Hypogastric artery aneurysm rupture after endovascular graft exclusion with shrinkage of the aneurysm: significance of endotension from a "virtual," or thrombosed type II endoleak

Internal Iliac Artery Aneurysm Ruptures with No Visualized Endoleak 2 Years after Endovascular Repair

We report a case of an 83-year-old man with a ruptured internal iliac artery (IIA) aneurysm after endovascular repair, which was treated via the ligation of IIA and tight suture of the aneurysm sac. Although there were no findings of obvious endoleak after endovascular treatment, the IIA aneurysm increased in size and eventually ruptured. We presumed that pressure to IIA aneurysm via the embolized IIA led to rupture. Aneurysm sac expansion may lead to a rupture despite no endoleak being detected; therefore, close follow-up or re-intervention must be considered. Tight embolization of IIA may prevent endotension in the same case.

Hybrid Treatment of an Enlarging Hypogastric Aneurysm Previously Excluded During Abdominal Aortic Aneurysm Repair

Hypogastric aneurysm is rare, often asymptomatic, but associated with high mortality if it ruptures. Given the deep location of the artery and proximity to critical anatomical structures (i.e., ureter, bladder, and rectum), open surgical repair carries high morbidity and mortality compared with an endovascular approach. We report a simple hybrid approach to repair an enlarging isolated hypogastric aneurysm after a previous aortic aneurysm repair during which the origin of the hypogastric artery was ligated.

Coil embolization of an excluded internal iliac artery aneurysm with rapid expansion via gluteal artery approach

The aim of the paper is to describe open approach of gluteal arteries for coil embolization of internal iliac artery (IIA) aneurysm. We observed enlargement of the IIA to 5.8 cm at the four-year follow-up evaluation of a 78-year-old man who had undergone surgical abdominal aortic aneurysm repair during which the IIA had been ligated at its origin. Following dissection of the gluteal artery with the patient in the prone position, a catheter was placed inside the aneurysmal sac, and coil embolization was possible to exclude the aneurysm. Postoperative angio-computed tomography showed good coil positioning and no demonstrable blood flow or type 2 endoleak.

Technical and outcome considerations of endovascular treatment for internal iliac artery aneurysms

PURPOSE

This study was designed to analyze the outcomes of endovascular treatment for internal iliac artery aneurysm (IIAA) at mid-term follow-up.

METHODS

We retrospectively analyzed 33 patients (28 males, mean age 77.4 years) who underwent endovascular treatment of 35 IIAAs (mean diameter 39.8 mm) from 2002 to 2012. We attempted to completely and selectively embolize all distal branches with permanent embolic materials, followed by proximal controls either by stent-graft placement (type 1) or coil embolization (type 2).

RESULTS

Procedural success rate was 97.1% (n = 34). Complete permanent distal branches embolization was achieved in 27 (79.4%), type 1 in 24 (70.6%), and type 2 in 10 (29.4%) cases. During mean follow-up period of 29.1 months (range, 1.2-92.8), no IIAA-related mortality and stent/stent-graft related complications occurred. Pelvic ischemia occurred and resolved in 8 (25%) patients. Among 32 cases followed by CT, the aneurysm diameter was stable in 18 (56.3%), shrank in 11 (34.4%), and enlarged in 3 (9.4%) cases. In 22 assessed by contrast-enhanced CT, secondary endoleak occurred in 3 (13.6%) cases and 2 required secondary interventions (2/32, 6.3%). Type 1 procedure tends to have better mid-term outcomes. Incomplete permanent distal branches embolization was associated with enlargement and secondary intervention (p = 0.007 and p = 0.042, respectively). The secondary intervention-free rate at 3 years in the complete and incomplete distal embolization group was 100 and 83.3%, respectively (p = 0.128).

CONCLUSIONS

Endovascular treatment for IIAA is feasible and safe. Complete permanent distal branches embolization is important to achieve satisfactory mid-term outcomes.

