Ischemic-type biliary strictures in liver allografts: the Achilles heel revisited?

Ultrasound-Based Multimodal Imaging Predicting Ischemic-Type Biliary Lesions After Living-Donor Liver Transplantation

BACKGROUND

Ischemic-type biliary lesions (ITBL) are accepted as the most incomprehensible biliary complications after living-donor liver transplantation (LDLT). Early predicting the development of ITBL in pediatric patients permits more preventive strategies. However, few studies have focused on the early prediction of ITBL.

OBJECTIVE

This study aimed to establish a nomogram including ultrasound-based multimodal imaging to predict ITBL in children with biliary atresia (BA) within 2 years after receiving LDLT.

METHODS

The records of 94 BA children with at least one year of follow-up after LDLT were reviewed retrospectively. They were randomly divided into a training cohort for constructing a nomogram (n=64) and a validation cohort (n=30). In the training cohort, patients diagnosed as ITBL were included in the ITBL group and those without any vascular and biliary complication were included in the non-ITBL group. Multivariate Cox regression was used for the establishment of the nomogram in predicting the risk of ITBL within 2 years post-LDLT. The discrimination and calibration of the nomogram were internally and externally validated. The performances of the nomogram and the individual components were compared by the area under the curve (AUC) of receiver operating characteristic (ROC) curve.

RESULTS

In the training cohort, 18 BA children were included in the ITBL group and 46 were in the non-ITBL group. Last pediatric end-stage liver disease (PELD) score, gamma-glutamyl transpeptidase (GGT), resistive index (RI), and liver stiffness measurement (LSM) were the independent predictors for the development of ITBL within 2 years post-LDLT. The nomogram incorporating these independent predictors showed good discrimination and calibration by the internal and external validation. Its performance was better than any individual component in predicting the prognosis (P < 0.05).

CONCLUSION

The established nomogram may be used to predict the risk of ITBL within 2 years post-LDLT in BA children.

Impact of machine perfusion of the liver on post-transplant biliary complications: A systematic review

AIM

To review the clinical impact of machine perfusion (MP) of the liver on biliary complications post-transplantation, particularly ischaemic-type biliary lesions (ITBL).

METHODS

This systematic review was performed in accordance with the Preferred Reporting Systematic Reviews and Meta-Analysis (PRISMA) protocol. The following databases were searched: PubMed, MEDLINE and Scopus. The keyword “liver transplantation” was used in combination with the free term “machine perfusion”. Clinical studies reporting results of transplantation of donor human livers following ex situ or in situ MP were analysed. Details relating to donor characteristics, recipients, technique of MP performed and post-operative biliary complications (ITBL, bile leak and anastomotic strictures) were critically analysed.

RESULTS

Fifteen articles were considered to fit the criteria for this review. Ex situ normothermic MP was used in 6 studies, ex situ hypothermic MP in 5 studies and the other 4 studies investigated in situ normothermic regional perfusion (NRP) and controlled oxygenated rewarming. MP techniques which have per se the potential to alleviate ischaemia-reperfusion injury: Such as hypothermic MP and NRP, have also reported lower rates of ITBL. Other biliary complications, such as biliary leak and anastomotic biliary strictures, are reported with similar incidences with all MP techniques. There is currently less clinical evidence available to support normothermic MP as a mitigator of biliary complications following liver transplantation. On the other hand, restoration of organ to full metabolism during normothermic MP allows assessment of hepatobiliary function before transplantation, although universally accepted criteria have yet to be validated.

CONCLUSION

MP of the liver has the potential to have a positive impact on post-transplant biliary complications, specifically ITBL, and expand extended criteria donor livers utilisation.

Risk factors for and management of ischemic-type biliary lesions following orthotopic liver transplantation: A single center experience

INTRODUCTION

Biliary complications can cause morbidity, graft loss, and mortality after liver transplantation. The most troublesome biliary complications are ischemic-type biliary lesions (ITBL), which occur since transplants can now be performed after the donor has undergone circulatory death. The exact origin of this type of biliary complication remains unknown.

MATERIAL AND METHODS

A total of 528 patients were retrospectively analyzed following liver transplantation after excluding 30 patients with primary sclerosing cholangitis and those lost to follow-up from January 2007 to January 2014. The incidence of and risk factors for ITBL were evaluated.

RESULTS

Cold ischemia time (CIT) (P = 0.042) and warm ischemia time (WIT) (P = 0.006) were found to be independent risk factors for the development of ITBL. Use of the cytochrome P450 (CYP) 3A5 genotype assay to guide individualization of immunosuppressive medications resulted in significantly fewer ITBL (P = 0.027. Autoimmune hepatitis might be a risk factor for ITBL, as determined using univariate analysis (P = 0.047).

