Organ Preservation with HistidineTryptophan-Ketoglutarate (HTK) Solution:
Clinical Results
Charles M. Miller MD
Director, Liver Transplantation Program
Professor of Surgery
Cleveland Clinic
Organ Preservation Solutions
Preservation solutions are used to
maintain the hypothermic organ in
optimal condition from the time of
explantation until implantation
Principles of Organ Preservation
• Exsanguination to reduce
intravascular thrombosis
• Hypothermia to reduce
cellular metabolism
• Maintain cell membrane
integrity to avoid cellular
swelling
• Susceptibility to cold
ischemic injury: vascular
endothelium > parenchymal
cells
Ischemia
• Decreased mitochondrial
function
– Anaerobic conditions depletion of ATP
– Alterations in ion
permeability
– Accumulation of lactate
• Accumulation of hypoxanthine
• Cell swelling
• Cytosolic calcium
accumulation
Reperfusion
• Generation of reactive oxygen
species
• Increased oxidative stress
• Lipid peroxidation of cellular
membranes
• Free radical formation leads to
cellular destruction
• Results in macrophage/Kupffer
cell activation
– Increased serum tumor
necrosis factor (TNF)
• Damage can lead to prolonged
hypoxia after reperfusion
History of Organ Preservation
•
•
•
•
•
•
•
Simple cooling with cold solution
Continuous hypothermic perfusion
Collins (1967)
Euro-Collins (1980)
University of Wisconsin - ViaSpan (1986)
HTK - Custodiol (1980’s)
Celsior - 1994
Euro-Collins Solution
• High potassium, glucose, and phosphate-based
solution
• Designed to mimic composition of intracellular fluid
• Low cost
• Poor preservation quality
• Short preservation times achievable
UW Solution
• Use of impermeant molecules, lactobionate and
raffinose, in preventing cell swelling
• First developed for and applied in preservation of
canine pancreas
• Hydroxyethyl starch to minimize interstitial edema
during machine perfusion, not necessary during cold
storage
• High [K+], low [Na+]
Southard and Belzer
UW Solution: Disadvantages
• Glutathione is oxidized during storage: addition of fresh
GSH immediately before use; other additives
• High viscosity
• Solution cannot be released into circulation (high K
content)
• Huge particles ~ 100 µm in diameter contained in original
solution: must use in-line filtration with 40 µm pore
size.Particles caught in capillary bed of perfused organ,
resulting in vascular constriction, impeded reperfusion,
and reduction of functional recovery
Crystals in UW solution stored at sub-zero temperature (a )
perfused livers (b)
pancreas (c)
kidneys (d)
Tullius et al: AJT 2:627
HTK Solution (Custodiol)
• Developed as cardioplegia
• Low potassium
• High buffering capacity of histidine
• No colloid - viscosity equal to that of pure water
from 1 to 350C, with mean flow rate 3X that of
UW solution at equal perfusion pressure organs exsanguinate and cool down to lower
temperatures more rapidly than with UW
M.M. Gebhard, H.J. Kirlum, C. Schlegel. Organ preservation with the solution HTK
Component
UW
HTK
Sodium (mmol/L)
40
15
Pottasium (mmol/L)
120
10
Lactobionate (mmol/L)
100
-
