Extended travel for donor organs: Is cold static storage still relevant

Table 1 Recipient characteristics, n (%)

Variable	Overall (n = 897)	Cold static storage (n = 792)	Ex vivo lung perfusion (n = 105)	P value
Age	64 (57, 68)	64 (57, 68)	63 (56, 68)	0.365
Male sex	551 (61.4)	490 (61.9)	61 (58.1)	0.522
Race				0.816
White	659 (73.5)	582 (73.5)	77 (73.3)
Black	89 (9.9)	77 (9.7)	12 (11.4)
Other	149 (16.6)	133 (16.8)	16 (15.2)
Body mass index (kg/m2)	26.6 (23.3, 29.4)	26.7 (23.3, 29.4)	26.4 (23.7, 29.3)	0.67
Diabetes	150 (16.8)	128 (16.3)	22 (21)	0.286
Former smoker	509 (56.7)	444 (56.1)	65 (61.9)	0.404
Glomerular filtration rate (mL/minute/1.73 m2)	91 (74.6, 119.3)	90.3 (74.4, 117.8)	97.2 (76.7, 125.3)	0.286
Mean pulmonary artery pressure (mm Hg)	25 (20, 30.5)	25 (20, 30)	24 (21, 32)	0.477
Diagnosis				0.755
Cystic fibrosis/immunodeficiency	24 (2.7)	21 (2.7)	3 (2.9)
Obstructive lung disease	207 (23.1)	179 (22.6)	28 (26.7)
Pulmonary vascular disease	36 (4)	31 (3.9)	5 (4.8)
Restrictive lung disease	630 (70.2)	561 (70.8)	69 (65.7)
Lung allocation score	41.2 (35.7, 55.2)	41.3 (35.8, 55.9)	40.5 (35.5, 53.7)	0.434
Hospitalized prior to transplant				0.8
Not hospitalized	643 (75.5)	561 (75.1)	82 (78.1)
Hospitalized	82 (9.6)	73 (9.8)	9 (8.6)
In intensive care unit	127 (14.9)	113 (15.1)	14 (13.3)
Pre-operative ventilator	47 (5.2)	44 (5.6)	3 (2.9)	0.351
Pre-operative extracorporeal membrane oxygenation	58 (6.5)	54 (6.8)	4 (3.8)	0.334
Days on wait list	34 (12, 117)	33 (12, 116)	42 (14, 122)	0.482

Variables are either presented as median, interquartile range or n, percentage when appropriate.

Table 2 Donor characteristics, n (%)

Variable	Overall (n = 897)	Cold static storage (n = 792)	Ex vivo lung perfusion (n = 105)	P value
Age	35 (25, 48)	35 (24, 47)	38 (25, 51)	0.082
Male sex	562 (62.7)	497 (62.8)	65 (61.9)	0.951
Coronary artery disease	57 (6.5)	52 (6.8)	5 (4.8)	0.585
Smoking history	86 (9.8)	74 (9.6)	12 (11.5)	0.648
Recent cocaine use	195 (22.1)	172 (22.1)	23 (22.1)	0.5
Diabetes	95 (10.7)	84 (10.7)	11 (10.6)	0.999
Hypertension	240 (26.9)	211 (26.8)	29 (27.6)	0.954
Alcohol abuse	180 (20.7)	162 (21.2)	18 (17.3)	0.429
Body mass index (kg/m2)	26 (23, 30)	25.9 (23, 29.9)	27.1 (23, 32.7)	0.15
PaO2/FiO2 ratio	449 (396.9, 506)	454 (400, 507.4)	408.5 (361, 487.1)	< 0.001
Donor cause of death				0.568
Neuro (seizure/cerebral vascular accident)	259 (28.9)	231 (29.2)	28 (26.9)
Drug overdose	136 (15.2)	126 (15.9)	10 (9.6)
Asphyxiation	56 (6.2)	48 (6.1)	8 (7.7)
Cardiovascular	71 (7.9)	61 (7.7)	10 (9.6)
Trauma (gun shot wound/stab/blunt)	331 (36.9)	290 (36.6)	41 (39.4)
Drowning	4 (0.4)	3 (0.4)	1 (1)
Other	39 (4.4)	33 (4.2)	6 (5.8)
Donation after circulatory death	94 (10.5)	62 (7.8)	32 (30.5)	< 0.001

Variables are either presented as median, interquartile range or n, percentage when appropriate.

