Retrieval of abdominal organs for transplantation

Effect of donor pancreas extraction time on pancreas transplantation-a Swiss tertiary center experience

We aimed to assess the effect of donor pancreas extraction time (ET) on postoperative complications and graft function after pancreas transplantation (PT). We analyzed all consecutive donor pancreas procurements for the simultaneous pancreas and kidney transplantation (SPK) and the associated PT in a Swiss transplant center over a 20-year period. Pancreas ET was defined as the time from cold flush to static storage of the pancreas on ice. The primary endpoint was the effect of extraction time on surgical complications. Secondary endpoints comprised the effect of ET on graft function (insulin-free survival) and graft pancreatitis. Of 115 procured pancreas grafts the median donor pancreas ET was 65 min (IQR: 48-78 min). In multivariable analysis, ET did not negatively affect major complications (OR 1.41 [95% CI: .59-3.36]; p = .438) and insulin-free survival (HR 1.42 [95% CI: .55-3.63]; p = .459). The median CIT was 522 (441-608) min. CIT was associated with major complications (OR 2.51 [95% CI: 1.11-5.68]; p = .027), but without impact on insulin-free survival (HR 1.94 [95% CI: .84-4.48]; p = .119). Patients with and without graft pancreatitis had no statistically significant differences in ET and CIT (p = .164 and p = .47, respectively). In multivariable analysis, Amylase levels > 270 U/L on postoperative day 1 were significantly associated with major complications (OR 3.61 [95% CI: 1.06-12.32]; p = .040). Our results suggest that although no effect of ET on complications and graft function after PT was found, shorter CIT and less graft pancreatitis can have a positive impact on surgical complications. Results could possibly be influenced by the exceptional quality of the pancreas donors, with short travel distances and preservation times in Switzerland.

Noninvasive assessment of steatosis and viability of cold-stored human liver grafts by MRI

PURPOSE

A shortage of suitable donor livers is driving increased use of higher risk livers for transplantation. However, current biomarkers are not sensitive and specific enough to predict posttransplant liver function. This is limiting the expansion of the donor pool. Therefore, better noninvasive tests are required to determine which livers will function following implantation and hence can be safely transplanted. This study assesses the temperature sensitivity of proton density fat fraction and relaxometry parameters and examines their potential for assessment of liver function ex vivo.

METHODS

Six ex vivo human livers were scanned during static cold storage following normothermic machine perfusion. Proton density fat fraction, T1 , T2 , and T 2 ∗ were measured repeatedly during cooling on ice. Temperature corrections were derived from these measurements for the parameters that showed significant variation with temperature.

RESULTS

Strong linear temperature sensitivities were observed for proton density fat fraction (R2 = 0.61, P < .001) and T1 (R2 = 0.78, P < .001). Temperature correction according to a linear model reduced the coefficient of repeatability in these measurements by 41% and 36%, respectively. No temperature dependence was observed in T2 or T 2 ∗ measurements. Comparing livers deemed functional and nonfunctional during normothermic machine perfusion by hemodynamic and biochemical criteria, T1 differed significantly: 516 ± 50 ms for functional versus 679 ± 60 ms for nonfunctional, P = .02.

CONCLUSION

Temperature correction is essential for robust measurement of proton density fat fraction and T1 in cold-stored human livers. These parameters may provide a noninvasive measure of viability for transplantation.

"Time is tissue"-A minireview on the importance of donor nephrectomy, donor hepatectomy, and implantation times in kidney and liver transplantation

Donor organs are exposed to sequential temperature changes during the transplantation process. The role of donor warm ischemia and cold ischemia times on post-transplant outcomes has been extensively studied. Much less attention has been paid to the transient ischemia occurring during donor organ removal and implantation. Recently, it has become clear that prolonged donor nephrectomy and implantation time are independently associated with delayed graft function after kidney transplantation. In addition, implantation time correlates with post-transplant kidney graft function, histology, and survival. Similar detrimental associations of donor hepatectomy and implantation time with early allograft dysfunction, ischemic cholangiopathy, and graft and patient survival after liver transplantation have been demonstrated. This review details kidney and liver temperature changes occurring during procurement and transplantation. It summarizes the effects of the ischemia the kidney and liver sustain during these phases on short- and long-term post-transplant outcomes, advocating the standardized reporting of donor hepatectomy, donor nephrectomy, and implantation times in (inter)national registries. The review also explores strategies to protect the graft from this ischemic injury.

