Comparing Patency Rates of Arteriovenous Dialysis Access following Percutaneous Thrombectomy Using Various Catheter Directed Therapies.

BACKGROUND: Arteriovenous fistulas often require frequent interventions to maintain patency for hemodialysis. Interventions may include open or percutaneous thrombectomy with additional targeted interventions as indicated. We evaluated the primary and cumulative functional patency rates following three unique approaches to percutaneous thrombectomy of thrombosed dialysis access. METHODS: A retrospective review of 236 unique patients who presented with thrombosed hemodialysis access was analyzed over a period of 4 years from 2016 to 2020. We analyzed a total of 413 procedures that utilized 3 separate percutaneous thrombectomy devices to assist with restoring patency. The Indigo System CAT-D Aspiration Thrombectomy Catheter (Penumbra; Alameda, CA), the Arrow-Trerotola Rotational Thrombectomy System (Teleflex; Wayne, PA) and the Angiojet Rheolytic Thrombectomy Catheter (Boston Scientific, Marlborough, MA) devices were compared for primary and cumulative functional patency. Primary patency was defined as time from percutaneous thrombectomy to next intervention (Angioplasty, stenting, and repeat thrombectomy). Cumulative functional patency was defined as time from percutaneous thrombectomy to time of access abandonment. Medical record chart review was utilized to determine patency rates. RESULTS: A total of 413 percutaneous thrombectomy procedures were performed. Of the procedures performed, 98 utilized Angiojet, 103 utilized Trerotola, and 212 used Penumbra. The mean primary patency rates in (days) for the devices were as follows: Angiojet (194), Trerotola (204), and Penumbra (107). The mean cumulative functional patency rates (in days) for the devices were as follows: rheolytic thrombectomy (450 days), aspiration thrombectomy (292 days), and rotational thrombectomy (475 days). Angiojet versus Penumbra and Trerotola versus Penumbra both showed diminished patency rates when using the Penumbra catheter that were statistically significant (P < 0.05). CONCLUSIONS: All percutaneous thrombectomy approaches do not result in the same primary or cumulative functional patency rates. Approaches with Trerotola and Angiojet resulted in improved primary and cumulative functional patency rates compared to those using Penumbra.

Liposomal Nanocarriers Designed for Sub-Endothelial Matrix Targeting under Vascular Flow Conditions.

Vascular interventions result in the disruption of the tunica intima and the exposure of sub-endothelial matrix proteins. Nanoparticles designed to bind to these exposed matrices could provide targeted drug delivery systems aimed at inhibiting dysfunctional vascular remodeling and improving intervention outcomes. Here, we present the progress in the development of targeted liposomal nanocarriers designed for preferential collagen IV binding under simulated static vascular flow conditions. PEGylated liposomes (PLPs), previously established as effective delivery systems in vascular cells types, served as non-targeting controls. Collagen-targeting liposomes (CT-PLPs) were formed by conjugating established collagen-binding peptides to modified lipid heads via click chemistry (CTL), and inserting them at varying mol% either at the time of PLP assembly or via micellar transfer. All groups included fluorescently labeled lipid species for imaging and quantification. Liposomes were exposed to collagen IV matrices statically or via hemodynamic flow, and binding was measured via fluorometric analyses. CT-PLPs formed with 5 mol% CTL at the time of assembly demonstrated the highest binding affinity to collagen IV under static conditions, while maintaining a nanoparticle characterization profile of ~50 nm size and a homogeneity polydispersity index (PDI) of ~0.2 favorable for clinical translation. When liposomes were exposed to collagen matrices within a pressurized flow system, empirically defined CT-PLPs demonstrated significant binding at shear stresses mimetic of physiological through pathological conditions in both the venous and arterial architectures. Furthermore, when human saphenous vein explants were perfused with liposomes within a closed bioreactor system, CT-PLPs demonstrated significant ex vivo binding to diseased vascular tissue. Ongoing studies aim to further develop CT-PLPs for controlled targeting in a rodent model of vascular injury. The CT-PLP nanocarriers established here show promise as the framework for a spatially controlled delivery platform for future application in targeted vascular therapeutics.

