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Biomedical subjects

E Buffolo

Publications and source records attributed to E Buffolo.

At least 19 recordsLinked to original sources
PubMed2004

Expression of inducible nitric oxide synthase is increased in patients with heart failure due to ischemic disease.

The objective of the present study was to determine the relationship between nitric oxide synthases (NOS) and heart failure in cardiac tissue from patients with and without cardiac decompensation. Right atrial tissue was excised from patients with coronary artery disease (CAD) and left ventricular ejection fraction (LVEF) <35% (N = 10), and from patients with CAD and LVEF >60% (N = 10) during cardiac surgery. NOS activity was measured by the conversion of L-[H(3)]-arginine to L-[H(3)]-citrulline. Gene expression was quantified by the competitive reverse transcription-polymerase chain reaction. Both endothelial NOS (eNOS) activity and expression were significantly reduced in failing hearts compared to non-failing hearts: 0.36 +/- 0.18 vs 1.51 +/- 0.31 pmol mg-1 min-1 (P < 0.0001) and 0.37 +/- 0.08 vs 0.78 +/- 0.09 relative cDNA absorbance at 320 nm (P < 0.0001), respectively. In contrast, inducible NOS (iNOS) activity and expression were significantly higher in failing hearts than in non-failing hearts: 4.00 +/- 0.90 vs 1.54 +/- 0.65 pmol mg-1 min-1 (P < 0.0001) and 2.19 +/- 0.27 vs 1.43 +/- 0.13 cDNA absorbance at 320 nm (P < 0.0001), respectively. We conclude that heart failure down-regulates both eNOS activity and expression in cardiac tissue from patients with LVEF <35%. In contrast, iNOS activity and expression are increased in failing hearts and may represent an alternative mechanism for nitric oxide production in heart failure due to ischemic disease.

Aged↗
PubMed2004

Anomalous left coronary artery from pulmonary artery: autogenous arterial tube for aortic implantation.

Many surgical procedures for the implantation of anomalous left coronary artery from pulmonary artery have been described. A dual coronary system offers most benefit and is most advantageous for the patient. Two autogenous flaps of the pulmonary trunk and ascending aorta, without mobilizing the coronary artery, were created for use in this procedure. This technique was successfully used in an 8 month-old patient with severe myocardial dysfunction and moderate mitral regurgitation. This procedure allows 2 coronary systems to be repaired for any anatomic change of the left coronary artery without the use of prosthetic material. There were no technical complications. During the postoperative course minimal inotropic support was used. The magnetic resonance study, 11 months postoperative, showed wood flow of the left coronary artery and mild mitral regurgitation. The operative technique was simple and its execution easy. The follow-up in the intermediate and late period showed the growth of this endothelized tube.

Anastomosis, Surgical↗
PubMed2001

Percutaneous balloon mitral valvuloplasty in comparison with open mitral valve commissurotomy for mitral stenosis during pregnancy.

OBJECTIVES: We sought to compare the maternal and fetal outcomes of patients with severe mitral stenosis submitted to percutaneous balloon dilation versus open mitral valve commissurotomy (MVC) during pregnancy. BACKGROUND: Heart failure in patients with mitral stenosis complicating pregnancy is a common problem in developing countries. Since 1984, percutaneous dilation of the mitral valve using a balloon catheter has become a therapeutic alternative to open heart surgery. Although the efficacy of percutaneous mitral valve balloon dilation is well established, its results have never before been compared with the results of commissurotomy during pregnancy. METHODS: We compared the clinical and obstetric complications in 45 women who were treated with percutaneous mitral valve balloon dilation (group I, n = 21; from 1990 to 1995) or open MVC (group II, n = 24; from 1985 to 1990) for severe heart failure due to mitral stenosis during pregnancy. RESULTS: In our study, percutaneous balloon dilation of the mitral valve had a success rate of 95% (Gorlin formula) and 90.5% (echocardiographic "pressure half-time" method), as demonstrated by the final mitral valve area achieved. This improvement was followed by a marked decrease in the mitral valve gradient, left atrial pressure and mean pulmonary artery pressure. Patients in both groups had similar improvements in symptoms. Patients who underwent percutaneous balloon dilation had significantly fewer fetal complications, with a reduction in fetal and neonatal mortality (1 death in group I vs. 8 in group II, p = 0.025). CONCLUSIONS: Percutaneous balloon mitral valvuloplasty is safe and effective and appears to be preferable for the fetus, compared with open MVC during pregnancy.

