Effect of Donor Hepatic Steatosis on Ischemia Reperfusion Injury in Liver Transplant Recipient

Abstract

Introduction

Ischemia reperfusion injury (IRI) is an important complication of liver transplant (LT). The donor risk index, which does not incorporate steatosis, includes several variables known to impact on allograft survival. The purpose of this study was to report on donor liver allograft steatosis and its association with severity of IRI.

Aim

The aim of this study was to determine the effect of type and grade of donor liver steatosis on the occurrence and severity of IRI in LT recipients.

Methods

This was an observational study conducted at a single center over a period of 37 months from July 2013 to August 2016. Liver biopsy was performed twice, initially at the time of procurement before graft perfusion for steatosis assessment. Steatosis was classified as microsteatosis (MiS) or macrosteatosis (MaS) with mild, moderate, or severe grade. Second biopsy for IRI assessment was taken before skin closure in death donor LT (DDLT) and at the time of transaminitis in postoperative period (<72 hrs) in living donor LT (LDLT). IRI was graded as per neutrophil infiltrate, apoptosis, and hepatocyte cell dropout. Prevalence of IRI and association steatosis was studied along with other factors.

Results

Among 53 subjects, 35 were DDLTs and 18 were LDLTs. All live donor grafts were restricted to <15% MaS and the deceased liver grafts had different type and degree of steatosis. In DDLTs, the association between occurrence of IRI and MaS was not statistically significant (P = 0.201). In DDLTs, the mild steatosis was not significantly associated with IRI. Death donor and ischemic time were significantly associated with IRI. Child's stage and MELD scores, gender, and age were not associated with risk of IRI. Severity of IRI is significantly associated with 3-month mortality (P = 0.001).

Conclusion

In patients with mild steatosis, IRI does not correlate with steatosis. However, more patients with moderate and severe steatosis are needed to define the relationship of the two in this group of patients.

Liver transplant (LT) has evolved as the therapy of choice for patients with end-stage liver disease over the past 3 decades. However, the waiting list for liver transplantation is growing at fast pace, whereas the number of available organs is not growing at a proportional rate particularly in countries such as India. The potential use of steatotic livers for transplant, one of the most common types of organs from marginal donors, has become a major focus of investigations. However, the clinical problem is still unresolved because steatotic livers are more susceptible to ischemia reperfusion injury (IRI) and, when used, have poorer outcome than nonsteatotic livers. IRI is an important cause of liver damage occurring during surgical procedures including hepatic resections and LT.^{1, 2, 3} There are recent reports of allograft outcomes with varying combinations of donor macrosteatosis with or without microsteatosis. But there are very few studies on IRI particularly in regard with donor steatosis. The purpose of this study was to report on donor liver allograft steatosis and its association with the severity of IRI. Other confounding factors including the age of donor and recipient, sex, ischemia time, the model of end-stage liver disease (MELD) score, and Child's stage were also studied.

Aim

The aim of the study is to determine the effect of type and grade of donor liver steatosis on the occurrence and severity of ischemia reperfusion injury in liver transplant recipients.

Objectives

Primary Objective

In liver transplant recipients, the primary objectives are as follows:

• •To identify the incidence of IRI.
• •To analyze the effect of donor liver steatosis on IRI in DDLT.

Secondary Objective

The secondary objectives are as follows:

• (a)
  To identify factors associated with occurrence of ischemia reperfusion injury.

  • •
    Age (donor and recipient)
  • •
    Sex (recipient)
  • •
    Ischemia time (cold and warm)
  • •
    Child's stage
  • •
    MELD score
• (b)To study association of these factors with mortality at the end of three months.

Materials and methods

Study Area and Setting

This study was conducted in KIMS hospital, which is a tertiary care center in Trivandrum, India. We studied the occurrence of IRI in all live and deceased LT recipients and the effect of liver steatosis type and grade on ischemia reperfusion injury in recipients of deceased liver transplant.

Study Population

Liver transplantations performed over 37 months in KIMS hospital were included as study subjects. Liver transplant patient and donor were the source of demographic, biochemical, and clinical data.

Study Design and Duration

It was an observational study conducted over a period of 37 months from July 2013 to Aug 2016. Liver transplant patients and their respective liver graft donors were studied.

