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Biomedical subjects

M F Giannoni

Publications and source records attributed to M F Giannoni.

At least 19 recordsLinked to original sources

Total knee replacement: prevention of deep-vein thrombosis using pharmacological (low-molecular-weight heparin) and mechanical (intermittent foot sole pump system) combined prophylaxis. Preliminary results.

AIM: The aim of this study was to determine the role of combined mechanical and pharmacological prophylaxis in the prevention of deep venous thrombosis (DVT) after total knee replacement (TKR). DESIGN: prospective case series study. METHODS: Between October 2002 and June 2003, 38 total knee procedures were carried out on 34 patients (4 patients had bilateral TKR). To exclude the presence of a concomitant DVT echo-color-flow of the legs was performed between 2 and 1 week prior to surgery, in the postoperative period (before discharging) and 30 days after surgery. Patients received one daily subcutaneous injection of nadroparin calcium (dosage adapted to body-weight). An intermittent foot sole pump (IFSP) was applied in the recovery room postoperatively, in both feet for about 5 h a day and all night long, and continued at home until the 15(th) day. RESULTS: No major perioperative or rehabilitation phase-related complications were observed (2 patients required manual drainage of blood clots from the wound). The incidence of DVT was 7.9% (3 cases). In one of these cases we observed a previous DVT so it was classified as rethrombosis. All were successfully treated with therapeutic introduced low molecular weight heparin (LMWH) therapy. No pulmonary embolism or deaths associated with the use of LMWH or IFSP were observed. CONCLUSIONS: In our experience the combined prophylaxis with nadroparin calcium and IFSP significantly reduced the incidence of DVT.

Aged↗

What is the best management for abdominal aortic aneurysm in patients at high surgical risk? A single-center review.

AIM: To determine the best treatment for high-risk patients with abdominal aortic aneurysms (AAA). METHODS: We reviewed a prospective database of all patients who underwent conventional (OPEN) or endovascular aneurysm repair (EVAR) between January 1998 and December 2002. Patients were preoperatively classified according to the American Society of Anesthesiology (ASA). Comorbidities and medical risk factors were categorized according to the Ad Hoc Committee on Reporting Standards. Perioperative mortality and morbidity rates were analyzed according to the type of surgical procedure (OPEN vs EVAR) and ASA class. Patients in ASA classes I and II were excluded. Continuous data were expressed as mean +/- standard deviation. All data were calculated using the cumulated actuarial method of event outcome probability. Kaplan-Meier curves were constructed and the log-rank statistic and chi squared test were used for comparative data. P values less than 0.05 were considered to indicate statistical significance. RESULTS: Of the total 375 patients who underwent AAA repair, 168 (45%) belonged in ASA classes III and IV (85 submitted OPEN and 83 EVAR to repair). Among general risk factors only coronary artery disease differed significantly between the 4 groups (P = 0.04). The Bonferroni correction identified a statistically significant difference between ASA classes III and IV for the OPEN technique and for EVAR (P = 0.007 and P = 0.012). Neither 30-day morbidity or mortality differed significantly according to ASA class and surgical technique. The median follow-up was 19 months (range 5-60 months). The overall survival was 78% at 60 months. Survival rates during follow-up differed significantly in the 2 risk classes (ASA III 5/123, 4% vs ASA IV 9/38, 24%), (P = 0.0001). The deaths in the ASA class 4 patients (12/14; 86%) were caused by preexisting medical comorbidities (in 9 patients cardiovascular, in 1 cancer and in 2 cirrhosis). CONCLUSIONS: Except patients with small aneurysms (< 6 cm), in whom the risk of death at 1-year due to comorbidities exceeds the risk of a ruptured aneurysm, all patients at high surgical risk (ASA class IV) benefit from AAA repair. Patients with small aneurysms must undergo strict surveillance to assess growth and aneurysmal wall changes to prevent unexpected rupture.

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Ultrasound echo-enhancers in the evaluation of endovascular prostheses.

