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G Melissano

Publications and source records attributed to G Melissano.

At least 37 records · Page 2Linked to original sources
PubMed1999

Chlamydia pneumoniae DNA detection in peripheral blood mononuclear cells is predictive of vascular infection.

Abdominal aortic aneurysm tissue and peripheral blood mononuclear cells (PBMC) of 41 consecutive subjects undergoing abdominal aortic aneurysm surgery were analyzed by polymerase chain reaction (PCR) for the presence of Chlamydia pneumoniae, Mycoplasma pneumoniae, and Helicobacter pylori DNA. Twenty patients (49%) were positive for C. pneumoniae DNA-16 (39%) in both PBMC and aneurysm tissue, 3 (7.3%) in PBMC only, and 1 (2.4%) in the artery specimen only. Previous exposure to C. pneumoniae was confirmed in 19 (95%) of the 20 PCR positive subjects by C. pneumoniae-specific serology, using the microimmunofluorescence test. None was positive for H. pylori or M. pneumoniae DNA, either in the PBMC or in the artery specimens. In conclusion, carriage of C. pneumoniae DNA is common both in PBMC and in abdominal aortic tissue from patients undergoing abdominal aneurysm surgery. Blood PCR may be a useful tool for identifying subjects carrying C. pneumoniae in the vascular wall.

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PubMed1999

Endovascular treatment of aortic aneurysms of the abdominal aorta with covered stents.

Abdominal aortic aneurysms are common in the aging population; their surgical treatment is well established and allows good results in specialized centers. Endovascular exclusion of abdominal aortic aneurysms has been shown to be feasible since 1991 and nowadays commercially available bifurcated endografts allow safe exclusion in selected cases. In the last year 22 patients with an aorto-iliac aneurysm received endovascular treatment at our Institution. We included patients with favorable anatomic characteristics (i.e. neck > 15 mm length, and < 28 mm diameter, iliac neck < 12 mm diameter, absence of > 90 degrees iliac or aortic angulation) and, in particular, those with increased surgical risk for systemic pathology (12 patients), or hostile abdomen (9 patients). We employed Vanguard II (Boston Scientific) endovascular grafts introduced through a surgically exposed common femoral artery; the contralateral limb of bifurcated grafts was inserted percutaneously. The endograft was successfully implanted in all cases, requiring additional iliac cuffs for complete aneurysm exclusion in 3 cases. Periprocedural morbidity included one case of thrombosis and one case of pseudoaneurysm of the punctured femoral artery, which required surgical treatment. In one case surgical exposure of the iliac artery was required in order to advance the device into the aorta. In one patient who previously underwent hemicolectomy, postoperative colonic ischemia was observed, and pharmacological treatment was required. Moreover we also observed one case of groin infection that was treated successfully with local wound care and systemic antibiotics, and one late contralateral limb thrombosis that was successfully treated with loco-regional thrombolysis. The mean follow-up was 6.1 months: one patient died because of congestive heart failure. No further morbidity was recorded. A type-II endoleak was observed in one patient, originating from the inferior mesenteric artery with no sac enlargement; this patient is still under observation. In conclusion, with proper clinical selection, commercially available endovascular devices allow safe exclusion of abdominal aortic aneurysms. Long-term follow-up is needed to ascertain the durability of the procedure.

Aorta, Abdominal↗
PubMed1998

In search of biological markers of high-risk carotid artery atherosclerotic plaque: enhanced LDL oxidation.

The oxidation of low density lipoprotein (LDL) is a key event in the development and progression of atherosclerosis because it generates molecular epitopes that are more atherogenic than parent LDL. We found previously that patients with carotid atherosclerosis have a significantly higher titer of autoantibodies against oxidatively modified LDL than normal subjects. The aim of this study is to correlate biological markers of in vivo LDL oxidation with the degree of carotid stenosis and of plaque ulceration (PU) in a series of patients undergoing carotid endoarteriectomy (CEA). Ninety-four consecutive patients (68M and 26F, aged 67.3 +/- 8.2 years) who underwent CEA at our institution between June 1993 and January 1994 were included in the study. The degree of carotid stenosis and the presence and extent of PU were correlated with the level of autoantibodies (IgG) against oxidatively modified LDL (Cu++-oxidized [oxLDL] or malondialdehyde derivatized LDL [MDA-LDL]), that consistently mirrors the occurrence of oxidative modifications in vivo. A statistically significant correlation (r = 0.23, p = 0.039) was found between the degree of carotid stenosis and antiMDA-LDL specific ratio (a parameter that describes the specificity of LDL towards other proteins as target for oxidative modification). A statistically significant correlation was also found between the PU score and antioxLDL IgG (r = 0.32, p = 0.011), antiMDA-LDL IgG (r = 0.25, p = 0.045) and antiMDA-LDL IgG specific ratio (r = 0.38, p = 0.002). None of the classical biochemical parameters (total, LDL and HDL cholesterol and triglycerides) correlated with the above-mentioned plaque characteristics. The results shown, support the use of biological markers of in vivo LDL oxidation (antioxidatively modified LDL autoantibody titers) to evaluate the clinical setting of high-risk carotid atherosclerosis both in screening and in follow-up studies.

