Temporary Vena Cava Filters and Ultrahigh Streptokinase Thrombolysis Therapy: A Clinical Study

Purpose: To assess the efficacy of temporary vena cava filters in patients undergoing ultrahigh-dose streptokinase thrombolysis for iliocaval thrombosis and to determine therapy success and filter and therapy complications. Methods: Forty-five patients were studied regarding extension and characteristics of thrombosis, duration, success, and complications of thrombolysis therapy, filter type, access route, pulmonary embolisms, and filter complications. Results: Complete recanalization was achieved in 57% of cases. Filters were inserted predominantly via a transbrachial route. One fatal pulmonary embolism (2%) occurred 1 day after starting thrombolysis. No other pulmonary embolism was noted. Other complications were induced by thrombolysis alone (n = 12), thrombolysis and filter (n = 9), and filter alone (n = 11). Conclusion: Fatal pulmonary embolisms as a complication of ultrahigh-dose treatment of pelvic or caval thrombosis can not safely be prevented by the temporary vena cava filters currently available. Filter design needs to be improved.     

经皮介入碎栓及溶栓治疗大面积肺栓塞

目的　总结经皮介入碎栓联合局部灌注尿激酶加全身溶栓治疗大面积肺栓塞疗效及安全性。探讨其适应证。方法　经DSA确诊并行介入治疗肺栓塞患者 5例。采用普通造影导管及导丝行介入碎栓。 4例联合局部灌注加全身应用尿激酶 ,总量 2 0万～ 14 0万U ,低分子肝素应用 10～ 15d ,口服华法林 3～ 6个月。 1例因有咯血未用溶栓剂及抗凝。疗效评价包括临床症状、肺动脉压测定、Miller指数、血氧分压、D 二聚体等。结果　所有患者均获显著临床症状改善。技术成功率 10 0 %。肺动脉平均压从(2 9± 3)mmHg下降至 (16± 8)mmHg ,治疗后平均Miller指数为 0 .33。动脉血氧分压从 (34.6 0± 8.76 )mmHg升至 (6 4 .6 0± 2 .97)mmHg。所有病例未见肺栓塞复发。结论　经皮机械性碎栓及溶栓治疗肺栓塞是安全有效的 ,可显著改善临床症状     

Interventional radiological procedures in impaired function of surgically implanted catheter-port systems

Purpose: System-related complications in surgically implanted catheter-port systems (CPS) for intraarterial (i.a.) chemotherapy are well known. In most cases of complications, the treatment must be interrupted and the catheter-port system must be repaired surgically. We describe microinvasive interventional radiological procedures to correct some dysfunctions of CPS. Methods: Five patients with repetitive dysfunction of CPS were treated with interventional techniques. Two patients presented with perfusion impairment, one patient had a pseudoaneurysm of the hepatic artery, and two patients presented with catheter displacement. Radiological interventions included mechanical recanalization with a guidewire, vascular stenting, and correction of catheter dislocation with a goose-neck snare. Results: In all cases, correct function of the CPS was restored. No intervention-related complications occurred and surgery was avoided. Chemotherapy could be continued for a period of 4–10 months. Conclusion: For some system-related complications, minimally invasive radiological interventions can be used to restore the function of CPS for i.a. chemotherapy.     

Selective thrombolysis in acute deep vein thrombosis: Evaluation of adjuvant therapy in vivo

