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D Pagano

Publications and source records attributed to D Pagano.

At least 19 recordsLinked to original sources
PubMed2003

Amyand's hernia: case report and review of the literature.

The authors report a case of gangrenous acute appendicitis in the sac of an inguinal hernia (Amyand's hernia). After a review of the literature, they emphasise the extreme rarity of the case reported, they underline how the clinical picture is highly similar to that of a strangulated inguinal hernia. They affirm that appendicectomy and hernioplasty may be performed at the same time, since the repair of the hernia should be performed without prosthesis implantation due to the contamination of the operating field.

Aged↗
PubMed2002

Electronically excited states and transport properties of thermal plasmas: the reactive thermal conductivity.

The role of excited states in affecting the transport of ionization energy in thermal plasmas in the temperature range 10,000 < or = T < or = 25,000 K is discussed by taking into account the dependence of diffusion cross sections on principal quantum number. The results show a strong effect at high pressure, while compensation effects reduce the role of excited states at atmospheric pressure. Extension of the results to nonequilibrium situations is discussed by presenting calculations of effective multicomponent diffusion coefficients. In this case also the presence of excited states dramatically affects these coefficients.

Journal Article↗
PubMed2002

Failure of retrograde cerebral perfusion to attenuate metabolic changes associated with hypothermic circulatory arrest.

OBJECTIVES: Although retrograde cerebral perfusion has become a popular adjunctive technique and may improve cerebral ischemic tolerance during hypothermic circulatory arrest, direct cerebral metabolic benefit has yet to be demonstrated in human subjects. We investigated the post-arrest metabolic phenomena with and without retrograde cerebral perfusion in patients. METHODS: In a prospective randomized trial, 42 patients undergoing aortic surgery requiring hypothermic circulatory arrest were allocated to receive hypothermic circulatory arrest alone (n = 21) or hypothermic circulatory arrest with additional retrograde cerebral perfusion (n = 21). Circulatory arrest was commenced at 15 degrees C, and retrograde perfusion was instituted through the superior vena cava at a maximum jugular bulb pressure of 25 mm Hg. Transcranial, paired, repeated samples of the arterial and jugular bulb blood were analyzed for oxygen and glucose. Velocity in the right middle cerebral artery was also measured simultaneously. RESULTS: There were 3 (7.1%) deaths and 3 (7.1%) episodes of neurologic deficit. Mean bypass and circulatory arrest duration (in minutes) were similar between groups (P =.4 and.14). The mean retrograde perfusion duration was 23 minutes. Post-arrest nasopharyngeal temperature was similar (15.3 degrees C vs. 15.3 degrees C). Retrograde perfusion did not affect post-arrest oxygen extraction, glucose extraction, or jugular bulb Po(2). There was no immediate lactate release immediately after hypothermic circulatory arrest. CONCLUSIONS: Retrograde cerebral perfusion did not influence immediate post-arrest nasopharyngeal temperature or cerebral metabolic recovery. The low jugular bulb Po(2) suggests equivalent ischemia. These findings cast doubt on the effectiveness of retrograde cerebral perfusion as a metabolic adjunct to hypothermic circulatory arrest.

Adult↗
PubMed2001

Effects of coronary revascularisation on myocardial blood flow and coronary vasodilator reserve in hibernating myocardium.

OBJECTIVE: Previous studies have suggested that resting myocardial blood flow is within normal limits in most chronically dysfunctional left ventricular segments which improve function after coronary artery revascularisation (hibernating myocardium). The aim of this study was to assess myocardial blood flow and coronary vasodilator reserve in hibernating myocardium before and after coronary revascularisation. PATIENTS AND METHODS: 30 patients with multivessel coronary disease undergoing coronary revascularisation (21 patients with bypass grafting and nine with coronary angioplasty), and 21 age and sex matched healthy volunteers (controls). Myocardial blood flow (MBF, ml/min/g) was measured by positron emission tomography using oxygen-15 water at rest and after dipyridamole (MBFdip, 0.56 mg/kg in four minutes). Coronary vasodilator reserve was calculated as MBFdip/MBF. Regional wall motion was assessed with echocardiography. RESULTS: Before revascularisation there were 48 remote and 275 dysfunctional myocardial segments, of which 163 (59%) improved function after revascularisation (hibernating). In hibernating segments coronary vasodilator reserve before revascularisation was significantly lower than in remote segments (1.97 (0.7), p < 0.0001) and controls (3.2 (1.5), p < 0.0001). In hibernating segments, myocardial blood flow remained unchanged after revascularisation (0.94 (0.3) v 0.95 (0.3) ml/min/g, p = 0.3) while coronary vasodilator reserve increased (1. 47 (0.7) v 1.98 (1.0), p < 0.0001). Myocardial blood flow was similar in remote, hibernating segments before and after revascularisation and in controls. CONCLUSIONS: This study confirms that myocardial blood flow at rest in hibernating myocardium is within normal limits in most segments, and that hibernating myocardium is characterised by an impaired coronary vasodilator reserve which improves significantly after coronary revascularisation.

