Paolo Perini

Single-centre Prospective Comparison Between Contrast-Enhanced Ultrasound and Computed Tomography Angiography after EVAR

AIM To evaluate contrast-enhanced ultrasound (CEUS) as an effective alternative to CT-angiography (CTA) for endoleak detection and aneurismal sac diameter measurement in the follow-up after endovascular abdominal aortic aneurysm repair (EVAR). METHODS From January 2006 to December 2010, 395 patients underwent EVAR follow-up with both CTA and CEUS. The diameter of the aneurismal sac and the presence of endoleaks were evaluated in all the 395 paired examinations. RESULTS Bland-Altman plots showed a good agreement in aneurismal sac diameter evaluation between the two imaging modalities. The mean diameter was 54.93 mm (standard deviation (SD) ±12.57) with CEUS and 56.01 mm (SD ± 13.23) with CTA. The mean difference in aneurismal sac diameter was -1.08 mm ± 3.3543 (95% confidence interval (CI), -0.75 to -1.41), in favour of CTA. The number of observed agreement in endoleak detection was 359/395 (90.89%). The two modalities detected the same type I and type III endoleaks. McNemars χ(2) test confirmed that CTA and CEUS are equivalent in endoleak detection. CONCLUSIONS CEUS demonstrated to be as accurate as CTA in endoleak detection and abdominal aortic aneurysm diameter measurements during EVAR follow-up, without carrying the risks of radiation exposure or nephrotoxicity. Even if it cannot be proposed as the sole imaging modality during follow-up, our analysis suggests that it should have a major role.

Evaluation of Radiation during EVAR Performed on a Mobile C-arm

BACKGROUND The aim of this study was to evaluate radiation exposure during aortic endovascular aneurysm repair (EVAR) on a mobile C-arm using a low dose and pulse mode. METHODS We performed a retrospective analysis of a prospectively maintained database on patients undergoing EVAR. Indirect dose measurements of dose area product (DAP, mGy m²) calculated by the C-arm (OEC 9900MD), fluoroscopic time (FT), type of procedure, contrast media volume and body mass index were analysed. To confirm the correlation between direct and indirect DAP measurements, direct dose was measured with radiochromic films on a sample of 15 patients. Film grey level response was calibrated according to a reference dose measurement performed with a calibrated dosimeter. DAP and peak skin dose (PSD, Gy) were measured on each film. Correlation between DAP from direct and indirect measures, and between DAP and PSD, were analysed. RESULTS From January 2009 to April 2011, 335 patients underwent EVAR. Complete data were available on 301 procedures including 188 bifurcated, 54 fenestrated, 28 thoracic, 20 branched and 11 aorto-uni-iliac endografts implantation. The respective median FT and DAP was 9.36 min (1.8-67) and 3 mGy m(2) (0.4-28); 27.2 min (2-69) and 7.3 mGy m(2) (1.2-29); 7.75 min (1.2-19.1) and 2 mGy m(2) (0.3-11); 42.98 min (2.4-95.4) and 15.95 mGy m(2) (2.98-77.7); 6.2 min (0.5-36.3) and 2 mGy m(2) (0.3-11). Direct DAP measurement on radiochromic films was strongly correlated with DAP values provided by the C-arm (r = 0.98). PSD correlated weakly with DAP. DAP was significantly increased (p < 0.001) in patients with a body mass index >30. Contrast media volume was significantly increased in the branched endograft group. CONCLUSION Indirect DAP values measured by the C-arm are accurate to evaluate radiation exposure. Compared to the literature, our values for standard procedures are significantly decreased by the usage of low dose and pulse mode. DAP for fenestrated and branched procedures was comparable to published DAP values with standard procedures using a regular fluoroscopic mode.