Adult↗
PubMed2001

Cytokines and pediatric open heart surgery with cardiopulmonary bypass.

It is well known that, subsequent to cardiopulmonary bypass, and particularly in children, an inflammatory response within the body can often result in a characteristic syndrome. Recently, it has been suggested that this phenomenon is due to a systemic inflammatory response, with significant involvement of cytokines. With this in mind, we investigated the behavior of tumour necrosis factor-alpha and interleukin-6 during the operative and in the immediate postoperative period in a group of children submitted to open heart surgery. We investigated any possible relation between the levels of these cytokines in the serum and the length of cardiopulmonary bypass, with the serum levels of lactate, and with the extent of use of inotropic drugs in postoperative period. The cytokines were measured in samples withdrawn after induction of anesthesia, after 10 minutes of cardiopulmonary bypass, after re-establishment of circulation, and then 2 and 24 hours after the end of cardiopulmonary bypass. The levels of tumour necrosis factor-alpha and interleukin-6 increased between the beginning and at two hours of the end of cardiopulmonary bypass. There was no correlation between the levels of these cytokines in the serum and the length of cardiopulmonary bypass, although there was a positive relation between levels of interleukin-6 and lactate in samples withdrawn at two hours of the end of bypass, and the measured levels of the cytokines correlated with the extent of inotropic drugs employed in the postoperative period.

Cardiopulmonary Bypass↗
PubMed2001

Is the number of microembolic signals related to neurologic outcome in coronary bypass surgery?

Coronary artery bypass surgery (CABG) without cardiopulmonary bypass (CPB) may potentially reduce the number of microembolic signals (MES) associated with aortic manipulation or generated by the pump circuit, resulting in a better neurologic outcome after surgery. Our aim was to compare the frequency of MES and neurologic complications in CABG with and without CPB. Twenty patients eligible to routine CABG without CPB were randomized to surgery with CPB and without CPB and continuously monitored by transcranial Doppler. Neurologic examination was performed in all patients before and after surgery. The two groups were similar with respect to demographics, risk factors, grade of aortic atheromatous disease and number of grafts. The frequency of MES in the nonCPB group was considerably lower than in CPB patients, however, we did not observe any change in the neurologic examination during the early postoperative period. Neurologic complications after CABG may be related to the size and composition of MES rather than to their absolute numbers. A large prospective multicentric randomized trial may help to elucidate this complex issue.

Aortic Diseases↗
PubMed2001

[Use of transesophageal echocardiography during implantation of aortic endoprosthesis (stent). Initial experience].

OBJECTIVE: To report the role played by transesophageal echocardiography during implantation of self-expanding aortic endoprostheses (stent) at a hemodynamics laboratory. METHODS: Thirteen patients underwent stent implantation in the descending thoracic aorta with the aid of transesophageal echocardiography during the entire procedure. Indications for stenting were as follows: 8 aortic dissections, 2 true aneurysms, 2 penetrating atherosclerotic ulcers, and 1 traumatic pseudoaneurysm. RESULTS: No complications resulting from the use of transesophageal echocardiography were observed. In 12 patients, the initial result was considered appropriate, with total or partial resolution of the major lesion confirmed by a posterior examination. In 1 patient, the procedure was suspended after transesophageal echocardiography and angiography showed that the proximal aortic diameter was inappropriate. Transesophageal echocardiography contributed to clarifying relevant points, such as aortic diameter, anatomic detail of the intimal lesion, and location and size of the communicating orifice. In addition, it facilitated placing the stent in the target lesion, reduced the time of exposure to radiation and the use of contrast medium, and provided rapid identification of intercurrent events, possibly reducing the total duration of the procedure. CONCLUSION: The use of transesophageal echocardiography during placement of aortic stents seems appropriate. The actual advantages of the procedure will be defined in a comparative prospective study.

