Sreeja Pavithran

Hydrocortisone induced hypertrophic cardiomyopathy

A preterm infant developed recurrent, hypertrophic obstructive cardiomyopathy (HOCM) on administration of steroids which resolved after discontinuation of the drug. Following a course of hydrocortisone for treatment of broncho-pulmonary dysplasia, echocardiography showed left ventricular hypertrophy with outflow tract obstruction, resolving on stopping the drug, only to recur after a second course.

Analysis of explanted ePTFE cardiovascular grafts (modified BT shunt)

Structural, chemical, mechanical and surface changes were studied in expanded polytetrafluroethylene vascular grafts explanted from children undergoing planned surgical management of congenital heart disease. These grafts were implanted when recipients were aged 7 days to 8 years (median--48 weeks) and they had been in circulation for a period of 10-52 months (median--74 weeks). While no chemical changes were observed in the shunt, on average the tensile strength had decreased by 50%, total elongation by 61% and crystallinity by 3%. No salt deposits were observed on the surface of the graft. Soluble and insoluble proteins were bound to the polymer surface, which had made the surface hydrophilic. The external surface roughness had increased by 254.5 and the internal surface roughness by 2.6 times the initial value. The fine polymer structure had become fused and clumped. The fusing of strands on the polymer surface became more pronounced with longer duration of implantation. In one instance of previously documented graft stenosis, the heat capacity was found to be more than that of the unimplanted sample, indicating an increase in crystallinity. A longer period of study with a larger sample size would likely shed more light on the relation between physico-chemical changes and graft stenosis.

Atrial septostomy with a predefined diameter using a novel occlutech atrial flow regulator improves symptoms and cardiac index in patients with severe pulmonary arterial hypertension

A novel Occlutech atrial flow regulator (AFR) implantation gives an atrial septal predefined predictable fenestration.

A novel snare assistance safeguards against early embolization of devices and facilitates quick retrieval of malpositioned devices in atrial septal defects with deficient margins

Background : Embolization might complicate device closure of large atrial septal defects (ASDs) with deficient margins. When margins are deficient, a precariously placed device can appear to be held in good position by the rigid delivery cable. Once the cable is unscrewed, the device adopts the natural lie of the interatrial septum. This can occasionally expose the inadequately captured margins and lead to device embolization. Most embolizations occur immediately after release. Retrieval of the embolized device required prolonged fluoroscopy and sometimes open heart surgery. Objective : To evolve a new strategy of retrieval of a malpositioned device after unscrewing the cable before impending embolization. Materials and Methods : After deploying the device in place, a snare is passed through the delivery sheath around the cable to grip the screw on the right atrial disc of the device. With the snare holding the screw end, the device is released by unscrewing the cable. The device position is reconfirmed on echocardiography. The snare is subsequently removed if the device was stable. In case of device migration, the same snare is used to retrieve the device before it embolizes completely. Results : Snare assistance was used in 24 patients considered as high-risk for device embolization. Its usefulness was demonstrated in two patients with deficient posterior margin and small inferior margin where the device got malpositioned immediately after release. As the snare was still holding on to the screw end, the device could be retrieved into the sheath easily. Conclusion : This novel snare assisted device release strategy safeguards against device embolization in large ASDs with deficient rims and allows simplified retrieval.

Preliminary evaluation of a microtransesophageal probe in neonates and young infants undergoing surgery for congenital heart disease

Background: The larger size of the currently available transesophageal echocardiography (TEE) probes limits their use to relatively older infants undergoing cardiac surgery. In very young neonates and infants, epicardial echocardiogram is used to assess postoperative residual defects. Recently, a miniaturized microTEE probe compatible in neonates has been introduced for clinical use. We evaluated the use of this probe in small infants undergoing cardiac surgery. Materials and Methods: Thirty-three consecutive neonates and infants undergoing cardiac surgery at our institution were included in the study. Intraoperative echocardiography with Philips s8-3t microTEE probe done using IE33 platform was utilized to study the preoperative anatomy and assess postoperative results. Results: Thirty-three patients aged 3 days-2 years (mean 5.1 months) and weighing 2.5-11 kg (mean 4.4 kg) underwent perioperative evaluation using the microTEE probe. Good quality two-dimensional and color Doppler images were obtained in all patients. There were no complications related to the probe insertion or manipulation. The findings on microTEE led to revision of surgery in five patients. Certain echocardiographic parameters that could never be recorded with epicardial echocardiogram could be easily seen in microTEE. Conclusion: On preliminary evaluation, the microTEE probe provided good quality images in very small infants who were not amenable for transesophageal echocardiographic evaluation so far. The probe could be used safely in small infants without complications. It appears to be a promising imaging modality in the perioperative assessment of young infants undergoing cardiac surgery, in whom intraoperative epicardial echocardiography is currently the only tool.

