Outcomes of secondary interventions after abdominal aortic aneurysm endovascular repair

Effect of iliac tortuosity on outcomes after iliac branch procedures

OBJECTIVE

To report a two-centers evaluation of the effects of iliac axis tortuosity on iliac branch device (IBD) results.

METHODS

From 2015 to 2021, all IBD procedures performed at two European centers were analyzed retrospectively. The preoperative pelvic tortuosity index (PTI), external tortuosity index (ETI), and double iliac sign (DIS) were assessed for each iliac axis submitted to IBD. The primary endpoints were technical success, early and mid-term IBD complications (occlusion, stenosis, endoleaks [ELs]) and reinterventions, and the association with the PTI, ETI, and DIS. The 30-day mortality, survival, freedom from complications and freedom from reinterventions (FFR) were the secondary endpoints.

RESULTS

During the study period, 224 patients had undergone 256 IBD procedures for 165 (64.5%) aortoiliac aneurysms, 44 (17.2%) isolated iliac aneurysms, 11 (4.3%) abdominal aortic aneurysms with a short iliac landing zone, and 36 (14.1%) type Ib ELs. IBD was planned with endovascular aortic aneurysm repair for 158 (61.7%), fenestrated/branched endovascular aortic aneurysm repair for 45 (7.6%), and isolated for 53 (20.7%) cases. Technical success and 30-day mortality were 99.2% (254 of 256) and 0.9% (2 of 224), respectively. A PTI >1.4, an ETI >1.7, and the DIS were tested to identify the risk factors for the endpoints. No ELs and 9 (3.5%) IBD occlusions, requiring five reinterventions (2%), had occurred within 30 days. No association with the PTI, ETI, or DIS was identified; IBD oversizing of ≥25% on the external iliac artery was independently related to occlusion (odds ratio, 4.3; 95% confidence interval [CI], 1-18.1; P = .045). The mean follow-up was 31 ± 27 months, with 11 IBD occlusions, 14 ELs, and 21 reinterventions. At 1, 3, and 5 years of follow-up survival, IBD patency, and FFR were 95%, 89%, and 80%; 93%, 91%, and 90%; and 93%, 89%, and 83%, respectively. The risk factors for overall complications (n = 34; 13.3%) and reinterventions (n = 26; 10.2%) were an ETI >1.7 (P = .037 and P = .019), a PTI >1.4 (P = .016 and P = .012), and a type Ib EL as the indication (P = .025 and P = .001), respectively. Cox regression confirmed PTI >1.4 as an independent predictor of overall complications and reinterventions (hazard ratio [HR], 2.3; 95% CI, 1.1-4.4; P = .018; and HR, 3 95% CI, 1.3-6.8; P = .018, respectively) and ETI >1.7 as an independent risk factor for ELs (HR 6; 95% CI, 2.1-17.5; P = .001). The freedom from complications and FFR were significantly lower with a PTI >1.4 at 3 years (73% vs 92% [log-rank P = .01] and 77% vs 93% [log-rank P = .001], respectively).

CONCLUSIONS

We found IBDs to be safe and effective in the treatment of aortoiliac aneurysms. Early complications are uncommon and related to endograft oversizing rather than anatomic characteristics in the present study. Iliac tortuosity is a risk factor for overall complications and reinterventions, in particular for IBD-related ELs.

Postoperative Intensive Care Management of Aortic Repair

Vascular surgery patients have multiple comorbidities and are at high risk for perioperative complications. Aortic repair surgery has greatly evolved in recent years, with an increasing predominance of endovascular techniques (EVAR). The incidence of cardiac complications is significantly reduced with endovascular repair, but high-risk patients require postoperative ST-segment monitoring. Open aortic repair may portend a prohibitive risk of respiratory complications that could be a contraindication for surgery. This risk is greatly reduced in the case of an endovascular approach, and general anesthesia should be avoided whenever possible in the case of endovascular repair. Preoperative renal function and postoperative kidney injury are powerful determinants of short- and long-term outcome, so that preoperative risk stratification and secondary prevention are critical tasks. Intraoperative renal protection with selective renal and distal aortic perfusion is essential during open repair. EVAR has lower rates of postoperative renal failure compared to open repair, with approximately half the risk for acute kidney injury (AKI) and one-third of the risk of hemodialysis requirement. Spinal cord ischemia used to be the most distinctive and feared complication of aortic repair. The risk has significantly decreased since the beginning of aortic surgery, with advances in surgical technique and spinal protection protocols, and is lower with endovascular repair. Endovascular repair avoids extensive aortic dissection and aortic cross-clamping and is generally associated with reduced blood loss and less coagulopathy. The intensive care physician must be aware that aortic repair surgery has an impact on every organ system, and the importance of early recognition of organ failure cannot be overemphasized.

