Minimally Invasive Cardiovascular Surgery: Incisions and Approaches

Zebrafish as an innovative model for exploring cardiovascular disease induction mechanisms and novel therapeutic interventions: a molecular insight

Cardiovascular disease (CVD) is a common cardiac disorder that leads to heart attacks, strokes, and heart failure. It is primarily characterized by conditions that impact the heart and blood arteries, including peripheral artery disease, arrhythmias, atherosclerosis, myocardial ischemia, congenital heart abnormalities, heart failure, rheumatic heart disease, hypertension, and cardiomyopathies. These conditions are mainly effect the heart and blood vessels, causing blockages or weakened pumping, due to severe hereditary and environmental factors. The frequency of CVD is rising significantly as life expectancy increases. Despite this, no effective treatment or management for its symptoms has been found. One of the most difficult obstacles to overcome, is finding a suitable animal model for drug screening and drug development. Although rodents, mice, swine, and mammals serve as the basis for most animal models of cardiovascular disease, no model accurately captures the epidemiology of the condition. Zebrafish (Danio rerio) have drawn the interest of the international scientific community due to certain shortcomings of the previously discussed animal models because they are smaller, less costly, and have an incredibly high rate of reproduction. This review article emphasizes the significance of using zebrafish as an animal model to investigate the possible facets of cardiovascular disease. Moreover, the ultimate purpose of this review article is to establish the advantages of employing zebrafish over other animal models and to investigate the boundaries of using zebrafish to study human disease. Furthermore, the mechanisms of cardiovascular diseases induction in zebrafish were covered to improve understanding for readers. Finally, the analysis of cardiotoxicity using Zebra fish model, is also explained. In order to stop the health index from deteriorating, the current study also covers some innovative, effective, and relatively safer treatments for treatment and management of cardiotoxicity.

Upper partial sternal split for pediatric cardiac surgery

OBJECTIVES

We introduced the use of an upper partial sternal split for pediatric cardiac surgical procedures in our unit in 2016. We report the outcomes of our experience in 51 patients using this approach.

METHODS

From February 2016 to September 2022, 51 patients underwent congenital cardiac surgical procedures using an upper partial sternal split including vascular ring repair (n = 20), subaortic membrane (n = 12), ventricular septal defect closure with aortic valve resuspension (n = 9), aortic arch repair (n = 4), pulmonary artery band (n = 2), pulmonary artery sling (n = 1), supravalvular aortic stenosis (n = 1), aortic valve replacement (n = 1), and pulmonary artery plasty (n = 1). The surgical approach involved a midline skin incision, based on the manubrium, followed by an upper manubriotomy. No special surgical instrumentation was required. Median patient age was 2.9 years (IQR 1.3, 6.0); median body weight was 15 kg (IQR 9.8, 20).

RESULTS

There was no mortality and no patient required intraoperative conversion to full sternotomy. One patient required re-exploration for bleeding when the incision was converted to a full sternotomy. There were no wound complications in any patient. Twenty-one patients (41%) were extubated on the table and of the remaining 30 patients, 23 patients (76%) were extubated within 24 h of surgery. Eleven patients did not require intensive care unit (ICU) admission. Median ICU and hospital stay was 1 day (IQR 1, 1.25) and 5 days (IQR 4, 8) ,respectively.

CONCLUSION

An upper partial sternal split approach is straightforward and can be performed safely with a preferable cosmetic result in selected pediatric cardiac operations.

Role of surgical simulation on self-reported confidence level on cardiothoracic surgical trainees

BACKGROUND

Simulated self-practice using simulation models could improve fine motor skills and self confidence in surgical trainees.

AIMS

The purpose of this study is to evaluate on self-reported confidence level in cardiothoracic surgical trainees by using surgical simulation models.

METHODS

We conducted a cross-sectional study on all surgeons (n=10) involved in MIS simulation training. All surgeons are required to perform on three minimally invasive surgery (MIS) procedures (Mitral Valve Repair, Mitral Valve Replacement and Aortic Valve Replacement). A questionnaire was designed based on two existing scales related to self-confidence, the surgical self-efficacy scale [SSES] and the perceived competency scale [PCS]. We assessed their self-confidence (before and after training) in the use of simulation in MIS procedures using rating scales 1-5. The mean score was calculated for each domain and used as the predictor variable. We also developed six questions (PCS) using Objective Structured Assessment of Technical Skills (OSAT) related to each domain and asked participants how confident they were after performing each MICS procedure.

RESULTS

The mean score was 4.7 for all assessed domains, except "knowledge" (3.8). Surgeons who had performed one or more MIS procedures had higher scores (P<0.05). There was no correlation between the number of MIS procedures performed and self-confidence scores.

