Post-liver transplant biliary complications: Current knowledge and therapeutic advances

Role of Donor-derived Cell-free DNA In Predicting Short-term Allograft Health In Liver Transplant Recipients

Background/Aims

Predicting allograft dysfunction prior to clinical or biochemical evidence remains one of the challenges in transplantation, and a preclinical detection and early management of its cause allows for improved post-transplant outcomes. Donor-derived cell-free DNA (ddcfDNA) has been proposed as an important biomarker of allograft injury and has shown to predict dysfunction prior to any biochemical derangements. We aimed to investigate the diagnostic performance of ddcfDNA in detecting and differentiating the causes of early pre-biochemical detection of graft injury and in predicting the short-term outcomes of graft health using a patented protocol and proprietary set of single-nucleotide polymorphisms.

Methods

Blood samples were collected on defined postoperative days (1, 3, 7, and at 3 months) and were analysed through relatively economical patented protocol (Trunome™). Biopsy, biochemical tests, and clinical criteria were analysed between various subgroups.

Results

Of a total 50 patients, percentage ddcfDNA (%ddcfDNA) levels were significantly elevated in the rejection group (n = 8) as compared to that in the non-rejection group (n = 42; median elevation: 12.8% vs 4.3%, respectively), with a significant correlation (r = 0.92, P < 0.0001). Area under the receiver operating characteristic curve (AUC-ROC) analysis revealed that the %ddcfDNA levels can predict graft health more precisely than the conventional liver function tests (AUC for %ddcfDNA: 0.86; P < 0.001; AUC for aspartate transaminase 0.65, P = 0.08; AUC for alanine transaminase: 0.75, P < 0.01). Moreover, %ddcfDNA levels (with a threshold of >10.2%) on post-operative day 7 accurately predicted short-term (3 months) health status of the graft with 93.33% sensitivity, 94.44% specificity, 87.50% positive predictive value, 97.14% negative predictive value, and 94.12% accuracy.

Conclusion

A single-timepoint ddcfDNA on postoperative day 7 accurately predicts graft health and improves risk stratification in the short-term.

Recipient-associated risk factors for post-liver transplantation biliary complications: A cohort study

INTRODUCTION

Biliary complications (BCs) are a well-documented post-liver transplantation concern with potential implications for patient survival. This study aims at identifying risk factors associated with the development of BCs in recipients after liver transplantation (LT) and exploring strategies for their management.

METHODS

We conducted a retrospective analysis of 1595 adult patients (age > 18 years) who underwent LT surgery between 2019 and 2021. The study assessed the incidence of BCs in this cohort.

RESULTS

Of 1595 patients, 178 (11.1%) experienced BCs, while 1417 (88.8%) did not exhibit any signs of such complications. Patients who developed BCs were found to have a significantly lower average age (p < 0.001) and longer cold ischemic times (p < 0.001) compared to those without BCs. Variables such as sex, body mass index (BMI), model for end-stage liver disease (MELD) score, primary diagnosis, type of anastomosis, hepatectomy technique, type of transplanted liver and mortality did not demonstrate statistically significant differences between the two groups (p > 0.05). Univariate logistic regression analysis revealed that a cold ischemic time exceeding 12 hours and duct-to-duct anastomosis were positive predictors for BC development (odds ratios of 6.23 [CI 4.29-9.02] and 1.47 [CI 0.94-2.30], respectively). Conversely, increasing age was associated with a protective effect against BC development, with an odds ratio of 0.64 (CI 0.46-0.89).

CONCLUSION

Our multi-variate analysis identified cold ischemia time (CIT) as the sole significant predictor of post-liver transplantation biliary complications. Additionally, this study observed that advancing patient age had a protective influence in this context. Notably, no significant disparities were detected between hepatectomy techniques and the etiology of liver disease types in the two study groups.

Normal morphometry of the biliary tree in pediatric and adult populations: A systematic review and meta-analysis

PURPOSE

This study aimed to characterise the normal morphometry of the biliary tree in pediatric and adult populations, through a systematic review and meta-analysis.

METHODS

This study, conducted using the PRISMA guidelines and registered with PROSPERO, searched MEDLINE, EMBASE, SCOPUS and Web of Science databases up to October 2022, and updated to August 2023. Studies that reported extractable data on diameter and length of the right, left and common hepatic ducts (LHD, RHD and CHD), and common bile duct (CBD) were included. Quality of the included studies were assessed using the Anatomical Quality Assessment (AQUA) tool. Statistical analysis included subgroup analyses according to sex, age, geographical location, and imaging modality.

