Risk factors for and clinical course of non-anastomotic biliary strictures after liver transplantation

Imaging of Ischemic Cholangiopathy Following Donation after Circulatory Death Liver Transplant

Ischemic cholangiopathy (IC) is the leading cause of inferior long-term outcomes following donation after circulatory death (DCD) liver transplant. Biliary strictures related to IC are nonanastomotic strictures (NASs) by definition and involve the donor hepatic ducts proximal to the anastomosis, compared with postsurgical anastomotic strictures that form due to fibrotic healing. IC-related NASs can be microangiopathic with patent hepatic artery or macroangiopathic with occluded or stenotic hepatic artery. Recently, IC with NASs have been described to have four distinct patterns at imaging: diffuse necrosis, multifocal progressive, confluence dominant, and minor form, which correlate clinically with graft prognosis. Severe IC can lead to ductal wall breakdown with subsequent bile leaks that can cause significant patient morbidity, with imaging playing a vital role in diagnosis and guiding intervention. IC also predisposes the transplanted liver to biliary stasis and subsequent formation of stones, casts, and sludge. Some cases of posttransplant biliary stricturing are not IC but are a sequela of reflux cholangitis seen with choledochojejunal anastomosis. Other biliary findings in the posttransplant liver can be explained by sphincter of Oddi dysfunction that results from denervation. The authors describe and comprehensively categorize the various IC types and their imaging patterns at MRI and MR cholangiopancreatography, review the prognostic significance of these imaging patterns, and discuss imaging features of additional biliary complications associated with IC after DCD liver transplant. ©RSNA, 2024 Supplemental material is available for this article.

Prolonged warm ischemia time in the recipient is associated with post-transplant biliary stricture following living-donor liver transplantation

PURPOSE

Post-transplant biliary stricture (PBS) is a common and important complication following orthotopic liver transplantation (LT). This study clarified the incidence of PBS and identified its risk factors.

METHODS

We retrospectively reviewed the medical records of 67 patients who underwent living-donor LT (LDLT) at our institute between June 2010 and July 2022 and analyzed their clinical characteristics, prognosis, and risk factors for PBS.

RESULTS

Of the 67 patients, 26 (38.8%) developed PBS during the observation period. Multivariate analyses revealed the following independent risk factors for PBS formation: increased red cell transfusion volume per body weight (> 0.2 U/kg; hazard ratio [HR], 3.8; P = 0.002), increased portal vein pressure (PVP) at the end of LT (> 16 mmHg; HR, 2.88; P = 0.032), postoperative biliary leakage (HR, 4.58; P = 0.014), and prolonged warm ischemia time (WIT) (> 48 min; HR, 4.53; P = 0.008). In patients with PBS, the cumulative incidence of becoming stent free was significantly higher in patients with a WIT ≤ 48 min than in those with a WIT > 48 min (P = 0.038).

CONCLUSION

Prolonged WIT is associated with intractable PBS following LDLT.

The Promise of Complement Therapeutics in Solid Organ Transplantation

Transplantation is the ideal therapy for end-stage organ failure, but outcomes for all transplant organs are suboptimal, underscoring the need to develop novel approaches to improve graft survival and function. The complement system, traditionally considered a component of innate immunity, is now known to broadly control inflammation and crucially contribute to induction and function of adaptive T-cell and B-cell immune responses, including those induced by alloantigens. Interest of pharmaceutical industries in complement therapeutics for nontransplant indications and the understanding that the complement system contributes to solid organ transplantation injury through multiple mechanisms raise the possibility that targeting specific complement components could improve transplant outcomes and patient health. Here, we provide an overview of complement biology and review the roles and mechanisms through which the complement system is pathogenically linked to solid organ transplant injury. We then discuss how this knowledge has been translated into novel therapeutic strategies to improve organ transplant outcomes and identify areas for future investigation. Although the clinical application of complement-targeted therapies in transplantation remains in its infancy, the increasing availability of new agents in this arena provides a rich environment for potentially transformative translational transplant research.

Ultrasound innovations in abdominal radiology: multiparametic imaging in liver transplantation

PURPOSE

Ultrasound plays a central role in liver transplant evaluation. Acute, subacute, and chronic complications can be readily identified using grayscale and color Doppler ultrasound. Contrast-enhanced ultrasound adds a new dimension to liver transplant evaluation, depicting vascular and parenchymal processes with exquisite detail. In addition, emerging evidence suggests that contrast-enhanced ultrasound may allow for localization of biliary leak in select patients. We aimed to assess the use of multiparametric ultrasound-including grayscale, color and spectral Doppler, and contrast-enhanced ultrasound-in the setting of liver transplantation.

METHODS

A literature review was performed using the MEDLINE bibliographic database through the National Library of Medicine. The following terms were searched and relevant citations assessed: "abdominal ultrasound," "contrast-enhanced ultrasound," "liver transplant," and "ultrasound."

RESULTS

Grayscale and color Doppler ultrasound represent the mainstay imaging modalities for postoperative liver transplant evaluation. The addition of contrast enhancement plays a complementary role and can provide valuable information related to the allograft vasculature, parenchyma, and biliary tree. The appropriate implementation of grayscale, color Doppler, and contrast-enhanced ultrasound can optimize sensitivity, specificity, and accuracy for the detection of liver transplantation complications, including hepatic artery stenosis, biliary leakage, and infection.

CONCLUSION

Multimodal sonographic evaluation is essential to identify postoperative complications in liver transplant recipients. Contrast-enhanced ultrasound may be of value in challenging cases, providing excellent anatomic delineation and reducing the risk of false-positive and false-negative diagnoses. A broad familiarity with appropriate applications of both nonenhanced and contrast-enhanced ultrasound may help radiologists optimize allograft assessment and improve patient outcomes.

Current Understanding of Marginal Grafts in Liver Transplantation

End-stage liver disease (ESLD), stemming from a spectrum of chronic liver pathologies including chronic liver failure, acute cirrhosis decompensation and hepatocellular carcinoma, imposes a significant global healthcare burden. Liver transplantation (LT) remains the only treatment for ESLD. However, the escalating mortality on transplant waitlists has prompted the utilization of marginal liver grafts in LT procedures. These grafts primarily encompass elderly livers, steatotic livers, livers from donation after circulatory death, split livers and those infected with the hepatitis virus. While the expansion of the donor pool offers promise, it also introduces concomitant risks. These encompass graft failure, biliary and cardiovascular complications, the recurrence of liver disease and reduced patient and graft survival. Consequently, various established strategies, ranging from improved donor-recipient matching to surgical interventions, have emerged to mitigate these risks. This article undertakes a comprehensive assessment of the current landscape, evaluating the viability of diverse marginal liver grafts. Additionally, it synthesizes approaches aimed at enhancing the quality of such marginal liver grafts. The overarching objective is to augment the donor pool and ameliorate the risk factors associated with the shortage of liver grafts.

A practical approach to the endoscopic management of biliary strictures after liver transplantation

Biliary tract complications are an important cause of morbidity and mortality after liver transplantation (LT) occurring in 5% to 25% of patients. The most common biliary complication in LT recipients are strictures representing approximately half of these biliary adverse events. Bile duct strictures can be divided into anastomotic biliary strictures (ABS) and non-anastomotic biliary strictures (NABS) depending on their location in the biliary tree, being ABS the most encountered type. Several risk factors identified in previous studies can predispose to the development of ABS and NABS, especially those related to surgical techniques and donor characteristics. Magnetic resonance cholangiopancreatography (MRCP) is the recommended noninvasive imaging test for detecting post-LT biliary strictures, given its high sensitivity and specificity. Once the diagnosis of a biliary stricture after LT has been made, endoscopic retrograde cholangiopancreatography (ERCP) is the preferred initial therapy with good short and long-term results. Biliary sphincterotomy plus balloon dilation (BD) with placement of multiple plastic stents (MPS) has been the classic endoscopic approach for treating ABS, although fully-covered metallic stents (FCSEMS) have emerged as an alternative thanks to shorter total duration of stenting and fewer endoscopic procedures compared to MPS. In this review, we provide a practical update on the management of biliary strictures after LT, focusing our attention on the available evidence in the endoscopic therapy.

Endoscopic management of benign biliary strictures: Looking for the best stent to place

Benign biliary strictures (BBS) might occur due to different pancreaticobiliary conditions. The etiology and location of biliary strictures are responsible of a wide array of clinical manifestations. The endoscopic approach endoscopic retrograde cholangiopancreatography represents the first-line treatment for BBS, considering interventional radiology and surgery when endoscopic treatment fails or it is not suitable. The purpose of this review is to provide an overview of possible endoscopic treatments for the optimal management of this subset of patients.

