Brachial artery aneurysm as a late complication of arteriovenous fistula

Introduction: Brachial artery aneurysm (BAA) is a rare late complication of arteriovenous fistula (AVF). It brings the risk of peripheral embolism and hand ischemia and is defined by brachial artery diameter above 10 mm or by regional dilatation by >50%. BAA is described in the literature in closed radiocephalic arteriovenous fistulas after kidney transplantation. The aim of the study was to analyze the prevalence of BAA and of their more dangerous forms. Method: A observational one center study performed on patients after kidney transplantation with AVF or arteriovenous graft (AVG). We invited all patients followed up for kidney transplantation in our center. Arterial diameter greater than 10 mm was considered as a brachial artery aneurysm to simplify the detection and evaluation of aneurysms. Results: About 162 patients with AVF after kidney transplantation were examined between 4/2018 and 4/2020. Brachial artery aneurysm was detected in 34 patients (21%) with AVF or AVG, of them 7 had confirmed wall thrombi. AVF flow volume of more than 1500 ml/min increased the risk of BAA development by 4.54x. Eight aneurysms were treated surgically. After this surgery, the primary patency was 87.5% in 12 months. Conclusion: Brachial artery aneurysm was relatively frequent in our study compare to the literature. Aneurysm or dilatation of the brachial artery is more frequent in functional AVFs. Surgical correction is necessary in cases of complicated aneurysms to prevent distal embolization.

Transradial access for pediatric teenage neurointervention: A single-center case series

Transradial access is widely used in cardiological adult interventions and less in pediatrics. In recent years, this access has become more popular in the neuroradiological community in adult patients since it has fewer complications and is more comfortable for the patient after the procedure. We present a single-center case series of 52 transradial access neurointerventions (43 angiographies and 9 therapeutic procedures) in pediatric patients, with a failure of 4 cases (7.7%) in which we could not puncture the artery, crossing over to transfemoral access. Since in five cases we did angiography followed by therapeutic intervention, thus doing only one puncture access for both procedures, then our access failure rate was 10.6%. The 34 successful transradial access solely angiographies had a median radiation exposure of 887 mGy (interquartile range 628–1352), median fluoroscopy time of 9.5 min (interquartile range 7.5–15.3), and median procedure time of 28 min (interquartile range 24–33 min) Therapeutic procedure diagnosis were: one ruptured saccular aneurysm, two juvenile nasopharyngeal angiofibromas, and five arteriovenous malformations. The transradial access neurointerventions for pediatric population older than 11 years is safe and feasible, having previous experience in adults. Younger population should be considered on a case-to-case basis, depending on ultrasound measurement of the arterial diameter and the materials available.

Study on prediction of arterio-venous fistula maturation by flow mediated dilatation and AVF blood flow

Background: The physiology and pathology of AVF maturation depends on the vessels characteristics and its ability to remodel. Outcome of AVF using flow mediated dilatation (FMD), AVF blood flow and diameter has been studied. Methodology: Present observational study included single stage AVF (both Radiocephalic and Brachiocephalic) in consecutive CKD five patients ( n = 158) prospectively over 1 year. Demographic and Doppler ultrasound parameters of upper limb (for vessel diameter and FMD) at baseline were recorded. Blood flow, diameter and depth of AVF were studied at 2, 6 and 12 weeks and their association with clinical maturation (usage of fistula with two needles for 75% of dialysis sessions during 15 day period) was studied ( n = 129, after excluding lost to followup and expired patients; accordingly cohort was divided in matured ( M) or non-matured (NM) groups. Clinical and radiological parameters between both groups were compared; receiver operator curve (ROC) and correlation of Doppler parameters were analysed. Results: Of 129 AVF, 67.4% were matured and 32.5% non-matured. Mean age was 40 years with male predominance75% in both the groups. The mean arterial diameter for distal (NM = 1.96 ± 0.58 and M = 2.02 ± 0.41) and proximal AVF (NM = 3.37 ± 0.82 and M = 3.36 ± 0.75) was not statistically different in both the groups. The matured fistula group had a mean FMD of 11.67 ± 4.09 as against FMD value of 9.365 ± 3.55 in the failed fistula group ( p value 0.01). For maturation prediction, sensitivity and specificity of blood flow at 2 weeks were 86.2% and 59.5% and at 6 weeks 96.6% and 64.3%, respectively. In multivariate analysis predictors for AVF maturation were FMD (adjusted odds ratio (AOR) = 1.15) and blood flow (AOR = 1.67). Conclusion: Second and Sixth week AVF blood flow was found to be predicting AVF maturation. Higher baseline FMD correlated with the AVF maturation, but not with vessel diameter.

