Biodegradable biliary stent implantation in the treatment of benign bilioplastic-refractory biliary strictures: preliminary experience

Biliary stents for active materials and surface modification: Recent advances and future perspectives

Demand for biliary stents has expanded with the increasing incidence of biliary disease. The implantation of plastic or self-expandable metal stents can be an effective treatment for biliary strictures. However, these stents are nondegradable and prone to restenosis. Surgical removal or replacement of the nondegradable stents is necessary in cases of disease resolution or restenosis. To overcome these shortcomings, improvements were made to the materials and surfaces used for the stents. First, this paper reviews the advantages and limitations of nondegradable stents. Second, emphasis is placed on biodegradable polymer and biodegradable metal stents, along with functional coatings. This also encompasses tissue engineering & 3D-printed stents were highlighted. Finally, the future perspectives of biliary stents, including pro-epithelialization coatings, multifunctional coated stents, biodegradable shape memory stents, and 4D bioprinting, were discussed.

Biodegradable biliary stents placement using a "kissing-stent" technique for management of a recalcitrant stricture post-live donor liver transplant

BACKGROUND

Biliary complications are common in pediatric liver transplant. Strictures resistant to interventional radiology procedures can be extremely challenging to manage and may result in the need of surgery or retransplantation.

METHODS

This case report illustrates the use of biodegradable stents post left lateral segment live donor liver transplant in a pediatric patient with a recalcitrant chronic stricture of the biliary-enteric anastomosis. The patient developed a high stricture requiring multiple interventions and eventual access of both the segment II and segment III ducts of the graft.

RESULTS

To ensure adequate biliary drainage, two biodegradable stents were deployed using a "kissing-stent" technique. The stents were successfully deployed and allowed the patient to remain free from an internal-external biliary drain for 11 months, with eventual redeployment of an additional biodegradable stent.

CONCLUSION

In patients with recalcitrant stenosis of the biliary anastomosis, biodegradable stents may provide durable drainage, optimizing graft function and delaying retransplantation in addition to keeping patients without external devices, thus improving quality of life.

The behavior between fluid and structure from coupling system of bile, bile duct, and polydioxanone biliary stent: A numerical method

The performance and effects of 12 different structures of stents in the bile duct were compared and used the finite element method. Numerical models of the 12 kinds of fluid-structure interaction(FSI) coupling systems were established to investigate the relationship between three aspects (velocity distribution of bile, wall shear stress (WSS) distribution of bile, and Von Mises Stress(VMS) distribution on the stent and bile duct) and the structural parameters of the stent (monofilament diameter and the number of braiding heads). After calculating and analyzing the simulation results yielding distributions of velocity, WWS, and VMS and regions of bile duct susceptibility to stenosis, they were consistent with previous findings on the locations of restenosis occurring after stent removal, indicating that the simulation results could provide a useful reference for studying biliary stents. The results of the simulations showed that (i) eddy currents were prone to occur at the stent ends regions; (ii) the WSS distribution of the bile fluid in contact with the stent and bile duct related to the stent structure; (iii) the high VMS on the stent and bile duct was prone to occur at the stent ends. The simulation results of 12 FSI coupling systems were studied and two superior stent model structures were obtained by comprehensive evaluation.

Feasibility and safety of a novel 3D-printed biodegradable biliary stent in an in vivo porcine model: a preliminary study