Aorta, Thoracic↗
PubMed2001

Conventional and conventional plus modified ultrafiltration during cardiac surgery in high-risk congenital heart disease.

BACKGROUND: This prospective nonrandomized study is the critical assessment of conventional ultrafiltration (CUF) and modified ultrafiltration (MUF) techniques and their efficiency in congenital heart disease surgeries. Use of cardiopulmonary bypass (CPB) in children is associated with body water retention as a consequence of prime volume and systemic inflammatory reaction. The CUF during CPB has reduced body water excess and the MUF after CPB, removes inflammatory mediators, improves hemodynamic performance, and decreases transfusion requirements. METHODS: Forty-one patients, aged 9 to 36 months, submitted to surgical correction for cardiac defects, using CPB, were divided into 2 similar groups: CUF (21 patients) operated between 1996-1997 were ultrafiltered during CPB, and CUF+MUF, (20 patients) operated between 1997-1998 and ultrafiltered during and after CPB. Postoperative duration of ventilator support, pediatric intensive care unit stay (PICU), hospital stay of the groups with and without preoperative pulmonary hypertension (PH), as well as transfusion requirement, hematocrit and platelet counts were compared. RESULTS: There were no technical complications and a significant ultrafiltrate in the CUF+MUF group was observed as compared to the CUF group. No significant differences were observed between the CUF and CUF+MUF groups regarding ventilatory support, PICU stay and hospital stay. Requirements for red cell transfusion, Ht and platelet counts were not statistically different. CONCLUSIONS: CUF and CUF+MUF were safe and efficient methods for patient stabilization independent of diagnosis and complexity of surgery. Future clinical evaluation should address a larger population of patients to research the different variables.

Algorithms↗
PubMed2001

A juvenile sheep model for the long-term evaluation of stentless bioprostheses implanted as aortic root replacements.

BACKGROUND AND AIM OF THE STUDY: Orthotopic valve replacement in large animals is an important component of the preclinical assessment of bioprosthetic valves. To provide the most useful preclinical information, the development of models that parallel clinical practice patterns is essential. Therefore, we sought to develop a technically feasible and reproducible model for chronic evaluation of stentless bioprosthetic aortic valves implanted as aortic root replacements in juvenile sheep. METHODS: Juvenile domestic sheep (mean age 21+/-2.28 weeks; range: 17-26 weeks) underwent aortic root replacement using standard cardiopulmonary bypass (CPB) and surgical techniques. Animals were implanted with 19 mm (n = 21), 21 mm (n = 18) or 23 mm (n = 4) bioprostheses from two different manufacturers, and followed for 150 days. Animals surviving at least 150 days were considered long-term survivors; those which died prior to postoperative day (POD) 31 were considered operative deaths. RESULTS: Forty-three animals underwent aortic root replacement. The mean CPB time was 91+/-20 min (range: 62-149 min); mean cross-clamp time was 63+/-13 min (range: 39-95 min). Thirty-five animals (81%) survived the first 30 days of the study period. Five deaths occurred at POD 0 due to anastomotic complications. One death occurred each on POD 3, 6, and 26 as a result of prosthesis size mismatching, thromboembolic complications, and endocarditis, respectively. There were five late deaths. Twenty animals survived the minimum 150-day study period, and 12 were sacrificed at 183+/-17 days. Six animals remain alive at 151+/-0.98 days, and one animal died each on POD 184 and 190. The remaining 10 animals are not yet 150 days from their operation. Currently, all are well at 102+/-34 days (range: 33-140) days. CONCLUSION: These data suggest that long-term evaluation of stentless aortic bioprostheses implanted as aortic root replacements can be accomplished using juvenile sheep.

Animals↗
PubMed2001

A multicenter initial clinical experience with right heart support and beating heart coronary surgery.

