Robotically enhanced coronary artery bypass surgery.

Robotically enhanced telemanipulation surgery is a rapidly developing technique which enables totally endoscopic cardiac surgery with utmost precision and perfection on both beating heart and arrested heart. Between December 2002 and September 2006, 268 patients underwent robotically enhanced coronary artery bypass surgery using the da Vinci telemanipulation system. Fourteen patients underwent total endoscopic coronary artery bypass surgery. Of these 12 were performed on a beating heart and 2 on an arrested heart. Two-hundred and fifty-four patients had endoscopic takedown of the internal mammary artery followed by minimally invasive direct coronary artery bypass in 193 patients and left anterolateral thoracotomy in 61 patients. The internal mammary artery mobilization time was 36 min (28-76 min) and the left internal mammary artery to left anterior descending artery anastomosis time ranged from 20 to 36 min for the totally endoscopic coronary artery bypass patients. The right internal mammary artery of one patient was anastomosed to diagonal artery totally endoscopically. The mean internal mammary artery flow by Doppler measurement in patients undergoing minimally invasive direct coronary artery bypass was 58 ml min(-1). Seven patients required conversion to median sternotomy and coronary bypass surgery on the beating heart. The mean intensive care unit stay was 1.2 days and the mean hospital stay 4.5 days. There was one in-hospital mortality. All 14 patients who underwent total endoscopic bypass surgery had coronary angiography 3 months later which showed 100% patency in 13 patients. One patient had 50% anastomotic narrowing for which coronary angioplasty was performed in the same sitting. By using telematic technology, a complete endoscopic anastomosis is possible in both single vessels and suitable double vessel disease patients. The use of robotics is now extended to achieve complete myocardial revascularization by harvesting both the internal mammary arteries and making a small thoracotomy for direct anastomosis also.

Robotically enhanced coronary artery bypass surgery.

BACKGROUND: Robotically enhanced telemanipulation surgery is a fast developing technique which allows totally endoscopic cardiac surgery with utmost precision and perfection on both beating heart as well as arrested heart. METHODS AND RESULTS: Between December 2002 and February 2004, 125 patients underwent robotically enhanced coronary artery bypass surgery using the da Vinci telemanipulation system (Intuitive Surgical Inc., California). Eleven patients underwent totally endoscopic coronary artery bypass surgery. Of them 9 were done on beating heart while 2 were done on arrested heart. One hundred and fourteen patients had endoscopic takedown of internal mammary artery followed by minimally invasive direct coronary artery bypass in 63 patients and left anterolateral thoracotomy in 51 patients. The internal mammary artery mobilization time was 42 min (35-74 min) while the left internal mammary artery to left anterior descending artery anastomosis time ranged from 20 to 36 min for the totally endoscopic coronary artery bypass patients. In 1 patient, the right internal mammary artery was anastomosed to diagonal artery totally endoscopically. The mean internal mammary artery flow by Doppler measurement done in patients undergoing minimally invasive direct coronary artery bypass was 64 ml/min. Seven patients required conversion to median sternotomy and coronary bypass surgery on beating heart. The mean intensive care unit stay was 1.2 days and the mean hospital stay 4.5 days. There was 1 in-hospital mortality. All 11 patients who underwent totally endoscopic bypass surgery had coronary angiography done at 3 months interval which showed 100% patency in 10 patients while one patient had 50% anastomotic narrowing for which coronary angioplasty was done in the same sitting. CONCLUSIONS: Using telematic technology, a complete endoscopic anastomosis is possible in both single vessel and suitable double vessel disease patients. The use of robotics is now extended to achieve complete myocardial revascularization by harvesting both the internal mammary arteries and making a small thoracotomy for direct anastomosis as well.

Mitral valve replacement with chordal preservation in a rheumatic population.

