Nature, frequency, and predictors of secondary procedures after endovascular repair of abdominal aortic aneurysm

Indication and Outcome of Late Open Conversion after Abdominal Endovascular Aortic Repair

BACKGROUND

Endovascular aortic repair (EVAR) has become the standard of care for patients with infrarenal aortic aneurysms over the last 2 decades. Endograft technology and treatment of complications like endoleaks, graft migration, or graft occlusion developed over time. However, sometimes open surgical conversion maybe required. Our aim was to analyze the indications, the technical aspects and outcomes in patients who underwent open conversion after EVAR with different types and generations of endografts.

METHODS

This retrospective single-center study reviewed all patients who underwent EVAR from 2004 to 2020. Open surgical conversions >1 month post EVAR were identified. Conversions for graft infection were excluded. Indications for conversion and operative technique were analyzed. Primary endpoint of the study was 30-day mortality. Secondary endpoints were re-interventions and follow-up mortality.

RESULTS

During 2004 and 2020, 443 consecutive EVARs were performed, and 28 patients required open surgical conversion, with an additional 3 referred from other hospitals (N = 31). The median age was 75 (range 58-93); 94% were male. Conversion was performed after a median time of 55 months (range 16-209). Twenty patients underwent elective and 11 emergency conversion. Indications for open conversion were graft migration, respectively, disease progression with endoleak type Ia and/or Ib in 52% (16/31) and sac expansion due to endoleak type II in 26% (8/31). Of the 31 patients, 17 (55%) had at least one previous endovascular re-intervention. All patients met the device-specific instructions for use for each implanted endograft. In-hospital intervention rate was 16% (5/31). Thirty-day mortality rate was 3% (1/31) with one patient died due to multiorgan failure after rupture with complete endograft replacement. Five patients (16%) died during follow-up. Mid-term follow-up was 47.5 months (range 24-203) with estimated cumulative survival rates of 97%, 89%, and 84%, at 1, 3, and 5 years, respectively.

CONCLUSIONS

Late open conversion remains a valuable treatment option and can be performed safely in elective and emergency setting with a low early mortality. Lifelong surveillance and prompt intervention when necessary are essential in ensuring optimal outcomes after EVAR and preventing the need for emergent conversions.

Comparative Efficacy and Safety of Self-Expandable vs. Balloon-Expandable Stent Grafts in Visceral Artery Aneurysm Management

PURPOSE

This study assesses the efficacy and safety of self-expandable (SE) versus balloon-expandable (BE) stent grafts for managing visceral artery aneurysms (VAAs), focusing on procedural success and complication rates.

MATERIALS AND METHODS

We conducted a retrospective analysis of VAA patients treated at our institution from April 2006 to September 2021. The study reviewed patient demographics, aneurysm characteristics, treatment details, and outcomes, including endoleaks.

RESULTS

Among the 23 patients analyzed, splenic artery aneurysms represented 44% of cases. Fifteen patients were treated with balloon-expandable stent grafts (BE SGs), and eight patients were treated with self-expandable stent grafts (SE SGs). For saccular aneurysms, the average neck size was 10.10 ± 8.70 mm in the BE group versus 18.50 ± 3.40 mm in the SE group (p = 0.23), with an average sac size of 20.10 ± 18.9 mm in the BE group versus 15.60 ± 12.7 mm in the SE group (p = 0.16). The average sac-to-neck ratio was 1.69 ± 2.23 in the BE group versus 1.38 ± 0.33 in the SE group (p = 0.63). The BE group exhibited a significantly higher endoleak rate (60%) compared to the SE group (12.5%; p = 0.03).

CONCLUSIONS

While further investigation is needed to fully assess the outcomes of stent graft treatment for VAAs, initial data show a significantly higher endoleak rate with BE SGs compared to SE SGs. The SE SGs may offer better outcomes due to their superior ability to conform to tortuous and mobile visceral arteries.

Retrospective Cohort Study on EVAR Open Surgical Conversion: Focus on Endoleaks With Wrong Preoperative Categorization

BACKGROUND

Late open conversion (LOC) following endovascular aneurysm repair (EVAR) is a rare complication with a high morbidity and mortality and is often proposed as the last line of treatment after failure of endovascular reintervention of any type. This study aimed to highlights the limitations of EVAR follow-up imaging in characterizing endoleaks, which may contribute to the failure of endovascular reinterventions and lead to LOC.

METHODS

This retrospective cohort study recruited all EVAR implanted in Amiens University Hospital (France) between January 2008 and December 2022. Elective LOC was defined as surgical conversion >1 month after EVAR. The primary endpoint was the rate of wrong categorization of endoleaks by follow-up exams before LOC. Secondary endpoints were the morbidity and the mortality associated with LOC.

RESULTS

Seven hundred eight EVARs were performed in our institution, 30 required elective LOC. Twenty-five of them were treated for sac enlargement due to an endoleak (83.3%) (all types). Wrong categorization of the endoleak was noted in 13 patients (52.2%). Twelve of these recategorizations involved the preoperative diagnosis of a type II endoleaks (92.3%). The change in categorization in 7 out of 12 cases (58%) was in favor of a type I endoleak, other recategorization included 1 type III (8%) and 4 type IV (33%). One patient died during the 30-day postoperative period and 7 patients (28%) presented a major complication; the median length of stay was 13 days (interquartile range 9-21).

CONCLUSIONS

Routine follow-up examinations such as angioscanner and contrast Doppler ultrasound appear to be limited in their ability to categorize the type of persistent endoleak, which may increase the number of patients requiring LOC. New precision diagnostic imaging techniques, such as dynamic examinations, need to be developed to limit the need for LOC.

Type III Endoleak Incidence and Outcomes in Endovascular Aortic Repair: Comparison of Anatomical and Proximal Fixation Devices

PURPOSE

To evaluate the influence of endograft fixation type on the incidence, treatment, and outcomes of type III endoleaks (TIIIELs).

MATERIALS AND METHODS

Abdominal aortic aneurysms (AAAs) treated with bifurcated endografts between 1994 and 2020 were prospectively collected and reviewed. The endograft included were classified as "Anatomical Fixation" (AF) (Powerlink [Endologix] and AFX [Endologix]) or "Proximal Fixation" (PF). The primary outcome was the incidence of TIIIEL over time, stratified by fixation type. Secondary outcomes included between-group comparisons of baseline characteristics, intraoperative details during TIIIEL correction, and survival analysis after TIIIEL diagnosis.

RESULTS

A total of 2065 endovascular aneurysm repairs were performed: 872 (42.2%) with AF and 1193 (57.8%) with PF devices. The estimated incidence of TIIIEL at 1, 5, and 10 years was 0.4%, 4.2%, and 7.3%, and 0.5%, 3.2%, and 4.6% for AF and PF, respectively (p=0.157), and fixation type was not associated with TIIIEL development in the competing risk regression model (p=0.101). The cumulative overall survival rate in patients diagnosed with TIIIEL did not differ significantly between the groups (p=0.077). The rate of recurrent TIIIELs was significantly lower in the AF group (7.1% vs 22.7%; p=0.044); however, no significant difference was found in secondary reintervention between the two groups (11.9% vs 27.3%, p=0.074). Patients with angulated and calcified aortic neck (SHR 3.4, 95% CI 1.2-9.6, p=0.022) and larger aneurysms (SHR 1.2; 95% CI 1.1-1.3; p<0.001) had a higher risk of TIIIEL. Likewise, the use of three or more endograft components increased the risk of TIIIEL by 3.1 times (SHR 3.1; 95% CI 1.7-5.4; p<0.001).

CONCLUSIONS

The occurrence of TIIIELs was not affected by the type of endograft fixation. For larger abdominal aortic aneurysms (AAAs) and aneurysms with angulated and calcified aortic necks, there is a higher likelihood of developing TIIIELs during follow-up, regardless of the endograft type used.