To assess the feasibility and safety of a novel 3D-printed biodegradable biliary stent using polycaprolactone (PCL) in an in vivo porcine model. In this animal study using domestic pigs, biodegradable radiopaque biliary stents made of polycaprolactone (PCL) and barium sulfate were produced using 3D printing and surgically inserted into the common bile duct (CBD) of pigs (stent group, n = 12). Another five pigs were allocated to the control group that only underwent resection and anastomosis of the CBD without stent insertion. To check the position and status of the stents and stent-related complications, follow-up computed tomography (CT) was performed every month. The pigs were sacrificed 1 or 3 months after surgery, and their excised CBD specimens were examined at both the macroscopic and microscopic levels. Three pigs (one in the stent group and two in the control group) died within one day after surgery and were excluded from further analysis; the remaining 11 in the stent group and 3 in the control group survived the scheduled follow-up period (1 month, 5 and 1; and 3 months, 6 and 2 in stent and control groups, respectively). In all pigs, no clinical symptoms or radiologic evidence of biliary complications was observed. In the stent group (n = 11), stent migration (n = 1 at 3 months; n = 2 at 1 month) and stent fracture (n = 3 at 2 months) were detected on CT scans. Macroscopic evaluation of the stent indicated no significant change at 1 month (n = 3) or fragmentation with discoloration at 3 months (n = 5). On microscopic examination of CBD specimens, the tissue inflammation score was significantly higher in the stent group than in the control group (mean ± standard deviation (SD), 5.63 ± 2.07 vs. 2.00 ± 1.73; P = 0.039) and thickness of fibrosis of the CBD wall was significantly higher than that of the control group (0.46 ± 0.12 mm vs. 0.21 ± 0.05 mm; P = 0.012). Despite mild bile duct inflammation and fibrosis, 3D-printed biodegradable biliary stents showed good feasibility and safety in porcine bile ducts, suggesting their potential for use in the prevention of postoperative biliary strictures.

A review on biodegradable biliary stents: materials and future trends

Biliary stricture is defined as the reduction and narrowing of the bile duct lumen, which can be caused by many factors such as cancer and inflammation. Biliary stent placement can effectively alleviate benign and malignant biliary strictures. However, the commonly used plastic or metallic biliary stents are far from ideal and do not satisfy all clinical requirements，although several types of biodegradable biliary stents have been developed and used clinically. In this review, we summarized current development status of biodegradable stents with the emphasis on the stent materials. We also presented the future development trends based on the published literature.

•

Summary of current development status of bioresorbable biliary stents with the emphasis on the stent materials.

•

The future development trends based on the published literature.

•

The advantages of bioresorbable biliary stents compared with metallic and plastic biliary stents.

Futuristic Developments and Applications in Endoluminal Stenting

Endoscopic stenting is a well-established option for the treatment of malignant obstruction, temporary management of benign strictures, and sealing transmural defects, as well as drainage of pancreatic fluid collections and biliary obstruction. In recent years, in addition to expansion in indications for endoscopic stenting, considerable strides have been made in stent technology, and several types of devices with advanced designs and materials are continuously being developed. In this review, we discuss the important developments in stent designs and novel indications for endoluminal and transluminal stenting. Our discussion specifically focuses on (i) biodegradable as well as (ii) irradiating and drug-eluting stents for esophageal, gastroduodenal, biliary, and colonic indications, (iii) endoscopic stenting in inflammatory bowel disease, and (iv) lumen-apposing metal stent.

Bio-Degradable Stents: Primary Experience in a Tertiary Hepatopancreaticobiliary Center in the United Kingdom

BACKGROUND

Management of benign biliary strictures (BBS) post bilioenteric anastomoses requires a multidisciplinary approach including surgical, radiological, and/or endoscopic input. Patients often need multiple hospital visits for treatment with the long-term possibility of restenosis. Conventionally BBS have been treated with serial percutaneous transhepatic biliary dilatations necessitating repeat procedures for drain exchange or removal. Surgery may become necessary in refractory strictures. In the last decade, there have been increasing reports of the use of biodegradable stents (BDS) in treating biliary strictures mainly to address the need for repeated procedures for drain exchange.

AIM

 This study aimed to report the early outcomes in patients with BBS treated with BDS.

METHODS

Retrospective analysis of prospectively collected data was performed in patients who had a bilioenteric anastomosis presenting with an anastomotic stricture and were intended to be treated with BDS. The primary endpoints reported were technical success (defined as a successful resolution of stricture on repeat cholangiogram) and clinical success (defined as the absence of repeated cholangitis). Clavien-Dindo (CD) grade of complication was reported.

RESULTS

Twelve patients presented with BBS and nine patients had BDS. Three patients were not considered suitable for BDS due to a non-traversable stricture and had surgery. The male-female ratio was 1:2. There was 100% technical and clinical success with one patient having stent migration not needing intervention. The procedure took an average of 45 min. In seven (77.7%) patients, it was safely performed under local anesthesia with sedation. Two patients preferred general anesthesia. There was no restenosis noted at a median follow-up of 11 months.

