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Biomedical subjects

A Pierangeli

Publications and source records attributed to A Pierangeli.

At least 55 records · Page 3Linked to original sources
PubMed1996

[Brucella endocarditis: role of drug treatment associated with surgery].

Brucella infective endocarditis is an uncommon, but serious complication of brucellosis. The aortic valve is the most commonly affected cardiac valve, and a fearful complication is the formation of aortic root abscess. Due to the characteristics of the infection, medical therapy alone is not sufficient in treating the disease and best results are achieved in combination with surgery. We describe 2 cases of brucella endocarditis involving the aortic valve. Aggressive treatment, with surgery performed during a period of active infection, produced good results in eradication of infection and in preventing fatal complications such as rupture of aortic root abscesses.

Anti-Bacterial Agents↗
PubMed1996

[Heart surgery with cardiopulmonary bypass in patients on chronic dialysis treatment: our experience].

METHODS: To determine the mortality and the morbidity of cardiac surgery in patients on chronic hemodialysis, we retrospectively reviewed eighteen adult patients (13 males and 5 females) with a mean age of 54.7 years (range: 30-67 years) who underwent cardiopulmonary bypass procedures between 1987 and 1995. The operations included: isolated coronary artery bypass grafting in 12 patients, coronary artery bypass grafting plus mitral ring annuloplasty in 1 patient, mitro aortic valve replacement in 2 patients, isolated aortic valve replacement in 1 patient, aortic valved conduit implantation in 1 patients and mitral valve replacement plus tricuspid annuloplasty in 1 patient. There were 10 and 3 patients in CCS functional classification III and IV respectively; 1 and 4 patients were in NYHA classification II and III respectively. All of them were hemodialyzed the day before surgery: the average time they had been on hemodialysis was 6.5 years. Anesthesia and the cardiopulmonary bypass (CPB) in these patients required attention in order to provide the optimal fluids and electrolytes balance: particularly intravenously administered fluids were kept to a minimum and drug dosages were reduced to recommended levels for anephric patients. An hemoconcentrator was used in all patients during the CPB and, in the last 4 cases, we used a dialysis filter and a sterilized perfusional solution to reduce the level of potassium and to put off postoperative dialysis. RESULTS: In three patients there were major bleeding problems resulting in reoperation; 5 perioperative deaths occurred: two of them due to myocardial infarction and three due to irreversible low cardiac output state. In our experience there were four late deaths: one patient died four months after surgery for chronic heart failure, another one died twelve months after surgery for dilated cardiomyopathy and two patients died respectively seventeen and seventy two months after discharge for myocardial infarction. Two of the remaining patients reported recurrence of angina while the others achieved symptomatic improvement. CONCLUSIONS: In conclusion, cardiac surgery is performed on chronic renal dialysis patients with high mortality and morbidity and it's indicated only if medical treatment is ineffective. The successful surgical results, obtained with an adequate management between surgeons, anesthesiologists and nephrologists, don't assure the long-term survival of the patients.

Adult↗
PubMed1996

[Intima flap of the external carotid and postoperative stroke in a patient surgically treated with thromboendarterectomy of the internal carotid].

Retrograde thrombosis of the carotid bifurcation rising from an intimal flap of the external carotid artery represent a rare complication of carotid surgery. We present the case of a patient who had undergone carotid thromboendarterectomy (TEA) whose postoperative course was complicated by the appearance of left hemiplegia and coscience disorders. The timely diagnosis of acute carotid thrombosis and the immediate reoperation prevented neurological deficits becoming settled. An attentive intraoperative evaluation of carotid bifurcation showed only the presence of an intimal flap of the external carotid artery from which a big occluding thrombus, involving the bifurcation, rose. The internal and common carotid arteries showed a successful result of the TEA and a good retrograde flow through the internal carotid artery. The authors underline the existence of this perioperative complication and the need for a timely recognition and treatment to avoid serious neurologic consequences.

Carotid Artery Thrombosis↗
PubMed1995

Mutational analysis of the 3'-terminal extra-cistronic region of poliovirus RNA: secondary structure is not the only requirement for minus strand RNA replication.

A series of mutations were introduced in the 3'-terminal untranslated region (3'-UTR) of full-length infectious poliovirus cDNA clones, and following transfection of COS-1 cells the ability of these constructs to generate viable viral particles and/or to support viral RNA synthesis was assayed. Substitution of the 3'-UTR of poliovirus RNA with the equivalent sequences of HAV RNA abrogated viral RNA replication, whereas the introduction of extended 'foreign' sequences between the open reading frame and the 3'-UTR was well tolerated. Point mutation that either destabilized the stem-and-loop structure or altered the sequence of the loop in domain 'Y' (nomenclature as per Pilipenko et al., [Nuclei Acids Res. 20 (1992) 1739-1745]) abolished both the infectivity and viral RNA synthesis. These were not restored by compensatory mutation that reconstructed the native secondary structure of this domain, suggesting that the secondary/tertiary folding of the 3'-UTR is not the only determinant for template recognition at initiation of RNA synthesis, but rather that a specific primary sequence is indeed required.

