Rajneesh Malhotra

Ten-year experience with single-vessel and multivessel reoperative off-pump coronary artery bypass grafting

OBJECTIVE Patients undergoing reoperative coronary artery bypass have increased mortality and morbidity compared with those undergoing primary coronary bypass. The experience in applying off-pump techniques to coronary reoperations is limited. In this article we report a 10-year experience using various techniques of reoperative off-pump coronary bypass. METHODS Between January 1996 and December 2005, 332 patients underwent reoperative off-pump coronary artery bypass grafting. Data were collected regarding the preoperative, intraoperative, and postoperative clinical course of all patients. These were compared with similar data obtained from patients who had undergone conventional coronary reoperation during this period. RESULTS Two hundred ninety-six (89.2%) male and 36 female patients underwent reoperative off-pump coronary artery bypass. Of these, 265 (79.8%) patients underwent multivessel bypass through a median sternotomy, an anterolateral thoracotomy was performed in 63 (19%) patients, and a posterolateral thoracotomy was performed in 4 (1.2%) patients. The early mortality for patients undergoing off-pump surgery was lower than for those undergoing conventional reoperations (3.3% vs 5.5%, P = .066). Those who had undergone off-pump reoperations had less need for prolonged ventilation or prolonged inotropic support and had shorter intensive care unit and hospital stays than patients who had undergone redo coronary artery bypass grafting. CONCLUSION For many patients requiring coronary reoperations, off-pump techniques are safe and feasible. Complete revascularization was achieved in at least 75% of patients in an unselected population, with mortality and perioperative event rates that are comparable with those of conventionally performed coronary reoperations.

Evaluation of Right Ventricular Function During CABG: Transesophageal Echocardiographic Assessment of Hepatic Venous Flow Versus Conventional Right Ventricular Performance Indices.

The vulnerability of right ventricle (RV) to ischemic insult during cardiac surgery is being increasingly recognized. This study aims to evaluate right ventricular function by measuring hepatic venous flow (HVF) patterns using intraoperative transesophageal echocardiography (TEE), and to compare HVF with other conventional two‐dimensional echocardiographic and hemodynamic indices of RV performance. Patients undergoing coronary artery bypass grafting (CABG) were studied intraoperatively using a multiplane dual frequency 5/3.7‐MHz phased array transducer, a pulmonary artery catheter, and an arterial catheter. Peak velocities and time velocity integrals of HVF pattern were studied. Peak systolic‐diastolic ratio (S/D) of biphasic HVF and reverse flow ratio (% reverse flow/forward flow =% RF/FF) were also examined. Two‐dimensional echocardiographic measurements included: (1) transverse plane long‐axis (LA) and short‐axis (SA) planimetered areas expressed as ratios; LA maximum major and minor‐axis shortening fractions; (2) tricuspid annular plane systolic excursion (TAPSE) ratio. All data were obtained after induction of anesthesia (stage 1), after sternotomy (stage 2), aftercardiopulmonary bypass (CPB) (stage 3), and after sternal closure (stage 4). Pre‐CPB all 35 patients had biphasic HVF by Doppler. In 31 patients peak S/D ratio was > 1. After CPB, there was significant reduction in systolic forward flow (S wave), along with an increase in late systolic reverse flow (V wave) and an increase in % RF/FF. At this stage TAPSE ratio decreased (pre CPB 0.33 ± 0.12 vs post CPB 0.30 ± 0.11). There was simultaneous decrease in 2‐D long‐axis LA (pre CPB 0.52 ± 0.11 vs post CPB 0.31 ± 0.01) and max major axis LA (pre CPB 0.38 ± 0.06 vs post CPB 0.31 ± 0.11). Max major axis LA correlated significantly with changes in right atrial pressure (P < 0.05). Tricuspid annular motion diminished significantly at sternal closure. Hepatic systolic forward flow and TAPSE ratio can be an indirect measure of RV systolic functions in correlation with maximum major axis LA changes. Evaluation of HVF provides unique insight into right ventricular dynamics. It is an easy, safe, and sensitive method for assessing RV functions intraoperatively.

