Israel Medical Association Journal

Background: Hemodialysis requires reliable, recurrent access to the circulatory system. Central venous tunneled dialysis catheters (TDC) are frequently used for patients receiving hemodialysis as a bridge to permanent vascular access or as a final option. TDC are prone to complications such as infection and dysfunction.

Objective: To assess the prevalence and predictors of TDC dysfunction in a cohort of chronic hemodialysis patients.

Methods: This single-center, retrospective study was based on data from an electronic database of chronic hemodialysis patients during 5 years of follow-up.

Results: A total of 625 TDC were inserted in 361 patients, of which 234 (37.4%) were replaced due to dysfunction. The main insertion site was the right internal jugular vein. Diabetes mellitus was an important predictor of TDC dysfunction and was significantly correlated with TDC extraction. Chronic anticoagulation and antiplatelet treatment did not affect the rate of TDC dysfunction or replacement.

Conclusions: TDC use for chronic dialysis patients is increasing and dysfunction is a major problem. In our study, we highlighted the high prevalence of TDC dysfunction and the need for further research to improve hemodialysis access as well as TDC patency and function.

Background: Reliable vascular access is a fundamental tool for providing effective hemodialysis. Vascular access dysfunction is associated with increased morbidity and mortality among hemodialysis patients. Current vascular access guidelines strongly recommend creating an arteriovenous fistula (AVF) as the first option; however, a substantial proportion of new AVFs may not be usable.

Objectives: To assess possible predictors of primary and secondary failure of vascular access.

Methods: This retrospective cohort study included all vascular access sites created at Meir Medical Center from 2006 through 2012. Vascular access site, primary and secondary failure rates, and relevant demographic and clinical data were recorded during 60 months of follow-up.

Results: A total of 612 vascular accesses were created and followed for a median of 32 ± 29.4 months. Of these, 490 (80%) were suitable for initiating hemodialysis. Vascular access site was the most important predictor of primary failure but did not predict secondary failure. Co-morbidities such as diabetes mellitus and congestive heart failure, as well as the use of antiplatelet agents did not predict primary or secondary failure. Preoperative vascular mapping using Doppler ultrasonography was performed in 36.4% of cases and was not associated with lower rates of primary or secondary failure.

Conclusions: Vascular access site is an important predictor of primary failure. We did not find a benefit of pre-operative vessel mapping or chronic antiplatelet therapy in terms of decreasing primary and secondary failure rates. Physicians should carefully consider the characteristics of the patient and blood vessels before creating vascular access in patients requiring chronic hemodialysis.

Background: Healthcare workers (HCWs) have close interaction with confirmed or suspected coronavirus disease 2019 (COVID-19) patients. Infection rates reported among HCWs is between 3% and 17%, and asymptomatic HCWs are a potential source of nosocomial transmission to vulnerable patients and colleagues. Universal mask use and good supply of personal protective equipment was implemented early at our institution.

Objectives: To determine the rate of infection by the serologic status of HCWs during first three COVID-19 waves, based on occupation and risk of exposure, compared to Israeli general population.

Methods: We conducted a prospective cohort study at Emek Medical Center from April 2020 to April 2021. A total of 101 HCWs volunteered to be followed at six time points by a serology test and a questionnaire.

Results: A total of 101 HCWs completed six serologic tests. All participants were seronegative at the four initial tests. The cumulative seropositivity rate for COVID-19 in HCWs was 9.9% (10/101). Only three seropositive HCWs (2.97%) were hospital-acquired.

Conclusions: Seroprevalence and seroconversion dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in 101 HCWs during COVID-19 outbreaks at Emek Medical Center were similar to the epidemiological curve of positive polymerase chain reaction results of the Israeli population, as published by the Israeli Ministry of Health, at each time point. Universal mask use and infection control measures may have contributed to a low hospital infection rate.

Background: Congenital factor VII deficiency is a rare recessive autosomal bleeding disorder with a wide spectrum of clinical manifestations.

Objectives: To compare the clinical and laboratory findings in Jewish and Bedouin patients with factor VII deficiency.

Methods: The clinical and laboratory findings of patients with factor VII deficiency treated at Soroka Medical Center, a tertiary hospital in Israel, from 2005 to 2015 were analyzed regarding blood factor levels, illness severity, treatment administration, and disease outcome.

Results: Seventy-eight patients were enrolled (1:13,000 of the population in southern Israel) of whom 26 were diagnosed with severe factor VII deficiency (1:40,000). Sixty (76.9%) patients were Jewish and 18 (23.1%) were Bedouin. In univariable analysis, Bedouin patients exhibited a more severe illness, with significantly higher complication and fatality rates, and required more preventive treatment than the Jewish patients.

Conclusions: The prevalence of congenital factor VII deficiency (including severe deficiency) in the Jewish and Bedouin populations of southern Israel is higher than previously reported. The clinical spectrum of the disease was found to be more severe in the Bedouin population.

Background: Idiopathic membranous nephropathy (IMN) is one of the most common causes of nephrotic syndrome (NS) in Caucasian adults. Most patients have good renal prognosis, but 30–40% may progress to end stage renal disease (ESRD). 

Objectives: To evaluate the efficacy and safety of immunosuppressive treatment (IST) in high-risk patients.

Methods: All IMN patients diagnosed by kidney biopsy from 2004–2010 were included. Clinical and laboratory data were collected at each follow-up visit. Risk assessment for renal progression classified patients as high risk if: 24 hour protein excretion > 6 g/day, estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m2, and severe disabling or life-threatening clinical symptoms of NS were present.

