Failure of aneurysm sac shrinkage after endovascular repair; the effect of mural calcification

AIM: To evaluate the effect of abdominal aortic aneurysm wall calcification on subsequent sac shrinkage after endovascular repair. MATERIALS AND METHODS: Seventy-three patients underwent endovascular aneurysm repair. The degree of sac wall calcification on pre-procedural computed tomography (CT) examination was graded from 1 to 4 according to the degree of circumferential involvement. On follow-up CT imaging, the maximum transverse diameter (MTD) of the sac was recorded, as well as the presence or absence of endoleak. In those patients with a non-shrinking aneurysm, but no CT evidence of endoleak, contrast-enhanced ultrasound (USS) was performed. Any patient with an endoleak, however diagnosed, was excluded from the study. Kruskal-Wallis and Spearman's rank correlation coefficient testing was applied to compare the degree of calcification and change in MTD. RESULTS: Sixty-three pre-procedural CT images were available for calcification grading. Six of this group had endoleaks resulting in 57 sets of data being available for the study. A reduction in MTD occurred in 68.25% of these patients by 1 year post-procedure. Our figures show aortic calcification is inversely associated with MTD reduction at 6 months (p = 0.01), 1 year (p = 0.05) and 2 years (p = 0.05). CONCLUSION: This study indicates that the degree of aortic wall calcification is significant in predicting MTD reduction post-endovascular repair. The possible mechanisms and implications of this are discussed.     

Abdominal aortic aneurysm: contrast-enhanced US for missed endoleaks after endoluminal repair

PURPOSE: To evaluate contrast material-enhanced ultrasonography (US) for depiction of endoleaks after endovascular abdominal aortic aneurysm repair (or endovascular aneurysm repair [EVAR]) in patients with aneurysm enlargement and no evidence of endoleak. MATERIALS AND METHODS: From November 1998 to February 2003, 112 patients underwent EVAR. At follow-up, duplex US and biphasic multi-detector row computed tomographic (CT) angiography were performed. In 10 patients (group A), evident aneurysm enlargement was observed, with no evidence of complications, at both CT angiography and duplex US. Group A patients, 10 men (mean age, 69.6 years +/- 10 [standard deviation]), underwent US after intravenous bolus injection of a second-generation contrast agent, with continuous low-mechanical index (0.01-0.04) real-time tissue harmonic imaging. Group B patients, 10 men (mean age, 71.3 years +/- 8.2) with aneurysm shrinkage and no evidence of complications, and group C patients, 10 men (mean age, 73.2 years +/- 6) with CT angiographic evidence of endoleak, underwent contrast-enhanced US. Digital subtraction angiography (DSA) was performed in groups A and C. Endoleak detection and characterization were assessed with imaging modalities used in groups A-C; at contrast-enhanced US, time of detection of endoleak, persistence of sac enhancement, and morphology of enhancement were evaluated. RESULTS: In group A, contrast-enhanced US depicted one type I, six type II, one type III, and two undefined endoleaks that were not detected at CT angiography. All leakages were characterized by slow and delayed echo enhancement detected at longer than 150 seconds after contrast agent administration. DSA results confirmed findings in all patients; percutaneous treatment was performed. In group B, contrast-enhanced US did not show echo enhancement; in group C, results with this modality confirmed findings at CT angiography and DSA. CONCLUSION: Contrast-enhanced US depicts endoleaks after EVAR, particularly when depiction fails with other imaging modalities.     

