Magnetic resonance angiography versus duplex sonography for diagnosing renovascular disease.
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Noninvasive testing for renovascular disease is required to identify patients who may benefit from revascularization procedures without exposing an unnecessary amount of patients to the risks of catheter angiography. All available methods of diagnosing renal artery stenosis have significant limitations. We compared a new technique, contrast-enhanced magnetic resonance angiography, with an established technique, duplex ultrasonography, for the detection of renal artery stenosis using catheter angiography as the standard of reference. Eighty-nine patients with clinically suspected renovascular disease underwent duplex renal scanning and contrast-enhanced magnetic resonance angiography. Sixty of these also underwent catheter angiography. All studies were interpreted for the presence of renal artery stenosis blinded to the results of the other imaging modalities. For detection of hemodynamically significant (>/=60% diameter reduction) main renal artery stenosis, sensitivity and specificity were 90% and 86%, respectively, for magnetic resonance angiography and 81% and 87% for duplex sonography. Most false readings involved differential grading of stenoses detected with all 3 techniques. When patients with fibromuscular dysplasia were excluded from the analysis, the sensitivity of magnetic resonance angiography increased to 97%, with a negative predictive value of 98%. Magnetic resonance angiography detected 96% and duplex 5% of accessory renal arteries seen at catheter angiography. Contrast-enhanced magnetic resonance angiography is a useful technique for diagnosing atherosclerotic renovascular disease. It overcomes the major limitations of duplex renal scanning. However, duplex has the advantage of providing hemodynamic information and appears better suited for the assessment of patients with suspected fibromuscular dysplasia. (+info)
Venous duplex scanning of the leg: range, variability and reproducibility.
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Despite the many studies on venous haemodynamics using duplex, only a few evaluated the normal values, variability and reproducibility. Therefore, the range and variability of venous diameter, compressibility, flow and reflux were measured. To obtain normal values, 42 healthy individuals (42 limbs, 714 vein segments) with no history of venous disease were scanned by duplex. To determine the reproducibility the intra-observer variability was measured in 11 healthy individuals (187 vein segments) and the inter-observer variability in 15 healthy individuals (255 vein segments) and 13 patients (169 vein segments) previously diagnosed with deep venous thrombosis. Of the 714 normal vein segments, 708 (99%) were traceable, including the crural veins. Of the traceable vein segments, 675 (95%) were compressible and in 696 (98%) flow was present. Of the 42 common femoral vein segments, in 25 (60%) the reflux duration exceeded 1.0 s, but in the other proximal vein segments the reflux duration was less than 1.0 s (95% confidence interval 3.0-10.0). With the exception of the distal long saphenous vein, in the distal vein segments the reflux duration was less than 0.5 s (95% confidence interval 3.5-8.2). The coefficient of variation of the diameter measurements ranged from 14 to 50% and that of the reflux measurements from 28 to 60%. The kappa-coefficient of the inter-observer variability in the classification of compressibility measurements in the patients was 0. 77 and that of the reflux measurements was 0.86. This study shows that almost all veins were compressible in healthy individuals, except the distal femoral veins. In healthy individuals the duration of reflux of the proximal veins was less than 1.0 s and in the distal veins it was less than 0.5 s. The inter-observer variability of the reflux and compressibility measurements in the patients was good. (+info)
Surgical transluminal iliac angioplasty with selective stenting: long-term results assessed by means of duplex scanning.
