[Stent-graft implantation in the thoracic aorta. Results of an interdisciplinary survey in Germany]. / Thorakale Aorten-Stentgraftimplantation. Ergebnisse einer interdisziplinären Umfrage in Deutschland.

BACKGROUND AND OBJECTIVE: Endovascular stent-graft placement is emerging as a novel therapeutic option in patients with disease of the descending thoracic aorta. Quality standards for performing stent-graft procedures as well as for pre- and postoperative patient management are lacking, so far. It was the aim of this present survey to assess the current therapeutic standard of thoracic aortic stent-graft placement in Germany. METHODS: In a nationwide survey, a total of 206 vascular surgical, radiologic, cardiologic, and cardiothoracic surgical departments were contacted. Data concerning preoperative procedure planning, logistics, practical/technical issues of stent-graft placement, and postoperative patient management were evaluated using a standardized questionnaire comprising 29 items. Data analysis was performed using univariate analysis. RESULTS: 184 (89.3 %) of the 206 departments participated in the survey. Of these, 71 centers reported intending to perform or having performed thoracic aortic stent-graft placement. The survey overall represents 2267 endovascular stent-graft procedures performed in Germany between 1997/98 and 2003. On average, 7.4 stent-graft procedures/year were performed by each center, with half the centers performing fewer than 5 procedures/year. Thoracic aortic aneurysms was the main indication for endovascular stent-graft placement, followed by aortic dissection. There were significant differences between the different medical specialties which perform stent-graft procedures with respect to indications, choice of preoperative and intraoperative imaging methods, and technical equipment. There was strong agreement between the different centers concerning the necessity of a life-long follow-up after stent-graft placement, with computed tomography being the preferred imaging technique (90 % of centers). CONCLUSION: The present survey documents an increasing use of endovascular stent-graft placement in patients with disease of the descending thoracic aorta. There were differences regarding the technical execution of this procedures between specialties with respect to indication, procedure planning, and practical-technical aspects of stent-graft placement.

[An unusual foreign body in the upper gastrointestinal tract causing nonspecific abdominal pain]. / Ungewöhnlicher Fremdkörper im oberen Gastrointestinaltrakt als Ursache eines unklaren Abdomens.

The risk of penetration of vena cava filters through the wall of the vena cava is estimated to be as high as 25%, although clinical symptoms are observed far less frequently in patients with this complication. Due to the close relationship between vena cava and duodenum, the latter can be injured by dislocated filters. We describe the presentation, evaluation, and treatment of a patient with a cava filter protruding into the duodenum, and we review the literature.

Endovascular exclusion of thoracic aortic aneurysms: mid-term results of elective treatment and in contained rupture.

PURPOSE: The purpose is to present results of endovascular exclusion (stent-graft treatment) of aneurysms of the descending thoracic aorta both in elective cases and in emergencies. METHODS: Indications for stent-graft treatment were dependent on multislice angio-CT evaluation revealing a proximal neck of at least 10 mm between the left common carotid artery and the onset of aneurysm. All stent grafts were inserted in the operating room; 43 transfemoral, 2 transiliac. The stent grafts used were Corvita, Stenford, Vanguard, AneuRx, Talent, and Excluder. Deployment was achieved under fluoroscopic control, endoleaks were checked for with D S A on the operating table and postoperatively by angio-CT. Long-term follow-up consisted of evaluation with angio-CT after 6 and 12 months, and from there on once a year and with plain chest X-rays. Follow-up was achieved in all patients. RESULTS: Mean follow-up is 21 months (1-66); 30-day mortality is 3/45, no permanent neurologic deficit. Thirty patients were treated electively, 15 with contained rupture. Left subclavian artery overstenting proved to be necessary in 12 patients for proper proximal sealing of the aneurysm, type I endoleaks were observed in 10 patients, one early conversion, 7 proximal extension cuffs, one sealed spontaneously, one still at risk. Among patients where LSA had been overstented only one wanted a transposition, all others did well without left-hand ischemia or subclavian steal syndrome. CONCLUSION: Endovascular treatment is less invasive and has reasonable mortality and morbidity but is limited to well-defined morphologies. Mid-term results are promising but it has to be observed whether these will translate into long-term durability.

