Cardiac surgery in the morbidly obese.

BACKGROUND: Obesity rates globally continue to rise and in turn the body mass index (BMI) of patients undergoing cardiac surgery is set to mirror this. Patients who are Class III obese (BMI ≥ 40) pose significant challenges to the surgical teams responsible for their care and are also at high risk of complications from surgery and even death. To improve outcomes in this population, interventions carried out in the preoperative, operative, and postoperative periods have shown promise. Despite this, there are no defined best practice national guidelines for perioperative management of obese patients undergoing cardiac surgery. AIM: This review is aimed at clinicians and researchers in the field of cardiac surgery and aims to form a basis for the future development of clinical guidelines for the management of obese cardiac surgery patients. METHODS: The PubMed database was utilized to identify relevant literature and strategies employed at various stages of the surgical journey were analyzed. CONCLUSIONS: Data presented identified the benefits of preoperative respiratory muscle training, off-pump coronary artery bypass grafting where possible, and early extubation. Further randomized controlled trials are required to identify optimal operative and perioperative management strategies before the introduction of such guidance into clinical practice.

Cardiac amyloidosis in non-transplant cardiac surgery.

Cardiac amyloidosis is a rare infiltrative cardiomyopathy that portends a poor prognosis. There is a growing recognition of co-existent aortic valve stenosis and transthyretin cardiac amyloidosis, with some studies suggesting that dual pathology may be associated increased risk of complication and mortality during surgical intervention. This review aims to evaluate the available literature on non-transplant cardiac surgical interventions in patients with cardiac amyloidosis, with particular focus on diagnosis, high surgical risk and areas of uncertainty that require further research.

Spontaneous splenic rupture following mitral valve replacement for infective endocarditis successfully managed with splenic artery embolisation.

We report a rare case of infective endocarditis complicated by postoperative splenic rupture. A patient underwent urgent mitral valve replacement for infective endocarditis believed to be associated with a recent spinal surgical intervention. The patient developed haemodynamic compromise on the third day postoperatively. Computed tomography showed a splenic rupture as the cause. The patient underwent emergency radiological intervention with coil embolization avoiding the need for a splenectomy and was discharged home.

The Pan London Emergency Cardiac Surgery service: Coordinating a response to the COVID-19 pandemic.

Over the last 4 months, the novel coronavirus, SARS-CoV-2, has caused a significant economic, political, and public health impact on a global scale. The natural history of the disease and surge in the need for invasive ventilation has required the provision of intensive care beds in London to be reallocated. NHS England have proposed the formation of a Pan-London Emergency Cardiac surgery (PLECS) service to provide urgent and emergency cardiac surgery for the whole of London. In this initial report, we outline our experience of setting up and delivering a pan-regional service for the delivery of urgent and emergency cardiac surgery with a focus on maintaining a COVID-free in-hospital environment. In doing so, we hope that other regions can use this as a starting point in developing their own region-specific pathways if the spread of coronavirus necessitates similar measures be put in place across the United Kingdom.

Differentially expressed genes for atrial fibrillation identified by RNA sequencing from paired human left and right atrial appendages.

Atrial fibrillation is a significant worldwide contributor to cardiovascular morbidity and mortality. Few studies have investigated the differences in gene expression between the left and right atrial appendages, leaving their characterization largely unexplored. In this study, differential gene expression was investigated in atrial fibrillation and sinus rhythm using left and right atrial appendages from the same patients. RNA sequencing was performed on the left and right atrial appendages from five sinus rhythm (SR) control patients and five permanent AF case patients. Differential gene expression in both the left and right atrial appendages was analyzed using the Bioconductor package edgeR. A selection of differentially expressed genes, with relevance to atrial fibrillation, were further validated using quantitative RT-PCR. The distribution of the samples assessed through principal component analysis showed distinct grouping between left and right atrial appendages and between SR controls and AF cases. Overall 157 differentially expressed genes were identified to be downregulated and 90 genes upregulated in AF. Pathway enrichment analysis indicated a greater involvement of left atrial genes in the Wnt signaling pathway whereas right atrial genes were involved in clathrin-coated vesicle and collagen formation. The differing expression of genes in both left and right atrial appendages indicate that there are different mechanisms for development, support and remodeling of AF within the left and right atria.