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PURPOSE: The safety of iliac angioplasty and selective stenting performed in the operating room by vascular surgeons was evaluated, and the short- and long-term results were assessed by means of serial duplex scanning. METHODS: Between 1989 and 1996, 281 iliac stenotic or occlusive lesions in 235 consecutive patients with chronic limb ischemia were treated by means of percutaneous transluminal angioplasty (PTA) alone (n = 214) or PTA with stent (n = 67, 23.8%). There were 260 primary lesions and 21 restenosis after a first PTA, which were analyzed separately. Stents were implanted in selected cases, either primarily in totally occluded arteries or after suboptimum results of PTA (ie, residual stenosis or a dissection). Data were collected prospectively and analyzed retrospectively. Results were reported in an intention-to-treat basis. Clinical results and patency were evaluated by means of symptom assessment, ankle brachial pressure index, and duplex scanning at discharge and 1, 3, 6, and every 12 months after angioplasty. To identify factors that may affect outcome, 12 clinical and radiological variables, including the four categories of lesions defined by the Standards of Practice Committee of the Society of Cardiovascular and Interventional Radiology, were analyzed separately. The statistical significances of life-table analysis of patency were determined by means of the log-rank test. RESULTS: There were no postoperative deaths or amputations. Local, general, and vascular complications occurred in 2.1%, 1.3% and 4.7% of cases, respectively (total, 8.1%). The mean follow-up period was 29.6 months. The cumulative patency rates +/- SE of the 260 PTAs (including 55 PTAs plus stents) were 92.9% +/- 1.5% at 1 month, 86. 5% +/- 1.7% at 1 year, 81.2% +/- 2.3% at 2 years, 78.8% +/- 2.9% at 3 years, and 75.4% +/- 3.5% at 5 and 6 years. The two-year patency rate of 21 redo PTAs (including 11 PTAs plus stents) was 79.1% +/- 18.2%. Of 12 predictable variables studied in the first PTA group, only the category of the lesion was predictive of long-term patency. The two-year patency rate was 84% +/- 3% for 199 category 1 lesions and 69.7% +/- 6.5% for 61 category 2, 3, and 4 lesions together (P =. 02). There was no difference of patency in the stented and nonstented group. CONCLUSION: Iliac PTA alone or with the use of a stent (in cases of occlusion and/or suboptimal results of PTA) offers an excellent long-term patency rate. Categorization of lesions remains useful in predicting long-term outcome. PTA can be performed safely by vascular surgeons in the operating room and should be considered to be the primary treatment for localized iliac occlusive disease. (+info)
Relief of obstructive pelvic venous symptoms with endoluminal stenting.
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PURPOSE: To select patients for percutaneous transluminal stenting of chronic postthrombotic pelvic venous obstructions (CPPVO), we evaluated the clinical symptoms in a cohort of candidates and in a series of successfully treated patients. METHODS: The symptoms of 42 patients (39 women) with CPPVO (38 left iliac; average history, 18 years) were recorded, and the venous anatomy was studied by means of duplex scanning, subtraction venography, and computed tomography or magnetic resonance imaging. Successfully stented patients were controlled by means of duplex scanning and assessment of symptoms. RESULTS: The typical symptoms of CPPVO were reported spontaneously by 24% of patients and uncovered by means of a targeted interview in an additional 47%. Of 42 patients, 15 had venous claudication, four had neurogenic claudication (caused by dilated veins in the spinal canal that arise from the collateral circulation), and 11 had both symptoms. Twelve patients had no specific symptoms. Placement of a stent was found to be technically feasible in 25 patients (60%), was attempted in 14 patients, and was primarily successful in 12 patients. One stent occluded within the first week. All other stents were fully patent after a mean of 15 months (range, 1 to 43 months). Satisfaction was high in the patients who had the typical symptoms, but low in those who lacked them. CONCLUSION: Venous claudication and neurogenic claudication caused by venous collaterals in the spinal canal are typical clinical features of CPPVO. We recommend searching for these symptoms, because recanalization by means of stenting is often feasible and rewarding. (+info)
Popliteal artery occlusion as a late complication of liquid acrylate embolization for cerebral vascular malformation.
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Occlusion of arteriovenous malformations of the brain (BAVMs) by means of an endovascular approach with liquid acrylate glue is an established treatment modality. The specific hazards of this procedure are related to the central nervous system. In the case of unexpectedly rapid polymerization of the cyanoacrylate glue and adhesion of the delivering microcatheter to the BAVM, severing the catheter at the site of vascular access is considered an acceptable and safe management. We present a unique complication related to this technique that has not been described yet. Fragmentation and migration of the microcatheter, originally left in place, had caused popliteal artery occlusion, which required saphenous vein interposition, in a 25-year-old man. Suggestions for avoiding this complication are discussed. (+info)
Effect and outcome of balloon angioplasty and stenting of the iliac arteries evaluated by intravascular ultrasound.
