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S. William Stavropoulos - One of the best experts on this subject based on the ideXlab platform.

  • Type 2 Endoleak Management.
    Seminars in Interventional Radiology, 2020
    Co-Authors: James X. Chen, S. William Stavropoulos
    Abstract:

    Type 2 Endoleaks are the most common Endoleak type following endovascular aneurysm repair. The natural history of these Endoleaks can vary, with some demonstrating a self-limited or indolent course, while others can contribute to aneurysm sac enlargement and rupture. A variety of embolization techniques, including transarterial catheterization and direct sac puncture techniques, have been developed for the treatment of type 2 Endoleaks. In this article, the authors review the indications, techniques, and outcomes of current treatment strategies for type 2 Endoleaks.

  • Type 2 Endoleak Embolization Comparison: Translumbar Embolization versus Modified Transarterial Embolization
    Journal of Vascular and Interventional Radiology, 2009
    Co-Authors: S. William Stavropoulos, Ronald M Fairman, Jin Park, Jeffrey P. Carpenter
    Abstract:

    PURPOSE: To evaluate the success of Endoleak repair using translumbar (TL) Endoleak embolization compared with a transarterial (TA) technique that involves embolization of the Endoleak cavity itself in addition to the feeding artery. MATERIALS AND METHODS: Eighty-four patients (mean age, 78.2 years; age range, 58-94 years) with type 2 Endoleaks were included in this retrospective study. Patients underwent either TL Endoleak embolization or TA embolization between January 2002 and December 2007. TA embolization involved entering the Endoleak cavity through the inferior mesenteric or lumbar artery. Both the Endoleak cavity and the feeding artery were then embolized by using coils through a microcatheter. TL embolizations were performed by using standard technique with coils and n-butyl cyanoacrylate as the embolization agents. Clinical success was defined as the absence of an Endoleak and/or aneurysm enlargement at follow-up CT angiography. Statistical comparison was performed with the Fisher exact test. RESULTS: Endoleak repair was successful in 72% (45/62) of the TL embolizations and 78% (18/23) of the TA embolizations, with a mean follow-up of 18.7 months (range, 1-84 months). There was no significant difference in clinical success between the two groups (P = .41). There were two (3.2%) complications in the TL group and no complications in the TA group. CONCLUSIONS: The effectiveness of the TA Endoleak embolization technique, which involves embolizion of the Endoleak cavity and the feeding artery, is similar to that of TL embolization for treatment of type 2 Endoleaks.

  • Endoleaks after endovascular repair of thoracic aortic aneurysms
    Journal of vascular surgery, 2006
    Co-Authors: Shane S. Parmer, Ronald M Fairman, Jeffrey P. Carpenter, S. William Stavropoulos, Alberto Pochettino, Edward Y. Woo, G. William Moser, Joseph E. Bavaria
    Abstract:

    Objective Endoleaks are one of the unique complications seen after endovascular repair of thoracic aortic aneurysms (TEVAR). This investigation was performed to evaluate the incidence and determinants of Endoleaks, as well as the outcomes of secondary interventions in patients with Endoleaks, after TEVAR. Methods Over a 6-year period, 105 patients underwent TEVAR in the context of pivotal Food and Drug Administration trials with the Medtronic Talent (n = 64) and Gore TAG (n = 41) devices. The medical and radiology records of these patients were reviewed for this retrospective study. Of these, 69 patients (30 women and 39 men) had follow-up longer than 1 month and were used for this analysis. The patients were evaluated for the presence of an Endoleak, Endoleak type, aneurysm expansion, and Endoleak intervention. Results The mean follow-up in this patient cohort was 17.3 ± 14.7 months (range, 3-71 months). Endoleaks were detected in 29% (20/69) of patients, of which 40% (8/20) were type I, 35% (7/20) were type II, 20% (4/20) were type III, and 5% (1/20) had more than one type of Endoleak. Patients without Endoleaks experienced greater aneurysm sac regression than those with Endoleaks (−2.89 ± 9.1 mm vs −0.13 ± 7.2 mm), although this difference was not statistically significant ( P = .232). All but 2 Endoleaks (90%; 18/20) were detected on the initial postoperative computed tomographic scan at 30 days. Two Endoleaks (10%; 2/20) developed late. The Endoleak group had more extensive aneurysms with significantly larger aneurysms at the time of intervention (69.4 ± 10.5 mm vs 60.6 ± 11.0 mm; P = .003). Factors predictive of Endoleak included male sex ( P = .016), larger aneurysm size ( P = .003), the length of aorta treated by stent grafts ( P = .0004), and an increasing number of stents used ( P Conclusions Endoleaks are not uncommon after TEVAR. Many type I Endoleaks may be treated successfully by endovascular means. Short-term follow-up suggests that observational management of type II Endoleaks is associated with continued sac expansion, and these patients should be monitored closely.