MRI versus helical CT for endoleak detection after endovascular aneurysm repair

OBJECTIVE: The objective of our study was to investigate the diagnostic accuracy of MRI and helical CT for endoleak detection. SUBJECTS AND METHODS: Fifty-two patients underwent endovascular aneurysm repair with nitinol stent-grafts. Follow-up data sets included contrast-enhanced biphasic CT and MRI within 48 hr after the intervention; at 3, 6, and 12 months; and yearly thereafter. The endoleak size was categorized as < or = 3%, > 3% < or = 10%, > 10% < or = 30%, or > 30% of the maximum cross-sectional aneurysm area. A consensus interpretation of CT and MRI was defined as the standard of reference. RESULTS: Of 252 data sets, 141 showed evidence for endoleaks. The incidence of types I, II, and III endoleaks and complex endoleaks was 3.2%, 40.1%, 8.7%, and 4.0%, respectively. The sensitivity for endoleak detection was 92.9%, 44.0%, 34.8%, and 38.3% for MRI, biphasic CT, uniphasic arterial CT, and uniphasic late CT, respectively. The corresponding negative predictive values were 91.7%, 58.4%, 54.7%, and 56.1%, respectively. The overall accuracy of endoleak detection and correct sizing was 95.2%, 58.3%, 55.6%, and 57.1% for MRI, biphasic CT, uniphasic arterial CT, and uniphasic late CT, respectively. CONCLUSION: MRI is significantly superior to biphasic CT for endoleak detection and rating of endoleak size, followed by uniphasic late and uniphasic arterial CT scans. MRI shows a significant number of endoleaks in cases with negative CT findings and may help illuminate the phenomenon of endotension. Endoleak rates reported after endovascular aneurysm repair substantially depend on the imaging techniques used.     

Detection of endoleaks after endovascular repair of abdominal aortic aneurysm: value of unenhanced and delayed helical CT acquisitions

PURPOSE: To assess unenhanced and delayed phase computed tomographic (CT) images combined with arterial phase images for detecting endoleaks after endovascular treatment for abdominal aortic aneurysm (AAA). MATERIALS AND METHODS: CT scans were retrospectively evaluated for the presence of endoleaks after endovascular treatment of AAAs in 33 patients with endoleak (positive group) and 40 patients without evidence of endoleak or aneurysm enlargement (negative group). All patients underwent unenhanced and biphasic contrast material-enhanced CT. The CT scans were reviewed in the following combinations: (a) arterial phase and unenhanced scans (uniphasic/unenhanced set), (b) arterial and delayed phase scans only (biphasic set), and (c) arterial and delayed phase scans with unenhanced scans (complete set). Each set was reviewed by two radiologists blinded to the diagnosis of endoleak. Findings were recorded as positive, negative, or indeterminate for endoleak. RESULTS: Within the positive group, endoleaks were diagnosed with the uniphasic/unenhanced, biphasic, and complete image sets in 30 (91%), 32 (97%), and 33 (100%) patients, respectively. With the uniphasic/unenhanced set, three (9%) endoleaks (seen only on delayed phase images) were missed. With the biphasic set, one (3%) endoleak was interpreted as indeterminate. Within the negative group, uniphasic/unenhanced, biphasic, and complete image sets were negative for endoleaks in 100%, 80%, and 100% of patients, respectively. With the biphasic set, results were indeterminate in 20% of cases. CONCLUSION: A delayed CT acquisition enables detection of additional endoleaks, while an unenhanced acquisition helps eliminate indeterminate results. Thus, both acquisitions contribute to accurate diagnosis of endoleaks when combined with an arterial phase acquisition.     

Embolotherapy of persistent endoleaks after endovascular repair of abdominal aortic aneurysm with the ancure-endovascular technologies endograft system.

PURPOSE: Endoleak is a potential complication after endovascular repair of abdominal aortic aneurysm (AAA). It may result in continued growth of the aneurysm and potentially result in aneurysm rupture. The authors present their experience with embolotherapy in patients with persistent perigraft flow treated with the Ancure-Endovascular Technologies endograft system. MATERIALS AND METHODS: Between February 1996 and August 1998, 54 patients underwent successful repair of AAA with use of the Ancure system. All underwent operative angiography and discharge computed tomography (CT). Follow-up included CT at 6, 12, and 24 months, and CT was also performed at 3 months if an endoleak was present on the discharge CT. Persistent endoleak was defined as perigraft flow still present on the 6-month CT. Seven of 21 initial endoleaks persisted at 6 months. Six patients returned for embolization of the perigraft space and outflow vessels including lumbar arteries and the inferior mesenteric artery (IMA). RESULTS: Five of the six patients had leaks from the proximal (n = 1) or distal attachment sites (n = 4) of the Ancure system with outflow into lumbar arteries and/or the IMA; one leak was caused by retrograde IMA flow. The six patients underwent nine embolization procedures with only one minor complication. Follow-up CT showed complete resolution of endoleak and decrease in size of the aneurysm sac in all patients. CONCLUSIONS: Although endoleak is commonly seen initially with the Ancure system, persistent leak occurred in 13% of the patients in the study. Persistent flow in most patients arises from a graft attachment site combined with patent outflow vessels such as the IMA or lumbar arteries. Persistent endoleaks can be effectively and safely embolized with use of a combination of coil embolization of the perigraft space and embolization of outflow vessels. Such intervention resulted in a decrease in size of the aneurysm sac.     

