Paradigm shifts in the treatment of abdominal aortic aneurysm: Trends in 721 patients between 1996 and 2008

Custom-Made Device (CMD) for the Repair of Thoraco-Abdominal Aneurysm (TAA): Mid-Long Term Outcomes from a Single Southeast Asian Centre Experience in Singapore

Introduction: Given the high risk of peri-operative morbidity and mortality associated with open repair, endovascular repair for thoraco-abdominal aneurysms is increasingly performed. This study aims to describe mid to long-term results for patients who were treated with COOK Custom-Made Endograft Device at a single Southeast Asian tertiary centre. Methods: Mid to long-term results of patients treated from 2012 to 2022 were retrospectively reviewed. Indications for treatment were aortic diameter > 5.5 cm, enlargement > 5 mm in 6 months or high-risk morphology. Clinical, operative, early to late complications and reintervention details were captured. The endpoints were technical success, primary patency and primary assisted patency. Results: Electronic medical records of 29 consecutive patients (64.4 ± 1.6 years old; 26/29 males 89.6%) were reviewed. 24/29 (83%) were hypertensive, and 20/29 (69%) were smokers. The mean diameter was 5.5 cm, and the majority were treated for Crawford type IV (19/29, 65.5%). Endograft deployment was 100%. Catheterisation of fenestration was successful in 109/116 (94%). 30-day mortality and morbidity were observed in 12/29 (41%), for which access site complications were most common. No significant haemorrhage or graft explant was recorded. The mean follow-up period was 32.4 months (range 1-108 months). Primary patency was 92.9% (95% CI: 83.8-100.0) at 6 months and decreased to 77.7% (95% CI: 63.4-95.2) at 24 months. Sac shrinkage or stability was noted in 17/29 (58.6%). Re-intervention was performed in 9/29 (31%) for limb occlusion (2/9, 22.2%), renal artery stent occlusion (1/9, 11.1%) and endoleaks (6/9, 66.6%). Assisted patency was maintained at 100% for 12 months before decreasing to 66.7% (95% CI: 37.9-100.0) at 24 months. Conclusions: The study reports the first mid-long-term result in this region, though limited by the sample size. Re-intervention at 30% suggests that disease and procedures remain challenging, emphasising the need to assimilate lessons and experience at high-volume centres.

Outcome analysis of the surgical team in open surgical repair of intact abdominal aortic aneurysm surgery

OBJECTIVES

To analyze how the experience of the surgical team went to impact the outcomes after open surgical repair (OSR) of intact abdominal aortic aneurysms (AAAs).

METHODS

This is a single-center, observational cohort study with retrospective analysis of all OR for intact AAA performed between 1 January 2010 and 31 December 2022. The primary outcome was survival at 30 days and in follow-up, and a composite outcome of mortality and major complication. The secondary outcome was freedom from aorta-related reintervention. All outcomes were stratified according to the experience of the operating team (surgeons and anesthesiology).

RESULTS

We analyzed 103 (7.2%) patients: 97 (94.2%) males and 6 (5.8%) females. The mean age was 76 ± 8 years (range, 55-93). The best possible team composition was present in 52 (50.5%) interventions. The follow-up index was 0.82 ± 0.18 (range, 0.6-1.0). Mean follow-up duration was 59 ± 43 months (range, 0-158). We observed no differences between teams in major complications (best, 17.3% vs mixed, 21.6%; OR: 0.4, P = 0.622), 30 days mortality (best, 0% vs mixed, 5.9%; OR: 7.6, P = 0.118) and composite outcome (best, 11.5% vs mixed, 17.6%; OR: 0.8, P = 0.416). Cox regression analysis identified the best possible team as a protective factor against the need for reintervention (hazard ratio: 0.2; 95% confidence interval: 0.06-0.88, P = 0.032).

CONCLUSIONS

In our experience, OR of AAA yielded satisfactory results in terms of safety and efficacy independently of the team's experience. A more experienced team may protect against aorta-related reintervention.

Large-Diameter Fenestrated Endograft Repair of Abdominal Aortic Aneurysms Is Not Associated With Medium-Term Outcomes

INTRODUCTION

Recent data suggests that infrarenal abdominal aortic aneurysm (AAA) endovascular repair (EVAR) with large diameter grafts (LGs) may have a higher risk of endoleak and reintervention. However, this has not been studied extensively for fenestrated endovascular aneurysm repair (fEVAR). We, therefore, sought to evaluate the outcomes of patients undergoing fEVAR with large-diameter endografts.

METHODS

Patients from the national Vascular Quality Initiative registry who underwent fEVAR for intact juxtarenal AAA were identified. Patients with genetic causes for aneurysms, those with prior aortic surgery, and those undergoing repair for symptomatic or ruptured aneurysms were excluded. Rates of endoleaks and reintervention at periprocedural and long-term follow-up timepoints (9-22 mo) were analyzed in grafts 32 mm or larger (LG) and were compared to those smaller than 32 mm (small diameter graft).

RESULTS

A total of 693 patients (22.8% LG) were identified. Overall, demographic variables were comparable except LG exhibited a more frequent history of coronary artery disease (32.9% versus 25.4%, P = 0.037). There were no significant differences in the rates of endoleak at procedural completion. Overall survival at 5 y was no different. The rate of reintervention at 1 y was also no different (log-rank P = 0.86).

CONCLUSIONS

While graft size appears to have an association with outcomes in infrarenal aneurysm repair, the same does not appear to be true for fEVAR. Further studies should evaluate the long-term outcomes associated with LG which could alter the approach to repair of AAA with large neck diameters traditionally treated with standard infrarenal EVAR.

Impact of Previous Open Abdominal Surgery on Open Abdominal Aortic Repair: A Study from the NSQIP Database

BACKGROUND

While endovascular aneurysm repair has become a first-line strategy in many centers, open surgical repair (OSR) of abdominal aortic aneurysms (AAAs) is still the best option for certain patients. A significant number of patients who are offered OSR for AAA have been previously submitted to other open abdominal surgeries (PAS). It is unclear, however, how this may impact their outcomes. The purpose of this study was to determine if there is an association between PAS and outcomes of OSR of AAA.

METHODS

This is a retrospective cohort study based on clinical data from the American College of Surgeons National Surgical Quality Improvement Program database, including all patients undergoing elective OSR for AAA between 2011 and 2017. Excluded were patients with missing data on prior abdominal surgery, supramesenteric clamping, or urgent repairs. Patients with prior abdominal surgery (PAS) and patients without prior abdominal surgeries (nonPAS) were compared. The primary outcome was 30-day postoperative mortality. Secondary outcomes were operating time, ischemic colitis, postoperative complications, and lengths of hospital stay.

RESULTS

Of the 2034 patients included, 27% had previous open abdominal surgery and 73% did not. Overall, the median age was 71(interquartile range 65-76), 72% of patients were male, 44% were smokers, and the average body mass index was 27 kg/m2. Univariate analysis showed no difference in postoperative 30-day mortality (4.0% PAS vs. 4.1% nonPAS, P = 0.91) or overall postoperative complication rates (33% PAS vs. 29% nonPAS, P = 0.07). Previous open abdominal surgery was significantly associated with longer operating times (P = 0.032) and an almost doubled rate of ischemic colitis (4.7% PAS vs. 2.6% nonPAS, P = 0.02). Postoperative intensive care unit and hospitalization were also significantly longer in patients with prior abdominal surgery (P = 0.005 and P = 0.014, respectively). Finally, there were significantly less patients discharged home, as opposed to institutionalized care (75.7% PAS down from 82.4% nonPAS, P = 0.001). Despite these initial univariate analysis results, on multivariate analysis, PAS actually did not prove to be a statistically significant independent risk factor for 30-day mortality, ischemic colitis, or longer operating times.