Animals↗
PubMed1995

Role of the pyrimidine-rich tract on the translation of 'chimeric' polio-hepatitis A mRNAs with engineered 5'-terminal untranslated regions.

The 5'-terminal untranslated region (5'-UTR) of picornavirus RNA contains a series of cis-acting elements required for the internal initiation of translation, including a pyrimidine-rich tract (PRT), which in entero- and rhinoviruses is located about 20 nts upstream from a silent AUG triplet in the vicinity of the translation initiation site. In hepatitis A virus (HAV) RNA, the PRT is only 12 nts upstream from the legitimate AUG initiation codon, and a second, longer PRT in a region far removed from the translation initiation site. This 5'-distal PRT includes a 'core' sequence 80% homologous to the PRT of poliovirus RNA. A 'chimeric' polio-hepatitis A mRNA was constructed in which the sequences extending between nucleotides 45 and 156 of HAV RNA replaced the corresponding ones in poliovirus 5'-UTR. The construction was extended with poliovirus sequences up to position 1809. The recombinant mRNA so generated carried two copies of the PRT. In vitro translation in lysates of truncated poliovirus mRNAs generated a single peptide of Mr = 39 kDa, while the chimeric mRNA generated a series of short peptides as a result of fortuitous (or aberrant) initiation events. A more extensive substitution in the chimeric 5'-UTR which removed the 3'-most PRT brought by the poliovirus sequences, restored the translation at the authentic initiation site. Point mutations were engineered in the 5'-most PRT of the chimeras, and bi-cistronic plasmids were constructed in which either the parental poliovirus 5'-UTR or the chimeric ones were introduced in the intergenic region. Upon transfection of COS-1 cells, the chimeric polio-hepatitis A 5'-UTR containing two PRTs did not express the reporter gene. Removal of the 3'-distal PRT or point mutations engineered into the 5'-most PRT partially restored the transient expression of the reporter gene, consistent with the notion that a single (and only a single) functionally active PRT in a proper context is required to secure the internal initiation of translation of bi-cistronic mRNAs in vivo.

Base Sequence↗
PubMed1995

[Transvenous cardioverter-defibrillators: clinical experience at implantation and follow-up].

Thirty-seven patients with ventricular tachyarrhythmias refractory to antiarrhythmic drug treatment, guided by electrophysiological testing, were submitted to implantation of a cardioverter-defibrillator by the transvenous technique. Mean age was 55 +/- 14 years and the underlying heart disease was coronary heart disease in 24 patients, cardiomyopathy or other etiologies in 11 patients. In 2 patients ventricular arrhythmias were idiopathic. Left ventricular ejection fraction was < or equal to 40% in 65% of the patients. The following devices were implanted: CPI Ventak P in 2 patients, Ventak P2 in 9 patients, Ventak PRx in 9 patients, Ventak PRxII in 2 patients, Telectronics Guardian ATP III 4215 in 9 patients, Siemens Siecure in 5 patients, Medtronic Jewel PCD in 1 patient. At implantation defibrillation threshold was lower with biphasic shocks than with monophasic shocks (17.0 +/- 3.2 vs 20.9 +/- 3.8 J, p < 0.003) and the need for subcutaneous patches was lower when biphasic shocks were employed. Operative and perioperative mortality were 0% and no significant complications were observed. During the follow-up (16 +/- 11 months) 35% of the patients had appropriate shocks and 93% of the patients with antitachycardia pacing availability (n = 15) had effective antitachycardia pacing interventions. The following complications were observed: lead failure in 4 patients (3 insulation breaks and 1 elongation for stretching), late lead dislodgement in 2 patients, lead recall in 1 patient, all of which required reintervention. Inappropriate shocks occurred in 30% of the patients and were related to lead failure, supraventricular arrhythmias or alternating current interference. During the follow-up one patient died of sudden death and one was submitted to heart transplantation. In conclusion, implantation of a cardioverter-defibrillator by the transvenous technique is a procedure relatively free from complications. During the follow-up lead failure appears to be one of the most relevant complications. Antitachycardia pacing allows effective termination of ventricular tachycardias without cardioversion, with a better compliance.