Endoleaks – wann behandeln?

Currently the majority of infrarenal abdominal aortic aneurysm repairs are endovascular procedures using a stent graft. This method continues to be questioned due to an up to 50?% incidence of endoleaks, i.e. the postinterventional persistence of blood flow outside the graft and within the aneurysm sac, potentially bearing the risk of a further increase of the aneurysm diameter and aneurysm rupture. Currently a total of five different endoleak types can be distinguished. Multiphase computed tomography (CT) is the standard imaging method for the detection and classification of endoleaks or alternatively contrast-enhanced ultrasound can be used. The different types of endoleak have very different therapeutic implications. In direct endoleaks (types I and III) the systemic blood pressure is directly transferred to the aneurysm wall which carries a high risk of rupture and in general an immediate intervention is indicated. Indirect endoleaks (types II, IV and V) take a more benign course and in the majority of cases treatment is only necessary when further aneurysm expansion occurs.     

Percutaneous Transabdominal Approach for the Treatment of Endoleaks after Endovascular Repair of Infrarenal Abdominal Aortic Aneurysm

Objective

The purpose of this study was to evaluate the technical feasibility and clinical efficacy of percutaneous transabdominal treatment of endoleaks after endovascular aneurysm repair.

Materials and Methods

Between 2000 and 2007, six patients with type I (n = 4) or II (n = 2) endoleaks were treated by the percutaneous transabdominal approach using embolization with N-butyl cyanoacrylate with or without coils. Five patients underwent a single session and one patient had two sessions of embolization. The median time between aneurysm repair and endoleak treatment was 25.5 months (range: 0-84 months). Follow-up CT images were evaluated for changes in the size and shape of the aneurysm sac and presence or resolution of endoleaks. The median follow-up after endoleak treatment was 16.4 months (range: 0-37 months)

Results

Technical success was achieved in all six patients. Clinical success was achieved in four patients with complete resolution of the endoleak confirmed by follow-up CT. Clinical failure was observed in two patients. One eventually underwent surgical conversion, and the other was lost to follow-up. There were no procedure-related complications.

Conclusion

The percutaneous transabdominal approach for the treatment of type I or II endoleaks, after endovascular aneurysm repair, is an alternative method when conventional endovascular methods have failed.     

Abdominal aortic aneurysm: can the arterial phase at CT evaluation after endovascular repair be eliminated to reduce radiation dose?

PURPOSE: To retrospectively determine if arterial phase computed tomographic (CT) imaging is necessary for follow-up imaging of patients who have undergone endovascular stent-graft therapy for abdominal aortic aneurysm. MATERIALS AND METHODS: This HIPAA-compliant study was exempt from institutional review board approval; informed patient consent was waived. Eighty-five patients (66 men, 19 women; mean age, 66 years; range, 45-81 years) underwent 110 multidetector CT examinations after endovascular repair of abdominal aortic aneurysms. Nonenhanced CT images were obtained. Intravenous contrast material was then injected at 4 mL/sec, and arterial and venous phase (60 seconds) CT images were obtained. The nonenhanced and venous phase images were evaluated to determine if an endoleak was present. Subsequently, arterial phase images were analyzed. The effective dose was calculated. Ninety-five percent confidence intervals as indicators of how often arterial phase imaging would contribute to the diagnosis of endoleak were determined. RESULTS: Twenty-eight type II endoleaks were detected by using combined nonenhanced and venous phase acquisitions. Twenty-five of the 28 endoleaks were also visualized during the arterial phase. Three type II endoleaks were seen only during the venous phase. The arterial phase images depicted no additional endoleaks. Seventy-eight CT examinations performed in 67 patients revealed no endoleak during the venous phase. The arterial phase images also depicted no endoleaks at these examinations. Thus, for no more than 3.1% of all examinations, there was 95% confidence that arterial phase imaging would depict an endoleak missed at venous phase imaging. Arterial phase imaging contributed to a mean of 36.5% of the effective dose delivered. CONCLUSION: Study results indicate that arterial phase imaging may not be necessary for the routine detection of endoleaks. Radiation exposure can be decreased by eliminating this phase.     