Factors Determining Left Main Coronary Artery Luminal Area.

BACKGROUND: A certain minimal luminal cross-sectional area has been traditionally used in clinical practice as a cut-off value to determine severity of left main coronary artery (LMCA) stenosis. The severity of stenosis, however, depends on the baseline luminal area (ie, area prior to stenosis), which may vary among individuals. The present study was undertaken to define normal LMCA luminal area using current technology in vivo. METHODS: LMCA luminal area was determined using multislice computed tomography coronary angiography. Eighty-six subjects with normal coronary arteries and calcium score of zero were included in this study. Left ventricular (LV) mass and LV volumes (systolic, diastolic) were also measured. RESULTS: A wide distribution was found in LMCA luminal area, with median value 17.3 mm² and range 8.1-33.9 mm². A relationship was found between log(LMCA luminal area) and log(LV mass) (r=.515; P<.001) and with body surface area (r=.273; P=.01). Significant relationships were also found between LMCA luminal area and LV volumes (systolic, diastolic). In multiple regression analysis, however, the LV mass was the only independent predictor of LMCA luminal area. CONCLUSION: LMCA luminal area varies substantially among individuals with normal coronary arteries and is related to many other factors. The data suggest that the current practice of using a minimal luminal area cut-off when assessing LMCA stenosis may be misleading, and thus available information should be individualized.

Left atrial myxoma causing coronary steal: an atypical cause of angina.

Cardiac myxomas are rare primary cardiac tumors that usually present with dyspnea or manifestations of systemic embolization. Coronary steal is a rare phenomenon of unbalanced blood flow that is seen primarily in patients who have undergone coronary artery bypass grafting and have subclavian artery stenosis. We report the case of a 72-year-old woman who presented with fatigue, weakness, and exertional chest heaviness and had abnormal results on a cardiac stress test. The results of coronary angiography showed no obstructive coronary artery disease but revealed a large intracardiac left atrial mass that was supplied by 2 anomalous coronary arteries. The patient underwent successful ligation of the anomalous coronary arteries and resection of the mass, which was histologically an atrial myxoma. The patient's symptoms resolved, and results of a repeat cardiac stress test were normal. To our knowledge, this is the first report of a highly vascularized atrial myxoma that caused coronary steal with objective evidence of ischemia, and with subsequent resolution after resection of the mass and ligation of the anomalous coronary arteries.

Evaluation of imaging utilization prior to referral of musculoskeletal tumors: a prospective study.

BACKGROUND: Imaging studies are essential when evaluating a patient with a musculoskeletal neoplasm, and they represent a potential waste of resources when used inappropriately. The objective of this study was to prospectively evaluate a consecutive series of patients for inappropriate utilization of imaging prior to referral to a tertiary care facility. Our hypothesis was that advanced imaging is overutilized prior to referral of musculoskeletal neoplasms to a tertiary care center. METHODS: All new patients referred for evaluation of a musculoskeletal neoplasm were prospectively analyzed over a three-month time period. All pre-referral imaging studies were recorded, including radiographs, computed tomographic scans, magnetic resonance imaging scans, bone scans, and 18-fluorodeoxyglucose positron emission tomography scans. Studies were reviewed by two musculoskeletal radiologists and two orthopaedic oncologists and were defined with use of specific preselected criteria as inappropriate if they were not indicated for diagnosis or treatment, if they required repeating because of excessive time since the study was obtained, or if they had poor image quality or technique. RESULTS: We evaluated 298 consecutive patients (550 imaging studies). The inappropriate utilization rate was 1.5% (three of 204) for radiographs, 36.5% (twenty-three of sixty-three) for computed tomographic scans, 26.7% (fifty-six of 210) for magnetic resonance imaging scans, 45.1% (twenty-three of fifty-one) bone scans, and 45.5% (ten of twenty-two) for positron emission tomography scans. The overall inappropriate use of advanced imaging (magnetic resonance imaging, computed tomography, bone scan, positron emission tomography) was 32.4% (112 of 346 images). With regard to inappropriate use of magnetic resonance imaging, there was no difference between orthopaedic surgeons (28.2%) and primary care physicians (26.5%). CONCLUSIONS: Our data indicate a high prevalence (32.4%) of inappropriate advanced imaging of musculoskeletal tumors prior to referral. This represents a substantial cost to the patient and health-care system, a potential delay of referral, an increase in radiation exposure, and identification of other incidental findings.

