Analysis of current mortality risk scores for acute type A aortic dissection: The Siena experience

OBJECTIVE

In literature, various risk scores have been described to predict in-hospital mortality of patients undergoing surgery for acute type A dissection. We want to evaluate which factors are most correlated with a negative outcome and testing the validity of the current scores in literature analyzing our experience of over 20 years in the surgery of type A aortic dissections.

MATERIALS AND METHODS

A total of 324 patients were included in the study. Patients were divided into two groups according to 30-day survival or mortality. The preoperative variables analyzed are the parameters necessary for the calculation of scores: Penn Classification, Leipzig Halifax and adjusted Leipzig Halifax score, GERAADA score and EuroSCORE II. Intra- and post-operative mortality were 10.2% and 17.5%, respectively. In multivariate analysis, the preoperative predictors of 30-day mortality were age greater than 70 years, low eject fraction levels, visceral and coronary malperfusion. Both GERAADA and EuroSCORE II were statistically significant predictors of 30-day mortality. However, EuroSCORE II underestimates the mortality compared to GERAADA score probably due to the lack of evaluation of fundamental preoperative factors in the course of type A aortic dissection.

RESULTS

The study has demonstrated the efficacy of the GERAADA score in predicting the outcome of patients undergoing surgery and the underestimation of the mortality of EuroSCORE II in our population.

Intercostal artery's access for type II endoleak embolization

Endoleaks represent a main issue of endovascular approach of thoracic aorta diseases and their treatment continue to be challenging. According to some authors, type II endoleaks sustained by intercostal arteries should not be treated because of the technical difficulties. However, the persistence of a pressurized aneurysmal may confer an ongoing risk of enlargement and/or aortic rupture. We describe the successful treatment of type II endoleak in two patients with an intercostal artery's access. In both cases, the endoleak was discovered during follow-up and was treated with its direct coil embolization under local anesthesia.

Left Ventricular Lead Placement for Biventricular Pacing in a Left Lateral Vein in a Patient with Congenital Atresia of the Coronary Sinus Ostium

Coronary sinus ostial atresia (CSOA) is a rare kind of congenital heart anomaly. This creates a new drainage pathway for the cardiac venous flow, with the most common being a persistent left superior vena cava (PLSVC). During the implantation of a cardiac resynchronization therapy defibrillator, we discovered a case of CSOA in a patient who underwent aortic valve and ascending aorta replacement. CSOA led to the research and subsequent identification of a PLSVC, which drained in the CS. The left ventricular pacing lead was appropriately placed in a left lateral vein. This case report highlights the technical aspects and procedural difficulties that characterize this specific anatomical variant.

(s)INE: (soft-graft)-induced new entry tear after elephant trunk procedure

Elephant trunk and frozen elephant trunk are established procedures for the treatment of aortic arch pathologies, such as aneurysm or dissection. The aim of open surgery is to re-expand the true lumen, favouring correct organ perfusion and the thrombosis of the false lumen. Frozen elephant trunk, with its stented endovascular portion, is sometimes associated with a life-threatening complication: the stent graft-induced new entry. In the literature, many studies reported the incidence of such issue after thoracic endovascular prosthesis or frozen elephant trunk, but in our knowledge, there are no case studies about the occurrence of stent graft-induced new entry with the use of soft grafts. For this reason, we decided to report our experience, highlighting how the use of a Dacron graft can cause distal intimal tears. We decided to coin the term soft-graft-induced new entry to indicate the development of an intimal tear induced by the soft prosthesis in the arch and proximal descending aorta.

How to perform a direct axillary artery cannulation

The choice of the arterial cannulation site has been a matter of debate over the years. The femoral artery has been used for a long time due to its ease of isolation and the possibility of percutaneous cannulation. However, it is associated with the risk of embolization because of the retrograde flow, and it is more dangerous in the case of aortic dissection because perfusion is unpredictable and retrograde flow exposes the patient to the risk of malperfusion. Cannulation of the axillary artery has recently gained popularity because of its advantages, in particular for antegrade aortic perfusion during cardiopulmonary bypass and for its ability to facilitate cerebral perfusion during hypothermic circulatory arrest. We show tips and tricks to facilitate the isolation and direct cannulation of the axillary artery because we think that this procedure should be practiced by all cardiac surgeons, even those who are just beginning their practices.

