Association of Baseline Chronic Kidney Disease Stage With Short- and Long-Term Outcomes After Fenestrated Endovascular Aneurysm Repair

Significant Radiation Reduction Using Cloud-Based AI Imaging in Manually Matched Cohort of Complex Aneurysm Repair

BACKGROUND

Cloud-based, surgical augmented intelligence (Cydar Medical, Cambridge, United Kingdom) can be used for surgical planning and intraoperative imaging guidance during complex endovascular aortic procedures. We aim to evaluate radiation exposure, operative safety metrics, and postoperative renal outcomes following implementation of Cydar imaging guidance using a manually matched cohort of aortic procedures.

METHODS

We retrospectively reviewed our prospectively maintained database of endovascular aortic cases. Patients repaired using Cydar imaging were matched to patients who underwent a similar procedure without using Cydar. Matching was performed manually on a 1:1 basis using anatomy, device configuration, number of branches/fenestrations, and adjunctive procedures including in-situ laser fenestration. Radiation, contrast use, and other operative metrics were compared. Preoperative and postoperative maximum creatinine was compared to assess for acute kidney injury (AKI) based on risk, injury, failure, loss of kidney function, and end-stage kidney disease (RIFLE) criteria.

RESULTS

Hundred patients from 2012 to 2023 were identified: 50 cases (38 fenestrated endovascular aortic repairs, 2 thoracic endovascular aortic repairs, 3 octopus-type thoracoabdominal aortic aneurysm repair, 7 endovascular aneurysm repairs) where Cydar imaging was used, with suitable matches to 50 non-Cydar cases. Baseline characteristics including body mass index did not differ significantly between the 2 groups (27.8 ± 5.6 vs. 26.7 ± 6.1; P = 0.31). Radiation dose was significantly lower in the Cydar group (2529 ± 2256 vs. 3676 ± 2976 mGy; P < 0.03), despite there being no difference in fluoroscopy time (51 ± 29.4 vs. 58 ± 37.2 min; P = 0.37). Contrast volume (94 ± 37.4 vs. 93 ± 43.9 mL; P = 0.73), estimated blood loss (169 ± 223 vs. 193 ± 222 mL; P = 0.97), and procedure time (154 ± 78 vs. 165 ± 89.1 min) did not differ significantly. Additionally, Cydar versus non-Cydar patients did not show a significant difference between precreatinine and postcreatinine changes (0.13 ± 0.08 vs. 0.05 ± 0.07; P = 0.34). Only one patient in the non-Cydar group met RIFLE criteria for AKI postoperatively.

CONCLUSION

The use of cloud-based augmented intelligence imaging was associated with a significant reduction in radiation dose in a cohort of matched aortic procedures but did not appear to affect other parameters or renal function. Even with advanced imaging, surgeons should remain conscientious about radiation safety and administration of nephrotoxic contrast agents.

Comparison of EndoSuture vs fenestrated aortic aneurysm repair in treatment of abdominal aortic aneurysms with unfavorable neck anatomy

BACKGROUND

Hostile aortic neck anatomy is associated with loss of proximal seal and increased late reinterventions. Although both EndoSuture aneurysm repair (ESAR) and fenestrated endovascular aortic repair (FEVAR) are commercially available options for treatment of short neck aneurysms, branch vessel patency is a potential tradeoff for improved seal with FEVAR owing to the incorporation of renovisceral vessels. This study compares the performance of ESAR vs FEVAR in hostile aortic necks.

METHODS

Patients who underwent elective ESAR or FEVAR for hostile neck AAAs at a single center from 2012 to 2024 were reviewed retrospectively. Exclusion criteria included pararenal or thoracoabdominal aortic aneurysm, off-label modifications, and nonstandard FEVAR configurations. Propensity matching weights were generated based on age, year of operation, preoperative estimated glomerular filtration rate, neck length, neck diameter, and infrarenal angulation. Rates of survival, reintervention, dialysis, chronic kidney disease stage progression, type IA endoleak (EL), and sac regression (>5 mm) were assessed at latest follow-up.

