Endoleak after endovascular repair of abdominal aortic aneurysm.

PURPOSE: We sought to assess the role of endovascular techniques in the management of perigraft flow (endoleak) after endovascular repair of an abdominal aortic aneurysm. METHOD: We performed endovascular repair of abdominal aortic aneurysm in 114 patients, using a variety of Gianturco Z-stent-based prostheses. Results were evaluated with contrast-enhanced computed tomography (CT) at 3 days, 3 months, 6 months, 12 months, and every year after the operation. An endoleak that occurred 3 days after operation led to repeat CT scanning at 2 weeks, followed by angiography and attempted endovascular treatment. RESULTS: Endoleak was seen on the first postoperative CT scan in 21 (18%) patients and was still present at 2 weeks in 14 (12%). On the basis of angiographic localization of the inflow, the endoleak was pure type I in 3 cases, pure type II in 9, and mixed-pattern in 2. Of the 5 type I endoleaks, 3 were proximal and 2 were distal. All five resolved after endovascular implantation of additional stent-grafts, stents, and embolization coils. Although inferior mesenteric artery embolization was successful in 6 of 7 cases and lumbar embolization was successful in 4 of 7, only 1 of 11 primary type II endoleaks was shown to be resolved on CT scanning. There were no type III or type IV endoleaks (through the stent-graft). Endoleak was associated with aneurysm dilation two cases. In both cases, the aneurysm diameter stabilized after coil embolization of the inferior mesenteric artery. There were two secondary (delayed) endoleaks; one type I and one type II. The secondary type I endoleak and the associated aneurysm rupture were treated by use of an additional stent-graft. The secondary type II endoleak was not treated. CONCLUSIONS: Type I endoleaks represent a persistent risk of aneurysm rupture and should be treated promptly by endovascular means. Type II leaks are less dangerous and more difficult to treat, but coil embolization of feeding arteries may be warranted when leakage is associated with aneurysm enlargement.     

Laparoscopic transperitoneal clipping of the inferior mesenteric artery for the management of type II endoleak after endovascular repair of an aneurysm

We report the case of a high risk patient with an abdominal infrarenal aortic aneurysm (AAA) who was treated by endovascular technique and the subsequent management of a type II endoleak by the laparoscopic approach. In this case, a 74-year-old woman with a 6-cm infrarenal AAA underwent endovascular repair using a bifurcated stent-graft device. Surveillance CT scan showed a persistent type II endoleak at 1 week and 3 months after the operation. Angiography confirmed retrograde flow from the inferior mesenteric artery (IMA). Attempted transarterial embolization of the IMA via the superior mesenteric artery was not successful. Laparoscopic transperitoneal IMA clipping was performed. Subsequent aortic duplex scan and CT scan confirmed complete elimination of the type II endoleak. We conclude that a combination of endovascular and laparoscopic procedures can be used to manage AAA successfully.     

Treatment of an early type II endoleak causing hemorrhage after endovascular aneurysm repair for ruptured abdominal aortic aneurysm

We report a case of ruptured abdominal aortic aneurysm emergently treated by endovascular aneurysm repair (EVAR) that developed a primary type II endoleak leading to persistent blood loss and retroperitoneal hematoma increase. Coil embolization resolved this. Although to our knowledge there are no recommendations regarding this, our report suggests that early type II endoleaks occurring after emergency EVAR for ruptured AAA should be treated when it is associated with blood extravasation outside the aneurysm sac.     