CONCLUSION

The use of BDS in the treatment of BBS is a safe and effective procedure. Longer-term follow-up with multi-institutional reporting on a national database is needed to assess its long-term benefits.

Indian College of Radiology and Imaging Evidence-Based Guidelines for Percutaneous Image-Guided Biliary Procedures

Percutaneous biliary interventions are among the commonly performed nonvascular radiological interventions. Most common of these interventions is the percutaneous transhepatic biliary drainage for malignant biliary obstruction. Other biliary procedures performed include percutaneous cholecystostomy, biliary stenting, drainage for bile leaks, and various procedures like balloon dilatation, stenting, and large-bore catheter drainage for bilioenteric or post-transplant anastomotic strictures. Although these procedures are being performed for ages, no standard guidelines have been formulated. This article attempts at preparing guidelines for performing various percutaneous image-guided biliary procedures along with discussion on the published evidence in this field.

CIRSE Standards of Practice on Percutaneous Transhepatic Cholangiography, Biliary Drainage and Stenting

This CIRSE Standards of Practice document is aimed at interventional radiologists and provides best practices for performing percutaneous transhepatic cholangiography, biliary drainage and stenting. It has been developed by an expert writing group established by the CIRSE Standards of Practice Committee.

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.

Absorbable stents for treatment of benign biliary strictures: long-term follow-up in the prospective Spanish registry

OBJECTIVES

Benign strictures of the bile duct may be difficult to treat endoscopically due to altered bowel anatomy. Furthermore, recurrence of stenosis and symptoms remains high. The aim of the Spanish Prospective Registry BiELLA study was to investigate the safety and efficacy of absorbable stents in the treatment of benign biliary strictures and their outcomes on the medium and long-term follow-up.

METHODS

A prospective, multicenter, observational, non-randomized study (the BiELLA study) was conducted from January 2014 to September 2018. One hundred fifty-nine patients with benign biliary strictures, mostly postsurgical, were enrolled for implantation of absorbable biliary stents in the 11 participating Spanish tertiary hospitals. The average patient follow-up was 45.4 ± 15.9 months (range, 12-60 months). The follow-up data included symptoms, biochemical parameters, and ultrasound images at 1, 6, and 12 months and then yearly for up to 60 months.

RESULTS

The immediate technical and clinical success rates were 100%. In all patients, stent placement resulted in improvement of clinical symptoms and biochemical parameters. The primary mean patency for stent was 86.7, 79.6, and 78.9% at 12, 36, and 60 months, respectively (95% CI). Biliary restenosis and occlusion occurred in 40 (26.6%) patients. Of the 40 patients, 18 (12%) patients were treated with a second stent and 22 (14.6%) patients had operative repair of the recurrent strictures. There were no major complications associated with stent implantation.

CONCLUSIONS

Implantation of an absorbable polydioxanone biliary stent is safe and effective for treatment of benign biliary strictures refractory to balloon dilatation or other biliary intervention.

KEY POINTS

• Percutaneous implantation of biodegradable prostheses for the treatment of benign postsurgical biliary strictures is a safe and effective procedure. • More than 75% of the patients presented patency of the stented biliary tree at 5 years follow-up. • Absorbable stents improved clinical symptoms and signs (jaundice, itching, fever), and laboratory parameters in a few days after stent placement.

Duodenum sparing technique for preventive stenting of biliary tract anastomosis in pigs

The main aim of this study was to find a standardized method for preventive stenting of biliary tract anastomosis with biodegradable self-expandable stent from polydioxanone and to evaluate the functionality of the stent. The experimental study was conducted using four pigs with a follow-up of eight weeks. The procedure was done under general anaesthesia. The function of the stent was verified by clinical stage, blood test, magnetic resonance cholangiopancreatography and necropsy. Our duodenum sparing technique was described in detail and photographically documented. All pigs finished the follow-up period without clinical, laboratory or radiologic signs of biliary obstruction. Necropsy did not reveal complication of the procedure or anastomotic stricture. In conclusion, this study demonstrated a simple new duodenum sparing method of transanastomotic insertion of a biodegradable self-expandable stent from polydioxanone. We did not find any complications during the follow-up. This method will be used in our follow-up study with an extended experimental control group of animals and a longer follow-up period to verify the preventive functionality of this stent.