Complications during multiorgan retrieval and pancreas preservation

In pancreas transplantation, complications can arise at each step of the process, from the initial selection of donors and recipients through the surgical technique itself and the post-operative period, when lifelong immunosuppression is required. In the early steps, careful retrieval and preservation of the pancreas are crucial for the viability of the organ and ultimate success of the transplant. The pancreas is a low-flow gland, making it highly sensitive to transplantation conditions and presenting risk of pancreatitis due to periods of ischemia. The two groups of donors - after brain death (DBD) or after cardiac arrest (DCD) - require different strategies of retrieval and preservation to avoid or reduce the risk of complications developing during and after the transplantation. For DBD donor transplantation, multiorgan retrieval and cold preservation is the conventional technique. Asystole donor (DCD) transplantation, in contrast, can benefit from the newest technologies, such as hypothermic and especially normothermic preservation machines (referred to as NECMO), to optimize organ preservation. The latter has led to an increase in the pool of donors by facilitating recuperation of organs for transplantation that would have been discarded otherwise.

The Impact of Hepatectomy Time of the Liver Graft on Post-transplant Outcome: A Eurotransplant Cohort Study

OBJECTIVE

Assessing the effect of donor hepatectomy time on outcome after transplantation.

SUMMARY OF BACKGROUND DATA

When blood supply in a deceased organ donor stops, ischemic injury starts. Livers are cooled to reduce cellular metabolism and minimize ischemic injury. This cooling is slow and livers are lukewarm during hepatectomy, potentially affecting outcome.

METHODS

We used the Eurotransplant Registry to investigate the relationship between donor hepatectomy time and post-transplant outcome in 12,974 recipients of deceased-donor livers (January 1, 2004, to December 31, 2013). Cox regression analyses for patient and graft survival (censored and uncensored for death with a functioning graft) were corrected for donor, preservation, and recipient variables. Donor hepatectomy time was defined as time between start of aortic cold flush and placement of the liver in the ice-bowl.

RESULTS

Median donor hepatectomy time was 41 minutes [interquartile range (IQR) 32 to 52]. Livers donated after circulatory death had longer hepatectomy times than those from brain-dead donors [50 minutes (35 to 68) vs 40 minutes (32 to 51), P < 0.001]. Donor hepatectomy time was independently associated with graft loss [adjusted hazard ratio (HR) 1.03 for every 10-minute increase, 95% confidence interval (95% CI) 1.02-1.05; P < 0.001]. The magnitude of this effect was comparable to the effect of each hour of additional cold ischemia time (adjusted HR 1.04, 95% CI 1.02-1.05; P < 0.001). Donor hepatectomy time had a similar effect on death-censored graft survival and patient survival. Livers donated after circulatory death and those with a higher donor risk index were more susceptible to the effect of donor hepatectomy time on death-censored graft survival.

CONCLUSION

Donor hepatectomy time impairs liver transplant outcome. Keeping this time short together with efficient cooling during hepatectomy might improve outcome.

Aortic Versus Dual Perfusion for Retrieval of the Liver After Brain Death: A National Registry Analysis

There is lack of consensus in the literature regarding the comparative efficacy of in situ aortic-only compared with dual (aortic and portal venous) perfusion for retrieval and transplantation of the liver. Recipient outcomes from the Australia/New Zealand Liver Transplant Registry (2007-2016), including patient and graft survival and causes of graft loss, were stratified by perfusion route. Subgroup analyses were conducted for higher-risk donors. A total of 1382 liver transplantation recipients were analyzed (957 aortic-only; 425 dual perfusion). There were no significant differences in 5-year graft and patient survivals between the aortic-only and dual cohorts (80.1% versus 84.6% and 82.6% versus 87.8%, respectively) or in the odds ratios of primary nonfunction, thrombotic graft loss, or graft loss secondary to biliary complications or acute rejection. When analyzing only higher-risk donors (n = 369), multivariate graft survival was significantly less in the aortic-only cohort (hazard ratio, 0.49; 95% confidence interval, 0.26-0.92). Overall, there was a trend toward improved outcomes when dual perfusion was used, which became significant when considering higher-risk donors alone. Inferences into the ideal perfusion technique in multiorgan procurement will require further investigation by way of a randomized controlled trial, and outcomes after the transplantation of other organs will also need to be considered.

