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Haraldur Bjarnason

Publications and source records attributed to Haraldur Bjarnason.

10 recordsLinked to original sources
PubMed2007

Successful iliac vein and inferior vena cava stenting ameliorates venous claudication and improves venous outflow, calf muscle pump function, and clinical status in post-thrombotic syndrome.

OBJECTIVES: Stent therapy has been proposed as an effective treatment of chronic iliofemoral (I-F) and inferior vena cava (IVC) thrombosis. The purpose of this study was to determine the effects of technically successful stenting in consecutive patients with advanced CVD (CEAP3-6 +/- venous claudication) for chronic obliteration of the I-F (+/-IVC) trunks, on the venous hemodynamics of the limb, the walking capacity, and the clinical status of CVD. These patients had previously failed to improve with conservative treatment entailing compression and/or wound care for at least 12 months. METHODS: The presence of venous claudication was assessed by > or =3 independent examiners. The CEAP clinical classification was used to determine the severity of CVD. Outflow obstruction [Outflow Fraction at 1- and 4-second (OF1 and OF4) in %], venous reflux [Venous Filling Index (VFI) in mL/100 mL/s], calf muscle pump function [Ejection Fraction (EF) in %] and hypertension [Residual Venous Fraction (RVF) in %], were examined before and after successful venous stenting in 16 patients (23 limbs), 6 females, 10 males, median age 42 years; range, 31-77 yearas, left/right limbs 14/9, using strain gauge plethysmography; 7/16 of these had thrombosis extending to the IVC. Contralateral limbs to those stented without prior I-F +/- IVC thrombosis, nor infrainguinal clots on duplex, were used as control limbs (n = 9). Excluded were patients with stent occlusion or stenoses, peripheral arterial disease (ABI <1.0), symptomatic cardiac disease, unrelated causes of walking impairment, and malignancy. Preinterventional data (< or =30 days) were compared with those after endovascular therapy (8.4 months; interquartile range [IQR], 3-11.8 months). Nonparametric analysis was applied. RESULTS: Compared with the control group, limbs with I-F +/- IVC thrombosis before stenting had reduced venous outflow (OF4) and calf muscle pump function (EF), worse CEAP clinical class, and increased RVF (all, P < 0.05). At 8.4 months (IQR, 3-11.8 months) after successful I-F (+/-IVC) stenting, venous outflow (OF1, OF4) and calf muscle pump function (EF) had both improved (P < 0.001) and the RVF had decreased (P < 0.001), at the expense of venous reflux, which had increased further (increase of median VFI by 24%; P = 0.002); the CEAP status had also improved (P < 0.05) from a median class C3 (range, C3-C6; IQR, C3-C5) [distribution, C6: 6; C4: 4; C3: 13] before intervention to C2 (range, C2-C6; IQR, C2-C4.5) [distribution, C6: 1; C5: 5; C4: 4; C2: 13] after intervention. At this follow up (8.4 months median), venous outflow (OF1, OF4), calf muscle pump function (EF), and RVF of the stented limbs did not differ significantly from those of the control; significantly worse (P < 0.025) were the amount of venous reflux (VFI), and the CEAP clinical class, despite the improvement with stenting. Incapacitating venous claudication noted in 62.5% (10 of 16, 95% CI, 35.8%-89.1%) of patients (15 of 23 limbs; 65.2%, 95% CI, 44.2%-86.3%) before stenting was eliminated in all after stenting (P < 0.001). CONCLUSIONS: Successful I-F (+/-IVC) stenting in limbs with venous outflow obstruction and complicated CVD (C3-C6) ameliorates venous claudication, normalizes outflow, and enhances calf muscle pump function, compounded by a significant clinical improvement of CVD. The significant increase in the amount of venous reflux of the stented limbs indicates that elastic or inelastic compression support of the successfully stented limbs would be pivotal in preventing disease progression.

Adult↗
PubMed2006

Multiple hepatic artery aneurysms: use of transcatheter embolization for rupture.