Treatment of thoracoabdominal aortic aneurysms with a combined endovascular and surgical approach.

AIM: The conventional approach for the repair of thoracoabdominal aneurysms remains complex and demanding and is associated with substantial morbidity and mortality. Moreover, in cases of reoperation the impact can be dramatic either in survival or in quality of life of the patients, albeit the use of adjuncts. A combined endovascular and surgical approach with retrograde perfusion of visceral and renal vessels has been realized in order to minimize intraoperative and postoperative complications. METHODS: Within an experience of 231 aortic stent-grafts between 1995-2000, 4 of the patients with thoracoabdominal aneurysms were treated with a combined endovascular and surgical approach. Three procedures were electively conducted and 1 on emergency basis. Two women, 59 and 68 years old, and 2 men, 68 and 73 years old (maximum aneurysm's diameter was 10, 6, 8 and 9 cm, respectively) were operated with the combined method (the first 2 patients had a previous open repair of a thoracoabdominal aneurysm). The surgical approach was executed in all patients without thoracotomy or re-do retroperitoneal exposure. Revascularization of renal, superior mesenteric (and celiac in 2 cases) arteries was accomplished via transperitoneal bypass grafting. Aneurysmal exclusion was performed by stent-graft deployment. RESULTS: The entire procedure was technically successful in all patients. The 1(st) patient was discharged 6 weeks after the operation, while the postoperative studies revealed the patency of the vessels and no evidence of leak or secondary rupture of the aneurysm; the patient died 3 months after the repair, due to rupture of an aneurysm of the ascending aorta. In the 2(nd) patient, 30 months after the operation, spiral-CT scanning revealed distinct shrinkage of the aneurysm, no graft migration or endoleak and patency of all revascularized vessels. The 3(rd) patient died on the 6th postoperative day due to multiorgan failure after having developed ischemic-related pancreatitis, albeit the successful combined repair. The 4(th) patient followed an uneventful course. No patient experienced any temporary or permanent neurological deficit. CONCLUSION: The combined endovascular and surgical approach is feasible, without cross-clamping of the aorta and with minimized ischemia time for renal and visceral arteries, and seems the appropriate strategy for high risk and previously operated, with a thoracoabdominal trans-diaphragmatic approach, patients.

Endovascular treatment in diseases of the descending thoracic aorta: 6-year results of a single center.

OBJECTIVE: The purpose of this study was to evaluate endovascular treatment in diseases of the descending thoracic aorta. MATERIAL AND METHODS: This study was designed as a single center's (university hospital) experience. Over a 6-year period (1995 to 2001), thoracic endografts were placed in 74 patients with a diseased descending thoracic aorta who were at high risk for conventional open surgical repair: 34 had atherosclerotic aneurysms, six had posttraumatic aneurysms, 14 had type B dissection with aneurysmal dilatation of the false lumen, 12 had isthmic transections from blunt trauma, five had thoracoabdominal aneurysms (treated with a combined procedure), two had aortic coarctation, and one had an aortobronchial fistula. Twenty-six procedures (35.1%) were conducted as emergencies, and 48 (64.9%) were elective. The feasibility of endovascular treatment and sizing of stent grafts were determined with preoperative spiral computed tomography and intraoperative angiography. RESULTS: Endovascular operations were completed successfully in all 74 patients; postprocedural conversion to open repair was necessary in three cases. The overall 30-day mortality rate was 9.5% (seven deaths). Temporary neurologic deficits developed in two patients; not one patient had permanent paraplegia. The primary endoleak rate was 20.3% (15 patients). The mean follow-up period was 22 months (range, 3 to 72 months). Five deaths occurred in the follow-up period, and three patients needed secondary conversion to open repair 2, 3, and 14 months after initial endografting. CONCLUSION: Endoluminal treatment in diseases of the thoracic descending aorta is feasible and may offer results as good as the open method.