Artificial intelligence's role in vascular surgery decision-making

Artificial intelligence (AI) is the next great advance informing medical science. Several disciplines, including vascular surgery, use AI-based decision-making tools to improve clinical performance. Although applied widely, AI functions best when confronted with voluminous, accurate data. Consistent, predictable analytic technique selection also challenges researchers. This article contextualizes AI analyses within evidence-based medicine, focusing on "big data" and health services research, as well as discussing opportunities to improve data collection and realize AI's promise.

Secondary Interventions and Long-term Follow-up after Endovascular Abdominal Aortic Aneurysm Repair

BACKGROUND

Early morbidity and mortality are low after endovascular abdominal aneurysm repair (EVAR), but secondary interventions and late complications are common. The aim of the present multicenter cohort study is to detail the frequency and indication for interventions after EVAR and the impact on long-term survival.

METHODS

A retrospective multicenter cohort study of secondary interventions after elective EVAR for an infrarenal abdominal aortic aneurysm was conducted. Consecutive patients (n = 349) undergoing EVAR between January 2007 and January 2012 were analyzed, with long-term follow-up until December 2018. Those requiring intervention were classified in accordance with the indications and specific nature of the intervention and treatment. The primary study end point was overall survival classified for patients with and without intervention. Kaplan-Meier analysis was used to estimate overall survival for those who did and who did not undergo secondary interventions. Univariable and multivariable Cox regression were performed to identify independent variables associated with mortality.

RESULTS

Some 56 patients (16%) underwent 72 secondary interventions after EVAR during a median (interquartile range) follow-up period of 53.2 months (60.1). Some 45 patients (80.4%) underwent one intervention. Indications for intervention included mainly endograft kinking/outflow obstruction and type II endoleak. An endovascular technique was used in 40.3% of interventions. Median time to secondary intervention was 24.1 months. In 93 patients with abnormalities on imaging, no intervention was performed mainly because the abnormality had disappeared on follow-up imaging (43%). Kaplan-Meier curves showed no difference in survival for patients with and without secondary interventions (P = 0.153). Age (hazard ratio [HR]: 1.089, 95% confidence interval [CI]: 1.063-1.116), ASA classification (ASA III, IV HR: 1.517, 95% CI: 1.056-2.178) were significantly related to mortality.

CONCLUSIONS

Secondary intervention rates are still considerable after EVAR. Endograft kinking/outflow obstruction and endoleak type II are the most common indications for a secondary intervention. Secondary interventions did not adversely affect long-term overall survival after EVAR.

Decreased Ischemic Complications After Endovascular Aortic Aneurysm Repair With Newer Devices

Ischemic complications after endovascular abdominal aortic aneurysm repair (EVAR) are well-recognized and have been reported to be as high as 9%. The goal of our study was to examine the incidence, management, and outcome of ischemic complications at our institution after EVAR and to compare complications according to graft type and time period. This is a retrospective review of all EVARs performed at our institution from 1993 through 2005 (n = 430). EVAR was performed in asymptomatic patients in most cases. Follow-up consisted of a computed tomography scan and office visit at 1, 6, and 12 months and yearly thereafter. Ischemic complications after EVAR have decreased significantly with the advent of lower-profile devices with easier delivery systems and supported limbs. Simultaneous coil embolization of internal iliac artery at the time of EVAR implant does not appear to increase the risk of pelvic or lower-extremity ischemia, can be done safely, and does not need to be staged.

Clinical and anatomical variables associated in the literature to limb graft occlusion after endovascular aneurysm repair compared to the experience of a tertiary referral center

INTRODUCTION

Limb graft occlusion (LGO) is the third reason for hospital readmission after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm. We reviewed the clinical features, incidence, anatomical and devices related predictive factors for LGO after EVAR, and compared them with our experience.

EVIDENCE ACQUISITION

EVAR between 2010-2017 were included. Patients with LGO (LGO group) were matched for age and type of endograft with the rest of the entire cohort without LGO (control group). Clinical, anatomical, operative, outcome, and follow-up data were collected.