  • Use of CT angiography to classify Endoleaks after endovascular repair of abdominal aortic aneurysms.
    Journal of vascular and interventional radiology : JVIR, 2005
    Co-Authors: S. William Stavropoulos, Ronald M Fairman, Jeffrey P. Carpenter, Timothy Clark, Harold Litt, Omaida C. Velazquez, Erik K Insko, Michael C. Farner, Richard A. Baum
    Abstract:

    PURPOSE Accurate Endoleak detection and classification is critical for the follow-up of patients who have undergone endovascular aneurysm repair (EVAR). This determination is often made with computed tomography angiography (CTA). This investigation was performed to determine the accuracy of CTA in the classification of Endoleaks in patients who have undergone EVAR. MATERIALS AND METHODS Thirty-six patients with Endoleaks underwent both CTA and conventional contrast digital subtraction angiography (DSA) to determine Endoleak etiology. Two independent radiologists determined the source of the Endoleak based on a retrospective review of the CTA. The results of the CTA-based Endoleak classification were compared to the reference standard, contrast DSA. RESULTS There was agreement regarding Endoleak classification between CTA and DSA on 86% of the patients (31 of 36 patients). Correlation between the CTA reading of the two readers was 94% (34 of 36 patients), yielding a kappa statistic of 0.8. In three patients, the CTA reading incorrectly classified Endoleaks as type 2 when the Endoleaks were actually type 1 Endoleaks on DSA. One patient was incorrectly classified as having a type 1 Endoleak on CTA when it was a type 2 Endoleak on DSA. Finally, one patient had a type 1 Endoleak on DSA that was incorrectly classified as a type 3 Endoleak on CTA. The change in CTA Endoleak classification based on the DSA resulted in a significant change in patient management in four of the 36 patients (11%). CONCLUSIONS Endoleak classification based on CTA correlates fairly well with DSA findings. However, optimal Endoleak management requires performance of selective angiograms with DSA to classify Endoleaks that are detected on CTA.

  • Recurrent Endoleak Detection and Measurement of Aneurysm Size with CTA After Coil Embolization of Endoleaks
    Journal of vascular and interventional radiology : JVIR, 2005
    Co-Authors: S. William Stavropoulos, Ronald M Fairman, Jeffrey P. Carpenter, Harold Litt, Horia L Marin, Maxim Itkin, Timothy Clark
    Abstract:

    PURPOSE The optimal modality for following aneurysm size and detecting Endoleaks after endovascular aneurysm repair (EVAR) remains controversial. Computed tomographic angiography (CTA) has been widely employed but can be limited by metal artifact from stents, which is exacerbated by embolization coils placed during the treatment of type 2 Endoleaks. The authors assessed interobserver agreement of CTA for measuring aneurysm size and presence of recurrent Endoleak in patients with prior coil embolization of type 2 Endoleaks. MATERIALS AND METHODS A total of 65 CTAs were retrospectively reviewed in a cohort of 27 patients (25 men; two women; mean age, 77.4 years) who had prior Endoleak embolization after EVAR. Endoleak embolizations included transarterial ( n = 8) and translumbar ( n = 19) approaches. In each patient, maximal aneurysm diameter and presence/absence of recurrent Endoleak was measured independently by two observers. Cohen's Kappa statistic was used to assess interobserver agreement, as well as paired two-tailed Student t tests for aneurysm diameter. RESULTS Recurrent type 2 Endoleaks were detected with CTA in eight of 27 patients (30%) and on 13 of 65 CTAs (20%). A high degree of correlation (98.5%) was also seen between the two observers for presence of Endoleak (Kappa 0.95). Mean aneurysm diameter for the entire cohort correlated closely between both observers: 54.8 mm ± 1.1 for observer A and 54.9 mm ± 1.1 for observer B ( P = .66). There was a disagreement between the readers of greater than 2 mm regarding aneurysm size in 13.8% of the CTAs (nine of 65 CTAs). CONCLUSION Despite the presence of streak artifact on CTA following coil embolization of type 2 Endoleaks, CTA remains a useful study for following patients. The presence of embolization coils does not prevent CTA measurement of aneurysm diameter and detection of recurrent Endoleak with a high degree of interobserver agreement.

Hence J M Verhagen - One of the best experts on this subject based on the ideXlab platform.

  • editor s choice systematic review and meta analysis of the outcome of treatment for type ii Endoleak following endovascular aneurysm repair
    European Journal of Vascular and Endovascular Surgery, 2018
    Co-Authors: Klaas H J Ultee, Marc L. Schermerhorn, Frederico Bastos Goncalves, Stefan Buttner, Roy Huurman, Sanne E Hoeks, Wichor M Bramer, Hence J M Verhagen
    Abstract:

    Objectives The efficacy and need for secondary interventions for type II Endoleaks following endovascular abdominal aortic aneurysm repair (EVAR) remain controversial. This systematic review aimed at investigating the clinical outcomes of different type II Endoleak treatments in patients with a persistent type II Endoleak after EVAR. Data sources Embase, Medline via Ovid, Web of Science Core Collection, the Cochrane CENTRAL, and Google Scholar. Review methods This systematic review was performed in accordance with the PRISMA Statement. Outcomes of interest were technical and clinical success, change in sac diameter, complications, need for additional interventions, abdominal aortic aneurysm (AAA) rupture, and (AAA related) mortality. Meta-analyses were performed with random effects models. Results A total of 59 studies were included, with a cumulative cohort of 1073 patients with persistent type II Endoleak. Peri-operative complications following treatment of type II Endoleaks occurred in 3.8% of patients (95% CI 2.7–5.2%), and AAA related mortality was 1.8% (95% CI 1.1–2.7%). Overall technical success was 87.9% (95% CI 83.1–92.1%), while clinical success was 68.4% (95% CI 61.2–75.1%). Among studies detailing sac dynamics, decrease or stable sac, with or without resolution, was achieved in 78.4% (95% CI 70.2–85.6%). Changes in sac diameter following type II Endoleak treatment were documented in 157 patients to at least 24 months. Within this group an actual decrease in sac diameter was reported in only 27 of 40 patients. Conclusion There is little evidence supporting the efficacy of secondary intervention for type II Endoleaks after EVAR. Although generally safe, the lack of evidence supporting the efficacy of type II Endoleak treatment leads to difficulty in assessing its merits.