Aneurysmal disease of the hepatic artery is a rare and potentially life-threatening entity. Aneurysms occur anywhere along the hepatic artery and its branches, but they have a predilection for occurring as a solitary lesion of the common or right hepatic artery. Diffuse intrahepatic hepatic artery aneurysm is the rarest form and is especially challenging. Treatment of these lesions has been described in only a few case reports. We present a patient with ruptured intrahepatic hepatic artery aneurysms treated by percutaneous transcatheter embolization.

Aged↗
PubMed2006

Endovascular repair of ruptured saccular aneurysms of the descending thoracic aorta.

Open repair of ruptured aneurysms of the descending thoracic aorta (DTA) is associated with early mortality rates of 20%-60% and severe morbidity rates exceeding 40%. The present report describes three octogenarian patients and one sexagenarian patient at poor surgical risk admitted with acutely ruptured saccular DTA aneurysms (two of four were anastomotic) unrelated to trauma or infection who underwent successful endovascular therapy, which involved the use of aortic endovascular cuffs in three cases. Mean intensive care unit and total hospital stay durations were 1.75 days (range, 1-4 d) and 6 days (range, 3-13 d), respectively. At 30 days, all patients were alive and free of repeat intervention, with aneurysm exclusion achieved in all cases but one, which featured a marginal type II endoleak. These data support endovascular therapy for ruptured saccular DTA aneurysms enabling short-term outcomes that otherwise would have been unrealistic.

Aged↗
PubMed2005

Adventitial remodeling with increased matrix metalloproteinase-2 activity in a porcine arteriovenous polytetrafluoroethylene grafts.

BACKGROUND: We hypothesized the source of early proliferating cells contributing to venous stenosis formation in a porcine hemodialysis grafts is the adventitia and media, and migration of these cells is greatest within the first two weeks following graft placement, resulting in increased matrix metalloproteinase-2 (MMP-2) activity. METHODS: Polytetrafluoroethylene grafts from the iliac artery to the ipsilateral iliac vein were placed in 23 pigs and 5-Bromo-2'-deoxyuridine (BrdU) was given at 24 and 48 hours after surgery to assess cell proliferation and migration. Angiography and magnetic resonance angiography was performed. Animals were euthanized on day three (N= 6), day seven, (N= 5), day 14 (N= 6), and days 19 to 26 (N= 6) after graft placement, and stenotic tissue and unaffected contralateral iliac vein were removed for zymography and immunostaining. RESULTS: Migration of cells derived from the adventitia and media peaked at day 14. Adventitial diameter of the stenotic vein decreased, while the intima to media ratio increased. MMP-2 activity peaks at day seven in the adventitia and days 19 to 26 in the intima. CONCLUSION: These results confirm our hypothesis that the source of cells resulting in venous stenosis formation is derived from the adventitia and media, with cell migration being greatest within the first two weeks after graft placement with translocation of these cells into the intima at four weeks. MMP-2 activity peaks at day seven in the adventitia and again at days 19 to 26 in the intima. A key to limiting venous stenosis formation may lie in inhibiting MMP-2 by adventitial and medial targeting.

Animals↗
PubMed2003

Open surgical and endovascular treatment of superior vena cava syndrome caused by nonmalignant disease.