Whereas conventional vascular surgical procedures are routinely monitored by ultrasound imaging, endovascular prostheses are usually monitored by radiographical imaging techniques. The aim of this study was to determine the safety, patient acceptance and role of ultrasound echo-enhancers (SHU 508 A) in the evaluation of endovascular devices. Nine patients were studied: six had stents (four in the internal carotid artery and two in the renal artery) and three had endoluminal prostheses (one in the abdominal aorta, one in the subclavian and one in the iliac artery). Endovascular patency and correct placement were studied with contrast angiography and ultrasound examination with and without contrast enhancement. Patients underwent angiography at the end of the endovascular procedure, and ultrasound examinations on the first postoperative day. Ultrasound contrast media (SHU 508 A) was injected through an antecubital vein at a rate of 1 ml/s. A total of 13 injections were given in nine patients. Ultrasonograms were obtained with 7.5 and 3.5 MHz transducers (Acuson 128 XP) and recorded on videotape for off-line visual inspection. Baseline and echo-enhanced sequences were assessed by two independent observers. None of the patients reported side-effects during or after the injection of the ultrasound echo-enhancer. Postoperative angiography showed endovascular patency and correct placement in all patients. The baseline ultrasound examination confirmed endoprosthesis patency in seven of nine patients: none revealed endoprosthesis malplacement. Contrast-enhanced ultrasound examination confirmed endoprosthesis patency. In two cases, the echo-contrast examination revealed persisting flow within the aneurysmal sac: in another patient it showed the incomplete adhesion of the distal portion of the endoprosthesis to the arterial wall. The preliminary findings suggest that ultrasound echo-enhancers are safe to use and induce no side-effects. Echo-enhanced sequences often provide additional information on the technical success of endovascular procedures. They promise to be useful in follow-up studies for assessing the functioning of endoprostheses.

Aged↗

Ischemic nephropathy in an elderly nephrologic and hypertensive population.

BACKGROUND: Atherosclerotic renovascular disease is a frequent cause of end-stage renal failure leading to dialysis in the elderly population. Its prevalence is known from autopsy or retrospective arteriographic investigations. This prospective study was conducted in 133 subjects with the inclusion criteria of hypertension and/or chronic renal failure starting after 50 years of age. Renal failure was unrelated to other known causes of renal disease. METHODS: The patients were subjected to echo-color doppler ultrasonography of renal arteries (104) and/or to renal scintigraphy (112). Thirteen of 27 patients with positivity using one or both noninvasive techniques were subjected to digital selective angiography. RESULTS: All the patients with positivity of echo-color doppler technique were true positives, with a consequent predictive value reaching 100%. Renal scintigraphy was of markedly lower predictive value. Based on the echo-color doppler investigation, percentage positivity for hemodynamically significant stenosis (> 50%) was 3.2 (16.3% had mild nonsignificant stenosis of renal arteries) in the 50- to 59-year-old group, 20% (plus 12.5% with nonsignificant stenosis) in the 60- to 69-year-old group and 25% (plus 17.8% nonsignificant stenosis) in the > 70-year age group. Patients with significant stenosis also had a significantly higher degree of renal insufficiency and received a higher number of hypotensive drugs (p < 0.013). The percentage of hypertensive patients was not different in the stenotic and nonstenotic groups. CONCLUSIONS: A large percentage of the elderly population is affected by renal vascular obstructive disease and is at risk of developing end-stage renal failure. Considering the wide number of cases with foreseeable renal arterial stenosis in the vast population meeting the selection criteria, it is possible to conclude that not all cases evolve to renal failure due to different rates of progression or to untimely nonrenal death.

Aged↗

[The role of vena cava filters in the prevention of pulmonary embolism and hemodynamic changes in the venous system of the lower limbs].

BACKGROUND: On the basis of recent investigations, pulmonary embolism represents the third cause of death. If only hospitalized population over 65 years of age is considered, this pathology is quite the first cause of mortality. As deep venous thrombosis of the lower limbs represents the main cause of pulmonary embolism (90%), it should be right to suggest interruption of venous flow at caval level. The aim of this prospective report is to evaluate the efficacy of vena cava filter in pulmonary embolism prevention and the hemodynamic variations it can cause in the venous district of lower limbs. METHODS: 137 definitive caval filters were positionated from 1989 to 1996. Average follow-up was 12.6 months. Patients were controlled at 2-7 days, 1 month and than every 6 months. RESULTS: Filter perviousness was observed with Kaplan and Meyer's curve and it was 94.7%. There was pulmonary embolism in just 2 cases (1.4%). Filter perviousness was not depending on anticoagulant treatment. CONCLUSIONS: In conclusion, this prospective experience underlines that: caval filter is effective in pulmonary embolism prophylaxis; there are not important hemodynamic alterations of inferior vena cava, below filter; anticoagulating treatment does not influence filter perviousness; there are not hemodynamic alterations after slight dislocations of caval filter; finally there is a direct relation between level of deep venous thrombosis and post-phlebitic manifestations.

Hemodynamics↗

Bacterial and clinical criteria relating to the outcome of patients undergoing in situ replacement of infected abdominal aortic grafts.