Results: Among 290 biopsies, 37 patients (12.7%) were IMN. They were allocated to the high-risk IST group (n=16) or low-risk supportive treatment (ST) group (n=21) according to the likelihood of developing renal failure. Mean follow-up was 47 ± 17.3 months. Complete and partial remission rate was 68.7% for high-risk IST vs. 90.4% for low-risk ST. In the high-risk IST group, eGFR was significantly lower at 30 months (65.5 ± 28.6 vs. 85.3 ± 21.6 at baseline, P < 0.05). Four high-risk patients reached ESRD. In the low-risk ST group, eGFR remained stable at 30 and 60 months. 

Conclusions: This study showed a high remission rate for IMN. IST with prednisolone and cyclophosphamide provided favorable renal outcomes in most high-risk patients. The very high remission rate obtained in the low-risk patients confirms the adequacy of supportive treatment in this group.

Background: Upper respiratory tract infection (URTI) occurs frequently in the general population and is considered a benign self-limited disease. Dialysis patients constitute a high risk population whose morbidity and mortality rate as a result of URTI is unknown. 

Objectives: To assess the local incidence, morbidity and mortality of URTI in dialysis patients compared to the general population. 

Methods: In this retrospective cohort study we reviewed the charts of all chronic dialysis patients diagnosed with URTI at Meir Medical Center, Kfar Saba, Israel during the 2014–2015 winter season. 

Results: Among 185 dialysis patients, 40 were found to be eligible for the study. The average age was 66.1 ± 15.7 years, and the co-morbidity index was high. Influenza A was the most common pathogen found, followed by rhinovirus, respiratory syncytial virus and para-influenza. Of the 40 patients 21 (52.5%) developed complications: pneumonia in 20%, hospitalization in 47.5%, and respiratory failure requiring mechanical ventilation in 12.5%. Overall mortality was 10%. General population data during the same seasonal period showed a peak pneumonia incidence of 4.4% compared to 20% in the study population (P < 0.0001). 

Conclusions: The study findings show that compared to the general population, URTI in dialysis patients is a much more severe disease and has a higher complication rate. Influenza A, the most common pathogen, is associated with a worse prognosis. 

 

Abstract

Background: Hyperhomocysteinemia is associated with increased cardiovascular risk, but treatment with folic acid has no effect on outcome in unselected patient populations.

Objectives: To confirm previous observations on the association of homozygosity for the TT MTHFR genotype with B12 deficiency and endothelial dysfunction, and to investigate whether patients with B12 deficiency should be tested for 677MTHFR genotype.

Methods: We enrolled 100 individuals with B12 deficiency, tested them for the MTHFR C677T polymorphism and measured their homocysteine levels. Forearm endothelial function was checked in 23 B12-deficient individuals (13 with TT MTHFR genotype and 10 with CT or CC genotypes). Flow-mediated dilatation (FMD) was tested after short-term treatment with B12 and folic acid in 12 TT MTHFR homozygotes.

Results: Frequency of the TT MTHFR genotype was 28/100 (28%), compared with 47/313 (15%) in a previously published cohort of individuals with normal B12 levels (P = 0.005). Mean homocysteine level was 21.2 ± 16 mM among TT homozygotes as compared to 12.3 ± 5.6 mM in individuals with the CC or CT genotype (P = 0.008). FMD was abnormal (£ 6%) in 9/13 TT individuals with B12 deficiency (69%), and was still abnormal in 7/12 of those tested 6 weeks after B12 and folic treatment (58%).

Conclusions: Among individuals with B12 deficiency, the frequency of the TT MTHFR genotype was particularly high. The TT polymorphism was associated with endothelial dysfunction even after 6 weeks of treatment with B12 and folic acid. Based on our findings we suggest that B12 deficiency should be tested for MTHFR polymorphism to identify potential vascular abnormalities and increased cardiovascular risk. 

Objectives: To present our experience with endovascular management of blunt renal artery injury, and review the literature.

Methods: We conducted a retrospective study of 18 months at a level 1 trauma center. Search of our electronic database and trauma registry identified three patients with renal artery injury from blunt trauma who were successfully treated endovascularly. Data recorded included the mechanism of injury, time from injury and admission to revascularization, type of endovascular therapy, clinical and imaging outcome, and complications.

Results: Mean time from injury to endovascular revascularization was 193 minutes and mean time from admission to revascularization 154 minutes. Stent-assisted angioplasty was used in two cases, while angioplasty alone was performed in a 4 year old boy. A good immediate angiographic result was achieved in all patients. At a mean follow-up of 13 months the treated renal artery was patent in all patients on duplex ultrasound. The mean percentage renal perfusion of the treated kidney at last follow-up was 36% on DTPA renal scan. No early or late complications were encountered.

Conclusions: Endovascular management for blunt renal artery dissection is safe and feasible if an early diagnosis is made. This approach may be expected to replace surgical revascularization in most cases.

Objectives: To determine whether reliable data could be obtained at lower cost.

Methods: The study sample consisted of 50 patients with mild to severe stable COPD]1[. All underwent pulmonary function test and the cardiopulmonary exercise test, 6 minute walk and 15 step exercise oximetry test as part of their regular follow-up visit. Functional capacity was graded according to each test separately and the functional capacities obtained were correlated.

Results: The results showed that most of the patients had severe COPD according to pulmonary function tests (mean forced expiratory volume in the first second 46.3 ± 19.9% of predicted value). There was a good correlation between the cardiopulmonary exercise test and the 6 minute walk functional capacity classes (r = 0.44, P = 0.0013). We did not find such correlation between the 15 step exercise oximetry test and the cardiopulmonary exercise test (r = 0.07, P = 0.64).

Conclusions: The study shows that the 6 minute walk is a reliable and accurate test in the evaluation of functional capacity in COPD patients.