OBJECTIVES: The purpose of this study was to evaluate the role of endovascular and open surgical reconstructions in patients with superior vena cava (SVC) syndrome caused by nonmalignant disease. METHODS: Clinical data from 32 consecutive patients who underwent endovascular or open surgical reconstruction of central veins because of symptomatic benign SVC syndrome between November 1983 and June 2001 were retrospectively reviewed. RESULTS: The study included 17 male and 15 female patients (mean age, 38 years; range, 5-69 years). Presenting symptoms were head fullness (n = 26), dyspnea or orthopnea (n = 23), headache (n = 17), or dizziness (n = 11); physical signs were head swelling (n = 31), chest wall collateral vessels (n = 29), facial cyanosis (n = 18), or arm swelling (n = 17). Etiologic factors included mediastinal fibrosis (n = 19), indwelling catheter (n = 8), idiopathic thrombosis (n = 4), or post-surgery (n = 1). Two patients were heterozygous for factor V Leiden; 1 patient had antithrombin III deficiency. Twenty-nine patients underwent surgical reconstruction with 31 bypass grafts: spiral saphenous vein (n = 20), superficial femoral vein (n = 4), human allograft (n = 1), or expanded polytetrafluoroethylene (ePTFE, n = 6). Eleven patients underwent percutaneous transluminal angioplasty or stenting; 3 primary and 8 secondary endovascular procedures were performed to treat graft stenosis (n = 7) or occlusion (n = 1). There were no early deaths. Five early graft failures in 3 ePTFE grafts and 2 bifurcated vein grafts (thrombosis, n = 4; stenosis, n = 1) were successfully treated with open surgical revision. Over a mean follow-up of 5.6 years (range, 0.4-16.6 years) in surgical patients, 17 additional secondary interventions were performed in 8 patients, 14 endovascular and 3 surgical. Primary, assisted primary, and secondary patency rates of surgical bypass grafts were 63%, 79%, and 85%, respectively, at 1 year, and 53%, 68%, and 80%, respectively, at 5 years. Graft patency was significantly higher in vein grafts compared with ePTFE grafts (P =.02). Mean follow-up after percutaneous transluminal angioplasty or stenting was 3.1 years (range, 1 day-11.7 years). Twelve secondary endovascular interventions were performed in 6 patients (primary group, 3 of 3; secondary group, 3 of 9 grafts in 8 patients) to maintain patency in 11 of 12 reconstructions. Mean follow-up in the entire patient cohort was 5.3 years (range, 0.4-16.6 years). In 79% of patients symptoms had resolved or were significantly improved at last follow-up. CONCLUSIONS: Surgical treatment of benign SVC syndrome is effective over the long term, with secondary endovascular interventions to maintain graft patency. Straight spiral saphenous vein graft remains the conduit of choice for surgical reconstruction, with results superior to those with bifurcated vein and ePTFE. Endovascular treatment is effective over the short term, with frequent need for repeat interventions. It does not adversely affect future open surgical reconstruction and may prove to be a reasonable primary intervention in selected patients. Patients who are not suitable for or who fail endovascular intervention merit open surgical reconstruction.

Adolescent↗
PubMed2003

Renal artery stent placement: complications at a single tertiary care center.

PURPOSE: To describe complications after renal artery stent placement in patients with atherosclerotic renal artery stenosis (RAS) at a single tertiary care center and analyze the risk factors for these complications. MATERIALS AND METHODS: Medical records and angiograms of 171 patients who underwent a total of 179 consecutive percutaneous transluminal renal artery stent placement (PTRS) procedures for atherosclerotic RAS were retrospectively reviewed. Data on patient comorbidities, procedure indication, lesion location, serum creatinine level, and procedure-related complications were analyzed. The Wilcoxon rank-sum test was used to assess the association of continuous risk factors with complications, and the chi(2) test was used to assess the association of categoric risk factors with outcomes. RESULTS: The technical success rate for PTRS was 98%. Major complications included renal infarction in five patients (2.8%), permanently increased serum creatinine level in 10 patients (5.6%) that required hemodialysis in five (2.8%), blood transfusion in four patients (2.2%), surgical intervention for procedure-related complications in two patients (1.1%), and deep vein thrombosis in one patient (0.6%). Overall, major complications occurred in 15 procedures (8.4%). Death within 30 days after PTRS occurred in two patients (1.1%), but neither death was definitively caused by the procedure. No risk factors were found to be significantly (P <.05) associated with major complications. Patients with renal artery site or renal function complications tended to be older (P =.01) and have higher creatinine levels (P =.06). CONCLUSIONS: Renal artery stent placement allows treatment of advanced atheromatous RAS in patients with significant medical and surgical comorbidities. Complications are frequent but few have long-term significance.