Purpose: To evaluate in a porcine model of acute deep vein thrombosis (DVT) the efficacy of dalteparin and antithrombin with respect to heparin for local adjuvant therapy during selective thrombolysis, and the utility of nitroglycerin and iloprost as heparin supplements. Methods: DVT was induced in both hind limbs using a previously described technique (n = 20). Thirty minutes later, the animal was heparinized (2500 IU IV), and bilateral sequestrated thrombolysis was performed using 8 mg alteplase: both external iliac veins were endoluminally occluded with Swan-Ganz catheters, and a multi-sideport infusion wire coaxially introduced through each catheter and advanced into the ipsilateral popliteal vein. In the control limbs, tissue plasminogen activator (tPA) 8 mg was injected as 0.8-ml boluses at 3-min intervals for 2 hr as a 0.25-mg/ml solution containing heparin 50 IU/ml (n = 20). On the contralateral side, heparin was substituted with either dalteparin 50 IU/ml (n = 5) or antithrombin 12.5 IU/ml (n = 5), or supplemented with either nitroglycerin 0.075 mg/ml (n = 5) or iloprost (150 ng/ml) (n = 5). Blood samples were taken at predetermined intervals to measure the activated partial thromboplastin time (aPTT), prothrombin time (PT), and fibrinogen concentration. At autopsy, the thrombus mass in the iliofemoral veins was measured, and the extent of residual thrombosis in the venous tributaries graded at four sites. Results: Bilateral thrombolysis was successfully completed in all animals. The median thrombus mass in the iliofemoral veins after thrombolysis was 0.48 g (range 0.06–1.58 g), 0.95 g (0.59–1.29 g), 0.74 g (0.52–0.96 g), and 0.29 g (0.0–0.77 g) for dalteparin, antithrombin, iloprost, and nitroglycerin respectively, as compared with 0.53 g (0.18–0.88 g) (p = 0.69), 0.97 g (0.46–1.15 g) (p = 0.69), 0.53 g (0.48–1.10 g) (p = 0.69), and 0.18 g (0.13–1.04 g) (p = 0.5) for the respective controls. Likewise, the severity of residual thrombosis in the venous tributaries was not affected by the constituents of adjuvant therapy. Nitroglycerin induced a small drop in blood pressure, which was transient. The temporal change in aPTT was similar in all four groups. Invariably PT progressively shortened during thrombolysis (p = 0.0001); this effect was somewhat blunted with antithrombin. Fibrinogen levels demonstrated a time-dependent increase (p = 0.004) that was not influenced by the adjuvant therapy used. Conclusions: Dalteparin or antithrombin demonstrated no appreciable advantage over heparin as local adjuvant therapy for selective venous thrombolysis. Supplementation of heparin with iloprost or nitroglycerin also had virtually no effect on thrombolytic efficacy.     

Sequestrated thrombolysis: Comparative evaluation in vivo

Purpose: Lysis of a thrombus is a function of the local concentration of thrombolytic enzymes. This study was designed to determine in a porcine model of acute deep vein thrombosis (DVT) whether perithrombic sequestration of small volumes of a concentrated enzyme solution can accelerate the process of thrombolysis. Methods: DVT was induced in both hind limbs using a previously described technique (n = 32). Thirty minutes later the animal was heparinized and unilateral thrombolysis was attempted using 8 mg recombinant tissue plasminogen activator (rt-PA); saline was administered in the opposite leg. For conventional high-volume infusion (CI) (n = 5) rt-PA (0.067 mg/ml) was infused at 1 ml/min. For sequestrated thrombolysis the external iliac vein was endoluminally occluded, and rt-PA (0.25 mg/ml) administered either for proximal injection (ST-P) (n = 5), as a bolus every 3 min through a microcatheter placed via the balloon catheter, or for transthrombic injection (ST-T) (n = 5), as a bolus every 3 min through a Katzen wire in the balloon catheter. At autopsy, the thrombus mass in the iliofemoral veins was measured, and the extent of residual thrombosis in the venous tributaries graded at four sites. From these data a thrombolysis score was calculated. Results: One pig died before thrombolysis could be performed. Only with ST-T was residual thrombus mass in the test limb normalized to control, residual thrombus index (RTI), consistently less than unity. The median RTI of this group was 0.50 (range 0.39–0.97) compared with 1.22 (0.64–1.38) for ST-P and 0.88 (0.37–1.13) for CI. Compared with contralateral controls, a lower grade of residual thrombosis in tributaries was observed in test limbs at more venous sites with ST-T (8/20; 95% confidence interval 5–13) and ST-P (9/20; confidence interval 5–13) than with CI (2/20; confidence interval 0–5) (p= 0.04). A trend toward lower thrombolysis scores was observed with ST-T (p = 0.08). Systemic fibrinogenolysis was not observed in any of the groups. Changes in coagulation parameters during thrombolysis were similar irrespective of treatment protocol. Conclusions:“Transthrombic” sequestrated thrombolysis may offer some advantages over conventional selective infusion for the treatment of acute DVT. However further refinements will be necessary before it can be considered an alternative to the latter.     