Phosphate (mmol/L)
25
-
Raffinose (mmol/L)
30
-
Adenosine (mmol/L)
5
-
Ketoglutarate (mmol/L)
-
1
Histidine (mmol/L)
-
198
50
-
Mannitol (mmol/L)
-
30
Tryptophan (mmol/L)
-
2
Osmolality (mOsm/L)
320
310
Starch (gm/L)
Randomized Controlled Trials
• Kidney
1 European, 3-year follow-up
1998, n = 650 transplants, Deceased
donors
• Pancreas 1 European
2009, n=68 transplants
• Liver
3 European
1994 (n=60) – Deceased donors
2003 (n=30) – Living donors
2005 (n=40) – Deceased donors
Kidney Preservation
Transplants:
HTK 332, UW 312
DGF:
Need for dialysis 2 or more times
during first 7-days post-transplant
Flush volume:
HTK 5 – 6 L
UW 1 – 2 L
EC
4L
16
Kidney preservation
de Boer, et al, Transpl Proc, 1999; 31: 2065
17
Kidney preservation
de Boer, et al, Transpl Proc, 1999; 31: 2065
18
Kidney preservation
Lynch RJ, et al. AJT 2008; 8:567-73
19
Kidney preservation
Post-transplant kidney graft survival
Living Donor:
HTK n=475
UW n=475
Deceased donor:
HTK n=317
UW n=317
Lynch RJ, et al. AJT 2008; 8:567-73
20
Pancreas preservation
Transplants:
randomized 68 transplants over 18 months
at 4 centers
Outcomes:
6-month graft survival –
NO DIFFERENCE
Graft function –
NO DIFFERENCE
Fasting BG C-peptide level
HbA1c
Insulin requirement
Flush volume:
HTK
UW
5–8L
3L
n=41
n=67
21
Pancreas preservation
Figure 1. No insulin requirement
Figure 2. Serum amylase level
Figure 3. Serum lipase level
22
Pancreas preservation
Figure 4. C-peptide level
Figure 5. Units exogenous insulin
Figure 6. HbA1c
23
Pancreas preservation
Indiana University, 2003 to 2007-- Largest center in USA
N = 310
HTK 262, UW 48
Simultaneous, retrospective
1-year graft survival – 91% (U.S. 79-86%)
24
Liver Transplantation
• Hatano et al: Hepatic preservation with histidinetryptophan-ketoglutarate solution in living-related
and cadaveric liver transplantation. Clinical
Science (1997), 93:81
• Evaluated graft oxygenation state after reperfusion
in LRLT using near-infrared (NIR) tissue
spectroscopy
• LRD liver: HTK (15) vs UW (49)
• CAD liver: HTK (30) vs UW (18)
E. Hatano, et al. Tissue oxygenation in living related liver
transplantation (Clinical Science, 1997)
LRLT
Intraoperative
changes
in mean value of
oxygen saturation of
Hb at 10 points in
liver graft
After reflow
of operation
Biliary Complications Develop up to 30%
of Patients After Liver Transplantation
Post-liver Transplant Biliary
Strictures
• Biliary strictures after liver transplantation:
10-30%
• Adequate flushing of peri-biliary arterial tree
is important
• High viscosity preservation solutions might
not completely flush the small donor peribiliary plexus
Peri-Biliary Vascular Plexus
Alpini et al.
et al. 7:540-545, 2001
Pirenne et al. LiverPirenne
Transplantation,
Liver Transplantation, 7:540-545, 2001
Two group of liver recipients:
Group 1 (24): Donor aortic flush with Marshall solution
Portal vein with UW
Group 2 (27): Donor aortic flush with UW
Portal vein with UW
CIT: 692+190 ( group 1) vs. 535+129, (group 2),
(P=.001)
Preservation cost 1.9 times greater in the UW than in
the Marshall group
Pirenne et al.
