Thoraflex Hybrid Prosthesis (THP): the profile

INTRODUCTION

With the incidence of thoracic aortic disease on the rise, total arch replacement (TAR) with frozen elephant trunk (FET) remains the gold-standard management strategy due to optimal results. Several FET devices exist commercially on the global market. However, the mainstay and most commonly used and reported device is the Thoraflex Hybrid Prosthesis (THP), with several recent reports suggesting its superiority.

AREAS COVERED

This review aims to collate and summarize the evidence in the literature on the clinical outcomes of TAR with FET using THP, with a focus on mortality, neurological complications, endoleak, distal stent-induced new entry (dSINE), aortic remodeling, coagulopathy, and graft kinking. In addition, the design features of THP is discussed, and an overview of market competitors is also highlighted.

EXPERT OPINION

THP consistently demonstrates its effectiveness in treating complex thoracic aortic pathology through favorable clinical outcomes, which can be attributed to its unique and innovative design. Rates of early mortality ranged 0.6-14.2%, neurological complications 0-25%, endoleak 0-8.4% and dSINE 0-14.5%, with minimal incidence of graft kinking and coagulopathy. Aortic remodeling is favorable and comparable to competitors. All this evidence solidifies THP as the leading FET device, particularly when combined with appropriate patient selection and surgical planning.

Stanford type B aortic dissection in a patient with aberrant right subclavian artery

An aberrant right subclavian artery is a rare aortic arch anomaly where the right subclavian artery arises from the proximal part of the descending thoracic aorta and distal to origin of left subclavian artery. It usually courses behind the esophagus. Type B aortic dissection along with aberrant right subclavian artery is not common. A middle-aged man presented with complaints of epigastric pain and on evaluation was found to have aberrant right subclavian artery with type B aortic dissection. A total arch replacement with frozen elephant trunk surgery and an extra-anatomic bypass of right subclavian artery were performed. Type B aortic dissection is more often an incidental finding and its association with aberrant right subclavian artery is unusual. Such association should be identified and treated accordingly to avert clinical complications.

Aortic Arch Debranching and Thoracic Endovascular Aortic Repair (TEVAR) for Type B Aortic Dissection

BACKGROUND

Since its introduction, thoracic endovascular aortic repair (TEVAR) has revolutionized the treatment of type B aortic dissections (TBADs). However, the proximal aspect of the aortic pathology treated may infringe on the origin of the left subclavian artery or even more proximally. Hence, to ensure durable outcomes, the origin of these vessels needs to be covered, but an extra-anatomical bypass is required to perfuse vital branches, known as aortic arch debranching. This series aims to describe and delineate the disparities of aortic arch debranching during TEVAR for TBAD.

METHODS

A retrospective review and analysis of a multicenter international database was conducted to identify patients with TBAD treated with TEVAR between 2005 and 2021. Data analyzed included patient demographics, disease characteristics, operative characteristics, and postoperative outcomes with follow-up on mortality and reintervention. All statistical analyses were carried out using IBM SPSS 26. Patient survival was calculated using a Kaplan-Meier survival analysis, and a P value of less than 0.05 was considered statistically significant.

RESULTS

A total of 58 patients were included in the analysis, of which 27 (46.6%) presented with complicated disease and 31 were uncomplicated, of which 10 (17.2%) were classed as high risk and 21 (36.2%) low risk. Zone 2 was the most common proximal landing zone for the stent graft. Left subclavian artery bypass was performed selectively (26%), with 1 stroke occurring, likely due to embolic reasons. A further 6 underwent more proximal aortic debranching before TEVAR (10%) and was a significant risk factor for mortality and the number of stents deployed. The overall rates of reintervention and mortality were 17.2% (n = 10) and 29.3% (n = 17).

CONCLUSIONS

Aortic arch debranching and TEVAR for TBAD is associated with significant mortality. Future developments to treat aortic arch pathology could incorporate branched graft devices, eliminating the need for debranching, improving stroke rates, and reducing future reinterventions.