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PubMed1998

Fresh and cryopreserved arterial homografts in the treatment of prosthetic graft infections: experience of the Italian Collaborative Vascular Homograft Group.

Following the experience of cardiac surgeons with homografts in the treatment of infective aortic valve endocarditis, cardiovascular surgeons have investigated in situ revascularization by means of homografts in the management of vascular prosthetic graft infections. Preliminary results are encouraging, but their late fate in long-term follow-up and the influence of preservation techniques are still under investigation. This article reports the experience of the Italian Collaborative Vascular Homograft Group, with the use of fresh and cryopreserved arterial homografts for the treatment of prosthetic graft infections. Between March 1994 and December 1996, 44 patients with prosthetic graft infection were treated with homografts (13 preserved at 4 degrees C, 31 cryopreserved). The mean age of the patients was 65 years. Emergency surgical procedures were performed in eight patients (18%). Sepsis was diagnosed in 11 patients, aortoenteric fistula in 13, and false aneurysms in 10. Staphylococcus was the main cause of infection. The types of vascular reconstruction with homograft were: 32 aortobifemoral, 3 aortoaortic, 2 iliofemoral, 4 peripheral, and 3 axillobifemoral. Human lymphocyte antigen (HLA) and antibody (ABO) blood group system compatibility between donors and recipients was not respected. The mean duration of follow-up was 15 months (range 1-33). Clinical and duplex scanning evaluations were routinely performed. Computed tomography (CT) or magnetic resonance (MR) scanning or arteriography were performed on the basis of duplex scanning results. There were six deaths during the early postoperative period (30 days) with a mortality rate of 13.6%. During the follow-up there were five late deaths with a mortality rate of 11.4%. Eight patients had graft occlusion. Three cases were successfully treated with thrombectomy. Two cases were successfully treated with femoropopliteal bypass with autologous vein. In three cases leg amputation was necessary. The results of fresh and cryopreserved homograft were compared. No significative differences of early postoperative mortality, late mortality, homograft related mortality, and graft occlusion were observed. We have evaluated the actuarial survival of the patients and the actuarial patency of the homografts on the aortoiliac reconstructions. Twelve months after the surgery the actuarial survival of the patients was 73% and the actuarial patency of the homografts was 56%. In our preliminary experience, we have not observed any significant difference in terms of clinical outcome by using fresh rather than cryopreserved homografts. In the near future it will be our policy to employ only cryopreserved homografts. Moreover, we will extend vessel harvesting to nonheart-beating donors, thus maximizing retrieval. The aforementioned solutions will supply the best graft availability to obtain dimensional and ABO compatibility between donors and recipients.

Adult↗
PubMed1998

Biomechanics of abdominal aortic aneurysm in the presence of endoluminal thrombus: experimental characterisation and structural static computational analysis.

OBJECTIVES: To evaluate the role played by biomechanical and geometrical parameters of endoluminal thrombus and of aortic wall on abdominal aortic aneurysm (AAA) behaviour. MATERIALS AND METHODS: Tensile tests on 21 AAA thrombus specimens from six patients undergoing AAA repair and numerical evaluation of aneurysmal aortic wall stress and strain distribution. Parameters of the analysis were lumen eccentricity, thrombus Young's Modulus and the aortic wall constitutive equation. RESULTS: There was a linear stress/strain for all the thrombus specimens. The numerical analyses show the mechanical behaviour of AAA as a function of lumen eccentricity and biomechanical parameters. CONCLUSIONS: Well organised thrombus reduces the effect of the pressure load on the aneurysmal aortic wall.

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PubMed1998

Successful surgical treatment of visceral artery aneurysms. After failure of percutaneous treatment.

