Microballoon Occlusion Test to Predict Colonic Ischemia After Transcatheter Embolization of a Ruptured Aneurysm of the Middle Colic Artery

A 76-year-old woman presented with sudden massive melena, and superior mesenteric arteriography showed an aneurysm in the middle colic artery (MCA). Because she had a history of right hemicolectomy and ligation of the inferior mesenteric artery (IMA) during open abdominal aortic aneurysm repair, embolization of the MCA aneurysm was considered to pose a risk comparable to that of colonic ischemia. A microballoon occlusion test during occlusion of the MCA confirmed retrograde visualization of the IMA branches through the collateral arteries by way of the left internal iliac artery, and embolization was successfully performed using microcoils. No colonic ischemia or aneurysm rupture occurred after embolization.     

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.     

Preoperative Inferior Mesenteric Artery Embolization before Endovascular Aneurysm Repair: Decreased Incidence of Type II Endoleak and Aneurysm Sac Enlargement with 24-month Follow-up

PurposeTo review the effect of preoperative embolization of the inferior mesenteric artery (IMA) before endovascular aneurysm repair (EVAR) on subsequent endoleaks and aneurysm growth.Materials and MethodsBetween August 2002 and May 2010, 108 patients underwent IMA embolization before EVAR. Coil embolization was performed in all patients in whom the IMA was successfully visualized and accessed during preoperative conventional angiography. In this cohort, the incidences of type II endoleak, aneurysm sac volume enlargement at 24 months, and repeat intervention were compared with a group of 158 consecutive patients with a patent IMA on preoperative computed tomography angiography but not on conventional angiography, who therefore did not undergo preoperative embolization.ResultsThe incidence of type II endoleak was significantly higher in patients not treated with embolization (49.4% [78 of 158] vs 34.3% [37 of 108]; P = .015). The incidence of secondary intervention for type II endoleak embolization was also significantly higher in those who did not undergo embolization (7.6% [12 of 158] vs 0.9% [one of 108]; P = .013). At 24 months, an increase in aneurysm sac volume was observed in 47% of patients in the nonembolized cohort (21 of 45), compared with 26% of patients in the embolized cohort (13 of 51; P = .03). No aneurysm ruptures or aneurysm-related deaths were observed in either group. One patient in the embolization group developed mesenteric ischemia and ultimately died.ConclusionsPreoperative embolization of the IMA was associated with reduced incidences of type II endoleak, aneurysm sac volume enlargement at 24 months, and secondary intervention.     

Inferior mesenteric artery embolization before endovascular aneurysm repair: technique and initial results

PURPOSE: To report a single center's technique and initial results in the preoperative embolization of the inferior mesenteric artery (IMA) before endovascular aneurysm repair (EVAR). MATERIALS AND METHODS: Over a 3-year period, 102 patients at a single clinical site, including 86 men and 16 women aged 54-93 years (mean, 75 years), were found to have a patent IMA on computed tomographic (CT) angiography before EVAR. Coil embolization was performed after subselective catheterization with use of microcoils placed in the IMA proximal to the origin of the left colic artery. All patients in whom the IMA was visualized on flush aortography and successfully accessed underwent embolization. One month and 6 months after surgery, results in this cohort were retrospectively compared with those from a similar group of patients who underwent EVAR during the same period. These patients had patent IMAs on preoperative CT angiography but did not undergo embolization as a result of nonvisualization during flush aortography. All patients underwent EVAR with bifurcated modular devices with proximal transrenal fixation. All patients underwent postoperative follow-up with multiphase CT angiography to detect the presence of endoleak. Six-month follow-up data were available for 18 patients who underwent embolization and 54 patients who did not. Change in sac diameter was compared in these patients. RESULTS: Embolization was technically successful in 30 of 32 patients (94%) in whom it was attempted. There were no complications. At 1-month follow-up, five of 30 patients in the embolization group were noted to have a type II endoleak (17%). None of the endoleaks in this group were related to the IMA. The group with patent IMAs who did not undergo preoperative embolization had a 42% incidence of type II endoleak (P < .05). At 6 months after surgery, three of 18 patients who had undergone embolization (17%) had a type II endoleak, compared with 26 of 54 in the other group (48%; P < .05). Among the patients in whom 6-month data were available, mean changes in sac diameter were -5.2 mm (range, -24 to 2 mm) in the embolized group and -2.1 mm (range, -19 to 8 mm) in the nonembolized group. CONCLUSION: These initial results demonstrate that embolization of the IMA with subselective microcoils before EVAR is a safe and effective procedure to reduce the incidence of type II endoleaks. The data also suggest that preoperative embolization of the IMA is associated with greater shrinkage of aneurysm sac diameter at 6 months.     