EVIDENCE SYNTHESIS

Two hundred seventy-six EVAR, (30 aorto-uniliac), 276 patients. The incidence of LGO was 2.5% (seven limbs, seven patients) at 27±24.6 days. Symptomatic patients were successfully treated. No mortality, limb loss, critical limb ischemia or residual claudication due to LGO was observed. Fifty patients resulted from the matching. Among the predictive factors of LGO between the two groups, significant differences were observed in graft limb oversizing ≥15% (57.1% vs. 8%, P=0.005), or kinking (42.9% vs. 2%, P=0.01), and diameter of the aortic bifurcation <20 mm (71.4% vs. 20%, P=0.01). Logistic regression analysis showed that these three variables increased the risk of LGO (P=0.003, P=0.006, and P=0.01, respectively).

CONCLUSIONS

The strongest predictive factors of LGO issued from our review were: extension in the external iliac artery, or small diameter; tortuous, angled, and calcific iliac axis; excessive oversizing of the limb graft, or kinking; use of old generation devices; EVAR performed outside the instructions for use. Limb graft oversizing >15%, or kinking, and aortic bifurcation <20 mm appear to be independent predictive factors of LGO.

[Endovascular aneurysm repair (EVAR) : Complication management]

A variety of complications may be experienced during or after endovascular repair (EVAR) of abdominal aortic aneurysms (AAA). Acute procedure-related complications include injury to the access vessels, improper endograft placement, ischaemic and systemic complications as well as the postimplantation syndrome. Femoral pseudoaneurysms, endograft migration, kinking or occlusion, endoleaks and endograft infection are complications that have been observed at follow-up. Meticulous patient selection and preprocedural work-up can reduce the incidence of these complications. The majority of the complications, acute as well those at follow-up, can be dealt with endoluminally. It is of essence, however, that a wide variety of catheters, guidewires, stents, stent-grafts and embolics are readily available in the repertoire of the interventionalist. In a small number of patients with endograft occlusion or infection or with bleeding complications/pseudoaneurysms of the access vessels, open surgical intervention may become necessary. To obtain optimal results, close interdisciplinary co-operation, especially between the interventionist, the vascular surgeon and the anaesthetist is mandatory.

Follow-up after endovascular aortic aneurysm repair can be stratified based on first postoperative imaging

Background

Lifelong postoperative surveillance is recommended following endovascular aneurysm repair (EVAR). Although the purpose is to prevent and/or identify complications early, it also results in increased cost and workload. This study was designed to examine whether it may be possible to identify patients at low risk of complications based on their first postoperative CT angiogram (CTA).

Methods

All patients undergoing EVAR in two Swedish centres between 2001 and 2012 were identified retrospectively and categorized based on the first postoperative CTA as at low risk (proximal and distal sealing zone at least 10 mm and no endoleak) or high risk (sealing zone less than 10 mm and/or presence of any endoleak) of complications.

Results

Some 326 patients (273 men) with a CTA performed less than 1 year after EVAR were included (low risk 212, 65·0 per cent; high risk 114, 35·0 per cent). There was no difference between the groups in terms of sex, age, co-morbidities, abdominal aortic aneurysm (AAA) diameter, preoperative AAA neck anatomy, stent-graft type or duration of follow-up (mean(s.d.) 4·8(3·2) years). Five-year freedom from AAA-related adverse events was 97·1 and 47·7 per cent in the low- and high-risk groups respectively (P &lt; 0·001). The corresponding freedom from AAA-related reintervention was 96·2 and 54·1 per cent (P &lt; 0·001). The method had a sensitivity of 88·3 per cent, specificity of 77·0 per cent and negative predictive value of 96·6 per cent to detect AAA-related adverse events. The number of surveillance imaging per AAA-related adverse event was 168 versus 11 for the low-risk versus high-risk group.

Conclusion

Two-thirds of patients undergoing EVAR have an adequate seal and no endoleak on the first postoperative CTA, and a very low risk of AAA-related events up to 5 years. Less vigilant follow-up after EVAR may be considered for these patients.

An Institution-Wide Algorithm for Treatment of Type II Endoleak Following Endovascular Aneurysm Repair (EVAR)

Objectives:

Multiple endovascular techniques have been described for the treatment of persistent type II endoleaks (pT2ELs) causing aneurysm sac growth following endovascular aneurysm repair (EVAR). In the event of a failed endovascular procedure and a pT2EL, a consensus regarding further treatment is lacking, and the literature suggests repeated endovascular attempts are rarely successful. Herein, we propose an algorithm for definitive management of pT2ELs with persistent sac growth following EVAR.