CLINICAL IMPACT

The type of fixation does not influence the incidence of TIII ELs. EVAR in larger AAAs and aneurysms with angulated and calcified aortic necks have a higher risk of developing TIII EL. Moreover, the risk of TIII EL is considerably increased by the use of three or more modular components.

Sequential Graft Limb Occlusion Following Endovascular Aneurysm Repair: A Case Report and Literature Review

Limb graft occlusion (LGO) is a common complication that can occur after endovascular aneurysm repair (EVAR). There are many factors that can contribute to LGO, including patient-related variables, device-related considerations, and factors associated with the procedural technique. Patients with LGO may exhibit no symptoms, have intermittent claudication, or suffer from acute limb ischemia. In this manuscript, we present a case of a 64-year-old male who experienced sequential LGOs after EVAR accompanied by a comprehensive review of the pertinent literature.

Multicenter Comparative Analysis of Late Open Conversion in Patients With Adherence and Nonadherence to Instructions for Use Endovascular Aneurysm Repair

PURPOSE

The widespread adoption of endovascular aneurysm repair (EVAR) as preferred treatment modality for abdominal aortic aneurysm (AAA) has enlarged the number of patients needing open surgical conversion (OSC). The relationship between adherence to Instructions For Use (IFU) and EVAR long-term outcomes remains controversial. The aim of this study is to compare preoperative differences and postoperative outcomes between EVAR patients not adjusted to IFU and adjusted to IFU who underwent OSC.

METHODS

This multicenter retrospective study reviewed 33 explanted EVARs between January 2003 and December 2019 at 14 Vascular Units. Patients were included if OSC occurred >30 days after implantation and excluded if explantation was performed to treat an endograft infection, aortic dissection, or traumatic transections. Variables analyzed included baseline characteristics, adherence to IFU, implant and explant procedural details, secondary reinterventions, and postoperative outcomes.

RESULTS

Fifteen explanted patients (15/33, 45.5%) were identified not accomplished to IFU (out-IFU) at initial EVAR vs 18 explanted patients adjusted (in-IFU). During follow-up, a mean of 1.73±1.2 secondary reinterventions were performed, with more type I endoleaks treated in the subgroup out-IFU: 16.7% vs 6.3% in-IFU patients and more type III endoleaks (8.3% vs 0%). Patients out-IFU had shorter mean interval from implant to explant: 47.60±28.8 months vs 71.17±48. Type II endoleak was the most frequent indication for explantation. Low-flow endoleaks (types II, IV, V) account for 44% of indications for OSC in subgroup of patients in-IFU, compared with 13.3% in patients out-IFU and high-flow endoleaks (types I and III) were the main indication for patients out-IFU (33.3% vs 16.7% in-IFU). Total endograft explantation was performed in 57.5% of cases (19/33) and more suprarenal clamping was required in the subgroup out-IFU. Overall, 30-day mortality rate was 12.1% (4/33): 20% for patients out-IFU and 5.6% in-IFU.

CONCLUSIONS

In our experience, type II endoleak is the most common indication for conversion and differences have been found between patients treated outside IFU with explantation taking place earlier during follow-up, mainly due to high-flow endoleaks and with higher mortality in comparison with patients adjusted to IFU. Ongoing research is required to delve into these differences.

Brazilian Society for Angiology and Vascular Surgery guidelines on abdominal aortic aneurysm

The Brazilian Society of Angiology and Vascular Surgery, through the Guidelines Project, presents new Abdominal Aortic Aneurysm Guidelines, on the subject of care for abdominal aortic aneurysm patients. Its development prioritized descriptive guidelines, using the EMBASE, LILACS, and PubMed databases. References include randomized controlled trials, systematic reviews, meta-analyses, and cohort studies. Quality of evidence was evaluated by a pair of coordinators, aided by the RoB 2 Cochrane tool and the Newcastle Ottawa Scale forms. The subjects include juxtarenal aneurysms, infected aneurysms, and new therapeutic techniques, especially endovascular procedures. The current version of the guidelines include important recommendations for the primary topics involving diagnosis, treatment, and follow-up for abdominal aortic aneurysm patients, providing an objective guide for medical practice, based on scientific evidence and widely available throughout Brazil.

Partial and complete explantation of aortic endografts in the modern era

OBJECTIVE

Despite the progressive advancement of devices for endovascular aortic repair (EVAR), endografts continue to fail, requiring explant. We present a single-institutional experience of EVAR explants, characterizing modern failure modes, presentation, and outcomes for partial and complete EVAR explantation.

METHODS

A retrospective analysis was performed of all EVARs explanted at an urban quaternary center from 2001 to 2020, with one infected endograft excluded. Patient and graft characteristics, indications, and perioperative and long-term outcomes were analyzed. Partial versus complete explants were performed per surgeon discretion without a predefined protocol. This process was informed by patient risk factors; asymptomatic, symptomatic, or ruptured aneurysm presentation; and anatomical or intraoperative factors, including endoleak type.

RESULTS

From 2001 to 2020, 52 explants met the inclusion and exclusion criteria. More than one-half (57.7%) were explants of EVAR devices placed at outside institutions, designated nonindex explants. Most patients were male (86.5%), the median age was 74 years (interquartile range, 70-78 years). More than one-half (61.5%) were performed in the second decade of the study period. The most commonly explanted grafts were Gore Excluder (n = 9 grafts), Cook Zenith (n = 8), Endologix AFX (n = 7), Medtronic Endurant (n = 5), and Medtronic Talent (n = 5). Most grafts (78.8%) were explanted for neck degeneration or sac expansion. Five were explanted for initial seal failure, five for symptomatic expansion, and seven for rupture. The median implant duration was 4.2 years, although ranging widely (interquartile range, 2.6-5.1 years), but similar between index and nonindex explants (4.2 years vs 4.1 years). Partial explantation was performed in 61.5%, with implant duration slightly lower, 3.2 years versus 4.4 years for complete explants. Partial explantation was more frequent in index explants (68.2% vs 56.7%). The median length of stay was 8 days. The median intensive care unit length of stay was 3 days, without significant differences in nonindex explants (4 days vs 3 days) and partial explants (4 days vs 3 days). Thirty-day mortality occurred in two nonindex explants (one partial and one complete explant). Thirty-day readmission was similar between partial and complete explants (9.7% vs 5.0%), without accounting for nonindex readmissions. Long-term survival was comparable between partial and complete explants in Cox regression (hazard ratio, 2.45; 95% confidence interval, 0.79-7.56; P = .12).

CONCLUSIONS

Explants of EVAR devices have increased over time at our institution. Partial explant was performed in more than one-half of cases, per operating surgeon discretion, demonstrating higher blood loss, more frequent acute kidney injury, and longer intensive care unit stays, however with comparable short-term mortality and long-term survival.

Fast and Accurate Computation of the Displacement Force of Stent Grafts after Endovascular Aneurysm Repair

Purpose: Currently, the displacement force of stent grafts is generally obtained using computational fluid dynamics (CFD), which requires professional CFD knowledge to perform the correct simulation. This study proposes a fast, simple, and clinician-friendly approach to calculating the patient-specific displacement force after endovascular aneurysm repair (EVAR). Methods: Twenty patient-specific post-EVAR computed tomography angiography images were used to reconstruct the patient-specific three-dimensional models, then the displacement forces were calculated using CFD and the proposed approaches, respectively, and their numerical differences were compared and analyzed. Results: Based on the derivation and simplification of the momentum theorem, the patient-specific displacement forces were obtained using the information of the patient-specific pressure, cross-sectional area, and angulation of the two stent graft ends, and the average relative error was no greater than 1.37% when compared to the displacement forces calculated by CFD. In addition, the linear regression analysis also showed good agreement between the displacement force values calculated by the new approach and CFD (R = 0.999). Conclusions: The proposed approach can quickly and accurately calculate the patient-specific displacement force on a stent graft and can therefore help clinicians quickly evaluate the post-EVAR displacement force.

