Iatrogenic Anomalous Origin of the Right Pulmonary Artery From the Aorta: A Rare Complication of Ligation of Aortopulmonary Window.

An aortopulmonary window (APW) is a communication between the main pulmonary artery (MPA) and the ascending aorta in the presence of two separate semilunar valves. Surgical strategies described for the management of APW include ligation, division and suturing, patch closure of APW (transaortic or transpulmonary or transwindow), and device closure. Ligation of a type-2 APW can result in stenosis or complete closure of the right pulmonary artery (RPA) off the MPA, while leaving the aorta still opening into the RPA. We describe a delayed presentation of iatrogenic anomalous origin of the RPA from the aorta, post APW ligation, and its management.

Harlequin effect and central veno-arterial extracorporeal life support.

"Harlequin effect" may be observed in the watershed region of a patient with pulmonary dysfunction, receiving peripheral veno-arterial extracorporeal membrane oxygenation via the femoral vessels. In such cases, retrograde oxygenated blood from the peripheral inflow cannula converges with the antegrade deoxygenated blood ejected from the left ventricle. This occurs when the left ventricle is ejecting significantly but the recovery of pulmonary function lags behind. Herein, we describe the occurrence of "Harlequin effect" in the setting of central veno-arterial extracorporeal membrane oxygenation that ensues due to the persistence of right ventricular dysfunction in the presence of an interatrial communication. This results in right to left shunting at the atrial level while weaning the patient from extracorporeal life support.

The Role of Shunt Occlusion During Extracorporeal Life Support.

INTRODUCTION: The current recommendation for systemic to pulmonary artery shunt (SPS) patients requiring extracorporeal life support (ECLS) is to keep the shunt open, maintaining a higher pump flow. The practice in our center is to totally occlude the shunt while on ECLS, and we are presenting the outcome of this strategy. METHODS: This is a retrospective analysis of patients who underwent SPS for cyanotic congenital heart disease with decreased pulmonary blood flow and required postoperative ECLS between January 2016 and December 2020. ECLS indication was excessive pulmonary blood flow, leading to either refractory low cardiac output syndrome (LCOS) or cardiac arrest. All patients had their shunts totally occluded soon after ECLS establishment. RESULTS: Of the 27 SPS patients who needed postoperative ECLS (13 refractory LCOS, 14 extracorporeal cardiopulmonary resuscitation), wherein the strategy of occluding the shunt on ECLS initiation was followed, 16 (59.3 %) survived ECLS weaning and eight (29.6%) survived to discharge. CONCLUSION: Increased flow to maintain systemic circulation for a SPS patient while on ECLS is an accepted strategy, but it should not be applied universally. A large subset of SPS patients, who require ECLS either due to cardiac arrest or refractory LCOS due to excessive pulmonary flow, might benefit from complete occlusion of the shunt soon after commencement of ECLS, especially in cases with frank pulmonary edema or haemorrhage in the pre-ECLS period. A prospective randomized trial could be ethically justified for the subset of patients receiving ECLS for the indication of excessive pulmonary blood flow.

The Role of Shunt Occlusion During Extracorporeal Life Support

ABSTRACT Introduction: The current recommendation for systemic to pulmonary artery shunt (SPS) patients requiring extracorporeal life support (ECLS) is to keep the shunt open, maintaining a higher pump flow. The practice in our center is to totally occlude the shunt while on ECLS, and we are presenting the outcome of this strategy. Methods: This is a retrospective analysis of patients who underwent SPS for cyanotic congenital heart disease with decreased pulmonary blood flow and required postoperative ECLS between January 2016 and December 2020. ECLS indication was excessive pulmonary blood flow, leading to either refractory low cardiac output syndrome (LCOS) or cardiac arrest. All patients had their shunts totally occluded soon after ECLS establishment. Results: Of the 27 SPS patients who needed postoperative ECLS (13 refractory LCOS, 14 extracorporeal cardiopulmonary resuscitation), wherein the strategy of occluding the shunt on ECLS initiation was followed, 16 (59.3 %) survived ECLS weaning and eight (29.6%) survived to discharge. Conclusion: Increased flow to maintain systemic circulation for a SPS patient while on ECLS is an accepted strategy, but it should not be applied universally. A large subset of SPS patients, who require ECLS either due to cardiac arrest or refractory LCOS due to excessive pulmonary flow, might benefit from complete occlusion of the shunt soon after commencement of ECLS, especially in cases with frank pulmonary edema or haemorrhage in the pre-ECLS period. A prospective randomized trial could be ethically justified for the subset of patients receiving ECLS for the indication of excessive pulmonary blood flow.