A case of hepaticojejunal anastomotic obstruction after a living-donor liver transplantation and recanalization using a high-frequency knife under the rendezvous technique

A 65-year-old woman underwent living-donor liver transplantation (left-lobe graft: GWRW ratio, 0.54) for cirrhosis caused by autoimmune hepatitis. At 68 years, she was diagnosed with obstructive cholangitis due to stricture during a hepaticojejunostomy following impaired liver function. Endoscopic balloon dilation of anastomosis and placement of a plastic stent resulted in improved liver function. However, at 72 years, the patient experienced a flare-up of liver damage. The plastic stent had fallen out, and although endoscopic stenotic dilation was attempted, the anastomotic site was obstructed completely. Therefore, recanalization of the hepaticojejunostomy was attempted using a rendezvous technique. A percutaneous transhepatic biliary drainage tube was inserted through the B3 bile duct, and the complete obstructed anastomosis was confirmed by percutaneous transhepatic and transjejunal approaches. The anastomosis was reopened by excising the scarred tissues from the jejunal side using a 1.5-mm high-frequency knife. A 14-Fr. catheter for the internal fistula tube was percutaneously placed at the opened anastomosis to achieve anastomotic site recanalization. The patient's liver damage improved after the re-internalization, and no symptom recurrence such as obstructive cholangitis developed for 1 year. There are few reports of recanalization of the hepaticojejunostomy with a high-frequency knife. Herein, we report the case with a literature review.

Machine perfusion in liver transplantation

BACKGROUND

Liver transplantation is the only chance of cure for people with end-stage liver disease and some people with advanced liver cancers or acute liver failure. The increasing prevalence of these conditions drives demand and necessitates the increasing use of donated livers which have traditionally been considered suboptimal. Several novel machine perfusion preservation technologies have been developed, which attempt to ameliorate some of the deleterious effects of ischaemia reperfusion injury. Machine perfusion technology aims to improve organ quality, thereby improving outcomes in recipients of suboptimal livers when compared to traditional static cold storage (SCS; ice box).

OBJECTIVES

To evaluate the effects of different methods of machine perfusion (including hypothermic oxygenated machine perfusion (HOPE), normothermic machine perfusion (NMP), controlled oxygenated rewarming, and normothermic regional perfusion) versus each other or versus static cold storage (SCS) in people undergoing liver transplantation.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 10 January 2023.

SELECTION CRITERIA

We included randomised clinical trials which compared different methods of machine perfusion, either with each other or with SCS. Studies comparing HOPE via both hepatic artery and portal vein, or via portal vein only, were grouped. The protocol detailed that we also planned to include quasi-randomised studies to assess treatment harms.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. overall participant survival, 2. quality of life, and 3. serious adverse events. Secondary outcomes were 4. graft survival, 5. ischaemic biliary complications, 6. primary non-function of the graft, 7. early allograft function, 8. non-serious adverse events, 9. transplant utilisation, and 10. transaminase release during the first week post-transplant. We assessed bias using Cochrane's RoB 2 tool and used GRADE to assess certainty of evidence.

MAIN RESULTS

We included seven randomised trials (1024 transplant recipients from 1301 randomised/included livers). All trials were parallel two-group trials; four compared HOPE versus SCS, and three compared NMP versus SCS. No trials used normothermic regional perfusion. When compared with SCS, it was uncertain whether overall participant survival was improved with either HOPE (hazard ratio (HR) 0.91, 95% confidence interval (CI) 0.42 to 1.98; P = 0.81, I2 = 0%; 4 trials, 482 recipients; low-certainty evidence due to imprecision because of low number of events) or NMP (HR 1.08, 95% CI 0.31 to 3.80; P = 0.90; 1 trial, 222 recipients; very low-certainty evidence due to imprecision and risk of bias). No trials reported quality of life. When compared with SCS alone, HOPE was associated with improvement in the following clinically relevant outcomes: graft survival (HR 0.45, 95% CI 0.23 to 0.87; P = 0.02, I2 = 0%; 4 trials, 482 recipients; high-certainty evidence), serious adverse events in extended criteria DBD liver transplants (OR 0.45, 95% CI 0.22 to 0.91; P = 0.03, I2 = 0%; 2 trials, 156 participants; moderate-certainty evidence) and clinically significant ischaemic cholangiopathy in recipients of DCD livers (OR 0.31, 95% CI 0.11 to 0.92; P = 0.03; 1 trial, 156 recipients; high-certainty evidence). In contrast, NMP was not associated with improvement in any of these clinically relevant outcomes. NMP was associated with improved utilisation compared with SCS (one trial found a 50% lower rate of organ discard; P = 0.008), but the reasons underlying this effect are unknown. We identified 11 ongoing studies investigating machine perfusion technologies.

AUTHORS' CONCLUSIONS

In situations where the decision has been made to transplant a liver donated after circulatory death or donated following brain death, end-ischaemic HOPE will provide superior clinically relevant outcomes compared with SCS alone. Specifically, graft survival is improved (high-certainty evidence), serious adverse events are reduced (moderate-certainty evidence), and in donors after circulatory death, clinically relevant ischaemic biliary complications are reduced (high-certainty evidence). There is no good evidence that NMP has the same benefits over SCS in terms of these clinically relevant outcomes. NMP does appear to improve utilisation of grafts that would otherwise be discarded with SCS; however, the reasons for this, and whether this effect is specific to NMP, is not clear. Further studies into NMP viability criteria and utilisation, as well as head-to-head trials with other perfusion technologies are needed. In the setting of donation following circulatory death transplantation, further trials are needed to assess the effect of these ex situ machine perfusion methods against, or in combination with, normothermic regional perfusion.

Redo hepatic artery reconstruction for thrombosis without retransplantation in 1355 adult living donor liver transplantations

Hepatic artery thrombosis (HAT) after liver transplantation is associated with a marked increase in morbidity, leading to graft and patient loss. We evaluated the outcomes of adult living donor liver transplantation patients with HAT under an aggressive surgical intervention. A total of 1355 recipients underwent adult living donor liver transplantation at the Seoul National University Hospital. Surgical redo reconstruction for HAT was performed in all cases except in those with graft hepatic artery injury and late detection of HAT. Postoperative HAT developed in 33 cases (2.4%) at a median time of 3.5 days. Thirty patients (90.9%) underwent redo-arterial reconstruction. The survival rates in patients with HAT were similar to the rates in those without HAT (72.7% vs. 83.8%, p = 0.115). Although graft survival rates were lower in patients with HAT (84.8%) than in those without HAT (98.0%) ( p < 0.001), the graft survival rate was comparable (92.0% vs. 98.0%, p = 0.124) in the 25 patients with successful revascularization. Biliary complication rates were higher in patients with HAT (54.5%) than in those without HAT (32.0%) ( p = 0.008). In conclusion, the successful redo reconstruction under careful selection criteria saved the graft without retransplantation in 96.0% of the cases. Surgical revascularization should be preferentially considered for the management of HAT in adult living donor liver transplantation.

Post-transplant biliary complications using liver grafts from deceased donors older than 70 years: Retrospective case-control study

BACKGROUND

The shortage of liver grafts and subsequent waitlist mortality led us to expand the donor pool using liver grafts from older donors.

AIM

To determine the incidence, outcomes, and risk factors for biliary complications (BC) in liver transplantation (LT) using liver grafts from donors aged > 70 years.

METHODS

Between January 1994 and December 31, 2019, 297 LTs were performed using donors older than 70 years. After excluding 47 LT for several reasons, we divided 250 LTs into two groups, namely post-LT BC (n = 21) and without BC (n = 229). This retrospective case-control study compared both groups.

RESULTS

Choledocho-choledochostomy without T-tube was the most frequent technique (76.2% in the BC group vs 92.6% in the non-BC group). Twenty-one patients (8.4%) developed BC (13 anastomotic strictures, 7 biliary leakages, and 1 non-anastomotic biliary stricture). Nine patients underwent percutaneous balloon dilation and nine required a Roux-en-Y hepaticojejunostomy because of dilation failure. The incidence of post-LT complications (graft dysfunction, rejection, renal failure, and non-BC reoperations) was similar in both groups. There were no significant differences in the patient and graft survival between the groups. Moreover, only three deaths were attributed to BC. While female donors were protective factors for BC, donor cardiac arrest was a risk factor.

CONCLUSION

The incidence of BC was relatively low on using liver grafts > 70 years. It could be managed in most cases by percutaneous dilation or Roux-en-Y hepaticojejunostomy, without significant differences in the patient or graft survival between the groups.

