Surendra Kumar Agarwal

Failure of devices used for closure of atrial septal defects: Mechanisms and management

Various devices for transcatheter ASD closure are undergoing clinical trials. Each new device claims advantages in terms of safety and efficacy over earlier devices. We report three cases in which a new investigational device--the Das angel wings--failed. Emergency operations were necessary for device retrieval and defect closure. The possible mechanisms of the event and the options in management are discussed with a review of literature on all devices.

Cardiac surgery and cold-reactive proteins

Cold agglutinins are commonly found in sera of healthy persons. They rarely become clinically apparent due to their activity at low temperatures. In these patients, cardiovascular operations requiring hypothermia can result in complications such as hemolysis, renal failure, and myocardial damage and can cause unexpected morbidity and mortality. The literature on cold-reactive proteins is reviewed, and methods of diagnosis and management related to cardiac surgery are suggested. Ideally all patients should be routinely tested preoperatively for the antibodies, and appropriate changes in cardiopulmonary bypass and myocardial management plans should be made in positive patients. Preoperative plasmapheresis may be a useful adjunct, especially in patients requiring operation under profound hypothermia and circulatory arrest. Currently, warm heart surgery appears to be the most expedient method. Unexpected detection of agglutination during operation or hemolysis after operation requires a specific treatment plan.

Therapeutic Dosing of Acenocoumarol: Proposal of a Population Specific Pharmacogenetic Dosing Algorithm and Its Validation in North Indians

Objectives To develop a population specific pharmacogenetic acenocoumarol dosing algorithm for north Indian patients and show its efficiency in dosage prediction. Methods Multiple and linear stepwise regression analyses were used to include age, sex, height, weight, body surface area, smoking status, VKORC1 -1639 G>A, CYP4F2 1347 G>A, CYP2C9*2,*3 and GGCX 12970 C>G polymorphisms as variables to generate dosing algorithms. The new dosing models were compared with already reported algorithms and also with the clinical data for various performance measures. Odds ratios for association of genotypes with drug sensitive and resistant groups were calculated. Results The pharmacogenetic dosing algorithm generated by multiple regression analysis explains 41.4% (p-value <0.001) of dosage variation. Validation of the new algorithm showed its predictive ability to be better than the already established algorithms based on similar variables. Its validity in our population is reflected by increased sensitivity, specificity, accuracy and decreased rates of over- and under- estimation in comparison to clinical data. The VKORC1-1639 G>A polymorphism was found to be strongly associated with acenocoumarol sensitivity according to recessive model. Conclusions We have proposed an efficient north India specific pharmacogenetic acenocoumarol dosing algorithm which might become a baseline for personalised medicine approach for treatment of patients in future.

Mitral Valve Replacement in Severe Pulmonary Arterial Hypertension

The immediate postoperative hemodynamics in 43 patients with severe pulmonary arterial hypertension who underwent mitral valve replacement between January 2000 and September 2001 were studied prospectively. The mean age was 30.6 years. There was mitral stenosis in 19 (44.1%), mitral regurgitation in 9 (20.9%), and mixed lesions in 15 (34.9%). In 36 patients (83.7%, group 1) pulmonary arterial pressure was sub-systemic, with a mean of 58.1 mm Hg and pulmonary vascular resistance of 743.4 dyne·s·cm−5. Seven patients (16.3%, group 2) had supra-systemic pulmonary arterial pressure of 83.2 mm Hg and pulmonary vascular resistance of 1,529 dyne·s·cm−5. Lung biopsies were taken from the right lower lobe in 24 patients. Operative mortality was 5.5% in group 1 and 28.5% in group 2. After mitral valve replacement, the pulmonary arterial pressure and vascular resistance decreased significantly in group 1. In group 2, pulmonary arterial pressure decreased significantly but pulmonary vascular resistance remained elevated. Pulmonary vascular changes did not progress beyond grade III (Heath-Edwards’ classification). Mitral valve replacement is safe even in the presence of severe pulmonary arterial hypertension as long as pulmonary arterial pressures are below systemic pressures. Lung biopsy did not help in identifying patients with irreversible pulmonary arterial changes.

Emergency cardiopulmonary bypass for impassable airway.

INTRODUCTION Some medical emergencies need compromised airway management as the first measure. Most of these cases are first seen by an ENT surgeon, whose proper evaluation and timely intervention can prove decisive. Knowledge of alternatives for airway management can prove life-saving, although these may require the active involvement of other specialities. CASE REPORTS Two patients, a 27-year-old man and a 31-year-old woman, presented in respiratory distress with cyanosis. Each had a pedunculated mass in the lower trachea above the carina, with about 90 per cent tracheal lumen obstruction. They were managed successfully with femorofemoral cardiopulmonary bypass and restoration of airway. CONCLUSION Femorofemoral cardiopulmonary bypass can be a relatively safe option which gains time for airway management in such conditions. Knowledge of this procedure among ENT surgeons can lead to timely intervention, in properly selected cases, which can save valuable time.

Pulmonary arterial hypertension in rheumatic mitral stenosis: does it affect right ventricular function and outcome after mitral valve replacement?