CONCLUSIONS

The results indicate that the cardiac surgery training based on MIS simulation improves trainees and consultants in terms of the level of self-confidence. Although surgeons generally have high levels of self-confidence after simulation training in MIS cardiac procedures, there is still room for improvement with respect to technical skills related to the procedure itself and its results.

Sternal Complications Following Coronary Artery Bypass Grafting and Robicsek Repair: Comprehensive Sternal Reconstruction With Sternal Plating and the Use of Novel Biologic Therapies

Sternal non-union and fractured sternal wires are rare but devastating complications of median sternotomy for cardiac surgery, and these can lead to chronic pain, instability, and impaired quality of life. Patients may present with various symptoms such as clicking sensations, chest wall discomfort, and even respiratory difficulties. The underlying causes are multifactorial, including patient comorbidities, surgical technique, and postoperative management. The treatment options range from conservative measures to complex surgical interventions, such as sternal debridement, rewiring, and reconstruction with rigid fixation systems. Novel therapeutic technologies, including amniotic membranes and platelet-rich plasma, have shown promise in promoting wound healing and reducing complications in these challenging cases. We present the case of a 58-year-old male who underwent coronary artery bypass grafting (CABG) and subsequently developed sternal dehiscence requiring Robicsek repair. Despite undergoing this procedure, the patient experienced poor sternal healing, and hence he was referred to our center, presenting with shortness of breath, pain due to fractured sternal wires, and sternal non-union. The patient underwent a complex sternal reconstruction involving redo full median sternotomy, removal of sternal wires, and sternal plating, along with the application of amniotic membranes and platelet-rich plasma to the sternal wound. The procedure successfully stabilized the sternum. This report highlights the benefits of a multifaceted approach to addressing repeated sternal breakdown following CABG and the potential therapeutic benefits of novel technologies in promoting wound healing.

[Learning curve and clinical efficacy of aortic surgery through upper hemisternotomy]

OBJECTIVE

To investigate the learning curve and clinical efficacy of aortic dissection and non-dissection aortic surgeries through upper hemisternotomy.

METHODS

We retrospectively analyzed the perioperative data of aortic dissection and non-dissection surgeries through upper hemisternotomy performed by the same surgical team. Based on cardiopulmonary bypass time and aortic cross-clamping time, the learning curves were plotted using cumulative (CUSUM) analysis and the fitting curve, and the learning process was divided into the improvement period and proficiency period. We compared the perioperative parameters in the two stages, and verified whether the critical point was the number of operations required to overcome the learning curve. The safety and short-term efficacy of the aortic surgeries were analyzed after achieving proficiency.

RESULTS

A total of 107 patients were analyzed, including 47 undergoing aortic dissection (ascending aorta replacement + arch replacement + descending aorta stent implantation and/or aortic root treatment) and 60 undergoing non-dissection surgeries (artery root surgery and/or ascending aorta replacement). The optimal fitting equation was y=-0.019x3+0.251x2+28.852x-6.076 (R2=0.918, P < 0.05) for CPB time and y=-0.015x3-0.093x2+34.799x-27.316 (R2=0.92, P < 0.05) for aortic cross-clamping time. In the dissection group, with 27 cases as the boundary, the perioperative parameters were significantly better in the proficiency stage than in the improvement stage, and the critical point was the number of surgeries needed to overcome the learning curve. The best fitting equation was y=0.013x3-1.826x2 + 62.353x+193.189 (R2=0.906, P < 0.05) for CPB time and y= 0.009x3-1.416x2+49.389x+177.335 (R2=0.90, P < 0.05) for aortic cross-clamping time. In the non-dissecting aorta group, where 22 cases served as the boundary, the perioperative parameters were also better in the proficiency period than in the improvement period.

CONCLUSION

Both aortic dissection and non-dissection surgeries through upper hemisternotomy are safe and can significantly improve the short-term postoperative efficacy after achieving proficiency, but the latter approach has a shorter learning curve.

Chronic pain after posterolateral and axillary approaches to lung surgery: a monocentric observational study

PURPOSE

Post-thoracotomy pain syndrome (PTPS) and chronic postsurgical neuropathic pain (CPNP) were evaluated 4 months after thoracic surgery whether the approach was a posterolateral (PL) incision or the less invasive axillary (AX) one.

METHODS

Patients, 79 in each group, undergoing a thoracotomy between July 2014 and November 2015 were analyzed 4 months after surgery in this prospective monocentric cohort study.

