Serum lipidomics reveals early differential effects of gastric bypass compared with banding on phospholipids and sphingolipids independent of differences in weight loss

BACKGROUND/OBJECTIVES

Circulating phospholipids and sphingolipids are implicated in obesity-related comorbidities such as insulin resistance and cardiovascular disease. How bariatric surgery affects these important lipid markers is poorly understood. We sought to determine whether Roux-en-Y gastric bypass (RYGB), which is associated with greater metabolic improvement, differentially affects the phosphosphingolipidome compared with adjustable gastric banding (AGB).

SUBJECTS/METHODS

Fasting sera were available from 59 obese women (body mass index range 37-51 kg m^-2; n=37 RYGB and 22 AGB) before surgery, then at 1 (21 RYGB, 12 AGB) and 3 months follow-up (19 RYGB, 12 AGB). HPLC-MS/MS was used to quantify 131 lipids from nine structural classes. DXA measurements and laboratory parameters were also obtained. The associations between lipids and clinical measurements were studied with P-values adjusted for the false discovery rate (FDR).

RESULTS

Both surgical procedures rapidly induced weight loss and improved clinical profiles, with RYGB producing better improvements in fat mass, and serum total cholesterol, low-density lipoprotein-cholesterol (LDL-C) and orosomucoid (FDR <10%). Ninety-three (of 131) lipids were altered by surgery-the majority decreasing-with 29 lipids differentially affected by RYGB during the study period. The differential effect of the surgeries remained statistically significant for 20 of these lipids after adjusting for differences in weight loss between surgery types. The RYGB signature consisted of phosphatidylcholine species not exceeding 36 carbons, and ceramides and sphingomyelins containing C22 to C25 fatty acids. RYGB also led to a sustained increase in unsaturated ceramide and sphingomyelin species. The RYGB-specific lipid changes were associated with decreases in body weight, total and LDL-C, orosomucoid and increased HOMA-S (FDR <10%).

CONCLUSIONS

Concomitant with greater metabolic improvement, RYGB induced early and sustained changes in phosphatidylcholines, sphingomyelins and ceramides that were independent of greater weight loss. These data suggest that RYGB may specifically alter sphingolipid metabolism, which, in part, could explain the better metabolic outcomes of this surgical procedure.

Specific gut microbiota features and metabolic markers in postmenopausal women with obesity

BACKGROUND

Gut microbial gene richness and specific bacterial species are associated with metabolic risk markers in humans, but the impact of host physiology and dietary habits on the link between the gut microbiota and metabolic markers remain unclear. The objective of this study was to identify gut metagenomic markers associated with estimates of insulin resistance, lipid metabolism and inflammation in obesity, and to explore whether the associations between metagenomic and metabolic markers persisted after adjustment for body fat, age and habitual dietary intake.

METHODS

Faecal DNA from 53 women with obesity was analysed through quantitative metagenomic sequencing and analysis, and a systematic search was performed for bacterial genes associated with estimates of insulin resistance, inflammation and lipid metabolism. Subsequently, the correlations between metagenomic species and metabolic markers were tested by linear regression models, with and without covariate adjustment.

RESULTS

One hundred and fourteen metagenomic species correlated with metabolic markers (P<0.001) including Akkermansia muciniphila, Bilophila wadsworthia, Bifidobacterium longum and Faecalibacterium prausnitzii, but also species not previously associated with metabolic markers including Bacteroides faecis and Dorea longicatena. The majority of the identified correlations between bacterial species and metabolic markers persisted after adjustment for differences in body fat, age and dietary macronutrient composition; however, the negative correlation with insulin resistance observed for B. longum and F. prausnitzii appeared to be modified by the intake of dietary fibre and fat, respectively.

CONCLUSIONS

This study shows that several gut bacterial species are linked to metabolic risk markers in obesity, also after adjustment for potential confounders, such as long-term diet composition. The study supports the use of gut metagenomic markers for metabolic disease prediction and warrants further investigation of causality.

Macrophage gene expression in adipose tissue is associated with insulin sensitivity and serum lipid levels independent of obesity

OBJECTIVE

Obesity is linked to both increased metabolic disturbances and increased adipose tissue macrophage infiltration. However, whether macrophage infiltration directly influences human metabolism is unclear. The aim of this study was to investigate if there are obesity-independent links between adipose tissue macrophages and metabolic disturbances.

DESIGN AND METHODS

Expression of macrophage markers in adipose tissue was analyzed by DNA microarrays in the SOS Sib Pair study and in patients with type 2 diabetes and a BMI-matched healthy control group.

RESULTS

The expression of macrophage markers in adipose tissue was increased in obesity and associated with several metabolic and anthropometric measurements. After adjustment for BMI, the expression remained associated with insulin sensitivity, serum levels of insulin, C-peptide, high density lipoprotein cholesterol (HDL-cholesterol) and triglycerides. In addition, the expression of most macrophage markers was significantly increased in patients with type 2 diabetes compared to the control group.

