Reporting mid- and long-term results of endovascular grafting for abdominal aortic aneurysms using the aortomonoiliac configuration

Incidence, Long Term Clinical Outcomes, and Risk Factor Analysis of Type III Endoleaks Following Endovascular Repair of Abdominal Aortic Aneurysm

OBJECTIVE

To assess the real world incidence, outcomes, and risk factors of type III endoleaks (TIIIEL) after endovascular aneurysm repair (EVAR).

METHODS

This was a single centre, retrospective, observational, cohort study. All patients with abdominal aortic aneurysms (AAAs) receiving EVAR between 1994 and 2020 were collected prospectively and reviewed. The primary outcome was the cumulative incidence and impact on survival of TIIIELs, either defined as disconnections of modular graft components (TIIIaEL) or fabric defects (TIIIbEL). Secondary outcomes included risk factor analysis evaluating baseline morphological and stent graft details, as well as a comparison of TIIIaEL and TIIIbEL.

RESULTS

In total, 2 565 EVARs were performed and 95 (3.7%) TIIIELs were diagnosed at a median interval of 49.5 months (interquartile range [IQR] 19.4, 67.6). Estimated TIIIEL incidence at five years was 6.8%, 2.2%, and 3.6% for first and second generation, third and fourth generation, and fifth and sixth generation, respectively. The survival rate in patients without any high flow endoleak was 88.0%, 67.9%, 56.9%, and 52.1%, while in TIIIEL patients it was 98.6%, 77.2%, 49.8%, and 32.3% at one, five, 10, and 15 years, respectively (p = .77). The distribution of TIIIaEL and TIIIbEL was 70.5% and 29.5%, respectively. TIIIbEL received a higher rate of open treatment (28.6% vs. 7.5%; p = .005) and device or procedure related re-interventions (35.7% vs. 13.4%; p = .013). Fourteen (15.4%) recurrent TIIIELs were diagnosed at a median of 16.8 months (IQR 7.6, 32.1). Old generation endografts (hazard ratio [HR] 2.1, 95% confidence interval [CI] 1.3 - 3.4; p = .002) and non-proprietary extensions (HR 3.6, 95% CI 1.9 - 6.8; p < .001), and angulated and calcified aneurysm neck (HR 3.6, 95% CI 1.2 - 10.6; p = .017) were risk factors for TIIIEL. Every 10 mm maximum AAA diameter increase presented a 1.4 fold higher risk of TIIIEL.

CONCLUSION

TIIIEL is a severe condition that is often fatal if left untreated. Old endografts, the implantation of non-proprietary extensions, large AAAs, and angulated and calcified necks are risk factors for TIIIEL that require careful follow up due to the high rate of recurrence.

A Comparison of the Short-Term Outcomes After use of Aorto-Uni-Iliac Versus Bifurcated Endografts for Endovascular Repair of Ruptured Abdominal Aortic Aneurysms

BACKGROUND

To compare short-term outcomes of endovascular aneurysm repair (EVAR) with aorto-uni-iliac (AUI) versus bifurcated (BIFUR) endografts in ruptured abdominal aortic aneurysm (rAAA).

METHODS

A total of 26 rAAA patients receiving EVAR with AUI device (14 patients) or the BIFUR graft (12 patients) between January 2016 and December 2020 were enrolled and reviewed. All EVARs for rAAA were performed in an emergency basis. Graft implantation success, short-term survival rates, and major complications were analyzed.

RESULTS

Endograft implantation success was achieved in all patients. AUI group had shorter operative time than BIFUR group (121.77 ± 75.03 vs. 138.45 ± 143.34; P < 0.05). The 24-hr and 30-day survival rates were 85.7% (12/14) and 71.4% (10/14), respectively, whereas BIFUR group have 58.3% and 58.3%. None of the rAAA patients in both groups required reintervention. AUI group exhibited less incidence of compartment syndrome and endoleak compared with those of BIFUR ones.

CONCLUSIONS

The short-term results of EVAR with the AUI configuration graft in patients with rAAAs are encouraging.

