Randy Shafritz

Bio: Randy Shafritz is an academic researcher from Rutgers University. The author has contributed to research in topics: Inferior vena cava & Embolization. The author has an hindex of 3, co-authored 12 publications receiving 48 citations.

Vessel lumen segmentation in internal carotid artery ultrasounds with deep convolutional neural networks

Abstract: Carotid ultrasound is a screening modality used by physicians to direct treatment in the prevention of ischemic stroke in high-risk patients. It is a time intensive process that requires highly trained technicians and physicians. Evaluation of a carotid ultrasound requires identification of the vessel wall, lumen, and plaque of the carotid artery. Automated machine learning methods for these tasks are highly limited. We propose and evaluate here single and multi-path convolutional U-neural network for lumen identification from ultrasound images. We obtained de-identified images under IRB approval from 98 patients. We isolated just the internal carotid artery ultrasound images for these patients giving us a total of 302 images. We manually segmented the vessel lumen, which we use as ground truth to develop and validate our model. With a basic simple convolutional U-Net we obtained a 10-fold cross-validation accuracy of 95%. We also evaluated a dual-path U-Net where we modified the original image and used it as a synthetic modality but we found no improvement in accuracy. We found that the sample size made a considerable difference and thus expect our accuracy to rise as we add more training samples to the model. Our work here represents a first successful step towards the automated identification of the vessel lumen in carotid artery ultrasound images and is an important first step in creating a system that can independently evaluate carotid ultrasounds.

An Institution-Wide Algorithm for Treatment of Type II Endoleak Following Endovascular Aneurysm Repair (EVAR)

Abstract: Objectives:Multiple endovascular techniques have been described for the treatment of persistent type II endoleaks (pT2ELs) causing aneurysm sac growth following endovascular aneurysm repair (EVAR)....

Chronic refractory venous ulcer exacerbated by a congenital pelvic arteriovenous malformation successfully treated by transarterial Onyx embolization.

Abstract: Congenital arteriovenous malformations (AVMs) are an important but often neglected cause of lower extremity venous hypertension. A case of a chronic refractory venous stasis ulcer of the lower extremity exacerbated by a pelvic AVM is presented. Healing of the ulcer was achieved at 2 months without recurrence at 1 year after superselective ethylene vinyl alcohol copolymer (Onyx 34; ev3, Covidien, Plymouth, Minn) embolization of the AVM nidus. Chronic venous arterialization should be considered in cases of refractory, nonhealing venous ulcers. Embolotherapy in addition to standard of care therapy can be a therapeutic measure. Modification of the Clinical, Etiology, Anatomy, and Pathophysiology (CEAP) classification to include AVMs as a contributing pathophysiologic process is suggested.

The Risk of Bloodstream Infection in Adults With Different Intravascular Devices: A Systematic Review of 200 Published Prospective Studies

Abstract: OBJECTIVE: To better understand the absolute and relative risks of bloodstream infection (BSI) associated with the various types of intravascular devices (IVDs), we analyzed 200 published studies of adults in which every device in the study population was prospectively evaluated for evidence of associated infection and microbiologically based criteria were used to define IVD-related BSI. METHODS: English-language reports of prospective studies of adults published between January 1, 1966, and July 1, 2005, were identified by MEDLINE search using the following general search strategy: bacteremia [Medical Subject Heading, MeSH] OR septicemia [MeSH] OR bloodstream infection AND the specific type of intravascular device (eg, central venous port). Mean rates of IVDrelated BSI were calculated from pooled data for each type of device and expressed as BSIs per 100 IVDs (%) and per 1000 IVD days. RESULTS: Point incidence rates of IVD-related BSI were lowest with peripheral intravenous catheters (0.1%, 0.5 per 1000 IVDdays) and midline catheters (0.4%, 0.2 per 1000 catheter-days). Far higher rates were seen with short-term noncuffed and nonmedicated central venous catheters (CVCs) (4.4%, 2.7 per 1000 catheter-days). Arterial catheters used for hemodynamic monitoring (0.8%, 1.7 per 1000 catheter-days) and peripherally inserted central catheters used in hospitalized patients (2.4%, 2.1 per 1000 catheter-days) posed risks approaching those seen with short-term conventional CVCs used in the intensive care unit. Surgically implanted long-term central venous devices—cuffed and tunneled catheters (22.5%, 1.6 per 1000 IVD-days) and central venous ports (3.6%, 0.1 per 1000 IVD-days)—appear to have high rates of infection when risk is expressed as BSIs per 100 IVDs but actually pose much lower risk when rates are expressed per 1000 IVD-days. The use of cuffed and tunneled dual lumen CVCs rather than noncuffed, nontunneled catheters for temporary hemodialysis and novel preventive technologies, such as CVCs with anti-infective surfaces, was associated with considerably lower rates of catheter-related BSI. CONCLUSIONS: Expressing risk of IVD-related BSI per 1000 IVDdays rather than BSIs per 100 IVDs allows for more meaningful estimates of risk. These data, based on prospective studies in which every IVD in the study cohort was analyzed for evidence of infection by microbiologically based criteria, show that all types of IVDs pose a risk of IVD-related BSI and can be used for benchmarking rates of infection caused by the various types of IVDs in use at the present time. Since almost all the national effort and progress to date to reduce the risk of IVD-related infection have focused on short-term noncuffed CVCs used in intensive care units, infection control programs must now strive to consistently apply essential control measures and preventive technologies with all types of IVDs.

