Auto-Pericardial Mitral Valve Implantation: A Pilot Study.

INTRODUCTION: Developing nations continue to grapple with rheumatic heart disease, particularly in the young. There is a need for an alternative to prosthetic mitral valve replacement in irreparable mitral valves, which avoids the need for anticoagulation and risks of thromboembolism. METHODS: Twelve (12) patients with irreparable severe mitral valve disease underwent auto-pericardial mitral valve implantation from August 2020 to February 2021. The mitral valve leaflets were excised. Autologous pericardium treated with 0.5% glutaraldehyde for 8 minutes was fashioned into anterior and posterior mitral leaflets as per the dimensions on an indigenously designed template based on the studies by Ranganathan and Lam. The pericardial leaflets were sutured onto an appropriately sized mitral annuloplasty ring. The ring with the leaflets was implanted onto the mitral annulus. The leaflets were supported with neo-chordae prepared with Gore-Tex (W L Gore and Associates, Inc. Newark, DE, USA) and polyester sutures to mimic a repaired mitral valve in its structure and dynamics. RESULTS: The mean cross-clamp time was 138±21.7 minutes. None of the patients required re-exploration. On the third postoperative day, a mean mitral valve orifice area of 3±0.47 cm and mean mitral valve gradient of 2±1.04 were observed. None of the patients had any more than 1+ mitral regurgitation. None of them have required a re-intervention for mitral insufficiency to date. DISCUSSION: Auto-pericardial mitral valve re-implantation is a safe and effective procedure for severe, irreparable, mitral valve pathologies. However, the mid-term and long-term results need to be compared with conventional mitral valve replacement with a prosthetic valve in a randomised controlled trial.

Rheumatic Heart Disease in India in 2020: Advances in Diagnostic and Therapeutic Options.

Rheumatic Fever (RF)/ Rheumatic Heart Disease (RHD) is the result of autoimmune response triggered by group A Beta-haemolytic streptococcal pharyngitis leading to immune-inflammatory injury to cardiac valves. It is practically disappeared in developed countries. However, it continues to be a major cause of disease burden among children, adolescents, and young adults in low-income countries and even in high-income countries with socioeconomic inequalities. For decades, many cases of Acute Rheumatic Fever (ARF) and RHD were missed and were denied the secondary prophylaxis, as a result these patients used to end up with complications and untimely death. Advanced understanding of the echocardiography can prevent both under diagnosis and over diagnosis and thus help in management strategy. Another new advancement in recent past is the mitral valve repair, which is technically demanding, and the results are acceptable in experienced cardiac surgical units. Whenever feasible, valve repair should be preferred over valve replacement since it precludes the need for anticoagulation and future risks of prosthesis dysfunction.

The String Puppet Technique to Improve Exposure in Totally Endoscopic Mitral Valve Surgery.

AIM: To determine the feasibility of the string puppet technique as a flexible, dynamic alternative to atrial retractors in totally endoscopic non-robotic mitral and tricuspid valve surgeries. METHOD: Fifty-one (51) consecutive patients were operated on for totally endoscopic mitral valve repair from July 2017 to February 2018. A 3 cm peri-areolar (males) or submammary (females) incision was placed on the right chest. The thoracic cavity was accessed via the fourth intercostal space. A temporary pacing wire was placed transcutaneously as a puppeteering sling in the thoracic cavity under endoscopic vision. Multicoloured sutures were used to expose the right atrium and interatrial septum by weaving and suspending the sutures on the sling. The sling was tightened to pull up the walls of the cardia and manipulate them externally, like a puppet on a string, to improve selective exposure. RESULTS: We were able to obtain adequate exposure of the mitral and tricuspid valves in all patients without the use of atrial retractors. No patient required conversion to sternotomy due to lack of exposure. None of our patients had postoperative mitral regurgitation of more than 1+ over a mean follow-up of 2 years. CONCLUSIONS: The string puppet technique improves exposure of mitral and tricuspid valves in totally endoscopic cardiac surgery. It is safe, effective, easy to perform, and inexpensive.

Toward the development of a polarimetric tool to diagnose the fibrotic human ventricular myocardium.

