Are there differences in cardiothoracic surgery performed by trainees versus fully trained surgeons?

OBJECTIVES: We sought to assess the safety of training in cardiothoracic surgery comparing outcomes of cases performed by trainees versus fully trained surgeons. METHODS: EmBase, Scopus, PubMed, and OVID MEDLINE were searched in August 2021 independently by two authors. A third author arbitrated decisions to resolve disagreements. Inclusion criteria were articles on cardiothoracic surgery reporting on outcomes for trainees. Studies were assessed for appropriateness as per CBEM criteria. Eight hundred and ninety-two results were obtained, 27 represented best evidence (2-meta-analyses, 1-RCT, and 24 retrospective cohort studies). RESULTS: In all 474,160 operative outcomes were assessed for 434,535 coronary artery bypass grafting (CABG) (431,329 on-pump vs. 3206 off-pump), 3090 AVR, 1740 MVR/repair, 26,433 mixed, 3565 congenital, and 4797 thoracic procedures. In all 398,058 cases were performed by trainees and 75,943 by consultants. One hundred fifty-nine cases were indeterminate. There were no statistically significant differences in the patients' preoperative risk scores. All studies excluded extreme high-risk patients in emergency setting, patients with poor left ventricular function, and reoperation cases that were undertaken by consultants. There were no differences in cardiopulmonary bypass and clamp times for CABG. Times for valve replacement and repair cases were longer for trainees. There were no differences in the postoperative outcomes including perioperative myocardial infarction, resternotomy for bleeding, stroke, renal failure, intensive therapy unit length of stay, and total length of stay. One study reported no differences on angiographic graft patency at 1 year. There were no differences in in-hospital or midterm mortality out to 5-years. DISCUSSION: Trainees can perform cardiothoracic surgery in dedicated high-volume units with outcomes comparable to those of fully trained surgeons.

Do in-hospital outcomes of isolated coronary artery bypass grafting vary between male and female octogenarians?

OBJECTIVES: Female gender and advanced age are regarded as independent risk factors for adverse outcomes after isolated coronary artery bypass grafting (CABG). There is paucity of evidence comparing outcomes of CABG between male and female octogenarians. We aimed to analyse in-hospital outcomes of isolated CABG in this cohort. METHODS: All octogenarians that underwent isolated CABG, from January 2000 to October 2017, were included. A retrospective analysis of a prospectively collected cardiac surgery database (PATS; Dendrite Clinical Systems, Oxford, UK) was performed. A propensity score was generated for each patient from a multivariable logistic regression model based on 25 pre-treatment covariates. A total of 156 matching pairs were derived. RESULTS: Five hundred and sixty-seven octogenarians underwent isolated CABG. This included 156 females (mean age 82.1 [SD: 0.9]) and 411 males (mean age 82.4 [SD: 2.1 years]). More males were current smokers (P = 0.002) with renal impairment (P = 0.041), chronic obstructive pulmonary disease (P = 0.048), history of cerebrovascular accident (P = 0.039) and peripheral vascular disease (P = 0.027) while more females had New York Heart Association class 4 (P = 0.02), left ventricular ejection fraction 30-49% (P = 0.038) and left ventricular ejection fraction <30% (P = 0.049). On-pump, CABG was performed in 140 males and 52 females (P = 0.921). There was no difference in in-hospital mortality (5.4% vs 6.4%; P = 0.840), stroke (0.9% vs 1.3%; P = 0.689), need for renal replacement therapy (17.0% vs 13.5%; P = 0.732), pulmonary complications (9.5% vs 8.3%; P = 0.746) and sternal wound infection (2.7% vs 2.6%; P = 0.882). The outcomes were comparable for the propensity-matched cohorts. CONCLUSIONS: No gender difference in outcomes was seen in octogenarians undergoing isolated CABG.

Surgical pericardial heart valves: 50 Years of evolution.