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.

Efficacy of Different Endoscopic Stents in the Management of Postoperative Biliary Strictures: A Systematic Review and Meta-analysis

BACKGROUND

Endoscopic stents are the first-line treatment in the management of benign biliary stricture (BBS) which include multiple plastic stents (MPSs), fully covered self-expandable metal stents (FCSEMS) including the conventional and modified ones (FCSEMS-C and FCSEMS-M) and biodegradable stents. However, different stents have their distinct advantages and disadvantages. We aim to conduct this systematic review to compare the efficacy of different stents in the management of BBS.

METHODS

Several databases were searched from inception through March 2018. Studies including >10 patients with postoperative stricture treated with endoscopic stents were enrolled. Pooled odds ratio of outcomes were calculated to compare MPS with FCSEMS. Weighted pooled rates were calculated to show the efficacy of FCSEMS-M, FCSEMS-C, and MPS.

RESULTS

Twenty-two articles were reviewed including 4 randomized controlled studies, 4 cohort studies, and 14 case series studies. Comparing FCSEMS with MPS, the pooled odds ratio was 0.48 [95% confidence interval (CI): 0.22-1.05] (P=0.07) for stricture resolution, 0.3 (95% CI: 0.1-0.92) (P=0.03) for adverse event, 1.9 (95% CI: 0.3-12) (P=0.49) for stent migration, and 1.38 (95% CI: 0.36-5.3) (P=0.34) for stricture recurrence. The pooled rates for stricture recurrence of MPS, FCSEMS-C, and FCSEMS-M were 19%, 19%, and 7%, respectively. The pooled rates for stent migration were 4% of MPS, 25% of FCSEMS-C, and 3% of FCSEMS-M.

CONCLUSIONS

FCSEMS-M is more favorable in the management of BBS comparing with MPS or FCSEMS-C. The biodegradable stent may be a promising option but currently available data is insufficient to draw a firm conclusion.

Benign biliary strictures: prevalence, impact, and management strategies

Benign biliary strictures (BBSs) may form from chronic inflammatory pancreaticobiliary pathologies, postoperative bile-duct injury, or at biliary anastomoses following liver transplantation. Treatment aims to relieve symptoms of biliary obstruction, maintain long-term drainage, and preserve liver function. Endoscopic therapy, including stricture dilatation and stenting, is effective in most cases and the first-line treatment of BBS. Radiological and surgical therapies are reserved for patients whose strictures are refractory to endoscopic interventions. Response to treatment is dependent upon the technique and accessories used, as well as stricture etiology. In this review, we discuss the various BBS etiologies and their management strategies.

Endobiliary Radiofrequency Ablation in the Percutaneous Management of Refractory Benign Bilioenteric Anastomosis Strictures

OBJECTIVE

The purpose of this study is to evaluate the safety and efficacy of endobiliary radiofrequency ablation (RFA) in the percutaneous management of benign bilioenteric anastomosis strictures that are refractory to balloon dilatation and long-term drainage.

MATERIALS AND METHODS

Twenty-one patients (11 men) with a mean age of 47.9 years (range, 26-73 years) underwent percutaneous balloon dilatation and long-term drainage for benign bilioenteric anastomosis strictures. Endobiliary RFA was performed in six patients (four men; mean age, 53.1 years; range, 43-63 years) whose strictures did not respond to balloon dilatation and long-term drainage.

RESULTS

Presenting symptoms were jaundice (n = 21), pain (n = 19), pruritus (n = 17), and cholangitis (n = 15). The symptoms appeared 1384 days (range, 4-7592 days) after surgery. The technical success rate was 100%. The overall clinical success rate was 95.2% (20/21) with a mean follow-up of 67.3 months (range, 9-148 months) after catheter removal. In 15 patients, associated biliary stones were removed. Two patients with recurrent strictures were successfully retreated. Endobiliary RFA was successful and catheter removal could be achieved in all six patients (100%) whose disease did not respond to multiple balloon dilatation sessions and long-term drainage. The mean symptom-free period after endobiliary RFA and catheter removal was 430 days (range, 270-575 days). One patient with refractory disease (4.7%), for whom endobiliary RFA was not performed, underwent surgery. There were no major complications.