CONCLUSIONS

This study suggests that patients who have undergone PAS may have some disadvantages in OSR of AAA. However, these negative trends do not go so far as to statistically significantly identify PAS as an independent risk factor for 30-day mortality, ischemic colitis, or longer operating times. As such, we suggest that a history of previous open abdominal surgery, in and of its own, should not exclude patients from consideration for open aortic abdominal aneurysm repair.

Beyond Diameter: Enhancing Abdominal Aortic Aneurysm Surveillance with Volumetric Assessments after Endovascular Aneurysm Repair (EVAR)

This study aimed to investigate the relationship between maximum transverse diameter (MTD) and volume measurements in patients who underwent reoperations after endovascular aneurysm repair (EVAR), and their association with the occurrence of endoleaks. The study included 51 patients who underwent EVAR and subsequent re-operations caused by endoleaks type I-III. In some number of events, multiple re-operations were needed. MTD was measured using the Horos software, and segmentations of the AAA were performed using 3D Slicer. This study first evaluated post-operative computed tomography angiography (CTA) to measure MTD and volume. Then, similar measurements were made in the control scan for re-operation qualification. Negative remodeling (increase in MTD and/or volume) was observed in 40 cases using MTD, and 48 cases using volume measurements. The volume measurement showed lower missed negatives than MTD, indicating its effectiveness in screening for negative remodeling (p < 0.001). Combining both methods identified 51 negative remodeling cases and 8 positive changes, with a higher sensitivity compared to MTD alone. The volume of the sac did not predict specific endoleak types. Decreases in MTD were observed in smaller sacs, with smaller volume changes. Volume measurement is a valuable screening tool, and combining MTD and volume enhances sensitivity. However, sac volume does not predict endoleak type.

Detection of Endoleaks Following Thoracic and Abdominal Aortic Endovascular Aortic Repair-: A Comparison of Standard and Dynamic 4D-Computed Tomography Angiography

PURPOSE

Endoleaks are a common complication after endovascular aortic repair (EVAR) and thoracic endovascular aortic repair (TEVAR). The detection and correct classification of endoleaks is essential for the further treatment of affected patients. However, standard computed tomography angiography (CTA) provides no hemodynamic information on endoleaks, which can result in misclassification in complex cases. The aim of this study was to compare standard CTA (sCTA) with dynamic, dual-energy CTA (dCTA) for detection and classification of endoleaks following EVAR or TEVAR.

MATERIALS AND METHODS

This retrospective evaluation compared 69 sCTA diagnostic examinations performed on 50 different patients with 89 dCTA diagnostic examinations performed on 69 different patients.

RESULTS

In total, 15.9% of sCTA examinations and 49.4% of dCTA examinations led to the detection of endoleaks. With sCTA, 20.0% of patients were diagnosed with endoleaks, while with dCTA, 37.7% of patients were diagnosed with endoleaks. With sCTA, mainly Type 1 endoleaks were detected, whereas, with dCTA, the types of detected endoleaks were more evenly distributed. In comparison with the literature, the frequencies of endoleak types detected with dCTA better reflect the natural distribution than the frequencies detected with standard CTA.

CONCLUSION

Based on the retrospective comparative evaluation, dCTA could pose a valuable supplementary diagnostic tool resulting in a more accurate and realistic detection and classification of suspected endoleaks.

Peptidergic G Protein-Coupled Receptor Regulation of Adrenal Function: Bench to Bedside and Back

An altered secretion of adrenocortical and adrenomedullary hormones plays a role in the clinical syndromes of primary aldosteronism (PA), Cushing, and pheochromocytoma. Moreover, an altered production of adrenocortical hormones and/or an abnormal release of factors by the adrenal medulla are involved in several other diseases, including high blood pressure, congestive heart failure, liver cirrhosis, nephrotic syndrome, primary reninism, renovascular hypertension, Addison disease, Bartter, Gitelman, and virilization syndromes. Understanding the regulation of adrenal function and the interactions between adrenal cortex and medulla is, therefore, the prerequisite for mechanistic understanding of these disorders. Accumulating evidence indicates that the modulation of adrenal hormone biosynthesis is a process far more complex than originally thought, as it involves several factors, each cooperating with the other. Moreover, the tight vascular and neural interconnections between the adrenal cortex and medulla underlie physiologically relevant autocrine/paracrine interactions involving several peptides. Besides playing a pathophysiological role in common adrenal diseases, these complex mechanisms could intervene also in rare diseases, such as pheochromocytoma concomitant with adrenal Cushing or with PA, and PA co-occurring with Cushing, through mechanisms that remain to be fully understood at the molecular levels. Heterodimerization of G protein-coupled receptors (GPCRs) induced by peptide signaling is a further emerging new modulatory mechanism capable of finely tuning adrenal hormones synthesis and release. In this review we will examine current knowledge on the role of peptides that act via GPCRs in the regulation of adrenal hormone secretion with a particular focus on autocrine-paracrine signals.

Endovascular repair of abdominal and thoracoabdominal aneurysms using chimneys and periscopes is associated with poor outcomes

OBJECTIVE

Chimneys and periscopes are often used to treat pararenal or thoracoabdominal aneurysms de novo or after failed open or endovascular repair. We sought to describe our institutional experience, given their limited success and questionable long-term outcomes.

METHODS

We retrospectively reviewed the electronic records for patients treated with chimneys/periscopes from 1997 through 2020. Baseline characteristics, procedural details, periprocedural complications, reinterventions, and midterm outcomes were collected.

RESULTS

Fifty-eight patients (86 vessels) were treated; the median follow-up was 32 months (range, 0.03-104 months). There were 36% (n = 21) juxta-renal, 2% (n = 1) para-visceral, and 21% (n = 12) thoracoabdominal aneurysms, and 41% (n = 24) had pararenal failure of prior endovascular aneurysm repair (n = 17) or open repair (n = 7). Stent configuration for the majority of the 86 vessels (n = 80; 93%) treated were chimney configuration (n = 6 periscopes; 7%). The most common stent graft utilized was Viabahn, and 8.1% (n = 7) were reinforced with a bare metal stent. Although the majority of the cases were elective, 36.2% (n = 21) of the cases were urgent/emergent. At the conclusion of the initial procedure, 16 of 58 patients had an endoleak (gutter, 50% [8/16]; type Ia, 25% [4/16]; and type II, 25% [4/16]). On follow-up, 14 of 58 patients developed one or more endoleaks, with the most common endoleaks being a gutter endoleak (35% [7/20]). Other endoleaks observed included 30% (6/20) type III, 15% (3/20) type Ia, 15% (3/20) type Ib, and 5% (1/20) type II. Eleven of 58 patients underwent interventions for one or more endoleak (gutter, 33% [5/15]; type Ib, 20% [3/15]; type II, 7% [1/15]; and type III, 40% [6/15]). Twelve of 58 patients returned to the operating room for one or more procedures during the index hospitalization (five laparotomies, three dialysis access, three acute limb ischemia, and four chimney/periscope interventions). Ten of 58 patients underwent angioplasty/stenting for chimney/periscope compression or occlusion during the follow-up period. Survival was 61.3% at 1 year by Kaplan-Meier analysis (75% for elective, 37% for urgent/emergent) (aneurysm-related death, 22%). Cox hazard modeling showed that aneurysm diameter (hazard ratio, 1.03; 95% confidence interval, 1.004-1.05; P = .02) and urgent/emergent interventions (hazard ratio, 3.6; 95% confidence interval, 1.33-9.74; P = .01) were predictors of mortality.

