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Biomedical subjects

G D Angelini

Publications and source records attributed to G D Angelini.

At least 235 records · Page 13Linked to original sources
PubMed1985

Pseudocoarctation of the aortic arch associated with bicuspid aortic valve lesion: is it a surgical entity?

Three patients with bicuspid aortic valve lesion associated with pseudocoarctation of the aortic arch are presented. At operation, 2 had a bicuspid calcified stenotic aortic valve, and one a bicuspid non-calcified incompetent aortic valve. All required replacement of the diseased aortic valve. The pseudocoarctation was not corrected because it caused no hemodynamic abnormality.

Adult↗
PubMed1985

A comparative study of median sternotomy and standard thoracotomy wound skin closure methods.

Complications from skin closure after median sternotomy or standard thoracotomy incision, although uncommon, may be the source of undesireable morbidity and even death. A prospective randomized study of 3 different methods of wound skin closure has been carried out in 205 patients undergoing cardiothoracic surgery. These methods were: 1. continuous nylon vertical mattress suture; 2. continuous subcuticular absorbable (Dexon) suture; 3. adhesive sutureless skin closure (Op-Site). All wounds were examined by independent observers at 5, 10 and 45 days after operation, and the findings were graded from 0 to 4. At 5 days, assessments were made of inflammation, edema, discharge and infection. At 10 days, attention was paid to the state of wound healing, and at 45 days to the final cosmetic appearance. The use of continuous subcuticular Dexon suture resulted in less discharge than Op-site (p less than 0.001) and less swelling or redness than nylon (p less than 0.001). Assessment of the final cosmetic appearance of the wound 6 weeks following surgery showed subcuticular Dexon to be superior to either nylon (p less than 0.01) or Op-site (p less than 0.01).

Adhesives↗
PubMed1985

Metabolic damage to human saphenous vein during preparation for coronary artery bypass grafting.

Segments of saphenous vein from patients undergoing coronary artery by-pass graft surgery were frozen in liquid nitrogen immediately on dissection (control), after stripping of the adventitia and side branch ligation (manipulation), after distention with blood (distention), or at completion of the last proximal anastomosis (prepared vein). Vein was stored during the operation in patient's heparinised arterial blood at room temperature. Frozen vein was extracted with perchloric acid. ATP, ADP, and AMP, adenosine, inosine and hypoxanthine concentrations were measured by high pressure liquid chromatography. Prepared vein had ca 50% lower ATP concentrations and ATP/ADP ratio than control vein, higher concentrations of inosine and hypoxanthine and lower concentrations of AMP and adenosine. ATP concentration and ATP/ADP ratio did not correlate with the time elapsed between dissection and freezing of the prepared vein. The characteristic changes seen in prepared vein were not seen when control vein was simply stored in arterial blood at 23 degrees C, in normal saline at 23 degrees C or 4 degrees C, in Krebs-Ringer bicarbonate buffer at 37 degrees C or at St Thomas's Hospital cardioplegic solution at 4 degrees C. Distention with unlimited pressure did not distension at less than 300 mmHg gave rise to the same changes in ATP concentration and ATP/ADP ratio as in the prepared vein. These results show that vein suffered metabolic changes during preparation for bypass grafting and suggest that uncontrolled distention may contribute to these changes. Such biochemical measurements provide a quantitative estimate of tissue damage and allow objective comparison of different preparative techniques.

Adenine Nucleotides↗
PubMed1984

Right coronary artery occlusion by cloth from a Starr-Edwards aortic valve prosthesis.

We report a case of sudden onset of angina 11 years after implantation of a No. 8 Model 2300 Starr-Edwards cloth-covered aortic valve prosthesis for aortic stenosis and insufficiency. At operation the cloth covering one strut of the metal cage was tenuously attached to the ring of the prosthesis, with its free end completely occluding the right coronary artery ostium. The valve was replaced and the obstructing foreign body removed, re-establishing the patency of the right coronary artery.

Angina Pectoris↗
PubMed1984

Comparative study of leg wound skin closure in coronary artery bypass graft operations.

