Negative renal angiography with subsequent denied angioembolization: findings in a series of 180 patients at a tertiary interventional uroradiology unit

Background Renal arterial embolization (RAE) is considered to be a safe and effective method for treating a variety of renal lesions and pathology. It is the optimal method not only to stop bleeding, but to preserve renal parenchyma and renal function. Patients who are scheduled to RAE who showed negative catheter angiography with the procedure subsequently denied have a special concern because they are subjected to unnecessary procedure with its complications and didn’t get its benefits. This circumstance is infrequently reported in the literature, and that compelled us to identify the predictors of negative renal angiography findings that would result in a failure to undertake RAE. Results The study included 180 patients (126 males; 70%) with a mean ± SD age of 44 ± 14 years. Iatrogenic causes were the most common indication for RAE (108 of 180; 60%), while spontaneous unknown reasons constituted (17 of 180 patients; 9%). Angiography showed various lesions in 148 patients: pseudoaneurysm (80 of 148; 54%), tumours (28 of 148; 19%), arteriovenous (AV) fistulas (22 of 148; 15%) and both pseudoaneurysm and AV fistulas (18 of 148; 12%). However, in the remaining 32 of 180 patients (18%) no lesions were identified on renal angiography and RAE procedures were not undertaken. On bivariate analysis, neither gender, side of the lesions, haematuria prior to RAE, or renal artery anatomy were predictors for negative angiography. However, the indication for RAE (spontaneous unknown reasons) of renal haemorrhage was the only predictor for negative angiography (9/17 (53%), P = 0.001). Conclusion Patients scheduled for RAE may show negative findings with no lesions on renal angiography. Among the different indications for RAE, patients with spontaneous (unknown) have the highest probability (53%) of being associated with negative renal angiography findings, however, those with renal tumours and post-traumatic causes have a low probability. In those patients with spontaneous (unknown), conservative management should be the initial treatment of choice in order to avoid unnecessary RAE and its associated complications.

Flow volume measured by duplex ultrasound in native arteriovenous fistula for hemodialysis: a case report

Background : Native arteriovenous fistula (AVF) is the vascular access of choice for hemodialysis patients. AVF lasts longer than artificial grafts or central venous catheters. In addition, AVF has fewer complications than other vascular accesses. The use of Doppler ultrasound is used to facilitate fistula construction (vascular mapping) including AVF maturation to see if AVF can be used. Doppler ultrasound monitoring for maturation of AV fistulas should be monitored sonographically until the fistula is ready for use, especially when maturation is slow and in patients whose veins cannot easily be assessed by physical examination alone (eg because of obesity). The AVF DUS flow volume measurement may be the only imaging tool that can be used to monitor a fistula even during its maturation. Even so, DUS should always be done before AVF is used for the first time. This examination provides baseline data on vascular access, which can be useful in subsequent tests performed to evaluate functional problems. Case report : A man, 52 years old who has done AV Fitula two weeks ago. Currently patients are using a double lumen catheter (CDL) for routine hemodialysis. One day the patient had his CDL removed. Even though the patient feels thrill in the AV fistula, the nephrorologist still doubts whether the AV fistula is ripe and can be used. For this reason, a Duplex Ultrasound is performed to assess the diameter, velocity flow, PSV and TAMV .By positioning the sample volume in the presumed stenosis site, the Doppler velocity test detects a systolic peak velocity. Conclusion: Color flow Doppler imaging should be used as a tool to screen for areas of high velocity and to aid in the optimal placement of the pulsed Doppler sample volume. The pulsed Doppler sample volume should be set at the smallest size possible to detect discrete changes in blood flow meanwhile doppler ultrasound should be use in monitoring for maturation of AV fistulas

12-lead ECG artefacts in patients with AV fistulas for haemodialysis

We report on electrocardiographic arterial tapping pseudo-artifacts due to arterio-venous fistulas. ST segment are not organized in any distribution. They don’t affect all peripheral electrodes and can be diagnosed by changing electrodes positioning.

