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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 32, No 2, March/April 2021
AFRICA
99
after initiating dialysis with a CVC (90 to 95%).
12,13
Factors
associated with improved outcomes in these countries include
early referral and a multidisciplinary approach.
14,15
Late referral,
conduit damage by venepuncture and a lack of secondary
intervention for failing fistulae contributes to high failure rates.
16
Another strategy proven to improve outcomes includes
pre-operative ultrasound to evaluate the size and quality of the
vein to be used.
6,17
A structured pre-dialysis care programme
allows the patient to be adequately prepared with counselling
and training, as well as early referral to the vascular access
surgeon.
17
Regular multidisciplinary meetings are useful to
refer new patients, discuss patients with early concerns about
access complications and deal with problematic vascular
access.
17
Having a dedicated vascular access co-ordinator with
a pre-operative ultrasound protocol was shown to be the most
important factor in improving haemodialysis access outcomes.
18
There is currently no database for vascular access in South
Africa, and high-quality data in low- and middle-income
countries are limited.
4
The South African Renal Registry was
the only active African registry until the establishment of the
African Renal Registry in 2015.
19
Unfortunately, they do not yet
record vascular access data. Having data in registries helps to
inform future planning, guides practice, assists in future research
and helps decide on resource allocation.
19
In order to improve
access utilisation in the haemodialysis population, one needs to
evaluate the current practice.
19
The aim of this study was therefore to examine the current
and past use of AVFs, AVGs and CVCs in our unit, in light of
national and international recommendations. This was done by
performing an audit of all patients enrolled in the haemodialysis
programme at our hospital. The objective was to identify any
factors preventing this unit from achieving guideline targets
and to propose changes that could be implemented to achieve a
better haemodialysis access service.
Methods
Ethical clearance was obtained from the Faculty of Health
Sciences Postgraduate Education, Training, Research and Ethics
Unit of the Walter Sisulu University.
We performed an audit on the vascular access for chronic
haemodialysis patients in Livingstone Tertiary Hospital in Port
Elizabeth, South Africa. A retrospective folder review was done
to identify demographic data and full vascular access history.
The data were used to calculate the time from commencement
of haemodialysis until the first attempt at the creation of a
permanent vascular access. Each modality of haemodialysis access
was then evaluated in the patient’s records. The date of insertion
or creation of each modality was recorded. Where available, the
complications associated with each were also recorded.
All patients enrolled in the haemodialysis programme at
Livingstone Hospital on 1 June 2018, who had adequate records,
were included in the study. Patients requiring temporary dialysis
or awaiting transfer to peritoneal dialysis were excluded.
Results
Sixty-six patients formed the study sample, with age ranging
from 21 to 67 years and a mean age of 44 years (95% CI:
42–46.8). Demographic details are shown in Table 1.
The majority of subjects [37 (56%)] were using a tunnelled
CVC as their permanent vascular access, an autogenous AVF was
used in 25 (38%) and an AVG in three (5%) patients. One patient
was using a temporary CVC while awaiting a more definitive
access modality (Table 2). Within the group that was using a
CVC as permanent access, three subgroups were identified: those
who had no AVF created or AVG inserted (12%), those with one
previous failed AVF or AVG (21%), and those who had had more
than one previous attempt at an AVF or AVG (23%).
Central venous catheters were used in 95% of the studied
patients as the initial modality. This included 38 patients (58%)
who started with a temporary CVC and 25 (38%) who started
with a tunnelled CVC. Only six (10%) patients had pre-emptive
creation of permanent access, of which three were successfully
used. The other three had a primary failure and had to have
dialysis initiated using a CVC (Table 2).
The timing from initiation of haemodialysis until the first
attempt at AVF creation was also investigated (Fig. 1). In total,
101 AVFs were created in the study group. The number of access
creation attempts and the complications experienced are shown
in Table 2. There was no recorded episode of significant dialysis
access-associated steal syndrome. The data were inadequate to
calculate primary and secondary patency rates.
Discussion
Despite the young age of this population receiving haemodialysis
in our unit, there was a high rate of CVC use and a very high
rate of serious complications, such as clinically apparent central
venous stenosis. The target for AVF use in any unit, as set by
the Fistula First Breakthrough Initiative, is 65%. Several high-
income countries are reporting AVF prevalence this high.
7
Only
38% of our study population were using an AVF. The high
rate of CVC use in this study is therefore not in keeping with
guideline recommendations. However, on further investigation,
it is clear that CVC use was not the primary strategy, since most
of these patients had had prior AVFs that failed.
While only 12% of the entire group had never had, or was
not then using an AVF, unfortunately 95% of the patients
started dialysis using a CVC, with only 5% having a successful
pre-emptive fistula. This reliance on CVCs increases the failure
rate of AVFs created in the future as prior CVC use decreases the
benefit of an AVF.
11
Table 1. Demographic data of the 66 patients
Demographics
Values
Mean age, years (95% CI)
44 (42–46.8)
Gender,
n
(%)
Male
Female
35 (53)
31 (47)
Race,
n
(%)
Black
Coloured
White
43 (65)
17 (23)
6 (9)
Aetiology of renal failure,
n
(%)
Hypertension
Unknown
Polycystic kidney disease
Systemic lupus erythematosus
Vesico–ureteric reflux
Sepsis
Glomerulonephritis
50 (76)
6 (9)
3 (5)
3 (5)
2 (3)
1 (2)
1 (2)
Mean BMI, kg/m² (95% CI)
24.4 (22.6–25.3)
BMI, body mass index.