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Wire guide cannulation alone is no treatment of proximal tubal occlusion.

Tubal catheterization procedures have become standard of care as a primary treatment of proximal tubal occlusions. They successfully utilize a variety of catheter techniques, though all usually include a wire guide. This raises the question whether guide wire catheterizations alone can be used to treat proximal tubal occlusions. We therefore investigated consecutively 25 women with at least one proximally occluded oviduct by attempting wire guide cannulations bilaterally in 10 and unilaterally in 12 women with two tubes and in three women with a single tube. Among the 10 patients with bilateral occlusion, seven were recanalized bilaterally (70%), one unilaterally (10%) and two not at all (20%). Among the 15 patients with unilateral tubal occlusion, 12 (80%) were recanalized. In total, 27 out of 35 (77%) obstructed oviducts were recanalized. In a follow-up period of 5-17 months only one pregnancy was, however, recorded and this was a tubal pregnancy. We conclude that wire guide cannulation of proximally obstructed tubes achieves tubal patency in a large percentage of cases, comparable to other catheter techniques reported in the literature. In contrast to those, however, wire guide cannulations alone result in much lower pregnancy rates. This observation strongly suggests that wire guides, used with co-axial and balloon catheter systems, are not responsible for the pregnancy success reported for these procedures. Wire guide cannulation alone does not therefore represent adequate treatment for patients with proximally occluded Fallopian tubes.

Catheterization↗

Influence of carbon dioxide gas perfusion to thermal distribution of sapphire probe. A comparative study with saline.

RATIONALE AND OBJECTIVES: A previous study confirmed that the direct laser-thermal conduction of the sapphire probe with carbon dioxide gas perfusion increased the width of the laser-recanalized channel. This caused us to further investigate the thermal distribution characteristics of the sapphire probe when lasing with CO2 gas perfusion. METHODS: The surface temperature of a sapphire probe in a circulation model using 37 degrees C flowing whole blood was measured. Two hundred and sixteen measurements were obtained by directly contacting a flexible thermocouple wire onto the sapphire probe at different sites: 1) metal connector; 2) lateral side of the sapphire crystal; 3) top of the sapphire crystal; and 4) 3 mm in front of the sapphire probe. During lasing with a neodymium-yttrium-aluminum garnet (Nd-YAG) laser, the CO2 gas or saline was infused through the sapphire probe at different flow rates. RESULTS: The lateral side of the sapphire crystal was heated up to 75 degrees C when lasing without any perfusion, but up to 220 degrees C when lasing with CO2 gas perfusion. At all four sites, the mean temperature increases were statistically higher (P < .01) with CO2 gas than with saline perfusion. The mean peak temperatures increased with increasing flows of CO2 gas perfusion and decreased with increasing flows of saline perfusion. CONCLUSIONS: The thermal conduction from the sapphire probe can be significantly enhanced by increasing flows of CO2 gas perfusion. This may play an important role in creating a greater diameter of the recanalized channel and in better delaying the formation of restenosis or re-occlusion after laser recanalization of atheromatous arteries.

Aluminum Oxide↗

Factors affecting survival rates for acute vertebrobasilar artery occlusions treated with intra-arterial thrombolytic therapy: a meta-analytical approach.

OBJECTIVE: To determine whether recanalization, coma at presentation, or clot location in the basilar artery influences the relative mortality risk after intra-arterial thrombolytic therapy for acute vertebrobasilar artery occlusions. METHODS: Studies were identified using the MEDLINE database for January 1987 to November 1997. Series were included if they involved 10 or more patients with basilar or vertebrobasilar artery occlusions, used urokinase and/or recombinant tissue plasminogen activator, and were written in English. A fixed-effect meta-analysis approach was used to estimate the risk of death with the aforementioned risk factors. Each study was weighted according to sample size. Relative risks were calculated with 95% confidence intervals. RESULTS: As calculated from peer-reviewed published data, the relative mortality risk for patients for whom recanalization was attempted but not achieved was 2.34 (95% confidence interval, 1.48-3.71; n = 126). Coma at presentation was associated with a relative mortality risk of 1.95 (95% confidence interval, 1.26-2.99; n = 145). Clot locations in the distal one-third of the basilar artery were shown to favor survival, compared with clots located in the proximal and/or middle portions of the basilar artery (relative risk, 0.52; 95% confidence interval, 0.31-0.86; n = 126). CONCLUSION: The combined data suggest that coma at presentation has an independent and adverse effect on survival rates. Complete recanalization, distal clot location, and responsiveness at the time of presentation are statistically significant factors for increased patient survival rates.