RESULTS

In total, 60 studies were included, of which 44 studies reported adequate data for meta-analysis on 23,796 subjects. Overall, the pooled mean diameter of the CBD was 4.69 mm (95 % CI: 4.28-5.11). Significant differences were found between pediatric (1.32 mm, 95 % CI: 1.03-1.61) and adult (4.97 mm, 95 % CI: 4.67-5.27) subjects, as well as US (3.82 mm, 95 % CI: 3.15-4.49) and other imaging modalities, including MRI (6.21 mm, 95 % CI: 4.85-7.57) and ERCP (7.24 mm, 95 % CI: 6.08-8.40). The CBD diameter measured significantly larger distally (5.20 mm, 95 % CI: 4.60-5.80) than proximally (4.01 mm, 95 % CI: 3.51-4.51).

CONCLUSIONS

The results obtained from this evidence-based study may guide the establishment of standardised reference values and ranges of the normal biliary tree in pediatric and adult populations and aid clinical understanding.

Role of endoscopy in hepatology

The growing and evolving field of EUS and advanced hepatobiliary endoscopy has amplified traditional upper gastrointestinal endoscopy and unveiled novel options for remaining unsolved hepatobiliary issues, both diagnostically and therapeutically. This conceptually appealing and fascinating integration of endoscopy within the practice of hepatology is referred to as 'endo-hepatology'. Endo-hepatology focuses on the one hand on disorders of the liver parenchyma and liver vasculature and of the hepatobiliary tract on the other hand. Applications hanging under the umbrella of endohepatology involve amongst others EUS-guided liver biopsy, EUS-guided portal pressure measurement, EUS-guided portal venous blood sampling, EUS-guided coil & glue embolization of gastric varices and spontaneous portosystemic shunts as well as ERCP in the challenging context of (decompensated cirrhosis) and intraductal cholangioscopy for primary sclerosing cholangitis. Although endoscopic proficiency however does not necessarily equal in an actual straightforward end-solution for currently persisting (complex) hepatobiliary situations. Therefore, endohepatology continues to generate high-quality data to validate and standardize procedures against currently considered (best available) "golden standards" while continuing to search and trying to provide novel minimally invasive solutions for persisting hepatological stalemate situations. In the current review, we aim to critically appraise the status and potential future directions of endo-hepatology.

Biliary stenosis after liver transplant is not associated with cytomegalovirus infection

Background

Liver transplantation (LT) is the best treatment for end-stage liver disease; however, biliary complications (BCs) still pose a significant challenge. Among the post-transplant BC, strictures and biliary fistulas are the most common. Biliary strictures are classified as anastomotic and non-anastomotic. Some previous studies suggest an association between post-transplant biliary strictures and cytomegalovirus (CMV) infection. In this study, we aimed to identify whether there is an association between CMV infection and biliary strictures in patients undergoing LT.

Methods

A retrospective study of 175 patients aged ≥18 years undergoing LT at Felicio Rocho Hospital between 2011 and 2017 was conducted. All included patients received grafts perfused with Institut Georges Lopez-1 (IGL-1) solution from brain-dead donors, survived post-transplantation for more than 120 days, and had a minimum follow-up of 12 months after LT. The diagnosis of CMV was made by antigenemia and biliary strictures by magnetic resonance cholangiopancreatography (MRCP).

Results

The average age of the recipients was 54 years. Postoperative BCs occurred in 12% of transplants. The most common BC was stricture (9.1%), with a predominance of anastomotic strictures (AS) over non-AS (NAS) (87.5% vs. 12.5%, respectively). CMV infection was confirmed in 22.9% of patients. In the univariate analysis, post-transplant CMV infection correlated with the development of BCs (P=0.01), as well as biliary strictures (P=0.008). In the multivariate analysis, however, only model for end-stage liver disease (MELD) >21 was a risk factor for the development of BCs in general (P=0.02) and biliary strictures (P=0.01).

Conclusions

CMV infection was not an independent risk factor for the development of non-anastomotic post-transplant biliary strictures in this study.