Minimally invasive mitral valve surgery through right anterolateral minithoracotomy

BACKGROUND This study evaluates the feasibility of minimally invasive mitral valve surgery. The aim of the study was to minimize surgical access to achieve better cosmetic results, less postoperative discomfort, and faster recovery. METHODS From September 1997 to October 1998, 76 patients underwent mitral valve surgery through a right anterolateral minithoracotomy at the fourth intercostal space. The mitral valve was either repaired (n = 21) or replaced (n = 55). In all cases, open femoral artery-femoral vein cannulation was used for cardiopulmonary bypass. In 27 cases, an endoluminal aortic clamp was used, but in 49 cases, the aorta was cross-clamped with a transthoracic, sliding-rod-design clamp. RESULTS There were no approach-related limitations to surgical intervention. Intraoperative transesophageal echocardiography revealed excellent results after valve repair and no paravalvular leak in any patient after mitral valve replacement. Mean duration of intensive care and postoperative hospital stay was 32+/-5.2 hours and 7+/-1.1 days, respectively. There were no major complications related to femoral vessel cannulation. In 1 patient, transient neurological problems developed, with subsequent complete recovery. There was one hospital mortality (85-year-old male patient died of upper GI bleeding). CONCLUSIONS Minimally invasive port access mitral valve surgery can accelerate recovery and decrease pain, while maintaining overall surgical efficacy. It also provides better cosmetic results to our patients, and now it has become our standard approach for isolated mitral valve surgery.

Off-pump redo coronary artery bypass grafting

BACKGROUND Conventional redo coronary artery bypass grafting is associated with significant morbidity. The danger of reoperation is mainly in reopening the sternum and in the manipulation of the heart and the old grafts. Therefore, off-pump redo coronary artery bypass grafting with a patient-specific approach in selected cases seems an ideal technique. METHODS Between October 1995 to September 1999, 50 patients with mean age of 61.8+/-8 years underwent reoperative coronary artery bypass grafting without cardiopulmonary bypass. Isolated left internal mammary artery (LIMA) to left anterior descending artery (LAD) anastomosis was carried out in 25 cases through left anterior minithoracotomy. In 1 patient LIMA was grafted on a previous vein graft to LAD, which was critically stenosed proximally but distal anastomosis was patent. In another case LIMA was grafted to Ramus intermedius branch. Midsternotomy approach was used to carry out LAD and right coronary artery grafting in 21 cases. In 2 patients a posterolateral thoracotomy approach was used to bypass obtuse marginal branches without cardiopulmonary bypass; in these cases proximal anastomosis was performed on the descending aorta. RESULTS Mortality rate was 4% (2 deaths). Two patients sustained perioperative myocardial infarction. No patient was reexplored for hemorrhage and 38 patients did not require homologous blood transfusion. Sixteen patients underwent check angiogram and all of them were found to have patent redo grafts. Cardiac recovery room stay was 22+/-7 hours and hospital stay 5+/-2 days. CONCLUSIONS In selected patients, reoperative coronary artery bypass grafting can be performed without cardiopulmonary bypass with a low perioperative morbidity and mortality and satisfactory graft patency.

Cardioprotective effects of diltiazem infusion in the perioperative period.

OBJECTIVE To evaluate the perioperative effects of intravenous diltiazem infusion on left ventricular functions, hemodynamics and as an anti-ischemic and antiarrhythmic agent in patients undergoing coronary artery bypass grafting (CABG). METHODS A double blind, randomised study was performed on 71 patients undergoing elective CABG. Infusion of diltiazem (0.1 mg/kg per h, n = 34) or nitroglycerin (1 microgram/kg per min, n = 37) was given for 24 h starting from onset of cardiopulmonary bypass. Holter monitoring, electrocardiogram and serum cardiac enzymes levels were used to diagnose myocardial ischemia. Myocardial function was assessed by perioperative transesophageal echocardiography. RESULTS The two groups did not differ with respect to preoperative and operative data. Diltiazem had no influence on hemodynamic parameters except for significant reduction in post operative heart rate and pulse pressure rate. Transient ischemic events (dilitiazem 10.2% versus nitroglycerin 33.3%, P = 0.15) and transient coronary spasm (diltiazem-6.8% versus nitroglycerin 25.9%, P = 0.15) were reduced in the diltiazem group as compared with the nitroglycerin group. The postoperative incidence of atrial fibrillation (diltiazem 3% versus nitroglycerin 22%, P = 0.03), supra ventricular tachycardia (diltiazem-3% versus nitroglycerin-22%, P = 0.03) and average ventricular premature contraction per h (diltiazem-40.2 +/- 10.2 versus nitroglycerin 53.8 +/- 12.3, P < 0.01) were significantly lower in the diltiazem group. Transesophageal echocardiography showed no significant difference in left ventricular functions and better preservation of left ventricular diastolic functions in post cardiopulmonary bypass period in diltiazem group. In addition mean deceleration time for the E wave on a 12 h post cardiopulmonary bypass period was significantly lower in the diltiazem group as compared with nitroglycerin (diltiazem 131 +/- 6 versus nitroglycerin 171 +/- 6, P < 0.01). CONCLUSION The present study demonstrates that diltiazem infusion provides superior anti-ischemic protection and control of supraventricular arrhythmias as compared to nitroglycerin and does not produce any negative inotropic effect, as demonstrated by transesophageal echocardiography.

