Color Doppler ultrasound for surveillance following EVAR as the primary tool.

OBJECTIVE: As aneurysm-related events and rupture is not eliminated, postoperative lifelong surveillance is mandatory after endovascular aneurysm repair (EVAR). For surveillance colored Doppler ultrasound (CDUS) is a standard method of noninvasive evaluation having the advantages of availability, cost-effectiveness, and lack of nephrotoxicity and radiation. We evaluated CDUS for primary surveillance tool after elective EVAR by comparing with computerized tomography. METHODS: Between January 2018 and March 2020, 84 consecutive post-EVAR patients were evaluated. First, CDUS was performed by two Doppler operators from the Radiology Department and then computed tomographic angiography (CTA) was performed. The operators were blind to CTA reports. A reporting protocol was organized for endoleak detection and largest aneurysm diameter. RESULTS: Among 84 patients, there were 11 detected endoleaks (13.1%) with CTA and seven of them was detected with CDUS (r = .884, p < .001). All Type I and III endoleaks were detected perfectly. There is an insufficiency in detecting low flow by CDUS. Eliminating this frailty, there was a strong correlation of aneurysm sac diameter measurement between CTA and CDUS (r = .777, p < .001). The sensitivity and specificity of CDUS was 63.6% and 100%, respectively. The accuracy was 95.2%. Positive and negative predictive values were 100% and 94.8%. Bland-Altman analysis and linear regression analysis showed no proportional bias (mean difference of 1.5 ± 2.2 mm, p = .233). CONCLUSIONS: For surveillance, CDUS promises accurate results without missing any potential complication requiring intervention as Type I or III endoleak. Lack of detecting Type II endoleaks may be negligible as sac enlargement was the key for reintervention in this situation and CDUS has a remarkably high correlation with CTA in sac diameter measurement. CDUS may be a primary surveillance tool for EVAR and CTA will be reserved in case of aneurysm sac enlargement, detection of an endoleak, inadequate CDUS, or in case of unexplained abdominal symptomatology. By this way we not only avoid ionizing radiation and nephrotoxic agents, but also achieve cost saving issue also.

Visceral oxidative stress during antegrade cerebral perfusion and lower body circulatory arrest.

Background: Antegrade cerebral perfusion (ACP) is the standard neuroprotection method in aortic surgery. Visceral ischemia during this modality brings out some controversies. We aimed to investigate the level of oxidative stress at the lower part of body during ACP. Methods: Thirty consecutive patients underwent elective ascending aorta and hemiarch repair with ACP (without distal perfusion) were enrolled to study. The patients were enrolled into two groups which were based on 50th percentile of ACP duration (15 patients in each group). Blood samples from inferior vena cava at the end of ACP were collected to assess oxidative stress with biochemical parameters such as lactate, advanced oxidative protein products (AOPP) and thiol levels. Clinical follow-up parameters regarding to visceral and spinal cord ischemia were recorded. There were no clinical complications at both groups. Results: Mean ACP duration for the study group was found to be 15 min (10-28 min). Lactate, AOPP, and thiol levels were found to be similar between two groups. Furthermore, correlation analysis revealed only low level of correlation between ACP duration and lactate levels. Renal and liver function tests were found to be similar between groups. Conclusions: Immediate parameters (such as lactate, AOPP, and thiol) that show alterations in response to oxidative stress were not affected by the duration of ACP. Therefore, ACP without distal perfusion may not be harmful when conducted for short duration.