Robotic living donor hepatectomy is associated with superior outcomes for both the donor and the recipient compared with laparoscopic or open - A single-center prospective registry study of 3448 cases

Minimally invasive donor hepatectomy is an emerging surgical technique in living donor liver transplantation (LDLT). We examined outcomes across open, laparoscopic, and robotic LDLT using a prospective registry. We analyzed 3448 cases (1724 donor-recipient pairs) from January 2011 to March 2023 (NCT06062706). Among donors, 520 (30%) were female. Adult-to-adult LDLT comprised 1061 (62%) cases. A total of 646 (37%) of the donors underwent open, 165 (10%) laparoscopic, and 913 (53%) robotic hepatectomies. Primary outcomes: donor overall morbidity was 4% (35/903) for robotic, 8% (13/165) laparoscopic, and 16% (106/646) open (P < .001) procedures. Pediatric and adult recipient mortality was similar among the 3 donor hepatectomy approaches: robotic 1.5% and 7.0%, compared with 2.3% and 8.3% laparoscopic, and 1.6% and 5.5% for open donor surgery, respectively (P = .802, P = .564). Secondary outcomes: pediatric and adult recipients major morbidity after robotic hepatectomy was 15% and 23%, compared with 25% and 44% for laparoscopic surgery and 19% and 31% for open surgery, respectively (P = .033, P < .001). Graft and recipient 5-year survival were 90% and 93% for pediatrics and 79% and 80% for adults, respectively. In conclusion, robotic LDLT was associated with superior outcomes when compared with the laparoscopic and open approaches. Both donors and, for the first time reported, recipients benefitted from lower morbidity rates in robotic surgery, emphasizing its potential for further advancing this field.

Algorithmic Approach to Deranged Liver Functions After Transplantation

Liver transplant (LT) recipients require close follow-up with regular monitoring of the liver function tests (LFTs). Evaluation of deranged LFT should be individualized depending upon the time since LT, peri-operative events, clinical course, and any complications. These derangements can range from mild and asymptomatic to severe and symptomatic elevations requiring expedited personalized assessment and management. Pattern of LFT derangement (hepatocellular, cholestatic, or mixed), donor-recipient risk factors, timing after LT (post-operative, 1-12 months, and >12 months since LT) along with clinical context and symptomatology are important considerations before proceeding with the initial evaluation. Compliance to immunosuppression and drug interactions should be ascertained along with local epidemiology of infections. Essential initial evaluation must include an ultrasound abdomen with Doppler to rule out any structural causes such as biliary or vascular complications apart from focussed laboratory evaluation. Early allograft dysfunction, ischemia reperfusion injury, small-for-size syndrome, biliary leaks, hepatic artery, and portal vein thrombosis are usual culprits in the early post-operative period whereas viral hepatitis (acute or reactivation), opportunistic infections, and recurrence of the primary disease are more frequent in the later period. Graft rejection, biliary strictures, sepsis, and drug induced liver injury remain possible etiologies at all times points after LT. Initial evaluation algorithm must be customized based on history, clinical examination, risk factors, and pattern and severity of deranged LFT. Allograft rejection is a diagnosis of exclusion and requires liver biopsy to confirm and assess severity. Empirical treatment of rejection sans liver biopsy is discouraged.

The Usefulness of High-Magnification Loupe for Reducing Biliary Complications After Liver Transplantation

BACKGROUND

Despite advances in surgical techniques, biliary complications are still considered to be a technical "Achilles' heel" of liver transplantation (LT). The purpose of this study was to evaluate the effect of loupe magnification in reducing biliary complications after LT.

MATERIALS AND METHODS

From April 2017 to February 2022, LT was performed on 307 patients in our center. Among them, except for 3 patients who underwent hepaticojejunostomy, 304 adult patients with LT were enrolled. They were divided into 3 groups according to the loupe magnification: 2.5 times (×2.5 group, n = 105), 3.5 times (×3.5 group, n = 95), and 5.0 times (×5.0 group, n = 105).

RESULTS

Biliary complications occurred in 63 (20.7%) patients. Anastomosis site leakage occurred in 37 patients (12.2%), and stricture occurred in 52 patients (17.1%). Anastomosis site leakage occurred in 15 patients (14.3%) in the ×2.5 group, 15 patients (16.0%) in the ×3.5 group, and 7 patients (6.7%) in the ×5.0 group (P = .097). Biliary stricture occurred in 26 patients (24.8%) in the ×2.5 group, 15 patients (16.0%) in the ×3.5 group, and 11 patients (10.5%) in the ×5.0 group (P = .021). Total biliary complications occurred in 31 patients (29.5%) in the ×2.5 group, 19 patients in the ×3.5 group (20.2%), and 13 patients in the ×5.0 group (12.4%) (P = .009).

CONCLUSION

The use of a high magnification loupe can reduce biliary complications in liver transplantation. Further large-scale analyses of clinical data or randomized controlled trials are required to support this study.

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.

Emergency Liver Retransplantation With Marginal Donors

BACKGROUND

The goal of the present study is to determine if using marginal donors negatively impacts the outcomes of emergency liver retransplantation.

