Internal biliary stenting in liver transplantation

Novel Silk Fibroin Based Bilayer Scaffolds for Bioabsorbable Internal Biliary Stenting

Biliary duct reconstruction is one of the most challenging parts of liver transplantation and accounts for 40%-60% of complications. While current stent-based devices on the market show promising results in reducing complications, they are manufactured from permanent synthetic materials and require a second reintervention for their removal. This exposes the patients to other potential complications and increases healthcare costs. This study develops a fabrication technique to produce a bioabsorbable biliary stent based on silk fibroin. The process used a dip-coating procedure for silk fibroin that produced highly smooth monolayer tubular specimens without the use of any additional surfactants during removal. This process was combined with an electrospinning step to produce bilayer structures through the deposition of electrospun silk fibroin on the outer surface. The structures proved to have promising mechanical, morphological, and cytocompatibility properties for use in the field of biliary stenting. Furthermore, the technique investigated proved to be reproducible, achieving an important requirement for large-scale use even in the presence of a biomaterial derived from a natural source. These results show the possibility of obtaining a completely bioabsorbable internal biliary stent that does not require any second reintervention. This study can be the starting point for further investigations both in vitro and in vivo to assess the suitability of silk fibroin biliary stents for clinical applications.

How to do it: rescue duct-to-duct biliary reconstruction techniques to avoid severe biliary complications of hepatic resection for hepatocellular carcinoma

There are few reports on duct-to-duct biliary reconstruction for complex liver resection with limited bile duct resection. We performed duct-to-duct biliary reconstruction in two patients undergoing limited bile duct resection where Roux-en-Y hepaticojejunostomy (HJ) was difficult. An external biliary drainage tube was placed routinely at the anastomotic site to prevent stenosis. In case 1, the tumor-infiltrated part of the left hepatic duct (LHD) was resected and the LHD was repaired using duct-to-duct reconstruction with interrupted sutures. In case 2, after the tumor-infiltrated part of the LHD and posterior hepatic duct (PHD) were resected, T-tube reconstruction was performed on the PHD, and the LHD was anastomosed using interrupted sutures for the posterior wall and a round ligament patch for the anterior wall. Our literature review suggests that an external biliary drainage tube with stenting over the anastomosis may reduce the risk of biliary complications.

Biodegradable biliary stents coated with mesenchymal stromal cells in a porcine choledochojejunostomy model

BACKGROUND AIMS

Roux en y anastomosis is a preferred method of biliary reconstruction in liver transplantation that involves living donors or pediatric patients. However, biliary stricture is a frequent and serious complication, accounting for up to 40% of biliary complications in these patients. Previously, we demonstrated that extraluminal delivery of adipose-derived (AD) mesenchymal stromal cells (MSCs) decreased peri-biliary fibrosis and increased neo-angiogenesis in a porcine model of duct-to-duct biliary anastomosis. In this study, we used a porcine model of Roux en y anastomosis to evaluate the beneficial impact of a novel intraluminal MSC delivery system.

METHODS

Nine animals were divided into three groups: no stent (group 1), bare stent (group 2) and stent coated with AD-MSCs (group 3). All animals underwent cholecystectomy with roux en y choledochojejunostomy. Two animals per group were followed for 4 weeks and one animal per group was followed for 8 weeks. Cholangiograms and blood were sampled at baseline and the end of study. Biliary tissue was collected and examined by Masson trichrome staining and immunohistochemical staining for MSC markers (CD34 and CD44) and for neo-angiogenesis (CD31).

RESULTS

Two of three animals in group 1 developed an anastomotic site stricture. No strictures were observed in the animals of group 2 or group 3. CD34 and CD44 staining showed that AD-MSCs engrafted successfully at the anastomotic site by intraluminal delivery (group 3). Furthermore, biliary tissue from group 3 showed significantly less fibrosis and increased angiogenesis compared with the other groups.

CONCLUSIONS

Intraluminal delivery of AD-MSCs resulted in successful biliary engraftment of AD-MSCs as well as reduced peri-biliary fibrosis and increased neo-angiogenesis.