RESULTS

More PL patients suffered PTPS (60.8% vs. 40.5%; p = 0.017) but CPNP was equally present (45.8% and 46.9% in the PL and AX groups). Patients with PTPS have more limited daily activities (p < 0.001) but a similar psychological disability (i.e., catastrophism). Patients with CPNP have an even greater limitation of daily activities (p = 0.007) and more catastrophism (p = 0.0002). Intensity of pain during mobilization of the homolateral shoulder at postoperative day 6 (OR = 1.40, CI 95% [1.13-1.75], p = 0.002); age (OR = 0.97 [0.94-1.00], p = 0.022), and presence of pain before surgery (OR = 2.22 [1.00-4.92], p = 0.049) are related to the occurrence of PTPS; while, height of hypoesthesia area on the breast line measured 6 days after surgery is the only factor related to that of CPNP (OR = 1.14 [1.01-1.30], p = 0.036).

CONCLUSION

Minimally invasive surgery was associated with less frequent PTPS, but with equal risk of CPNP. Pain before surgery and its postoperative intensity are associated with PTPS. This must lead to a more aggressive care of pain patients before surgery and of a better management of postoperative pain. CPNP can be forecasted according to the early postoperative height of hypoesthesia area on the breast line.

Serratus anterior and pectoralis plane blocks for robotically assisted mitral valve repair: a randomised clinical trial

BACKGROUND

Minimally invasive cardiac surgery provokes substantial pain and therefore analgesic consumption. The effect of fascial plane blocks on analgesic efficacy and overall patient satisfaction remains unclear. We therefore tested the primary hypothesis that fascial plane blocks improve overall benefit analgesia score (OBAS) during the initial 3 days after robotically assisted mitral valve repair. Secondarily, we tested the hypotheses that blocks reduce opioid consumption and improve respiratory mechanics.

METHODS

Adults scheduled for robotically assisted mitral valve repairs were randomised to combined pectoralis II and serratus anterior plane blocks or to routine analgesia. The blocks were ultrasound-guided and used a mixture of plain and liposomal bupivacaine. OBAS was measured daily on postoperative Days 1-3 and were analysed with linear mixed effects modelling. Opioid consumption was assessed with a simple linear regression model and respiratory mechanics with a linear mixed model.

RESULTS

As planned, we enrolled 194 patients, with 98 assigned to blocks and 96 to routine analgesic management. There was neither time-by-treatment interaction (P=0.67) nor treatment effect on total OBAS over postoperative Days 1-3 with a median difference of 0.08 (95% confidence interval [CI]: -0.50 to 0.67; P=0.69) and an estimated ratio of geometric means of 0.98 (95% CI: 0.85-1.13; P=0.75). There was no evidence of a treatment effect on cumulative opioid consumption or respiratory mechanics. Average pain scores on each postoperative day were similarly low in both groups.

CONCLUSIONS

Serratus anterior and pectoralis plane blocks did not improve postoperative analgesia, cumulative opioid consumption, or respiratory mechanics during the initial 3 days after robotically assisted mitral valve repair.

CLINICAL TRIAL REGISTRATION

NCT03743194.

Comparative Analysis of Patient-Specific Aortic Dissections through Computational Fluid Dynamics Suggests Increased Likelihood of Degeneration in Partially Thrombosed False Lumen

Aortic dissection is a life-threatening vascular disease associated with high rates of morbidity and mortality, especially in medically underserved communities. Understanding patients’ blood flow patterns is pivotal for informing evidence-based treatment as they greatly influence the disease outcome. The present study investigates the flow patterns in the false lumen of three aorta dissections (fully perfused, partially thrombosed, and fully thrombosed) in the chronic phase, and compares them to a healthy aorta. Three-dimensional geometries of aortic true and false lumens (TLs and FLs) are reconstructed through an ad hoc developed and minimally supervised image analysis procedure. Computational fluid dynamics (CFD) is performed through a finite volume unsteady Reynolds-averaged Navier–Stokes approach assuming rigid wall aortas, Newtonian and homogeneous fluid, and incompressible flow. In addition to flow kinematics, we focus on time-averaged wall shear stress and oscillatory shear index that are recognized risk factors for aneurysmal degeneration. Our analysis shows that partially thrombosed dissection is the most prone to false lumen degeneration. In all dissections, the arteries connected to the false lumen are generally poorly perfused. Further, both true and false lumens present higher turbulence levels than the healthy aorta, and critical stagnation points. Mesh sensitivity and a thorough comparison against literature data together support the reliability of the CFD methodology. Image-based CFD simulations are efficient tools to assess the possibility of aortic dissection to lead to aneurysmal degeneration, and provide new knowledge on the hemodynamic characteristics of dissected versus healthy aortas. Similar analyses should be routinely included in patient-specific hemodynamics investigations, to plan and design tailored therapeutic strategies, and to timely assess their effectiveness.