Thoraflex Hybrid vs. AMDS: To replace the arch or to stent it in type A aortic dissection?

BACKGROUND

Acute type A aortic dissection (ATAAD) is a life-threatening medical emergency that requires urgent surgical intervention. The mainstay surgical approach to treating ATAAD with aortic arch involvement is total arch replacement (TAR). The frozen elephant trunk (FET) procedure involves TAR with hybrid endovascular stenting of the DTA in a single step using a hybrid prosthesis (HP). The prime example of a FET HP is Thoraflex Hybrid Prosthesis (THP). Another treatment option is the novel Ascyrus Medical Dissection Stent (AMDS) that is deployed as a non-covered stent along with the aortic arch as an adjunct to prior hemi-arch replacement.

AIMS

This comparative review highlights the clinical applications and outcomes of THP and AMDS in the treatment of ATAAD and discusses the main differences between both approaches.

METHODS

A comprehensive literature search was conducted using multiple electronic databases including PubMed, Google Scholar, Ovid, Scopus and Embase.

RESULTS

TAR with FET can be considered the superior approach to managing ATAAD with arch involvement relative to AMDS with hemi-arch replacement due to more optimal clinical outcomes. Upon comprehensively searching the literature, early mortality was substantially lower with FET ranging from 0-11% compared to 12.5-18.7% using AMDS, with more favourable long-term survival. The incidence of kidney injury and new stroke post-FET ranged from 3-20% and 5-16%, and 11-37.5% and 0-18.8% following AMDS implantation. However, evidence supporting the use of AMDS is extremely limited. Meanwhile, TAR with FET is a well-established and well-described procedure for ATAAD repair.

CONCLUSION

Despite the novel nature of AMDS, its clinical safety and effectiveness are yet to be proven. In conclusion, THP remains the best evidenced-based approach to treat ATAAD in this era.

Uncomplicated Type B Aortic Dissection: Challenges in Diagnosis and Categorisation

BACKGROUND

Acute type B aortic dissection (TBAD) is a rare disease that is likely under-diagnosed in the UK. As a progressive, dynamic clinical entity, many patients initially diagnosed with uncomplicated TBAD deteriorate, developing end-organ malperfusion and aortic rupture (complicated TBAD). An evaluation of the binary approach to the diagnosis and categorisation of TBAD is needed.

METHODS

A narrative review of the risk factors predisposing patients to progression from unTBAD to coTBAD was undertaken.

RESULTS

Key high-risk features predispose the development of complicated TBAD, such as maximal aortic diameter > 40 mm and partial false lumen thrombosis.

CONCLUSION

An appreciation of the factors that predispose to complicated TBAD would aid clinical decision-making surrounding TBAD.

Surgical techniques in acute Type A aortic dissection: How we do it

Acute Type A aortic dissection (ATAAD), a surgical emergency, has high mortality and morbidity. More than half of the patients dies within 2 weeks and the 30-day mortality is 90%. Here we describe our technique of ATAAD repair.

Structural abnormalities in the non-dilated ascending aortic wall of bicuspid aortic valve patients

BACKGROUND

A bicuspid aortic valve (BAV) is the most common congenital cardiac malformation. The development of the aortic valve is closely related to the development of the ascending aorta, associated with structural differences in the bicuspid aorta. Here we describe the non-dilated ascending aortic wall in bicuspid aortic valve patients.

METHODS

BAV (n=41) and tricuspid aortic valve (TAV) (n=18) non-dilated ascending aortic wall samples were studied. We investigated the following features of the aortic wall: vessel wall thickness, endothelial cell morphology, atherosclerosis, and elastic lamellae organization. Medial pathologic features encompassing elastic fiber thinning, fragmentation and degeneration, overall medial degeneration, mucoid extracellular matrix accumulation, and smooth muscle cell nuclei loss were studied. Furthermore, we included apoptosis, periaortic inflammation, and the level of expression of differentiated vascular smooth muscle cells.