Patency of Infrarenal Aortic Side Branches Determines Early Aneurysm Sac Behavior after Endovascular Repair

In this study we sought to determine whether initial abdominal aortic aneurysm (AAA) sac anatomy, morphology, and side branch patency influence changes in aneurysm size and development of endoleak following endovascular repair. A blinded, retrospective review of preintervention CT scans and angiograms was conducted on 70 consecutive patients treated for infrarenal AAA (mean size 6.0 +/- 0.8 cm) by AneuRx stent-graft exclusion. Initial AAA diameter and side branch (inferior mesenteric artery [IMA], lumbar artery pair) patency, AAA clot/sac diameter ratio, wall thrombus and calcification distributions, attachment site anatomy, endograft size, and other clinical parameters were correlated with postoperative persistent side branch patency, presence of type II endoleak, and change in AAA diameter (increase/decrease ? 5 mm) using contingency table analyses. Patients underwent CT scanning and/or color duplex imaging at 1 month and at 3 (with endoleak) or 6 (without) month intervals postoperatively with 50 patients followed beyond 6 months (mean follow-up 11 +/- 7 months). The majority of patients possessed patent side branches prior to intervention (lumbar [n = 60, 86%], IMA [n = 45, 64%]). Development of type II endoleak or persistence of side branches could not be predicted (p > 0.05) from preoperative AAA side branch patency or any of the other initial anatomic AAA variables. On serial post-repair CT or duplex cans, 42% (19/45) of IMAs and 27% (16/60) of lumbar artery pairs remained patent. For patients followed beyond 6 months, type II endoleaks persisted in half (13/25) of the patients with patent side branches with roughly equal proportions fed by IMA and lumbar sources. Persistent side branches or presence of type II endoleak was associated with AAA expansion or the failure of aneurysm size diminution after endografting (p <0.01). Aneurysm sac regression was most likely in the absence of endoleak and patent side branches. We conclude that persistent side branch patency not only fuels development of type II endoleak but also influences early aneurysm sac behavior after endovascular repair. Optimal anatomic patient selection for endografting may not be possible on the basis of our initial experience, since preoperative AAA variables did not predict persistence of side branches or type II endoleaks.     

Increased Recognition of Type II Endoleaks Using a Modified Intraoperative Angiographic Protocol: Implications for Intermittent Endoleak and Aneurysm Expansion

Retrograde arterial perfusion of the aneurysm sac (type II endoleak) may complicate endovascular abdominal aortic aneurysm (AAA) repair and may lead to AAA expansion and rupture. Aneurysm expansion may also occur in the absence of a demonstrable endoleak. Current intraoperative assessment techniques may underrepresent the incidence of type II endoleaks. This study evaluated the incidence and impact of previously unrecognized type II endoleaks using a modified intraoperative angiographic protocol. A total of 391 patients undergoing endovascular AAA repair were evaluated. In 264 patients standard completion angiograms were performed. In 127 patients a modified angiographic protocol was used to visualize collateral lumbar and inferior mesenteric arteries as well as the aneurysm sac. The modified protocol uses digital subtraction fluoroscopy continuously for 60 sec after injections of 20 mL iodinated contrast both in the pararenal aorta and within the endovascular graft. Postoperative CT scans were performed at 1, 6, and 12 months and annually thereafter. The average age was 73.3 years; 324 patients were men and 67 were women. Mean follow-up was 11.4 months (range, 1-60 months). Type II endoleaks were documented intraoperatively in a significantly increased proportion of patients in whom the modified angiographic protocol was used: modified, 53/127 = 41% vs. standard, 17/264 = 6%; p < 0.001. No significant difference in the incidence of type II endoleaks was present on CT scan at 6 or 12 months after surgery (6 months: modified, 6/72 = 8% vs. standard, 10/159 = 6%, p = NS; 12 months: modified, 2/36 = 5% vs. standard, 6/138 = 4%, p = NS). Forty-six type II endoleaks resolved spontaneously (10 in the standard cohort, 36 in the modified cohort). One patient had a 10-mm increase in AAA diameter after spontaneous thrombosis of a type II endoleak 18 months postoperatively. One patient had a type II endoleak intraoperatively and at 12 months after surgery but the endoleak was absent at 1 and 6 months. Thirteen patients from the standard protocol cohort and 1 from the modified protocol cohort developed newly visualized type II endoleaks during follow-up. These findings may imply intermittent patency of the artery supplying the type II endoleak. The overall morbidity rate was 14% and the perioperative mortality rate was 1.8%. Retrograde (type II) endoleaks originating from AAA side branches occur intraoperatively more frequently than is currently recognized. Intermittent patency and thrombosis of these vessels may also occur and may contribute to AAA expansion. The full significance of these previously unrecognized endoleaks with respect to risk of aneurysm rupture remains to be definitively determined. Presented at the Thirteenth Annual Winter Meeting of the Peripheral Vascular Surgery Society, Snowmass, CO, January 31-February 2, 2003. Faries et al. Intraoperative angiographic protocol for type II endoleaks     