Postgraduate nurse practitioner training: what nurse executives need to know.

Nurse executives should be familiar with postgraduate nurse practitioner training programs. Supplemental training opportunities are gaining popularity across the country and are primarily funded by employers interested in recruiting and retaining qualified healthcare professionals. There is considerable variability in program learning objectives, clinical content, and titles used to describe participants' roles. This article offers program descriptions, associated costs, and a call for evidence of their impact on a growing constituent of the healthcare workforce.

Intramuscular hemangiomas.

CONTEXT: Intramuscular hemangiomas are common in the general population and often present at medical and surgical clinics. Unfortunately, unfamiliarity with these lesions has led to a high percentage of misdiagnoses, inappropriate workup, and unnecessary referrals. EVIDENCE ACQUISITION: A literature search was performed using Medline, Embase, PubMed, and Cochrane. The relevant articles and referenced sources were reviewed for additional articles that discussed the epidemiology, pathophysiology, investigation, and management of intramuscular hemangiomas. Clinical experience from experts in orthopaedics, musculoskeletal pathology, and musculoskeletal radiology was compared. The selected case studies are shared cases of the authors. RESULTS AND CONCLUSION: The pathophysiology of these lesions is not completely understood, but much can be implied from their underlying vascular nature. Isolated lesions are benign tumors that never metastasize but tend to enlarge and then involute over time. Magnetic resonance imaging is the imaging modality of choice. If a systemic disorder or malignancy is not suspected or has been ruled out, conservative management is the treatment of choice for most intramuscular hemangiomas.

Comparison of Impella and intra-aortic balloon pump in high-risk percutaneous coronary intervention: vascular complications and incidence of bleeding.

OBJECTIVE: Compare vascular complications and incidence of bleeding of Impella 2.5 and intra-aortic balloon pump (IABP) in high-risk percutaneous coronary interventions (PCI). BACKGROUND: Large arterial sheath size for device insertion is associated with vascular and/or bleeding complications; gastrointestinal bleeding may also occur with anti-coagulation use. METHODS: Patients with an acute coronary syndrome receiving Impella 2.5 or IABP during high-risk PCI were studied (13 Impella; 62 IABP). Vascular complications and incidence of bleeding were compared. RESULTS: Post-procedure hematocrit was similar between groups. Blood transfusion occurred in 38.4% and 32.2% of patients in the Impella and IABP groups, respectively (P = NS); 65.3%, 30.7% and 3.8% of bleeding were due to vascular access site/procedure related, gastrointestinal and genitourinary, respectively. There was no statistical significant difference in vascular complications between the Impella and IABP groups (15.3% and 6.4% of patients, respectively); mesenteric ischemia (n = 1) and aortic rupture (n = 1) were only in the IABP group. In-hospital and one-year mortality were not statistically significant between groups. CONCLUSION: Impella can be used as safely as IABP during high-risk PCI with similar vascular and bleeding complications. Importantly, approximately one third of bleeding was from the gastrointestinal system warranting careful prophylactic measures and monitoring.

Isolated cardiac metastasis from plasmacytoid urothelial carcinoma of the bladder.

