INFECTIOUS COMPLICATIONS OF ARTERIOVENOUS ePTFE GRAFTS FOR HEMODIALYSIS

Application and implications of a standardised reporting system for arteriovenous access graft infection

INTRODUCTION

The perception that arteriovenous graft infection (AVGi) is frequent and severe is not based on contemporary data from large units using modern AVG. Furthermore, older reports compounded misperceptions by using non-standardised reporting that prevents easy comparison against the alternative modalities. The aim of this article is to use a recently published reporting scheme to analyse the frequency, management and outcome of AVGi in a large series of sequential early-cannulation AVG with long-term follow-up.

METHODS

A single-center series analysis was performed of 277 early-cannulation AVG with minimum 1-year follow-up (total 120,082 days). Infections relating to the AVG were classified, root-cause analysed and the outcomes presented.

RESULTS

Sixteen percent of all AVG implanted (51 episodes) developed infection related to the AVG. Primary AVGi (related to the insertion procedure or within 28 days) occurred in 9 (3%); secondary AVGi (related to AVG in use) occurred 33 times (rate 0.27/1000 haemodialysis days), at a mean of 382 days, and tertiary AVGi (in AVG no longer in use) occurred nine times. Only 1/3 of all AVGi led to bacteraemia, and ½ did not lead to loss of functional access.

SUMMARY

AVG infection is not common, caused a systemic infection in only one-third, did not lead to metastatic infection, and importantly, was treatable without loss of access in one-half of all cases. Using an objective system that discriminates between aetiology and outcome allows a more complete objective understanding of relative infection risks and outcomes for AVG that can inform discussions with patients requiring vascular access for haemodialysis.

Complications Associated with Permanent Internal Jugular Hemodialysis Catheter: A Retrospective Study

Introduction

A significant increase in patients with end-stage renal disease has been observed currently in our community. Kidney transplantation is the most promising cure but the problem is that large numbers of people are not good candidates for transplantation. Hemodialysis is the next appropriate medication for such patients and for patients with end-stage renal disease, who have no chance for transplantation. Morbidity and mortality are the consequences of vascular access complications. Local data related to the complication rate of permanent hemodialysis catheters is not available. The current study examines the complication rate in people due to permanent intrajugular hemodialysis catheterization.

Materials and methods

The study has been conducted in Dr Ziauddin University Hospital, Karachi. The dataset consists of 212 patients who had gone through jugular catheterizations for hemodialysis at this hospital from the year 2014 to the year 2015. A descriptive method has been chosen for obtaining appropriate results. Complications have also been categorized as early or late.

Results

Complications have been detected in around 24% of the patients from the dataset. Among these complications, infection has the highest percentage (around 13%) while 4% percent of patients have a failed puncture. The others have venous thrombosis, catheter thrombosis, hematoma, wrong canulation, and hemothorax and pneumothorax problems.

Conclusion

The study concludes that the placement of a permanent hemodialysis catheter in the internal jugular vein has a low complication rate. In addition, the method is safe and easy. So, it can be said that the internal jugular vein is a reliable and preferred route for hemodialysis catheterization.

Alternative grafts for brachioaxillary hemodialysis access: 1-year comparative results

BACKGROUND: Many chronic renal patients lack autologous veins in the upper limbs suitable for construction of arteriovenous fistulas for hemodialysis. Alternative fistula options for these patients should be evaluated and compared.OBJECTIVE: To compare different types of grafts used for brachioaxillary access in hemodialysis patients in terms of their patency and complication rates.METHOD: Forty-nine patients free from arterial system abnormalities and with no venous options for creation of arteriovenous fistulae in the arm and/or forearm underwent brachioaxillary bypass with implantation of autologous saphenous vein, polytetrafluoroethylene (PTFE), or PROPATEN(r) grafts. Patients were assessed by Doppler ultrasonography at 3, 6, and 12 months after surgery,.RESULTS: The four first saphenous vein grafts had failed by 3 or 6 months after surgery. The autologous saphenous vein group was discontinued at the beginning of the study because of extreme difficulty in achieving puncture and hematoma formation. Failure rates of PTFE and PROPATEN(r) grafts did not differ after 3 (p = 0.559), 6 (p = 0.920), or 12 months (p = 0.514). A log-rank test applied to cumulative survival of grafts at 1 year (0.69 for PTFE, 0.79 for PROPATEN(r)) detected no significant differences (p = 0.938). There were no differences in complications resulting in graft failure between the two types of prosthetic graft.CONCLUSION: Autologous saphenous vein grafts do not appear to be a good option for brachioaxillary hemodialysis access because of difficulties with achieving puncture. Brachioaxillary fistulae constructed using PTFE or PROPATEN(r) grafts exhibited similar patency and complication rates. Further studies with large samples size are warranted to confirm our findings.

