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C Pratesi

Publications and source records attributed to C Pratesi.

At least 37 records · Page 2Linked to original sources
PubMed2001

Carotid endarterectomy in rare bilateral carotid-vertebral anastomosis.

In the embryo, the anterior and the posterior cerebral circulations are connected by several longitudinal anastomotic vessels. These anastomoses disappear progressively, until the carotid and vertebrobasilar systems are connected only by a pair of posterior communicating arteries. These embryonal anastomoses rarely persist in adults and may have an important physiologic role during carotid surgery. We report a case in which a patient with bilateral embryonal carotid-vertebral anastomoses underwent right carotid endarterectomy for asymptomatic internal carotid stenosis.

Aged↗
PubMed2001

Antibiotic prophylaxis in clean surgery: vascular surgery.

The commonest and most dangerous infective complication in vascular surgery is prosthetic graft infection. Despite the use of routine systemic antibiotic prophylaxis, graft infection occurs after 3-5% of all prosthetic vascular reconstructions. Infection is associated with a high rate of major morbidity and mortality, with significant time and cost implications. Management can be difficult and the outcome is often disappointing. Data from Italian Registry of Prosthetic Graft Infections show that the commonest site of infection is the aorto-femoral district and that involved bacteria are usually gram-positive in early and low-grade infections and gram-negative in late and high-grade infections. Results are poor, with a mortality rate of 15% for elective surgery and of 60% for emergency interventions. We report the results of a multicenter randomized controlled trial of rifampicin-bonded Dacron grafts in aorto-femoral surgery, in which our Department was involved. Data demonstrate a reduction in total early wound and graft infection rates, and 2-year results show a small, non-significant reduction in graft infection (1.7% in study group, 2.3% in control group). The same results were obtained in two other multicenter trials.

Antibiotic Prophylaxis↗
PubMed2000

High prevalence of mild hyperhomocysteinemia in patients with abdominal aortic aneurysm.

PURPOSE: In vitro studies have recently demonstrated that homocysteine interacts with the aortic wall by inducing both elastolysis and endothelial perturbation. The aim of this study was to evaluate homocysteine plasma levels and their relationships with aortic diameter and endothelial damage in patients with abdominal aortic aneurysm. SUBJECTS AND METHODS: Fifty-eight consecutive male patients (mean age, 69.5 +/- 6.6 years; age range, 49-78 years) who underwent abdominal aortic aneurysm surgery were enrolled in the study. Twenty-two of 58 patients had no clinical or instrumental evidence of atherosclerosis. Sixty control subjects were age matched and sex matched with the patients. In all of the subjects, we evaluated total homocysteine and thrombomodulin plasma levels and the distribution of the C677T methylenetetrahydrofolate reductase gene mutation. RESULTS: Hyperhomocysteinemia was found in 26 (48%) of the 58 patients with abdominal aortic aneurysm, and homocysteine plasma levels were significantly higher in patients than in control subjects (15.7 +/- 6.5 micromol/L vs 9.6 +/- 3.9 micromol/L; P <. 0001). In addition, the subgroup of patients with abdominal aortic aneurysm who did not show evidence of atherosclerosis showed homocysteine plasma levels significantly higher than those in the controls (14.8 +/- 6.1 micromol/L vs 9.6 +/- 3.9 micromol/L; P <. 001). A larger aneurysmal size was detected in hyperhomocysteinemic patients than in those with normal homocysteine plasma levels (5.09 +/- 0.84 cm vs 5.79 +/- 1.5 cm; P <.05). The genotype distribution of the C677T methylenetetrahydrofolate reductase mutation was as follows: TT 21%, TC 55%, and CC 24% in the patients; TT 10%, TC 58%, and CC 32% in the controls. Moreover, in patients a significant correlation (P <.005) between homocysteine plasma level and 677TT methylenetetrahydrofolate reductase genotype was found. Thrombomodulin plasma levels were significantly higher (P <.00005) in patients (median, 30 ng/mL; range, 10-164 ng/mL) than in controls (median, 19 ng/mL; range, 13-44 ng/mL), and thrombomodulin levels were significantly higher (P <.005) in hyperhomocysteinemic patients (median, 39.5 ng/mL; range, 15-164 ng/mL) than in normohomocysteinemic patients (median, 27.5 ng/mL; range, 10-85 ng/mL). In addition, in patients with abdominal aortic aneurysm, a direct significant correlation (P <.005) was found between homocysteine and thrombomodulin. CONCLUSIONS: These data indicate an association between the presence of AAA in patients selected for surgical treatment of AAA and elevated homocysteine plasma levels and suggest that homocysteine may induce endothelial perturbation and stimulation in these patients.