Evaluation of Graft Effluent High Mobility Group Box-1 (HMGB-1) for Prediction of Outcome After Liver Transplantation

BACKGROUND Pre-transplant assessment of the graft for liver transplantation is crucial. Based on experimental data, this study was designed to assess both nuclear high mobility group box-1 (HMGB-1) protein and arginine-specific proteolytic activity (ASPA) in the graft effluent. MATERIAL AND METHODS In a non-interventional trial, both HMGB-1 and ASPA were measured in the effluent of 30 liver grafts after cold storage before transplantation. Values of HMGB-1 and ASPA levels were compared with established prognostic parameters such as the donor risk index, balance of risk score, and Donor-Model for End-Stage Liver Disease. RESULTS The early allograft dysfunction (EAD) was best predicted by recipient age (p=0.026) and HMGB-1 (p=0.031). HMGB -1 thresholds indicated the likelihood for initial non-function (1608 ng/ml, p=0.004) and EAD (580 ng/ml, p=0.017). The multivariate binary regression analysis showed a 21-fold higher (95% CI: 1.6-284.5, p=0.022) risk for EAD in cases with levels exceeding 580 ng/ml. The ASPA was lower in cases of initial non-function (p=0.028) but did not correlate with the rate of EAD (p=0.4). CONCLUSIONS This study demonstrates the feasibility of HMGB-1 detection in the graft effluent after cold storage. Along with conventional prognostic scores, it may be helpful to predict the early fate of a graft in human liver transplantation.

A systematic review and meta-analysis of cold in situ perfusion and preservation of the hepatic allograft: Working toward a unified approach

The efficacy of cold in situ perfusion and static storage of the liver is a possible determinant of transplantation outcomes. The aim of this study was to determine whether there is evidence to substantiate a preference for a particular perfusion route (aortic or dual) or perfusion/preservation solution in donation after brain death (DBD) liver transplantation. The Embase, MEDLINE, and Cochrane databases were used (1980-2017). Random effects modeling was used to estimate effects on transplantation outcomes based on (1) aortic or dual in situ perfusion and (2) the use of University of Wisconsin (UW), histidine tryptophan ketoglutarate (HTK), Celsior, and/or Institut Georges Lopez-1 (IGL-1) solutions for perfusion/preservation. A total of 22 articles were included (2294 liver transplants). The quality of evidence ranged from very low to moderate Grading of Recommendations, Assessment, Development and Evaluations score. Meta-analyses were conducted for 14 eligible studies. Although there was no difference in the primary nonfunction (PNF) rate, a higher peak alanine aminotransferase (ALT) was recorded in dual compared with aortic-only UW-perfused livers (standardized mean difference, 0.24; 95% confidence interval, 0.01-0.47); a back-table portal venous flush was undertaken in the majority of aortic-only perfused livers. There were no relevant differences in peak enzymes, PNF, thrombotic graft loss, biliary complications, or 1-year graft survival in comparisons between dual-perfused livers using UW, HTK, Celsior, or IGL-1. In conclusion, there is no significant evidence that aortic-only perfusion of the DBD liver compromises transplantation outcomes, and it may be favored because of its simplicity. However, there is currently insufficient evidence to advocate for the use of any particular perfusion/preservation fluid over the others. Liver Transplantation 23 1615-1627 2017 AASLD.

A systematic review and meta-analysis of cold in situ perfusion and preservation for pancreas transplantation

BACKGROUND

This study aimed to identify the most effective solution for in situ perfusion/preservation of the pancreas in donation after brain death donors, in addition to optimal in situ flush volume(s) and route(s) during pancreas procurement.

METHODS

Embase, Medline and Cochrane databases were utilized (1980-2017). Articles comparing graft outcomes between two or more different perfusion/preservation fluids (University of Wisconsin (UW), histidine-tryptophan-ketoglutarate (HTK) and/or Celsior) were compared using random effects models where appropriate.

RESULTS

Thirteen articles were included (939 transplants). Confidence in available evidence was low. A higher serum peak lipase (standardized mean difference 0.47, 95% CI 0.23-0.71, I² = 0) was observed in pancreatic grafts perfused/preserved with HTK compared to UW, but there were no differences in one-month pancreas allograft survivals or early thrombotic graft loss rates. Similarly, there were no significant differences in the rates of graft pancreatitis, thrombosis and graft survival between UW and Celsior solutions, and between aortic-only and dual aorto-portal perfusion.

CONCLUSION

UW cold perfusion may reduce peak serum lipase, but no quality evidence suggested UW cold perfusion improves graft survival and reduces thrombosis rates. Further research is needed to establish longer-term graft outcomes, the comparative efficacy of Celsior, and ideal perfusion volumes.