Extract of fetal membrane would inhibit thrombosis and hemolysis

The innermost layer of fetal membranes is amnion which has anti-adhesive, anti-inflammation and viscoelastic properties, as well as low immunogenicity. Amniotic membrane has been employed in variety of clinical fields as a natural biomaterial. Amniotic epithelial cells possess stem cell characteristics and capability to differentiate into endothelial cells. The basement membrane of amnion is an extracellular matrix enriched scaffold to support adhesion of endothelial cells. The matrix of amniotic membrane contains two kinds of glycosaminoglycans including perlecan (a heparan sulfate proteoglycan) and hyaluronic acid which both inhibit blood coagulation. Moreover, the other ingredients of amniotic membrane such as pigment-epithelium derived factor (PEDF), IL-10, MMP-9 inhibit platelet aggregation. Based on some biochemical and biomechanical evidences, we hypothesized in this paper that amniotic membrane could prevent thrombosis and hemolysis; therefore, has the capability to be applied in blood contacting devices and implants.

Membranes for the Guided Bone Regeneration

Many kinds of membrane have been used for the guided bone regeneration (GBR) technique. However, most membranes do not fulfill all requirements for the ideal membrane for the GBR technique. Among them, collagen membrane has been most widely used. However, its high price and weak tensile strength in wet condition are limitations for wide clinical application. Synthetic polymers have also been used for the GBR technique. Recently, silk based membrane has been considered as a membrane for the GBR technique. Despite many promising preclinical data for use of a silk membrane, clinical data regarding the silk membrane has been limited. However, silk based material has been used clinically as vessel-tie material and an electrospun silk membrane was applied successfully to patients. No adverse effect related to the silk suture has been reported. Considering that silk membrane can be provided to patients at a cheap price, its clinical application should be encouraged.

Diabetes mellitus suppresses hemodialysis-induced increases in tear fluid secretion

Background

Hemodialysis is essential for the survival of patients suffering from chronic renal failure. However, in diabetics the incidence of dry eye disease is higher than in non-diabetic individuals. Accordingly, we evaluated if this difference is attributable to different effects of hemodialysis on basal tear fluid secretion.

Methods

A modified Schirmer´s eye test determined if hemodialysis improved basal tear secretion rates in 36 diabetic and non-diabetic patients undergoing hemodialysis.

Results

Basal tear secretion was invariant in diabetic patients whereas in non-diabetic individuals this process increased.

Conclusion

In non-diabetic patients, autonomic neuropathy appears to be less severe and somewhat reversible since only in these individuals hemodialysis improved basal tear fluid secretion. This difference may be a factor contributing to the lower incidence of dry eye disease in non-diabetic patients.

Quality of care of vascular access in hemodialysis patients in a hemodialysis center in Iran

Because of the lack of study in the field of vascular access care for hemodialysis patients, an observational study was conducted on 110 patients undergoing chronic hemodialysis in the Isfahan's AliAsghar Hospital. Data were collected using a demographic questionnaire and a checklist related to vascular access care techniques. A total of 63 male and 47 female with an average of 40.02 months of hemodialysis were studied. In addition, 72 patients were under hemodialysis through arteriovenous fistula and 38 patients through subclavian catheters. The overall quality of care for vascular access site was moderate. Selecting an inappropriately high speed for the apparatus at the beginning of dialysis, needling of an aneurysm or needling near the fistula, and incomplete priming of the filter and the tubes were the most frequent inappropriate actions. Reinforcement of the nurses' continuing education programs and development of standard vascular access care protocols are recommended.