BACKGROUND AND AIM OF THE STUDY: Mitral valve replacement (MVR) with preservation of the subvalvular apparatus may maintain postoperative left ventricular (LV) function better than conventional MVR. A prospective study was undertaken to assess the advantages of chordal preservation in rheumatic patients undergoing isolated MVR. METHODS: Between January 1996 and January 1999, 240 patients with rheumatic etiology and normal LV ejection fraction (>50%) underwent isolated MVR using a St. Jude Medical prosthesis. Patients were allocated to two groups: in group I (n = 168), both the anterior and posterior chordae were preserved; in group II (n = 72), the entire native mitral valve apparatus was excised. Patients from both groups were evaluated postoperatively (mean 12.5 months) by echocardiography and treadmill testing. RESULTS: Demographic and clinical profiles were comparable in both groups. There were three early deaths in group I, and one in group II. There were no late deaths. One patient in group I required reoperation for a stuck mitral prosthesis. LV function (ejection fraction >50%) was better in group I (94%) than in group II (82%) (p <0.05). No patient in either group had LV outflow tract obstruction on echocardiography. Patients in group I showed better exercise performance on treadmill (Bruce protocol): 92% of group I patients versus 88% of group II patients (p >0.05) completed stage I; 16% of group I patients, but no group II patients, were able to complete stage IV (p <0.05). CONCLUSION: Mitral valve replacement with preservation of the subvalvular apparatus maintains LV function, and does not cause LV outflow tract obstruction.

Pretreatment of human myocardium with adenosine.

OBJECTIVES: While the role of adenosine pretreatment in animals has been well established, the role in humans has been controversial. We performed this prospective, randomized study to find out the usefulness of adenosine pretreatment in humans. PATIENTS AND METHODS: Twenty patients undergoing coronary artery bypass surgery for severe triple vessel disease and left ventricular dysfunction (ejection fraction<35%) formed the study population. The adenosine group (n=10) received adenosine infusion (200 microg/kg) before aortic cross-clamp. The control group (n=10) received only normal saline injection. Cardiac function indices were assessed post-operatively. RESULTS: In the adenosine group there was a significant increase in cardiac output in the post-operative period from 3.46+/-1.06 to 4.46+/-0.92 l/min (P<<0.05). The cardiac index increased significantly in the adenosine group from 1.97+/-0.43 to 2.54+/-0.5 l/min per m2 (P<<0.05) and even when compared with the control group this increase was significant (adenosine group vs. control group, P=0.03). Systemic vascular resistance fell from 1898.8+/-558.4 to 1134.9+/-530.7 dyne/s per cm(-5) (P<<0.05) in the adenosine group. The pulmonary artery wedge pressure fell significantly in the adenosine group from 11.1+/-5.0 to 7.2+/-2.6 mmHg (P<<0.05). Patients in the adenosine group maintained a lesser increase in resting heart rate post-operatively (96.1+/-13.4 to 114.1+/-18.7 beats/min) (P=0.7), as compared to the control group where the increase in the heart rate was significant (77.1+/-8.3 to 109.7+/-14.9 beats/min) (P<<0.05). In the adenosine group only one patient (10%) had a raised creatine phosphokinase (MB) level at 12 h post-operatively as compared to three patients (30%) in the control group (P<0.05). CONCLUSIONS: Adenosine pretreatment appears to protect against reperfusion injury in human hearts and thus results in improved post-operative haemodynamics.

Isolated cardiac aspergillosis.

A 40-year-old man, a known case of Wolff-Parkinson-White syndrome, was admitted to the hospital in an unconscious state. In spite of medical treatment, the patient died within two hours of admission. At autopsy, the deceased was found to have aspergillosis involving the interatrial septum, aortic valve and root of the aorta. The rest of the organs were unremarkable. The patient did not show any obvious signs of being immunocompromised. We report this case of isolated cardiac aspergillosis in an apparently healthy individual.

Adenosine for cardioplegic induction: a comparison with St Thomas solution.