Adolescent↗

Effects of a mixture of a low concentration of n-butylcyanoacrylate and ethiodol on tissue reactions and the permanence of arterial occlusion after embolization.

OBJECTIVE: Cyanoacrylates are the most commonly used liquid embolic agents. For embolization of arteriovenous malformations, a mixture of a low concentration of n-butylcyanoacrylate (NBCA) and Ethiodol (Savage Laboratories, Melville, NY) has been recommended for deeper penetration of the nidus. Dilution of NBCA, however, might result in different degrees of tissue reaction and might influence the permanence of vessel occlusion, with an increased risk of vessel recanalization. We compared tissue reactions induced by different NBCA/Ethiodol mixtures and analyzed the permanence of their embolic effects. METHODS: NBCA was diluted with Ethiodol to prepare the following standard solutions: Mixture A, low concentration (NBCA/Ethiodol ratio of 20:80); Mixture B, high concentration (50:50). The study was designed in two parts, because tissue reactions after embolization are considered to be a combination of foreign body reactions to solidified material and reactions to the injured blood vessel. Foreign body reactions were studied by intramuscularly injecting both glue mixtures into the backs of 18 rats. Specimens were obtained at various times after implantation. Immunohistochemical analysis and esterase staining were used to detect macrophages and neutrophils, respectively. The densities of these inflammatory cells were calculated and statistically compared. To study the degree of vascular wall injury and the permanence of embolic effects, the renal arteries in 48 rabbits were embolized with NBCA Mixture A or B. Six specimens for each group were obtained at various times after embolization. RESULTS: There was no significant difference in foreign body reactions between groups treated with Mixtures A and B, at any time. However, the macrophage density was larger for both groups at 3 months versus 3 days and for the group treated with Mixture B at 3 months versus 2 weeks. There was no difference in the degree of vessel wall injury. None of the embolized vessels demonstrated evidence of recanalization. CONCLUSION: The low concentration of NBCA induced a tissue response similar to that of the high-concentration form. Embolized vessels exhibited no greater incidence of recanalization. Therefore, embolization of arteriovenous malformations with diluted NBCA may be safe.

Animals↗

Intra-arterial third-generation recombinant tissue plasminogen activator (reteplase) for acute ischemic stroke.

