Virtual and Augmented Reality in Cardiac Surgery

Abstract Virtual and augmented reality can be defined as a three-dimensional real-world simulation allowing the user to directly interact with it. Throughout the years, virtual reality has gained great popularity in medicine and is currently being adopted for a wide range of purposes. Due to its dynamic anatomical nature, permanent drive towards decreasing invasiveness, and strive for innovation, cardiac surgery depicts itself as a unique environment for virtual reality. Despite substantial research limitations in cardiac surgery, the current literature has shown great applicability of this technology, and promising opportunities.

Virtual and Augmented Reality in Cardiac Surgery.

Virtual and augmented reality can be defined as a three-dimensional real-world simulation allowing the user to directly interact with it. Throughout the years, virtual reality has gained great popularity in medicine and is currently being adopted for a wide range of purposes. Due to its dynamic anatomical nature, permanent drive towards decreasing invasiveness, and strive for innovation, cardiac surgery depicts itself as a unique environment for virtual reality. Despite substantial research limitations in cardiac surgery, the current literature has shown great applicability of this technology, and promising opportunities.

Open Transcatheter Multivalve Replacement in Degenerated Valve Prostheses in High-Risk Patients with Endocarditis

Abstract Multivalve redo procedures carry a high surgical risk. We describe an alternative surgical treatment for patients presenting with severely degenerated aortic and mitral valve prostheses who have to undergo open surgery due to endocarditis. Open transcatheter multivalve implantation is a feasible bailout strategy in high-risk patients to save cross-clamp and procedural times to reduce morbidity and mortality.

Aortic Root Replacement for Destructive Endocarditis - Clinic and Microbiology

Abstract Introduction: Destructive aortic root endocarditis is associated with high mortality rates. The objective of this article was to characterize the clinical and microbiological profiles of these patients, especially concerning an already implanted aortic valve prosthesis. We also focused on prognostic factors. Methods: Eighty patients underwent aortic root replacement due to destructive endocarditis from 1999 to 2018 in our institution. We analyzed their pre, intra, and postoperative data, outcomes, and predictors of mortality. Results: Thirty-one patients had native valve endocarditis (NVE), eight patients had early-onset prosthetic valve endocarditis (PVE), and 41 patients had late-onset PVE. Streptococcus was found in 19.4% of NVE cases and no PVE case. Coagulase-negative Staphylococcus was responsible for 62.5% of the cases of early-onset PVE. Thirty-four (42.5%) patients had received inappropriate antibiotics before admission. No microorganism was associated with higher risk of mortality. Aortoventricular dehiscence was identified as an independent risk factor of mortality along with PVE, concomitant bypass surgery, and delayed diagnosis. The incidence of postoperative complications was similar in all three groups. Rates of long-term survival (P=0.044) and freedom from the composite endpoint (P=0.024) defined as death, stroke, aortic valve reinfection, and aortic valve reoperation were the lowest within the NVE group and the highest among the PVE patients. Conclusion: In endocarditis, prolonged diagnostics, inadequate antimicrobial treatment, and late surgery led to destructive local complications and worsened the prognosis. PVE is associated with higher mortality than NVE.

Aortic Root Replacement for Destructive Endocarditis - Clinic and Microbiology.