CONCLUSIONS

Efforts should be taken to minimize risk factors associated with ITBL, such as CIT and WIT. The CYP3A5 genotype assay should be used to guide selection of immunosuppressive therapy in an effort to reduce the occurrence of ITBL.

Endoscopic management of biliary complications after liver transplantation: An evidence-based review

Biliary tract diseases are the most common complications following liver transplantation (LT) and usually include biliary leaks, strictures, and stone disease. Compared to deceased donor liver transplantation in adults, living donor liver transplantation is plagued by a higher rate of biliary complications. These may be promoted by multiple risk factors related to recipient, graft, operative factors and post-operative course. Magnetic resonance cholangiopancreatography is the first-choice examination when a biliary complication is suspected following LT, in order to diagnose and to plan the optimal therapy; its limitations include a low sensitivity for the detection of biliary sludge. For treating anastomotic strictures, balloon dilatation complemented with the temporary placement of multiple simultaneous plastic stents has become the standard of care and results in stricture resolution with no relapse in > 90% of cases. Temporary placement of fully covered self-expanding metal stents (FCSEMSs) has not been demonstrated to be superior (except in a pilot randomized controlled trial that used a special design of FCSEMSs), mostly because of the high migration rate of current FCSEMSs models. The endoscopic approach of non-anastomotic strictures is technically more difficult than that of anastomotic strictures due to the intrahepatic and/or hilar location of strictures, and the results are less satisfactory. For treating biliary leaks, biliary sphincterotomy and transpapillary stenting is the standard approach and results in leak resolution in more than 85% of patients. Deep enteroscopy is a rapidly evolving technique that has allowed successful treatment of patients who were not previously amenable to endoscopic therapy. As a result, the percutaneous and surgical approaches are currently required in a minority of patients.

Delayed rearterialization unlikely leads to nonanastomotic stricture but causes temporary injury on bile duct after liver transplantation

Nonanastomotic strictures (NAS) are common biliary complications after liver transplantation (LT). Delayed rearterialization induces biliary injury in several hours. However, whether this injury can be prolonged remains unknown. The correlation of this injury with NAS occurrence remains obscure. Different delayed rearterialization times were compared using a porcine LT model. Morphological and functional changes in bile canaliculus were evaluated by transmission electron microscopy and real-time PCR. Immunohistochemistry and TUNEL were performed to validate intrahepatic bile duct injury. Three months after LT was performed, biliary duct stricture was determined by cholangiography; the tissue of common bile duct was detected by real-time PCR. Bile canaliculi were impaired in early postoperative stage and then exacerbated as delayed rearterialization time was prolonged. Nevertheless, damaged bile canaliculi could fully recover in subsequent months. TNF-α and TGF-β expressions and apoptosis cell ratio increased in the intrahepatic bile duct only during early postoperative period in a time-dependent manner. No abnormality was observed by cholangiography and common bile duct examination after 3 months. Delayed rearterialization caused temporary injury to bile canaliculi and intrahepatic bile duct in a time-dependent manner. Injury could be fully treated in succeeding months. Solo delayed rearterialization cannot induce NAS after LT.

Aetiology and risk factors of ischaemic cholangiopathy after liver transplantation

Liver transplantation (LT) is the best treatment for end-stage hepatic failure, with an excellent survival rates over the last decade. Biliary complications after LT pose a major challenge especially with the increasing number of procured organs after circulatory death. Ischaemic cholangiopathy (IC) is a set of disorders characterized by multiple diffuse strictures affecting the graft biliary system in the absence of hepatic artery thrombosis or stenosis. It commonly presents with cholestasis and cholangitis resulting in higher readmission rates, longer length of stay, repeated therapeutic interventions, and eventually re-transplantation with consequent effects on the patient’s quality of life and increased health care costs. The pathogenesis of IC is unclear and exhibits a higher prevalence with prolonged ischaemia time, donation after circulatory death (DCD), rejection, and cytomegalovirus infection. The majority of IC occurs within 12 mo after LT. Prolonged warm ischaemic times predispose to a profound injury with a subsequently higher prevalence of IC. Biliary complications and IC rates are between 16% and 29% in DCD grafts compared to between 3% and 17% in donation after brain death (DBD) grafts. The majority of ischaemic biliary lesions occur within 30 d in DCD compared to 90 d in DBD grafts following transplantation. However, there are many other risk factors for IC that should be considered. The benefits of DCD in expanding the donor pool are hindered by the higher incidence of IC with increased rates of re-transplantation. Careful donor selection and procurement might help to optimize the utilization of DCD grafts.