RESULTS

The non-dilated BAV ascending aortic wall is characterized by a significantly thinner intimal layer, without features of atherosclerosis (P<.001). The medial layer is significantly thicker (P<.001) with more mucoid extracellular matrix accumulation (P<.001). All other medial pathologic features were more prominent in the TAV (P<.001). The media has significantly less differentiated vascular smooth muscle cells (P<.001) between the neatly regulated elastic lamellae which are thinner in the BAV as compared to the TAV (P<.0001).

CONCLUSIONS

The BAV ascending aorta without dilatation is characterized by a differentiation defect of vascular smooth muscle cells in the media and a significantly thinner intimal layer without overt pathologic features.

Ethnic & Sex Disparities in Type B Aortic Dissection Patients Undergoing Thoracic Endovascular Aortic Repair: An International Perspective

BACKGROUND

There has been a revolution in the management of type B aortic dissection (TBAD) over the last 2 decades due to the increasing development of endovascular techniques, with the prime example being thoracic endovascular aortic repair (TEVAR). However, many controversies concerning the use of TEVAR in TBAD exist. For instance, there is little available evidence suggesting any differences in demographics, disease characteristics, intervention technicalities, and clinical outcomes between males and females as well as different ethnicities when undergoing TEVAR for TBAD, both in the short and long term. Also, there is no risk prediction model/tool available. The objective of this international study is to describe and delineate the disparities between male and female patients of different ethnicities in terms of demographics, disease and interventional characteristics, and clinical outcomes.

METHODS

Over 17 years a total of 58 TBAD patients were admitted to 2 tertiary vascular centres and treated using TEVAR. Mortality, postoperative complications and reintervention data were recorded for the first 30 days after the procedure as well as during follow-up. Follow-up for all patients lasted until the study endpoint or until a patient's death. Data were analysed retrospectively using IBM SPSS statistical package 26 for Windows.

RESULTS

The mean age was similar between the 2 groups, with the majority of patients in both being Caucasian. More than half of the males had complicated TBAD, while the majority of females were classed as having uncomplicated disease. The most commonly utilized proximal and distal landing zone for the TEVAR stent graft was zone 2 and zone 4, respectively. The mean proximal stent diameter was significantly larger in males compared to females (P = 0.004). The difference in mean distal diameter between the 2 groups was insignificant (P = 0.721). The mean total stent coverage of the thoracic aorta was 251.3 mm in male patients compared to 291.2 mm in females (P = 0.203). A total of 32 patients underwent adjunctive procedures. Seven (17%) of the males had one or more postoperative complications compared to 2 (12%) females. Nine (22%) males underwent a reintervention procedure post TEVAR compared to only 1 (6%) female (P = 0.136). Overall, males had a mortality rate of 24% (n = 10) compared to 41% of females (n = 7) (P = 0.201). Estimated survival of males and females post TEVAR was 80.4 ± 9.6 months and 69.7 ± 14.4 months (P = 0.428). For the total population, the number of stent grafts was inversely correlated with mortality.

CONCLUSIONS

Despite the favourable clinical outcomes achieved by TEVAR in TBAD, there remains a grey area concerning its management. Thus, it is important to perform risk stratification of individual patients using their demographics and comorbidities, particularly scrutinizing patient sex and ethnic origin, when considering intervention for TBAD to achieve optimum results.

Coronary artery involvement in type A aortic dissection: Fate of the coronaries

BACKGROUND

Type A aortic dissection (TAAD) involves a tear in the intimal layer of the thoracic aorta proximal to the left subclavian artery, and hence, carries a high risk of mortality and morbidity and requires urgent intervention. This dissection can extend into the main coronary arteries. Coronary artery involvement in TAAD can either be due to retrograde extension of the dissection flap into the coronaries or compression and/or blockage of these vessels by the dissection flap, possibly causing myocardial ischemia. Due to the emergent nature of TAAD, coronary involvement is often missed during diagnosis, thereby delaying the required intervention.