INTRODUCTION: Destructive aortic root endocarditis is associated with high mortality rates. The objective of this article was to characterize the clinical and microbiological profiles of these patients, especially concerning an already implanted aortic valve prosthesis. We also focused on prognostic factors. METHODS: Eighty patients underwent aortic root replacement due to destructive endocarditis from 1999 to 2018 in our institution. We analyzed their pre, intra, and postoperative data, outcomes, and predictors of mortality. RESULTS: Thirty-one patients had native valve endocarditis (NVE), eight patients had early-onset prosthetic valve endocarditis (PVE), and 41 patients had late-onset PVE. Streptococcus was found in 19.4% of NVE cases and no PVE case. Coagulase-negative Staphylococcus was responsible for 62.5% of the cases of early-onset PVE. Thirty-four (42.5%) patients had received inappropriate antibiotics before admission. No microorganism was associated with higher risk of mortality. Aortoventricular dehiscence was identified as an independent risk factor of mortality along with PVE, concomitant bypass surgery, and delayed diagnosis. The incidence of postoperative complications was similar in all three groups. Rates of long-term survival (P=0.044) and freedom from the composite endpoint (P=0.024) defined as death, stroke, aortic valve reinfection, and aortic valve reoperation were the lowest within the NVE group and the highest among the PVE patients. CONCLUSION: In endocarditis, prolonged diagnostics, inadequate antimicrobial treatment, and late surgery led to destructive local complications and worsened the prognosis. PVE is associated with higher mortality than NVE.

Step-by-Step Minimally Invasive Aortic Valve Replacement: the RAT Approach

Abstract In the growing era of transcatheter aortic valve implantation, it is crucial to develop minimally invasive surgical techniques. These methods enable easier recovery from surgical trauma, especially in elderly and frail patients. Minimally invasive aortic valve replacement (MIAVR) is frequently performed via upper hemisternotomy. We describe MIAVR via right anterior thoracotomy, which is associated with less trauma, rapid mobilization, lower blood transfusion rates, and lower risk of postoperative wound infections. As minimally invasive procedures tend to take longer operative times, we suggest using rapid-deployment valve prostheses to overcome this limitation. This description focuses on the technical aspects and preoperative assessment.

Step-by-Step Minimally Invasive Aortic Valve Replacement: the RAT Approach.

In the growing era of transcatheter aortic valve implantation, it is crucial to develop minimally invasive surgical techniques. These methods enable easier recovery from surgical trauma, especially in elderly and frail patients. Minimally invasive aortic valve replacement (MIAVR) is frequently performed via upper hemisternotomy. We describe MIAVR via right anterior thoracotomy, which is associated with less trauma, rapid mobilization, lower blood transfusion rates, and lower risk of postoperative wound infections. As minimally invasive procedures tend to take longer operative times, we suggest using rapid-deployment valve prostheses to overcome this limitation. This description focuses on the technical aspects and preoperative assessment.

Open Transcatheter Multivalve Replacement in Degenerated Valve Prostheses in High-Risk Patients with Endocarditis.

Multivalve redo procedures carry a high surgical risk. We describe an alternative surgical treatment for patients presenting with severely degenerated aortic and mitral valve prostheses who have to undergo open surgery due to endocarditis. Open transcatheter multivalve implantation is a feasible bailout strategy in high-risk patients to save cross-clamp and procedural times to reduce morbidity and mortality.

Balloon versus self-expandable transcatheter aortic valve implantation for bicuspid aortic valve stenosis: A meta-analysis of observational studies.

BACKGROUND: There is a rising trend for transcatheter aortic valve implantation (TAVI) in bicuspid aortic stenosis patients. Data on the use of self-expandable (SEV) vs. balloon-expandable (BEV) valves in these patients are scarce. Therefore, we systematically compared clinical outcomes in bicuspid aortic stenosis patients treated with SEV and BEV. METHODS: Data were extracted from PubMed/MEDLINE, EMBASE, CENTRAL/CCTR, ClinicalTrials.gov, SciELO, LILACS, Google Scholar and reference lists of relevant articles. Eight studies published from 2013 to 2020 including a total of 1,080 patients (BEV: n = 620; SEV: n = 460) were selected. Primary endpoints were procedural, 30-day and 1-year mortality. Secondary endpoints were new pacemaker implantation, annular rupture, coronary obstruction, moderate-to-severe paravalvular leak, need of second valve, stroke and acute kidney injury. RESULTS: We found no statistically significant difference in mortality between patients treated with BEV vs. SEV during index procedure, at 30 days and at 1 year. BEVs showed a statistically significant higher risk of annulus rupture (2.5%) in comparison with SEV (0%) (OR 5.81 [95% CI, 3.78-8.92], p < .001). New generation BEVs were also associated with significantly less paravalvular leak when compared to new generation SEVs (OR 0.08 [95% CI, 0.02-0.35], p = .001). CONCLUSIONS: This meta-analysis of observational studies of TAVI for bicuspid valves, showed no difference in short- and mid-term TAVI mortality with BEVs and SEVs. BEVs presented a higher risk of annular rupture in comparison with SEV.

