Endovascular aneurysm repair with a bifurcated endovascular graft at a primary referral center: Influence of experience, age, gender, and aneurysm size on suitability

Evaluando la experiencia local: primeros 50 casos de reparo endovascular de aneurismas aórticos en Manizales, Colombia

Introducción. En las últimas décadas, la terapia endovascular en aneurismas aórticos abdominales ha ganado un papel representativo en los escenarios quirúrgicos, lo que nos motivó a conocer los resultados de este procedimiento en nuestra población. Métodos. Estudio analítico retrospectivo en el cual se incluyeron los primeros 50 casos de aneurismas aórticos abdominales con terapia endovascular, en la ciudad de Manizales, Colombia, entre los años 2015 y 2021. Se describió la población estudiada, la relación de los antecedentes prequirúrgicos con las complicaciones posoperatorias, la estancia hospitalaria y la mortalidad. Resultados. La edad promedio fue de 73 años, el sexo predominante fue el femenino (72 %), el aneurisma fusiforme fue el tipo más frecuente (63,3 %), con un diámetro promedio de 70 mm (+/- 17,3 mm). En relación con los antecedentes, el más frecuente fue hipertensión arterial (86 %), encontrándose una asociación entre la presencia de enfermedad pulmonar obstructiva crónica e hipertensión arterial con las complicaciones. Se encontró también relación entre el valor de creatinina con las complicaciones. Las complicaciones tempranas fueron de carácter leve en la mayoría de los casos (30,6 %), a diferencia de las tardías, que fueron principalmente graves (12,5 %), asociadas a una mortalidad del 10,2 % y una estancia hospitalaria promedio de 10,8 días (mediana de 5 días). Conclusiones. La población analizada tiene una alta carga de morbilidad, en la cual factores como los antecedentes médicos prequirúrgicos y la función renal, se asocian con una mayor morbilidad postquirúrgica y mortalidad.

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.

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

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

Suitability of endovascular repair with current stent grafts for abdominal aortic aneurysm in Korean patients

Suitability rate of endovascular aneurysm repair (EVAR) and the anatomic features causing unsuitability have not been well determined in Asian patients who have abdominal aortic aneurysm (AAA). In a single Korean center, a total of 191 patients with abdominal aortic aneurysm (maximal diameter ≥ 4 cm) were identified. Aortoiliac morphologic characteristics in contrast-enhanced computed tomography images were retrospectively reviewed to determine suitability for EVAR with four FDA-approved stent-grafts. AAA was considered ideally suitable for EVAR in 46.6% of patients. The most frequent causes for unsuitability were common iliac artery (CIA) aneurysm (61.8%) and excessive neck angulation (52.9%). Problems such as small and/or short neck and small access were found in minor incidences. If CIA aneurysm is dealt by overstenting with sacrifice of internal iliac artery, suitability rate can increase to 65%. Larger aneurysms were more frequently unsuitable for EVAR and had more chance of having multiple unfavorable features. In conclusion, the overall feasibility rate for EVAR in Korean patients was not different from that in Western patients. However, considering the difference in the major causes of unsuitability, more attention has to be paid to neck angulation and CIA aneurysm to provide EVAR for more Korean patients especially who have large aneurysm.

Use of baseline factors to predict complications and reinterventions after endovascular repair of abdominal aortic aneurysm

BACKGROUND

It is uncertain which baseline factors are associated with graft-related complications and reinterventions after endovascular aneurysm repair (EVAR) in patients with a large abdominal aortic aneurysm.

METHODS

Patients randomized to elective EVAR in EVAR Trial 1 or 2 were followed for serious graft-related complications (type 2 endoleaks excluded) and reinterventions. Cox regression analysis was used to investigate whether any prespecified baseline factors were associated with time to first serious complication or reintervention.

RESULTS

A total of 756 patients who had elective EVAR were followed for a mean of 3.7 years, by which time there were 179 serious graft complications (rate 6.5 per 100 person years) and 114 reinterventions (rate 3.8 per 100 person years). The highest rate was during the first 6 months, with an apparent increase again after 2 years. Multivariable analysis indicated that graft-related complications increased significantly with larger initial aneurysm diameter (P < 0.001) and older age (P = 0.040). There was also evidence that patients with larger common iliac diameters experienced higher complication rates (P = 0.011).

CONCLUSION

Graft-related complication and reintervention rates were common after EVAR in patients with a large aneurysm. Younger patients and those with aneurysms closer to the 5.5-cm threshold for intervention experienced lower rates.

Spleno-renal bypass facilitating endovascular stenting of a juxta-renal aortic aneurysm in a high risk patient

The management of juxta-renal abdominal aortic aneurysms (AAA) is challenging. Open surgical repair is associated with significant morbidity (predominantly renal) and the absence of an adequate length of normal infra-renal aorta precludes the placement of a standard endograft. In high-risk patients who are unsuitable for standard open repair the endovascular options include fenestrated or branched stent grafts, which are complex, expensive and not widely available, especially in the acute setting. In this report, we describe a case of a hybrid endovascular graft utilising a spleno-renal bypass to facilitate the supra-renal fixation of an aorto-bi-iliac endovascular stent graft in a high-risk patient.