Endovascular Repair of a Type III Thoracoabdominal Aortic Aneurysm in a Patient with Occlusion of Visceral Arteries

The successful endovascular repair of a type III thoracoabdominal aortic aneurysm (TAAA) with the use of a tube endograft is reported. A 56-year-old male with a 6.4-cm type III TAAA, a 4.2-cm infrarenal abdominal aortic aneurysm, and chronic renal insufficiency presented with flank pain, nausea, acute anuria, and serum creatinine of 6.1 mg/dl. Acute occlusion of the left solitary renal artery was diagnosed and emergent recanalization with percutaneus transluminal angioplasty and stenting was performed successfully, with reversal of the serum creatinine level at 1.6 mg/dl. Further imaging studies for TAAA management revealed ostial occlusion of both the celiac artery (CA) and the superior mesenteric artery (SMA) but a hypertrophic inferior mesenteric artery (IMA) providing retrograde flow to the aforementioned vessels. This rare anatomic serendipity allowed us to repair the TAAA simply by using a two-component tube endograft without fenestrations (Zenith; William Cook, Bjaeverskov, Denmark) that covered the entire length of the aneurysm, including the CA and SMA origins, since a natural arterial bypass from the IMA to the CA and SMA already existed, affording protection from gastrointestinal ischemic complications. The patient had a fast and uneventful recovery and is currently doing well 6 months after the procedure. To our knowledge, this is the first report in the English literature of successful endovascular repair of a TAAA involving visceral arteries with the simple use of a tube endograft.     

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.     

Inferior Mesenteric Artery Embolization Before Endovascular Aortic Aneurysm Repair Using Amplatzer Vascular Plug Type 4

Purpose

This study was designed to evaluate the efficacy and safety of Amplatzer Vascular Plug type 4 (AVP-4) for embolization of the inferior mesenteric artery (IMA) before endovascular aneurysm repair (EVAR) of the abdominal aorta to prevent endoleaks.

Methods

A single-center retrospective review of 31 patients who underwent IMA embolizations before EVAR using the AVP-4 was performed. We analyzed the insertion and detachment procedure, the technical success, and the final position of the plug. Technical success was defined as complete occlusion of the IMA. To compare the incidence of IMA-related type II endoleaks in patients with and without preoperative IMA embolization, we additionally reviewed the course of 43 patients with a preoperatively patent IMA who underwent no IMA embolization.

Results

Plugs with a diameter of 5, 6, and 8 mm were used in 5 (16.1 %), 21 (67.7 %), and 5 (16.1 %) patients, respectively (50–100 % oversizing). In 29 of 31 patients (93.5 %), we observed complete occlusion of the IMA within 10 min (mean 5.1 min). Precise placement of the plug in the proximal segment of the IMA without occlusion of the first IMA branches was achievable in all patients. The distance between the AVP-4 and the first branches was on average 12 (range 2–57) mm. Preoperative IMA embolization with AVP-4 significantly reduced the incidence of complex IMA-lumbar type II endoleaks after EVAR (0/31 vs. 11/43; p = 0.002).

Conclusions

The AVP-4 is a safe, feasible, and technically effective embolization device for IMA embolization before EVAR.     