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OBJECTIVES: To document the mechanism of percutaneous transluminal angioplasty (PTA) and stenting of the iliac arteries, and to relate the effect to patency. MATERIALS AND METHODS: Thirty-seven stenotic iliac arteries were examined by intravascular ultrasound (IVUS) and arteriography before and after PTA, and after stent deployment (n = 16). The patients were followed prospectively by duplex scanning at 3, 6, 12, 18 and 24 months after the intervention. RESULTS: The effect of PTA was established by both compression and stretching with the major contribution arising from stretching. There were differences in the effect of PTA dependent on plaque morphology: in homogeneous eccentric lesions, stretching contributed significantly more than compression to the luminal gain, while stretching and compression contributed equally in concentric or heterogeneous plaques. Stenting of the arteries had no effect on the free luminal area as measured by IVUS. The primary 1-year patency rate was 72%. The patency was related to the free luminal area and diameter and the heterogenicity of the plaque as evaluated by IVUS. The arteriographic measurements did not have any predictive value. CONCLUSION: IVUS was able to document the effect of PTA and stenting in the iliac arteries, and predict the outcome. The luminal gain and reduction in degree of stenosis seemed to be accomplished primarily by stretching of the arteries and to a lesser extent by plaque compression. Stenting did not change the IVUS measurements. Patency was related to the size of the free lumen and the heterogenicity of the plaque. (+info)
Antegrade visceral revascularisation via a thoracoabdominal approach for chronic mesenteric ischaemia.
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OBJECTIVES: It has been suggested that patients with chronic visceral ischaemia are elderly and emaciated hence they may not tolerate antegrade visceral revascularisation via a thoracoabdominal approach. There are no studies to support this assumption. The purpose of this study is to assess the efficacy of this approach for the treatment of chronic visceral ischaemia. METHODS: Between 1988 and 1996, 10 patients underwent antegrade visceral revascularisation for chronic visceral ischaemia via a thoracoabdominal approach and were followed-up for a mean of 40 months. Eight patients were treated with aorto superior mesenteric artery bypass and implantation of the coeliac axis in the graft and two patients with aorto superior mesenteric bypass alone. Graft patency was monitored with duplex scanning. RESULTS: There were no postoperative deaths in this series. Two patients developed postoperative pulmonary infections and required intubation for a short period of time. All patients were discharged after a mean of 17 days (range 7-38). Follow up with duplex scanning revealed that all grafts were patent. One patient developed a high grade anastomotic stenosis which was followed by recurrence of the symptoms. This was dilated on three occasions by balloon angioplasty within a period of 17 months. On the last occasion a stent was placed and since the patient remains asymptomatic. CONCLUSIONS: Antegrade visceral revascularisation via a thoracoabdominal approach is a durable and effective method of relieving symptoms of chronic visceral ischaemia. The low morbidity in this series justifies larger studies in order to establish the true incidence of complications. (+info)
Duplex-derived evidence of reflux after varicose vein surgery: neoreflux or neovascularisation?
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BACKGROUND: Recurrent varicose veins remain a problem in surgical practice despite improvements to the preoperative investigation of, and surgery for varicose veins. Neovascularisation accounts for some cases of recurrence within a few years of surgery, but other factors relating to disease progression must also play a part. We investigated whether new venous reflux (neoreflux) could occur in the early postoperative period (within 6 weeks) following successful varicose vein surgery. METHODS: Eighteen-month prospective observational study in the dedicated vascular surgery unit of a university teaching hospital. Forty-six patients, with primary saphenofemoral junction reflux, awaiting varicose vein surgery were chosen consecutively from the waiting list. All saphenofemoral surgery was performed in a standardised fashion. Assessments were performed prior to, at 6 weeks and at 1 year after surgery. Duplex ultrasound was used to identify and locate sites of reflux. RESULTS: Neoreflux was present at the 6-week postoperative scan in nine limbs after varicose vein surgery (19.6%), and resolved in 55.6% of patients within 1 year. Neovascularisation was noted in two limbs at the 1-year scan. CONCLUSION: New sites of reflux, which may resolve spontaneously, occur in the early postoperative period despite adequate varicose vein surgery. It is our hypothesis that this is a manifestation of the effect of altered venous haemodynamics in a system of susceptible veins. (+info)