Comparison of Contrast-Enhanced Ultrasound and Computed Tomography in Classifying Endoleaks After Endovascular Treatment of Abdominal Aorta Aneurysms: Preliminary Experience

The purpose of the study was to assess the effectiveness of contrast-enhanced ultrasonography (CEUS) in endoleak classification after endovascular treatment of an abdominal aortic aneurysm compared to computed tomography angiography (CTA). From May 2001 to April 2003, 10 patients with endoleaks already detected by CTA underwent CEUS with Sonovue to confirm the CTA classification or to reclassify the endoleak. In three conflicting cases, the patients were also studied with conventional angiography. CEUS confirmed the CTA classification in seven cases (type II endoleaks). Two CTA type III endoleaks were classified as type II using CEUS and one CTA type II endoleak was classified as type I by CEUS. Regarding the cases with discordant classification, conventional angiography confirmed the ultrasound classification. Additionally, CEUS documented the origin of type II endoleaks in all cases. After CEUS reclassification of endoleaks, a significant change in patient management occurred in three cases. CEUS allows a better attribution of the origin of the endoleak, as it shows the flow in real time. CEUS is more specific than CTA in endoleak classification and gives more accurate information in therapeutic planning.     

Diagnosis and treatment of inferior mesenteric arterial endoleaks after endovascular repair of abdominal aortic aneurysms

PURPOSE: To review the incidence and repair of inferior mesenteric arterial (IMA) type II endoleaks after endovascular repair of abdominal aortic aneurysms. MATERIALS AND METHODS: Fifty patients who underwent endovascular repair of abdominal aortic aneurysms were examined. If an endoleak was identified at 30-day postoperative computed tomography, conventional arteriography was performed to identify and eliminate its source. After the exclusion of attachment site leaks, a catheter was placed selectively in the superior mesenteric artery (SMA). If retrograde filling of the IMA and aneurysm was identified, coil embolization was attempted through the SMA and middle colic artery. Intrasac pressures were measured at embolization. RESULTS: Eight of 50 patients (16%) had type II endoleaks that were attributed to retrograde flow in the IMA. Intrasac measurements demonstrated systemic pressure in six patients and one-half systemic pressure in two patients. The IMA was embolized through the SMA and left colic artery in seven patients and through the translumbar aorta in one patient. CONCLUSION: Retrograde flow in the IMA is responsible for many type II endoleaks. Systemic pressures are transmitted into the aneurysm sac from the IMA. The IMA can be embolized successfully with an SMA approach in most patients.     

Imaging of aortic stent-grafts and endoleaks

Although the technical success of stent-graft implantation is established and relatively safe, data on the long-term safety and efficacy of endovascular repair are just emerging. Because several late complications of aortic stent-graft placement have been observed, life-long follow-up remains essential. Imaging methods form an integral part of every stage of endovascular aortic aneurysm repair. The current imaging strategy should include initial plain films, CT angiography, and color-coded Duplex sonography. Plain films are an excellent means to detect migration, angulation, kinking, and structural changes of the stent mesh, including material fatigue, at follow-up. Helical CT angiography is considered a potentially revolutionary method for the noninvasive complete postprocedural assessment of aortic sten-grafting. Current data justify the use of biphasic C angiography as the postprocedural imaging technique of choice in most patients [118]. Ultrasound offers the advantages of low cost and lack of radiation exposure. High-quality ultrasound reliably excludes endoleaks in patients after stent-grafting of AAAs. There is a substantial variability, however, in measuring the diameter of aneurysm sacs; thus, confirmation using an alternative study is prudent in cases that demonstrate a significant change in size during follow-up. MR angiography serves as an attractive alternative to CT angiography in patients with impaired renal function or known allergic reaction to iodinated contrast media. With current techniques, the visualization of aortic stent-grafts (with the exception of stainless-steel-based devices) is sufficient with MR angiography. There is evidence that MR imaging is superior to CT angiography in detecting small type 2 endoleaks or for excluding retrograde perfusion in patients with suspected endotension. The role of diagnostic catheter angiography is limited to assessment of vascular pathways in equivocal cases or for suspected endotension. Currently, a consensus view about postprocedural management after aortic stent-graft implantation is lacking. The authors propose performing a baseline CT angiography at discharge and a biphasic CT angiography and Duplex ultrasound scan at three months. In patients with no evidence of an endoleak, CT angiography, plain film and Duplex sonography (abdomen) should be repeated every year after endovascular repair. If an endoleak is present at follow-up, immediate appropriate treatment should be initiated.     