Massive Pulmonary Embolism: Treatment with Thrombus Fragmentation and Local Fibrinolysis with Recombinant Human-Tissue Plasminogen Activator

Purpose: To report the results of thrombus fragmentation in combination with local fibrinolysis using recombinant human-tissue plasminogen activator (rtPA) in patients with massive pulmonary embolism. Methods: Five patients with massive pulmonary embolism were treated with thrombus fragmentation followed by intrapulmonary injection of rtPA. Clot fragmentation was performed with a guidewire, angiographic catheter, and balloon catheter. Three patients had undergone recent surgery; one of them received a reduced dosage of rtPA. Results: All patients survived and showed clinical improvement with a resultant significant (p < 0.05) decrease in the pulmonary blood pressure (mean systolic pulmonary blood pressure before treatment, 49 mmHg; 4 hr after treatment, 28 mmHg). Angiographic follow-up in three patients revealed a decrease in thrombus material and an increase in pulmonary perfusion. Two patients developed retroperitoneal hematomas requiring transfusion. Conclusion: Clot fragmentation and local fibrinolysis with rtPA was an effective therapy for massive pulmonary embolism. Bleeding at the puncture site was a frequent complication. Received: 0/00/00/Accepted: 0/00/00     

Systemic supply to a pulmonary arteriovenous malformation: Potential explanation for recurrence

A pregnant woman presented with hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome) and a single pulmonary arteriovenous malformation (AVM) that had been embolized 5 years previously. Partly due to pregnancy, recanalization of the aneurysm occurred with subsequent hemoptysis. Despite successful therapeutic reembolization of the afferent pulmonary artery, hemoptysis recurred 5 days later. At this time, recanalization of the pulmonary artery was not demonstrated by pulmonary angiography, but a systemic angiogram revealed a bronchial arterial supply to the pulmonary AVM. A systemic supply should always be sought in cases of recurrent hemoptysis after technically successful embolization of the feeding pulmonary artery. Received: 0/00/00/Accepted: 0/00/00     

Long-term results of vena cava filters: Experiences with the LGM and the Titanium Greenfield devices

Purpose: Vena cava filter (VCF) application is the method of choice to prevent recurrent pulmonary embolism in patients with deep venous thrombosis. Because of the reported complications after VCF placement we summarize our long-term follow-up results with the LGM and Titanium Greenfield (TG) devices. Methods: Eighty-seven LGM VCF and 17 TG VCF were placed in 104 patients (average age 64 years). The follow-up examinations were performed by color-coded duplex sonography, plain radiographs, cavography, and computed tomo-graphy (CT). The maximum observation time was 81 months. Results: Filter migration occurred in 11% (8/76) of the LGM VCF and 15% (2/13) of the TG VCF. Vena cava thrombosis was seen in 17% (13/76) of the patients with an LGM VCF and in 31% (4/13) of those with a TG VCF. The patency rate was 95% (72/76) for the LGM VCF and 92% (12/13) for the TG VCF. Pulmonary embolism was noted in 3 patients after LGM VCF insertion and in no patient after TG VCF insertion. Conclusion: A VCF should only be inserted in a patient after pulmonary embolism and when there is strict proof of the indication.     

Percutaneous implantation of a catheter with subcutaneous reservoir for intraarterial regional chemotherapy: Technique and preliminary results

