Sac Shrinkage Research Articles

Factors Influencing on the Aneurysm Sac Shrinkage after Endovascular Abdominal Aortic Aneurysm Repair by the Analysis of the Patients with the Aneurysm Sac Shrinkage and Expansion

Factors Influencing on the Aneurysm Sac Shrinkage after Endovascular Abdominal Aortic Aneurysm Repair by the Analysis of the Patients with the Aneurysm Sac Shrinkage and Expansion

Association of High-Sensitivity C-Reactive Protein With Aneurysm Sac Shrinkage in Patients Undergoing Endovascular Abdominal Aneurysm Repair

Purpose: The factors associated with aneurysm sac shrinkage after endovascular aneurysm repair (EVAR) are not well established. As inflammation is implicated in aneurysm pathophysiology, we hypothesized that high-sensitivity C-reactive protein (hsCRP) was associated with aneurysm sac shrinkage after EVAR and compared the preoperative level of hsCRP between patients with and without postoperative aneurysm sac shrinkage after EVAR. Methods: From November 2013 to April 2019, 143 patients undergoing EVAR using Gore C3 Excluder (W. L. Gore & Associates, Inc, Flagstaff, Arizona) at our university hospital were included in this study. Aneurysm sac size was compared between that on baseline preoperative computed tomography (CT) and that on postoperative CT scans. A change in aneurysm sac size ≥5 mm was considered to be significant, whether due to enlargement or shrinkage. Results: Aneurysm sac size showed a significant decrease from 50.6 ± 9.8 mm to 47.1 ± 10.3 mm at 1 year. At 1 year postoperatively, aneurysm sac shrinkage (≥5 mm) was observed in 48 patients (34%), a stable aneurysm sac was noted in 93 patients (65%), and aneurysm sac enlargement was noted in 2 patients (1.4%). The mean preoperative hsCRP was 0.33 ± 0.54 mg/dL. Univariable analysis showed that preoperative hsCRP (p=0.029) and the presence of a renal cyst (p=0.002) were associated with aneurysm sac shrinkage. Multivariable analysis showed that preoperative hsCRP [>0.19mg/dL] (odds ratio [OR] = 0.22; 95% confidence interval [CI] = 0.05–0.96; p=0.042), and the presence of a renal cyst (OR = 0.31; 95% CI = 0.15–0.67; p=0.002) were independent risk factors for aneurysm sac shrinkage after EVAR. Conclusions: The level of preoperative hsCRP was independently associated with aneurysm sac shrinkage after EVAR in patients with abdominal aortic aneurysms. These data suggest that the high level of hsCRP can be a negative predictor for aneurysm sac shrinkage after EVAR.

The impact of obesity on perioperative and postoperative outcomes after elective endovascular abdominal aortic aneurysm repair.

Obesity is a common and growing health problem in vascular surgery patients, as it is in all patient groups. Evidence regarding body mass index (BMI) on endovascular aneurysm repair (EVAR) outcomes is not clear in the literature. We aimed to determine the impact of obesity on perioperative and midterm outcomes of elective EVAR between obese and non-obese patients. Under a retrospective study design, a total of 120 patients (109 males, 11 females, mean age: 74.45 ± 8.59 (53-92 years)) undergoing elective EVAR between June 2012 and May 2020 were reviewed. Patients were stratified into two groups: obese (defined as a body mass index (BMI) ≥ 30kg/m2) and non-obese (mean BMI < 30kg/m2 (32.25 ± 1.07kg/m2 vs 25.85 ± 2.69kg/m2)). Of the 120 patients included in the study, 81 (67.5%) were defined as "nonobese," while 39 (32.5%) were obese. The mean BMI of the study group was 27.93 ± 3.78kg/m2. In obese patients, the procedure time, fluoroscopy time, and dose area product (DAP) values were longer than those of non-obese patients: 89.74 ± 20.54 vs 79.69 ± 28.77 min (p = 0.035), 33.23 ± 10.14 vs 38.17 ± 8.61 min (p = 0.01) and 133.69 ± 58.17 vs 232.56 ± 51.87Gy.cm2 (p < 0.001). Although there was no difference in sac shrinkage at 12-month follow-up, there was a significant decrease at 6-month follow-up in both groups (p = 0.017). Endoleak occurred in 17.9% (n = 7) of the obese group versus 11.1% (n = 9) of the non-obese group (p = 0.302). Iliac branch occlusion developed in four patients, 3 (3.7%) in the non-obese group and 1 (2.6%) in the obese group (p = 0.608). The all-cause mortality rate was slightly higher in the obese group; however, it did not differ between the groups (p = 0.463). In addition to the longer procedure times, fluoroscopy times, and DAP values in obese patients, regardless of obesity, significant sac shrinkage in the first 6months of follow-up was observed in both groups. No difference was documented with regards to mortality or morbidity following EVAR.

