The effects of combining fusion imaging, low-frequency pulsed fluoroscopy, and low-concentration contrast agent during endovascular aneurysm repair.

OBJECTIVE: This study evaluated the effects of a combined imaging protocol using low-frequency pulsed fluoroscopy, fusion imaging, and low-concentration iodine contrast for endovascular aneurysm repair (EVAR) of aortic aneurysms of varying complexity. METHODS: The study retrospectively reviewed the data of 103 patients treated between May 2013 and November 2014 with the combined imaging protocol (group A) with low-dose fluoroscopy at 3.75 frames/s, fusion imaging, and iodine contrast of 140 mg iodine/mL. A control group (group B) consisted of 123 consecutive patients who underwent EVAR before the combined imaging protocol was introduced by matching the type of procedure. In group B, low-dose 7.5 frames/s fluoroscopy, no fusion imaging, and 200 mg iodine/mL contrast were used. All patients were reviewed for preoperative, intraoperative, and postoperative variables, with emphasis on intraoperative radiation (dose area product) and iodine exposure, fluoroscopy, and operation times, as well as technical success. Values are presented as median and interquartile range (IQR) when not stated otherwise. RESULTS: Group A included 22 infrarenal EVARs, 17 iliac branch devices, 10 thoracic endovascular aortic repairs, 21 fenestrated EVARs, and 33 thoracoabdominal branched/fenestrated EVARs. Groups A and B were similar in types of procedure, body mass index (P > .05), and intraoperative technical success (92% and 92%, respectively; P > .05). Operation time (230 [IQR, 138-331] minutes vs 235 [IQR, 158-364] minutes) and fluoroscopy time (66 [IQR, 33-101] minutes vs 72 [IQR, 42-102] minutes) were similar in both groups (P > .05), but radiation exposure (19,934 [IQR, 11,340-30,615] µGym(2) vs 32,856 [IQR, 19,562-55,677] µGym(2); P < .0001), contrast volume usage (63 [IQR, 103-145] mL vs 215 [IQR, 166-280] mL; P < .0001), and iodine dose (14.5 [IQR, 8.8-20.4] g iodine vs 43.0 [IQR, 32.2-56.0] g iodine; P < .0001) were lower in group A than in group B. The differences were uniform throughout the different procedure types, with the exception of fenestrated grafts, where radiation exposure was similar between group A and B; however, group A had a much higher involvement of the superior mesenteric artery in the repairs (81% vs 17%; P < .0001) explaining this finding. Fluoroscopic frame rate reduction contributed to a median reduction of the dose area product by 22%. Only four of the group A patients (3.9%) showed a decrease in the glomerular filtration rate ≥30% after EVAR, although 32% of the entire group had at least moderately impaired renal function preoperatively. CONCLUSIONS: Combining low-frequency pulsed fluoroscopy, fusion imaging, low-concentration, and iodine contrast medium during EVAR reduces the exposure to radiation and iodine.

Postoperative CT Evaluation After EVAR: A Comparison of Image Assessment.

PURPOSE: To compare the postoperative computed tomography angiography (CTA) assessment made by vascular surgeons and interventional radiologists after endovascular aneurysm repair (EVAR) at a tertiary vascular clinic to an outside core review facility. METHODS: One hundred patients (mean age 78.7 years, range 88-55; 84 men) with consecutive, elective, routine CTA controls after EVAR were retrospectively studied. Consultant vascular surgeons or radiologists had evaluated all original scans and written the original report. All scans were then reevaluated by an independent core clinic. Findings were classified as vascular or extravascular and stratified as clinically significant or clinically nonsignificant by an independent external reviewer. RESULTS: The number of vascular findings detected by the vascular clinic was 72 vs 69 by the core clinic. The vascular clinic reported more clinically significant findings (primarily stent compression or kinks) as well as endoleaks and their origin. The core clinic reported more pseudoaneurysms (24 vs 12). None of the patients with puncture complications needed reintervention. Interrater analysis of all findings between the 2 clinics showed good agreement when comparing endoleaks overall (without subclassification) and moderate agreement when assessing aneurysm growth. The core clinic reported extravascular findings in 58 patients; 37 of these were classified as clinically significant. The vascular clinic reported extravascular findings in 23 patients; 7 of these were clinically significant. The core clinic also reported 2 cases of suspected malignancies, which had not been reported by the vascular clinic. CONCLUSION: During routine CTA follow-up after EVAR, a significant number of vascular and nonvascular findings are detected. Whereas a highly dedicated vascular clinic identifies most vascular findings regardless of the specialty of the reader, some extravascular findings are missed. However, the frequency of clinically significant findings or findings that might warrant reintervention was low in this study.

Suitability of the Zenith p-Branch Standard Fenestrated Endovascular Graft for Treatment of Ruptured Abdominal Aortic Aneurysms.