Table 3 Transplant outcomes, n (%)

Variable	Overall (n = 897)	Cold static storage (n = 792)	Ex vivo lung perfusion (n = 105)	P value
Center volume	30 (12, 56)	30 (12, 56)	32 (14, 56)	0.526
Center volume yearly	2 (0.8, 3.7)	2 (0.8, 3.7)	2.1 (0.9, 3.7)	0.526
Perfused by
Organ perfusion organization			2 (1.9)
Transplant program			61 (58.7)
External perfusion center			41 (39.4)
Perfusion time			296 (218, 496)
Warm ischemic time	24 (19.3, 28)	24 (19, 26.8)	25.5 (20, 30.3)	0.113
Type of lung transplant				0.001
Bilateral	653 (72.8)	561 (70.8)	92 (87.6)
Right single	100 (11.1)	96 (12.1)	4 (3.8)
Left single	144 (16.1)	135 (17)	9 (8.6)
Distance traveled (nautical miles)	898 (824, 1006)	900 (824, 1006)	892 (826, 1058)	0.96
Ischemic time (hours)	7.3 (6.2, 8.8)	7.1 (6.1, 8.2)	13.5 (10.8, 16.2)	< 0.001
Length of stay (days)	20 (13, 38)	20 (13, 37)	22 (14, 48.5)	0.553
In-hospital mortality	59 (7.2)	50 (7)	9 (8.7)	0.668
Postop dialysis	81 (9.6)	65 (8.8)	16 (15.4)	0.049
Postop stroke	34 (4)	30 (4)	4 (3.8)	0.999
Airway dehiscence	16 (1.9)	16 (2.2)	0 (0)	0.254
Post-operative extracorporeal membrane oxygenation	97 (11.5)	79 (10.7)	18 (17.3)	0.068
Post-operative ventilator				0.011
None	7 (0.8)	5 (0.7)	2 (1.9)
< 2 days	445 (53.1)	405 (55.1)	40 (38.8)
2-5 days	167 (19.9)	143 (19.5)	24 (23.3)
5+ days	219 (26.1)	182 (24.8)	37 (35.9)
Primary graft dysfunction grade 3	123 (13.7)	108 (13.6)	15 (14.3)	0.975
Acute rejection (hospitalization)				0.014
Yes and treated with immunosuppressant	49 (5.8)	38 (5.1)	11 (10.5)
Yes and not treated with Immunosuppressant	5 (0.6)	3 (0.4)	2 (1.9)
No	792 (93.6)	700 (94.5)	92 (87.6)
Treated rejection (1st year)	84 (16.2)	63 (13.9)	21 (30.9)	0.001
Cause of death				0.827
Graft failure	35 (17.9)	32 (18.3)	3 (15)
Malignancy	4 (2.1)	4 (2.3)	0 (0)
Cardio/cerebrovascular	29 (14.9)	25 (14.3)	4 (20)
Pulmonary	33 (16.9)	29 (16.6)	4 (20)
Infection	58 (29.7)	51 (29.1)	7 (35)
Other	36 (18.5)	34 (19.4)	2 (10)
Year of transplant
2018	96 (10.7)	83 (10.5)	13 (12.4)
2019	142 (15.8)	122 (15.4)	20 (19)
2020	170 (19)	153 (19.3)	17 (16.2)
2021	209 (23.3)	180 (22.7)	29 (27.6)
2022	220 (24.5)	197 (24.9)	23 (21.9)
2023	60 (6.7)	57 (7.2)	3 (2.9)

Variables are either presented as median, interquartile range or n, percentage when appropriate.