Normothermic ex vivo liver perfusion using steen solution as perfusate for human liver transplantation: First North American results

The European trial investigating normothermic ex vivo liver perfusion (NEVLP) as a preservation technique for liver transplantation (LT) uses gelofusine, a non-US Food and Drug Administration-approved, bovine-derived, gelatin-based perfusion solution. We report a safety and feasibility clinical NEVLP trial with human albumin-based Steen solution. Transplant outcomes of 10 human liver grafts that were perfused on the Metra device at 37 °C with Steen solution, plus 3 units of erythrocytes were compared with a matched historical control group of 30 grafts using cold storage (CS) as the preservation technique. Ten liver grafts were perfused for 480 minutes (340-580 minutes). All livers cleared lactate (final lactate 1.46 mmol/L; 0.56-1.74 mmol/L) and produced bile (61 mL; 14-146 mL) during perfusion. No technical problems occurred during perfusion, and all NEVLP-preserved grafts functioned well after LT. NEVLP versus CS had lower aspartate aminotransferase and alanine aminotransferase values on postoperative days 1-3 without reaching significance. No difference in postoperative graft function between NEVLP and CS grafts was detected as measured by day 7 international normalized ratio (1.1 [1-1.56] versus 1.1 [1-1.3]; P = 0.5) and bilirubin (1.5; 1-7.7 mg/dL versus 2.78; 0.4-15 mg/dL; P = 0.5). No difference was found in the duration of intensive care unit stay (median, 1 versus 2 days; range, 0-8 versus 0-23 days; P = 0.5) and posttransplant hospital stay (median, 11 versus 13 days; range, 8-17 versus 7-89 days; P = 0.23). Major complications (Dindo-Clavien ≥ 3b) occurred in 1 patient in the NEVLP group (10%) compared with 7 (23%) patients in the CS group (P = 0.5). No graft loss or patient death was observed in either group. Liver preservation with normothermic ex vivo perfusion with the Metra device using Steen solution is safe and results in comparable outcomes to CS after LT. Using US Food and Drug Administration-approved Steen solution will avoid a potential regulatory barrier in North America. Liver Transplantation 22 1501-1508 2016 AASLD.

[Diagnostic workup of brain-dead organ donors and organ retrieval]

Renal transplantation is well established as the best and often the only treatment for many patients with end-stage kidney failure. Because of an increasing shortfall between the diminishing number of deceased donor organs available and the increasing waiting list of patients in need of transplantation the shortage of suitable donors remains one of the most pressing challenges. The success of organ transplantation can be attributed to many factors but ultimately depends upon retrieval and preservation techniques to maintain the quality of an organ. Although the literature on organ retrieval is extensive, the level of evidence provided is mainly low. But as techniques and treatments improve, it may be possible to use organs from donors who were previously thought to be unsuitable. This article provides the reader an overview on the topic of organ donation.

Outcomes of transplantation of livers from donation after circulatory death donors in the UK: a cohort study

OBJECTIVES

Outcomes of liver transplantations from donation after circulatory death (DCD) donors may be inferior to those achieved with donation after brain death (DBD) donors. The impact of using DCD donors is likely to depend on specific national practices. We compared risk-adjusted graft loss and recipient mortality after transplantation of DCD and DBD livers in the UK.

DESIGN

Prospective cohort study. Multivariable Cox regression and propensity score matching were used to estimate risk-adjusted HR.

SETTING

7 liver transplant centres in the National Health Service (NHS) hospitals in England and Scotland.

PARTICIPANTS

Adults who received a first elective liver transplant between January 2005 and December 2010 who were identified in the UK Liver Transplant Audit.

INTERVENTIONS

Transplantation of DCD and DBD livers.

OUTCOMES

Graft loss and recipient mortality.

RESULTS

In total, 2572 liver transplants were identified with 352 (14%) from DCD donors. 3-year graft loss (95% CI) was higher with DCD livers (27.3%, 21.8% to 33.9%) than with DBD livers (18.2%, 16.4% to 20.2%). After adjustment with regression, HR for graft loss was 2.3 (1.7 to 3.0). Similarly, 3-year mortality was higher with DCD livers (19.4%, 14.5% to 25.6%) than with DBD livers (14.1%, 12.5% to 16.0%) with an adjusted HR of 2.0 (1.4 to 2.8). Propensity score matching gave similar results. Centre-specific adjusted HRs for graft loss and recipient mortality seemed to differ among transplant centres, although statistical evidence is weak (p value for interaction 0.08 and 0.24, respectively).

CONCLUSIONS

Graft loss and recipient mortality were about twice as high with DCD livers as with DBD livers in the UK. Outcomes after DCD liver transplantation may vary between centres. These results should inform policies for the use of DCD livers.

