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Biomedical subjects

M Ricci

Publications and source records attributed to M Ricci.

At least 307 records · Page 17Linked to original sources
PubMedDate not supplied

Molecular analysis of strains of Shigella boydii isolated in northern and southern Italy.

In the years 1981-1988, Shigella boydii played a very limited role in the aetiology of diarrhoeal disease in Italy. However, between September and November, 1985, 19 isolates of serotype 2 were recovered in northern Italy from a dysentery outbreak which occurred in a geriatrics hospital in Abbiategrasso (Milan, Lombardy) and seven were identified in southern Italy during the period January-July, 1986 from apparently unrelated infection cases occurring in Brindisi (Apulia). These isolates were compared by molecular methods to seven strains of S. boydii of serotype 2 isolated since 1981 from the same geographic areas. Plasmid DNA analysis showed a large variety of patterns, whereas hybridization of chromosomal DNA with E. coli rRNA identified only two different profiles, one of which was exclusively found in all isolates from the hospital outbreak. No differences were detected among rDNA patterns of the remaining strains of S. boydii, irrespective of their geographic origin. These findings are consistent with the hypothesis that the infrequent cases of infection from S. boydii of serotype 2 which occurred during the years under study could probably be attributed to two different bacterial clones. Hybridization procedure and detection of hybrids were simplified by replacement of radioactive labelling of rRNA by the use of photobiotin.

Azides↗
PubMedDate not supplied

Histopathologic findings in synthetic and biologic explanted grafts used in peripheral arterial reconstruction.

Surgically explanted vascular grafts, including 47 autografts, 14 allografts, 103 chemically processed human umbilical vein (HUV) grafts, and 406 polytetrafluoroethylene (PTFE) grafts, were studied histopathologically. Autografts, HUV, and PTFE grafts were implanted mostly in the femoropopliteal position, whereas allografts were used as a blood access for hemodialysis. The main cause for explantation in autografts (53.6%), HUV (74.8%), and PTFE (61.3%) was thrombosis, whereas allograft failure was usually related to aneurysmal degeneration (72.7%). The infection rates of HUV (20.9%) and PTFE (25%) grafts were higher than those of autografts (4.8%) and allografts (9.1%). Furthermore, bacterial colonization occurred more frequently in HUV (63.9%) and PTFE (64.7%) than in autografts (6.7%) and allografts (0%). Leukocyte infiltration was detected mostly in HUV (39.4%) and PTFE (27%) explants. Autografts and allografts both showed a 7.1% rate of lipid uptake, whereas lipid retention was observed in 84.9% of HUV and 79.8% of PTFE grafts. These results suggest that biologic vascular grafts are to be used preferentially in small diameter arterial reconstruction because of their resistance to bacterial colonization and lipid uptake.

Adult↗
PubMedDate not supplied

Role of coronary graft flow measurement during reoperations for early graft failure after off-pump coronary revascularization.

Doppler-based techniques of coronary graft flow measurement are frequently used, especially during coronary artery bypass grafting (CABG) without cardiopulmonary bypass (CPB), to exclude graft dysfunction resulting from technical errors. Nevertheless, early graft failure in the immediate postoperative period continues to affect a small percentage of patients who may require emergent reoperation as a result of severe hemodynamic deterioration. In this setting, in which coronary angiography is infrequently an option, expeditious intraoperative assessment of previously constructed coronary grafts may be performed by using the Doppler-based technique Transit Time Flow Measurement (TTFM). As a result, the hemodynamic values obtained during reoperations may guide the operative strategy. In this study we report on eight patients who underwent "off-pump" CABG and necessitated early reintervention as a result of presumed graft dysfunction. In these patients, graft dysfunction was confirmed or excluded by using intraoperatively the TTFM technique, comparing newly obtained flow hemodynamic variables with those recorded as a baseline during primary operations.

Blood Flow Velocity↗
PubMedDate not supplied

Prevention of bleeding in aortic root surgery.

Bleeding after aortic root replacement with a valved conduit may be problematic and difficult to control. A few technical details that may facilitate hemostasis in aortic root surgery are described.

Aorta, Thoracic↗
PubMedDate not supplied

Techniques of exposure and stabilization in off-pump coronary artery bypass graft.