Abdominal aortic aneurysm neck dilatation and sac remodeling in fenestrated compared to standard endovascular aortic repair.

Contemporary commercially available endovascular devices for the treatment of abdominal aortic aneurysm (AAA) include standard endovascular aortic repair (sEVAR) or fenestrated EVAR (fEVAR) endografts. However, aortic neck dilatation (AND) can occur in nearly 25% of patients following EVAR, resulting in loss of proximal seal with risk of aortic rupture. AND has not been well characterized in fEVAR, and direct comparisons studying AND between fEVAR and sEVAR have not been performed. This study aims to analyze AND in the infrarenal and suprarenal aortic segments, including seal zone, and quantify sac regression following fEVAR implantation compared to sEVAR. A retrospective review of prospectively collected data on 20 consecutive fEVAR patients (Cook Zenith® Fenestrated) and 20 sEVAR (Cook Zenith®) patients was performed. Demographic data, anatomic characteristics, procedural details, and clinical outcome were analyzed. Pre-operative, post-operative (1month), and longest follow-up CT scan at an average of 29.3months for fEVAR and 29.8months for sEVAR were analyzed using a dedicated 3D workstation (iNtuition, TeraRecon Inc, Foster City, California). Abdominal aortic aneurysm neck diameter was measured in 5mm increments, ranging from 20mm above to 20mm below the lowest renal artery. Sub-analysis comparing the fEVAR to the sEVAR group at 12months and at greater than 30months was performed. Standard statistical analysis was done. Demographic characteristics did not differ significantly between the two cohorts. The fEVAR group had a larger mean aortic diameter at the lowest renal artery, shorter infrarenal aortic neck length, increased prevalence of nonparallel neck shape, and longer AAA length. On follow-up imaging, the suprarenal aortic segment dilated significantly more at all locations in the fEVAR cohort, whereas the infrarenal aortic neck segment dilated significantly less compared to the sEVAR group. Compared to the sEVAR cohort, the fEVAR patients demonstrated significantly greater positive sac remodeling as evident by more sac diameter regression, and elongation of distance measured from the celiac axis to the most cephalad margin of the sac. Device migration, endoleak occurrence, re-intervention rate, and mortalities were similar in both groups. Compared to sEVAR, patients undergoing fEVAR had greater extent of suprarenal AND, consistent with a more diseased native proximal aorta. However, the infrarenal neck, which is shorter and also more diseased in fEVAR patients, appears more stable in the post-operative period as compared to sEVAR. Moreover, the fEVAR cohort had significantly greater sac shrinkage and improved aortic remodeling. The suprarenal seal zone in fEVAR may result in a previously undescribed increased level of protection against infrarenal neck dilatation. We hypothesize that the resultant decreased endotension conferred by better seal zone may be responsible for a more dramatic sac shrinkage in fEVAR.

Comparison of Early and Mid-Term Outcomes After Fenestrated-Branched Endovascular Aortic Repair in Patients With or Without Prior Infrarenal Repair

Objective: The purpose of this study was to compare short- and mid-term outcomes of fenestrated-branched endovascular repair (F-BEVAR) of pararenal (PRAA)/thoracoabdominal (TAAA) aortic aneurysms in patients with or without prior endovascular/open (EVAR/OAR) infrarenal aortic repair. Methods: Data from consecutive F-BEVAR (2010–2019) at two high-volume aortic centers were retrospectively reviewed. Primary endpoints were technical success, 30-day mortality, and overall survival. Secondary endpoints included 30-day major adverse events (MAE), freedom from type I/III endoleaks, reinterventions, sac expansion, and target vessel (TV) primary patency. Results: A total of 222 consecutive patients were included for analysis; of these 58 (26.1%) had prior infrarenal repair (EVAR=33, OAR=25) and 164 (73.9%) had native PRAA/TAAA. At baseline, patients with prior infrarenal repair were older (mean age=75.1 vs 71.6 years, p=.005) and the proportion of females was lower (8.6% vs 29.3%, p=.002). Technical success was 97.8% (n=217) in the entire cohort, without any significant differences between study groups (94.8% vs 98.8%, p=.08). At 30 days, there were no significant differences between patients with prior infrarenal repair as compared with those without in rate of MAE (44.8% vs 54.9%, p=.59). The 5-year estimate of survival for those who underwent native aortic repair was 61.6%, versus 61.3% for those who had a previous repair (p=.67). The 5-year freedom from endoleaks I/III estimates were significantly lower in patients who had prior infrarenal repair as compared with patients undergoing treatment of native aneurysms (57.1% vs 66.1%, p=.03), mainly owing to TV-related endoleaks (ie, type IC and/or IIIC endoleaks). No significant differences were found between study groups in rates of reinterventions and TV primary patency. Five-year estimates of freedom from sac increase >5mm were significantly lower in patients who received F-BEVAR after previous infrarenal repair as compared with those who underwent treatment of native aneurysms (48.6% vs 77.5%, p=.002). Conclusions: F-BEVAR is equally safe and feasible for treatment of patients with prior infrarenal repair as compared with those undergoing treatment for native aneurysms. Increased rates of TV-related endoleaks were observed which could lead to lower freedom from aneurysm sac shrinkage during follow-up. Nevertheless, the 5-year rates of reinterventions and TV patency were similar, thereby indicating that overall effectiveness of treatment remained satisfactory at mid-term.

