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Biomedical subjects

G Torsello

Publications and source records attributed to G Torsello.

51 records · Page 3Linked to original sources
PubMed1988

[Captopril-stimulated plasma renin activity in the diagnosis of renovascular hypertension].

In 67 patients thought to have renovascular hypertension, plasma renin activity was measured in both renal veins and peripherally (common femoral v.) before and after administration of 25 mg captopril. Other antihypertensive medication, except diuretics and ACE inhibitors, had been discontinued. The renin ratio, renin secretion indices before and after ACE inhibition, as well as the percentage rise in peripheral plasma renin activity, after captopril were calculated from the measured data. The diagnostic and prognostic value of the various calculation models were compared on the basis of blood pressure changes in 29 patients after intervention (28 operations, one percutaneous transluminal angioplasty). Of the various calculations the renin ratio after ACE stimulation--measuring plasma renin activity separately for each side--was of the greatest value in discriminating for renovascular hypertension (sensitivity 89%, specificity 100%). Comparable results in the discrimination for renovascular hypertension were achieved by determining the rise in peripheral plasma renin activity after captopril. This method is, therefore, a simple, noninvasive test for diagnosing renovascular hypertension with great accuracy even while existing medication is being continued.

Adult↗
PubMed1988

[An experimental study of liver perfusion using non-diffusible radiotracers: differentiation of the arterial and portal venous components by deconvolution analysis of first-pass time-activity curves].

The transfer function of the liver perfusion is an idealized time-activity curve that could be registered over the liver if a non-diffusible tracer would be injected directly into the abdominal aorta and no tracer recirculation would occur. The reproducibility of the transfer function was experimentally investigated in foxhounds. Both the routes of tracer application and the modes of data evaluation were varied and the perfusion was investigated under physiological and pathological conditions. The transfer function was calculated by deconvolution analysis of first-pass time-activity curves using the matrix regularization method. The transfer function showed clearly distinguishable arterial and portal-venous components. Repeated peripheral venous and central aortic applications resulted in reproducible curves. In addition to the arterial and portal-venous components the subcomponents of the portal-venous component could also be identified in the transfer function after ligation of the appropriate vessels. The accuracy of the mathematical procedure was tested by computer simulations. The simulation studies demonstrated also that the matrix regularization technique is suitable for deconvolution analysis of time-activity curves even when they are significantly contaminated by statistical noise. Calculation of the transfer function of liver perfusion and of its quantitative parameters seems thus to be a reliable method for non-invasive investigation of liver hemodynamics under physiological and pathological conditions.

Animals↗
PubMed1987

Absorbable polydioxanone suture for venous anastomoses: experimental studies using venography and transluminal angioscopy.

Because of their increased tendency to stenosis and spasm and thrombosis, results after venous anastomoses are often unsatisfactory. Nonabsorbable sutures and a continuous suture technique have been suggested to have a negative effect on the compliance of vascular anastomoses. Eighty venous anastomoses were performed with either an interrupted or continuous suture technique, using polypropylene or polydioxanone (PDS) sutures, according to a randomised experimental model. The anastomoses were divided in four groups: (1) Nonabsorbable suture material, continuous suture technique; (2) Nonabsorbable suture material, interrupted suture technique; (3) Absorbable suture material, continuous suture technique; and (4) Absorbable suture material, interrupted suture technique. The morphology of the anastomoses was controlled by venography directly after closure of the wound and at weekly intervals for 2 months and monthly intervals thereafter until 2 years had passed. In 10 cases venography was followed by transluminal angioscopy in the early postoperative period and after 1, 2, 4, 8 and 12 weeks. In the first 2 months moderate and high degree stenoses were found in all 4 groups by venography. After 8 weeks there was a significant decrease in the incidence of stenosis in all groups with the exception of the group, in which continuous nonabsorbable suture had been used. Using angioscopy a marked swelling of the intima at the site of the anastomoses could be detected in the early postoperative period in all experimental groups. After 2 months no significant narrowing could be identified in groups 2, 3 and 4.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗
PubMed1987

Ten years experience with reconstruction of the chronic totally occluded renal artery.

The criteria for selection of patients who may benefit from reconstruction of totally occluded renal arteries are not well defined. Of those patients who underwent renal artery reconstruction for renal artery occlusive disease at our institution 13% (52/397) had a chronic renal artery occlusion at preoperative arteriography. In 38 cases (73%) the contralateral renal artery had a significant (greater than 70%) stenosis, which was reconstructed simultaneously. Renovascular hypertension alone (n = 27;52%) or in combination with impaired renal function (n = 25;48%) was the indication for surgical treatment and transaortic thromboendarterectomy was the preferred method of reconstruction (n = 38;73%). Operative mortality was 5.7% and during follow-up (38 +/- 31 months) 4 patients died from myocardial infarction (n = 2), aortic dissection (n = 1) or cerebral haemorrhage (n = 1). Postoperatively 20 patients (44.5%) had a normal blood pressure; in a further 20 (44.5%) the hypertension was easier to control and medication could be reduced. Five patients (11%) remained hypertensive. Postoperative arteriography showed a normal patent renal artery in 40 cases (89%). Postoperative plasma creatinine levels ranged from 0.8 to 3.4 mg% (1.32 +/- 0.74) which was a significant reduction from preoperative levels. Two patients with severe uraemia improved to an extent where haemodialysis could be discontinued. Radionuclide scan and the measurements of plasma renin activity before and after administration of a converting enzyme inhibitor (Captopril) were the most reliable diagnostic methods for preoperative patient selection and postoperative follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic Disease↗
PubMed1985

Reconstructive vascular surgery for hypertension in renal vascular dysplasia.