Abnormally proximal aortic origin of the brachiocephalic artery: Surgical implications.

Abnormal proximal aortic origin of the brachiocephalic artery is a very rare condition. It can occur in isolation or associated with complex congenital heart disease affecting the right ventricular outflow tract. Its recognition carries relevant surgical implications for the safe conduct of cardiopulmonary bypass and for any surgical procedures that directly involve the proximal ascending aorta and its branches.

A Novel Surgical Technique to Address Post-Septal Myectomy Ventricular Septal Defect.

Iatrogenic ventricular septal defect is a rare complication in patients undergoing septal myectomy for hypertrophic obstructive cardiomyopathy, and it necessitates closure in the postoperative period. We describe a novel surgical technique for closure of the ventricular septal defect using a biventricular approach with a custom-made polytetrafluoroethylene device. Our method is easily reproducible.

Coronavirus disease 2019 convalescent children: outcomes after congenital heart surgery.

BACKGROUND: Children with exposure to coronavirus disease 2019 in recent times (asymptomatic or symptomatic infection) approaching congenital heart surgery programme are in increasing numbers. Understanding outcomes of such children will help risk-stratify and guide optimisation prior to congenital heart surgery. OBJECTIVE: The objective of the present study was to determine whether convalescent coronavirus disease 2019 children undergoing congenital heart surgery have any worse mortality or post-operative outcomes. DESIGN: Consecutive children undergoing congenital heart surgery from Oct 2020 to May 2021 were enrolled after testing for reverse transcription-polymerase chain reaction or rapid antigen test and immunoglobulin G antibody prior to surgery. Convalescent coronavirus disease 2019 was defined in any asymptomatic patient positive for immunoglobulin G antibodies and negative for reverse transcription-polymerase chain reaction or rapid antigen test anytime 6 weeks prior to surgery. Control patients were negative for any of the three tests. Mortality and post-operative outcomes were compared among the groups. RESULTS: One thousand one hundred and twenty-nine consecutive congenital heart surgeries were stratified as convalescence and control. Coronavirus disease 2019 Convalescent (n = 349) and coronavirus disease 2019 control (n = 780) groups were comparable for all demographic and clinical factors except younger and smaller kids in control. Convalescent children had no higher mortality, ventilation duration, ICU and hospital stay, no higher support with extracorporeal membrane oxygenation, high flow nasal cannula, no higher need for re-intubations, re-admissions, and no higher infections as central line-associated bloodstream infection, sternal site infection, and ventilator-associated pneumonia on comparison with coronavirus disease 2019 control children. CONCLUSIONS: Convalescent coronavirus disease 2019 does not have any unfavourable outcomes as compared to coronavirus disease 2019 control children. Positive immunoglobulin G antibody screening prior to surgery is suggestive of convalescence and supports comparable outcomes on par with control peers.

Veno-arterial extracorporeal membrane oxygenation: Special reference for use in 'post-cardiotomy cardiogenic shock' - A review with an Indian perspective.

The ultimate goals of cardiovascular physiology are to ensure adequate end-organ perfusion to satisfy the local metabolic demand, to maintain homeostasis and achieve 'milieu intérieur'. Cardiogenic shock is a state of pump failure which results in tissue hypoperfusion and its associated complications. There are a wide variety of causes which lead to this deranged physiology, and one such important and common scenario is the post-cardiotomy state which is encountered in cardiac surgical units. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is an important modality of managing post-cardiotomy cardiogenic shock with variable outcomes which would otherwise be universally fatal. VA-ECMO is considered as a double-edged sword with the advantages of luxurious perfusion while providing an avenue for the failing heart to recover, but with the problems of anticoagulation, inflammatory and adverse systemic effects. Optimal outcomes after VA-ECMO are heavily reliant on a multitude of factors and require a multi-disciplinary team to handle them. This article aims to provide an insight into the pathophysiology of VA-ECMO, cannulation techniques, commonly encountered problems, monitoring, weaning strategies and ethical considerations along with a literature review of current evidence-based practices.