Intestinal Bacteremia After Liver Transplantation Is a Risk Factor for Recurrence of Primary Sclerosing Cholangitis

BACKGROUND

Primary sclerosing cholangitis (PSC) is a chronic progressive pathological process, related to inflammatory bowel disease and subsequent bacterial translocation. Liver transplantation (LT) is the only curative therapy, but outcomes are compromised by recurrence of PSC (rPSC). The aim of the study was to investigate a potential link between intestinal bacteremia, fucosyltransferase-2 (FUT2), and rPSC after LT.

METHODS

LT recipients with PSC (n = 81) or without PSC (n = 271) were analyzed for clinical outcomes and positive bacterial blood cultures. A link between bacteremia and the genetic variant of the FUT2 gene was investigated.

RESULTS

The incidence of inflammatory bowel disease was significantly higher in PSC recipients but not associated with rPSC. Bacteremia occurred in 31% of PSC recipients. The incidence of rPSC was 37% and was significantly more common in patients with intestinal bacteremia versus no bacteremia (82% versus 30%; P = 0.003). The nonsecretor polymorphism of the FUT2 gene was identified as a genetic risk factor for both intestinal bacteremia and rPSC. Combined FUT2 genotype and intestinal bacteremia in recipients resulted in the highest risk for rPSC (hazard ratio, 15.3; P < 0.001).

CONCLUSIONS

Thus, in this article, we showed that bacterial translocation is associated with rPSC after LT and related to the FUT2 nonsecretor status.

Treatment of Non-Anastomotic Biliary Strictures after Liver Transplantation: How Effective Is Our Current Treatment Strategy?

BACKGROUND

Non-anastomotic biliary strictures (NAS) are a common cause of morbidity and mortality after liver transplantation.

METHODS

All patients with NAS from 2008 to 2016 were retrospectively analyzed. The success rate and overall mortality of an ERCP-based stent program (EBSP) were the primary outcomes.

RESULTS

A total of 40 (13.9%) patients with NAS were identified, of which 35 patients were further treated in an EBSP. Furthermore, 16 (46%) patients terminated EBSP successfully, and nine (26%) patients died during the program. All deaths were caused by cholangitis. Of those, one (11%) patient had an extrahepatic stricture, while the other eight patients had either intrahepatic (3, 33%) or combined extra- and intrahepatic strictures (5, 56%). Risk factors of overall mortality were age (p = 0.03), bilirubin (p < 0.0001), alanine transaminase (p = 0.006), and aspartate transaminase (p = 0.0003). The median duration of the stent program was 34 months (ITBL: 36 months; IBL: 10 months), and procedural complications were rare.

CONCLUSIONS

EBSP is safe, but lengthy and successful in only about half the patients. Intrahepatic strictures were associated with an increased risk of cholangitis.

Biliary and Vascular Complications after Liver Transplantation-From Diagnosis to Treatment

The last decades have brought impressive advances in liver transplantation. As a result, there was a notable rise in the number of liver transplants globally. Advances in surgical techniques, immunosuppressive therapies and radiologically guided treatments have led to an improvement in the prognosis of these patients. However, the risk of complications remains significant, and the management of liver transplant patients requires multidisciplinary teams. The most frequent and severe complications are biliary and vascular complications. Compared to vascular complications, biliary complications have higher incidence rates but a better prognosis. The early diagnosis and selection of the optimal treatment are crucial to avoid the loss of the graft and even the death of the patient. The development of minimally invasive techniques prevents surgical reinterventions with their associated risks. Liver retransplantation remains the last therapeutic solution for graft dysfunction, one of the main problems, in this case, being the low number of donors.

Liver transplantation for autoimmune hepatitis: Pre-transplant does not predict the early post-transplant outcome

BACKGROUND AND AIMS

Autoimmune hepatitis (AIH) is a rare indication (<5%) for liver transplantation (LT). The aim of this study was to describe the early outcome after LT for AIH.

METHODS

A multicenter retrospective nationwide study including all patients aged ≥16 transplanted for AIH in France was conducted. Occurrences of biliary and vascular complications, rejection, sepsis, retransplantation and death were collected during the first year after LT.

RESULTS

A total of 344 patients (78.8% of women, 17.0% of (sub)fulminant hepatitis and 19.2% of chronic liver diseases transplanted in the context of acute-on-chronic liver failure [ACLF]) were included, with a median age at LT of 43.6 years. Acute rejection, sepsis, biliary and vascular complications occurred in respectively 23.5%, 44.2%, 25.3% and 17.4% of patients during the first year after LT. One-year graft and patient survivals were 84.3% and 88.0% respectively. The main cause of early death was sepsis. Pre-LT immunosuppression was not associated with an increased risk for early infections or surgical complications. Significant risk factors for septic events were LT in the context of (sub)fulminant hepatitis or ACLF, acute kidney injury at the time of LT (AKI) and occurrence of biliary complications after LT. AKI was the only independent factor associated with graft (HR = 2.5; 95% CI: 1.1-5.4; p = .02) and patient survivals (HR = 2.6; 95% CI: 1.0-6.5; p = .04).

CONCLUSION

Early prognosis is good after LT for AIH and is not impacted by pre-LT immunosuppression but by the presence of AKI at the time of LT.

Anatomical classification and clinical outcomes of biliary strictures in living donor liver transplantation using right liver grafts

This study aimed to classify the anatomical types of biliary strictures, including intrahepatic biliary stricture (IHBS), after living donor liver transplantations (LDLTs) using right liver grafts and evaluate their prognosis. Among 692 adult patients who underwent right liver LDLT, 198 recipients with biliary strictures (28.6%) were retrospectively reviewed. Based on data obtained during the first cholangiography, the patients' biliary strictures were classified into the following three types according to the levels and number of branches involved: Types 1 (anastomosis), 2 (second-order branch [a, one; b, two or more; c, extended to the third-order branch]), and 3 (whole graft [a, multifocal strictures; b, diffuse necrosis]). IHBS was defined as a nonanastomotic stricture. Among the 198 recipients with biliary strictures, the IHBS incidence rates were 38.4% ( n = 76). The most common type of IHBS was 2c ( n = 43, 56.6%), whereas Type 3 ( n = 10, 13.2%) was uncommon. The intervention frequency per year significantly differed among the types (Type 1, 2.3; Type 2a, 2.3; Type 2b, 2.8; Type 2c, 4.3; and Type 3, 7.2; p  < 0.001). The intervention-free period for more than 1 year, which was as follows, also differed among the types: Type 1, 84.4%; Type 2a, 87.5%; Type 2b, 86.7%; Type 2c, 72.1%; and Type 3, 50.0% ( p = 0.048). The graft survival rates of Type 3 (80.0%) were significantly lower than those of the other types ( p = 0.001). IHBSs are relatively common in right liver LDLTs. Although Type 3 IHBSs are rare, they require more intensive care and are associated with poorer graft survival rates than anastomosis strictures and Type 2 IHBS.

Prognostic Factors for Non-anastomotic Biliary Strictures Following Adult Liver Transplantation: A Systematic Review and Meta-Analysis

INTRODUCTION

The development of non-anastomotic biliary strictures (NAS) following orthotopic adult liver transplantation (OLT) is associated with significant morbidity. We performed a systematic review and meta-analysis to identify all prognostic factors for the development of NAS.

METHODS

A systematic review was conducted following preferred reporting items for systematic reviews and meta-analyses (PRISMA) and the meta-analysis of observational studies in epidemiology (MOOSE) guidelines. We used the Newcastle-Ottawa scale to assess the quality of the included studies. Using the random-effects model, we calculated the weighted pooled odds ratios (OR), mean differences (MD), hazard ratios (HR), and 95% confidence intervals (CI) of the risk factors.

RESULTS

Based on 19 international studies that included a total of 8269 adult LT patients, we calculated an 8% overall incidence of NAS. In this study, 7 potential prognostic factors were associated with a statistically significant hazard ratio for NAS in pooled analyses including (1) DCD donors compared to DBD donors (2) PSC as an indication for a liver transplant (3) Roux-en-Y bile duct reconstruction compared to duct-to-duct reconstruction (4) hepatic artery thrombosis (5) longer cold ischemia time (6) longer warm ischemia time (7) and total operative times.

CONCLUSION

In this systematic review and meta-analysis, we identified 7 prognostic factors for the development of NAS following OLT. These findings might lay the groundwork for development of diagnostic algorithms to better risk stratify patients at risk for development of NAS.