Prospective evaluation of magnetic resonance imaging after endovascular treatment of infrarenal aortic aneurysms.

OBJECTIVES: to evaluate the sensitivity and specificity of magnetic resonance imaging (MRI) in the detection of type II endoleaks during follow-up after endovascular treatment of intra-renal aortic aneurysms. DESIGN: prospective study. MATERIAL AND METHODS: between March 1996 and November 1999, 31 patients with infra-renal aortic aneurysms who underwent stentgraft implantation were followed with helical CT and MRI, including magnetic resonance angiography (MRA), at 1 and 6 months after the procedure. Arteriography was performed between 6 and 12 months after intervention. The parameters studied included the change in the maximum anteroposterior and transverse diameters, the nature of the signal on T1 and T2 weighted sequences (homogeneous vs heterogeneous), the presence or absence of Gadolinium uptake on MRI or of contrast uptake on helical CT (early and late phases) in the sac of the aneurysm. On MRA, stentgraft patency and endoleak detection were studied. RESULTS: arteriography demonstrated an endoleak in 19 patients (18 type II, and 1 type I endoleak). MRI at 6 months detected 18/19 endoleaks on T1 weighted sequences after injection of Gadoliniumj; there were 2 false positives. MRA sequences confirmed stentgraft patency in all patients, but did not diagnose type II endoleaks. Helical CT (late phase) at 6 months detected 10/19 endoleaks; there was 1 false positive. The sensitivity of MRI after injection of Gadolinium and of helical CT for the detection of type II endoleaks were 94% and 50% (p=0.003) respectively. The mean maximal anteroposterior and transverse diameters were similar on MRI and on helical CT at 1 month and at 6 months. CONCLUSION: MRI after injection of Gadolinium is more sensitive than helical CT in the detection of type II endoleaks after stentgraft implantation. Its more widespread use may permit earlier intervention in such patients.     

Follow-up evaluation of endoluminally treated abdominal aortic aneurysms with duplex ultrasonography: validation with computed tomography

OBJECTIVE: A growing number of patients with abdominal aortic aneurysms are currently being offered endoluminal treatment. However, the incidence of endoleaks, stenosis, and thrombosis is around 25% to 30%. As a result, a strict post procedure imaging surveillance protocol is necessary. The purpose of this study was to compare duplex ultrasonography (DU) and computed tomography (CT) for the follow-up of endoluminally treated aortic aneurysms. METHODS: A total of 89 patients were followed up with serial CT and DU at 1, 3, 6, 12, and 24 months after endoluminal treatment. Special attention was directed toward the presence of endoleaks and aneurysm diameter evolution. Preoperative CT and DU were also reviewed to assess aneurysm diameter correlation. RESULTS: With DU, 14 type I and 21 type II endoleaks were identified. In one case the DU did not visualize a type II endoleak present on CT, and CT did not confirm three type II leaks identified with DU. There was only one false positive for type I endoleak with DU. The sensitivity of DU was 96% with a specificity of 94%, when compared with CT. A linear regression analysis of the diameters obtained with DU and CT revealed a good correlation. However, variability was high, indicating poor agreement. Regarding diameter evolution, the range was identical in 45%, and the trend was similar in 73%. However, in 9% of the cases, DU showed a decrease in diameter, whereas CT showed a significant increase. CONCLUSION: DU is an accurate tool for the diagnosis of endoleaks, but is less valuable for diameter measurements, when compared with CT. Currently, DU is a useful tool, but CT remains a key part of the postoperative evaluation after endoluminal treatment of abdominal aortic aneurysms. At institutions where DU is used for follow-up, researchers should perform quality control studies to avoid potentially significant errors.     