Effect of sub-toxic exposure to Malathion on glucose uptake and insulin signaling in L6 myoblast derived myotubes.

Biochemical basis of Malathion exposure-induced diabetes mellitus is not known. Hence, effects of its sub-toxic exposure on redox sensitive kinases (RSKs), insulin signaling and insulin-induced glucose uptake were assessed in rat muscle cell line. In this in vitro study, rat myoblast (L6) cells were differentiated to myotubes and were exposed to sub-toxic concentrations (10 mg/l and 20 mg/l) of Malathion for 18 hours. Total antioxidant level and insulin-stimulated glucose uptake by myotubes were assayed. Activation of JNK, NFκB, p38MAPK and insulin signaling from tyrosine phosphorylation of insulin receptor substrate-1 (IRS-1) and serine phosphorylation of Akt were assessed in myotubes after Malathion exposure by western blot and was compared with those in controls. Paraoxonase (PON) activity was measured in cell lysate using p-nitrophenyl acetate as substrate. PON1 and PON2 expression in myotubes were assessed by PCR. The glucose uptake and total antioxidant level in L6-derived myotubes after sub-toxic exposure to Malathion were decreased in a dose-dependent manner. Phosphorylation levels of RSKs (JNK, p38MAPK and IκBα component of NFκB) were increased and that of IRS-1 and Akt on insulin stimulation was decreased following Malathion exposure as compared to those in controls. PON1 and PON2 genes were expressed in myotubes with and without Malathion exposure. Significant PON activity was present in cell lysate. We conclude that sub-toxic Malathion exposure induces oxidative stress in muscle cells activating RSKs that impairs insulin signaling and thereby insulin-stimulated glucose uptake in muscle cells. This probably explains the biochemical basis of Malathion-induced insulin resistance state and diabetes mellitus.

Effect of sub-toxic chlorpyrifos on redox sensitive kinases and insulin signaling in rat L6 myotubes.

OBJECTIVES: Sub-chronic exposures to chlorpyrifos, an organophosphorus pesticide is associated with incidence of diabetes mellitus. Biochemical basis of chlorpyrifos-induced diabetes mellitus is not known. Hence, effect of its sub-toxic exposure on redox sensitive kinases, insulin signaling and insulin-induced glucose uptake were assessed in rat muscle cell line. METHODS: In an in vitro study, rat myoblasts (L6) cell line were differentiated to myotubes and then were exposed to sub-toxic concentrations (6 mg/L and 12 mg/L) of chlorpyrifos for 18 h. Then total anti-oxidant level in myotubes was measured and insulin-stimulated glucose uptake was assayed. Assessment of activation of NFκB & p38MAPK and insulin signaling following insulin stimulation from tyrosine phosphorylation of insulin receptor substrate-1 (IRS-1) and serine phosphorylation of Akt were done in myotubes after chlorpyrifos exposure by western blot (WB) and compared with those in vehicle-treated controls. RESULTS: The glucose uptake and total antioxidant level in L6-derived myotubes after sub-toxic exposure to chlorpyrifos were decreased in a dose-dependent manner. As measured from band density of WB, phosphorylation levels increased for redo-sensitive kinases (p38MAPK and IκBα component of NFκB) and decreased for IRS-1 (at tyrosine 1222) and Akt (at serine 473) on insulin stimulation following chlorpyrifos exposure as compared to those in controls. CONCLUSION: We conclude that sub-toxic chlorpyrifos exposure induces oxidative stress in muscle cells activating redox sensitive kinases that impairs insulin signaling and thereby insulin-stimulated glucose uptake in muscle cells. This probably explains the biochemical basis of chlorpyrifos-induced insulin resistance state and diabetes mellitus.