Methods:

A retrospective review of 29 patients who underwent treatment of persistent sac growth in the setting of pT2ELs was performed. Intervention methods were determined at the discretion of the operating surgeon. Aneurysmal sac enlargement was defined as a diameter increase > 5 mm, and persistent endoleak was defined as lasting greater than 6 months.

Results:

From 2000 to 2015, 917 EVAR procedures were performed at our institution. Isolated pT2ELs with sac enlargement were identified in 29 patients. Twenty-five patients underwent direct translumbar sac puncture and coiling and/or Onyx (Onyx, Plymouth, Minnesota) embolization of the culprit vessels. Thirteen (52%) of 25 patients had pT2EL after first endovascular intervention, and 10 (40%) of 25 patients failed 2 endovascular treatments. Of those 10, 7 displayed persistent aneurysmal sac growth and underwent a third embolization procedure. Type II endoleaks persisted in 6 patients; 3 patients were subsequently treated with laparotomy, ligation of lumbar vessels, sac exploration, and sac plication around the endograft. Technical success for this technique was 100%. During a mean follow-up of 38.4 months, no recurrent T2ELs, stent graft migration, and/or disjunction were observed.

Conclusions:

We propose a new algorithm for the management of pT2ELs. If 2 endovascular procedures fail to control of the endoleak, repeat endovascular attempts are not recommended. Endovascular failure should be followed by laparotomy with surgical ligation of culprit feeding vessels followed by sac exploration and plication of the sac, and endoaneurysmorrhaphy.

Limb graft occlusion following endovascular aortic repair: Incidence, causes, treatment and prevention in a study cohort

The present study investigated the incidence, causes, treatment and prevention of limb graft occlusion following endovascular aortic repair (EVAR). A total of 66 cases of abdominal aortic aneurysm receiving EVAR at our department from January 2005 to December 2013 were enrolled. After EVAR, patients received routine antiplatelet therapy of 75 mg PLAVIX for 6 months and then 100 mg Aspirin for another 6 months by oral administration. According to previous clinical experiences, antiplatelet therapy is able to effectively reduce the incidence of iliac occlusion after EVAR. A total of 61 bifurcated grafts and 5 aortauniilac grafts (127 limbs in total) were used. Physical examination, ankle-brachial-index and computer tomographic angiography were performed at 10 days, at 3, 6 and 12 months and annually thereafter. It was found that 7 limbs in 7 patients (10.6% of patients, 5.5% of limbs) were occluded between 20 days and 12 months (average, 7.8±5.3 months) after EVAR. Acute and severe ischemia was found in 2 cases, claudication was in found 3 cases, asthenia in both legs was found in 1 case and 1 case was asymptomatic. Femoral-femoral bypass, femoral-femoral bypass and stenting, aorto-iliac/femoral bypass, thrombectomy and conservative treatment were performed in 1 patient each and thrombectomy together with stenting was performed in 2 cases. Limb graft occlusion was not rare after EVAR. Treatment of this complication included surgery and endovascular therapy such as bypass, thrombectomy and thrombolysis. In conclusion, aggressive pre-emptive treatment including angioplasty and stenting prevented occlusion in certain cases.

Early Elective Conversion for Failing Evar

Background:

The aim of the study was to assess the long term results of endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms at the Helsinki University Central Hospital 1996–2004 with a special emphasis on elective conversion procedures and their outcome.

Methods:

Treatment results and follow-up data of all 110 elective EVAR procedures performed in our institution were gathered prospectively and evaluated.

Results:

Conversion to open surgery was performed in 23 (21%) of 110 EVAR patients. 30-day mortality after elective stent-graft deployment was 0% as it was also on elective conversions (n = 20). Secondary elective conversions were performed due to infection in two and after failing stent-graft treatment in 12 patients. Six of the conversions were performed primarily. Three urgent conversions (3% overall) were performed: two of these patients died, corresponding to an overall mortality of 9% (2/23) in all conversions. Five-year aneurysm-related mortality after EVAR among patients with elective conversion was 0% and 19% in patients with secondary procedures other than elective conversions.

Conclusions:

As conversions seem to be hazardous only when performed in urgent situations, elective conversion could be an alternative treatment method in complex failing first-generation stent-grafts as it may reduce mortality associated with urgent conversions or repeated attempts to maintain graft integrity with endovascular procedures.