Do We Need to Use a Stent in Biliary Reconstruction to Decrease the Incidence of Biliary Complications in Liver Transplantation? A Systematic Review and Meta-Analysis

BACKGROUND AND AIM

Biliary complications are a significant cause of morbidity post-transplantation, and the routine use of biliary stents in liver transplantation to reduce these complications remains controversial. This study aimed to compare the incidence of biliary complications with and without the use of trans anastomotic biliary stent in liver transplantation.

METHOD

PubMed, Scopes, Web of Science, and Cochrane library were searched for eligible studies from inception to February 2022, and a systematic review and meta-analysis were done to compare the incidence of biliary complications in the two groups.

RESULTS

Seventeen studies with a total of 2623 patients were included. The pooled results from the included studies showed an equal rate of biliary complications (i.e., strictures, leaks and cholangitis) in stented and non-stented patients after liver transplantation. However, the cost and biliary intervention rates are higher in stented patients. In addition to that, our sub-group analysis showed no significant decrease in the incidence of biliary complications after using trans anastomotic biliary stent in living donor liver transplant (LDLT), deceased donor liver transplant (DDLT), Roux-en-Y hepaticojejunostomy (RYHJ), and duct-to-duct anastomosis, pediatric, and adult liver transplantation.

CONCLUSION

No added benefit on the routine use of endobiliary stent in liver transplantation. However, stented patients are at higher risk of needing multiple ERCPs.

Feasibility and Safety of ERCP in the Treatment of Biliary Strictures after Liver Transplantation: With a Report of 37 Cases

Background. Liver transplantation (LT) is an effective treatment option for patients with end-stage liver disease; biliary complications are important cause of death in posttransplant patients. Endoscopic retrograde cholangiopancreatography (ERCP) has an irreplaceable role in the diagnosis and treatment of patients with biliary tract disease. Methods. The clinical data of patients with biliary strictures (BS) after LT treated with ERCP admitted to the Third Xiangya Hospital of Central South University from September 2016 to October 2021 were reviewed; the changes in temperature, bilirubin, and albumin before and after treatment and postoperative complications were analyzed. Results. A total of 41 patients were included in the study, and biliary stents were successfully placed in 37 cases (90.2%), while 4 cases (9.8%) were unsuccessful due to complete BS. Patients with ERCP guided biliary stenting had a significant improvement in bilirubin index compared to the preoperative period ( $P<0.05$ ). 27 patients (73.0%) had complete relief of symptoms after 1 ERCP-guided treatment, and 10 patients (27.0%) developed BS again at different times after the first ERCP treatment, among which 8 patients developed BS again within 1 year after the first treatment and 2 patients developed BS again after 1 year after the first treatment. The incidence of endoscopy-related adverse events was 35.14%, with no serious adverse events. Conclusion. ERCP-guided biliary stenting was an effective and safety treatment for BS after LT.

Biliary Internal Stents and Biliary Complications in Adult Liver Transplantation

BACKGROUND

Biliary complications in liver transplantation (LT) can cause significant morbidity or even lead to a potential graft loss and patient mortality. Oftentimes biliary internal stents (ISs) are used at the time of LT to lower the risk for or prevent these biliary complications; however, their efficacy and outcomes remain controversial.

METHODS

A retrospective cohort study was conducted on all of the adult patients who underwent a deceased-donor LT (DDLT) with an end-to-end choledococholedocostomy. An IS was placed across the biliary anastomosis, passing through the ampulla. We compared the demographic profiles and various outcomes between the 2 groups (no-IS group vs IS group) and examined risk factors associated with anastomotic biliary complications.

RESULTS

The study comprised 350 patients in the no-IS group and 132 patients in the IS group. Anastomotic biliary fistula (ABF) occurred in 5 (1.4%) and 1 (0.8%) patients in the no-IS group and the IS group, respectively (P = .55). Anastomotic biliary stricture (ABS) occurred in 53 (15.1%) and 18 (13.6%) patients, respectively (P = .68). No significant difference was found in the overall biliary complications between the 2 groups (P = .33). In multivariate logistic regression analysis, acute rejection was the only risk factor for ABS (P = .02). One biliary complication-induced mortality occurred in the no-IS group in which the patient died of an ABF-induced hepatic artery pseudoaneurysm rupture.

CONCLUSION

The use of biliary ISs in DDLT did not reduce the overall risk for biliary complications, but more research is needed to draw definite conclusions.

