Long-term results after endovascular repair of abdominal aortic aneurysms with the Stentor and Vanguard stent-graft.

PURPOSE: To present a single institution experience of long-term results after endovascular repair of abdominal aortic aneurysms (AAA) with the Stentor and Vanguard stent-grafts. MATERIAL AND METHODS: Twenty-three patients (20 men, 3 women; mean age 68 years, range 53-81 years) were included in this prospective study. A first generation nitinol stent-graft (Stentor) was used in 12 patients and a second generation (Vanguard) in 11 patients. Follow-up was performed with magnetic resonance imaging (MRI) with contrast-enhanced MR angiography (CE MRA) at 1, 6, and 12 months, and thereafter annually (median follow-up 3 years; range 8 months to 8 years). A conventional radiograph of the abdomen was also performed. Before secondary intervention the findings on MRI with CE MRA were confirmed with spiral computed tomography (CT) and/or angiography (DSA). RESULTS: Only one patient (4%) had no complication. Endoleak was found in 15 patients (65%), graft migration in 8 (35%), and graft deformation in 18 (78%). Secondary endovascular repair was required in 7 patients (30%) and 7 (30%) were converted to open repair. CONCLUSION: Complications with the Stentor and Vanguard stent-grafts were common. Long-term follow-up of endovascularly repaired AAA is mandatory.

Costs in follow-up of endovascularly repaired abdominal aortic aneurysms. Magnetic resonance imaging with MR angiography versus EUROSTAR protocols.

AIM: Endovascular repair of abdominal aortic aneurysms (AAA) necessitates a long-term follow-up. These patients are often old and renal insufficiency is not unusual. Cost-effectiveness needs to be addressed in evaluating methods of follow-up. The aim of this study was to compare costs of 5 years follow-up with magnetic resonance imaging with contrast enhanced three-dimensional magnetic resonance angiography (MRI/MRA) with follow-up using CT with DSA, or CTA. We also assessed the impact of contrast media induced (CMI) nephropathy on follow-up costs. METHODS: We have implemented Swedish costs of CT with DSA, and CTA on the reported follow-up examinations from the EUROSTAR progress report 2000. The costs of follow-up with CT with DSA, or CTA were compared to a follow-up protocol with MRI/MRA. A cost analysis including a risk analysis of CMI nephropathy was made between MRI/MRA and CT with DSA, or CTA. RESULTS: Excluding the risk of CMI nephropathy, the 5 years follow-up cost in Euro ( ) with MRI/MRA ( 5715) is substantially higher than CT with DSA ( 3 095) or CTA ( 3573). The cost analysis favours MRI/MRA if the risk of CMI nephropathy from CT with DSA, or CTA is more than 5%. CONCLUSION: MRI/MRA can be cost-effective for follow-up of endovascularly repaired AAA depending on the risk of CMI nephropathy for CT with DSA, and CTA. MRI/MRA should be the method of choice for patients with pre-existing renal insufficiency.

Measurements before endovascular repair of abdominal aortic aneurysms. MR imaging with MRA vs. angiography and CT.

PURPOSE: 1) To compare measurements obtained with MR imaging (MRI)/contrast-enhanced MR angiography (CE MRA) with measurements obtained with angiography (DSA) and CT, for stent-graft sizing of abdominal aortic aneurysms (AAA). 2) To compare MRA measurements obtained with the two post processing techniques MIP (maximum intensity projection) and VRT (3D volume rendering technique). MATERIAL AND METHODS: The prospective study included 20 consecutive patients with AAA identified by DSA and CT as suitable for endovascular repair. For the study, MRI/CE MRA was performed. Five measurement variables for stent-graft sizing were chosen. Comparisons were made between MRI/CE MRA, DSA and CT, and between observers. Comparisons were also made between MIP and VRT. RESULTS: Significantly shorter lengths were obtained with MRA-MIP than with DSA. Three out of six diameter measurements were significantly smaller on MRI/CE MRA than on DSA and CT. No significant differences were found between the observers. One diameter measurement was significantly smaller on MIP than on VRT, while the other measurements showed no significant differences. CONCLUSION: The length measurements obtained with MRA-MIP were probably more correct than those with DSA. For more reliable diameter measurements with CE MRA, improvements of the technique, including VRT reconstructions and a standardized determination of the vessel boundaries, are needed.

Peripheral arterial disease. Contrast-enhanced 3D MR angiography of the lower leg and foot compared with conventional angiography.