Total Arterial Coronary Bypass Graft Surgery is Associated with Better Long-Term Survival in Patients with Multivessel Coronary Artery Disease: a Systematic Review with Meta-Analysis.

INTRODUCTION: The benefit of total arterial revascularization (TAR) in coronary artery bypass grafting (CABG) remains a controversial issue. This study sought to evaluate whether there is any difference on the long-term results of TAR and non-TAR CABG patients. METHODS: The Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica dataBASE (EMBASE), Cochrane Central Register of Controlled Trials (CENTRAL/CCTR), Clinical Trials.gov, Scientific Electronic Library Online (SciELO), Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), and Google Scholar databases were searched for studies published by October 2020. Randomized clinical trials and observational studies with propensity score matching comparing TAR versus non-TAR CABG were included. Random-effects meta-analysis was performed. The current barriers to implementation of TAR in clinical practice and measures that can be used to optimize outcomes were reviewed. RESULTS: Fourteen publications (from 2012 to 2020) involving a total of 22,746 patients (TAR: 8,941 patients; non-TAR: 13,805 patients) were included. The pooled hazard ratio (HR) for long-term mortality (over 10 years) was lower in the TAR group than in the non-TAR group (random effect model: HR 0.676, 95% confidence interval 0.586-0.779, P<0.001). There was evidence of low heterogeneity of treatment effect among the studies for mortality, and none of the studies had a particular impact on the summary result. The result was not influenced by age, sex, or comorbidities. We identified low risk of publication bias related to this outcome. CONCLUSION: This review found that TAR presents the best long-term results in patients who undergo CABG. Given that many patients are likely to benefit from TAR, its use should be encouraged.

Total arterial coronary bypass graft surgery is associated with better long-term survival in patients with multivessel coronary artery disease: a systematic review with meta-analysis

Abstract Introduction: The benefit of total arterial revascularization (TAR) in coronary artery bypass grafting (CABG) remains a controversial issue. This study sought to evaluate whether there is any difference on the long-term results of TAR and non-TAR CABG patients. Methods: The Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica dataBASE (EMBASE), Cochrane Central Register of Controlled Trials (CENTRAL/CCTR), Clinical Trials.gov, Scientific Electronic Library Online (SciELO), Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), and Google Scholar databases were searched for studies published by October 2020. Randomized clinical trials and observational studies with propensity score matching comparing TAR versus non-TAR CABG were included. Random-effects meta-analysis was performed. The current barriers to implementation of TAR in clinical practice and measures that can be used to optimize outcomes were reviewed. Results: Fourteen publications (from 2012 to 2020) involving a total of 22,746 patients (TAR: 8,941 patients; non-TAR: 13,805 patients) were included. The pooled hazard ratio (HR) for long-term mortality (over 10 years) was lower in the TAR group than in the non-TAR group (random effect model: HR 0.676, 95% confidence interval 0.586-0.779, P<0.001). There was evidence of low heterogeneity of treatment effect among the studies for mortality, and none of the studies had a particular impact on the summary result. The result was not influenced by age, sex, or comorbidities. We identified low risk of publication bias related to this outcome. Conclusion: This review found that TAR presents the best long-term results in patients who undergo CABG. Given that many patients are likely to benefit from TAR, its use should be encouraged.

Asymptomatic severe aortic stenosis, bicuspid aortic valves and moderate aortic stenosis in heart failure: New indications for transcatheter aortic valve implantation.