Beyond poiseuille: preservation fluid flow in an experimental model

Poiseuille's equation describes the relationship between fluid viscosity, pressure, tubing diameter, and flow, yet it is not known if cold organ perfusion systems follow this equation. We investigated these relationships in an ex vivo model and aimed to offer some rationale for equipment selection. Increasing the cannula size from 14 to 20 Fr increased flow rate by a mean (SD) of 13 (12)%. Marshall's hyperosmolar citrate was three times less viscous than UW solution, but flows were only 45% faster. Doubling the bag pressure led to a mean (SD) flow rate increase of only 19 (13)%, not twice the rate. When external pressure devices were used, 100 mmHg of continuous pressure increased flow by a mean (SD) of 43 (17)% when compared to the same pressure applied initially only. Poiseuille's equation was not followed; this is most likely due to “slipping” of preservation fluid within the plastic tubing. Cannula size made little difference over the ranges examined; flows are primarily determined by bag pressure and fluid viscosity. External infusor devices require continuous pressurisation to deliver high flow. Future studies examining the impact of perfusion variables on graft outcomes should include detailed equipment descriptions.

Comparative analysis of in situ versus ex situ perfusion on flow and microcirculation in kidney procurement: research on a porcine model

Background

The first crucial step in transplantation appears to be the effective rinsing of the graft during organ procurement. Even though there is strong suspicion that ex situ perfusion results in better rinsing of the graft, there is no proof for this hypothesis. The aim of this study was to analyse the differences of in situ and ex situ kidney perfusion in a porcine model.

Methods

Standardised multiorgan procurement was performed in 15 German landrace pigs. Perfusion was carried out using histidine–tryptophan–ketoglutarate solution (HTK) under the application of pressure. In one kidney, in situ perfusion via the aorta was carried out while the second kidney received ex situ perfusion via the renal artery (RA). Perfusate flow inside the aorta and the RA was recorded at different pressure steps. In order to visualise the effect on the microcirculation, different coloured microparticles (MPs; 10 μm) were administered via the aorta or RA. Subsequently, frozen sections of the explanted kidneys were analysed histologically and MPs were evaluated quantitatively.

Results

Ex situ kidney perfusion resulted in significantly improved flow rates (P<0.0001) compared with in situ perfusion. By applying ex situ perfusion it was even possible to attain physiological flow levels on the RA under the application of external pressure of 150 to 200 mmHg. The amount of MPs was able to highlight the positive impact of ex situ perfusion on microcirculation of the kidney graft (P<0.0001).

Conclusions

The use of MPs represents a valuable tool for quantitative investigation and illustration of kidney perfusion in experimental setups. Additional ex situ perfusion is able to improve the quality of kidney perfusion.

Donor risk factors, retrieval technique, preservation and ischemia/reperfusion injury in pancreas transplantation

PURPOSE OF REVIEW

Pancreas transplantation is still hampered by a high incidence of early graft loss, and organ quality concerns result in high nonrecovery/discard rates. Demographic donor characteristics, surgical retrieval strategy, preservation fluid and ischemia time are crucial factors in the process of organ selection and are discussed in this review.

RECENT FINDINGS

The donor shortage is driving an increasing utilization of nonideal organs which would previously have been identified as unsuitable. Recent literature suggests that organs from extended criteria donors - older (>45 years), BMI >30  kg/m(2), and donation after cardiac death (DCD) - can achieve the same graft and patient survival as those from standard criteria donors, with the proviso that the accumulation of risk factors and long ischemic times should be avoided. Visual assessment of the pancreas is advisable before declining/accepting a pancreas. University of Wisconsin represents the gold standard solution; however, histidine-tryptophan-ketoglutarate and Celsior result in equal outcomes if cold ischemia time (CIT) is less than 12  h. Currently in pancreas transplantation, there is no proven effective ischemia/reperfusion injury prophylaxis than trying to keep CIT as short as possible.

SUMMARY

Demographic risk factors, inspection of the pancreas by an experienced surgeon and predicted CIT are crucial factors in deciding whether to accept a pancreas for transplantation. However, there is a need for an improved evidence base to determine where to set the 'cut-off' for unsuitable pancreatic grafts.

Extracorporeal membrane oxygenation for resuscitation of deceased cardiac donor livers for hepatocyte isolation

BACKGROUND

Deceased cardiac donors (DCDs) have become a useful source of organs for liver transplantation; nevertheless, there are concerns about the longevity of these grafts. The aim of this study was to evaluate the use of extracorporeal membrane oxygenation (ECMO) to resuscitate DCD porcine livers as a preclinical model using hepatocyte isolation and viability as a marker to assess whole-graft preservation.