An Expert Review of Chest Wall Fascial Plane Blocks for Cardiac Surgery

The recent integration of regional anesthesia techniques into the cardiac surgical patient population has become a component of enhanced recovery after cardiac surgery pathways. Fascial planes of the chest wall enable single-injection or catheter-based infusions to spread local anesthetic over multiple levels of innervation. Although median sternotomy remains a common approach to cardiac surgery, minimally invasive techniques have integrated additional methods of performing cardiac surgery. Understanding the surgical approach and chest wall innervation is crucial to success in choosing the appropriate chest wall block. Parasternal intercostal plane techniques (previously termed "pectointercostal fascial plane" and "transversus thoracic muscle plane") provide anterior chest and ipsilateral sternal coverage. Anterolateral chest wall coverage is feasible with the interpectoral plane and pectoserratus plane blocks (previously termed "pectoralis") and superficial and deep serratus anterior plane blocks. The erector spinae plane block provides extensive coverage of the ipsilateral chest wall. Any of these techniques has the potential to provide bilateral chest wall analgesia. The relative novelty of these techniques requires ongoing research to be strategic, thoughtful, and focused on clinically meaningful outcomes to enable widespread evidence-based implementation. This review article discusses the key perspectives for performing and assessing chest wall blocks in a cardiac surgical population.

Single-blind, randomized study comparing clinical equivalence of trulene and prolene polypropylene sutures in elective primary coronary artery bypass graft surgery

BACKGROUND

Coronary artery bypass graft surgery (CABG) is one of the principle therapies for coronary artery disease, as it improves survival rate and quality of life (QoL). Polypropylene suture is commonly used in vascular and cardiac surgeries for anastomosis due to its long-term tensile strength and minimal tissue trauma. This study compared the clinical equivalence of Trulene® (Healthium Medtech Limited) and Prolene® (Ethicon-Johnson & Johnson) polypropylene sutures regarding incidence of myocardial infarction, stroke, renal failure and cardiac death (MACCE) occurring up to 26 weeks' period post-CABG surgery.

METHODS

This multicenter, prospective, two-arm, parallel-group, randomized (1:1), single-blind study (n = 89) was conducted between August 2020 and September 2021. The primary endpoint, post-surgery cumulative incidence of MACCE was evaluated. In addition, anastomotic revision, surgical site infection (SSI), operative time, length of post-operative hospital stay, repeat revascularization, intraoperative suture handling characteristics, time taken to return to work and resume normal day to day activities, subject satisfaction score and QoL, and other adverse events were also recorded.

RESULTS

A total of 80 (89.89%) males and 9 (10.11%) females participated in the study. No incidence of MACCE was recorded in any of the study participants. Non-significant difference was observed in anastomotic revision, SSI, operative time, post-operative hospital stay, revascularization, return to work and normal day-to-day activities, subject satisfaction score and QoL, and intraoperative handling parameters (except ease of passage) between the treatment groups, Trulene® and Prolene®. Compared to screening visit, proportion of subjects with 'no problems' for each QoL dimension and the mean visual analogue scale increased with each subsequent follow-up visit.

CONCLUSION

Trulene® polypropylene suture is clinically equivalent to Prolene® polypropylene suture and is safe and effective for anastomosis construction in CABG surgery during a routine clinical procedure. Trial registration CTRI Registration No.: CTRI/2020/05/025157 (Registered on: 13/05/2020).

Comorbidity Trends in Patients Requiring Sternectomy and Reconstruction: Updated Data Analysis From 2005 to 2020

INTRODUCTION

Comorbidity trends after median sternectomy were studied at our institution by Vasconze et al (Comorbidity trends in patients requiring sternectomy and reconstruction. Ann Plast Surg. 2005;54:5). Although techniques for sternal reconstruction have remained unchanged, the patient population has become more complex in recent years. This study offers insight into changing trends in this patient population.

METHODS

A retrospective review was performed of patients who underwent median sternectomy followed by flap reconstruction at out institution between 2005 and 2020. Comorbidities, reconstruction method, average laboratory values, and complications were analyzed.