  • regarding outcomes of persistent intraoperative type ia Endoleak after standard endovascular aneurysm repair
    Journal of Vascular Surgery, 2015
    Co-Authors: Nelson Oliveira, Frans L Moll, Frederico Bastos Goncalves, Joost A Van Herwaarden, Hence J M Verhagen
    Abstract:

    Objective This study analyzed outcomes for patients with persistent intraoperative type Ia Endoleaks after standard endovascular aneurysm repair (EVAR). Methods The study group was identified from a consecutive cohort of 209 patients undergoing EVAR in a tertiary center in the United Kingdom during a 2-year period. Data prospectively collected on departmental computerized databases were retrospectively analyzed. Primary outcome parameters were defined as freedom from type Ia Endoleak, EVAR-related reintervention, aneurysm rupture, and aneurysm-related mortality. Results A completion angiogram identified 44 patients (21%) as having a type Ia Endoleak, and 33 (75%) had a persistent Endoleak after intraoperative adjunctive procedures, including repeated balloon moulding, aortic cuff extension, and Palmaz stent (Cordis, Miami Lakes, Fla) deployment. In the 11 patients (25%) whose Endoleak was successfully abolished intraoperatively, there was no recurrence of type Ia Endoleak or secondary intervention to treat type 1a Endoleak during a median follow-up period of 27 months. Of the 33 patients with persistent Endoleak, 31 (94%) demonstrated resolution of the Endoleak on first surveillance computed tomography angiography. One patient was lost to follow-up. Embolization of the Endoleak in another patient was successful using Onyx (Micro Therapeutics, Inc, Irvine, Calif) 8 days after the initial procedure. No type Ia Endoleak was identified after this on any surveillance imaging, and the patient was alive 28 months later with a stable aneurysm size. In the rest of the patients, no recurrence of the Endoleak in any subsequent imaging was noticed, and no secondary intervention was required during follow-up. No aneurysm-related deaths occurred, and 91% of the patients had a stable or shrinking aneurysm. Conclusions Despite adjunctive intraoperative maneuvers, persistent type Ia Endoleaks can be relatively common. Our study indicates that they may be observed in selected patients. Further research is required to investigate the natural course and management of type Ia Endoleaks identified intraoperatively.

  • spontaneous delayed sealing in selected patients with a primary type ia Endoleak after endovascular aneurysm repair
    European Journal of Vascular and Endovascular Surgery, 2014
    Co-Authors: Hence J M Verhagen, Bastos F Goncalves, K Vasanthananthan, Herman J A Zandvoort, F L Moll, Joost A Van Herwaarden
    Abstract:

    Objective Direct additional therapy is advised for type-Ia Endoleaks detected on completion angiography after endovascular aneurysm repair (EVAR). Additional intraoperative endovascular procedures are, however, often challenging or not possible, and direct open conversion is unattractive. The results of a selective, conservative strategy for patients with primary type-Ia Endoleak has been analysed. Methods This was a retrospective, single-centre study (UMC, Utrecht, NL). From 2004 to 2008, all patients with a primary type-Ia Endoleak and suitable anatomy for EVAR, stentgraft oversizing ≥15%, and optimal deployment were included. Complications during follow-up were studied and all sequential CTA scans were reviewed. These were compared with the remaining patients, treated during the same period. Results Fifteen patients were included (14 male, median age 77, range 67–85) with a median aneurysm diameter of 60 mm (48–80), an aneurysm neck diameter of 26 mm (21–32), a neck length of 29 mm (11–39), and infrarenal angulation of 49° (31–90). One patient suffered rupture 2 days after EVAR – leading to the only AAA-related death. Eight of the 15 type-Ia Endoleaks disappeared spontaneously on the first postoperative CTA, obtained within 1 week of EVAR. On the second postoperative CTA, obtained a median of 5 months (1–12) after EVAR, all remaining Endoleaks had sealed. One recurrence occurred at 4.85 years. During a median follow-up of 3.3 years, there were five secondary interventions. Compared with controls, there were more secondary (or recurrent) type-1a Endoleaks (13% vs. 4%), endograft migrations (13% vs. 3%), sac growths (33% vs. 16%), and secondary interventions (33% vs. 23%). None of these differences however, were statistically significant. Conclusions All but one of the primary type-Ia Endoleaks sealed spontaneously. Until sealing, the risk of rupture persisted, but subsequently only one recurrence of type-Ia Endoleak was seen. In selected patients, a conservative approach for primary type-Ia Endoleaks may be justified.

  • Intervention for type II Endoleaks? "Primum non nocere": appraisal for the conservative management of low-pressure Endoleaks after endovascular aneurysm repair.
    The Journal of cardiovascular surgery, 2013
    Co-Authors: Barend Mees, Frederico Bastos Goncalves, Michiel T. Voûte, L Mota Capitão, Hence J M Verhagen
    Abstract:

    Endoleaks are the most common problem following endovascular aneurysm repair. The importance of a type II Endoleak has often been subject of discussion in scientific literature. Conflicting data on the natural history of type II Endoleak have been published. There is no consensus on the threshold for treatment of type II Endoleak and controversy exists about the optimal treatment modality. This paper discusses the evidence behind treating type II Endoleak and investigates the need for treatment.