CONCLUSIONS

Endovascular repair of aortic aneurysms with chimneys/periscopes is associated with poor outcomes, including limited technical success and aneurysm exclusion, as well as high morbidity and mortality, with a high rate of reinterventions both in the immediate postoperative period and on follow-up. They should be used only when other surgical or endovascular options are not possible.

Retroperitoneal versus Transperitoneal Approach for Open Repair of Complex Abdominal Aortic Aneurysms

OBJECTIVE

Several studies have demonstrated advantages of the retroperitoneal approach (RP) over the transperitoneal approach (TP) for infrarenal abdominal aortic aneurysm (AAA) repair. A retrospective analysis was performed comparing the outcomes of a TP vs. RP surgical approach for open complex AAA (cAAA) repair and evaluated their relative use over time.

METHODS

Patients undergoing open repair for intact cAAA (juxtarenal, suprarenal, or type IV thoraco-abdominal aortic aneurysms) between 2011 and 2019 were identified in the National Surgical Quality Improvement Program. The primary outcome was peri-operative death. Secondary outcomes included peri-operative complications and approach use over time. Multivariable adjustment was performed by creating propensity scores and using inverse probability weighted logistic regression.

RESULTS

Among 1 195 patients identified, 729 (61%) underwent cAAA repair via a TP approach and 466 (39%) via an RP approach. Compared with a TP approach, RP patients more frequently had a supracoeliac clamp position (32% vs. 20%, p < .001) and concomitant renal revascularisation (30% vs. 18%, p < .001). After adjustment, an RP approach was associated with lower odds of peri-operative death (4.0% vs. 7.2%; odds ratio [OR] 0.54; 95% confidence interval [CI] 0.32 - 0.91; p = .022). Furthermore, an RP approach was associated with lower odds of any major complication (24% vs. 30%; OR 0.73; 95% CI 0.56 - 0.94), cardiac complications (4.9% vs. 8.2%; OR 0.60; 95% CI 0.37 - 0.96), wound complications (2.1% vs. 6.0%; OR 0.34; 95% CI 0.17 - 0.64), and post-operative sepsis (0.8% vs. 2.4%; OR 0.37; 95% CI 0.12 - 0.99). The proportion of repairs using an RP approach decreased between 2011 - 2015 and 2016 - 2019 (42% vs. 35%, p = .020), particularly for suprarenal and type IV thoraco-abdominal aneurysms (49% vs. 37%, p = .023).

CONCLUSION

In open cAAA repair, the RP approach may be associated with lower peri-operative mortality and morbidity rates compared with the TP approach. However, it was found that the relative use of the RP approach is decreasing over time, even in suprarenal/type IV thoraco-abdominal aneurysms, and repairs using a supracoeliac clamp. Increased use of the RP approach, when appropriate, may lead to improved outcomes following open cAAA repair.

"Large Diameter" Aortic Endografts Are Associated With Aneurysm Sac Expansion

INTRODUCTION/OBJECTIVES

The purpose of this study was to evaluate the association between aortic endograft diameter and long-term outcomes following endovascular aneurysm repair (EVAR) performed in accordance with manufacturer instructions for use (IFU).

METHODS

Retrospective review of consecutive patients undergoing on-IFU EVAR (2000-2018) was performed to facilitate a comparative analysis of long-term patient outcomes based on device diameter. "Large diameter" devices were defined as >34mm. The primary outcome of interest was freedom from sac expansion throughout long-term follow-up. Analyses included standard bivariate analyses, Kaplan Meier with log-rank comparison, and Cox proportional hazards multivariate analysis.

RESULTS

A total of 1099 underwent on-IFU EVAR from 2000-2018. Follow-up data were available for 980 patients. Of these, 75 patients (7.6%) were treated with >34 mm devices. There were no significant differences in demographics or co-morbidities between the 2 groups, although pre-operative AAA size was greater in patients undergoing implantation of >34mm devices (58 ± 8.5 mm vs. 56 ± 17.4 mm; P=0.05). Median follow-up was 10.3 years. Patients with grafts >34 mm had reduced freedom from sac expansion throughout follow-up (P=0.038). There were no significant differences in reintervention rates, open conversion, or rupture when stratified by graft diameter. Multivariate Cox Regression identified patient age, pre-operative AAA size, need for reintervention, and use of >34 mm endografts as independent factors associated with expansion.

CONCLUSION

The use of large diameter aortic endografts is associated with higher rates of sac expansion during long-term follow-up. While there is undoubtedly a role for large diameter graft use in selected patients, it is important to recognize that these devices were typically approved post-hoc without the same regulatory scrutiny of smaller endografts. These findings underscore the importance of ongoing surveillance for patients treated with >34 mm grafts, irrespective of compliance with manufacturer IFU.

Predictors of Abdominal Aortic Aneurysm Shrinkage after Endovascular Repair

Recent studies demonstrate that patients with a shrinking abdominal aortic aneurysm (AAA), one-year after endovascular repair (EVAR), have better long-term outcomes than patients with a stable AAA. It is not known what factors determine whether an AAA will shrink or not. In this study, a range of parameters was investigated to identify their use in differentiating patients that will develop a shrinking AAA from those with a stable AAA one-year after EVAR. Hundred-seventy-four patients (67 shrinking AAA, 107 stable AAA) who underwent elective, infrarenal EVAR were enrolled between 2011-2018. Long-term survival was significantly better in patients with a shrinking AAA, compared to those with a stable AAA (p = 0.038). Larger preoperative maximum AAA diameter was associated with an increased likelihood of developing AAA shrinkage one-year after EVAR-whereas older age and larger preoperative infrarenal β angle were associated with a reduced likelihood of AAA shrinkage. However, this multivariate logistic regression model was only able to correctly identify 66.7% of patients with AAA shrinkage from the total cohort. This is not sufficient for implementation in clinical care, and therefore future research is recommended to dive deeper into AAA anatomy, and explore potential predictors using artificial intelligence and radiomics.

A systematic review on anatomical predictors of abdominal aortic aneurysm remodeling after endovascular repair

OBJECTIVE

Long-term outcomes after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs) are inferior to open surgical repair with regard to reinterventions and late mortality. AAA sac remodeling after EVAR has been associated with endoleaks, reinterventions, and mortality. Therefore, predictors of AAA sac remodeling could indirectly give insight into long-term EVAR outcomes. This review aims to provide an overview of the evidence on anatomical predictors of positive and negative AAA sac remodeling after EVAR.