Validation of Duplex Ultrasound Graft Surveillance in the Immediate Postoperative Period

A femoral crossover polytetrafluoroethylene graft was performed in a patient immediately, after a failed iliac endograft limb recanalization, performed 2 years after endovascular aortic aneurysm repair. Although graft patency was confirmed clinically by palpation of groin pulses as well as noninvasively by segmental pressure measurements and Doppler examination, in the immediate postoperative period, duplex ultrasound failed to show any blood flow inside the graft lumen until the fourth postoperative day. Subcutaneous air and air tapped within the wall structure of the graft are possible explanation for the failure to show flow.

Endovascular Aortic Repair Complications and the Power of Endovascular Solutions

We report the case of a 75-year-old man submitted to traditional endovascular aortic repair (EVAR) for infrarenal abdominal aortic aneurysm. He presented a late type II endoleak 6 months after operation, initially without sac enlargement. One year later, a computed tomography scan control demonstrated a sac expansion >10 mm, also responsible for a secondary proximal type I endoleak. The patient was submitted to transarterial embolization of lumbar arteries through left internal iliac artery, followed by type I endoleak correction with a proximal cuff deployment. Intraoperative angiography revealed no signs of endoleak. Six months later, a sudden enlargement of the sac was detected, with evidence of type III endoleak, probably consequence of the lumbar arteries embolization, promptly corrected through an aortoaortic endograft. In conclusion, even if a conservative approach for type II endoleak without sac enlargement is proposed, sometimes a sudden sac enlargement could be responsible for catastrophic events in the absence of strict follow-up. The sac embolization during EVAR could reduce the incidence of type II endoleak during follow-up, with reoperation and hospital cost reduction.

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.

Editor's Choice - Management of Secondary Aorto-enteric and Other Abdominal Arterio-enteric Fistulas: A Review and Pooled Data Analysis

OBJECTIVES

To compare management strategies for secondary abdominal arterio-enteric fistulas (AEFs).

METHODS

This study is a review and pooled data analysis. Medline and Scopus databases were searched for studies published between 1999 and 2015. Particular emphasis was given to short- and long-term outcomes in relation to AEF repair type.

RESULTS

Two hundred and sixteen publications were retrieved, reporting on 823 patients. In-hospital mortality was 30.7%. Open surgery had higher in-hospital mortality (246/725, 33.9%), than endovascular methods (7/98, 7.1%, p < .001, OR 6.7, 95% CI 3-14.7, including staged endovascular to open surgery, 0/13, 0%). In-hospital mortality after graft removal/extra-anatomical bypass grafting was 31.2% (66/226), graft removal/in situ repair 34% (137/403), primary closure of the arterial defect 62.5% (10/16), and for miscellaneous open procedures 41.3% (33/80), p = .019. Among the subgroups of in situ repair, homografts were associated with a higher mortality than impregnated prosthetic grafts (p = .047). There was no difference in recurrent AEF-free rates between open and endovascular procedures. Extra-anatomical bypass/graft removal and in situ repair had a lower AEF recurrence rate than primary closure and homografts. Late sepsis occurred more often after endovascular surgery (2-year rates 42% vs. 19% for open, p = .001). The early survival benefit of endovascular surgery was blunted during follow-up, although it remained significant (p < .001). Within the in situ repair group, impregnated prosthetic grafts were associated with the worst overall and AEF related mortality free rates and vein grafts with the best. No recurrence, sepsis, or mortality was reported following staged endograft placement to open repair after a mean follow-up of 16.8 months (p = .18, p = .22, and p = .006, respectively, compared with patients in other groups).

CONCLUSIONS

Endovascular surgery, where appropriate, is associated with better early survival than open surgery for secondary AEFs. Most of this benefit is lost during long-term follow-up, implying that a staged approach with early conversion to in situ vein grafting may achieve the best results in selected patients.