[The contribution of MRI to the detection of endovascular aneurysm repair]. / Wertigkeit der MRT in der Erkennung von Leckagen nach endovaskulärer Aneurysmaausschaltung.

PURPOSE: Evaluation of MR-imaging in the follow-up of patients after endovascular repair of abdominal aortic aneurysms concerning detection of endoleaks. MATERIALS AND METHODS: In the postoperative follow-up after endovascular repair of aortic aneurysms, 10 consecutive patients (mean age: 68 years) were suspected to have an endoleak by helical CT and were scheduled for conventional angiography, preceded by supplemental MR-imaging to confirm or refute the diagnosis. The images of helical CT and MRI were evaluated by two independent readers concerning leak, feeding vessel and artifacts. RESULTS: The follow-up MRI was able to detect all endoleaks (type 1 endoleak, n = 7; type 2 endoleak, n = 3) compared to all but one detected by helical CT. Of the 10 patients with an endoleak, MR-angiography visualized the feeding vessel in 7 patients and CT in one patient. MRI did show fewer metal artifacts from the stent wire than CT. For the visualization of feeding vessels and endoleaks, MRA achieved statistically significant superiority. In a single case, helical-CT was not reliable because of strange metal artefacts after previous coil embolization. CONCLUSION: MRI is comparable to helical-CT in detecting endoleaks and superior to CT in demonstrating the anatomy of the feeding vessel after endovascular repair of aortic aneurysms. The major advantages are fewer artifacts after coil embolization and absent radiation exposure.

[Endoluminal stent-assisted management of acute traumatic aortic rupture]. / Endoluminale stentgestützte Versorgung der akuten traumatischen Aortenruptur.

INTRODUCTION: Open repair of traumatic descending aortic rupture in trauma patients is associated with a mortality rate of 15-20% and a risk of paraplegia of 5-10%. Stent grafts may decrease the morbidity and mortality of these procedures by reducing blood loss and aortic occlusion time. MATERIAL AND METHODS: Within an experience of 52 thoracic stent grafts between 1995 and 2000, eight men with acute traumatic descending aortic rupture were conducted as emergencies without delay. All patients had severe coinjuries and presented with acute onset of mediastinal hematoma due to periaortic bleeding. Successful stent deployment was performed in all eight patients, seven of them required one single stent and one required two stents; within the aortic arch all stents covered the origin of the left subclavian artery. RESULTS: All acute aortic ruptures were sealed successfully. One death occurred in hospital from multiorgan failure. There was no conversion to open repair. Not one patient's condition resulted in temporary or permanent paraplegia. One endoleak required treatment by overstenting. Two patients required secondary surgical procedures (iliac access complication and revascularisation of left subclavian artery). Mean follow-up was 11 months (1-21 months). Mid-term freedom from endoleak was monitored in all patients. CONCLUSION: The treatment of acute traumatic descending aortic rupture with an endovascular approach is feasible and safe and may offer the best means of therapy. The mortality rate and risk of paraplegia are low compared with the risks associated with open operations. Continued surveillance is essential.

[What is the cost of vascular operations? A prospective cost analysis of conventional and combined endovascular interventions]. / Was kosten gefässchirurgische Operationen? Eine prospektive Kostenanalyse konventioneller und kombiniert endovaskulärer Eingriffe.