Ruptured Hypogastric Artery Aneurysms

The ruptured hypogastric artery aneurysm (RHAA) is a rare clinical entity with an evolving and dynamic therapeutic armamentarium. The anatomical location and varied clinical presentation can pose a challenge for successful repair. Recently, endovascular and hybrid operative repairs have significantly improved the historically high-operative mortality rate. We present an illustrative case and contemporary review of the literature with respect to RHAA.

Current Endovascular Management of Abdominal Aortic Aneurysm

Fatal rupture of abdominal aortic aneurysm (AAA) remains a feared complication. Development of vascular surgery techniques over 50 years ago has fulfilled the promise of preventing rupture, but the significant morbidity associated with open repair causes physicians and their older patients pause. With the advent of less invasive endovascular techniques and devices, patients now have another viable treatment option. We review some of the important trials as well as discuss developments in the continually evolving field of endovascular repair of AAAs.

[Endovascular repair of aortic aneurysm--preliminary results]

INTRODUCTION

Endovascular aneurysm repair (EVAR) has been introduced into clinical practice at the beginning of the 90's of the last century. Because of economic, political and social problems during the last 25 years, the introduction of this procedure in Serbia was not possible.

OBJECTIVE

The aim of this study was to present preliminary experiences and results of the Clinic for Vascular Surgery of the Serbian Clinical Centre in Belgrade in endovascular treatment of thoracic and abdominal aortic aneurysms.

METHODS

The procedure was performed in 33 patients (3 female and 30 male), aged from 42 to 83 years. Ten patients had a descending thoracic aorta aneurysm (three atherosclerotic, four traumatic--three chronic and one acute as a part of polytrauma, one dissected, two penetrated atherosclerotic ulcers), while 23 patients had the abdominal aortic aneurysm, one ruptured and two isolated iliac artery aneurysms. The indications for EVAR were isthmic aneurismal localisation, aged over 80 years and associated comorbidity (cardiac, pulmonary and cerebrovasular diseases, previous thoracotomy or multiple laparotomies associated with abdominal infection, idiopathic thrombocitopaenia). All of these patients had three or more risk factors. The diagnosis was established using duplex ultrasonography, angiography and MSCT. In the case of thoracic aneurysm, a Medtronic-Valiant endovascular stent graft was implanted, while for the abdominal aortic aneurysm Medtronic-Talent endovascular stent grafts with delivery systems were used. In three patients, following EVAR a surgical repair of the femoral artery aneurysm was performed, and in another three patients femoro-femoral cross over bypass followed implantation of aortouniiliac stent graft.

RESULTS

During procedure and follow-up period (mean 1.6 years), there were: one death, one conversion, one endoleak type 1, six patients with endoleak type 2 that disappeared during the follow-up period, one early graft thrombosis. No other complications, including aneurysm expansion, collapse, deformity and migration of the endovascular stent grafts, were registered.

CONCLUSION

According to all medical and economic aspects, we recommend EVAR to treat acute traumatic thoracic aortic aneurysm, as well as in elderly and high-risk patients with abdominal or thoracic aneurysms, when open surgery is related to a significantly higher mortality and morbidity.

Surgical access of the gluteal artery to embolize a previously excluded, expanding internal iliac artery aneurysm

We describe open exposure of the inferior gluteal artery to allow coil embolization on an enlarging internal iliac artery aneurysm after previous abdominal aortic aneurysm (AAA) repair. An 84-year-old man with a stoma had undergone open AAA repair surgery 8 years previously, during which the proximal aortic neck and both proximal external iliac arteries were ligated, followed by an aorta to right external iliac and left common femoral bypass. Eight years later, he complained of abdominal pain, and a computed tomographic (CT) scan revealed persistent flow in the right internal iliac artery with enlargement to 8 cm in diameter. Because prograde access to the internal iliac artery was not possible as a result of the previous exclusion, the inferior gluteal artery was exposed surgically. Coil embolization of the arteries supplying the internal iliac artery aneurysm was successfully performed. The AAA and internal iliac artery aneurysm were treated by the exclusion technique. Eight years after the operation, CT revealed that the iliac artery had expanded to approximately 8 cm in diameter. The patient was placed face down, and a catheter was directly inserted into the internal iliac artery from the inferior gluteal artery. Four embolization coils were placed in the internal iliac artery and its branches. Absence of blood flow and shrinkage of the aneurysm were subsequently confirmed in the aneurysm, as shown by echogram color duplex scanning and CT scanning at 1 year. This technique could also be applicable for persistent blood flow in an internal iliac aneurysm after endovascular AAA repair, and the size of the aneurysm was reduced to approximately 1 cm 1 year after the operation.