Early Clinical Outcomes of Initial Launch of the Zenith Alpha Abdominal Endovascular Graft in Japan

Purpose:

This study retrospectively evaluated the 12-month outcomes of the Zenith Alpha Abdominal Endovascular graft (Zenith Alpha AAA, Cook, Inc, Bloomington, Indiana), which was launched partially in Japan in March 2019, starting with 9 selected sites.

Methods:

A retrospective analysis was performed of all endovascular aneurysm repairs (EVAR) for abdominal aortic aneurysms using the Zenith Alpha AAA. Late complications were defined as any aneurysm-related events occurring >30 days after EVAR, including an aneurysm sac enlargement of >5 mm and any reinterventions performed. Endoleaks without sac enlargement or reinterventions were excluded from late complications.

Results:

During the study period, 79 EVARs using the Zenith Alpha AAA were performed. The mean age was 76.6±6.9 years old, 91.1% of patients were male, and the mean aneurysm diameter was 51.1±7.5 mm. Instructions for use violation was observed in 27 patients (34.2%), most frequently being a severely angulated proximal neck (>60°). There were 4 intraoperative complications, including 2 unintentional partial renal artery coverages caused by the premature anchoring of the exposed suprarenal stent barb to the aortic wall, which was a result of the design change of the top cap deletion. Since it was a partial coverage without flow impairment and since renal stenting was unsuccessful, it was left untreated and had no subsequent renal function impairment. During the mean follow-up of 444±123 days, 74 patients completed 12 months of follow-up. Freedom from late complications at 12 months was 90.8%, which included 2 limb occlusions (2.5%). Of 71 patients with a 12-month computed tomography scan, there was only 1 type 1a endoleak (1.3%), 1 sac enlargement of >5 mm (1.3%), and an aneurysm sac shrinkage of >5 mm was observed in 42.2% of patients. There was no type 3 endoleak during the follow-up.

Conclusions:

This study demonstrated that the new generation of low-profile Zenith Alpha AAA has satisfactory early clinical outcomes, comparable to those obtained with the conventional Zenith endovascular graft. Long-term follow-up is needed to determine whether these favorable outcomes persist.

Intraoperative cone beam computed tomography to improve outcomes after infra-renal endovascular aortic repair

OBJECTIVE

To evaluate whether a combination of intraoperative ceCBCT and postoperative contrast enhanced ultrasound (CEUS) assessment after infra-renal endovascular aortic repair (EVAR) could reduce late stent-graft related complications and consequently re-interventions.

METHODS

All consecutive patients receiving infra-renal bifurcated stent-grafts in our hybrid room (IGS 730, GE Healthcare) during two discrete periods were included in this study: i) from November 2012 to September 2013, a 2D completion angiogram was performed after each EVAR, followed by computed tomography angiography (CTA) before discharge (group 1), ii) from October 2013 to January 2015, an intraoperative ceCBCT was performed, followed by CEUS within the first postoperative days (group 2). Comparative analyses of outcomes were undertaken. The primary endpoint was late stent-graft related complications, a composite factor incorporating aneurysm-related death, type 1 or 3 endoleaks, kink or occlusion of iliac limb and aortic sac enlargement beyond the first 30 postoperative days. The secondary endpoint was all stent-graft related re-interventions. All-cause and aneurysm related deaths were also reported.

RESULTS

Overall, 100 consecutive patients (50 in group 1 and 50 in group 2) were enrolled with a median follow up of 60 months [IQR 41-69]. At 60 months from the index procedure, freedom from late stent-graft related complications in each group was 61.6% (95 % CI [47.0-80.6]) for group 1 and 81.7% (95 % CI [70.1-95.2]) for group 2 (p=.033). Intraoperative CBCT was independently associated with a reduced rate of late stent-graft related complications after multivariate analysis (HR = 0.39, 95% CI 0.16-0.95, p=.038), but did not appear to significantly protect against stent-graft related re-interventions (HR=0.53; 95% CI 0.20-1.39, p=.198) or all cause death (p=.47).

CONCLUSION

This study is the first to report the influence of routine ceCBCT on late outcomes after EVAR and shows a potential reduction in late stent-graft related complications associated with its use.

Short-Term Re-intervention of Endovascular Abdominal Aortic Aneurysm Repair

Background and aim

Endovascular aneurysm repair (EVAR) has revolutionized the management of abdominal aortic aneurysm (AAA). The re-intervention rate following EVAR has been a subject of debate in many studies. The study aims to evaluate the short-term outcomes in terms of the early (four-year) re-intervention rate following EVAR at our centre and compare it to the average re-intervention rate of the main studies assessed by the National Institute of Health and Care Excellence (NICE).

Methods

The EVAR procedures performed over two years (2015 and 2016) were retrieved using the operation codes. The clinical portal and PACS systems were used to review the discharge summaries, clinic and multidisciplinary team (MDT) letters, as well as the scans and interventional radiology procedures to assess the patients’ adherence to follow-up and identify any re-intervention procedure done to correct underlying problems related to the EVAR performed. Patients who switched their follow-up to another hospital were contacted and interviewed about any re-intervention undergone. 

Results

A total of 108 patients underwent EVAR during the two-year study period. Twenty EVAR-related re-interventions (18.5%) were recorded, irrespective of the cause or the type of intervention. This is slightly higher than the average rate by NICE (16.89%). Type 1 endoleak represented the leading cause for re-intervention (30%). Most of the cases of re-intervention were done endovascularly (60%). Forty-five percent of the patients had a re-intervention during the first year and 35% in the third year.

Conclusion

This study shows that although our re-intervention rate following EVAR was slightly higher than the international average, EVAR is still a safe method for the repair of AAA with relatively low peri-operative morbidity and mortality. However, long-term follow-up of these patients is mandatory as re-interventions are frequently required. Nonetheless, the majority of re-interventions can be done with minimal morbidity to the patient.

Application of the AngioJet Ultra Thrombectomy Device for the Percutaneous Mechanical Treatment (PMT) of Iliac Limb Occlusion after Endovascular Aneurysm Repair (EVAR)

BACKGROUND

To investigate the safety and efficacy of applying the AngioJet Ultra thrombectomy device in treating endograft occlusions in the iliac arteries following endovascular aneurysm repair (EVAR).

METHODS

This study utilized a retrospective analysis of 452 patients with infrarenal abdominal aortic aneurysm (AAA). Twelve of the patients experienced iliac limb occlusion during their follow-up period, and the AngioJet Ultra thrombectomy device was used in tandem with iliac angioplasty to treat these patients. The safety of the device was assessed through the amount of blood drawn, the duration of the procedure, and the occurrence of post-operative complications, while its efficacy was assessed through aortic computed tomography angiography (CTA) imaging and post-operative symptomatology results.

RESULTS

All 12 patients were male, and they had a mean age of 62.8 ± 11.8 years. Iliac limb occlusion occurred on the left side of 4 patients and on the right side of 8 patients. The AngioJet Ultra thrombectomy device was used together with iliac angioplasty during surgery, with a success rate of 100%. A bifurcated endograft was successfully implanted in 9 patients following AngioJet Ultra thrombectomy and balloon dilation angioplasty, while a unibody endograft was successfully implanted in 3 patients following AngioJet Ultra thrombectomy and balloon dilation angioplasty. The mean surgery duration was 2.4 hrs, and the patients were hospitalized for an average of 4.5 days. After surgery, the patients' intermittent claudication/buttock claudication gradually vanished. Two patients experienced hemoglobinuria, with one of them developing mild renal dysfunction. Currently, the twelve patients have been followed up for an average of 12 months, and none have experienced any lower extremity ischemia.

CONCLUSIONS

The use of the AngioJet Ultra thrombectomy device as a supplementary treatment for iliac limb occlusion following abdominal EVAR is safe, effective, and minimally invasive.