PURPOSE: To determine whether contrast-enhanced 3D MR angiography (CE MRA) could replace digital subtraction angiography (DSA) for the evaluation of atherosclerotic peripheral vascular disease of the lower leg and foot. MATERIAL AND METHODS: Thirty-five patients with symptoms of atherosclerotic disease of the leg were examined prospectively with CE MRA of the foot and the lower legs as well as with DSA from the aorta to the pedal arches. The MRA technique was focused on optimal imaging of the arteries of the foot. RESULTS: The agreement between CE MRA and DSA for grading of stenosis was moderate to good (weighted kappa-values 0.48-0.80). The sensitivity of CE MRA for detection of significant stenosis (> or = 50%) was 92% and the specificity was 64% with DSA as gold standard. CONCLUSION: CE MRA is a fairly accurate method for the demonstration of atherosclerotic disease below the knee including the pedal arches. It can replace DSA for the assessment of distal arteries in patients with impaired renal function. However, image quality and resolution still needs to be improved before CE MRA can become the method of choice in all patients.

Percutaneous transluminal angioplasty of crural arteries: diabetes and other factors influencing outcome.

OBJECTIVE: to evaluate the efficacy of percutaneous transluminal angioplasty (PTA) of the crural arteries. PATIENTS AND METHODS: a retrospective review of patients treated with PTA of at least one crural artery during an 8-year period (1990--1997). RESULTS: one hundred and fifty-five legs in 140 consecutive patients (mean age 74 years, range 38--91 years) were treated. In 76% a more proximal lesion was also treated. After 1 year, results were significantly better in non-diabetics (improvement rate of 66% vs 32%p <0.05). The outcome for patients with a combination of diabetes, heart disease and renal disease was significantly worse compared to all other patients with an improvement rate of only 9% after 1 year. Patients alive and not amputated at 1 year were significantly more common (p <0.05) among non-diabetics (90%), compared to diabetics (66%). The 1-year mortality for the whole group was 15%, significantly higher for diabetic patients (p =0.04). CONCLUSION: PTA of crural arteries produces reasonably good results in non-diabetic patients. Diabetic patients were doing worse than non-diabetics after a year, though 1-month results were not significantly different. Patients with diabetes, heart disease and renal disease make a high-risk group that has a significantly worse outcome.

MR evaluation ex vivo and in vivo of a covered stent-graft for abdominal aortic aneurysms: ferromagnetism, heating, artifacts, and velocity mapping.

Magnetic resonance imaging (MRI) safety was evaluated at 1.5 T in a covered nickel titanium stent-graft (Vanguard) used for endovascular treatment of abdominal aortic aneurysms (AAAs). Imaging artifacts were assessed on MRI with contrast-enhanced (CE) three-dimensional (3D) MR angiography (MRA) and spiral computed tomography (CT) in 10 patients as well as ex vivo. Velocity mapping was performed in the suprarenal aorta and femoral arteries in 14 patients before and after stent-graft placement. For comparison it was also performed in six healthy volunteers. No ferromagnetism or heating was detected. Metal artifacts caused minimal image distortion on MRI/MRA. The artifacts disturbed image evaluation on CT at the graft bifurcation and graft limb junction. No significant differences in mean flow were found in patients before and after stent-graft placement. Our study indicates that MRI at 1.5 T may be performed safely in patients with the (Vanguard) stent-graft. MRI/MRA provides diagnostic image information. Velocity mapping is not included in our routine protocol.

Response of inflammatory markers to balloon angioplasty in peripheral arterial occlusive disease.

OBJECTIVES: To study the inflammatory response to balloon angioplasty (PTA). DESIGN: Prospective study. MATERIALS: Blood samples were drawn for cytokine analysis from 10 patients undergoing PTA before, after 60 min and 6 h after the balloon inflation. Adhesion molecules were analysed in 14 patients undergoing PTA and in seven patients undergoing angiography only. Arterial samples were taken in eight patients, before PTA, immediately after and 15 min later. Venous samples were taken in six patients and in the group undergoing angiography only. The sampling was before, 60, 90 and 120 min after the procedure. As controls served 15 patients with no signs of peripheral arterial disease. METHODS: Cytokines (IL-6, TNF-alpha) were analysed using ELISA. Adhesion molecule expression on WBC was measured by flow cytometry. RESULTS: A significant increase of IL-6 in the sample taken 6 h after the last balloon inflation was seen in five patients. TNF-alpha was raised only in one patient. The group of patients with peripheral arterial occlusive disease (PAOD) expressed pre-interventionally a higher level of adhesion molecules on WBC compared to the controls. The expression of adhesion molecules (CD11b/CD18) was significantly decreased after PTA. CONCLUSION: Only a very limited cytokine response is caused by PTA reflecting the small surgical trauma. PTA results in a downregulation of detectable CD11b/CD18 expression on WBC in the circulation, which may reflect removal of activated cells through adhesion and extravasation.