What is the safety and efficacy of the use of automated fastener in heart valve surgery?

INTRODUCTION: Cor-Knot automated fastener has been used as an adjunct in heart valve surgery to eliminate the need for manual tying during valve implantation. Although reduced operative time and facilitation for minimally invasive surgery are clear benefits, whether their use translates to improved patient outcome remains debatable. This study aims to review the safety and efficacy of automated fasteners in heart valve surgeries. METHOD: Specific searches were conducted via online medical databases (Pubmed, Embase, Ovid) between 1950 and June 2019. Longitudinal studies were included that provided operative parameters. RESULTS: The initial literature search identified 3773 articles, but only eight met the inclusion criteria and were used for analysis: four studies related to aortic valve replacement (AVR), four related to mitral valve (MV) intervention (total n = 810). The meta-analysis revealed the significantly shorter aortic cross-clamp time in the Cor-knot group compared to manual tying, both in AVR and MV surgeries (P < .05). Cardiopulmonary bypass time was significantly shorter in the Cor-knot group when analyzing studies in MV surgery (weighted mean difference [WMD]: 110.0; 95% confidence interval: 12.3-207.7; P = .027) The use of Cor-Knot did not increase the risk of permanent pacemaker implantation, paravalvular leak, and 30-day mortality. The majority of studies reported no change in the length of intensive unit care and total hospital stay. CONCLUSION: We confirmed that the majority of existing literatures indicated the safety and intraoperative efficacy with automated fastener application. Nevertheless, there is currently no evidence to support automated fastened sutures can translate its intraoperative advantages to improved patient outcome.

Reconstruction of the right atrium and superior vena cava with extracellular matrix.

We describe our technique for reconstructing the free right atrial wall and superior vena cava using CorMatrix (CorMatrix Alpharetta, GA, USA) extracellular matrix following resection of a large leiomyosarcoma.

The impact of weather factors, moon phases, and seasons on abdominal aortic aneurysm rupture.

BACKGROUND: Several studies have documented that weather factors, seasons of the year, time of the day, and even changes in moon phases have an impact on the occurrence of rupture of an abdominal aortic aneurysm (RAAA); however, the available data are confounding. The objective of this study was to determine the impact of these factors on the prevalence and mortality rate of RAAA. METHODS: This is a retrospective analysis of medical records of patients treated for RAAA over a 10-year period. Weather data (i.e., atmospheric pressure, air temperature, humidity, visibility, and wind speed) and weather events (i.e., rain, snow, and storms, etc) were obtained from the local meteorologic weather station and analyzed for a correlation with RAAA. RESULTS: Five hundred thirty patients with RAAA were identified, and these patients presented on 478 days during the 10-year study period (3,652 days), with the overall in-hospital mortality rate of 48.7%. The RAAA mortality was higher during weekends and national holidays, when compared to weekdays (59% vs 45%; P = 0.006) and in patients admitted between 3-7 am when compared to work day hours (65.5% vs 44.1%; P = 0.035). Season changes had no influence on the frequency of RAAA; however, summer seemed to be associated with an increase in mortality as opposed to autumn (54.4% vs 42.5%; P = 0.047). Mean atmospheric pressure (and fluctuations thereof) and other weather factors, including phases and parts of the moon, did not correlate with RAAA occurrence or its mortality. CONCLUSIONS: Patients with RAAA who were admitted on weekends, national holidays and in late night hours had lower survival rates. Weather factors (including atmospheric pressure) do not influence the prevalence and mortality of RAAA.

Right coronary artery dissection after aortic valve replacement presenting with refractory ventricular fibrillation.