CONCLUSION

Endobiliary ablation may be used safely and effectively in the percutaneous management of benign bilioenteric anastomosis strictures that are refractory to balloon dilatation and long-term drainage, with promising results.

Management of Biliary Strictures: State-of-the-Art Review

Biliary strictures can be broadly classified as benign or malignant. Benign biliary strictures are most commonly iatrogenic in nature and are a consequence of hepatobiliary surgery. Cholangiocarcinoma and adenocarcinoma of the pancreas are the most common causes of malignant biliary obstruction. This article reviews state-of-the-art minimally invasive techniques used to manage these strictures. In addition, the roles of (a) recently introduced biodegradable biliary stents in the management of benign biliary strictures and (b) intraprocedural imaging and navigation tools, such as cone-beam CT, in percutaneous reconstruction of the biliary-enteric anastomosis are discussed.

Percutaneous treatment of benign bilioenteric anastomotic strictures: temporary covered stent placement versus balloon dilatation

OBJECTIVES

To compare percutaneous temporary covered stent placement with balloon dilatation in the treatment of benign stricture of bilioenteric anastomosis.

METHODS

From November 2004 to August 2017, 56 patients with benign bilioenteric anastomotic strictures underwent percutaneous transhepatic treatment. A temporary covered stent designed for spontaneous migration was placed in 23 patients (stent group). Balloon dilatation was performed in 33 patients (balloon group). The technical success, percutaneous transhepatic biliary drainage (PTBD) indwelling times, stent indwelling times and patency rates were retrospectively compared between the two groups.

RESULTS

Technical success was achieved in all patients in the stent group and in 96.8% (32/33) of patients in the balloon group. All stents spontaneously migrated into the jejunum, and stent indwelling times were 3-9 months (median, 6 months). The PTBD indwelling time was shorter for the stent group than for the balloon group (median, 7 vs. 71 days, p = 0.001). Recurrent strictures occurred more frequently in the balloon group than in the stent group (54.5% vs. 13.0%, p = 0.002; hazard ratio 3.7). The 1- and 3-year primary patency rates were 90.2% and 84.9% for the stent group and 75.1% and 52.8% for the balloon group, respectively (p = 0.04).

CONCLUSIONS

Percutaneous temporary covered stenting is an effective treatment in patients with benign bilioenteric anastomotic strictures. It provides longer patency and shorter PTBD indwelling time compared with balloon dilatation.

KEY POINTS

• A temporary covered stent designed for spontaneous migration is a feasible and effective treatment for patients with benign bilioenteric anastomotic strictures. • Percutaneous temporary covered stents provide longer patency and shorter drainage catheter indwelling time compared with conventional balloon dilatation. • A covered stent with flared ends spontaneously migrated after 3-9 months.

A systematic review of biodegradable biliary stents: promising biocompatibility without stent removal

Biodegradable self-expanding stents are an emerging alternative to standard biliary stents as the development of endoscopic insertion devices advances. The aim was to systematically review the existing literature on biodegradable biliary stents. In-vivo studies on the use of biodegradable stents in the biliary duct were systematically reviewed from 1990 to 2017. Despite extensive research on the biocompatibility of stents, the experience so far on their clinical use is limited. A few favorable reports have recently been presented on endoscopically and percutaneously inserted self-expanding biodegradable polydioxanone stents in benign biliary strictures. Another potential indication appears to be postcholecystectomy leak of the cystic duct. The main benefit of biodegradable stents is that stent removal can be avoided. The biocompatibility of the current biodegradable stent materials, most prominently polydioxanone, is well documented. In the few studies currently available, biodegradable stents are reported to be feasible and safe, also in humans. The initial results of the endoscopic use of these stents in benign biliary stricture management and for treating postcholecystectomy bile leaks are promising. Further controlled studies on long-term clinical results and cost-effectiveness are needed.

Unusual tumour ablations: report of difficult and interesting cases

Image-guided ablations are nowadays applied in the treatment of a wide group of diseases and in different organs and regions, and every day interventional radiologists have to face more difficult and unusual cases of tumour ablation. In the present case review, we report four difficult and unusual cases, reporting some tips and tricks for a successful image-guided treatment.