MATERIALS AND METHODS

We randomized Landrace pigs into three groups after cardiac death and 30 min of warm ischemia: group 1, peritoneal cooling with intravascular cooling for 2 h; group 2, ECMO for 2 h; and group 3, control (conventional intravascular cooling and retrieval). We then reperfused group 1 and 2 livers for 2 h on an ex vivo reperfusion circuit and isolated hepatocytes.

RESULTS

After reperfusion, hepatocyte viability was significantly improved in the ECMO group compared to the cooling groups, as measured by trypan blue, methylthiazolyldiphenyl-tetrazolium bromide, and seeding efficiency. Glycogen and reduced glutathione content were significantly used in the ECMO group both before and after reperfusion compared with group 2. The adenosine diphosphate:adenosine triphosphate ratio showed an improved trend (lower) in the ECMO group compared with the cooling group but did not reach statistical significance either before or after reperfusion.

CONCLUSIONS

This preclinical study suggests that ECMO is a viable technique for liver preservation that gives an improved yield of hepatocytes when isolated from a DCD liver, suggesting improved liver preservation.

[Abdominal organ retrieval: strategies to improve quality]

The blatant problem of organ shortage leads to an increasing acceptance of organs from extended criteria donors. This increases the importance of the process of organ donation and retrieval. A working group of representatives of Bavarian retrieval surgeons and the procurement organization German Foundation of Organ Transplantation (DSO) was initiated to develop consensus-based recommendations for quality improvements in the field of organ retrieval on the basis of regional data. The main aim was to professionalize retrieval teams by specified training standards and to define objective qualifications for retrieval surgeons. Initial measures of the working group included agreement on standardized retrieval techniques and improvement of documentation in terms of quality forms and the return rate of the forms. Quality data are being analyzed prospectively with a new categorization of complications. Communication among centers and teams and complication reporting has already been improved and initial structural changes have been set up.

Liver damage during organ donor procurement in donation after circulatory death compared with donation after brain death

BACKGROUND

During the past decade the number of livers recovered and transplanted from donation after circulatory death (DCD) donors has increased significantly. As reported previously, injuries are more frequent during kidney procurement from DCD than from donation after brain death (DBD) donors. This aim of this study was to compare outcomes between DCD and DBD with respect to liver injuries.

METHODS

Data on liver injuries in organs procured between 2000 and 2010 were obtained from the UK Transplant Registry.

RESULTS

A total of 7146 livers were recovered from deceased donors during the study, 628 (8·8 per cent) from DCD donors. Injuries occurred in 1001 procedures (14·0 per cent). There were more arterial (1·6 versus 1·0 per cent), portal (0·5 versus 0·3 per cent) and caval (0·3 versus 0·2 per cent) injuries in the DBD group than in the DCD group, although none of these findings was statistically significant. Capsular injuries occurred more frequently in DCD than DBD (15·6 versus 11·4 per cent; P = 0·002). There was no significant difference between DCD and DBD groups in liver discard rates related to damage.

CONCLUSION

There were no differences in terms of vascular injuries between DCD and DBD livers, although capsular injuries occurred more frequently in DCD organs. Continuing the trend for increased frequency of DCD liver recovery, and ensuring that there is an adequately skilled surgical team available for procurement, is vital to improving the utilization of DCD livers.

Clinical impact of right accessory hepatic artery injury in deceased donor livers

BACKGROUND

Right accessory hepatic artery (RAHA) injury at retrieval is a rare complication of deceased liver procurement. Arterial reconstruction is often required under these circumstances which could potentially increase the risk of hepatic artery thrombosis (HAT). The aim of this study is to investigate whether RAHA injury affects the incidence of HAT, early biliary complications, or 3-month graft and patient survival rates.

METHODS

All adult liver transplants performed between 1994 and February 2007 at Addenbrooke's Hospital, Cambridge, UK were considered for inclusion in the study. Grafts were divided into three groups depending on the presence of RAHA and injury (Group 1: normal anatomy and single hepatic artery anastomosis; Group 2: RAHA requiring reconstruction; Group 3: RAHA injury requiring reconstruction).

RESULTS

Eight hundred and forty-four liver transplants were included in the study (Group 1: 654 grafts; Group 2: 63 grafts; Group 3: 14 grafts). The incidence of HAT (Group 1, 2.9%; Group 2, 6.4%; Group 3, 14.3%) was significantly different between the three groups (P = 0.01); biliary complications at 3 months (Group 1, 7.1%; Group 2, 11.1%; Group 3, 7.1%) were not significantly different. Graft and patient survival at 3 months were significantly worse in Group 3 when compared with Group 2 (61.5 vs. 88.3%, P = 0.01; 81.8 vs. 98.2%, P = 0.02).