From in vitro evaluation to human postmortem pre-validation of a radiopaque and resorbable internal biliary stent for liver transplantation applications

The implantation of an internal biliary stent (IBS) during liver transplantation has recently been shown to reduce biliary complications. To avoid a potentially morbid ablation procedure, we developed a resorbable and radiopaque internal biliary stent (RIBS). We studied the mechanical and radiological properties of RIBS upon in vivo implantation in rats and we evaluated RIBS implantability in human anatomical specimens. For this purpose, a blend of PLA₅₀-PEG-PLA₅₀ triblock copolymer, used as a polymer matrix, and of X-ray-visible triiodobenzoate-poly(ε-caprolactone) copolymer (PCL-TIB), as a radiopaque additive, was used to design X-ray-visible RIBS. Samples were implanted in the peritoneal cavity of rats. The radiological, chemical, and biomechanical properties were evaluated during degradation. Further histological studies were carried out to evaluate the degradation and compatibility of the RIBS. A human cadaver implantability study was also performed. The in vivo results revealed a decline in the RIBS mechanical properties within 3 months, whereas clear and stable X-ray visualization of the RIBS was possible for up to 6 months. Histological analyses confirmed compatibility and resorption of the RIBS, with a limited inflammatory response. The RIBS could be successfully implanted in human anatomic specimens. The results reported in this study will allow the development of trackable and degradable IBS to reduce biliary complications after liver transplantation. STATEMENT OF SIGNIFICANCE: Biliary reconstruction during liver transplantation is an important source of postoperative morbidity and mortality although it is generally considered as an easy step of a difficult surgery. In this frame, internal biliary stent (IBS) implantation is beneficial to reduce biliary anastomosis complications (leakage, stricture). However, current IBS are made of non-degradable silicone elastomeric materials, which leads to an additional ablation procedure involving potential complications and additional costs. The present study provides in vitro and human postmortem implantation data related to the development and evaluation of a resorbable and radiopaque internal biliary stent (RIBS) that could tackle these drawbacks.

Abdominal drain straying into right atrium: a case report

Background

A drain exchange with the use of a guidewire may be accompanied by serious complications.

Case presentation

This case involved an 86-year-old man with overlapping cancers of intrahepatic cholangiocarcinoma and perihilar cholangiocarcinoma. A left hepatectomy, a left caudal lobectomy (with a medial hepatic vein preservation), an extrahepatic bile duct resection, and a right hepatojejunostomy were performed. The abdominal drain was placed into the hepatectomy side. Bile leakage occurred on the seventh day after the surgery, and the drain was exchanged. Since the bile leakage was still detectable via a computed tomography (CT) scan on the 15th postoperative day, the drain was exchanged again. On the next day, blood had discharged from the drain. A CT scan revealed that the tip of the drain was straying into the right atrium (RA) and the drain was removed from the inferior vena cava (IVC) under general anesthesia. One week later, a fiburin thrombus was observed from the IVC to the RA via the use of transthoracic echocardiography. A right atrial incision, a thrombus removal, and a middle hepatic vein merging section closure surgery were performed. Afterward, the patient’s general condition gradually improved, and he was transferred to the hospital for rehabilitation.

Conclusion

More careful guidewire operations are necessary at the time of the exchange of the drain to prevent the drain from being placed too close to blood vessels.

Biomechanical behaviour of human bile duct wall and impact of cadaveric preservation processes

Biliary diseases are the third most common cause of surgical digestive disease. There is a close relationship between the mechanical performance of the bile duct and its physiological function. Data of biomechanical properties of human main bile duct are scarce in literature. Furthermore, mechanical properties of soft tissues are affected by these preservation procedures. The aim of the present work was, on the one hand, to observe the microstructure of the human bile duct by means of histological analysis, on the other hand, to characterize the mechanical behavior and describe the impact of different preservation processes. A mechanical study in a controlled environment consisting of cyclic tests was made. The results of the mechanical tests are discussed and explained using the micro-structural observations. The results show an influence of the loading direction, which is representative of an anisotropic behavior. A strong hysteresis due to the viscoelastic properties of soft tissues was also observed. Embalming and freezing preservation methods had an impact on the biomechanical properties of human main bile duct, with fiber network deterioration. That may further provide a useful quantitative baseline for anatomical and surgical training using embalming and freezing.