Valve disease carries a huge burden globally and the number of heart valve procedures are projected to increase from the current 300 000 to 800 000 annually by 2050. Since its genesis 50 years ago, pericardial heart valve has moved leaps and bounds to ever more ingenious designs and manufacturing methods with parallel developments in cardiology and cardiovascular surgical treatments. This feat has only been possible through close collaboration of many scientific disciplines in the fields of engineering, material sciences, basic tissue biology, medicine and surgery. As the pace of change continues to accelerate, we ask the readers to go back with us in time to understand developments in design and function of pericardial heart valves. This descriptive review seeks to focus on the qualities of pericardial heart valves, the advantages, successes and failures encapsulating the evolution of surgically implanted pericardial heart valves over the past five decades. We present the data on comparison of the pericardial heart valves to porcine valves, discuss structural valve deterioration and the future of heart valve treatments.

Surgical management of misdeployed transcatheter aortic valve due to eccentric leaflet calcification.

A serious complication of transcatheter valves is the mechanistic failure of the deployment system and prosthesis migration. We report the case of a transcatheter aortic valve implantation which failed during implantation resulting in dislodgement of the prosthesis. Emergency surgery to retrieve the deployment system and surgically replace the native valve was the only option to salvage the patient.

Outcomes of open and endovascular repair of Kommerell diverticulum.

OBJECTIVES: Kommerell diverticulum (KD) is a rare congenital vascular anomaly often associated with an aberrant subclavian artery (ASCA). Definitive indications for intervention remain unclear. We present open and endovascular (EV) operative outcomes in a large contemporary series and propose a management algorithm. METHODS: Between 2004 and 2020, 224 patients presented with ASCA and associated KD to our institution. Of the 43 (19.2%) patients who underwent operative repair, 31 (72.1%) had open surgical (OS) repair via thoracotomy and 12 (27.9%) had EV repair. Univariable and bivariable statistical analyses were conducted stratified by approach. The median follow-up time was 5.4 years (IQR, 2.9-9.7). RESULTS: Patients in EV group were older (68 years vs 47 years, P < 0.001) and had larger aneurysms (base diameter 3.2 cm vs 21.5 cm, P = 0.007). All patients with dysphagia lusoria were treated with open surgery (n = 20). Asymptomatic patients with incidentally detected KD (50% vs 16.1%), those with chest or back pain (50% vs 19.4%) and patients who presented with an aortic emergency (25% vs 6.5%) were more likely to be treated endovascularly (P = 0.001). Carotid-to-subclavian bypass was used in 38 (88.4%) patients. There were no operative mortalities. In-hospital mortality was similar between groups (3.2% vs 16.7%, P = 0.121). Mid-term mortality was higher in the EV group [4 (33.8%) vs 0, P < 0.001]. There were 2 (15.4%) postoperative strokes in the EV group. There were no statistically significant differences in other postoperative complications or hospital length of stay between groups. CONCLUSIONS: KD can be managed using open or EV approaches with low morbidity and mortality. Treatment strategy should depend on clinical presentation and patient factors.

Veno-venous Extracorporeal Membrane Oxygenation for Respiratory Failure in COVID-19 Patients: Early Experience From a Major Academic Medical Center in North America.

AND BACKGROUND DATA: VV ECMO can be utilized as an advanced therapy in select patients with COVID-19 respiratory failure refractory to traditional critical care management and optimal mechanical ventilation. Anticipating a need for such therapies during the pandemic, our center created a targeted protocol for ECMO therapy in COVID-19 patients that allows us to provide this life-saving therapy to our sickest patients without overburdening already stretched resources or excessively exposing healthcare staff to infection risk. METHODS: As a major regional referral program, we used the framework of our well-established ECMO service-line to outline specific team structures, modified patient eligibility criteria, cannulation strategies, and management protocols for the COVID-19 ECMO program. RESULTS: During the first month of the COVID-19 outbreak in Massachusetts, 6 patients were placed on VV ECMO for refractory hypoxemic respiratory failure. The median (interquartile range) age was 47 years (43-53) with most patients being male (83%) and obese (67%). All cannulations were performed at the bedside in the intensive care unit in patients who had undergone a trial of rescue therapies for acute respiratory distress syndrome including lung protective ventilation, paralysis, prone positioning, and inhaled nitric oxide. At the time of this report, 83% (5/6) of the patients are still alive with 1 death on ECMO, attributed to hemorrhagic stroke. 67% of patients (4/6) have been successfully decannulated, including 2 that have been successfully extubated and one who was discharged from the hospital. The median duration of VV ECMO therapy for patients who have been decannulated is 12 days (4-18 days). CONCLUSIONS: This is 1 the first case series describing VV ECMO outcomes in COVID-19 patients. Our initial data suggest that VV ECMO can be successfully utilized in appropriately selected COVID-19 patients with advanced respiratory failure.