CONCLUSION

This is the first study analysing the clinical impact of RAHA injury during liver procurement. We conclude that the use of liver grafts with RAHA injury does result in a higher HAT rate and is also associated with lower graft and patient survival rates at 3 months.

Is routine sternotomy necessary for organ recovery from deceased donors? A comparative retrospective study

BACKGROUND

Traditionally, sternotomy and laparotomy are performed to recover thoracoabdominal organs from deceased donors; however, recovering abdominal organs without sternotomy is possible. We evaluated and compared organ recovery from deceased donors, with and without sternotomy.

METHODS

Between February 2006 and November 2011, organ recovery was performed in 68 deceased donors by our transplantation team. The recovery procedure was carried out using standard techniques in 31 donors (with sternotomy; Group A) and with modified techniques in 37 donors (without sternotomy; Group B). Average age, gender, body mass index (BMI), and time to cold ischemia were compared retrospectively in both groups. The demographic and clinical parameters were compared using a Student t test and chi-square test. The level of statistical significance was set at P < .05.

RESULTS

Organ recovery was performed on 31 of 67 (45.6%) deceased donors with sternotomy (Group A) and 37 of 67 (54.4%) without sternotomy (Group B). Thirty-six donors were male and 32 were female. The average donor age was 40.4 ± 3.4 years in Group A and 52.4 ± 4.6 years in Group B (P < .02). The average BMI of donors was 26.2 ± 0.8 kg/m(2) in Group A and 23.9 ± 0.8 kg/m(2) in Group B. The average time to cold ischemia was 127 ± 6.2 minutes in Group A and 47.5 ± 1.8 minutes in Group B (P < .0001).

CONCLUSION

The transition time to cold ischemia can be shortened by harvesting organs without sternotomy in unstable donors, or under conditions in which intrathoracic organs are not recovered.

Kidney damage during organ recovery in donation after circulatory death donors: data from UK National Transplant Database

During the last 10 years, kidneys recovered/transplanted from donors after circulatory death (DCD) have significantly increased. To optimize their use, there has been an urgent need to minimize both warm and cold ischemia, which often necessitates more rapid removal. To compare the rates of kidney injury during procurement from DCD and donors after brain death (DBD) organ donors. A total of 13 260 kidney procurements were performed in the United Kingdom over a 10-year period (2000-2010). Injuries occurred in 903 procedures (7.1%). Twelve thousand three hundred seventy-two (93.3%) kidneys were recovered from DBD donors and 888 (6.7%) from DCD donors. The rates of kidney injury were significantly higher when recovered from DCD donors (11.4% vs. 6.8%, p < 0.001). Capsular, ureteric and vascular injuries were all significantly more frequent (p = 0.002, p < 0.001 and p = 0.017, respectively). Discard because of injury was more common after DCD donation (p = 0.002). Multivariate analysis demonstrated procurement injuries were significantly associated with DCD donors (p = 0.035) and increased donor age (<0.001) and donor body mass index (BMI; 0.001), donor male gender (p = 0.001) and no liver donation (0.009). We conclude that procurement from DCD donors leads to higher rates of injury to the kidney and are more likely to be discarded.

Organ retrieval from brain-dead patients by a single organ procurement center in Iran

INTRODUCTION

The majority of transplantations depend solely on cadaveric organs. In recent years, special focus has been directed toward brain-dead patients in Iran, but it seems that there is limited information regarding the characteristics of cadaveric organ donation in our country.

MATERIALS AND METHODS

This is a retrospective analysis of data of our Organ Procurement Unit (OPU), which is one of the most active organ procurement units in Iran. We incorporated the data on all organ donations from brain-dead patients between 2004 and 2008 into the present study. Demographic characteristics of the patients along with data regarding brain death and organ donation were extracted from already registered data on patients.

RESULTS

Among 93 brain-dead patients registered in the database of the OPU, organs were retrieved from 85% (n = 79). Out of the 14 patients from whom no organ was retrieved, the cause for this failure was death before donation in 85% (n = 12). The numbers of donated organs varied between zero and six (mean +/- standard deviation = 3.1 +/- 1.7). The most donated organs in terms of frequency and count were: right kidney (n = 68; 73.1%), left kidney (n = 67; 72%), liver (n = 63; 67.7%), heart (n = 40; 43%), pancreas (n = 5; 5.4%), and lung (n = 4; 4.3%).

DISCUSSION

The overall organ retrieval rate from brain-dead patients by this OPU was comparable to that of developed countries; however, we still believe we can improve this rate/scale.