Percutaneous transluminal angioplasty with or without stenting for femoropopliteal occlusions? A randomized controlled study.

BACKGROUND: To investigate the-one year outcome of PTA and stenting and PTA alone for femoropopliteal occlusions. DESIGN: Randomized prospective study METHODS: 32 patients with femoropopliteal occlusions were randomized into two treatment groups: PTA and Strecker-stent (n=15) and PTA alone (n=17). The median age of the patients was 71 years. All patients had chronic limb ischaemia, 66% had tissue loss, 19% had rest pain and 15% had disabling claudication. The median ABPI was 0.45. The occlusion was confined to the superficial femoral artery in 30 cases and to the popliteal artery in 2 cases. The median length of the occlusions was 7.3 cm. Aspirin (ASA), 160 mg daily, was administrated postoperatively but no anticoagulation was used. The follow-up included: clinical examination, measurement of ABPI and control angiography at 12 months or earlier when necessary (20 patients). RESULTS: There was no mortality or limb loss as a consequence of the treatment. There were six (16%) immediate major complications in five patients. In the PTA group, one patient had a myocardial infarction and three patients needed arteriography due to bleeding. In the stent group, one patient required arteriography and embolectomy. The one-year mortality was 6% and there were no amputations. Four patients (two in each group) were operated on with a femorodistal bypass. The rate of clinical improvement was 71% after PTA and stent and 60% after PTA alone (p=0.17). An increased ABPI (>0.10) was shown in 50% of the stent group and 61% in the PTA group (p=0.17). Angiographic re-occlusions were seen in 33% and 75% in the stent and PTA groups respectively (p=0.17), while the rate of restenosis was significantly higher in the stent group (50% vs 25%) (p=0.033). CONCLUSIONS: Stenting following PTA for femoropopliteal occlusions does not significantly improve neither the clinical state nor the clinical/angiographic patency. The results do not justify any routine placement of stent following PTA in the successfully recanalized femoropopliteal arteries. The low rate of acceptance of a follow-up angiography indicates that this kind of study should preferably use duplex scanning instead of angiography for follow-up.

Prevention of deep vein thrombosis in knee arthroplasty. Preliminary results from a randomized controlled study of low molecular weight heparin vs foot pump compression.

BACKGROUND: We evaluated in a randomized controlled study the possibility to use foot pump mechanical compression compared to routine LMWH as prophylaxis against deep vein thrombosis during knee arthroplasty. METHODS: Forty patients were included in this preliminary report. Eleven patients withdrew, usually during the early phase of the study. RESULTS: Among the 29 patients completing a venography, 27% in the compression group and none in the LMWH group had a DVT. This difference was statistically significant (p<0.05). One further patient in the compression group died from pulmonary embolism 17 days postoperatively. CONCLUSIONS: With the present study protocol, mechanical foot pump compression failed to be as efficient as LMWH prophylaxis.

Magnetic resonance imaging and MR angiography of endoluminally treated abdominal aortic aneurysms.

OBJECTIVES: To evaluate magnetic resonance imaging (MRI) with gadolinium-based contrast medium-enhanced MR angiography (MRA) for the follow-up of endoluminally treated abdominal aortic aneurysms. DESIGN: MRI/MRA, angiography and computed tomography (CT) were performed 1 month after endoluminal stent-graft placement. MRI/MRA was repeated at 6 and 12 months and angiography and CT were added to confirm unexpected findings. MATERIALS: Fifteen male patients with endoluminally treated abdominal aortic aneurysms. METHODS: MRI with MRA, spiral CT with transverse images and angiography were performed. RESULTS: MRI/MRA demonstrated changes of stent-graft morphology, aortic neck- and aneurysmal diameter, stent-graft blood flow, stent-graft leakage, blood flow in lumbar arteries, intra-aneurysmal thrombus, periaortic inflammation and vertebral body infarction. For most of these features MRI/MRA provided more information than angiography and/or CT. MRI was the only method demonstrating thrombus reorganisation and vertebral body infarction. CONCLUSIONS: MRI with MRA provides the relevant information needed for follow-up of endoluminally treated abdominal aortic aneurysms (AAA). This may be the method of choice because of its use of contrast media with very low nephrotoxicity, lack of ionising radiation and non-invasiveness.

[Endovascular technique in aortic aneurysm. A promising alternative to open surgery]. / Endovaskulär teknik vid aortaaneurysm. Lovande alternativ till öppen kirurgi.