Trans-limb embolization for treatment of Type 2 endoleak post EVAR: Case report

IntroductionType 2 endoleaks (T2EL) occur after 10%–25% of endovascular abdominal aortic aneurysm repairs and increase the risk factor of endograft repair failure and rupture. Herein we report a case of endovascular treatment of T2EL where we performed a trans-limb embolization.Presentation of caseA 63-years-old male previously treated for AAA with endovascular aortic aneurysms repair (EVAR), showed an angio-CT scan followup with a type 2 endoleak fed from inferior mesenteric artery (AMI) with growth of AAA greater of 1 cm than preoperative CT-scan and increase of chronic lumbar pain. Due to high risk of rupture was performed a trans-limb embolization with complete sealing. The 6 months CT-angiography showed complete type 2 endoleak exclusion without changes of AAA.DiscussionThe risk of aneurysm rupture in the presence of an isolated T2EL is exceptionally low. However, when a persistent T2EL is associated with a significant sac size increase, commonly considered as at least 5 mm over 6 months, should be treated. Detachable coils are repositionable, allowing an extremely precise deployment and subsequent embolization of different targets.ConclusionIn this experience trans-limb embolization was feasible and this tool should be taken in account especially when no other surgical options exists.     

Endovascular management of isolated iliac artery aneurysms

OBJECTIVE: We reviewed our experience with endovascular treatment of isolated iliac artery aneurysms (IAAs). METHODS: Medical records for consecutive patients undergoing endovascular IAA repair from 1995 to 2004 were reviewed. Computed tomography (CT) angiograms were used to assess IAA location, size, and presence of endoleaks after endovascular repair. Rates of primary patency and freedom from secondary interventions were estimated using the Kaplan-Meier life-table method. RESULTS: From July 1995 to November 2004, 45 patients (42 men), with a mean age of 75 years, underwent endovascular repair of 61 isolated IAAs: 41 common iliac, 19 internal iliac, and one external iliac. Five patients (11%) were symptomatic, although none presented with acute rupture. The mean preoperative IAA diameter was 4.2 +/- 1.7 cm. Fifteen patients (33%) had prior open abdominal aortic aneurysm repair. Local or regional anesthesia was used in 28 cases (62%). Thirty-four patients (75%) were treated with unilateral iliac stent-grafts, eight (18%) with bifurcated aortic stent-grafts, and three (7%) with coil embolization alone. Perioperative major complications included one early graft thrombosis that eventually required conversion to open repair and one groin hematoma that required operative evacuation. On follow-up, late complications included one additional graft thrombosis and one late death after amputation. No late ruptures occurred after endovascular repair, with a mean follow-up of 22 months (range, 0 to 60 months). The mean postoperative length of stay was 1.3 +/- 1.0 days. On postoperative CT scans obtained at 1, 6, 12, 24, and 36 months, aneurysm shrinkage was noted in 18%, 29%, 57%, 67%, and 83% of IAAs, respectively, compared with the baseline diameter. One hypogastric aneurysm enlarged in the presence of a later identified type II endoleak. Five endoleaks were noted (4 type II, 1 indeterminate) at 1 month, with four other endoleaks (1 type II, 1 type III, 2 indeterminate) identified on later CT scans. At 2 years, primary patency was 95%, and freedom from secondary interventions was 88%. CONCLUSIONS: Endovascular repair of isolated IAAs appears safe and effective, with initial results similar to those after endovascular abdominal aortic aneurysm repair.     