Endovascular Treatment of an Internal Iliac Artery Aneurysm Using a Nitinol Vascular Occlusion Plug

PURPOSE

To report endovascular occlusion of an internal iliac artery (IIA) aneurysm with an Amplatz nitinol vascular occlusion plug.

CASE REPORT

A 71-year-old asymptomatic man who had previously undergone open aortic aneurysm repair presented for annual follow-up. A bifurcated Dacron graft had been inserted 12 years ago from the infrarenal aorta to the left common femoral artery and the right common iliac artery. The left common iliac artery was ligated proximally, and the left external iliac artery (EIA) provided retrograde flow into the IIA. Magnetic resonance imaging (MRI) revealed a 7.4-cm aneurysm of the left IIA. After transfemoral calibrated catheter angiography was performed, the proximal EIA was occluded with an Amplatz nitinol vascular occlusion plug. In addition, microcoils were placed distal to the vascular plug to achieve complete thrombosis of the vessel. One day after treatment, the patient was discharged free of symptoms after MRI had shown complete obliteration of the IIA aneurysm. At 6 months, the patient was free from symptoms, and angiography confirmed exclusion of the IIA aneurysm.

CONCLUSIONS

This case illustrates the technical feasibility and successful short-term follow-up of a novel embolization approach to IIA aneurysms in patients with an aortofemoral graft.

Influence of type II endoleak volume on aneurysm wall pressure and distribution in an experimental model

OBJECTIVE(S)

We have previously shown that type II endoleak size is a predictor of aneurysm growth after aortic endografting. To better understand this observation, we investigated the influence of endoleak size on pressure transmitted to the aneurysm wall and its distribution within the aneurysm sac.

METHODS

In an ex vivo model, an artificial aneurysm sac was incorporated within a mock circulation comprised of rubber tubing and a pulsatile pump. Three strain-gauge pressure transducers were placed in the aneurysm wall at different locations, including the site of maximum aneurysm diameter. The aneurysm was filled with either human aneurysm thrombus or dough that mimicked thrombus and simulated type II endoleaks of varying volumes (1 to 10 mL) were created. Aneurysm wall pressure (AWP) measurements were recorded at mean arterial pressures (MAPs) of 60, 80, and 100 mm Hg. Correlation coefficients ( r ) and analysis of variance were used to assess the relationship between endoleak volume and AWP.

RESULTS

Increasing endoleak volume '3 cm 3 resulted in proportionally increased AWP at all levels of MAP and at all sites, with highest pressures recorded at the site of the maximum aneurysm diameter (r = 0.83 when MAP = 100 mm Hg; r = 0.85 when MAP = 80 mm Hg; r = 0.88 when MAP = 60 mm Hg; P < .001). AWP plateaued when the endoleak volume was >3 cm 3 . Pressure distribution within the sac was not uniform. Although the difference was within +/-10%, statistically significant higher AWPs were observed at the site of maximum aneurysm diameter (P <.001). AWP also correlated with MAP.

CONCLUSIONS

Increasing type II endoleak volume results in proportionally higher AWP, which is greatest at the site of maximum aneurysm diameter. This study confirms the clinical observation that type II endoleak volume and MAP may be important predictors of aneurysm expansion.