Purpose: We present the technique and the preliminary results of percutaneous implantation of intraarterial catheters connected to a subcutaneous infusion reservoir for prolonged regional chemotherapy of hepatic and extrahepatic tumors. Methods: Two hundred patients with primary or secondary hepatic neoplasms, pelvic, pancreatic, renal, lingual, and breast cancer underwent the procedure. The access was the left axillary artery (188 patients) and the femoral artery (12 patients). The catheter tip was placed in the hepatic (170 patients), hypogastric (18), splenic (4), internal thoracic (2), gastroduodenal (3), renal (2) or the external carotid artery (1). The catheter was connected to a subcutaneous reservoir and filled with heparin; chemotherapeutic infusion was subsequently started. Results: One hundred percent immediate technical success was obtained. Forty-three of 200 (21.5%) patients had a complication: 29 patients had a catheter dislodgment, nine had arterial thrombosis, three had a pseudoaneurysm of the left axillary artery and two had a port pocket hematoma. Most complications (37/43, 86%) were treated percutaneously without interruption of chemotherapy. In only six cases (3% of the total population) was chemotherapy discontinued due to the complication itself. The mean duration of catheter patency was 7.2 months. Conclusion: Percutaneous placement of an intraarterial catheter is feasible and causes less discomfort to the patient than the surgical approach. The technique has an acceptable complication rate (21.5%), similar to that for surgical implantation (17.8%), with the advantage that in most cases the complications can be resolved percutaneously. This technique represents an alternative to surgical implantation in the treatment of liver metastases from colorectal cancer and opens new therapeutic possibilities for the local prolonged treatment of other kinds of tumor, though its clinical efficacy must be assessed in selected trials.     

Postcatheterization Retroperitoneal Hematoma Due to Spontaneous Lumbar Arterial Hemorrhage

A patient developed retroperitoneal hemorrhage after cardiac catheterization, initially thought to be a complication of the puncture. Diagnostic evaluation revealed the source to be spontaneous bleeding from a lumber artery, which was successfully embolized. Spontaneous hemorrhage is a recognized complication of anticoagulation therapy and must be considered in the differential diagnosis even in the face of a seemingly obvious source of bleeding.     

Microcatheter embolization of Intractable Idiopathic Epistaxis

Purpose: To assess the efficacy and safety of microcatheter embolization in the treatment of intractable idiopathic epistaxis. Methods: Thirty-seven patients underwent microcatheter embolization in 1991–1998. We evaluated retrospectively the technical and clinical outcome, the number of complications, the duration of embolization in each case, and the number of blood transfusions needed. All embolizations were done with biplane digital subtraction angiography (DSA) equipment. The procedure was carried out under local anesthesia using transfemoral catheterization, except in one case where the translumbar route was used. Tracker 18 or 10 microcatheters were advanced as far as possible to the distal branches of the sphenopalatine artery. Polyvinyl alcohol (PVA) particles were used for embolization in most cases, while platinum coils or a combination of these two materials were occasionally used. The primary outcome was always assessed immediately by angiography. Follow-up data were obtained from patient records, by interviewing patients on the telephone or by postal questionnaires when necessary. The mean follow-up time was 21 months. Results: The embolization was technically successful in all 37 cases. A curative outcome was achieved in 33 cases (89%). The mean duration of the procedure was 110 min. Four patients (8%) had mild transient complications, but no severe or persistent complications were encountered. Twenty-three patients needed a blood transfusion. Slight rebleeding occurred in three patients during the follow-up; all responded to conservative treatment. One patient suffered two episodes of rebleeding within 2 months after primary embolization. Re-embolizations successfully stopped the bleeding. Conclusion: Embolization is the primary invasive modality for treating intractable idiopathic epistaxis. It proved both safe and effective over a relatively long follow-up.     

In Vivo Evaluation of a Retrievable Vena Cava Filter—The Dibie-Musset Filter: Experimental Results

Purpose: To evaluate, in an animal model, the efficacy and safety of a 7 Fr percutaneous vena cava filter for temporary or permanent use. Methods: The Dibie-Musset (DM) filter is a wire preformed into a double-spiral shape with a spring effect. The experiment was performed in 15 adult sheep and consisted of the insertion of 45 filters, clot trapping tests, and filter retrieval. Follow-up in all sheep consisted of radiologic (abdominal radiograph, inferior vena cavogram, abdominal computed tomography), macroscopic, and microscopic examinations between days 8 and 386 after filter placement. Results: Of the 45 filters implanted in 15 sheep, 29 were retrieved between day 0 and day 15. Filtration efficiency was 100% for clots 4 × 4 × 20 mm. No long-term (1 year) side-effects were detectable. Microscopic examination of the vein wall showed only a dense intimal fibrosis without signs of acute inflammation at 1 year. Conclusion: These results support the efficiency and safety of the DM filter in an animal model.     