Meta-Analysis of the Long Term Success Rate of Different Interventions in Benign Biliary Strictures

Background

Benign biliary stricture is a rare condition and the majority of the cases are caused by operative trauma or chronic inflammation based on various etiology. Although the initial results of endoscopic, percutaneous and surgical treatment are impressive, no comparison about long term stricture resolution is available.

Aims

The goal of this study was to compare the long term disease free survival in benign biliary strictures with various etiology after surgery, percutaneous transhepatic—and endoscopic treatment.

Methods

PubMed, Embase, and Cochrane Library were searched by computer and manually for published studies. The investigators selected the publications according to the inclusion and exclusion criteria, processed the data and assessed the quality of the selected studies. Meta-analysis of data of 24 publications was performed to compare long term disease free survival of different treatment groups.

Results

Compared the subgroups surgery resulted in the highest long term stricture resolution rate, followed by the percutaneous transhepatic treatment, the multiple plastic stent insertion and covered self-expanding metal stents (SEMS), however the difference was not significant. All compared methods are significantly superior to the single plastic stent placement. Long term stricture resolution rate irrespectively of any therapy is still not more than 84%.

Conclusions

In summary, the use of single plastic stent is not recommended. Further randomized studies and innovative technical development are required for improving the treatment of benign biliary strictures.

Biodegradable biliary stents have a different effect than covered metal stents on the expression of proteins associated with tissue healing in benign biliary strictures

BACKGROUND

Benign biliary strictures (BBS) are primarily treated endoscopically with covered self-expandable metal stents (CSEMS). Biodegradable biliary stents (BDBS) may be the future of endoscopic therapy of BBS. The aim was to assess the expression of proteins related to tissue healing in BBS compared with the intact bile duct (BD), and to study the protein expression after therapy with CSEMS or BDBS.

METHODS

Pigs with ischemic BBS were endoscopically treated either with BDBS or CSEMS. Samples were harvested from pigs with intact BD (n = 5), untreated BBS (n = 5), and after six months of therapy with BDBS (n = 4) or CSEMS (n = 5) with subsequent histologic analysis. Two-dimensional electrophoresis with protein identification was performed to evaluate protein expression patterns.

RESULTS

In BBS, the expression of galectin-2 and annexin-A4 decreased, compared to intact BD. Treatment with biodegradable stents normalized galectin-2 level; with CSEMS therapy it remained low. Transgelin expression of intact BD and BBS remained low after BDBS treatment but increased after CSEMS therapy. Histologic analysis did not show unwanted foreign body reaction or hyperplasia in the BD in either group.

CONCLUSIONS

The expression of proteins related to tissue healing in BBS is different after treatment with biodegradable stents and CSEMS. Treatment with biodegradable stents may bring protein expression towards what is seen in intact BD. BDBS seem to have a good biocompatibility.

Long-Term Efficacy of Percutaneous Internal Plastic Stent Placement for Non-anastomotic Biliary Stenosis After Liver Transplantation

PURPOSE

We aimed to evaluate the long-term efficacy of percutaneous management of non-anastomotic biliary stenosis after liver transplantation, using plastic internal biliary stents.

MATERIALS AND METHODS

This study included 35 cases (28 men, 7 women; mean age: 52.09 ± 8.13 years, range 34-68) in 33 patients who needed repeated interventional procedures because of biliary strictures. After classification of the biliary strictures, we inserted percutaneous biliary plastic stents through the T-tube or percutaneous transhepatic biliary drainage tracts. Stents were exchanged according to percutaneous methods at regular 2- to 6-month intervals. The stents were removed if the condition improved, as observed on cholangiogram as well as based on clinical findings. The median patient follow-up period after initial diagnosis and treatment was 6.04 years (range 0.29-9.95 years). We assessed treatment success rate and patient and graft survival times.