Scheduled endoscopic treatment of biliary anastomotic and nonanastomotic strictures after orthotopic liver transplantation

BACKGROUND AND AIMS

Biliary strictures after liver transplantation are associated with significant morbidity and mortality. Although various endoscopic treatment strategies are available, consensus on a particular strategy is lacking. Moreover, the influence of endoscopic therapy on overall survival has not been studied. This retrospective study aimed to evaluate the impact of scheduled endoscopic dilatation of biliary strictures after orthotopic liver transplantation on therapeutic success, adverse events, and survival.

METHODS

Between 2000 and 2016, patients with post-transplant anastomotic and nonanastomotic strictures were treated with balloon dilatation at defined intervals until morphologic resolution and clinical improvement. The primary clinical endpoint was overall survival, whereas secondary outcomes were technical and sustained clinical success, adverse events, treatment failure, and recurrence.

RESULTS

Overall, 165 patients with a mean follow-up of 8 years were included; anastomotic and nonanastomotic strictures were diagnosed in 110 and 55 patients, respectively. Overall survival was significantly higher in patients with anastomotic strictures than in those with nonanastomotic strictures (median, 17.6 vs 13.9 years; log-rank: P < .05). Sustained clinical success could be achieved significantly more frequently in patients with anastomotic strictures (79.1% vs 54.5%, P < .001), and such patients showed significantly superior overall survival (19.7 vs 7.7 years; log-rank: P < .001). Sustained clinical success and the presence of nonanastomotic strictures were independently associated with better and worse outcomes (P < .05), respectively.

CONCLUSIONS

Scheduled endoscopic treatment of biliary anastomotic and nonanastomotic strictures after liver transplantation is effective and safe, with high success rates. The implementation of this strategy controls symptoms and significantly improves survival.

The reasonable therapeutic modality for biliary duct-to-duct anastomotic stricture after liver transplantation: ERCP or PTC?

Objective

To compare the initial success rate, feasibility, and effectiveness of endoscopic retrograde cholangiopancreatography (ERCP) versus percutaneous transhepatic cholangiography (PTC) for anastomotic biliary stricture after liver transplantation (LT).

Methods

We retrospectively analyzed the data collected during January 2015 to December 2021 from liver transplantation recipients who developed anastomotic biliary stricture after liver transplantation and treated by ERCP and/or PTC. The success rate, complications and patients’ survival rate of ERCP and PTC procedures was evaluated.

Results

Forty-eight patients who underwent LT and were confirmed to have the anastomotic biliary stricture were enrolled. Overall, 48/48 patients underwent single or multiple ERCP procedures as the first line therapy; 121 therapeutic ERCPs (3.36 ± 2.53 ERCPs per patient) were performed in 36/48 patients successfully. All the 12 patients who failed ERCP tend to have special bile duct conditions such as overlong, angle shaped, and/or extremely narrowed bile duct and underwent PTC as an alternative treatment. The initial success rate of ERCP was 75% (36/48) while the success rate of ERCP for the 12 patients with special bile duct was 0% (0/12). PTC was an effective second-line treatment for those 12 patients who failed ERCP, and 58.33% (7 of 12 cases) were treated successfully. The average procedure time in PTC group was significantly lower than ERCP group (t=2.292, P=0.027). The feasibility of ERCP was associated with the anatomical shape of bile duct and the severity of the stricture site. Finally, the cumulative survival rate was 100% (12/12) in PTC group compared to 86.11% (31/36) in ERCP group (χ^{2 =}0.670, P=0.413).

Conclusion

ERCP is the gold standard method for the diagnosis and effective intervention for the management of biliary complications after LT. However, its use in certain types of biliary complications (e.g., patients with severe anastomotic biliary stricture and those with overlong and angle shaped bile ducts) is not promising and associated with significant risk of complications. PTC and other interventions should be studied along with ERCP for patients for whom ERCP may not work. The feasibility and efficacy of primary management can be predicted by the noninvasive imaging examinations like Magnetic Resonance Cholangiopancreatography (MRCP) before the procedure, which may help with the choice of the most reasonable therapeutic modality and avoiding unnecessary financial burden and complications.

PDGFRα/Sca-1 Sorted Mesenchymal Stromal Cells Reduce Liver Injury in Murine Models of Hepatic Ischemia-Reperfusion Injury

Liver transplantation is an effective therapy, but increasing demand for donor organs has led to the use of marginal donor organs with increased complication rates. Mesenchymal stromal cells (MSC) pleiotropically modulate aberrant immune-mediated responses and represent a potential therapy to target the inflammation seen post-transplant with marginal donor livers. To avoid the confounding effects of xenotransplantation seen in studies with human MSC, a PDGFRα/Sca-1 (PaS) sorted MSC population was used which was analogous to human MSC populations (LNGFR+Thy-1+VCAM-1Hi). PaS MSC are a well-described population that demonstrate MSC properties without evidence of clonal mutation during expansion. We demonstrate their anti-inflammatory properties herein through their suppression of T-lymphocyte proliferation in vitro and secretion of anti-inflammatory cytokines (IL-10 and OPG) after stimulation (P = .004 and P = .003). The MDR2-/- model of biliary injury and hepatic ischemia-reperfusion (HIR) injury models were used to replicate the non-anastomotic biliary complications seen following liver transplantation. Systemic MSC therapy in MDR2-/- mice led to reduced liver injury with an increase in restorative macrophages (5913 ± 333.9 vs 12 597 ± 665.8, P = .002, n = 7) and a change in lymphocyte ratios (3.55 ± 0.37 vs 2.59 ± 0.139, P = .023, n = 17), whereas subcutaneous administration of MSC showed no beneficial effect. MSC also reduced cell death in the HIR model assessed by Periodic acid-Schiff (PAS) staining (91.7% ± 2.8 vs 80.1% ± 4.6, P = .03). Systemically administered quantum dot-labeled MSC were tracked using single-cell resolution CryoViz imaging which demonstrated their sequestration in the lungs alongside retention/redistribution to injured liver tissue. MSC represent a potential novel therapy in marginal organ transplantation which warrants further study.

Cerium oxide nanoparticles administration during machine perfusion of discarded human livers: A pilot study

The combined approach of ex situ normothermic machine perfusion (NMP) and nanotechnology represents a strategy to mitigate ischemia/reperfusion injury in liver transplantation (LT). We evaluated the uptake, distribution, and efficacy of antioxidant cerium oxide nanoparticles (nanoceria) during normothermic perfusion of discarded human livers. A total of 9 discarded human liver grafts were randomized in 2 groups and underwent 4 h of NMP: 5 grafts were treated with nanoceria conjugated with albumin (Alb-NC; 50 µg/ml) and compared with 4 untreated grafts. The intracellular uptake of nanoceria was analyzed by electron microscopy (EM) and inductively coupled plasma-mass spectrometry (ICP-MS). The antioxidant activity of Alb-NC was assayed in liver biopsies by glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) assay, telomere length, and 4977-bp common mitochondrial DNA deletion (mtDNA⁴⁹⁷⁷ deletion). The cytokine profile was evaluated in perfusate samples. EM and ICP-MS confirmed Alb-NC internalization, rescue of mitochondrial phenotype, decrease of lipid droplet peroxidation, and lipofuscin granules in the treated grafts. Alb-NC exerted an antioxidant activity by increasing GSH levels (percentage change: +94% ± 25%; p = 0.01), SOD (+17% ± 4%; p = 0.02), and CAT activity (51% ± 23%; p = 0.03), reducing the occurrence of mtDNA⁴⁹⁷⁷ deletion (-67.2% ± 11%; p = 0.03), but did not affect cytokine release. Alb-NC during ex situ perfusion decreased oxidative stress, upregulating graft antioxidant defense. They could be a tool to improve quality grafts during NMP and represent an antioxidant strategy aimed at protecting the graft against reperfusion injury during LT.

Post-transplant biliary complications: advances in pathophysiology, diagnosis, and treatment

Liver transplantation (LT) is the only curative therapy in patients with end-stage liver disease. Long-term survival is excellent, yet LT recipients are at risk of significant complications. Biliary complications are an important source of morbidity after LT, with an estimated incidence of 5%-32%. Post-LT biliary complications include strictures (anastomotic and non-anastomotic), bile leaks, stones, and sphincter of Oddi dysfunction. Prompt recognition and management is critical as these complications are associated with mortality rates up to 20% and retransplantation rates up to 13%. This review aims to summarise our current understanding of risk factors, natural history, diagnostic testing, and treatment options for post-transplant biliary complications.