Case Definition

Steatosis

Liver biopsy examination was performed using haematoxilin & eosin (H & E) stain to estimate fat content of the donor liver. Donors were categorized in two group: macrosteatotic (MaS; large fat droplet replacing most of the hepatocyte cytoplasm and pushing the nucleus to the edges of the cytoplasmic border) and microsteatotic (MiS; multiple small droplets with a centrally placed nucleus).⁴ The degree of steatosis is subdivided into mild (<30% of hepatocytes), moderate (30%–60% of hepatocytes), and severe (>60% of hepatocytes).^{4, 5}

Ischemia Time

The cold ischemia time (CIT) was defined as the time from the perfusion of the donor with preservation solution (University of Wisconsin) to the removal of the liver from cold storage. The warm ischemia time (WIT) is a term used to describe two periods of ischemia; first warm ischemia is during organ retrieval, from the time of cross-clamping until cold perfusion is commenced, and second warm ischemia is during implantation, from removal of the organ from ice until reperfusion. In much transplant literature, however, the term “warm ischemia” is used to describe both periods indiscriminately. In this study WIT means total WIT, that is, first and second WIT combined.^{6, 7, 8}

Ischemia Reperfusion Injury

IRI occurrence and severity was determined by histological grading of liver biopsies sampled after graft revascularization in case of DDLT and during postoperative period in case of LDLT when they had liver enzymes elevation (AST or ALT >1500 IU/L).

Post-transplant Outcome

In addition to IRI, post-transplant outcome was assessed by occurrence of primary dysfunction, that is, elevation in the transaminases (AST, ALT) level (>1500U/L) within postoperative 72 hrs in absence of technical complications of procedure as mention in exclusion criteria.⁹ Also, three months post-transplant mortality was studied.

Significant Hypotension

It was defined as hypotensive events (i. e. systolic blood pressure <90 mmHg for >15 min),^{10, 11} and those patients who had it were excluded from study.

Inclusion Criteria

• •Liver graft donors including living and deceased.
• •All liver transplant recipients.

Exclusion Criteria

• •Significant hypotension
• •
  Patient with technical complication during procedure

  • ○
    Hepatic artery thrombosis
  • ○
    Portal vein thrombosis
  • ○
    Outflow tract obstruction

Methods

Consent and Ethics

Approval of the institute's scientific and ethical committee was taken for conducting the study. The patient and bystander of patient were informed about the study being conducted. They were explained about their right to deny participating in the study. They were explained about the limitations and complications of the procedure. Their written consent was taken.

Donor

Liver biopsy for all transplant donor liver grafts was taken preoperatively, and histopathological examination (HPE) was carried out. Grafts with macrosteatosis (MaS) of <15% were considered for living donor liver transplant (LDLT). For both live and death donor liver transplant (DDLT), grafts biopsies were obtained during liver procurement immediately before graft perfusion, 2 cores one each from right and left lobe, and steatosis was assessed. HPE was performed, using H & E stain. Steatosis classified as MaS and MiS as already described.

Quantitative evaluation of steatosis was based on average percentage of fatty droplet occupying surface area of parenchyma. Potential graft with <60% MaS, without evidence of steatohepatitis were indicated for donation, regardless of MiS degree. The second biopsy (postreperfusion biopsy) was taken before skin closure for DDLT. For LDLT patients for whom intraoperative biopsy was not taken, it was taken during postoperative period (only one biopsy) when they had elevation in liver enzymes (AST or ALT >1500IU/L: normal level of ALT taken as 19IU/L for women and 30 IU/L for men. For AST, 40IU/L was considered as upper normal limit).⁹ HPE was performed by expert pathologist under low- and high-power field for IRI.

Overall incidence of the IRI in all recipients (LDLT + DDLT) was assessed. As all LDLT grafts are restricted to MaS of <15% and also the ischemia time is limited, in our study the effect of steatosis on severity of the IRI was studied among the recipients underwent DDLT only.

Severity of IRI

Several components of the biopsy were considered to make a global assessment of the severity of the IRI. The components were the presence of neutrophilic infiltrate, apoptosis, and hepatocyte cell dropout. The degree of neutrophilic infiltrate was based on their presence within sinusoids as single cells or as clusters. The presence of apoptotic cells was based on morphological criteria (cell shrinkage, chromatin condensation, and acidophilic bodies):

Nil IRI severity showed a scanty infiltration of single neutrophils within the sinusoids without a loss of hepatocytes.

Mild IRI severity was characterized by occasional detachment of single hepatocytes from the basement membrane or acidophilic bodies with a minor neutrophilic sinusoidal infiltrate, predominantly of single cells, with only rare small clusters.