METHODS

A systematic literature review and analysis were conducted according to the PRISMA and Cochrane guidelines. PubMed and Scopus databases were searched using terms of AAA sac growth, shrinkage, and remodeling. Eligible articles were identified and only papers that included currently used endografts were included.

RESULTS

Nineteen studies that reported on a total of 27 anatomical parameters of the aortoiliac anatomy were included. Only 4 parameters were investigated by >5 studies, 7 parameters were investigated by 3-5 studies, 6 parameters were investigated by 2 studies, and 10 parameters were investigated by 1 study. For the presence of neck thrombus, 3 out of 4 studies reported similar results indicating that it may predict less AAA sac shrinkage. AAA thrombus, total AAA volume, flow-lumen volume, and the number of hostile neck parameters were only investigated by 2-3 studies, but they seem promising in predicting sac remodeling. For hostile neck anatomy, neck length, infrarenal neck angulation, and patency of the inferior mesenteric artery, no significant association with any category of AAA sac remodeling was found.

CONCLUSIONS

This review presents neck thrombus, AAA thrombus, number of hostile neck parameters, total AAA volume, and AAA flow-lumen volume as important anatomical features that are likely to play a role in AAA remodeling after endovascular repair that should be further explored using advanced imaging techniques. This review also showed that strong consistent evidence on anatomical predictors of AAA sac remodeling after EVAR is lacking. Therefore, further research with large patient groups on a broad range of predictors of AAA sac change after EVAR is needed to complement the current gap in the evidence.

An International, Multicenter Retrospective Observational Study to Assess Technical Success and Clinical Outcomes of Patients Treated with an Endovascular Aneurysm Sealing Device for Type III Endoleak

INTRODUCTION

Type III endoleaks post-endovascular aortic aneurysm repair (EVAR) warrant treatment because they increase pressure within the aneurysm sac leading to increased rupture risk. The treatment may be difficult with regular endovascular devices. Endovascular aneurysm sealing (EVAS) might provide a treatment option for type III endoleaks, especially if located near the flow divider. This study aims to analyze clinical outcomes of EVAS for type III endoleaks after EVAR.

METHODS

This is an international, retrospective, observational cohort study including data from 8 European institutions.

RESULTS

A total of 20 patients were identified of which 80% had a type IIIb endoleak and the remainder (20%) a type IIIa endoleak. The median time between EVAR and EVAS was 49.5 months (28.5-89). Mean AAA diameter prior to EVAS revision was 76.6±19.9 mm. Technical success was achieved in 95%, 1 patient had technical failure due to a postoperative myocardial infarction resulting in death. Mean follow-up was 22.8±15.2 months. During follow-up 1 patient had a type Ia endoleak, and 1 patient had a new type IIIa endoleak at an untreated location. There were 5 patients with aneurysm growth. Five patients underwent AAA-related reinterventions indications being: growth with type II endoleak (n=3), type Ia endoleak (n=1), and iliac aneurysm (n=1). At 1-year follow-up, the freedom from clinical failure was 77.5%, freedom from all-cause mortality 94.7%, freedom from aneurysm-related mortality 95%, and freedom from aneurysm-related reinterventions 93.8%.

CONCLUSION

The EVAS relining can be safely performed to treat type III endoleaks with an acceptable technical success rate, a low 30-day mortality rate and no secondary ruptures at short-term follow-up. The relatively low clinical success rates, related to reinterventions and AAA enlargement, highlight the need for prolonged follow-up.

Angiotensin peptides in the regulation of adrenal cortical function

The adrenal cortex plays a key role in the regulation of metabolism, salt and water homeostasis and sex differentiation by synthesizing glucocorticoid, mineralocorticoid and androgen hormones. Evidence exists that angiotensin II regulates adrenocortical function and it has been contended that angiotensin peptides of the non-canonical branch of the renin angiotensin system (RAS) might also modulate steroidogenesis in adrenals. Thus, the aim of this review is to examine the role of the RAS, and particularly of the angiotensin peptides and their receptors, in the regulation of adrenocortical hormones with particular focus on aldosterone production.

Utility of Noncontrast Magnetic Resonance Angiography for Aneurysm Follow-Up and Detection of Endoleaks after Endovascular Aortic Repair

Objective

To assess the noncontrast two-dimensional single-shot balanced turbo-field-echo magnetic resonance angiography (b-TFE MRA) features of the abdominal aortic aneurysm (AAA) status following endovascular aneurysm repair (EVAR) and evaluate to detect endoleaks (ELs).

Materials and Methods

We examined four aortic stent-grafts in a phantom study to assess the degree of metallic artifacts. We enrolled 46 EVAR-treated patients with AAA and/or common iliac artery aneurysm who underwent both computed tomography angiography (CTA) and b-TFE MRA after EVAR. Vascular measurements on CTA and b-TFE MRA were compared, and signal intensity ratios (SIRs) of the aneurysmal sac were correlated with the size changes in the AAA after EVAR (AAA prognoses). Furthermore, we examined six feasible b-TFE MRA features for the assessment of ELs.

Results

There were robust intermodality (r = 0.92–0.99) correlations and interobserver (intraclass correlation coefficient = 0.97–0.99) agreement. No significant differences were noted between SIRs and aneurysm prognoses. Moreover, “mottled high-intensity” and “creeping high-intensity with the low-band rim” were recognized as significant imaging findings suspicious for the presence of ELs (p < 0.001), whereas “no signal black spot” and “layered high-intensity area” were determined as significant for the absence of ELs (p < 0.03). Based on the two positive features, sensitivity, specificity, and accuracy for the detection of ELs were 77.3%, 91.7%, and 84.8%, respectively. Furthermore, the k values (0.40–0.88) displayed moderate-to-almost perfect agreement.

Conclusion

Noncontrast MRA could be a promising imaging modality for ascertaining patient follow-up after EVAR.

Migration After Endovasclar Aneurysm Sealing in Conjunction With Chimney Grafts

Purpose

To assess the incidence of migration after endovascular aneurysm sealing (EVAS) in conjunction with chimney grafts (chEVAS) for repair of abdominal aortic aneurysms (AAAs).

Materials and Methods

A retrospective, observational cohort study was conducted of 31 patients (mean age 75.7 years; 27 men) treated for juxtarenal AAA between April 2013 and December 2018 at single centers in New Zealand and the Netherlands. The majority of patients received >1 chimney graft (13 single, 13 double, and 5 triple) during chEVAS. Six patients had only the first postoperative scan, so the migration analysis was based on 25 patients.

Results

Median seal length assessed on the first postoperative computed tomography scan was 36.5 mm. The assisted technical success rate was 93.5% with 2 technical failures. Median time to final imaging follow-up was 17 months in 25 patients. At the latest follow-up, there were no cases of caudal migration >10 mm. Freedom from caudal movement of 5 to 9 mm was estimated as 86.1% at 1 year and 73.9% at 2 years; freedom from clinically relevant migration (movement requiring reintervention) was 100% at both time intervals. However, at 3 years there were 2 cases of caudal movement of 5 to 9 mm and a type Ia endoleak warranting reintervention. No correlation between migration and aneurysm growth (p=0.851), endoleak (p=0.562), or the number of chimney grafts (p=0.728) was found. During follow-up, 2 patients (7%) had aneurysm rupture and 10 (33%) had reinterventions. Eight patients (27%) died; 2 were aneurysm-related (7%) and due to the consequences of a reintervention.