Aortoduodenal fistula occurring after type II endoleak treatment with coil embolization of the aortic sac

A bifurcated stent graft device was successfully deployed to exclude an asymptomatic abdominal aortic aneurysm (AAA) with adequate proximal aortic neck morphology. At 6 months, a type II endoleak was successfully embolized through a proximal perigraft channel with metallic coils. The patient was seen with upper gastrointestinal bleeding and a pulsatile abdominal mass 11 months later. Surgical exploration revealed an aortoduodenal fistula in the vicinity of the previous embolization. We discuss the possible causes of this complication and review the literature on the subject. We conclude that aortoduodenal fistula can occur after endovascular AAA repair despite the absence of endoleak or AAA diameter increase on follow-up computed tomographic scan.     

Comparison of Color Duplex Ultrasound and Computed Tomography Scan for Surveillance after Aortic Endografting

Endovascular repair of abdominal aortic aneurysms (AAA) requires regular surveillance for early detection of endograft failure. CT scanning is the gold standard surveillance procedure. The purpose of this study was to assess the reliability of color duplex ultrasound (CDU) in comparison to CT scanning for detection of endoleaks and changes in aneurysmal diameter. From November 1996 to September 1999, a total of 41 patients treated by aortic endografting underwent regular surveillance with both CT scanning and CDU. There were 39 men and 2 women with a mean age of 71 years (range, 50-83). Endovascular treatment involved deployment of a straight aorto-aortic stent in 6 cases, bifurcated stent in 33, and aorta-to-unilateral iliac artery stent in 2. Stent deployment failed in one case; the procedure was conversion to open surgery. Primary or secondary endoleaks were detected in 17 patients (42%). Our findings indicated that CDU is less reliable than the CT scan for detection of endoleaks, but that reliability of CDU for surveillance of aneurysmal diameter is fair.     

Late-onset Type II Endoleaks and the Incidence of Secondary Intervention

Type II endoleaks are a recognized complication of endoluminal treatment of abdominal aortic aneurysms. In order to better understand the natural history of type II endoleaks and their influence on secondary procedures, we examined our experience with patients who developed isolated type II endoleaks 6 months or more after their original procedure. We conducted a retrospective review of patients who underwent endoluminal repair of infrarenal abdominal aortic aneurysms with bifurcated endoluminal devices at a single institution from June 1996 to June 2000. Endoleak surveillance was performed on all patients by using a defined CT angiogram protocol. Patients with definitive and isolated type II endoleaks on CT angiogram were identified. Patients with indeterminate endoleaks or a combination of different types of endoleaks were excluded. Data were analyzed on the basis of early (<6 months) or late occurrence of isolated type II endoleak. Fifty patients were identified with isolated type II endoleaks. Of these patients, 20 (40%) had endoleaks discovered before the 6-month follow-up interval whereas the majority (60%) had new type II leaks discovered at least 6 months after their initial procedure. The timing of endoleak occurrence did not significantly influence the rate of spontaneous endoleak resolution between the early- (<6 months) and late-onset (>6 months) groups, which was nearly identical (40% vs. 43%). Ten patients in the early group and seven of the late-onset group required secondary intervention for treatment of type II endoleak (50% vs. 23%; NS). Three patients in the early group underwent surgical conversion (vs. 0 patients in the late-onset group). The mortality rate was not significantly different between groups (15% vs. 7%). Most isolated type II endoleaks in this patient population occurred 6 months or more after initial endoluminal repair of infrarenal abdominal aortic aneurysm. Timing of type II endoleak occurrence did not significantly affect the rates of spontaneous resolution or mortality. Although differences were observed in the number of patients receiving secondary interventions, these findings did not reach statistical difference. All patients who required surgical conversion had early type II endoleaks. There were no observed ruptures in patients with increased aneurysm size treated with secondary intervention or those with stable aneurysm volumes who were followed without intervention. The continued development of type II endoleaks beyond the perioperative period supports the need for continued endoleak surveillance. Presented at the Annual Meeting of the Southern California Vascular Surgical Society, Carlsbad, CA, April 11-13, 2003.     