METHODS

A retrospective case-control study was performed, including all emergency liver retransplantations done in our center between 1990 and 2021. Recipients from the control group received the second grafts from "ideal donors", and patients from the case group received them from marginal donors. Analyzed variables included demographics of recipients and donors, complications, and survival rates.

RESULTS

38 emergency retransplantations were performed. 23 recipients were included in the control group, and the remaining 15 were in the case group. The second donors from the case group were significantly older (mean age 58 vs 71 years old, P < 0.0001). On the contrary, there were no differences between groups regarding the mean age of recipients, comorbidities, Model for End-Stage Liver Disease scores, or causes of retransplantation (the most common was hepatic artery thrombosis). No differences were found in early perioperative death rates (control group 26.1% vs case group 20%, P =1) and, although the case group seemed to have slightly poorer outcomes in long-term survival (control group 70%, 61%, and 55% vs case group 73%, 59%, and 39%, respectively, at 1, 5, and 10 years), the differences were not statistically significant (log-rank = 0.808).

CONCLUSIONS

The use of marginal donors for emergency liver retransplantation was proved safe in our study, as there were no differences in complications or in short- or mid-term survival rates.

Liver Transplantation: Protocol for Recipient Selection, Evaluation, and Assessment

Liver transplantation (LT) is the definitive therapy for patients with end-stage liver disease, acute liver failure, acute-on-chronic liver failure, hepatocellular carcinoma, and metabolic liver diseases. The acceptance of LT in Asia has been gradually increasing and so is the expertise to perform LT. Preparing a patient with cirrhosis for LT is the most important aspect of a successful LT. The preparation for LT begins with the first index decompensation for a patient with cirrhosis. Patients planned for LT should undergo a thorough screening for infections, and a complete cardiac, pulmonology, and psychosocial evaluation pre-LT. In this review, we discuss the indications and contraindications of LT and the evaluation and assessment of patients with liver disease planned for LT.

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.

Fully Covered Metal Stents Safely Facilitate Extraction of Difficult Bile Duct Stones

BACKGROUND

Ten to 15% of the common bile duct (CBD) stones require advanced endoscopic extraction techniques during endoscopic retrograde cholangiopancreatography. The study aimed to evaluate the efficacy and safety of fully covered self-expandable metal stents (FC-SEMS) for facilitating the extraction of difficult bile duct stones.

METHODS

Patients who received FC-SEMS for the extraction of difficult CBD stones were retrospectively reviewed. Group 1 included patients with extrahepatic stones above a distal CBD stricture, Group 2 included patients with intrahepatic stones above a hilar stricture, and Group 3 included patients with complex stone(s) and no biliary stricture. Complete stone clearance rate and complications of FC-SEMS treatment were evaluated.

RESULTS

The study group included 33 procedures on 32 patients (mean age: 55±17, 56.3% male). FC-SEMS was placed as a primary treatment in 15 (45.5%) procedures. Complete stone clearance was achieved in 84.6% of the procedures in Group 1, 100% in Group 2, and 87.5% in Group 3 ( P =0.23). Overall, complete stone clearance was achieved in 30 of the 33 procedures (90.9%). None of the patients developed pancreatitis, cholecystitis, or cholangitis. Stent migration occurred in 4 procedures (12.1%), and all were clinically insignificant.

CONCLUSION

FC-SEMS is effective and safe for facilitating treatment of difficult bile duct stones.

Safety and feasibility of a novel recanalization technique using guidewire puncture under cholangioscopy for complete biliary stricture after liver transplantation

Cholangioscopy is reportedly useful for selective guidewire placement across difficult biliary strictures, but few methods are available for complete stricture of biliary anastomosis. This study aimed to propose a guidewire puncture technique to recanalize totally obstructed anastomosis and discuss its safety and feasibility. From January 2015 to December 2021, a total of 11 patients with complete biliary anastomotic stricture after liver transplantation were enrolled. These patients underwent peroral single operator cholangioscopy (SpyGlass), whereas two failed cases on SpyGlass finally underwent percutaneous transhepatic cholangioscopy (PTCS). The steps of the recanalization technique were as follows: the stricture was viewed carefully to detect the closure point (CP) of the scar endoscopically, then the CP was targeted by the hard tip of the guidewire and broke through under guidance of the cholangioscope and fluoroscope. Complete occlusions were confirmed by SpyGlass in all cases. A total of 13 hard-tip guidewire punctures were performed under cholangioscopy, and ten punctures were successful (technical success rate, 76.9% [10/13]). After recanalization of the occluded anastomosis, plastic stent or metallic stent was deployed in three and seven patients, respectively. No procedure-related complications occurred during or after the cholangioscopy-assisted guidewire puncture. After a mean follow-up of 12 months, stents had been removed in five patients. The other six patients were still receiving stent treatment. This study demonstrated that the guidewire puncture technique under cholangioscopy is safe and feasible for complete stricture of biliary anastomosis, and the success rate is satisfactory.