Right ventricular function affects the outcome in valvular heart disease but less is known about the relation between indices of dysfunction and outcome. Seventy patients undergoing mitral valve replacement between April 2007 and April 2008 for predominant rheumatic mitral stenosis were included in the study. Two groups were formed based on right ventricular systolic pressure (RVSP), <or=40 mmHg (group I, n=16) and >41 mmHg (group II, n=54). Right ventricle (RV) function indices were studied by echocardiography. RVSP reduced significantly in group II (P=0.0001) but not in group I. Brain natriuretic peptide (BNP) was raised in all cases and reduced significantly postoperatively. Tricuspid annular plane excursion, myocardial performance index, RV descent and tricuspid valve annular shortening (TV shortening) conformed to RV dysfunction in both groups, and did not change significantly postoperatively. Regression analysis for outcome revealed TV shortening as the only significant factor (P=0.03). Receiver operating characteristic of TV shortening and adverse outcome showed worse outcome with TV shortening of <11%. RV dysfunction was observed in all cases irrespective of RVSP. TV shortening of <11% was associated with adverse outcome. Postoperative fall in BNP levels may indicate a trend towards recovery.

Coronary pseudoaneurysm in a non-polymer drug-eluting stent: a rare entity

Coronary pseudoaneurysms following implantation of drug-eluting stents, although rare, are not unknown. Nearly all such cases have been reported in patients with sirolimus or paclitaxel polymer-based stents. We describe a case of coronary pseudoaneurysm developing with a non-polymer-based drug-eluting stent in a 50-year-old man who was successfully managed by coronary artery bypass grafting.

Valvuloplasty in the Treatment of Rheumatic Tricuspid Disease

Organic involvement of the tricuspid valve is uncommon. Valve repair is preferred over replacement as it results in a low gradient across the valve and obviates the risk of prosthesis-related complications. From October 2002 to October 2004, 37 patients who required tricuspid valve repair for organic involvement were included in this study. They were divided into 2 groups depending on the surgical procedure for valve repair: 20 patients in group 1 had tricuspid commissurotomy and De Vega annuloplasty; 17 in group 2 had tricuspid commissurotomy only. There were significant reductions in peak and mean tricuspid gradients and right ventricular systolic pressure in both groups. Annular shortening was similar in both groups (median, 23% in group 1, 21% in group 2), but the ratio of the tricuspid regurgitation jet area to right atrial area was greater in group 2 (median, 0.40 in group 2, 0.19 in group 1). There was no postoperative death. We recommend supporting the tricuspid annulus with annuloplasty in patients with organic tricuspid valve disease and no dilatation of the annulus, if annular shortening is < 30%.

Management of difficult airway in intratracheal tumor surgery

BackgroundTracheal malignancies are usual victim of delay in diagnosis by virtue of their symptoms resembling asthma. Sometimes delayed diagnosis may lead to almost total airway obstruction. For difficult airways, not leaving any possibility of manipulation into neck region or endoscopic intervention, femorofemoral cardiopulmonary bypass can be a promising approach.Case PresentationWe are presenting a case of tracheal adenoid cystic carcinoma (cylindroma) occupying about 90% of the tracheal lumen. It was successfully managed by surgical excision of mass by sternotomy and tracheotomy under femorofemoral cardiopulmonary bypass (CPB).ConclusionAny patient with recurrent respiratory symptoms should be evaluated by radiological and endoscopic means earlier to avoid delay in diagnosis of such conditions. Femorofemoral cardiopulmonary bypass is a relatively safe way of managing certain airway obstructions.

Role of an operative score in mitral reconstruction in dominantly stenotic lesions.

OBJECTIVE The role of an operative score in selection and results of mitral valve reconstruction in dominantly stenotic mitral lesions was assessed. METHODS A total of 136 patients consecutively underwent reconstruction for rheumatic mitral stenosis with or without regurgitation from December 1989 through December 1994. Mitral valve structure was scored for cuspal pliability and thickness, cuspal area loss, chordal length, papillary muscle length, annular dilatation and degree of associated regurgitation and calcification. A score of 0 indicated normal valve while a score of 24 indicated a grossly deformed valve. Age, sex, functional class, cardiac rhythm, mitral valve orifice area, left ventricular and left atrial dimensions, transmitral gradients, pulmonary artery pressures and thoroughness of repair were evaluated. RESULTS Mitral valve architecture was disorganised moderately in 50 (37%) and severely in 69 (52%) patients. Extent of thoroughness in different operative techniques correlated with good (n = 30) or adequate (n = 60) outcome. Mean mitral valve orifice area increased from 0.77 +/- 0.2 to 2.56 +/- 0.6 cm2, peak gradient dropped from 20.3 +/- 6.2 to 8.6 +/- 3.5 torr, mean gradient from 13.5 +/- 4.9 to 4.76 +/- 2.2 torr and end-diastolic gradient from 10.1 +/- 5.0 to 3.2 +/- 1.9 torr. Lack of recognition of anatomical details and of all necessary componental measures constituted the learning curve of different operators. CONCLUSIONS Recurrent disease, learning curve, inadequate repair and higher operative mitral valve score were the factors for poorer results in the intermediate term follow-up to 64 months. Thoroughness of repair was the most important correlate of outcome and indicative of expertise.