A rapid aneurysmal formation after late open conversion of endovascular abdominal aortic repair with complete endograft explant

Late open conversion (LOC) after endovascular aneurysm repair (EVAR) is associated with high morbidity and mortality. Standard surgical technique of LOC has not been established. This report presents a rapid aneurysmal formation in the unreplaced infrarenal aorta after LOC with complete endograft explantation without suprarenal fixations. A 76-year-old man presented with a left common iliac artery aneurysm (CIAA), for which he underwent EVAR to embolize the left internal iliac artery. Although his aneurysmal sac size initially showed a reduction, computed tomography at the 3-year interval post-EVAR demonstrated an increased sac size. Thus, he underwent open aortic repair of the CIAA. Though the postoperative course was uneventful, the size of the unreplaced infrarenal aorta showed a significant increase one year after open conversion. Reoperation was performed, but vascular prosthesis infection occurred as a complication and the patient died on the 196th postoperative day.

Impact of Cone Beam Computed Tomography in Advanced Endovascular Aortic Aneurysm Repair Using Last Generation 3D C-arm

BACKGROUND

To report the early outcomes of cone beam computed tomography (CBCT) using last generation 3D C-arm in patients undergone advanced endovascular aortic aneurysm repair (AdEVAR) and to identify risk factors that may predict any un-planned procedures.

METHODS

Patients undergone AdEVAR between December 2017 and December 2018 were enrolled. Final CBCT was performed in all patients after digital subtraction angiography. Primary end points were the incidence of any positive findings and the following unplanned procedures intended as any endovascular manoeuvre performed to fix such technical defect. The secondary endpoints were comparison of outcomes between patients with positive findings undergone unplanned procedure (Group A) versus patients without findings (Group B).

RESULTS

132 patients underwent endovascular treatment for aortic aneurysm. Of these, 22 (33%) fenestrated-branched endovascular aneurysm repairs (F-BEVAR), 21 (29%) EVAR with iliac branch devices, 19 (26%) abdominal and 10 (14%) thoracic EVAR were included in the study. Unplanned procedures after CBCT were necessary in 22 patients (31%). Patients in both groups were similar excepted for BMI >25 kg/m² (55% vs. 26%), hostile iliac anatomy (64% vs. 32%) and previous aortic treatment (73% vs. 32%) (P < 0.05). The odds ratios for unplanned procedure in case of previous aortic treatment was 6.76 (95% CI, 1.97-23.16; P = 0.002).

CONCLUSION

The use of CBCT, especially in challenging scenarios, can reveal technical defects and may potentially limit the need for late reintervention. Patients undergone previous aortic surgery should be carefully evaluated and routine CBCT should be performed.

Limb Occlusion Rate after EVAR With Individualized Graft Limb Selection and a Liberal Protocol of Primary Relining

BACKGROUND

This study analyses limb occlusion rates after endovascular aneurysm repair (EVAR) with a strategy including stent-graft limb selection and liberal primary stenting (relining) in anatomies at higher risk for occlusion with uncovered self-expandable or balloon-expandable stents.

METHODS

All patients undergoing elective EVAR with a bifurcated stent-graft between January 2010-August 2018 were included. A protocol involving personalized stent-graft selection and liberal primary relining based on preoperative imaging was followed during the whole period. Primary endpoints were technical success and primary limb patency during follow-up. Secondary endpoints included mortality and limb reintervention rates. Risk factors associated to limb patency and reintervention rates were analyzed.

RESULTS

Six hundred and fifteen patients (548 males; mean age 72.9 ± 9 years) were included. Overall technical success was 98.5% (606/615). One (0.16%) patient died during the first 30 days. Of the 1230 limbs, 96 (8%) were deemed at risk for occlusion in view of the anatomy, and primarily relined in 62 patients. Estimated primary limb patency at 6 months, 1 year and 3 years was 99.5 ± 0.2%, 99.2 ± 0.3% and 98.5 ± 0.5%, respectively. Freedom from limb-related reintervention at 6 months, 1 year and 3 years was 98.1 ± 0.4%, 97.4 ± 0.5% and 95.6 ± 0.7%, respectively. Only one (1%) of the 96 relined limbs occluded during follow-up. No differences were found in terms of patency or freedom from reintervention between limbs at risk that were primary stented and limbs without adjunctive stents. Gore Excluder stent-grafts presented better patency (Breslow P = 0.005) and lower reintervention rates (Breslow P = 0.001) than other devices during follow-up. Peripheral artery disease was also a risk factor for reintervention (Breslow P = 0.015).

CONCLUSION

Liberal use of primary limb relining in patients with iliac anatomy at higher risk for occlusion appears to be a safe and effective strategy to preserve limb patency after EVAR. Gore Excluder graft limbs present better patency and lower reintervention rates than other stent-graft types.

Results of adjunctive stenting with high-radial force stents to prevent or treat limb occlusion after EVAR

BACKGROUND

The aim of this study was to report the results of a multicenter experience on the use of adjunctive stents deployed inside abdominal aortic endografts with the purpose to prevent or treat limb occlusion after endovascular aneurysm repair (EVAR).

METHODS

Between 2010 and 2018, there were 35 patients with aorto-iliac aneurysm presenting one or more risk factors for endograft limb occlusion (narrow aortic bifurcation and/or stenotic, highly angulated or occluded iliac arteries), who were treated with standard bifurcated stent graft reinforced by the means of a single model of balloon-expandable platinum/iridium bare stent (CP Stent; NuMED, Inc., Hopkinton, NY, USA). Technical success, mortality, limb patency and reintervention rate during follow-up were the main endpoints assessed.

RESULTS

Technical success was 100%. No patients died perioperatively and no major complication was registered. During a mean follow-up of 48 months (range 1-87), neither aortic-related death nor secondary intervention was registered. At a mean follow-up imaging of 39.4 months (range 1-81) no endograft limb lost its patency.

CONCLUSIONS

The use of high-radial force balloon-expandable stents deployed inside bifurcated endografts to prevent or treat limb occlusion is a safe and effective adjunctive procedure, with outstanding long-term outcomes in terms of patency and reinterventions.

A Canadian multicenter experience describing outcomes after endovascular abdominal aortic aneurysm repair stent graft explantation

BACKGROUND

Most studies describing the outcomes after endovascular abdominal aortic aneurysm repair (EVAR) explantation have been from single, high-volume, centers. We performed a multicenter cross-Canadian study of outcomes after EVAR stent graft explantation. Our objectives were to describe the outcomes after late open conversion and EVAR graft explantation at various Canadian centers and the techniques and outcomes stratified by the indication for explant.

METHODS

The Canadian Vascular Surgery Research Group performed a retrospective multicenter study of all cases of EVAR graft explantation at participating centers from 2003 to 2018. Data were collected using a standardized, secure, online platform (RedCap [Research Electronic Data Capture]). Univariate statistical analysis was used to compare the techniques and outcomes stratified the indication for graft explantation.

RESULTS

Patient data from 111 EVAR explants collected from 13 participating centers were analyzed. The mean age at explantation was 74 years, the average aneurysm size was 7.5 cm, and 28% had had at least one instructions for use violation at EVAR. The average time between EVAR and explantation was 42.5 months. The most common indication for explantation was endoleak (n = 66; type Ia, 46; type Ib, 2; type II, 9; type III, 2; type V, 7), followed by infection in 20 patients; rupture in 18 patients (due to type Ia endoleak in 10 patients, type Ib in 1, type II in 1, type III in 2, and type V in 1), and graft thrombosis in 7 patients. The overall 30-day mortality was 11%, and 45% of the patients had experienced at least one major perioperative complication. Mortality was significantly greater for patients with rupture (33.3%) and those with infection (15%) compared with patients undergoing elective explantation for endoleak (4.5%; P = .003). The average center volume during the previous 15 years was 8 cases with a wide range (2-19 cases). A trend was seen toward greater mortality for patients treated at centers with fewer than eight cases compared with those with eight or more cases (19% vs 9%). However, the difference did not reach statistical significance (P = .23). Overall, 41% of patients had undergone at least one attempt at endovascular salvage before explantation, with the highest proportion among patients who had undergone EVAR explantation for endoleak (51%). Only 22% of patients with rupture had undergone an attempt at endovascular salvage before explantation.