Long-Term Renal Function after Endovascular Aneurysm Repair

BACKGROUND AND OBJECTIVES

Endovascular repair (EVAR) is a common treatment for abdominal aortic aneurysm (AAA). However, its long-term effects on renal function remain unclear. We aimed to assess long-term renal dysfunction after EVAR using a contemporary estimate of GFR and to compare long-term renal outcomes in patients after EVAR with open aneurysm repair (OAR) and in patients without an AAA.

DESIGN, SETTINGS, PARTICIPANTS, & MEASUREMENTS

We performed a nested case-matched analysis of 726 patients (using a prospectively maintained database for repairs that took place between January 2000 and May 2010 in a tertiary center): 121 patients undergoing OAR (with data at baseline and 5 years postrepair) were case matched (age, sex, smoking, diabetes, baseline eGFR) to patients undergoing suprarenal and infrarenal fixation EVAR (242 in each group) and to 121 patients undergoing carotid endarterectomy (CEA) without AAA. Changes in eGFR were compared (1 and 5 years).

RESULTS

The OAR patients lost an average of 7.4 ml/min per 1.73 m2 at 5 years (95% confidence interval [95% CI], 4.8 to 10.6), compared with 8.2 ml/min per 1.73 m2 (95% CI, 6.5 to 10.8; P<0.001) for infrarenal-fixation EVAR, 16.9 ml/min per 1.73 m2 (95% CI, 13.0 to 21.9, P<0.001) for suprarenal-fixation EVAR, and 5.4 ml/min per 1.73 m2 (95% CI, 1.7 to 7.5; P<0.001) for CEA. The decrease in eGFR was steeper during the first postoperative year, with each group losing -2.2 ml/min per 1.73 m2 (infrarenal-fixation EVAR), -10.7 ml/min per 1.73 m2 (suprarenal-fixation EVAR), and -4.6 ml/min per 1.73 m2 (OAR), compared with -1.9 ml/min per 1.73 m2 for CEA.

CONCLUSIONS

Elective EVAR is associated with a significant decline in eGFR after 5 years, which is steeper in the first postoperative year and more pronounced compared with a similar population with atherosclerotic disease.

Endovascular conversion into aorto-uniiliac configuration of acute failed endovascular aneurysm repair is associated with better one-year survival rates compared to open conversion

BACKGROUND

Open conversions (OC) due to failed endovascular repair of infrarenal abdominal aortic aneurysms (EVAR) are technically demanding because of preexisting prostheses and advanced aortic disease. This study evaluates the feasibility and outcomes of aorto-uniiliac endografting (AUI) as an alternative treatment option in acute failed EVAR.

METHODS

From March 1995 through February 2012, 26 patients underwent acute conversion of failed EVAR at our tertiary care university center. All data were prospectively entered in our institutional database. Outcomes included 30-day or in-hospital mortality, postoperative complications, and mid-term survival.

RESULTS

During the investigation period, a total of 692 patients received EVAR at our institution, while five of the 26 patients with acute conversion (19.2%) had an initial EVAR at an outlying institution and were referred for treatment. Therefore, our estimated institutional rate of acute conversions was 3% (21 of 692 EVAR). OC were performed in 14 patients (53.8%), while 12 patients underwent AUI (46.2%). An average time of 20.3 months (median: 18.6; interquartile range Q1-Q3: 0.0-38.6) elapsed between the initial EVAR and the acute conversion. All acute AUI conversion procedures were completed successfully. The 30-day mortality following acute conversions was 42.3% and since the use of AUI, it could be reduced to 33.3%. Kaplan-Meier estimates revealed a survival advantage for AUI at one year (p = 0.046), but the benefit was lost by mid-term follow-up (p = 0.103).

CONCLUSIONS

AUI for the treatment of acute failed EVAR represents a feasible and less invasive alternative to OC, and is associated with better one-year survival rates.

Emergent conversion of the Ovation Stent Graft System to aortouniiliac modification via occlusion of a unilateral internal iliac artery with a stentgraft as a bailout solution

Purpose

To present a case of inadvertent collapse of the contralateral limb gate caused by misorientation during the deployment of the Ovation Abdominal Stent Graft System in a narrow aortic lumen and the bailout conversion to aortouniiliac modification, using a covered stent to exclude the orifice of the internal iliac artery (IIA).