CLINICAL RELEVANCE

Our experimental model of a type II endoleak revealed that endoleak size is a significant factor that influences the magnitude of pressure transmission into the aneurysm wall. Increasing volume of the endoleak nidus was associated with proportionally higher aneurysm sac pressures. This mechanism may, in fact, account for the increased risk of aneurysm expansion observed in our clinical experience, thereby suggesting the need for more aggressive surveillance and possibly earlier intervention for patients with larger endoleaks.

Endovascular Aortic Aneurysm Repair with the Zenith Endograft in Patients with Ectatic Iliac Arteries

Endovascular aortic aneurysm repair (EVAR) in patients with ectatic iliac arteries is feasible; however, most studies have reported experience from single institutions where distal flare techniques with endograft components were used on an "off-label basis." The Zenith endovascular graft allows adequate seal in ectatic common iliac arteries (CIAs) with diameters up to 20 mm. To determine whether large or ectatic CIAs are a risk factor for early and late endograft failure, we analyzed data from the Zenith U.S. multicenter trial. Among 352 patients receiving the endograft in the Zenith u.s. clinical study, 156 patients (44%) had at least one ectatic iliac artery (maximum diameter between 14 and 20 mm), whereas 22 (6.3%) had bilateral CIAs of normal diameter (< 14 mm). Variables analyzed included those defined by the reporting standards for EVAR (SVS/AAVS) as well as iliac-related outcome and indications for secondary iliac interventions. Univariate (Kaplan-Meier [KM] receiver operating characteristics curve, and Cox regression analyses were used to determine the association between CIA diameter and iliac-related complications. The median follow-up period was 24 months. Technical success was similar (>99%) for patients with ectatic and normal CIAs. Only one late type I distal endoleak was reported and was attributed to failure of distal iliac seal in a patient with ectatic CIAs. Freedom from iliac-related secondary intervention (IRSI) was not significantly different between the groups (KM, log-rank test, p = 0.98) with rates at 1, 12, and 24 months of 98%, 97%, and 95% for patients with ectatic CIAs, and 100%, 95%, and 95% for patients with normal iliac arteries, respectively. Moreover, Cox regression analysis revealed that the maximum CIA diameter was not a significant predictor of freedom from IRSI (hazard ratio, 0.98; 95% confidence interval, 0.7-1.4; p = 0.98). In patients with large CIAs, indications for IRSI included distal type I endoleak (1, 0.6%), type III endoleak (1, 0.6%), graft limb occlusion (4, 2.6%), and device stenosis (1, 0.6%). The only IRSI in a patient with normal CIAs was performed for device stenosis (4.6%). In conclusion, the Zenith endograft is effective for EVAR in patients with ectatic CIAs. Moreover, the presence of large CIAs was not associated with an increased risk of adverse iliac-related outcome or subsequent IRSI. Long-term surveillance, however, is mandatory, as IRSIs may be necessary.

Outcome of popliteal artery aneurysms after exclusion and bypass: Significance of residual patent branches mimicking type II endoleaks

PURPOSE

Popliteal aneurysms (PAs) often are treated with exclusion and bypass. However, excluded aneurysms can transmit systemic pressure from persistent flow through collateral arteries (endoleak), resulting in aneurysm growth and rupture. We used duplex ultrasound scanning for postoperative surveillance more than 2 years after PA repair with exclusion and bypass, to determine the presence of flow and aneurysm growth.

METHODS

From 1995 to 2001, 23 patients with 26 PAs (mean diameter, 3.2 cm; range, 1.6-5.6 cm) underwent surgical repair and were available for more than 2 years of follow-up. The popliteal artery was ligated proximal and distal to the aneurysm, and autogenous revascularization was performed. All patients who underwent PA endoaneurysmorrhaphy through a posterior approach were excluded from the study. During long-term follow-up, aneurysm sac flow and size were evaluated with duplex ultrasound scanning, computed tomography, or magnetic resonance angiography, and standard angiography. Patients with increased PA size and persistent flow were offered repair through a posterior approach.

