| 1. |
- Malina, Martin, et al.
(author)
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Endovascular AAA exclusion: will stents with hooks and barbs prevent stent-graft migration?
- 1998
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In: Journal of Endovascular Surgery. - 1074-6218. ; 5:4, s. 310-317
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Journal article (peer-reviewed)abstract
- PURPOSE: To investigate if stents with hooks and barbs will improve stent-graft fixation in the abdominal aorta. METHODS: Sixteen- to 24-mm-diameter Dacron grafts were deployed inside cadaveric aortas. The grafts were anchored by stents as in endovascular abdominal aortic aneurysm repair. One hundred thirty-seven stent-graft deployments were carried out with modified self-expanding Z-stents with (A) no hooks and barbs (n = 75), (B) 4 5-mm-long hooks and barbs (n = 39), (C) 8 10-mm-long, strengthened hooks and barbs (n = 19), or (D) hooks only (n = 4). Increasing longitudinal traction was applied to determine the displacement force needed to extract the stent-grafts. The radial force of the stents was measured and correlated to the displacement force. RESULTS: The median (interquartile range) displacement force needed to extract grafts anchored by stent A was 2.5 N (2.0 to 3.4), stent B 7.8 N (7.4 to 10.8), and stent C 22.5 N (17.1 to 27.9), p < 0.001. Both hooks and barbs added anchoring strength. During traction, the weaker barbs were distorted or caused intimal tears. The stronger barbs engaged the entire aortic wall. The radial force of the stents had no impact on fixation, while aortic calcification and graft oversizing had marginal effects. CONCLUSIONS: Stent barbs and hooks increased the fixation of stent-grafts tenfold, while the radial force of stents had no impact. These data may prove important in future endograft development to prevent stent-graft migration after aneurysm exclusion.
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| 2. |
- Malina, Martin, et al.
(author)
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Late aortic arch perforation by graft-anchoring stent: complication of endovascular thoracic aneurysm exclusion
- 1998
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In: Journal of Endovascular Surgery. - 1074-6218. ; 5:3, s. 274-277
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Journal article (peer-reviewed)abstract
- PURPOSE: To describe a fatal case of late aortic perforation by an endograft-anchoring stent. METHODS AND RESULTS: A 69-year-old woman presented 2 years after thoracoabdominal aneurysm repair with a 9-cm dilatation of the descending thoracic aorta proximal to the conventional aortic graft. A 38-mm Dacron graft with multiple Gianturco Z-stents sutured inside was placed transluminally across the aortic arch such that part of the uncovered portion of the proximal stent was partially across the left subclavian orifice. Four months later, the patient died from massive hemorrhage. Autopsy showed that the uncovered portion of the proximal stent had perforated the aortic arch. CONCLUSIONS: This case stresses the need for low-profile stent-grafts and smaller, more flexible introducer systems. Anchoring stents must be flexible, less traumatic, and strong enough to create a watertight seal even in tortuous vessels. To avoid aortic arch damage by thoracic stent-grafts, the proximal stent should be fully covered by the fabric.
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| 3. |
- Sonesson, Björn, et al.
(author)
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Dilatation of the infrarenal aneurysm neck after endovascular exclusion of abdominal aortic aneurysm
- 1998
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In: Journal of Endovascular Surgery. - 1074-6218. ; 5:3, s. 195-200
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Journal article (peer-reviewed)abstract
- PURPOSE: To determine the fate of the infrarenal aneurysm neck and suprarenal aorta after endovascular exclusion of abdominal aortic aneurysms (AAAs). METHODS: Thirty-four patients underwent endovascular AAA repair between January 1994 and December 1995 using custom-made stent-grafts constructed from polyester graft material and modified self-expanding Gianturco Z-stents sutured to the graft orifices. Thirty-one patients were available for follow-up. Pre- and postimplantation diameters were measured using spiral computed tomography in the infrarenal aneurysm neck and the suprarenal aorta at the level of the superior mesenteric artery (SMA). RESULTS: The mean follow-up time was 25 months. There was a significant increase of the diameter of the infrarenal aneurysm neck (+ 1.65 mm, p = 0.002), but not in the aorta at the level of the SMA (+0.52 mm, p = 0.100). There was no difference in the change in diameter in the infrarenal neck in the group with a stent adjacent to the level of measurement (n = 20) compared with the group without an adjacent stent (n = 11, p = 0.790). There was no correlation between preimplantation size of the infrarenal neck and its diameter change (r = 0.14, p = 0.488). There was no correlation (r = 0.10, p = 0.603) or association (chi-square test, p = 0.211) between aortic diameter change at the level of the SMA and the infrarenal neck. CONCLUSIONS: This investigation shows a significant dilatation of the infrarenal aneurysm neck, but not in the suprarenal aorta, after endovascular AAA repair with this device. The clinical significance of these findings is unclear. Whether such a dilatation in the infrarenal aneurysm neck may affect the long-term attachment of stent-grafts remains to be shown in the future.
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| 4. |
- Nyman, Ulf, et al.