Adult↗
PubMed1994

[An echocardiographic analysis of the insufficient mitral valve: its intraoperative functional anatomy in relation to valvular reconstruction].

Mitral valve repair in patients with mitral regurgitation requires a precise evaluation of the mechanism of valvular pathology before surgery. Transesophageal echocardiography has become the principal method for imaging valvular pathology, especially with the latest introduction of multiplanar transesophageal technology. Traditionally, echocardiographic analysis of regurgitant mitral valves has concentrated on the description of abnormalities of leaflet motion such as prolapse, while surgical correction aims at restoring the coaptation of the edges of the leaflets. To reconcile these different approaches, the echocardiographic features the findings on direct inspection, and the types of repair performed were analyzed in 37 incompetent mitral valves. The zone of coaptation of the mitral valve was studied in a series of left ventricular long-axis views obtained with a transesophageal multiplanar echo-transducer from the anterolateral via the central, to the posteromedial segment. Four patterns of leaflet closure were found: normal apart from a dilated annulus (24%), normal apposition but absent coaptation (8%); asymmetrical apposition but intact coaptation (16%); and abnormal apposition and absent coaptation (52%). In addition leaflet motion was described (prolapse, retraction, normal), and the anteroposterior dimension of the mitral annulus was measured. There was a direct relationship between these echocardiographic findings and the types of reconstructive techniques used. The echocardiographic analysis offers a logical approach to the preoperative diagnosis of regurgitant mitral valves, with the possibility to predict the feasibility and the type of mitral repair.

Adult↗
PubMed1994

New bileaflet bioprosthesis: early and mid term results.

A new bovine pericardial bioprosthesis (AMB bioprosthesis) with a bileaflet geometry was designed and developed, with the aim of achieving uniform stress distribution within the prosthesis. The ultimate goal was to limit tissue degeneration to a minimum by attaining optimum fluid dynamics, thereby obtaining an extended clinical durability. The two-leaflet, dome-shaped geometry with a central hinge allowed a very low profile, low ventricular projection in the mitral position, large effective orifice area and low gradients. The design of the thin Delrin stent and the centrally crossing bridge was developed using finite element analysis. Pre-clinical laboratory investigations showed very low trans-valvular gradients and no mechanical or tissue failure after 400 million cycle accelerated wear test. The final model of the prosthesis was manufactured by Baxter-Edwards CVS Division and tested in sheep with good results for up to five months. A limited clinical trial was started in January 1990 and stopped one year later encompassing 12 aortic and six mitral implants. The patients were followed clinically and by echocardiography three, six and 12 months, and four years after surgery. Mean gradients were 4 mmHg in the mitral and 10 mmHg in the aortic position with only minimum regurgitation and no tissue failure. We conclude that early and mid term results with this new pericardial bioprosthesis appear to be favorable and intend to closely monitor further outcome within the limited patient population.

Animals↗
PubMed1994

[Neoplastic caval and intracardiac thrombosis secondary to reno-adrenal tumors. One-stage surgical treatment in deep hypothermia and cardiocirculatory arrest].

Due to the considerable progress made by instrumental total body diagnostics (ECO, CAT, RMN, angiography, etc.) in recent years heart surgery has increasingly often been used to treat pathologies which are not primarily cardiac but which see the involvement of the heart and large vessels in the advanced stages of cancer and non-cancer diseases of other organs or apparatus. This is the case of malignant renal or adrenal tumours which infiltrate along the caval lumen until they reach the right atrium. In these cases caval and atrial involvement must be seen as a prolapse of the tumour and not a long-distance metastasis: prognosis only appears to be linked to the hemodynamic impairment caused by the obstacle to systemic lower venous drainage. On the bases of this observation radical surgery may be justified at a renal, caval and cardiac level. The authors report their preliminary experience in 6 patients with renal cancer (4 renal carcinoma, 1 Wilm's tumour, 1 adrenal carcinoma) who underwent combined surgery, in a single stage, involving enlarged nephrectomny and caval and atrial thrombectomy, the latter performed in profound hypothermia and cardiocirculatory arrest. Two patients died later and 4 are living, in good condition and with perviousness of the lower caval venous drainage. Similar to other analogous experience reported in the literature, the authors suggest taking a combined approach performed in a single stage into consideration for these patients.

Adolescent↗
PubMed1994

Aortic arch aneurysm in Behçet's disease: an unusual association.

Vascular complications of Behçet's disease particularly affect the venous system. Arterial lesions include thrombosis and aneurysms. There are few reports of aortic involvement, usually of the abdominal aorta. Aortic arch involvement has not been reported previously. A patient with Behçet's disease who developed an aortic aneurysm involving the ascending aorta to the hiatus with massive incompetence of the aortic valve is described.