Liver Transplantation, 7:540-545, 2001
• Recipient surgeon : Same surgeon
• All biliary reconstruction duct-to-duct except in one
patient
• One-year patient and graft survival 92% (1) and
100% (2)
• Biliary stricture: 1/24 (4.1%) group 1
8/27 (29.2%) group 2
Biliary stricture in group 1: 4 months after LTX and
anastomotic
Biliary strictures in group 2: 1-12 months after LTX
and anastomotic, extrahepatic, intrahepatic or a
combination of intra-and extrahepatic
HTK and UW for Liver Preservation
Hannover (1988 - 2000) n = 1068
HTK
UW
• n
461
607
• PF
439
578
• INF
22
29
• INF %
4.8 %
4.8 %
p = 1.00
HTK and UW for Liver Preservation
Hannover (1988 - 2000) n = 1068
CIT >15 hours
HTK
UW
• n
36
154
• PF
34
143
• INF
2
11
• INF %
5.6
7.1
p = 1.000
Liver Transplant Patient Survival
Hannover (1988 - 2000)
100
%
80
HTK (n = 400)
60
UW (n =4 92)
40
20
P < 0.0331 (LogRank)
0
0
1
2
3
4
years
5
Liver Transplants Graft Survival
Hannover (1988 - 2000)
100
%
80
HTK (n = 461)
60
40
UW (n = 607)
20
P < 0.0029 (LogRank)
0
0
1
2
3
4
years
5
HTK and UW for Liver Preservation
Hannover (1988 - 1998) n = 836
Biliary Tract Complications
HTK
UW
• n
305
531
• BTC
39
65
• BTC %
12.8
12.2
HTK vs. UW
University of Gottingen
Patients and Methods
Patients
123
120 Adults, 3 Children;
Age 1 - 70 years
Transplantations: Total 134
Cadaveric:
123 primary, 10 secondary, 1 tertiary
114 standard orthotopic, 5 split, 4 partial
Living donation:
11 (right lobe)
Combined:
6 kidney transplantation
1 bone marrow transplantation
1 heart and kidney transplantation
Preservation solution: 63 HTK und 71 UW
HTK vs. UW:
University of Gottingen
Initial Liver Function
OLT total
HTK
UW
63
71
Initial function (IF)
45 (71.5%)
43 (60.5%)
Initial dysfunction (IDF)
13 (20.6%)
26 (36.6%)
Initial nonfunction (INF)
5 (7.9%)
2 (2.8%)
HTK vs. UW
University of Gottingen
Biliary Complications
HTK
Bile duct necrosis
Localized strictures
UW
3 (16, 17, 485 d) 3 (44, 10, 8, 46 d)
2 (72, 150 d)
Diffuse strictures (ITBL)
-
Total
5
ITBL = ischemic type biliary lesion
2 (210, 305 d)
3 (610, 210, 365 d)
8
HTK vs. UW
University of Gottingen
Biochemical Parameters
HTK
AST
UW
(U/l)
1320 + 1254
1389 + 1214
“
pod 7 (U/l)
26.7 + 17.5
24.3 + 18.4
AP
pod 7 (U/l)
159.7 + 94.6
214.8 + 109.2
81 + 52.9
84.6 + 59.5
Bilirubin pod 14 (mg/dL) 9.5 + 9.7
13.8 + 12.6
max
GGT pod 7 (U/l)
HTK vs. UW
University of Gottingen
Comparative Analysis
- Similar ischemic damage (AST) in both groups.
- Similar length of ICU stay in both groups.
- The rate of IDF/INF was similar in both groups.
- Bilirubin was higher in UW group
(13.8 vs. 9.5 mg/dL pod 14).
- Biliary complications significantly higher in UW
group (8/71 vs. 5/63). No ITBL in the HTK group.
HTK solution for organ preservation in human
liver transplantation
A prospective multi-center observation study
Pokorny et. al. Transplant International 2004; 17:256-260 (Austria, Germany)
•
•
•
•
•
•
214 patients in 4 European centers (1996-1999)
5 liters of HTK for preservation CIT 444 + 224
All vascular anastomoses completed before reperfusion
No pre-reperfusion flush
PNF 2.3%, Initial dysfunction 6.5%
Graft dysfunction not correlated with CIT
• 1-year patient and graft survival 83% and 80% (unrelated to CIT)
• HTK: safe and effective and easy to use.
• Comparable to UW with less cost.
