Long-term outcome after aortic endovascular repair: the Sydney experience

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.

Elective endovascular aortic repair conversion for type Ia endoleak is not associated with increased morbidity or mortality compared with primary juxtarenal aneurysm repair

OBJECTIVE

Type Ia endoleak after endovascular aortic repair (EVAR) can be a challenging complication to manage, and due to concerns regarding morbidity and mortality of open surgical conversion (OSC), reports of complex endoluminal salvage techniques are increasing. Despite development of these endovascular remedial strategies, many patients ultimately require OSC. The purpose of this analysis was to outcomes of elective OSC for type Ia endoleak and compare them with elective primary open juxtarenal aneurysm repair (OJAR) to determine if these concerns are warranted.

METHODS

From 2000 to 2012, 54 patients underwent EVAR OSC at median time of 27 months (interquartile range, 9-55 months). Indications included endograft thrombosis in 2 (4%), intraoperative EVAR failure in 3 (6%), rupture in 5 (9%), graft infection in 6 (11%), and type Ia endoleak in 25 (all: 38 [70%]). Because many OSCs are performed for emergency indications without endovascular options, we chose elective type Ia endoleak patients as our study group. These 25 patients were compared with an elective OJAR cohort matched by anatomy and comorbidities. Primary end points were 30-day and 1-year mortality. Secondary end points included early complications, cross-clamp time, procedure time, blood loss, and length of stay.

RESULTS

Demographic and comorbidity data in the OSC and OJAR groups did not differ, with the exception that OJAR patients presented with smaller aneurysm diameter and a higher rate of chronic obstructive pulmonary disease (P = .03). OSC patients more frequently underwent a nontube graft repair (OSC, n = 20 [80%] vs OJAR, n = 6 [24%]; P = .0002), required longer procedure times (P = .03), and received more plasma transfusions (P = .03). The 30-day mortality was 4% in both groups (observed difference in rates, 0%; 95% confidence interval for difference in mortality rates, -14.0% to 14.0%; P = 1). A similar rate of major complications occurred (OSC, n = 9 [36%] vs OJAR, n = 8 [32%]; P = 1). One-year survival was 83% in OSC and 91% in OJAR (observed difference, 7%; 95% confidence interval, -15% to 29%; P = .65).

CONCLUSIONS

Despite many advances in EVAR technology, the need for OSC persists and will likely become more common as older-generation devices fail or providers attempt EVAR in more anatomically complex patients. Elective OSC for type Ia endoleak can be technically challenging but is not associated with increased morbidity or mortality compared with OJAR in appropriately selected patients. These results should be considered before pursuing complex endovascular remediation of EVAR failures.

Secondary interventions following endovascular abdominal aortic aneurysm repair using current endografts. A EUROSTAR report

OBJECTIVE

The purpose of this study was to evaluate the need for secondary interventions after endovascular abdominal aortic aneurysm repair with current stent-grafts.

METHODS

Studied were data from 2846 patients treated from December 1999 until December 2004. The data were recorded from the EUROSTAR registry. The only patients studied were those with a follow-up of at least 12 months or until they had a secondary intervention within the first 12 months. The cumulative incidences of secondary transabdominal, extra-anatomic, and transfemoral interventions during follow-up (after the first postoperative month) were investigated.

RESULTS

A secondary intervention was performed in 247 patients (8.7%) at a mean of 12 months after the initial procedure within a follow-up period of a mean of 23 +/- 12 months. Of these, 57 (23%) transabdominal, 43 (16%) involved an extra-anatomic bypass, and 147 (60%) were by transfemoral approach. The cumulative incidence of secondary interventions was 6.0%, 8.7%, 12%, and 14% at 1, 2, 3, and 4 years, respectively. This corresponded with an annual rate of secondary interventions of 4.6%, which was remarkably lower than in a previously published EUROSTAR study of patients treated before 1999. Type I endoleaks (33% of procedures), migration (16%), and rupture (8.8%) were the most frequent reasons for secondary transabdominal interventions. Graft limb thrombosis was the indication for extra-anatomic bypass (60%). Type I endoleak (17%), type II endoleak (23%), device limb stenosis (14%), thrombosis (23%), and device migration (14%) were the most frequent reasons for secondary transfemoral interventions. Operative mortality was higher after secondary transabdominal interventions (12.3%, P = .007) compared with transfemoral interventions (2.7%). Overall survival was lower in patients with secondary transabdominal (P = .016) and extra-anatomic interventions (P < .0001) compared with patients without a secondary intervention.

CONCLUSION

Although the incidence of secondary interventions after endovascular aneurysm repair has substantially decreased in recent years, continuing need for surveillance for device-related complications remains necessary.