A case of pulmonary placental transmogrification.

Pulmonary placental transmogrification is a rare lung lesion that microscopically resembles placenta with cystic spaces filled with papillary structures. Considered a histological variant of bullous emphysema, only 30 reported cases have been published in the world's literature. We report a rare case of pulmonary placental transmogrification in a 72-year-old man, in whom the clinical presentation of the disease mimicked lung carcinoma. Histopathology of the surgically resected segment showed a complex bulla with squamous metaplasia and placental transmogrification. Whilst rare, pulmonary placental transmogrification must be ruled out in all patients presenting with unilateral bullous emphysema, without known risk factors.

Minimally Invasive Versus Conventional Aortic Valve Replacement: A Propensity-Matched Study From the UK National Data.

OBJECTIVE: Minimally invasive aortic valve replacement (MIAVR) has been demonstrated as a safe and effective option but remains underused. We aimed to evaluate outcomes of isolated MIAVR compared with conventional aortic valve replacement (CAVR). METHODS: Data from The National Institute for Cardiovascular Outcomes Research (NICOR) were analyzed at seven volunteer centers (2006-2012). Primary outcomes were in-hospital mortality and midterm survival. Secondary outcomes were postoperative length of stay as well as cumulative bypass and cross-clamp times. Propensity modeling with matched cohort analysis was used. RESULTS: Of 307 consecutive MIAVR patients, 151 (49%) were performed during the last 2 years of study with a continued increase in numbers. The 307 MIAVR patients were matched on a 1:1 ratio. In the matched CAVR group, there was no statistically significant difference in in-hospital mortality [MIAVR, 4/307,(1.3%); 95% confidence interval (CI), 0.4%-3.4% vs CAVR, 6/307 (2.0%); 95% CI, 0.8%-4.3%; P = 0.752]. One-year survival rates in the MIAVR and CAVR groups were 94.4% and 94.6%, respectively. There was no statistically significant difference in midterm survival (P = 0.677; hazard ratio, 0.90; 95% CI, 0.56-1.46). Median postoperative length of stay was lower in the MIAVR patients by 1 day (P = 0.009). The mean cumulative bypass time (94.8 vs 91.3 minutes; P = 0.333) and cross-clamp time (74.6 vs 68.4 minutes; P = 0.006) were longer in the MIAVR group; however, this was significant only in the cross-clamp time comparison. CONCLUSIONS: Minimally invasive aortic valve replacement is a safe alternative to CAVR with respect to operative and 1-year mortality and is associated with a shorter postoperative stay. Further studies are required in high-risk (logistic EuroSCORE > 10) patients to define the role of MIAVR.

Fluoroscopic guide to an ideal implant position for Sapien XT and CoreValve during a valve-in-valve procedure.