The pressures of surgicel(®) in cardiac surgery.

Surgicel® is bioabsorbable hemostatic mesh, frequently packed around oozing surgical bed. We report two morbidities due to it. Following transannular patch repair for Fallot′s tetralogy, Surgicel® was packed around distal main pulmonary artery. Echocardiography in the intensive care unit (ICU) showed right ventricular dysfunction due to extrinsic obstruction and complete occlusion of left pulmonary artery (LPA) flows. Another patient with arterial switch operation had postoperative fibrillatory cardiac arrest, needing resuscitation with internal cardiac massage. The arrest was triggered by coronary ischemia due to periaortic compression. Both instances were caused by hygroscopic nature of Surgicel®, which absorbed blood, swelled, and compressed the luminal tissues.

Stent angioplasty of narrowed right ventricular outflow conduits and pulmonary arteries consistently reduces right ventricular systolic pressures and delays subsequent surgeries

OBJECTIVES Narrowed right ventricular (RV) outflow conduits and pulmonary arteries (PA) increase RV pressures and warrant interventions. Stent angioplasty is an alternative to more morbid redo-surgery in developing countries. We evaluate the efficacy and safety of stenting and assess need for redo-surgical reinterventions on midterm follow-up after stent angioplasty. METHODS Patients who underwent conduit, main PA and bilateral branch PA stenting for elevated RV pressures were analyzed retrospectively. Success was defined as 20% reduction in RV pressures or RV-aortic pressure ratio; 50% reduction in gradients or 50% increase of luminal diameter. Procedural results, complications and need for redo surgeries on follow-up were assessed. RESULTS Among 60 patients aged 1-46years, 57 were post-operative patients, who needed stenting at a median period of 48 months after surgery. Stenting succeeded in 98% and reduced RV pressures from 105.42±28.39mmHg to 54.46±16.89mmHg. Direct major procedural complications in five (8%) patients included procedural failure in one, stent migration in three and lung hemorrhage in one. None of the stented conduits needed a surgical change on a follow-up ranging 3-120 months. Following bilateral PA stenting in twenty-four patients, only two needed a repeat open-heart surgery during follow-up ranging 3-108 months. Catheter reinterventions on follow-up included elective percutaneous pulmonary valve implantation in nine patients and stent redilation in seven patients. CONCLUSIONS Stent angioplasty was safe and effective. Surgery was postponed in all stenosed conduits. Elective redilation of stents after bilateral PA stenting may be needed for somatic growth; but open-heart repeat surgeries can be avoided in a majority.

Surgical Repair of Interrupted Aortic Arch and Interrupted Pulmonary Artery

Interrupted aortic arch (IAA) is usually associated with ventricular septal defect and patent ductus arteriosus. We report surgical repair in a case of IAA, ventricular septal defect, and interruption of the pulmonary artery with the right pulmonary artery arising from the innominate artery through a separate ductus arteriosus.

Giant coronary artery aneurysms in a 58-year-old.

All giant Kawasaki aneurysms may not regress fully; some may eventually calcify, undergo thrombosis, and get detected in asymptomatic adults at later age. Tomisaku Kawasaki initially described this illness as mucocutaneous lymph node syndrome in childhood in 1967 and coronary arteritis was recognized later. We present a 58-year-old male, possibly one of the oldest surviving patients with giant coronary aneurysms who presented with large secundum atrial septal defect (ASD) with heart failure. This indicates that the disease was perhaps prevalent outside Japan even before the first Kawasakis description.