RESULTS

A total of 105 patients were identified. Comorbidities noted were diabetes (27%), immunosuppression (16%), hypertension (58%), renal insufficiency (23%), chronic obstructive pulmonary disease (16%), and tobacco utilization (24%). The most common reconstruction methods were omentum (45%) or pectoralis major flaps (34%). Thirty-day mortality rates were 10%, and presence of at least 1 complication was 34% (hematoma, seroma, osteomyelitis, dehiscence, wound infection, flap failure, and graft exposure). Univariate analysis demonstrated that sex (P = 0.048), renal insufficiency, surgical site complication, wound dehiscence, and flap failure (P < 0.05) had statistically significant associations with mortality. In addition, body mass index, creatinine, and albumin had a significant univariate association with mortality (P < 0.05).

CONCLUSIONS

Similar to the original study, there is an association between renal insufficiency and mortality. However, the mortality rate is decreased to 10%, likely because of improved medical management of patients with increasing comorbidities (80% with greater than one comorbidity). This has led to the increased use of omentum as a first-line option. Subsequent wound dehiscence and flap failure demonstrate an association with mortality, suggesting that increasingly complex patients are requiring a method of reconstruction once used a last resort as a first-line option.

Esophagectomy combined with off-pump coronary artery bypass grafting through left posterolateral incision is safe and feasible for esophageal cancer associated with coronary artery disease

Controversy still exists as to whether surgical treatment has any impact on the long-term survival of esophageal cancer (EC) patients with coronary artery disease treated with curative esophagectomy combined with off-pump coronary artery bypass grafting (OPCABG). Therefore, the aim of this study was to introduce and assess the effect of esophagectomy combined with OPCABG on both short- and long-term outcomes. From January 2010 to January 2015, 1428 EC or esophagogastric junction cancer patients underwent surgical treatment at Henan Chest Hospital, Zhengzhou, China. The clinical data of 25 patients who underwent EC resection through a left thoracotomy following OPCABG and the perioperative characteristics and follow-up results were analyzed. The majority of the patients were male, and the EC stage was predominantly cT2N0-1M0 II. The most common pathological types were squamous cell carcinoma. The EC surgeries consisted of 15 chest anastomosis procedures and 10 cervical anastomosis procedures with aortocoronary graft implantation (mean: 2.36 grafts per patient). The mean total operative time was 330.8 ± 83.5 minutes. The median intensive care unit and hospital lengths of stay were 1.72 and 21.16 days, respectively. Resection without macroscopic residual disease (R0) was achieved in all of the patients. The most frequent complications included pulmonary infections (24%), arrhythmias (24%), pleural effusion (12%), and esophageal anastomotic leakage (8%). There were no postoperative deaths or myocardial infarctions within 30 days after the surgery. The overall 1-, 3-, and 5-year survival rates were 88%, 40%, and 24%, respectively, with a median survival time of 43 months. In the short-term, radical resection of EC following OPCABG is a safe and feasible treatment with low postoperative mortality rates. In the long-term, simultaneous surgery is acceptable and is associated with favorable overall and disease-free survival.

Management of Leukemia and Partial Atrioventricular Septal Defect during Pregnancy

Background  Pregnancy-associated acute myeloid leukemia (PA-AML) is rare. Cardiac surgery in the context of AML poses challenges that are seldom encountered.

Case Description  The subject is a 31-year-old woman at 38 weeks' gestational age diagnosed with AML and partial atrioventricular septal defect. After multidisciplinary consulting, an urgent cesarean section was performed, then chemotherapy was initiated, followed by minimally invasive cardiac surgery with an uneventful recovery.

Conclusion  Efficient multidisciplinary approach is essential in the management of PA-AML and cardiac disease. Minimally invasive cardiac surgery may be safe and useful in patients with AML.

Minimally invasive versus conventional surgery of the ascending aorta and root: a systematic review and meta-analysis

Limited uptake of minimally invasive surgery (MIS) of the aorta hinders assessment of its efficacy compared to median sternotomy (MS). The objective of this systematic review is to compare operative and perioperative outcomes for MIS versus MS. Online databases Medline, EMBASE, Cochrane Library and Web of Science were searched from inception until July 2018. Both randomized and observational studies of patients undergoing aortic root, ascending aorta or aortic arch surgery by MIS versus MS were eligible for inclusion. Primary outcomes were 30-day mortality, reoperation for bleeding, perioperative renal impairment and neurological events. Intraoperative and postoperative timing measures were also evaluated. Thirteen observational studies were included comparing 1101 MIS and 1405 MS patients. The overall quality of evidence was very low for all outcomes. Mortality and the incidence of stroke were similar between the 2 cohorts. Meta-analysis demonstrated increased length of cardiopulmonary bypass (CPB) time for patients undergoing MS [standardized mean difference 0.36, 95% confidence interval (CI) 0.15-0.58; P = 0.001]. Patients receiving MS spent more time in hospital (standardized mean difference 0.30, 95% CI 0.17-0.43; P < 0.001) and intensive care (standardized mean difference 0.17, 95% CI 0.06-0.27; P < 0.001). Reoperation for bleeding (risk ratio 1.51, 95% CI 1.06-2.17; P = 0.024) and renal impairment (risk ratio 1.97, 95% CI 1.12-3.46; P = 0.019) were also greater for MS patients. There was substantial heterogeneity in meta-analyses for CPB and aortic cross-clamp timing outcomes. MIS may be associated with improved early clinical outcomes compared to MS, but the quality of the evidence is very low. Randomized evidence is needed to confirm these findings.