Recent advances in techniques of coronary artery exposure and myocardial stabilization in off-pump myocardial revascularization have provided cardiac surgeons with a wide variety of new devices and techniques. Until recently, the main obstacle to performing complete myocardial revascularization without using cardiopulmonary bypass (CPB) has been the technical difficulties of exposing and stabilizing coronary targets, especially those located on the lateral and inferior wall of the heart. The extraordinary cardiac tolerance to nonconstrictive anterior elevation and lateral displacement, however, has allowed the development of new strategies of coronary exposure. These advances, in combination with the development of new techniques of mechanical myocardial stabilization, have impacted on the feasibility and safety with which coronary anastomoses on the beating heart can be constructed. The aim of this article is to describe the technical aspects involved in off-pump coronary revascularization, focusing primarily on the most recent strategies of cardiac elevation and coronary exposure, the various techniques of myocardial stabilization, and some of the technical details of constructing distal anastomoses on the beating heart.

Anastomosis, Surgical↗
PubMedDate not supplied

Reoperative grafting of the LAD system using the LAST approach: technical details.

In patients in whom the left internal mammary artery (LIMA) has been previously utilized, reoperative grafting of the left anterior descending (LAD) or diagonal coronary arteries can be performed through a left anterior small thoracotomy (LAST) approach, utilizing the subclavian artery as inflow source. In such cases, however, the left upper lobe of the lung and the lingula may exert unwanted traction on the newly constructed coronary graft. Herein, we describe a detail of technique that eliminates this inconvenience.

Coronary Artery Bypass↗
PubMedDate not supplied

Hemodynamic effects of elevation and stabilization of the heart during off-pump coronary surgery.

BACKGROUND: Coronary artery bypass grafting (CABG) surgery is now being performed without the use of cardiopulmonary bypass (CPB). To achieve complete myocardial revascularization off-CPB, a technique has been developed to expose target coronary arteries while hemodynamics are maintained. METHODS: Complete myocardial revascularization was performed in 18 consecutive patients. Exposure of target coronary arteries was achieved by a "single-suture" technique, placed in the oblique sinus of the pericardium. Traction on the suture elevates and rotates the heart, thereby exposing all target coronary arteries. Cardiac index (CI) and intracardiac pressures were measured with a Swan-Ganz catheter during the different phases of the operation. RESULTS: All patients were successfully operated on without CPB. There were no postoperative complications or deaths. There were no major hemodynamic changes during the different stages of the operation; in other words, CI was unchanged during elevation of the heart and snaring of the main coronary branches. Pulmonary artery wedge pressure (PAWP) increased markedly during occlusion and stabilization of the circumflex coronary artery (p < 0.05). A marked increase in CI and cardiac output (CO) from baseline values was also recorded before chest closure (p < 0.05). CONCLUSION: Complete myocardial revascularization can be achieved safely without CPB. The single-suture technique allows for exposure of all target coronary arteries without hemodynamic compromise.

Cardiopulmonary Bypass↗
PubMedDate not supplied

"H" graft from the right internal mammary artery to the left anterior descending coronary artery: an alternative strategy in reoperative grafting of the LAD territory.

Reoperative grafting of the left anterior descending (LAD) coronary artery or its diagonal branches can be accomplished through a left anterior small thoracotomy (LAST) on the beating heart using the left internal mammary artery (LIMA) as a conduit. Patients in whom the LIMA has been used previously, however, are generally excluded from this approach unless an alternative technique is utilized. We describe a new technique applicable to these patients that consists of grafting the LAD through a LAST approach and connecting the graft to the right internal mammary artery (RIMA).

Coronary Artery Disease↗
PubMedDate not supplied

Myocardial revascularization of the beating heart in high-risk patients.