Adult↗
PubMed2000

Hibernating myocardium: morphological correlates of inotropic stimulation and glucose uptake.

BACKGROUND: In patients with postischaemic left ventricular dysfunction, segments recovering function after revascularisation (hibernating myocardium) may not respond during dobutamine echocardiography, despite preserved [(18)F] 2-fluoro-2-deoxy-D-glucose (FDG) uptake at positron emission tomography. OBJECTIVE: To investigate whether this lack of response might reflect the degree of ultrastructural change in hibernating myocardium. METHODS: Transmural biopsies were obtained from 22 dysfunctional segments in 22 patients during coronary artery bypass grafting and examined by light and electron microscopy. Wall motion scores and coronary vasodilator reserve were assessed before and after coronary artery bypass grafting (CABG). RESULTS: Mean (SD) wall motion score improved in all segments following CABG (from 2.24 (0.4) to 1.55 (0.4); p < 0.0001), confirming hibernating myocardium. In these segments myocardial blood flow (positron emission tomography with H(2)(15)O) before CABG was similar to that in normal volunteers (1.02 (0.24) v 1.02 (0.23) ml/min/g), while the coronary vasodilator reserve was blunted (1.26 (0.7) v 3.2 (1.6); p < 0.0001). Myocardial blood flow was unchanged after CABG, whereas coronary vasodilator reserve increased to 2.10 (0.90) (p < 0.0007). In hibernating myocardium myofibrillar loss, interstitial fibrosis, and glycogen-rich myocytes were more marked than in control donor hearts. On the basis of the response to dobutamine before CABG, two functional groups were identified: group A, segments with inotropic reserve (n = 15); group B, segments without inotropic reserve (n = 7). FDG uptake was similar in group A and group B (0.40 (0.1) v 0.44 (0.1) micromol/min/g). In group B there was more myofibrillar loss (26 (8)% v 11 (5)%; p = 0.0009) and glycogen-rich myocytes (28 (11)% v 17 (10)%; p = 0.02), whereas interstitial fibrosis, myocardial blood flow, and coronary vasodilator reserve were similar in the two groups. Myofibrillar loss was the only independent predictor of inotropic reserve (p = 0.01). CONCLUSIONS: Hibernating myocardium is characterised by a reduced coronary vasodilator reserve which improves on revascularisation and shows a spectrum of ultrastructural changes that influence the response to dobutamine, while FDG uptake is invariably preserved.

Adult↗
PubMed2000

Clinical and patho-anatomical factors affecting expansion of thoracic aortic aneurysms.

OBJECTIVE: To examine the expansion of aneurysmal aortic segments (> or = 35 mm) and to assess the impact of clinical and patho-anatomical factors on aneurysm expansion. DESIGN: 87 consecutive patients (mean age 63.6 years, range 22-84 years) were studied using serial (six month intervals) computed tomographic or magnetic resonance imaging to monitor progression of thoracic aortic aneurysms. Aortic diameter was measured at seven predetermined segments and at the site of maximum aortic dilatation (MAX). RESULTS: 780 segment intervals were identified. The median overall aneurysm expansion rate was 1.43 mm/year. This increased exponentially with incremental aortic diameter (p < 0.01) and varied by anatomical segment (p < 0.05). The presence of intraluminal thrombus (p < 0.01) but not dissection or calcification was associated with accelerated growth. Univariate analysis identified thrombus (p < 0.001), previous stroke (p < 0.002), smoking (p < 0. 01), and peripheral vascular disease (p < 0.05) as factors associated with accelerated growth in MAX. Dissection, wall calcification, and history of hypertension did not affect expansion. beta Blocker treatment was not associated with protection. Multivariate analysis confirmed the positive effect of intraluminal thrombus and previous cerebral ischaemia, and the negative effect of previous aortic surgery on aneurysm growth. These findings translated into a mathematical equation describing exponential aneurysm expansion. CONCLUSIONS: Aneurysmal thoracic aortic segments expand exponentially according to their initial size and their anatomical position within the aorta. The presence of intraluminal thrombus, atherosclerosis, and smoking history is associated with accelerated growth and may identify a high risk patient group for close surveillance.