Is Internal Iliac Artery Embolization Essential Prior to Endovascular Repair of Aortoiliac Aneurysms?

Patients who undergo endovascular repair of aorto-iliac aneurysms (EVAR) require internal iliac artery (IIA) embolization (IIAE) to prevent type II endoleaks after extending the endografts into the external iliac artery. However, IIAE may not be possible in some patients due to technical factors or adverse anatomy. The aim of this study was to assess retrospectively whether patients with aorto-iliac aneurysms who fail IIAE have an increase in type II endoleak after EVAR compared with similar patients who undergo successful embolization. We retrospectively analyzed the records of 148 patients who underwent EVAR from December 1997 to June 2005. Sixty-one patients had aorto-iliac aneurysms which required IIAE before EVAR. Fifty patients had successful IIAE and 11 patients had unsuccessful IIAE prior to EVAR. The clinical and imaging follow-up was reviewed before and after EVAR. The endoleak rate of the embolized group was compared with that of the group in whom embolization failed. After a mean follow-up of 19.7 months in the study group and 25 months in the control group, there were no statistically significant differences in outcome measures between the two groups. Specifically, there were no type II endoleaks related to the IIA in patients where IIAE had failed. We conclude that failure to embolize the IIA prior to EVAR should not necessarily preclude patients from treatment. In patients where there is difficulty in achieving coil embolization, it is recommended that EVAR should proceed, as clinical sequelae are unlikely.     

Internal iliac artery embolization before endovascular repair of abdominal aortic aneurysms: frequency, efficacy, and clinical results

OBJECTIVE: The aim of our study was to assess the frequency, efficacy, and incidence of adverse effects of internal iliac artery embolization. MATERIALS AND METHODS: Of 343 patients examined for stent-graft repair, 147 were suitable for endovascular treatment. Fifty-five patients underwent preprocedural embolization of the internal iliac artery either unilaterally (46 patients) or bilaterally (nine patients). Successful embolization was assessed angiographically and with helical CT follow-up examinations. Colonic ischemia was ruled out clinically or colonoscopically. Buttock claudication, and sexual dysfunction in men, were evaluated through a questionnaire. RESULTS: Embolization of the internal iliac artery increased by 16% the percentage of patients for whom endovascular repair was suitable. After successful embolization in all patients, routine CT follow-up examinations after a mean time of 16.7 months showed no evidence of endoleaks related to retrograde perfusion via embolized internal iliac arteries. Nevertheless, in all patients who had undergone embolization, a primary endoleak was detected in 43.4% at the first postoperative CT examination. None of our patients had evidence of colonic ischemia. Clinical follow-up data of 46 patients were available. Of these patients, mild to severe new onset buttock claudication was found in 13 (36.1%) of 36 patients with unilateral, and in eight (80%) of 10 patients with bilateral, internal iliac artery embolization (p = 0.03). Five (25%) of 20 men had an erectile dysfunction after the procedure. CONCLUSION: Embolization of the internal iliac artery is a safe and efficient procedure that increases the applicability for endovascular repair of aortoiliac aneurysms. However, buttock claudication and erectile dysfunction are a drawback in a substantial number of patients.     

Inferior mesenteric artery as outflow vessel in endoleaks after abdominal aortic stent-graft implantation: 36-month follow-up CT study

The aim of this study was to determine the role of the inferior mesenteric artery (IMA) as an outflow vessel in endoleaks after abdominal aortic stent-graft implantation. Forty consecutive patients in whom abdominal aortic aneurysms (AAA) had been treated with stent-graft implantation were evaluated retrospectively. Spiral-CT examinations and angiographies up to 36 months after implantation were analyzed. In 29 (73%) of the 40 patients the IMA was perfused prior to implantation. In 5 (17%) of these 29 cases, the artery remained perfused after stent-graft insertion. In all 5 cases, endoleaks were detected; however, in none of these cases was the IMA the sole cause. In 3 of these 5 cases, angiography showed antegrade flow in the IMA. Implantation of extension stent grafts caused thrombosis of the aneurysmal sac and the IMA. There were no secondary endoleaks caused by the IMA at the 36-month follow-up examinations. The majority of IMAs which are patent prior to intervention occlude after successful stent-graft insertion. In cases with leaks and angiographically proven antegrade flow in the IMA, implantation of extension stent grafts is a therapeutic alternative to embolization. In this study, the IMA was not responsible for secondary endoleaks.     