HTK vs. UW in LDLT
Chan et. al. Liver Transplantation 2004; 10:1415-1421 (Hong Kong)
Number of patients
Age
CIT
Biliary stricture*
Pre-reperfusion flush
Graft loss
Hospital mortality
UW
30
38.5
112 (79 + 334)
10 (33%)
Yes
0
0
Biochemistry: No significant differences
Cost analysis: UW $137.6 higher than HTK/patient
* Not significant
HTK
30
35.5
111.5 (75 + 222)
6 (20%)
No
1
0
Liver Preservation
Liver Preservation
Indiana University, 2001 to 2008
All adult, deceased donor
n=1013
HTK 632, UW 381
Simultaneous, retrospective
Liver Preservation
Indiana University, 2001 to 2008
Post-liver transplant serum ALT, n=1013
600
All adult, deceased donor
Simultaneous, retrospective
500
HTK 632 UW 381
HTK
300
UW
Serum ALT
200
100
0
0
5
10
15
20
25
30
35
Days post-transplant
Post-liver transplant serum total bilirubin, n=1013
4
3.5
Serum total bilirubin
n=1013
Serum ALT
400
3
2.5
HTK
2
UW
1.5
1
0.5
0
0
5
10
15
20
Days post-transplant
25
30
35
Serum
Bilirubin
Liver Preservation
3 Randomized Studies:
1. Erhard J, et al. Comparison of HTK versus UW for organ preservation in human liver
transplantation: A prospective, randomized study. Transplant International 1994; 7: 177-81.
• 60 deceased donor liver transplants (HTK n=30 and UW n=30)
• No difference in early and late graft survival, even for 7 donor livers with cold ischemia time >15 hrs
• More late biliary complications in UW group.
• Higher initial transaminases in HTK group.
2. Testa G, et al. HTK versus UW in living donor liver transplantation: results of a prospective
study. Liver Transplantation 2003; 9(8): 822-26.
• 30 consecutive living donor right lobe transplants flushed alternately with HTK (n=16) or UW (n=14)
• Patients were randomly allocated based upon timing of transplantation
• 1-year post-transplant, there is no difference in graft and patient survival, liver enzymes and complications
3. Nardo B, et al. Preliminary results of a clinical randomized study comparing Celsior and HTK
solutions in liver preservation for transplantation. Transpl Proc 2005; 37:320-2.
• European randomized trial comparing Celsior and HTK.
• No difference in initial function or survival up to 1-year post-transplant.
HTK vs. UW in liver transplantation
A meta analysis
Feng et.al. Liver Transplant, 2007
HTK vs. UW in liver transplantation
A meta analysis
P= 0.87
RR 1.01
Patient Survival
P= 0.86
RR 1.01
Graft Survival
Feng et.al. Liver Transplant, 2007
HTK vs. UW in liver transplantation
A meta analysis
Feng et.al. Liver Transplant, 2007
HTK vs. UW in liver transplantation
A meta analysis
• Cost: HTK cheaper than UW
• Biliary complications:
Trend for less biliary strictures with HTK
• PNF, PDF, DGF:
No difference
• Graft survival:
No difference
• Patient survival:
No difference
• Biochemical values: No difference
Feng et.al. Liver Transplant, 2007
Recent retrospective database
reviews
Conclusion of all 3: These results suggest that the
increasing use of HTK for abdominal organ
preservation should be reexamined.
Recent retrospective database
reviews
•
Data review:
– Usually large database is better to increase numbers
– In large transplant research, single center better to maintain
homogeneous patient, donor and management factors
•
Database review
Selection bias
• Do surgeons who use HTK differ from those that use UW ?
• CONFOUNDING – database differences likely just highlight
differences in practice patterns between surgeons who use
HTK and those who use UW
– Kidney study – exclude all machine pumped kidneys
– Pancreas study – unable to differentiate high risk grafts
– Liver study – no ability to analyze steatosis, hypernatremia,
etc
53
Histidine-Tryptophan-Ketoglutarate
Solution Vs. University of Wisconsin
Solution for Deceased Donor Liver
Transplantation: Analysis of SRTR
Database
Cleveland Clinic
Purpose
• This analysis aims to evaluate the
impact of the organ preservation
solutions (OPS) ,(Histidine-TryptophanKetoglutarate (HTK) vs. University of
Wisconsin (UW) solution) on the
outcome of adult deceased donor liver
transplantation (DDLT) using the
Scientific Registry of Transplant
Recipient (SRTR) database.