OBJECTIVE: To determine if quicker cardiac standstill obtained by adding adenosine to potassium crystalloid cardioplegia translated into better myocardial preservation and cardiac function in the early postoperative period compared with the same cardioplegia without adenosine. DESIGN: A prospective study. SETTING: Cardiac center of a teaching institute. PARTICIPANTS: Sixty consecutive patients with left main vessel or triple-vessel disease undergoing coronary artery bypass surgery under moderate hypothermia. INTERVENTIONS: The study comprised two groups of patients. Group N (n = 15) was the control group, given St Thomas cardioplegic solution after aortic cross-clamping, without adenosine; whereas group A (n = 45) received 250 microg/kg of adenosine into the aortic root after aortic cross-clamping, followed by the same St Thomas cardioplegia as in group N. The two groups were otherwise similar in all aspects of perfusion management. MEASUREMENTS AND MAIN RESULTS: Time taken to achieve cardiac standstill after aortic cross-clamping was significantly greater, 18.7+/-3.1 seconds, in the control group compared with the adenosine group, 3.4+/-0.9 seconds (p<0.001). The quicker arrest of the adenosine group led to better postoperative function, in the form of higher cardiac index (p<0.01), lower filling pressures (pulmonary artery wedge pressure) (p<0.05), and lower mean pulmonary artery pressure (p<0.05) at 6 hours. In the adenosine group, only 3 of 45 (6.6%) patients had elevated creatine phosphokinase (CPK) (MB) values greater than 50 U/L over preoperative CPK values compared with 3 of 15 (20%) in the control group (p<0.01). CONCLUSIONS: Injection of 250 microg/kg of adenosine into the aortic root before administration of cold crystalloid St Thomas cardioplegia solution after cross-clamping, in patients with severe coronary artery disease, produces significantly faster cardiac standstill, better myocardial preservation, and better cardiac function in the early postoperative period.

Reversal of slow flow phenomenon during primary stenting by bail-out administration of abciximab.

BACKGROUND: Slow flow or no reflow phenomenon is increasingly being recognized as a serious problem during coronary angioplasty and stenting. This phenomenon is seen more often during angioplasty in highly thrombogenic milieux, especially in a setting of acute myocardial infarction. The treatment of this complication is often not satisfactory. In this study the authors assessed the efficacy of abciximab, a potent antiplatelet drug, in treating slow flow or no reflow phenomenon during primary percutaneous transluminal coronary angioplasty (PTCA) for acute myocardial infarction (AMI). METHODS: Twenty-one instances of persistent slow flow phenomenon were encountered in 131 consecutive patients subjected to primary PTCA for AMI (16%). It was more common in patients presenting with AMI complicated by cardiogenic shock (nine of 21, 43%). Of these 21 cases of slow flow, 10 patients were given injection abciximab during the procedure of primary PTCA as a bail-out measure after encountering the complication of slow flow or no reflow. A pre-discharge coronary angiography was carried out in all patients who survived. RESULTS: In seven of 10 patients in the abciximab group flow had improved to TIMI-3. In contrast, in the non-abciximab group TIMI flow improved in only four of 11 patients. Patients with persistent slow flow had significantly higher mortality at the first 30-day follow-up than patients with TIMI-3 flow (33% versus 1.8%, p<0.001). CONCLUSION: In this small nonrandomized study significant improvement in coronary flow was achieved by using intravenous abciximab after observing slow flow or no reflow phenomenon during primary PTCA. More frequent use of this drug in this milieu might help in preventing the development of this complication. Larger studies are warranted to confirm this life-saving beneficial effect of bail-out administration of abciximab during primary angioplasty.

Cardiac myxomas: clinical and echocardiographic profile.