Percutaneous fragmentation of pulmonary emboli in dogs with the impeller-basket catheter

A new catheter system for rapid percutaneous fragmentation of pulmonary emboli was tested in nine dogs. The system consisted of a high-speed rotating impeller, placed within the center of a self-expandable basket. Preformed radiopaque emboli were introduced via the right external jugular vein. In nine tests in five dogs, a single embolus was launched after the right pulmonary artery had been balloon occluded and the impeller-basket catheter had been positioned into the left pulmonary artery, Seven of nine emboli were completely fragmented, each within less than 10 s. In two tests, performed in two different dogs, the catheter was positioned after complete embolization of the left pulmonary artery. In both cases, the central pulmonary arteries could be fully, and the segmental arteries partly, recanalized. Mobility of the system within the pulmonary arteries was limited. There was no evidence of wall damage at the rotation site of the impeller. Free serum hemoglobin did not increase after treatment. We conclude that the device can be safely operated in the left pulmonary artery system of dogs. It causes no significant hemolysis, and is able to accomplish rapid recanalization of the central arteries. Due to limited steerability, occluded side branches cannot be treated consistently.     

Percutaneous Biliary Reconstruction: A Report of Two Cases Utilizing “Blunt” Recanalization and “Rendezvous” Techniques

We present two cases where percutaneous transhepatic intervention provided initial and definitive therapy following early and late diagnosis of bile duct transection by blunt abdominal trauma.     

In Vitro Evaluation of a Rheolytic Thrombectomy System for Clot Removal from Five Different Temporary Vena Cava Filters

Purpose: To evaluate the feasibility of thrombus removal from temporary vena cava filters using a rheolytic thrombectomy device and to assess the embolization rate of this procedure. Methods: Five temporary vena cava filters together with porcine thrombi were placed in a vena cava flow model (semitranslucent silicone tube of 23 mm diameter, pulsatile flow at a mean flow rate of 4 L/min). A rheolytic thrombectomy system (Hydrolyser) was used with a 9 Fr guiding catheter to remove the clots. The effluent was passed through filters of different size and the amount of embolized particles as well as the remaining thrombus were measured. Results: Thrombus removal rates ranged from 85% to 100%. Embolization rates between 47% and 60% were calculated for the different filters. Conclusion: The Hydrolyser is able to remove sufficiently high amounts of thrombus from temporary vena cava filters. However, the amount of embolized particles makes it impossible to utilize this method without special precautions against embolization. Received: 0/00/00/Accepted: 0/00/00     

Balloon Occlusion Versus Wedged Hepatic Venography Using Carbon Dioxide for Portal Vein Opacification During TIPS

Balloon occlusion hepatic venography using carbon dioxide (CO₂) is proposed as a safer yet simpler alternative to wedged catheter techniques that have caused hepatic lacerations during the transjugular intrahepatic portosystemic shunt (TIPS) procedure. The image quality of CO₂ wedged catheter and balloon occlusion venograms was comparable in our small series, with no venographic-related complications occurring in the balloon occlusion group.     

