Atresia of the descending aorta in a young woman requiring bypass graft

Congenital aortic atresia is a malformation accounting for 4 - 6% of all congenital heart diseases in children. Left ventricular outflow obstruction due to atresia is common at the aortic valve but rarely has atresia been identified in the descending aorta. We report the case of a 25-year woman who was evaluated for headache and uncontrolled hypertension. CTscan chest showed a short atretic segment in the descending aorta at the isthmus, distal to the takeoff of the subclavian artery. She underwent surgery; a 22 mm Dacron graft was taken and jump graft was placed between the arch of the aorta and the descending aorta, using partial occlusion clamps. Patient tolerated the procedure well and was discharged on ACE Inhibitors and beta blockers, which were then weaned off over a period of one year. She remained stable and had no further complaints

Resection of posterior mediastinal tumors by video assisted thoracic surgery

Abstract This case report illustrates successful Video Assisted Thoracic Surgery (VATS) performed on a 45-year-old woman and 52-year-old man presenting with a mass in left and right paravertebral space on the CT scan respectively. VATS has many benefits over traditional open operation (thoracotomy), resulting in less pain and shorten recovery time. However, VATS has higher equipment cost but when an experienced surgeon performs the surgery, better outcomes are achieved. VATS is not common in Pakistan\u27s surgical setup as it is an expensive method of eradicating mediastinal pathologies and not every patient undergoes VATS. The primary objective of presenting these cases is to promote the use of VATS specifically for removal of posterior mediastinal tumors and improve the surgical outcomes

Successful tricuspid valvectomy in a septic patient with tricuspid valve endocarditis

Abstract Endocarditis is characterized by vegetations, which is a mass of platelets, fibrin, micro-colonies of micro-organisms, and inflammatory cells, in the endocardium. Over the past three decades, the incidence of right-sided endocarditis has risen dramatically in Pakistan. We report a 36-year woman with a history of repeated intravenous analgesic injections for low back pain, presenting with high grade fever, sepsis and a white cell count of 44,000 with 90% neutrophils. Echocardiography showed large mobile vegetations on TricuspidValve (TV). Tricuspid Valve Endocarditis (TVE) is generally responsive to medical treatment; however, about 25% of TVE patients require surgical intervention. Long-term survival of a patient is possible without a prosthetic TV replacement, particularly if the pulmonary artery pressure is normal

Superior septal approach versus left atrial approach for mitral valve replacement: a retrospective cohort study

Abstract OBJECTIVE: To compare the outcomes of superior septal approach and left atrial approach for mitral valve replacement. METHODS: This retrospective cohort study was conducted at the Aga Khan University Hospital, Karachi, and comprised records of patients who had undergone isolated mitral valve replacement from May 2003 to April 2012. Cases were reviewed for the outcomes [primary: loss of normal sinus rhythm; secondary: complications, residual defect and mortality]. Patients with prior history of dysrhythmia, low ejection fraction (\u3c30%), emergency/redo mitral valve replacement and concomitant coronary artery bypass grafting were excluded. SPSS 19 was used for data analysis. RESULTS: Of the 78 patients, 52(66.67%) were of superior septal approach and 26(33.33%) of left atrial approach. Both groups were comparable for baseline variables except cardiopulmonary bypass and cross-clamp times, which were significantly shorter in the superior septal approach group than the left septal approach group (p\u3c0.05). No residual atrial septal defect was found in any approach. Although loss of normal sinus rhythm was observed more frequent in superior septal approach 25(48%) compared to left septal approach 10(38.4%), but the difference was statistically insignificant (p=0.28). Age was the only significant variable affecting loss of normal sinus rhythm after adjusting for approaches. The difference of post-operative complications was also statistically insignificant between superior 9(17.3%) and left septal approach 4(15.38%) (p=1.0)]. CONCLUSIONS: The operative durations were significantly higher in left atrial approach compared to superior septal approach

Radiation pattern synthesis in conformal antenna arrays using modified convex optimization technique