CONCLUSION

Our study shows that infiltration of macrophages in human adipose tissue, estimated by the expression of macrophage markers, is increased in subjects with obesity and diabetes and associated with insulin sensitivity and serum lipid levels independent of BMI. This indicates that adipose tissue macrophages may contribute to the development of insulin resistance and dyslipidemia.

Urgent/emergent surgical revascularization in unstable angina: influence of different type of conduits

AIM

In patients with unstable angina (UA) undergoing nonelective myocardial revascularization we compare the outcomes of skeletonized bilateral internal mammary arteries (BIMA) vs left internal mammary artery (LIMA) and saphenous vein grafts (SVGs) vs SVGs only.

METHODS

Between January 1997 and December 2003, 758 patients: 612 (80.7%) males, mean age 62+/-12 years, underwent nonelective coronary artery bypass grafting (CABG) for unstable angina; 205 (27%) were operated emergently and 553 (73%) urgently. BIMA were employed in 320 (42%) patients (Group B) , isolated LIMA and/or SVGs in 332 (44%) patients (Group M) and only SVGs in 106 (14%) (Group S).

RESULTS

In-hospital mortality (B=5.9%, M=4.5% and S=7.5%), and perioperative myocardial infarction (B=2.2%; M=1.9%, S=3.7%) were similar between the 3 groups (P=NS). Actuarial survival at 1, 3 and 7 years was 98.7%, 97.5% and 96.2% in group B, 99.3%, 94.8% and 89.4% in group M (P< 0.057 at 7 years follow-up) and 98%, 93.2% and 84.3% in group S (P=0.001). At 7 years follow-up, the event-free cardiac survival (92% vs 89.1%, P=0.045), angina-free survival (98.6% vs 95.8%, P=0.056), reoperation-free cardiac survival (98% vs 96%, P= 0.05) and infarct-free cardiac survival (98.7% vs 96.9%, P=0.062) showed a consistent trend to be superior in group B. Multivariate analysis identified age >65 years (P= 0.02), left ventricular ejection fraction (LVEF) <35% (P= 0.01), >1 ischemic irreversible area (P= 0.03) as independent predictors for late deaths, while the use of the LIMA (P= 0.006) and both mammary arteries (P= 0.001) decreased the risk of late deaths.

CONCLUSIONS

The use of BIMA in nonelective CABG for UA is safe and effective. There is a trend, however, toward a survival benefit with improved freedom from late cardiac events (recurrence of angina, freedom from reoperation and infarction).

Congenital tuberculous lymphadenitis in a preterm infant in Greece

Congenital tuberculosis is a rare disease. The risk of tuberculosis in pregnancy has increased owing to recent changes in the epidemiology of the disease, which have led to an increased risk of congenital tuberculosis. We present a case report on a 6-d-old premature infant with tuberculous lymphadenitis. Smears of the lymphatic tissue contained acid-fast bacilli, and cultures were positive for Mycobacterium tuberculosis hominis. Polymerase chain reaction (PCR) assay of the suppurative material of the lymph node was positive for M. tuberculosis. Twenty days before onset of labour, the mother developed miliary tuberculosis and meningitis.

CONCLUSION

The atypical clinical manifestations of congenital tuberculosis and the devastating consequences in the absence of early therapy signify the importance of early diagnosis and treatment during the neonatal period. PCR assay is a useful technique for prompt diagnosis in neonates with clinically suspected infection.

Accessory mitral valve leaflet in an adult with coronary artery disease

Accessory mitral valve leaflet is a very rare cause of left ventricular outflow tract obstruction. We report a patient presenting this cardiac abnormality who undergone cardiac surgery. A 60-year-old man, presented coronary artery disease and moderate left ventricular tract obstruction due to accessory mitral valve leaflet. The accessory mitral valve leaflet had the typical morphology of a parachute-shaped attached partially to the anterior mitral valve leaflet, with chordae tendinae attached to: 1) an accessory papillary muscle inserted at the free-wall closed to the apex; 2) interconnected with the chordae tendinae of the anterior mitral valve leaflet; 3) a second accessory papillary muscle inserted to the interventricular septum. He underwent successful coronary revascularization of 2 vessels and accessory leaflet excision. A review of 21 cases with accessory mitral valve leaflet is reported.

Antiphospholipid antibodies and intracardiac thrombosis. A case report

The antiphospholipid syndrome (APS) has been associated with multiple cardiac abnormalities. The present report describes a case of right ventricle thrombus in a 51-year-old woman with a history of autoimmune haemolytic anemia and antiphospholipid antibodies. Transthoracic echocardiography demonstrated the presence of a right ventricle mass, mimicking a myxoma. She underwent open heart removal of the mass and was started on indefinitely anticoagulant therapy. At 2 years follow-up she was free of symptoms.