We report 2 cases involving aneurysms of visceral arteries that needed surgical treatment after unsuccessful percutaneous treatment. In the 1st case, repeated embolizations with Gianturco coils and angiographic guidewires had failed to obliterate a large aneurysm of the hepatic artery. In the 2nd case, a peripancreatic pseudoaneurysm caused recurrent gastrointestinal bleeding despite embolization with Gianturco coils. In both patients, left medial rotation of the viscera provided access to the origin of the affected artery at the aorta, enabling the surgeon to control bleeding before opening the aneurysm. The advantages and limitations of the most commonly performed percutaneous procedures are discussed, as are the surgical options.

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PubMed1998

Combined lung volume reduction surgery and thoracic aortic aneurysm resection.

Postoperative improvement of respiratory function has been reported with lung volume reduction surgery (LVRS) in patients with severe emphysema. Since smoking is an established risk factor for lung cancer, vascular diseases and emphysema, it is not infrequent to find these diseases associated in the same patient. Combined treatment of lung cancer and emphysema has already been reported. Surgical treatment of vascular diseases in emphysematous patients could also benefit from the application of LVRS techniques. We report resection of an aortic aneurysm combined with LVRS in a patient with concomitant thoracic aortic aneurysm and severe emphysema. Respiratory function improved in the postoperative period.

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PubMed1997

Safe and cost-effective approach to carotid surgery.

OBJECTIVE: To evaluate the safety and cost effectiveness of carotid surgery performed altering the perioperative protocol in an attempt to decrease resource utilisation. SETTING: Department of vascular surgery in a large metropolitan teaching hospital in northern Italy. DESIGN: Prospective, non-selective study. MATERIALS AND METHODS: Three hundred and eighty carotid procedures were performed in 1995 on 343 patients (274 males, 69 females, mean age 68.2 years, range 47-86 years). The most important cost containment measures, were: (i) limiting the use of contrast arteriography to cases of dubious ultrasonographic diagnosis; (ii) routine use of loco-regional anaesthesia; (iii) postoperative admission to an intensive care unit (ICU) only in selected cases; (iv) early postoperative discharge where possible. RESULTS: Mortality was 0.26% and neurological morbidity 1.58%. General anaesthesia was required in eight patients (2.1%), and only seven patients (1.8%) were admitted postoperatively to the ICU. Arteriography was performed in 56 cases (14.7%). The average hospital stay was 5 days with a global cost of 43,036 ECU, as compared with a cost of 6764 ECU for patients treated traditionally with routine arteriography, general anaesthesia and routine ICU admission. CONCLUSIONS: Selective use of arteriography and ICU, routine use of loco-regional anaesthesia and reduced hospital stay make it possible to lower the cost of carotid surgery without sacrificing quality.

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PubMed1997

Is endoscopy useful for early diagnosis of ischaemic colitis after aortic surgery? Results of a prospective trial.

BACKGROUND: Ischaemic colitis is an infrequent, but potentially fatal, complication of abdominal aortic surgery. Its presentation is often underestimated on account of a paucity of symptoms, thus the real incidence of ischaemic colitis may be higher. AIM: To determine the prognostic value and sensitivity of endoscopy, early postoperative endoscopic findings were evaluated. METHODS: Over a period of three years a prospective study was undertaken in a consecutive series of 105 patients (mean age 68.9 years, range 51-85) undergoing routine rectosigmoidoscopy within 72 hours of aortic reconstructive surgery. RESULTS: Colonic ischaemia was found in 12 patients (11.4%); five had endoscopic evidence of mild ischaemic colitis, ulcerations were identified in five and diffuse superficial necrosis in two. Seven of the 12 patients were symptomatic. Laparotomy was never deemed necessary and all patients were successfully treated with a conservative regimen. There were no deaths. Elective reconstruction or urgent procedure did not correlate with the development of colonic ischaemia, nor did duration of aortic cross-clamp time, patency of the inferior mesenteric artery and its possible ligation or reimplantation or patency of the hypogastric arteries. CONCLUSIONS: Rectosigmoidoscopy is effective for early diagnosis of ischaemic colitis. Early endoscopy should be routinely performed only for patients in whom impaired blood flow is suspected on the basis of the intraoperative objective assessment of the colon and in presence of symptoms.

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PubMed1996

Detection of prosthetic vascular graft infection using avidin/indium-111-biotin scintigraphy.