Retrievable IVC square stent filter: Experimental study

Purpose: In vitro and in vivo evaluation of a new retrievable, home-made, inferior vena cava (IVC) Square stent filter (SSF) with two trapping levels. Methods: In vitro, the SSF was compared in a flow model with the stainless steel Greenfield filter (SGF) for emboli- trapping efficiency by serially passing 300 emboli of 3 and 6 mm in diameter and 15–30 mm in length in each type of filter. Nine swine were used for the in vivo testing of the SSF for deployment and retrievability, emboli-trapping efficiency, stability, and self-centering ability and two were used (total of 11 swine) for testing repositioning and retrievability of the SSF at 2 weeks and for gross and histologic IVC changes at 2 months. Results: In vitro, the SSF and SGF had similar efficiency in trapping large emboli but the SSF had significantly better efficiency than the SGF for trapping all sizes of emboli (91.7% vs 81%), medium size emboli (93% vs 80%), and small emboli (86% vs 69%). Efficiency decreased in both filters from the first to the fifth embolus in each series but was still significantly better for the SSF. With the SSF, 89% of emboli were caught at the primary and 11% at the secondary filtration level. In the nine animals used for acute studies, the SSF was easily placed in all 27 attempts, assumed a central position 26 times, and was easily retrieved in 21 of 22 attempts. One tilted filter needed additional manipulation for retrieval. During emboli injection in five swine, the SSF had 97.2% emboli-trapping efficiency and demonstrated good stability. In the two animals used for longer-term evaluation, the filters were easily retrieved 2 weeks after implantation. Histologic evaluation at 2 months showed neointimal proliferation around the SSF wires in contact with the IVC wall, which was otherwise normal. Conclusion: The SSF is a promising filter. It is easy to place and retrieve, is stable after placement, and has high efficiency for trapping emboli. Promising results justify further experimental and eventual clinical studies with a commercially manufactured SSF.     

Nonlinear Geometric Warping of the Mask Image: A New Method for Reducing Misregistration Artifacts in Digital Subtraction Angiography

Purpose: Misregistration artifact is the major cause of image degradation in digital subtraction angiography (DSA). The purpose of this study was to evaluate the efficacy of a newly developed nonlinear geometric warping method to reduce misregistration artifact in DSA. Methods: The processing of the images was carried out on a workstation with a fully automatic computerized program. After making differential images with a lapracian filter, 49 regions of interest (ROIs) were set in the image to be processed. Each ROI of the live image scanned the corresponding ROI of the mask image searching for the best position to match itself. Each pixel of the mask image was shifted individually following the data calculated from the shifts of the ROIs. Five radiologists compared the images produced by the conventional parallel shift technique and those processed with this new method in 16 series of cerebral DSA. Results: In 14 of 16 series (88%), more radiologists judged the images processed with the new method to be better in quality. Small arteries near the skull base and veins of low density were clearly visualized in the images processed by the new method. Conclusion: This newly proposed method could be a simple and practical way to automatically reduce misregistration artifacts in DSA.     

Local intraarterial thrombolysis: In vitro comparison between automatic and manual pulse-spray infusion

Purpose Manual and automatic pulse-spray infusion techniques are compared in vitro to evaluate the efficacy of thrombolysis and the distribution of urokinase and saline solution within thrombus using a pulse-spray catheter. Methods A pulse-spray catheter was introduced into a human thrombus within a stenotic flow model. Automatic and manual pulsed infusion of urokinase and automatic pulsed infusio of saline solution were compared. To quantify the efficacy of thrombolysis, pressure gradients were recorded proximal and distal to the thrombus and during the course of infusion. Distribution of infused urokinase was assessed radiographically. Results The fastest and most homogeneous dissolution of the thrombus was achieved with automatic pulsed infusion of urokinase, shown by decreasing transthrombotic pressure gradients (p<0.001, Wilcoxon, matched pairs). Manual pulsed infusion of urokinase or saline solution resulted in inhomogeneous thrombus dissolution and delayed thrombolysis. Conclusion Application of automatic pulse-spray injectors seems beneficial for more effective and homogeneous intraarterial pulse-spray thrombolysis when compared with conventional manual pulsed technique.     

Square Stent: A New Self-Expandable Endoluminal Device and Its Applications

The square stent is a new, simply constructed, self-expanding device that has recently been described. Compared with other stents, the square stent has a minimal amount of metal and thus requires a smaller-diameter catheter for introduction. Despite the small amount of metal present, the square stent has adequate expansile force. We have been evaluating the square stent for various interventional applications. In addition to the basic square stent, combinations of square stents and coverings for square stents were developed and evaluated to expand its uses and indications. One of the coverings tested is a new biomaterial: small intestinal submucosa (SIS). This paper will discuss the various applications of the square stent, which include a retrievable inferior vena cava filter, vascular occluder, graft adapter, and venous and aortic valves. In addition, we will review the important properties of SIS as a covering for the square stent.