Emergency management of spontaneous coronary artery dissection

Six cases of spontaneous coronary arteries dissection are reported. In one patient, triple vessel spontaneous coronary artery dissection was identified. Another patient presented spontaneous left main coronary artery dissection. In one case we found the spontaneous dissection of the left anterior descending artery associated with distal aortic arch dissection. These conditions are very rare and may present a surgical dilemma. Causative factors and underlying pathology are clarified. Prompt diagnosis and surgical intervention is safe and effective. Early recognition of left main coronary artery dissection or three-vessel dissection is essential because urgent coronary artery bypass grafting may be life saving.

Concomitant carotid endarterectomy and coronary bypass surgery: should cardiopulmonary bypass be used for the carotid procedure?

BACKGROUND AND OBJECTIVES

With the increasing age of patients undergoing coronary artery bypass grafting (CABG), a greater number have associated clinically significant carotid disease. This study determined the morbidity and mortality for combined carotid endarterectomy (CEA)/CABG using cardiopulmonary bypass (CPB) for both procedures versus a combined approach using CPB only during CABG.

PATIENTS AND METHODS

Between 1993 and 2000, 65 patients (Group I) underwent combined CEA and CABG using CPB for both surgical procedures and 88 patients (Group II) underwent combined CEA and CABG using CPB only during CABG. The demographic, clinical, and carotid and coronary angiographic data were similar between groups. In Group I, 22 (33.8%) patients and 32 (36%) patients in Group II presented with contralateral carotid artery stenosis.

RESULTS

CPB time was significantly longer in Group I, 127+/-21 minutes versus 98+/-11 minutes in Group II patients (p = 0.001). The incidence of surgical revision for bleeding and deep sternal wound infection was higher in Group I patients, 2 (3%) versus 1 (1.1%) and 5 (7.7%) versus 2 (2.2%), respectively, but not significant. Hospital mortality in Group I was 6% (4 patients) versus 5.7% (5 patients) in Group II (p = ns). Neurologic complications occurred in 4 (6%) and 5 (5.7%) patients in Group I and II, respectively (p = ns). Postoperative renal dysfunction was more common in Group I patients (22 [33.8%]) then in Group II patients 16 (19%) (p = 0.04). Of these patients, (16 [19%]) 8 (12.3%) in Group I and 6 (6.8%) in Group II required postoperative ultrafiltration (p = ns). Infectious complications were more frequent in Group I patients, 5 (7.7%) versus 2 (2.3%), but not statistically significant (p = ns). Overall actuarial survival at 1, 3, and 5 years, including all deaths, was 92%, 88%, and 82% in Group I versus 93%, 86%, and 81% in Group II (p = ns). Overall freedom from stroke at 5 years was 87.5% in Group I and 86.4% in Group II.

CONCLUSIONS

We conclude that combined CEA/CABG using CPB only during the myocardial revascularization procedure remains the technique of choice in patients with coronary and carotid artery disease, offering better outcome in terms of perioperative morbidity than a combined CEA/CABG using CPB for both procedures.

Restoration of patency after apparent occlusion of the lambda-graft's right branch

The "string sign" is a physiological and reversible response of the internal mammary artery (IMA) anastomosed to a moderately stenotic coronary artery. We describe a patient who presented postoperatively with a string sign phenomenon of the right branch of the lambda-composite graft. The graft regained full patency 32 months after the surgical procedure with progression of the native coronary artery stenotic lesion. This case demonstrates that under specific conditions, such as the progression of native coronary artery disease, a no-flow composite graft employing IMAs can only regain patency and functional status in the same way as in situ IMAs. These findings confirm that the IMA remains the conduit of choice not only for its long-term patency, but also for its physiological adaptation characteristics.

Beating heart myocardial revascularization on extracorporeal circulation in patients with end-stage coronary artery disease

OBJECTIVES

To evaluate in a cohort of ESCAD patients (pts) the effects of on-pump/beating-heart versus conventional CABG in terms of early and mid-term survival and morbidity and LV function improvement.

METHODS

Between January 1993 and December 2000, 78 (Group I) ESCAD pts underwent on-pump/beating-heart surgery. Mean age in Group I was 66.2+/-6 (58-79), NYHA and CCS class were 3.2+/-0.6 and 3.3+/-0.4 respectively, Myocardial viability index 0.69+/-0.1 (%), LVEF (%) 24.8+/-4, LVEDP (mmHg) 28.1+/-5.8 and LVEDD(mm) 69.5+/-6. Group II consisted in 78 ESCAD patients undergoing conventional CABG selected in a randomized fashion from an age, sex, and LVEF corrected group of patients. Mean age in Group II was 65.7+/-5 (57-78), NYHA 3.1+/-0.7, CCS 3.4+/-0.8, LVEF(%) 25+/-5, LVEDP(mmHg) 27.9+/-4.4 and LVEDD(mm) 69.2+/-7.2.