AIMS

The main scope of this review is to summarize the literature on the incidence, mechanism, diagnosis, and treatment of coronary artery involvement in TAAD.

METHODS

A comprehensive literature search was performed using multiple electronic databases, including PubMed, Ovid, Scopus and Embase, to identify and extract relevant studies.

RESULTS

Incidence of coronary artery involvement in TAAD was seldom reported in the literature, however, some studies have described patients diagnosed either preoperatively, intraoperatively following aortic clamping, or even during autopsy. Among the few studies that reported on this matter, the treatment choice for coronary involvement in TAAD was varied, with the majority revascularizing the coronary arteries using coronary artery bypass grafting or direct local repair of the vessels. It is well-established that coronary artery involvement in TAAD adds to the already high mortality and morbidity associated with this disease. Lastly, the right main coronary artery was often more implicated than the left.

CONCLUSION

This review reiterates the significance of an accurate diagnosis and timely and effective interventions to improve prognosis. Finally, further large cohort studies and longer trials are needed to reach a definitive consensus on the best approach for coronary involvement in TAAD.

Cardiothoracic surgery leadership and learning are indispensable to each other

Cardiothoracic surgery is facing a multitude of challenges in leadership and training on the global scale, these being a complex and aging patient population, shortage of cardiac surgeons, diminishing student interest and trainee enthusiasm, increasingly challenging training obstacles and work-life imbalances, suboptimal job prospects, reports of discrimination and bullying and lack of diversity as well as gap between innovation and technology, clinical application, and training of future surgeons. The survival of cardiac surgery hinges on the leadership attracting and retaining young surgeons into the specialty. Mentoring, leading through example, recognizing the work-life imbalances, adapting to diverse and modern training models and embracing diversity with respect to gender and race, will ultimately be required to create and cultivate a nurturing environment of training and preparing future leaders. The vision for training future generations of cardiothoracic surgeons must rely heavily on strengthening the unity of the heart team. In doing so we can provide the best possible care for our patients and a most fulfilling career for the future generation of cardiac surgeons.

The motivators and barriers to a career in cardiothoracic surgery: a cross-sectional study among surgical residents in India

Introduction

A consistent decline in the number of applicants to cardiothoracic and vascular surgery (CTVS) training programs has been observed across the country over the last few years. This disenchantment with the speciality will lead to a shortage of trained CTVS surgeons at a time when incidence of cardiovascular diseases is continuously rising in India.

Aims/Objectives

The aim of the study was to reflect on the reasons that averted applicants from pursuing a career in CTVS and measures that would make CTVS a more attractive option to future applicants.

Methods

An online nationwide prospective cross-sectional survey was conducted. The participants were from a pool of general surgery residents/residents who had just completed the training. A 5-point Likert scale was utilized to rate and evaluate the factors influencing CTVS as the primary choice, factors influencing any super-speciality, and factors that would aid in decision-making and encourage an interest in CTVS.

Results

A total of 618 responses were obtained, 25.6% (N = 158) of the responses were from female residents. Only 10.7% (N = 66) of the respondents wanted to pursue CTVS as their primary choice. While interest in CTVS among the 1st year residents was 26%, it was further observed to decline to 18.72% after completion of training. The main disincentives for pursuing CTVS were the need for a hospital with required infrastructure and the dependence on a multi-disciplinary team. The perception of the participants that the cardiologist will take over CTVS procedures was another misguided but important factor. Those residents interested in pursuing CTVS identified the dynamic nature of the speciality as well as the thrills of being a cardiac surgeon as important motivators. Participants felt that adding catheter-based technology to the CTVS curriculum, mandatory CTVS rotation during surgical training, and closer interaction with CTVS residents will generate more interest in CTVS.

Conclusion

Although surgical residents report early interest in CTVS, a lack of adequate exposure to the speciality leads to a decline in interest in CTVS. An overhaul of the surgical training that mandates rotating to CTVS, increased interactions with medical students and surgical trainees by CTVS faculty, and incorporation of catheter-based training in the CTVS syllabus is urgently required to increase the number of applicants to CTVS.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-022-01406-2.