Rapid generation of functional engineered 3D human neuronal assemblies: network dynamics evaluated by micro-electrodes arrays

Objective.In this work we adapted a protocol for the fast generation of human neurons to build 3D neuronal networks with controlled structure and cell composition suitable for systematic electrophysiological investigations.Approach.We used biocompatible chitosan microbeads as scaffold to build 3D networks and to ensure nutrients-medium exchange from the core of the structure to the external environment. We used excitatory neurons derived from human-induced pluripotent stem cells (hiPSCs) co-cultured with astrocytes. By adapting the well-established NgN2 differentiation protocol, we obtained 3D engineered networks with good control over cell density, volume and cell composition. We coupled the 3D neuronal networks to 60-channel micro electrode arrays (MEAs) to monitor and characterize their electrophysiological development. In parallel, we generated two-dimensional neuronal networks cultured on chitosan to compare the results of the two models.Main results.We sustained samples until 60 din vitro(DIV) and 3D cultures were healthy and functional. From the structural point of view, the hiPSC derived neurons were able to adhere to chitosan microbeads and to form a stable 3D assembly thanks to the connections among cells. From a functional point of view, neuronal networks showed spontaneous activity after a couple of weeks.Significance.We presented a particular method to generate 3D engineered cultures for the first time with human-derived neurons coupled to MEAs, overcoming some of the limitations related to 2D and 3D neuronal networks and thus increasing the therapeutic target potential of these models for biomedical applications.

Arch replacement with collared elephant trunks: The Siena approach

Objective

To illustrate our experience and results in patients with diffuse aneurysmal disease treated with arch replacement using the Siena collared graft, a device designed in 2002 to improve the elephant trunk technique. Results of the first step surgical implant and the subsequent treatment strategies, with extensive use of endovascular techniques, are reported.

Methods

All aortic arch–replacement procedures using the Siena graft between February 2002 and January 2020 were retrospectively analyzed for early and late clinical outcomes.

Results

Of 146 patients (54 women, 36.9%) with a median age of 69.1 years (interquartile range 58.4-75.0 years), 55 (37.6%) had acute/chronic dissection with false lumen aneurysmal dilatation, 91 (62.3%) had degenerative aneurysms, 45 (30.8%) were redo operations, and 14 (9.5%) had connective tissue disease. First-stage outcomes: 10.9% 30-day mortality (n = 16); 5.4% stroke (n = 8, 6 disabling, 2 nondisabling; 3 fatal); and 0.6% paraplegia. Outcomes for 113 second-stage procedures (77.3%, n = 97 endovascular [66.4%], n = 16 surgical [10.9%]) were 5.3% and 8.8% 30-day and 180-day mortality; no stroke; 10.6% paraplegia. Median follow-up was 5.7 years (range: 0-18.02 years) median survival was 16.65 years (95% lower confidence limit, 10.06 years) with no significant difference between aneurysm and dissection patients. Freedom from further treatment was 87.0% (95% confidence interval, 79.9%-94.7%) at 5 years and 71.4% (95% confidence interval, 71.4%-84.7%) at 10 years; median time to reintervention was 2.59 years (interquartile range, 0.52-5.20 years) with no difference (P = .22) between dissection and aneurysm groups.

Conclusions

Siena collared graft represents a reliable platform for the treatment of diffuse aneurysmal disease. This device offers the flexibility required in the treatment of extended aortic lesions and guarantees the choice of the most appropriate approach for treatment completion. In this context, the availability of hybrid grafts has not modified the role of this device in arch surgery.

Emergency fast Bentall operation

We herein report an emergency technique of composite Bentall operation using a fast release valve. The technique was successfully performed in 2 emergency cases after failed supracoronary ascending aortic replacement in acute Type A aortic dissection. The speed and ease of execution are the main advantages of the procedure.