Aged↗
PubMed2002

Biliary stricture in living-related donor liver transplantation: management with balloon dilation.

Biliary stricture is a recipient graft complication, occurring late in the post-operative period, which appears to occur with increased frequency in living-related donor liver transplantation (LRD LTx). We reviewed the experience at the University of Minnesota in managing a biliary complication of LRD LTx. Since January 1997, 13 LRD transplants have been performed using the technique of transplantation of the left lateral segments with a small portion of segment IV. All patients had hepaticojejunostomies using a Roux-en-Y loop. Of the 11 surviving patients, eight had evidence of cholangitis (Gram-negative sepsis, two patients; ascending cholangitis, three patients; or unexplained fever with elevated liver enzymes, three patients) 4-8 months after otherwise successful transplantation. Six of the patients underwent percutaneous transhepatic cholangiography (PTC) with demonstration of a stenosis at the site of the biliary anastomosis. Repeated dilation of the anastomosis led to resolution of the stenoses, normalization of liver enzymes, and prevention of further episodes of infection. No patient required revision of the hepaticojejunostomy. Computed axial tomography evidence of ductal stenosis may be subtle in this group of patients, but PTC is diagnostic. We suggest a high index of suspicion of biliary stricture in the LRD LTx population. Biliary dilation reduces the risk of life-threatening sepsis.

Catheterization↗
PubMed2002

Using a dopamine type 1A receptor agonist in high-risk patients to ameliorate contrast-associated nephropathy.

OBJECTIVE: The objective of our study was to evaluate the effects of fenoldopam mesylate, a dopamine type 1A receptor agonist and a potent renal vasodilator that markedly increases renal blood flow, on kidney function of patients who were receiving iodinated contrast material for an interventional procedure and thought to be at high risk of contrast-associated nephropathy. MATERIALS AND METHODS: We retrospectively reviewed the records of all patients who received fenoldopam mesylate to determine the acute and, when possible, the longer term effects on kidney function. RESULTS: Twenty-nine cases were reviewed. The average serum creatinine value before contrast administration was 2.55 mg/dL (range, 1.3-5.8 mg/dL) [corrected]. Twenty-four hours after contrast administration, serum creatinine was measured in 28 of the 29 patients. The serum creatinine values had decreased in 16 of the 28 patients by an average of 0.55 mg/dL [corrected]. In nine patients, the serum creatinine value had not changed. Two of the three increases in the serum creatinine value appear to have been caused primarily by problems that did not involve the contrast material. CONCLUSION: The use of fenoldopam mesylate at appropriate doses offers patients at high risk for contrast-associated nephropathy a chance to avoid this complication. To learn the extent and true nature of the effect of fenoldopam mesylate in this patient population requires a rigorous scientific trial, which is currently underway.

Adult↗
PubMedDate not supplied

An investigation of operator exposure in interventional radiology.

A study was conducted to investigate how operator exposure in interventional radiology is affected by various common fluoroscopic imaging conditions. Stray radiation levels surrounding the imaging chain of a C-arm angiographic system were measured with an anthropomorphic abdomen phantom under different imaging conditions, and isodose curves were constructed. Operator exposure was shown to increase with patient dose-area product as the imaging field of view (FOV) is changed, with the highest scatter levels occurring with an intermediate-sized FOV. Use of copper spectral beam filtration was found to result in decreased operator exposure, whereas use of wedge-shaped equalization filters was found to increase exposure. The effect of increasing patient abdomen thickness was simulated by surrounding the phantom with plastic bolus material. Increasing the thickness by 5 cm resulted in a doubling of exposure at the operator's waist. Exposure to the operator's upper body was significantly reduced when the FOV was positioned on the far side of the patient. Operator exposure can be maintained at an acceptable level by taking these variables into consideration and incorporating the suggested dose reduction techniques into routine practice to the greatest extent possible.

Body Burden↗