Severe IRI was characterized by zonal or confluent coagulative hepatocyte loss, which was most often seen in the perivenular location, although more severe cases could present as bridging necrosis or as periportal confluent necrosis. There was an associated neutrophilic inflammatory infiltrate within these areas, with further clustered neutrophils within more distant sinusoids.

Moderate IRI lays between mild and severe cases and was defined by the presence of clustered (>5) neutrophils; some of which were associated with hepatocyte necrosis or loss. Importantly, if zonal necrosis was identified in the absence of a neutrophilic infiltrate, this was considered an ischemic lesion in the donor and was not categorized as a reperfusion injury (see Figure 1).¹²

Figure 1.

Allograft assessment. MaS, macrosteatosis; HPE, histopathological examination; BMI, body mass index; CT, computerized tomography; LFT, liver function test.

Recipients

Perioperative variables age, CHILD status, MELD score, and graft CIT and WIT were analyzed (Figure 2). All postoperative laboratory tests were performed as a part of routine clinical follow-up. Plasma ALT, AST, and alkaline phosphatase (ALP) were measured daily during the first postoperative week. Post-transplant outcome was assessed based on the recording of elevation in transaminases (AST, ALT >1500 U/L) within first 72 hrs.⁹ No separate blood sample was collected for this study, and required laboratory data was collected from investigations done as a routine protocol for the liver transplant patients during hospital stay. Variables of donor and recipient such as age, sex, Child–Pugh score, MELD score, CIT, and WIT were recorded.

Figure 2.

Post-transplant assessment. MELD, model for end-stage liver disease; CIT, cold ischemia time; WIT, warm ischemia time; ALT, alanine transferase; AST, aspartate transferase. ICH, intra cerebral haemorrhage; ALF, acute liver failure.

Statistical Analysis

Quantitative variables were described by mean, standard deviation, and minimum and maximum values. Qualitative variables were described by percentage distribution. Between groups, comparison of qualitative variables was done by chi-square test and Fisher's exact test, and comparison of quantitative data between two was analyzed by independent sample t test and that of more than two groups was analyzed by analysis of variance (ANOVA). Multivariate analysis of binary logistic regression model was run for the factors associated with ischemia reperfusion injury. A P value of <0.05 was taken as the level significance. Data analysis was performed using SPSS ver. 17.0.

Results

Total 60 patients were enrolled, and 7 subjects were excluded after applying exclusion criteria (acute liver failure in 2, sepsis in 2, intracranial hemorrhage in 1, and technical difficulty in 1 subject); hence, 53 subjects were studied (48 male and 5 female). Among these 53 recipients, 35 subjects were DDLT and 18 subjects were LDLT.

Most common etiology-wise indication for liver transplant was alcohol 15 (28.3%) followed by cryptogenic 14 (26.4%), NASH 10 (18.9%), hepatitis C virus (HCV) 5 (9.4%), hemochromatosis 3 (5.7%), and extrahepatic biliary atresia (EHBA) 2 (3.8%) (Table 1).

Table 1.

Etiology of Patients Undergoing Liver Transplant.

Etiology	Frequency	Percentage (%)
Alcohol	15	28.3
Cryptogenic	14	26.4
NASH	10	18.9
HCV	5	9.4
Hemochromatosis	3	5.7
EHBA	2	3.8
Others	4	7.5
Total	53	100.0

NASH, nonalcoholic hepatosteatosis; EHBA, extrahepatic biliary atresia; HCV, hepatitis C virus.

Of 35 DDLT subjects, mild IRI was seen in 22 patients (62.9%), moderate in 11 (31.3%), severe in 1 (2.9%) patient, and no IRI noticed in 1 (2.9%) patient. Among 18 LDLT subjects, IRI was seen in 7 patients (mild IRI in 4 [22.2%], moderate IRI in 2 [11.1%], and severe IRI in one patient [5.6%]) (Table 2 & Figure 3). The difference in incidence of IRI between DDLT and LDLT was statistically significant (P=<0.001).

Table 2.

Incidence of IRI in Both DDLT and LDLT Patients.

IRI	DDLT, n (%)	LDLT, n (%)
No	1 (2.9%)	11 (61.1%)
Mild	22 (62.9%)	4 (22.2%)
Moderate	11 (31.3%)	2 (11.1%)
Severe	1 (2.9%)	1 (5.6%)
Total	35 (100%)	18 (100%)

DDLT, death donor liver transplant.