Morphometric analysis of the right gastroepiploic artery and the internal mammary artery

BACKGROUND The internal mammary artery (IMA) and the right gastroepiploic artery (RGEA) are frequently used as conduits for coronary artery bypass grafting. METHODS Morphometric measurements and histologic characteristics of the RGEA and the IMA were studied in 25 patients undergoing coronary artery bypass grafting. RESULTS External radius was found to be more in the IMA (range, 18 to 56 microns; mean, 39.56 microns) in comparison with the RGEA (range, 24 to 51 microns; mean, 32.52 microns; p < 0.01). There was no significant difference between the vessels in intimal thickness (IMA: 0.0 to 0.25 micron; mean, 0.05 micron; RGEA: 0.0 to 0.28 micron; mean, 0.09 micron), internal radius (IMA: 5 to 47 microns; mean, 28.40 microns; RGEA: 16 to 42 microns; mean, 23.56 microns), area of media (IMA: 1,690 to 3,476 microns2; mean, 2,777.52 microns2; RGEA: 1,659 to 3,600; mean, 3,012.44 microns2), intimal thickening index (IMA: 0.0 to 0.02; mean, 0.01; RGEA: 0.0 to 0.13; mean, 0.01), and medial index (IMA: 0.14 to 0.60; mean, 0.36; RGEA: 0.18 to 0.63; mean, 0.39). Histologic examination of the RGEA showed more defects in continuity of internal elastic lamina and rich smooth muscle cells in the media. CONCLUSIONS There was no difference in the morphometric measurements of the IMA and the RGEA except external radius, which was greater for the IMA. The histologic differences found in the RGEA may indicate an increased propensity for atherosclerosis of the RGEA as compared with the IMA. Some concern regarding the long-term patency of the RGEA in myocardial revascularization is warranted.

Left Ventricular Fibroma Causing Atypical Chest Pain

A 29-year-old man with atypical chest pain for 3 years and exertional angina for 3 months was found to have a large homogenous mass in the apicolateral area of the left ventricle. The mass, weighing 78 g, was excised successfully and identified as a fibroma.

Evolution of Off-Pump Coronary Artery Bypass Grafting over 15 Years: A Single-Institution Experience of 14,030 Cases.