CONCLUSIONS

The performance of EVAR graft explantation has increasing in Canada. Patients who had undergone elective explantation for endoleak had lower mortality than those treated for either infection or rupture. Thus, patients with an indication for explanation should be offered surgery before symptoms or rupture has occurred. A trend was seen toward greater mortality for patients treated at centers with lower volumes.

Comparing and Correlating Outcomes between Open and Percutaneous Access in Endovascular Aneurysm Repair in Aortic Aneurysms Using a Retrospective Cohort Study Design

Objective

This retrospective cohort study is aimed at determining the safety and efficacy between Femoral Open-Cutdown access and Percutaneous access with Endovascular Aneurysm Repair (EVAR) by contrasting perioperative complication rates. We hypothesized that the percutaneous approach is a better alternative for aortic aneurysm patients as it is minimally invasive and has been demonstrated to decrease the length of hospital stay.

Methods

We retrospectively reviewed data for patients undergoing EVAR between the years of 2005 and 2013. We then compared overall mortality, hematoma or seroma formation, graft infection, arterio-venous injury, distal embolization, limb loss, myocardial infarction or arrhythmia, and renal dysfunction. Results were demonstrated using a retrospective cohort study design to confirm the hematoma rate associated with EVAR open compared to percutaneous access.

Results

Our series involves 73 patients who underwent percutaneous access for EVAR (n = 49) or traditional open cutdown (n = 24). Percutaneous access resulted in significantly less hematoma formation when compared to the traditional open cutdown (4% vs. 12.5%; p < 0.059). Our analysis suggests decreased mortality rates associated with EVAR as compared to the Open-Cutdown method using Northside Medical Center's Study and the OVER Veterans Affairs Cooperative Study (p = 0.0053).

Conclusion

Percutaneous access for EVAR is safe and effective when compared to Open-Cutdown access for aortic aneurysm patients. Percutaneous access was associated with decreased rates of in-hospital mortality, hematoma formation, graft infection, and respiratory failure.

Impact of Stent Graft Design on External Iliac Artery Limb Occlusion Rates After Endovascular Aneurysm Repair: Post-hoc Analysis of a Japanese Multicentre Database

OBJECTIVE/BACKGROUND

It was hypothesised that a helical stent with expanded polytetrafluoroethylene (ePTFE) grafts could provide a preventive effect for external iliac artery (EIA) limb occlusion following endovascular aortic aneurysm repair (EVAR). Therefore, a post-hoc analysis of a Japanese multicentre database was conducted to assess the impact of the stent graft design on EIA limb occlusion rates.

METHODS

Patients who underwent EVAR with EIA limb deployment between 2008 and 2016 were evaluated. The stent graft limbs were divided into two groups: group A comprised stent graft limbs made of a helical stent with ePTFE grafts (Excluder; n = 255), and group B comprised stent graft limbs made of a Z stent with polyester grafts (Zenith, Flex and Endurant; n = 173). The main outcome was the incidence of limb occlusion and severe limb stenosis (EIA related limb complications). The risk factors for EIA related limb complications were analysed and the midterm results between groups A and B compared. Fine-Gray generalisation of the proportional hazards model was used after propensity score matching to calculate the hazard ratio (HR).

RESULTS

One complication occurred in group A and 10 complications occurred in group B. The risk factors for EIA related limb complications for the entire group were a stent graft limb size ≤10 mm (HR 5.41; p = .01) and inclusion in group B (HR 14.9; p = .009). After propensity matching, group A (n = 159) was matched with group B (n = 159). The cumulative incidence function of EIA related limb complications at five years was 0.66% in group A and 7.8% in group B (HR 8.67; p = .039).

CONCLUSION

Stent graft design can affect limb patency in EIA limb deployment. When EIA limb deployment is necessary for patients with a small EIA, such as Japanese patients, stent graft limbs made of a helical stent with ePTFE should be used to reduce the risk of limb occlusion.

Outcomes of Late Open Conversion after Endovascular Abdominal Aneurysm Repair

Objective: To review our experience with a late open conversion as a final option for an endograft infection and aneurysm expansion after endovascular aneurysm repair (EVAR), especially in endoleaks for which radiological intervention is impossible. Materials and Methods: In this retrospective study, 13 late open conversions out of 513 consecutive patients treated by EVAR were analyzed. Indications for an open conversion were aneurysm enlargement, including all endoleaks, endograft migration, and endograft infection. The patients' data on demographics, operative details, and outcomes were reviewed. Results: Indications for a late open conversion included endoleaks, infection, and migration in 61.5%, 30.8%, and 7.7% of patients, respectively. The median interval from the initial EVAR was 32.4 months. Complete endograft explantation was performed in four patients with an endograft infection. In endoleak cases, the endograft was partially preserved and a neo-neck was used. Sacotomy and branch ligation were performed in one case. One major operative complication was an aortic injury during infrarenal aortic cross-clamping in an endograft migration case. There was no operative mortality. Conclusion: A late open conversion after EVAR is valuable as a final option. The aortic cross-clamp site, especially in endograft migration cases, should be carefully considered. To avoid aneurysm-related events, graft replacement is recommended, if possible.

Long-term results after standard endovascular aneurysm repair with the Endurant and Excluder stent grafts

OBJECTIVE

Many endografts are currently available for standard endovascular repair of infrarenal abdominal aortic aneurysms. Comparison of long-term outcomes between devices might aid in this decision process, but comparative data are scarce. The purpose of this study was to report long-term clinical outcomes of two commercially available endoprosthesis, the Endurant (Medtronic Vascular, Inc, Minneapolis, Minn) and the Excluder (W. L. Gore & Associates, Flagstaff, Ariz) stent grafts.

METHODS

Patients undergoing standard endovascular repair from July 2004 to December 2011 in a single institution with the Endurant or the Low-Porosity Excluder endografts were eligible. Only patients treated for intact degenerative abdominal infrarenal aneurysms were included. All measurements were performed on center-lumen line reconstructions obtained on dedicated software. The primary end point was primary clinical success, defined as clinical success without the need for an additional or secondary surgical or endovascular procedure. Neck-related events (a composite of type IA endoleak, neck-related secondary intervention, or migration of >5 mm), neck morphology changes, renal function, and overall survival were secondary end points.

RESULTS

The study included 277 patients (156 Endurants; 121 Excluders). The median follow-up was 5.8 years (range, 0.1-12.4 years) and did not differ between groups (P = .18). Patients treated with the Endurant stent graft had wider (neck diameter of >28 mm, 27.3% vs 1.7% [P < .001]; neck diameter of 27 mm, [interquartile range (IQR), 24-29 mm] for Endurant and 24 mm [IQR, 22-25 mm] for Excluder; P < .001) and more angulated necks (β-angle of >60°, 26.7% vs 12.5%; P = .004). Oversizing was greater in the Endurant group (16% [IQR, 12%-22%] vs 13% [IQR, 8%-17%], respectively; P < .001). Patients were treated outside device instructions for use regarding proximal neck: 16.7% in the Endurant and 17.3% in the Excluder group (P = .720). The 7-year primary clinical success was 54.7% for the Endurant and 58.1% for the Excluder groups (P = .53). Freedom from neck-related events at 7 years was 76.7% for the Endurant and 78.8% for Excluder group (P = .94). The Endurant stent graft (hazard ratio [HR], 2.7; 95% confidence interval [CI], 1.3-5.8; P = .009) was an independent predictor of significant renal function decline. Neck dilatation was greater in Endurant-implanted patients (13% [95% CI, 2%-22%] vs 4% [95% CI, 0%-10%]; P < .001). Overall survival at 7 years was 61.4% in the Endurant and 50.3% (n = 50; standard error, 0.047) in the Excluder group (P = .39).