We reviewed our clinical and echocardiographic experience in 70 consecutive patients with 73 cardiac myxomas, diagnosed over an 11 year period. There were 21 males and 49 females, ages ranged from 18 to 80 years. Only in 5.7% cases was the diagnosis of myxomas made clinically. 88.6% cases were initially diagnosed as having: mitral valve disease (70%), tricuspid valve disease (10%), ischemic heart disease (5.7%), cardiomyopathy (2.9%), and the remaining 5.7% were detected during family screening and follow-up. The mean duration of symptoms was 10.6 months. The commonest symptom was dyspnoea (80%), followed by constitutional symptoms (45.7%), embolization (30%), palpitation (25.7%), syncope (15.7%), pedal oedema (15.7%) and pain chest (12.9%). The sites of myxomas were as follows: left atrium, 58; right atrium, 9; and, biatrium, 3. All myxomas except 3 were attached to the interatrial septum. The site, size, shape, attachment, mobility, prolapse into ventricle, and surface characteristic of myxomas were accurately assessed by 2D-echocardiography and confirmed in all (65 of 70) who underwent surgery. When the morphological characteristic of myxomas were studied and correlated with clinical features large left atrial myxoma size was closely related with constitutional symptoms, congestive heart failure, with syncope and auscultatory findings suggestive of mitral valve disease, whereas smaller myxoma size and irregular surface were associated with embolization. Constitutional symptoms were only present in left atrial myxoma. Post-operative mean echocardiographic follow-up of 60 months showed no recurrence except in 2 with familial myxoma. We conclude that the majority of myxomas mimic many cardiovascular diseases and were detected in symptomatic patients, so a high index of clinical suspicion is important for its early and correct diagnosis. The size and appearance of the myxomas correlated with the presenting symptoms.

Pulsed Doppler echocardiographic study of left ventricular diastolic function in patients with idiopathic dilated cardiomyopathy.

Dilated cardiomyopathy is basically regarded as a disease of left ventricular systolic dysfunction. There are only a few studies evaluating diastolic function in patients with dilated cardiomyopathy. To assess the LV diastolic function, 25 patients with idiopathic dilated cardiomyopathy and 20 age and sex matched normal subjects were studied with transmitral spectral tracings derived from pulsed Doppler echocardiography. All cardiomyopathy patients were in New York Heart Association class III to IV with dilated left ventricles and reduced systolic function (mean ejection fraction of 36.6 +/- 6.7 Vs 65 +/- 6 in normal subjects, p < 0.001). Patients with cardiomyopathy demonstrated an increased ratio of early to late diastolic velocity (E/A) (1.89 +/- 0.59 Vs 1.50 +/- 0.27 m/sec, p < 0.05), short deceleration time (E-E/2) (57.05 +/- 13.36 Vs 70.20 +/- 16.56 msec, p < 0.01) and short isovolumic relaxation time (IVRT) (53.5 +/- 22.7 Vs 72 +/- 12 msec, p < 0.05) as compared to normal subjects. The early filling fraction (EFF) was higher (0.71 +/- 0.11 Vs 0.66 +/- 0.06, p < 0.05) and atrial filling fraction (AFF) was lower (0.28 +/- 0.11 Vs 0.33 +/- 0.06, p < 0.05) in cardiomyopathy patients than in normal subjects. Our observations in a select group of dilated cardiomyopathy patients with advanced disease demonstrate a restrictive pattern on pulsed Doppler echocardiography.

Balloon mitral valvotomy: comparison between antegrade Inoue and retrograde non-transseptal techniques.