Safety and Validity of the Proposed European Society for Vascular Surgery Infrarenal Endovascular Aneurysm Repair Surveillance Protocol: A Single Centre Evaluation

Long term surveillance after endovascular aneurysm repair (EVAR) is essential to detect late complications, but there is variation in practice. The European Society for Vascular Surgery (ESVS) made a recommendation for a new surveillance protocol; one element involves risk stratifying patients depending on sac size reduction and presence of endoleak at their 30 day computed tomography angiogram into low risk groups (delayed imaging to five years) or higher risk groups (continue with the current protocol). The aim was to test this suggested protocol retrospectively within an EVAR patient cohort. Data on EVARs performed from October 2009 to October 2019 were collected. Information gathered from an existing surveillance programme was used to assess the proposed ESVS protocol. All patients who underwent re-intervention were reviewed to see whether adopting the proposed ESVS protocol would have detected these events. In total, 309 procedures were included. Altogether, 219 of these patients had no endoleak (70.9%) and 86 had a type II (27.8%) endoleak. Only four developed a type I or III endoleak. No patient in the low risk cohort (no initial endoleak or sac shrinkage > 1 cm) required secondary intervention. Five year follow up data were available for 103 patients. In the type II endoleak group, there were 28 secondary interventions in 22 patients. No patient experienced a ruptured aneurysm within five years post-operatively. Had the proposed ESVS protocol been followed, all patients requiring a secondary intervention or with increasing sac size would have been detected/captured. Further, adherence to the ESVS guidelines would have resulted in 103 patients with a five year follow up history qualifying for reduced surveillance. A further 120 patients who had reached the three and four year follow up timepoints could have qualified for a reduced surveillance, reducing imaging cost further. Adopting the proposed ESVS EVAR surveillance protocol safely identified "low risk" patients who did not go on to require a secondary intervention. These patients could benefit from reduced surveillance scanning.

Effects of Antithrombotic Therapy on Abdominal Aortic Aneurysm Sac Size after Endovascular Repair in Patients with Favorable Neck Anatomy

PurposeTo evaluate the influence of antiplatelet or anticoagulant therapy on sac behavior after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA). Materials and MethodsThis study retrospectively analyzed data from patients with favorable neck anatomy who underwent EVAR between 2007 and 2019. Patients with ruptured AAA and ≤1 year of sac behavior evaluation were excluded. Sac shrinkage after 1 year, persistent type II endoleak, and late sac expansion were examined. ResultsIn total, 182 patients with favorable neck anatomy were included in this study. A multivariable analysis identified an occluded inferior mesenteric artery (IMA; P = .049), the presence of a posterior thrombus (P = .009), and no antiplatelet therapy (P = .012) as factors positively associated with sac shrinkage at 1 year. Persistent type II endoleak was detected in 56 (30.8%) patients, with patent IMA (P = .006), the lack of a posterior thrombus (P = .004), the number of patent lumbar arteries (P = .004), and antiplatelet therapy (P = .039) being identified as significant risk factors. The multivariable analysis identified a larger initial AAA diameter (P < .001), the lack of a posterior thrombus (P = .038), and antiplatelet and anticoagulant therapies (P = .038 and P = .003, respectively) as risk factors for late sac expansion. ConclusionsAfter EVAR in patients with favorable neck anatomy, antiplatelet therapy is associated with the lack of sac regression at 1 year, whereas antiplatelet and anticoagulant therapies are risk factors for late sac expansion.

Stability of the aneurysmatic sac post-EVAR could no longer be a reliable criterion of healing.