BACKGROUND: During coronary surgery without CPB, exposure of posterior vessel via sternotomy can cause deterioration of cardiac hemodynamics requiring inotrope drugs support. Recent animal experiments demonstrate hemodynamic benefit of right heart support (RHS) with the AMED system. The purpose of this study was to evaluate the hemodynamic effects during cardiac manipulation to expose the posterior coronary arteries, and determine the effect of RHS in restoring hemodynamics, increasing anastomotic exposure and reducing inotropic requirements. MATERIAL AND METHODS: From July 28 to December 29, 32 patients (25 men/7 women), mean age of 63.4 (+/- 6.2 years, ages: 49-78) received coronary revascularization with the A-Med RHS device. They were divided into two groups of 16 patients, A and B. Group A patients had at least one circumflex branch bypassed. The anterior wall was systematically bypassed off-pump without RHS. The right coronary artery (RCA) and the obtuse coronary artery (OM) were completed utilizing RHS. In group B patients, all vessels including anterior vessels were bypassed with the RHS. Mean arterial pressure (MAP), mean pulmonary arterial pressure (PAP), cardiac output (CO) and the average pump flow (APF) were recorded during the OM and RCA bypass for group A, and for group B LAD data was also recorded. RESULTS: Elective beating heart coronary artery bypass graft (CABG) was successfully accomplished in 32 patients with RHS. Data measurements recorded in Group A showed the improved hemodynamic recovery for OM and RCA bypass with RHS. The MAP increased from 44 to 68 mmHg (OM) and from 63 to 81 mmHg (RCA); the CO from 2.1 to 4.4 L/min (OM) and from 3.3 to 4.7 L/min (RCA). In group B, the data recorded showed the stability of the MAP in all vessels bypassed (LAD, OM and RCA). No device-related patient incidents occurred. All 32 patients were discharged to their homes. CONCLUSIONS: The AMED system, as RHS support, facilitated coronary bypass without CPB to posterior vessels, restoring hemodynamics, providing better exposure to anastomotic sites and apparently reducing inotropes need. Prospective randomize trials are necessary to confirm this initial experience.

Aged↗
PubMed2000

Right heart circulatory support facilities coronary artery bypass without cardiopulmonary bypass.

BACKGROUND: Revascularization of the posterior wall often causes hemodynamic instability in beating heart coronary artery bypass (CAB). Our previous clinical studies have shown that tilting the heart primarily alters right-heart hemodynamics. The purpose of this study was to evaluate right-heart support in clinical cases. METHODS: Seventeen patients underwent beating heart CAB with right-heart support. The right-heart support system (A-Med Systems, West Sacramento, CA) consisted of a coaxial cannula placed through the right atrium and the tip of the cannula positioned in main pulmonary artery. Blood was removed from the right atrium and returned to the main pulmonary artery. RESULTS: Elective beating heart CAB was accomplished successfully in 17 patients with right-heart support. Anastomoses performed were left anterior descending coronary artery (11), diagonal (3), circumflex (5), obtuse marginal artery (11), and right coronary artery (10). Right-heart support between 1 and 3 L/min improved hemodynamics especially in the circumflex position. No device-related patient incidents occurred, nor were there incidents of infection or air embolism. All 17 patients were discharged to their homes. CONCLUSIONS: The right-heart support system was safe without complications. Exposure of the posterior wall was possible in all cases without hemodynamic compromise.

Aged↗
PubMed2000

Reconstruction of the pulmonary valve and outflow tract with bicuspid prosthesis in tetralogy of Fallot.

BACKGROUND: Right ventricular outflow tract and pulmonary valve implant in patients with tetralogy of Fallot may be required to avoid late postoperative right ventricular impairment. The use of porcine bicuspid prosthesis might be a technical alternative, although comprehensive studies on the long-term use of these prostheses are not available. METHODS: Sixty-three patients (aged 5 months to 34 years; mean, 6 years) with tetralogy of Fallot and pulmonary hypoplasia underwent surgical repair and enlargement of the right ventricular outflow using preserved porcine pulmonary bicuspid prostheses. Fifty-two patients (82.5%) were followed and underwent clinical evaluation and serial Doppler echocardiography. The first 15 patients (29.4%), with ages ranging from 5 to 16 years (mean, 8.2 years) and postoperative follow-up of 48 to 87 months (mean, 65.1 months) underwent hemodynamic and cineangiographic evaluations. RESULTS: There were 11 deaths (17.4%) in the early postoperative period. Of the 52 surviving patients (82.5%), 51 (80.9%) were followed for 1 to 87 months (mean, 42.0 months). Four patients (7.6%) had additional treatment. Of the 15 patients (29.1%) undergoing hemodynamic evaluation, 9 (60%), had mild valvular pulmonary insufficiency and 6 (40%) had moderate insufficiency. Only the right ventricle-to-pulmonary artery pressure gradients and the right ventricular ejection fraction showed statistically significant differences between groups. Right ventricular dimension, although increased in all patients, did not show statistically significant differences. CONCLUSIONS: Right ventricular outflow tract and pulmonary valve repair in patients with tetralogy of Fallot using a bicuspid porcine pulmonary prosthesis is a simple, reliable procedure with good results in postoperative medium term follow-up.