Post-Transplant Biliary Strictures: An Updated Review

Liver transplantation (LT) is the only curative therapy in patients with end-stage liver disease with excellent long-term survival; however, LT recipients are at risk of significant complications. Among these complications are biliary complications with an incidence ranging from 5 to 32% and associated with significant post-LT morbidity and mortality. Prompt recognition and management are critical as these complications have been associated with mortality rates up to 19% and retransplantation rates up to 13%. An important limitation of published studies is that a large proportion does not discriminate between anastomotic strictures and nonanastomotic strictures. This review aims to summarize our current understanding of risk factors and natural history, diagnostic testing, and treatment options for post-LT biliary strictures.

The biliary microbiome in ischaemic-type biliary lesions can be shaped by stenting but is resilient to antibiotic treatment

This study aims to characterize the biliary microbiome as neglected factor in patients with ischaemic-type biliary lesions (ITBL) after liver transplantation. Therefore, the V1-V2 region of the 16S rRNA gene was sequenced in 175 bile samples. Samples from patients with anastomotic strictures (AS) served as controls. Multivariate analysis and in silico metagenomics were applied cross-sectionally and longitudinally. The microbial community differed significantly between ITBL and AS in terms of alpha and beta diversity. Both, antibiotic treatment and stenting were associated independently with differences in the microbial community structure. In contrast to AS, in ITBL stenting was associated with pronounced differences in the biliary microbiome, whereas no differences associated with antibiotic treatment could be observed in ITBL contrasting the pronounced differences found in AS. Bacterial pathways involved in the production of antibacterial metabolites were increased in ITBL with antibiotic treatment. After liver transplantation, the biliary tract harbours a complex microbial community with significant differences between ITBL and AS. Fundamental changes in the microbial community in ITBL can be achieved with biliary stenting. However, the effect of antibiotic treatment in ITBL was minimal. Therefore, antibiotics should be administered wisely in order to reduce emerging resistance of the biliary microbiome towards external antibiotics.

Persistent biliary hypoxia and lack of regeneration are key mechanisms in the pathogenesis of posttransplant nonanastomotic strictures

BACKGROUND AND AIMS

Nonanastomotic biliary strictures (NAS) are a major cause of morbidity after orthotopic liver transplantation (OLT). Although ischemic injury of peribiliary glands (PBGs) and peribiliary vascular plexus during OLT has been associated with the later development of NAS, the exact underlying mechanisms remain unclear. We hypothesized that bile ducts of patients with NAS suffer from ongoing biliary hypoxia and lack of regeneration from PBG stem/progenitor cells.

APPROACH AND RESULTS

Forty-two patients, requiring retransplantation for either NAS (n = 18), hepatic artery thrombosis (HAT; n = 13), or nonbiliary graft failure (controls; n = 11), were included in this study. Histomorphological analysis of perihilar bile ducts was performed to assess differences in markers of cell proliferation and differentiation in PBGs, microvascular density (MVD), and hypoxia. In addition, isolated human biliary tree stem cells (hBTSCs) were used to examine exo-metabolomics during in vitro differentiation toward mature cholangiocytes. Bile ducts of patients with NAS or HAT had significantly reduced indices of PBG mass, cellular proliferation and differentiation (mucus production, secretin receptor expression, and primary cilia), reduced MVD, and increased PBG apoptosis and hypoxia marker expression, compared to controls. Metabolomics of hBTSCs during in vitro differentiation toward cholangiocytes revealed a switch from a glycolytic to oxidative metabolism, indicating the need for oxygen.

CONCLUSIONS

NAS are characterized by a microscopic phenotype of chronic biliary hypoxia attributed to loss of microvasculature, resulting in reduced proliferation and differentiation of PBG stem/progenitor cells into mature cholangiocytes. These findings suggest that persistent biliary hypoxia is a key mechanism underlying the development of NAS after OLT.

Management of Biliary Complications in Liver Transplant Recipients

Biliary complications are often referred to as the Achilles' heel of liver transplantation (LT). The most common of these complications include strictures, and leaks. Prompt diagnosis and management is key for preservation of the transplanted organ. Unfortunately, a number of factors can lead to delays in diagnosis and make adequate treatment a challenge. Innovations in advanced endoscopic techniques have increased non-surgical options for these complications and in many cases is the preferred approach.

Risk Factors for Development of Biliary Stricture After Liver Transplant in Adult Patients: A Single-Center Retrospective Study

Identification of risk factors for biliary stricture after liver transplant and its potential prevention is crucial to improve the outcomes and reduce the complications. We retrospectively analyzed donor and recipient characteristics with intraoperative and postoperative parameters to identify the risk factors for development of post-transplant anastomotic and nonanastomotic biliary strictures with additional analysis of the time onset of those strictures. A total of 412 patients were included in this study. Mean (SD) follow-up time was 79 (35) months (range, 1-152 months). Biliary stricture was diagnosed in 84 patients (20.4%). Multivariate analysis indicated that postoperative biliary leakage (odd ratio [OR], 3.94; P = .001), acute cellular rejection (OR, 3.05; P < .001), donor age older than 47.5 years (OR, 2.05; P = .032), preoperative recipient platelet value < 77.5 × 10³/mL (OR, 1.91; P = .023), University of Wisconsin solution (OR, 1.73; P = .041)), recipient male sex (OR, 1.78; P = .072), portal/arterial flow ratio > 4 (OR, 1.76; P = .083), and intraoperative bleeding > 2850 mL (OR, 1.70; P = .053) were independent risk factors for biliary stricture regardless of the time of their appearance. Multiple risk factors for biliary stricture were determined in this study. Some of these risk factors are preventable, and implementation of strategies to eliminate some of those factors should reduce the development of post-transplant biliary stricture.

Machine Perfusion of Donation After Circulatory Death Liver and Lungs Before Combined Liver-lung Transplantation

Shortage of deceased donor organs for transplantation has led to the increased use of organs from donation after circulatory death (DCD) donors. There are currently no reports describing outcomes after multiorgan transplantation with DCD livers. The use of DCD organs for multiorgan transplantation can be enhanced if the detrimental effects of prolonged cold ischemia and subsequent ischemia-reperfusion injury are overcome. We present a case in which the liver and lungs of a DCD donor were preserved using ex situ machine perfusion for combined liver-lung transplantation. The recipient was a 19-year-old male patient requiring bilateral lung transplantation for severe progressive pleural parenchymal fibroelastosis and portal hypertension with portal vein thrombosis. The donor liver was preserved with dual hypothermic oxygenated machine perfusion, whereas the lungs were perfused using ex vivo lung perfusion. With ex vivo lung perfusion, total preservation time of right and left lung reached 17 and 21 h, respectively. Now, 2 y after transplantation, liver function is normal and lung function is improving. To conclude, we suggest that combined transplantation of DCD liver and lungs is feasible when cold ischemia is reduced with ex situ machine perfusion preservation.

Management and outcome of hepatic artery thrombosis after pediatric liver transplantation

BACKGROUND

Pediatric LT are at particular risk of HAT, and its management still constitutes a matter of debate. Our purpose was to study predisposing factors and outcome of HAT post-LT, including the impact of surgical revisions on survival and biliary complications.

METHODS

Among 882 primary pediatric LT performed between 1993 and 2015, 36 HAT were encountered (4.1%, 35 fully documented). Each HAT case was retrospectively paired with a LT recipient without HAT, according to diagnosis, age at LT, type of graft, and era.

RESULTS

Five-year patient survivals were 77.0% versus 83.9% in HAT and non-HAT paired groups, respectively (P = .321). Corresponding graft survivals were 20.0% versus 80.5% (P < .001), and retransplantation rates 77.7% versus 10.7%, respectively (P < .001). One-year biliary complication-free survivals were 16.6% versus 83.8% in the HAT and non-HAT groups, respectively (P < .001). Regarding chronology of surgical re-exploration, only HAT cases that occurred within 14 days post-LT were re-operated, fourteen of them being explored within 7 days post-LT (revascularization rate: 6/14), versus two beyond 7 days (no revascularization). When revascularization was achieved, graft and biliary complication-free survival rates at 1 year were 33.3% and 22.2%, respectively, both rates being 0.0% in case of failure.

CONCLUSIONS

The pejorative prognosis associated with HAT in terms of graft survival is confirmed, whereas patient survival could be preserved through retransplantation. Results suggest that HAT should be re-operated if occurring within 7 days post-LT, but not beyond.

Post-transplant hepatic fibrosis in pediatric liver-small bowel transplant recipients: A single-center, retrospective, observational study

BACKGROUND

Little is known about the prevalence of hepatic graft fibrosis in combined LSBT children. We aimed to determine the prevalence of and identify potential predictors for hepatic graft fibrosis in LSBT children and to compare them with those in LT children.

METHODS

We retrospectively included children younger than 19 years who had received a primary LT/LSBT between 2000 and 2018 and had a liver biopsy performed at least 6 months post-transplant. A Cox proportional hazards regression model was used to determine predictors associated with significant hepatic graft fibrosis (≥F2) in LSBT vs LT children.

