Bjarnason, Haraldur

AbstractObjectivesTo evaluate the outcomes of transcatheter coronary artery fistula (CAF) closure and to identify anatomic/procedural factors that may impact outcomes.BackgroundDue to the rarity of CAF, reported experience with transcatheter closure remains limited and anatomic and procedural factors that may lead to unsuccessful closure, complications, or recanalization of CAF are unclear.MethodsAll patients who underwent transcatheter CAF closure at Mayo Clinic from 1997 to 2018 were retrospectively reviewed. CAF anatomic characteristics, procedural techniques, and clinical/angiographic outcomes were assessed.ResultsA total of 45 patients underwent transcatheter closure of 56 CAFs. The most commonly used devices were embolization coils in 40 (71.4%) CAFs, vascular occluders in 10 (17.8%), or covered stent in 2 (3.6%). Acute procedural success with no or trivial residual flow occurred in 50 (89.3%) CAFs. Residual flow was small in three (5.4%) and large in three (5.4%). Eight (17.8%) patients had complications, including device migration in three, intracranial hemorrhage from anticoagulation in one, and myocardial infarction (MI) in four. MI was a result of covered stent thrombosis or stagnation of flow after closure of large distal CAF. Twenty‐two patients with 27 CAFs had follow‐up angiography after successful index procedure at median time of 423 (IQ 97‐1348) days. Of these, 23 (85.2%) had no/trace flow and 4 had large flow from recanalization.ConclusionsTranscatheter CAF closure is associated with a favorable acute procedural success and complication rate in selected patients. Procedural success and risk for complication are highly dependent on CAF anatomy and closure technique.

AbstractFibrosing mediastinitis is a rare, often debilitating and potentially lethal disease characterized by an exuberant fibroinflammatory response within the mediastinum. Patients typically present with insidious symptoms related to compression of adjacent structures including the esophagus, heart, airways, and cardiac vessels. Fibrosing mediastinitis is most often triggered by Histoplasmosis infection; however, antifungal and anti‐inflammatory therapies are largely ineffective. While structural interventions aimed at alleviating obstruction can provide significant palliation, surgical interventions are challenging with high mortality and clinical experience with percutaneous interventions is limited. Here, we will review the presentation, natural history, and treatment of fibrosing mediastinitis, placing particular emphasis on catheter‐based therapies.

The authors report on a patient with craniospinal hypovolemia and inferior vena cava obstruction, and describe how the two conditions may be linked. This unique report further advances the emerging literature on spinal CSF venous fistulae.

AbstractBackgroundLow molecular weight heparin (LMWH) is the guideline‐endorsed treatment for cancer‐associated venous thromboembolism (cVTE). Study objectives were to compare the efficacy and safety of rivaroxaban and enoxaparin in cVTE.MethodsUsing a cohort study design, consecutive patients with cVTE (3/1/2013‐7/31/2016), enrolled in the Mayo Thrombophilia Clinic Direct Oral Anticoagulants Registry, were compared to contemporary cancer patients receiving enoxaparin. The cumulative incidence of venous thromboembolism (VTE) recurrence, major and clinically relevant non‐major bleeding, and survival were assessed at 3 and 12 months.ResultsNinety‐eight patients received rivaroxaban (51% female, mean age 63 ± 12 years) and 168 enoxaparin (34.5% female, mean age 62 ± 15 years). The most common cancers included gastrointestinal/pancreatic, genitourinary and hematologic cancers. More than half of patients had pulmonary emboli at presentation. More than half had metastases, and two‐thirds were receiving chemotherapy. At 3 months, there were no differences in VTE recurrence (rivaroxaban 1.0% vs enoxaparin 4.2%; P = .15), major bleeding (rivaroxaban 5.1% vs enoxaparin 3.6%; P = .55), or all‐cause mortality (rivaroxaban 4.1% vs enoxaparin 8.9%; P = .14). At 12 months, these outcomes did not differ by treatment strategy.ConclusionThe results of this “real‐world” experience with cVTE suggest that rivaroxaban may offer a safe and effective alternative to LMWH.

This study examined the potential correlation between pulmonary embolism (PE) attenuation on computed tomography pulmonary angiography (CTPA) and pulmonary artery hemodynamic response to catheter-directed thrombolysis (CDT) in 10 patients with submassive PE. Treatment parameters, PE attenuation, clot burden, computed tomography signs of right ventricle dysfunction and right ventricular systolic pressure at echocardiography were retrospectively analyzed to determine correlation with pulmonary artery pressure improvement using Spearman correlation. A single reader, blinded to the treatment results, measured PE attenuation of all patients. There was a significant positive correlation between PE attenuation and absolute pulmonary artery pressure improvement with a Spearman correlation of 0.741, p=0.014. When attenuation was greater than or equal to the median (44.5 HU, n=5), CDT was associated with significantly better pulmonary artery pressure improvement ( p=0.037). Clot attenuation at CTPA may be a potential imaging biomarker for predicting pulmonary artery pressure improvement after CDT.