OBJECTIVE: We prospectively evaluated the safety and recanalization efficacy of intra-arterially administered reteplase, a third-generation recombinant tissue plasminogen activator, for treating ischemic stroke in patients considered poor candidates for intravenously administered alteplase therapy. METHODS: Patients were considered poor candidates for intravenously administered therapy because of severity of neurological deficits, interval from onset of symptoms to presentation of 3 hours or more, or recent major surgery. We administered a maximum total dose of 8 U of reteplase intra-arterially in 1-U increments via superselective catheterization. Adjunctive angioplasty of the occluded artery was performed in seven patients. Angiographic evidence of perfusion and thrombus was graded by use of modified Thrombolysis in Myocardial Infarction (TIMI) criteria. Neurological examinations were performed before and 24 hours and 7 to 10 days after treatment. RESULTS: Sixteen consecutive patients were treated (mean age, 64.1 +/- 16.4 yr; seven were men). Initial National Institutes of Health Stroke Scale scores ranged from 10 to 26. Time from onset of symptoms to treatment ranged from 2 to 9 hours. Occlusion sites were the cervical internal carotid artery (n = 4), intracranial internal carotid artery (n = 4), middle cerebral artery (n = 6), and vertebrobasilar artery (n = 2). Complete or near-complete perfusion (TIMI Grade 3 or 4) was achieved in the arteries in 14 patients (88%), with partial recanalization (TIMI Grade 2) or minimal response (TIMI Grade 1) in the arteries in one patient each. Neurological improvement (defined as decrease of four or more points in National Institutes of Health Stroke Scale score) was observed in 7 (44%) of the 16 patients at 24 hours. Symptomatic intracerebral hemorrhage occurred in one patient; three other patients experienced intracerebral hemorrhages that did not result in neurological worsening. The overall mortality during hospitalization was 56%, related to massive ischemic stroke (n = 7), withdrawal of care at the family's request after the development of aspiration pneumonia and renal failure (n = 1), and a combination of intracerebral hemorrhage and massive ischemic stroke (n = 1). CONCLUSION: In this study, intra-arterially administered reteplase in doses up to 8 U with or without angioplasty resulted in a high rate of recanalization. This strategy should be considered in treating patients considered poor candidates for intravenous thrombolysis.

Acute Disease↗

Coronary thrombolysis with K1K2Pu, a chimeric tissue-type and urokinase-type plasminogen activator: a feasibility study in six patients with acute myocardial infarction.

BACKGROUND: K1K2Pu is a recombinant chimeric tissue-type and urokinase-type plasminogen activator consisting of the two kringle domains (K1 and K2) of human tissue-type plasminogen activator (t-PA) and the serine proteinase domain (Pu) of single-chain urokinase-type plasminogen activator (scu-PA). In experimental animal models of thrombosis, its thrombolytic potency has been shown to be five- to 10-fold greater than that of its parent molecules. METHODS: The effect of a bolus injection of K1K2Pu on coronary thrombolysis over 30 min was evaluated in six patients with acute myocardial infarction of less than 5 h duration in whom total occlusion of the infarct-related artery was confirmed using angiography. RESULTS: In two patients given an intravenous bolus of 10 mg over 5 min, persistent coronary artery recanalization was not observed within 30 min. In two out of four patients given a second bolus of 10 mg K1K2Pu, 15 min after the first, persistent coronary recanalization occurred within 30 min. The four patients without recanalization within 30 min were immediately given 100 mg t-PA over 90 min. In all patients the infarct-related artery was patent after 24 h, and the hospital course was uneventful. The bolus injections did not produce significant fibrinogen breakdown or alpha 2-antiplasmin consumption within 30 min. The plasma K1K2Pu level increased to 2-3 micrograms/ml after the first bolus injection and to 4-5 micrograms/ml after the second. K1K2Pu disappeared from the plasma with an initial half-life of 9 min and a clearance of approximately 50 ml/min. CONCLUSION: A bolus injection of 20 mg K1K2Pu is well tolerated and can induce clot-selective coronary thrombolysis in patients with acute myocardial infarction.

Aged↗

Reperfusion arrhythmias during coronary angioplasty for acute myocardial infarction predict ST-segment resolution.