Aged↗
PubMed1999

Duplex scanning exploration of the ophthalmic artery for the detection of the hemodynamically significant ICA stenosis.

BACKGROUND AND PURPOSE: The North American and the European Carotid Endarterectomy Trials demonstrated a significant benefit of surgery in preventing stroke for patients with symptomatic hemodynamically significant internal carotid artery (ICA) stenosis. Because the 3 angiographic methods of measuring carotid stenosis provide discrepant results, the indication for surgery depends on the method used for the evaluation of the angiogram. The goal of this study was to verify whether color duplex scanning of the ophthalmic artery alone might be reliable for detection of the extracranial hemodynamically significant ICA stenosis. METHODS: Three groups of patients (351 total patients) with transient ischemic attack or minor stroke referred for possible carotid endarterectomy were examined by means of color duplex scanning of the ICA, transcranial Doppler, color duplex scanning of the ophthalmic artery, and angiography of the ICA. RESULTS: In the first group (n=31) the comparison of findings from each method and the direct measurement of the residual lumen of plaque removed "en bloc" showed that the findings of the ophthalmic artery color duplex scanning, subdivided into 5 categories--NP (normal positive), LP (low positive), NF (no flow), REV (reverse flow), PP (pathological positive)--were associated with the best overall agreement (96.7%). The accuracy of the various categories of the ophthalmic artery color duplex scanning signals was studied in the second group of patients (n=200). The results pointed out that all but low positive categories were associated with high diagnostic accuracy. Finally, the results obtained in the third group (n=120) showed that a significant increase in the specificity of the low positive signal could be obtained by processing this signal in terms of pulsatility index and of transmission of pulsatility index. CONCLUSIONS: Our results suggest that the diagnostic capacity of color duplex scanning for the detection of ICA critical stenosis can be appropriately increased if it is performed also at the level of the ophthalmic artery and if the Doppler signals are processed on the basis of criteria we applied.

Aged↗
PubMed1999

Aorto-iliac steal syndrome. A rare case of renal hypoperfusion.

In aorto-iliac occlusive disease a diversion of blood flow from visceral arteries to lower limbs rarely occurs. This condition is known as aorto-iliac steal syndrome. This report is about the case of a male patient affected by chronic atherosclerotic occlusion of the aorta associated with an aorto-iliac steal supported by an anomalous vessel coming from the left renal artery to the homolateral external iliac artery to the detriment of the renal blood flow. Renal sequential scintiscan (RSS) at rest and after stress test was employed to assess renal blood flow and excretory functions before and after an aorto-bifemoral bypass. Surgical revascularization permitted reversal of the steal phenomenon and the improvement of left renal blood flow.

Aorta, Abdominal↗
PubMed1999

[Arteriovenous fistulas for hemodialysis: transposition of the cephalic veins, a personal experience].

BACKGROUND: Vascular access for hemodialysis has remarkably developed during these years. Since 1966 we have the Brescia-Cimino fistula which is considered nowadays the best choice for angioaccess. The transposed cephalic vein is the "variant" which has been evaluated in a single stage surgical technique. METHODS: A prospective and randomized study regarding 23 patients submitted to operation for first fistula during 1998. With a median follow-up of 10 months, these fistulas have been studied with echocolordoppler in order to verify their primary patency, diameter and blood flow in artery, in vein and anastomosis. RESULTS: Fistulas have been patented in all cases (15 males e 8 females) and used for dialysis after 3 weeks. No early or late complications have been observed. Mean diameter has been 1.2 cm with mean velocity of 1.8 m/sec, in artery mean velocity 2.3 m/sec and in vein 1.1 m/sec. CONCLUSIONS: Increasing length of life even for high critical patients like these with chronic renal failure underlines the need of surgical strategies which may improve the quality to life. This technique of transposed cephalic vein has the same advantages of direct fistulas also for those patients in which we should have used prosthetic grafts.

Adult↗
PubMed1997

Vitamin E protects human skeletal muscle from damage during surgical ischemia-reperfusion.