Cyanoacrylate embolization of endoleaks after abdominal aortic aneurysm repair

Introduction: Type II endoleaks occur in up to a fifth of endoluminal repairs for abdominal aortic aneurysms and are commonly treated when aortic sac expansion can be demonstrated. Technical failure is common when catheter‐guided particulates or coil embolic agents are used. Presented here is a feasibility study using catheter‐directed N‐butyl‐2‐cyanoacrylate (Histoacryl, Braun, Tuttlingen, Germany) embolotherapy. Method: A retrospective review of the case notes of patients undergoing embolization procedures for type II endoleaks with expanding sacs was performed from this centre's cohort of endoluminal aortic repair patients under surveillance. Data on patients with type II endoleaks who were treated with either or both cyanoacrylate and coil embolization were extracted. The outcomes were then compared. Results: In total, five cases were identified, and four of these cases had both coil and glue embolization. Technical success was defined as endoleak closure proven on follow‐up computed tomographic imaging. Technical success was achieved in all four patients treated with intra‐sac cyanoacrylate. One case treated initially with coil embolization was successful. All patients had a computed tomographic scan at 3 months. One minor complication occurred that resolved without treatment. Discussion: Type II endoleaks after EVAR with expanding sacs require treatment. Percutaneous catheter‐directed cyanoacrylate embolization offers an alternative to coil or particulate embolization and, in this series, was found to be more likely to result in endoleak closure.     

Ultrasound surveillance of endovascular aneurysm repair: a safe modality versus computed tomography

Routine ultrasound surveillance is adequate and safe for monitoring endovascular aneurysm repairs (EVARs). A retrospective chart review including 160 endograft patients was performed from August 2000 to September 2005. All ultrasound examinations (n = 359) were performed by a board-certified vascular surgery group's accredited laboratory. Registered vascular technologists utilized the same equipment consisting of Siemens Antares high-definition ultrasonography with tissue harmonics and color flow Doppler. An identical protocol was followed by each technologist: scan body and both limbs of the endograft and distal iliac vessels, measure anterior-posterior aneurysm sac size, and detect intrasac pulsatility and color flow. Statistical analysis utilized Pearson's correlation coefficient and the paired t-test. Forty-one endoleaks were discovered out of the 359 exams (11.4%). There were type I (7, 17%), type II (26, 63%), and combined type I with type II (8, 20%) endoleaks. Correlation with computed tomography (CT) was obtained in 35 of these cases. CT discovered three endoleaks that were not seen with ultrasound. However, these particular ultrasound exams were inadequate due to additional factors (bowel gas, body habitus, hernia), which prompted CT investigation and, hence, endoleak discovery. Of the 41 endoleaks found on ultrasound, only 14 were seen on CT. Specifically, 26 type II endoleaks were seen with ultrasound versus only nine during CT. Additional factors addressed included comparison between ultrasound and CT of residual aneurysm sac measurements and conditions limiting ultrasound examination. Although criticized in the past, color flow ultrasonography is a safe and effective modality for surveillance of aortic endografts. Utilizing ultrasound to analyze abdominal aortic aneurysm (AAA) sac dimensions and endoleak detection is statistically sound for screening AAA status post-EVAR.     

腔内人造血管移植术治疗腹主动脉瘤

目的 评价腔内人造血管移植术治疗腹主动脉瘤早期临床疗效。方法 总结对14例腹主动脉瘤患者采用经腹股沟切口腹主动脉瘤腔内人造管移植术的经验。结果 12例选用分叉型腔内人造血管,2例选用直型腔内人造人管,术后即刻DSA造影显示动脉瘤消失,近远端人造血管与宿主动脉结合处均未见渗漏,11例患者术后生命体征平稳,1例术后24h出现小面积急性心肌梗塞,经溶栓和抗凝治疗后缓解,术后死亡2例,技术成功率85.7%。12例患者术后1周随访螺旋CT,其中有4例术后3个月、1例术后12个月再次做螺旋CT,显示人造血管无移位,2例有渗漏,但动脉瘤腔无增大。结论 腔内人造血管移植术是一种创伤小、恢复快的治疗腹主动脉瘤新方法,但远期疗效有待随访。     

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.     