A prospective randomised study of four different methods of leg wound skin closure after removal of the long saphenous vein was carried out in 113 patients undergoing coronary artery bypass grafting. These methods were: (1) continuous nylon vertical mattress suture (27 patients); (2) continuous subcuticular absorbable (Dexon) suture (29 patients); (3) metal skin staples (Autosuture) (27 patients); and (4) adhesive sutureless skin closure ("Op-site") (30 patients). All wounds were examined by two independent observers at five, 10, and 45 days after operation. At five days, inflammation, extent of oedema, discharge, and infection were assessed. At 10 days attention was paid to the state of wound healing and at 45 days to the final cosmetic appearance. The use of continuous subcuticular suture resulted in significantly less discharge than did the use of metal staples, nylon vertical mattress suture, or Op-site. The incidence of established wound infection was 4.5% overall, with no infection in the wounds closed with Dexon. Assessment of the healing process showed subcuticular Dexon to be more effective than metal staples or vertical mattress nylon suture. The final cosmetic result showed continuous subcuticular suture to be superior to nylon vertical mattress suture and skin staples but as effective as Op-site sutureless skin closure.

Coronary Artery Bypass↗
PubMedDate not supplied

Differential alterations of spontaneous and stimulated 45Ca(2+) uptake by platelets from patients with type I and type II diabetes mellitus.

Diabetes mellitus (DM) is associated with hyperaggregability of platelets. Although the mechanisms underlying this abnormality remain unknown, Ca(2+) imbalance has been implicated. Both activators (alpha-adrenoceptor agonists, collagen, and ADP) and inhibitors (beta-adrenoceptor agonists, iloprost and dibutyryl cAMP) of platelet function, respectively, elicit the uptake of [45Ca(2+)] in human platelets. It was determined that the [45Ca(2+)] uptake methods employed reflected signal transduction events at the plasma membrane rather than absolute changes of Ca(2+) fluxes or levels of cytosolic Ca(2+). In the present study, basal (unstimulated) [45Ca(2+)] uptake by platelets from both type I and type II diabetic patients was significantly enhanced when compared to age-matched controls. When basal values were subtracted from stimulated values, there were highly significant decreases in [45Ca(2+)] uptake in platelets from type I diabetic patients compared to controls when stimulated with adrenaline, isoprenaline, noradrenaline, collagen, A23187, or iloprost. In contrast, when basal values were subtracted from stimulated values there were significant increases in [45Ca(2+)] uptake by platelets from type II diabetic patients when stimulated with adrenaline, isoprenaline, noradrenaline, A23187, iloprost, and collagen. It is concluded that in type I and type II DM there are differential alterations in [45Ca(2+)] sequestration linked to inhibitors and stimulators of platelet activation. These data indicate that the hyperaggregability of platelets that is associated with both type I and type II DM may be due to an aetiology other than Ca(2+) mobilization linked to signal transduction.

Adult↗
PubMedDate not supplied

Does external stenting reduce porcine vein-graft occlusion via an action on vascular nerves?

BACKGROUND: Neural reorganization occurs in porcine vein grafts and placement of an external stent reduces graft occlusion. AIM OF THE STUDY: To determine the effect of external stenting on the innervation of porcine vein grafts. METHODS: Saphenous vein into carotid artery grafting (with and without external stents) was performed in 16 pigs. After one and six months, grafts were removed, nerves were counted, and neointima was assessed. RESULTS: In vein graft compared to ungrafted vein, there was a significant (p < 0.05) decrease in medial perivascular nerves, but a dramatic increase in paravascular nerves in the adventitia (p < 0.05). In stented vein grafts there was also a reduction of perivascular nerves and the paravascular nerve proliferation observed in vein grafts at one month was inhibited (p < 0.05). Neointima formation and the appearance of large paravascular nerve bundles in the adventitia of vein grafts were abolished by external stenting. CONCLUSIONS: Neural reorganization plays a role in vein-graft failure, possibly through the local release of mitogens; the prevention of this reorganization contributes to the inhibitory effect of the external stent on neointima formation.