χ² = 24.047, P < 0.001.

Figure 3.

Incidence of IRI in both DDLT and LDLT (χ² = 24.047 P < 0.001). DDLT, death donor liver transplant.

In prior biopsy of allografts of DDLT, mild MaS was seen in 33 (94.3%) grafts and moderate MaS was present in 2 (5.7%) grafts. Mild MiS was seen in 24 (68.6%) grafts, moderate in 5 (14.3%), and severe in 6 (17.1%) grafts. All LDLT grafts consisted <15% MaS.

In DDLT recipients, of 33 subjects with mild MaS, 22 patients had mild IRI, 9 subjects had moderate IRI, and one patient had severe IRI. No IRI was observed in one subject. Two subjects received grafts with moderate MaS, and both had moderate IRI (Table 3). The association between occurrence of IRI and MaS was not statistically significant (P = 0.201).

Table 3.

Association of MaS With IRI in DDLTs.

MaS (%)	Ischemia reperfusion injury (IRI)								Total
	No		Mild		Moderate		Severe
	N	%	N	%	N	%	N	%	N	%
<30	1	100	22	100	9	81.9	1	100	33	94.3
30–60	0	0	0	0	2	18.2	0	0	2	5.7
Total	1	100	22	100	11	100	1	100	35	100

DDLT, death donor liver transplant; MaS, macrosteatosis.

χ² = 4.6, P value = 0.201.

Of 35 DDLTs, all grafts had MiS. In 24 subjects with mild MiS, one patient had no IRI, 16 had mild, 6 had moderate and one had severe IRI. Of 5 moderate MiS subjects, 2 had mild IRI, 3 subjects had moderate IRI. Of 6 patients with severe MiS, 4 had mild IRI, 2 patients had moderate IRI (Table 4). MiS was found to have no significant association with IRI (P = 0.806).

Table 4.

Association of MiS With IRI in DDLTs.

MiS%	Ischemia reperfusion injury (IRI)								Total
	No		Mild		Moderate		Severe
	N	%	N	%	N	%	N	%	N	%
<30	1	100	16	72.7	6	54.5	1	100	24	68.6
30–60	0	0	2	9.1	3	27.3	0	0	5	14.3
>60	0	0	4	18.2	2	18.2	0	0	6	17.1
Total	1	100	22	100	11	100	1	100	35	100

DDLT, death donor liver transplant; MiS, microsteatosis.

χ² = 3.02, P value = 0.806.

On univariate analysis, it was found that none of the factors such as MaS, MiS, Sex, Child's score, AST, and ALT were found to be associated significantly with risk of IRI (Table 5).

Table 5.

Factors Associated With Occurrence of IRI.

Factors	Ischemia reperfusion injury				Total		Χ2	P
	Present		Absent
	N	%	N	%	N	%
MaS							0.062	0.803
<30	32	97	1	3	33	100
30-60	2	100	0	0	2	100
MiS							0.472	0.790
<30	23	95.8	1	4.2	24	100
30-60	5	100	0	0	5	100
>60	6	100	0	0	6	100
Sex							0.062	0.803
Male	32	97	1	3	33	100
Female	2	100	0	0	2	100
Child's stage							4.97	0.083
A	1	100	0	0	1	100
B	5	83.3	1	16.7	6	100
C	28	100	0	0	28	100
AST							0.772	0.380
Not elevated	19	95	1	5	20	100
Elevated	15	100	0	0	15	100
ALT							0.356	0.551
Not elevated	25	96.2	1	3.8	26	100
Elevated	9	100	0	0	9	100

MaS, macrosteatosis; MiS, microsteatosis; ALT, alanine transferase; AST, aspartate transferase.

Among 35 subjects of DDLT, 2 were died within 3 months after enrollment. During analysis, it was found that IRI and elevated ALT were strongly associated with mortality and none of the other factors were observed to be significant (Table 6, Table 7).

Table 6.

Factors Affecting 3-Month Mortality.