The article consists in a presentation of endovascular surgery for abdominal aortic aneurysm repair in 23 cases. Two cases required conversion to open surgery, but the procedure could be completed in the remaining 21 cases, with a current duration of follow-up of up to 30 months. There was early leakage in one case, and late leakage in five cases. Late conversion has been necessary in three instances, and supplementary endovascular measures have been required in a further two instances. All complications have occurred in those cases operated during the first half of the study period. Modification of the endoprosthesis used and increasing skill have reduced both operation time and the complication rate. Intensive care is no longer required, and the median duration of hospitalisation is three days. Follow-up with magnetic resonance imaging has yielded new and important information.

Effect of hemithorax irradiation alone or combined with doxorubicin and cyclophosphamide in 47 pleural mesotheliomas: a nonrandomized phase II study.

In order to assess the value of radiotherapy in the treatment of pleural mesotheliomas, we studied tumour response and survival after hemithorax irradiation alone (RT), or radiotherapy combined with doxorubicin and cyclophosphamide chemotherapy (RTCT). Forty seven patients with pleural mesotheliomas received irradiation of the diseased hemithorax at 8 MV (megavolt) photons to a total dose of 40 Gy, administered in 20 daily fractions of 2 Gy for 5 days a week. One month after RT, patients aged < or = 70 yrs with a good performance status were offered supplementary chemotherapy (CT) with doxorubicin 30 mg.m-2 body surface on Day 1 and Day 8, combined with cyclophosphamide 600 mg.m-2 on Day 1, in cycles of 21 days. Tumour response was evaluated by computed axial tomography (CAT) before and 1 month after RT and/or CT. Only 3 of the 47 (95% confidence interval (95% CI)-0.6-13%) irradiated tumours responded with a partial response (PR). In 31 patients treated with RT alone, one PR was observed; whereas, in the combined treatment group, 2 out of 16 responded with PR to RT. CT with doxorubicin and cyclophosphamide induced only 2 out of 16 PRs (95% CI -3.4-28.4%), and the combined treatment consisting of RT followed by CT induced 2 out of 16 PRs. The median survival following the initiation of RT was 7 months in all patients (n = 47), 6 months in the RT group (n = 31), and 13 months in the combined RTCT group (n = 16). Chest pain, performance status and body weight were not favourably affected by the radiotherapy. We conclude that hemithorax irradiation of pleural mesotheliomas with a moderately high dose is not useful, since it produces no improvement in chest pain, few objective tumour responses and no prolongation of survival.

Dilatation of aorto-bifemoral knitted Dacron grafts after a mean implantation of 5 years.

OBJECTIVE: To evaluate the dilatation-rate of a reverse locknitted Dracon graft. EXPERIMENTAL DESIGN: Comparative study, a follow-up after 5 years. SETTING: Department of Surgery, University Hospital. PATIENTS: During 1987 to 1990, 105 patients underwent elective aorto-bifemoral bypass surgery for aorto-iliac occlusive disease. Nineteen patients received a reverse locknitted Dacron graft. During follow-up in 1993 ten patients were available for evaluation of graft-diameter. For comparison 14 patients who received a wrap knitted Dacron graft (12 collagen impregnated and two uncoated) operated during the same time period were randomly chosen. INTERVENTION: CT-scan evaluation. RESULTS: A significantly lower increase (a mean aortic body dilatation of 6.8%) of the graft-size was found for this reverse locknitted Dacron (p < 0.001) compared to two wrap knitted Dacron grafts (collagen impregnated and uncoated knitted Dacron) (31.0% and 37.8% respectively). At the femoral level mean dilatation rates of respectively, 2.5%; 23.8% and 31.7% were found. Mural thrombus was observed in three grafts. No false aneurysms, graft degradation or graft occlusions were observed. CONCLUSION: It was concluded that reverse locknitted Dacron dilates to a minimum, however, further studies are needed to evaluate the relation of graft-composition/structure and dilatation.

Biological responses differ considerably between endovascular and conventional aortic aneurysm surgery.

