Long-term outcomes following arteriovenous fistula ligation in kidney transplant recipients

Table 1 Patient demographics, n (%)

	AVF ligation, n = 176	No AVF ligation, n = 352	P value	All AVF, n = 528	CVC, n = 352	P value
Sex
Female	52 (29.5)	76 (21.6)	0.045	128 (24.2)	125 (35.5)	< 0.001
Male	124 (70.5)	276 (78.4)		400 (75.8)	227 (64.5)
Age at Tx
Years (median)	50 (40-59)	54 (45-63)	0.002	53 (43-62)	52 (42-62)	0.38
Ethnicity
Black	25 (14.2)	68 (19.3)	0.2	93 (17.6)	73 (20.7)	0.013
Caucasian	60 (34.1)	94 (26.7)		154 (29.2)	114 (32.4)
Indoasian	64 (36.5)	125 (35.5)		189 (35.8)	131 (37.2)
Other	27 (15.3)	65 (18.5)		92 (17.4)	34 (9.7)
Cause of ESKD
APKD	20 (11.4)	38 (10.8)	< 0.001	58 (11.0)	28 (8.0)	0.09
Diabetes	27 (15.3)	106 (30.1)		133 (25.2)	86 (24.4)
GN	62 (35.2)	82 (23.3)		144 (27.3)	78 (22.2)
Other	9 (5.1)	35 (9.9)		44 (8.3)	34 (9.7)
Unknown	54 (30.7)	74 (21.0)		128 (24.2)	103 (29.3)
Urological	4 (2.3)	17 (4.8)		21 (4.0)	23 (6.5)
Time at ESKD
Years (median)	3.5 (1.8-5.8)	2.7 (1.5-4.6)	0.023	2.9 (1.6-5.0)	2.9 (1.3-5.7)	0.95
Transplant type
LD	24 (13.6)	41 (11.6)	0.09	65 (12.3)	99 (28.1)	< 0.001
DD	136 (77.3)	297 (84.4)		433 (82.0)	220 (62.5)
SPK	8 (4.5)	7 (2.0)		15 (2.8)	21 (6.0)
Antibody incompatible	8 (4.5)	7 (2.0)		15 (2.8)	12 (3.4)
Diabetes
Yes	34 (19.3)	135 (38.5)	< 0.001	169 (32.1)	121 (34.4)	0.48
No	142 (80.7)	216 (61.5)		358 (67.9)	232 (65.6)
Graft number
1st	155 (88.1)	318 (90.3)	0.42	473 (89.6)	300 (85.2)	0.05
≥ 2nd	21 (11.9)	34 (9.7)		55 (10.4)	52 (14.8)
Induction
Alemtuzumab	150 (85.2)	314 (89.2)	0.19	465 (88.1)	298 (84.7)	0.14
IL2	26 (14.8)	38 (10.8)		63 (11.9)	54 (15.3)
DGF
No	139 (79.0)	245 (69.6)	0.02	384 (72.7)	260 (73.9)	0.71
Yes	37 (21.0)	107 (30.4)		144 (27.3)	92 (26.1)
HLA sensitization status
Non-sensitized	119 (67.6)	235 (66.8)	0.92	354 (67.0)	229 (65.1)	0.33
Sensitized	48 (27.3)	101 (28.7)		149 (28.2)	98 (27.8)
Preformed	9 (5.1)	16 (4.5)		25 (4.7)	25 (7.1)
Total HLA mismatch
Median ABDR	3 (3-4)	3 (3-4)	0.29	3 (3-4)	3 (3-4)	0.73
Duration of follow-up
Months (median)	128 (83-177)	82 (54-121)	< 0.001	96 (58-145)	123 (72-173)	< 0.001

Continuous variables are presented as median (interquartile range). Antibody-incompatible transplants refer to kidney transplants (living- or deceased-donor) performed across an ABO- or human leukocyte antigen (HLA)-incompatible barrier using desensitization protocols. Total HLA mismatch is reported out of 6 (HLA-A, -B, and -DR loci). ABDR: Total mismatch HLA-A, -B, and -DR loci; APKD: Adult polycystic kidney disease; AVF: Arteriovenous fistulae; CVC: Central venous catheter; DD: Deceased donor; DGF: Delayed graft function; ESKD: End-stage kidney disease; GN: Glomerulonephritis; HLA: Human leukocyte antigen; LD: Living donor; SPK: Simultaneous kidney-pancreas; Tx: Transplant.