  • detection of occult Endoleaks after endovascular treatment of abdominal aortic aneurysm using magnetic resonance imaging with a blood pool contrast agent preliminary observations
    Investigative Radiology, 2010
    Co-Authors: Sandra A Cornelissen, Mathias Prokop, Hence J M Verhagen, Miraude E A P M Adriaensen, Frans L Moll, Lambertus W Bartels
    Abstract:

    OBJECTIVE: To determine whether blood pool contrast agent-enhanced magnetic resonance imaging (MRI) can visualize Endoleaks that are occult on computed tomography (CT) in patients with nonshrinking aneurysms after endovascular aneurysm repair. MATERIALS AND METHODS: Written informed consent was obtained for this prospective institutional review board approved study. Twelve patients with nonshrinking aneurysms but no evidence of Endoleak on CT angiography and delayed CT underwent MRI with a blood pool contrast agent (Gadofosveset trisodium, Bayer Schering Pharma, Berlin, Germany). Patients could participate once in the study. T1-weighted images were acquired before injection, 3 minutes and 30 minutes after injection. Two blinded readers independently scored the images into "Endoleak," "possible Endoleak," or "no Endoleak" by comparing postcontrast MR images with precontrast images. Weighted kappas with linear weighting scheme were calculated for interobserver agreement. RESULTS: One MRI examination was nondiagnostic because of patient motion. In the successful 11 MRI exams, MRI 3 minutes after injection demonstrated Endoleak in 2/11 MRI exams (18%) and possible Endoleak in 2/11 MRI exams (18%). After 30 minutes, MRI demonstrated Endoleak in 6/11 scans (55%) and possible Endoleak in 1/11 scans (9%). Weighted kappa was 0.78 and 0.89 for early and late postcontrast images. CONCLUSION: Endoleaks that are occult on CT can be detected by MRI with blood pool contrast agents. Late phase MRI 30 minutes after injection revealed additional Endoleaks not seen 3 minutes after injection.

Michel S. Makaroun - One of the best experts on this subject based on the ideXlab platform.

  • Occult type I or III Endoleaks are a common cause of failure of type II Endoleak treatment after endovascular aortic repair.
    Journal of vascular surgery, 2018
    Co-Authors: Michael C. Madigan, Michael J. Singh, Rabih A. Chaer, Georges E. Al-khoury, Michel S. Makaroun
    Abstract:

    Abstract Objective Most type II Endoleaks have a benign natural history, but 6% to 8% are associated with sac enlargement and respond poorly to treatment. Our aim was to evaluate whether these enlargements are associated with delayed or occult type I and III Endoleaks. Methods Patients with interventions for Endoleak after endovascular aortic repair from 2000 to 2016 were reviewed retrospectively. Patient demographics, comorbidities, Endoleak type, secondary procedures, aortic sac growth (≥5 mm), and mortality were collected. Successful treatment was defined as Endoleak resolution with no further aortic sac growth. Secondary procedures, ruptures, endograft explant, and death were captured. Results There were 130 patients diagnosed with a primary type II Endoleak after endovascular aortic repair at a median of 1.3 months (interquartile range, 1.0-13.3 months). One hundred eighteen had their initial treatment for a primary type II. Twelve of the 130 were initially stable and observed, but were treated for a delayed type I or III Endoleak. The 130 patients underwent 279 procedures for Endoleaks (mean of 2.2 ± 1.3) over 6.9 ± 3.8 years of follow-up. Of the 118 patients treated for primary type II Endoleaks, 26 (22.0%) later required interventions for delayed type I and III Endoleaks. The mean time to intervention for a delayed type I or III Endoleak was 5.4 ± 2.8 years. Overall, there were 16 type IA, 11 type IB, 2 type III, 7 combined type IA/IB, and 2 type IA/III delayed Endoleaks. The odds of harboring a delayed type I or III Endoleak was 22.0% before the first attempt at type II Endoleak treatment, 35.1% before the second, 44.8% before the third, and 66.6% before the fourth attempts. Rapid aortic sac growth of ≥5 mm/y before initial Endoleak treatment was associated with increased risk for delayed type I or III Endoleak (47.8 vs 14.1%; P = .003). Patients with delayed type I or III Endoleaks had a lower successful treatment rate (8.3% vs 52.3%; P = .001) than those with only type II Endoleaks. Late rupture was increased with delayed type I or III Endoleak (P = .002), whereas mortality (P = .96) and aortic-related mortality (P = .46) were similar. Graft explant (P = .06) trended toward an increase with a delayed type I or III Endoleak, but was not statistically significant. Conclusions Failed attempts treating type II Endoleaks and/or a rapid aortic sac growth of 5 mm/y or greater should raise the suspicion of a delayed or occult type I or III Endoleak. Occult Endoleaks are associated with decreased chance of Endoleak resolution.

  • Type II Endoleaks
    Journal of vascular surgery, 2014
    Co-Authors: Efthymios D. Avgerinos, Rabih A. Chaer, Michel S. Makaroun
    Abstract:

    Type II Endoleaks after endovascular aneurysm repair are the most common type of Endoleak and generate the majority of secondary interventions. Their natural history is mostly benign, but they can occasionally lead to sac expansion and eventual rupture. Three-phase computed tomography angiography is the "gold standard" for diagnosis, but duplex ultrasound with or without contrast enhancement and magnetic resonance angiography offer an alternative for Endoleak detection or surveillance. Whereas there are concerns as to whether sac expansion can be a dependable marker for risk of rupture, it is currently the best surrogate available and guides the indication for intervention. Obliteration of type II Endoleaks can be challenging, and a variety of techniques, endovascular, open, and laparoscopic, have been proposed. The most common approaches are transarterial and translumbar embolization, and they are usually successful, provided the operator is experienced and persistent, targeting both the branches and the nidus of the Endoleak. Recurrences and subsequent reinterventions should be anticipated, and on continuing sac expansion, repeated endovascular or open surgical and laparoscopic alternatives may be required.