Effect of ramipril vs amlodipine on renal outcomes in hypertensive nephrosclerosis: a randomized controlled trial.

Abstract: ContextIncidence of end-stage renal disease due to hypertension has increased in recent decades, but the optimal strategy for treatment of hypertension to prevent renal failure is unknown, especially among African Americans.ObjectiveTo compare the effects of an angiotensin-converting enzyme (ACE) inhibitor (ramipril), a dihydropyridine calcium channel blocker (amlodipine), and a β-blocker (metoprolol) on hypertensive renal disease progression.Design, Setting, and ParticipantsInterim analysis of a randomized, double-blind, 3 × 2 factorial trial conducted in 1094 African Americans aged 18 to 70 years with hypertensive renal disease (glomerular filtration rate [GFR] of 20-65 mL/min per 1.73 m2) enrolled between February 1995 and September 1998. This report compares the ramipril and amlodipine groups following discontinuation of the amlodipine intervention in September 2000.InterventionsParticipants were randomly assigned to receive amlodipine, 5 to 10 mg/d (n = 217), ramipril, 2.5 to 10 mg/d (n = 436), or metoprolol, 50 to 200 mg/d (n = 441), with other agents added to achieve 1 of 2 blood pressure goals.Main Outcome MeasuresThe primary outcome measure was the rate of change in GFR; the main secondary outcome was a composite index of the clinical end points of reduction in GFR of more than 50% or 25 mL/min per 1.73 m2, end-stage renal disease, or death.ResultsAmong participants with a urinary protein to creatinine ratio of >0.22 (corresponding approximately to proteinuria of more than 300 mg/d), the ramipril group had a 36% (2.02 [SE, 0.74] mL/min per 1.73 m2/y) slower mean decline in GFR over 3 years (P = .006) and a 48% reduced risk of the clinical end points vs the amlodipine group (95% confidence interval [CI], 20%-66%). In the entire cohort, there was no significant difference in mean GFR decline from baseline to 3 years between treatment groups (P = .38). However, compared with the amlodipine group, after adjustment for baseline covariates the ramipril group had a 38% reduced risk of clinical end points (95% CI, 13%-56%), a 36% slower mean decline in GFR after 3 months (P = .002), and less proteinuria (P<.001).ConclusionRamipril, compared with amlodipine, retards renal disease progression in patients with hypertensive renal disease and proteinuria and may offer benefit to patients without proteinuria.

Guidelines for venous access in patients with chronic kidney disease. A Position Statement from the American Society of Diagnostic and Interventional Nephrology, Clinical Practice Committee and the Association for Vascular Access.

Abstract: At the time of hemodialysis vascular access evaluation, many chronic kidney disease patients already have iatrogenic injury to their veins which impedes the surgical construction of an arteriovenous fistula (AVF). Achieving the important goal of a greater prevalence of arteriovenous fistulae in the US hemodialysis population will require identification of those patients prior to reaching end-stage renal disease and an educational and procedural system for preserving their veins.

Risk Factors of Catheter-Related Bloodstream Infections in Parenteral Nutrition Catheterization

Abstract: Background: Intravascular catheters are integral to the practice of modern medicine. Potential risk factors for catheter-related bloodstream infection (CRBSI) include underlying disease, method of catheter insertion, and duration and purpose of catheterization. The administration of parenteral nutrition (PN) through intravascular catheters increases CRBSI risks. The purpose of this study was to evaluate the risk factors of CRBSI in patients with PN administration. Methods: This study was conducted at the Karadeniz Technical University Hospital between October 2003 and November 2004. All the patients to whom PN was administered through intravascular catheters were prospectively monitored for the presence of CRBSI and risk factors. Results: During the study period, 111 intravascular catheters through which PN was administered were monitored for a total of 1646 catheter-days. CRBSI was determined in 31 cases, a CRBSI rate of 18.8 per 1000 catheter-days. When risk factors affecting CRBSI were investigated usi...