RESULTS

Ninety-six children (47 LSBT, 54 females) were included. The median post-transplant follow-up (years) was 12.8 in LT vs 10.5 in LSBT patients (P = .06). Hepatic graft fibrosis was found in 81.6% of LT vs 70.2% of LSBT children (P = .19), after a median time of 2.5 years and 2.6 years, respectively. On multivariate analyses, having post-transplant biliary complications was found to be associated with significant graft fibrosis in LT children, whereas AST/ALT ratio was found to predict significant hepatic graft fibrosis in LSBT children. The use of parenteral nutrition after transplant was not associated with significant hepatic graft fibrosis.

CONCLUSIONS

The prevalence of hepatic graft fibrosis in LSBT children did not significantly differ from that in LT children, but the predictors may differ. Future studies should investigate the role of post-transplant autoimmune antibodies and donor-specific antibodies in the development and progression of hepatic graft fibrosis in LSBT children.

Percutaneous transhepatic techniques for management of biliary anastomotic strictures in living donor liver transplant recipients

AIM

To retrospectively analyze the percutaneous transhepatic techniques and their outcome in the management of biliary strictures in living donor liver transplant (LDLT) recipients.

MATERIALS AND METHODS

We retrieved the hospital records of 400 LDLT recipients between 2007 and 2015 and identified 45 patients with biliary strictures. Among them, 17 patients (37.8%) (Male: female = 13:4; mean age, 36.1 ± 17.5 years) treated by various percutaneous transhepatic biliary techniques alone or in combination with endoscopic retrograde cholangiopancreatography (ERCP) were included in the study. The technical and clinical success of the percutaneous management was analyzed.

RESULTS

Anastomotic strictures associated with leak were found in 12/17 patients (70.6%). Ten out of 12 (83.3%) patients associated with leak had more than one duct-duct anastomoses (range, 2-3). The average duration of onset of stricture in patients with biliary leak was 3.97 ± 2.68 months and in patients with only strictures it was 14.03 ± 13.9 months. In 6 patients, endoscopic-guided plastic stents were placed using rendezvous technique, plastic stent was placed from a percutaneous approach in 1 patient, metallic stents were used in 2 patients, cholangioplasty was performed in 1 patient, N-butyl- 2-cyanoacrylate embolization was done in 1 child with biliary-pleural fistula, internal-external drain was placed in 1 patient, and only external drain was placed in 5 patients. Technical success was achieved in 12/17 (70.6%) and clinical success was achieved in 13/17 (76.5%) of the patients. Posttreatment mean time of follow-up was 19.4 ± 13.7 months. Five patients (29.4%) died (two acute rejections, one metabolic acidosis, and two sepsis).

CONCLUSIONS

Percutaneous biliary techniques are effective treatment options with good outcome in LDLT patients with biliary complications.

Extended criteria grafts and emerging therapeutics strategy in liver transplantation. The unstable balance between damage and repair

Due to increasing demand for donor organs, "extended criteria" donors are increasingly considered for liver transplantation, including elderly donors and donors after cardiac death. The grafts of this subgroup of donors share a major risk to develop significant features of ischemia reperfusion injury, that may eventually lead to graft failure. Ex-situ machine perfusion technology has gained much interest in liver transplantation, because represents both a useful tool for improving graft quality before transplantation and a platform for the delivery of therapeutics directly to the organ. In this review, we survey ongoing clinical evidences supporting the use of elderly and DCD donors in liver transplantation, and the underlying mechanistic aspects of liver aging and ischemia reperfusion injury that influence graft quality and transplant outcome. Finally, we highlight evidences in the field of new therapeutics to test in MP in the context of recent findings of basic and translational research.

Association between intraoperative fluid balance, vasopressors and graft complications in liver transplantation: A cohort study

Introduction

Biliary complications following liver transplantation are common. The effect of intraoperative fluid balance and vasopressors on these complications is unknown.

Materials and methods

We conducted a cohort study between July 2008 and December 2017. Our exposure variables were the total intraoperative fluid balance and the use of vasopressors on ICU admission. Our primary outcome was any biliary complication (anastomotic and non-anastomotic strictures) up to one year after transplantation. Our secondary outcomes were vascular complications, primary graft non-function and survival.

Results

We included 562 consecutive liver transplantations. 192 (34%) transplants had a biliary complication, 167 (30%) had an anastomotic stricture and 56 had a non-anastomotic stricture (10%). We did not observe any effect of intraoperative fluid balance or vasopressor on biliary complications (HR = 0.97; 95% CI, 0.93 to 1.02). A higher intraoperative fluid balance was associated with an increased risk of primary graft non-function (non-linear) and a lower survival (HR = 1.40, 95% CI, 1.14 to 1.71) in multivariable analyses.

Conclusion

Intraoperative fluid balance and vasopressors upon ICU admission were not associated with biliary complications after liver transplantation but may be associated with other adverse events. Intraoperative hemodynamic management must be prospectively studied to further assess their impact on liver recipients’ outcomes.

Endoscopic management of non-anastomotic biliary strictures following liver transplantation: Long-term results from a single-center experience

OBJECTIVES

Studies on endoscopic treatment of non-anastomotic biliary strictures (NABS) following orthotopic liver transplantation (OLT) are scanty and with a short follow-up. The long-term results of endoscopic treatment with plastic stents of NABS following OLT were analyzed.

METHODS

Retrospective analysis of consecutive enrolled patients who underwent endoscopic treatment for NABS after OLT between 1997 and 2015. Endoscopic treatment success was defined as stricture resolution, without recurrence.

RESULTS

During the study period, 33 patients with NABS underwent endoscopic retrograde cholangiopancreatography (ERCP) in our center. A total of 68 ERCP were performed with a 4.4% of procedure-related adverse events. Mortality related to cholangitis secondary to endoscopic procedures was 12%. After median follow-up of 70.3 months from stents removal, NABS resolution was obtained in 12 out of 24 (50%) patients. Only one case of late NABS recurrence was observed which was successfully retreated endoscopically. According to our data analysis NABS occurring <12 months from OLT showed a worse prognosis (P < 0.04).

CONCLUSIONS

The follow-up of this study confirms that endoscopic treatment of NABS is unsatisfactory. However, patients who respond to endoscopic treatment maintain the response over time. Prompt treatment of acute cholangitis due to stents occlusion is advised in these patients to avoid high mortality rates.

Static cold storage compared with normothermic machine perfusion of the liver and effect on ischaemic-type biliary lesions after transplantation: a propensity score-matched study

BACKGROUND

Given the susceptibility of organs to ischaemic injury, alternative preservation methods to static cold storage (SCS), such as normothermic machine perfusion (NMP) are emerging. The aim of this study was to perform a comparison between NMP and SCS in liver transplantation with particular attention to bile duct lesions.

METHODS

The outcomes of 59 consecutive NMP-preserved donor livers were compared in a 1 : 1 propensity score-matched fashion to SCS control livers. Postoperative complications, patient survival, graft survival and bile duct lesions were analysed.

RESULTS

While patients were matched for cold ischaemia time, the total preservation time was significantly longer in the NMP group (21 h versus 7 h, P < 0.001). Patient and graft survival rates at 1 year were 81 versus 82 per cent (P = 0.347) and 81 versus 79 per cent (P = 0.784) in the NMP and SCS groups, respectively. The postoperative complication rate was comparable (P = 0.086); 37 per cent NMP versus 34 per cent SCS patients had a Clavien-Dindo grade IIIb or above complication. There was no difference in early (30 days or less) (NMP 22 versus SCS 19 per cent, P = 0.647) and late (more than 30 days) (NMP 27 versus SCS 36 per cent, P = 0.321) biliary complications. However, NMP-preserved livers developed significantly fewer ischaemic-type bile duct lesions (NMP 3 versus SCS 14 per cent, P = 0.047).

CONCLUSION

The use of NMP allowed for a significantly prolonged organ preservation with a lower rate of observed ischaemic-type bile duct lesions.

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.

Intensified Endoscopic Evaluation for Biliary Complications After Orthotopic Liver Transplantation

Background

Biliary complications are common causes of morbidity and mortality after liver transplantation.

Material/Methods

From 2013 to 2018, 102 whole-organ liver transplantations were conducted in our department. Patients were closely monitored for biliary complication development. In all suspected cases, patients underwent either endoscopic retrograde cholangiopancreatography or percutaneous transhepatic cholangial drainage. Patients’ demographic characteristics, preexisting conditions, and perioperative characteristics, as well as morbidity and mortality, were analyzed. Risk factors for 1-year survival were calculated.