Aortic side branch embolization before endovascular aneurysm repair: incidence of type II endoleak

PURPOSE: To assess the feasibility of embolization of aortic side branches and its impact on the incidence of type II endoleak after endovascular aneurysm repair. MATERIALS AND METHODS: Endovascular aneurysm repair was performed in 74 patients. Aortic side branch vessels were evaluated on the preoperative angiogram and computed tomography (CT) and, where embolization of lumbar and inferior mesenteric vessels was considered technically possible, this was attempted prior to endovascular repair. Follow-up CT was used to assess the presence of type II endoleak. RESULTS: Seventy-two patients were followed up for longer than 1 month. Embolization was attempted in 25 cases, successfully in 10, with partial success in 11, and failure in four. Twenty patients with successful or partly successful preoperative embolization were discharged and followed-up. Four (20%) had demonstrable type II endoleak during follow-up, with two of these persisting at latest follow-up. Of 43 patients without previous embolization, there were 10 (23.3%) type II endoleaks during the follow-up period, four of these persisting. In cases with type II endoleak, mean sac diameter change was -0.5 mm in the cases with previous embolization and +3.1 mm without. The mean period to onset of type II endoleak was 6.9 months without, and 15.3 months with, previous embolization. CONCLUSION: Although the cohort size is below a level that would confer significance, the trend of these findings is such as to suggest a lack of influence of aortic side branch embolization on the incidence of type II endoleak during the follow-up period.     

MRA is useful as a follow-up technique after endovascular repair of aortic aneurysms with nitinol endoprostheses

PURPOSE: To evaluate whether MR angiography (MRA) is a useful tool for the follow-up of aortic aneurysms treated with nitinol endoluminal grafts. MATERIALS AND METHODS: We examined 28 patients treated with nitinol endovascular stents to repair an aortic aneurysm with CT angiography (CTA) and MRA. Eleven patients (group 1) underwent an MRA after a positive CTA for endoleak was observed. Afterwards, 17 patients (group 2) were scheduled for both follow-up examinations. The kind of endoleak that occurred and the maximum aortic diameter were compared. The sensitivity of CTA relative to MRA for detecting endoleaks in group 2 was calculated. Signal-to-noise ratios (SNRs) were measured in the aortoiliac lumen at the arterial phase in, above, and below the endoprostheses. Student's t-test was used to compare aneurysm dimensions and SNR measurements. RESULTS: Three type III leaks were correctly assessed at both examinations; however, CTA was less sensitive (50%) than MRA in depicting type II or unclassified leaks. No differences in aneurismal size were observed between the two examinations or between arterial SNRs observed in or out of the devices. CONCLUSION: MRA can provide all relevant information necessary for the follow-up of patients treated with nitinol endoprostheses, and performs better than CTA in detecting endoleaks.     

Time-resolved MR angiography for the classification of endoleaks after endovascular aneurysm repair

PURPOSE: To evaluate the utility of time-resolved MR angiography (TR-MRA), compared with digital subtraction angiography (DSA), in the classification of endoleaks in patients who have undergone endovascular aneurysm repair (EVAR). MATERIALS AND METHODS: Thirty-one patients who had undergone EVAR to repair an abdominal aortic aneurysm were evaluated with both TR-MRA and DSA to determine endoleak etiology. The patient population consisted of 26 men and 5 women with a mean age of 78.5 years (range, 55-93 years). The mean time interval between TR-MRA and DSA was 1.5 weeks (range, 1-8 weeks). Endoleaks were classified as type II when enhancement of the external iliac vessels was observed before the appearance of the endoleak; otherwise the endoleak was classified as type I or III. The results of TR-MRA classification were compared with the reference gold standard, DSA. RESULTS: Agreement between TR-MRA and DSA regarding endoleak classification occurred in 30 of 31 cases (97%). Discordant classification occurred in a case in which a Type II endoleak was misclassified as a Type III due to failure to visualize a lumbar vessel. CONCLUSION: TR-MRA is highly effective in classifying endoleaks following EVAR when compared with DSA.     