Table 4 Matched recipient characteristics, n (%)

Variable	Overall (n = 416)	Cold static storage (n = 312)	Ex vivo lung perfusion (n = 104)	P value
Age	62 (55.8, 67)	62 (55.8, 67)	63 (55.5, 68)	0.621
Male sex	244 (58.7)	183 (58.7)	61 (58.7)	0.999
Race				0.92
White	305 (73.3)	229 (73.4)	76 (73.1)
Black	44 (10.6)	32 (10.3)	12 (11.5)
Other	67 (16.1)	51 (16.3)	16 (15.4)
Body mass index (kg/m2)	26.4 (23, 29.2)	26.4 (23, 29.2)	26.4 (23.6, 29.3)	0.75
Diabetes	95 (22.8)	73 (23.4)	22 (21.2)	0.736
Former smoker	236 (56.7)	171 (54.8)	65 (62.5)	0.209
Glomerular filtration rate (mL/minute/1.73 m2)	93.8 (76, 121.1)	93.2 (76, 118)	97.6 (76.5, 125.5)	0.54
Mean pulmonary artery pressure (mm Hg)	24 (20, 31)	24 (19, 31)	24 (21, 31.5)	0.457
Diagnosis				0.999
Cystic fibrosis/immunodeficiency	12 (2.9)	9 (2.9)	3 (2.9)
Obstructive lung disease	114 (27.4)	86 (27.6)	28 (26.9)
Pulmonary vascular disease	20 (4.8)	15 (4.8)	5 (4.8)
Restrictive lung disease	270 (64.9)	202 (64.7)	68 (65.4)
Lung allocation score	40.5 (34.9, 52.7)	40.4 (34.6, 52.8)	40.5 (35.4, 52.2)	0.987
Hospitalized prior to transplant				0.992
Not hospitalized	324 (77.9)	243 (77.9)	81 (77.9)
Hospitalized	35 (8.4)	26 (8.3)	9 (8.7)
In intensive care unit	57 (13.7)	43 (13.8)	14 (13.5)
Pre-operative ventilator	18 (4.3)	15 (4.8)	3 (2.9)	0.578
Pre-operative extracorporeal membrane oxygenation	24 (5.8)	20 (6.4)	4 (3.8)	0.466
Days on wait list	38 (12, 123)	34.5 (12, 121.8)	41.5 (13.8, 123)	0.765

Variables are either presented as median, interquartile range or n, percentage when appropriate.

Table 5 Matched donor characteristics, n (%)

Variable	Overall (n = 416)	Cold static storage (n = 312)	Ex vivo lung perfusion (n = 104)	P value
Age	38 (27, 51)	38.5 (28, 51)	38 (25, 51.2)	0.708
Male sex	250 (60.1)	186 (59.6)	64 (61.5)	0.817
Coronary artery disease	27 (6.5)	22 (7.1)	5 (4.9)	0.58
Smoking history	41 (10)	29 (9.5)	12 (11.5)	0.677
Recent cocaine use	98 (23.6)	75 (24.1)	23 (22.1)	0.209
Diabetes	41 (9.9)	30 (9.6)	11 (10.6)	0.924
Hypertension	116 (27.9)	88 (28.2)	28 (26.9)	0.9
Alcohol abuse	95 (23.1)	77 (25.1)	18 (17.3)	0.136
Body mass index (kg/m2)	27.2 (23.7, 30.8)	27.3 (24.1, 30.7)	27 (22.9, 32.1)	0.544
PaO2/FiO2 ratio	446 (394, 503.1)	453.5 (400, 504.2)	409 (360, 488.2)	0.001
Donor cause of death				0.252
Neuro (seizure/cerebral vascular accident)	118 (28.4)	91 (29.2)	27 (26.2)
Drug overdose	58 (14)	48 (15.4)	10 (9.7)
Asphyxiation	20 (4.8)	12 (3.8)	8 (7.8)
Cardiovascular	41 (9.9)	31 (9.9)	10 (9.7)
Trauma (gun shot wound/stab/blunt)	154 (37.1)	113 (36.2)	41 (39.8)
Drowning	1 (0.2)	0 (0)	1 (1)
Other	23 (5.5)	17 (5.4)	6 (5.8)
Donation after circulatory death	56 (13.5)	25 (8)	31 (29.8)	< 0.001

Variables are either presented as median, interquartile range or n, percentage when appropriate.