Cost analysis of thoracic endovascular aortic repair in type B aortic dissection: How much does quality cost?

BACKGROUND

Aortic dissection (AD) is a life-threatening medical emergency that affects an estimated 3-4 people per 100,000 annually, with 40% of cases classified as type B AD (TBAD). TBAD can be further classified as being complicated (co-TBAD) or uncomplicated (un-TBAD) based on the presence or absence of certain features such as malperfusion and rupture. TBAD can be managed conservatively with optimal medical therapy (OMT), or invasively with open surgical repair (OSR) or thoracic endovascular aortic repair (TEVAR), depending on several factors such as type of TBAD and its clinical acuity. The cost-effectiveness, or cost-benefit profile, of these strategies must be given equal consideration. However, TBAD studies featuring cost analyses are limited within the literature. This narrative review aims to address the gap in the literature on cost-effectiveness of TBAD treatments by providing an overview of cost analyses comparing OMT with TEVAR in un-TBAD and TEVAR with OSR in co-TBAD. Another aim is to provide a market analysis of the commercially available TEVAR devices.

METHODS

A comprehensive literature search was performed using several search engines including PubMed, Ovid, Google Scholar, Scopus, and Embase to identify and extract relevant studies.

RESULTS

Several TEVAR devices are available commercially on the global market costing $12,000-19,495. Nevertheless, the Terumo Aortic RELAY® stent graft seems to be the most cost-effective, yielding highly favourable clinical outcomes. Despite the higher initial cost of TEVAR, evidence in the literature strongly suggest that it is superior to OMT for un-TBAD on the long-term. In addition, TEVAR is well established in the literature as being gold-standard repair technique for co-TBAD, replacing OSR by offering a more optimal cost-benefit profile through lower costs and improved results.

CONCLUSIONS

The introduction of TEVAR has revolutionized the field of aortovascular surgery by offering a highly efficacious and long-term cost-effective treatment for TBAD.

Retroaortic left renal vein in open thoracoabdominal aneurysm repair: A modified approach

The incidence of retro aortic left renal vein (raLRV) in less than 6%. This anatomical variation will hinder the exposure and anastomosis of visceral arteries during open thoraco-abdominal aneurysm repair. This may warrant a division and ligation of the raLRV with the conventional retroperitoneal approach. This report describes a modified approach, wherein the vein is not divided without compromising the exposure for surgery.

Malperfusion syndrome in acute type A aortic dissection: It's not what you know, it's what you can prove!

Organ malperfusion after type A aortic dissection represents a high-risk group for open surgical repair. This is particularly the case when mesenteric ischemia occurs. Central aortic repair should be considered for all presenting with malperfusion as many are due to dynamic obstruction. However, depending on imaging and clinical appearance many should be considered for adjunctive techniques including catheter-based endovascular and even open surgical revascularisation may be appropriate. This is due to as many as 20% with a static component to the malperfusion syndrome. Improving methods of ascertaining the type of malperfusion being treated and presenting symptoms requires a multidisciplinary team with access to a hybrid theater where all techniques can be accessed 24/7. This would only be achieved by centralization of vascular units whereby sufficient funding and organization are in place to deal with the consequences of this unpredictable and invariably deadly aortic pathology.

The misnomer of uncomplicated type B aortic dissection

BACKGROUND

Acute type B aortic dissection (TBAD) is a rare condition that can be divided into complicated (CoTBAD) and uncomplicated (UnCoTBAD) based on certain presenting clinical and radiological features, with UnCoTBAD constituting the majority of TBAD cases. The classification of TBAD directly affects the treatment pathway taken, however, there remains confusion as to exactly what differentiates complicated from uncomplicated TBAD.

AIMS

The scope of this review is to delineate the literature defining the intervention parameters for UnCoTBAD.