Iatrogenic coronary artery dissection is a rare complication seen in 0.07% of coronary procedures. Presentations of this condition vary, ranging from signs of myocardial ischemia to rarer presentations of ventricular arrhythmias. We present a rare case of a 55-year-old patient with native aortic valve endocarditis who developed right coronary artery dissection (RCAD) in the immediate post-op period presenting with refractory ventricular fibrillation (VF). Emergency coronary angiogram revealed an extensive RCAD extending from the ostium to the mid-vessel as the cause of VF. A consensus between the cardiologists and the cardiac surgeons led to an emergency right coronary artery bypass graft (CABG) that resolved the VF. This case illustrates a rare presentation of iatrogenic RCAD and the successful management of the same. We highlight the importance of prompt detection via angiography in patients suspected of having coronary artery dissection and showcase the successful implementation of emergency CABG in a patient with unstable haemodynamics.

Managing the Root in Acute Type A Aortic Dissections: Are We Ready for a Standardized Approach?

OBJECTIVES: Surgical repair of Type A aortic dissection (TAAD) requires exclusion of the primary entry tear and reestablishment of flow into the distal true lumen. Provided that the majority of tears occur within the ascending aorta (AA), replacing only that segment seems a safe option; however, this strategy leaves the root susceptible to dilatation and need for reintervention. We aimed to review the outcomes of the two strategies: aortic root replacement (ARR) and isolated ascending aortic replacement. METHODS: Retrospective analysis of prospectively collected data for all consecutive patients who underwent repair of acute TAAD at our institution from 2015 to 2020 was conducted. Patients were divided into two groups: (1) ARR and (2) isolated AA replacement as index operation for TAAD repair. Primary outcomes were mortality and need for reintervention during the follow-up. RESULTS: A total of 194 patients were included in the study; 68 (35%) in the ARR group and 126 (65%) in the AA group. There were no significant differences in postoperative complications or in-hospital mortality (23%; p = 0.51) between groups. Seven patients (4.7%) died during follow-up and eight patients underwent aortic reinterventions, including proximal aortic segments (two patients) and distal procedures (six patients). CONCLUSION: Both aortic root and AA replacement are acceptable and safe techniques. The growth of an untouched root is slow, and reintervention in this aortic segment is infrequent compared with distal aortic segments, hence preserving the root could be an option for older patients provided that there is no primary tear within the root.

Obesity and diabetes are major risk factors for epicardial adipose tissue inflammation.

BACKGROUNDEpicardial adipose tissue (EAT) directly overlies the myocardium, with changes in its morphology and volume associated with myriad cardiovascular and metabolic diseases. However, EAT's immune structure and cellular characterization remain incompletely described. We aimed to define the immune phenotype of EAT in humans and compare such profiles across lean, obese, and diabetic patients.METHODSWe recruited 152 patients undergoing open-chest coronary artery bypass grafting (CABG), valve repair/replacement (VR) surgery, or combined CABG/VR. Patients' clinical and biochemical data and EAT, subcutaneous adipose tissue (SAT), and preoperative blood samples were collected. Immune cell profiling was evaluated by flow cytometry and complemented by gene expression studies of immune mediators. Bulk RNA-Seq was performed in EAT across metabolic profiles to assess whole-transcriptome changes observed in lean, obese, and diabetic groups.RESULTSFlow cytometry analysis demonstrated EAT was highly enriched in adaptive immune (T and B) cells. Although overweight/obese and diabetic patients had similar EAT cellular profiles to lean control patients, the EAT exhibited significantly (P ≤ 0.01) raised expression of immune mediators, including IL-1, IL-6, TNF-α, and IFN-γ. These changes were not observed in SAT or blood. Neither underlying coronary artery disease nor the presence of hypertension significantly altered the immune profiles observed. Bulk RNA-Seq demonstrated significant alterations in metabolic and inflammatory pathways in the EAT of overweight/obese patients compared with lean controls.CONCLUSIONAdaptive immune cells are the predominant immune cell constituent in human EAT and SAT. The presence of underlying cardiometabolic conditions, specifically obesity and diabetes, rather than cardiac disease phenotype appears to alter the inflammatory profile of EAT. Obese states markedly alter EAT metabolic and inflammatory signaling genes, underlining the impact of obesity on the EAT transcriptome profile.FUNDINGBarts Charity MGU0413, Abbott, Medical Research Council MR/T008059/1, and British Heart Foundation FS/13/49/30421 and PG/16/79/32419.