OBJECTIVES: To determine the inflammatory responses in endovascular abdominal aortic aneurysm (AAA) repair and their relation to clinical findings. DESIGN: Prospective non-randomised study. SETTING: University Hospital, Department of Surgery. PATIENTS AND METHODS: Seven patients treated with an endoluminal procedure (AAA-E) and seven patients undergoing conventional surgery (AAA-C) were included. Inflammatory parameters were assessed by measurements of the cytokines interleukin (IL)-1 beta, IL-6, IL-8 and Tumour Necrosis Factor-alpha (TNF-alpha); analyses of complement proteins C1q, C4, C3, C5a and Terminal Complement Complexes (TCC); haematologic parameters and determination of C-reactive protein (CRP). RESULTS: In six of seven patients in the AAA-E group blood pressure decreases were recorded during introduction of the device. IL-6 and CRP levels were found to be significantly higher in AAA-C patients compared to the AAA-E group. On the other hand, high TNF-alpha levels were recorded in the AAA-E group. Less consumption of the complement proteins C1q, C4 and C3 was observed in AAA-E compared to AAA-C patients. Increased C5a levels were recorded in the AAA-C group, whereas only slight fluctuations were noticed in the AAA-E group. TCC levels were unchanged in both groups. CONCLUSION: Endovascular aortic aneurysm repair induced a significant inflammatory response, mainly involving TNF-alpha and differing from the findings during open AAA repair. These inflammatory responses were probably related to blood pressure decreases during the procedures. On the other hand, conventional repair induced responses related to the more extensive surgical trauma and reperfusion injury.

Iodixanol in femoral arteriography. A randomized, double-blind, phase III, parallel study with iodixanol 270 mg I/ml and iohexol 300 mg I/ml.

Two contrast media, iodixanol (Visipaque, Nycomed) 270 mg I/ml and iohexol (Omnipaque, Nycomed) 300 mg I/ml, were compared in femoral arteriography, in 147 patients. Both contrast media were diagnostically effective for use in femoral arteriography, without any significant difference. Pain was reported in connection with injection of iohexol by 36% of the patients, after injection of iodixanol none reported pain. Seventy-two percent of the patients in the iodixanol group reported a sensation of warmth in connection with contrast injection versus 90% in the iohexol group. The average intensity of the warmth was greater with iohexol than with iodixanol. Fourteen percent of patients in the iodixanol group and 1% in the iohexol group reported one or more subjective adverse events.

Iodixanol--a new nonionic dimer--in aortofemoral angiography.

In 26 patients iodixanol, a new nonionic dimer, isotonic to blood in all concentrations, was used as contrast medium in aortofemoral angiography. Half of the patients received contrast medium in a concentration of 270 mg I/ml and the other half 320 mg I/ml. The aim of the trial was to evaluate the safety and tolerability of iodixanol and the radiographic efficacy of the two concentrations. The degree of discomfort, adverse events, changes in serum chemistry parameters, and diagnostic information were assessed. There were no changes or trends of clinical importance in serum chemistry parameters. The side effects were mild and consisted mostly of some sensation of warmth of short duration. No other adverse events were seen. The overall radiographic efficacy did not show any significant difference between the two concentrations. This indicates that iodixanol is safe and well tolerated when used in adult femoral angiography.

Digital luminescence radiography using a chest phantom. Comparison between radiographs displayed on monitor and hard-copy.

Ninety-eight digital radiographs of a chest phantom with simulated tumors in the mediastinum and left lung and a pneumothorax-simulation in the right hemithorax were compared with the corresponding examinations saved on optical disk and viewed on a 1,000-line monitor. The examinations were reviewed by 7 radiologists with different experience, and receiver operating characteristic (ROC) curves were constructed. There was no significant difference between the hard-copy and the monitor results. A significant interobserver difference was seen only with the low attenuating 6 mm "tumor" and then only between the observer with the highest and the one with the lowest scores.

Surgical treatment versus thrombolysis in acute arterial occlusion: a randomised controlled study.

Thrombolytic treatment has been tried in various forms for acute limb ischaemia with varying degrees of success but is also often accompanied by bleeding problems. The present investigation compares the effect of surgical thrombectomy (TE) and thrombolysis (TL) using recombinant tissue plasminogen activator (rt-PA). Twenty patients with a need for intervention owing to ischaemia lasting more than 24 h but less than 14 days were included. Patients randomised to TE were operated under epidural anaesthesia and patients in the TL group received 30 mg rt-PA during a 3 h period through a catheter placed into the thrombus and advanced as lysis was achieved. Thrombectomy resulted in an immediate restitution of blood flow in six out of nine cases, in three cases a bypass procedure was performed, and one of these failed with a resultant amputation. Thrombolysis gave a good primary result in six cases which lasted in four of them. Three had a subsequent percutaneous transluminal angioplasty. Partial lysis was seen in two cases and a further two failed. Five went to surgery with three bypass and two fogarty procedures being necessary. There was no hospital mortality and there were no bleeding complications due to the rt-PA treatment in this series. In 19 out of 20 patients the circulation was re-established. Appropriate handling of acute ischaemic conditions implies the use of both thrombolysis and appropriate surgical procedures, including distal bypass grafts.