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Biomedical subjects

H Bjarnason

Publications and source records attributed to H Bjarnason.

27 records · Page 2Linked to original sources
PubMedDate not supplied

Venous recanalization by metallic stents after failure of balloon angioplasty or surgery: four-year experience.

PURPOSE: This retrospective study describes our updated experience in treating venous stenoses and occlusions with metallic endovascular stents. METHODS: Gianturco, Palmaz, and Wallstent stents were placed in 55 patients over a 4-year period. Stent sites included the subclavian veins (9), innominate veins (3), superior vena cava (4), inferior vena cava (3), iliac veins (29), femoral veins (5), and portal veins (6). The most common indications for stent placement were malignant stenoses and chronic pelvic venous occlusions. Venoplasty and/or urokinase were used as ancillary therapy. Patients were anticoagulated for 3-6 months. Follow-up included clinical assessment and duplex ultrasound. RESULTS: Lifetable analysis shows 59%, 63%, and 72% primary, primary assisted, and secondary 1-year patency rates, respectively. The 4-year primary patency rates were the same. Duration of patency depended on the venous site. Death was a complication of stent placement in 2 patients and 12 patients died within 6 months after stent placement from primary disease progression. Although early failures were more common in stents placed across occlusions than stenoses, 1-year secondary patency rates were comparable. Primary patency rates were only slightly lower in patients with malignant obstruction than in patients with benign disease. CONCLUSION: Endovascular stent placement provides a nonsurgical alternative for reestablishment of venous flow and symptomatic relief in patients with benign as well as malignant venous obstruction.

Angioplasty, Balloon↗
PubMedDate not supplied

Early sonographic evaluation of the transjugular intrahepatic portosystemic shunt (TIPS).

The purpose of this study was to evaluate duplex and color Doppler findings in patients before and within 24 h after transjugular intrahepatic portosystemic shunts (TIPS). Conventional duplex and color Doppler were used in the assessment of 19 patients who underwent TIPS as part of a prospective protocol. Patients were examined within 24 h before and after the procedure. Before TIPS, patency, flow direction, and peak flow velocity in the main portal vein and hepatic artery were studied, as well as patency and flow direction in hepatic veins, splenic vein, and inferior vena cava (IVC). Immediately after the procedure, sonographic identification of stent position, shunt patency, and flow dynamics were evaluated and patency and flow direction of hepatic veins, splenic vein, and IVC were determined. The portogram performed at the end of the procedure was compared with the 24-h sonographic studies after TIPS to determine sonographic/angiographic correlation. No intraparenchymal abnormalities or perihepatic fluid collections were detected after the procedure. The metallic stent was clearly seen in all patients. Mean peak shunt flow velocities were 139 +/- 50 cm/sec within 24 h after TIPS. Absence of flow through the shunt was correctly identified in one case and confirmed angiographically. Mean peak flow velocity in the portal vein before TIPS was 22 +/- 13.6 cm/sec and increased to 43.6 +/- 9.1 cm/sec after TIPS (p < 0.05). The hepatic artery peak systolic velocity increased from 77 +/- 51 cm/sec before TIPS to 119 +/- 53 cm/sec after the procedure (p = 0.029).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Flow Velocity↗
PubMedDate not supplied

Placement of the Palmaz stent with use of an 8-F introducer sheath and Olbert balloons.

PURPOSE: The authors describe a modified technique for delivering Palmaz 30-mm stents. MATERIALS AND METHODS: The modification is based on the use of an 8-mm Olbert balloon mounted on a 5.8-F shaft. The Palmaz stent is crimped onto the balloon by using finger pressure only. An 8-F introducer sheath can be used instead of a 10-F sheath. The surface material of the balloon prevents the stent from moving as it is introduced through the sheath and lesion. The balloon has a very small profile after deflation, which means it can be easily removed without dislodging the stent. The balloon can be used for placement of more than one stent. RESULTS: Nineteen Palmaz 30-mm stents have been placed with this method, and there have been no complications or difficulties related to this method. In one case, four stents were delivered by using the same balloon. CONCLUSION: This modification should reduce the complications of stent delivery, especially in small iliofemoral systems.

Arteries↗
PubMedDate not supplied

Chronic iliac artery occlusions: primary recanalization with endovascular stents.

PURPOSE: The authors describe treatment of chronic iliac artery occlusions with primary stent placement without prior thrombolysis or angioplasty. PATIENTS AND METHODS: Eight patients with chronic iliac artery occlusions (six men and two women) underwent primary stent placement without prior use of thrombolytic agents or angioplasty. Palmaz stents were placed in seven patients and a Wallstent device was placed in one. RESULTS: In all patients, revascularization was successful without residual stenoses or pressure gradients. There was no angiographic evidence of distal embolization. CONCLUSION: Primary stent placement for chronic iliac artery occlusions without prior thrombolysis or angioplasty appears to be safe and efficacious and is potentially cost effective.

Adult↗
PubMedDate not supplied

Iliofemoral deep venous thrombosis: safety and efficacy outcome during 5 years of catheter-directed thrombolytic therapy.

PURPOSE: To prospectively evaluate the angiographic and clinical results of using catheter-directed thrombolytic therapy for the treatment of acute iliofemoral deep venous thrombosis (IFDVT). MATERIALS AND METHODS: All consecutive patients with acute IFDVT referred for thrombolytic treatment from July 1990 to December 1995 were included in this clinical data analysis. Infusions of urokinase were administered via a multisidehole infusion catheter. Angioplasty, stent placement, mechanical thrombectomy, and other procedures were often performed in conjunction with the thrombolytic procedure. RESULTS: Seventy-seven patients and 87 limbs were treated. The overall technical success rate was 79%, and was 86% for iliac veins and 63% for femoral veins. The primary and secondary patency rates at 1 year were 63% and 78%, respectively, for the iliac veins, and 40% and 51%, respectively, for the femoral veins. Patients with malignant disease fared worse. Patients requiring stent placement appeared to have inferior outcomes. A previous history of DVT did not appear to affect the results. Bleeding requiring transfusion and hematomas were the major complications encountered. Pulmonary embolus was not a significant problem. Technical success rates were lower in patients who had had symptoms for more than 4 weeks compared to those who had a more recent onset of symptoms. CONCLUSION: Current data suggest that catheter-directed thrombolytic therapy is safe and effective in achieving intermediate-term venous Patency. The long-term clinical benefits of this procedure remain, however, to be established.

Angioplasty↗
PubMedDate not supplied

Changes in tunneled catheter tip position when a patient is upright.

PURPOSE: To determine the relative changes in position of tunneled catheters from supine to upright patient position and factors affecting catheter tip migration. MATERIALS AND METHODS: One hundred forty-six different tunneled catheters were placed through the subclavian or jugular veins radiologically, and catheter positions were documented with use of cine radiography at the time of placement. Follow-up chest radiographs were obtained with the patient in the upright position within 48 hours after placement. Catheter tip positions were numbered from 1 to 8, with 1 representing the innominate/superior vena cava junction and 8, the lower right atrium. Patient sex and weight, the site of catheter entry, and the size and type of catheter were correlated with the relative change in position on the follow-up chest radiogrpahs. RESULTS: There was a statistically significant (P < .0001) change in catheter position on the follow-up chest radiographs, with a mean difference of 1.5 catheter positions (usually mid-right atrium initially to low superior vena cava on follow-up). Catheter tip migration was greater for catheters in the subclavian veins, in females, and in obese patients. CONCLUSIONS: The catheter tip migrates significantly from the initial position at the time of placement as compared to when the patient assumes the upright position. This knowledge is important in achieving the desired final catheter position.

Adult↗