Celiac Trunk Embolization,as a Means of Elongating Short Distal Descending Thoracic Aortic Aneurysm Necks,Prior to Endovascular Aortic Repair

The purpose of this study was to report our experience in elongating short distal necks of descending thoracic aortic aneurysms (DTAAs) by coil embolization of the celiac trunk prior to endovascular aneurysm repair (EVAR). During 6 years seven patients (five men and two women; mean age, 74) who had DTAAs with short distal necks unsuitable for conventional EVAR, and well patent superior and inferior mesenteric arteries based on CT, were treated in one session with EVAR after the celiac trunk was coil embolized to elongate the neck. All patients were followed by CT every 3 months in the first year and every 6 months thereafter. Technical success was achieved in all patients, and no early or late ischemic complications were noted. No procedural complications occurred and good aneurysm sealing was obtained in all patients. Three endoleaks were identified after 3 months (one patient) and 6 months (two patients); all were treated successfully with insertion of an additional stent-graft. In patients with DTAAs who are candidates for EVAR but have short aneurysm distal necks, celiac trunk embolization—only if the superior and inferior mesenteric arteries are patent—is a good and safe way to elongate the neck and enable EVAR.     

Internal Iliac Artery Embolization during an Endovascular Aneurysm Repair with Detachable Interlock Microcoils

Objective

The purpose of this study was to evaluate the effectiveness of detachable interlock microcoils for an embolization of the internal iliac artery during an endovascular aneurysm repair (EVAR).

Materials and Methods

A retrospective review was conducted on 40 patients with aortic aneurysms, who had undergone an EVAR between January 2010 and March 2012. Among them, 16 patients were referred for embolization of the internal iliac artery for the prevention of type II endoleaks. Among 16 patients, 13 patients underwent embolization using detachable interlock microcoils during an EVAR. Computed tomographic angiographies and clinical examinations were performed during the follow-up period. Technical success, clinical outcome, and complications were reviewed.

Results

Internal iliac artery embolizations using detachable interlock microcoils were technically successful in all 13 patients, with no occurrence of procedure-related complications. Follow-up imaging was accomplished in the 13 cases. In all cases, type II endoleak was not observed with computed tomographic angiography during the median follow-up of 3 months (range, 1-27 months) and the median clinical follow-up of 12 months (range, 1-27 months). Two of 13 (15%) patients had symptoms of buttock pain, and one patient died due to underlying stomach cancer. No significant clinical symptoms such as bowel ischemia were observed.

Conclusion

Internal iliac artery embolization during an EVAR using detachable interlock microcoils to prevent type II endoleaks appears safe and effective, although this should be further proven in a larger population.     

Transcatheter embolization of a type II endoleak after hybrid repair for thoracoabdominal aortic aneurysm

Hybrid stent-graft procedures with visceral revascularization have been reported as an alternative treatment option for thoracoabdominal aortic aneurysms (TAAAs), although the potential advantages of reduced morbidity and mortality compared with open surgical repair have not been definitively demonstrated. Endovascular aneurysm repair is associated with endoleaks in as many as 20% of cases in some series, often requiring repeat intervention. In the present case, during follow-up after a hybrid TAAA repair, a patient developed a type II endoleak originating from a celiac artery that was not ligated at its origin. The endoleak was successfully treated by transcatheter coil embolization.     

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.     