Adolescent↗
PubMed2000

A new surgical approach for treating dilated cardiomyopathy with mitral regurgitation.

OBJECTIVE: To evaluate the early outcome of mitral valve prostheses implantation and left ventricular remodeling in 23 patients with end-stage cardiomyopathy and secondary mitral regurgitation (NYHA class III and IV). METHODS: Mitral valvular prosthesis implantation with preservation of papillary muscles and chordae tendinae, and plasty of anteriun cuspid for remodeling of the left ventricle. RESULTS: The surgery was performed in 23 patients, preoperative ejection fraction (echocardiography) varied from 13% to 44% (median: 30%). In 13 patients associated procedures were performed: myocardial revascularization (9), left ventricle plicature repair (3) and aortic prosthesis implantation (1). Early deaths (2) occurred on the 4th PO day (cardiogenic shock) and on the 20th PO day (upper gastrointestinal bleeding), and a late death in the second month PO (ventricular arrhythmia). Improvement occurred in NYHA class in 82. 6% of the patients (P<0.0001), with a survival rate of 86.9% (mean of 8.9 months of follow-up). CONCLUSION: This technique offers a promising therapeutic alternative for the treatment of patients in refractory heart failure with cardiomyopathy and secondary mitral regurgitation.

Adult↗
PubMed2000

Video-endoscopic dissection of multiple pedicled arterial grafts for use in minimally invasive coronary artery bypass surgery.

BACKGROUND: We evaluated the possibility of video-endoscopic dissection of both internal thoracic arteries (rTAs) through the left thoracic approach and right gastroepiploic artery (GEA) via a small laparoscopic access, for use in minimally invasive coronary artery bypass surgery. METHODS: The procedure was performed on twenty-two mongrel dogs. Three 10 mm ports were inserted in the left hemithorax to enable the introduction of a rigid 0-degree videoscope and forceps which allowed access to the left and right ITAs. For dissection of the GEA, one 10 mm and two 5 mm ports were inserted in the para-umbilical region. RESULTS: The left and right ITAs and the GEA were easily visualized and dissection and complete mobilization was achieved without injury, which was checked by the presence of good blood flow. The ITAs and GEA were divided distally, exteriorized through a small left anterior thoracotomy and the length of these three grafts were able to reach all of the left coronary artery branches. CONCLUSIONS: We have demonstrated, in dogs, the feasibility of video-assisted dissection of both the left and right ITAs through the left thoracic approach, without sternotomy, avoiding the risks of sternal complications and expanding its use for all patients. Furthermore, a third arterial conduit (the RGA) can be used without requiring laparotomy.

Angioscopy↗
PubMed2000

Arterial wall damage caused by snaring of the coronary arteries during off-pump revascularization.