Technique description

Despite the repeated efforts from the femoral and brachial site, the collapsed/occluded contralateral limb gate could not be catheterized. In order to exclude successfully the orifice of the IIA, an oversized stentgraft was placed immediately at the common-to-external iliac artery (CIA-EIA) transition followed by peripheral ligation of the latter. The procedure was completed with crossover femorofemoral bypass.

Conclusion

Occlusion the IIA orifice with an oversized stentgraft in the CIA-EIA transition can be considered as a safe, simple, fast, and efficient bailout maneuver, followed by EIA ligation and crossover bypass.

Rates of adverse events and correction procedures after elective versus emergent aortouni-iliac endografting during mid-term follow-up: A prospective cohort study

BACKGROUND

Due to preferential implantation of bifurcated devices during endovascular repair of infrarenal abdominal aortic aneurysms (AAA), longer-term results following aortouni-iliac (AUI) endografting are scarce. The aim of this study was to determine the rate of endoleaks as well as frequency of secondary correction procedures after elective and emergent AUI endografting.

METHODS

A prospectively gathered database at a tertiary care university hospital was retrospectively reviewed from January 2000 until January 2012. This interrogation identified 61 patients who had undergone AUI endografting to treat their AAA. Data retrieval obtained 47 patients with elective AAA repairs while 14 patients received emergent AUI endografting in case of rupture. Procedural outcomes, endoleaks, complications, and secondary interventions during mid-term follow-up were recorded for analysis.

RESULTS

Fifty-five patients of the study cohort were male (90.2%) and mean age was 76.5 years (median: 77.2, Q1-Q3: 72.1-81.6). Patient demographics, comorbidities, procedural characteristics, as well as median follow-up length (39.8 months versus 34.9 months) were similar between groups. Endoleaks, complications, and rate of secondary correction procedures were not increased following emergent AUI endografting. The majority of these interventions comprised catheter-based or less invasive surgical procedures. All patients requiring major surgery (three open surgical conversions with endograft explantation and one open aortic banding) survived, while one patient sustained fatal myocardial infarction after a transluminal correction procedure.

CONCLUSION

Emergent AUI endografting was not associated with higher rates of adverse events or correction procedures during mid-term follow-up. Secondary interventions to maintain aneurysm exclusion could be carried out with low mortality.

Secondary modification into aortouniiliac configuration to salvage failed endovascular aneurysm repair is safe and effective but not associated with higher intervention rates during long-term follow-up

BACKGROUND

Reports of secondary modifications into aortouniiliac configuration to salvage-failed endovascular aneurysm repair (EVAR) are limited. We evaluated long-term results after these procedures and compared them with those after primary aortouniiliac endografting (AUE).

METHODS

A retrospective review of all EVAR performed from March 1995 until July 2011 was conducted. Patients were included when primary AUE (group I) or modification into aortouniiliac configuration (group II) was done.

RESULTS

Data analysis obtained 27 group I and 23 group II patients. Salvage of failed EVAR could be achieved in 96% of group II patients, and mortality was zero. Frequency of adverse events and amount of interventions to maintain aneurysm exclusion were not increased after secondary AUE. Kaplan-Meier estimates for long-term survival between groups were comparable (P = .36).

CONCLUSIONS

Secondary AUE allows correction of graft-related endoleaks potentially leading to late aneurysm rupture. Complications and adverse events throughout long-term follow-up were not necessarily increased when compared with primary AUE.

Aortouni-iliac endografting as an alternative salvage procedure to open conversion in failed endovascular aneurysm repair

PURPOSE

To present a single-center experience with failed EVAR requiring conversions comparing open surgery to a minimally invasive procedure modifying the existing stent-graft into an aortouni-iliac (AUI) configuration.