PURPOSE: The biochemical and morphological alterations induced in lower limb skeletal muscle by ischemia-reperfusion (I-R) during aortic surgery and the effect of vitamin E pretreatment were investigated. METHODS: Two groups of patients undergoing aortic aneurysm resection, one untreated and one treated with vitamin E, were examined. Quadricep muscle biopsies were taken after induction of anesthesia, at the end of ischemia, and after reperfusion. The malondialdehyde (MDA) content and morphology of biopsies were examined to assess peroxidative processes. RESULTS: Ischemia did not induce an increase in MDA content but did increase neutrophil infiltration in muscle fibers of untreated patients. Reperfusion led to a significant increase in MDA content and to intermyofibrillar edema and mitochondrial swelling. The MDA content was not increased during ischemia and neutrophil infiltration was minimal in vitamin E treated patients. At reperfusion, the MDA content, the ultrastructural injuries and neutrophil infiltration were significantly reduced by the treatment. CONCLUSIONS: Vitamin E is effective in reducing the oxidative muscle damage occurring after a period of I-R.

Aged↗
PubMed1997

Internal carotid pseudo-occlusion: early and late results.

Internal carotid pseudo-occlusion (ICP) is a pathology of difficult diagnostic evaluation and treatment in the group of extracranial carotid diseases. The authors report the results of 24 ICP(S) surgically treated in the last five years. No perioperative death was reported. The neurological morbility rate was as low as 4% (1/24), which is quite a good results for this high-risk pathology. Clinical and instrumental follow-up was performed (at 1-3-6-12-24 months from surgery). Six early asymptomatic thromboses (25%) were observed, and the remaining patients showed patent vessels and no symptoms at all. In conclusion surgical treatment of ICP is often able to prevent cerebral ischaemia, and the high rate of early occlusion should not limit surgical indication.

Aged↗
PubMed1997

Vitamin E prevents neutrophil accumulation and attenuates tissue damage in ischemic-reperfused human skeletal muscle.

Neutrophil accumulation and the consequent production of oxygen-derived free radicals are involved in the pathogenesis of Ischemia-Reperfusion syndrome. In this study we investigated whether a treatment with Vitamin E, which has antioxidant properties, could attenuate the tissue damage by interfering with the influx of neutrophils within the ischemic and reperfused human skeletal muscle. To this purpose, patients undergoing aortic cross-clamping during the surgical repair of aortic abdominal aneurysm were studied as a model of ischemia-reperfusion of the lower limb muscles. Muscle biopsies from the right femoral quadriceps of patients not receiving and receiving Vitamin E pretreatment before surgery were taken: a) after the induction of anaesthesia, as control samples, and b) after a period of ischemia followed by 30 min of reperfusion. The tissue samples were either routinely processed for morphological study and immunohistochemical analysis to detect an altered expression of specific endothelial adhesion proteins, such as E-selectin and ICAM-1. The results obtained showed that Vitamin E administration was able to prevent the accumulation of neutrophils within the ischemic and reperfused muscle. This beneficial effect of Vitamin E was due to its ability to hinder the expression of E-selectin and ICAM-1, molecules known to increase the adhesiveness of endothelium to circulating neutrophils. After treatment with Vitamin E a marked attenuation of the reperfusion injury was also evident. In conclusion, Vitamin E treatment may be considered a valuable tool for protection against the ischemia-reperfusion damage of human skeletal muscle.

Aged↗
PubMed1997

Extracranial carotid artery aneurysms.

BACKGROUND: Extracranial carotid aneurysms are quite rare diseases. Their importance is linked both to critical localization and natural history which can lead to neurological events such as TIA and stroke. The importance of an accurate diagnosis is related to the necessity to carry out an early repair of these lesions and so to achieve the prevention of serious complications with minimal surgical risk. MATERIALS AND METHODS: At the Department of Vascular Surgery of the University of Florence from January 1982 to December 1995, 2138 surgical procedures on extracranial carotid arteries carried out. Twenty-one (0.98%) were performed for aneurysms. On the basis of clinical history and instrumental findings we divided the patients into three groups: atherosclerotic aneurysms (AA, 10 cases), dysplasic aneurysms (DA, 6 cases) and pseudoaneurysms (PA, 5 cases). RESULTS: Global mortality and major morbility rate was 4.7% (one patient suffered perioperative stroke). Eighteen (85.7%) were followed by echo color Doppler. No one stenosis and/or dilatation of operated vessel was observed during the mean follow-up period of 24 months. In one case (5.5%) of pseudoaneurysms group an asymptomatic internal carotid artery occlusion was discovered 3 months after surgery. CONCLUSIONS: In our experience, surgical treatment of extracranial carotid aneurysms is associated with satisfactory results and low incidence of perioperative complications that justified an extensive and early surgical therapy.