Intimal re-layering technique for type A acute aortic dissection-reconstructing the intimal layer continuity to induce remodeling of the false channel

Background

Residual false channel is common after repair of type A acute aortic dissection (TAAAD). Starting from our recent series of TAAAD patients we carried out a retrospective analysis, regarding the failure of primary exclusion at the time of the initial operation. We classified the location of the principal entry tears perfusing the residual false channel. The proposed technique represents our attempt to correct the mechanism of false channel perfusion during primary repair. We describe a new technique designed to address some limitations of standard hemiarch aortic replacement. Its goal are: (I) to reinforce the intimal layer at the arch level; (II) to eliminate inter-luminal communications at the arch level using suture lines around the arch vessels; (III) to provide an elephant trunk configuration for further interventions.

Methods

Between August 2016 and January 2018, 11 patients underwent emergency surgery using this technique; 7 were men; the median age was 74 years. All patients were treated using systemic circulatory arrest under moderate hypothermia (26 °C) and selective cerebral perfusion. All patients had supra-coronary repair; 1 patient had aortic valve replacement + CABG. In the first two patients a manual suture around supra-aortic trunks was used; the subsequent seven patients were treated with a mechanical suture bladeless device. CT scan follow up was performed in all survivors with controls before discharge 3 months and 1 year after operation.

Results

No patient died in the operating room and no neurologic deficit was observed in this initial experience. One patient died in POD 5th for low cardiac output syndrome. Median ICU stay was 3 days (IQR, 2-6 days). Hospital mean length of stay was 15.2±8 days. Median cardiopulmonary bypass time was 130 min (IQR, 110-141 min); median arrest time for re-layering was 17 min (IQR, 16-20 min); median total arrest was 36 min (IQR, 29-39 min). Distal aortic anastomosis was performed in zone 0 in 4 patients, zone 1, with innominate replacement, in 5 patients, in zone 2, with branches to innominate and left common carotid arteries, in 2 patients. Median follow up (closing date 06/01/2018) was 443 days (IQR, 262-557 days); no late deaths occurred. No dehiscence at the level of stapler or manual sutures was observed. Proximal 1/3 of the thoracic aorta false channel was obliterated in all cases but one; in 3 cases complete exclusion of the false channel was obtained after operation. In one case stent graft completion was required.

Conclusions

This technique combines the advantages of arch replacement to the simplicity of anterior hemiarch repair. This study demonstrates the safety of the procedure and the possibility to induce aortic remodeling without complex arch replacement.

The role of stoichiometry in superconducting Nb1-βSnβ: electronic and vibrational properties from ab initio calculations

Using first principles calculations based on density functional theory, the electronic, vibrational and superconducting properties of compounds with different stoichiometry ratios in the A15 phase have been studied. To this purpose, the λ mass enhancement parameter, which determines the superconducting critical temperature through the Allen-Dynes modification of the McMillan formula, has been explicitly calculated in the context of the density functional perturbation theory that allows the calculation of the matrix elements of the electron-phonon interactions at different compositions related to the Sn content. Our results provide a better understanding of the inhomogeneous composition of one of the most widely employed low-temperature superconductors, evidencing the electronic properties and the phonon modes that are responsible for the critical temperature degradation as the Sn concentration is varied.

Pulse wave analysis to assess systemic blood flow during mechanical biventricular support

Measurement of systemic blood flow is of crucial importance in patients on mechanical circulatory support (MCS). We reported the case of a 65-year-old female patient in severe cardiogenic shock undergoing left (Jarvik 2000 axial flow pump) and right (Levitronix-Centrimag centrifugal pump) ventricular assist device implant. Evaluation of blood flow was obtained by ultrasonic flowmetry, continuous thermodilution technique, and pressure recording analytical method (PRAM). This pulse contour system allows beat-by-beat systemic blood flow assessment from the analysis of radial artery pressure waveform. At a Jarvik pump speed ≤ 10 000 rotations per minutes (rpm), thermodilution and PRAM showed similar blood flow values. At a Jarvik pump speed ≥11 000 rpm, the aortic valve did not open and PRAM did not provide blood flow values due to nonpulsatile blood flow. The present paper describes the first experience with PRAM in a single patient on MCS. Further studies are required to assess the validity of PRAM as an additional monitoring system in the setting of ventricular assist device support. Perfusion (2007) 22, 63-66.

