Targeted Duplex Ultrasound in a One-Stop Dialysis Vascular Access Assessment Clinic

Protocol for a qualitative study exploring haemodialysis dependent patients' arteriovenous fistula experience, values and concerns in Sydney, Australia

INTRODUCTION

The experiences of patients from culturally and linguistically diverse backgrounds, with chronic mental illness, disabilities or who identify as sexual or religious minorities are under-represented in clinical research on arteriovenous fistula (AVF) for haemodialysis access. A greater understanding of the experiences, values and concerns of these diverse patient groups are needed to provide haemodialysis access care that addresses the needs of all haemodialysis-dependent patients. This study seeks to describe a broad range of patient experiences related to the creation, care and surveillance of AVFs, including interactions with healthcare teams.

METHODS AND ANALYSIS

This qualitative study will use semistructured interviews with individual patients purposefully selected to provide a diverse patient population. A deliberate strategy will be used to recruit a demographically broad range of participants. Thematic analysis of interview transcripts, using a constant comparative methodology, will generate themes that describe patient experiences, values and concerns. Findings from this study will give a nuanced insight into the experiences of patients on haemodialysis with respect to their AVF.

ETHICS AND DISSEMINATION

Ethical approval for this study was provided by the Sydney Local Health District Human Research Ethics Committee (REGIS identifier: 2021/ETH00362, CH reference number: CH62/6/2021-033). Results will be made available to the participants, local health district, funders and other researchers through various hospital and academic forums. Data will also be published in peer-reviewed journals and be part of a larger body of work looking into patient-reported outcome measures for patients with AVF.

Ultrasound Vein and Artery Mapping by General Surgery Residents During Initial Consult Can Decrease Time to Dialysis Access Creation

BACKGROUND

Formal preoperative ultrasound (US) mapping of vascular anatomy by radiology is recommended before hemodialysis access surgery. We hypothesized that US performed by general surgery residents in place of formal US would decrease the time from initial consult to creation of dialysis access without affecting patient outcomes.

METHODS

This is a retrospective review of all patients who underwent dialysis access surgery from November 2014 to July 2016 and received preoperative upper extremity US vein and artery evaluation by either radiology or general surgery residents. The primary endpoints were days from initial consult to dialysis access creation, rate of arteriovenous fistula (AVF) creation, fistula maturation, and 1-year primary assisted patency.

RESULTS

Of 242 patients, 167 (69%) had formal US, and 75 (31%) had only a resident US. The resident US group had 100% AVF creation compared with the formal US group with 92.2% AVF creation (P = 0.01). There was no difference between the groups in rate of fistula maturation (P = 0.1) and 1-year assisted patency (P = 0.9). Of the resident US 90.7% occurred in the outpatient setting. On multivariable analysis controlling for outpatient consult, the average time to the operating room was 13.7 days longer for the formal US group in the outpatient setting (P = 0.0006).

CONCLUSIONS

Ultrasound vein and artery evaluation at the time of the initial consult by general surgery residents can decrease the time to dialysis access creation by bypassing the need for formal US with a higher rate of AVF creation and no difference in fistula maturation or 1-year primary assisted patency.

A Prospective Observational Study to Assess the Impact of Operator Seniority on outcome following Arteriovenous Fistula Formation

Purpose

Arteriovenous fistula (AVF) surgery affords an excellent opportunity for junior surgeons to learn key vascular techniques. However, implementation of the European Working Time Directive has reduced trainee surgeon's working hours, leading to concerns regarding a possible effect on patient outcomes. Given high early postoperative failure rates and limited AVF sites, it has been proposed that AVF surgery should be performed by Consultants and senior trainees only. This prospective observational study aimed to establish how seniority impacts upon AVF surgery outcomes.

Methods

All patients referred for AVF formation were considered for inclusion. Demographic data, comorbidities, medications and previous access history were recorded. Surgery was performed by a Consultant Vascular Surgeon or a junior surgeon. Clinical review was undertaken 30 days postoperatively to assess patency and record any complications.

Results

Seventy-seven patients underwent AVF formation. About 63.6% procedures were carried out by a junior surgeon. The groups were well matched for demographics, comorbidities and medications. There was no difference in anatomical site of formation between groups operated on by consultant versus juniors (p = 0.373). More general anaesthetic procedures were undertaken by Consultant surgeons, for example basilic vein transposition when compared with juniors (p = 0.039). There was no significant difference in terms of early AVF failure (p = 0.710), complication rates (p = 0.139) or requirement for re-intervention (p = 0.256) between the groups. Patency rates were also equivocal between the groups.

Conclusions

The seniority of the operating surgeon does not appear to impact on outcomes following AVF formation. A greater proportion of general anaesthetic cases were undertaken by a Consultant, which may introduce bias. Junior surgeons with appropriate training and modest experience can perform access surgery without detriment to patients patient detriment.

Pre-Operative Ultrasonography and Arteriovenous Fistulae Maturation

Background

Arteriovenous fistulae (AVF) are preferred for haemodialysis access, but maturation is unpredictable.

Results

Clinical examination alone is unreliable for AVF planning. Duplex ultrasonography may provide useful anatomical and physiological data to allow more accurate prediction of likely AVF success.

Conclusion

Selective use of duplex ultrasonography appears to enhance AVF success rates, but there are insufficient data to recommend routine duplex screening of AVF candidates. Agreed vessel criteria are needed.

Consider use of a collateral venous circuit before abandoning the arteriovenous fistula--the experience of a complex vascular access case

We describe a 65-year-old woman with diabetes on hemodialysis maintenance, with a number of complications associated with high-flow arteriovenous fistula (AVF, anastomosis between brachial artery and medial vein of the forearm) requiring an extended diagnostic and individual approach. The patient was admitted to our hospital because of pain, edema of the limb, hand ischemia, and infection caused by steal syndrome. To reduce fistula flow, banding of the proximal cephalic vein was performed. Simultaneously because of necrosis, amputation of the fifth finger was necessary. Following this procedure, the cephalic vein on the arm thrombosed. The fistula was patent through the collateral circuit, which was diagnosed in detail during the late course. A long course of antibiotics and sessions in a hyperbaric chamber allowed limb rescue. Single-needle dialysis was carried out because of problems in finding an appropriate second place. After an episode of bleeding from the puncture site caused by ulceration, we were forced to search for an alternative needling point. On the basis of ultrasound scans, an anatomic schema of the blood circuit was created. The fistula demonstrated flow from the brachial artery resulting in retrograde flow in the section of the cephalic vein distal to the anastomosis in the upper forearm. This was then seen to drain in an antegrade direction via the median vein of the forearm after the 2 vessels connected in the mid forearm. Using the diagram, 2 alternative places for needling were found and it allowed the adequate hemodialysis to be continued. Complex and complicated cases associated with native AVF could be resolved using simple diagnostic tools to preserve the fistula use for hemodialysis. Both clinical examination and ultrasound scan with the Doppler option appear to be valuable methods for finding the optimal cannulation place.