Factors	Outcome				Total		χ2	df	P
	Died (n = 2)		Survived (n = 33)
	N	%	N	%	N	%
Sex
Male	2	100	31	93.9	33	44.3	0.129	1	0.720
Female	0	0	02	6.1	2	5.7
Child's stage
A	0	0	1	3	1	2.9	1.635	2	0.442
B	1	50	5	15.2	6	17.1
C	1	50	27	81.8	28	80
MaS
<30	2	100	31	93.9	33	94.3	0.129	1	0.720
30–60	0	0	2	6.1	2	5.7
MiS
<30	1	50	23	69.7	24	68.6	2.364	2	0.307
30–60	1	50	4	12.1	5	14.3
>60	0	0	6	18.2	6	17.1
IRI
No	0	0	1	3	1	2.9	18.127	3	0.001
Mild	0	0	22	66.7	22	62.9
Moderate	1	50	10	30.3	11	31.4
Severe	1	50	0	0	1	2.9
AST
Not elevated	0	0	20	60.6	20	57.1	2.82	1	0.093
Elevated	2	100	13	39.4	15	42.9
ALT
Not elevated	0	0	26	78.8	26	74.3	6.128	1	0.013
Elevated	2	100	7	21.2	9	25.7

MaS, macrosteatosis; MiS, microsteatosis; ALT, alanine transferase; AST, aspartate transferase; df, factors.

P value is significant. i.e Presence of IRI and altered ALT were significantly associated with mortality.

Table 7.

Other Factors Associated With IRI.

Factors	Mortality				P
	Died (N = 3)		Survived (N = 50)
	Mean	SD	Mean	SD
Age recipient in years	51.5	4.9	50	11.6	0.833
Age of donor in years	28	12	37.9	18.9	0.454
MELD score	25	20.5	22.1	7.3	0.572
CIT	337	10.6	270	76.4	<0.001
WIT	66	16.9	53	7.5	0.046

MELD, model for end-stage liver disease; CIT, cold ischemia time; WIT, warm ischemia time; SD, standard deviation.

Discussion

The lack of available organs for LT associated with the increased mortality in patients on waiting list for LT has triggered the use of so-called extended criteria donor (ECD) grafts, previously called ‘suboptimal grafts’. Among the wide range of these ECD livers, hepatic steatosis is one of the most frequent disorders, which is mostly related to an increasing prevalence of nonalcoholic fatty liver disease. The decision to transplant or reject a steatotic liver for LT, however, is difficult because of a risk of post-transplantation complications. How much and what types of fat represent a significant risk for primary nonfunction of the graft remains under debate. In the literature as per international guidelines (European association for the study of the liver 2016),¹³ the steatosis of <30% in deceased donors is the most suitable level and >40% is considered as ECD grafts. Few other studies suggesting that even >60% donor steatosis also result in favorable outcomes.¹⁴ But until now, there are no standard guidelines available to define the acceptable upper limit of steatosis in the graft liver.

Ischemia reperfusion injury (IRI) is a phenomenon in which cellular damage in a hypoxic organ is accentuated after the restoration of oxygen delivery.^{15, 16, 17} In the liver, this form of injury was recognized as a clinically important pathological disorder by Toledo-Pereyra et al in 1975 during studies of experimental liver transplant (LT). However, it was not until the mid-1980s that the term reperfusion injury was generally used in the literature on LT.¹⁵

In this study, we analyzed 53 patients who underwent liver transplant in our center. We highlighted the presence of degree of steatosis in liver graft received from either of living or deceased donor. The overall incidence of IRI in both LDLT and DDLT was assessed. While 97.1% DDLTs developed IRI, only 38.9% of LDLTs had IRI. Presence of more CIT in DDLTs and restriction of LDLTs to only <15% MaS can explain this difference. The deceased liver grafts had different type and degree of steatosis. In this study, association of steatosis with IRI was analyzed in DDLTs. This was a selection bias so that, we could not study the association of severe MaS with IRI. Mild MiS was seen in 36 (67.9%) patients, moderate in 11 (20.8%), and severe in 6 (11.3%) patients. Although different studies graded steatosis as mild, moderate, and severe differently, all of them agreed on fact that >60% steatosis as severe. Frongillo et al¹⁸ reported the degree of steatosis in 39 deceased grafts. They classified steatosis as low steatosis, 5%–15%; mild steatosis, 16%–30%; moderate steatosis, 31%–60%; and severe steatosis, >60%). Similar to our study, they also excluded grafts with severe steatosis (>60%) and other 24 fatty grafts were utilized for the transplant. Among those 24 grafts low and mild MaS was seen in 70.8% (17/24) and moderate MaS was observed in 12.5% (3/24). Low MiS was seen in 35% (n-7), mild MiS in 35% (n-7), moderate MiS in 15% (n-3), and severe MiS in 10% (n-2). Distribution of the steatosis is similar to our data. Here, the authors found that primary dysfunction rate was 12.5%, primary nonfunction rate was 8.4%, and 6-month graft survival for all fatty livers was 80%. In this analysis, IRI was studied.

