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| 2. |
- Engellau, Lena, et al.
(författare)
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Long-term results after endovascular repair of abdominal aortic aneurysms with the Stentor and Vanguard stent-graft.
- 2004
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Ingår i: Acta Radiologica. - : SAGE Publications. - 1600-0455 .- 0284-1851. ; 45:3, s. 275-283
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 3. |
- Engellau, Lena, et al.
(författare)
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Magnetic resonance imaging and MR angiography of endoluminally treated abdominal aortic aneurysms
- 1998
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Ingår i: European Journal of Vascular and Endovascular Surgery. - 1532-2165. ; 15:3, s. 212-219
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 4. |
- Engellau, Lena, et al.
(författare)
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Measurements before endovascular repair of abdominal aortic aneurysms : MR imaging with MRA vs. angiography and CT
- 2003
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Ingår i: Acta Radiologica. - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 44:2, s. 177-184
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 6. |
- Engellau, Lena, et al.
(författare)
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MR evaluation ex vivo and in vivo of a covered stent-graft for abdominal aortic aneurysms: ferromagnetism, heating, artifacts, and velocity mapping
- 2000
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Ingår i: Journal of Magnetic Resonance Imaging. - 1522-2586. ; 12:1, s. 112-121
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 7. |
- Engellau, Lena
(författare)
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MRI with MR Angiography in Endovascular Repair of Abdominal Aortic Aneurysms
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this study was to evaluate MRI with contrast enhanced MR angiography (MRI/CE MRA) as imaging method before and after endovascular repair of abdominal aortic aneurysms (AAA). A 1.5 T scanner was used for all examinations. In this prospective study 26 consecutive patients were included. Follow-up was performed between February 1995 and May 2002 (median follow-up; 36 months, range 8-84 months). In Paper I, we assessed the value of MRI/CE MRA as follow-up method. MRI/CE MRA provided the relevant information. MRI was the sole method demonstrating intramural thrombus organization and vertebral body infarction. In Paper II, we evaluated MR safety; ferromagnetism and heating of a nitinol stent-graft. Image artefacts were also evaluated on MRI/CE MRA and CT. In addition, an extended MR protocol including velocity mapping was assessed. MRI in a 1.5 T system may be performed safely in patients with the nitinol stent-graft (Vanguard). MRI/CE MRA provided diagnostic image information with only minor metal artefacts. Image evaluation on CT can be disturbed at the graft limb junction and graft bifurcation by the beam hardening artefacts. MR velocity mapping did not provide additional information. In Paper III, we compared measurements for stent-graft planning. MRI/CE MRA was compared with DSA and CT. The MRA post processing techniques MIP and VRT were also compared. The length measurements obtained with MRA-MIP were significantly shorter, but probably more correct, than those obtained with DSA. The diameter measurements obtained with MRI/CE MRA were more variable. Improvements of the MRA technique and a standardized determination of the vessel boundaries are needed for more reliable diameter measurements. In Paper IV, we compared costs of follow-up with MRI/CE MRA with costs of follow-up with CT with DSA, or CTA. The cost analysis included a risk analysis of contrast media induced nephropathy. MRI/CE MRA can be cost-effective for follow-up depending on the risk of contrast media induced nephropathy for CT with DSA, or CTA. In Paper V, we presented mid-term results with the Stentor and Vanguard stent-grafts assessed with MRI/CE MRA. Complications and secondary interventions were common. Long-term follow-up is mandatory. This study has shown that for MR-compatible stent-grafts, MRI/CE MRA could be the method of choice for follow-up of endovascularly repaired AAA. For patients with pre-existing renal insufficiency MRI/CE MRA should be the method of choice.
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| 10. |
- Kristjansson, Axel, et al.
(författare)
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Reflux, stricture and glomerular filtration rate after two antireflux techniques in continent urinary reconstruction using the right colon
- 1997
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Ingår i: Scandinavian Journal of Urology and Nephrology. - : Informa UK Limited. - 0036-5599 .- 1651-2065. ; 31:5, s. 425-429
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Tidskriftsartikel (refereegranskat)abstract
- In the present study the incidence of reflux, stricture formation and changes in glomerular filtration rate in patients with the submucosal tunnel or the Camey-Le Duc technique of ureteric implantation into the caecum/detubularized right colon used for continent cutaneous diversion/orthotopic bladder substitution was investigated. Reflux was found in two renal units and ureterointestinal stenosis occurred in five renal units after submucosal tunnel ureteric implantation. After Camey-Le Duc ureteric implantation, one renal unit showed reflux and none had stenosis of the ureterointestinal anastomosis during follow-up. Mean glomerular filtration rate (ml/min/1.73 m2) fell from 98 to 85 in the submucosal tunnel group and from 88 to 81 in the Camey-Le Duc group after mean follow-ups of 9 and 5 years, respectively. Both methods of ureteric implantation in this study were effective in preventing reflux, and renal function was well preserved in both groups. The absence of ureterointestinal strictures in the Camey-Le Duc group is encouraging and indicates that this is a reliable method for reflux prevention.
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