  • Effectiveness of coiling in the treatment of Endoleaks after endovascular repair.
    Journal of vascular surgery, 2004
    Co-Authors: Maureen K. Sheehan, Joel E. Barbato, Christopher N. Compton, Albert B. Zajko, Robert Y. Rhee, Michel S. Makaroun
    Abstract:

    Background Persistent Endoleaks are a common problem following endovascular repair of abdominal aortic aneurysms, and the best method of treatment has been an issue of debate. Some experimental evidence has suggested that coiling may not be an effective method because it allows transmission of pressure across the coils with continued expansion of the sac. We reviewed our experience with Endoleak coiling to assess the degree of clinical success of this treatment. Methods A retrospective review of patients with type I or type II Endoleaks treated solely by coiling over a 7-year period (1997-2003) was performed. All Endoleaks had been observed for at least 6 months prior to intervention to detect spontaneous resolution. All coils were delivered by selective catheterization of the Endoleaks. For Type II Endoleaks, the branches were all coiled at their junction with the sac when feasible and the Endoleak cavity was packed. Clinical success was defined as cessation of Endoleak on follow-up computed tomography as well as no further aneurysmal growth (≥5mm minor axis). Results Twenty-eight patients had their Endoleaks treated only with coils. There were 22 Ancure, 2 Excluder, 2 AneuRx, and 2 Lifepath endografts in this patient cohort. Procedural morbidity was 0%. Mean follow-up after coiling for all patients was 18 months (range, 1-60 months) while mean follow-up for patients with a type I Endoleak was 24 months. Clinical success was achieved in 15 of 19 (79%) patients with type II Endoleaks and 8 of 9 (89%) patients with type I. Three patients, all with type I Endoleak, required more than 1 episode of coiling, while 2 others, both with type II lumbar Endoleaks, required repeat angiography due to inability to access the leak during the first attempt. There were 2 proximal and 6 distal type I Endoleaks (2 aortic, 6 iliac) successfully treated while the type II successes included 8 inferior mesenteric arteryand 7 sole lumbar Endoleaks. Five patients continued to show evidence of Endoleak over time: 2 Endoleaks were associated with aneurysm growth leading to conversion in 1 patient, 2 patients with type II Endoleaks are stable, and the sole type I Endoleak with continued perigraft flow has shown significant shrinkage of the sac and continues to be observed 18 months later.No ruptures were noted during follow-up. Conclusion Coiling as the sole method of Endoleak management may be a suitable treatment option in selected patients. Clinical success can be expected in over 80% of patients with type II and select type I Endoleaks, with minimal morbidity.

Michael L Marin - One of the best experts on this subject based on the ideXlab platform.

  • treatment of type ii Endoleaks with a novel polyurethane thrombogenic foam induction of Endoleak thrombosis and elimination of intra aneurysmal pressure in the canine model
    Journal of Vascular Surgery, 2005
    Co-Authors: Jason Rhee, Rabih A. Chaer, Susan M Trocciola, Rajeev Dayal, Naveen Kumar, Albeir Y Mousa, Joshua Bernheim, Paul J Christos, Martin R Prince, Michael L Marin
    Abstract:

    OBJECTIVE: The clinical significance and treatment of retrograde collateral arterial perfusion of abdominal aortic aneurysms after endovascular repair (type II Endoleak) have not been completely characterized. A canine abdominal aortic aneurysm model of type II Endoleak with an implanted pressure transducer was used to evaluate the use of polyurethane foam to induce thrombosis of type II Endoleaks. The effect on Endoleak patency, intra-aneurysmal pressure, and thrombus histology was studied. METHODS: Prosthetic aneurysms with an intraluminal, solid-state, strain-gauge pressure transducer were created in the infrarenal aorta of 14 mongrel dogs. Aneurysm side-branch vessels were reimplanted into the prosthetic aneurysm of 10 animals by using a Carrel patch. Type II (retrograde) Endoleaks were created by excluding the aneurysm from antegrade perfusion with an impermeable stent graft. Thrombosis of the type II Endoleak was induced by implantation of polyurethane foam into the prosthetic aneurysm sac of four animals. Six animals with type II Endoleaks were not treated. In four control animals, no collateral side branches were reimplanted, and therefore no Endoleak was created. Intra-aneurysmal and systemic pressures were measured daily for 60 to 90 days after the implantation of the stent graft. Endoleak patency and flow were assessed during surgery and at the time of death by using angiographic imaging and duplex ultrasonography. Histologic analysis of the intra-aneurysmal thrombus was also performed. RESULTS: Intra-aneurysmal pressure values are indexed to systemic pressure and are represented as a percentage of the simultaneously obtained systemic pressure, which has a value of 1.0. All six animals with untreated type II Endoleaks maintained patency of the Endoleak and side-branch arteries throughout the study period. Compared with control aneurysms that had no Endoleak, animals with patent type II Endoleaks exhibited significantly higher intra-aneurysmal pressurization (systolic pressure: patent type II Endoleak, 0.702 +/- 0.283; control, 0.172 +/- 0.091; P < .001; mean pressure: Endoleak, 0.784 +/- 0.229; control, 0.137 +/- 0.102; P < .001; pulse pressure: Endoleak, 0.406 +/- 0.248; control, 0.098 +/- 0.077; P < .001; P < .001 for comparison for all groups by analysis of variance). Treatment of the type II Endoleak with polyurethane foam induced thrombosis of the Endoleak and feeding side-branch arteries in all four animals with type II Endoleaks. This resulted in intra-aneurysmal pressures statistically indistinguishable from the controls (systolic pressure, 0.183 +/- 0.08; mean pressure, 0.142 +/- 0.09; pulse pressure, 0.054 +/- 0.04; not significant). Angiography and histology documented persistent patency up to the time of death (mean, 64 days) for untreated type II Endoleaks and confirmed thrombosis of polyurethane foam-treated Endoleaks in all cases. CONCLUSIONS: Untreated type II Endoleaks were associated with intra-aneurysmal pressures that were 70% to 80% of systemic pressure. Treatment with polyurethane foam resulted in a reduction of intra-aneurysmal pressure to a level that was indistinguishable from control aneurysms that had no Endoleak. CLINICAL RELEVANCE: Endovascular repair of abdominal aortic aneurysms is dependent on the successful exclusion of the aneurysm from arterial circulation. Type II Endoleaks originate from retrograde flow into the aneurysm sac. This study demonstrates the use of polyurethane foam to induce thrombosis in a canine model of a type II Endoleak, thereby reducing intra-aneurysmal pressure to levels similar to levels in animals without Endoleaks. This approach may be a strategy for future treatment of type II Endoleaks.