OBJECTIVES: This study sought to provide a guide to the fluoroscopic appearances of various valve-in-valve (VIV) combinations by deploying a transcatheter heart valve (THV) within a degenerated surgical heart valve (SHV) in an ideal position. BACKGROUND: VIV procedures are being increasingly performed with substantial experience acquired in treating degenerated SHV in the aortic position with Sapien/Sapien XT (Edwards Lifesciences Ltd., Irvine, California) and CoreValve/Evolute (Medtronic Inc., Minneapolis, Minnesota) valves. Although less invasive than conventional surgery, securing the THV in an optimal position within the SHV determines the success of this novel treatment. METHODS: For VIV implantation, we selected appropriate Sapien XT and CoreValve/Evolute sizes depending on the internal diameter of the SHV. Implantation was performed in vitro. In case of the Sapien XT valve, it was deployed 4 to 5 mm below the sewing ring of the SHV, whereas the CoreValve/Evolute was deployed 5 mm below the level of the sewing ring. Photographs and fluoroscopic images of the various VIV combinations were obtained in side profile to study the ideal position and end-on profile to study the circularity of the THV. RESULTS: Fluoroscopic images obtained in side profile highlighted the differences in various VIV combinations, as all SHV are unique in their fluoroscopic appearances. Also, all THV implants in various VIV combinations achieved a nearly circular shape. CONCLUSIONS: To achieve an optimal result when considering VIV, it is important to be familiar with the structure and fluoroscopic appearances of the failed SHV, the THV used, and their combination.

Magnetic resonance T1 relaxation time of venous thrombus is determined by iron processing and predicts susceptibility to lysis.

BACKGROUND: The magnetic resonance longitudinal relaxation time (T1) changes with thrombus age in humans. In this study, we investigate the possible mechanisms that give rise to the T1 signal in venous thrombi and whether changes in T1 relaxation time are informative of the susceptibility to lysis. METHODS AND RESULTS: Venous thrombosis was induced in the vena cava of BALB/C mice, and temporal changes in T1 relaxation time correlated with thrombus composition. The mean T1 relaxation time of thrombus was shortest at 7 days following thrombus induction and returned to that of blood as the thrombus resolved. T1 relaxation time was related to thrombus methemoglobin formation and further processing. Studies in inducible nitric oxide synthase (iNOS(-/-))-deficient mice revealed that inducible nitric oxide synthase mediates oxidation of erythrocyte lysis-derived iron to paramagnetic Fe3+, which causes thrombus T1 relaxation time shortening. Studies using chemokine receptor-2-deficient mice (Ccr2(-/-)) revealed that the return of the T1 signal to that of blood is regulated by removal of Fe3+ by macrophages that accumulate in the thrombus during its resolution. Quantification of T1 relaxation time was a good predictor of successful thrombolysis with a cutoff point of <747 ms having a sensitivity and specificity to predict successful lysis of 83% and 94%, respectively. CONCLUSIONS: The source of the T1 signal in the thrombus results from the oxidation of iron (released from the lysis of trapped erythrocytes in the thrombus) to its paramagnetic Fe3+ form. Quantification of T1 relaxation time appears to be a good predictor of the success of thrombolysis.

TIE2-expressing monocytes/macrophages regulate revascularization of the ischemic limb.

A third of patients with critical limb ischemia (CLI) will eventually require limb amputation. Therapeutic neovascularization using unselected mononuclear cells to salvage ischemic limbs has produced modest results. The TIE2-expressing monocytes/macrophages (TEMs) are a myeloid cell subset known to be highly angiogenic in tumours. This study aimed to examine the kinetics of TEMs in patients with CLI and whether these cells promote neovascularization of the ischemic limb. Here we show that there are 10-fold more circulating TEMs in CLI patients, and removal of ischemia reduces their numbers to normal levels. TEM numbers in ischemic muscle are two-fold greater than normoxic muscle from the same patient. TEMs from patients with CLI display greater proangiogenic activity than TIE2-negative monocytes in vitro. Using a mouse model of hindlimb ischemia, lentiviral-based Tie2 knockdown in TEMs impaired recovery from ischemia, whereas delivery of mouse macrophages overexpressing TIE2, or human TEMs isolated from CLI patients, rescued limb ischemia. These data suggest that enhancing TEM recruitment to the ischemic muscle may have the potential to improve limb neovascularization in CLI patients.