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.

Open hepatic artery flow with portal vein clamping protects against bile duct injury compared to pringles maneuver

BACKGROUND

Conventional hepatic artery and portal vein clamping strategies can prevent blood loss and ischemia-reperfusion liver injury, and such preventative measures are the key to successful liver surgery. However, ischemic-induced damage to cholangiocytes is rarely considered. Here, we aimed to investigate the effect of different hepatic inflow interruption methods on bile duct injury.

METHODS

Forty rats were randomly grouped as sham, Pringle maneuver (PM) and hepatic arterial blood flow open (HAFO) groups. We evaluated liver histology and function in liver sections, and biliary histology, cholangiocyte apoptosis and proliferation, cytokine production, and bile composition. RNA sequencing is performed to explore possible molecular mechanisms. The Blood-biliary barrier permeability and tight junctions were analyzed by HRP injection, immunofluorescence staining and analysis of ZO-1 expression by immunoblotting.

RESULTS

HAFO significantly attenuated ischemia-induced liver injury and decreased ALT, ALP, TBIL, and DBIL levels in serum. The histopathological observations showed that bile duct injury in the PM group was more serious than that in the HAFO group. The numbers of apoptotic biliary epithelial cells in HAFO-treated rat bile ducta were lower than those in the PM group. RNA-seq showed that tight junctions may be related to the mechanism underlying the protective effect of HAFO, as shown by the reduced HRP levels and increased ZO-1 and claudin-1/3 expression in the HAFO group compared to the PM group.

CONCLUSION

Compared with PM, HAFO alleviated the ischemic injury to the biliary system, which was characterized by decreased biliary epithelial cell apoptosis, reduced inflammatory responses and decreased blood-biliary-barrier permeability.

Gastroduodenal artery disconnection during liver transplantation decreases non-anastomotic stricture incidence

BACKGROUND

The hepatic artery is the only blood source nourishing the biliary duct and associated with biliary complication after liver transplantation (LT). Gastroduodenal artery (GDA) disconnection increased proper hepatic artery flow. Whether this procedure attenuates biliary non-anastomotic stricture (NAS) is not clear.

METHODS

A total of 241 patients with LT were retrospectively analyzed. The patients were divided into the GDA disconnection (GDA-) and GDA preservation (GDA+) groups. Propensity score matching (PSM) was administrated to reduce bias. Logistic regression was conducted to analyze risk factors for biliary NAS before and after PSM. Postoperative complications were compared. Kaplan-Meier survival analysis and log-rank tests were performed to compare overall survival.

RESULTS

In all, 99 patients (41.1%) underwent GDA disconnection, and 49 (20.3%) developed NAS. Multivariate logistic regression revealed that GDA preservation (OR = 2.24, 95% CI: 1.11-4.53; P = 0.025) and model for end-stage liver disease (MELD) score > 15 (OR = 2.14, 95% CI: 1.12-4.11; P = 0.022) were risk factors for biliary NAS. PSM provided 66 pairs using 1:2 matching method, including 66 GDA disconnection and 99 GDA preservation patients. Multivariate logistic regression after PSM also showed that GDA preservation (OR = 3.15, 95% CI: 1.26-7.89; P = 0.014) and MELD score > 15 (OR = 2.41, 95% CI: 1.08-5.36; P = 0.031) were risk factors for NAS. When comparing complications between the two groups, GDA preservation was associated with a higher incidence of biliary NAS before and after PSM (P = 0.031 and 0.017, respectively). In contrast, other complications including early allograft dysfunction (P = 0.620), small-for-size graft syndrome (P = 0.441), abdominal hemorrhage (P = 1.000), major complications (Clavien-Dindo grade ≥ 3, P = 0.318), and overall survival (P = 0.088) were not significantly different between the two groups.

CONCLUSIONS

GDA disconnection during LT ameliorates biliary NAS incidence and may be recommended for application in clinical practice.