Current and future legislation demand improved efficiency in the medical services. The aim of this study was to analyse the costs of vascular surgery in order to reveal potential ways of reducing expense. Taking into account the staff, equipment and operating theatre supplies, we analyzed 58 elective operations comprising 47 conventional and 11 combined endovascular procedures. The mean overall costs calculated for the different operations were: 5.269 DM for a transfemoral embolectomy (n = 3), 8.504 DM for a patchplasik of the profunda arteria (n = 8), 10.265 DM for a femoro-popliteal bypass with a prosthesis (n = 6)--13.180 DM with a vein (n = 2), 9.864 DM for conventional iliac artery reconstruction (n = 7)--iliac endovascular combined procedure (n = 4) 14.494 DM, 14.951 DM for a Y-prosthesis in case of stenosis (n = 3)--13.288 DM in case of infrarenal aortic aneurysm (IAA, n = 4), 11.954 DM for a tube prosthesis in case of IAA (n = 3), 23.571 DMY-stent prothesis for IAA (n = 5), 19.914 DM stent for a thoracic aneurysm (n = 2), 7.153 DM a carotid thrombendarterectomy (n = 6), 5.503 DM for varicosis surgery (n = 5). Because of the high cost of materials, the total outlay for combined endovascular procedures appeared to be high when compared to conventional vascular surgery. Substantial savings concerning the operation may only be achieved if facility structure and qualification of staff meets the particular requirements.

Endovascular repair of aortic rupture due to trauma and aneurysm.

OBJECTIVES: to report a single centre experience with endovascular repair of the ruptured descending thoracic and abdominal aorta. DESIGN: prospective non-randomised study in a university hospital. MATERIAL AND METHODS: between 1995 and 2000, endovascular treatment was utilised for 231 aortic repairs; in 37 cases (16%) endografting was conducted on an emergency basis for 21 ruptured infrarenal aortic aneurysms, 15 ruptured descending thoracic aortic lesions, and 1 ruptured thoracoabdominal aortic aneurysm. The feasibility of endovascular treatment and the prostheses' size were determined, based on preoperative spiral CT and intraoperative angiography, both obtained in each patient. RESULTS: endografting was successfully completed in 35 patients (95%). Primary conversion to open repair was necessary in 2 patients (5%). Postoperative 30-day mortality rate was 11% (4 deaths). No patient developed postoperative temporary or permanent paraplegia. In 2 patients (5%) primary endoleaks required overstenting and in 6 patients (16%) secondary surgical interventions were required. Mean follow-up was 19 months (1-70 months); three deaths occurred within three months postoperatively (1-year survival rate 81+/-6%). In one case, secondary conversion to open repair was necessary 14 months postoperatively. CONCLUSION: the feasibility of endoluminal repair of the ruptured aorta has been demonstrated. Endoluminal treatment may reduce morbidity and mortality, and may in time become the procedure of choice in certain centres. However, further follow-up is required to determine the long-term efficacy.

Endovascular stent-graft placement versus conventional open surgery in infrarenal aortic aneurysm: a prospective study on acute phase response and clinical outcome.

BACKGROUND: For the treatment of aortic aneurysm, stent-graft implantation is an alternative method to open surgery. There is no study comparing both methods with regard to endotoxaemia, the acute phase cascade, and clinical outcome. METHODS: In this prospective study, we enrolled 40 patients (34 males, 6 females; mean age 72.1+/-7.5 [58-92] years) with infrarenal abdominal aortic aneurysm who underwent aortic surgery. Comparable groups of patients were treated with open (n=20) or endovascular (n=20) stent-graft implantation. To characterize the inflammatory response, plasma levels of endotoxin, endotoxin-neutralizing capacity (ENC), interleukin-6 (IL-6), C-reactive protein (CRP), and white blood cell count were determined. In all patients, measurements were performed on admission, skin suture, 4 h and from the first to fifth postoperative day. As parameters for the clinical outcome, we assessed daily temperature, lung function, pain, duration of postoperative hospital stay, and morbidity. Wilcoxon rank test was used for statistical analysis. RESULTS: In both groups, a significant increase of endotoxin plasma levels and a decrease of ENC was found already after skin incision. IL-6 levels peaked 4 h postoperatively in both groups, whereas CRP rose at the first postoperative day, reaching a maximum at day 2. Conventionally operated patients had significantly higher plasma levels of endotoxin, IL-6, and CRP and lower ENC during and after surgery than patients with stent-graft implantation. Moreover, patients with endovascular stent grafting had significant less postoperative pain, less restriction of total vital capacity, a shorter hospital stay, and a lower morbidity. CONCLUSIONS: Endovascular stent grafting of infrarenal aortic aneurysm seems to be superior not only in terms of the inflammatory response but also in overall clinical outcome.