Endovascular Treatment of Delayed Type 1 and 3 Endoleaks

Purpose  

Endovascular aortic aneurysm repair (EVAR) has revolutionized the treatment of abdominal aortic aneurysms. Type I and III endoleaks require prompt, definitive repair or explantation. We review a single center experience of endovascular treatment of type I and III endoleaks.     

Balloon-assisted coil embolization of the celiac trunk before endovascular aortic repair of thoracoabdominal aortic aneurysm

Purpose

Celiac trunk coil embolization before thoracic endovascular aneurysm repair (TEVAR) of a thoracoabdominal aortic aneurysm involving the celiac trunk can prevent type II endoleaks. One disadvantage of conventional coil embolization is the risk of coil displacement. We performed coil embolization under balloon occlusion of the celiac trunk to address this issue.

Materials and methods

Between December 2008 and January 2011, 5 patients (3 men and 2 women, mean age 76 years) were included in this study. For all patients, after confirming the collateral blood flow from the superior mesenteric artery via the pancreaticoduodenal arcades by using the balloon occlusion test, celiac trunk coil embolization proceeded under balloon occlusion of the proximal part of the celiac trunk.

Results

Balloon-assisted coil embolization of the celiac trunk was completed for all patients without any complications. All coils were deployed as planned in the short segment of the celiac trunk without displacement. Coil migration, ischemic complications, and endoleaks via the celiac trunk did not arise in any of the patients over a follow-up period of 77–637 (mean 258) days.

Conclusions

Balloon-assisted coil embolization of the celiac trunk before TEVAR could be a feasible treatment option for suitable patients.     

Internal iliac artery embolization with bilateral occlusion before endovascular aortoiliac aneurysm repair-clinical outcome of simultaneous and sequential intervention

PURPOSE: To retrospectively evaluate the clinical outcome of patients after simultaneous or sequential internal iliac artery (IIA) embolization for bilateral IIA occlusion. MATERIALS AND METHODS: Sixteen patients (65-88 y; mean, 75.6 y; two women), 11 with aortobiiliac aneurysms, three with bilateral common iliac artery (CIA)/IIA aneurysms, and two with unilateral CIA/IIA aneurysms, underwent IIA occlusion before endovascular aortoiliac repair. Eight patients underwent simultaneous bilateral IIA embolization before endovascular aortic repair (EVAR). Eight patients had sequential bilateral IIA occlusion. The outcome was assessed by clinical follow-up. RESULTS: There were no severe ischemic complications such as buttock necrosis or acute bowel, bladder, or spinal cord ischemia. Early ischemic complications occurred in 25% (buttock/thigh claudication, n = 3, 18.8%; and sexual dysfunction, n = 1, 6.2%) and had an onset not later than 6 months after intervention: buttock claudication resolved (n = 2) or persisted after aggravation by inferior mesenteric artery embolization for type II endoleak (n = 1). Impotence in a fourth patient persisted. The ischemic complication rate after 6 months was 30% (three of 10) because of a fifth patient who developed ischemic colitis with aggravation of ischemic heart disease after 15 months. The mean follow-up duration was 19.7 months. Patients with simultaneous embolization had a lower complication rate than those with sequential embolization (one of eight [12.5%] vs four of eight [50%], respectively). CONCLUSIONS: IIA embolization for bilateral IIA occlusion can be performed with a complication rate comparable with results of previous studies of unilateral IIA embolization. Chronic buttock claudication may be aggravated by embolization of aortic side branches. Late complications can have an insidious course and be initiated by low-output cardiac failure. Bilateral IIA occlusion is recommended only in patients who are considered unfit for aortic surgery.     