Assessment of serum and drain fluid bilirubin concentrations in liver transplantation patients

BACKGROUND

Bile leakage is a major complication after liver transplantation and remains as a significant source of morbidity and mortality. In 2011, the International Study Group of Liver Surgery (ISGLS) defined bile leakage as a drain/serum bilirubin ratio ≥3. However, to our knowledge there is no literature assessing serum and drain bilirubin concentrations after liver transplantation. The aim of this study was to describe the natural postoperative changes in serum and drain fluid bilirubin concentrations in patients after liver transplantation.

METHODS

We included 32 patients who underwent liver transplantation at Kobe University Hospital from January 2007 to December 2020. We enrolled 34 living donors who had no complications as the control group.

RESULTS

The recipient serum total/direct bilirubin concentration were higher compared with the donors from postoperative day (POD) 1 to 5 with a statistical difference (P < .05). The recipient drain/serum total bilirubin ratio was lower than donors on POD 3 (0.89 ± 0.07 vs 1.53 ± 0.07: P < .0001), which was also confirmed by the recipient drain/serum direct bilirubin ratio (0.64 ± 0.10 vs 1.18 ± 0.09: P < .0001). On POD 3, the drain fluid volume (647.38 ± 89.47 vs 113.43 ± 86.8 mL: P < .001) and serum total bilirubin concentration (6.73 ± 0.61 vs 1.23 ± 0.60 mg/dL: P < .001) was higher in the recipients than in donors. Categorized in 2 groups, the higher drain fluid volume and bilirubin concentration recipients showed lower drain/serum total bilirubin ratio compared with the other group (P = .03) CONCLUSION: The drain/serum bilirubin ratio in the transplanted patients could be calculated lower compared with the hepatectomy patients because of high drain fluid volume and hyperbilirubinemia. Great care should be taken when assessing the bile leakage in liver transplant recipients using the ISGLS definition.

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.

Utility of Digital Single-operator Video Cholangioscopy for the Endoscopic Management of Biliary Complications After Liver Transplantation-A Single-center Experience

BACKGROUND

Liver transplant recipients (LTRs) frequently develop biliary complications, and endoscopy is crucial for their subsequent management. Recently, single-operator video cholangioscopy (SOVC) with digital imaging quality was introduced. This study evaluated the utility of digital SOVC for the management of biliary complications in LTRs.

METHODS

This observational study retrospectively analyzed all LTRs undergoing digital SOVC between 2015 and 2019 at a tertiary referral center. Endpoints included the assessment of biliary strictures, performance of selective guidewire passage across biliary strictures, and diagnosis and treatment of biliary stone disease.

RESULTS

In total, 79 digital SOVCs performed in 50 LTRs were identified. Fifty-eight percent of the procedures were performed for biliary stricture assessment, and using visual signs or guided biopsies, SOVC excluded malignancy in all cases (100%). Of all the examinations, 29.1% (23/79) were performed solely because of a previous failure of conventional endoscopic methods to pass a guidewire across a biliary stricture. Using SOVC, guidewire passage was successfully performed in 73.9% of these examinations, enabling subsequent endoscopic therapy. Furthermore, biliary stones were found in 16.5% (13/79) of the examinations. In 38.5% of these cases, standard fluoroscopy failed to detect stones, which were only visualized using digital SOVC. Biliary stone treatment was successful in 92% (12/13) of the examinations. Complications occurred in 11.4% of all SOVCs. No procedure-associated mortalities were observed.

CONCLUSIONS

Digital SOVC is effective and safe for the endoscopic management of biliary complications in LTRs and offers unique diagnostic and therapeutic opportunities that strongly impact the clinical course in selected cases.

Outcomes of endoscopic retrograde cholangio-pancreatography in patients with liver transplant

Aim of the study

Biliary complications are the leading causes of morbidity and mortality after liver transplant (LT). However, national data on endoscopic retrograde cholangiopancreatography (ERCP) usage and outcomes in LT patients are lacking. Our study aims to identify the trends, outcomes, and predictors of ERCP and related complications in this patient subgroup.

Material and methods

We derived our study cohort from the Nationwide Inpatient Sample (NIS) of the Healthcare Cost and Utilization Project (HCUP) between 2007 and 2017. LT patients were identified using ICD-9/10CM diagnosis codes and patients who underwent ERCP were identified by ICD-9/10-CM procedure codes. We utilized the Cochrane-Armitage trend test and multivariate logistic regression to analyze temporal trends, outcomes, and predictors.