AIMS: The results of percutaneous mitral valvotomy performed by the antegrade transseptal method using the Inoue balloon (n = 1000; group 1) and by the retrograde non-transseptal technique using a polyethylene balloon (n = 100; group 2) were compared in a retrospective, non-randomized study. METHODS AND RESULTS: Both the groups were similar with respect to baseline characteristics. The success rate was 95% in group 1 and 93% in group 2. There was a significant increase in mitral valve area estimated by Gorlin's equation (Group 1: from 0.8 +/- 0.5 to 2.1 +/- 0.8 cm2; Group 2: from 0.8 +/- 0.3 to 1.9 +/- 0.8 cm2, both P < 0.001) and by Doppler echocardiography using the pressure half-time method (Group 1: from 0.9 +/- 0.4 to 2.2 +/- 0.6 cm2; Group 2: from 0.9 +/- 0.3 to 2.0 +/- 0.7 cm2, both P < 0.001). However, the calculated immediate post-valvotomy mitral valve area was larger with the Inoue technique (2.1 +/- 0.8 vs 1.9 +/- 0.8 cm2; (P < 0.02). Results were considered optimal when the mitral valve area increased to > or = 1.5 cm2, the percentage increase was > or = 50, and mitral regurgitation was < or = 2/4. Out of the total successful procedures, optimal results were obtained in 95% patients in Group 1 and 94% in Group 2. Incidence of significant mitral regurgitation (> or = grade 3/4) was similar in two groups (Group 1: 4% vs Group 2: 5%, P = ns). A significant left to right atrial shunt (Qp/Qs > or = 1.5:1) in 2.5% and tamponade in 2% of cases occurred exclusively with the Inoue technique, while conduction disturbances, such as transient (< 24 h) left bundle branch block (28%) and complete heart block (2%) were noted with the retrograde technique (Group 2). Local complications were significantly higher in Group 2 (3% vs 0.5%, P < 0.01). The procedure time with the Inoue technique was shorter than with the retrograde (Group 1: 15 +/- 8, range 10 to 35 min; Group 2: 22 +/- 14, range 15 to 45 min, P = 0.05). Echocardiographic follow-up at 1 year showed no significant difference in mitral valve area between the two groups (Group 1 (n = 300): 1.8 +/- 0.8 vs Group 2 (n = 60): 1.9 +/- 0.9 cm2; P = 0.3). CONCLUSIONS: Balloon mitral valvotomy using the Inoue balloon and the retrograde non-transseptal technique results in significant immediate haemodynamic and symptomatic improvement. The Inoue technique achieved a larger immediate post-valvotomy mitral valve area, but the difference was not apparent at 1 year follow-up. Incidence of significant mitral regurgitation was similar with both the techniques; however, local complications occurred more frequently with the retrograde technique. Both techniques may complement each other in technically difficult cases.

Predictors of arterial thrombosis after diagnostic cardiac catheterization in infants and children randomized to two heparin dosages.

Arterial thrombosis is the most frequent major complication of percutaneous arterial catheterization in children. We prospectively studied the effect of randomized dosage of heparin, 50 IU/kg-group I and 100 IU/kg-group II, on the incidence of arterial thrombosis in 366 children and analysed the various factors which may influence the occurrence of this complication. The age of patients ranged from 17 d to 11 yr (mean age 39.5 +/- 40.9 mo) and mean weight was 11.2 +/- 7.8 kg (range 3 to 39 kg). The incidence of arterial thrombosis was 9.8% in group I and 9.3% in group II (P = NS). There was no statistical difference in precatheterization and procedure variables in the two groups and also in the group with absent pulse (n = 35) to the group with pulse present post cath (n = 331). There were 24.9% infants in our study and 14.3% of these had arterial thrombosis. The loss of pulse was more often seen with more number of attempts at arterial puncture (P < 0.001), absence of back bleed at the end of the procedure (P < 0.001), and increased duration of catheterization (P < 0.01). Use of larger sheath size in a given weight and body surface area of children increased incidence of arterial thrombosis. The administration of heparin 50 IU/kg was equally efficacious to heparin 100 IU/kg. Of the patients with arterial thrombosis, 23 responded with intravenous heparin and 12 needed streptokinase. There was no bleeding or haematoma. Thus our study shows that less attempt for arterial puncture, use of smaller sheath size, maintaining shortest procedure time and ensuring back bleed minimises incidence of arterial thrombosis post catheterization.

Analysis of local electrograms at successful and unsuccessful sites for slow pathway ablation of atrioventricular nodal reentrant tachycardia.