RESULTS

Postoperatively, 5(7.7%) patients died in Group I versus 7(11.5%) patients in Group II (P>0.1). CPB time resulted to be in Group II patients (P=0.001) and the mean distal anastomoses per patient was similar between groups (P=Ns). Perioperative AMI (P=0.039), LCOS (P=0.002), necessity for ultrafiltration (P=0.018) and bleeding>1000 ml (P=0.029) were significantly higher in Group II. None of the Group I patients underwent surgical revision for bleeding versus 8(10.3%) patients in Group II (P=0.011). At 6 months after surgery, the LV function improved significantly in Group I patients, demonstrated by an increased LVEF=27.2+/-4(%)(P=0.001), lower LVEDP=26.4+/-3(mmHg)(P=0.029) and LVEDD=67+/-4(mm) (P=0.004) instead of a lower LVEDD=66.8+/-6(mm)(P=0.032) versus the preoperative data in Group II. The actuarial survival at 1, 3 and 5 yr were 90, 82 and 71% in Group I and 89, 83 and 74% in Group II (P=Ns).

CONCLUSION

In ESCAD patients who may poorly tolerate cardioplegic arrest, on-pump/beating-heart CABG may be an acceptable alternative associated with lower postoperative mortality and morbidity. Such a technique offers a better myocardial and renal protection associated with lower postoperative complications due to intraoperative hypoperfusion.

Ischemic mitral valve regurgitation grade II-III: correction in patients with impaired left ventricular function undergoing simultaneous coronary revascularization

BACKGROUND AND AIM OF THE STUDY

Mitral valve regurgitation (MVR), occurring as a result of myocardial ischemia and global left ventricular (LV) dysfunction, is predictive of poor outcome. The study aim was to assess the feasibility of mitral valve surgery concomitant with coronary artery bypass grafting (CABG) in patients with ischemic MVR grade II-III and impaired LV function.

METHODS

Between January 1996 and July 2000, 99 patients with grade II and III ischemic MVR and LV ejection fraction (LVEF) 17-30% underwent either combined mitral valve surgery and CABG (group I, n = 49) or isolated CABG (group II, n = 50). LVEF (%), LV end-diastolic diameter (LVEDD; mm), LV end-diastolic pressure (LVEDP; mmHg), LV end-systolic diameter (LVESD; mm) respectively were 27.5+/-5, 67.7+/-7, 27.7+/-4 and 51.4+/-7 in group I versus 27.8+/-4, 67.5+/-6, 27.5+/-5 and 51.2+/-6 in group II. In group I, mitral valve repair was performed in 43 patients (88%) and replacement in six (12%).

RESULTS

Preoperative data analysis showed no difference between groups. Five patients (10%) died in group I, compared with six (12%) in group II (p = NS). Within six months of surgery, LV function and geometry improved significantly in group I versus group II (LVEF, p <0.001; LVEDD, p = 0.002; LVESD, p = 0.003, LVEDP, p <0.001); only mild improvements were seen in group II. The regurgitation fraction decreased significantly in group I patients after surgery (p <0.001). Cardiac index increased significantly in groups I and II (p <0.001 and p = 0.03, respectively). In group I at follow up, four of six patients undergoing mitral valve replacement died, compared with five of 43 patients (11.5%) undergoing mitral valve repair (p = 0.007). At three years, the overall survival in group II was significantly lower than in group I (p <0.009).

CONCLUSION

Both MV repair and replacement preserving subvalvular apparatus in patients with impaired LV function offered acceptable outcome in terms of morbidity and survival. Surgical correction of grade II-III MVR in patients with impaired LV function should be taken into consideration as it provides better survival and improves LV function.

Accessory mitral valve tissue causing left ventricular outflow tract obstruction: case reports and literature review

Accessory mitral valve (AMV) tissue is a rare congenital malformation causing left ventricular outflow tract obstruction (LVOTO). We present three patients with AMV tissue undergoing surgery. A 60-year old man presented with an AMV leaflet, mild LVOTO and coronary artery disease and underwent accessory leaflet excision and coronary revascularization. A 24-year old man presented with an AMV leaflet, LVOTO and interatrial septal defect and underwent defect closure and accessory leaflet resection. An 8-month-old girl underwent interventricular septal closure and AMV leaflet resection but died on postoperative day 5 from progressive heart failure. Another 87 cases with AMV tissue were identified in the literature The anomaly was classified as: Type I (fixed: A = nodular, B = Membranous), and type II (mobile: A = pedunculated, B = leaflet like). Type IIB was further subdivided as rudimentary chordae and developed chordae. Patients with AMV tissue causing LVOTO may undergo mass removal with acceptable postoperative outcome. Prophylactic removal of AMV tissue should not be attempted in patients with no or mild LVOTO and no other associated heart defects. These patients should be followed and observed periodically by Doppler echocardiography to identify any progression in LVOTO.

Should mild-to-moderate and moderate ischemic mitral regurgitation be corrected in patients with impaired left ventricular function undergoing simultaneous coronary revascularization?

INTRODUCTION

Mitral valve regurgitation (MR) occurring as a result of myocardial ischemia and global left ventricular (LV) dysfunction predicts poor outcome. This study assessed the feasibility of mitral valve (MV) surgery concomitant with coronary artery bypass grafting (CABG) in patients with mild-to-moderate and moderate ischemic MR and impaired LV function.