Surgical aortic valve replacement in the era of transcatheter aortic valve implantation: a review of the UK national database.

OBJECTIVES: To date the reported outcomes of surgical aortic valve replacement (SAVR) are mainly in the settings of trials comparing it with evolving transcatheter aortic valve implantation. We set out to examine characteristics and outcomes in people who underwent SAVR reflecting a national cohort and therefore 'real-world' practice. DESIGN: Retrospective analysis of prospectively collected data of consecutive people who underwent SAVR with or without coronary artery bypass graft (CABG) surgery between April 2013 and March 2018 in the UK. This included elective, urgent and emergency operations. Participants' demographics, preoperative risk factors, operative data, in-hospital mortality, postoperative complications and effect of the addition of CABG to SAVR were analysed. SETTING: 27 (90%) tertiary cardiac surgical centres in the UK submitted their data for analysis. PARTICIPANTS: 31 277 people with AVR were identified. 19 670 (62.9%) had only SAVR and 11 607 (37.1%) had AVR+CABG. RESULTS: In-hospital mortality for isolated SAVR was 1.9% (95% CI 1.6% to 2.1%) and was 2.4% for AVR+CABG. Mortality by age category for SAVR only were: <60 years=2.0%, 60-75 years=1.5%, >75 years=2.2%. For SAVR+CABG these were; 2.2%, 1.8% and 3.1%. For different categories of EuroSCORE, mortality for SAVR in low risk people was 1.3%, in intermediate risk 1% and for high risk 3.9%. 74.3% of the operations were elective, 24% urgent and 1.7% emergency/salvage. The incidences of resternotomy for bleeding and stroke were 3.9% and 1.1%, respectively. Multivariable analyses provided no evidence that concomitant CABG influenced outcome. However, urgency of the operation, poor ventricular function, higher EuroSCORE and longer cross clamp and cardiopulmonary bypass times adversely affected outcomes. CONCLUSIONS: Surgical SAVR±CABG has low mortality risk and a low level of complications in the UK in people of all ages and risk factors. These results should inform consideration of treatment options in people with aortic valve disease.

Migration of a Varicocele Coil to the Right Heart.

We describe a case of an adult patient with embolization of a varicocele coil (7 × 70 mm) to the right ventricle. We review the multimodality imaging techniques used to identify location and the importance of a multidisciplinary approach in determining management. (Level of Difficulty: Advanced.).

Is ministernotomy superior to right anterior minithoracotomy in minimally invasive aortic valve replacement?

A best evidence topic was constructed according to a structured protocol. The question addressed was whether, in patients undergoing minimally invasive aortic valve replacement (AVR), right anterior thoracotomy (RT) or mini-sternotomy (MS) was superior in terms of postoperative outcome? A total of 840 publications were found using the reported search. Of these, 6 represented the best available evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. In all, except 1 study, the primary outcome was early mortality, ranging from in-hospital mortality to 90 days postoperatively. The remaining study was a cost-benefit analysis. Four studies were non-randomized observational studies, one of which was multicentre. Two were meta-analyses of studies comparing minithoracotomy or MS with conventional sternotomy for AVR, rather than direct comparisons of the 2 minimal access techniques. We conclude that there is a lack of high-quality evidence comparing RT and MS for minimally invasive AVR, with no randomized controlled trials to date. The available evidence shows no difference in early mortality between RT and MS for surgical AVR. In studies that directly compared RT and MS, RT was found to be associated with reduced length of hospital stay, despite longer cardiopulmonary bypass times and cross-clamp times. One study reported groin complications (10.8%) with the RT group, where peripheral cannulation was used, while the other 5 studies did not comment on groin complications associated with peripheral cannulation. In the only cost-benefit analysis, RT was found to carry considerably more cost than MS over and above conventional AVR.

Aortic Valve Replacement: Are We Spoiled for Choice?