Animals↗
PubMedDate not supplied

Side effects of cardiopulmonary bypass: what is the reality?

Despite many years of clinical and experimental research, the contribution of cardiopulmonary bypass (CPB) and cardioplegic arrest to morbidity and mortality following cardiac surgery remains unclear. This is due, in part, to lack of suitable control group against which bypass and cardioplegic arrest can be compared. The recent success of beating heart coronary artery bypass grafting has, however, for the first time, provided an opportunity to compare the same operation, in similar patient groups, with, or without CPB and cardioplegic arrest. CPB is associated with an acute phase reaction of protease cascades, leucocyte, and platelet activation that result in tissue injury. This is largely manifest as subclinical organ dysfunction that produces a clinical effect in those patients that generate an excessive inflammatory response or in those with limited functional reserve. The contribution of myocardial ischemia/reperfusion, secondary to aortic cross-clamping, and cardioplegic arrest, to the systemic inflammatory response and wider organ dysfunction is unknown, and requires further evaluation in clinical trials.

Cardiopulmonary Bypass↗
PubMedDate not supplied

Left ventricular volume reduction: new dawn or false horizon? Basic science and clinical doubts.

Left ventricular volume reduction surgery (LVVR) for end-stage dilated cardiomyopathy is a surgical option used selectively but with unclear long-term results. Increasing numbers of reports are appearing in the literature. These should be pooled into an international registry through collaborative efforts that allow for more effective analysis. Furthermore, high priority must be given to identify subgroups of patients who will potentially gain most benefit from LVVR. Basic science may add invaluable data and in this article we describe how intraoperative myocardial biopsies from patients with idiopathic dilated cardiomyopathy were utilized to isolate myocytes in an effort to determine differential physiological characteristics at the cellular level. The result showed various degrees of contractile anomalies in response to electrical stimulation associated with defective calcium handling as reflected by measurements of calcium transients. It is hoped that this approach may be extended to preoperative catheter biopsy to gain information that will facilitate patient selection to avoid unnecessary surgical failures.

Aged↗
PubMedDate not supplied

Perioperative care in left ventricular volume reduction.

BACKGROUND: While the operative technique of left ventricular volume reduction (LVVR) is rapidly becoming standardized, the optimal perioperative management strategy is yet to be determined. We present our experience with the care of patients undergoing LVVR. METHODS: LVVR was performed in 21 patients (mean age = 65.5 years) with congestive heart failure. Our management strategy was initially based on afterload reduction with sodium nitroprusside, but was later modified to include routine preoperative intra-aortic balloon support, normothermic cardiopulmonary bypass, antegrade intermittent warm blood cardioplegia, and postoperative support with phosphodiesterase-III inhibitors. Hemodynamic manipulations are aimed to attain systemic vascular resistance between 600 and 800 dyne/sec per cm(-5) and the lowest mean blood pressure that is able to maintain satisfactory systemic perfusion. Postoperatively, aggressive antifailure medical therapy with a high dose of angiotensin converting enzyme inhibitors, nitrates, and diuretics was initiated early and maintained indefinitely. RESULTS: Using this approach, postoperative progress was characterized by hemodynamic stability. IABP support was used for 59.6+/-9 hours following surgery, and inotropic support for 103+/-12 hours. In our series there were four (19%) in-hospital deaths, two of which were related to heart failure. CONCLUSION: The described approach is associated with an acceptable early outcome. However, further advances in myocardial protection methods and pharmacological and mechanical support techniques are necessary for a wider adoption of this procedure.

Aged↗
PubMedDate not supplied

A simple method of scapular retraction for posterolateral thoracotomy.

A simple method of scapular retraction for posterolateral thoracotomy is presented. This technique allows for retraction and stabilisation of the scapula and prevents it from protruding over the intercostal space chosen for entry into the chest cavity. It also facilitates insertion of the chest retractor and spreading of the intercostal space since reduced tension is now exerted on the rib cage by the retracted scapula and muscle layers.

Humans↗