Conclusion

In the 2 years following chEVAS, there was no caudal migration >10 mm, but nearly a quarter of patients had caudal movement of 5 to 9 mm. A trend was observed toward ongoing migration that required intervention at 3-year follow-up. chEVAS is technically challenging and should be considered only for patients with no viable alternative treatment option.

Analysis of Endovascular Aneurysm Repair for Small Abdominal Aortic Aneurysms in Males

BACKGROUND

Current guidelines recommend repair of abdominal aortic aneurysms (AAAs) when ≥5.5 cm. This study sought to evaluate the incidence of male patients undergoing endovascular aneurysm repair (EVAR) for AAAs of various diameters (small <4 cm; intermediate 4-5.4 cm; standard ≥5.5 cm). We analyzed predictors of mortality, hypothesizing that smaller AAAs (<5.5 cm) have no differences in associated risk of mortality compared to standard AAAs (≥5.5 cm).

METHODS

The 2011-2017 American College of Surgeons National Surgical Quality Improvement Program Procedure-Targeted Vascular database was queried for male patients undergoing elective EVAR. Patients were stratified by aneurysm diameter. A multivariable logistic regression analysis for clinical outcomes, adjusting for age, clinical characteristics, and comorbidities, was performed.

RESULTS

A total of 8037 male patients underwent EVAR with 3926 (48.9%) performed for AAAs <5.5 cm. There was no difference in mortality, readmission, major complications, myocardial infarction, stroke, or ischemic complications among the 3 groups (P > 0.05). In AAAs <5.5 cm, predictors of mortality included prior abdominal surgery (odds ratio [OR], 5.77; confidence interval [CI], 1.38-24.13; P = 0.016), weight loss (OR, 43.4; CI, 3.78-498.7; P = 0.002), disseminated cancer (OR, 17.9; CI, 1.30-245.97; P = 0.031), and diabetes (OR, 6.09; CI, 1.52-24.36; P = 0.011).

CONCLUSIONS

Nearly 50% of male patients undergoing elective EVAR were treated for AAAs <5.5 cm. There was no difference in associated risk of mortality for smaller AAAs compared to standard AAAs. The strongest predictors of mortality for patients with smaller AAAs were prior abdominal surgery, weight loss, disseminated cancer, and diabetes.

Innovations in Vascular Ultrasound

There are several vascular ultrasound technologies that are useful in challenging diagnostic situations. New vascular ultrasound applications include directional power Doppler ultrasound, contrast-enhanced ultrasound, B-flow imaging, microvascular imaging, 3-dimensional vascular ultrasound, intravascular ultrasound, photoacoustic imaging, and vascular elastography. All these techniques are complementary to Doppler ultrasound and provide greater ability to visualize small vessels, have higher sensitivity to detect slow flow, and better assess vascular wall and lumen while overcoming limitations color Doppler. The ultimate goal of these technologies is to make ultrasound competitive with computed tomography and magnetic resonance imaging for vascular imaging.

Transverse versus vertical groin incision for femoral artery approach

BACKGROUND

Access to the femoral vessels is necessary for a wide range of vascular procedures, including treatment of thromboembolic disease, arterial grafts (i.e. bifemoral aortic bypass or infrainguinal bypass), endovascular repair of abdominal aortic aneurysm (EVAR), thoracic endovascular aneurysm repair (TEVAR) and transcatheter aortic valve implantation (TAVI). The surgical technique used to access the femoral artery may be a factor in the occurrence of postoperative complications; this will be the focus of our review. We will compare the transverse surgical technique-a cut made parallel to the groin crease-versus the vertical groin incision surgical technique-classic technique: a surgical cut made across the groin crease-to access the femoral artery, in an attempt to determine which technique has the lower rate of complications, is safer and is more effective.

OBJECTIVES

To evaluate the efficacy and safety of transverse groin incision compared with vertical groin incision for accessing the femoral artery in endovascular surgical procedures and open surgery.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL and AMED databases, and the World Health Organization (WHO) International Clinical Trials Registry Platform and ClinicalTrials.gov to 17 February 2020. The review authors searched the IBECS database to 26 March 2020 and reference lists of relevant studies/papers.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-randomized trials (qRCTs) that compare transverse and vertical groin incision, during either endovascular or open surgery procedures.

DATA COLLECTION AND ANALYSIS

Two review authors (MVCRC, FCN) independently selected the studies, assessed risk of bias, extracted data, performed data analysis and graded the certainty of evidence according to GRADE.

MAIN RESULTS

We included one RCT and one qRCT in this review. These two studies had a combined total of 237 participants (283 groins). Infection of the surgical wound was the only outcome that was similar in both studies, and that could therefore be submitted to a combined analysis. Meta-analysis of the two studies showed low-certainty evidence that transverse groin incision resulted in a lower risk of surgical wound infection in the 10- to 28-day period following surgery (risk ratio [RR] 0.25, 95% confidence interval [CI] 0.08 to 0.76; 2 studies; 283 groin incisions). There was low heterogeneity between the studies. We downgraded the certainty of the evidence for surgical wound infection by one level due to serious limitations in the design (there was a high risk of bias in critical domains). The confidence interval for surgical wound infection is relatively wide, further indicating that the certainty of the effect estimate is low. This is likely due to the small number of studies and participants. We observed no evidence of a difference between the two surgical techniques for the other evaluated primary outcome 'lymphatic complications': lymphocele (RR 0.46, 95% CI 0.20 to 1.02; 1 study; 116 groins); and lymphorrhea (RR 2.77, 95% CI 0.92 to 8.34; 1 study; 116 groins). We downgraded the certainty of evidence for lymphatic complications by one level due to serious limitations in the design (there was a high risk of bias in critical domains); and by two further levels because of imprecision (small number of participants and only one study included). High-quality studies are needed to enable a comparison of the two surgical techniques with respect to other outcomes, such as infection of the vascular graft (endoprosthesis/prosthesis), prolonged hospitalization, reoperative surgery, death, neurological deficit (e.g. paresthesia), amputation, graft patency, and postoperative pain.

AUTHORS' CONCLUSIONS

In this systematic review, we found low-certainty evidence that performing transverse groin incision to access the femoral artery resulted in fewer surgical wound infections compared with performing vertical groin incision. We observed no evidence of a difference between the two surgical techniques for the other evaluated outcomes (lymphocele and lymphorrhea). Other outcomes were not evaluated in these studies. Limitations of this systematic review are, however, the small sample size, short clinical follow-up period and high risk of bias in critical domains. For this reason, the applicability of the results is limited.

Cross-clamp location affects short-term survival in patients undergoing open abdominal aortic aneurysm repair

INTRODUCTION

Open abdominal aortic aneurysm (oAAA) repair in the era of advanced endovascular aortic techniques is used in challenging anatomy. The impact of the location of the proximal aortic cross-clamp (suprarenal [SR] vs infrarenal [IR]) on outcomes remains to be determined. The aim of this study was to analyze the effect of proximal aortic cross-clamp location on short-term and overall survival after oAAA repair in a contemporary series.