Materials and Methods
Only adult first liver-only transplants
from 2002-2006 for whom both flush
and storage solutions were the same.
Risk-unadjusted graft survival was
estimated non-parametrically by the
method of Kaplan and Meier, and
parametrically by a multiphase hazard
decomposition method
Statistical Analysis
• Risk factors for graft survival were determined using
nonproportional, multiphase, multivariable hazard
methodology. This methodology allows modeling of
recipient, donor, and procedure variables in all
phases of the hazard model simultaneously.
Bootstrap aggregating was used for variable
selection with a probability for inclusion of 0.001;
variables appearing in at least 50% of bootstrap
analyses were considered reliably statistically
significant at p<0.001.
Patients
• The data set included 20,908 patients,
17,559 (84%) with UW and 3349 (16%)
with HTK solutions. Mean follow-up was
2.9 ± 1.5 years (3.0 ± 1.5 years for UW
and 1.9 ± 1.0 years for HTK). We
defined an early phase (EP) shortly
after DDLT followed by a constant
phase (CP) of hazard for graft failure.
Results
• Significant predictors of graft failure in
the EP after DDLT include the following
recipient factors: older age, race either
White or Black, portal vein thrombosis,
last creatinine and last MELD for the
transplant (tx) candidacy, on life support
just prior to tx, and previous kidney tx.
Risk Factors for Graft Failure Early Phase
Risk Factor
P
Bootstrap %
Early hazard phase
Older recipient age (years)
<.0001
93
.0005
69
Recipient portal vein thrombosis
<.0001
95
Recipient previous abdominal surgery
<.0001
48
Candidate last creatinine (used for MELD)
<.0001
86
Candidate last MELD
<.0001
71
Recipient on life support just prior to tx
<.0001
100
Recipient previous kidney transplant
<.0001
90
Donor race non-White
<.0001
67
Donor donation after cardiac death
<.0001
100
Donor risk index
<.0001
46
Recipient race White or Black
Risk Factors for Graft Failure Constant Phase
Risk Factor
P
Bootstrap %
Constant hazard phase
African American recipient
<.0001
97
Recipient tumor (incidental) at transplant
<.0001
88
Recipient primary diagnosis for tumors
<.0001
87
Recipient hepatitis C virus
<.0001
100
Donor age (years)
<.0001
97
Donor history of diabetes
<.0001
77
Results
• Significant donor factors in the EP are: race
other than White, donation after cardiac death
(DCD) and donor risk index (DRI). OPS did
not appear as a statistically significant
predictor of graft failure. Hospital death, retransplant rates (overall and within 14 days of
initial transplant) and relisting rates (overall
and within 30 days of tx) were similar
(p>0.05).
Patient Survival - Donor >65
•
•
•
•
Donor Age > 65
N=1698 UW
N= 311 HTK
p=.46 log rank
test
Patient Survival - Donor <65
•
•
•
•
Donor Age <65
N=15861 UW
N= 3038 HTK
p=.28 log rank
test
Patient Survival - DCD Donor
•
•
•
•
DCD Donor
N=570 UW
N=159 HTK
p=.73 log rank
test
Patient Survival - Non-DCD
Donor
• Non-DCD
Donor
• N=16989 UW
• N=3190 HTK
• p=.55 log rank
test
Patient Survival - DRI >2.5
•
•
•
•
Donor DRI >2.5
N=8663 UW
N=1682 HTK
p=.25 log rank
test
Patient Survival - DRI <2.5
•
•
•
•
Donor DRI <2.5
N=6600 UW
N=1218 HTK
p=.37 log rank
test
Graft Survival - Donor Age >65
•
•
•
•
Donor Age >65
N=1698 UW
N= 311 HTK
p=.64 log rank
test
Graft Survival - Donor Age <65
•
•
•
•
Donor Age <65
N=15861 UW
N= 3038 HTK
p=.045 log rank
test
Graft Survival - DCD Donor
•
•
•
•
DCD Donor
N=570 UW
N=159 HTK
p=.17 log rank
test
Survival Rate (%)
.