Does a postimplantation syndrome following endovascular treatment of aortic aneurysms exist?

The postimplantation syndrome (PIS) is a weakly defined condition that has been observed following endovascular treatment of aortic aneurysms; the postulated criteria include significant leukocytosis, fever, and/or coagulation disturbances. Among the factors that are supposed to contribute to this syndrome are contact activation by the stent covering with consecutive endothelial activation. Associated clinical parameters of a PIS were perioperatively monitored in the postoperative phase in a total of 69 patients with infrarenal aortic aneurysms treated with Y-stent grafts. C-reactive protein (CRP)-levels, leukocyte concentrations, and body temperature curves were directly compared to those of 50 patients undergoing conventional transperitoneal aneurysm resection. A subgroup of 10 patients of the endovascular group was compared with 13 operated-on patients with regard to an ischemia-reperfusion syndrome of the lower extremities. The mediator determinations were performed on venous (femoral vein) as well as in systemic (arterial) blood samples. The incidence of temperature values above 38 degrees C was higher in patients following endovascular treatment (72%) compared to conventionally operated-on patients (28%). CRP levels were not significantly different within the first 8 post-operative days. During open surgery, significantly higher values for lactate and lower pH levels were observed (p<0.01), as well as higher 6 keto prostaglandin F1alpha (PGF1alpha) levels. There was a short peak of PGF1alpha during eventeration of the intestine during the operative procedure that could not be detected during endovascular manipulations. The clinical and biochemical parameters do not prove the presence of a PIS following endovascular treatment of aortic aneurysms. In contrast, during open surgery the unspecific inflammatory reaction is higher, but not long-lasting. In the future, the suggested phenomenon of a decreased antiinflammatory cytokine response during endovascular surgery needs to be further examined.

Thrombus formation in aortic endografts.

PURPOSE: To examine the incidence of intraprosthetic thrombotic deposits in aortic endografts. METHODS: Transfemoral implantation of tube or bifurcated stent-grafts was performed in 82 patients (75 men; average age 67.7 years, range 25-88) for treatment of aneurysms of the abdominal (n = 73) or thoracic (n = 9) aorta in a 3.5-year period. Patients underwent 3-phase helical computed tomographic (CT) examinations at 3-month intervals. The length and cross-sectional area of any thrombotic deposits were measured from axial and 3-dimensional CT images. RESULTS: Over a 12.1-month mean follow-up, intraluminal deposits of thrombotic material were observed in 19 (23.2%) patients, all with infrarenal endografts that were predominately of a bifurcated design. The first signs of thrombus formation occurred on average 7 months postoperatively (range 1 week to 20 months). In 16 patients, nonocclusive deposits of thrombotic material were seen in the aortic segment of the endograft; a graft limb was involved in 5 patients. Three graft limbs occluded owing to kinking; no thrombus was seen on CT scans taken prior to occlusion. In 3 cases the thrombotic deposits disappeared completely from the prosthesis lumen during follow-up. CONCLUSIONS: Based on this small experience, nearly 1 in 5 patients may experience some degree of intraluminal thrombus following endovascular treatment of aortic aneurysms. Whether the deposition of thrombus is influenced by the geometry of the aortic stent-graft or by flow conditions within the prosthetic lumen must be determined in future studies.

Intraoperative, perioperative and late complications with endovascular therapy of aortic aneurysm.