Background— Atherosclerotic renal artery stenosis reduces renal blood flow (RBF) and amplifies stenotic kidney hypoxia. Revascularization with percutaneous transluminal renal angioplasty (PTRA) and stenting often fails to recover renal function, possibly because of ischemia/reperfusion injury developing after PTRA. Elamipretide is a mitochondrial-targeted peptide that binds to cardiolipin and stabilizes mitochondrial function. We tested the hypothesis that elamipretide plus PTRA would improve renal function, oxygenation, and RBF in patients with atherosclerotic renal artery stenosis undergoing PTRA. Methods and Results— Inpatient studies were performed in patients with severe atherosclerotic renal artery stenosis scheduled for PTRA. Patients were treated before and during PTRA with elamipretide (0.05 mg/kg per hour intravenous infusion, n=6) or placebo (n=8). Stenotic kidney cortical/medullary perfusion and RBF were measured using contrast-enhanced multidetector CT, and renal oxygenation by 3-T blood oxygen level−dependent magnetic resonance imaging before and 3 months after PTRA. Age and basal glomerular filtration rate did not differ between groups. Blood oxygen level−dependent imaging demonstrated increased fractional hypoxia 24 hours after angiography and stenting in placebo (+47%) versus elamipretide (−6%). These were reverted to baseline 3 months later. Stenotic kidney RBF rose (202±29–262±115 mL/min; P =0.04) 3 months after PTRA in the elamipretide-treated group only. Over 3 months, systolic blood pressure decreased, and estimated glomerular filtration rate increased ( P =0.003) more in the elamipretide group than in the placebo group ( P =0.11). Conclusions— Adjunctive elamipretide during PTRA was associated with attenuated postprocedural hypoxia, increased RBF, and improved kidney function in this pilot trial. These data support a role for targeted mitochondrial protection to minimize procedure-associated ischemic injury and to improve outcomes of revascularization for human atherosclerotic renal artery stenosis. Clinical Trial Registration— URL: https://www.clinicaltrials.gov . Unique identifier: NCT01755858.

Atherosclerotic renovascular disease (RVD) reduces renal blood flow (RBF) and GFR and accelerates poststenotic kidney (STK) tissue injury. Preclinical studies indicate that mesenchymal stem cells (MSCs) can stimulate angiogenesis and modify immune function in experimental RVD. We assessed the safety and efficacy of adding intra-arterial autologous adipose-derived MSCs into STK to standardized medical treatment in human subjects without revascularization. The intervention group ( n =14) received a single infusion of MSC (1.0 × 10 5 or 2.5 × 10 5 cells/kg; n =7 each) plus standardized medical treatment; the medical treatment only group ( n =14) included subjects matched for age, kidney function, and stenosis severity. We measured cortical and medullary volumes, perfusion, and RBF using multidetector computed tomography. We assessed tissue oxygenation by blood oxygen level–dependent MRI and GFR by iothalamate clearance. MSC infusions were well tolerated. Three months after infusion, cortical perfusion and RBF rose in the STK (151.8–185.5 ml/min, P =0.01); contralateral kidney RBF increased (212.7–271.8 ml/min, P =0.01); and STK renal hypoxia (percentage of the whole kidney with R2*>30/s) decreased (12.1% [interquartile range, 3.3%–17.8%] to 6.8% [interquartile range, 1.8%–12.9%], P =0.04). No changes in RBF occurred in medical treatment only subjects. Single-kidney GFR remained stable after MSC but fell in the medical treatment only group (−3% versus −24%, P =0.04). This first-in-man dose-escalation study provides evidence of safety of intra-arterial infusion of autologous MSCs in patients with RVD. MSC infusion without main renal artery revascularization associated with increased renal tissue oxygenation and cortical blood flow.

SummaryThe post thrombotic syndrome is one of the most dreaded complications of proximal deep vein thrombosis. This syndrome leads to pain and suffering with leg swelling, recalcitrant ulceration and venous claudication which greatly impairs mobility and quality of life. The prevalence can be high in patients with iliofemoral venous involvement particularly in the setting of a proximal venous stenosis, such as occurs in May Thurner syndrome. Anticoagulation alone does not reduce the likelihood of this outcome. Compression therapy may be effective but garment discomfort limits its implementation. Pharmacomechanical thrombectomy, which combines catheter‐directed thrombolysis with mechanical thrombus dissolution, provides an attractive treatment strategy for such patients. The rationale and delivery of pharmacomechanical thrombectomy, including patient selection and adjunctive antithrombotic therapy, will be reviewed in addition to tips and tricks for managing difficult patient scenarios.