Results

Of the 102 patients, 43 (42%) experienced biliary complications. In comparison with patients without biliary complications, patients with biliary complications exhibited the following risk factors: underlying liver disease (viral hepatitis; P=0.009), blood group A (P=0.005), and previous abdominal surgery (P=0.037). Neither perioperative characteristics, especially duration of cold ischemia (P=0.86), nor postoperative course differed between patients with and without biliary complications. Risk factors for mortality within 1 year were cirrhosis caused by entities other than viral hepatitis (P=0.017), cardiac comorbidities (P=0.019), re-transplantation (P=0.032), and reduced organ weight (P=0.002). Biliary complications, postoperative hemorrhage, primary nonfunction, and repeated surgery worsened outcome; moreover, serum bilirubin trough in the first 30 days after transplantation might be prognostic for mortality (P=0.043).

Conclusions

Biliary complications adversely affect outcome after liver transplantation. Neither frequency nor outcome of biliary complications was improved by intensified endoscopic evaluation. Patients on the waiting list for liver transplants should also be closely monitored for cardiac comorbidities.

Primary sclerosing cholangitis as an independent risk factor for cytomegalovirus infection after liver transplant

BACKGROUND

Cytomegalovirus (CMV) infection is one of the most common infectious complications after solid organ transplant; it is associated with morbidity and mortality and with many direct and indirect effects. However, monitoring and therapeutic procedures are very heterogeneous across treatment centers. Additionally, factors that place patients at risk of CMV infection are poorly defined.

METHODS

Clinical and demographic data from 833 LT recipients and their donors were retrospectively analyzed. Univariate and multivariate analysis were applied. CMV infection was detected by quantitative nucleic acid testing with a lower limit of detection of 40 IU/mL.

RESULTS

In total, 192 of 833 patients (23%) experienced at least one episode of CMV infection after LT; CMV infection occurred to a large extent during the first year after transplant (70%). Multivariate analysis demonstrated that CMV donor-recipient risk constellation (OR 2.05, 95% CI) and primary sclerosing cholangitis (PSC) before LT (OR 3.76, 95% CI) are independent risk factors for CMV infection after LT.

CONCLUSION

Patients with high-risk serostatus, PSC, or both should be monitored more thoroughly and should receive prolonged prophylaxis against CMV infection.

Diagnosis and management of benign biliary strictures post liver transplantation in adults

Benign biliary strictures after liver transplantation are common and can lead to graft dysfunction and decreased patient survival. Post-transplant strictures are classified as anastomotic or non-anastomotic which differ in response to therapy. Risk factors for biliary strictures following transplantation include impaired blood supply, surgical factors, and biliary anomalies. Patients can present with biliary obstruction but most will be asymptomatic, with only abnormal graft function. MRCP is the most sensitive noninvasive tool for diagnosing biliary complications. In most centres worldwide endoscopy is used first-line in the management of anastomotic strictures, although there is significant variation in endoscopic technique employed; including dilation, placing a single or multiple plastic stents, a fully covered metal stent and most recently using intra-ductal fully covered metal stents. With the introduction of fully covered metal stents the number of interventions patients require has reduced and overall the clinical success of the endoscopic approach has steadily improved. Percutaneous and surgical treatments are now reserved for patients in whom endoscopic management fails or who have had Roux-en-Y anastomoses. However even in these cases, combined procedures with interventional radiology, or implementation of enteroscopy and EUS-guided approaches now means very few patients ultimately require surgical revision.

Complications of Cryptosporidium infection after pediatric liver transplantation: Diarrhea, rejection, and biliary disease

BACKGROUND

Cryptosporidium enteritis can be devastating in the immunocompromised host. In pediatric liver transplant recipients, infection may be complicated by prolonged carriage of the parasite, rejection, and biliary tree damage and fibrosis. Herein, we report on six patients and their long-term outcomes following cryptosporidiosis.

METHODS

We reviewed all cases of cryptosporidiosis in a pediatric liver transplant population over a 17-year period at a single center. Six patients with infection were identified, and their outcomes were analyzed.

RESULTS

Infection was associated with significant diarrhea and dehydration in all cases, and led to hospitalization in one-half of patients. Four of the six patients developed biopsy-proven rejection following infection, with three of those patients developing rejection that was recalcitrant to intravenous steroid treatment. Additionally, three patients developed biliary tree abnormalities with similarity to sclerosing cholangitis. In one patient, those biliary changes led to repeated need for biliary drain placement and advancing fibrotic liver allograft changes.

CONCLUSIONS

Cryptosporidiosis in pediatric liver transplant recipients may lead to significant complications, including recalcitrant episodes of rejection and detrimental biliary tree changes. We advocate for increased awareness of this cause of diarrheal disease and the allograft injuries that may accompany infection.

Can ultrasonography differentiate anastomotic and non-anastomotic biliary strictures after orthotopic liver transplantation- a single-center experience

PURPOSE

To evaluate the role of ultrasonography (US) in differentiating anastomotic biliary strictures (AS) and non-anastomotic biliary strictures (NAS) after orthotopic liver transplantation (OLT).

METHOD

This retrospective study included 1259 OLT recipients between 2005-2018. Seventy-six with anastomotic strictures (AS) and 103 with non-anastomotic strictures (NAS) were analyzed. The reference standard was cholangiography. The sensitivity, specificity, accuracy of US was evaluated.

RESULTS

There were significant differences between AS and NAS groups (p < 0.001) for skipped and irregular dilatation of intrahepatic bile duct and visualization of hilar biliary lumen. The better US imaging feature for NAS was poorly visualized and non- visible hilar bile duct luminal contour. The sensitivity, specificity and accuracy were 94.2 %, 84.2 % and 88.9 % respectively. Combined two predictors greatly increased the specificity to 93.4 % while diminished its sensitivity and accuracy.

CONCLUSION

US is useful and efficient to differentiate AS and NAS after OLT.

Effect of mycophenolic acid on inosine monophosphate dehydrogenase (IMPDH) activity in liver transplant patients

BACKGROUND

Due to the development of immunosuppressants, the focus in transplanted patients has shifted from short-term to long-term survival as well as a better adjustment of these drugs in order to prevent over- and under-immunosuppression. Mycophenolic acid (MPA) is a noncompetitive inhibitor of inosine monophosphate dehydrogenase (IMPDH) and approved for prophylaxis of acute rejection after kidney, heart, and liver transplantation, where it has become a part of the standard therapy. Targeting inosine monophosphate IMPDH activity as a surrogate pharmacodynamic marker of MPA-induced immunosuppression may allow a more accurate assessment of efficacy and aid in limiting toxicity in liver transplanted patients.

AIM

Assess IMPDH-inhibition in liver transplant recipients and its impact on biliary/infectious complications, acute cellular rejection (ACR) and liver dependent survival.

METHODS

This observational cohort study comprises 117 liver transplanted patients that were treated with mycophenolate mofetil (MMF) for at least 3 months. Blood samples (BS) were collected and MPA serum level and IMPDH activity were measured before (t(0)), 30minutes (t(30)) and 2h after (t(120)) MMF morning dose administration. Regarding MPA, we assessed the area under the curve (AUC). Patients were prospectively followed up for one year and assessed for infectious and biliary complications, episodes of ACR and liver dependent survival.

RESULTS

The MPA levels showed a broad interindividual variability at t(0) (2.0±1.8ng/ml), t(30) (12.7±9.0ng/ml) and t(120) (7.5±4.3ng/ml). Corresponding IMPDH activity was at t(o) (23.2±9.5 nmol/h/mg), at t(30) (16.3±8.8 nmol/h/mg) and t(120) (18.2±8.7 nmol/h/mg). With regard to MPA level we found no correlation with infectious or biliary complications within the follow-up period. Patients with baseline IMPDH(a) below the median had significant more viral infections (6 (10.2%) vs. 17 (29.3%); P=0.009) with especially more cytomegalovirus (CMV) infections (1 (3.4%) vs. 6 (21.4%); P=0.03)). Furthermore, patients with baseline IMPDH(a) above the median developed more often non-anastomotic biliary strictures (8 (13.6%) vs. 1 (1.7%), P=0.03). We found the group reaching the combined clinical endpoint of death and re-transplantation showing significantly lower MPA baseline values (t(0) 0.9±0.7 vs. 2.1±1.8μg/ml Mann-Whitney-U: P=0.02). We calculated a simplified MPA(AUC) with the MPA level at baseline, 30 and 120minutes after MPA administration. Whereas we found no differences with regard to baseline characteristics at entry into the study patients with MPA (AUC) below the median experienced significantly more often the combined clinical endpoint (12.1% (7/58) vs. 0.0% (0/57); P=0.002) and had a reduced actuarial re-transplantation-free survival (1.0 year vs. 0.58 years; Log-rank: P=0.007) during the prospective one-year follow-up period. In univariate and multivariate analysis including gender, age, BMI, ACR, MPA (AUC) and IMPDH(a) only BMI, MPA (AUC) and IMPDH(a) were independently associated with reduced actuarial re-transplantation-free survival.