Evaluation of the impact of aneurysm sac behavior in terms of either stability or shrinkage after endovascular aneurysm repair (EVAR) on long-term clinical outcomes. A retrospective study was conducted on 1483 consecutive patients who underwent EVAR from 1999 to 2021 at our institution. 1037 patients met inclusion criteria (1037/1483, 69.9%): abdominal aortic or aorto-iliac aneurysm, elective surgery, follow-up (FU) ≥12 months. Patients who had sac stability (330/1037, 31.8%) and patients who demonstrated sac shrinkage (542/1037, 52.2%) at FU were compared; patients who presented sac increase at FU were excluded (165/1037, 16%). rupture rates, need for surgical conversion, and long-term aneurysm-related mortality. Secondary endpoints: all type endoleak rates and long-term reintervention rates. Mean FU was 61.2 months (IQ 26-85.7 months). In terms of comorbidities, the group of patients with stable sac showed greater association with polidistrectual atherosclerotic manifestations. Estimated 12-year survival was 42.9% in the stable sac group and 65% in the shrinked group (P<0.001), although there were no significant differences in terms of freedom from aneurysm-related death (97.3% vs. 95.4% estimated at 12 years, P=0.493). Patients with sac stability had higher rates of rupture (2.1% vs. 0.6%, P=0.035) and surgical conversion (2.1% vs. 0.6%, P=0.035). The stable sac group had significantly higher rates of all type endoleak during FU (45.8% vs. 24%, P<0.001). Estimated 12-year freedom from reintervention rates were 56.2% and 83.9% respectively (P<0.001). After more than 20 years of EVAR experience it is probably time to reconsider the procedure clinical success parameters as a patient with a stable sac cannot be considered healed.

Midterm Outcomes of Endovascular Abdominal Aortic Aneurysm Repair with Prevention of type 2 Endoleak by Intraoperative Aortic Side Branch Coil Embolization

The midterm results of endovascular abdominal aortic aneurysm repair (EVAR) with aortic side branch coil embolization during EVAR was evaluated. Our center began coil embolization for all patent inferior mesenteric artery (IMA) and lumbar artery (LA) with an inner diameter more than 2.0 mm during EVAR since June 2015. When four or more LA were patent, coil embolization for LA with inner diameter 2.0 mm or less was done. EVAR without aortic side branches coil embolization was performed for 59 patients prior to June 2015 (control group) and 79 patients underwent EVAR with coil embolization during EVAR (coil group). The success rate of coil embolization for IMA and LA was evaluated in coil group. The frequency of type 2 endoleak (T2EL), freedom from aneurysm sac expansion (5 mm or more) rate and the rate of the aneurysm sac shrinkage (10 mm or more) were compared between the coil and control groups. Additionally, multiple logistic regression analysis for all patients was conducted to analyze whether IMA patency and the number of patent lumbar artery at the end of EVAR were the risk factors of the aneurysm sac expansion of 5 mm or more. The success rate of IMA coil embolization was 96.4% and that of LA was 74.5%. Compared to the control group, the frequency of T2EL was significantly lower in coil group at 7 days (1.3% vs. 60.4%, P <0.0001) and at 6 months (2.1% vs 38.2%, P <0.0001) after EVAR. The freedom from aneurysm sac expansion rate was significantly better in the coil group at 5 years (100% in coil group and 65.2% in control group, P=0.002). The rate of aneurysm sac shrinkage was significantly better in coil group (15.5% vs. 2.0% at 1 year, 42.8% vs. 6.3% at 2 years and 53.4% vs. 17.8% at 3 years, p=0.0007). The risk of aneurysm sac expansion of 5 mm or more was estimated to be 11 times greater when the IMA was patent, and 4.9 times greater when 3 or more LAs were patent at the end of EVAR. When IMA was occluded and the number of patent LA became 2 or less by aortic side branch coil embolization during EVAR, favorable mid-term results were safely obtained and good long-term result could be expected with EVAR.

Fenestrated EVAR Promotes Positive Infrarenal Neck Remodeling Leading to Greater Sac Shrinkage Compared With EVAR

The standard of care treatment for abdominal aortic aneurysms (AAAs) in the modern era is endovascular aneurysm repair (EVAR). Numerous devices exist for standard infrarenal AAA repair, but in patients with short infrarenal necks, fenestrated endovascular aneurysm repair (fEVAR) offers a minimally invasive alternative to traditional open repair. Over time, aortic neck dilation can occur in the segment used as a seal zone, leading to loss of seal, endoleaks, and AAA sac growth. This study compares aortic remodeling post EVAR vs fEVAR and evaluates if fEVAR confers a benefit in terms of sac shrinkage.

Dural sac shrinkage signs on magnetic resonance imaging at the thoracic level in spontaneous intracranial hypotension-its clinical significance.