Liver transplantation for acute liver failure: are there thresholds not to be crossed?

Factors predicting survival after liver transplantation (LT) for irreversible acute liver failure (ALF) are rare. The aim of this study was to identify prognostic preoperative factors of patients with ALF that predict mortality after LT to avoid futile transplantation. From chart review, we identified 57 patients receiving transplants for ALF from 12/2000 to 09/2010. Recipient and donor data were analyzed and correlated with in-hospital mortality and patient survival by univariable/multivariable logistic regression and Cox proportional hazards. The survival rates at 30 days and 12 months were 77.2% and 64.9%, respectively. The in-hospital mortality rate was 29.8%. Follow-up of patients discharged from the hospital alive showed 30-day and 12-month survivals of 100% and 92.5%, respectively. Multivariable analysis of factors known preoperatively showed that the lowest pH of the recipient before LT (P = 0.03) was independently associated with in-hospital mortality, and the recipient's BMI (P = 0.03) and the lowest pH before LT (P = 0.03) were independently associated with patient survival. A pH of 7.26 was the calculated cutoff (ROC) for increased in-hospital mortality. Donor factors did not affect patient survival. Patients with ALF and a pH ≤ 7.26 have the worst outcome after liver transplantation. Therefore, emergency liver transplantation should be critically discussed for each individual.

Factors predicting ischemic-type biliary lesions (ITBLs) after liver transplantation

Among biliary complications, ischemic-type biliary lesions (ITBLs) remain a major cause of morbidity in liver transplant recipients, significantly affecting the chance of survival of both patients and grafts. We retrospectively reviewed 10 years of prospectively collected donor and recipient data from April 2001 to April 2011. We evaluated the incidence of ITBL occurrence, exploring the possible predisposing factors, including donor and recipient data. Two hundred fifty-one grafts were harvested: 222 of them were transplanted at our institution, the remaining 29 (11.6%) discarded by our donor team as showing >40% macrovesicular steatosis. Mild-moderate (20%-40%) macrovesicular steatosis (P < .001) and cold ischemia time (P = .048) significantly increased the risk of ITBL, also as an independent risk factor after multivariate analysis.

Optimized endoscopic treatment of ischemic-type biliary lesions after liver transplantation

BACKGROUND

Biliary strictures are the most common complication after liver transplantation. A particular problem is ischemic-type biliary lesions (ITBLs), which are often responsible for graft failure and early retransplantation. Although some encouraging results of successful endoscopic treatment have been reported, this has not yet resulted in a standardized therapeutic approach to date.

OBJECTIVE

To evaluate an optimized algorithm for the endoscopic treatment of ITBLs.

SETTING AND PATIENTS

All adult patients who underwent liver transplantation at the University of Essen between April 1998 and July 2006.

DESIGN

Retrospective outcome analysis.

MAIN OUTCOME MEASUREMENTS

Success or failure of 2 different therapeutic algorithms in terms of normalization of cholestasis parameters and graft survival.

RESULTS

Forty-eight patients who had undergone liver transplantation and had an endoscopically determined diagnosis of ITBL were identified. The median interval between liver transplantation and first endoscopic intervention was 242.5 (range, 16-3677) days. Patients received a median of 6 treatment sessions (range 2-13) every 8 to 10 weeks. In 16 of 48 patients, a combination of balloon dilation (BD) and implantation of a plastic endoprosthesis (BD+EP) was performed; in the remaining 32 patients, BD alone was performed. Overall, endoscopic therapy was successful in 73%. BD+EP was successful in 5 of 16 (31%) and BD alone in 30 of 32 patients (91%; P = .0027). In the BD+EP group, severe cholangitis developed in 25% of patients, but only 12% of the BD group (P = .01). The median duration of therapy was 374 (range 11-808) days. Six of 48 patients underwent retransplantation because of chronic graft rejection at a median of 1288 (range 883-4204) days after the primary liver transplantation. Six of 48 patients underwent hepaticojejunostomy because of unsuccessful endoscopic therapy, and 1 patient underwent surgery because of portal vein thrombosis.

LIMITATIONS

Retrospective design.

CONCLUSIONS

An endoscopic treatment regimen for ITBLs, preferably BD alone, could prolong the time to or could completely avoid surgical revision and early retransplantation and seems to be superior to endoscopic stenting.

Risk factors of severe ischemic biliary complications after liver transplantation

BACKGROUND

Ischemia-related biliary tract complications remain high after orthotopic liver transplantation. Severe ischemic biliary complications often involve the hepatic duct bifurcation and left hepatic duct, resulting finally in obstructive jaundice. Prevention and management of such complications remain a challenge for transplant surgeons.