Pancreas preservation for pancreas and islet transplantation

PURPOSE OF REVIEW

To summarize advances and limitations in pancreas procurement and preservation for pancreas and islet transplantation, and review advances in islet protection and preservation.

RECENT FINDINGS

Pancreases procured after cardiac death, with in-situ regional organ cooling, have been successfully used for islet transplantation. Colloid-free Celsior and histidine-tryptophan-ketoglutarate preservation solutions are comparable to University of Wisconsin solution when used for cold storage before pancreas transplantation. Colloid-free preservation solutions are inferior to University of Wisconsin solution for pancreas preservation prior to islet isolation and transplantation. Clinical reports on pancreas transplants suggest that the two-layer method may not offer significant benefits over cold storage with the University of Wisconsin solution: improved oxygenation may depend on the graft size; benefits in experimental models may not translate to human organs. Improvements in islet yield and quality occurred from pancreases treated with inhibitors of stress-induced apoptosis during procurement, storage, isolation or culture desirable before islet isolation and transplantation and may improve islet yield and quality. Methods for real-time, noninvasive assessment of pancreas quality during preservation have been implemented and objective islet-potency assays have been developed and validated. These innovations should contribute to objective evaluation and establishment of improved pancreas-preservation and islet-isolation strategies.

SUMMARY

Cold storage may be adequate for preservation before pancreas transplants, but insufficient when pancreases are processed for islets or when expanded donors are used. Supplementation of cold-storage solutions with cytoprotective agents and perfusion may improve pancreas and islet transplant outcomes.

Pancreas preservation for pancreas and islet transplantation

PURPOSE OF REVIEW

To summarize advances and limitations in pancreas procurement and preservation for pancreas and islet transplantation, and review advances in islet protection and preservation.

RECENT FINDINGS

Pancreases procured after cardiac death, with in-situ regional organ cooling, have been successfully used for islet transplantation. Colloid-free Celsior and histidine-tryptophan-ketoglutarate preservation solutions are comparable to University of Wisconsin solution when used for cold storage before pancreas transplantation. Colloid-free preservation solutions are inferior to University of Wisconsin solution for pancreas preservation prior to islet isolation and transplantation. Clinical reports on pancreas and islet transplants suggest that the two-layer method may not offer significant benefits over cold storage with the University of Wisconsin solution: improved oxygenation may depend on the graft size; benefits in experimental models may not translate to human organs. Improvements in islet yield and quality occurred from pancreases treated with inhibitors of stress-induced apoptosis during procurement, storage, isolation or culture. Pancreas perfusion may be desirable before islet isolation and transplantation and may improve islet yields and quality. Methods for real-time, noninvasive assessment of pancreas quality during preservation have been implemented and objective islet potency assays have been developed and validated. These innovations should contribute to objective evaluation and establishment of improved pancreas preservation and islet isolation strategies.

SUMMARY

Cold storage may be adequate for preservation before pancreas transplants, but insufficient when pancreases are processed for islets or when expanded donors are used. Supplementation of cold storage solutions with cytoprotective agents and perfusion may improve pancreas and islet transplant outcomes.

Determination of an adequate perfusion pressure for continuous dual vessel hypothermic machine perfusion of the rat liver

Hypothermic machine perfusion (HMP) provides better protection against ischemic damage of the kidney compared to cold-storage. The required perfusion pressures needed for optimal HMP of the liver are, however, unknown. Rat livers were preserved in University of Wisconsin organ preservation solution enriched with acridine orange (AO) to stain viable cells and propidium iodide (PI) to detect dead cells. Perfusion pressures of 12.5%, 25% or 50% of physiologic perfusion pressures were compared. Intravital fluorescence microscopy was used to assess liver perfusion by measuring the percentage of AO staining. After 1-h, the perfusion pressure of 12.5% revealed 72% +/- 3% perfusion of mainly the acinary zones one and two. The perfusion pressure of 25% and 50% showed complete perfusion. Furthermore, 12.5% showed 14.7 +/- 3.6, 25% showed 3.7 +/- 0.9, and 50% showed 11.2 +/- 1.4 PI positive cells. One hour was followed by another series of experiments comprising 24-h preservation. In comparison with 24-h cold-storage, HMP at 25% showed less PI positive cells and HMP at 50% showed more PI positive cells. In summary, perfusion at 25% showed complete perfusion, demonstrated by AO staining, with minimal cellular injury, shown with PI. This study indicates that fine-tuning of the perfusion pressure is crucial to balance (in)complete perfusion and endothelial injury.