Outcomes and predictors of failure of arteriovenous fistulae for hemodialysis

Purpose Arteriovenous fistula(AVF) is preferred vascular access for hemodialysis but has primary failure in 20–60%. Studying predictors of AVF failure would help plan appropriate management.We studied AVF outcomes, clinical and vascular factors predicting their failure in patients requiring hemodialysis. Methods Retrospective study of patients with AVF creation from January 2017 to December 2018. Outcomes studied were immediate (< 72 h), primary (3 months) AVF failure, six-month/one-year patency, analyzed for predictive clinical, vascular factors as assessed using Pre-operative Doppler Ultrasound(DUS). Results Of 530 AVFs in 460 patients, DUS was done in 426/530 (80.4%), 349/460 (75.8%) were males, mean age was 53.10 ± 14.54 (18–91), 215/460(46.7%) had Diabetes mellitus(DM), 423/460(92%) hypertension. AVFs were radiocephalic in 79/530 (14.9%), brachiocephalic 418/530 (78.9%), brachiobasilic 33/530 (6.2%). AVF Immediate/Primary failure was seen in 64/530 (12.1%), 90/352 (25.6%); Patency at six months/one year in 253/352(71.8%),191/305 (62.6%), respectively. Older age had less immediate failures (AOR 0.97, CI 0.95–0.99, p 0.03). Feeding arterial diameter predicted immediate and primary failure on univariate analysis [OR 0.64 (95% CI 0.49–0.83), 0.62 (95% CI 0.47–0.89), respectively], but not multivariate. Artery diameter of > 4.0 mm had less failures [immediate (p 0.01), primary (p 0.02)], < 2.0 mm had specificity 95.9% and 95.4% for immediate, primary failure respectively. Conclusion AVF failure is 12.1%, immediately; 25.6% three months after construction, Patency at 6 months is 71.8%, one year 62.6%. Immediate failures decrease with age. Artery diameters > 4.0 mm had less, < 2.0 mm had more failures.

The Use of Fiji Image J as an Image Analysis Tool for Measuring Retinal Vessel Diameter in Rodent Model of Diabetic Retinopathy

The purpose of this study was to evaluate the use of Fiji Image J application for digital fundus image analysis of retinal vessel diameter in diabetic retinopathy rat model. Male Sprague-Dawley rats, weighing 200-250 grams, were divided into two groups: normal and diabetic. The diabetes was induced by intraperitoneal (IP) injection of streptozotocin (STZ, 55 mg/kg body weight). Normal rats received IP citrate buffer. Fundus images were captured at week 0, 6 and 12 post-induction to observe changes in retinal veins and arteries. Images obtained were then analyzed using Fiji Image J software. Retinal venous diameter was increased in both groups at week 6 and 12 compared to baseline (p<0.05). However, no significant differences were seen in the retinal venous diameter at week 12 compared to week 6 in both groups. When comparing between the groups, retinal venous diameter in diabetic group was significantly greater compared to normal group at week 6 and 12 by 1.37- and 1.35-folds (p<0.001), respectively. For the retinal arterial diameter in diabetic group, an increase was observed at week 6 and 12 compared to baseline by 1.17- and 1.2-folds (p<0.05) respectively, however, similar changes were not observed in normal group. There was also no significant difference between the retinal arterial diameter of normal and diabetic group at week 6 and 12. In conclusion, retinal vessels diameter analysis of fundus images using Fiji Image J can be utilized to determine quantitative changes between normal and rats with STZ-induced diabetic retinopathy.

