Is Size All That Matters? New Predictors of Complications and Bleeding in Renal Angiomyolipoma.

Purpose: Renal angiomyolipoma (AML) is the most common benign renal tumor. Whilst generally asymptomatic, they can cause life-threatening bleeding. Selective angioembolization (SAE) may be used to treat large symptomatic and asymptomatic AMLs. We aimed to evaluate the efficacy of SAE for symptomatic and asymptomatic renal AMLs and determine characteristics that predict spontaneous bleeding. Patients and Methods: Data were retrospectively collected from a prospectively maintained database from July 2011 to April 2022. Patients were included if AML was >4cm and they underwent subsequent SAE. Follow-up imaging was analyzed to calculate mean reduction in AML size. Clinical notes were reviewed to analyze lesion characteristics including vascularity, fat content and presence of aneurysm as well as post-procedural complications. Results: 26 patients with 30 AMLs were identified. Interval of follow-up imaging ranged from 1 to 60 months. 25 AMLs were embolized electively with 5 emergency embolizations performed for bleeding. Mean reduction in AML volume was 41% at 3 months (p=0.013) and 63% at 12 months (p=0.007). All 5 bleeding AMLs had a rich vascularity with 60% also having either aneurysms or a low fat content. Complications included post-embolic syndrome (n=9), segmental renal parenchyma devascularization (n=3), acute bleeding requiring re-embolization (n=2), nephrectomy for ongoing bleeding (n=1) and delayed bleeding managed conservatively (n=1). No deterioration in renal function was observed. Conclusion: SAE is an effective procedure for managing symptomatic and asymptomatic renal AML, with minimal significant complications. AML vascularity, fat content and aneurysms may be useful characteristics to assess future risk of bleeding in patients with renal AML.

Endovascular management of recurrent hemarthrosis of the knee: a case series.

BACKGROUND: Recurrent hemarthrosis of the knee is an uncommon but potentially debilitating occurrence with multiple etiologies, including previous total knee replacement. The purpose of this study is to present data of a group of patients undergoing angiography and embolization for recurrent hemarthrosis of the knee. Patient characteristics, angiographic findings, safety and efficacy of the procedure are reported. METHODS: A retrospective single centre review of patients undergoing angiography and embolization at a tertiary referral centre in Sydney, Australia from March 2006 to April 2018 was performed. A total of 25 patients undergoing a total of 29 procedures were identified (20 female, 5 male; mean age 67), the majority of which (23/25, 92%) had a history of total knee arthroplasty. Embolization was performed in 28 of the 29 procedures (97%). The embolic agent used was either polyvinyl alcohol particles (23/28), gelatin foam (3/28), detachable microcoils (1/28) or a combination of particles and coils (1/28). RESULTS: The most commonly identified dominant vascular abnormality was periarticular synovial hypervascularity (23/25, 92%). A pseudoaneurysm was demonstrated in two patients (8%). Technical success (elimination of angiographic abnormalities) was achieved in 27 of 29 procedures (93%). There were 6 episodes of recurrence (25%) following a single embolization procedure, three of which were managed successfully with repeat embolization. There were no complications relating to skin or periarticular ischemia. CONCLUSION: Angiography and embolization is a safe and effective tool for the management of recurrent hemarthrosis of the knee following arthroplasty and should be considered first line treatment following failure of conservative management. LEVEL OF EVIDENCE: Level 4, Case Series.

Establishing a Platform for Interest and Education in Interventional Radiology Amongst Radiology Trainees.

PURPOSE: Over recent times, procedural Radiologists have begun to establish themselves as the distinct subspecialty of Interventional Radiology (IR). The Interventional Radiology Society of Australasia (IRSA) was established in 1982 to share collaborative ideas, encourage research, and promote education. IRSA developed a weekend registrar workshop attended by Radiology Registrars from Australia and New Zealand. In the 2018 event, we surveyed the Registrars to identify their interest in IR training before and after the workshop. MATERIALS AND METHODS: The event was held over a weekend and consisted of both lectures and hands-on workshops. A survey was handed to all 67 registrants of the workshop and there was a 55% response rate including 78% of females in attendance. RESULTS: Before the workshop, trainees rated their interest in IR training at a mean of 3.7 out of 5. After the workshop, trainees rated their interest in IR training as an average of 4.4 out of 5 (p < 0.001). The difference in interest between males and females before the workshop (4.0 vs. 3.1) was significant (p = 0.003), however after the workshop (4.5 vs. 4.1) was not significant (p = 0.07). The change in interest from attending the workshop was significant between genders, p = 0.03 (male interest increased mean 0.5, female increased mean 1.0). CONCLUSION: We show that a program of lectures and workshops designed to generate interest in IR leads to a significant increase in training interest, particularly amongst females. Other subspecialty groups should consider this type of intervention and promote ongoing education and inspiration. LEVEL OF EVIDENCE: Cross-sectional study, Level IV.