Repair of ruptured abdominal aortic aneurysms by endovascular techniques

Emergency EVR for ruptured AAA is now technically feasible, and several reports with small numbers have appeared in the literature from major centers suggesting that the results may be the same as or better than seen with open repair. The immediate priority is avoidance of over-resuscitation together with the rapid transfer of the patient to CT and then to the operating theater. Because of the learning curve involved, these cases should be attempted only by major centers that have extensive elective endovascular experience. The requirement for 24-hour availability of surgeons and radiologists trained in endovascular techniques places an enormous strain on vascular and radiologic staff and is achievable only in major centers with large teams of doctors. These issues raise important questions about the delivery of vascular services and whether all cases of ruptured aortic aneurysm should be transferred to major vascular centers. The operating theater staff and other support persons need training in endovascular techniques and in rapid deployment of an aortic occlusion balloon. A wide selection of devices, guidewires, and catheters must be immediately available in the operating theater. The ideal way to establish the role of EVR for ruptured AAA would be a randomized trial, but there might be logistic difficulties in recruiting sufficient numbers in major vascular centers, particularly as screening for AAA becomes more common and reduces the number of cases. There also are ethical issues as to whether these patients can give informed consent for involvement in such a trial. The alternative is for major centers to continue to develop their endovascular programs, to do more cases, and to compare the results with historical controls undergoing open repair.

Endovascular aneurysm repair versus open repair in patients with abdominal aortic aneurysm (EVAR trial 1): randomised controlled trial

BACKGROUND

Although endovascular aneurysm repair (EVAR) has a lower 30-day operative mortality than open repair, the long-term results of EVAR are uncertain. We instigated EVAR trial 1 to compare these two treatments in terms of mortality, durability, health-related quality of life (HRQL), and costs for patients with large abdominal aortic aneurysm (AAA).

METHODS

We did a randomised controlled trial of 1082 patients aged 60 years or older who had aneurysms of at least 5.5 cm in diameter and who had been referred to one of 34 hospitals proficient in the EVAR technique. We assigned patients who were anatomically suitable for EVAR and fit for an open repair to EVAR (n=543) or open repair (n=539). Our primary endpoint was all-cause mortality, with secondary endpoints of aneurysm related mortality, HRQL, postoperative complications, and hospital costs. Analyses were by intention to treat.

FINDINGS

94% (1017 of 1082) of patients complied with their allocated treatment and 209 died by the end of follow-up on Dec 31, 2004 (53 of aneurysm-related causes). 4 years after randomisation, all-cause mortality was similar in the two groups (about 28%; hazard ratio 0.90, 95% CI 0.69-1.18, p=0.46), although there was a persistent reduction in aneurysm-related deaths in the EVAR group (4%vs 7%; 0.55, 0.31-0.96, p=0.04). The proportion of patients with postoperative complications within 4 years of randomisation was 41% in the EVAR group and 9% in the open repair group (4.9, 3.5-6.8, p<0.0001). After 12 months there was negligible difference in HRQL between the two groups. The mean hospital costs per patient up to 4 years were UK pound sterling 13,257 for the EVAR group versus pound sterling 9946 for the open repair group (mean difference pound sterling 3311, SE 690).

INTERPRETATION

Compared with open repair, EVAR offers no advantage with respect to all-cause mortality and HRQL, is more expensive, and leads to a greater number of complications and reinterventions. However, it does result in a 3% better aneurysm-related survival. The continuing need for interventions mandates ongoing surveillance and longer follow-up of EVAR for detailed cost-effectiveness assessment.

Laparoscopic aortic reinforcement and endovascular graft placement in swine: a new external wrap

OBJECTIVE

To evaluate the feasibility, safety, and histological response of laparoscopic external aortic wrap implantation in conjunction with an endovascular stent/stent-graft placement in the infrarenal aorta in a porcine model.

METHODS

Seven swine underwent laparoscopic retroperitoneal placement of a custom-made Dacron fabric wrap placed around the infrarenal aorta to create a landing zone for an endovascularly placed aortic stent/stent-graft.

RESULTS

Technical success was achieved in all animals without any major complications. Follow-up ranged from 1 to 4 weeks. At necropsy, the external wraps were well incorporated into the adventitia, and the stents/stent-grafts were well incorporated into the intima. Small patches of medial necrosis of the aortic wall were observed in one animal in the stent model and in two animals in the stent-graft model. There was no transmural necrosis observed. CONCLUSIONS This adjunct technique, an external wrap around the infrarenal aorta combined with endovascular grafting, is feasible and deserves further studies into how it may be used to facilitate endovascular repair of aortic aneurysms.

CLINICAL RELEVANCE

We hypothesize that our new device could provide capability of altering the proximal neck morphology of abdominal aortic aneurysm and reinforcement to the aortic wall. This, in turn, could improve eligibility for endovascular aneurysm repair and prevent or treat type I endoleak and graft migration. Future investigations will involve evaluation of the long-term effect of the external aortic wrap on the integrity of the aortic wall in an animal model and testing the clinical usefulness of this new technique.

Axillobifemoral bypass and aortic embolization for the treatment of two patients with ruptured infrarenal aortic aneurysms

We report two cases of hemodynamically stable patients with contained, ruptured, juxtarenal abdominal aortic aneurysm that were both successfully treated by nonresectional therapy including axillobifemoral bypass with externally supported polytetrafluoroethylene graft, followed by coil embolization of the aneurysm sac and bilateral common iliac arteries. The patients were elderly with multiple comorbidities and complex aneurysm morphology not amenable to endovascular repair. In both cases complete thrombosis of the aneurysm was verified by computed tomography. Both patients are alive at follow-up without evidence of an increase in aneurysm size, postoperative leak, or rupture or impairment of renal function. To our knowledge these are the first reported cases in which this modality has been successfully used in patients presenting with ruptured abdominal aortic aneurysms. Earlier results of nonresectional therapy for abdominal aortic aneurysm have reported a significant incidence of postoperative aneurysm rupture and renal failure. Growing experience at our institution with nonresectional therapy for high risk patients with abdominal aortic aneurysms suggests that nonresectional therapy can be a valuable treatment modality for high risk patients including those with contained rupture of the aneurysm who are hemodynamically stable.