MATERIALS AND METHOD

From January 1996 to July 2000, 49 patients (group 1) and 50 patients (group 2) with grade II and grade III ischemic MR and LV ejection fraction (EF) between 17% and 30% underwent combined MV surgery and CABG (group 1) or isolated CABG (group 2). LVEF (%), LV end-diastolic diameter (EDD) (mm), LV end-diastolic pressure (EDP) (mmHg), and LV end-systolic diameter (ESD) (mm) were 27.5 +/- 5, 67.7 +/- 7,27.7 +/- 4, and 51.4 +/- 7, respectively in group 1 versus 27.8 +/- 4, 67.5 +/- 6, 27.5 +/- 5, and 51.2 +/- 6, respectively in group 2. Groups 1 and 2 were divided into Groups 1A and 2A with mild-to-moderate MR (22 [45%] and 28 [56%] patients, respectively) and groups 1B and 2B with moderate MR (27 [55%] and 22 [46%], respectively). In group 1, MV repair was performed in 43 (88%) patients and MV replacement in 6 (12%) patients.

RESULTS

Preoperative data analysis did not reveal any difference between groups. Five (10%) patients in group 1 died versus 6 (12%) in group 2 (p = ns). Within 6 months after surgery, LV function and its geometry improved significantly in group 1 versus group 2 (LVEF, p < 0.001; LVEDD, p = 0.002; LVESD, p = 0.003; and LVEDP (p < 0.001) improved significantly in group 1 instead of a mild improvement in Group 2). The regurgitation fraction decreased significantly in group 1 patients after surgery (p < 0.001). There was an inverse strong correlation between postoperative forward cardiac output and regurgitation fraction (p < 0.001). LVEF and LVESD improved significantly in group 1 versus group 2 patients (p = 0.04 and p = 0.02, respectively). The cardiac index increased significantly in group 1 and 2 (p < 0.001 and p = 0.03, respectively). LV function and geometry improved significantly postoperatively in group 1B versus group 2B (LVEDD, p = 0.027; LVESD, p = 0.014; LVEDP, p = 0.034; and LVEF, p = 0.02), instead of a mild improvement in group 1A versus group 2A (LVESD, p = 0.015; LVEF, p = 0.046; and LVEDD and LVEDP, p = 0.05). At follow-up, 4 (67%) of 6 patients undergoing MV replacement died versus 5 (11.5%) of 43 patients undergoing MV repair in group 1 (p = 0.007). The overall survival at 3 years in Group 2 was significantly lower than group 1 (p < 0.009).

CONCLUSION

MV repair and replacement-preserving subvalvular apparatus in patients with impaired LV function offered acceptable outcomes in terms of morbidity and survival. Surgical correction of mild-to-moderate and moderate MR in patients with impaired LV function should be taken into consideration since it yields better survival and improved LV function.

Lambda graft with the radial artery or free left internal mammary artery anastomosed to the right internal mammary artery: flow dynamics

BACKGROUND

The aim of this study was to evaluate the outcome and flow dynamics of the lambda graft configuration, relative to a second arterial graft.

METHODS

From 1998 to 2000, 47 patients (mean age 55.5 +/- 4.7 years) with triple-vessel disease underwent arterial revascularization using the lambda graft. The in situ left internal mammary artery (LIMA) and right internal mammary artery (RIMA) were anastomosed to the left anterior descending (LAD) and obtuse marginal arteries, respectively. In 21 patients (group I) presenting proximal or middle-third LAD or right coronary (RC) arterial stenoses, the lambda graft was constructed by anastomosing the distal LIMA, as a free LIMA graft, to the RC and proximally to the in situ RIMA. In the other 26 patients (group II) presenting with middle-distal third LAD or RC arterial stenoses, the radial artery (RA) was used to construct the lambda graft. All patients underwent transthoracic echo color Doppler before and after an adenosine test at 1 week and 3 months after operation.

RESULTS

There were no hospital deaths. Overall, 47 lambda grafts were constructed. There was no difference between baseline and maximal flows and coronary flow reserve (CFR) between groups. CFR at IMA stems increased in both groups within 3 months versus 1 week [(LIMA)CFR = 2 +/- 0.3 vs 2.3 +/- 0.3 (p = 0.002) and (RIMA)CFR = 2.2 +/- 0.4 vs 2.5 +/- 0.3 (p = 0.009) in group I, and (LIMA)CFR = 2.12 +/- 0.33 vs 2.4 +/- 0.35 (p = 0.005) and (RIMA)CFR = 2.17 +/- 0.32 vs 2.52 +/- 0.26 (p = 0.001) in group II]. At 3 months versus 1 week, the (RIMA)diameter(i) (mm) at rest was 1.69 +/- 0.32 versus 1.48 +/- 0.2 (p = 0.015) in group I and 1.66 +/- 0.3 versus 1.47 + 0.2 (p = 0.01) in group II. At 6 +/- 2.4 months, all patients were free of angina.