METHODS

A retrospective cohort study was performed comparing the outcomes of patients undergoing oAAA repair with SR and IR aortic cross-clamping using the Vascular Quality Initiative registry from January 2003 to September 2018. Our primary end point was short-term mortality.

RESULTS

There were 7601 patients who underwent oAAA repair. Their mean age was 69.3 ± 8.5 years and 5555 patients (73.1%) were male. The aortic cross-clamp location was IR in 4044 patients (53.2%). The SR group had increased maximum AAA diameter (58 mm vs 56 mm; P < .0001), hypertension (85.5% vs 82.0%; P < .0001), preoperative creatinine (1.11 vs 1.08; P = .001), and were more likely to be in American Society of Anesthesiologists class IV (37.4% vs 30.6%; P < .0001). Postoperative renal failure occurred significantly more often in the SR group (24.4 vs 11.4%; P < .0001). Short-term mortality was 2.7% in the IR group and 4.7% in the SR group (P < .0001). Kaplan-Meier survival estimates were 93.7% and 83.8% in the IR group and 90.9% and 81.2% in the SR group at 1 and 5 years, respectively (P = .007). Multivariable analysis demonstrated that SR cross-clamping was significantly associated with short-term mortality (hazard ratio, 1.38; 95% confidence interval, 1.07-1.78; P = .01); however, it did not affect overall survival (hazard ratio, 1.13; 95% confidence interval, 1.00-1.28; P = .06).

CONCLUSIONS

A SR cross-clamp location is associated with an increased short-term mortality in patients undergoing oAAA repair. Overall survival is not affected by a SR cross-clamp location.

Single-center Study Comparing Short and Mid-Term Results of EVAR in Old and Young Populations

Objective

The purpose of this study was to compare the operative mortality rate and outcomes of endovascular aneurysm repair (EVAR) between young and geriatric people in a single center.

Methods

Eighty-five patients with abdominal aortic aneurysms who underwent EVAR between January 2012 and September 2016 were included. Outcomes were compared between two groups: the young (aged < 65 years) and the geriatric (aged ≥ 65 years). The primary study outcome was technical success; the secondary endpoints were mortality and secondary interventions. The mean follow-up time was 36 months (3-60 months).

Results

The study included 72 males and 13 females with a mean age of 71.08±8.6 years (range 49-85 years). Of the 85 patients analyzed, 18 (21.2%) were under 65 years old and 67 patients (78.8%) were over 65 years old. There was no statistically significant correlation between chronic disease and age. We found no statistically significant difference between aneurysm diameter, neck angle, neck length, or right and left iliac angles. The secondary intervention rate was 7% (six patients). The conversion to open surgery was necessary for only one patient and only three deaths were reported (3.5%). There was no statistically significant difference in the mortality and reintervention rates between the age groups. The three deaths occurred only in the geriatric group and two died secondary to rupture. Kidney failure was observed in three patients in the geriatric group (4.5%).

Conclusion

Our single-center experience shows that EVAR can be used safely in both young and geriatric patients.

Unplanned 30-day readmissions after endovascular aneurysm repair: An analysis using the Nationwide Readmissions Database

BACKGROUND

Endovascular aneurysm repair (EVAR) is the preferred method for addressing abdominal aortic aneurysms (AAAs), with proven reduction in perioperative morbidity and mortality. There are, however limited data examining the readmissions after EVAR that are associated with increased patient morbidity and cost. As EVAR use continues its dominance in the management of AAAs, it becomes imperative to identify and mitigate risk factors associated with unplanned hospital readmissions.

METHODS

The Nationwide Readmissions Database (NRD) was queried for all 30-day readmissions after an index EVAR procedure from 2012 to 2014. Preoperative patient demographics, hospital characteristics, readmission diagnosis, and costs were compared between those who were and were not readmitted within 30 days of the index operation. Multivariable logistic regression was used to identify potential risk factors associated with unplanned readmissions within 30 days.

RESULTS

We identified 120,646 patients who underwent an EVAR from 2012 to 2014 in the United States. The overall unplanned readmission rate during this period was 11.6% (n = 14,073) within 30 days of the index EVAR procedure. The readmission rate was the highest in 2012, with a rate of 12.3% (P = .02). Multivariate regression analysis showed that EVAR readmissions were significantly higher in patients who were of younger age (18 to 49 years) compared with other age groups (odds ratio [OR], 1.9-2.17; P < .001), female sex (OR, 1.367; P < .001), had Medicare (OR, 1.39) or Medicaid (OR, 1.25) insurance, or a combination of these. Underlying patient comorbidities significantly associated with readmissions included congestive heart failure (OR, 2.4), peripheral vascular disease (OR, 1.1), chronic pulmonary disease (OR, 1.2), cancer with no metastasis (OR, 1.5), metastatic cancer (OR, 2.2), renal failure (OR, 1.8), and diabetes (OR, 1.5).

CONCLUSIONS

The trend in 30-day readmission rates after EVAR has decreased slightly since 2012, but overall rates are at 11.6%, which is not insubstantial. Patient factors strongly associated with hospital readmission were younger age and patient comorbidities, including congestive heart failure, concurrent cancer diagnosis, renal failure, and diabetes.

Comparative effectiveness of open surgery versus endovascular repair for hemodynamically stable and unstable ruptured abdominal aortic aneurysm

Several observational studies and randomized trials have compared open surgery (OS) and endovascular aortic repair (EVAR) for ruptured abdominal aortic aneurysm (rAAA). However, none of these studies addressed optimal management of hemodynamically (hd) unstable patients. Our objective was to compare perioperative outcomes in patients undergoing OS vs EVAR for hd-stable and hd-unstable rAAAs.This retrospective study was conducted in West China Hospital from January 2005 to December 2015. Unstable patients were defined as those who have at least 1 of the following: preoperative shock, preoperative transfusion >4 units, preoperative intubation, cardiac arrest, or unconsciousness. Univariable and multivariable logistic regression analyses were performed.Of the 102 patients, 70.6% underwent OS and 29.4% EVAR. About 46.1% were unstable, and for these patients, OS was performed in 70.2% and EVAR in 29.8%. The 30-day mortality was 23.6% (OS, 25.6%; EVAR, 18.8%; P = .585) for hd-stable patients and was 42.6% (OS, 45.5%; EVAR, 35.7%; P = .537) for hd-unstable patients. Patients with OS had longer operative time and more transfusion. Amongst hd-stable patients, OS subgroup had a higher rate of pneumonia (33.3% vs 6.3%, P = .045), longer intensive care unit (ICU) stay (43.2 vs 15.2 hours, P = .02), and length of stay (11.6 vs 8.6 days, P = .041). Among hd-unstable patients, OS subgroup had a longer ICU stay (134.3 vs 63.8 hours, P = .047). Hospitalization costs of OS group were significantly lower than those of EVAR group, regardless of hemodynamic stability.Approximately one-third of patients with rAAA were treated by EVAR at our institution. EVAR may be the preferred approach for anatomically suitable rAAAs. However, patients treated by EVAR had a similar mortality compared with those treated by OS. In addition, OS is not an independent factor for a higher 30-day mortality, and the costs of OS were much cheaper than those of EVAR. Therefore, OS is difficult to replace, especially in developing countries.

