P197
30-DAY MORTALITY FOR HAEMODIALYSIS VASCULAR ACCESS SURGERY
INCREASES WITH MODE OF ANAESTHESIA AND TYPE OF ACCESS; RESULTS
FROM A 5-YEAR SINGLE CENTRE STUDY.
Jorna T, Bushnell J, Ravanan R, Mouton R, Weale A.
Richard Bright Renal Unit, Southmead Hospital, Bristol, UK.
INTRODUCTION: Renal association guidelines state that patients with end-stage renal failure
(ESRF) known to nephrology services should commence haemodialysis (HD) using established
access such as an arterio-venous fistula or graft. Patients with ESRF, often by their very nature
will have significant co-morbidities that increase their risk or morbidity and mortality associated
with anaesthesia and vascular surgery. Planning for vascular access surgery should address this
to enable surgical and anaesthetic risk to be minimised, and for patients to be informed of the
mortality associated with these procedures. A literature review has shown there is a dearth of
mortality data for patients with ESRF undergoing vascular access surgery in preparation for
HD. The aims of this study were to establish the 30-day mortality for patients undergoing
vascular access surgery and investigate for variation in mortality for different types of vascular
access and surgery carried out under general (GA) or local anaesthesia (LA).
METHODS: The database for the Bristol Renal Unit was used to identify all cases of surgery
to establish vascular access for HD for the 5 year period between 5th April 2008 and 4th April
2013. Electronic notes were reviewed for patient demographics, co-morbidities, type of access
created, mode of anaesthesia and mortality.
RESULTS: 1577 operations to establish vascular access were identified, 1483of these were
included. 899 (60.6%) cases were men and 584 (39.4%) were women. There was a mean age of
62.0 years (S.D. 16.5, range 17-93). 660(44.5%) operations were for pre-dialysis patients and
823(55.5%) were for those already established on renal replacement therapy (RRT).
1242(83.7%) upper limb fistulae were created, 189(12.7%) upper limb grafts inserted and
52(3.50%) procedures were for lower limb access. 890(60.0%) procedures were for first access,
592(39.9%) were for second or subsequent access and 1 was unknown. 932(62.8%) procedures
were carried out under LA, 473(31.9%) under GA and there were no data for 78(5.30%).The
30-day mortality for all access surgery (n=1483) was 1.08%; there had been 16 deaths at 30
days. 30 day mortality for upper limb fistulae was 0.729%; for upper limb grafts was 2.55% and
for all lower limb access was 3.85%. In cases of death at 30 days, 11(68.8%) of those
procedures had been under GA and 5(31.5%) under LA. Procedures performed under GA were
associated with a significantly higher 30-day mortality than those done under LA (p=0.003).
Upper limb grafts were associated with a significantly higher mortality than upper limb fistulae
(p=0.002). There was no statistical difference in survival between upper and lower limb access
surgery. Kaplan-Meier estimates show the difference in survival between GA and LA
procedures and upper limb grafts and fistulae remained statistically significant over time.
DISCUSSION: These results show that vascular access surgery for HD, although often thought
of as relatively low risk, is associated with mortality comparable to that of other forms of more
invasive arterial surgery. Mortality varies significantly between fistulae and grafts and the mode
of anaesthesia used. These variations in part are likely to be a reflection of increased time on
RRT which carries increased cardiovascular co-morbidity and the need for multiple, ever more
complex access procedures requiring GA; all of these factors will increase mortality. These
results have not been corrected for pre-operative comorbidity but further investigation the data
will shed light on this. This study gives valuable information to guide nephrologists, surgeons,
anaesthetists and patients undergoing vascular access surgery to be able to estimate mortality
and plan access and anaesthesia accordingly.