OBJECTIVES: In a retrospective non-randomised study we assessed the outcome after in situ replacement of infected knitted Dacron abdominal aortic grafts in patients without septicaemia or retroperitoneal abscesses. We also assessed whether the specific bacterial infection influenced outcome. MATERIALS AND METHODS: Over the 5 years studied, 18 patients (9 with perigraft infection and 9 with aortoenteric erosion) underwent in situ replacement of aortofemoral grafts. All patients were haemodynamically stable, none required emergency treatment. Preoperative assessment included CT, MRI, leukocyte-labelled scintigraphy, and bacterial cultures whenever possible. Infected grafts were totally excised and replaced in situ with standard PTFE prostheses. Bacterial diagnosis included intraoperative Gram-staining and postoperative graft cultures. None of the patients had retroperitoneal collections or proximal anastomotic dehiscence. All patients had 6 week intravenous antibiotic therapy. RESULTS: One patient died of myocardial infarction, and another of haemorrhagic shock from proximal anastomotic dehiscence, accounting for a graft-related mortality of 6%. Dehiscence resulted from a polymicrobial infection. Mean 37 month surveillance showed no amputations and no graft-related infections. CONCLUSIONS: In clinically and bacteriologically selected patients, total in situ replacement of infected abdominal aortic grafts offers an excellent outcome.

Adult↗

Intraoperative transcranial Doppler sonography monitoring during carotid surgery under locoregional anaesthesia.

OBJECTIVES: Studies comparing transcranial Doppler ultrasonography (TCD) with other intraoperative monitoring techniques for detecting clamping ischaemia during carotid endarterectomy under general anaesthesia suggest that a reduction of > two-thirds in the mean middle cerebral artery velocity (mMCAv) or a reduction of > 0.4 in the preclamping mMCAv: clamping mMCAv ratio warrants cerebral protection. Our aim was to study the relationship between mMCAvs and clamping ischaemia during carotid endarterectomy in awake patients. MATERIALS AND METHODS: In a consecutive series of 57 patients undergoing carotid endarterectomy under locoregional anaesthesia 51 were monitored by intraoperative TCD, continuous EEG, and neurologic awake testing. RESULTS: Five of the 51 (9.8%) patients had transient clamping ischaemia, which carotid shunting reversed. TCD showed that these five patients had significant lower mean mMCAvs than the other 46 patients, who had no deficits (1.8 +/- 1.1 cm/s vs. 26.2 +/- 8.5, p = 0.0003). Current TCD criteria indicated that four other patients (7.8%) should have been shunted. All four had significantly higher clamping mMCAvs than the five shunted patients (11.5 +/- 1.9 vs. 1.8 +/- 1.1, p = 0.0012). CONCLUSIONS: Intraoperative TCD detected cerebral ischaemia and yielded no false-negative. An mMCAv of 10 cm/s or less may indicate the risk of clamping ischaemia better than the higher threshold currently proposed. This would avoid unnecessary shunting due to false-positives.

Aged↗

[Transcranial Doppler: diagnostic methodology].

The transcranial doppler is a kind of pulsed doppler (frequency 2 Mhz) which, by arrangement of the probe in particular regions of the skull (temporal, orbital, and occipital fenestra), permits the assessment of the flow velocity on the level of the main intracranial arteris, giving information about the perviety and the characteristics of the flow and about Willis polygon being functional. This non-invasive vascular diagnostic is methodology concerned, and, therefore, fundamental in the evaluation of patients suffering from cerebral-vascular insufficiency and likely to be operated by carotid-TEA.

Cerebrovascular Disorders↗

For how long should carotid endarterectomy surveillance be continued?

Early restenosis represent the most important and more common failure after carotid endarterectomy. For this reason, after its first description made in 1976 by Stoney and String, it raised general interest among vascular surgeons. In spite of the efforts to clear the causes of this phenomenon, none of the numerous papers published in the literature has defined a specific cause determining restenosis. Nevertheless, at present, this hyperplastic response of the arterial wall to trauma after operation is generally considered benign because it is rarely responsible for new neurological symptoms or early internal carotid artery occlusion. This unanimous conviction has been achieved after years of instrumental and clinical postoperative follow-up performed all over the world. At the same time and probably for these reasons, recently, a new discussion has begun about the usefulness and cost-effectiveness of prolonged Duplex scanning postoperative surveillance of the endarterectomized carotid arteries. This new question raised our curiosity in verifying the validity of this new approach, so we reviewed accurately our laboratory follow-up registry and the data regarding onset, evolution and clinical outcome of early restenosis. These data associated with a meticulous review of the experience of other authors convinced us that the patients operated on, need, in most cases, a short even aggressive period of careful follow-up (generally the first six months).(ABSTRACT TRUNCATED AT 250 WORDS)

Arterial Occlusive Diseases↗

[Renal artery stenosis and aorto-iliac restoration: is it necessary to do extensive evaluation?].

In patients with aortoiliac disease and a stenosis of one or two renal artery, renal hypertension is rarely the sole mechanism of the elevated blood pressure. The preservation of nephron mass being the aim of the renal revascularization, we firmly believe that only three tests are required for the operative decision: renal ultrasonography, nephroscintigraphy and global and selective aortography.

Aorta↗

Post-carotid endarterectomy hyperperfusion syndrome: preliminary observations for identifying at risk patients by transcranial Doppler sonography and the acetazolamide test.