METHODS

A comprehensive literature search was conducted using multiple electronic databases including PubMed, Scopus, and EMBASE to collate and summarize all research evidence on intervention parameters and protocols for UnCoTBAD.

RESULTS

A TBAD without evidence of malperfusion or rupture might be classified as uncomplicated but there remains a subgroup who might exhibit high-risk features. Two clinical features representative of "high risk" are refractory pain and persistent hypertension. First-line treatment for CoTBAD is TEVAR, and whilst this has also proven its safety and effectiveness in UnCoTBAD, it is still being managed conservatively. However, TBAD is a dynamic pathology and a significant proportion of UnCoTBADs can progress to become complicated, thus necessitating more complex intervention. While the "high-risk" UnCoTBAD do benefit the most from TEVAR, yet, the defining parameters are still debatable as this benefit can be extended to a wider UnCoTBAD population.

CONCLUSION

Uncomplicated TBAD remains a misnomer as it is frequently representative of a complex ongoing disease process requiring very close monitoring in a critical care setting. A clear diagnostic pathway may improve decision making following a diagnosis of UnCoTBAD. Choice of treatment still predominantly depends on when an equilibrium might be reached where the risks of TEVAR outweigh the natural history of the dissection in both the short- and long-term.

Frozen elephant trunk in acute type A aortic dissections: frontiers and challenges

Acute type A aortic dissection (ATAAD), a surgical emergency, has high mortality and morbidity. More than half of the patients die within 2 weeks and the 30-day mortality is 90%. Frozen elephant trunk in ATAAD addresses the primary and secondary goals - resection of the primary tear in the ascending aorta and promoting remodelling in the downstream aorta. Though the literature supports this fact, in reality these literatures emerge from high-volume centres. But in the "real world" most of the ATAAD are operated on in the low-volume centres. Furthermore, in India, there are unique challenges including the financial burden, transport, emergent availability of the hybrid prosthesis and aortic supercentres.

A giant ascending aortic aneurysm in a patient with previous aortic valve replacement

A 64-year male presented with dyspnoea for 2 months. At age of 40 years, he underwent aortic valve replacement. Presently, his echocardiogram reveals a normal functioning prosthetic valve, moderate left ventricular dysfunction and a large ascending aortic aneurysm. A computer tomography aortogram shows a large ascending aortic aneurysm (maximum diameter: 12.2×13.5cm, length: 11.9cm). He underwent prosthetic valve-sparing aortic root replacement with hemiarch replacement. To our best of knowledge, this is the largest reported ascending aortic aneurysm among the Asian population.

Exploring the Correlation and Protective Role of Diabetes Mellitus in Aortic Aneurysm Disease

Introduction: Diabetes mellitus is recognised as a significant risk factor for cardiovascular and peripheral vascular disease, as the abnormal metabolic state increases the risk for atherosclerosis, occlusive arterial disease and vascular dysfunction. There have been reports of potential association across the literature that illustrates a link between diabetes mellitus and aortic aneurysm, with the former having a protective role on the development of the latter.

Methods: A thorough literature search was performed through electronic databases, to provide a comprehensive review of the study's reporting on the association of diabetes mellitus and aortic aneurysm, discussing the mechanisms that have been reported; furthemore, we reviewed the reports of the impact of oral hypoglycameic agents on aortic aneurysms.

Results: Various proposed mechanisms are involved in this protective process including endothelial dysfunction, chronic hyperglycemia and insulin resistance. The evidence suggests a negative association between these disease process, with prevelance of diabetes mellitus resulting in lower rates of aortic aneurysm, via its protective mechanistic action. The increase in advanced glycation end products, increased arterial stiffness and vascular remodelling seen in diabetes, was found to have a profound impact on aneurysm development, its slow progression and lower rupture rate in these individuals. This review has also highlighted the role of oral hypoglycaemic agents having a protective effect against AA disease.

Conclusion: A decrease in development, progression and mortality from aortic aneurysms as well as reduced rates of dissection, have been observed in those with diabetes. This review has provided a comprehensive insight on the effect of diabetes and its physiological processes, and elements of its con-committant treatment, having a protective role against these aortic diseases.