MICS CABG: a single-center experience of the first 100 cases

PURPOSE

To study the learning curve and outcomes of the first 100 cases of minimally invasive cardiac surgery (MICS) coronary artery bypass grafting (CABG) performed at our center.

METHODS

From January 2017 to November 2019, a total of 100 patients underwent CABG via left anterior thoracotomy approach. We have studied the operative times within the MICS CABG patients to analyze our learning curve. We also studied the postoperative outcomes and compared these with those of patients who underwent sternotomy during the same period.

RESULTS

The mean age was 59.33 ± 9.95 (range 37-82) years. The numbers of males and females were 72 and 28 respectively. The preoperative average ejection fraction (EF) was 51.08 ± 9.75%. All these patients underwent CABG via left thoracotomy approach, after satisfying the exclusion criteria. All patients received left internal mammary artery (LIMA) to left anterior descending (LAD) as a standard graft, with the radial artery and saphenous vein being the next alternative conduits. The average length of the incision was 6.06 ± 0.45 cm. Only 2 cases were done on pump. The average number of grafts per patient was 2.33 ± 0.92. The mean operative time was 132.40 ± 11.56 min. The mean duration of ventilation was 4.79 ± 1.90 h and average intensive care unit (ICU) stay was 2.62 ± 0.84 days. There was one conversion and no mortalities in our study. We had analyzed our operative times and noticed a significant reduction after the first 20 cases, which was our learning curve.

CONCLUSION

MICS CABG can be performed for multivessel disease with the same comfort as for a single or a double vessel disease, once the learning curve has been achieved. Only significant difference from the sternotomy approach was noted in the longer operative times for MICS CABG during the learning curve, and not thereafter. Significant benefits of MICS over sternotomy were noticed in the immediate postoperative parameters like duration of ventilation, mean drainage, postoperative pain, ICU stay, and hospital stay, with no difference in postoperative adverse events.

Cardiac Surgery: Beyond Conventional Sternotomy With Cardiopulmonary Bypass

Minimally invasive cardiac surgery options, which originated with off-pump coronary artery bypass grafting and aortic valve procedures, continue to evolve in order to address complex conditions, including those requiring mitral and tricuspid valve repair. Although these procedures are primarily indicated for high-risk patient populations, favorable patient outcomes have resulted in recommendations being expanded to include intermediate-risk groups. This article increases nursing-related knowledge of minimally invasive cardiac procedures, providing an overview of current minimally invasive cardiac surgeries and their associated risks and benefits.

Minimally invasive and transcatheter approaches for mitral valve surgery

Mitral valve surgery has evolved through the ages, in response to prevalent epidemiology of mitral pathologies. In the modern era, advances in technology has allowed physicians to help a wider spectrum on increasingly sicker patients. This review summarises these advances and its associated evidence base for safety and efficacy.

Regional oxygen saturation change rate for detection of leg ischemia in minimally invasive cardiac surgery

INTRODUCTION

The criteria for placement of distal perfusion cannulas vary among reports. This cohort study aimed to establish a reproducible method to monitor critical leg ischemia during minimally invasive cardiac surgery.

METHODS

We included 121 patients who underwent minimally invasive cardiac surgery via right thoracotomy with right femoral arterial cannulation from 2015 to 2018. The change rate of regional oxygen saturation (ΔrSO₂) was calculated as follows: rSO₂ (baseline) - rSO₂ (actual number)/rSO₂ (baseline). Patients were divided into Group N (ΔrSO₂ < 40%): 100/121 (83%) and Group H (ΔrSO₂ > 40%, <10 minutes if >40%): 21/121 (17%). A distal perfusion cannula was placed when ΔrSO₂ was >40% over 10 minutes.