Management of aortic valve disease and, in particular, aortic valve stenosis has evolved through the course of time from medical management and balloon valvuloplasty to the presumed gold-standard surgical intervention. However, with the advent of surgical innovation, intra- and postoperative patients monitoring, understanding of hemodynamic dysfunction, and choices of prosthesis, conventional surgical aortic valve replacements are currently being challenged in particular in moderate- and high-risk patients. Although the long-term results and survival are not robustly available, the durability of the new prosthesis, repair, and the freedom from reoperation remain debatable. In this review, we aim to highlight the surgical innovation attained, choices of aortic valve prosthesis, and also dwell on the current evidence, practice, and trend steered to managing patients with aortic valve stenosis.

When should cardiopulmonary bypass be used in the setting of severe hypothermic cardiac arrest?

A best evidence topic was written according to a structured protocol. The question addressed was regarding the indication and timing of the use of cardiopulmonary bypass (CPB), following severe hypothermic cardiac arrest. A total of 284 papers were found using the reported searches, of which nine represented the best evidence to answer the clinical question. The authors, date, journal, study type, population, main outcome measures and results are tabulated. Reported measures were survival, rewarming speed, incidence of arrhythmia during rewarming, resolution of full neurological function, long-term neurological function, evidence of damage on neurological imaging and venous metabolic parameters in hypothermic patients. The most recent of the best evidence studies, a retrospective comparative study of 68 patients, demonstrated CPB rewarming to be far superior to conventional methods of rewarming, with mortality rates of 15.8 and 53.3%, respectively. Another study of similar size, comparing CPB with extracorporeal membrane oxygenation (ECMO) for rewarming, revealed superior survival rates with ECMO, 75 vs 34%. A systematic review of 68 patients demonstrated an overall survival of 60%, and 80% of survivors returning to a previous level of activity. Two smaller observational studies reported survival rates of 73.1 and 45.5%, respectively. A retrospective study analysing long-term neurological outcomes of survivors reported normal history and physical examination in 93.3%, normal neurovascular ultrasound in 100%, normal neuropsychological findings in 93.3% and normal brain magnetic resonance imaging in 86.7%. A small comparative study demonstrated a significant survival benefit when CPB was preceded with emergency thoracotomy, internal cardiac massage and warm mediastinal irrigation compared with CPB alone. We conclude that, following deep hypothermic circulatory arrest, the urgent use of cardiopulmonary bypass is widely indicated for rewarming where it has been shown to provide good survival and neurological outcomes far superior in comparison with conventional methods of rewarming.

Infected calcified homograft root: a sutureless solution.

Aortic valve reoperation after homograft root implantation is high risk and may be technically challenging. Dense calcification of the annulus may prevent suture placement and often necessitates impromptu high-risk redo root replacement. Although transcutaneous aortic valve implantation is an attractive option in such scenarios, in the context of endocarditis it is contraindicated. We describe a novel approach to aortic valve replacement in a patient with infective endocarditis of a heavily calcified homograft root, using a sutureless valve. This approach successfully avoided the need for redo root replacement with its attendant risks.

Coronary revascularization in adults with dextrocardia: surgical implications of the anatomic variants.

Most reports of coronary artery bypass grafting in adult patients with dextrocardia have focused on the surgeon's position with respect to the operating table. Herein, we describe the cases of 2 patients with dextrocardia who underwent surgery at our own institution, then discuss preoperative evaluation, surgical approaches, and patient outcomes that have been reported in the medical literature. Whereas most patients, including ours, have presented with classic situs inversus totalis and dextrocardia, a few patients have had other associated anomalies or atypical morphologic conditions. Careful imaging, and perhaps cardiac catheterization, is required. Particular attention should be paid to cannulation technique and conduits that can best be used within the altered orientation of the heart. Morbidity rates in these revascularized patients seem comparable with those in coronary artery bypass patients whose coronary anatomy is normal. Anatomic variants in dextrocardia are important from the surgical viewpoint due to the increasing population of patients with repaired congenital heart disease who reach adulthood, and in whom other cardiac defects and abnormalities of cardiac position are common.