RESULTS

Over 7 years, 26 PAs (symptomatic, 11; asymptomatic, 15) treated with aneurysm exclusion and bypass were available for more than 2 years of follow-up (mean, 38 months; range, 24-78 months). In the postoperative period 16 PAs (62%) became thrombosed, 10 (38%) had persistent collateral flow through geniculate vessels, 6 (23%) increased in size, and 3 (12%) ruptured; 1 (4%) resulted in limb loss. Operative findings for all ruptured PAs and 3 of 6 PAs with increased sac size that underwent aneurysm sac exploration and endoaneurysmorrhaphy revealed retrograde flow through geniculate vessels, mimicking type II endoleak.

CONCLUSIONS

These findings question the effectiveness of PA exclusion through proximal or distal ligation and bypass. In addition, retrograde flow into the aneurysm sac (ie, type II endoleak after endovascular abdominal aortic aneurysm repair) may transmit systemic pressure that can result in aneurysm rupture. We recommend PA treatment with aneurysm sac decompression and ligation of geniculate vessels whenever possible and routine postoperative surveillance of the excluded aneurysm sac.

Transcatheter Embolization of Hypogastric Artery Aneurysms: Lessons Learned

Transcatheter embolization of hypogastric artery aneurysms has become an attractive therapeutic alternative for many patients with this difficult lesion. Because of the increasing use of stent grafting for treatment of abdominal aortic aneurysms, transcatheter embolization of normal-caliber hypogastric arteries has become an almost routine procedure, usually accomplished with little morbidity. Applying this treatment to aneurysmal hypogastric arteries, however, involves greater technical complexity and a significantly higher risk of ischemic complications. We present three cases to illustrate the technical challenges of hypogastric aneurysm embolization, the potentially devastating ischemic complications, and the clinical situations that may predispose to poor outcomes.

Predicting aneurysm enlargement in patients with persistent type II endoleaks

OBJECTIVE

The clinical significance of type II endoleaks is not well understood. Some evidence, however, indicates that some type II endoleaks might result in aneurysm enlargement and rupture. To identify factors that might contribute to aneurysm expansion, we analyzed the influence of several variables on aneurysm growth in patients with persistent type II endoleaks after endovascular aortic aneurysm repair (EVAR).

METHODS

In a series of 348 EVARs performed during a 10-year period, 32 patients (9.2%) developed type II endoleaks that persisted for more than 6 months. Variables analyzed included those defined by the reporting standards for EVAR (SVS/AAVS) as well as other endoleak characteristics. Univariate, receiver operating characteristic curve, and Cox regression analyses were used to determine the association between variables and aneurysm enlargement.

RESULTS

The median follow-up period was 26.5 months (range, 6-88 months). Thirteen patients (41%) had aneurysm enlargement by 5 mm or more (median increase in diameter, 10 mm), whereas 19 (59%) had stable or shrinking aneurysm diameter. Univariate and Cox regression analyses identified the maximum diameter of the endoleak cavity, ie, the size of the nidus as defined on contrast computed tomography scan, as a significant predictor for aneurysm enlargement (relative risk, 1.12; 95% confidence interval, 1.04-1.19; P =.001). The median size of the nidus was 23 mm (range, 13-40 mm) in patients with aneurysm enlargement and 8 mm (range, 5-25 mm) in those without expansion (Mann-Whitney U test, P <.001). Moreover, receiver operating characteristic curve and Cox regression analyses showed that a maximum nidus diameter greater than 15 mm was particularly associated with an increased risk of aneurysm enlargement (relative risk, 11.1; 95% confidence interval, 1.4-85.8; P =.02). Other risk factors including gender, smoking history, hypertension, need of anticoagulation, aneurysm diameter, type of endograft used, and number or type of collateral vessels were not significant predictors of aneurysm enlargement.