CONCLUSIONS

This study reveals that durable and sustainable results can be obtained with either of these late generation devices. This finding suggests that careful planning and a tailored device selection taking into account the patient's anatomy are more relevant determinants than the graft model itself to obtain clinical success. The Endurant endoprosthesis seems to be associated with a higher rate of neck dilatation and faster decrease in the estimated glomerular filtration rate, but further studies with longer follow-up are necessary to determine the clinical relevance of these findings.

Ruptured popliteal artery aneurysms

Background

Rupture is a recognised complication of ruptured popliteal artery aneurysms that requires emergency intervention. There is little evidence collating the presentation, intervention and outcomes of ruptured popliteal artery aneurysms.

Objective

The primary aim of this study was to deduce the sequelae following different management modalities of ruptured popliteal artery aneurysm.

Methods

We performed a systematic review of all available cases reports of ruptured popliteal artery aneurysms in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analysis Protocol.

Results

We identified 48 cases taken from 35 case reports and series. Men were more commonly affected ( n = 96%), and mean age was 71 years. Acute limb ischemia was the commonest presentation (32%) whilst incidental deep vein thrombosis was found in 43% of patients. The mean aneurysm size was 8.2 cm (range, 2.7 to 13.3 cm). Management consisted of open surgery (58%), endovascular treatment (25%) and ‘other’ treatment (evacuation of haematoma, ligation of aneurysm, amputation or palliation) (17%). The perioperative mortality rate in the whole cohort was 13%. Perioperative mortality was similar between comparing the open and endovascular surgery groups. Re-intervention rate amongst endovascular patients was 25% over an average follow-up period of 14 months. There was one re-intervention in the re-constructive group (3%) over a follow-up period of 17 months and none in the ‘other’ group.

Conclusion

Popliteal artery aneurysm rupture is a serious complication associated with significant morbidity and mortality. Open surgical reconstruction and endovascular repair are both feasible for the treatment of ruptured popliteal artery aneurysms; however, open surgery is less likely to require further re-intervention.

Long-Term Outcomes of Percutaneous Stenting of Aortic Endograft Limb Occlusion

INTRODUCTION

To investigate the safety and efficacy of percutaneous stenting for the management of chronic ischemia caused by endograft limb occlusion following endovascular aortic aneurysm repair (EVAR).

METHODS

This is a retrospective, single-center study investigating all patients who underwent percutaneous endovascular covered or bare metal stent placement for the management of intermittent claudication (IC) or critical limb ischemia following EVAR limb occlusion, between January 2010 and October 2017. Cases suffering from acute limb ischemia were treated surgically and were excluded from the analysis. Primary outcome measures were technical success and symptoms-free interval. Secondary outcome measures included clinically driven target-lesion reintervention (TLR)-free survival, primary patency, and complication rates.

RESULTS

Of 29 limb occlusions, 11 limbs (11 patients; 100% male; mean age: 71.6 ± 6.9 years) were treated percutaneously and were included in the study. The majority suffered from IC (10/11; 90.9%) with a single case of rest pain. Technical success was obtained in 10 patients (90%). No major complications occurred. Mean follow-up time was 37.6 ± 25.7 months. Stent grafts were mainly used, while and in 2 cases (18.18%), only nitinol bare stents were deployed. According to Kaplan-Meier analysis, both symptoms-free interval and primary patency were 83.33% in up to 5 years follow-up. TLR-free survival was 100% at 5 years, as 2 cases of claudication relapse were managed conservatively.

CONCLUSIONS

Percutaneous stenting for the management chronic ischemia due to EVAR limb occlusion is feasible and safe, with satisfactory long-term outcomes. Careful patient selection warrants clinical success.

Late open conversion after endovascular repair of abdominal aneurysm failure: Better and easier option than complex endovascular treatment

AIM

Conversion to open repair becomes the last option in case of endovascular repair of abdominal aneurysm failure, when radiological interventional procedures are unfeasible. While early conversion to open repair generally derives from technical errors, aetiopathogenesis and results of late conversion to open repair often remain unclear.

METHODS

We report data from our Institute's experience on late conversion to open repair. Twenty-two late conversion to open repairs out of 435 consecutive patients treated during a 18 years period, plus two endovascular repair of abdominal aneurysms performed in other centres, are analysed. The indication for conversion to open repair was aneurysm enlargement because of type I, type III, type II endoleak and endotension. Even if seven cases (23%) had shown an initial aneurysmal shrinkage, in a later phase, the sac began to enlarge again. In 12 patients, conversion to open repair was the last chance after unsuccessful secondary endovascular procedures.

RESULTS

Three cases (12.5%) were treated in emergency. Aortic cross-clamping was only infrarenal in 10 cases, only or temporarily suprarenal in 14 and temporarily supraceliac in 9 cases, for 19 total and 5 partial endograft excisions. Two patients died for Multiple Organ Failure (MOF), on 42nd (endovascular repair of abdominal aneurysm infection) and 66th postoperative day. No other conversion to open repair-related deaths or major complications were revealed by follow-up post-conversion to open repair (mean: 68 months ranging from 24 to 180 months).

CONCLUSION

Late conversion to open repair is often an unpredictable event. It represents a technical challenge: specifically, the most critical point is the proximal aortic clamping that often temporarily excludes the renal circulation. In our series, conversion to open repair can be performed with a low rate of complications. In response to an endovascular repair of abdominal aneurysm failure, before applying complex procedures of endovascular treatment, conversion to open repair should be taken into account.

Endovascular and open surgical treatment of complications after endovascular aortic aneurysm repair: A single-center experience

While endovascular aortic aneurysm repair (EVAR) has proven to be a safer alternative to open surgical repair for infrarenal abdominal aortic aneurysms (AAA) repair, the development of stent-graft complications mandates follow-up computed tomography imaging to minimize AAA-related mortality. In this single-institution report, adverse EVAR events identified in 150 consecutive patients are detailed. Early morbidity was low (<3%), with only 1 patient death on post-procedure day 2. After discharge (mean follow-up of 24 months), 2 patients died from cancer and one AAA-related mortality occurred after open conversion for stent-graft migration. Although computed tomography imaging detected no EVAR endoleak at 30 days, 19 patients developed an endoleak, including three Type I and four Type III leaks. Our institutional series review confirmed that EVAR of infrarenal AAA is a safe and valid alternative to open surgical repair, but sac embolization at the primary procedure in patients judged to be at high risk for Type II endoleak should be considered.

Risk factors of secondary intervention for type II endoleaks in endovascular aneurysm repair: An 8-year single institution study

BACKGROUND/OBJECTIVES

The natural history of type II endoleaks (T2ELs) is still not completely understood; however, it is widely accepted that those associated with aneurysmal sac growth are harmful. We aimed to review our experience with T2ELs in endovascular aneurysm repair (EVAR).

METHODS

We retrospectively reviewed electronic medical records of all patients who underwent EVAR for infrarenal-type abdominal aortic aneurysms (AAAs) at a single institution from August 2007 to November 2015. Demographic and clinical data were collected. Preoperative contrast computed tomography scans were reviewed to determine aneurysm morphology (the maximum AAA diameter, number of lumbar arteries that enter the AAA sac, size of the inferior mesenteric artery (IMA), proximal neck diameter, proximal neck angle, existence of thrombosis, presence of atheroma, and existence of rupture).

RESULTS

Sixty-two patients underwent EVAR; the follow-up duration was 35.82 ± 31.89 months. There were statistically significant differences in female sex (P = .040), number of lumbar arteries on preoperative computed tomography scans (P = .010), and non-smoking status (P = .031) between patients with and without T2ELs. There were statistically significant differences in the maximum AAA diameter (P = .034) and size of the IMA (P = .043) between patients with and without secondary intervention in T2EL. There was one mortality after EVAR but no mortality associated with T2ELs.