SIGNIFICANCE: Optical polarimetry is an emerging modality that effectively quantifies the bulk optical properties that correlate with the anisotropic structural properties of cardiac tissues. We demonstrate the application of a polarimetric tool for characterizing healthy and fibrotic human myocardial tissues efficiently with a high degree of accuracy. AIM: The study was aimed to characterize the myocardial tissues from the left ventricle and right ventricle of N = 7 control and N = 10 diseased subjects. The diseased subjects were composed of two groups: N = 7 with rheumatic heart disease (RHD) and N = 3 with myxomatous valve (MV) disease. APPROACH: A portable, affordable, and accurate linear polarization-based diagnostic tool is developed to measure the degree of linear polarization (DOLP) of the myocardial tissues while working at a wavelength of 850 nm. RESULTS: The sensitivity, specificity, and accuracy of the polarimetric tool in distinguishing the control group from the RHD group were found to be 73.33%, 76.92%, and 75%, respectively, and from the MV group were 91.6%, 62.5%, and 80%, respectively, which demonstrates the efficacy of the polarimetric tool to distinguish the healthy myocardial tissues from diseased tissues. CONCLUSIONS: We have successfully developed a polarimetric tool that can aid cardiologists in characterizing the myocardial tissues in conjunction with endomyocardial biopsy. This work should be followed up with experiments on a large cohort of control and diseased subjects. We intend to create and develop a probe to quantify the DOLP of in vivo heart tissue during surgery.

PROSE: Prospective Randomized Trial of the On-X Mechanical Prosthesis and the St Jude Medical Mechanical Prosthesis Evaluation: Part 2: Study results-prostheses, positions, and economic development.

Objectives: The Prospective Randomized On-X Mechanical Prosthesis Versus St Jude Medical Mechanical Prosthesis Evaluation (PROSE) trial purpose was to investigate whether a current-generation mechanical prosthesis (On-X; On-X Life Technologies/Artivion Inc) reduced the incidence of thromboembolic-related complications compared with a previous-generation mechanical prosthesis (St Jude Medical Mechanical Prosthesis; Abbott/St Jude Medical). This second report documents the valve-related complications by individual prostheses and by Western and Developing populations. Methods: The PROSE trial study was conducted in 28 worldwide centers and incorporated 855 subjects randomized between 2003 and 2016. The study enrollment was discontinued on August 31, 2016. The study protocol, and analyses of 10 demographic variables and 24 risk factors were published in detail in 2021. Results: The total patient population (N = 855) included patients receiving an On-X valve (n = 462) and a St Jude Medical valve (n = 393). The overall freedom evaluation showed no differences at 5 years between the prostheses for thromboembolism or for valve thrombosis. There were also no differences in mortality. There were several differences between Developing and Western populations. The freedom relations at 5 years for mortality favored Western over Developing populations. Valve thrombosis was differentiated by position and site: aortic < mitral (P = .007) and Western < Developing (P = .005). In the mitral position there were no cases in Western populations, whereas there were 8 in Developing populations (P = .217). Conclusions: The On-X valve and St Jude Medical valve performed equally well in the study with no differences found. The only differentiation occurred with valve thrombosis in the mitral position more than the aortic position and occurring in Developing more than Western populations. The occurrence of valve thrombosis was also related to a younger population possibly due to anticoagulation compliance based on record review.

PROSE: Prospective Randomized Trial of the On-X Mechanical Prosthesis and the St Jude Medical Mechanical Prosthesis Evaluation : Part 1(Patient Dynamics): Preoperative demographics and preoperative and operative risk factors.

OBJECTIVES: The PROSE trial purpose is to investigate whether the incidence of thromboembolic-related complications is reduced with a current generation mechanical prosthesis (On-X Life Technologies/CryoLife Inc.-On-X) compared with a previous generation mechanical prosthesis (St Jude Medical-SJM). The primary purpose of the initial report is to document the preoperative demographics, and the preoperative and operative risk factors by individual prosthesis and by Western and Developing populations. METHODS: The PROSE study was conducted in 28 worldwide centres and incorporated 855 subjects randomized between 2003 and 2016. The study enrollment was discontinued on August 31, 2016. The preoperative demographics incorporated age, gender, functional class, etiology, prosthetic degeneration, primary rhythm, primary valve lesion, weight, height, BSA and BMI. The preoperative and operative evaluation incorporated 24 risk factors. RESULTS: The total patient population (855) incorporated On-X population (462) and the St Jude Medical population (393). There was no significant difference of any of the preoperative demographics between the On-X and SJM groups. The preoperative and operative risk factors evaluation showed there was no significant difference between the On-X and St Jude Medical populations. The preoperative and operative risk factors by valve position (aortic and mitral) also documented no differentiation. The dominant preoperative demographics of the Western world population were older age, male gender, sinus rhythm, aortic stenosis, congenital aortic lesion, and mitral regurgitation. The dominant demographics of the Developing world population were rheumatic etiology, atrial fibrillation, aortic regurgitation, mixed aortic lesions, mitral stenosis and mixed mitral lesions. The Developing world group had only one significant risk factor, congestive heart failure. The majority of the preoperative and operative risk factors were significant in the Western world population. CONCLUSIONS: The preoperative demographics do not differentiate the prostheses but do differentiate the Western and Developing world populations. The preoperative and operative risk factors do not differentiate the prostheses BUT do differentiate the Western and Developing world populations.

Universal trends in human cough airflows at large distances.

