designed for minimally invasive procedures. The following review describes the strategies and safety systems that should be considered when performing minimally invasive cardiac surgery.

Imaging of cardiac valves by computed tomography

This paper describes "how to" examine cardiac valves with computed tomography, the normal, diseased valves, and prosthetic valves. A review of current scientific literature is provided. Firstly, technical basics, "how to" perform and optimize a multislice CT scan and "how to" interpret valves on CT images are outlined. Then, diagnostic imaging of the entire spectrum of specific valvular disease by CT, including prosthetic heart valves, is highlighted. The last part gives a guide "how to" use CT for planning of transcatheter aortic valve implantation (TAVI), an emerging effective treatment option for patients with severe aortic stenosis. A special focus is placed on clinical applications of cardiac CT in the context of valvular disease.

Retrograde femoral arterial perfusion and stroke risk during minimally invasive mitral valve surgery: is there cause for concern?

Recent data have suggested that retrograde arterial perfusion (RAP) during minimally invasive mitral valve surgery (MIMVS) is associated with a higher stroke rate than sternotomy approaches. To assess whether there is genuine cause for concern, we examine the strengths and weaknesses of this data. A multitude of confounding factors obfuscate interpretation of the data including imprecise definitions of MIMVS, the effect of the substantial learning curve, retrospective comparisons of small historic cohorts with baseline differences and differing risk profiles for atherosclerosis, different methods of aortic occlusion and lack of reporting of peripheral vascular disease (PVD)/aortic assessment in patient populations. In patients with severe (grades IV and V) aortic arch/ascending aortic atherosclerosis, RAP has clearly been shown to be associated with an increase in risk of cerebral embolic complications. It would be reasonable to assume that grades IV/V atheroma anywhere along the aorto-iliac axis (from femoral cannulation site to carotid arteries) may also increase the risk of stroke. Hence those at risk of severe atherosclerotic vascular disease should be screened to fully assess the aortoiliac axis. Apart from this patient group, there is no convincing evidence (without confounding variables) that retrograde perfusion per se during minimally invasive mitral surgery increases the risk of stroke. This may be due to the largely differing aetiologies of vascular and mitral degenerative disease.

Robotic and minimally invasive cardiac surgery

The transition of mitral valve surgery away from the traditional sternotomy approach toward more minimally invasive strategies continues to evolve. The use of telemanipulative robotic arms with near 3-dimensional valve visualization has allowed for near complete endoscopic robotic-assisted mitral valve surgery, providing increased patient satisfaction and cosmesis. Studies have shown rapid recovery times without sacrificing perioperative safety or the durability of surgical repair. Although a steep learning curve exists as well as high fixed and disposable costs, continued technological development fueled by increasing patient demand may allow for further expansion in the use of robotic-assisted minimal invasive surgery.