Aortic neck morphology after endovascular repair of descending thoracic aortic aneurysms

BACKGROUND

Endovascular repair has emerged as a less-invasive treatment for descending thoracic aortic (DTA) aneurysms. However, the durability of this procedure relies on the stability of proximal and distal fixation sites. This study analyzes 3 years of computed tomography (CT) data on aortic neck morphology after endovascular DTA aneurysm repair.

METHODS

Between 1999 and 2001, 139 patients underwent successful endovascular DTA repair as part of a prospective, multicenter clinical trial investigating the Gore TAG thoracic endoprosthesis. Contrast-enhanced, high-resolution CT scans were obtained at 1 (baseline), 12, 24, and 36 months and submitted to an independent core laboratory for image analysis. The aorta was carefully measured by using computerized planimetry and a standardized protocol. Neck diameter was measured at 10-mm intervals for 2 cm above and below the aneurysm and correlated with graft migration and endoleak.

RESULTS

The mean proximal neck diameter increased from a baseline of 30.2 +/- 4.6 mm to 32.0 +/- 4.3 mm at 36 months (P <.05), and the annual diameter increase was 0.8, 0.4, and 0.6 mm at 12, 24, and 36 months. The mean distal neck diameter increased from 29.4 +/- 3.8 mm to 32.1 +/- 5.0 mm at 36 months (P <.05), and the annual diameter increase was 1.1, 0.4, and 1.2 mm at 12, 24, and 36 months. At 36 months, freedom from neck dilation of > or =5 mm was 87%, and freedom from migration of > or =10 mm was 83%. An endoleak was present in 11 (9%) of 122 patients at baseline, 7 (7%) of 96 at 12 months, 6 (9%) of 68 at 24 months, and 1 (3%) of 33 at 36 months. Neck dilation was not associated with graft migration or endoleak.

CONCLUSIONS

Three years after endovascular repair of DTA aneurysms, there is progressive enlargement of the proximal and distal aortic necks. Although uncommon for patients to develop significant neck dilation, when it does occur, it is not associated with graft migration or endoleak. Continued surveillance of aortic neck morphology after descending thoracic aneurysm endografting is recommended.

Secondary interventions after endovascular abdominal aortic aneurysm repair

BACKGROUND

One adverse outcome of endovascular abdominal aortic aneurysm (AAA) repair (EVAR) is a significantly increased incidence of secondary interventions (SIs) required compared with traditional open aortic repair. We present a consecutive series of EVARs using a single endograft to identify the incidence and types of SIs performed.

METHODS

From February 1, 2000, to January 31, 2005, we repaired 136 AAAs with the Zenith (Cook, Bloomington, Indiana) endograft. All patients met the same strict anatomic inclusion and exclusion criteria. Follow-up lasted from 1.5 to 61 months (median 36). The indications for SI group A were procedural and technical errors, for group B were aortic morphology, and for group C were device failures.

RESULTS

Twenty-one SIs were required in 17 of 136 patients (12.5%). Three patients required multiple interventions. Nine patients were in group A, four were in group B, and six were in group C. All but 4 patients required SIs for late (>30 days) complications.

CONCLUSIONS

Although it is a viable alternative to open aortic repair, EVAR is associated with a significantly higher rate of SIs. To maintain the efficacy of EVAR, patients must be followed-up in a vigilant graft surveillance protocol for life.

Does Chronic Oral Anticoagulation With Warfarin Affect Durability of Endovascular Aortic Aneurysm Exclusion in a Midterm Follow-up?

PURPOSE

To evaluate the effect of oral anticoagulation on durability of endovascular aortic aneurysm repair (EVAR).

METHODS

Retrospective review was conducted of 182 consecutive EVAR patients (169 men; mean age 75.3 years, range 53-89) between 1999 and 2003. Patients on warfarin anticoagulation (WA, n=21; International Normalized Ratio of 2 to 3) were compared against a control group (CG) with no postoperative anticoagulation (n=161). Death, aneurysm rupture, and reintervention were considered primary endpoints; endoleaks, endograft migration, and aneurysm remodeling were secondary endpoints.

RESULTS

Mean follow-up was 16.3+/-12.6 months. One-year mortality was 6.6% (9.5% WA versus 6.2% CG); overall mortality was 14.3% (p=0.414). No aneurysm rupture occurred. At 1, 2, and 3 years, respectively, cumulative reinterventions (20%/20%/20% WA versus 12%/15%/20% CG; p=0.633) and endoleak rates (25%/25%/25% WA versus 17%/22%/34% CG; p=0.649) were comparable. In both groups, most completion endoleaks resolved (42.9% WA versus 74.4% CG; p=0.474), but few de novo endoleaks did (0% WA versus 12.8% CG; p=0.538). Anticoagulation did not affect mean time to aneurysm sac shrinkage (1.3+/-0.3 WA versus 1.4+/-0.1 years CG; p=0.769).

