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Biomedical subjects

M Sapoval

Publications and source records attributed to M Sapoval.

At least 19 recordsLinked to original sources

[Lower limb arterial disease: Doppler sonography follow-up after revascularization].

Follow-up color duplex sonography after arterial surgery or angioplasty for lower limb arterial disease evaluates the outcome of the procedure and searches for lesions compromising patency. The various types of lesions are described. After surgical bypass, lesions include stenosis, anastomotic abnormality (enlargement, false-aneurysm), arterio-venous fistula, intrinsic bypass abnormalities, and collections. After endoluminal treatment, the main lesions include residual stenosis, restenosis, and in-stent hyperplasia. Local complications related to arterial puncture are described. The frequency and the type of lesions encountered depend on the interval between the date of the revascularization and the follow-up examination.

Aftercare↗

Manual catheter-directed aspiration and other thrombectomy techniques for declotting native fistulas for hemodialysis.

Recent articles reported excellent results in the percutaneous declotting of native fistulas for hemodialysis with use of thromboaspiration, mechanical devices, or thrombolytic drugs, with success rates ranging from 76% to 100%. These results challenge the surgical approach, the effectiveness of which is not supported by comparable publications. Although it is more difficult to declot forearm native fistulas than grafts, declotting of fistulas is more rewarding because it achieves better long-term patency (1-year primary rates as high as 50% and secondary rates of 80%). The results reported from declotting of fistulas in the upper arm are not as good. The unmasking of stenoses in close to 100% of cases warrants stenosis detection programs similar to those used for grafts.

Arteriovenous Shunt, Surgical↗

Unilateral renal artery stenosis: perfusion patterns with electron-beam dynamic CT--preliminary experience.

Renal dynamic computed tomographic (CT) data for 16 patients with unilateral renal artery stenosis were compared with those for 12 control subjects. Three patterns of perfusion were distinguished in stenotic kidneys: pattern A, symmetric time-attenuation curves; pattern B, asymmetric time-attenuation curve with similar perfusion; and pattern C, asymmetric time-attenuation curve with impaired perfusion. Additional functional data can be obtained from the initial timing scan in a CT study of unilateral renal artery stenosis.

Adult↗

Spontaneous renal artery dissection revealed by helical CT angiography.

Spontaneous renal artery dissection is rare and may be misdiagnosed because its clinical presentation is confusing. Diagnosis is usually made by intra-arterial angiography. We report a case where a spontaneous renal artery dissection was initially misdiagnosed as a renal abscess. Diagnosis was made later with helical CT for suspicion of renal artery stenosis in a patient with recent onset of hypertension. This unusual case shows that helical CT can be useful for non-invasive diagnosis of renal artery dissection.

Abscess↗

Endovascular repair of aortic allograft aneurysmal degeneration: a case report.

Aortoenteric graft fistula remains a dreadful complication of aortic surgery. Good results have been reported using in situ graft replacement with arterial allografts. Late aneurysmal degeneration of the graft itself may necessitate further repair. We report the case of such an aneurysmal degeneration 7 years after implantation of the allograft. Endovascular repair was performed with a Vanguard device; complete exclusion was obtained immediately. At 6-month follow-up, the patient was alive and well. Duplex and computed tomography scans showed an excluded aneurysm with a slight reduction in size. Endovascular stent grafting may be a therapeutic option for treating patients with late allograft degeneration.

Aged↗

[Pulmonary embolism: is scintigraphy useful after initial angio-CT?].

PURPOSE: To assess the value of ventilation-perfusion scintigraphy after an initial helical CT with absence of pulmonary embolism (PE). MATERIAL: and methods. Twenty eight consecutive patients with clinical suspicion of pulmonary embolism underwent helical CT scan to look for an intra-luminal clot. When the CT-scan was positive for PE, diagnosis was retained. If the result was negative, a ventilation-perfusion scintigraphy was performed. If the result was also negative, diagnosis of PE was excluded. In case of discrepancy, a pulmonary angiography was performed and used as gold-standard. RESULTS: Twenty-one patients showed PE at CT-angio and 7 did not. Two of these 7 had normal or low probability scintigraphy, excluding diagnosis of PE. One had intermediate V/P scan and 4 had high probability V/P scan. For these 5 discrepancies, none of them had PE on angiography. CONCLUSION: In this population, scintigraphy was not appropriate after a negative CT-angio for PE. In case of persistent doubt after a normal initial helical CT, pulmonary angiography is required

Aged↗

[Use of radiotherapy in cardiovascular disease. Radiophysical basis, current results, indications and perspectives].