Artery of Davidoff and Schechter: A Large Angiographic Case Series of Dural AV Fistulas

The artery of Davidoff and Schechter (ADS) is the only meningeal branch of the posterior cerebral artery (PCA), supplying the medial tentorial margin and posterior portions of the falx. Given its small size, it is rarely identified on angiographic studies, unless enlarged in pathologies such as dural arteriovenous fistulas (DAVFs) or vascularized masses. This artery was first described by Wollschlaeger and Wollschlaeger in 1965, and to date, only a few reports have described its significance. The objective of this study is to report our experience with the ADS in dural fistulas from 2 tertiary medical centers and to emphasize the importance of recognizing this artery during angiographic examination of vascular tentorial and posterior fossa lesions. To our knowledge, this report demonstrates the largest angiographic case series published to date, recognizing a total of 7 patients with ADS arising secondary to a posterior fossa or tentorial DAVF and one of the largest reported series of DAVFs supplied by the ADS treated by endovascular and surgical techniques. Our cases validate the importance of prompt identification of the ADS for the diagnosis as well as endovascular treatment of vascular malformations in the posterior fossa and tentorial region.

Entrapment of fractured balloon after angioplasty in an AV access using a covered stent

Fracture of the angioplasty balloon is a known complication during endovascular procedures in arteriovenous (AV) fistulas and grafts. We describe a case of a patient with end-stage renal disease (ESRD) on dialysis with a brachiocephalic AV fistula that had become dysfunctional. After a percutaneous angioplasty procedure during balloon withdrawal, a portion of the balloon fractured and separated due to the balloon being caught in the struts of a previously placed bare metal stent. A covered stent was used to contain the segment of the fractured balloon to the wall of the fistula. The use of a covered stent in jailing the fractured balloon to prevent further complications is not well described. This strategy may be implemented in some circumstances such as this case to avoid surgical interventions.

Delayed presentation of a traumatic scalp arteriovenous fistula

Background: Arteriovenous (AV) fistulas of the scalp are extracranial vascular malformations commonly caused by trauma and typically present within 3 years. Although they follow a benign course, they can be esthetically displeasing. Case Description: We present an atypical onset of scalp AV fistula in a patient with a 1-year history of the left-sided pulsatile tinnitus and scalp swelling 7 years after a traumatic epidural hematoma evacuation. Our patient was found to have an 8 mm AV fistula supplied by the deep temporal artery. Endovascular embolization was performed using eight coils. There was no complication from the procedure, and the patient’s pulsatile tinnitus and swelling resolved immediately after embolization. Follow-up angiogram demonstrated complete obliteration of the AV fistula. Conclusion: Delayed presentation of traumatic scalp AV fistula is very rare, and it is important to keep this in the differential in patients with scalp swelling after head trauma.

Results of first stage brachiobasilic and brachiobrachial fistula creation: Implications for staged versus single procedure decision making

Introduction: Transposed brachiobasilic AV fistulas (BVT) have increasingly been performed in two stages. Published reports give conflicting results, perhaps in part as many reports of staged procedures eliminate those patients who “fail” the first stage (i.e. are lost to follow-up in addition to anatomic failure). Methods: A prospectively maintained database was reviewed to identify all patients at two institutions who underwent the first stage of planned two-stage BVT by the senior author. Success in this context was defined as patients who eventually underwent second stage fistula creation, leaving the operating room after the second stage with a patent, transposed fistula. Results: From October 2012 to June 2020, 218 patients underwent first-stage procedures. At the first visit, 185 (85%) of fistulas were patent, 23 (11%) were occluded, 8 (4%) of patients were lost to follow-up, and 2 (1%) died. In the interval before the second operation, another eight (4%) patients were lost to follow-up, two were cancelled for medical reasons, and two declined surgery, leaving a total of 173 patients who made it to the second stage (80%). At operation, four patients were found to have unusable veins, leaving a total of 169 patients who completed both stages. If all patients who underwent first stage are included, 77% of patients entering this pathway left the OR after their second stage with patent access. If those lost to follow-up are excluded, this number increases to 84%, while if all those lost to follow-up are assumed to mature, success increases to 85%. Conclusions: Depending on results in patients lost to follow-up, between 77% and 85% of patients undergoing first stage brachiobasilic fistulae undergo successful second stage transposition. These numbers are equivalent or slightly lower than published maturation rates for single-stage BVT, so there is little margin for failure at the second stage.