CONCLUSIONS

After EVAR, anticoagulation appears safe and does not significantly alter mortality, risk for rupture, or the incidence of reintervention. Early endoleaks appear more common in anticoagulated patients, but anticoagulation does not preclude spontaneous endoleak resolution nor does it increase late endoleak rates. Irrespective of the anticoagulation status, early but not late endoleaks usually sealed spontaneously. Observing type II endoleaks appears safe in the absence of aneurysm enlargement.

Characterization of endoleaks by dynamic computed tomographic angiography

BACKGROUND

Current imaging modalities may not be able to detect endoleaks, differentiate between type II and type III, or localize inflow and outflow sources. We describe a new technique that can characterize endoleaks to guide secondary intervention.

METHODS

One hundred four patients with Zenith (Cook, Inc.) endograft repair of abdominal aortic aneurysms (AAAs) were monitored by serial computed tomographic angiography (CTA). Endoleaks were evaluated with a dynamic CTA using a stationary table position, 24-mm beam collimation, and continuous scanning over 30 to 40 seconds to create a cine.

RESULTS

Twelve patients (12%) had endoleaks that persisted or appeared more than 30 days post-deployment. Five patients in whom the standard CT surveillance protocol could not differentiate type II versus type III endoleaks underwent dynamic CTA. This technique accurately characterized the endoleaks and localized inflow and outflow branches to guide the subsequent successful secondary interventions.

CONCLUSIONS

Dynamic CTA is a useful technique to evaluate endoleaks for characterization and precise localization to guide secondary interventional therapy.

Frequency and Outcome of Re-interventions after Endovascular Repair for Abdominal Aortic Aneurysm: A Prospective Cohort Study

PURPOSE

To describe frequency, type, and outcome of re-intervention after endovascular aortic aneurysm repair (EVAR).

METHODS

Between September 1996 and December 2003, 308 patients were treated, with data collected prospectively. No patient was lost to follow up, but two were excluded (one primary conversion, and one post-operative death). Vanguard, Talent, Excluder, Zenith, and Quantum devices were used. Follow up required a CT scan before discharge. Initially, a CT scan was done at each follow up. Subsequently, we used duplex ultrasound and abdominal X-ray, with CT scan used selectively.

RESULTS

Mean follow-up was 36+/-22 months. Re-interventions were required in 47 (15%) patients, 31 (66%) elective and 16 (34%) emergency cases. In 32 patients, the primary re-intervention was successful; in 15 patients an additional 13 secondary and four tertiary re-interventions were required. A total of 72 adjunctive manoeuvres were performed: 49 endovascular (68%) and 23 open (32%). The success of endovascular re-interventions was 80%. The success of open re-interventions was 96%. Open conversions were required in nine patients (3%). There was no mortality.

CONCLUSION

EVAR was associated with a low burden of re-interventions, with only 15% patients requiring re-intervention. Our long-term follow up, without regular CT, was simple and effective.

Aortic aneurysm repair with endovascular grafts: developing a graft surveillance program

The objective of this study was to describe the development of a comprehensive surveillance program for monitoring the long-term follow-up of endoluminal stent graft (ELG) patients. Despite high procedural success rates, ELG patients remain at ongoing risk for aneurysm sac expansion, rupture, and other adverse events that make long-term surveillance imperative. As they perform more ELG, practitioners face increased logistical difficulty performing appropriate patient follow-up. A computer-based data ELG registry was created using Epi Info, a program developed by the Centers for Disease Control and Prevention that enables users to design a data entry form, enter data, and perform statistical analyses. The database has been used to track 259 patients (214 men and 45 women) who underwent ELG between November 1999 and October 2003. One-year follow-up was available for 182 patients, 2-year follow-up for 104 patients, and 3-year surveillance data for 40 patients, which represent follow-up rates of 89.6%, 78.8%, and 61.5%, respectively. There were 25 late deaths. The Kaplan-Meier estimate for 1-year survival was 92.5%. Twenty-one patients underwent 24 secondary angiographic procedures at a mean 8.6 +/- 10.3 months (range, 1-37.6) after stent-graft repair. No mortality was observed in association with a secondary intervention. There were no late conversions to open aneurysm repair. The Kaplan-Meier estimate for freedom from secondary intervention for all patients at 1 year was 91.0%. A computer-based registry facilitates appropriate and timely patient follow-up and may improve the long-term outcome from ELG.