Low mortality rates after endovascular aortic repair expand use to high-risk patients

OBJECTIVE

The 2010 endovascular aneurysm repair (EVAR) trial 2 (EVAR 2) reported that patients with comorbidity profiles rendering them unfit for open aneurysm repair who underwent EVAR did not experience a survival advantage compared with those who did not undergo intervention. These patients experienced a 30-day mortality of 7.3%, whereas reports from similar cohorts reported far lower mortality rates. The primary objective of our study was to compare the incidence of 30-day mortality in low- and high-risk patients undergoing EVAR in a contemporary data set, using patient risk stratification criteria from EVAR 2. Secondarily, we sought to identify risk factors associated with a disproportionate contribution to 30-day mortality risk.

METHODS

Data were obtained from the 2005 to 2013 American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) Participant Use Data Files (N = 24,813). Patients were included in the high-risk cohort with the presence of renal, respiratory, or cardiac preoperative criteria alone or in combination. Renal impairment criteria were defined as dialysis and creatinine concentration >2.26 mg/dL. Respiratory impairment criteria included history of chronic obstructive pulmonary disease and preoperative ventilator support. Cardiac impairment criteria included history of myocardial infarction, congestive heart failure, angina, and prior coronary intervention. Patient and procedural characteristics and 30-day postoperative outcomes were compared using Pearson χ2 tests for categorical variables and Wilcoxon rank sum tests for continuous variables.

RESULTS

Among 24,813 patients undergoing EVAR, 12,043 (48%) patients were characterized as high risk (at least one impairment criterion); 12,770 (52%) patients were stratified as low risk. The 30-day mortality rate was 1.9% in the high-risk cohort compared with the 7.3% reported by EVAR 2, and it was higher in the high-risk cohort compared with the low-risk cohort (1.9% vs 0.9%; P < .001). Whereas the presence of each comorbidity increased the odds of 30-day mortality (respiratory odds ratio [OR], 1.62; 95% confidence interval [CI], 1.16-2.26; P = .005; cardiac OR, 1.55; 95% CI, 1.14-2.10; P = .005), the presence of renal criteria disproportionately increased the odds of mortality threefold (OR, 3.42; 95% CI, 2.31-5.09; P < .001).

CONCLUSIONS

Contemporary 30-day mortality after EVAR in high-risk patients is substantially lower than that reported in the EVAR 2 trial. Whereas low- and high-risk stratification by current comorbidity criteria is appropriate, attention needs to be paid to disproportionate risk contribution from renal disease to mortality compared with cardiac and pulmonary comorbidities. Given the lower mortality risk than previously described, patients stratified as high risk should be thoughtfully considered for definitive EVAR.

Is Age a Determinant Factor in EVAR as a Predictor of Outcomes or in the Selection Procedure? Our Experience

Introduction

Endovascular aneurysm repair (EVAR) is the therapy of choice in high risk patients with abdominal aortic aneurysm. The good results described are leading to the broadening of clinical indications to younger patients. However, reintervention rates seem higher and even with successful treatment sometimes there is growth of the aneurysm sac and rupture, meaning a failure of the therapeutic goal. This study proposes to analyse the impact of age in patients' selection and post-EVAR results.

Methods

The clinical records of consecutive patients undergoing endovascular aneurysm repair, between 2001 and 2013, were retrospectively reviewed. Patients were divided according to age groups (<70, 70-80 and >80 years). Gender, body mass index, aneurysm anatomic features, neck characteristics, iliac morphology, surgical indication, endograft type, anesthesic risk classification, length of stay, reinterventions and mortality were analysed and compared.

Results

The study included 171 patients, 161 (94.1%) men, and mean age 74.1±8.9 years. The age group under 70 had 32% of the patients. Only three characteristics were found different among age groups: 1) body mass index was higher in younger patients, with a considerable trend toward significance (P=0.06); 2) surgical indication, in the younger group, surgeon's and the patient's option were more proeminent (P<0.05); 3) erectile dysfunction was higher in elderly group (P<0.05). No other clinical and anatomical characteristics or final outcomes were found statisticaly different among age groups.

Conclusion

The absence of statistically differences in mortality and reinterventions among age groups suggests that age by itself is not a relevant factor in endovascular aneurysm repair. Indeed, the three characteristics different in younger (obesity, sexual function and patient's choice) favor endovascular aneurysm repair.

Treatment of Abdominal Aortic Pathology

Abdominal aortic pathology is a diverse topic, ranging through a broad span of possible pathologies. The treatment options are equally vast, particularly with the ever-expanding endovascular techniques. In this article, we discuss management strategies for abdominal aortic aneurysms and aortic occlusive disease, because they represent some of the most common pathologies encountered in clinical scenarios.

Duplex Ultrasound Surveillance After Uncomplicated Endovascular Abdominal Aortic Aneurysm Repair

OBJECTIVES

Health-care costs and risks of radiation and intravenous contrast exposure challenge computed tomography angiography (CTA) as the standard surveillance method after endovascular abdominal aortic aneurysm repair (EVAR). We reviewed our experience using Duplex ultrasound scan (DUS) as an initial and subsequent surveillance technique after uncomplicated EVAR.

METHODS

The medical records of patients who underwent EVAR from 2004 to 2014 with at least 1 postoperative imaging study were retrospectively reviewed. Duplex ultrasound scan was the primary modality, with CTA reserved for patients with suspicious findings.

RESULTS

Mean follow-up was 3.2 years for 266 patients. Fifty-seven endoleaks (7 type I, 50 type II) were detected in 51 patients (19%). Nineteen (33%) endoleaks were identified and monitored by DUS alone. Nine (16%) endoleaks were identified on CTA without prior DUS. Twenty-two (39%) endoleaks were identified on DUS and confirmed by CTA; 6 of these patients had a secondary intervention. When compared to subsequent CTA, there were 7 discordant results: 4 false-negative and 3 false-positive endoleaks on DUS. Two of these patients with discordant results required intervention. Follow-up CTA was not obtained for the other 2 patients due to severe comorbidities including renal disease. One of these patients eventually developed abdominal aortic aneurysm rupture and death. Among 88 patients with both DUS and CTA, positive predictive value and negative predictive value for DUS were 0.88 and 0.94, respectively. Sac size on DUS compared to CTA resulted in an interclass correlation coefficient of r = .84.

CONCLUSIONS

In our experience, DUS was safe and effective for initial and follow-up surveillance after uncomplicated EVAR.

Noninvasive Estimation of Aneurysm Sac Pressurization Following Endovascular Aneurysm Repair Using M-Mode Ultrasonography to Evaluate Significance of Endoleaks: A Feasibility Study

PURPOSE

To establish the feasibility of indirectly estimating aneurysm sac pressurization from recordings of aortic pulsatile wall motion (PWM) using M-mode ultrasonography before and after endovascular aneurysm repair (EVAR).