In this paper, a modified convex optimization technique is used for radiationpattern correction in a cylindrical-shaped conformal microstrip array antenna.The technique uses numerical simulations to optimize the amplitude andphase excitations, with the goal to decrease the Euclidean distance betweenthe desired field pattern and the obtained (simulated/measured) field patternwhile maintaining the main beam direction, null's location, and side lobelevels under control. Two prototypes of 1 4 and 2 4 conformal microstripantenna array deformed from linear/planar structure to the prescribed cylin-drical shape, with different radii of curvature, are studied to demonstrate theperformance of the proposed technique. The proposed convex optimizationmodel when applied to conformal antenna array possesses fast computingspeed and high convergence accuracy for radiation pattern synthesis, whichcan be a valuable tool for engineering applications.Dr. Mohammad Alibakhshikenari acknowledges supportfrom the CONEX-Plus programme funded by Universidad Carlos III de Madrid and the European Union's Horizon 2020 research and innovation programme under theMarie Sklodowska-Curie grant agreement No. 801538

EH-UWSN: Improved Cooperative Routing Scheme for UWSNs Using Energy Harvesting

The harsh testing environments of underwater scenarios make it extremely hard to plan a reasonable routing protocol for Underwater Sensor Networks (UWSNs). The main challenge in UWSNs is energy confinement. It is needed to plan an energy effective scheme which increases the life span of the network and also reduces the energy usage in data transfer from supplier to sink. In this research, we present the design of a routing protocol known as Energy Harvesting in UWSN (EH-UWSN). EH-UWSN is a compact, energy efficient, and high throughput routing protocol, in which we present utilization of energy gaining with coordinating transfer of data packets through relay nodes. Through Energy Harvesting, the nodes are capable to recharge their batteries from the outside surrounding with the ultimate objective to improve the time span of network and proceed data through cooperation, along with restricting energy usage. At the sink node, the mixing plan applied is centered on Signal-to-Noise Ratio Combination (SNRC). Outcomes of EH-UWSN procedure reveal good results in terms of usage of energy, throughput, and network life span in comparing with our previous Cooperative Routing Scheme for UWSNs (Co-UWSN). Simulation results show that EH-UWSN has consumed considerably lesser energy when compared with Co-UWSN along with extending network lifetime and higher throughput at the destination

Impact of the COVID-19 pandemic on patients with paediatric cancer in low-income, middle-income and high-income countries: a multicentre, international, observational cohort study

OBJECTIVES: Paediatric cancer is a leading cause of death for children. Children in low-income and middle-income countries (LMICs) were four times more likely to die than children in high-income countries (HICs). This study aimed to test the hypothesis that the COVID-19 pandemic had affected the delivery of healthcare services worldwide, and exacerbated the disparity in paediatric cancer outcomes between LMICs and HICs. DESIGN: A multicentre, international, collaborative cohort study. SETTING: 91 hospitals and cancer centres in 39 countries providing cancer treatment to paediatric patients between March and December 2020. PARTICIPANTS: Patients were included if they were under the age of 18 years, and newly diagnosed with or undergoing active cancer treatment for Acute lymphoblastic leukaemia, non-Hodgkin's lymphoma, Hodgkin lymphoma, Wilms' tumour, sarcoma, retinoblastoma, gliomas, medulloblastomas or neuroblastomas, in keeping with the WHO Global Initiative for Childhood Cancer. MAIN OUTCOME MEASURE: All-cause mortality at 30 days and 90 days. RESULTS: 1660 patients were recruited. 219 children had changes to their treatment due to the pandemic. Patients in LMICs were primarily affected (n=182/219, 83.1%). Relative to patients with paediatric cancer in HICs, patients with paediatric cancer in LMICs had 12.1 (95% CI 2.93 to 50.3) and 7.9 (95% CI 3.2 to 19.7) times the odds of death at 30 days and 90 days, respectively, after presentation during the COVID-19 pandemic (p<0.001). After adjusting for confounders, patients with paediatric cancer in LMICs had 15.6 (95% CI 3.7 to 65.8) times the odds of death at 30 days (p<0.001). CONCLUSIONS: The COVID-19 pandemic has affected paediatric oncology service provision. It has disproportionately affected patients in LMICs, highlighting and compounding existing disparities in healthcare systems globally that need addressing urgently. However, many patients with paediatric cancer continued to receive their normal standard of care. This speaks to the adaptability and resilience of healthcare systems and healthcare workers globally

Twelve-month observational study of children with cancer in 41 countries during the COVID-19 pandemic

Childhood cancer is a leading cause of death. It is unclear whether the COVID-19 pandemic has impacted childhood cancer mortality. In this study, we aimed to establish all-cause mortality rates for childhood cancers during the COVID-19 pandemic and determine the factors associated with mortality