28 patients with renovascular hypertension caused by fibromuscular dysplasia involving one or more renal arteries underwent reconstructive surgery. The renal artery stenosis was bilateral in 5 patients. Total artery occlusion occurred in 3 cases. Arteriography was the most useful diagnostic procedure. The operative technique of choice was replacement using saphenous vein or hypogastric artery. All patients survived. On follow-up, 27 patients (96.4%) were either cured or improved. Isotope nephrography suggested restenosis in 1 case. Our results support an aggressive approach to the diagnosis and surgical treatment of renal artery fibromuscular dysplasia causing hypertension.

Adolescent↗
PubMed1985

Parameters of 99mTc-DTPA transfer function in renal artery stenosis.

A new method is presented for decomposition of 99mTc-DTPA renal transfer functions (TF) into their capillary and tubular parts. Amplitudes and mean transit times of both parts were calculated and used for quantitative evaluation of renal perfusion, extraction and transport in 21 patients with renal artery stenosis. The amplitudes showed a positive correlation to the effective renal plasma flow and a negative correlation to the grade of stenosis. The parameters of TF are independent of the contralateral kidney, so they can be used for screening for renovascular disease as well as for pre- and postoperative evaluation of kidneys even in cases of bilateral disease.

Humans↗
PubMed1983

[Renal artery occlusion. Blood pressure and kidney function before and after surgical treatment].

Angioplasty was performed in 16 patients with renal artery occlusion. It was successful in each of six acute occlusions, although four patients died later of their underlying disease. Two patients are long-term survivors and have normal or compensated renal function up to three years postoperatively. Vessel reconstruction was successful in eight of ten patients with chronic occlusion. In seven there was definite improvement or normalization of the hypertension, in six renal function returned to normal. Thus the success rate as to organ preservation with improvement in pressure and function was 60%.

Adult↗
PubMed1983

[The use of glucagon in cholangiography].

Certainty of interpretation can be hindered by spasms of the sphincter of Oddi during cholangiography, since these impair the opaqueness of the image of the distal common duct and reduce the bile flow in the duodenum. Recently, especially in the English-speaking world, glucagon has been used to relax the bile ducts. The authors, following this line of experimentation, report on the use of glucagon in intravenous cholangiographic examination (15 cases), in postoperatory cholangiography (3) and in intra-operatory cholangiography (7), for a total of 25 patients, 13 of whom affected with pathological bile-duct conditions. In each type of examination, after the contrast material had been administered, X-rays were taken in the same position before and three or four minutes after the endovenous injection of glucagon. In every case glucagon revealed its intense hypotoning action, a consistent and rapid effect of short duration, the absence of side effects, the possibility of its use in every type of cholangiographic examination and its effectiveness in controlling the degree of diagnostic uncertainty.

Cholangiography↗
PubMed1979

[Sphenoidal pneumosinus dilatans: a case report (author's transl)].

Pneumosinus dilatans is an abnormal dilatation of a paranasal cavity containing air only. The case described here can be added to the 51 cases in the literature. Various pathogenetic theories have been proposed: mucocele, intrasinus hypertension, inflammation, endocrine disorder. The authors suggest that this pathological form is the result of overextension of a normal process in the morphogenesis of the sinuses. The symptomatology depends on the location and on the rate of onset of the dilatation.

Adolescent↗
PubMedDate not supplied

Effects of renal artery reconstruction on kidney perfusion and tubular function measured by new radionuclide techniques.

Therapeutic effects of renal artery reconstruction on kidney perfusion and function were studied in 36 patients using new methods for analyzing radionuclide studies. Effective renal plasma flow, glomerular filtration fraction and parameters indicating perfusion and tubular transport improved significantly in patients with postoperative normalization of blood pressure. Patients with a patent renal artery on angiogram but without normalization of blood pressure showed an improvement of parameters such as effective renal plasma flow, glomerular filtration fraction and tubular transport time, whereas the perfusion index remained unchanged. In the group with re-stenosis or re-occlusion all parameters deteriorated after surgery. Discriminant analysis of preoperative data showed that success of surgery could be predicted with high degree of certainty (65% for improvement and 92% for no improvement). The results indicate, that radionuclide methods and arteriography are complementary in the evaluation of the hemodynamic consequences of a renal artery stenosis. They also help to assess the effects of reconstructive surgery and to predict operative success.

Glomerular Filtration Rate↗