METHODS

All 160 patients were followed up for at least 180 days after transplantation. One-way analysis of variance (ANOVA) and comparative univariate analysis were made using 3 groups (no complications; mild complications; severe complications), to analyze risk factors associated with biliary complications. Multiple logistic regression and linear regression analysis were used to analyze independent risk factors for severe ischemic biliary complications, after excluding other confounding factors.

RESULTS

By ANOVA and comparative univariate analysis, the risk factors associated with biliary complications were preoperative bilirubin level (P=0.007) and T-tube stenting of the anastomosis (P=0.016). Multiple logistic regression analysis showed that the use of T-tube and preoperative serum bilirubin were not independent risk factors for severe ischemic biliary complications after orthotopic liver transplantation. Chi-square analysis indicated that in the incidence of severe ischemic biliary lesions, bile duct second warm ischemic time longer than 60 minutes was a significant risk factor. Linear regression demonstrated a negative correlation between cold preservation time and warm ischemia time.

CONCLUSIONS

Preoperative serum bilirubin level and the use of T-tube stenting of the anastomosis were independent risk factors for biliary complications after liver transplantation, but not for severe ischemic biliary complications. The second warm ischemia time of bile duct longer than 60 minutes and prolonged bile duct second warm ischemia time combined with cold preservation time were significant risk factors for severe ischemic biliary complications after liver transplantation with grafts from non-heart-beating donors.

Establishment of a rat model of extrahepatic biliary ischemic stenosis

AIM: To develop a rat model of extrahepatic biliary ischemic stenosis.

METHODS: Forty-eight Sprague-Dawley rats were divided randomly and equally into four groups: rats undergoing sham operation and those subjected to clamping of the common bile duct with a clip for 60, 120, or 180 min. After scheduled clamping, the clip was removed to recover blood supply. The animals were killed 4 and 8 wk after operation. The survival, liver function, and histopathological changes were observed in rats of each group.

RESULTS: The survival rate was 100% in rats undergoing sham operation and those undergoing clamping for 60 or 120min, and 75% in those undergoing clamping for 180 min. At week 4, the body weight of rats undergoing clamping for 60, 120 or 180 min was lower than that of rats undergoing sham operation (240.4 g ± 11.5 g, 212.7 g ± 13.6 g, 200.6 g ± 11.8 g vs 260.6 g ± 15.7 g, all P < 0.05). Liver function parameters were higher in rats undergoing clamping for 60, 120 or 180 min than in those undergoing sham operation (ALT: 55.3 IU/L ± 5.3 IU/L, 215.6 IU/L ± 26.8 IU/L, 245.5 IU/L ± 38.5 IU/L vs 45.5 IU/L ± 3.9 IU/L, all P < 0.05; AST: 161.3 IU/L ± 15.9 IU/L, 645.3 IU/L ± 50.5 IU/L, 698.8 IU/L ± 46.7 IU/L vs 140.3 IU/L ± 6.1 IU/L, all P < 0.05; TILB: 8.5 μmol/L ± 1.2 μmol/L, 72.6 μmol/L ± 11.0 μmol/L, 78.7 μmol/L ± 12.2 μmol/L vs 6.1 μmol/L ± 1.2 μmol/L, all P < 0.05; ALP: 202.4 IU/L ± 20.7 IU/L, 815.4 IU/L ± 68.1 IU/L, 902.9 IU/L ± 96.6 IU/L vs 158.5 IU/L ± 23.6 IU/L, all P < 0.05; GGT: 10.6 IU/L ± 2.7 IU/L, 52.3 IU/L ± 8.6 IU/L, 57.4 IU/L ± 11.3 IU/L vs 7.6 IU/L ± 1.4 IU/L, all P < 0.05). Histopathological examination showed that biliary stenosis was not apparent and wall fibrosis was milder in rats undergoing sham operation and those undergoing clamping for 60 min, while severe biliary stenosis and wall fibrosis were observed in those undergoing clamping for 120 or 180 min. At week 8, these lesions could not regress spontaneously.

CONCLUSION: An animal model of extrahepatic biliary ischemic stenosis is successfully established with the clamping method in rats, which provides a useful tool for basic and clinical research of the etiology, development and prophylaxis of extrahepatic biliary ischemic stenosis after liver transplantation.