OBJECTIVE: Myocardial revascularization without cardiopulmonary bypass (CPB) has been proposed as an alternative technique in patients at high risk for conventional coronary artery bypass grafting (CABG). The purpose of this article is to evaluate the potential benefit of such an approach. METHODS: We retrospectively evaluated the perioperative results of off-pump CABG (OPCAB) performed from January 1995 to December 1999. Patients were divided into three groups on the basis of their preoperative risk factors: age greater than 80 years, reoperative CABG, and left ventricular ejection fraction percentage (LVEF%) less than 40%. The three subgroups were compared with patients operated on-CPB (ONCAB) during the same period of time. A total of 172 octogenarians had ONCAB versus 97 OPCAB, 307 reoperations were ONCAB versus 274 OPCAB, and 514 patients with LVEF% less than 40% were operated ONCAB versus 220 OPCAB. RESULTS: Preoperative comorbidities were homogeneously distributed in the OPCAB and ONCAB groups. More extensive coronary artery disease was found in the ONCAB groups. A trend for a lower number of perioperative complications was reported in the OPCAB groups. Freedom from overall complications was significantly higher (p < 0.005) in the OPCAB group. Actual mortality rates in the OPCAB and ONCAB groups were comparable (p = NS). CONCLUSIONS: CABG can be performed safely without CPB in patients with a high preoperative risk profile. Freedom from perioperative complications is markedly higher when the OPCAB approach is utilized.

Aged↗
PubMedDate not supplied

Acute right ventricular failure during aortic root replacement: intraoperative diagnosis and treatment.

The scope of this article is to report on a patient who underwent a Bentall procedure for type A aortic dissection. Right ventricular (RV) failure developed immediately after completion of the operation. The etiology was determined by using transit time flow measurement (TTFM), an ultrasound-based technique which demonstrated the absence of blood flow to the right coronary artery. This allowed for early and effective treatment, which was followed by a successful outcome.

Adult↗
PubMedDate not supplied

On-pump and off-pump coronary artery bypass grafting in the elderly: predictors of adverse outcome.

OBJECTIVE: To establish the role that coronary artery bypass grafting (CABG) without cardiopulmonary bypass (CPB) may have in improving perioperative outcomes of patients 70 years of age and older. BACKGROUND: Coronary revascularization in elderly patients is associated with morbidity and mortality rates higher than those observed in younger patients. The impact of CABG without CPB on perioperative outcomes has not been clearly established. METHODS: This retrospective, nonrandomized study consisted of 1,872 CABG patients. Of these, 1389 underwent CABG with CPB (CPB group) and 483 patients underwent CABG without CPB (off-pump group). Preoperative variables and outcomes were compared between the two groups. Multivariate logistic regression analysis was used to identify independent predictors of mortality, stroke, and adverse outcome. RESULTS: Demographics, Canadian Cardiovascular Society staging, operative priority, and other preoperative variables were comparable between the two groups. The prevalence of previous myocardial infarction was higher in the CPB group (62.6% vs 56.7%; p < 0.005), whereas the prevalence of calcified aorta and preoperative renal failure were higher in the off-pump group (5.4% vs 9.5%; p = 0.04 and 1.7% vs 3.3%; p = 0.04, respectively). Although the graft/patient ratio was higher in the CPB group (3.4 vs 1.9), these patients displayed more extensive coronary artery involvement. At univariate analysis, patients in the off-pump group had a higher rate of freedom from complications (88.2% vs 81.3%; p < 0.005) and a lower incidence of stroke (2.1% vs 4.2%; p = 0.034) than patients in the CPB group. Although there was a trend for a higher actual mortality in the off-pump group (4.8% vs 3.7%; p = ns), the risk adjusted mortality in this group was lower (1.9% vs 2.1%). Multivariate analysis showed that while the use of CPB correlated independently with an increased risk of overall complications, it was not associated with a higher probability of death or stroke. CONCLUSIONS: This investigation suggests that elderly patients undergoing CABG may benefit from off-pump revascularization, as the use of CPB correlated independently with an increased risk of overall complications. However, CPB did not emerge as an independent predictor of death or stroke at multivariate analysis.

Aged↗
PubMedDate not supplied

Transmitral endoventricular repair of left ventricular pseudoaneurysm following mitral valve replacement.

Left ventricular (LV) pseudoaneurysm is a rare but serious complication of mitral valve replacement and is usually the consequence of atrioventricular separation. Although there may be a role for nonoperative treatment in the presence of a small false aneurysm and in the absence of paravalvular leak, the presence of a large false aneurysm usually mandates surgical intervention. This may be hazardous in patients with concomitant LV dysfunction. We report a case of a patient who presented with a large LV pseudoaneurysm following numerous attempts of mitral valve replacements for a variety of reasons, including endocarditis. Some of the technical details of aneurysm repair and aspects of myocardial protection are discussed. In our patient, avoidance of cardioplegic arrest may have contributed to the successful outcome.