METHODS

A prospectively maintained database at our tertiary care university hospital was interrogated to identify all patients with failed EVAR who had undergone either stent-graft modification into an AUI configuration or open conversion between March 1995 and January 2012. Patients with late aneurysm ruptures were excluded. The search found 30 patients (one had initial treatment elsewhere) who required conversion among the 688 patients who had undergone EVAR in that time period. Before conversion, 16 (53%) patients had prior endovascular corrections to maintain aneurysm exclusion.

RESULTS

An average time of 52.2 months (median 46.9, IQR 0.0-92.5) elapsed between initial EVAR and conversion. There were 11 early conversions (including 7 on-table), while 19 procedures were done >30 days post EVAR. Twenty-two (73%) patients underwent AUI endografting, while open conversions were carried out in 8 (27%). Mean hospital stay after conversion was 19.5 days (median 13.0, IQR 8.0-17.0). Overall mortality after conversion was 3.3% (1 patient after on-table open conversion), but since the introduction of AUI endografting as an alternative treatment approach, 30-day mortality following conversions fell to zero.

CONCLUSION

Modification of a failed stent-graft into an AUI configuration serves as a less invasive treatment option compared to open conversion and allows salvage of the failed device. With the implementation of this alternative approach, mortality after conversion parallels the mortality of elective abdominal aneurysm repair.

Stent graft performance in the treatment of abdominal aortic aneurysms: the influence of compliance and geometry

The long-term success of the endovascular procedure for the treatment of Abdominal Aortic Aneurysms (AAAs ) depends on the secure fixation of the proximal end and the geometry of the stent-graft (SG) device. Variations in SG types can affect proximal fixation and SG hemodynamics. Such hemodynamic variations can have a catastrophic effect on the vascular system and may result from a SG/arterial wall compliance mismatch and the sudden decrease in cross-sectional area at the bifurcation, which may result in decreased distal perfusion, increased pressure wave reflection and increased stress at the interface between the stented and non-stented portion of the vessel. To examine this compliance mismatch, a commercial SG device was tested experimentally under a physiological pressure condition in a silicone AAA model based on computed tomography scans. There was a considerable reduction in compliance of 54% and an increase in the pulse wave velocity of 21%, with a significant amount of the forward pressure wave being reflected. To examine the SG geometrical effects, a commercial bifurcated geometry was compared computationally and experimentally with a geometrical taper in the form of a blended section, which provided a smooth transition from the proximal end to both iliac legs. The sudden contraction of commercial SG at the bifurcation region causes flow separation within the iliac legs, which is known to cause SG occlusion and increased proximal pressure. The blended section along the bifurcation region promotes a greater uniformity of the fluid flow field within the distal legs, especially, during the deceleration phase with reduced boundary layer reversal. In order to reduce the foregoing losses, abrupt changes of cross-section should be avoided. Geometrical tapers could lead to improved clinical outcomes for AAA SGs.

Anemia is Associated With Mortality Following Endovascular Repair of Abdominal Aortic Aneurysm

Aim: The aim of this study was to compare midterm mortality between anemic and nonanemic patients undergoing endovascular repair of abdominal aortic aneurysm and to assess a correlation with markers of inflammation. Methods: Anemia was defined as hemoglobin <13 (men) and <12 g/dL (women). The impact of anemia and inflammatory markers on mortality was assessed using Kaplan-Meier curves and Cox regression. Results: A total of 224 patients (12 females [5.36%]; age: 69.73 ± 8.72 years) were included; 102 (45.53%) were anemic. Median follow-up was 17 months (interquartile range: 7-25 months). Nine patients died (1.79%; 8 anemic vs 1 nonanemic). Survival was lower for patients with anemia (log-rank, P = .01). White blood cell count and C-reactive protein (CRP) differed significantly ( P < .001 and P = .01). Anemia and CRP were associated with decreased survival (Cox regression, P = .01, hazard ratio [HR]: 0.35, 95% confidence interval: 0.14-0.84 and P = .002, HR: 1.18, 95% CI: 1.06-1.31). Conclusion: Patients with anemia had decreased survival over the midterm; inflammatory markers were higher among this group.