Restenosis is the main limitation of percutaneous angioplasty, especially in vessels of small diameters such as the coronary arteries, the femoro-popliteal and tibial-peroneal arteries and the arterio-venous dialysis grafts. The extensive use of tents has not entirely prevented its occurrence, whereas treating in-stent restenosis gives even more uncertain results. Endovascular radiotherapy has emerged over the past few years as a promising approach to both prevent and cure it. The analogy between the tumour-like cellular proliferations observed in post-angioplasty restenosis and tumour processes prompted pioneering works to study the effect of ionizing radiations in animal models of arterial restenosis. The demonstrated feasibility, tolerance and efficacy of this approach lead to test this strategy in humans. The results of 3 recently presented randomized double-blind trials in the treatment of coronary in-stent restenosis have been so promising that endovascular brachytherapy might now be considered the treatment of choice in this indication. Other randomized trials are currently carried out to test whether endovascular brachytherapy may prevent restenosis in coronary and femoro-popliteal arteries as well as in hemodialysis shunts. In the present review, we describe the basics of the biological effects of ionizing radiations, the technical modalities to deliver endovascular radiations, our current knowledge about their effects on the vascular wall and the restenosis mechanisms, and the results of the first clinical studies. Finally, we address the remaining problems in the use of endovascular curietherapy and question the promises and challenges of its clinical application.

Angioplasty, Balloon, Coronary↗

Preoperative assessment of the efficacy of distal radial artery ligation in treatment of steal syndrome complicating access for hemodialysis.

Hand ischemic steal syndrome due to a forearm arteriovenous fistula is a rare occurrence. We report here a case in which we applied a new diagnostic method to assess the efficacy of distal radial ligation to treat this syndrome. A favorable comparison of distal radial artery pressure measurements before and after temporary occlusion of the artery with a balloon catheter indicated that perfusion of the hand would be dramatically improved after surgical artery ligation.

Angiography↗

[Immediate results and 2-year follow-up of percutaneous transluminal angioplasty in intermittent claudication in patients over 70 years of age].

PURPOSE: This retrospective study was aimed at assessing immediate and mid-term results of percutaneous transluminal angioplasty for intermittent claudication in patients over 70 years of age, and the overall morbidity and mortality during follow-up. METHODS: Fifty-one percutaneous transluminal angioplasties were performed between 1993 and 1997 in 30 men and eight women (mean age: 78 +/- 5.2; range 71-91) for intermittent claudication (walking distance < 250 m). RESULTS: Angioplasties were supra-inguinal in 24 cases (47%) and infra-inguinal in 27 cases (53%). Clinical success (walking distance > 500 m) was obtained in 92% of the patients. Significant complications (5.9%) were inguinal hematoma requiring subsequent surgery in one patient and common femoral false aneurysms in two patients. Mean duration of hospitalization was 3 days and a half. After a mean follow-up of 25 months (range: 4-51 months), improvement in the walking distance was still present in 31 patients (82%). The condition of seven (18%) patients did not improve. No patient presented with critical ischemia. As well, no patient underwent surgical revascularization or amputation. However, the condition of eight (21%) patients required subsequent percutaneous transluminal angioplasty. Four (10.5%) patients died. Following percutaneous transluminal angioplasty, six (18%) patients presented with a major non-fatal clinical event. All the patients lived at home. CONCLUSION: Percutaneous transluminal angioplasty has little immediate risk when lesions are accessible and leads to positive mid-term clinical results in the treatment of intermittent claudication in patients over 70 years of age.

Age Factors↗

Endovascular management of bleeding iliac artery pseudoaneurysms complicating radiation therapy for pelvic malignancies.

OBJECTIVE: We evaluated arteriographic findings and endovascular treatments of eight patients who had bleeding iliac artery pseudoaneurysms and who had undergone radiation therapy (3000-6500 rad [30-65 Gy]) and surgery for pelvic malignancies. CONCLUSION: Angiography revealed contrast media extravasation in 75% of patients who had bleeding iliac artery pseudoaneurysms and failed to show the source of bleeding in 25%. The patients who had positive findings at angiography were all successfully treated percutaneously, although two patients required additional bypass surgery. Among embolic materials, coils and balloons were safe and efficient, whereas cyanoacrylate was unsafe and led to complications in two of three patients. A covered stent, which was not available for most of our patients, was used in one patient and may be an effective means of treating pseudoaneurysms.

Aneurysm, False↗

Percutaneous recanalization of acutely thrombosed vessels by hydrodynamic thrombectomy (Hydrolyser).