Impact of a trained vascular access coordinator on a vascular access program in India

Background: Native AV fistulas are the ideal access for hemodialysis but require monitoring and multiple interventions in some patients to keep them functioning. The aim of the study was to assess the impact of the appointment of a trained vascular access coordinator (VAC) for fistula monitoring, on the evolution of the vascular access program at our institute. Method: Data was retrieved from the departmental database for the baseline year 2014 and compared with the data from 2018. Initial review showed that appointment of the VAC in 2015 resulted in a steady increase in the number of AV fistula interventions over 2 years to a plateau in 2018 which was chosen as the comparison year. The number of AVF’s created, number of salvage procedures performed, and follow-up data were compared. Other parameters like number of operation theatre hours, surgeons, and nursing staff remained constant during this period. Result: Total numbers of AVFs increased from 511 to 713 (39.3%). The number of follow-up visits to surgeons reduced from an average of 4–0.25 visits per patient during this period. Follow up Doppler examinations increased from 761 to 1296 (70%) indicating improved follow up. The salvage procedures increased from 44 to 161 (272%) with early detection of fistula dysfunction. Primary and secondary patency rates of 86% and 92% at 3 months could be achieved whereas limited follow-up data was available for 2014. Conclusion: Appointment of trained VAC increased the number of vascular access procedures, improved follow-up care, and led to early detection and intervention for access dysfunction while reducing the workload of surgeons.

Complications of Endovascular Treatment of Intracranial Dural Arteriovenous Fistulas

Aims: To report the endovascular treatment and complications of intracranial and spinal dural arteriovenous (AV) fistulas. Methods: A retrospective analysis of 863 cases with dural AV fistulas was completed in the nationwide registry study of the Japanese Society of Neuroendovascular Therapy. Results: Treatments included transarterial/transvenous embolization (TAE/TVE), open surgery, stereotactic radiation, and their combinations. Modified Rankin Scale 0 (mRS-0) of the patients before and after treatment were 21% and 68%, and mRS 0-1were 69% and 86%, respectively. Mortality rate after treatment was 0.6%. Major complications of TAE and TVE were cranial nerve palsy and cerebral infarction. Conclusions: Major complications resulted from occlusion of vasa nervosum and material migration via dangerous intracranial and extracranial arterial anastomosis.

Spinal epidural arteriovenous fistula embolization with ethylene vinyl alcohol (EVOH) copolymer using the Scepter Mini dual-lumen balloon

Left unattended, spinal epidural arteriovenous fistulas (EAVFs) have a potentially severe clinical course. Embolization using ethylene vinyl alcohol (EVOH) copolymers through regular dual-lumen balloons has emerged as a potential option for the treatment of spinal arteriovenous (AV) fistulas;1–3 the main issue with this technique is the navigability of these balloons. The Scepter Mini is a low-profile, dual-lumen balloon, which may be helpful for EVOH embolization of spinal AV fistulas, as it may help to overcome the navigation drawbacks. In this technical video, we present a case of EVOH embolization of a right T6 spinal EAVF through a Scepter Mini balloon. Of note, particular attention should be paid to radiculomedullary arteries arising at the same level or at adjacent levels to avoid severe neurologic complications related to uncontrolled migration of the liquid embolic agent. Moreover, excessive use of embolic material should be avoided to prevent spinal cord compression (video 1).Video 1