UNLABELLED: A 57-year-old male with a history of hypertension presented with shortness of breath, intermittent substernal chest pain, subjective fevers, and a 30-pound weight loss. He was found to have a bladder mass four months prior to presentation, for which he underwent cystoscopy and surgical removal. Pathology demonstrated high-grade superficial plasmacytoid urothelial carcinoma extending into the submucosa but not the muscularis propria. Given the superficial nature of his bladder cancer, a cystectomy was deferred. He was subsequently lost to follow-up care. On arrival, physical exam was notable for tachycardia, tachypnea, and distant heart sounds. An ECG showed an incomplete right bundle branch block and sinus tachycardia. Computed tomography pulmonary angiography revealed a three-cm pericardial effusion. Transthoracic echocardiography confirmed this finding and revealed a mass in the right ventricle (RV) extending into the outflow tract and infiltrating the free wall. The RV was dilated with an estimated RV systolic pressure of 37 mmHg. Pericardiocentesis yielded nearly one liter of serosanguinous fluid with non-diagnostic cytology. Partial median sternotomy with biopsy showed pathologic findings consistent with metastatic urothelial carcinoma, plasmacytoid variant. A PET scan showed increased uptake exclusively in the heart. The oncology team discussed options with the patient including chemotherapy and palliative care. The patient decided to withhold further therapy and went home with hospice care. He died two months later. DISCUSSION: Bladder cancer is the fourth most common cancer in men in the United States. Most patients (69%) with metastatic bladder cancer have multiple organs involved; conversely, our patient had a PET scan indicating his disease was localized to the heart. Plasmacytoid urothelial carcinoma is a rare subtype of bladder cancer, and is estimated to make up less than three percent of all invasive bladder carcinomas. At the time of this publication we are aware of only three other reported instances of isolated cardiac metastasis with urothelial bladder origin; none of which were the plasmacytoid variant. CONCLUSION: This case highlights a previously unreported presentation of plasmacytoid urothelial carcinoma. Clinicians must remember that even superficial cancers can have significant metastatic potential.

Bone Tumor Radiology 101 for Pathologists.

This review discusses how certain imaging features of bone tumors can give valuable clues as to their histology. The author emphasizes the clinical presentation of the patient, and how close cooperation among the radiologist, pathologist, and orthopedic surgeon are paramount in achieving an accurate diagnosis of bone tumors as well as optimizing their management.

Detection of Skeletal Lesions by Whole Body Multidetector Computed Tomography in Multiple Myeloma has no Impact on Long-Term Outcomes Post Autologous Hematopoietic Cell Transplantation.

BACKGROUND: Multiple myeloma (MM), a plasma cell malignancy, is the most common cancer to involve the skeleton. Skeletal related events such as pathologic fractures and lytic bone lesions have been associated with poor prognosis. Whole body multidetector computed tomography (WBCT) has been shown to be the most sensitive imaging modality in detecting small osteolytic lesions (< 5 mm) in the spine. The significance of lytic lesions detected only by CT is unknown as is their impact on overall survival of MM. The aim of this study was to evaluate the impact of lytic bone lesions seen only by WBCT on progression free survival (PFS) and overall survival (OS) in MM patients after hematopoietic cell transplantation (HCT). METHODS: We evaluated 72 patients who had WBCT and conventional radiographic skeletal survey (CSS) after initial or salvage chemotherapy prior to HCT. RESULTS: Forty-one patients (57%) had more findings on WBCT than CSS, 31 patients (43%) had no differences in the two imaging techniques, 9 patients had no bone lesions on either modality, and 5 patients had lesions only identified by WBCT and not on CSS. PFS and OS were similar in patients with lesions seen by CSS irrespective of whether additional lesions were noted by WBCT; similarly, in patients without lesions on CSS, OS and PFS were better than patients with lytic lesions, but detection of occult lesions by WBCT did not adversely affect PFS or OS. CONCLUSIONS: Our study shows that although WBCT is more sensitive in defining existing myelomatous bony disease in MM, these additional findings may not have any impact on PFS and OS of MM patients. Only patients without any bone lesions on conventional skeletal survey had significantly better PFS and OS. This suggests CSS remains the gold standard for evaluating myeloma bone disease.

Three-dimensional entertainment as a novel cause of takotsubo cardiomyopathy.