CONCLUSIONS

A more judicious approach that considers risk factors of T2ELs is needed before EVAR. The risk of secondary intervention in patients developing a T2EL after EVAR could increase with the maximum AAA diameter ≥7 cm or IMA ≥3 mm.

Ultrasonography for endoleak detection after endoluminal abdominal aortic aneurysm repair

BACKGROUND

People with abdominal aortic aneurysm who receive endovascular aneurysm repair (EVAR) need lifetime surveillance to detect potential endoleaks. Endoleak is defined as persistent blood flow within the aneurysm sac following EVAR. Computed tomography (CT) angiography is considered the reference standard for endoleak surveillance. Colour duplex ultrasound (CDUS) and contrast-enhanced CDUS (CE-CDUS) are less invasive but considered less accurate than CT.

OBJECTIVES

To determine the diagnostic accuracy of colour duplex ultrasound (CDUS) and contrast-enhanced-colour duplex ultrasound (CE-CDUS) in terms of sensitivity and specificity for endoleak detection after endoluminal abdominal aortic aneurysm repair (EVAR).

SEARCH METHODS

We searched MEDLINE, Embase, LILACS, ISI Conference Proceedings, Zetoc, and trial registries in June 2016 without language restrictions and without use of filters to maximize sensitivity.

SELECTION CRITERIA

Any cross-sectional diagnostic study evaluating participants who received EVAR by both ultrasound (with or without contrast) and CT scan assessed at regular intervals.

DATA COLLECTION AND ANALYSIS

Two pairs of review authors independently extracted data and assessed quality of included studies using the QUADAS 1 tool. A third review author resolved discrepancies. The unit of analysis was number of participants for the primary analysis and number of scans performed for the secondary analysis. We carried out a meta-analysis to estimate sensitivity and specificity of CDUS or CE-CDUS using a bivariate model. We analysed each index test separately. As potential sources of heterogeneity, we explored year of publication, characteristics of included participants (age and gender), direction of the study (retrospective, prospective), country of origin, number of CDUS operators, and ultrasound manufacturer.

MAIN RESULTS

We identified 42 primary studies with 4220 participants. Twenty studies provided accuracy data based on the number of individual participants (seven of which provided data with and without the use of contrast). Sixteen of these studies evaluated the accuracy of CDUS. These studies were generally of moderate to low quality: only three studies fulfilled all the QUADAS items; in six (40%) of the studies, the delay between the tests was unclear or longer than four weeks; in eight (50%), the blinding of either the index test or the reference standard was not clearly reported or was not performed; and in two studies (12%), the interpretation of the reference standard was not clearly reported. Eleven studies evaluated the accuracy of CE-CDUS. These studies were of better quality than the CDUS studies: five (45%) studies fulfilled all the QUADAS items; four (36%) did not report clearly the blinding interpretation of the reference standard; and two (18%) did not clearly report the delay between the two tests.Based on the bivariate model, the summary estimates for CDUS were 0.82 (95% confidence interval (CI) 0.66 to 0.91) for sensitivity and 0.93 (95% CI 0.87 to 0.96) for specificity whereas for CE-CDUS the estimates were 0.94 (95% CI 0.85 to 0.98) for sensitivity and 0.95 (95% CI 0.90 to 0.98) for specificity. Regression analysis showed that CE-CDUS was superior to CDUS in terms of sensitivity (LR Chi² = 5.08, 1 degree of freedom (df); P = 0.0242 for model improvement).Seven studies provided estimates before and after administration of contrast. Sensitivity before contrast was 0.67 (95% CI 0.47 to 0.83) and after contrast was 0.97 (95% CI 0.92 to 0.99). The improvement in sensitivity with of contrast use was statistically significant (LR Chi² = 13.47, 1 df; P = 0.0002 for model improvement).Regression testing showed evidence of statistically significant effect bias related to year of publication and study quality within individual participants based CDUS studies. Sensitivity estimates were higher in the studies published before 2006 than the estimates obtained from studies published in 2006 or later (P < 0.001); and studies judged as low/unclear quality provided higher estimates in sensitivity. When regression testing was applied to the individual based CE-CDUS studies, none of the items, namely direction of the study design, quality, and age, were identified as a source of heterogeneity.Twenty-two studies provided accuracy data based on number of scans performed (of which four provided data with and without the use of contrast). Analysis of the studies that provided scan based data showed similar results. Summary estimates for CDUS (18 studies) showed 0.72 (95% CI 0.55 to 0.85) for sensitivity and 0.95 (95% CI 0.90 to 0.96) for specificity whereas summary estimates for CE-CDUS (eight studies) were 0.91 (95% CI 0.68 to 0.98) for sensitivity and 0.89 (95% CI 0.71 to 0.96) for specificity.

AUTHORS' CONCLUSIONS

This review demonstrates that both ultrasound modalities (with or without contrast) showed high specificity. For ruling in endoleaks, CE-CDUS appears superior to CDUS. In an endoleak surveillance programme CE-CDUS can be introduced as a routine diagnostic modality followed by CT scan only when the ultrasound is positive to establish the type of endoleak and the subsequent therapeutic management.

Extensive ischemic ulcers due to limb occlusion after endovascular aneurysm repair: a case report

Introduction

Limb occlusion after endovascular aneurysm repair (EVAR) is a well-known complication. However, extensive ischemic ulcers due to limb occlusion are extremely rare.

Case description

We report a rare case of extensive ischemic ulcers that developed seven months after EVAR in an 85-year-old Japanese man. He had been taking appropriate anticoagulant therapy because of paroxysmal atrial fibrillation. Angiography showed a left limb occlusion and superficial femoral artery (SFA) chronic total occlusion (CTO), and intravascular ultrasound showed limb kinking. Endovascular therapy (EVT) was performed, and stent placement was used to cover a large amount of thrombi and correct the limb kinking, leading to complete recovery of left limb blood flow. After additional EVT was performed for the SFA CTO, outflow improved and the ulcers healed completely.

Discussion and evaluation

It seemed that the combination of poor inflow and poor outflow led to limb thrombosis.

Conclusions

Here, we describe an extremely rare case of extensive ischemic ulcers due to limb occlusion after EVAR. Patients should undergo careful follow-up after EVAR to monitor blood flow to the lower extremities. Additionally, the early detection and correction of limb kinking and poor outflow are essential to prevent the development of ischemic ulcers.

Open Conversion after Aortic Endograft Infection Caused by Colistin-Resistant, Carbapenemase-Producing Klebsiella pneumoniae

A 62-year-old man presented with fever, abdominal pain, and malaise 13 months after emergency endovascular aortic repair. Computed tomographic angiograms showed a periprosthetic fluid and gas collection, so infection was diagnosed. Open conversion was performed, involving endograft explantation and in situ aortic reconstruction. Cultures and the explanted prosthesis were positive for carbapenemase-producing Klebsiella pneumoniae, resistant to colistin. Because of the sparse data on endograft infections caused by this pathogen, we placed the patient on an empiric double-carbapenem regimen for 4 weeks. Symptomatic recovery occurred after 21 days. On the 30th day, we deployed a stent to treat a new pseudoaneurysm. Three years later, the patient had no signs of persistent or recurrent infection. We think that this is the first report of aortic endograft infection caused by colistin-resistant, carbapenemase-producing K. pneumoniae.

Endovascular Repair of Small Abdominal Aortic Aneurysms: A Paradigm Shift?