RESULTS

No patients experienced significant leg ischemia. Significantly longer cardiopulmonary bypass and aortic cross-clamp times were observed in Group H than in Group N (cardiopulmonary bypass time, 129 ± 36 minutes (Group N) vs. 151 ± 34 minutes (Group H), p = 0.01). ΔrSO₂ correlated positively with plasma creatine phosphokinase elevation (R = 0.40, p < 0.001) on postoperative day 1. Serum lactate on intensive care unit admission showed a significant positive correlation (R = 0.40, p < 0.001) with ΔrSO₂.

CONCLUSION

ΔrSO₂ measurement by near-infrared spectroscopy can facilitate distal leg perfusion monitoring and assist surgeons in preventing critical leg ischemia during minimally invasive cardiac surgery.

Catheter segmentation in X-ray fluoroscopy using synthetic data and transfer learning with light U-nets

Background and objectivesAutomated segmentation and tracking of surgical instruments and catheters under X-ray fluoroscopy hold the potential for enhanced image guidance in catheter-based endovascular procedures. This article presents a novel method for real-time segmentation of catheters and guidewires in 2d X-ray images. We employ Convolutional Neural Networks (CNNs) and propose a transfer learning approach, using synthetic fluoroscopic images, to develop a lightweight version of the U-Net architecture. Our strategy, requiring a small amount of manually annotated data, streamlines the training process and results in a U-Net model, which achieves comparable performance to the state-of-the-art segmentation, with a decreased number of trainable parameters. MethodsThe proposed transfer learning approach exploits high-fidelity synthetic images generated from real fluroscopic backgrounds. We implement a two-stage process, initial end-to-end training and fine-tuning, to develop two versions of our model, using synthetic and phantom fluoroscopic images independently. A small number of manually annotated in-vivo images is employed to fine-tune the deepest 7 layers of the U-Net architecture, producing a network specialized for pixel-wise catheter/guidewire segmentation. The network takes as input a single grayscale image and outputs the segmentation result as a binary mask against the background. ResultsEvaluation is carried out with images from in-vivo fluoroscopic video sequences from six endovascular procedures, with different surgical setups. We validate the effectiveness of developing the U-Net models using synthetic data, in tests where fine-tuning and testing in-vivo takes place both by dividing data from all procedures into independent fine-tuning/testing subsets as well as by using different in-vivo sequences. Accurate catheter/guidewire segmentation (average Dice coefficient of  ~ 0.55,  ~ 0.26 and  ~ 0.17) is obtained with both U-Net models. Compared to the state-of-the-art CNN models, the proposed U-Net achieves comparable performance ( ± 5% average Dice coefficients) in terms of segmentation accuracy, while yielding a 84% reduction of the testing time. This adds flexibility for real-time operation and makes our network adaptable to increased input resolution. ConclusionsThis work presents a new approach in the development of CNN models for pixel-wise segmentation of surgical catheters in X-ray fluoroscopy, exploiting synthetic images and transfer learning. Our methodology reduces the need for manually annotating large volumes of data for training. This represents an important advantage, given that manual pixel-wise annotations is a key bottleneck in developing CNN segmentation models. Combined with a simplified U-Net model, our work yields significant advantages compared to current state-of-the-art solutions.

Nanoparticle-Mediated Drug Delivery for the Treatment of Cardiovascular Diseases

Cardiovascular diseases (CVDs) are one of the foremost causes of high morbidity and mortality globally. Preventive, diagnostic, and treatment measures available for CVDs are not very useful, which demands promising alternative methods. Nanoscience and nanotechnology open a new window in the area of CVDs with an opportunity to achieve effective treatment, better prognosis, and less adverse effects on non-target tissues. The application of nanoparticles and nanocarriers in the area of cardiology has gathered much attention due to the properties such as passive and active targeting to the cardiac tissues, improved target specificity, and sensitivity. It has reported that more than 50% of CVDs can be treated effectively through the use of nanotechnology. The main goal of this review is to explore the recent advancements in nanoparticle-based cardiovascular drug carriers. This review also summarizes the difficulties associated with the conventional treatment modalities in comparison to the nanomedicine for CVDs.

A new viewpoint on endoscopic CABG: technique description and clinical experience

BACKGROUND

The aim of this paper is to describe a newly developed endoscopic coronary artery bypass graft (Endo-CABG) technique to treat patients with single- and multi-vessel disease and discuss the short-term clinical results in a large patient cohort. This technique avoids a median sternotomy by combining a thoracoscopic technique via three ∼5 mm thoracic ports and a mini-thoracotomy utility 3-4 cm port through the intercostal space.