Contrast-Enhanced Ultrasound vs. CT Angiography in Fenestrated EVAR Surveillance: A Single-Center Comparison

Purpose To evaluate contrast-enhanced ultrasound (CEUS) as an effective alternative to computed tomographic angiography (CTA) during follow-up after fenestrated endovascular aneurysm repair (EVAR) of juxtarenal aortic aneurysms. Methods Between January 2008 and April 2011, 62 patients (all men; mean age 72 years) underwent fenestrated EVAR follow-up with both CTA and CEUS. In a retrospective analysis, the first CTA and CEUS postoperative examinations after EVAR were compared for endoleak detection, aneurysm sac diameter, and target vessel patency. The examinations were performed within 30 days of the procedure and the interval between the 2 scans was <7days. Only fenestrated endografts with up to 3 fenestrations (with or without a scallop) were eligible so that the entire implant could be visualized with standard abdominal ultrasound. Results The mean diameters of the aneurysm sac were 56.58 ± 8.56 mm with CEUS and 57.70 ± 8.59 mm with CTA. The mean difference in aneurysm sac diameter was –1.13 ± 3.19 mm (95% CI –0.34 to –1.92), with CTA measurements tending to be slightly larger. Bland-Altman plots showed good agreement between the imaging modalities with respect to aneurysm sac diameter (Spearman correlation coefficient rs=0.921, p<0.01). Endoleaks were detected by CTA in 7 (11.3%) of 62 patients and by CEUS in 6 (9.7%). In 59 (95.16%) cases, the tests agreed, and their equivalence was confirmed by binomial distribution testing. There was complete agreement between CEUS and CTA in the assessment of target vessels (144/146 patent target arteries; 1 had a significant stenosis and another was thrombosed). Conclusion CEUS is as accurate as CTA in endoleak detection, abdominal aortic aneurysm diameter measurement, and the evaluation of target vessels during surveillance of fenestrated stent-grafts. Although it cannot yet be proposed as the only imaging modality during follow-up, CEUS could be usefully employed with the self-evident advantage of reducing lifetime exposure to ionizing radiation.

Total endovascular repair of an aortic arch aneurysm using an externalized transseptal guidewire technique.

Total endovascular treatment of complex ascending and arch disease remains extremely challenging with difficulties provided by the curvature of the arch, the variable anatomy of the great vessels, the proximity of the coronary ostia, potential damage to the aortic valve, and ventricle and instability during deployment. Given this background, reports of the total endovascular treatment of aortic arch are sparse. We describe one challenging case using an arch branched endograft that was safely advanced and precisely positioned into the ascending aorta using an externalized transseptal guide wire technique.

Transcatheter Transcaval Embolization of a Type II Endoleak After EVAR Using a Transseptal Needle-Sheath System

Purpose. The purpose of this study is to present an alternative technique for management of a type II endoleak associated with aneurysm sac enlargement. Technique. We report the use of a transseptal needle-sheath system for a transcatheter transcaval embolization (TTE) in a 3-staged treatment of a persistent type II endoleak after abdominal EVAR. Inferior vena cava is cannulated through a femoral venous access, and aneurysmal sac access is gained with a puncture through the walls of the 2 vessels at the site where the vein is adjacent to the aneurysm. The whole system (sheath–dilator–needle) is then advanced across the vascular walls into the aortic sac. Thus, embolization with glue is performed. Conclusion. The TTE using a transseptal needle-sheath system demonstrated to be feasible and effective to treat a persistent type II endoleak after failure of 2 attempts of transarterial embolization of the feeding vessels.

Use of a Thoracic Endograft in an Acute Abdominal Aortic Setting: Case Report and Literature Review.

Purpose: We report the case of a thoracic endograft used to achieve exclusion of a ruptured proximal paranastomotic abdominal aortic aneurysm (PAAA) as a consequence of aortic ballooning. Case Report: A type I proximal endoleak was evidenced following endovascular repair of a PAAA with an aortic cuff. The leak was treated with ballooning, which caused distal aortic rupture. A thoracic endograft was deployed inside the cuff, achieving complete exclusion. At 1 year, there are no signs of migration or endoleak with complete PAAA thrombosis, according to computed tomographic angiography. Conclusion: In hostile proximal abdominal aortic neck, challenging anatomies, or urgent cases, the structural adaptability of thoracic endografts could provide safe and successful abdominal aortic endovascular exclusion.