Levosimendan in critical illness: a literature review

Levosimendan, the active enantiomer of simendan, is a calcium sensitizer developed for treatment of decompensated heart failure, exerts its effects independently of the beta adrenergic receptor and seems beneficial in cases of severe, intractable heart failure. Levosimendan is usually administered as 24-h infusion, with or without a loading dose, but dosing needs adjustment in patients with severe liver or renal dysfunction. Despite several promising reports, the role of levosimendan in critical illness has not been thoroughly evaluated. Available evidence suggests that levosimendan is a safe treatment option in critically ill patients and may reduce mortality from cardiac failure. However, data from well-designed randomized controlled trials in critically ill patients are needed to validate or refute these preliminary conclusions. This literature review is an attempt to synthesize available evidence on the role and possible benefits of levosimendan in critically ill patients with severe heart failure.

Juxtarenal aortic aneurysms: preliminary experience with fenestrated E-vita abdominal stent-graft

Endovascular aneurysm repair (EVAR) offers a minimally invasive treatment to patients with improved short-term and similar mid-term results compared to conventional, open repair. Approximately 20% of patients have an aneurysm neck morphology inadequate for a standard stent-graft and requires an endograft to cross vital aortic side branches to achieve a seal. This work describes the promising single center preliminary results in the management of juxtarenal aortic aneurysm using E-vita stent-graft.

Strain sensitivity and superconducting properties of Nb3Sn from first principles calculations

Using calculations from first principles based on density-functional theory we have studied the strain sensitivity of the A15 superconductor Nb3Sn. The Nb3Sn lattice cell was deformed in the same way as observed experimentally on multifilamentary, technological wires subject to loads applied along their axes. The phonon dispersion curves and electronic band structures along different high-symmetry directions in the Brillouin zone were calculated, at different levels of applied strain, ε, on both the compressive and the tensile side. Starting from the calculated averaged phonon frequencies and electron-phonon coupling, the superconducting characteristic critical temperature of the material, T(c), has been calculated by means of the Allen-Dynes modification of the McMillan formula. As a result, the characteristic bell-shaped T(c) versus ε curve, with a maximum at zero intrinsic strain, and with a slight asymmetry between the tensile and compressive sides, has been obtained. These first-principle calculations thus show that the strain sensitivity of Nb3Sn has a microscopic and intrinsic origin, originating from shifts in the Nb3Sn critical surface. In addition, our computations show that variations of the superconducting properties of this compound are correlated to stress-induced changes in both the phononic and electronic properties. Finally, the strain function describing the strain sensitivity of Nb3Sn has been extracted from the computed T(c)(ε) curve, and compared to experimental data from multifilamentary, composite wires. Both curves show the expected bell-shaped behavior, but the strain sensitivity of the wire is enhanced with respect to the theoretical predictions for bulk, perfectly binary and stoichiometric Nb3Sn. An understanding of the origin of this difference might open potential pathways towards improvement of the strain tolerance in such systems.

Successful use of a military haemostatic agent in patients undergoing extracorporeal circulatory assistance and delayed sternal closure

We report the successful control of bleeding in two patients who underwent post-cardiotomy extracorporeal circulatory support (ECMO) and then developed life-threatening bleeding due to severe coagulopathy. After the failure of conventional techniques, bleeding control was achieved using Celox Gauze (MedTrade Products Ltd, Cheshire, UK) packed on the sternal edges and pericardial cavity.

Cardiogenic shock as a complication of acute mitral valve regurgitation following posteromedial papillary muscle infarction in the absence of coronary artery disease

A 48 year old man was transferred to our department with cardiogenic shock, pyrexia, a high white cell count and significant serum troponin T level. Clinical evaluation revealed severe mitral regurgitation secondary to a flail of both mitral valve leaflets. An emergency cardiac catheterisation did not reveal any significant coronary artery disease. Left ventricular angiogram and echocardiography demonstrated a good left ventricular function and massive mitral regurgitation. Blood cultures were negative for aerobics, anaerobics and fungi. The patient underwent emergency mitral valve replacement with a mechanical valve. Intraoperatively, the posteromedial papillary muscle was found to be ruptured. Histology of the papillary muscle revealed myocardial necrosis with no signs of infection. Cultures obtained from a mitral valve specimen were negative. The patient's recovery was uneventful and he was discharged on the 6^th postoperative day.