Type II Endoleak After Endovascular Repair of Abdominal Aortic Aneurysm: Effectiveness of Embolization

The purpose of this study was to report our experience in treating type II endoleaks after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms. Two hundred eighteen patients underwent EVAR with a Zenith stent-graft from January 2000 to December 2005. During a follow-up period of 4.5 ± 2.3 years, solely type II endoleak was detected in 47 patients (22%), and 14 of them underwent secondary interventions to correct this condition. Ten patients had transarterial embolization, and four patients had translumbar/transabdominal embolization. The embolization materials used were coils, thrombin, gelatin, Onyx (ethylene–vinyl alcohol copolymer), and glue. Disappearance of the endoleak without enlargement of the aneurysm sac after the first secondary intervention was achieved in only five of these patients (5/13). One patient without surveillance imaging was excluded from analyses of clinical success. After additional interventions in four patients and the spontaneous disappearance of type II endoleak in two patients, overall clinical success was achieved in eight patients (8/12). One patient did not have surveillance imaging after the second secondary intervention. Clinical success after the first secondary intervention was achieved in two patients (2/9) in the transarterial embolization group and three patients (3/4) in the translumbar embolization group. The results of secondary interventions for type II endoleak are unsatisfactory. Although the small number of patients included in this study prevents reliable comparisons between groups, the results seem to favor direct translumbar embolization in comparison to transarterial embolization.     

Risk factors associated with late aneurysmal sac expansion after endovascular abdominal aortic aneurysm repair

PURPOSE

We aimed to identify the risk factors associated with late aneurysmal sac expansion after endovascular abdominal aortic aneurysm repair (EVAR).

METHODS

We retrospectively reviewed contrast-enhanced computed tomography (CT) images of 143 patients who were followed for ≥6 months after EVAR. Sac expansion was defined as an increase in sac diameter of 5 mm relative to the preoperative diameter. Univariate and multivariate analyses were performed to identify associated risk factors for late sac expansion after EVAR from the following variables: age, gender, device, endoleak, antiplatelet therapy, internal iliac artery embolization, and preprocedural variables (aneurysm diameter, proximal neck diameter, proximal neck length, suprarenal neck angulation, and infrarenal neck angulation).

RESULTS

Univariate analysis revealed female gender, endoleak, aneurysm diameter ≥60 mm, suprarenal neck angulation >45°, and infrarenal neck angulation >60° as factors associated with sac expansion. Multivariate analysis revealed endoleak, aneurysm diameter ≥60 mm, and infrarenal neck angulation >60° as independent predictors of sac expansion (P < 0.05, for all).

CONCLUSION

Our results suggest that patients with small abdominal aortic aneurysms (<60 mm) and infrarenal neck angulation ≤60° are more favorable candidates for EVAR. Intraprocedural treatments, such as prophylactic embolization of aortic branches or intrasac embolization, may reduce the risk of sac expansion in patients with larger abdominal aortic aneurysms or greater infrarenal neck angulation.The aim of endovascular abdominal aortic aneurysm repair (EVAR) is to prevent rupture of an abdominal aortic aneurysm (AAA) by depressurizing the aneurysm and excluding it from the systemic circulation using a stent-graft. Aneurysmal sac reduction is a reliable marker for the long-term prognosis after EVAR. Although most aneurysmal sacs shrink after EVAR, some sacs continue to expand. A relationship between aneurysm size and endoleaks was previously reported (1, 2). Most type II endoleaks spontaneously disappear over time, but 10%–25% persist for more than six months after EVAR (3–6). Persistent endoleaks with aneurysmal sac expansion are at high risk of rupture because of the continuously elevated intra-aneurysmal pressure and require a second intervention, such as embolization (7–11). However, it is difficult to predict sac expansion and persistent endoleak before performing EVAR. Although intraoperative intrasac thrombin injection and prophylactic embolization of aortic branches such as the inferior mesenteric artery and lumbar artery are reported to reduce the incidence of type II endoleak, the efficacy and clinical benefit of these procedures in terms of late postoperative aneurysm shrinkage have not been fully evaluated (12–15). Therefore, the purpose of this study was to identify the risk factors associated with late aneurysmal sac expansion after EVAR to determine possible indications for intrasac embolization and prophylactic embolization of aortic branches.