Aortic stenosis (AS) remains one of the most common valvular heart diseases, with enormous impact on patient survival. Over the past years, transcatheter aortic valve implantation (TAVI) has become a reality worldwide, offering a less invasive method to treat AS. Apart from the classical indications for aortic valve disease, recent studies tried to address unanswered questions for TAVI - asymptomatic severe AS, bicuspid aortic valves and moderate AS in patients with heart failure. This review discusses the rationale of those possible indications, pitfalls and current evidence in the medical literature.

Stentless Root Replacement versus Tissue Valves in Infective Endocarditis - A Propensity-Score Matched Study.

INTRODUCTION: People with aortic/prosthetic valve endocarditis are a high-risk cohort of patients who present a challenge for all medically involved disciplines and who can be treated by various surgical techniques. METHODS: We analyzed the results of treatment of root endocarditis with Medtronic Freestyle® in full-root technique over 19 years (1999-2018) and compared them against treatment with other tissue valves. Comparison was made with propensity score matching, using the nearest neighbor method. Various tests were performed as suited for adequate analyses. RESULTS: Fifty-four patients in the Medtronic Freestyle group (FS group) were matched against 54 complex root endocarditis patients treated with other tissue valves (Tissue group). Hospital mortality was 9/54 (16.7%) in the FS group vs. 14/54 (25.6%) in the Tissue group (P=0.24). Cox regression performed for early results demonstrated coronary heart disease (P=0.004, odds ratio 2.3), among others, influencing early mortality. Recurrent infection was low (1.8% for FS and Tissue patients) and freedom from reoperation was 97.2% at a total of 367 patient-years of follow-up (median of 2.7 years). CONCLUSION: The stentless xenograft is a viable alternative for treatment of valve/root/prosthetic endocarditis, demonstrating a low rate of reinfection. The design of the bioroot allows for complex reconstructive procedures at the outflow tract and the annular level with at an acceptable operative risk. Endocarditis patients can be treated excluding infective tissue from the bloodstream, possibly with benefits, concerning bacteremia and recurrent infection. Furthermore, the use of the stentless bioroot offers varying treatment options in case of future valve degeneration.

State-of-the-Art Pediatric Coronary Artery Bypass Surgery: a Literature Review.

OBJECTIVE: To examine the results of various myocardial revascularization techniques in pediatric patients to better understand the strategies for surgical treatment of coronary artery pathologies. METHODS: We analyzed 61 publications dedicated to the indications, methods, and results of coronary bypass surgery in children. Due to the small size of this cohort, case reports are also included in our review. RESULTS: The main indications for coronary bypass grafting in children are Kawasaki disease, myocardial revascularization as a necessary procedure during the congenital cardiac surgery, to manage intraoperative iatrogenic damage to coronary arteries, and homozygous familial hypercholesterolemia. The use of internal thoracic arteries as conduits for coronary bypass grafting in children with Kawasaki disease showed significantly better results in long-term functionality compared to autovenous conduits (87% and 44%, respectively, P<0.001). Acute and late coronary events after arterial switch operation for the transposition of the great arteries, anomalous origin of the left coronary artery from the pulmonary artery, and left main coronary artery atresia are the main congenital heart diseases where surgical correction involves interventions on the coronary arteries. CONCLUSION: The internal thoracic artery is a reliable and durable conduit that demonstrates proven growth potential in children.