PURPOSE: To describe the incidence and management of the intraoperative, perioperative and late complications of endovascular aortic aneurysm repair. METHODS: Endovascular aneurysm repair was attempted in 130 patients between October, 1995 and January, 2000. Follow-up including computed tomography (CT) was performed in the immediate postoperative period and then at 3, 6, 9 and 12 months and biannually thereafter. The median follow-up period was 20 months. RESULTS: Intra- and perioperative problems occurred in 26 patients (20%). Conversion to open surgery was required in five cases (4%). The primary technical success rate was 86%. Three patients (2%) died within the first 30 postoperative days. Late problems occurred in 28 patients (26%). These included: endoleaks (type I: 5%; type II: 10%; type III: 1%) and limb occlusion (3%). The cumulative rate of freedom from secondary intervention was in the first 65 patients treated: 86% and 65% after 1 and 3 years, respectively, and in the last 65 patients: 90% at 1 year. CONCLUSIONS: Endovascular aneurysm repair is associated with a higher complication rate than open surgery.

Endovascular grafting of traumatic aortic aneurysms in contaminated fields.

PURPOSE: To evaluate the potential of endovascular stent-grafts to treat traumatic aortic lesions in contaminated areas. METHODS: Four patients (3 women; ages 26-78 years) underwent stent-grafting to repair an aortic rupture sustained in a motorcycle accident, aortic lacerations secondary to surgical treatment of spondylitis in 2 patients, and an aortobronchial fistula following surgical thoracic aortic repair 10 years earlier. Stent-grafts (2 Corvita, 1 Talent, and 1 Vanguard) were placed endoluminally into the infected areas via a transfemoral approach. Follow-up included erythrocyte sedimentation rate, white blood count, C-reactive protein, blood cultures, and computed tomography (CT). RESULTS: The stent-grafts were successfully placed in all cases and excluded the aortic lesion. Under supportive antibiotic therapy, inflammation parameters returned to normal. CT imaging showed no evidence of paraprosthetic infection, nor were there any other complications over a follow-up that ranged from 3 to 34 months. CONCLUSIONS: Endovascular therapy may be an alternative in the acute management of aortic ruptures in the setting of infection. Long-term results are required for definitive evaluation of the method.

Influence of treatment of type II leaks on the aneurysm surface area.

OBJECTIVE: to determine whether interventional treatment of type II endoleaks leads to a decrease in aneurysm surface area. MATERIAL AND METHOD: type II endoleaks were detected in a group of 14 male patients (median age: 70.2 years) following endovascular repair of a total number of 160 infrarenal aneurysms of the abdominal aorta. The surface area of the aneurysm was determined by computed tomography (CT) pre- and postoperatively and at subsequent follow-up examinations. If type II endoleaks were documented at CT, patients underwent treatment by means of coil embolisation. RESULTS: interventional treatment resulted in successful occlusion of type II endoleaks in eight patients. One of the cases exhibited spontaneous occlusion. Occlusion was associated with an average decrease in aneurysm surface area of 3.3 cm(2)( p =0.01). In one of these patients, treatment resulted in a temporary occlusion of the endoleak, also with associated decrease in aneurysm size. After recurrence of the type II endoleak, however, the patient experienced an increase in aneurysm surface area. In the remaining four patients the type II endoleaks persisted, resulting in a non significant increase in aneurysm surface area. CONCLUSION: only complete occlusion of endoleaks results in decrease in the size of the aneurysm sac. Because of endotension and the risk of rupture we favour an early interventional treatment of type II endoleaks.

Endoleaks after endovascular repair of aortic aneurysm: are they predictable?-initial results.