Challenges in chemotherapy delivery: comparison of standard chemotherapy delivery to locoregional vascular mass fluid transfer.

Standard intravenous chemotherapy delivery to neoplasms relies on simple diffusion gradients from the intravascular to the interstitial space. Systemic perfusion creates untoward effects on normal tissue limiting both concentration and exposure times. Regional intra-arterial therapy is limited by drug recirculation and vascular isolation repeatability and does not address the interstitial microenvironment. Barriers to delivery relate to chaotic vascular architecture, heterogeneous fluid flux, increased interstitial and variable solid tumor pressure and ischemia. To address these difficulties, a delivery system was developed allowing mass fluid transfer of chemotherapeutic agents into the interstitium. This implantable, reusable system is comprised of multiple independently steerable balloons and catheters capable of controlling the locoregional hydraulic and oncotic forces across the vascular endothelium.

Safety and Feasibility of Repeatable Hepatic Vascular Isolation Chemotherapy: A Pilot Study.

BACKGROUND: The authors herein describe a novel method of repeatable hepatic isolation using an implantable access system allowing simultaneous control of hepatic arterial and portal flows by multiple endovascular catheters. PURPOSE: The aim of this study was to assess the feasibility and safety of the system and to compress standard intravenous chemotherapy into 4 weeks of targeted intra-arterial delivery. METHODS: An arterial access system was implanted to the axillary artery via an anastomosis. Infusions of oxaliplatin were performed biweekly for 4 weeks, using balloon catheters to achieve hepatic isolation and segmental selectivity for 20-25 min. Fifty-seven treatments under general anesthetic were performed in ten patients with inoperable chemotherapy-refractory metastatic colorectal cancer. Systemic, intrahepatic, and hepatic venous pressures were recorded to assess vascular isolation, and platinum levels were measured to assess chemotherapy distribution. RESULTS: Pressure verified, multiple day-only hepatic vascular isolation infusions were achieved in nine of ten patients, with a single patient receiving multiple hepatic arterial infusions. Positron emission tomography-computed tomography (PET-CT) imaging confirmed partial response in three of ten patients and stable disease in three of ten patients. Systemic toxicity was minimal as all treatment-related gastrointestinal and neuropathic symptoms reported throughout the 4 weeks were grades 1-2. CONCLUSIONS: Intra-arterial chemotherapy infusions with hepatic vascular isolation can be achieved repeatedly with targeted selectivity and minimal complications using an implantable multicatheter access system. Oxaliplatin infusions over a 4-week period may achieve tumor response in selected patients in the salvage setting. The technique should be further assessed in a phase Ib/II study.

Novel Treatment of an Enlarging Internal Iliac Artery Aneurysm in Association with a Type 2 Endoleak via Percutaneous Embolisation of the Superior Gluteal Artery through a Posterior Approach.

Internal iliac artery (IIA) aneurysms, while rare, carry a significant risk of mortality if they rupture. Endovascular intervention is now the preferred method of treatment for IIAs; however, due to technical considerations, this is not always feasible. We report a case of a patient who developed an enlarging IIA aneurysm in association with a type 2 endoleak supplied by multiple feeding arteries where conventional endovascular treatment was not possible. A novel method of effectively treating the IIA aneurysm with a posterior approach via image-guided puncture of the superior gluteal artery was employed. Five arteries supplying the superior gluteal from the contralateral internal iliac artery were selectively catheterised and coiled before the aneurysmal sac was embolised. The patient made an uneventful recovery, and follow-up imaging demonstrated resolution of the endoleak and decompression of the aneurysmal sac. This case demonstrates that the posterior approach is a safe and viable method of treating internal iliac artery aneurysm when traditional endovascular approaches are technically possible.

Entrapment neuropathy of the ulnar nerve by a constriction band: the role of MRI.

The diagnosis of ulnar nerve entrapment at the elbow has relied primarily on clinical and electrodiagnostic findings. Magnetic resonance imaging (MRI) has been used in the evaluation of peripheral nerve entrapment disorders to document signal and configurational changes in nerves. In this case report we review the MRI and operative findings of a rare constriction band causing ulnar nerve compression at the elbow. We review the sensitivity and specificity in diagnosing ulnar nerve entrapment at the elbow as defined by MRI findings.