Transaortic transcatheter aortic valve implantation for failed surgical aortic valve replacement due to 'porcelain aorta'.

Transcatheter aortic valve implantation (TAVI) is an emerging surgical approach in patients with severe aortic stenosis unsuitable for conventional aortic valve replacement (AVR). TAVI has been performed through both transfemoral and transapical approaches, each with a specific suitability criterion. A transaortic (TAo-TAVI) approach has been recently established at the authors' institution for high-risk patients who are unsuited to the above techniques. Herein, the case is described of a successful aortic valve implantation using TAo-TAVI in a patient with porcelain ascending aorta that was identified as an incidental finding during conventional AVR. The patient recovered well and was discharged home without any complications.

What is the best timing of surgery in patients with post-infarct ventricular septal rupture?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'in which patients with a post-infarct ventricular septal rupture (PIVSR) might immediate surgery give better results than delayed surgery in terms of mortality'? Altogether, 88 papers were found using the reported search criteria, of which 6 represented the best 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. The recommendations are based on outcomes from 3238 patients undergoing surgery for PIVSR. Mean age was 67.5 ± 8.8 (40-88 years). Left ventricular function was compromised in most patients with mean ejection fraction of 40%. All papers carried out univariate and/or multivariate analyses of variables that contributed to different in-hospital mortalities. Early surgery, i.e. from >3 days to within 4 weeks after MI, had an overall in-hospital mortality of 52.4%; delayed surgery, typically from 1 week to after 4 weeks post-myocardial infarction, had an overall operative in-hospital mortality of 7.56%. Most authors observe that a shorter time between rupture and surgery is an unfavourable predictor of outcome independent of haemodynamic status. The consensus was that nearly all patients with PIVSR, particularly if >15 mm diameter with a significant shunt and resultant haemodynamic deterioration, should undergo early surgical repair. The precise timing of surgery depends on patients' haemodynamic status. Exclusion from surgery should be considered if life expectancy or quality is severely limited by another limiting underlying pathology. If the patient is in cardiogenic shock, due to pulmonary to systemic blood flow ratio shunt rather than infarct size, immediate surgery should follow resuscitation measures and cardiac support. If the patient is haemodynamically stable, surgery could be performed after 3-4 weeks of medical optimization with inotropic and mechanical cardiac support. If there is clinical deterioration, immediate surgery is indicated.

Encapsulation of angiogenic monocytes using bio-spraying technology.

Therapeutic neovascularisation using angiogenic cells has been hampered by the loss of cells from the target tissue. Encapsulation of these cells within a semi-permeable membrane could improve their retention within the ischaemic tissue without affecting the excretion of the angiogenic growth factors produced. Bio-spraying is a novel cell-handling technique that does not adversely affect cell viability. We used this technique to encapsulate human peripheral blood monocytes and found that cell viability, cell phenotype and functional downstream angiogenic signalling were preserved. Encapsulation of monocytes with macrophage-colony stimulating factor resulted in increased vascular-endothelial growth factor production and enhanced angiogenic function. Bio-spraying/encapsulation has the potential to enhance the efficacy of current angiogenic cell therapy strategies and merits further investigation.

Distribution of calcium in the ascending aorta in patients undergoing transcatheter aortic valve implantation and its relevance to the transaortic approach.