METHODS

Twenty consecutive patients (mean age 72 years; 19 men) scheduled for EVAR in a single institution underwent M-mode ultrasonography 1 day before EVAR to record PWM of the abdominal aortic aneurysm wall during the cardiac cycle, along with simultaneous blood pressure measurements. The recording was repeated the first postoperative day. Pressure-strain elastic modulus (Ep) was calculated from the preoperative displacement and pressure data. This value and the postoperative PWM were used to inverse estimate pulse pressure in the abdominal aortic aneurysm sac post EVAR. Immediate pressure reduction post EVAR was compared between groups of endoleak vs no endoleak and expansion vs no expansion during 6-month follow-up.

RESULTS

Intraobserver variability of the method presented a mean value of 0.04 mm with a 1.2-mm coefficient of variation (95% limits of agreement -1.16 to 1.24 mm). PWM was significantly reduced postoperatively (1.2 vs 0.3 mm, p<0.001) as was pulse pressure exerted on the aneurysm sac (67 vs 16 mm Hg, p<0.001). The pressure reduction was similar between the endoleak vs no endoleak groups (79% vs 75%, p=0.65), but it was significantly greater in the no expansion group (79.5%) vs the group with aneurysm expansion (50%, p=0.008).

CONCLUSION

M-mode ultrasonography may provide a useful adjunct during EVAR surveillance to noninvasively estimate sac pressurization and identify aneurysms at risk of enlargement.

Analysis of anatomical risk factors for persistent type II endoleaks following endovascular abdominal aortic aneurysm repair using CT angiography

PURPOSE

To predict persistent type II endoleaks (pT2Es) following endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms, we examined factors related to post-EVAR pT2Es.

METHODS

Eighty-four cases of EVAR were analyzed. T2Es that persisted for ≥6 months were defined as pT2Es. pT2Es flowing from an inferior mesenteric artery (IMA) and lumbar artery (LA) were termed pIMA-T2Es and pLA-T2Es, respectively. The anatomical factors concerning the aneurysm, IMA and LAs were assessed in the preoperative CT angiography images. A statistical analysis was performed on the factors associated with pT2Es.

RESULTS

The incidence of pT2Es was 25 %. pT2Es were associated with postoperative changes in the aneurysm diameter. A univariate analysis showed that a sac thrombus and the number of patent side branches arising from an aneurysm were significant factors associated with pT2Es. The IMA diameters were significantly larger in cases of pIMA-T2Es. The significant factors associated with pLA-T2Es were a circumferential thrombus, the number of patent LAs and the mean LA diameter. Multivariate analyses indicated that a circumferential thrombus was a protective factor for pT2Es, whereas an IMA ≥2.6 mm and each additional LA branch ≥1.9 mm were powerful risk factors for a pT2E.

CONCLUSION

Significant anatomical factors associated with pT2E were found in this study. These factors may be useful in selecting patients for perioperative intervention.

Comparative occupational radiation exposure between fixed and mobile imaging systems

OBJECTIVE

Endovascular intervention exposes surgical staff to scattered radiation, which varies according to procedure and imaging equipment. The purpose of this study was to determine differences in occupational exposure between procedures performed with fixed imaging (FI) in an endovascular suite compared with conventional mobile imaging (MI) in a standard operating room.

METHODS

A series of 116 endovascular cases were performed over a 4-month interval in a dedicated endovascular suite with FI and conventional operating room with MI. All cases were performed at a single institution and radiation dose was recorded using real-time dosimetry badges from Unfors RaySafe (Hopkinton, Mass). A dosimeter was mounted in each room to establish a radiation baseline. Staff dose was recorded using individual badges worn on the torso lead. Total mean air kerma (Kar; mGy, patient dose) and mean case dose (mSv, scattered radiation) were compared between rooms and across all staff positions for cases of varying complexity. Statistical analyses for all continuous variables were performed using t test and analysis of variance where appropriate.

RESULTS

A total of 43 cases with MI and 73 cases with FI were performed by four vascular surgeons. Total mean Kar, and case dose were significantly higher with FI compared with MI. (mean ± standard error of the mean, 523 ± 49 mGy vs 98 ± 19 mGy; P < .00001; 0.77 ± 0.03 mSv vs 0.16 ± 0.08 mSv, P < .00001). Exposure for the primary surgeon and assistant was significantly higher with FI compared with MI. Mean exposure for all cases using either imaging modality, was significantly higher for the primary surgeon and assistant than for support staff (ie, nurse, radiology technologist) beyond 6 feet from the X-ray source, indicated according to one-way analysis of variance (MI: P < .00001; FI: P < .00001). Support staff exposure was negligible and did not differ between FI and MI. Room dose stratified according to case complexity (Kar) showed statistically significantly higher scattered radiation in FI vs MI across all quartiles.

CONCLUSIONS

The scattered radiation is several-fold higher with FI than MI across all levels of case complexity. Radiation exposure decreases with distance from the radiation source, and is negligible outside of a 6-foot radius. Modern endovascular suites allow high-fidelity imaging, yet additional strategies to minimize exposure and occupational risk are needed.

Outcomes Following Limb Crossing in Endovascular Aneurysm Repairs

Background:

Crossing the limbs of the stent during endovascular aneurysm repair (EVAR) is often used to aid cannulation of the contralateral limb. This study assessed outcomes following the use of this technique.

Methods:

Retrospective review of crossed (n = 43) and uncrossed (n = 269) EVARs was performed at a tertiary vascular center over 5 years. Primary end points were graft limb occlusion (GLO), endoleak, and sac expansion rates. Indications for limb crossing were also assessed.

Results:

Two-year GLO ( P = .34) and type 1 endoleak ( P = .413) rates were similar between groups. Patients undergoing crossed EVAR experienced more type 2 endoleaks ( P = .002) at 24 months but no increase in sac expansion rates was observed ( P = .275). Thirty-day ( P = .57) and late ( P = .268) mortalities were similar between groups. The main indication for limb crossing was distal aortic angulation (48.8%).

Conclusions:

Crossed EVAR does not increase the risk of GLOs or clinically significant endoleaks. Further studies are needed to determine the effect on type 2 endoleak rates.

External aortic wrap for repair of type 1 endoleak

INTRODUCTION

Type 1 endoleak is a rare complication after endovascular abdominal aortic aneurysm repair (EVAR) with a reported frequency up to 2.88%. It is a major risk factor for aneurysmal enlargement and rupture.

PRESENTATION OF CASE

We present a case of a 68 year old gentleman who was found to have a proximal type 1 endoleak with loss of graft wall apposition on routine surveillance imaging post-EVAR. An initial attempt at endovascular repair was unsuccessful. Given the patient's multiple medical co-morbidities, which precluded the possibility of conventional graft explantation and open repair, we performed a novel surgical technique which did not require aortic cross-clamping. A double-layered Dacron wrap was secured around the infra-renal aorta with Prolene sutures, effectively hoisting the posterior bulge to allow wall to graft apposition and excluding the endoleak. Post-operative CT angiogram showed resolution of the endoleak and a stable sac size.

DISCUSSION

Several anatomical factors need to be considered when this technique is proposed including aortic neck angulation, position of lumbar arteries and peri-aortic venous anatomy. While an external wrap technique has been investigated sporadically for vascular aneurysms, to our knowledge there is only one similar case in the literature.

CONCLUSION

Provided certain anatomical features are present, an external aortic wrap is a useful and successful option to manage type 1 endoleak in high-risk patients who are unsuitable for aortic clamping.