BACKGROUND: Despite early recanalization of an occluded infarct-related artery, myocardial reperfusion may remain impaired due to microvascular injury. Reperfusion arrhythmias may indicate successful microvascular reperfusion. METHODS: Microvascular reperfusion was assessed prospectively in 42 consecutive patients with ST-segment elevation acute myocardial infarction (AMI) by evaluation of the resolution of ST-segment elevation (<50% of initial level) immediately after successful coronary angioplasty. Patients were divided into two groups: those with ST resolution (n=24) and those without ST resolution (n=18). The presence of reperfusion arrhythmias immediately after recanalization was recorded. RESULTS: Patients with ST resolution were younger (54+/-12 years compared with 64+/-17 years, P=0.04), their pain-to-recanalization time was shorter (195+/-87 min compared with 294+/-179 min, P=0.05), they were less often diabetic (13% compared with 24%, P=0.05) and were more often given IIb/IIIa inhibitors (58% compared with 22%, P=0.02). Reperfusion arrhythmias were observed in 15 out of 24 patients with ST resolution (62%) but in only one out of 18 without ST resolution (5%) (P<0.01). Reperfusion arrhythmias included accelerated idioventricular rhythm, 13 (81%); multifocal ventricular premature beats, two (13%); and ventricular tachycardia, one (6%). The sensitivity and specificity of reperfusion arrhythmias for ST resolution were 62 and 95%, respectively. In a logistic regression model including age, time to treatment, diabetes, use of IIb/IIIa inhibitors and reperfusion arrhythmias, only the latter was found to be an independent predictor of ST resolution (P<0.01). CONCLUSION: Reperfusion arrhythmias following coronary angioplasty for AMI are a highly specific marker for ST resolution and may indicate successful microvascular reperfusion.

Adult↗

Hemodynamic and metabolic changes in a patient with cerebral venous sinus thrombosis: evaluation using O-15 positron emission tomography.

The cerebral hemodynamics and oxygen metabolism before and after the recanalization of the occluded sinus were evaluated using O-15 positron emission tomography (PET) scanning in a 21-year-old woman with superior sagittal sinus thrombosis. During the initial presentation, there was increased regional cerebral blood volume (rCBV) in the left frontal and parietal lobes with moderately increased rCBV in the right parietal lobe. Recanalization of the occluded sinus resulted in a normalization of elevated rCBV in the frontal and parietal lobes and improvements of rCBF and regional cerebral metabolic rate for oxygen in the occipital lobe. Clinical improvement after recombinant tissue plasminogen activator therapy was accompanied by restoration of cerebral hemodynamics and oxygen metabolism, although magnetic resonance venography showed only partial recanalization of the occluded sinus. PET evaluation of the cerebral hemodynamics and oxygen metabolism may be of value in gaining further insight into pathophysiological characteristics of human cerebral venous sinus thrombosis.

Adult↗

Embolotherapy of pulmonary arteriovenous malformations: long-term results in 112 patients.

PURPOSE: To evaluate the long-term results of embolotherapy of pulmonary arteriovenous malformations (PAVMs) in a large group of patients. MATERIALS AND METHODS: Between July 1988 and August 2001, 134 consecutive patients underwent embolotherapy of PAVMs with feeding arteries larger than 3 mm or that had previously caused bleeding or systemic complications. The mean follow-up was 62.2 months. The primary endpoints of the study were the efficacy of embolotherapy, decrease in right-to-left shunt, and increase in partial arterial oxygen pressure (PaO(2)); the secondary endpoint was the prevalence of complications. Standard follow-up consisted of yearly history, chest radiography, and arterial blood gas measurement. RESULTS: Follow-up was available in 112 patients. Initially, 296 PAVMs were embolized in these patients. Nineteen patients (17%) underwent a second procedure and four patients underwent a third procedure because of recanalization of originally occluded feeding arteries (25 PAVMs, 8%) or interval enlargement of untreated PAVMs (53 PAVMs). In total, 349 PAVMs were embolized in 157 sessions. The mean diameter of occluded vessels was 4.7 mm. The long-term outcomes of embolotherapy were successful in 83% of patients overall and in 96% of patients in whom all angiographically visible PAVMs were embolized. Recanalization occurred in 12 of 16 patients who underwent repeat treatment because of enlargement of nonembolized PAVMs. Postprocedural pleurisy occurred after 14 of 157 sessions (9%). Periprocedural complications occurred in 12 sessions (8%) and included migration of an embolic device, transient ischemic attack (TIA), angina pectoris, and early cerebral infarction after embolization. Three patients experienced TIA and two patients experienced a cerebral abscess during follow-up after embolotherapy. CONCLUSIONS: Embolotherapy of PAVMs is efficacious and durable in the majority of patients. Patients should remain under regular review because recanalization of PAVMs or enlargement of untreated PAVMs can occur years after treatment.