Adult↗
PubMed1993

Interrupted aortic arch and aortopulmonary window: one-stage repair in the first week of life.

Aortic arch interruption associated with an aortopulmonary window is a rare congenital malformation that needs an early diagnosis and surgical treatment to avoid irreversible pulmonary lesions. Here we describe a case of a successful one-stage surgical repair in a 3-day-old neonate, without the use of prosthetic material, for the correction of the aortic arch interruption.

Aorta, Thoracic↗
PubMed1993

Aortic coarctation with hypoplastic arch in neonates: a spectrum of anatomic lesions requiring different surgical options.

Hypoplasia of the transverse aortic arch is frequently associated with isthmic coarctation in many patients referred for operation in early infancy, and the surgical technique should be adjusted to suit each type of anatomic lesion. Referring to the anatomic description of hypoplastic aortic arch reported by Moulaert and associates, between January 1988 and July 1991 we operated on 32 consecutive infants (< or = 3 months old) using a surgical approach based on the echocardiographic and angiographic findings; 20 patients (62%) were younger than 2 weeks of age and 20 patients (62%) had associated intracardiac lesions. According to the location, extension, and size of the hypoplasia of the aortic arch, we had three groups of patients: in group 1 (21 patients) we performed resection and extended end-to-end anastomosis, as previously described in 1985; in group 2 (5 patients) we performed resection, posterior end-to-end anastomosis, and anterior subclavian flap enlargement; and in group 3 (6 patients) we performed direct side-to-end anastomosis between ascending and descending aorta through a median sternotomy. One patient died during the postoperative course in group 3. With a mean follow-up time of 26 months we had 4 cases (13%) of "residual" or "recurrent" coarctation in group 1, successfully repaired at 2 months of age by an anterior approach in 2 patients and by percutaneous angioplasty in the others. In conclusion, hypoplastic aortic arch in neonates represents a common difficulty, and optimal reconstruction of the entire aortic arch is mandatory to reduce operative mortality and incidence of recoarctation, especially when there are complex associated intracardiac lesions or left ventricular dysfunction.

Aorta, Thoracic↗
PubMed1993

[Role of transesophageal echography in the diagnosis of aortic dissection and in therapy programming].

The diagnostic accuracy of transesophageal echocardiography and its relevance on the decision making process were evaluated in 80 patients with suspected aortic dissection during a 37-month period. The diagnosis was proven by aortography and/or magnetic resonance and/or computerized tomography and/or surgery and/or autopsy in each case. Transesophageal echocardiography had no serious complication. A correct diagnosis of aortic dissection was made in 39 of 40 patients (sensitivity, 97.5%; specificity, 100%) and the type of dissection was correctly demonstrated in each case. Thrombi in the false lumen were detected in 16 patients. The primary entry site was correctly identified in 33 patients (85%). Aortic regurgitation was detected in 25 cases (severe in 9) and pericardial effusion in 14 (with tamponade in 2). Transesophageal echocardiography was more accurate than aortography in the diagnosis of noncommunicating intramural dissection (2 cases) and identified more precisely the retrograde extension of the dissection in DeBakey type III patients (4 cases). In 9 cases surgical indication was based on clinical data and transesophageal echocardiography alone. We conclude that transesophageal echocardiography allows a bedside, safe and accurate diagnosis of aortic dissection. In the majority of the patients it provides the minimal diagnostic information necessary to the therapeutical decision making.

Acute Disease↗
PubMed1993

Ultrasonic classification of carotid plaques causing less than 60% stenosis according to ultrasound morphology and events.

Carotid plaque morphology studied by ultrasound has been used to classify 3 types of bifurcation plaques, producing less than 60% stenosis on duplex scanning: Type A, the homogeneous, highly echogenic plaque; Type B, the heterogeneous (mainly echogenic, B-1 or mainly echolucent, B-2) plaque; Type C, the complex plaque with irregular surface, echogenic and/or echolucent with calcifications. One hundred asymptomatic subjects in each plaque group were included in a prospective 4-year follow-up study to evaluate clinical events and brain damage by yearly cerebral CT and MR scans. After four years 96 subjects with type A plaque, 89 with type B-1 and 67 with type C plaques completed the study. While there were no clinical events or positive cerebral scans in subjects with type A plaques there was a significantly increasing number of cerebral and vascular events in subjects with plaque B and C type with a zero mortality in the plaque A group, a 2.24% mortality in type B plaques and a significantly higher (p > 0.05) mortality (13.4%) in type C plaques. CT and MR scans revealed brain damage which had been totally asymptomatic with MR detecting a larger number of lesions. Also the number of cerebral lesions observed by CT/MR were significantly greater than the number of recorded clinical episodes. ECG stress test revealed a larger number of asymptomatic coronary disease in the C type plaques. In conclusion ultrasound plaque morphology is linked to different incidences of cerebral and cardiac events, brain damage and asymptomatic coronary disease. Also CT and MR may reveal lesions which do not cause signs or symptoms.