Anatomic and electrogram approaches have been described for ablation of slow pathway in patients with atrioventricular nodal tachycardia. The purpose of this study was to identify parameters to predict successful slow pathway ablation using the anatomic approach. Local electrograms at successful and unsuccessful sites were compared in 36 patients undergoing slow pathway ablation using anatomic approach. A total of 208 local electrograms were studied. Fragmented atrial electrogram was seen in 24/36 (67%) of successful and in 46/172 (26%) of unsuccessful sites (p < 0.001). The sensitivity, specificity and positive and negative predictive values of fragmented atrial electrogram were 67, 73, 34 and 91 percent respectively. A slow pathway potential was noted in three of successful sites. There was no difference in the atrial to ventricular amplitude ratio in these sites. In conclusion, fragmentation of atrial electrogram and presence of possible slow pathway potential are seen more often at successful than at unsuccessful sites. In our opinion, while using an anatomic approach for slow pathway ablation, an analysis of local electrogram may help in identifying the proper site and avoiding unnecessary radiofrequency energy delivery.

Guide wire outer coat shearing and embolisation: an unusual complication of pericardiocentesis.

We report a case of shearing of the outer coat of the guide wire and its embolization into the pulmonary artery during pericardiocentesis. This unusual foreign body was successfully removed by pervenous method.

Transcatheter alcohol ablation of the septum in a patient of hypertrophic obstructive cardiomyopathy.

We performed transcatheter alcohol ablation of the septum in a case of hypertrophic obstructive cardiomyopathy. The patient showed marked reduction in LVOT gradient; however, he developed complete atrioventricular (AV) dissociation following the procedure, requiring AV sequential pacing. This important complication of this novel technique is highlighted.

Comparison of echocardiographic acoustic quantification system and radionuclide ventriculography for estimating left ventricular ejection fraction: validation in patients without regional wall motion abnormalities.

Echocardiographic automated border detection of blood-endocardium interface is made on the basis of the principle of acoustic quantification. The automated border system is capable of providing on-line left ventricular (LV) cavity area and function. Recently, ABD algorithms have been devised to estimate LV volume on line from a long-axis image, calculated by established area-length method or Simpson's formula. To test the clinical validity of this newly developed echocardiographic method, LV volumes and ejection fraction measured by real-time acoustic quantification were compared with radionuclide ejection fraction in 24 subjects on the same day. Patients were included in the study if > or = 75% of their endocardium was visualized with conventional two-dimensional echocardiography. Sixteen (66%) of 24 patients had a technically adequate conventional echocardiogram with a broad range of ventricular dimensions and systolic function. None of the study patients had regional wall motion abnormalities. Echocardiographic measurements were obtained from the LV apical four-chamber, long-axis view. Ejection fraction, determined by the acoustic quantification and by radionuclide ventriculography, showed a strong linear relation (r = 0.92, standard error of the estimate = 4.4, p < 0.05). However, acoustic quantification overestimated the radionuclide ejection fraction with rather wide limits of agreement (3.8% +/- 16.4%; bias +/- 2 SD). Thus echocardiographic automated border detection technique is a reasonably accurate method for on-line assessment of LV function.

Versatility of Inoue balloon catheter.

Inoue rubber nylon single balloon catheter is being used worldwide for performing balloon mitral valvuloplasty (BMV). The popularity of Inoue balloon is attributed to its self-positioning configuration, size-adjustability, rapid inflation-deflation sequence and the ease of performance. We report its use in performing various non-mitral interventions. Its utility in treating patients with mitral stenosis and combined mitral and tricuspid stenosis is well established. Seventeen patients with valvular pulmonic stenosis (age 32+/-16 years; 11 males and 6 females) achieved significant reduction of peak systolic gradient (PSG) from 125+/-28 to 32+/-16 mmHg (P<0.005). Four patients with inferior vena-cava obstruction (age 20-48 years; 3 males and 1 female) derived symptomatic benefit following successful dilatation. Inoue balloon was used to create percutaneous pericardial window in four cases (age 43-68 years; 2 males and 2 females) of recurrent pericardial collection secondary to carcinoma lung/breast, thus alleviating the symptoms of tamponade. One patient each with coarctation of aorta (32 years, male), discrete subaortic membrane (16 years, female), and critical valvular aortic stenosis (13 years, male) derived immediate hemodynamic improvement with Inoue balloon dilatation. No major complications were encountered. We conclude that Inoue balloon can be used to successfully manage various stenotic lesions.