Midterm follow-up of a single-center experience of endovascular repair of abdominal aortic aneurysms with use of the Talent stent-graft

PURPOSE: To review the midterm results of endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs) with the Talent stent-graft. MATERIALS AND METHODS: All patients who underwent EVAR of AAAs with Talent stent-grafts from February 1998 to April 2002 at a single institution were monitored for a minimum of 2 years or until an endpoint of death or rupture was reached. RESULTS: There were 68 eligible patients, who were monitored for a mean period of 39 months (range, 24-72 months). Forty-nine (72.9%) were alive at 2 years; among the 19 deaths, two resulted from aneurysm rupture and the other 17 were unrelated to EVAR. There was one immediate conversion to open repair and five primary proximal endoleaks; the remaining 62 patients (91.2%) all had a technically successful procedure. There were 33 endoleaks during follow-up: 23 (69.7%) were treated conservatively and 10 (30.3%) underwent secondary intervention in the form of embolization (n=2), attempted embolization (n=2), endovascular stent-graft placement (n=3), combined stent-graft placement and embolization (n=1), or surgical conversion (n=2). Overall, there were five persistent endoleaks, and the remaining patients were free of endoleak at their last review or endpoint. Three stent-grafts migrated and required further endovascular intervention. Wire fracture was seen in two stents but presented no clinical sequelae. There was one case of graft limb thrombosis that required surgical thrombectomy. CONCLUSIONS: EVAR of AAAs with use of the Talent stent-graft is a promising and acceptable alternative to open surgery. Our 30-day mortality rate of zero compares extremely well with historical data from open surgery and the findings of more recently published trials. The risk of endoleak and uncertainty over durability require long-term surveillance.     

Ten-Year Follow-Up of Endovascular Aneurysm Treatment with Talent Stent-Grafts

The purpose of this study was to evaluate the clinical results, complications, and secondary interventions during long-term follow-up after endovascular aneurysm repair (EVAR) and to investigate the impact of endoleak sizes on aneurysm shrinkage. From 1997 to March 2007, 127 patients (12 female, 115 male; age, 73.0 ± 7.2 years) with abdominal aortic aneurysms were treated with Talent stent-grafts. Follow-up included clinical visits, contrast-enhanced MDCT, and radiographs at 3, 6, and 12 months and then annually. Results were analyzed with respect to clinical outcome, secondary interventions, endoleak rate and management, and change in aneurysm size. There was no need for primary conversion surgery. Thirty-day mortality was 1.6% (two myocardial infarctions). Procedure-related morbidity was 2.4% (paraplegia, partial infarction of one kidney, and inguinal bleeding requiring surgery). Mean follow-up was 47.7 ± 34.2 months (range, 0–123 months). Thirty-nine patients died during follow-up; three of the deaths were related to aneurysm (aneurysm rupture due to endoleak, n = 1; secondary surgical reintervention n = 2). During follow-up, a total of 29 secondary procedures were performed in 19 patients, including 14 percutaneous procedures (10 patients) and 15 surgical procedures (12 patients), including 4 cases with late conversion to open aortic repair (stent-graft infection, n = 1; migration, endoleak, or endotension, n = 3). Overall mean survival was 84.5 ± 4.7 months. Mean survival and freedom from any event was 66.7 ± 4.5 months. MRI depicted significantly more endoleaks compared to MDCT (23.5% vs. 14.3%; P < 0.01). Patients in whom all aneurysm side branches were occluded prior to stent-grafting showed a significantly reduced incidence of large endoleaks. Endoleaks >10% of the aneurysm area were associated with reduced aneurysm shrinkage compared to no endoleaks or <10% endoleaks (Δ at 3 years, −1.8% vs. −12.0%; P < 0.05). In conclusion, endovascular aneurysm treatment with Talent stent-grafts demonstrated encouraging long-term results with moderate secondary intervention rates. Primary occlusion of all aortic side branches reduced the incidence of large endoleaks. Large endoleaks significantly impaired aneurysm shrinkage, whereas small endoleaks did not.     