Open Surgical Treatment of Aneurysmal Sac Expansion following Endovascular Abdominal Aneurysm Repair: Solution for an Unresolved Clinical Dilemma

The advantages of endovascular aneurysm repair (EVAR) are probably related to the avoidance of the three major physiological insults associated with open abdominal aortic aneurysm (AAA) repair: laparotomy, aortic cross-clamping and ischemia reperfusion injury. Continuing aneurysm expansion indicates a failure to exclude the AAA from the circulation. We describe our experience with open surgery of post-EVAR sac expansion. A consecutive series of 68 EVAR patients was followed up. Endovascular and minimally invasive procedures were the initial treatment option. Failure of these attempts to curtail AAA sac expansion or type 2 large endoleaks (EL) resulted in opening of the aneurysm sac. The procedure includes positioning of a deflated occlusion balloon proximal to the stent graft (SG). Laparotomy with opening of the eneurysm sac was then performed. The thrombus was removed and backbleeding vessels oversewn. The aneurysm sac was then plicated over the SG. Four patients (5.9%) were diagnosed as having either persistent large type 2 EL or sac enlargement. In all patients the procedure was accomplished successfully. One patient died from acute myocardial infarction perioperatively. Three patients recovered uneventfully and follow-up computed tomography confirmed the absence of endoleak and a disappearance of the AAA. We believe that whenever EVAR fails to exclude the aneurysm from the circulation, open exploration without graft replacement should be considered.

A multiregional registry experience using an electronic medical record to optimize data capture for longitudinal outcomes in endovascular abdominal aortic aneurysm repair

OBJECTIVE

Registries have been proven useful to assess clinical outcomes, but data entry and personnel expenses are challenging. We developed a registry to track patients undergoing endovascular aortic aneurysm repair (EVAR) in an integrated health care system, leveraging an electronic medical record (EMR) to evaluate clinical practices, device performance, surgical complications, and medium-term outcomes. This study describes the registry design, data collection, outcomes validation, and ongoing surveillance, highlighting the unique integration with the EMR.

METHODS

EVARs in six geographic regions of Kaiser Permanente were entered in the registry. Cases were imported using a screening algorithm of inpatient codes applied to the EMR. Standard note templates containing data fields were used for surgeons to enter preoperative, postoperative, and operative data as part of normal workflows in the operating room and clinics. Clinical content experts reviewed cases and entered any missing data of operative details. Patient comorbidities, aneurysm characteristics, implant details, and surgical outcomes were captured. Patients entered in the registry are followed up for life, and all relevant events are captured.

RESULTS

Between January 2010 and June 2013, 2112 procedures were entered in the registry. Surgeon compliance with data entry ranges from 60% to 90% by region but has steadily increased over time. Mean aneurysm size was 5.9 cm (standard deviation, 1.3). Most patients were male (84%), were hypertensive (69%), or had a smoking history (79%). The overall reintervention rate was 10.8%: conversion to open repair (0.9%), EVAR revision (2.6%), other surgical intervention (7.3%). Of the reinterventions, 27% were for endoleaks (I, 34.3%; II, 56.9%; III, 8.8%; IV and V, 0.0%), 10.5% were due to graft malfunction, 3.4% were due to infection, and 2.3% were due to rupture.

CONCLUSIONS

Leveraging an EMR provides a robust platform for monitoring short-term and midterm outcomes after abdominal aortic aneurysm repair. Use of standardized templates in the EMR allows data entry as part of normal workflow, improving compliance, accuracy, and data capture using limited but expert personnel. Assessment of patient demographics, device performance, practice variation, and postoperative outcomes benefits clinical decision-making by providing complete and adjudicated event reporting. The findings from this large, community-based EVAR registry augment other studies limited to perioperative and short-term outcomes or small patient cohorts.

Hybrid treatment of arteriovenous fistula between popliteal vessels

The authors describe treatment of a patient who presented an arteriovenous fistula between the popliteal vessels more than 20 years after a gunshot wound. The patient underwent endovascular treatment using Viabahn (Gore®) stent grafts, but, because of the large disparity in popliteal artery diameters proximal and distal of the fistula, the endovascular treatment was unsuccessful. The superficial femoral artery was then banded around the stent graft that was deployed previously. This improvised strategy allowed an open surgical approach to be performed far from the fistula site, reducing the risks of operating in a region with anatomic distortions and significant enlargement of the surrounding venous structures, which would certainly have increased the likelihood of iatrogenic injuries.

Essentials of endovascular abdominal aortic aneurysm repair imaging: postprocedure surveillance and complications

OBJECTIVE

Lifelong postprocedural imaging surveillance is necessary after endovascular abdominal aortic aneurysm repair (EVAR) to assess for complications of endograft placement, as well as device failure and continued aneurysm growth. Refinement of the surveillance CT technique and development of ultrasound and MRI protocols are important to limit radiation exposure.