Paving the way for E-vita open NEO hybrid prosthesis implantation for complex aortic arch disease in Asia-Pacific

We report first in man implantations of the newly designed Evita-open-NEO hybrid prosthesis for complex aortic arch disease from three different countries in Asia-Pacific including instructions on how to proceed with perioperative coagulation management.

COVID-19: An Indian perspective

Lockdown, quarantine, self-isolation, personal protection equipment, and social distancing have become words of daily usage ever since the world health organization declared coronavirus disease 2019 (COVID-19) as a pandemic. The impact of COVID-19 extends over the medical field, economy, education, and politics. Though the knowledge of the virus is evolving, we are yet to find a solution. India, country with the second largest population, went into a phase of lockdown from 25th March 2020 to 31st May 2020. There was phased measure to "Unlock" starting from 1st June 2020. This has affected the clinical practice and training of the resident. The challenges faced during this unprecedented time are multifaceted which includes overcrowding, healthcare system, and educational background. Indian Association of Cardiovascular-Thoracic Surgeons kept continuing the educational program through a series of "Masterclass."

Left subclavian artery management in frozen elephant trunk: A novel technique

Proximilization of frozen elephant trunk (FET) necessitates the ligation and reimplantation of the left subclavian artery (LSA), the origin of which is distal and posterior, make rerouting difficult and cumbersome. We describe a rather simple technique for subclavian artery exposure and effective anatomical reconstruction in the mediastinum coupled with hybrid FET utilization for aortic aneurysm in elective and nonelective settings. The division of the sternocleidomastoid coupled with the sandbag behind the left shoulder brings the LSA superficial enabling anastomosis without any difficulty.

Narrowing of the dark valve: aortic stenosis in alkaptonuria

The commonest cardiac pathology in patients with alkaptonuria is aortic stenosis. Patients with alkaptonuria and aortic stenosis may remain asymptomatic until the 6th decade. Surgeons may have to deal with per-operative difficulties as alkaptonuria is a systemic disease. Proper preoperative planning is important. The mechanical valve prosthesis is advisable in a patient with alkaptonuria and aortic stenosis considering disease pathophysiology. We report a 70-year-old male diagnosed with alkaptonuria and aortic stenosis, who underwent aortic valve (mechanical valve prosthesis) and ascending aorta replacement.

Frozen elephant trunk in acute type A aortic dissection: surgical techniques and the extracorporeal circuit management

Acute type A aortic dissection (ATAAD) is a challenging clinical condition with immediate and late complications. Frozen elephant trunk (FET) has been offered as a solution for it promises to address the late complications-false lumen thrombosis and aortic remodelling. Here, we describe the implantation of the FET in ATAAD with the surgical technique and extracorporeal circuit management. A 54-year-old male presented with retrograde type A aortic dissection with an entry point distal to the left subclavian artery. He underwent FET using Thoraflex™ hybrid vascular prosthesis (Vascutek, Inchinnan, Scotland). Three-month follow-up showed a complete obliteration of the false lumen in the descending thoracic aorta. FET in ATAAD is a valid option in the hands of experienced surgeons, while patient selection still remains the key in this surgery.

An Indian study: impact of COVID-19 on clinical decision-making and consensus in cardiac surgery practice across the country

PURPOSE

There is a paucity of evidence and guidelines to support clinical decisions in the present unprecedented time. We aimed to use the experience and consensus of the cardiac surgeons for clinical decisions until evidence-based guidelines are formed.

METHODS

An electronic questionnaire was emailed to all the 1434 members of the Indian Association of Cardiovascular and Thoracic Surgery, starting from May 13, 2020, and the members were followed up with reminder emails. For a wider reach, social media like WhatsApp was also used to circulate the questionnaire. Participation was voluntary and anonymized. An effective consensus was considered when > 70% opted the same opinion, and moderate consensus when > 50% opted the same opinion.