Aged↗
PubMedDate not supplied

Intermediate-sized filament proteins (keratin, vimentin, desmin) in metaplastic carcinomas, carcinosarcomas and stromal sarcomas of the breast.

The distribution of intermediate-filament (IF) proteins of the keratin, vimentin and desmin type in breast stromal sarcomas, carcinosarcomas, metaplastic carcinomas and phyllodes tumors has been compared using the avidin-biotin complex immunoperoxidase technique. Keratin reactivity was found in carcinomatous and pseudosarcomatous areas of all metaplastic carcinomas, in the cuboidal epithelial cells of carcinosarcomas and in the epithelial component of phyllodes tumors. Vimentin and desmin were detected in the sarcomatous portion of carcinosarcoma, focally in the stromal component of phyllodes tumors and not always in the stromal sarcomas. These data confirm that combined analysis of IF expression is a reliable and convincing way to differentiate stromal sarcomas, metaplastic carcinomas and carcinosarcomas in breast pathology.

Breast Neoplasms↗
PubMedDate not supplied

[Obstruction of terminal ileum due to heterotopic gastric mucosa].

Heterotopic gastric mucosa situated in the small bowel distal to the Treitz suspensory ligament is very rare, except in Meckel's diverticulum and in intestinal duplications. There are two forms of this disease, congenital and acquired. The former is secondary to inflammatory bowel disease. The main difference between these forms is histological, although determining diverse physiopathological aspects. A case of a 34 year old man with heterotopic gastric mucosa in the terminal ileum manifested by intestinal obstruction is reported. He was treated surgically by enterectomy of two small bowel segments, both reconstructed by primary suture. His postoperative course was remarkable. The histopathologic study showed a typical pattern of the acquired type because of the presence of antral the antral mucosa and intense fibrosis. That is probably related to intestinal tuberculosis, but was not histologically confirmed. Individual and family recent history of pulmonary tuberculosis corroborates the suspicion. This is a unique report in the literature, among 28 other heterotopic gastric mucosa situated in the jejunum and ileum.

Adult↗
PubMedDate not supplied

Surgical treatment of HIV-related immune thrombocytopenia.

Immune related thrombocytopenia has been described extensively in patients infected with the human immunodeficiency virus (HIV). The efficacy and safety of splenectomy performed in 21 patients affected with HIV-related immune thrombocytopenia (platelet count less than 50,000/mm3), between 1992 and 1996, were evaluated. All the patients were symptomatic and had failed medical therapy. Nine of them were affected with acquired immune deficiency syndrome (AIDS), whereas 12 were HIV-positive (non-AIDS). In all the patients, a pre-operative bone marrow biopsy revealed increased megakaryocytes. Follow-up ranged from 5-16 months. The response rate to splenectomy (platelet count greater than 100,000/mm3) in the AIDS group was 83%, as opposed to 100% in the HIV-positive (non-AIDS) group. During the follow-up period, 19 of the 21 patients maintained platelet counts greater than 98,000/mm3; of the two non-responders, one patient expired 3 weeks after surgery, and a second patient had never responded. None of the HIV-positive (non-AIDS) patients developed AIDS during the follow-up period. All the complications observed (24%) were treated without sequelae. Based on these data, splenectomy can be considered safe and effective in treating patients with symptomatic HIV-related thrombocytopenia, when medical therapy has failed. Moreover, splenectomy did not appear to adversely affect the rate of conversion from the HIV-positive to the AIDS status, nor did it accelerate the progression of the disease in patients already diagnosed with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Use of the "single suture" technique to expose the anterior surface of the heart.

The "single suture" technique, which consists of placing a suture in the oblique sinus of the posterior pericardium and connecting it to a vaginal tape, is commonly adopted in off-pump coronary artery revascularization to obtain elevation of the heart and coronary artery exposure. This report describes the use of this technique to expose the anterior wall of the heart in the setting of ventricular aneurysm repair.

Heart Aneurysm↗