CONCLUSIONS

In patients with persistent type II endoleaks after EVAR, the maximum diameter of the endoleak cavity or nidus is an important predictor of aneurysm growth and might indicate the need for more aggressive surveillance as well as earlier treatment.

Type II endoleak after endovascular abdominal aortic aneurysm repair: a conservative approach with selective intervention is safe and cost-effective

OBJECTIVES

The conservative versus therapeutic approach to type II endoleak after endovascular repair of abdominal aortic aneurysm (EVAR) has been controversial. The purpose of this study was to evaluate the safety and cost-effectiveness of the conservative approach of embolizing type II endoleak only when persistent for more than 6 months and associated with aneurysm sac growth of 5 mm or more.

METHODS

Data for 486 consecutive patients who underwent EVAR were analyzed for incidence and outcome of type II endoleaks. Spiral computed tomography (CT) scans were reviewed, and patient outcome was evaluated at either office visit or telephone contact. Patients with new or late-appearing type II endoleak were evaluated with spiral CT at 6-month intervals to evaluate both persistence of the endoleak and size of the aneurysm sac. Persistent (>or=6 months) type II endoleak and aneurysm sac growth of 5 mm or greater were treated with either translumbar glue or coil embolization of the lumbar source, or transarterial coil embolization of the inferior mesenteric artery.

RESULTS

Type II endoleaks were detected in 90 (18.5%) patients. With a mean follow-up of 21.7 +/- 16 months, only 35 (7.2%) patients had type II endoleak that persisted for 6 months or longer. Aneurysm sac enlargement was noted in 5 patients, representing 1% of the total series. All 5 patients underwent successful translumbar sac embolization (n = 4) or transarterial inferior mesenteric artery embolization (n = 4) at a mean follow-up of 18.2 +/- 8.0 months, with no recurrence or aneurysm sac growth. No patient with treated or untreated type II endoleak has had rupture of the aneurysm. The mean global cost for treatment of persistent type II endoleak associated with aneurysm sac growth was US dollars 6695.50 (hospital cost plus physician reimbursement). Treatment in the 30 patients with persistent type II endoleak but no aneurysm sac growth would have represented an additional cost of US dollars 200000 or more. The presence or absence of a type II endoleak did not affect survival (78% vs 73%) at 48 months.

CONCLUSIONS

Selective intervention to treat type II endoleak that persists for 6 months and is associated with aneurysm enlargement seems to be both safe and cost-effective. Longer follow-up will determine whether this conservative approach to management of type II endoleak is the standard of care.

Delayed open conversion following endovascular aortoiliac aneurysm repair: partial (or complete) endograft preservation as a useful adjunct

OBJECTIVES

The purpose of this study was to review our experience with delayed open conversion (>30 days) following endovascular aortoiliac aneurysm repair (EVAR) and to introduce the concept and advantages of endograft retention in this setting.

METHODS

From January 1992 to January 2003, a total of 386 EVARs using a variety of endografts were successfully deployed. Eleven (2.8%) patients required delayed conversion to open repair at an average of 30 months (range, 10-64). Data from all patients undergoing both EVAR and open conversion were prospectively collected.

RESULTS

EVARs were performed using grafts made by Talent (4), Vanguard (2,) AneuRx (1), and Surgeon (4). Conversion to open repair (9 transabdominal, 1 retroperitoneal, 1 transabdominal plus thoracotomy) was performed for aneurysm rupture in 7 patients (4 type 1 endoleak, 2 type 2 endoleak, 1 aortoenteric fistula) and aneurysm enlargement in 4 patients (1 type 1 endoleak, 1 type 2 endoleak, 1 type 3 endoleak, 1 endotension). Patients with aneurysm rupture were treated on an emergent basis. Complete removal of the endograft with supraceliac cross-clamping was performed in two cases. One patient (rupture) did not survive the operation, and one patient (aortoenteric fistula) died 2 weeks postoperatively. In the remaining nine cases, the endograft was either completely (1) or partially (6) removed, or left in situ (2). Supraceliac balloon control (2), supraceliac clamping (1), suprarenal clamping (1), or infrarenal clamping (5) was used in these cases. All nine of these patients survived the operation. In one procedure in which the endograft was left intact (endotension), repair was accomplished by exposing the endograft and by placing a standard tube graft over it as a sleeve. In the second procedure in which the graft was left in situ (rupture), the graft was well incorporated, and bleeding lumbar arteries were oversewn and the sac was closed tightly over the endograft. In the remaining 7 cases, the endograft was transected and the proximal portion only (6) or the proximal and distal portions (1) were excised. All surviving patients continue to do well and remain without complications associated with the endograft remnant at a mean follow-up of 22 months (range, 3-56) from the time of open conversion and 46 months (range, 10-73) from the time of original EVAR.