Table 2 Multivariable analysis of peri-transplant clinical variables associated with allograft outcomes in patients receiving hemodialysis via arteriovenous fistulae vs central venous catheter pre-transplant

	Univariate			Multivariate
	HR	95%CI	P value	HR	95%CI	P value
All-cause allograft survival
Age (years)	1.03	1.02-1.03	< 0.001	1.02	1.01-1.03	< 0.001
Black ethnicity	1.21	0.95-1.55	0.13
Female	0.82	0.65-1.02	0.08
Diabetes	1.66	1.35-2.03	< 0.001	1.46	1.18-1.81	< 0.001
Time at ESKD	1.04	1.01-1.07	0.003	1.03	1.00-1.06	0.04
Living donor transplant	0.76	0.60-0.97	0.025
Total HLA mismatch	1.08	1.00-1.16	0.04
Delayed graft function	1.91	1.55-2.36	< 0.001	1.68	1.36-2.08	< 0.001
CVC	0.91	0.75-1.12	0.37
Death with a functioning graft
Age (years)	1.07	1.05-1.08	< 0.001	1.06	1.05-1.08	< 0.001
Female	1.03	0.43-0.91	0.015	0.64	0.43-0.94	0.021
Diabetes	1.96	1.43-2.69	< 0.001	1.57	1.13-2.19	0.008
Time at ESKD	1.05	1.01-1.09	0.013
Living donor transplant	0.62	0.42-0.92	0.019
Delayed graft function	1.82	1.31-2.54	< 0.001
CVC	1.15	0.84-1.57	0.38
Death-censored allograft survival
Black ethnicity	1.35	0.99-1.85	0.06
Diabetes	1.48	1.13-1.95	0.005	1.48	1.11-1.97	0.007
Time at ESKD	1.03	0.999-1.07	0.05
No alemtuzumab induction	1.34	0.96-1.87	0.09
Total HLA mismatch	1.10	1.00-1.21	0.043
Delayed graft function	2.01	1.54-2.64	< 0.001	1.80	1.37-2.38	< 0.001
CVC	0.74	0.56-0.96	0.023	0.74	0.57-0.97	0.028

Variables investigated; age, gender, ethnicity, cause of end-stage kidney disease (ESKD), time at ESKD, type of donor, allograft number, induction, diabetes, delayed graft function, total human leukocyte antigen mismatch, sensitization, in addition to type of hemodialysis access. Variables are reported in the table if considered potentially significant (P < 0.15). These variables were included in multivariable model, with only statistically significant variables (P < 0.05) reported on adjusted analysis. CI: Confidence interval; CVC: Central venous catheter; ESKD: End-stage kidney disease; HLA: Human leukocyte antigen; HR: Hazard ratio.

Table 3 Multivariable analysis using time-varying events comparing outcomes in patients with post-transplant arteriovenous fistulae ligation vs non-ligation

	Univariate			Multivariate
	HR	95%CI	P value	HR	95%CI	P value
All-cause allograft survival
Age (years)	1.02	1.01-1.03	< 0.001	1.02	1.01-1.03	< 0.001
Diabetes	1.59	1.18-2.14	0.002	1.59	1.20-2.10	0.001
Time at ESKD	1.03	0.99-1.07	0.14
Living donor transplant	0.67	0.43-1.05	0.08
Delayed graft function	1.53	1.15-2.03	0.004	1.56	1.18-2.06	0.002
AVF ligation	0.73	0.52-1.03	0.072	0.72	0.51-1.01	0.059
Death with a functioning graft
Age (years)	1.08	1.06-1.11	< 0.001	1.08	1.05-1.10	< 0.001
Diabetes	1.89	1.18-3.04	0.009	2.02	1.30-3.16	0.002
Living donor transplant	0.43	0.17-1.08	0.072	0.39	0.15-0.96	0.042
AVF ligation	1.55	0.93-2.58	0.1
Death-censored allograft survival
Diabetes	1.41	0.98-2.04	0.067
Time at ESKD	1.03	0.99-1.08	0.14
Delayed graft function	1.71	1.20-2.44	0.003	0.85	1.31-2.59	< 0.001
AVF ligation	0.43	0.27-0.69	< 0.001	0.42	0.26-0.66	< 0.001

Variables investigated; age, gender, ethnicity, cause of end-stage kidney disease (ESKD), time at ESKD, type of donor, allograft number, induction, diabetes, delayed graft function, total human leukocyte antigen mismatch, sensitization, in addition to type of hemodialysis access. Variables are reported in the table if considered potentially significant (P < 0.15). These variables were included in multivariable model, with only statistically significant variables (P < 0.05) reported on adjusted analysis. AVF: Arteriovenous fistulae; CI: Confidence interval; ESKD: End-stage kidney disease; HR: Hazard ratio.