Adult↗
PubMed1999

Prediction of thoracic aortic aneurysm expansion: validation of formulae describing growth.

BACKGROUND: The expansion rate of thoracic aortic aneurysms may be an important and clinically relevant index of the risk of rupture. The aims of this study were to assess the validity of three published exponential equations that predict expansion rate in a separate sample population, and to calculate an expansion rate formula for this cohort of patients. METHODS: We studied 88 consecutive patients undergoing serial computed tomographic or magnetic resonance imaging scanning to monitor thoracic aortic aneurysm progression. In interval scans of at least 6 months, we measured minimum coronal aortic diameter at seven set levels and maximal diameter, yielding 780 segment-intervals. RESULTS: The linear expansion rate (mean 2.6 mm/year) increased with incremental aortic diameter (aortic diameter < 40 mm: 2.0; 40-49 mm: 2.3; 50-59 mm: 3.6; > or = 60 mm: 5.6 mm/year; p < 0.01). Regression analysis showed close correlation between predicted and sample data, but there were significant differences between observed and expected measurements. The Yale formula underestimated growth by 0.8 mm, while Mt. Sinai and Osaka formulae overestimated actual change by 1.5 and 0.2 mm, respectively. The expansion rate derived from our population was: last diameter = initial diameter x e(0.00367 x time) (r = 0.617). CONCLUSIONS: Although formulae derived from one thoracic aortic aneurysm sample population may not extrapolate exactly to others, there is close concordance of results for patient populations in three different continents.

Aortic Aneurysm, Thoracic↗
PubMed1999

Insulin resistance in patients with cardiac hypertrophy.

OBJECTIVE: Animal studies suggest that left ventricular hypertrophy might be associated with insulin resistance and alterations in glucose transporters. We have previously demonstrated myocardial insulin resistance in patients with post-ischemic heart failure. The aim was to investigate whether myocardial insulin resistance could be demonstrated in human cardiac hypertrophy in the absence of hypertension, diabetes and coronary artery disease. METHODS: Eleven normotensive nondiabetic patients with cardiac hypertrophy due to aortic stenosis and angiographically normal coronary arteries were compared to 11 normal volunteers. Myocardial glucose uptake (MGU) was measured with positron emission tomography and [18F]2-fluoro-2-deoxy-D-glucose during fasting (low insulinemia) or during euglycemic-hyperinsulinemic clamp (physiologic hyperinsulinemia). Myocardial biopsies were obtained in order to investigate changes in insulin-independent (GLUT-1) and insulin-dependent (GLUT-4) glucose transporters. RESULTS: During fasting, plasma insulin (7 +/- 1 vs. 6 +/- 1 mU/l) and MGU (0.12 +/- 0.05 vs. 0.11 +/- 0.04 mumol/min/g) were comparable in patients and controls. By contrast, during clamp, MGU was markedly reduced in patients (0.48 +/- 0.02 vs. 0.70 +/- 0.03 mumol/min/g, p < 0.01) despite similar plasma insulin levels (95 +/- 6 vs. 79 +/- 6 mU/l). A decreased GLUT-4/GLUT-1 ratio was shown by Western blot analysis in patients. CONCLUSIONS: Insulin resistance seems to be a feature of the hypertrophied heart even in the absence of hypertension, coronary artery disease and diabetes and may be explained, at least in part, by abnormalities in glucose transporters.

Aortic Valve Stenosis↗
PubMed1999

Replacement of the proximal aorta and aortic valve using a composite bileaflet prosthesis and gelatin-impregnated polyester graft (Carbo-Seal): early results in 143 patients.

