Joshua D. Dowell

Surgical and endovascular treatment of hepatic arterial complications following liver transplant.

Vascular complications after liver transplantation increase post‐operative morbidity and contribute to the incidence of retransplantation. Vascular complications comprise arterial, caval, and portal venous pathology, with the majority of complications being arterial in etiology, including anastomotic stricture, pseudoaneurysm, and thrombosis. There are two major therapeutic options for the treatment of these arterial complications: endovascular intervention and surgery. The former includes intra‐arterial thrombolysis, embolization, percutaneous transluminal angioplasty, and stent placement. The latter includes thrombectomy, reanastomosis, and retransplantation. Although surgical treatment has been considered the first choice for management in the past, advances in endovascular intervention have increased and make it a viable therapeutic option following orthotopic liver transplantation. This review focuses on the role of surgical and endovascular therapy in the management of hepatic arterial complications after liver transplantation.

Celect Inferior Vena Cava Wall Strut Perforation Begets Additional Strut Perforation

PURPOSE To identify risk factors for strut perforation following Celect inferior vena cava (IVC) filter (IVCF) placement and to use finite element modeling to predict the mechanical impact of long-dwelling filters. MATERIALS AND METHODS Ninety-one patients with three computed tomography (CT) studies were evaluated following Celect IVCF placement (2007-2013). Three-dimensional finite element models of the Celect IVCF were developed to simulate mechanical deformation of the IVCF encountered in vivo. Simulated forces applied by the primary struts on the IVC wall were measured as a function of luminal area and tilt angle. RESULTS Although 33 patients (36%) showed primary strut perforation on initial follow-up CT, 60 patients (66%) showed progressive perforation over time (P < .0001), with 72 patients (79%) showing primary strut perforation on the final CT (average, 554 d). Female patients (P = .004) and those with malignancy history (P = .01) had significantly higher perforation rates at a given time. Caval area also decreased after primary filter strut perforation, and we therefore proposed that this was the mechanism for progressive perforation. Consistent with this mechanism, three-dimensional finite element modeling demonstrated increasing strut force with decreasing IVC diameter. CONCLUSIONS Celect IVCF primary strut perforation is progressive over time and is more common in female patients and those with a history of malignancy. In addition, this progressive perforation may be predicted by three-dimensional finite element modeling. These patient populations may require closer follow-up after IVCF placement to prevent or reduce the risk for filter complication or worsening perforation.

A Systematic Review of Acquired Uterine Arteriovenous Malformations: Pathophysiology, Diagnosis, and Transcatheter Treatment

Objective An acquired uterine arteriovenous malformation (AVM) is a rare cause of vaginal bleeding and, although hysterectomy is the definitive therapy, transcatheter embolization (TCE) provides an alternative treatment option. This systematic review presents the indications, technique, and outcomes for transcatheter treatment of the acquired uterine AVMs. Study Design Literature databases were searched from 2003 to 2013 for eligible clinical studies, including the patient characteristics, procedural indication, results, complications, as well as descriptions on laterality and embolic agents utilized. Results A total of 40 studies were included comprising of 54 patients (average age of 33.4 years). TCE had a primary success rate with symptomatic control of 61% (31 patients) and secondary success rate of 91% after repeated embolization. When combined with medical therapy, symptom resolution was noted in 48 (85%) patients without more invasive surgical procedures. Conclusion Low-level evidence supports the role of TCE, including in the event of persistent bleeding following initial embolization, for the treatment of acquired uterine AVMs. The variety of embolic agents and laterality of approach delineate the importance of refining procedural protocols in the treatment of the acquired uterine AVM. Condensation A review on the management of patients with acquired uterine AVMs.

Quantification of aortic stiffness using magnetic resonance elastography: Measurement reproducibility, pulse wave velocity comparison, changes over cardiac cycle, and relationship with age.

To assess MR elastography (MRE)‐derived aortic shear stiffness (μMRE) measurements for: 1) reproducibility, 2) comparison to pulse wave velocity, 3) changes over the cardiac cycle, and 4) relationship with age.

Symptomatic Perforation of a Gunther Tulip Inferior Vena Cava Filter With Subsequent Strut Fracture and Pulmonary Embolization

Long-dwelling retrievable inferior vena cava filters (IVCFs) are associated with adverse events, including migration, thrombosis, penetration, fracture, and embolization. Despite the safety and efficacy profile of the Gunther Tulip (GT) retrievable IVCF (Cook Medical Inc, Bloomington, IN), long-dwelling GT IVCFs are at risk for migration and penetration [1, 2]. We present a case of symptomatic perforation of a GT IVCF with subsequent pulmonary embolization of a main strut fracture fragment 10 years after placement. These findings further contribute to our understanding of the risks associated with the ‘‘permanent’’ placement of GT retrievable filters.

Design-of-Experiments Approach to Improving Inferior Vena Cava Filter Retrieval Rates