(author)
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Kronisk mesenteriell ischemi. Endovaskulär behandling lika effektiv som öppen kirurgi
- 1998
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In: Läkartidningen. - 0023-7205. ; 95:36, s. 3785-3790
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Journal article (peer-reviewed)abstract
- Chronic mesenteric ischaemia is a rare but serious condition, which if untreated may cause death secondary to starvation or bowel infarction. As the symptoms are sometimes unspecific, its diagnosis may be delayed or missed. Although open surgical revascularisation has been the traditional treatment, a review of published reports suggests it to be associated with operative mortality rates of 6-9 per cent, and major morbidity rates of 22-26 per cent. Reports by others, and our own experience, suggest that endovascular treatment of mesenteric atherosclerotic obstructions with PTA (percutaneous transluminal angioplasty) and stenting may yield patency rates differing little from those associated with surgery, but significantly lower mortality (1.6%) and morbidity (5.6%).
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| 5. |
- Malina, Martin, et al.
(author)
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Reduced pulsatile wall motion of abdominal aortic aneurysms after endovascular repair
- 1998
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In: Journal of Vascular Surgery. - 1097-6809. ; 27:4, s. 624-631
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Journal article (peer-reviewed)abstract
- PURPOSE: The reduced size of abdominal aortic aneurysms (AAAs) after endovascular repair suggests lowered intraaneurysmal pressure. In the presence of endoleaks, the size is not decreased. Although postoperative intraaneurysmal pressure is difficult to record, the pulsatile wall motion (PWM) of aneurysms can be measured noninvasively. The aim of this study was to assess the PWM of AAAs before and after endovascular repair and to relate the change in the PWM to aneurysmal size and presence of endoleaks. METHODS: Forty-seven patients underwent endovascular repair of an AAA. The aneurysm diameter and PWM were measured with the use of ultrasonic echo-tracking scans preoperatively; at 1, 3, and 6 months; and thereafter biannually. Fifteen aneurysms developed endoleaks, whereas 32 were completely excluded. The leaks were characterized with the use of computed tomographic scanning and angiography. Median follow-up was 12 months (interquartile range, 5 to 24 months). RESULTS: The preoperative PWM of the aneurysms was 1.0 mm (range, 0.8 to 1.3 mm). After complete endovascular exclusion, the PWM was 25% (range, 16% to 37%) of the preoperative value (p < 0.001), and aneurysm diameter decreased by 8 mm (range, 6 to 14 mm) (p < 0.001). After 18 months, no further diameter reduction occurred. In three patients without endoleaks but with enlarging aneurysms, the postoperative PWM showed less reduction (p < 0.05). Aneurysms with endoleaks showed no diameter decrease, and the postoperative PWM was 50% higher than that in the totally excluded cases (p < 0.01). In five patients with transient endoleaks, the PWM was reduced after leakage ceased (p < 0.05). Leaks of various sources displayed similar PWM. CONCLUSION: The size and PWM of aneurysms are reduced after endovascular repair. The diameter reduction may cease after 1.5 years. Endoleaks are associated with higher PWM than expected. Pressure may be transmitted without evidence of leaks.
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| 6. |
- Resch, Tim, et al.
(author)
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Persistent collateral perfusion of abdominal aortic aneurysm after endovascular repair does not lead to progressive change in aneurysm diameter
- 1998
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In: Journal of Vascular Surgery. - 1097-6809. ; 28:2, s. 242-249
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Journal article (peer-reviewed)abstract
- PURPOSE: To differentiate between the phenomenon of collateral perfusion from a side branch versus graft-related endoleaks after endovascular repair of abdominal aortic aneurysms (AAA), with respect to aneurysm size and prognosis. METHODS: We successfully treated 64 AAA patients with endovascular grafting. We followed all the patients postoperatively with spiral computed tomography at one, three, six and 12 months, and biannually thereafter. We measured aneurysm diameters preoperatively and postoperatively. We calculated preoperatively the relation of maximum aortic diameter (D) to the thrombus-free lumen diameter (L) expressed as an L/D ratio. Median follow-up was 15 months. RESULTS: Sixteen patients had collateral perfusion during follow-up. We successfully treated two patients with embolization. One patient showed resolution of collateral perfusion after we stopped warfarin treatment. Two patients died of unrelated causes during follow-up. One patient was converted to surgical treatment, and two patients showed spontaneous resolution of their collateral perfusion. The group of patients with perfusion showed no statistically significant change of their aortic diameter on follow-up. The group of patients without perfusion showed a median decrease in aortic diameter of 8mm (p < 0.0001) at 18 months postoperatively. The group of patients with perfusion had significantly less thrombus in their aneurysm sac preoperatively than the group without perfusion, as expressed by the L/D ratio (mean L/D 0,61 versus 0,78, respectively; p=0.0021.) CONCLUSION: There was no significant increase in aortic diameter on an average 18 months postoperatively despite persistent collateral perfusion. This may indicate a halted disease progression in the short term. Embolization of collateral vessels is associated with risk of paraplegia. We recommend a conservative approach with close observation if aneurysm diameter is stable.
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| 7. |
- Syk, Ingvar, et al.