CONCLUSIONS

Open repair in the setting of a long-standing endograft offers several unique technical challenges but can be successfully accomplished in most patients. Preservation of all or part of the endograft is possible in many patients. This technique simplifies the operative approach and is preferred over complete endograft removal if possible.

Fate of excluded popliteal artery aneurysms

OBJECTIVE

Popliteal artery aneurysms (PAA) are frequently treated with ligation and exclusion bypass grafting. It is assumed that these aneurysms will shrink and remain asymptomatic. This may not always be true. We sought to elucidate the fate of excluded PAA over time.

METHODS

Data for all PAAs treated with ligation and exclusion bypass grafting between 1986 and 1999 were retrospectively reviewed. Computed tomography (CT) scans and duplex ultrasound scans provided aneurysm patency data and maximal transverse diameter measurements of the popliteal artery during late postoperative follow-up. This information was compared with that from similar preoperative studies.

RESULTS

Forty-one patients (39 men, 2 women) underwent 57 ligation and exclusion bypass grafting procedures. Both preoperative and late postoperative (mean, 4.0 years; range, 0.43-13.5 years) CT scans or duplex ultrasound scans were available for review of 25 PAAs in 18 patients (ages 42-80 years; mean, 63 years). Preoperative PAA size ranged from 14 to 45 mm (mean, 28.7 mm). In late follow-up, 12 (48%) PAA had decreased in size (mean, 7.3 mm), 5 (20%) remained unchanged, and 8 (32%) increased in mean transverse diameter (mean, 5.9 mm). One large aneurysm increased by 50%. Contrast material enhancement was identified in the excluded sac in 11 aneurysms.

CONCLUSIONS

PAA treated with ligation and exclusion bypass grafting often expand and can become symptomatic. This may be analogous to type II endoleak or endotension noted after aortic endovascular repair. We recommend PAA excision or endoaneurysmorrhaphy when feasible.

Significance of endotension, endoleak, and aneurysm pulsatility after endovascular repair

OBJECTIVE

The lack of aneurysm pulsatility after endovascular aneurysm repair (EVAR) is deemed by some an important guide to the effectiveness of exclusion. However, factors that contribute to aneurysm pulsatility after EVAR have not been elucidated. This study quantitatively analyzed the effects of systemic pressure, aneurysm sac pressure, endoleak, branch outflow from aneurysm sac, and intra-sac thrombus on aneurysm pulsatility after EVAR.

METHODS

In an ex vivo model, an artificial aneurysm sac was incorporated within a mock circulation comprised of rubber tubing and a pulsatile pump. The aneurysm sac was then completely excluded from the circulatory circuit with two types of stent-grafts, ie, supported and unsupported, and heparinized canine blood was circulated. Systemic circulation and aneurysm sac pressure was recorded in the absence and presence of endoleaks, and simulated open and closed lumbar branch outflow from the aneurysm sac. The aneurysm sac was then filled with organized human thrombus, and all pressure measurements were repeated. Two observers blinded to the above-mentioned variables independently evaluated aneurysm sac pulsatility with palpation in five separate experiments. Analysis of variance was performed, with significance accepted at P =.05.