RESULTS

Of 391 patients, 60 with ESAR and 207 with FEVAR were included. FEVAR patients were younger (74.4 years vs 79.8 years; P < .001) with larger neck diameters (25.0 mm vs 23.6 mm; P = .016), shorter neck length (5.0 mm vs 9.8 mm; P < .001), and decreased infrarenal angulation (20° vs 40°; P < .001). After propensity score-adjusted regression (58 ESAR, 169 FEVAR), FEVAR, compared with ESAR, was associated with decreased IA EL (hazard ratio, 0.341; 95% confidence interval [CI], 0.061-0.72; P = .031) and increased sac regression (hazard ratio, 3.92; 95% CI, 1.25-5.14; P = .02). Notably, FEVAR was associated with increased 1-year aneurysm-related reintervention (odds ratio, 4.33; 95% CI, 1.12-10.54; P = .046). On Kaplan-Meier analysis, FEVAR was associated with reduced freedom from reinterventions at 3 years (71.8% [95% CI, 0.63-0.78] vs 93.5% [95% CI, 0.80-0.97]; log-rank P = .019) but a trend toward improved survival at 3 years (79.15% [95% CI, 0.70-0.85] vs 61.5% [95% CI, 0.44-0.74]; log-rank P = .095). There was no significant difference in new-onset chronic dialysis between ESAR and FEVAR at 3 years (94.2% [95% CI, 0.82-0.98] vs 97.4% [95% CI, 0.93-0.99]; log-rank P = .124).

CONCLUSIONS

In the treatment of abdominal aortic aneurysms with hostile neck anatomy in this propensity-matched cohort, FEVAR was associated with fewer type IA ELs and greater sac regression compared with ESAR, with no detrimental impact on long-term renal function. There were more reinterventions, mostly branch related, in the FEVAR group. We await the results of the current randomized prospective trial comparing these strategies to further determine the impact of these clinical differences on aneurysm-related mortality.

Sex Related Differences in Perioperative Outcomes after Complex Endovascular Aortic Aneurysm Repair

BACKGROUND

Prior studies suggest female sex is associated with worse outcomes after complex endovascular aortic aneurysm repair (EVAR) due to anatomic differences. Therefore, we aimed to compare 30-day perioperative and long-term outcomes after complex EVAR by sex.

METHODS

A single-center retrospective review of consecutive elective and emergent complex EVAR with company-manufactured devices, laser fenestration, snorkel/periscope, or octopus technique was performed from 2012-2023. The primary outcome was a composite endpoint of any major adverse event (MAE), new-onset dialysis, or death within 30 days. Secondary 30-day technical and long-term outcomes were also assessed.

RESULTS

293 patients (57 females, 19%), mean age 74 years, underwent complex EVAR with commercially available Zenith fenestrated endovascular graft (71%), p-Branch (2%), laser fenestration (8%), snorkel/periscope (16%), or octopus (2%) techniques. Females had significantly different aneurysm-related anatomic characteristics compared to males, including smaller aneurysm diameters (58 ± 7.2 vs. 64 ± 13.2 mm, P < 0.001), more involved aneurysm extent (21.7% vs. 9.8% thoracoabdominal, P = 0.04), increased renal artery calcification (43.9% vs. 27.1%, P = 0.01), and smaller iliac (7.6 ± 1.3 vs. 8.9 ± 1.8 mm, P < 0.01). Operative outcomes were similar; however, females had a greater need for adjunctive access conduits (21.1% vs. 10.6%, P = 0.04), lower technical success (91.2% vs. 98.3%, P = 0.02), and longer median [interquartile range] length of stay (3.0 [4.0] vs. 2.0 [2.5] days, P < 0.001). The composite 30-day outcome of any MAE, new dialysis, or death was not significantly different (15.8% females vs. 11.4% males, P = 0.37). Technical endpoints including 30-day rates of target artery occlusion and type 1 or 3 endoleak were also similar between groups. At mean follow-up of nearly 3 years, females had significantly lower rate of renal function decline (16.0% vs. 41.9%, P < 0.001), but no differences were found in long-term all-cause mortality, aneurysm sac regression, reintervention, or total follow-up imaging studies between groups.

CONCLUSIONS

Females undergoing complex EVAR had challenging anatomy with higher intraoperative target artery occlusion, conduit use, and longer length of stay. However, 30-day and long-term outcomes were similar, suggesting females can undergo complex EVAR with high technical success and comparable perioperative outcomes to males. Females appeared to have protection from long-term renal function decline, which will be important for future study.

Effect of Chronic Kidney Disease on 30-Day Outcomes in Endovascular Repair of Complex Abdominal Aortic Aneurysm

BACKGROUND

Chronic kidney disease (CKD) has been identified as an independent predictor of poorer long-term prognosis after endovascular aneurysm repair (EVAR) for complex abdominal aortic aneurysm (AAA). However, its impact on short-term perioperative outcomes is conflicting, which can be important for preoperative risk stratification. This study aimed to evaluate the 30-day outcomes of patients with CKD following non-ruptured complex EVAR in a national registry.