Background Off-pump coronary artery bypass grafting for multivessel disease is an important alternative to conventional myocardial revascularization using cardiopulmonary bypass. The development of exposure and stabilization techniques has made this surgery simple, safe, and routine. Experience with the technique, its evolution, the learning curve, and the pitfalls is presented. Methods A retrospective analysis was made of 28,216 patients who underwent elective coronary artery bypass grafting over a 15-year period from January 1990 through December 2004. Isolated off-pump coronary artery bypass grafting was performed in 14,030 patients and on-pump coronary artery bypass grafting in 14,186 patients. The overall period was divided into 3 groups of 5 years each: group I (1990–1994), group II (1995–1999), and group III (2000–2004). Initially, off-pump coronary artery bypass grafting was performed selectively in high-risk patients (eg, atheromatous aorta, severe systemic impairment, chronic obstructive pulmonary disease, octogenarian). Recently (2000–2004), multivessel off-pump coronary artery bypass grafting has been performed electively in 96% to 98% of patients undergoing coronary artery bypass grafting. Patients’ medical charts were reviewed for age, preoperative risk factors, operative findings, intraoperative conversion rate to cardiopulmonary bypass, postoperative complications, and length of hospital stay. Results In the years 1990–1994 (group I), mostly high-risk cases and cases with left anterior descending coronary artery lesions were included for off-pump coronary artery surgery. In the years 1995–1999 (group II), patients with double and triple vessel disease presenting for coronary artery bypass surgery were accepted for off-pump surgery irrespective of preoperative risk factors. However, in the years 2000–2004 (group III), off-pump coronary artery bypass surgery was the first choice of approach for any patient presenting for coronary artery bypass surgery. The mean number of grafts was lower in off-pump cases than in on-pump cases in group I (2.0 ± 0.4 vs. 3.2 ± 0.80) and group II (2.6 ± 0.6 vs. 3.3 ± 0.4), whereas the mean number of grafts was higher in off-pump cases than in on-pump cases in group III (3.5 ± 0.2 vs. 3.4 ± 0.8). In groups I and II, the conversion to cardiopulmonary bypass was 5.2% and 5.9%, respectively. The conversion to cardiopulmonary bypass decreased to 1.7% in group III, which was statistically significant. Perioperative myocardial infarction was 5.2% in group I, 1.7% in group II, and 1.5% in group III. The difference between groups II and III was not statistically significant. Hospital mortality was higher in group I (5.2%) than in group II (1.2%) or III (1.1%). The difference between groups II and III was not statistically significant. Length of intensive care unit stay was 36 ± 8 hours in group I, 28 ± 7 hours in group II, and 20 ± 8 hours in group III. These differences were statistically significant. Length of postoperative hospital stay was 8 ± 2 days in group I, 7 ± 2 days in group II, and 5 ± 2 days in group III These differences were statistically significant. Conclusions As surgeons’ experience matures, off-pump coronary artery bypass surgery permits total myocardial revascularization in virtually all patients with multivessel coronary artery disease. Despite a significant learning curve, evolution to routine off-pump coronary artery bypass with good patient outcomes can be achieved with careful patient selection during the “learning curve.” The method is safe and reproducible, and patients benefit with shorter intensive care unit and hospital stays.

Three-Dimensional Reconstruction of Ultrafast 16-Slice Computed Tomography Images and CT Angiography Versus Conventional Coronary Angiography at One Year in Multivessel Coronary Artery Bypass Surgery.

Background The aim of this study was to evaluate and compare the postoperative graft patency assessment by multislice spiral computed tomography (MSCT) scan and conventional coronary angiography (CCA) in coronary artery bypass grafting (CABG) patients 1 year after surgery. Methods Sixty-nine patients who underwent isolated CABG at least 1 year before the study, were subjected to both MSCT angiography with cardiac gating and CCA. The results were evaluated and compared. Results There were 209 grafts in 69 patients. All grafts were evaluated by both MSCT angiography and CCA. Seventy-eight grafts were on the anterior wall, 83 on the lateral wall and 48 on the inferior wall of the heart. On MSCT angiography, all left internal mammary arteries were visualized with 3-dimensional reconstruction and found to be patent. Of 209 grafts, 11 grafts (5.26%) were blocked, 6 grafts on the lateral wall and 5 on the inferior wall. All patent grafts were correctly evaluated by MSCT angiography (specificity 100%). However, 2 grafts that were found to be patent on MSCT angiography were blocked on CCA (MSCT sensitivity 81.8%). Conclusions Postoperative evaluation of coronary bypass grafts is possible with very good resolution by MSCT angiography. This method allows evaluation of the bypass grafts and the quality of anastomosis with a noninvasive method that is comparable with CCA.

Off-Pump Surgery: A Choice in Unstable Angina

The benefit and safety of off-pump coronary artery bypass surgery in patients with unstable angina was assessed retrospectively. From February 1996 to October 2001, 5,306 patients underwent multivessel off-pump coronary artery bypass, of whom 920 (17%) had unstable angina. In these 920 patients, ejection fractions ranged from 15% to 70%, 203 (22%) had an ejection fraction of 20%–35%, and 11 (1%) had an ejection fraction < 20%. Triple-vessel disease was present in 625 patients. Preoperative intraaortic balloon pump support was used in 28 patients. Operative approaches included mid sternotomy (86%), lower partial sternotomy (9%), and left anterior thoracotomy (2%). The number of grafts ranged from 1 to 5 with a mean of 2.43 ± 0.86, and 92.3% of patients received a left internal mammary artery graft. Twenty-two patients need intraoperative intraaortic balloon pumping. Ten patients (1%) suffered perioperative myocardial infarction. The mean hospital stay was 7.8 ± 4.3 days. Hospital mortality was 2/920 (0.22%). Intraaortic balloon pumping was helpful in these cases of unstable angina refractory to medical therapy. Off-pump coronary artery surgery was found to be safe and beneficial in these patients.