OBJECTIVE: We report the combined early results from two centers in the United Kingdom using a composite conduit consisting of a bileaflet mechanical valve incorporated into a gelatin-impregnated, ultra-low porosity, woven polyester graft (Carbo-Seal; Sulzer Carbomedics, Inc, Austin, Tex). METHODS: Between August 1992 and March 1997, 143 patients underwent aortic root replacement with the Carbo-Seal composite prosthesis. The indication for surgery was acute type A dissection in 31 (22%), chronic type A dissection in 9 (6%), ascending aortic aneurysm without dissection in 100 (70%), and false aneurysm of the ascending aorta in 3 (2%). Twenty-seven patients (19%) had undergone previous sternotomy, and 40 (28%) were seen as emergencies. Concomitant procedures were performed in 38 (27%), including 18 aortic arch or hemiarch replacements. Total follow-up is 270 patient-years. Follow-up is 100% complete. RESULTS: The early (30-day) mortality was 7% (10 patients). Permanent neurologic events occurred in 2%. At a mean follow-up of 23 months, 94% of survivors were in New York Heart Association functional class I. Freedom from reoperation was 97.2% +/- 1.6% (1 standard error [1 SE]) at 12 months and 95.7% +/- 2.2% at 48 months. Including early mortality, survival was 90.1% +/- 2.6% at 12 months and 83.1% +/- 3. 5% at 48 months. CONCLUSIONS: Aortic root replacement with use of the Carbo-Seal prosthesis can be undertaken with a relatively low early mortality and morbidity. A low reoperation rate and high intermediate-term survival can be expected, but continued follow-up is needed to determine the long-term efficacy of this prosthesis.

Aged↗
PubMed1999

Myocardial revascularization for the treatment of post-ischemic heart failure.

Heart failure due to coronary artery disease is a major public health problem. Medical treatment ameliorates symptoms and prognosis, although mortality remains high. Heart failure occurs when a sizeable number of myocytes do not contract. This may be due to irreversible myocyte loss (infarct) and/or dysfunctional but viable myocytes (hibernating), which can resume function following coronary artery bypass surgery. The presence of hibernating myocardium can be predicted by noninvasive nuclear imaging using both single photon (SPECT) and positron emission tomography, and also by stress echocardiography. A number of uncontrolled studies have demonstrated a promising role for coronary artery bypass surgery in patients with heart failure in whom a substantial amount of hibernating myocardium is present. These findings, particularly the magnitude of the benefits reported, justify the need for a randomized trial in this patient population.

Angina, Unstable↗
PubMed1999

A report system for PET assessment of myocardial viability.

Coronary bypass surgery can improve the prognosis of patients with heart failure due to coronary artery disease. However, these patients have a high operative risk and should be operated on only if they have a sizeable amount of viable tissue (i.e. asynergic myocardium) that can recover contractile function following coronary revascularization. In the clinical setting, regional wall motion is usually evaluated by two-dimensional echocardiography, whereas retained metabolic activity assessed by positron emission tomography (PET) and 18F-fluorodeoxyglucose is a well-established means for the evaluation of myocardial viability. Unfortunately, the two-dimensional echocardiography and PET reports are often different, and this renders the matching of information difficult and the estimation of the risk-benefit ratio of the operation unreliable. In this paper, we present a report system for the evaluation of myocardial viability with PET. We divided the left ventricle into 16 segments following the proposal of the American Society of Echocardiography for wall motion analysis by two-dimensional echocardiography. Following this partition, three portions of the left ventricle are identified along the long axis: basal, mid and apical. Each plane of the basal and mid portions is automatically divided into six segments with the super-imposition of a radial divider over the short-axis images. Similarly, each plane of the apical portion is automatically divided, but into four segments. This partition of the left ventricle permits a precise match between the information on wall motion obtained with two-dimensional echocardiography and that on viability obtained with PET.

Coronary Artery Bypass↗
PubMed1999

Coronary revascularisation for postischaemic heart failure: how myocardial viability affects survival.

OBJECTIVE: To assess the impact of revascularisation of viable myocardium on survival in patients with postischaemic heart failure. METHODS: 35 patients (mean (SD) age 58 (7) years) with severe heart failure (New York Heart Association (NYHA) functional class > or = III), mean left ventricular ejection fraction (LVEF) 24 (7)% (range 10-35%), and limited exercise capacity (peak oxygen consumption (VO(2)) 15 (4) ml/kg/min) were studied. 21/35 patients had no angina. Myocardial viability was assessed with quantitative positron emission tomography and the glucose analogue (18)F-fluorodeoxyglucose (FDG) (viable segment = FDG uptake > or = 0.25 micromol/min/g) in all patients before coronary artery bypass grafting. Patients were divided into two groups: group 1, > or = 8 viable dysfunctional segments (mean 12 (2), range 8-15); and group 2, < 8 viable dysfunctional segments (mean 3.5 (3), range 0-7). The two groups were comparable for age, sex, NYHA class, LVEF, and peak VO(2). RESULTS: Two patients died perioperatively and seven patients died during follow up (mean 33 (14) months). All deaths were from cardiac causes. Kaplan-Meyer survival analysis showed 86% survival for group 1 patients versus 57% for group 2 (p = 0.03). Analysis by Cox proportional hazard model revealed three independent factors for cardiac event free survival: presence of > or = 8 viable segments (p = 0.006); preoperative LVEF (p = 0.002); and patient age (p = 0.01). CONCLUSION: Revascularisation for postischaemic heart failure can be associated with good survival, which is critically dependent upon the amount of viable myocardium.

