Onyx™ Cast Fragmentation After Embolization of Endoleaks.

PURPOSE: Endoleaks are common following endovascular aneurysm repair (EVAR), and the liquid embolic material Onyx has been widely used in their treatment. We report our experience of long-term morphological changes of Onyx casts on surveillance imaging. MATERIALS AND METHODS: We identified 10 patients over 10 years who underwent Onyx embolization in our institution. Morphological changes of Onyx casts were assessed on surveillance radiographs and computed tomography (CT) scans. Relevant outcome data and sequelae were obtained via electronic patient records. RESULTS: Twelve procedures were performed on 10 cases, 9 for type 2, and 1 for a type 1a endoleak. Five cases showed evidence of Onyx fragmentation on follow-up imaging ranging from a single fracture to gross fragmentation with migration of fragments. Of these 5, 3 had achieved primary success but 2 went on to develop recurrence of endoleak. Onyx volume ranged from 4 to 46.5 ml (median 10.5 ml) per patient with larger volumes demonstrating the most marked fragmentation on follow-up. Follow-up ranged from 9 months to 8 years (median 2.25 years). CONCLUSION: To our knowledge, this is the first report of Onyx fragmentation after endoleak embolization. If long-term morphological stability of the Onyx cast is necessary to maintain aneurysm seal, then Onyx may not offer a permanent solution to some patients with post-EVAR endoleaks. Our study cannot ascertain whether the observed changes were the cause or the effect of ongoing aneurysm growth, persistent endoleak, and/or other forces acting on the solidified polymer, but it raises important questions on the use of Onyx in this setting.

Endovascular Repair of Type IIIb Endoleak With the Amplatzer Septal Occluder.

PURPOSE: To report the successful treatment of a type IIIb endoleak with an Amplatzer Septal Occluder. CASE REPORT: A 76-year-old man was found to have a type IIIb endoleak in the proximal body component of a fenestrated graft at 4-year surveillance imaging; the leak was associated with rapid aneurysm growth. The anatomy of the graft and position of the fabric defect precluded treatment by relining with a secondary endograft. The defect was demonstrated with catheter angiography, sized with an angioplasty balloon, and repaired using an Amplatzer Septal Occluder. Follow-up imaging at 6 months showed no endoleak and marked reduction in the aneurysm size. CONCLUSION: The Amplatzer Septal Occluder may be considered as an option for managing type IIIb endoleaks.

Prospective, single UK centre, comparative study of the predictive values of contrast-enhanced ultrasound compared to time-resolved CT angiography in the detection and characterisation of endoleaks in high-risk patients undergoing endovascular aneurysm repair surveillance: a protocol.

INTRODUCTION: Diagnosis of endoleaks is imperative to prevent failure of endovascular aneurysm repairs (EVARs). The gold standard for diagnosis of endoleaks is catheter-directed subtraction angiography, which is not a practicable choice for surveillance. CT angiography (CTA) is the historical surveillance modality of choice. Concerns over cost, potential nephrotoxicity of contrast agents and repeated radiation exposure led to colour duplex ultrasound scan (CDUS) becoming an established alternative. CDUS has a lower sensitivity and specificity for endoleaks detection compared to CTA. Contrast-enhanced ultrasound scan (CEUS) represents an improvement of ultrasound imaging but comparisons against CTA report widely varying results, likely due to technical factors of CEUS and limitations of single-phase CTA.The development of time-resolved CTA (tCTA) offers timing information that much more closely mirrors the dynamic information available from CEUS. Theoretically, these two imaging modalities have the best potential for diagnostic accuracy. The aim of this study will be to compare CEUS to tCTA and investigate the utility of other measurements available from tCTA. METHODS AND ANALYSIS: This is a prospective, single UK centre, comparative study of paired binary diagnostic imaging modalities. Patients identified in routine post-EVAR surveillance as at risk of having a graft-related endoleak will undergo a CEUS and tCTA on the same day. This will allow the first comparison of CEUS to a semidynamic form of CTA. CEUS sensitivity and specificity to endoleak detection will be calculated. ETHICS AND DISSEMINATION: The study has achieved ethical approval. We hope the results will define the diagnostic accuracy of CEUS in comparison to a semidynamic form of CTA, representing a methodological improvement from previous studies. Results will be submitted for presentation at national and international vascular surgeryandradiology meetings. The full results are planned to be published in a medical journal. TRIAL REGISTRATION NUMBER: NCT02688751.

Giant faecaloma-a rare cause of life-threatening lower gastrointestinal haemorrhage.

Chronic constipation and faecal impaction are common in the elderly, particularly in institutionalized patients and those with neurological impairment. Faecaloma formation is an extreme manifestation of coprostasis that can lead to stercoral ulcerations and perforation, a recognized severe complication. We present the case of an uncommon life-threatening complication resulting from a giant rectal faecaloma, which has rarely been reported in the literature. The patient presented with haemodynamic shock from profuse per-rectum haemorrhage. Clinical examination revealed a hard central abdominal mass and triple-phase CT of the abdomen demonstrated a tumour-like mass of hard stool in the rectum measuring up to 25 cm and stretching the adjacent vasculature, causing intraluminal active arterial haemorrhage. Emergency selective arterial embolization performed by the interventional radiologists successfully controlled the bleeding with a good outcome. This case highlights a rare but possibly fatal complication of chronic constipation and emphasizes the importance of having access to an acute interventional radiology service capable of promptly dealingwith life-threatening presentations.

A retrospective comparative study of tunneled haemodialysis catheters inserted through occluded or collateral veins versus conventional methods.

Tunneled hemodialysis catheters become essential in dialysis access when there is no possibility of using a functioning arteriovenous fistula. Collateral or occluded veins visible on ultrasound are used for puncture and passage of catheters into the central venous system. Chronically occluded veins are crossed with guidewires to allow dilatation and subsequent passage of hemodialysis catheters. We performed a retrospective analysis of patient demographics, comorbidities, procedural complications, functional survival, performance, and history of previous vascular access. The study group was compared with two control groups in which dialysis catheters were inserted either by radiologists in the interventional suite or by clinicians on the wards. Nineteen patients from the study group were compared with same number of patients in both control groups. The mean age of the study group was higher compared with the control groups. There was no significant difference in mean functional survival, infection rates, dialysis pump speeds in the first 2 weeks, and procedural complications between the study group and the controls. The study group had a significantly higher number of previous vascular access interventions, longer dialysis careers, and more comorbidities. Tunneled dialysis catheter placement by way of collateral or occluded veins appears safe and effective. These techniques give the operator further options when faced with patients possessing challenging vascular access. Indeed, there may be a case for preferential use of these veins to keep patent central veins in reserve.