Results

A total of 372,814 hospitalizations occurred in LT patients between 2007 and 2017. ERCP was performed in 2.05% (n = 7632) of all hospitalizations. There was a rise in ERCP procedures from 1.96% (n = 477) in 2007 to 2.05% (n = 845) in 2017. Among LT patients who underwent ERCP, the in-hospital mortality rate was 1% (n = 73) and 8% (n = 607) were discharged to facilities. Mean length of hospital stay was 7 ±0.3 days. Septicemia was the most common periprocedural complication (18.3%, n = 1399) followed by post-ERCP pancreatitis (8.8%, n = 674).

Conclusions

There has been an increase in ERCP procedures over the past decade among LT patients. Our study highlights the periprocedural complications and outcomes of ERCP in LT patients from a nationally representative dataset.

Risk factors and management of biliary stones after living donor liver transplant and its effect on graft outcome

Background

Bile stones are associated with numerous complications in liver transplant recipients. Endoscopic retrograde cholangiopancreatography (ERCP) has been proven to be safe and highly effective in dealing with most post-transplant biliary complications.

Objective

The objective of this study was to identify the possible risk factors for bile stone formation on top of biliary stricture, the effects of stones on graft outcomes, and their management.

Methods

This case–control study included 83 patients who underwent living donor liver transplant (LDLT) and suffered from postoperative biliary stricture with or without stones. Patients were divided into two groups. Group 1 (n = 55) included patients with biliary strictures with no stones and group 2 (n = 28) included patients who developed stones on top of biliary strictures. Data about the recipient and donor characteristics, surgical technique, blood lipid profile, immunosuppressive drugs, post-transplant complications, and interventions were collected from the medical records.

Results

The frequency of hepatitis C virus (HCV) was significantly higher in group 2 compared to group 1 (71.4% vs. 47.3%, p = 0.036). The body mass index (BMI) of the donors was significantly higher in group 2 than in group 1 (25.17 ± 2.53 vs. 23.68 ± 2.63, p = 0.015). Episodes of acute rejection were significantly higher in group 2 than in group 1 (21.4% vs. 5.5%, p = 0.027). The ERCP was sufficient in most of the cases (89.2%) to ensure biliary drainage. The identified independent risk factors for biliary stones included HCV, biliary drain, donor's BMI, and serum cholesterol level.

Conclusion

Positive HCV, biliary drain insertion, donor's BMI, and serum cholesterol level were independent risk factors for developing bile stones on top of biliary strictures. Biliary stones were associated with high episodes of acute graft rejection, and they could be successfully managed by the ERCP modality.

Role of the Intramural Vascular Network of the Extrahepatic Bile Duct for the Blood Circulation in the Recipient Extrahepatic Bile Duct Used for Duct-to-Duct-Biliary-Anastomosis in Living Donor Liver Transplantation

A duct-to-duct-biliary-anastomosis is the preferred biliary reconstruction technique in liver transplantation; biliary complications remain the major concerns for the technique. We examined the significance of the intramural vascular network of the extrahepatic bile duct (EBD) and its relevant vessels. We microscopically examined the axial sections of the EBD with 5 mm intervals of 10 formalin-fixed deceased livers. The luminal-areas of the 3 and 9 o’clock arteries correlated significantly and positively with the distance from the bifurcation of the right and left hepatic ducts (the 3 o’clock artery, r = 0.42, p < 0.001; the 9 o’clock artery, r = 0.39, p < 0.001); the ratios of the numbers of the intramural vessels to the areas of the corresponding sections of the EBD significantly correlated positively with the distance from the bifurcation of the right and left hepatic ducts (total vessels, r = 0.78, p < 0.001; arterioles, r = 0.52, p < 0.001; venules, r = 0.45, p < 0.001). This study demonstrated that there is a significant locoregional distributional heterogeneity of the intramural vessels among the EBD. The hepatic arteries neighboring the EBD primarily supply the blood flow to the EBD; thus, when the broader isolation of the EBD from the neighboring arteries is necessary, this locoregional distributional heterogeneity of the intramural vessels may render the EBD likely to suffer ischemia of the anastomotic site.

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.

Peroral cholangioscopy: Update on the state-of-the-art

Peroral cholangioscopy (POC) is an endoscopic procedure that allows direct intraductal visualization of the biliary tract. POC has emerged as a vital tool for indeterminate biliary stricture evaluation and treatment of difficult biliary stones. Over several generations of devices, POC has fulfilled additional clinical needs where other diagnostic or therapeutic modalities have been inadequate. With adverse event rates comparable to standard endoscopic retrograde cholangioscopy and unique technical attributes, the role of POC is likely to continue expand. In this frontiers article, we highlight the existing and growing clinical applications of POC as well as areas of ongoing research.

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.