Routine Shunting During Carotid Endarterectomy in Patients With Acute Watershed Stroke

Aim: To evaluate the protective role of routine shunting in patients with acute watershed stroke (WS) undergoing carotid endarterectomy (CEA). Methods: A total of 138 patients with symptomatic carotid stenosis (SCS) who underwent CEA after acute ischemic stroke from March 2008 to March 2015 were included in this study. Transient ischemic attacks were excluded. These patients were divided into 2 groups according to the topographic pattern of the stroke on magnetic resonance imaging: group 1, territorial strokes (TS) caused by emboli of carotid origin, and group 2, WS caused by a hemodynamic mechanism related to an SCS. Primary end points were 30-day mortality and postoperative neurological morbidity. The insertion of a Pruitt carotid shunt was performed systematically. Results: Ninety (65.2%) patients presented a TS of carotid origin and were included in group 1, and 48 (34.8%) of the 138 patients had a WS related to an SCS and were included in group 2. The median time between clinical onset of the cerebral ischemic event and surgery was 9 days (range: 0-89 days). Postoperative mortality was 0%. Seven (5.1%) patients had an aggravation of the neurological status during the postoperative period, of whom 2 presented a complete regression of the symptoms in less than 1 hour (definitive postoperative neurologic morbidity: 3.6%). Postoperative neurologic morbidity rate was significantly higher in the TS group (7 of 90; 7.8%) compared to the WS group (0 of 48; P = .04). No other independent predictive factor of neurologic morbidity after CEA for an SCS was found. Conclusions: Our results suggest that routine shunting should be considered in case of acute WS since it may play a protective role. Further studies are eagerly awaited to better define the timing and the best treatment option for both acute WS and TS related to an SCS in order to reduce postoperative neurologic morbidity.

Endovascular Applications for Thoracoabdominal Pathologies

This chapter describes and discusses several graft designs to accommodate the various anatomy configurations of thoracoabdominal aneurysms. The discussion will include the selection of a branch, a fenestration, or a scallop to perfuse a visceral vessel arising from the diseased aorta or located at the level of the sealing zone. Unusual cases will also be presented.

Advanced computed tomography imaging, workstations, and planning tools

Multidetector-row computed tomography (MDCT) has now replaced the old “gold standard,” intra-arterial digital subtraction angiography (DSA), for assessing abdominal, thoracic, and cranial vasculature. MDCT raw data are captured in two-dimensional (2D) transverse sections. Therefore, to generate an angiographic display, a three-dimensional (3D) workstation is required. To depict vascular anatomy on the workstation, specific anatomical projections must be created using one or more visualization techniques. The image projections must display the vascular region of interest in the correct viewing planes without being obscured by other vascular territories or noncardiovascular structures. Furthermore, the resultant images must be rendered with the correct window, level, and lighting settings to accurately depict normal anatomy and pathology. The volumetric data acquired enable the acquisition of views from any angle and perspective. MDCT has a superior diagnostic accuracy compared with intra-arterial DSA in characterizing the neck of the abdominal aortic aneurysm, identifying accessory renal arteries, and characterizing renal arterial stenoses.

Endovascular Applications for Abdominal Aortic Pathologies

In this section, we will present various abdominal aortic aneurysm endovascular repair cases. We will start with a “classic” infrarenal aortic aneurysm treated with a standard bifurcated endograft. The treatment of a saccular aneurysm and a ruptured atherosclerotic plaque will then be presented. We will also illustrate the use of aorto-uni-iliac endografts, and various clinical scenarios will conclude by describing the fenestrated endografts used to treat juxtarenal and pararenal abdominal aortic aneurysms.