(author)
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Postoperative fever, bowel ischaemia and cytokine response to abdominal aortic aneurysm repair--a comparison between endovascular and open surgery
- 1998
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In: European Journal of Vascular and Endovascular Surgery. - 1532-2165. ; 15:5, s. 398-405
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Journal article (peer-reviewed)abstract
- OBJECTIVES: To study bowel ischaemia in transfemorally placed endoluminal grafting (TPEG) for abdominal aortic aneurysms, and any relation to cytokine response or postoperative fever. DESIGN: Prospective not randomised. University hospital setting. MATERIAL: Fourteen cases of conventional surgery and 23 cases of endovascular technique for infrarenal abdominal aortic aneurysm repair. METHODS: Tonometry was used for sigmoid colon pH, and ELISAs for serum IL-6. RESULTS: Mucosal pH in the sigmoid colon fell significantly during clamping and reperfusion in both groups. Lowest measured sigmoid colon pH was 7.10 in the open group, compared to 7.22 in the TPEG group (p < 0.05). The IL-6 levels in serum peaked after 4 h of reperfusion; 249 pg/ml in the open group, compared to 89 pg/ml in the TPEG group (p < 0.05). High levels of IL-6 in the postoperative period and persisting low sigmoidal pH were associated with serious complications. Postoperative temperature did not differ significantly between the groups, and no significant correlation could be found with sigmoid colon pH or IL-6 levels. CONCLUSIONS: The less pronounced perioperative bowel ischaemia in TPEG patients indicates an advantage of the TPEG technique. Splanchnic ischaemia was not related to postoperative fever, nor the IL-6 or TNF response.
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| 8. |
- Greenberg, R, et al.
(author)
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Aggressive treatment of acute limb ischemia due to thrombosed popliteal aneurysms
- 1998
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In: European Journal of Radiology. - 1872-7727. ; 28:3, s. 211-218
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Journal article (peer-reviewed)abstract
- OBJECTIVE: The absence of infra-popliteal runoff in patients with acute limb ischemia and thrombosed popliteal aneurysms carries a high risk of amputation. A combined treatment method involving thrombolysis and surgery is reported. MATERIAL AND METHODS: Information regarding six patients was reviewed. Ankle brachial indices and degree of ischemia were recorded. All patients underwent digital subtraction angiography. In five patients thrombus dissolution was achieved using a combination of mechanical and pharmacologic therapy. One patient was judged incapable of withstanding any delay in reperfusion and was treated with isolated limb perfusion using a thrombolytic agent. All patients underwent surgical revascularization. Follow-up (1-3 years) consisted of duplex examinations at 6 months and yearly thereafter. RESULTS: Five patients had no measurable ankle brachial index (ABI), while one patient had an ABI of 0.4. Initial angiography noted all patients to have no runoff in continuity to the pedal arch. Following thrombolytic therapy, an adequate bypass vessel was noted in all cases, with reconstitution of the plantar arch in five patients. Distal revascularizations included one peroneal, and five below knee popliteal arterial bypasses. Fasciotomies were performed in four of the six patients. There were no amputations. One patient developed a persistent foot drop. Two patients developed bypass grafts occlusions; one of which required therapy. CONCLUSION: The pre-operative use of thrombolytic therapy is a safe and effective method to achieve limb salvage in this patient population. Patients must be capable of withstanding an additional period of ischemia allowing for reconstitution of distal runoff. Isolated limb perfusion is of use when a delay to reperfusion cannot be tolerated.
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| 9. |
- Nyman, Ulf, et al.
(author)
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Endovascular treatment of chronic mesenteric ischemia: report of five cases
- 1998
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In: Cardiovascular and Interventional Radiology. - : Springer Science and Business Media LLC. - 1432-086X .- 0174-1551. ; 21:4, s. 305-313
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Journal article (peer-reviewed)abstract
- PURPOSE: To evaluate the midterm results of percutaneous transluminal angioplasty (PTA) and stent placement in stenotic and occluded mesentesic arteries in five consecutive patients with chronic mesenteric ischemia. METHODS: Five patients with 70%-100% obliterations of all mesenteric vessels resulting in chronic mesenteric ischemia (n = 4) and as a prophylactic measure prior to abdominal aortic aneurysm repair (n = 1) underwent PTA of celiac and/or superior mesenteric artery (SMA) stenoses (n = 2), primary stenting of ostial celiac occlusions (n = 2), and secondary stenting of a SMA occlusion (n = 1; recoil after initial PTA). All patients underwent duplex ultrasonography (US) (n = 3) and/or angiography (n = 5) during a median follow-up of 21 months (range 8-42 months). RESULTS: Clinical success was obtained in all five patients. Asymptomatic significant late restenoses (n = 3) were successfully treated with repeat PTA (n = 2) and stenting of an SMA occlusion (n = 1; celiac stent restenosis). Recurrent pain in one patient was interpreted as secondary to postsurgical abdominal adhesions. Two puncture-site complications occurred requiring local surgical treatment. CONCLUSIONS: Endovascular techniques may be attempted prior to surgery in cases of stenotic or short occlusive lesions in patients with chronic mesenteric ischemia. Surgery may still be preferred in patients with long occlusions and a low operative risk.
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