Spontaneous intracranial hypotension (SIH) is secondary to a cerebrospinal fluid leak at the spinal level without obvious causative events. Several signs on brain and cervical spine magnetic resonance (MR) imaging (MRI) have been associated with SIH but can be equivocal or negative. This retrospective study sought to identify characteristic SIH signs on thoracic spinal MRI. Cranial and spinal MR images of 27 consecutive patients with classic SIH symptoms, who eventually received epidural autologous blood patches (EBPs), were analyzed. The most prevalent findings on T2-weighted MRI at the thoracic level were anterior shift of the spinal cord (96.3%) and dorsal dura mater (81.5%), probably caused by dural sac shrinkage. These dural sac shrinkage signs (DSSS) were frequently accompanied by cerebrospinal fluid collection in the posterior epidural space (77.8%) and a prominent epidural venous plexus (77.8%). These findings disappeared in all six patients who underwent post-EBP spinal MRI. Dural enhancement and brain sagging were minimum or absent on the cranial MR images of seven patients, although DSSS were obvious in these seven patients. For 23 patients with SIH and 28 healthy volunteers, a diagnostic test using thoracic MRI was performed by 13 experts to validate the usefulness of DSSS. The median sensitivity, specificity, positive-predictive value, negative-predictive value, and accuracy of the DSSS were high (range, 0.913-0.931). Detection of DSSS on thoracic MRI facilitates an SIH diagnosis without the use of invasive imaging modalities. The DSSS were positive even in patients in whom classic cranial MRI signs for SIH were equivocal or minimal.

Association of preoperative pulse wave velocity to aneurysm sac shrinkage after endovascular aneurysm repair.

Arterial stiffness may be the underlying cause of divergent sac behavior after endovascular aortic repair (EVAR). We evaluated arterial stiffness using pulse wave velocity (PWV) in patients undergoing EVAR for abdominal aortic aneurysm (AAA) to determine whether arterial stiffness predicts sac behavior after EVAR. One hundred nineteen patients with infrarenal AAA undergoing EVAR between November 2013 and July 2019 were included in this study. Preoperative brachial-ankle PWV was measured using an automated oscillometric method at our Vascular Laboratory. PWV and other risk factors were assessed with respect to being a risk factor for sac shrinkage at 2 years postoperatively. Univariable and multivariable analyses revealed both preoperative PWV (odds ratio [OR]=0.87; 95% confidence interval [CI]: 0.79-0.98; P=0.045) and the incidence of operative type II endoleak (OR 0.68; 95% CI 0.10-0.81; P=0.048) as independent risk factors for sac shrinkage at 2 year postoperatively. The receiver-operating characteristic curve analysis showed that the optimal cut-off value for predicting sac shrinkage was 17.79 m/s, and significantly predicted sac shrinkage. Preoperative PWV was independently associated with sac shrinkage after EVAR, suggesting that arterial stiffness may be one of the key factors for determining sac behavior after EVAR.

Funnel technique for wide infrarenal aneurysm neck with Lifetech Ankura™ Stent Graft System.

Background In this study, we present our mid-term results in patients undergoing treatment with the funnel technique and describe technical issues for this bailout technique in extra-wide infrarenal necks. Methods Between January 2018 and June 2020, a total of seven male, symptomatic patients (median: 74.5 years; range, 64 to 84 years) who had comorbidities and were in the American Society for Anesthesiologists Class IV and treated by the funnel technique in an endovascular fashion were included. Pre- and post-procedural data of the patients, early mortality and technical success rates were evaluated. Results There was no early mortality. Technical success rate was 100%. There was no type I or III endoleaks at the completion angiography. All patients were discharged without any problem on the second or third day of the procedure. The median follow-up was 13 (range, 6 to 28) months. The aneurysm sac shrinkage was achieved in all patients over six months of follow up. During the follow-up period, no proximal endoleak or infrarenal aortic neck diameter enlargement was found. Conclusion Based on our limited experience, the funnel technique may be considered more than a bailout procedure under special circumstances.

Postoperative imaging follow-up at 2 years as a predictor of long-term outcomes after endovascular aneurysm repair

ObjectiveLifelong imaging follow-up remains the reference standard after endovascular aneurysm repair (EVAR). Because the number of EVARs has been increasing, an individually optimized follow-up protocol is desirable. The aim of the present study was to investigate the possibility of creating such a protocol by evaluating patients' follow-up images and to compare the findings with their freedom from reintervention and abdominal aortic aneurysm (AAA) rupture. MethodsFrom 2000 to 2010, 282 patients with an AAA had undergone elective EVAR with the Zenith stent-graft. The patients were followed up annually until the end of 2019. The patients were categorized into two groups according to the presence of any endoleak or sac shrinkage at 2 years. Group A included those with no detectable endoleak plus aneurysm sac shrinkage of ≥5 mm (n = 137; 63%), and group B included those with any type of endoleak and/or no significant aneurysm sac shrinkage (<5 mm; n = 82; 37%). ResultsThe mean follow-up was 83 months (range, 0-229 months), and the overall survival at 2 years was 84% (n = 237). No significant difference was found in overall survival between groups A and B (P = .73). However, a significant difference was found in freedom from AAA rupture at 12 years, favoring group A (group A, 100%; group B, 91%; P = .002). Furthermore, in group A, the freedom from reintervention was 95% at 12 years compared with only 31% in group B (P < .001). The sensitivity of the categorization was 89% and the specificity was 74% for the finding of a complication requiring a reintervention during long-term follow-up. ConclusionsPatients without an endoleak and a reduction of ≥5 mm in aneurysm size at 2 years had significantly fewer late reinterventions and ruptures during long-term follow-up compared with their counterparts using the Zenith stent-graft (Cook Medical, Bloomington, Ind). This finding suggests that, for these patients, the follow-up interval can be personalized and safely extended after 2 years.