Adolescent↗

Interventional radiologic treatment for hepatic arterial occlusion after repeated hepatic arterial infusion chemotherapy via implanted port-catheter system.

The present study evaluated the feasibility of interventional radiologic treatments for hepatic arterial occlusion after hepatic arterial infusion chemotherapy (HAIC) via an implanted port-catheter system. Treatment for hepatic arterial occlusion was attempted in seven patients with unresectable liver cancer. In six, the obstructed hepatic artery was recanalized. In three patients, the recanalized hepatic artery again became obstructed. However, by performing additional interventional radiologic procedures, secondary patency of the hepatic artery was successfully obtained in two patients. In conclusion, when hepatic arterial occlusion occurs, HAIC can be resumed in the attempt to recanalize the hepatic artery.

Adult↗

Cut-to-the-light technique and potassium titanyl phosphate laser ureterotomy for complete ureteral obstruction.

We describe a case of complete ureteral obstruction managed by endoscopic recanalization using a 'cut-to-the-light' technique followed by potassium titanyl phosphate (KTP) laser ureterotomy. A 53-year-old man developed a ureteral obstruction following the transurethral resection of a bladder tumor (TUR-Bt) at the left ureteral orifice. The length of the obstructed segment was estimated at 1 cm based on combined antegrade and retrograde contrast studies. Histopathological analysis indicated that the obstruction was caused by fibrosis. The 'cut-to-the-light' technique was used for recanalization, and KTP laser ureterotomy was performed to obtain an adequate ureteral lumen. A 14 F/7 F endoureterotomy stent was removed 6 weeks after the operation. No significant complications and no signs of stenosis were observed 24 months after endoscopic repair. Endoscopic recanalization is a safe, effective technique for the management of a completely obliterated ureteral segment, especially in combination with subsequent KTP laser ureterotomy.

Endoscopy↗

Laser angioplasty of the iliac arteries.

Laser-assisted balloon angioplasty has the potential to reduce mortality and morbidity by replacing aorto-femoral bypass operations in patients with occlusion of the iliac arteries. We present our early experience with 16 patients undergoing this procedure, using a Cardiolase neodymium:yttrium aluminum garnet (Nd:YAG) laser in the operating room. Initial recanalization was achieved in 14 of the 16 patients. Early re-occlusion occurred in 4 patients, one of whom had a successful repeat laser angioplasty. This patient, together with the remaining 10 patients with successful initial recanalization remain patent at a mean follow-up period of 10 months. There were no deaths or chest complications. Angiographically demonstrated arterial perforation occurred in 2 patients, neither of whom required operation on the perforated segment. We conclude that recanalization of the iliac arteries is possible and safe. The procedure is unlikely to replace aorto-femoral bypass until the proportion of early failures is reduced. This may require larger probes or the immediate placement of intra-arterial stents following laser angioplasty.

Aged↗

Evaluation of the efficacy of polidocanol in the form of foam compared with liquid form in sclerotherapy of the greater saphenous vein: initial results.