Aged↗
PubMed1997

Kinking of the human internal carotid artery: a statistical study in 100 healthy subjects by echocolor Doppler.

BACKGROUND: Kinking of the internal carotid artery is a rather frequent anomaly. It is still controversial whether it has a clinical relevance, causing cerebral vascular disturbances, or if it is a mere morphologic anomaly. A study concerning its frequency in asymptomatic subjects and an evaluation of its possible correlations were, therefore, considered interesting. METHODS: The internal carotid artery was studied in 100 apparently healthy subjects (50 men and 50 women; age range: 18 to 98 years) with no history of atherosclerotic disease of the supra-aortic trunks, or diabetes mellitus, or hypertension. Each patient underwent color Doppler ultrasonography. RESULTS: In 38 subjects out of 100, and in 53 out of 200 examined arteries (100 right and 100 left arteries), a kinking was found (26.5%). In 23 kinkings (43% of all the kinkings), the maximal systolic velocity (MSV) was greater than 1 m/sec at the level of the kinking. The kinkings were more frequent in women; such prevalence was statistically significant. The frequency of kinkings was uncorrelated with the side of the artery, the age, the body weight, the height and the length of the neck. Moreover, the presence of the kinkings was not significantly correlated with the lumen of the internal carotid artery. CONCLUSIONS: Hypotheses regarding the genesis of the kinkings were discussed, and the embryogenic hypothesis was emphasized. The importance of the MSV in the diagnosis of kinkings was stressed.

Adolescent↗
PubMed1996

Topological mapping of the cysteine residues of N-carbamyl-D-amino-acid amidohydrolase and their role in enzymatic activity.

The N-carbamyl-D-amino-acid amidohydrolase from Agrobacterium radiobacter NRRL B11291, the enzyme used for the industrial production Of D-amino acids, was cloned, sequenced, and expressed in Escherichia coli. The protein, a dimer constituted by two identical subunits of 34,000 Da with five cysteines each, was susceptible to aggregation under oxidizing conditions and highly sensitive to hydrogen peroxide. To investigate the role of the cysteines in enzyme stability and activity, mutant proteins were constructed by site-directed mutagenesis in which the five residues were substituted by either Ala or Ser. Only the mutant carrying the Cys172 substitution was catalytically inactive, and the other mutants maintained the same specific activity as the wild type enzyme. The crucial role of Cys172 in enzymatic activity was also confirmed by chemical derivatization of the protein with iodoacetate. Furthermore, chemical derivatizations using both acrylamide and Ellman's reagent revealed that (i) none of the five cysteines is engaged in disulfide bridges, (ii) Cys172 is easily accessible to the solvent, (iii) Cys193 and Cys250 appear to be buried in the protein core, and (iv) Cys243 and Cys279 seem to be located within or in proximity of external loops and are derivatized under mild denaturing conditions. These data are discussed in light of the possible mechanisms of enzyme inactivation and catalytic reaction.

Alanine↗
PubMed1996

Dexamethasone suppression test: corticosteroid receptors regulation in mononuclear leukocytes of young and aged subjects.

The dexamethasone suppression test (DST) is considered an indicator of the function of the adrenal pituitary axis. The effect of the steroid is mediated by its binding to corticosteroid receptors. We previously suggested that the measurement of corticosteroid receptors in lymphocytes is an index of an analogous pattern in brain. In the present study, corticosteroid Type I and Type II receptors in mononuclear leukocytes were measured in 10 elderly subjects and in 9 young adults, before and after overnight DST (1 mg). Receptors were measured by radioreceptor assay. In all the subjects, dexamethasone was able to suppress plasma cortisol. The number of Type I and Type II receptors before the test was lower in elderly subjects than in adults. In the control group, dexamethasone produced a significant depression of Type I receptors (from 267 +/- 72 to 169 +/- 71 receptors per cell), which can be interpreted as a primary involvement of Type I receptors in the response to dexamethasone; Type II receptors decreased in half the subjects (from 2849 +/- 703 to 2345 +/- 569 receptors per cell). In elderly healthy subjects, Type II receptors were also significantly decreased (from 1796 +/- 671 to 720 +/- 345). We suggest that in young subjects Type II receptors are initially up-regulated by dexamethasone, and then down-regulated, while in aged subjects an up-regulation cannot be achieved, as suggested by the higher values of plasma cortisol usually found in aging subjects.

Adult↗