Flow-mediated dilation analysis coupled with nitric oxide transport to enhance the assessment of endothelial function

Flow-mediated dilation (FMD), mainly mediated by nitric oxide (NO), aims to assess the shear-induced endothelial function, which is widely quantified by the relative change in arterial diameter after dilation (FMD%). However, FMD% is affected by individual differences in blood pressure, blood flow and arterial diameter. To reduce these differences and enhance the assessment of FMD to endothelial function, we continuously measured not only the brachial artery diameter and blood flow with ultrasound but also blood pressure with non-invasive monitor during standard FMD test. We further constructed an analytical model of FMD coupled with NO transport, blood flow, and arterial deformation. Combining the time-averaged and peak values of arterial diameter, blood flow and pressure, and the modeling, we assumed the artery was completely healthy and calculated an ideally expected FMD% (eFMD%). Then, we expressed the fractional flow-mediated dilation (FFMD%) for the ratio of measured FMD% (mFMD%) to eFMD%. Furthermore, using the continuous waveforms of arterial diameter, blood flow and pressure, the endothelial characteristic parameter (ϵ) was calculated, which describes the function of the endothelium to produce NO and ranges from 1 to 0 representing the endothelial function from healthiness to complete loss. We found that the mFMD% and eFMD% between the young age (n=5, 21.2±1.8yr) and middle age group (n=5, 34.0±2.1yr) have no significant difference (P=0.222, P=0.385). In contrast, the FFMD% (P=0.008) and ϵ (P=0.007) both show significant differences. Therefore, the fractional flow-mediated dilation (FFMD%) and the endothelial characteristic parameter (ϵ) may have the potential for specifically diagnosing the endothelial function.

Intraoperative variations of the sphenopalatine artery between epistaxis and non-epistaxis cases: a comparative endoscopic analysis

Background Severe epistaxis is one of the most common emergencies in rhinology practices. The commonly used endoscopic cauterization of the sphenopalatine artery (SPA), alone or with the anterior ethmoidal artery (AEA), has a high success rate for controlling severe epistaxis. The current study was conducted to evaluate the endoscopic intra-operative variations of SPA between epistaxis and non-epistaxis cases. Forty consecutive patients who underwent exploration of SPA were included in the study. They were distributed into two groups depending upon the indication of SPA exploration; the epistaxis group (group A, n=25 patients, n=26 sides) and the non-epistaxis group (group B, n=15 patients, n=25 sides). Criteria of the main SPA in the two groups were compared regarding four parameters; arterial diameter, arterial adherence to the mucosa of the lower part of the basal lamella, sphenopalatine nerve bundle, and crista ethmoidalis erosion. Results A significant difference was found regarding the diameter of SPA between the two groups; a mean diameter of 4.2±0.64 mm was compared to 3.2±0.35 mm for group A and B, respectively (p=0.043). Moreover, a highly significant tendency was observed regarding the arterial adherence to the mucosa of the lower part of the basal lamella and sphenopalatine nerve bundle in the epistaxis group; (p≤0.01). Conclusion These data clearly signify the importance of intraoperative identification of SPA criteria during surgical management of severe epistaxis. These criteria may help in altering the surgical decision between solely SPA and concomitant SPA/AEA cauterization.

Analysis for Stroke Etiology in Duplicated/Accessory MCA-Related Cerebral Infarction: Two Case Report and Brief Literature Review

Duplication and accessory of the middle cerebral artery (MCA) constitute a rare congenital variation. MCA anomalies are found at a lesser frequency than the vascular anomalies of the other major intracranial arteries. Duplicated/accessory MCA was usually noted incidentally with subarachnoid hemorrhage, due to resulted aneurysmal formation. However, duplicated/accessory MCA-related cerebral infarction is rarer. We report two cases of cerebral infarction due to dissection at the entry of the duplicate/accessory MCA. Both cases were similar in dissected site and clinical course, without headache or injury. In 20 previously reported cases and our two cases of duplicated/accessory MCA-related infarction, mean age (55.8 ± 21.2 years) was slightly younger for cerebral infarction, and stroke etiology was mainly embolism. The main etiologies of stroke were embolism and dissection. Considering embolism etiology, proximal site of arterial diameter changing lesion was a common site for embolism, as duplicated/accessory MCA was usually smaller than normal M1 segment. In cerebral dissection cases, the dissected site was similar to our cases. Numerous mechanisms of dissection were considered, but they mainly included dysfunction of the media and endothelium or shearing stress at the entry of duplication. As the detailed mechanisms of cerebral dissection remain unknown, clinicians should include a differential diagnosis for MCA dissection.