BACKGROUND: Foamed sclerosing agents have been used with enthusiasm by phlebologists for more than 5 decades. Any type of varicose veins can and has been treated with this technique. Numerous publications have stressed the advantages of foamed sclerosing agents on the basis of empiric and experimental criteria and have described various individual techniques to prepare foams. Until now, however, no comparative study for the treatment of large varicose veins with foam or liquid exists. OBJECTIVE: The purpose of this first randomized, prospective, multicenter trial was to study the elimination of reflux, the rate of recanalization, and possible side effects of foam sclerotherapy (FS) compared with conventional liquid sclerotherapy for the greater saphenous vein (GSV). METHODS: Eighty-eight patients were randomized into two groups: One group was treated with sclerosing foam (45 patients) and the other with sclerosing liquid (43 cases). Sclerotherapy was performed with direct puncture of the vessel under duplex guidance. The reference sclerosing agent was polidocanol in a 3% solution. The foam was prepared using the Double Syringe System (DSS) method. Only one injection of 2.0 or 2.5 mL liquid or foam was allowed, depending on the diameter of the GSV. Results were assessed according to the protocol. RESULTS: Follow-up after 3 weeks showed 84% elimination of reflux in the GSV with DSS foam versus 40% with liquid sclerosant (P < 0.01). At 6 months, six recanalizations were found in the liquid group versus two in the foam group. After 1 year, no additional recanalization was observed with either foam or liquid. Longer term studies are underway. Side effects did not differ between both groups. CONCLUSION: The efficacy of sclerosing foam (DSS) compared with sclerosing liquid in therapy of the GSV is superior, a finding that had already gained empirical recognition but for which there has not been any clinical evidence to date.

Dosage Forms↗

Nonocclusion and early reopening of the great saphenous vein after endovenous laser treatment is fluence dependent.

BACKGROUND: Parameters influencing failure and recanalization rates of endovenous laser treatment (ELT) of the great saphenous vein (GSV) are still to be determined. OBJECTIVE: To evaluate treatment-related parameters of ELT with respect to early failure of occlusion or recanalization of GSVs. METHODS: A series of 77 consecutive patients received ELT of 106 GSVs with continuous pullback of the laser fiber. Duplex examination was performed at 1 day, 4 weeks, and 3 months after the procedure. Clinical patient and vessel characteristics as well as technical parameters of the ELT procedure were evaluated via multiple logistic regression analysis. RESULTS: A median vein length of 60 cm (range of 18 to 90) was treated with a median pullback velocity of 0.6 cm/sec (range of 0.4 to 1.3), resulting in a median energy delivery of 23.4 J/cm (range of 11.8 to 35.5) and a median laser fluence of 11.8 J/cm2 (range of 2.8 to 37.3). At day 1 after ELT, 6 GSVs (6%) were not occluded. At 1 and 3 months after ELT, 9 GSVs (9%) and 11 GSVs (10%), respectively, were found open by color duplex examination. Risk factors for nonocclusion 3 months after ELT, by univariate analysis, were laser fluence, laser energy per centimeter of vein length, diameter of the vein before treatment, and distance of the thrombus to the sapheno-femoral junction at day 1 after treatment. Finally, multiple regression analysis selected laser fluence (p=0.004, odds ratio=0.40 J/cm2) as the relevant risk factor for ELT failure or recanalization. CONCLUSION: ELT failure seems to be related to the administration of low laser fluences.

Adult↗

Cardiovascular laser application.

With the invention of the laser, many clinical disciplines have taken advantage of this new energy source. Its precision, intensity and energy density is superior to all other known surgical devices. Based on the principle of light amplification from a photon-emitting resonator, the monochromaticity, collimation and coherence provide the high-energy density of the laser beam for medical applications. The state-of-the-art and future potential of laser use in cardiovascular diseases will be reviewed. Most of the work in this field has been accomplished during the past decade with numerous research projects. Although many technical advances have been made, so far the results in cardiovascular medicine are in the areas of vessel anastomosis, ablation of conduction passes for arrhythmia therapy, and angioplasty. In this paper, special attention will be given to the recent success in XeCl excimer laser application for photodecomposition of tissue with a goal of improved recanalization. The high-power density of the XeCl excimer laser provides significant advantages for the disruption of both embolic and calcified plaque. Regardless of the type of tissue ablated, gross, histologic, and ultra-structural analysis confirmed the absence of thermal injury in luminar recanalization as well as in animal studies. Progress in the manufacture of catheters, with multiple very small diameter fibers, led to the decisive breakthrough in clinical laser angioplasty. Peripheral as well as coronary arteries have been successfully recanalized followed by balloon dilatation. The ease of application and the success achieved thus far have resulted in an optimistic assessment for laser medicine.