A morphovolumetric analysis of aneurysm sac evolution after elective endovascular abdominal aortic repair

ObjectiveAbdominal aortic aneurysm (AAA) sac shrinkage after endovascular aortic repair (EVAR) has been regarded as positive marker of EVAR success durability. The purpose of this study was to describe the morphovolumetric changes of the AAA sac during follow-up after elective EVAR and to analyze sac shrinkage-related variables. MethodsThis is a single-center, retrospective, observational cohort study from a tertiary referral university hospital. All patients treated with EVAR between January 2013 and December 2018 were identified. Inclusion criteria were elective EVAR for AAA, preoperative computed tomography angiography within 6 months before EVAR and at least one postoperative computed tomography angiography during the follow-up, using a standardized protocol. Aneurysm sac shrinkage was defined as diameter decrease of 1 cm or more, volume shrinkage threshold was identified by a 16% decrease compared with the preoperative value. Primary outcomes were early (≤30 days) and late survival, and freedom from aneurysm-related mortality (ARM), and aortic reintervention. ResultsThere were 149 of the 325 patients (45.8%) who met the inclusion criteria: 133 (89.3%) were male and 16 (10.7%) female. The mean age was 74 ± 7 years (range, 55-87 years); the median AAA diameter was 56 mm (interquartile range, 50.0-61.2 mm) and the median volume was 138.8 cm3 (range, 99.0-178.3 cm3). Primary technical success was achieved in 145 patients (97.3%). The in-hospital mortality rate was 1.3%. The median follow-up was 42 months (interquartile range, 22.5-58.0 months). Both AAA diameter and volume decreased (P = .001 and P = .035, respectively) compared with preoperative measurements. Diameter shrinkage was adjudicated in 27 patients (18.1%), volume shrinkage was observed in 42 patients (28.2%). A Cox regression analysis demonstrated an association between the AAA diameter shrinkage and the preoperative diameter (P = .002; hazard ratio, 1.03; 95% confidence interval [CI], 1.011-1.052). The presence of a persistent endoleak predicted the absence of volume shrinkage (P = .001; hazard ratio, 7.75; 95% CI, 2.282-26.291). The estimated freedom from ARM was 97.5 ± 1.0% (95% CI, 93-99) at 12 months, and 96 ± 2% (95% CI, 90-98) at both 36 and 60 months. Aortic reintervention during the follow-up period was necessary in 7 patients (4.7%). ARM was only observed in the group characterized by the concomitant absence of diameter and volume shrinkage. ConclusionsVolumetric analysis showed to have higher sensitivity than the simple two-dimensional measurement of the diameter to study AAA sac changes after EVAR. Although no predictor was found to be associated with AAA volume shrinkage, ARM occurred only in the group of AAAs with the absence of volume shrinkage.

Clinical Comparison between Early and Late Spontaneous Sac Shrinkage after Endovascular Aortic Aneurysm Repair

BackgroundEarly spontaneous shrinkage (ESS) of abdominal aortic aneurysm (AAA) within 1 year after endovascular aortic aneurysm repair (EVAR) could be a predictor of durable success. However, late spontaneous shrinkage (LSS) during longer follow-up has not been well addressed. We compared late complications of ESS and LSS. MethodsOur series of elective EVAR for infrarenal AAA from June 2007 to December 2017 was reviewed. Patients with ≥1 year of follow-up with computed tomography (CT) studies were included. Patients with any reintervention within 1 year were excluded. Spontaneous shrinkage (SpS) was defined as a diameter reduction ≥10 mm without any reintervention. ESS was defined as SpS within 1 year, and LSS was defined as SpS occurring after 1 year of follow-up. Aneurysms that became larger than the original size after SpS were defined as re-expansion. Late complications (re-expansion, reintervention, and aneurysm-related death) and related factors were compared between ESS and LSS. ResultsA total of 495 patients were enrolled. Median follow-up was 43 months [24–67, interquartile range (IQR)]. Among patients, 126 ESS and 55 LSS occurred. The cumulative rates of SpS were 25.7±2.0%, 37.4±2.4%, and 47.3±3.7% at 1, 3, and 7 years, respectively. There was 1 re-expansion and 6 reinterventions during further follow-up after SpS. The rates of freedom from late complications at 5 years were not significantly different between ESS (89.2±4.0%) and LSS (95.8±4.1%) (P = 0.465). Regression analysis revealed that the Zenith device was significantly related to ESS compared to the Excluder (P = 0.006) and Endurant (P = 0.040) . More than 6 preoperative patent lumbar arteries negatively correlated with ESS (P = 0.023). However, these factors had no significant impact on LSS. ConclusionsThe rates of late complications after SpS were comparable between ESS and LSS. Patients with delayed sac shrinkage with a reduction in diameter ≥10 mm should expect the same durable success as patients with quick shrinkage.