Biliary reconstruction, its complications and management of biliary complications after adult liver transplantation: a systematic review of the incidence, risk factors and outcome

Biliary reconstruction remains common in postoperative complications after liver transplantation. A systematic search was conducted on the PubMed database and 61 studies of retrospective or prospective institutional data were eligible for this review. The study comprised a total of 14,359 liver transplantations. The overall incidence of biliary stricture was 13%; 12% among deceased donor liver transplantation (DDLT) patients and 19% among living donor liver transplantation (LDLT) recipients. The overall incidence of biliary leakage was 8.2%, 7.8% among DDLT patients and 9.5% among LDLT recipients. An endoscopic strategy is the first choice for biliary complications; 83% of patients with biliary stricture were treated by endoscopic modalities with a success rate of 57% and 38% of patients with leakage were indicated for endoscopic biliary drainage. T-tube placement was not performed in 82% of duct-to-duct reconstruction. The incidence of biliary stricture was 10% with a T-tube and 13% without a T-tube and the incidence of leakage was 5% with a T-tube and 6% without a T-tube. A preceding bile leak and LDLT procedure are accepted risk factors for anastomotic stricture. Biliary complications remain common, which requires further investigation and the refinement of reconstruction techniques and management strategies.

Incidence of and risk factors for ischemic-type biliary lesions following orthotopic liver transplantation

Ischemic-type biliary lesions (ITBL) account for a major part of patients' morbidity and mortality after orthotopic liver transplantation (OLT). The exact origin of this type of biliary complication remains unknown. This study retrospectively evaluated 1843 patients. Patients with primary sclerosing cholangitis were excluded from this study. The diagnosis of ITBL was established only when all other causes of destruction of the biliary tree were ruled out. Donor age (P = 0.028) and cold ischemic time (CIT) (P = 0.002) were found to be significant risk factors for the development of ITBL. Organs that were perfused with University of Wisconsin (UW) solution developed ITBL significantly more often than Histidine-Tryptophan-Ketoglutarate (HTK)-perfused organs (P = 0.036). The same applied to organs harvested externally and shipped to our center versus those that were procured locally by our harvest teams (P < 0.001). Pressure perfusion via the hepatic artery significantly reduced the risk of ITBL (P = 0.001). The only recipient factor that showed a significant influence was Child-Pugh score status C (P = 0.021). Immunologic factors had no significant impact on ITBL. The clinical consequences of this study for our institution have been the strict limitation of CIT to <10 h and the exclusive use of HTK solution. We further advocate that all organ procurement teams perform pressure perfusion on harvested organs.

Secondary sclerosing cholangitis

Secondary sclerosing cholangitis (SSC) is a chronic cholestatic biliary disease, characterized by inflammation, obliterative fibrosis of the bile ducts, stricture formation and progressive destruction of the biliary tree that leads to biliary cirrhosis. SSC is thought to develop as a consequence of known injuries or secondary to pathological processes of the biliary tree. The most frequently described causes of SSC are longstanding biliary obstruction, surgical trauma to the bile duct and ischemic injury to the biliary tree in liver allografts. SSC may also follow intra-arterial chemotherapy. Sclerosing cholangitis in critically ill patients is a largely unrecognized new form of SSC, and is associated with rapid progression to liver cirrhosis. The mechanisms leading to cholangiopathy in critically ill patients are widely unknown; however, the available clinical data indicate that ischemic injury to the intrahepatic biliary tree may be one of the earliest events in the development of this severe form of sclerosing cholangitis. Therapeutic options for most forms of SSC are limited, and patients with SSC who do not undergo transplantation have significantly reduced survival compared with patients with primary sclerosing cholangitis. Sclerosing cholangitis in critically ill patients, in particular, is associated with rapid disease progression and poor outcome.

Intrahepatic biliary strictures after liver transplantation

Biliary complication has been one of the most common complications after liver transplantation. Nonanastomotic strictures and dilatations involving the intrahepatic biliary tree have been recognized as biliary complications. These lesions were reported to be associated with hepatic artery thrombosis; prolonged preservation time; ABO-incompatible organs; and immunological injury, including injuries to vascular endothelial cells (chronic rejection) and the bile duct (primary sclerosing cholangitis). However, the etiology of these lesions appeared to be mostly related to ischemic injury. Anatomical research on the arterial supply of the bile duct has provided further insights into bile duct blood supply and its surgical implications. The biliary tract is supplied with arterial blood by a vasculature called the peribiliary vascular plexus. Any injury to the peribiliary vascular plexus may contribute to ischemic death of the biliary system mucosa. At many points, the process of liver transplantation exposes the endothelial cells and peribiliary vascular plexus to ischemic injury. The majority of intrahepatic biliary strictures (IHBS) are diffuse or bilateral. A percutaneous or an endoscopic approach has been used as the initial treatment. However, a low threshold for surgical intervention (retransplantation) should be adopted, because these patients demonstrate high mortality. The aim of this article is to review the anatomy, etiology, clinical picture, diagnosis, management, and prognosis of IHBS after liver transplantation.