Coughs are one of the primary means of transmission of diseases such as influenza and SARS-CoV-2 (COVID-19). Disease spreading occurs by the expulsion of pathogen containing aerosol droplets. Fine droplets can pass through layers of masks and are carried away by the exhaled airflow unlike larger droplets that settle down due to gravity. Hence, it is important to quantitatively assess the maximum distance of travel of typical human coughs with and without different types of masks. Even though near field data are available near the mouth, far field data are scarce. In this study, the schlieren method that is a highly sensitive, non-intrusive flow visualization technique is used. It can directly image weak density gradients produced by coughs. An assessment of different methods of covering the mouth while coughing is arrived at by using observations from high speed schlieren images. The effectiveness of coughing into the elbow is examined. The velocity of propagation of coughs and the distance of propagation with and without masks are quantified. It is also found that normalizing the distance-velocity profiles causes all the data to collapse onto a universal non-dimensional curve irrespective of the usage of different types of masks or test subjects. Visualization of cough flow fields and analysis of experimental data reveal that the flow physics is governed by the propagation of viscous vortex rings.

Autologous pericardial aortic valve reconstruction: early results and comparison with mechanical valve replacement.

INTRODUCTION: Autologous pericardial aortic valve reconstruction is an attractive option compared with prosthetic valve replacement due to the absence of anticoagulation, lower pressure gradient across the valve and excellent valve haemodynamics. OBJECTIVE: We wanted to share the early results of autologous pericardial aortic valve reconstruction from our centre. The outcomes were compared with that of mechanical valve replacement. MATERIALS AND METHODS: Between August 2016 to July 2018, 20 patients underwent autologous aortic valve reconstruction as per the techniques described by Ozaki et al. The surgery was done for aortic stenosis or regurgitation or a combination of both. All the surgeries were done by a single experienced surgeon. The results were compared to that of mechanical valve replacement. A comprehensive echocardiographic evaluation was done pre-discharge and at 6 months after surgery. The postoperative echocardiographic parameters that were evaluated include aortic valve pressure gradient, aortic valve orifice area, ejection fraction, left ventricular diameters etc. All the parameters were measured by a single expert. Other perioperative parameters were also evaluated like cardiopulmonary bypass and cross-clamp time, need for anticoagulation etc. Statistical analysis was done using chi-square test/Mann-Whitney U test/independent sample t test. RESULTS: Autologous pericardial aortic valve reconstruction had several favourable results including lower aortic valve pressure gradient, bigger aortic valve orifice area etc. None of the patients required anticoagulation. There were no conversions to prosthetic valve replacement or reinterventions in the follow-up period. CONCLUSION: Autologous pericardial aortic valve reconstruction is a feasible alternative to prosthetic valve replacement with several advantages.

Perioperative management of a patient with glanzmann's thrombasthenia for mitral valve repair under cardiopulmonary bypass.

A 30-year-old male patient presented with Glanzmann's thrombasthenia and mitral valve prolapse. He was in acute decompensated congestive heart failure due to severe mitral and tricuspid regurgitation. After his cardiac failure had been stabilized, the patient was subjected to mitral and tricuspid valve repair. His transfusion requirements were guided by thrombelastography and his bleeding disorder was managed by infusing single donor plasmapheresed platelet transfusions in the perioperative period. The patient underwent surgery uneventfully.

Myocardial preservation: controlled reperfusion.

Reperfusion injury after reestablishing coronary flow by releasing the aortic cross clamp after cardiac surgery with cardioplegic arrest causes myocardial damage and even death. Attenuation of this reperfusion response by controlling the biochemical and physical environment can avoid morbidity and mortality. Use of a warm reperfusate with addition of drugs that are known to decrease reperfusion injury with manipulation of coronary vascular resistance and the physical parameters of the reperfusion environment helps the heart to reestablish coronary perfusion while decreasing the harm produced by the period of ischemia that occurs during cardiac surgery with intermittent cardioplegic arrest.

Giant mediastinal thymolipoma simulating cardiomegaly.

Thymolipomas are rare anterior mediastinal tumors composed of mature adipose tissue and benign thymic tissue and they may rarely simulate cardiomegaly on chest radiograph. We report an adult male who presented with progressive dyspnea of 2 months' duration. Clinical examination was unremarkable. Chest radiograph showed enlarged cardiac silhouette. Computed tomography of chest revealed a giant anterior mediastinal noncontrast enhancing mass partially wrapping around the heart. A needle biopsy obtained lymphomatous material that was diagnosed as thymolipoma. The tumor was successfully removed en bloc through a median sternotomy. Histopathological examination confirmed thymolipoma. We emphasize the importance of considering mediastinal tumors as a differential diagnosis in patients with progressive dyspnea without any obvious cause and chest radiograph showing enlarged cardiac silhouette.