UNLABELLED: Prosthetic vascular graft infection, though rare, carries high morbidity and mortality rates; therefore, timely diagnosis is important. Patients, however, often present with vague symptoms, and radiological investigations are frequently inconclusive. These factors may lead to prolonged periods of observation and hospitalization, with the resultant increase in costs and complication rates, before reaching a final diagnosis. This prospective study evaluates the use of nonspecific avidin/111In-biotin imaging in diagnosing prosthetic vascular graft infection. METHODS: Twenty-five patients with a total of 29 grafts were investigated. Eighteen patients (19 grafts) had low probability of disease, whereas the remaining 7 patients (10 grafts) warranted surgical exploration based on clinical, laboratory or radiological evidence. Avidin was first injected intravenously and then followed 24 hr later by administration of 111In-biotin. Whole-body images were obtained 10 min and 2 hr postinjection of 111In-labeled biotin. SPECT imaging was performed 1 hr postinjection. Increased uptake along part or the whole length of the graft was considered evidence of graft infection. RESULTS: Avidin/111In-biotin scintigraphy correctly identified all infected grafts, as confirmed by culturing surgical specimens. In contrast, infection was correctly excluded in all but one of the grafts, and long-term follow-up was used to assess the presence of infection in patients who did not undergo surgical intervention. CONCLUSION: Avidin/111In-biotin scintigraphy is a simple and accurate imaging method for the routine diagnosis of vascular graft infection, and it may have a role in identifying the disease process in its initial stages, thus improving prognosis.

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PubMed1995

Avidin and 111In-labelled biotin scan: a new radioisotopic method for localising vascular graft infection.

OBJECTIVES: To evaluate a new imaging technique, for diagnosis of prosthetic vascular graft infection. Avidin is a protein which accumulates nonspecifically at sites of inflammation or infection. Due to its extremely low dissociation constant with biotin sites of infection can be imaged, using avidin as a pre-target, followed by injection of 111In-labelled biotin. This technique is much simpler than the common scintigraphic methods which employ labelling of blood components and its target-to-background ratio is greater than the methods employing radiolabelled proteins. DESIGN: Prospective clinical study. SETTING: A single department of vascular surgery and one of nuclear medicine of a Northern Italian hospital. MATERIALS: Between May 1993 and May 1994, 31 grafts in 26 patients were studied; the series included 23 men and three women with a mean age of 65.5 years (range 54-76 years). The prosthetic graft (Dacron -16, ePTFE -15) were: aortoaortic 5, aortobifemoral 15, aortoiliac 1, and femoropopliteal 10. Sixteen patients were suspected of having a vascular graft infection (Group A), the other 10 patients served as controls (Group B). 20 mg of Avidin were injected iv, followed 24 h later by i.v. injection of 500 micrograms of Biotin labelled with 74 MBq of 111In. CHIEF OUTCOME MEASURES: Whole-body imaging was performed at 10 min and 2 h post-injection, along with SPECT imaging when indicated. Scan results were correlated with the traditional imaging modalities and the clinical outcome of the patients. MAIN RESULTS: In Group A: two patients (three grafts) were excluded from the study, there were six true-positives, one false-positive and 11 true-negatives. Results in Group B: 10 true-negatives. The overall sensitivity was 100%, the specificity 95%, the accuracy 96%, the positive predictive value 86% and the negative predictive value 100%. CONCLUSIONS: These data suggest that Avidin/111In-labelled Biotin scintigraphy is a useful non invasive diagnostic method for early diagnosis of suspected prosthetic vascular graft infection.

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PubMed1995

A new ePTFE stretch graft for aorto-iliac reconstructions. Surgical evaluation and one year follow-up with magnetic resonance imaging.

Since its introduction at the beginning of the 60s Dacron has proved to be a reliable and durable substitute for aortic reconstructions. It is however susceptible to late thrombosis, infection and aneurysmal dilatation in a significant number of cases. ePTFE vascular prosthesis, introduced in 1972, have proved to perform well for peripheral reconstructions and was used in aortoiliac position since 1980. In 1991 a new type of ePTFE rendered longitudinally extensible (Gore-Tex Stretch) was introduced into clinical practice. The aim of this study is to evaluate surgical performance, short term patency and interaction with periprosthetic tissues of Gore-Tex Stretch straight and bifurcated prosthesis. Between October 1991 and December 1993, 59 patients underwent aortic reconstruction at our Institution either for infrarenal aortic aneurysm (19 patients, 16 males, 3 females, mean age 68.8 +/- 8.5 years) or for aortoiliac occlusive disease (40 patients, 36 males, 4 females, mean age 60.5 +/- 7.2 years). Forty-eight bifurcated and eleven straight grafts were implanted using Gore-Tex sutures. Preoperative workup included Ultrasonography, Magnetic Resonance Imaging (MRI) in patients with aneurysms and Intra Arterial Digital Subtraction Arteriography (DSA) in patients with occlusive disease. Intraoperative parameters were recorded. Postoperative follow-up included ultrasonographic evaluation at 1st and 7th day, 15th postoperative week and at 3 monthly intervals; Intra Venous DSA before dismission and MRI at the 1st and 15th postoperative week. Intraoperatively the grafts proved to be soft and flexible with good handling and suturing characteristics. Perioperative bleeding was 480 +/- 299 ml for occlusive disease cases and 633 +/- 314 for aneurysm cases. No operative mortality was recorded.(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMed1994