Table 6 Matched transplant outcomes, n (%)

Variable	Overall (n = 416)	Cold static storage (n = 312)	Ex vivo lung perfusion (n = 104)	P value
Center volume	32 (14, 56)	32 (14, 56)	32 (14, 56)	0.761
Center volume yearly	2.1 (0.9, 3.7)	2.1 (0.9, 3.7)	2.1 (0.9, 3.7)	0.761
Perfused by
Organ perfusion organization		0 (N/A)	2 (1.9)
Transplant program		0 (N/A)	61 (59.2)
External perfusion center		0 (N/A)	40 (38.8)
Perfusion time			294.5 (217, 507)
Warm ischemic time	24 (19.7, 28.5)	23 (18, 26)	25 (20, 30)	0.129
Type of lung transplant				0.009
Bilateral	319 (76.7)	228 (73.1)	91 (87.5)
Right single	40 (9.6)	36 (11.5)	4 (3.8)
Left single	57 (13.7)	48 (15.4)	9 (8.7)
Distance traveled (nautical miles)	894 (826, 1006.2)	900 (825.5, 1000.8)	892 (826.8, 1062.8)	0.862
Ischemic time (hours)	7.7 (6.4, 10.3)	7.1 (6.1, 8.2)	13.6 (10.8, 16.2)	< 0.001
Length of stay (days)	19 (13, 37)	19 (13, 35.8)	22 (14, 48.5)	0.278
In-hospital mortality	31 (7.7)	22 (7.3)	9 (8.7)	0.798
Postop dialysis	38 (9.2)	23 (7.4)	15 (14.6)	0.046
Postop stroke	18 (4.3)	14 (4.5)	4 (3.8)	0.99
Airway dehiscence	10 (2.4)	10 (3.2)	0 (0)	0.139
Post-operative extracorporeal membrane oxygenation	43 (10.4)	26 (8.3)	17 (16.5)	0.03
Post-operative ventilator				0.02
None	6 (1.5)	4 (1.3)	2 (2)
< 2 days	213 (51.8)	173 (56)	40 (39.2)
2-5 days	87 (21.2)	63 (20.4)	24 (23.5)
5+ days	105 (25.5)	69 (22.3)	36 (35.3)
Primary graft dysfunction grade 3	59 (14.2)	45 (14.4)	14 (13.5)	0.935
Acute rejection (hospitalization)				0.052
Yes and treated with immunosuppressant	26 (6.2)	15 (4.8)	11 (10.6)
Yes and not treated with Immunosuppressant	4 (1)	2 (0.6)	2 (1.9)
No	386 (92.8)	295 (94.6)	91 (87.5)
Treated rejection (1st year)	44 (17.7)	23 (12.7)	21 (30.9)	0.002
Cause of death				0.625
Graft failure	17 (18.1)	14 (18.7)	3 (15.8)
Malignancy	1 (1.1)	1 (1.3)	0 (0)
Cardio/cerebrovascular	13 (13.8)	9 (12)	4 (21.1)
Pulmonary	16 (17)	12 (16)	4 (21.1)
Infection	31 (33)	24 (32)	7 (36.8)
Other	16 (17)	15 (20)	1 (5.3)
Year of transplant
2018	44 (10.6)	31 (9.9)	13 (12.5)
2019	69 (16.6)	49 (15.7)	20 (19.2)
2020	88 (21.2)	71 (22.8)	17 (16.3)
2021	99 (23.8)	70 (22.4)	29 (27.9)
2022	109 (26.2)	87 (27.9)	22 (21.2)
2023	7 (1.7)	4 (1.3)	3 (2.9)

Variables are either presented as median, interquartile range or n, percentage when appropriate. N/A: Not applicable.