Angioplasty, Balloon↗

Peripheral laser angioplasty with sapphire tip.

UNLABELLED: To improve the result of peripheral laser recanalization (less perforation with wider tunnels of vaporization), we used the technique of sapphire laser angioplasty. A Nd:YAG laser with continuous emission was connected to a catheter with a 600 mum fiber and a sapphire probe to its extremity (1.8-3 mm in diameter). Treatment was performed on 127 patients with severe stenosis or occlusion of peripheral arteries (iliac, femoral, or popliteal arteries). Recanalization was obtained in 102 cases (80%) and was further embellished by balloon dilatation. The rate of success decreased proportionally with the length of occlusions (93% for 3 cm, 33% for 15 cm and more). Most failures were due to wall perforation or wall entry of the probe; passage of the sapphire tip was rarely blocked by the occlusion. At follow-up, 26.4% of arteries were reoccluded after 2 months. IN CONCLUSION: laser angioplasty with a sapphire tip can totally recanalize occluded arteries with low rate of failure and complications.

Adult↗

Effects of ultrasound energy on total peripheral artery occlusions: initial angiographic and angioscopic results.

Ultrasonic energy has been shown to ablate atherosclerotic plaques and arterial and venous thrombi. We used an ultrasonic angioplasty device developed by our group in ten patients with totally occluded femoral artery during surgical bypass. Ultrasonic angioplasty was performed with a 130-cm long and 0.8-cm diameter titanium probe with a 2- or 2.5-mm titanium ball-tip. In one patient, angioplasty could not be performed. Angiographic and angioscopic examination were performed before and after angioplasty in nine patients. Before ultrasound recanalization, angioscopic examination showed that the proximal end of the occlusion was formed by atheromatous material in 3 cases, red thrombus in 3 cases, amd white thrombus in 3 cases. After ultrasound recanalization, angioscopy showed residual stenosis at the site of entry in only one case. In three other cases, the artery was free of residual stenosis without persistent clot. In the five other patients, a residual stenosis was present beyond the proximal occlusion point with some fibrin mesh and small clots. At angiography, flow was restored in 4 cases; in 4 patients flow rate of entry was slow in the distal segment; and in 1 patient, the distal arterial bed could not be opacified. Altogether, ultrasonic angioplasty was able to recanalize a complete occlusion in nine out of ten patients, with partial or complete dissolution of clots and with no complication. At its present stage of development, adjunctive balloon angioplasty would be needed in most cases to obtain unrestricted flow and unsignificant residual stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Comparative study of a mutant tissue-type plasminogen activator, YM866, with a tissue-type plasminogen activator in a canine model of femoral arterial thrombosis.

Because tissue-type plasminogen activator (tPA), used to treat myocardial infarction, has several disadvantages thought to be connected with its low half-life, mutants of tPA have been prepared with longer half-lives. We have compared the thrombolytic effect of such a mutant, YM866, with that of tPA in copper-coil-induced femoral arterial thrombosis in dogs. One hour after thrombus formation, YM866 was administered by intravenous bolus injection, while tPA was given by the same method or by 60-min infusion under adequate heparinization. Both agents exhibited dose-dependent thrombolysis without systemic fibrinogenolysis. The recanalization rate and recanalization time of YM866 by bolus at 0.2 mg kg-1 were, however, equivalent to those of tPA by infusion at 0.4 mg kg-1 (total dose), whereas the recanalization rate of tPA by bolus was low (0.4 mg kg-1). No significant difference in reocclusion rate, reocclusion time, or patency status after successful thrombolysis was seen. These results suggest that YM866 administered at a lower dose by intravenous bolus injection exerted a thrombolytic effect equivalent to that of tPA by infusion, and that heparin could not prevent reocclusion after successful thrombolysis even under adequate anticoagulation.

Animals↗