Adult↗
PubMed1998

Coronary revascularization in the treatment of moderate and severe postischemic left ventricular dysfunction.

Chronic postischemic left ventricular (LV) dysfunction can improve following coronary revascularization (hibernating myocardium). However, it is not clear whether the severity of LV dysfunction determines functional outcome after revascularization and the accuracy of tests to predict myocardial viability. We studied 47 patients with coronary artery disease and chronic LV dysfunction. Before coronary bypass, patients underwent (18F)2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) during euglycemic hyperinsulinemic clamp to assess viability. Global and regional LV function were assessed before and 4 to 6 months after surgery. Patients were arbitrarily divided into 2 groups with moderate and severe LV dysfunction. Group 1 (n = 26) had an ejection fraction (EF) of < or = 30% and group 2 (n = 21) > 30%. After bypass, the EF (22+/-6% vs 31+/-10%; p <0.0001) and global wall motion score (WMS) (2.05+/-0.39 vs 1.56+/-0.34; p <0.001) improved in group 1, whereas the EF (43+/-9% vs 43+/-12%; p = NS) was unchanged in group 2, although WMS tended to improve (1.42+/-0.38 vs 1.32+/-0.39; p = 0.09). The proportion of dysfunctional segments (72% vs 32%; p <0.0001) and FDG uptake in these segments (0.44+/-0.15 vs 0.34+/-0.15 micromol/g/min, p <0.0001) were greater in group 1 than in group 2. The baseline EF influenced the predictive accuracy of PET, with highest positive predictive accuracy in group 2 and highest negative predictive accuracy in group 1. Thus, coronary revascularization has the potential for greatest benefit in patients with the most severe dysfunction, but with evidence of viability, and the entity of LV dysfunction affects the predictive accuracy of viability studies.

Adult↗
PubMed1998

Multiplanar reformatting and three-dimensional reconstruction: for pre-operative assessment of the thoracic aorta by computed tomography.

INTRODUCTION: Conventional CT demonstrates pathology of the thoracic aorta. This study aimed to evaluate the additional contributions to surgical planning of multiplanar reformatting, maximum intensity projections and three-dimensional (3-D) reconstruction. DESIGN: Retrospective. SUBJECT AND METHODOLOGY: Fifty-three patients with newly diagnosed pathology of the thoracic aorta were scanned over a 15-month period; 25 scans were spiral acquisitions. Scans were acquired during and following rapid injection of 100 ml of intravenous iopromide. The reconstructed data was displayed as axial images, oblique or other multiplanar reformats and shaded surface display 3-D reconstructions. Two radiologists and two surgeons reviewed the images. The axial images were assessed initially, subsequently the reformats and 3-D reconstructed views were examined looking particularly for additional information that might add to the surgical management. RESULTS: Pathologies encountered were aortic dissection (21 patients, including two with Marfan's syndrome), saccular aneurysms (eight), fusiform aneurysms (16), aortic root and ascending aortic dilatation (seven) and coarctation (one). The relationship of aneurysms and dissections to major vessels are better shown with 3-D reconstruction or oblique reformats. Morphology of saccular aneurysms, particularly the neck, is well shown with 3-D reconstruction. Coarctation was best demonstrated by oblique reformats. There was little additional information from 3-D reconstruction or reformats in assessment of type A dissection. Improved spatial orientation by visualization in varying projections was helpful for surgical planning in certain cases of type B dissection, fusiform aneurysms and aortic root and ascending aortic root dilatation. Spiral acquisitions have the advantage of speed and hence a greater anatomical coverage for a single breath-hold. CONCLUSION: Oblique reformats and 3-D reconstruction, although using identical data as the axial images, in specific cases were felt to aid surgical assessment of aneurysms and dissections, thus assisting pre-operative planning.

Aortic Dissection↗