  • time resolved magnetic resonance angiography as a noninvasive method to characterize Endoleaks initial results compared with conventional angiography
    Journal of Vascular Surgery, 2004
    Co-Authors: R Lookstein, Jeffrey Goldman, Lev Pukin, Michael L Marin
    Abstract:

    Abstract Purpose Several types of Endoleaks have been described, each with different methods of treatment. Conventional arteriography is widely regarded as the gold standard for the classification of Endoleaks. Recently, faster magnetic resonance gradients have allowed for rapid data acquisition and review of vascular studies as a real-time continuous angiogram (time resolved magnetic resonance angiography [TR-MRA]). This study was performed to compare the findings of TR-MRA with conventional angiography for the characterization of Endoleaks. Methods Between June 2002 and June 2003, 12 patients with documented Endoleaks following endovascular repair of aortic aneurysms (10 abdominal and two thoracic) underwent TR-MRA to identify and characterize the Endoleak. All patients had nitinol-based aortic stent grafts. MRA was performed on a 1.5-Tesla magnet (Sonata class; Siemens Medical Systems, Iselin, NJ). The TR-MRA studies were reviewed under continuous observation as a "cine MR angiogram." These MRA data sets were used to classify the Endoleaks into types 1 through 3. The patients underwent conventional angiography following the MRA to confirm the findings and to plan treatment. The MRA findings were compared with the findings made at conventional arteriography. Results TR-MRA identified seven patients with type 1 leaks, including four proximal and three distal. Four patients had type 2 leaks, including two arising from the inferior mesenteric artery and two from an iliolumbar artery. One patient had a type 3 leak. Conventional angiography confirmed the type of Endoleak in all 12 patients. Conclusion: These initial results demonstrate TR-MRA to be an effective noninvasive method for classifying Endoleaks. This technique may allow for screening of patients with Endoleaks to identify those requiring urgent repair.

  • Increased Recognition of Type II Endoleaks Using a Modified Intraoperative Angiographic Protocol: Implications for Intermittent Endoleak and Aneurysm Expansion
    Annals of vascular surgery, 2003
    Co-Authors: Peter L. Faries, K. Craig Kent, Larry H. Hollier, Joshua Bernheim, Vania L. Briggs, Michael L Marin
    Abstract:

    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.

  • Management of Endoleak after endovascular aneurysm repair: cuffs, coils, and conversion
    Journal of vascular surgery, 2003
    Co-Authors: Peter L. Faries, Hadley Cadot, Gautam Agarwal, K. Craig Kent, Larry H. Hollier, Michael L Marin
    Abstract:

    Abstract Objective The effectiveness of endovascular treatment of abdominal aortic aneurysm (AAA) may be limited by persistent perfusion of the aneurysm sac (Endoleak). Endoleak that results in persistent systemic pressurization of the aneurysm or in continued AAA expansion is believed to require treatment to prevent rupture. This report describes the results of three techniques used to treat Endoleak. Methods Endovascular repair of AAA was performed in 597 patients between January 1996 and September 2002. Seventy-three Endoleaks that required treatment developed in 70 patients (11.7%). These involved the graft attachment site (type I) or the graft junction site (type III) or originated from collateral side-branch vessels (type II) and were associated with an increase in aneurysm size. Endoleak type was confirmed at angiography in all cases. Average time between the initial endovascular procedure and Endoleak treatment was 14.5 ± 5.7 months. The techniques used for Endoleak treatment were deployment of an endovascular extension graft or cuff (n = 44), coil embolization (n = 24,) and conversion to conventional open repair (n = 5). Configurations of endovascular grafts in which Endoleak developed were bifurcated (n = 44), aortouniiliac (n = 15), and aortoaortic-tube (n = 11). Mean follow-up after Endoleak treatment was 24.5 ± 12.2 months (range, 1-60 months). Results Endovascular extension grafts or cuffs were used to treat 41 attachment site Endoleaks and 3 graft junction Endoleaks, with overall technical success rate of 97%. Embolic coils were used to treat 16 retrograde side-branch Endoleaks and 8 attachment site Endoleaks, with overall technical success rate of 87%. Conversion to open surgery was performed in 4 patients with attachment site Endoleaks and 1 patient with a graft junction site Endoleak, and was successful in all cases. After Endoleak treatment, aneurysm size decreased (>5 mm) in 38% of patients, stabilized in 58% of patients, and increased (>5 mm) in 4% of patients. Major morbidity occurred in 7.0%, with no perioperative deaths. Conclusions Endovascular extension grafts, coil embolization, and conversion to open surgery each may be used to effectively repair Endoleak. Selection of the treatment method used is determined by the anatomic characteristics of the Endoleak and the patient's ability to tolerate conventional repair. Conversion to open repair was uniformly successful. Deployment of an extension cuff was successful when complete closure of the Endoleak was achieved. Embolic coils were effective for retrograde Endoleaks and provided stabilization of AAA size in selected patients with attachment site Endoleaks in limited follow-up.