State-of-the-art pediatric coronary artery bypass surgery: a literature review

Abstract Objective: To examine the results of various myocardial revascularization techniques in pediatric patients to better understand the strategies for surgical treatment of coronary artery pathologies. Methods: We analyzed 61 publications dedicated to the indications, methods, and results of coronary bypass surgery in children. Due to the small size of this cohort, case reports are also included in our review. Results: The main indications for coronary bypass grafting in children are Kawasaki disease, myocardial revascularization as a necessary procedure during the congenital cardiac surgery, to manage intraoperative iatrogenic damage to coronary arteries, and homozygous familial hypercholesterolemia. The use of internal thoracic arteries as conduits for coronary bypass grafting in children with Kawasaki disease showed significantly better results in long-term functionality compared to autovenous conduits (87% and 44%, respectively, P<0.001). Acute and late coronary events after arterial switch operation for the transposition of the great arteries, anomalous origin of the left coronary artery from the pulmonary artery, and left main coronary artery atresia are the main congenital heart diseases where surgical correction involves interventions on the coronary arteries. Conclusion: The internal thoracic artery is a reliable and durable conduit that demonstrates proven growth potential in children.

Stentless root replacement versus tissue valves in infective endocarditis - a propensity-score matched study

Abstract Introduction: People with aortic/prosthetic valve endocarditis are a high-risk cohort of patients who present a challenge for all medically involved disciplines and who can be treated by various surgical techniques. Methods: We analyzed the results of treatment of root endocarditis with Medtronic Freestyle® in full-root technique over 19 years (1999-2018) and compared them against treatment with other tissue valves. Comparison was made with propensity score matching, using the nearest neighbor method. Various tests were performed as suited for adequate analyses. Results: Fifty-four patients in the Medtronic Freestyle group (FS group) were matched against 54 complex root endocarditis patients treated with other tissue valves (Tissue group). Hospital mortality was 9/54 (16.7%) in the FS group vs. 14/54 (25.6%) in the Tissue group (P=0.24). Cox regression performed for early results demonstrated coronary heart disease (P=0.004, odds ratio 2.3), among others, influencing early mortality. Recurrent infection was low (1.8% for FS and Tissue patients) and freedom from reoperation was 97.2% at a total of 367 patient-years of follow-up (median of 2.7 years). Conclusion: The stentless xenograft is a viable alternative for treatment of valve/root/prosthetic endocarditis, demonstrating a low rate of reinfection. The design of the bioroot allows for complex reconstructive procedures at the outflow tract and the annular level with at an acceptable operative risk. Endocarditis patients can be treated excluding infective tissue from the bloodstream, possibly with benefits, concerning bacteremia and recurrent infection. Furthermore, the use of the stentless bioroot offers varying treatment options in case of future valve degeneration.

Mitral valve repair with minimally invasive approaches vs sternotomy: A meta-analysis of early and late results in randomized and matched observational studies.

BACKGROUND AND AIM OF THE STUDY: Minimally invasive cardiac surgery (MICS) for mitral valve repair (MVRp) has been increasingly used. This study aimed to evaluate the early and late results of MICS for MVRp vs conventional sternotomy. MATERIALS AND METHODS: A systematic review of randomized controlled trials or observational studies (with matched populations) comparing MICS and conventional MVRp reporting any of the following outcomes: mortality, MVRp failure, complications, blood transfusion, readmission within 30 days after discharge, long-term reoperation for mitral regurgitation, operative times, mechanical ventilation time, intensive care unit (ICU) stay, or hospital stay. The pooled treatment effects were calculated using a random-effects model. RESULTS: Ten studies involving 6792 patients (MICS: 3396 patients; Conventional: 3296 patients) met the eligibility criteria. In the pooled analysis, MICS significantly reduced the risk for blood transfusion (odds ratio [OR], 0.654; 95% confidence interval [CI] 0.462-0.928; P = .017) and readmission within 30 days after discharge (OR, 0.615; 95% 0.456-0.829; P = .001). MICS was associated with a significantly longer cross-clamp time (mean difference 14 minutes; 95% CI, 7.4-21 minutes; P < .001), CPB time (24 minutes; 95% CI, 14-35 minutes; P < .001), and total operative time (36; 95% CI, 15-56 minutes; P < .001), but a significantly shorter ICU stay (-8.5; 95% CI -15; -1.8; P = .013) and hospital stay (-1.3, 95% CI -2.1; -0.45; P = .003). This meta-analysis found no significant difference regarding the risk of in-hospital and long-term mortality, nor complications. CONCLUSIONS: Despite longer operative times, MICS for MVRp reduces ICU and hospital stay, as well as readmission rates and the need for transfusion.