CONCLUSION

A comprehensive understanding of EVAR surveillance is necessary to identify life-threatening complications and to aid in secondary treatment planning.

Considerations for patients undergoing endovascular abdominal aortic aneurysm repair

Endovascular aneurysm repair has taken over open surgery as the primary strategy for treatment of patients with abdominal and thoracic aneurysms. The minimally invasive nature of these techniques requires alterations in preoperative workup, intraoperative management, and familiarity with unique complications that can occur. Familiarity from the anesthetic standpoint of endovascular techniques, including treatment of patients with fenestrated, chimney, snorkel, and periscope grafts, is necessary for the contemporary cardiac anesthesiologist.

Abdominal aortic aneurysm repair: long-term follow-up of endovascular versus open repair

INTRODUCTION

To compare early and long-term outcomes of endovascular abdominal aortic aneurysm repair (EVAR) versus open repair (OPEN).

DESIGN

Prospective observational, per protocol, non-randomized, with retrospective analyses.

MATERIAL AND METHODS

Between 2000 and 2005, a total of 311 patients having EVAR or OPEN repair of infrarenal abdominal aortic aneurysms were identified and included in this prospective single-center observational study. A propensity score-based optimal-matching algorithm was employed, and 138 patients undergoing EVAR procedures were matched (1: 1) to OPEN repair.

RESULTS

Open repair showed higher hospital mortality (17% vs. 6%, p = 0.004), respiratory failure (p < 0.026), transfusion requirement (p < 0.001), and intensive care unit admission (27% vs. 7%, p < 0.001), and longer hospitalization (p < 0.001). Median follow-up was 70 months (25(th) to 75(th) percentile, 24 to 101). Actuarial survival estimates at 1, 5 and 10 years were 93%, 74%, 49% for the OPEN group compared to 89%, 69%, 59% for the EVAR group (p = 0.465). A significant difference between groups was observed in younger patients (< 75 years) only (p < 0.044). Late complication and re-intervention rates were significantly higher in EVAR patients (p < 0.001 and p = 0.002, respectively). Freedom from late complications at 1, 5 and 10 years was 96%, 92%, 86%, and 84%, 70%, 64% for OPEN and EVAR procedures, respectively.

CONCLUSIONS

Our experience confirms the excellent results of the EVAR procedures, offering excellent early and long-term results in terms of safety and reduction of mortality. Patients < 75 years seem to benefit from EVAR not only in the immediate postoperative period but even in a long-term perspective.

Successful thrombolysis of a late acute thrombotic occlusion of an aortic prosthesis after endovascular aneurysm repair

A 79-year-old man with a previous endovascular aneurysm repair (EVAR) for a 5.4-cm abdominal aortic aneurysm presented 3 years after the procedure with sudden onset lower limb paralysis and pain. The diagnosis of acute aortic thrombosis within the aortic prosthesis graft was made and confirmed on computed tomography. Thrombolysis delivered into the graft via a radiologically placed catheter successfully dissolved the thrombus and resulted in improvement of the patient's symptoms. We discuss the presentation of, and role in management of thrombolysis in, this rare complication of aneurysm repair.

[Endoleaks - when is treatment necessary?]

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

Ten-year results of endovascular abdominal aortic aneurysm repair from a large multicenter registry

OBJECTIVE

To assess outcomes after endovascular abdominal aortic aneurysm repair (EVAR) in an integrated health care system.

METHODS

Between 2000 and 2010, 1736 patients underwent EVAR at 17 centers. Demographic data, comorbidities, and outcomes of interest were collected. EVAR in patients presenting with ruptured or symptomatic aneurysms was categorized as urgent; otherwise, it was considered elective. Primary outcomes were mortality and aneurysm-related mortality (ARM). Secondary outcomes were change in aneurysm sac size, endoleak status, major adverse events, and reintervention.