RESULTS

A total of 174 responses were obtained from the surgeons across the country. An effective consensus was obtained for the following: (i) emergency surgery in acute type A aortic dissection, (ii) urgent surgery in significant left main stem disease and mitral/aortic valves with pulmonary oedema, (iii) elective surgery in stable triple vessel disease and (iv) preoperative nasal swab examination for all patients undergoing surgery.

CONCLUSION

In the present era, where evidence is evolving and the country is entering a phase after lockdown, the surgeons face a dilemma in operating patients. These consensuses provide interim recommendation; still further evidence is published.

IACTS guidelines: practice of cardiovascular and thoracic surgery in the COVID-19 era

Patients undergoing cardiovascular and thoracic procedures are at an accentuated risk of higher morbidity and mortality, which are a consequence of the proliferative nature of the severe acute respiratory syndrome-corona virus 2 (SARS-CoV-2) on the lung vasculature, which in turn reflects as a cascading effect on the interdependent physiology of the cardiovascular and pulmonary organ systems. These are secondary to systemic inflammatory response syndrome and immunosuppressive responses to surgery and mechanical ventilation. Thus, the need to establish guidelines for the practice of cardiothoracic surgery which is safe for both the patient and the healthcare team presents as a priority, which is the mainstay of this article.

Aortopathy in tetralogy of Fallot-a collective review

The pathophysiology of aortic diseases in Tetralogy of Fallot has been analyzed in various studies, focusing on the histopathology of the aortic root, altered hemodynamics, and effect of early corrective repair on the incidence of aortic root dilatation. In this review article, we sought to integrate these studies for a better understanding of the natural history and practical implications of aortic root dilatation in Tetralogy of Fallot. This better equips us to appropriately implement potentially effective interventions.

Cerebellar processing of sensory inputs primes motor cortex plasticity

Plasticity of the human primary motor cortex (M1) has a critical role in motor control and learning. The cerebellum facilitates these functions using sensory feedback. We investigated whether cerebellar processing of sensory afferent information influences the plasticity of the primary motor cortex (M1). Theta-burst stimulation protocols (TBS), both excitatory and inhibitory, were used to modulate the excitability of the posterior cerebellar cortex and to condition an ongoing M1 plasticity. M1 plasticity was subsequently induced in 2 different ways: by paired associative stimulation (PAS) involving sensory processing and TBS that exclusively involves intracortical circuits of M1. Cerebellar excitation attenuated the PAS-induced M1 plasticity, whereas cerebellar inhibition enhanced and prolonged it. Furthermore, cerebellar inhibition abolished the topography-specific response of PAS-induced M1 plasticity, with the effects spreading to adjacent motor maps. Conversely, cerebellar excitation had no effect on the TBS-induced M1 plasticity. This demonstrates the key role of the cerebellum in priming M1 plasticity, and we propose that it is likely to occur at the thalamic or olivo-dentate nuclear level by influencing the sensory processing. We suggest that such a cerebellar priming of M1 plasticity could shape the impending motor command by favoring or inhibiting the recruitment of several muscle representations.

Survival of Ornithobacterium rhinotracheale in sterilized poultry litter

Ornithobacterium rhinotracheale (ORT) has been associated with respiratory disease, increased mortality, retarded growth, and decreased egg production in chickens and turkeys. Surveillance of exposure to ORT infection in the field has shown that prevalence of the infection is higher during winter months. The ability of ORT to remain viable in the poultry litter was studied at different temperatures over time. Presterilized poultry litter was inoculated with 10(11) colony-forming units of ORT and kept at -12 C, 4 C, 22 C, 37 C, and 42 C. Reisolation and titration of ORT from litter was attempted at intervals. Results indicate that ORT survived for 1 day at 37 C, 6 days at 22 C, 40 days at 4 C, and at least 150 days at -12 C. ORT did not survive 24 hr at 42 C. The survival of ORT at lower temperatures may be associated with the higher incidence of ORT infection in poultry during winter months.