Endoleaks after endovascular aneurysm repair lead to nonuniform intra-aneurysm sac pressure

OBJECTIVE: This was a study of intra-aneurysm sac pressures in patients who presented with endoleaks after endovascular repair (EVAR) of abdominal aortic aneurysms (AAA). METHODS: Twenty-five patients (18 men, 7 women) with endoleaks, age (IQR 68 to 80), underwent 31 direct intra-aneurysm sac pressure measurements, DISP at 16 months after EVAR (IQR, 14 to 26 months). Diameter of AAA was 59 mm (IQR, 52 to 67 mm). Six patients underwent DISP twice. Tip-pressure sensors were used through direct translumbar puncture of the AAA except in three patients (transabdominal puncture in 2; endoluminal in 1). Mean pressure index (MPI) was calculated between simultaneously registered intra-aneurysm sac and systemic pressures. Values presented are medians with interquartile range (IQR). RESULTS: Type I endoleaks (n = 1) showed MPI of 93% in the nidus and 62% in the thrombus. Type II endoleaks were associated with lower MPIs in the thrombus (35%; IQR 24% to 38%) when AAAs shrank (n = 4) compared with when the AAAs remained unchanged (n = 11; MPI, 78%; IQR, 47% to 85%) or expanded (n = 6; MPI, 74%; IQR, 58% to 87%; P = .019). The nidus of type II endoleaks (MPI, 79%; IQR, 70% to 90%) had higher pressure than the thrombus (45%, IQR, 34% to 85%; P = .047; n = 7). Successful embolization of type II endoleaks led to AAA shrinkage (n = 3; MPI reduction, 13% to 31%) or diameter stability (n = 3; unchanged MPIs, 37% to 44%). Type III endoleaks (n = 3) had MPIs in the thrombus of 33% to 70%. CONCLUSIONS: Endoleaks after EVAR pressurize the AAA sac nonuniformly, with higher, near-systemic, pressure in the endoleak nidus compared with the thrombus. Nevertheless, type II endoleaks in shrinking AAAs have lower intra-sac pressure than expanding or stable aneurysms, and successful endoleak embolization reduces pressure.     

Type II endoleaks: predictable,preventable, and sometimes treatable?

OBJECTIVE: The purpose of this study was to evaluate the effect of preoperative coil embolization of lumbar and inferior mesenteric arteries on the incidence of type II endoleak after endovascular abdominal aortic aneurysm repair. METHODS: The subjects were consecutive patients who underwent EVAR between January 1996 and January 2001. Patent aortic side branches were identified with preprocedural spiral computed tomographic scanning and calibrated angiography. Coil embolization was performed before EVAR. Patients were followed up with plain radiographs and ultrasound and dual phase spiral computed tomographic scans. Digital subtraction angiography was performed when endoleak was suspected. The outcome measures were the incidence of type II endoleaks and changes in maximum aortic sac diameter (Dmax). RESULTS: Forty patients underwent EVAR, with a median duration of follow-up of 24 months (range, 3 to 48 months). Before surgery, the inferior mesenteric artery was patent in 16 patients (45%) and the lumbar arteries in 21 patients (53%). Inferior mesenteric artery embolization was successful in 13 of 16 patients (81%). Lumbar embolization was attempted in 13 patients and was successful in eight (62%). During EVAR, successful sac exclusion was achieved in 38 patients (95%). None of the patients who underwent embolization before EVAR had type II endoleak develop, eight of 13 patients (62%) with patent lumbar arteries had endoleaks develop (P =.006), and three of these patients subsequently underwent successful coil embolization. Type II endoleak was associated with a 2.0-mm median increase in Dmax (P =.045). A 3.0-mm median reduction in Dmax was seen in the absence of type II endoleak (P =.002). CONCLUSION: Type II endoleaks are predictable, preventable, and sometimes treatable. Significant sac shrinkage occurs in the absence of lumbar endoleak but not in the presence of type II endoleak.