LDL oxidation in patients with severe carotid atherosclerosis. A study of in vitro and in vivo oxidation markers.

Among the various risk factors involved in the development and progression of carotid atherosclerosis, the oxidation of LDL has been proposed to play a relevant role. LDL oxidation has been investigated in 94 patients with severe carotid atherosclerosis undergoing elective carotid artery endarterectomy and in 42 matched control subjects. LDL oxidation was evaluated in all patients as (1) the susceptibility to in vitro oxidation, (2) vitamin E concentration and its efficiency in LDL, and (3) the presence of autoantibodies against oxidatively modified lipoprotein to monitor the occurrence of the oxidative processes taking place in vivo. No difference was detected between control subjects and patients concerning vitamin E concentration and the kinetics of conjugated diene formation in isolated LDL exposed to CuSO4. However, vitamin E efficiency was lower (9.6 +/- 4.2 versus 30.2 +/- 7.6 min/nmol vitamin E) and the duration of the vitamin E-independent lag phase was longer (105.5 +/- 16.5 versus 58 +/- 11.8 minutes) in the patient group. Autoantibodies against oxidatively modified lipoproteins were measured with an ELISA method using native LDL, Cu(2+)-oxidized LDL (oxLDL), or malondialdehyde-derivatized LDL (MDA-LDL) as antigens. To monitor cross-reactivity of the antibodies detected with other oxidatively modified proteins, human serum albumin (HSA) and MDA-derivatized HSA (MDA-HSA) were also employed. The antibody titer was calculated as the ratio of antibodies against modified versus native proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMed1993

[The surgical treatment of inflammatory aneurysms of the abdominal aorta. The usefulness of nuclear magnetic resonance (MR) in the preoperative diagnosis].

Inflammatory abdominal aortic aneurysms (IAAA) represent a peculiar variant compared with the common atherosclerotic origin of aortic aneurysms. Between January 1988 and March 1992, 111 aneurysmectomies were performed at our institution: 98 elective and 13 emergency procedures. In 10 cases (all males, mean age 68.5) an IAAA was found. 8/10 of those patients operated upon electively were studied preoperatively with MRI. All the IAAA but one were correctly identified preoperatively. Identification of IAAA with MRI in these cases improved the surgical approach. In conclusion, patients with IAAA can be operated upon safely especially if a preoperative diagnosis is present. MRI greatly improves our ability to characterize non invasively IAAA.

Aged↗
PubMed1993

Three dimensional time-of-flight magnetic resonance angiography in carotid artery surgery: a comparison with digital subtraction angiography.

Three dimensional time-of-flight magnetic resonance angiography (MRA) and intra-arterial digital subtraction angiography (DSA), considered the gold-standard technique, were compared for pre- and postoperative evaluation of the carotid bifurcation. Images of suitable quality of 194 bifurcations were available with both techniques. Percentage stenosis was graded into 5 groups: A = 0-29%, B = 30-59%, C = 60-89%, D = 90-99%, E = 100% (occlusion). Preoperative MRA (126 bifurcations) overgraded the stenosis in 14 cases and undergraded it in 11. The two techniques agreed in 101 cases and the extent of misgrading was never more than one category. Regression analysis showed a good correlation between the two methods. Severe ulceration was better identified by DSA. As far as the surgical indication was concerned, MRA had a sensitivity of 92.6% and a specificity of 98.3%. In 68 operated cases, postoperative MRA and intraoperative completion angiography showed a satisfactory endarterectomy with no residual stenosis in any of the cases. In conclusion, MRA seems an accurate modality for imaging of carotid bifurcations. Significant limitations still exist for an adequate demonstration of intracranial circulation.

Adult↗