Patients at risk of hyperperfusion syndrome after carotid endarterectomy are often severely hypertensive and have a high grade internal carotid artery stenosis with disordered autoregulation due to a loss of reserve capacity (RC). Cerebral RC can be studied by sophisticated and expensive technical devices (SPECT, PET). Recently it has been demonstrated that the transcranial Doppler (TCD) and acetazolamide provocation test can be used to assess RC. From September 1991 to January 1992, 36 patients were studied by the TCD and acetazolamide test prior to carotid endarterectomy to identify patients at high risk of the hyperperfusion syndrome. Preoperatively, the patients were studied by TCD at rest and after vasolidation with acetazolamide 1 g intravenously (i.v.). Mean blood flow velocity on the middle cerebral artery (MCAv) was recorded for the following 20 min at 5 min intervals. MCAv at rest was 49 +/- 17 cm/s. After acetzaolamide infusion in 33 patients (92%), the mean MCAv was 62 +/- 19 cm/s with an increase of 19 +/- 13 cm/s (normal RC). In three patients (8%), the mean MCAv was 43 +/- 22 cm/s with a decrease of -6 +/- 3 cm/s with respect to base values (reduction of RC). (t = 3.30; p = 0.0022). All these patients were hypertensive (BP > 180/100 mmHg) and had a carotid artery stenosis > 90%. Postoperatively, the three patients with reduction of RC complained of homolateral headache. TCD showed a mean MCAv of 67 +/- 17 cm/s, an increase compared to the preoperative rest values of 17 +/- 8 cm/s, the 33 patients with normal RC showed a mean change in MCAv -2 +/- 12 cm/s.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetazolamide↗

Blood brain barrier breaking. Is still an absolute contraindication to early surgical reperfusion of the brain?

In the early treatment of the patients with cerebrovascular insufficiency due to internal carotid artery stenosis, the presence of a cerebral infarct and especially the blood brain barrier breaking (BBB) are considered by many as a contraindication to early reperfusion by carotid endarterectomy (CEA). Generally, it has been recommended to differ the operation at least for 4-6 weeks because of the high risk to convert an ischemic infarct into an hemorrhagic one. On the other hand, because unfavorable natural history has been reported as for the progressing unstable neurological deficit as for the minor recent strokes, respectively by Millikan and Dosik, it seem to be justified a more aggressive management with the aim of: 1) eliminating the stenosis as embolic source of emboli; 2) obtaining early brain reperfusion to increase the probability of good recovery. Some previous experiences reported in the literature demonstrated satisfactory results of early reperfusion even in presence of BBB. The Authors present 4 cases of early CEA in patients with BBB. After the CT scan the patients have been submitted preoperatively to non invasive tests (duplex scanning and transcranial Doppler sonography) to assess the presence of the internal carotid artery stenosis and the viability of the intracranial cerebral arteries with special regard to the middle cerebral artery. All the patients underwent CEA in loco-regional anesthesia and particularly systemic blood pressure was carefully monitored and any hypertensive status was early corrected by prompt antihypertensive therapy (i.v. nitrates and or calcium blocking agents).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Minor asymptomatic carotid stenosis contralateral to carotid endarterectomy (CEA): our experience.

The authors report their experience from 1985 to 1988 with 75 consecutive patients affected by bilateral carotid artery stenosis in whom only one side was surgically treated and the other had a minor (15-45%) asymptomatic carotid stenosis. These patients have been followed for a period ranging from 10 to 50 months (mean follow-up 21 months) by clinical examinations and non-invasive investigations (Doppler CW, Duplex scanner). The non-invasive evaluation included assessment of haemodynamic data and characterisation of plaque morphology (regular vs. irregular or ulcerated surface, homogeneous vs. heterogeneous plaque). During follow-up eight patients died: two (2.6%) from acute myocardial infarction, four from stroke (5.3%), and two (2.6%) from other causes. Twenty-five patients (33.3%) had neurological symptoms related to the unoperated side: and four suffered stroke (5.3%). Twenty-one patients had TIAs (28%) related to the observed side. During follow-up five out of 29 (17.2%) homogeneous and 20 out of 46 (43.4%) heterogeneous plaques progressed (p less than 0.01). With regard to the surface characteristics, nine out of 25 regular plaques progressed and only three patients (12%) had neurological events; 19 out of 34 (55.9%) irregular plaques showed a progression and 14 caused neurological symptoms. Fourteen ulcerated plaques (87.5%) progressed (p less than 0.01). Our experience suggests that the basic trend in the follow-up of patients with bilateral carotid artery disease, is that the contralateral unoperated lesion may evolve and become symptomatic. These symptoms are generally TIAs but five patients (4.3%) suffered from strokes related to the unoperated side, all without warning TIAs.

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