Recent reports have documented poor long-term results following endovascular aneurysm repair (EVAR) of large abdominal aortic aneurysms (AAA). EVAR of small AAAs may result in improved long-term results compared to large AAAs. It is not known whether the frequency of anatomic suitability for EVAR is increased for small compared to large AAAs. This study compared the anatomic suitability of large and small AAAs for EVAR in an unselected patient population. Radiology reports for all computed tomography (CT) scans in a single hospital over a recent 3-year period were reviewed. AAAs diagnosed by contrasted CT scans with cuts >7 mm were excluded. Suitability for EVAR was determined by neck diameter, length, and angulation. In addition, iliac diameters and common iliac distal landing zone lengths were determined. Computerized 3-dimensional (3D) reconstruction was used to measure neck angulation and total aortic tortuosity. One hundred ninety-one patients were found to have AAAs with adequate CT scans for evaluation. Suitability for EVAR was highest in patients with AAA diameters of 3–4 cm and declined with increasing size of the AAA. Dividing AAAs into sizes greater than or less than 5.5 cm revealed that small AAAs had significantly longer necks, less neck angulation, longer common iliac landing zones, and less total aortic tortuosity. Multivariable analysis revealed that maximal aortic diameter was the only independent predictor of suitability for EVAR (p = 0.005, odds ratio 1.67, CI 95% = 1.17 to 2.38). The odds ratio predicts that with each 1 cm increase in size, the likelihood of suitability decreased by 5.3-fold. Small AAAs have less complex anatomy with longer aortic necks, less neck angulation, and less tortuosity. The poor outcomes following the treatment of large AAAs is thought to be due to complex anatomy. EVAR of less anatomically challenging small AAAs may improve longterm outcomes.

Endovascular versus “Fast-Track” Abdominal Aortic Aneurysm Repair

Recent studies have shown that endovascular abdominal aortic aneurysm repair (EVAR) has decreased costs, as well as decreased intensive care unit and total hospital length of stays when compared to abdominal aortic aneurysm (AAA) repair using a retroperitoneal exposure. The authors hypothesized that the fast-track AAA repair, which combines a retroperitoneal exposure with a patient care pathway that includes a gastric promotility agent and patient-controlled analgesia, would have no differences when compared to EVAR. Records of 58 patients who underwent AAA repair between April 14, 2000, and July 12, 2002, were reviewed retrospectively. Demographic information, length of stay, intraoperative and postoperative complications, mortality, and costs were evaluated. Fifty-eight AAA repairs were performed with the EVAR (n=28) and fast-track (n=30) techniques. The EVAR group was slightly older (72 vs 68 years, p=0.04), had slightly smaller average aneurysm size (5.5 ±0.13 vs 6.1 ±0.17 cm, p=0.008), and had more patients designated American Society of Anesthesia class 4 (p<0.0001). Both groups were predominantly male. Otherwise there were no statistically significant differences in risk factors. Patients who underwent fast-track repair tended to have a longer operation (216 ±7.4 vs 158 ±6.8 minutes, p<0.0001), with a greater volume of blood (1.8 ±0.29 vs 0.32 ±0.24 units, p=0.0005), colloid (565 ±89 vs 32 ±22 cc, p<0.0001), and crystalloid transfusions (4,625 ±252 vs 2,627 ±170 cc, p<0.0001). There were no statistically significant differences in the number of intraoperative or postoperative complications between the 2 groups. EVAR patients resumed a regular diet earlier (0.21 ±0.08 vs 1.8 ±0.11 days, p<0.0001). Intensive care unit stay was shorter for EVAR (0.50 ±0.10 vs 0.87 ±0.10 days, p=0.01), but floor (2.1 ±0.23 vs 2.6 ±0.21 days, p=0.17), and total hospital lengths of stay (2.8 ±0.32 vs 3.4 ±0.18 days, p=0.07) were similar between the 2 groups. Total hospital cost was lower in the fast-track ($10,205 ±$736 vs $20,640 ±$1,206, p<0.0001) leading to greater overall hospital earnings ($6,141 ±$1,280 vs $107 ±$1,940, p=0.01). Fast-track AAA repair is a viable alternative for the treatment of abdominal aortic aneurysms. Compared to endovascular repair, the fast-track method had increased transfusions of blood and intravenous fluids and increased operating room times, but equivalent lengths of floor and total hospital stay and increased total hospital earnings.

Direct sac puncture versus transarterial embolization of type II endoleaks: An evaluation and comparison of outcomes

Purpose To determine the outcomes of type II endoleak embolization with aneurysm sac obliteration and whether the approach - direct sac puncture or transarterial - affects outcome. Methods A retrospective review of patients who underwent endovascular aneurysm repairs and subsequent type II endoleak embolization over 10 years was performed. Twenty-three patients (median age: 73 years, range: 40-88 years) underwent 35 embolizations. Embolization was performed with the goal of obliterating both the endoleak sac and feeding vessels. Embolization agents used include cyanoacrylate glue only (48%), glue and coils (36%), coils only (13%), and other (3%). Results Mean follow-up was 21.8 months. Patients underwent an average of 1.5 embolizations, with 35% requiring more than one. Technical success rate was 89%. Freedom from aneurysm sac expansion was achieved in 91%. Freedom from type II endoleak was accomplished in 70%. There were no ruptured aneurysms during the follow-up period. Direct sac puncture and transarterial approaches had similar incidences of aneurysm sac growth ( p = 0.74), persistent type II endoleak ( p = 0.32), and complications ( p = 0.64). However, direct sac puncture had significantly shorter fluoroscopy ( p < 0.001) and total procedure times ( p < 0.001) than transarterial embolizations. Conclusion Direct sac puncture and transarterial embolization of type II endoleak with aneurysm sac obliteration are similarly effective for the prevention of aneurysm sac growth. However, direct sac puncture is our preferred approach given its significantly shorter fluoroscopic and procedural times.

Comparison of Radiation Exposure Associated With Intraoperative Cone-Beam Computed Tomography and Follow-up Multidetector Computed Tomography Angiography for Evaluating Endovascular Aneurysm Repairs

Purpose: To compare the radiation exposure associated with intraoperative contrast-enhanced cone-beam computed tomography (ceCBCT) acquisitions to standard 3-phase multidetector computed tomography (MDCT) angiography used for assessing technical success after endovascular aortic repair (EVAR). Methods: Effective doses (EDs) were calculated for 66 EVAR patients (mean age 71 years; 61 men) with a mean 27.7-kg/m2 body mass index (range 17–49) who had both intraoperative ceCBCT and postoperative 3-phase MDCT angiography between November 2012 and April 2015. In addition, EDs were directly determined using thermoluminescent dosimeters (TLDs) embedded in anthropomorphic phantoms with body mass indexes of 22 and 30 kg/m2. Effective doses were calculated by summing doses recorded by all TLDs corresponding to a specific tissue type before applying the International Commission on Radiological Protection (ICRP) 60 and 103 weighting factors. EDs were compared with each other for both imaging modalities as well as to TLD measurements. Results: Average EDs of the patient collective were 4.9±1.1 mSv for ceCBCT, 2.6±1.2 mSv for single-phase MDCT (46% decrease, covering solely the area of the implanted endograft), and 13.6±5.5 mSv for comprehensive 3-phase MDCT examinations (178% increase, anatomical coverage from the aortic arch to femoral artery bifurcation). EDs determined in phantom measurements ranged from 3.1 to 4.5 mSv for ceCBCT, amounting to 2.6 mSv for a single MDCT phase (15% to 40% decrease) using ICRP 60 conversion factors. Applying ICRP 103 factors resulted in higher values for ceCBCT and slightly lower ones for MDCT. Conclusion: ceCBCT offers the chance for immediate intraoperative revisions of endograft-related problems. Requiring only a single-phase acquisition, ceCBCT is associated with a considerable reduction in ED (50%–75%) compared to standard 3-phase MDCT angiography after EVAR. On the other hand, MDCT has a larger field of view and is associated with less radiation exposure for a single phase (reduction of 20%–60%) if only the stented region is covered; however, MDCT angiography also uses larger amounts of contrast.

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.