Transabdominal Direct Sac Puncture Embolization of Type II Endoleaks after Endovascular Abdominal Aortic Aneurysm Repair

Purpose

To determine the efficacy and safety of transabdominal direct sac puncture embolization of type II endoleaks after endovascular abdominal aortic aneurysm repair (EVAR).

Treatment of type II endoleaks with Onyx

Endoleaks are defined as persistent perfusion of an abdominal aortic aneurysm (AAA) after endovascular stent-graft deployment. The authors describe their experience treating six endoleaks with the liquid embolic agent Onyx (ethylene-vinyl-alcohol copolymer). Complete endoleak occlusion was achieved in five of six cases. Follow-up imaging has demonstrated decreased aneurysm diameter in all patients 7-29 weeks (mean = 19.2 weeks) after treatment.     

Dynamic CT Angiography after Abdominal Aortic Endovascular Aneurysm Repair: Differences in Contrast Agent Dynamics in the Aorta and Endoleaks—Preliminary Results

PurposeTo assess differences in aortic and endoleak enhancement in patients after endovascular aneurysm repair (EVAR) with dynamic computed tomography (CT) angiography.Materials and MethodsTwenty-one consecutive patients (mean age, 74.5 y ± 6; range, 61–88 y) with endoleaks after EVAR of the abdominal aorta were examined on a second-generation dual-source CT unit with 10 unidirectional scan phases (temporal resolution, 5 s; 80 kV; 120 reference-mAs; z-axis field of view, 283 mm), followed by a venous scan phase. Enhancement was assessed in aorta and endoleaks for all phases by density measurements. The diagnostic reliability of endoleak detection was assessed on a five-point confidence scale.ResultsIn total, 26 endoleaks (type I, n = 1; type II, n = 25) were detected. The highest detection rate was found in phase 5 (22 s after threshold; P < .01 vs other dynamic phases). Mean peak aortic enhancement (560 HU ± 96) was present in an early arterial phase (phase 3, 12 s after threshold), whereas the mean peak endoleak enhancement (398 HU ± 174) for type II endoleaks was present later, in phase 4 (17 s after threshold). Despite perceived high diagnostic confidence in phases 1 and 2 (ie, typical arterial phase of biphasic CT protocol), only 23% and 62% of endoleaks were detected, respectively, whereas peak diagnostic confidence (phases 4 and 5) corresponded well with the maximum endoleak detection rate but decreased significantly in later phases (ie, 6–10).ConclusionsPreliminary dynamic CT angiography results in post-EVAR follow-up revealed notably different peaks of endoleak and aortic enhancement, which are not covered sufficiently by conventional biphasic CT protocols. Phase 5 demonstrated the highest type II endoleak detection rate, with high diagnostic confidence.     

Endovascular treatment of endoleaks after endovascular abdominal aortic aneurysm repair: personal experience

PURPOSE: This paper describes the different endovascular treatments (cuffs, endografts and embolisation) available for types I, II and III endoleaks occurring after endovascular abdominal aortic aneurysm repair (EVAR). MATERIALS AND METHODS: From January 2000 to June 2006, 134 patients (118 men, 16 women; mean age 75.1 years) underwent EVAR. Ten patients (7%) developed significant endoleaks requiring endovascular treatment. RESULTS: Five endoleaks were type I, two were type II and three were type III. Of the five type I endoleaks, four were proximal and one was distal. The proximal endoleaks were treated by cuff deployment, whereas the distal endoleak was treated with a bifurcated graft. Of the two patients with type II endoleak, one was treated by translumbar puncture and coil embolisation, and the other was treated by superselective embolisation of the lumbar feeding vessel with nonresorbable particles. Of the three patients with type III endoleak, two were treated by deploying an aortouniiliac endograft inside the bifurcated graft and the other by implanting a cuff to restore continuity between the graft body and the contralateral limb. Endovascular treatment was successful in 6/10 cases, whereas three cases required surgical conversion. One patient did not undergo surgery owing to poor general condition. CONCLUSIONS: The reported incidence of endoleaks after EVAR is 10%-20%. Significant endoleaks should be treated promptly. Endovascular treatment can be done with different techniques, but success in not constant due to adverse anatomical conditions and technical difficulties.