CONCLUSION

MPA-levels and IMPDH-activity in liver transplanted patients allows individual risk assessment. Patients with higher IMPDH inhibition acquire more often viral infections. Insufficient IMPDH inhibition is associated with development of non-anastomotic bile duct strictures and reduced re-transplantation-free survival.

The Graz Liver Allocation Strategy-Impact of Extended Criteria Grafts on Outcome Considering Immunological Aspects

Background: Transplant centers are forced to use livers of extended criteria donors for transplantation due to a dramatic organ shortage. The outcome effect of extended donor criteria (EDCs) remains unclear. Thus, this study was designed to assess the impact of EDCs on outcome including immunological aspects after liver transplantation (LT).

Patients and Methods: Between November 2016 and March 2018, 49 patients (85.7% male) with a mean age of 57 ± 11 years underwent LT. The impact of EDCs on outcome after LT was assessed retrospectively using both MedOcs and ENIS (Eurotransplant Network Information System).

Results: About 80% of grafts derived from extended criteria donors. Alanine aminotransferase/aspartate aminotransferase (AST/ALT) levels elevated more than three times above normal values in organ donors was the only significant risk factor for primary dysfunction (PDF) and primary non-function (PNF)/Re-LT and early non-anastomotic biliary strictures (NAS). Balance of risk (BAR) score did not differ between EDC and non-EDC recipients. PDF (14.3% of all patients) and PNF (6.1% of all patients) occurred in 23.1% of EDC-graft recipients and in 10.0% of non-EDC-graft recipients (RR 2.31, p = 0.663). The 90-day mortality was 3.6%. There was no difference of early non-anastomotic biliary tract complications and biopsy proven rejections (BPR). There was no correlation of PDF/PNF with BPR and NAS, respectively; however, 66.7% of the patients with BPR also developed early NAS (p < 0.001).

Conclusion: With the Graz liver allocation strategy, excellent survival can be achieved selecting livers with no more than 2 not outcome-relevant EDCs for patients with MELD >20. Further, BPR is associated with biliary complications.

Is Surgery Necessary? Endoscopic Management of Post-transplant Biliary Complications in the Modern Era

BACKGROUND

Biliary complications are common following liver transplantation (LT) and traditionally managed with Roux-en-Y hepaticojejunostomy. However, endoscopic management has largely supplanted surgical revision in the modern era. Herein, we evaluate our experience with the management of biliary complications following LT.

METHODS

All LTs from January 2013 to June 2018 at a single institution were reviewed. Patients with biliary bypass prior to, or at LT, were excluded. Patients were grouped by biliary complication of an isolated stricture, isolated leak, or concomitant stricture and leak (stricture/leak).

RESULTS

A total of 462 grafts were transplanted into 449 patients. Ninety-five (21%) patients had post-transplant biliary complications, including 56 (59%) strictures, 28 (29%) leaks, and 11 (12%) stricture/leaks. Consequently, the overall stricture, leak, and stricture/leak rates were 12%, 6%, and 2%, respectively. Endoscopic management was pursued for all stricture and stricture/leak patients, as well as 75% of leak patients, reserving early surgery only for those patients with an uncontrolled leak and evidence of biliary peritonitis. Endoscopic management was successful in the majority of patients (stricture 94%, leak 90%, stricture/leak 90%). Only six patients (5.6%) received additional interventions-two required percutaneous transhepatic cholangiography catheters, three underwent surgical revision, and one was re-transplanted.

CONCLUSIONS

Endoscopic management of post-transplant biliary complications resulted in long-term resolution without increased morbidity, mortality, or graft failure. Successful endoscopic treatment requires collaboration with a skilled endoscopist. Moreover, multidisciplinary transplant teams must develop treatment protocols based on the local availability and expertise at their center.

Safety and Efficacy of Living Donor Hepatectomy Without Systemic Heparinization: Short- and Long-Term Outcomes

There is no consensus regarding the use of systemic heparin, and long-term outcomes of living donor hepatectomy (LDH) without systemic heparinization have not yet been determined. This study was performed to determine whether systemic heparinization can be omitted during LDH, with a focus on donor safety and long-term outcomes. We retrospectively analyzed the outcomes of 175 cases of LDH performed in our institution between January 2011 and December 2014: group I (n = 79) received systemic heparinization, whereas group II (n = 96) did not, but liver graft was flushed with a heparinized perfusate. Postoperative bleeding requiring blood transfusion or intervention was more frequent in group I than in group II (P = .028). The decreases in donor hemoglobin and hematocrit levels, and platelet count during the early postoperative period, were greater in group I than in group II. In multivariate analysis, systemic heparin was the only independent risk factor for blood transfusion (odds ratio [OR] = 5.114; 95% confidence interval [CI]: 1.201-21.775; P = .027) and significant postoperative bleeding (OR = 7.731; 95% CI: 1.345-44.429; P = .022) after LDH. Most postoperative complications including graft vascular thrombosis were similar between the 2 groups, as was the survival rate, and neither graft loss due to vascular thrombosis nor non-anastomotic biliary stricture was evident. In conclusion, omission of systemic heparinization during LDH is a feasible and safe option without adverse effects.

Biliary calprotectin, lactoferrin and dimeric pyruvate kinase after liver transplantation are associated with biliary damage and graft survival in a case-control study

BACKGROUND

After liver transplantation (LT), biliary complications are associated with reduced graft survival. We tested inflammation markers for their association with biliary damage and graft loss in bile.

MATERIAL AND METHODS

The study design was a retrospective case-control study. Calprotectin, lactoferrin and pyruvate kinase were measured in endoscopically retrieved bile with ELISA.

RESULTS

Calprotectin and lactoferrin were significantly higher in bile of ischemic-type biliary lesions and donor duct non-anastomotic strictures than in control, bile leakage, Cytomegalovirus infection, anastomotic stricture or acute cellular rejection patients (p<0.001) independent of serum liver values at endoscopy. Calprotectin (p=0.02) was independently associated with retransplantation free survival in multivariate analysis, as was γGT (p=0.03) but not ERC radiographic classification of the bile duct or cold ischemia time.

CONCLUSION

Calprotectin and lactoferrin are bile markers for biliary damage and are associated with re-transplantation free survival. They can differentiate progressive biliary damage from non-biliary liver value alterations after LT.

Biliary Complications After Liver Transplantation From Uncontrolled Donors After Circulatory Death: Incidence, Management, and Outcome

The utilization of livers from donation after uncontrolled circulatory death (uDCD) increases the availability of liver grafts, but it is associated with a higher incidence of biliary complications (BCs) and lower graft survival than those organs donated after brain death. From January 2006 to December 2016, we performed 75 orthotopic liver transplantations (OLTs) using uDCD livers. To investigate the relationship of BCs with the use of uDCD OLT, we compared patients who developed BCs (23 patients) with those who did not (non-BC group, 43 patients) after excluding cases of hepatic artery thrombosis (a known cause of BC) and primary nonfunction. The groups had similar uDCD donor maintenance, donor and recipient characteristics, and perioperative morbidity/mortality rates, but we observed a higher rate of hepatocellular carcinoma and hepatitis C virus in the non-BC group. Percutaneous transhepatic biliary dilation, endoscopic retrograde cholangiopancreatography dilation, Roux-en-Y hepaticojejunostomy (HJ), a T-tube, and retransplantation were used for BC management. In the BC group, 1-, 3-, and 5-year patient survival rates were 91.3%, 69.6%, and 65.2%, respectively, versus 77.8%, 72.9%, and 72.9%, respectively, in the non-BC group (P = 0.89). However, 1-, 3-, and 5-year graft survival rates were 78.3%, 60.9%, and 56.5%, respectively, in the BC group versus 77.8%, 72.9%, and 72.9%, respectively, in the non-BC group (P = 0.38). Multivariate analysis did not indicate independent risk factors for BC development. In conclusion, patient and graft survival rates were generally lower in patients who developed BCs but not significantly so. These complications were managed in the majority of patients through radiological dilation, endoscopic dilation, or Roux-en-Y HJ. Retransplantation is necessary in rare cases after the failure of biliary dilation or surgical procedures.