Aged↗
PubMed1992

Sick sinus syndrome and diffuse impairment of the conduction system in a child: successful pacing with a steroid eluting endocardial pacing lead.

A 9-year-old patient who had had a syncope was found to have atrial flutter in a resting electrocardiogram (ECG). Brief phases of sinus arrest had previously occurred after drug conversion to sinus rhythm. Structural heart disease was excluded by cardiac catheterization and angiography. Electrophysiologic study revealed a sick sinus syndrome, associated with diffuse impairment of the conduction system (supra-, infra-, and intrahisian block). Epimyocardial and an endocardial pacemaker implantation failed because of high stimulation threshold, after 3 years and 2 weeks, respectively. At the third implantation a steroid-eluting endocardial pacing lead was used and satisfactory pacing was still present 2 years later.

Atrial Flutter↗
PubMed1992

Left ventricular dynamics after aortic valve replacement: a long-term, combined radionuclide angiographic and ultrasonographic study.

Between January 1985 and July 1990, we studied 71 patients at our institution who underwent aortic valve replacement for either aortic valve regurgitation (40 patients) or stenosis (31 patients). The following prostheses were implanted: 25 St. Jude Medical valves (bileaflet), 16 Björk-Shiley (monoleaflet, tilting disc, 60 degrees convexo-concave), 16 Medtronic-Hall (monoleaflet, tilting disc), and 14 Starr-Edwards (caged ball). The patients were evaluated pre-and postoperatively by means of gated blood-pool scintigraphy and Doppler echocardiography. Postoperatively, each patient was studied at 6 months, 1 year, and then annually. The evaluations focused upon 1) scintigraphically assessed left ventricular performance indicators (end-diastolic and end-systolic volume, as well as resting and exercise ejection fraction) and 2) Doppler-derived hemodynamic indexes (peak and mean transvalvular pressure gradient, effective orifice area, regurgitant flow, and systolic wall stress). Early after aortic valve replacement, 55 (77.5%) of the patients had substantial symptomatic relief, with normal hemodynamic values both at rest and during exercise (New York Heart Association functional class I or II); another 6 patients (8.5%) maintained their preoperative status in those classes. Within a year after surgery, a majority of patients showed a significant reduction in left ventricular dimensions. The patients with preoperative aortic valve stenosis had a significantly reduced end-diastolic and end-systolic volume (p<0.05), a moderately reduced left ventricular mass index (p<0.01), and a significantly increased exercise ejection fraction (p<0.05); moreover, in all 31 of these cases, systolic wall stress returned to normal or lower-than-control values (p<0.005). The patients with preoperative aortic valve regurgitation had a significant reduction in end-diastolic and end-systolic volume (p<0.005), diastolic wall stress (p<0.005), and a significant increase in exercise ejection fraction (p<0.01); however, their left ventricular mass index was not significantly reduced. Optimal long-term survival was afforded by the St. Jude valve in the small size (21 mm) and the Starr-Edwards valve in the large size (27 mm). This study represents the first reported use of a serial, combined radionuclide and echocardiographic procedure for the follow-up of patients undergoing aortic valve replacement. During the 5(1/2)-year follow-up period, this combined technique proved highly accurate for collecting follow-up data, often complementing or correcting simple ultrasound results. This diagnostic approach enabled us to 1) obtain information comparable to or better than that provided by cardiac catheterization, 2) identify complications early, 3) differentiate between valvular and ventricular failure, and 4) suggest the valve of choice (not always that with the best hemodynamic performance) in patients with different cardiac variables. Further research is needed to confirm this study, the results of which could change many medical and surgical strategies for clinical management of the diseased aortic valve.

Journal Article↗
PubMed1990

Tubular supravalvar aortic stenosis: replacement of ascending aorta in a young patient.

The diffuse form of supravalvar aortic stenosis represents a surgical challenge when ascending aorta and proximal aortic arch are involved. We describe a technique performed on a 14-year-old patient with normal aortic annulus and severe diffuse supravalvar aortic stenosis in which the replacement of ascending aorta and proximal aortic arch with a tubular prosthetic graft completely relieved the obstruction as confirmed by cardiac catheterization.

Adolescent↗