In our study population, IRI was not seen in 12 (22.6%) patients. Mild IRI was seen in 26 (49.1%), moderate in 13 (24.5%), and severe in 2 (3.8%) patients. In a study conducted in Cambridge University Hospitals National Health Service Trust,¹² time-zero biopsies of 476 liver transplants were analyzed over a period of 10 years. They studied IRI and found to have nil IRI in 10.5%, mild in 58.8%, moderate in 26.1%, and severe in 4.6%, and here, they noticed that steatosis was significantly associated with IRI. In our analysis, the distribution of severity of IRI was correlating with these findings, but we could not derive the association of steatosis with IRI. It could be due to limited number of grafts with moderate steatosis.

In our study, most common indication for undergoing liver transplant was alcohol 15 (28.3%) followed by cryptogenic 14 (26.4%), NASH 10 (18.9%), HCV 5 (9.4%), hemochromatosis 3 (5.7%), EHBA 2 (3.8%). In other causes (4) for liver transplant Wilson's disease, primary familial intrahepatic cholestasis, autoimmune hepatitis, and primary hyperoxaluria type I had one case each, and the data are correlating with the already existing studies.¹⁹ In western countries, HCV and alcohol were the common causes. In our center, alcohol, cryptogenic, NASH, and then HCV were the common causes in descending order.

In human LT, a long ischemic period is a predicting factor for post-transplantation graft dysfunction, and some transplantation groups hesitate to transplant liver grafts preserved for more than 10 h.²⁰ Some studies in experimental models of LT indicate that cold ischemia for 24 h induces low survival at 24 h after LT. Mendes-Braz et al²¹ found that short periods (60 min) of warm ischemia result in reversible cell injury, in which liver oxygen consumption returns to control levels when oxygen is resupplied after ischemia. Reperfusion after more prolonged periods of warm ischemia (120–180 min) results in irreversible cell damage. These observations agree with a previous report on a rat liver subjected to IRI, indicating a cellular endpoint for hepatocytes after 90 min of ischemia. In our study also, both cold and warm ischemic time were strongly associating with IRI.

Finally, in our observation, three months mortality in DDLTs was significantly associated with severity of IRI, elevation ALT, and both CIT and WIT. Age of recipient and donor, MELD score, Child's score, and either MaS or MiS were not significantly associated with mortality. In a study conducted by Piratvisuth and colleagues,²² when WIT greater than 180 min, there were reductions in graft survival (58% v 80% for WIT greater than 180 min), but these just failed to reach significance (P = 0.055). CIT had no influence on graft survival using cut-offs of 12 or 18 h. In the observation of Ali et al,¹² it was reported that IRI is an independent determinant of 1-year graft survival and a better predictor of 1-year graft loss than graft steatosis, which is similar to our observation.

• •In patients with mild steatosis, IRI does not correlate with steatosis. However, more patients with moderate and severe steatosis are needed to define the relationship of the two in this group of patients.
• •Type of donor has significant association with risk of ischemia reperfusion injury. Ischemia reperfusion injury is being more common in deceased donor than living donor liver transplant.
• •CIT has significant association with severity of ischemia reperfusion injury. Prolonged CIT leads to more severe ischemia reperfusion injury.
• •Other factors such as gender, donor and recipient age, Child's stage, and MELD score does not significantly associate with Ischemia Reperfusion Injury.
• •Three months after liver transplant mortality is significantly higher in severe ischemia reperfusion injury and in those with more CIT and WIT.

Strengths of our study

• •Though results are similar to western counterparts it is one of the very few studies done in Indian subcontinent
• •It will help in better selection of extended criteria donors particularly those with hepatic steatosis.

Limitations

• •Factors such as hepatic dysfunction including prolonged intensive care, hypotension with high dose vasoactive support, blood products transfused, acid-base and sodium abnormalities are not considered. In our study these factors could not be analyzed because of heterogeneous patients.
• •Selection bias, as donor liver with >60% macrosteatosis were not taken for transplant. It could not be analyzed.

Conflicts of interest

The authors have none to declare.