CONCLUSIONS

These data, almost identical for free LIMA and RA to RIMA using the lambda graft, demonstrate that RIMA flow reserve is adequate for multiple coronary anastomoses irrespective of the second arterial graft.

Urgent surgical revascularization of unstable angina. Influence of double mammary arteries

OBJECTIVE

Aim of this study was to evaluate retrospectively: (1) the outcome in patients with unstable angina (UA) refractory to the medical therapy undergoing urgent-emergent CABG; (2) the influence of both IMAs employment.

PATIENTS AND METHODS

Between January 1995 and July 2000, 576 (28.5%) consecutive patients with UA underwent CABG procedure. 182 (31.6%, Group I) patients, presenting unstable hemodynamic or angina pectoris refractory to the maximal medical therapy, underwent urgent/emergent CABG. 397 (68.4%, Group II) patients, after the maximal medical therapy did not present angina's episodes or ECG alterations and underwent elective CABG procedure. Preoperative data were similar in the two groups. Both IMAs were used in 68 (37.4%) patients of I and 152 (38%) of II (P>0.05) to left side revascularization.

RESULTS

CAD extension was greater in Group I: 45 (24.7%) patients presented ischemia in >1 area vs 53 (13.5%) in II (P<0.001). Incidence of anteroseptal ischemia resulted significantly higher in I (P=0.017); left main coronary artery stenosis was present in 68 (37%) patients in I vs 108 (27%) in II (P=0.01). LV function resulted significantly depressed in I, demonstrated by a significantly lower LVEF (P<0.001), higher NYHA class (P<0.001) and preoperative incidence of IABP (P<0.001). Intraoperative data analysis did not reveal any difference between groups. Hospital mortality was 13 (7%) and 21 (5.3%) patients in I and II respectively (P=ns). Multivariate analysis of all preoperative and intraoperative variables revealed the age >65 years (P=0.01), congestive heart failure (P<0.001), LVEF<35% (P=0.03), >1 ischemic area (P=0.02) as strong predictors for poor overall survival, and LIMA (P=0.006) and both IMAs (P=0.001) as strong predictors for good overall survival. Actuarial survival at 1, 3 and 5 years resulted to be 98.5, 96.5 and 90% in I and 99, 96 and 92% in II (P=ns).

CONCLUSION

CABG has been associated with acceptable outcome in patients with UA which should be applied soonest possible in patients refractory to medical treatment. Total coronary revascularization and employment of both IMAs for left myocardial side are associated with low operative risk and incidence of complications, permit to have acceptable short and long-term outcome in this pool of patients.

Chylothorax: a complication after internal thoracic artery harvesting

Chylothorax is a rare but serious complication of cardiac surgery. A 64-year-old man with three-vessel disease underwent coronary artery bypass grafting. Ten days later he developed left pleural effusion. An intercostal drain was inserted and 1600 ml of pale pink, milky fluid were obtained. The results of biochemical analysis were consistent with chyle. The diagnosis of a left chylothorax was made. Conservative treatment consisting of total parenteral nutrition and pleural drainage was successfully employed. In the literature we found 17 cases in which the development of chylothorax after a coronary revascularization procedure is described.

Respiratory dysfunction after coronary artery bypass grafting employing bilateral internal mammary arteries: the influence of intact pleura

OBJECTIVE

To evaluate the role of intact pleurae regarding the postoperative respiratory functional status in patients undergoing coronary revascularization employing both internal mammary arteries (IMAs), according to the pedunculated or skeletonized technique (SKT) with opened or intact pleurae.

MATERIALS AND METHODS

Using both IMAs, 299 patients underwent elective coronary revascularization. They were randomized and divided into group I (n=82, undergoing IMA harvesting according to the SKT without opening the pleurae); group II (n=186, undergoing IMA harvesting according the pedunculated technique with open pleurae); and group III (n=31, undergoing IMA harvesting according the SKT with incidentally opened pleurae). There were no differences regarding the preoperative patient characteristics and the anaesthetic and surgical management.

RESULTS

There were two deaths in group I versus seven in group II and one in group III (P=ns). The number of total arterial myocardial revascularization and arterial composite grafts was significantly higher in groups I and III than in group II, (P<0.001 and P<0.005, respectively). The incidence of postoperative complications was similar between groups. Blood loss of >1000 ml was significantly higher in group II than group I (P<0.028); but the incidence of re-thoracotomy and blood transfusion was similar between groups. The mechanical ventilation time was significantly higher in groups II and III versus group I (P<0.018 and P<0.02, respectively). The incidence of prolonged ventilation (>24 h), pleural effusion, thoracocentesis and atelectasis, resulted in being significantly higher in group II than group I. The incidence of thoracocentesis was significantly higher in group III than group I. The pain score and analgesic requirements at 1-12 h after awakening were significantly higher in groups II and III versus group I, becoming similar after the chest tubes were removed. PaO(2) was significantly higher, and PaCO(2) and FiO(2) were significantly lower in group I than groups II and III at 1 and 4 h before extubation and at 1 and 4 h after extubation. PaO(2) and PaCO(2) became similar between groups at the 5th postoperative day.