PURPOSE The association of retrievable inferior vena cava filters (IVCFs) with adverse events has led to increased interest in prompt retrieval, particularly in younger patients given the progressive nature of these complications over time. This study takes a design-of-experiments (DOE) approach to investigate methods to best improve filter retrieval rates, with a particular focus on younger (<60 years) patients. METHODS A DOE approach was executed in which combinations of variables were tested to best improve retrieval rates. The impact of a virtual IVCF clinic, primary care physician (PCP) letters, and discharge instructions was investigated. The decision for filter retrieval in group 1 was determined solely by the referring physician. Group 2 included those patients prospectively followed in an IVCF virtual clinic in which filter retrieval was coordinated by the interventional radiologist when clinically appropriate. In group 3, in addition to being followed through the IVCF clinic, each patients PCP was faxed a follow-up letter, and information regarding IVCF retrieval was added to the patients discharge instructions. RESULTS A total of 10 IVCFs (8.4%) were retrieved among 119 retrievable IVCFs placed in group 1. Implementation of the IVCF clinic in group 2 significantly improved the retrieval rate to 25.3% (23 of 91 retrievable IVCFs placed, P < .05). The addition of discharge instructions and PCP letters to the virtual clinic (group 3) resulted in a retrieval rate of 33.3% (17 of 51). The retrieval rates demonstrated more pronounced improvement when examining only younger patients, with retrieval rates of 11.3% (7 of 62), 29.5% (13 of 44, P < .05), and 45.2% (14 of 31) for groups 1, 2, and 3, respectively. CONCLUSIONS DOE methodology is not routinely executed in health care, but it is an effective approach to evaluating clinical practice behavior and patient quality measures. In this study, implementation of the combination of a virtual clinic, PCP letters, and discharge instructions improved retrieval rates compared with a virtual clinic alone. Quality improvement strategies such as these that augment patient and referring physician knowledge on interventional radiologic procedures may ultimately improve patient safety and personalized care.

Conventional versus Drug-Eluting Bead Transarterial Chemoembolization for Neuroendocrine Tumor Liver Metastases

PURPOSE To compare outcomes of conventional transarterial chemoembolization with drug-eluting bead (DEB) chemoembolization for treatment of neuroendocrine tumor liver metastases. MATERIALS AND METHODS This single-center, retrospective study evaluated 177 transarterial chemoembolization treatments (78 conventional chemoembolization treatments using ethiodized oil-based cisplatin, mitomycin C, and doxorubicin and 99 DEB chemoembolization treatments using doxorubicin-loaded 100-300 μm DEBs) from 2012 to 2015. Hepatic disease distribution was 93% bilobar for both groups with largest lesion size 5.0 cm ± 2.7. No difference was noted in regard to lesion size or distribution, carcinoid syndrome, or pancreastatin production. Clinical outcomes including complications; liver function tests (LFTs); and radiologic (modified Response Evaluation Criteria in Solid Tumors), biochemical (pancreastatin levels), and symptomatic responses were evaluated at 1-month follow-up. RESULTS Higher symptomatic response (complete and partial) was identified with conventional transarterial chemoembolization compared with DEB chemoembolization (47% vs 30%; P < .05). Patients receiving DEB transarterial chemoembolization experienced lower elevation of LFTs (aspartate aminotransferase, 39 U/L vs 122 U/L; alanine aminotransferase, 20 U/L vs 93 U/L; bilirubin, 0.001 mg/dL vs 0.123 mg/dL; P < .05) and less postembolization syndrome (50% vs 67%; P < .05). Patients undergoing first-time DEB transarterial chemoembolization had lower periprocedural octreotide maximum rate requirements (58 μg/h vs 66 μg/h; P < .05). No difference was observed in biochemical (P = .60) or radiologic (P < .20) responses. CONCLUSIONS Conventional transarterial chemoembolization yields better symptomatic response and may be preferred for patients experiencing carcinoid symptoms. DEB transarterial chemoembolization, with lower LFT elevations and postembolization syndrome incidence, may be preferred for patients with poor liver function.

Cost-benefit analysis of establishing an inferior vena cava filter clinic

PURPOSE Adverse events associated with retrievable inferior vena cava filters (IVCFs) have generated an increased interest in improving IVCF retrieval rates to improve patient safety and quality care. This study aims to demonstrate the cost-benefit of implementing an IVCF clinic to improve patient care in an institution in the United States. METHODS An IVCF clinic was established at a single institution in September 2012 and for ten months referring physicians were contacted to facilitate retrieval when appropriate. Additionally, a retrospective review was conducted on filter placements over the eight preclinic months. Cost-benefit analysis was conducted by creating a model, which incorporated the average cost and reimbursement for permanent and retrievable IVCFs. RESULTS A total of 190 IVCFs (152 retrievable IVCFs and 38 permanent IVCFs) were implanted during the IVCF clinic period. Twenty-nine percent of the retrievable IVCFs were successfully retrieved compared to 10 of 119 retrievable IVCFs placed during the preclinic period (8.4%). Cost-benefit analysis, using the average of the institutions six most common reimbursement schedules, demonstrated an average net financial loss per permanent or retrievable IVCF not removed. However, a net financial gain was realized for each retrievable IVCF removed. The additional hospital cost to maintain the IVCF clinic was offset by removing an additional 3.1 IVCFs per year. CONCLUSION An IVCF clinic significantly increases retrieval rates, promotes patient safety, and is economically feasible. Given the adverse event profile of retrievable IVCFs, strategic efforts such as these ultimately can improve quality care for patients with in-dwelling IVCFs.

Etiology and treatment of acute inferior vena cava thrombosis

Inferior vena cava thrombosis (IVCT) is a rare but severe disease that is associated with a high rate of mortality. IVCT can be categorized into primary versus secondary thrombosis dependent upon the underlying pathophysiology. The diagnosis includes both clinical probability assessment as well as the imaging evaluation. The optimal therapeutic strategy remains the target of continued research. Although anticoagulation therapy remains fundamental in treating IVCT, its inherent limitations have led to the use of minimally invasive, endovascular treatment options, including transcatheter thrombolysis, mechanical thrombectomy or a combination of these techniques. This review focuses on the etiology, diagnostic assessment, and endovascular treatment options for IVCT.

Ureteroarterial fistula following retrograde ureteral stenting in a patient with a double-barreled wet colostomy for cervical cancer

Highlights • Ureteroarterial fistula (UAF) is a rare cause of massive hematuria.• Percutaneous retrograde ureteral stents via DBWC can be done safely in the compliant patient for improved comfort.• Understanding the anatomy, risks, and minimally invasive treatment options for UAF is important for prompt patient care.