METHODS

Patients who had EVAR for complex AAA were identified in ACS-NSQIP targeted database from 2012-2022. Complex AAA included juxtarenal, suprarenal, or pararenal proximal extent, Type IV thoracoabdominal aneurysm, and/or aneurysms treated with Zenith Fenestrated endograft. Exclusion criteria included age<18 years, ruptured AAA, acute intraoperative conversion to open, emergency presentation, and dialysis. Multivariable logistic regression was used to compare 30-day postoperative outcomes of CKD and non-CKD patients, where demographics, baseline characteristics, aneurysm diameter, distant aneurysm extent, anesthesia, and concomitant procedures were adjusted.

RESULTS

There were 695 (39.33%) and 1072 (60.67%) patients with and without CKD, respectively, who underwent EVAR for complex AAA. Patients with and without CKD have comparable 30-day mortality (aOR = 1.165, 95 CI = 0.646-2.099, P = 0.61). However, CKD patients had a higher risk of renal complications (aOR = 2.647, 95 CI = 1.399-5.009, P < 0.01) including higher progressive renal insufficiency (aOR = 3.707, 95 CI = 1.329-10.338, P = 0.01) and acute renal failure requiring renal replacement therapy (aOR = 2.533, 95 CI = 1.139-5.633, P = 0.02). All other 30-day outcomes were comparable between CKD and non-CKD patients.

CONCLUSION

Patients with CKD had similar 30-day mortality and morbidity rates but a higher risk of postoperative renal complications. Therefore, meticulous preoperative planning and postoperative management, which may include optimal hydration, appropriate contrast use, and close renal function monitoring, are essential for patients with CKD after complex EVAR.

Preoperative risk score for mortality within 3 years of visceral segment fenestrated endovascular aortic repair

OBJECTIVE

The purpose of this study was to create a risk score for the event of mortality within 3 years of complex fenestrated visceral segment endovascular aortic repair utilizing variables existing at the time of preoperative presentation.

METHODS

After exclusions, 1916 patients were identified in the Vascular Quality Initiative who were included in the analysis. The first step in development of the risk score was univariable analysis for the primary outcome of mortality within 3 years of surgery. χ2 analysis was performed for categorical variables, and comparison of means with independent Student t-test was performed for ordinal variables. Variables that achieved a univariable P value less than 0.1 were then placed into Cox regression multivariable time dependent analysis for the development of mortality within 3 years. Variables that achieved a multivariable significance of less than 0.1 were utilized for the risk score, with point weighting based on the beta-coefficient. Variables with a beta coefficient of 0.25 to 0.49 were assigned 1 point, 0.5 to 0.74 2 points, 0.75 to 0.99 3 points, and 1.0 to 1.25 4 points. A cumulative score for each patient was then summed, the percentage of patients at each score experiencing mortality within 3 weeks was then calculated, and a comparison of score outcomes was conducted with binary logistic regression. Area under the curve analysis was performed.

RESULTS

The primary outcome of mortality within 3 years of surgery occurred in 12.8% of patients (245/1916). The mean age for the study population was 73.35 years (standard deviation [SD], 8.26 years). The mean maximal abdominal aortic aneurysm (AAA) diameter was 60.43 mm (SD, 10.52 mm). The mean number of visceral vessels stented was 3.3 (SD, 0.76). Variables present at the time of surgery that were included in the risk score were: hemodialysis (3 points); age >87, chronic obstructive pulmonary disease, hypertension, AAA diameter >77 mm (all 2 points); and body mass index <20 kg/m2, female sex, congestive heart failure, active smoking, chronic renal insufficiency, age 80 to 87 years, and AAA diameter 67 to 77 mm (all 1 point). BMI >30 kg/m2 (mean, 34.46 kg/m2) and age <67 years were protective (-1 point). Testing the model resulted in an area under the curve of 0.706. Hosmer and Lemeshow goodness of fit test for logistic regression utilizing the 15 different risk score total groups revealed a model predictive accuracy of 87.3%. Significant escalations in 3-year mortality were noted to occur at scores of 6 and greater. Mean AAA diameter was significantly larger for patients who had higher risk scores (P < .001).

CONCLUSIONS

A novel risk score for mortality within 3 years of fenestrated visceral segment aortic endograft has been developed that has excellent accuracy in predicting which patients will survive and derive the strongest benefit from intervention. This facilitates risk-benefit analysis and counseling of patients and families with realistic long-term expectations. This potentially enhances patient-centered decision-making.