CONCLUSIONS

According to our results, we may conclude that pleural integrity has beneficial effects on the respiratory functional status after coronary revascularization using both IMAs. A meticulous and more careful IMA harvesting approach significantly reduces the postoperative morbidity regarding the pulmonary functional status, and as a consequence, reduces the hospital costs.

Does on-pump/beating-heart coronary artery bypass grafting offer better outcome in end-stage coronary artery disease patients?

OBJECTIVES

The purpose of our study was to evaluate in a cohort of end-stage coronary artery disease (ESCAD) patients the effects of on-pump/beating-heart versus conventional coronary artery bypass grafting (CABG) requiring cardioplegic arrest. We report early and midterm survival, morbidity, and improvement of left ventricular (LV) function.

METHODS

Between January 1992 and October 1999, 107 (Group I) ESCAD patients underwent on-pump/beating-heart surgery and 191 (Group II) ESCAD patients underwent conventional CABG requiring cardioplegic arrest. Mean age in Group I was 65.8 +/- 6.5 years (58-79 years); New York Heart Association (NYHA) and Canadian Cardiovascular Society (CCS) classifications were 3.2 +/- 0.4 and 3.3 +/- 0.5, respectively. LV ejection fraction (LVEF) was 24.8% +/- 4%, LV end diastolic pressure (LVEDP) was 28.2 +/- 3.8 mmHg, and LV end diastolic diameter (LVEDD) was 69.6 +/- 4.6 mm. Mean age in Group II was 64.1 +/- 5 years (57-76 years), NYHA class was 3 +/- 0.6, CCS class was 3.4 +/- 0.4, LVEF was 26.2% +/- 4.3%, LVEDP was 27.2 +/- 3.4 mmHg, and LVED was 68 +/- 4.2 mm.

RESULTS

Preoperatively, Group I patients versus Group II patients had a markedly depressed LV function (LVEF, p = 0.006; LVEDP, p = 0.02; LVEDD, p = 0.003; and NYHA class, p = 0.002), older age (p = 0.012), and higher incidences of multiple acute myocardial infarction (AMI; p = 0.004), cardiovascular disease (CVD; p = 0.008), and chronic renal failure (CRH, p = 0.002). Cardiopulmonary bypass (CPB) time was longer in Group II patients (p = 0.028). The mean distal anastomosis per patient was similar between groups (p = NS). Operative mortality between Groups I and II was 7 (6.5%) and 19 (10%), respectively (p = NS). Perioperative AMI (p = 0.034), low cardiac output syndrome (LCOS; p = 0.011), necessity for ultrafiltration (p = 0.017), and bleeding (p = 0.012) were higher in Group II. Improvement of LV function within 3 months after the surgical procedure was markedly higher in Group I, demonstrated by increased LVEF (p = 0.035), lower LVEDP (p = 0.027), and LVEDD (p = 0.001) versus the preoperative data in Group II. The actuarial survivals at 1, 3, and 5 years were 95%, 86%, and 73% in Group I and 95%, 84%, and 72% in Group II (p = NS).

CONCLUSIONS

ESCAD patients with bypassable vessels to two or more regions of reversible ischemia can undergo safe CABG with acceptable hospital survival and mortality and morbidity. In higher risk ESCAD patients, who may poorly tolerate cardioplegic arrest, on-pump/beating-heart CABG may be an acceptable alternative associated with lower postoperative mortality and morbidity. Such a technique offers better myocardial and renal protection associated with lower postoperative complications.

A circuit to perform a combined ultrafiltration procedure in pediatric open heart surgery

Cardiopulmonary bypass (CPB) induces an increased capillary permeability and tissues water content due to hemodilution and the inflammatory response, resulting in organ dysfunction. The reduction of the water accumulation and inflammatory response can be achieved by employing ultrafiltration during CPB. Recently we developed a simple CPB circuit for ultrafiltration using the aortic venting tube as an inlet line. Such a technique offers the advantages of performing a combined ultrafiltration procedure and eliminating the danger of air embolism. We employed this circuit in 12 consecutive pediatric patients undergoing open heart surgery.

Right Y-graft, a new surgical technique using mammary arteries for total myocardial revascularization

BACKGROUND

We report a new technique that consists of a right Y-graft using only skeletonized internal mammary arteries (IMA) for total arterial myocardial revascularization.

METHODS

This technique consists of anastomosing the in situ left IMA (LIMA) and right IMA (RIMA) to the left anterior descending and obtuse marginal artery, via the transverse sinus, respectively. The distal free LIMA was anastomosed to the right coronary artery and afterwards in a Y fashion to the RIMA stem. Eleven patients with triple-vessel disease underwent coronary artery bypass grafting using this technique. Postoperatively and at follow-up all patients underwent color Doppler contrast-enhanced transthoracic echocardiography (TTE) before and after an adenosine provocation test.