METHODS

From January 2016 to January 2018, data from consecutive patients undergoing an elective Endo-CABG were prospectively entered into a customized database and retrospectively reviewed. Patients scheduled for a combined hybrid intervention were excluded. Conversion rate to sternotomy, incidence of surgical revision and postoperative graft failure, one-month survival, morbidity, and length of stay (LOS) were investigated. Subgroup analyses were performed.

RESULTS

A total of 342 patients undergoing an Endo-CABG with one (n = 53) or multiple (n = 289) bypasses were included. No conversion to sternotomy occurred and incidence of surgical revision, graft failure, and 30-day mortality was 7.3%, 1.5%, and 1.8%, respectively. Adverse neurological outcomes were rare: cerebrovascular accident, transient ischemic attack, epilepsy, and postoperative delirium were observed in 0.6%, 0.3%, 0.3%, and 5.3% of patients, respectively. Median intensive care unit and hospital LOS were 2.75 (IQR 1.8 to 3.8) and 8.0 days (IQR 7.0 to 10.0), respectively. Thirty-day mortality in obese patients, diabetics, and octogenarians was 0%, 3.6%, and 5.6%, respectively. EuroSCORE II > 5% was associated with a high 30-day mortality (25%).

CONCLUSIONS

Endo-CABG can be considered a safe and effective procedure to treat single- and multi-vessel coronary artery disease. Individual patient selection seems not necessary to apply this technique.

Injectable Hydrogels for Cardiac Tissue Engineering

In light of the limited efficacy of current treatments for cardiac regeneration, tissue engineering approaches have been explored for their potential to provide mechanical support to injured cardiac tissues, deliver cardio-protective molecules, and improve cell-based therapeutic techniques. Injectable hydrogels are a particularly appealing system as they hold promise as a minimally invasive therapeutic approach. Moreover, injectable acellular alginate-based hydrogels have been tested clinically in patients with myocardial infarction (MI) and show preservation of the left ventricular (LV) indices and left ventricular ejection fraction (LVEF). This review provides an overview of recent developments that have occurred in the design and engineering of various injectable hydrogel systems for cardiac tissue engineering efforts, including a comparison of natural versus synthetic systems with emphasis on the ideal characteristics for biomimetic cardiac materials.

Minimally invasive valve surgery in high-risk patients

The use of minimally, or less invasive, approaches to cardiac valve surgery has increased over the past decade. Because of its less traumatic nature, early studies in lower risk patients demonstrated the approach to be associated with an enhanced recovery, increased patient satisfaction, and good operative outcomes. With time, despite a steep learning curve, surgeons expanded this approach to perform more complex procedures, and include patients with more co-morbidity. The aim of this publication is to review the current literature involving the use of minimally invasive valve surgery (MIVS) in higher-risk patients.

Staged percutaneous coronary intervention followed by minimally invasive mitral valve surgery versus combined coronary artery bypass graft and mitral valve surgery for two-vessel coronary artery disease and moderate to severe ischemic mitral regurgitation

BACKGROUND

The optimal treatment for concomitant two-vessel coronary artery disease (CAD) and moderate to severe ischemic mitral regurgitation (IMR) remains unclear. We compared the results of a staged percutaneous coronary intervention followed by minimally invasive mitral valve surgery (PCI+MIVS) versus combined coronary artery bypass graft and mitral valve surgery (CABG+MVS) in this population.

METHODS

All consecutive patients with two-vessel CAD and moderate to severe IMR, who underwent PCI+MIVS or CABG+MVS at our institution between February 2009 and April 2014, were retrospectively evaluated.

RESULTS

There were nine patients identified who underwent PCI+MIVS, and 15 who underwent CABG+MVS, with a mean age of 71±7, and 70±7 years, respectively (P=0.86). The remaining baseline characteristics were similar between both groups, with the exception of a higher prevalence of pre-operative clopidogrel administration (78% versus 27%, P=0.03) and left anterior descending plus left circumflex CAD (78% versus 27%, P=0.03), in those who underwent PCI+MIVS. The PCI+MIVS approach was associated with decreased mean cardiopulmonary bypass (111±41 versus 167±49 min, P=0.01) and aortic cross-clamp (79±32 versus 129±35 min, P=0.003) times, and less median number of intraoperative packed red blood transfusions {2 [interquartile range (IQR), 0-2] versus 3 units (IQR, 1-4), P=0.05}, when compared with CABG+MVS. The rate of mitral valve repair, postoperative complications, 30-day mortality, and 1-year survival did not differ between the surgical approaches.

CONCLUSIONS

PCI+MIVS for two-vessel CAD and moderate to severe IMR is feasible, and associated with satisfactory outcomes, as compared with CABG+MVS.