BACKGROUND: Anastomosis of a saphenous or mammary artery conduit to the coronary artery requires precise and reproducible microsurgical technique. Over the past 3 decades, the elective induction of cardiac arrest and circulatory support have provided the conditions suitable for microsurgical anastomosis to all coronary vessels. Beating heart coronary grafting was rejuvenated at our center in 1985 as an alternative to cardiopulmonary bypass and cardioplegic arrest. One of the requirements for off-pump grafting is local vascular control of the target vessel and prevention of bleeding into the field from the open coronary artery. The most common hemostasis technique in use today is the application of circumferential traction sutures and snares around the coronary artery. We performed a human cadaver study to evaluate the potential for local trauma to the native coronary artery caused by this method of hemostasis. METHODS: Our research team applied both 5-0 polypropylene and 2-0 polyester snares to the proximal and distal right coronary artery (RCA) and left anterior descending (LAD) in 25 isolated fresh human cadaver hearts. A total of 100 points of snare application to the native coronary vessels were induced and then investigated histologically, with hematoxylin-eosin, Weigert, and phosphotungstic hematoxylin staining. RESULTS: The results suggested a direct relationship between the severity of the arterial lesion induced by the snares and the degree of local atherosclerotic disease in the native coronary artery. Compression and buckling of the elastic lamellae with medial fractures (similar in nature to angioplasty but directed inward) were seen when snares were applied to a region with marked atherosclerotic disease. CONCLUSIONS: The application of snares to the coronary artery proximal and distal to the anastomotic site must be done with caution. In cases of marked atherosclerotic disease in the underlying coronary artery, a new intimal-medial lesion can occur with indiscriminate application of a tourniquet. This phenomenon may account for some of the reported cases of late peri-anastomotic or distal stenoses seen with off-pump coronary artery bypass grafting and significantly detract from the advantages offered by beating heart surgery. If one or both snares can be avoided entirely, or applied carefully to disease-free segments of the vessel, this problem may be avoided entirely.

Adult↗
PubMed1998

Replacement of infected thoracic aortic prosthesis with a spiral composite vein graft.

We describe a case of a patient who had a ruptured aorta repaired by femorofemoral bypass with an interposition graft and subsequently had a graft infection. The patient was taken to operation and the old graft was removed. It was replaced by a spiral great saphenous vein graft. The patient has been followed up for 36 months with computed tomographic scanning, which has shown that the vein graft has not dilated.

Acinetobacter Infections↗
PubMed1998

Inflammatory response after myocardial revascularization with or without cardiopulmonary bypass.

BACKGROUND: Tumor necrosis factor-alpha has been implicated in complications seen after cardiac operations with cardiopulmonary bypass. The release of tumor necrosis factor-alpha and its possible effects were studied in patients undergoing coronary artery bypass grafting with and without cardiopulmonary bypass. METHODS: Twenty patients were studied, 10 with (group 1) and 10 without cardiopulmonary bypass (group 2). Serial blood samples were obtained before, during, and up to 48 hours after operation. Circulating tumor necrosis factor-alpha levels, leukocyte counts, and erythrocyte sedimentation rates were measured. Hemodynamic variables (blood pressure and heart rate), temperature, orotracheal intubation time, postoperative bleeding, and inotropic drug requirements were compared. RESULTS: Serum levels of tumor necrosis factor-alpha were detected in 6 patients (60%) in group 1 and none in group 2. The patients in group 1 had more hypotension than those in group 2 (7.4 +/- 1.0 mm Hg versus 8.5 +/- 0.7 mm Hg), required more inotropic drugs (8 patients versus 1 patient), and had a higher heart rate (114 +/- 8 beats per minute versus 98 +/- 10 beats per minute), a higher temperature (37.1 degrees +/- 0.5 degrees C versus 36.6 degrees +/- 0.3 degrees C), increased postoperative bleeding (820 +/- 120 mL versus 360 +/- 84 mL), a longer orotracheal intubation time (13.6 +/- 2.2 hours versus 9.3 +/- 1.4 hours), and a more pronounced leukocytosis. CONCLUSIONS: Cardiopulmonary bypass induces the whole-body inflammatory response through the release of tumor necrosis factor alpha, resulting in adverse systemic effects.

Blood Pressure↗
PubMed1998

Endoscopic placement of stents in aneurysms of the descending thoracic aorta.

This is a case of a patient with two saccular aneurysms in the descending aorta. Two self-expanding stents were inserted through an opening in the aortic arch, guided by the use of an Olympus endoscope, under profound hypothermia and total circulatory arrest. The bloodless field made possible the identification of the main thoracic branches, facilitating the positioning and deployment of both stents. Immediate postoperative recovery was excellent.

Aged↗