RESULTS

Overall, 33 IMA-coronary anastomoses were made and 11 right Y-grafts were constructed. At 1 week after operation color Doppler contrast-enhanced TTE before and after the adenosine provocation test, respectively, showed an increase in LIMA stem diameter of 0.31 mm and in mean flow 62 mL/min. Coronary flow reserve (CFR) was 2+/-0.3. The increase in RIMA stem diameter was 0.2 mm and in mean flow was 121.7 mL/min. Coronary flow reserve was 2.5+/-0.4. Only 1 patient demonstrated an anomalous Doppler pattern, suggesting a partial Y-graft closure.

CONCLUSIONS

Such a technique permits total myocardial revascularization using only mammary arteries and left ventricular perfusion from both IMAs simultaneously. The color Doppler contrast-enhanced TTE is a rapid, accurate, and noninvasive test allowing a good assessment of IMA patency.

Undergoing cardiopulmonary bypass using enoxaparin only during a cardiac transplantation procedure

The use of enoxaparin as a replacement drug to standard heparin, for anticoagulation during extracorporeal circulation, in patients with heparin-induced thrombocytopenia, is still very limited. Enoxaparin significantly reduces thrombin formation and activity during cardiopulmonary bypass. The prolonged circulating rate, slow elimination rate and non-total reversion of enoxaparin by protamine can induce important postoperative bleeding. We are describing the first case of cardiac transplantation where enoxaparin was used as a replacement drug to standard heparin.

Axillary artery cannulation in type a aortic dissection operations

BACKGROUND

Femoral arteries are the preferred site of peripheral cannulation for arterial inflow in type A aortic dissection operations. The presence of aortoiliac aneurysms, severe peripheral occlusive disease, atherosclerosis of the femoral vessels, and distal extension of the aortic dissection may preclude their utilization. Axillary artery cannulation may represent a valid alternative in these circumstances.

METHODS

Between January 15, 1989, and August 20, 1998, in our institution, 22 of 152 operations (14.4%) for acute type A aortic dissection were performed with the use of the axillary artery for the arterial inflow. Axillary artery cannulation was undertaken in the presence of femoral arteries bilaterally compromised by dissection in 12 patients (54.5%), abdominal aorta and peripheral aneurysm in 5 patients (22.7%), severe atherosclerosis of both femoral arteries in 3 patients (13. 6%), and aortoiliac occlusive disease in 2 patients (9.1%). In all patients, distal anastomosis was performed with an open technique after deep hypothermic circulatory arrest. Retrograde cerebral perfusion was used in 9 patients (40.9%).

RESULTS

Axillary artery cannulation was successful in all patients. The left axillary artery was cannulated in 20 patients (90.9%), and the right axillary artery was cannulated in 2 patients (9.1%). Axillary artery cannulation followed an attempt of femoral artery cannulation in 15 patients (68. 2%). All patients survived the operation, and no patient had a cerebrovascular accident. No axillary artery thrombosis, no brachial plexus injury, and no intraoperative malperfusion were recorded in this series. Two patients (9.1%) died in the hospital of complications not related to axillary artery cannulation.

CONCLUSIONS

In patients with type A aortic dissection in whom femoral arteries are acutely or chronically diseased, axillary artery cannulation represents a safe and effective means of providing arterial inflow during cardiopulmonary bypass.

Mid-term outcome of surgical coronary ostial plasty: our experience

The conventional coronary artery bypass procedure that uses venous or arterial conduit for isolated critical stenosis of the left main coronary artery (LMCA) restores a less physiological perfusion of the myocardium and uses an appreciable length of bypass material. Coronary ostial plasty has been described as an alternative surgical technique in proximal obstructive coronary artery disease without calcifications. Here we report 23 patients (15 males and 8 females aged 37-78 years; mean age 57 years) who underwent surgical ostial plasty. Ostial reconstruction with fresh pericardial patch was performed in all patients: 15 patients with LMCA stenosis, 6 patients with right coronary (RC) ostial stenosis, and 2 patients with both RC artery and LMCA stenosis. In seven cases, coronary artery bypass grafting was added for contralateral distal stenosis with a total of five arterial conduits and six venous grafts. One patient died; the ostial plasty and grafts were patent at necropsy. Thallium-201 myocardial scintigraphy under stress at 30 days to 6 months after operation demonstrated good myocardial perfusion in 21 of 22 patients. Coronary angiography at follow-up (49 +/- 8 months) demonstrated good surgical ostial plasty results in 21 of 22 patients and good coronary flow in 19 of 22 patients; angiographic study at mid-term follow-up revealed only one failure of the surgical ostial plasty technique associated with venous graft obstruction. In 2 other patients CABG failure due to venous graft obstruction (1 patient) or distal stenotic lesions of the left coronary artery (1 patient) was noted. The overall successful outcome of the surgical ostial plasty was 22 of 23. We believe that surgical angioplasty of the coronary ostia may be used in the presence of proximal noncalcified obstructive lesions as an alternative technique, which offers a more physiological revascularization; it also spares grafting material and allows subsequent percutaneous transluminal angioplasty or coronary artery bypass surgery.