Kaplan-Meier Adult Graft Survival
Primary Deceased Donor Liver Transplants
2000-2006
100
90
80
70
60
50
40
30
20
10
0
0
2
4
6
8 10 12 14 16 18 20 22 24 26 28 30 32 34 36
Months Post Transplant
DBD
SRTR
DCD-UW
DCD-HTK
Includes adult, primary, liver alone transplants
Graft Survival - Non-DCD Donor
• Non-DCD
Donor
• N=16989 UW
• N=3190 HTK
• p=.23 log rank
test
Graft Survival - DRI >2.5
•
•
•
•
Donor DRI >2.5
N=8663 UW
N=1682 HTK
p=.053 log rank
test
Graft Survival - DRI <2.5
•
•
•
•
Donor DRI <2.5
N=6600 UW
N=1218 HTK
p=.15 log rank
test
Used casewise deletion of missing data, i.e.
threw out cases that were missing any of the
predictor variables they were studying. It means
they are using only patients for whom all
variables were reported - doing this can
potentially bias results
SRTR Information Flow
Monthly
Transfer
OPTN
Person
Linking
SRTR
CMSESRD
SSDMF
SEER
Data
Quality
Analysis File Creation
Data
Fixes
Feedback
OPTN
MPSC
OPOSpecific
Reports
Data Use Agreements
Standard
Analysis
Files
Center-Specific Analyses
CenterSpecific
Reports
NCHS,
AHA, etc
Reorganization for Research
Cleaning and Validation
Analysis Variables Added
Public
Release
External
Research
Analytical Procedures and Products
TAC
RFI
Journal
Articles
Conference
Present’ns
OPTN,
ACOT
Committees
Annual,
Biennial
Reports
Implications of Casewise
Deletions
• While they do say that data were
missing for less than 4% of covariates, if
the missing values were scattered over
20% of patients, then 20% of total data
might have been deleted.
• Example:
– SRTR CIT data: 100% complete
– UNOS CIT data: 86% complete
Critique
• Last transplant included was 2/28/08 - the
paper was submitted on 7/17/08. Assuming
that it took 45 days to analyze and write the
paper, then the data cutoff would have been
6/1/08. Given that the first recipient follow-up
form required by UNOS is at 6 months and
then they only release data after a 60 day
period for completion, they only have data for
transplants performed before 11/1/07
Other Considerations
• Slightly different timeframes:
– is there a change in clinical practice?
– is there a learning curve for new users of HTK?
• Do the conclusions make sense?
– Recipient age 18-34 HR 1.14
– COD - CVA, HR 1.04 (SRTR HR 1.16)
– COD - DCD, HR 1.97 (SRTR HR 1.51)
Does Not Fit Clinical Impressions
• Cleveland Clinic DCD experience
– 15 controlled DCD LTX preserved with HTK since
2005
– Heparin could not be given prior to declaration of
death
– Mean donor age was 38 ± 12 years
– Mean WIT and CIT was 25 ± 9 min and 427 ± 97
min, respectively
– No recipient developed ITBS. PNF was seen in
one recipient who was salvaged with
retransplantation
Summary and Conclusions
•
All randomized controlled trials large single center case series, across
multiple organs, countries and time periods demonstrate no difference in
clinical outcomes between HTK and UW
•
Question of appropriate flush volume - of particular importance to the
pancreas
•
There is a clear cost benefit in the use of HTK
•
Recent database reviews of tens of thousands of patients likely reflect
difference in practice patterns between surgeons who use HTK and those
who use UW. It is less likely to represent a true difference in the clinical
outcomes of the two solutions when the vast majority of high quality studies
show no difference.
84
Thank You