RESULTS

Overall, the median age was 76 years (interquartile range, 70-81 years), 86% were male, and 82% were Caucasian. Most cases (93.8%) were elective, but urgent use of EVAR increased from 4% in the first 5 years to 7.3% in the last 5 years of the study period. Mean aneurysm size was 5.8 cm. Patients were followed for an average of 3 years (range, 1-11 years); 8% were lost to follow-up. Intraoperatively, 4.5% of patients required adjunctive maneuvers for endoleak, fixation, or flow-limiting issues. The 30-day mortality rate was 1.2%, and the perioperative morbidity rate was 6.6%. Intraoperative type I and II endoleaks were uncommon (2.3% and 9.3%, respectively). Life-table analysis at 5 years demonstrated excellent overall survival (66%) and freedom from ARM (97%). Postoperative endoleak was seen in 30% of patients and was associated with an increase in sac size over time. Finally, the total reintervention rate was 15%, including 91 instances (5%) of revisional EVAR. The overall major adverse event rate was 7.9% and decreased significantly from 12.3% in the first 5 years to 5.6% in the second 5 years of the study period (P < .001). Overall ARM was worse in patients with postoperative endoleak (4.1% vs 1.8%; P < .01) or in those who underwent reintervention (7.6% vs 1.6%; P < .001).

CONCLUSIONS

Results from a contemporary EVAR registry in an integrated health care system demonstrate favorable perioperative outcomes and excellent clinical efficacy. However, postoperative endoleak and the need for reintervention continue to be challenging problems for patients after EVAR.

Transcaval embolization as an alternative technique for the treatment of type II endoleak after endovascular aortic aneurysm repair

The purpose of this report is to highlight our experience with transcaval embolization (TCE) for the management of type II endoleaks (T2Es) as well as to provide a technical description of how to improve procedural safety and success. All patients underwent transfemoral venous access with transcaval puncture into the excluded aneurysm sac with coil placement and selective thrombin injection. Six patients (100% male; mean age [standard deviation] 72.7 [10.8] years) underwent TCE. Technical success was 100% with no postoperative complications. At median follow-up of 8.1 months (range, 2-22 months), two patients had persistent T2Es, with one requiring repeat TCE and the other having cessation of aneurysm growth. The TCE provides a practical alternative to transarterial or translumbar access for the management of T2E, with high degrees of technical and clinical success in this small case series. Larger patient numbers and longer-term follow-up are needed to define procedural efficacy and durability.

Transcatheter Transcaval Embolization of a Type II Endoleak After EVAR Using a Transseptal Needle-Sheath System

Purpose. The purpose of this study is to present an alternative technique for management of a type II endoleak associated with aneurysm sac enlargement. Technique. We report the use of a transseptal needle-sheath system for a transcatheter transcaval embolization (TTE) in a 3-staged treatment of a persistent type II endoleak after abdominal EVAR. Inferior vena cava is cannulated through a femoral venous access, and aneurysmal sac access is gained with a puncture through the walls of the 2 vessels at the site where the vein is adjacent to the aneurysm. The whole system (sheath–dilator–needle) is then advanced across the vascular walls into the aortic sac. Thus, embolization with glue is performed. Conclusion. The TTE using a transseptal needle-sheath system demonstrated to be feasible and effective to treat a persistent type II endoleak after failure of 2 attempts of transarterial embolization of the feeding vessels.

A comparative study of the bell-bottom technique vs hypogastric exclusion for the treatment of aneurysmal extension to the iliac bifurcation

INTRODUCTION

A significant proportion of patients undergoing endovascular aneurysm repair (EVAR) have common iliac artery aneurysms (CIAA). Aneurysmal involvement at the iliac bifurcation potentially undermines long-term durability.

METHODS

Patients with CIAA who underwent EVAR were identified in two teaching hospitals. Bell-bottom technique (BBT; iliac limb ≥20 mm) or internal iliac artery embolization and limb extension to the external iliac artery (IIE + EE) were used. Outcome between these two approaches was compared.

RESULTS

We identified 185 patients. Indication for EVAR included asymptomatic abdominal aortic aneurysm (AAA) in 157, symptomatic or ruptured aneurysm in 19, and CIAA in nine. Mean AAA diameter was 59 mm. Among 260 large CIAAs that were treated, BBT was used to treat 166 CIAA limbs, and 94 limbs underwent IIE + EE. Total reintervention rates were 11% for BBT (n = 19) and 19.1% for IIE + EE (n = 18; P = .149). Rates of reintervention for type Ib or III endoleak were 4% for BBT (n = 7) and 4% for IIE + EE (n = 4; P > .99). The difference in limb patency rates was not significant. The 30-day mortality rate was 1%. Median follow-up was 22 months. Complications did not differ significantly between the two groups; however, the combined incidence of perioperative complications and reinterventions was higher in the IIE + EE group (49% vs 22%; P = .002).

CONCLUSIONS

The combined incidence of perioperative complications and reinterventions is significantly higher with IIE + EE than with BBT; therefore, when feasible, BBT is desirable.