Immediate Outcomes of Aortic Valve Neocuspidization with Glutaraldehyde-treated Autologous Pericardium: a Multicenter Study.

OBJECTIVE: To determine the feasibility of aortic valve neocuspidization (AVNeo) with glutaraldehyde-treated autologous pericardium. METHODS: One hundred and seventy (170) AVNeo (84 males/86 females) were performed from January 2017 through March 2019 in three centers. All the records were prospectively collected and retrospectively reviewed. RESULTS: Most of the patients were older than 60 years and over 95% were operated for aortic stenosis. Preoperatively, pressure gradients were 69.9±21.3 mmHg for patients with aortic stenosis, and the surgical annular diameter was 21.0±2.0 mm for all patients. Effective orifice area (EOA) and indexed EOA (iEOA) averaged 0.7±0.3 cm2 and 0.4±0.2 cm2/m2 for patients with aortic stenosis before surgery, respectively. There was no conversion to prosthetic aortic valve replacement. Eight patients needed reoperation for bleeding, but no patient needed reoperation due to early infective endocarditis. There were five in-hospital deaths due to noncardiac cause. Compared to preoperative echocardiographic measurements, postoperative peak pressure gradient decreased significantly (-58.7±1.7 mmHg; P<0.001) and reached 11.2±5.6 mmHg, and mean pressure gradient also decreased significantly (-36.8±1.1 mmHg; P<0.001) and reached 6.0±3.5 mmHg. Accordingly, EOA and iEOA increased significantly 2.0 cm2 and 1.0 cm2/m2 (both P<0.001) to reach 2.7±0.6 cm2 and 1.4±0.3 cm2/m2 after surgery, respectively, with minimal significant aortic regurgitation (0.6% > mild). CONCLUSION: AVNeo is feasible and reproducible with good clinical results. Hemodynamically, AVNeo produces immediate postoperative low-pressure gradients, large EOA, and minimal regurgitation of the aortic valve. Further studies are necessary to evaluate mid- and long-term evolution.

Surgical Options for Aortic Root Replacement in Destructive Endocarditis.

OBJECTIVE: To analyze patients' preoperative characteristics, surgical data, postoperative courses, and short- and long-term outcomes after implantation of different full-root prostheses for destructive aortic valve endocarditis. METHODS: Between 1999 and 2018, 80 patients underwent aortic root replacement due to infective endocarditis in our institution. We analyzed the abovementioned data with standard statistical methods. RESULTS: The Freestyle stentless porcine prostheses were implanted in 53 (66.25%) patients, biological valve conduits in 13 (16.25%), aortic root homografts in nine (11.25%), and mechanical valve conduits in five (6.25%). There were no significant preoperative differences between the groups. The incidence of postoperative complications and intensive care unit length of stay did not differ significantly between the groups. The 30-day mortality rate was low among Freestyle patients (n=8, 15.1%) and high in the mechanical conduit cohort (n=3, 60%), though with borderline statistical significance (P=0.055). The best mean survival rates were observed after homograft (13.7 years) and stentless prosthesis (8.1 years) implantation, followed by biological (2.8 years) and mechanical (1.4 years) conduits (P=0.014). The incidence of reoperations was low in the mechanical conduit group (0) and stentless bioroot group (n=1, 1.9%), but two (15.4%) patients with biological conduits and three (33.3%) patients with homografts required reoperations in the investigated follow-up period (P=0.005). CONCLUSION: In patients with the destructive form of aortic valve endocarditis, homografts and stentless porcine xenografts offer better survival rates than stented valve conduits; however, the reoperation rate among patients who received homograft valves is high.