Role of Endoscopic Retrograde Cholangiopancreatography in the Diagnosis and Management of Cholestatic Liver Diseases

Cholestatic liver diseases (CLDs) occur as a result of bile duct injury, emanating into duct obstruction and bile stasis. Advances in radiological imaging in the last decade has replaced endoscopic retrograde cholangiopancreatography (ERCP) as the first diagnostic tool, except in certain groups of patients, such as those with ischemic cholangiopathy (IsC) or early stages of primary sclerosing cholangitis (PSC). ERCP provides an opportunity for targeted tissue acquisition for histopathological evaluation and carries a diverse therapeutic profile to restore bile flow. The aim of this review article is to appraise the diagnostic and therapeutic roles of ERCP in CLDs.

Endoscopic management of difficult common bile duct stones: Where are we now? A comprehensive review

Endoscopic management for difficult common bile duct (CBD) stones still presents a challenge for several reasons, including anatomic anomalies, patients’ individual conditions and stone features. In recent years, variable methods have emerged that have attributed to higher stone removal success rates, reduced cost and lower adverse events. In this review, we outline a stepwise approach in CBD stone management. As first line therapy, endoscopic sphincterotomy and large balloon dilation are recommended, due to a 30%-50% reduction of the use of mechanical lithotripsy. On the other hand, cholangioscopy-assisted lithotripsy has been increasingly reported as an effective and safe alternative technique to mechanical lithotripsy but remains to be reserved in special settings due to limited large-scale evidence. As discussed, findings suggest that management needs to be tailored to the patient’s characteristics and anatomical conditions. Furthermore, we evaluate the management of CBD stones in various surgical altered anatomy (Billroth II, Roux-en-Y and Roux-en-Y gastric bypass). Moreover, we could conclude that cholangioscopy-assisted lithotripsy needs to be evaluated for primary use, rather than following a failed management option. In addition, we discuss the importance of dissecting other techniques, such as the primary use of interventional endoscopic ultrasound for the management of CBD stones when other techniques have failed. In conclusion, we recognize that endoscopic sphincterotomy and large balloon dilation, mechanical lithotripsy and intraductal lithotripsy substantiate an indication to the management of difficult CBD stones, but emerging techniques are in rapid evolution with encouraging results.

Preparation of Tubular Biocellulose Implants and Its Use in Surgery—A Review

This review highlights the current state regarding the preparation and characterization of tubular biocellulose materials as well as their application and application potential with a special focus on abdominal oncologic surgery. Biocellulose is a natural polymer synthesized by acetic acid bacteria from low molecular sugars and alcohols as a mechanically stable nanofiber network at the interface between the aqueous culture medium and air. This hydrogel is characterized by very high purity and biocompatibility, dimensional stability, and good surgical handling. With this property profile, biocellulose proves to be a promising candidate for the development of novel medical soft tissue implants. This requires close R&D cooperation between chemists, material scientists, biotechnologists, and surgeons. In this sense, this review spans from the natural polymer to the design of biocellulose implants and surgical suitability. It is also a concern of this article to show concretely the great need for such implants and the fields of application in oncological abdominal surgery where tubular biocellulose is or could be the focus of research. Furthermore, a critical assessment for the use of biocellulose materials concerning incidence malignancy and surgical interventions, complication rates, and current studies is emphasized. The regeneration of damaged bile ducts by the use of biocellulose implants is a first example.

Robotic Hepaticojejunostomy for Late Anastomotic Biliary Stricture After Liver Transplantation: Technical Description and Case Series

Biliary strictures after liver transplantation are common and when refractive to endoscopic and percutaneous intervention require surgical revision. Robotic technology facilitates minimally invasive biliary reconstruction and has not previously been described following liver transplantation. Robotic biliary revisions were retrospectively compared to all the historical open cases over a time period from May 2013 to October 2020. During the study period there were 3 robotic and 4 open surgical biliary revisions with a follow up of at least 6 months. All cases were hepaticojejunostomies for late choledochocholedochostomy anastomotic strictures presenting > 4 weeks after transplant and refractive to at least 3 endoscopic and/or percutaneous interventions. Median (range) case time was longer in the robotic group, 373 minutes (286-373) compared to open group, 280 minutes (163-321). The median length of stay was shorter in the robotic group, 4 days (1-4) compared to open group 7 days (4-10). Morbidity included 2 wound infections in the open group (grade II), 1 infected hematoma in the robotic group (grade IIIa) and 1 bile leak on the open group (grade IIIa). There was no biliary stricture recurrence or mortality in either group. Robotic biliary revision is a safe alternative to traditional open biliary revision for refractive biliary strictures after liver transplantation.