OBJECTIVES: This study sought to identify how many patients suitable for transcatheter aortic valve implantation (TAVI) would have a contraindication for the transaortic (TAo) approach due to ascending aortic calcification. BACKGROUND: TAo is an emerging approach for implantation of the Sapien valve through the ascending aorta. A "porcelain aorta" is often considered a contraindication for the TAo approach. This may not always be true, as the TAo procedure requires a small calcium-free area for the purse-string suture, usually in the upper outer quadrant of the distal ascending aorta, identified as the "TAo zone." METHODS: A total of 237 patients underwent TAVI between February 2008 and June 2011. Multislice computed tomography scans (MSCT) were analyzed for distribution of calcium with special attention to the TAo zone. Each MSCT was interrogated in cross section and three dimensional (3D) reconstructions. Correlation between the calcium distribution on MSCT and the 3D reconstruction with the clinical findings was sought in patients undergoing the TAo procedure. RESULTS: The vast majority of patients had calcification in the aortic arch (n = 154, 64.9%) and aortic root (n = 220, 92.8%). Of the 237 patients, only 1 patient had diffuse calcification in the ascending aorta, including the TAo zone, thus precluding a TAo procedure. MSCT and 3D reconstruction data in the 33 patients who underwent a TAo procedure, including 6 who were identified as having porcelain aorta preoperatively, correlated very well with the absence of calcium in the TAo zone during surgery. There were no post-procedure neurological events in this group. CONCLUSIONS: Conventionally defined porcelain aorta should not be considered a contraindication for performing TAVI by the TAo approach.

Aspergillus endocarditis: a case of near complete left ventricular outflow obstruction.

A 60-year old woman presented with dyspnoea and fatigue. She was frail and cachectic (BMI 17.5) with a pancytopenia. Previously she had received chemotherapy for chronic lymphatic leukaemia. She relapsed one year ago necessitating a reduced intensity conditioning allogeneic haematopoietic cell transplantation. Subsequently, graft versus host disease required high-dose immunosuppressants. Computerized tomography on admission showed bilateral lung nodules and a suspicious cardiac mass. Bronchial biopsies demonstrated abundant hypae consistent with Aspergillus fumigatus infection. Echocardiography demonstrated a large fungus ball attached to the right coronary cusp of the aortic valve with near complete obliteration of the left ventricular outflow tract. Due to the high risk of embolization this was resected under cardiopulmonary bypass. The mass was attached subvalvularly to the ventricular septal free wall and eroding through it. It peeled off leaving intact aortic leaflets. Unresectable fungal deposits were discovered on the interventricular septum, the left ventricle free wall and posterior aortic wall. High-dose systemic antifungal therapy (Voriconazole and Amphoteracin B) was given for 4 months. After discharge she remained well till a 4-month follow-up, after which she eventually succumbed to her disease. We discuss the clinical difficulties in managing patients with fungal infective endocarditis and present a brief review of cardiac aspergillosis management.

What are the differences in outcomes between right-sided active infective endocarditis with and without left-sided infection?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: in patients with isolated right-sided infective endocarditis (RSE) is the outcome of surgical management the same as in patients with or without left-sided involvement? Altogether, 419 papers were found using the reported search, six of which represented the best evidence to answer the clinical question. Two studies point towards better outcomes with isolated RSE. In one paper, mortality was significantly lower in isolated RSE patients (P = 0.0093) for the duration of the follow-up time (median 488 patient-years). Two studies reported early mortality (<30 days) for RSE patients at 3.6 and 3.8%, respectively. Combined right- and left-sided endocarditis (RLSE) patients were found to have a poorer pre-operative clinical presentation than isolated RSE patients with a greater requirement for inotropic support (P < 0.006) and the likelihood of an emergency operation (P < 0.001). They had a poorer intra-operative course with a higher incidence of cardiac abscess formation (P < 0.001). One study suggested that there is no significant difference in in-hospital and long-term mortality between intravenous drug abuse (IVDA) patients and non-IVDA patients. Left-heart involvement in the IVDA group was 61.5%. This was in-line with the published literature, demonstrating a rise in RLSE in IVDA compared with non-IVDA patients. Three articles looking at isolated left-sided endocarditis (LSE) gave mortality rates in the surgical group to be 27.1, 27.8 and 38%, respectively. In one study, the LSE mortality was not different for native vs. prosthetic valve infection (OR 0.65, 95% CI 0.23-1.87). After propensity matching and adjusting for hazards, the complication rate in the LSE group was higher and this translated to a higher mortality rate. We conclude from the literature that outcomes are more favourable with lower early and late mortality for isolated RSE patients over pure LSE or combined RLSE.