  • Endoleak after endovascular graft repair of experimental aortic aneurysms does coil embolization with angiographic seal lower intraaneurysmal pressure
    Journal of Vascular Surgery, 1998
    Co-Authors: Bettina Marty, Michael L Marin, Peter L. Faries, Jacob Cynamon, Takao Ohki, Luis A Sanchez, Reese A Wain, Frank J. Veith
    Abstract:

    Abstract Purpose: To investigate the relation between Endoleaks and intraaneurysmal pressure (IAP) and the effect of coil embolization in the management of Endoleaks. Methods: The infrarenal aorta of a dog ( n = 15) was replaced by a polytetrafluoroethylene aneurysm containing a pressure transducer. Group I ( n = 4) had untreated aneurysms. Group II ( n = 4) had endovascularly excluded aneurysms without an Endoleak. Group III ( n = 7) had aneurysms excluded by means of grafts with a defect that represented the source of an Endoleak. After 4 weeks of follow-up study, the Endoleaks in group III dogs were subjected to coil embolization. Systolic IAP was measured daily and expressed as a ratio of systolic blood pressure obtained from a forelimb cuff. Arteriography, duplex ultrasonography, and spiral contrast computed tomography were performed to evaluate Endoleaks. Results: In group I, the IAP remained close to systolic blood pressure (ratio of 0.96 ± 0.06), whereas in group II the IAP ratio showed a decline to 0.34 ± 0.16 ( p = 0.0009 group I versus II). After an initial decrease, the IAP ratio in group III stabilized at 0.75 ± 0.18 ( p = 0.003, group II versus III). Aneurysms with an Endoleak remained pulsatile with a pulse pressure of 30 ± 16 mm Hg, which was less than that of untreated aneurysms (62 ± 15 mm Hg; p Conclusions: Incomplete endovascular aneurysm exclusion caused by an Endoleak fails to reduce IAP ratio and may subject the aneurysm to a continued risk for rupture. Although coil embolization resulted in angiographic and computed tomographic sealing, it failed to reduce IAP ratio. (J Vasc Surg 1998;27:454-62.)

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  • Type 2 Endoleak Embolization Comparison: Translumbar Embolization versus Modified Transarterial Embolization
    Journal of Vascular and Interventional Radiology, 2009
    Co-Authors: S. William Stavropoulos, Ronald M Fairman, Jin Park, Jeffrey P. Carpenter
    Abstract:

    PURPOSE: To evaluate the success of Endoleak repair using translumbar (TL) Endoleak embolization compared with a transarterial (TA) technique that involves embolization of the Endoleak cavity itself in addition to the feeding artery. MATERIALS AND METHODS: Eighty-four patients (mean age, 78.2 years; age range, 58-94 years) with type 2 Endoleaks were included in this retrospective study. Patients underwent either TL Endoleak embolization or TA embolization between January 2002 and December 2007. TA embolization involved entering the Endoleak cavity through the inferior mesenteric or lumbar artery. Both the Endoleak cavity and the feeding artery were then embolized by using coils through a microcatheter. TL embolizations were performed by using standard technique with coils and n-butyl cyanoacrylate as the embolization agents. Clinical success was defined as the absence of an Endoleak and/or aneurysm enlargement at follow-up CT angiography. Statistical comparison was performed with the Fisher exact test. RESULTS: Endoleak repair was successful in 72% (45/62) of the TL embolizations and 78% (18/23) of the TA embolizations, with a mean follow-up of 18.7 months (range, 1-84 months). There was no significant difference in clinical success between the two groups (P = .41). There were two (3.2%) complications in the TL group and no complications in the TA group. CONCLUSIONS: The effectiveness of the TA Endoleak embolization technique, which involves embolizion of the Endoleak cavity and the feeding artery, is similar to that of TL embolization for treatment of type 2 Endoleaks.

  • Endoleaks after endovascular repair of thoracic aortic aneurysms
    Journal of vascular surgery, 2006
    Co-Authors: Shane S. Parmer, Ronald M Fairman, Jeffrey P. Carpenter, S. William Stavropoulos, Alberto Pochettino, Edward Y. Woo, G. William Moser, Joseph E. Bavaria
    Abstract:

    Objective Endoleaks are one of the unique complications seen after endovascular repair of thoracic aortic aneurysms (TEVAR). This investigation was performed to evaluate the incidence and determinants of Endoleaks, as well as the outcomes of secondary interventions in patients with Endoleaks, after TEVAR. Methods Over a 6-year period, 105 patients underwent TEVAR in the context of pivotal Food and Drug Administration trials with the Medtronic Talent (n = 64) and Gore TAG (n = 41) devices. The medical and radiology records of these patients were reviewed for this retrospective study. Of these, 69 patients (30 women and 39 men) had follow-up longer than 1 month and were used for this analysis. The patients were evaluated for the presence of an Endoleak, Endoleak type, aneurysm expansion, and Endoleak intervention. Results The mean follow-up in this patient cohort was 17.3 ± 14.7 months (range, 3-71 months). Endoleaks were detected in 29% (20/69) of patients, of which 40% (8/20) were type I, 35% (7/20) were type II, 20% (4/20) were type III, and 5% (1/20) had more than one type of Endoleak. Patients without Endoleaks experienced greater aneurysm sac regression than those with Endoleaks (−2.89 ± 9.1 mm vs −0.13 ± 7.2 mm), although this difference was not statistically significant ( P = .232). All but 2 Endoleaks (90%; 18/20) were detected on the initial postoperative computed tomographic scan at 30 days. Two Endoleaks (10%; 2/20) developed late. The Endoleak group had more extensive aneurysms with significantly larger aneurysms at the time of intervention (69.4 ± 10.5 mm vs 60.6 ± 11.0 mm; P = .003). Factors predictive of Endoleak included male sex ( P = .016), larger aneurysm size ( P = .003), the length of aorta treated by stent grafts ( P = .0004), and an increasing number of stents used ( P Conclusions Endoleaks are not uncommon after TEVAR. Many type I Endoleaks may be treated successfully by endovascular means. Short-term follow-up suggests that observational management of type II Endoleaks is associated with continued sac expansion, and these patients should be monitored closely.