Biliary complications after deceased-donor orthotopic liver transplantation

A wide range of potential biliary complications can occur after orthotopic liver transplantation (OLT). The most common biliary complications are bile leaks, anastomotic and intrahepatic strictures, stones, and ampullary dyfunction, which may occur in up to 20%-40% of OLT recipients. Leaks predominate in the early posttransplant period; stricture formation typically develops gradually over time. However, with the advent of new techniques, such as split-liver, reduced-size, and living-donor liver transplantation, the spectrum of biliary complications has changed. Risk factors for biliary complications comprise technical failure; T-tube or stent-related complications; hepatic artery thrombosis; bleeding; ischemia/reperfusion injury; and other immunological, nonimmunological, and infectious complications. Noninvasive diagnostic methods have been established and treatment modalities have been modified towards a primarily nonoperative, endoscopy-based strategy. Besides, the management of biliary complications after OLT requires a multidisciplinary approach, in which interventional and endoscopic treatment options have to be weighed up against surgical treatment options. The etiology and spectrum of bile duct complications, their diagnosis, and their treatment will be reviewed in this article.

Sclerosing cholangitis: a focus on secondary causes

Secondary sclerosing cholangitis (SSC) is a disease that is morphologically similar to primary sclerosing cholangitis (PSC) but that originates from a known pathological process. Its clinical and cholangiographic features may mimic PSC, yet its natural history may be more favorable if recognition is prompt and appropriate therapy is introduced. Thus, the diagnosis of PSC requires the exclusion of secondary causes of sclerosing cholangitis and recognition of associated conditions that may potentially imitate its classic cholangiographic features. Well-described causes of SSC include intraductal stone disease, surgical or blunt abdominal trauma, intra-arterial chemotherapy, and recurrent pancreatitis. However, a wide variety of other associations have been reported recently, including autoimmune pancreatitis, portal biliopathy, eosinophillic and/or mast cell cholangitis, hepatic inflammatory pseudotumor, recurrent pyogenic cholangitis, primary immune deficiency, and AIDS-related cholangiopathy. This article offers a comprehensive review of SSC.

Type of donor aortic preservation solution and not cold ischemia time is a major determinant of biliary strictures after liver transplantation

The development of biliary strictures (BSs) after liver transplantation (LT) continues to affect 10% to 30% of patients, causing substantial morbidity. The cause of BSs is multifactorial, including technical, immune, and, in particular, ischemic factors. The importance of adequate flushing of the peribiliary arterial tree has been stressed. We hypothesized that high-viscosity (HV) preservation solutions in the donor do not completely flush the small donor peribiliary plexus, leading to inadequate preservation of the bile ducts and posttransplant BSs. To test this hypothesis, we retrospectively compared the incidence of BSs in 2 groups of adults undergoing LT using different types of aortic preservation solution in the donor: group 1 (n = 24), low-viscosity (LV) Marshall solution; and group 2 (n = 27), HV University of Wisconsin (UW) solution. All donors in both groups received additional portal flushes with UW. All LTs were performed between November 1995 and August 1998 at 2 centers by the same surgeon, eliminating a technical bias. Terminal duct-to-duct anastomosis was performed in all recipients except 1 patient in group 1, who underwent a bile duct-to-jejunum anastomosis. BSs were first suspected on clinical and biochemical grounds and then confirmed by endoscopic retrograde cholangiopancreatography. Identical medical protocols were used in all patients. One-year patient survival rates in groups 1 and 2 were 92% and 100%, respectively (P =.9). One-year graft survival was identical to patient survival. The incidence of BSs in group 1 was 4.1% (1 of 24 patients), compared to 29.7% in group 2 (8 of 27 patients; P =.02). The BS in group 1 occurred 4 months post-LT and was anastomotic. BSs in group 2 occurred between 1 and 12 months post-LT and were anastomotic, extrahepatic, intrahepatic, or combined intrahepatic and extrahepatic. There were no significant differences in the following factors between groups 1 and 2: donor age, local versus imported liver, split-liver or full-liver transplantation, incidence of multiple vessels in the donor liver, indications for LT, recipient age, T-tube versus no T-tube, post-LT peak aspartate aminotransferase level, and treatment for rejection. There was no hepatic artery thrombosis or primary nonfunction in either group. Interestingly, cold ischemia time (CIT) was longer in group 1, which had the least incidence of BSs (692 +/- 190 v 535 +/- 129 minutes in group 2; P =.001). Follow-up was longer in group 1 (28.9 +/- 8.3 v 15.6 +/- 8 months in group 2; P =.0001). Preservation costs per procurement were 1.9 times greater in the UW group than in the Marshall group. Donor aortic flushing with an HV preservation solution leads to more frequent BSs compared with an LV preservation solution. The impact of preservation solution outweighs the previously described deleterious impact of prolonged CIT. Mixed preservation solution (Marshall solution in the aorta, UW solution in the portal vein) might protect against BS formation while providing optimal liver graft preservation, function, and survival despite a mean CIT longer than 10 hours.