Traumatic aortic arch false aneurysm after blunt chest trauma in a motocross rider

This article details a case report of a traumatic aortic arch false aneurysm after blunt chest trauma. Thoracic aorta false aneurysms are a rare and life-threatening complication of aortic surgery, infection, genetic disorders and trauma.

Primary hemangioma of the mitral valve: an unusual presentation

Cardiac hemangiomas are rare tumors, the presence of these neoplasms in heart valves is an exceptional finding, mainly because of their histological features. Normally, transesophageal echocardiography is used to establish a diagnosis of cardiac tumor, though careful interpretation is needed to avoid diagnostic errors. Herein is described an unusual presentation of a primary hemangioma of the mitral valve which was diagnosed as a prolapsing left atrial myxoma. The patient underwent successful surgical excision of the neoplasm, followed by mitral valve repair.

Massive mitral and pulmonary valve incompetence in a patient with left ventricular, non-compacted myocardium

The case is reported of a patient who underwent cardiac surgery for pulmonary valve stenosis as a child, and presented as an adult with signs and symptoms of severe congestive heart failure. The left ventricle showed an increased trabecular pattern in the region of the apex, the mitral annulus was severely dilated with mitral incompetence, the right ventricular out-flow tract (RVOT) was largely dilated with aneurysm of both pulmonary arteries, and there was evidence of pulmonary valve incompetence. Previously, rare cases have been reported of persistent left ventricular non-compaction in patients with congenital left or RVOT obstruction. Non-compaction of the ventricular myocardium is an inherited autosomal dominant disorder; to date, four genes and one genetic locus have been found to be associated with non-compacted ventricular myocardium. The condition is characterized by arrhythmias, thromboembolic events and heart failure, but affected individuals may not be symptomatic. The present case represented a strange association between non-compacted left ventricle, mitral annular dilation with persistence of a normal leaflet and subvalvular mitral valve apparatus, and RVOT dilation with pulmonary artery aneurysms.

Left ventricular postoperative false aneurysm following apical venting

We report a case of false aneurysm of the left ventricle occurring subsequently to the placing of a vent sump line through the apex during an aortic valve procedure; the diagnosis was made twelve months later during a routine echocardiographic examination. The lesion was successfully repaired. This case recommend the use of other routes of venting in order to reduce the incidence of such complications.

Large left atrial myxoma with severe mitral regurgitation: the inverted T-shaped biatrial incision revisited

Cardiac myxomas are primary cardiac tumors. In some cases of atrial myxoma, the standard left atriotomy alone does not enable safe tumor resection and easy access to the mitral valve. We report the cases of 2 patients with huge left atrial myxomas associated with severe mitral valve regurgitation who underwent an inverted T-shaped biatrial incision for tumor excision and mitral repair. This approach reduces tumor fragmentation and permits good mitral valve exposure.

TT virus infection of periodontal tissues: a controlled clinical and laboratory pilot study

BACKGROUND

A novel single-strand, circular DNA virus has been recently isolated and named TT virus (TTV). It has been demonstrated that peripheral blood cells harbor TTV DNA, suggesting that the virus might replicate in lymphoid cells and contribute to lymphocyte imbalances with consequent immunosuppressive effects. The purpose of this study was to investigate the prevalence of TTV DNA in healthy and periodontally compromised subjects, evaluating the presence of the virus in the gingiva and saliva, and comparing virological results with clinical data.

METHODS

Twenty-one patients (seven males and 14 females, aged 25 to 76 years) were enrolled in the study. Eleven subjects were diagnosed with moderate periodontitis, while 10 were periodontally healthy. A sample of saliva was taken from each patient before recording the periodontal data; subsequently, a gingival biopsy was performed. A real-time polymerase chain reaction was used to quantify the presence of TTV DNA in saliva and gingival specimens.

RESULTS

A statistically significant association was found between TTV in gingival tissue and the presence of periodontitis (P = 0.0351), while no association was observed between TTV in saliva and the presence of periodontitis (P = 0.4762).

CONCLUSIONS

A new DNA virus (TTV) was first identified in the gingival tissue and was found to be significantly associated with the presence of periodontitis. These findings need to be investigated in further studies.