PURPOSE: To evaluate the predictability of endoleak. MATERIALS AND METHODS: Thirteen women and 60 men (mean age, 69.8 years) underwent transfemoral insertion of endoluminal stent-grafts for treatment of aortic aneurysms. Follow-up included helical computed tomography (CT) at 3-month intervals. In the cases of endoleak, angiography also was performed to document the number of leak sites, their size and position, the feeding artery, the size of the aneurysm, the amount of thrombus, and the visualization of the lumbar arteries and inferior mesenteric artery. These data were correlated (Student t test) with the probability of endoleak. RESULTS: A total of seven (10%) endoleaks were identified at CT in 68 patients. The feeding vessels were lumbar arteries in three cases, the inferior mesenteric artery in three cases, and the median sacral artery in one case. Of all factors, only the number of lumbar arteries visualized preoperatively (P <.005) had a significant correlation with probability of endoleak. In 71% (five of seven patients) of the cases of lumbar endoleak, four lumbar arteries were patent, whereas among the 61 patients with successfully repaired aneurysm, only eight (13%) had four patent lumbar arteries. Endoleaks were never found in the primarily thrombosed sections of an aneurysm. CONCLUSION: Prediction of endoleaks with absolute certainty remains elusive. The single correlating risk factor identified from the data was patency of four or more lumbar arteries visualized preoperatively at CT.

Endograft treatment of anastomotic aneurysms following conventional open surgery for infrarenal aortic aneurysms.

OBJECTIVE: to evaluate the use of endograft therapy for treating anastomotic aneurysm following open surgical repair of infrarenal aneurysms of the abdominal aorta. METHODS: four male patients (age 47-75 years) at high surgical risk (ASA IV n=3, ASA III n=1) developed secondary aneurysms at the site of the central (four aneurysms) and additional peripheral (two aneurysms) anastomosis of their tube or bifurcation prosthesis an average of 13 years (range 1-23 years) after conventional open surgical correction of infrarenal aneurysm of the abdominal aorta. In two patients, there was covered rupture of the aneurysm sac. The aneurysm diameter was 4.8 cm, 8.0 cm, 7.4 cm, 7.0 cm, respectively (mean 6.8 cm). Follow-up included helical CT imaging at 1 week, 3 months and 6 months postoperatively. RESULTS: anastomotic aneurysm was successfully treated in all four cases. No evidence of endoleak was observed during the follow-up period. Two patients died 14 and 18 days after surgery due to myocardial infarction and cerebrovascular accident. The endovascular repair of the two patients who died was intact. CONCLUSION: although no long-term results are available, the use of a graft-in-graft method to repair anastomotic aneurysms following conventional implantation of tube or bifurcation prostheses appears to be effective, particularly in patients at high surgical risk.

Geometric changes in aortic endografts over a 2-year observation period.

PURPOSE: To report geometric changes in bifurcated aortic endografts observed over a 2-year follow-up period. METHODS: Twenty-two patients (21 men; mean age 68 years, range 57-83) with abdominal aortic aneurysms were treated with an endovascular stent-graft. Follow-up examinations included spiral computed tomographic scanning postoperatively and at 3, 6, 9, 12, 18, and 24 months after treatment. Geometric changes were measured using 3-dimensional reconstructed images in anteroposterior (AP) and lateral projections. Locations for the measurements were the proximal neck, the midportion of the endograft, and the graft limbs at the origin of the iliac arteries. RESULTS: Lateral changes predominated, demonstrating maximum angles on the side of the inserted left limb. For the proximal neck, the stent angle changed by a mean -0.71 degrees in the AP and 4.0 degrees in the lateral projection. At the midgraft, changes were -0.56 degrees for AP and 12.5 degrees for lateral. The right limb showed an angle of 6.43 degrees in AP and -0.43 degrees in lateral, whereas the left limb angles changed 1.38 degrees in AP and 11.71 degrees in the lateral plane after 2 years. There was no statistically significance difference in these changes from baseline. CONCLUSIONS: Aortic endografts are exposed to a significant amount of movement after insertion, but the resultant changes are very inhomogeneous, unpredictable, and ongoing even after 2 years. The most vulnerable location seems to be the attachment zone of the modular graft limb. These geometric changes might be one cause for late complications, including leaks and limb dislocations.