Clinical trial outcomes and thoracic aortic morphometry after one year with the Valiant Navion stent graft system

Authors' NoteOn February 17, 2021, Medtronic Incorporated issued a global voluntary recall of the Valiant Navion Thoracic Stent Graft System (the device under study in the Valiant Evo Global Clinical Program that is the subject of this publication), and instructed physicians to immediately cease use of the Valiant Navion system and return any unused product. Medtronic initiated the recall in response to three clinical trial subjects recently observed with stent fractures, two of whom have confirmed type IIIb endoleaks. The data collection, analysis, and manuscript submission occurred before the notice of this recall, and, specifically, the 100 procedures reviewed for this series were free of events at 1 year related to the reason for this device recall. The authors of this article and the manufacturer were unaware of the recently detected adverse events at the time of the preparation of the manuscript, and the 1-year trial results, and imaging-based analyses described are unchanged.Management of thoracic aortic aneurysms continues to be a challenging problem and outcomes are dependent on patient anatomy. The present publication focuses on the importance of achieving proximal and distal seals and the consideration of the temporal changes of the aortic morphology as a part of the TEVAR planning process. The authors believe there is still scientific merit in disclosing this information, despite the current nonavailability of the Valiant Navion system. ObjectiveThe Valiant Navion stent graft system (Medtronic Inc, Santa Rosa, Calif) is a third-generation device with improved conformability. We have reported the 1-year clinical trial outcomes, with a focus on an imaging-based analysis of the aortic morphology. We assessed the effects of graft implantation on the native anatomy and the effects of the 1-year changes in thoracic aorta morphology on the original seal zones of the stent graft. MethodsA total of 100 subjects were enrolled in a prospective single-arm clinical trial investigating the Valiant Navion stent graft system. An independent core laboratory (Syntactx, New York, NY) assessed the anatomic characteristics and performance outcomes. ResultsThrough 1 year of follow-up, the freedom from all-cause mortality, aneurysm-related mortality, and secondary procedures was 89.8%, 97.0%, and 94.8% respectively. Of the 100 patients, 5 had undergone a total of six secondary procedures, and 9 patients had developed an endoleak (type Ia and Ib in 1, type Ia in 1, type Ib in 3, and type II in 4 patients) within the first year. After 1 year, 2 of 76 patients (2.6%) had had an increase in their maximum aneurysm diameter of ≥5 mm, 62 (81.6%) had had stable sacs, and 12 (15.8%) had experienced sac shrinkage. Although no deployment failures had occurred, 36 of the 100 proximal (36%) and 31 of the 100 distal (31%) attachment zones were considered short according to our definitions. The stent graft had conformed to the native anatomy at implantation, because the preprocedural thoracic aorta tortuosity (1.45 ± 0.02) had not significantly changed at 1 month after implantation (1.46 ± 0.02). Despite a natural increase in thoracic tortuosity after 1 year (1.49 ± 0.02), wall apposition had been maintained over time, as evidenced by the low endoleak rates. Aortic elongation and dilation had occurred at the proximal end of the graft by an average of 1.2 mm and 1.6 mm, respectively. Aortic remodeling was more pronounced at the distal end, with an average increase of 4.2 mm in length and 2.8 mm in diameter. ConclusionsThe included patients had had positive 1-year outcomes with high freedom from mortality, endoleak development, and secondary procedures. Aortic elongation and dilation were more prevalent at the distal end, emphasizing the importance of distal attachment zone consideration as part of preoperative planning. Because aortic remodeling can be expected to continue over time, additional follow-up and imaging analysis in the trial will be necessary to assess the aortic morphology and its effects on stent graft performance.

