Could four-dimensional contrast-enhanced ultrasound replace computed tomography angiography during follow up of fenestrated endografts? Results of a preliminary experience.

OBJECTIVE: To evaluate four-dimensional contrast-enhanced ultrasound (4D-CEUS) as an alternative imaging method to computed tomography angiography (CTA) during follow up of fenestrated endovascular aneurysm repair (FEVAR) for juxta- and para-renal abdominal aortic aneurysms (AAA). METHODS: Between October 2011 and March 2012, all consecutive patients who underwent FEVAR follow up were included in the study and evaluated with both 4D-CEUS and CTA. The interval between the two examinations was always ≤ 30 days. Endpoints were the comparison of postoperative AAA diameter, AAA volume, presence of endoleaks, revascularized visceral vessel (RVV) visualization, and patency. Comparative analysis was performed using Bland-Altman plots and McNemar's Chi-square test. RESULTS: Twenty-two patients (96% male, 4% female; mean age 74 ± 7 years; American Society of Anesthesiologists grade III/IV 82%/18%) were enrolled. Seventy-eight RVV (fenestrations: 60; scallops: 17; branches: 1) were analyzed. The mean AAA diameter evaluated by 4D-CEUS and CTA was 45 ± 10 mm (range 30-69 mm) and 48 ± 9 mm (range 32-70 mm), respectively. The mean difference was 3 ± 3 mm. The mean AAA volume evaluated by 4D-CEUS and CTA was 150 ± 7 cc (range 88-300 cc) and 159 ± 68 cc (range 80-310 cc), respectively. The mean difference was 7 ± 4 cc; a Bland-Altman plot revealed agreement in AAA diameter and volume evaluation (p < .01) between 4D-CEUS and CTA. The observed agreement for the detection of endoleaks was 95%. McNemar's Chi-square test confirmed that 4D-CEUS and CTA were equivalent (p > .05) at detecting endoleaks. The first segment of six (8%) RVVs (four renal and two superior mesenteric arteries) was not directly visualized by 4D-CEUS owing to obesity, but the contrast enhancement into the distal part of vessel or into the relative parenchyma gave indirect information about their patency. McNemar's Chi-square test demonstrated the superiority of CTA (p = .031) in visualizing RVVs. The patency of 77/78 RVVs was confirmed with both techniques. McNemar's Chi-square test confirmed that 4D-CEUS and CTA were equivalent in their ability to detect visceral vessel patency. CONCLUSIONS: The data suggest that 4D-CEUS is as accurate as CTA in the evaluation of postoperative AAA diameter and volume, endoleak detection, and RVV patency after FEVAR. Four-dimensional CEUS could provide hemodynamic information regarding RVVs, and reduce radiation exposure and renal impairment during follow up. Obesity limits the diagnostic accuracy of 4D-CEUS.

Bypass to the ankle and foot in the era of endovascular therapy of tibial disease. Results and factors influencing the outcome.

AIM: Endovascular therapy (ET) is the treatment of choice for critical limb ischemia (CLI) and tibial arteries disease (TAD) in focal lesions with restorable run-off; ankle and foot bypass (BPG) is indicated in patients unfit for ET with foot or ankle arteries suitable for surgery. The aim of this study was to evaluate limb salvage (LS), primary patency (PP) and survival (S) of patients underwent BPG in the era of ET for TAD and to define the correlated prognostic factors. METHODS: Between February 2000 and November 2008, patients with CLI and TAD were collected prospectively in a data-base (demographics, Fontaine's stage, Texas University Wound Classification [TUC]of ulcers, risk-factors, TAD, techniques of foot revascularization and surgical factors). BPG was performed in tibial arteries occlusion longer than 4 cm or focal occlusion without line-flow to pedal arteries. Clinical and Duplex-ultrasound follow-up was performed at discharge, 1, 3, 6 months and every 6 months. LS, PP, and S rates were assessed with Kaplan-Meier method; factors influencing outcomes were sought by multivariate Cox proportional hazards model analysis. RESULTS: A total of 410 revascularizations were performed in patients with CLI and TAD; BPG in 153 patients (mean age: 69.3±10.6, male/female=117/36, diabetes mellitus=75.2% hyperlypidemia=54.9%, hypertension=87.6%, renal disease=32.7%, coronary arteries disease=51.6%, Fontaine stage IV=96.1%, TUC grade-III=65.4%, TUC stage-D=51%). All autologous grafts in 96.7% (non-reversed saphenous vein=74.5%, reversed=7.2%, composite vein graft=12.4%, arm's veins=2.6%). LS and S after 1 month were 88.2% and 97.1%, respectively. Mean follow-up was 23 months. At 12 and 36 months: LS 76.7% and 70.9%, PP 62.3% and 52.9%, S 91.5% and 74.6%. LS was negatively associated with age (HR=1.041 [95%CI=1.005-1.079]), infected ulcers (HR=3.377 [95%CI=1.571-7.258]), run-off arteries diameter <1.8 mm (HR=5.854[95% CI=2.274-15.070]). PP was negatively associated with hyperlipidemia (HR=2.555 [95% CI=1.418-4.603]), female gender (HR=2.125[95% CI=1.182-3.823]), run-off arteries diameter <1.8 mm (HR=6.165 [95% CI=2.774-13.699]), reversed saphenous graft (HR=3.105 [95% CI=1.166-8.272]), composite vein graft (HR=2.930 [95% CI=1.406-6.107]) and homograft (HR=2.762 [95% CI=1.040-7.333]); instead it is positively related with hypertension (HR=4.229 [95% CI=2.089-8.563]). S was negatively correlated with renal disease (HR=3.035 [95% CI=1.363-6.756]). CONCLUSION: BPG may be a reasonable first treatment for CLI patients with TAD unfit for ET; female gender, hyperlipidemia, use of reversed saphenous, composite vein or alternative grafts, foot infection and renal disease are associated with worse outcome.