PURPOSE: To evaluate the anatomic suitability of the Zenith pivot branch (p-branch) fenestrated device in ruptured abdominal aortic aneurysms (rAAA). METHODS: Contrast-enhanced computed tomography (CT) images of 206 patients (mean age 75±8 years; 175 men) with rAAA were evaluated in a dedicated 3-dimensional vascular workstation. All aneurysms found unsuitable for standard infrarenal repair were evaluated for Zenith p-branch suitability according to the Investigational Device Exemption protocol for both device configurations (A, pivot fenestrations at the same level; B, right renal fenestration located more cranially). RESULTS: The suitability of the p-branch (A or B configuration) for short neck aneurysms (<15 mm; n=89) was 49%; of the 26 different combinations of exclusion criteria, a mismatch between a renal artery takeoff and the positioning of the corresponding fenestration was the most common. For juxta- and pararenal aneurysms (neck length <10 mm; n=66), suitability was 48%. Suitability assessed by target vessel positioning only (excluding all other limiting factors) was 58% for short neck aneurysms (n=52) and 55% for juxta- and pararenal aneurysms (n=36). CONCLUSION: Approximately half of patients with short neck rAAAs would be suitable for the Zenith p-branch fenestrated device according to the instructions for use. In almost 60%, the pivot fenestrations can accommodate the corresponding target vessels. More studies are needed to confirm these findings.

Outcomes of fenestrated endovascular repair of juxtarenal aortic aneurysm.

OBJECTIVE: To evaluate late outcomes after fenestrated endovascular aortic repair (f-EVAR) in a tertiary European referral center. METHODS: In 2009, we published short- and midterm results after f-EVAR in the first 54 patients treated with this technique at our center between September 2002 and June 2007. In this paper, we provide long-term follow-up of the same patient cohort with the main focus on target vessel (TV) patency, renal function, reinterventions, and survival. RESULTS: A total of 54 patients were included in this study. Median age was 72 years (interquartile range [IQR], 68-76 years) at primary operation, and 85% were men. Median preoperative aneurysm diameter was 60 mm (IQR, 53-66 mm). One hundred thirty-four vessels were targeted (mean, 2.5 per patient), and 96 TV stents were placed. The median clinical follow-up was 67 months (IQR, 37-90 months), and computed tomography follow-up was 60 months (IQR, 35-72 months). Aneurysm diameter decreased ≥ 5 mm in 39% ± 7% at 12 months, 64% ± 8% at 36 months, and 71% ± 8% at 60 months. Primary TV patency was 94% ± 2% at 12 months, 91% ± 3% at 36 months, and 90% ± 3% at 60 months. Glomerular filtration rate decreased by 17% at 59 months (IQR, 26-73 months) follow-up (60 [IQR, 46-79] vs 50 [IQR, 38-72] mL/min/1.73 m(2); P < .001), and one patient became dialysis-dependent secondary to a renal stent occlusion. Reintervention-free survival was 88% ± 5% at 12 months, 69% ± 7% at 36 months, and 56% ± 5% at 60 months. At least one reintervention was done in 37% of patients, of which 29% were endoleak-related, 26% TV-related, 13% graft-limb-related, and 32% due to other causes. The majority of reinterventions (68%) were based on complications detected on routine follow-up. Estimated overall survival was 93% ± 4% at 12 months, 76% ± 6% at 36 months, and 60% ± 7% at 60 months. In total, 54% of the patients died during the 10-year study period, where 9% died of aneurysm-related causes. CONCLUSIONS: Long-term mortality after f-EVAR is high, but most patients die from nonaneurysmal causes. Aneurysm-related mortality is associated with technical complications that can be reduced with increased experience. Reinterventions are common, and most complications are detected on routine follow-up.

Techniques to reduce radiation for patients and operators during aortic endografting.

Endovascular aortic repair of aortic pathologies has become widely spread among vascular surgeons. Much focus has been directed at perfecting and developing endovascular procedures to treat evermore complex issues. Much less focus has been directed at the radiation hazards to patients as well as operators and staff when such procedures are performed. Radiation exposure must be used according to the ALARA (As Low As Reasonably Achievable) principle to avoid short- and long-term negative side effects. Modern imaging technology offers many technological developments to reduce radiation such as low-dose programs, pulsed imaging, flat-panel technology and advanced intraoperative imaging techniques. But beside this, simple measures, based on the understanding of radiation exposure, can easily be implemented in everyday standard practice. Appropriate shielding of patients and staff, using adjuncts to be able to keep a safe distance to the radiation source and avoiding working with inappropriate C-arm angulations should be used routinely. Continued education of vascular surgeons is imperative to implement changes in practice to reduce radiation exposure.