Hybrid Approach with Angiography and Limited Open Exposure to Treat Type Ia Endoleaks after Endovascular Aortic Aneurysm Repair

Type Ia endoleaks after endovascular aortic repair (EVAR) almost always mandate secondary percutaneous reinterventions. Several patients, however, will require conversion to open surgical repair with complete graft explant, which is associated with significant morbidity and mortality. We herein present 3 cases of hybrid surgical repair for type Ia endoleaks, using a limited open exposure for proximal stent graft edge revision to achieve graft preservation and effective aneurysm sac exclusion. Angiography was used to confirm type Ia endoleak in 3 patients (2 males) who had previous EVAR between October 2017 and October 2019. Time to the endoleak after the index EVAR was immediate in 1 patient during repair of a ruptured aneurysm, 2 months in 1 patient and 2 years in 1 patient. The aorta was exposed through a limited transabdominal (n = 1) or retroperitoneal (n = 2) approach and circumferential aortic control was achieved below the renal arteries. A row of interrupted horizontal mattress sutures of 3-0 polypropylene reinforced with Teflon pledgets was placed along the aortic neck circumference. Multi-planar angiography was then repeated to verify the absence of sac filling and successful type Ia endoleak exclusion. Follow-up abdominal duplex was obtained for all 3 patients after discharge to monitor the stent graft and confirm endoleak resolution. Furthermore, there were no instances of acute renal failure. In the period of review, 77 patients underwent EVAR. In the 3 patients described, we were able to achieve complete aneurysm sac exclusion and stent graft preservation in all cases. Follow-up imaging was available on 2 patients at 4-6 weeks after surgery demonstrating sustained exclusion of the endoleak. Two patients died during follow-up: one from a myocardial infarction 7 weeks after surgery and one from metastatic lung cancer at 8 months after surgery. Follow up duplex imaging at one year on the single survivor demonstrated sac shrinkage and absence of endoleak. Type Ia endoleaks represent a significant source of morbidity and mortality after EVAR and typically require repair to avoid aneurysm rupture. Our use of limited proximal revision without explant provides an alternative approach to resolve the endoleaks while reducing the magnitude of physiological stress when compared to an open explant. It represents a feasible option for high-risk patients.

High aneurysm wall enhancement values are associated with late sac shrinkage after endovascular repair of abdominal aortic aneurysms.

To analyze the correlation between aneurysm wall enhancement (AWE) values and early and late sac shrinkage after endovascular aneurysm repair (EVAR).We retrospectively analyzed 28 patients who underwent EVAR for abdominal aortic aneurysms (AAA) using a bifurcated main body stent graft. The value of AWE in the slice of the maximum AAA diameter was measured using a volumetric analysis of computed tomography images. Sac measurements before EVAR and more than 10 months after EVAR were compared, and the maximum sac shrinkage rate was calculated.The AWE value immediately after (4 to 7 days) EVAR correlated positively with the sac shrinkage rate (R2 = 0.0139). The AWE value at 6 months after EVAR was also strongly correlated with the sac shrinkage rate (R2 = 0.4982).Higher AWE values at 6 months after EVAR were strongly associated with the sac volume shrinkage rate. High AWE values may be a predictive factor for sac shrinkage and may aid in the selection of the appropriate clinical strategy after EVAR.

Type II endoleak and aortic aneurysm sac shrinkage after preemptive embolization of aneurysm sac side branches

ObjectiveType II endoleak (T2EL) is the most common endoleak after endovascular aneurysm repair (EVAR). Its optimal management has been controversially discussed. Thus, preliminary selective embolization of aneurysm sac side branches (ASSBs) has been adopted to prevent T2EL. Our goal was to determine the rate of T2EL and the diameter decrease of abdominal aortic aneurysms (AAAs) after EVAR performed after preemptive embolization of ASSBs. MethodsFrom September 2014 to September 2019, 139 patients with AAAs underwent percutaneous ASSB embolization before EVAR. Follow-up imaging studies were performed at 1 and 6 months and annually thereafter. The end points included freedom from T2EL, AAA sac shrinkage, T2EL-related reinterventions, and all-cause mortality. ResultsThe mean follow-up was 23 ± 16 months (range, 1-61 months). The patients had had a median of five (range, one to eight) patent ASSBs found on preoperative imaging studies. After completion of embolization, 76.4% of the initially patent ASSBs were occluded, with no major procedure-related complications. Follow-up imaging studies showed T2ELs in seven patients (5%), with an aneurysm sac increase seen in six of these patients. The number of ASSBs remaining patent after embolization was the only discriminative factor in patients with and without T2EL. Six T2EL-related reinterventions were performed during follow-up. Most patients (n = 91; 86.7%) had experienced aneurysm sac shrinkage, and the mean diameter reduction was 9.2 ± 7.7 mm (P < .001) in all patients with follow-up data available. One aneurysm-related death occurred within 30 days after EVAR. ConclusionsPreemptive embolization of ASSBs for patients with AAAs is safe and effective in preventing T2ELs after EVAR. Aneurysm sac shrinkage was observed in a high proportion of patients.