Predictive factors for portal fibrosis in pediatric liver transplant recipients

BACKGROUND

Recent histopathological studies showed an unexpected high incidence of pathological changes in asymptomatic survivors after pediatric liver transplantation. The aim of this study was to analyze the occurrence of histological abnormalities, to assess the clinical significance, and to identify predictive factors for these pathological changes.

METHODS

The first annual protocol graft biopsies of 84 consecutive liver transplants were analyzed and correlated with concomitant liver function tests. Identification of predictive factors for the histological abnormalities in the biopsies was performed by a multivariate logistic regression analysis.

RESULTS

The incidence of portal fibrosis (PF) was 31%. Liver function tests showed except for the albumin level, an increase in the PF group compared with the group without PF. Mean values of alkaline phosphatase and direct bilirubin were 264 U/liter and 3 micromol/liter, respectively, in the normal group, and 435 U/liter and 23 micromol/liter, respectively, in the PF group (P=0.043 and 0.037). Eight of 19 univariantly tested variables were entered into a logistic regression model: cold ischemia time, preservation solution, type of allograft, cytomegalovirus recipient status, type of biliary reconstruction, biliary complications, graft complications, and rejection. A significant positive correlation with PF was found for cold ischemia time, biliary complications, and cytomegalovirus status. Acute rejection showed a negative correlation.

CONCLUSIONS

The incidence of PF within 1 year post liver transplantation was 31%. This finding was accompanied by cholestatic liver function test abnormalities. Factors predisposing to PF were a prolonged cold ischemia time, biliary complications, and a positive cytomegalovirus recipient status. Acute rejection seemed to prevent for PF.

Reconstructive surgery for ischemic-type lesions at the bile duct bifurcation after liver transplantation

OBJECTIVE

To assess the feasibility, morbidity, mortality, and clinical success rate of surgical reconstruction of the biliary system in patients with ischemic-type biliary lesions in their liver graft.

SUMMARY BACKGROUND DATA

After liver transplantation, strictures in the biliary tree with secondary sludge formation can occur in the absence of vascular problems. Jaundice, pruritus, and recurrent cholangitis are predominant clinical features leading to considerable morbidity. Interventional measures are the first-line treatment but are frequently only of transient success. Retransplantation is usually considered when interventional treatment is not effective.

METHODS

Surgical exploration and reconstruction was performed in 17 patients with ischemic-type biliary strictures at a median of 2 years after liver transplantation. Findings during surgery, surgical strategies, and postsurgical courses are described. Clinical symptoms and biochemical parameters of cholestasis and liver function were analyzed in the postsurgical course.

RESULTS

During surgery, all 17 patients were found to have strictures or sclerotic changes involving the hepatic bifurcation and extrahepatic bile duct. Sludge or stones were present in nine patients. In 14 patients with viable bile ducts proximal to the bifurcation, surgical reconstruction was performed by resection of the bifurcation and hepaticojejunostomy. In three patients with more extensive biliary destruction, portoenterostomy with or without peripheral hepatojejunostomy was performed. The prevalence rate of biliary infection at surgery was 93%; the predominant organisms were Candida and enterococci. The perioperative mortality rate was 0%. Clinical symptoms and biochemical parameters became normal or were considerably improved in 14 of 16 patients (88%).

CONCLUSIONS

The hepatic bifurcation seems to be a predominant site for ischemic-type biliary changes after liver transplantation. Surgical treatment by resection of the bifurcation and reconstruction by high hepaticojejunostomy is a safe and highly effective approach leading to cure or persistent major improvement in most patients.

Ischemic cholangitis

Ischemia-induced bile duct lesions have been collectively labeled as ischemic cholangitis. The biliary epithelium is dependent on arterial blood flow, unlike the hepatic parenchyma with its dual arterial and portal venous blood supply. As such, the biliary epithelium is susceptible to injury when arterial blood flow is compromised. This compromise can occur at the level of the major, named hepatic artery branches or at the microscopic, peribiliary capillary plexus level. Typically, ischemic cholangitis manifests as segmental strictures and cholangiectases with resultant mechanical impairment of bile flow and, occasionally, secondary infection of the biliary system. Ischemic cholangitis after liver transplantation is becoming an important problem and likely is attributable to numerous factors. Hepatic arterial infusion of chemotherapy and systemic vasculitis are other causes of ischemic cholangitis. The role of ischemia in other chronic biliary and ductopenic diseases remains speculative.