Takotsubo cardiomyopathy (TC) is an uncommon entity. It is known to occur in the setting of extreme catecholamine release and results in left ventricular dysfunction without evidence of angiographically definable coronary artery disease. There have been no published reports of TC occurring with visual stimuli, specifically 3-dimensional (3D) entertainment. We present a 55-year-old woman who presented to her primary care physician's office with extreme palpitations, nausea, vomiting, and malaise <48 hours after watching a 3D action movie at her local theater. Her electrocardiogram demonstrated ST elevations in aVL and V1, prolonged QTc interval, and T-wave inversions in leads I, II, aVL, and V2-V6. Coronary angiography revealed angiographically normal vessels, elevated left ventricular filling pressures, and decreased ejection fraction with a pattern of apical ballooning. The presumed final diagnosis was TC, likely due to visual-auditory-triggered catecholamine release causing impaired coronary microcirculation.

Magnetic resonance imaging appearance of anterior cruciate ligament reconstruction using Calaxo screws.

Bioabsorbable interference screws are commonly used to secure the graft during anterior cruciate ligament (ACL) reconstruction, in part because they result in less image degradation on subsequent magnetic resonance imaging (MRI). However, some bioabsorbable screws are associated with abnormalities on MRI examination not reported with metallic interference screws. We describe a finding on knee MRI examination after ACL reconstruction using a polylactide carbonate (PLC) bioabsorbable screw that we believe to be previously unreported with any other bioabsorbable screws. The finding raised suspicion of hemorrhage or infection, neither of which were present clinically. Analysis of tissue from the tibial tunnel suggested an explanation for the MRI finding: calcite crystals. An additional five patients with knee MRI examinations after ACL reconstruction using a PLC screw were reviewed and correlated with clinical findings with four having similar imaging abnormalities present. The PLC (Calaxo screw, Smith and Nephew, Andover, MA) screw used in these patients has been recalled in the United States and Europe by the manufacturer after a greater than expected incidence of adverse reactions, and legal action may be pending.

Impaired myocardial perfusion from persistent mammary side branches: a role for functional imaging and embolization.

The diagnosis and management of ischemic symptoms in patients after coronary artery bypass surgery can be challenging. It has been hypothesized that persistent branches of the internal mammary artery can divert flow from the left anterior descending artery and cause symptoms. We present a case in which successful coil embolization of a side branch improved flow and clinical symptoms. Side branch embolization might be a useful treatment option and should be considered in the management of symptomatic patients with a patent mammary graft.

Percutaneous radionuclide ablation of axial aneurysmal bone cysts.

OBJECTIVE: The purpose of our study was to retrospectively examine the efficacy of intralesional injection of 32P chromic phosphate, a beta-emitting colloidal radiopharmaceutical, in the treatment of aneurysmal bone cysts of the axial skeleton. Five patients with large aneurysmal bone cysts were managed with injection of 32P chromic phosphate into their tumors under CT guidance. With only a single minor complication, all lesions were observed to ossify on follow-up CT, with an average follow up of 2 years. CONCLUSION: CT-guided injection of axial aneurysmal bone cysts with 32P chromic phosphate leads to excellent local lesion control. In addition, the morbidity associated with this procedure is lower than that associated with surgical or other nonsurgical treatments.

Impact of 64-slice multidetector computed tomography on other diagnostic studies for coronary artery disease.

BACKGROUND: The clinical role of cardiovascular multidetector computed tomography (CT) remains in evolution, and application varies widely. Understanding its impact on the utilization of other cardiovascular diagnostic modalities could help define best practices. METHODS: Utilization of diagnostic testing was examined for the initial 1053 consecutive patients who underwent cardiovascular multidetector CT examinations after scanner installation in 2005. Yearly procedural volumes in the invasive catheterization and noninvasive stress laboratories were assessed before and after the introduction of multidetector CT. RESULTS: Ninety-one patients (8.6%) of the 1053 required invasive diagnostic catheterization; of these, nearly half subsequently underwent percutaneous or surgical intervention. Diagnostic catheterization and interventional volumes maintained their previous rates of annual increase, while the volume of stress testing decreased once multidetector CT became available. CONCLUSIONS: The major impact of multidetector CT in initial cardiovascular practice is on the need and frequency of stress testing, with far less impact on utilization of cardiac catheterization and coronary interventions.