  • Use of CT angiography to classify Endoleaks after endovascular repair of abdominal aortic aneurysms.
    Journal of vascular and interventional radiology : JVIR, 2005
    Co-Authors: S. William Stavropoulos, Ronald M Fairman, Jeffrey P. Carpenter, Timothy Clark, Harold Litt, Omaida C. Velazquez, Erik K Insko, Michael C. Farner, Richard A. Baum
    Abstract:

    PURPOSE Accurate Endoleak detection and classification is critical for the follow-up of patients who have undergone endovascular aneurysm repair (EVAR). This determination is often made with computed tomography angiography (CTA). This investigation was performed to determine the accuracy of CTA in the classification of Endoleaks in patients who have undergone EVAR. MATERIALS AND METHODS Thirty-six patients with Endoleaks underwent both CTA and conventional contrast digital subtraction angiography (DSA) to determine Endoleak etiology. Two independent radiologists determined the source of the Endoleak based on a retrospective review of the CTA. The results of the CTA-based Endoleak classification were compared to the reference standard, contrast DSA. RESULTS There was agreement regarding Endoleak classification between CTA and DSA on 86% of the patients (31 of 36 patients). Correlation between the CTA reading of the two readers was 94% (34 of 36 patients), yielding a kappa statistic of 0.8. In three patients, the CTA reading incorrectly classified Endoleaks as type 2 when the Endoleaks were actually type 1 Endoleaks on DSA. One patient was incorrectly classified as having a type 1 Endoleak on CTA when it was a type 2 Endoleak on DSA. Finally, one patient had a type 1 Endoleak on DSA that was incorrectly classified as a type 3 Endoleak on CTA. The change in CTA Endoleak classification based on the DSA resulted in a significant change in patient management in four of the 36 patients (11%). CONCLUSIONS Endoleak classification based on CTA correlates fairly well with DSA findings. However, optimal Endoleak management requires performance of selective angiograms with DSA to classify Endoleaks that are detected on CTA.

  • Recurrent Endoleak Detection and Measurement of Aneurysm Size with CTA After Coil Embolization of Endoleaks
    Journal of vascular and interventional radiology : JVIR, 2005
    Co-Authors: S. William Stavropoulos, Ronald M Fairman, Jeffrey P. Carpenter, Harold Litt, Horia L Marin, Maxim Itkin, Timothy Clark
    Abstract:

    PURPOSE The optimal modality for following aneurysm size and detecting Endoleaks after endovascular aneurysm repair (EVAR) remains controversial. Computed tomographic angiography (CTA) has been widely employed but can be limited by metal artifact from stents, which is exacerbated by embolization coils placed during the treatment of type 2 Endoleaks. The authors assessed interobserver agreement of CTA for measuring aneurysm size and presence of recurrent Endoleak in patients with prior coil embolization of type 2 Endoleaks. MATERIALS AND METHODS A total of 65 CTAs were retrospectively reviewed in a cohort of 27 patients (25 men; two women; mean age, 77.4 years) who had prior Endoleak embolization after EVAR. Endoleak embolizations included transarterial ( n = 8) and translumbar ( n = 19) approaches. In each patient, maximal aneurysm diameter and presence/absence of recurrent Endoleak was measured independently by two observers. Cohen's Kappa statistic was used to assess interobserver agreement, as well as paired two-tailed Student t tests for aneurysm diameter. RESULTS Recurrent type 2 Endoleaks were detected with CTA in eight of 27 patients (30%) and on 13 of 65 CTAs (20%). A high degree of correlation (98.5%) was also seen between the two observers for presence of Endoleak (Kappa 0.95). Mean aneurysm diameter for the entire cohort correlated closely between both observers: 54.8 mm ± 1.1 for observer A and 54.9 mm ± 1.1 for observer B ( P = .66). There was a disagreement between the readers of greater than 2 mm regarding aneurysm size in 13.8% of the CTAs (nine of 65 CTAs). CONCLUSION Despite the presence of streak artifact on CTA following coil embolization of type 2 Endoleaks, CTA remains a useful study for following patients. The presence of embolization coils does not prevent CTA measurement of aneurysm diameter and detection of recurrent Endoleak with a high degree of interobserver agreement.

  • Endoleaks after Endovascular Repair of Abdominal Aortic Aneurysms
    Journal of Vascular and Interventional Radiology, 2003
    Co-Authors: Richard A. Baum, Ronald M Fairman, S. William Stavropoulos, Jeffrey P. Carpenter
    Abstract:

    Endovascular repair of abdominal aortic aneurysms shows promising initial results. Endoleaks represent one of the unique causes of endovascular repair failure not seen with traditional abdominal aortic aneurysm repair. Endoleaks occur when there is blood flow outside the stent-graft lumen but within the aneurysm sac. They can be difficult to diagnose and treat, and their management is a source of continued controversy. This review further defines Endoleaks and the clinical challenges that they create. Current methods for Endoleak detection, classification, and management are reviewed.