Significance of early aminotransferase elevation after liver transplantation

BACKGROUND

We retrospectively reviewed 213 consecutive patients who received their first liver allograft between January 1 and December 31, 1993, in order to study the impact of ischemia/preservation/reperfusion injury (IPRI) on patient and graft outcome.

METHODS

The extent of IPRI was assessed by the peak value of aspartate aminotransferase (ASTmax) observed within the first 72 hr after transplant. For the purpose of univariate analysis, categorical classification of recipients was done based upon ASTmax as follows: group 1, ASTmax<600 U/L (n=46); group 2, ASTmax=600-2000 U/L (n=97); group 3, ASTmax>2000-5000 U/L (n=50), and group 4, ASTmax>5000 U/L (n=17). For multivariate analysis, stepwise Cox regression was performed with age, ASTmax, and United Network for Organ Sharing (UNOS) status as covariates.

RESULTS

Groups were comparable with respect to age, UNOS status at the time of transplantation, and diagnostic case mix. Median follow-up was 644 days. The overall incidence of primary graft nonfunction (PNF) was 7.6%. PNF incidence was significantly correlated with the severity of IPRI (0%, 4%, 10%, and 41% for groups 1 to 4, respectively, P < 0.0001), but this impact was confined to the respective rates of retransplantation as early patient survival was unaffected. The 1-year survival of patients whose initial grafts manifested extreme IPRI (group 4) was significantly inferior to recipients in the three other groups (77%, 71%, 73%, and 52% for groups 1 to 4, respectively, P=0.03). This increased mortality was confined to patients who never achieved discharge from their initial hospitalization, with no significant differences between groups being detected in the survival of those patients who were discharged (84%, 80%, 85%, and 81% for groups 1 to 4, respectively, P=NS). Although overall 1-year graft survival was strongly correlated with the extent of IPRI (77%, 67%, 62%, and 41% for groups 1 to 4, respectively, P=0.001), this correlation was abolished when survival of grafts not lost to PNF was examined at 1 and 2 years. Stepwise Cox regression analysis confirmed the independent association between ASTmax and patient and graft survival. The long-term quality of allograft function as well as the incidence of chronic rejection and biliary complications were unrelated to the extent of IPRI.

CONCLUSIONS

We conclude that: (1) patient survival is influenced by IPRI only when it is extreme (ASTmax>5000 U/L), provided parameters of graft function are used in conjunction with aminotransferase values to assess the need for prompt retransplantation; (2) short-term graft survival is proportional to the extent of IPRI, but grafts that are not lost to PNF have equivalent 1- and 2-year survival irrespective of the magnitude of IPRI; (3) 40% of grafts with extreme IPRI are lost to PNF, but the same proportion also provide long-term function; and (4) for surviving grafts, long-term biochemical function as well as the incidence of biliary complications and of chronic rejection are unrelated to the extent of IPRI.

Failed allografts and causes of death after orthotopic liver transplantation from 1985 to 1995: decreasing prevalence of irreversible hepatic allograft rejection

Mayo Clinic pathology files from March 1985 to March 1995 contained records of 584 orthotopic liver transplantations in 515 patients. The most common indication for liver transplantation was primary sclerosing cholangitis (PSC), followed by primary biliary cirrhosis (PBC), and cryptogenic cirrhosis. In 59 patients, a total of 69 single or repeated retransplantations became necessary. Vascular complications necessitated retransplantation in 35 cases, followed by irreversible rejection in 16 cases, and primary graft failure in 8 cases. Ninety-nine patients died, 25 of them after one or more retransplantations. Infectious complications caused death in 38 cases, followed by graft-related complications (excluding rejection) in 22 cases, noninfectious systemic diseases such as intracerebral hemorrhage (21 cases), malignancies in 13 cases, and irreversible rejection in 5 cases. In the decade from 1985 to 1995, only 14 patients had irreversible rejection that often was associated with other complications such as ischemic cholangitis. Furthermore, the rate of irreversible rejection decreased dramatically. Thus, although 5 deaths were caused by irreversible rejection, none occurred since March 1991, and of the 16 retransplantations for irreversible rejection, only one needed to be performed during these last 4 years. The disappearance of irreversible rejection, which can be described as the "vanishing vanishing bile duct syndrome," must be considered when new immunosuppressants are tested, because graft loss and death from rejection are no longer suitable criteria.