RESULTS

Systemic pressure was simulated in the artificial circulation to range from 100/60 to 180/60 mm Hg. Regardless of the simulated lumbar branch outflow from the aneurysm, sac pressure was directly related to the presence of endoleak (P <.001). Aneurysm sac pulsatility was present only when the lumbar branch outflow was patent and not dependent on sac pressures. Aneurysm sac thrombosis or type of stent-graft did not influence sac pressure and pulsatility.

CONCLUSIONS

In this model, after EVAR pulsatility depends on aneurysm sac outflow, regardless of endoleak, sac thrombosis, sac pressure, or stent-graft. Furthermore, persistent pulsatility does not predict systemic intra-sac pressure, nor does lack of pulsatility reflect freedom of the aneurysm sac from systemic pressurization. This ex vivo model suggests that aneurysm pulsatility is an unreliable guide for predicting aneurysm sac pressurization after EVAR. Other diagnostic methods must be used to assess successful aneurysm exclusion.

Deep circumflex iliac artery as a cause of type II endoleak

PURPOSE

To report a collateral pathway involving the deep circumflex iliac artery causing a type II endoleak following endoluminal exclusion of an abdominal aortic aneurysm (AAA).

CASE REPORT

A 75-year-old man was investigated for a persistent type II endoleak 2 years after endovascular AAA repair with a Zenith Trifab stent-graft. Angiography revealed contrast in the sac from a lumbar artery fed via a collateral of the deep circumflex iliac artery. The lumbar artery was embolized with coils, but an endoleak persisted and is being followed.

CONCLUSIONS

This collateral pathway is easily missed during angiography for endoleaks and should be considered where an endoleak is suspected but cannot be found.

Controversies in the management of type II "branch" endoleaks following endovascular abdominal aortic aneurysm repair

Successful endovascular aortic aneurysm repair (EVAR) is often defined as complete exclusion of blood flow within the aneurysm sac. Perigraft flow, also known as endoleak, is the most common complication following EVAR. Attachment site related endoleaks (type I) are generally considered to warrant some form of intervention due to the belief that they represent a risk for future rupture. Management of type II endoleaks, also known as branch or collateral endoleaks, is more controversial. Some advocate a policy of watchful-waiting whereas others treat all type II endoleaks as soon as they are discovered. The following review explores the controversies pertaining to the management, diagnosis and surveillance imaging, and treatment of type II endoleaks.

Endovascular treatment of aneurysmal disease

Endovascular repair of abdominal aortic aneurysm using stent grafts that are delivered intraluminally by catheters is a less invasive alternative to open surgical repair. Endovascular surgery has been studied for over a decade, and early results are comparable to open repair. With extended follow-up care, however, postoperative complications and graft failures have been reported in some patients, resulting in reintervention, conversion to open repair, and death. The high incidence of secondary interventions causes some researchers to question the durability of endograft repair and emphasizes the need for detailed long-term follow-up care. This article describes the evolution of endovascular treatment of abdominal aortic aneurysm from its origin to its current state and discusses the future direction of endovascular therapy.

Are type II (branch vessel) endoleaks really benign?

The natural history and clinical significance of type II or branch vessel endoleaks following endovascular aortic aneurysm (AAA) repair remain unclear. Some investigators have suggested that these endoleaks have a benign course and outcome and that they can be safely observed. The purpose of this study was to document the natural history and outcome of all type II endoleaks that have occurred following endovascular AAA repair at our institution. A review of a prospectively compiled database of all endovascular AAA repairs performed at our institution was performed. From this review, we determined that type II endoleaks appear to have a relatively benign course, with a reasonable chance of spontaneously sealing within a 2-year period. No cases of rupture or aneurysm enlargement were documented in patients with open type II leaks. However, almost one-third of the patients did not manifest a type II leak until after their initial CT scan. The implications of such a "delayed" leak are unclear. Careful follow-up remains mandatory in patients with type II endoleaks to better define outcome.