A hydrodynamic thrombectomy catheter was prospectively evaluated for the treatment of recently thrombosed vessels. A total of 52 consecutive patients (42 males and 10 females; mean age 64 +/- 15 years) presenting with acute or subacute occlusion of dialysis shunts (n = 25), peripheral bypass (n = 14) or native arteries (n = 15) were treated with the Hydrolyser (Cordis Europa NV, Roden, The Netherlands). Mean occlusion time was 4 days (range 1-17 days) and mean thrombus length 19 +/- 11 cm. The Hydrolyser was effective and fast in removing thrombus, regardless of the thrombus length. No major complications were reported. The immediate procedure success rates were 82, 100, 87 and 79 % for Brescia Cimino, dialysis shunt, native arteries and bypass grafts, respectively. Adjunctive thrombolysis (applied for persistence of residual thrombus or thrombosed distal vessels too small for hydrolytic thrombectomy) was required in 4 % of thrombotic dialysis shunts, in 20 % of native arteries and in 50 % of bypass graft occlusions. On angiographic controls, distal embolizations were reported only in native arteries (13 %) and bypasses (14 %); all were successfully treated percutaneously, except for one case treated by Fogarty balloon. Cumulative primary patency rates were respectively at 6 months 56, 62, 78 and 65 % for each indication. We conclude from this preliminary clinical study that hydrodynamic thrombectomy with a Hydrolyser is a promising technique to treat acute occlusions. This device can reduce complications as well as the time required to remove large amounts of thrombus and the use of expensive thrombolytic drugs.

Angiography↗

Experimental bilateral lobar lung transplantation and its application in humans.

BACKGROUND: The critical lack of donor organs from people of small size or children has created great difficulties in transplantation for recipients who are of smaller size. Surgical techniques of organ reduction and partial transplantation may to some extent solve the problem of disparity in organ size, be it liver or lung, and lessen the problem of scarcity of paediatric organs. METHODS: In a series of experiments on dogs the surgical technique of pulmonary partition of a large organ from a grown dog followed by transplantation of lobes, either unilaterally or bilaterally, into a young dog was studied. Two series of experiments were performed in two groups of animals; in group 1 transplantation of a single right lobe (n = 6) or single left lobe (n = 6) from a split adult lung was carried out and in group 2 (n = 10) animals received bilateral lobar transplants from a single split adult lung. The animals were sacrificed at fixed intervals (days 8-120 in group 1, days 7-10 in group 2) and the results of the surgical technique were assessed. RESULTS: Healing of lobar bronchial anastomoses was found to be excellent with no histological evidence of dehiscence or ulceration. There was one bronchial anastomotic stenosis and one arterial thrombosis. Morphological and functional adaptation of the lobes in the thorax was found to be excellent in both groups of animals. The technique has been applied in a clinical setting and the first patient with bilateral lobar lung transplantation followed for 30 months is reported. CONCLUSION: Lung partition and subsequent lobar transplantation, either unilaterally or bilaterally, is associated with satisfactory early results in an animal experimental model. Initial clinical experience in one patient has been successful.

Adult↗

Aortocaval fistulae: a percutaneous model and treatment with stent grafts in sheep.

BACKGROUND: Treatment of aortocaval fistulae (ACFs) by open surgery is known to be a high-risk procedure. In this experimental study, we developed a percutaneous model of ACF to test a new nonsurgical method of treatment of ACF using endovascular stent grafts. METHODS AND RESULTS: An ACF was created percutaneously in eight sheep. Via a combined venous and arterial femoral approach, angioplasty balloons were inserted to occlude the infrarenal aorta and inferior vena cava (IVC). The IVC was punctured through the lateral aortic wall with a transjugular liver biopsy needle. The fistulous tract was then dilated with an 8-mm angioplasty balloon, and the animal was heparinized. Two weeks later, a 10-mm Cragg-Endopro-Stent was inserted into the aorta at the level of the fistula via a percutaneous femoral approach. ACFs were successfully created in all animals, with rapid dye shunt through the fistula and a 20% increase in cardiac pulsations. Follow-up angiograms at 2 weeks showed a patent ACF, and stent implantation excluded the fistula in every case. Angiographic and pathological examinations up to 6 months demonstrated normal aortic patency and persistent exclusion of the fistulae. CONCLUSIONS: ACFs were effectively treated by endovascular grafting of the aorta. The animal model and the stenting procedures were both performed percutaneously.

Angioplasty, Balloon↗