Clinical practice change requires more than comparative effectiveness evidence: abdominal aortic aneurysm management in the USA

Adoption of healthcare innovations frequently outpaces the evidence of effectiveness. Endovascular repair (EVAR) for abdominal aortic aneurysms in the USA demonstrates how comparative effectiveness research without evidence-based reimbursement changes may fail to influence clinical practice. Randomized controlled trials for small abdominal aortic aneurysms demonstrate no lasting benefits of EVAR or open surgical repair (OSR) compared with surveillance, and for large abdominal aortic aneurysms demonstrate no lasting survival benefit of EVAR over OSR, and do show poorer durability and higher costs for EVAR. Nonetheless, >50% of elective abdominal aortic aneurysm repairs in the USA use EVAR. Factors that may be driving the high use of EVAR include patient preference, surgeons’ desire to appear ‘up-to-date’ in the procedures they offer, higher hourly surgeon reimbursement for EVAR than OSR, and the expansion of physician specialties able to perform abdominal aortic aneurysm repair from only vascular surgeons with OSR, to vascular surgeons and interventional radiologists/cardiologists with EVAR. By comparison, in Canada, where government health insurance restricts EVAR coverage to high surgical risk patients, only approximately 25% of abdominal aortic aneurysm repairs are performed using EVAR. Country-specific cost studies and a prospective population-based study collecting detailed clinical data to identify patient subgroups that truly benefit from a particular management strategy are needed to inform policy regarding EVAR availability and reimbursement.

Treatment of complications following endovascular repair of abdominal aortic aneurysms

Endovascular aneurysm repair (EVAR) is an important treatment option for abdominal aortic aneurysms, with lower perioperative morbidity and mortality rates than open surgical aneurysm repair. However, EVAR is associated with several unique complications that are not encountered with surgical repair such as endoleaks, graft migration, and renal artery occlusion. Preservation of the morbidity and mortality advantages of EVAR relies on the successful treatment of these complications by minimally invasive, endovascular approaches. Some of the techniques used to treat EVAR complications include balloon dilation and stenting, deployment of additional stent-graft pieces, coil embolization, and thrombolysis. Although the employment of these endovascular salvage techniques is common, data regarding their intermediate- to long-term efficacy is sparse, and further studies are needed to determine their efficacy in preventing conversion to open aneurysm repair and aneurysm rupture.

Endoscopic type 2 endoleak repair following endovascular aortic aneurysm repair: acute results and follow-up experience

The purpose of this study was to evaluate immediate and long-term results of endoscopic type 2 endoleak repair (EER) following endovascular abdominal aortic aneurysm repair. The basic methods include a retrospective review of electronic and paper medical records of patients admitted or referred to our institution for EER. Between July 1999 and October 2007, eight consecutive patients underwent EER. Mean operative time was 190 (104–355) min. One patient died preoperatively, due to profuse venous bleeding . One procedure was redone due to a missed pair of lumbar arteries. Mean hospital stay was five days (2–10). During mean follow-up, 50 months (29–91), one patient required additional coil embolization for a persistent type 2 endoleak. Four patients were diagnosed with a type 1 and one with a type 3 endoleak; three of these patients required an additional procedure. In conclusion, in this small series EER proved not to be beneficial.

Evaluation of a new computerized analysis system developed for the processing of CT follow-up scans after EVR of infrarenal aneurysm

PURPOSE

The aim of this retrospective study was to present a new computerized analysis system developed for the evaluation of follow-up CT scans after endovascular repair (EVR) of infrarenal aneurysm and to compare it to the conventional evaluation method as regards preciseness and ease of application. The system is based on the extraction of the surface of the stent-graft (SG) and that of the spinal canal and the overlay of surfaces obtained at different points in time.

MATERIALS AND METHODS

A total of 116 CT follow-up data sets obtained from 49 patients after EVR of infrarenal aneurysm were evaluated using both, the conventional method and the new computerized system. Two parameters were analyzed: SG length and the distance between the most ventral point of the SG and the vertebral column. The correlation between the results of the two methods and the correlation between the results obtained by two independent observers (radiologist and lay person) using the new system were assessed by statistical analysis.

RESULTS

Comparison of the two methods yielded a very high correlation for both parameters, (correlation coefficients of around 0.9 and p<0.001). Comparison of the results obtained by the two observers yielded an equally high correlation (correlation coefficients of around 0.9 and p<0.001).

CONCLUSION

Our results show that the new computerized system is as precise and reliable as the conventional method, but allows better visualization and quantification of SG changes by surface overlay. Moreover, it is easier to apply and less time-consuming and can be easily integrated into existing systems.