RESULTS

During the follow-up period, 14 patients (14/33, 42.42 %) were successfully treated and were tube-free. The median tube-free time, time without a stent, was 4.13 years (range 1.00-9.01). In contrast, internal plastic stents remained in 9 patients (9/33, 27.27 %) until the last follow-up. These patients had acceptable hepatic function. Among the remaining 10 patients, 3 (3/33, 9.09 %) were lost to regular follow-up and the other 7 (7/33, 21.21 %) patients died. The overall graft loss rate was 20.0 % (7/35). The median time from initial treatment to graft loss was 1.84 years (range 0.42-4.25).

CONCLUSIONS

Percutaneous plastic stents placement is technically feasible and clinically useful in patients with multiple biliary stenoses following liver transplantation.

Biodegradable biliary stent in the endoscopic treatment of cystic duct leak after cholecystectomy: the first case report and review of literature

BACKGROUND

The preferred therapy for simple postcholecystectomy biliary leak consists of percutaneous drainage and biliary stent insertion under endoscopic retrograde cholangiopancreatography (ERCP). With a novel endoscopic insertion device, a biodegradable biliary stent (BDBS) may be used in the treatment of a cystic duct leak without repeated endoscopy for stent removal. The objective of this article was to report the first case of endoscopic insertion of BDBS for postoperative bile leak and assess its feasibility and safety.

PATIENT AND METHODS

A 64-year-old man with a postoperative leak from the cystic duct stump was treated with ERCP, biliary sphincterotomy, and insertion of a self-expandable 40- × 8-mm polydixanone BDBS (Ella CS, Hradec Králové, Czech Republic) after insertion of a percutaneous drain.

RESULTS

Endoscopic insertion of BDBS was successful and uncomplicated. On Day 7 after ERCP, the patient was in good condition, no signs of bile leak or inflammation were observed, and the percutaneous drain was removed. At 3 months, magnetic resonance imaging showed that the BDBS was patent and in the right location. At 6 months, the stent had expectedly degraded.

CONCLUSIONS

A novel endoscopic insertion device with a polydixanone BDBS appears feasible in treating disorders of the human biliary duct. BDBS now offers an encouraging option for endoscopic therapy of bile leaks.

Role of interventional radiology in the management of complications after pancreatic surgery: a pictorial review

Pancreatic resections are surgical procedures associated with high incidence of complications, with relevant morbidity and mortality even at high volume centres. A multidisciplinary approach is essential in the management of these events and interventional radiology plays a crucial role in the treatment of patients developing post-surgical complications. This paper offers an overview on the interventional radiological procedures that can be performed to treat different type of complications after pancreatic resection. Procedures such as percutaneous drainage of fluid collections, percutaneous transhepatic biliary procedures, arterial embolisation, venous interventions and fistula embolisation are viable treatment options, with fewer complications compared with re-look surgery, shorter hospital stay and faster recovery. A selection of cases of complications following pancreatic surgery managed with interventional radiological procedure are presented and discussed. Teaching Points • Interventional radiology is crucial to treat complications after pancreatic surgery • Percutaneous drainage of collections can be performed under ultrasound or computed tomography guidance • Percutaneous biliary procedures can be used to treat biliary complications • Venous procedures can be performed effectively through transhepatic or transjugular access • Fistulas can be treated effectively by percutaneous embolisation.

Self-expandable biodegradable biliary stents in porcine model

BACKGROUND

Treatment or prevention of a benign biliary tree stricture is an unresolved problem. A novel self-expandable biodegradable polydioxanon biliary stent in a porcine model was studied.

MATERIALS AND METHODS

This new stent was used in 23 pigs. Feasibility and safety of surgical stenting, time of biodegradation, and histologic reaction in 2, 8, 13, and 20 wk of a follow-up were studied. All stents were inserted into a common bile duct through a duodenal papilla following small dilatation. After surgical evaluation of abdominal cavities, the pigs were sacrificed to remove common bile ducts with the stents. All bile ducts were assessed by macroscopic and histopathologic examination.

RESULTS

Self-expansion was correct in all cases. Neither bile duct obstruction nor postsurgical complications were observed. Macroscopic evaluation indicated lightening of the stent color in 2 wk, a partial disintegration in 8 wk, and a complete absorption in 13 and 20 wk. Histologic evaluation in general substantiated a mild-to-moderate inflammatory reaction in the lamina propria during the whole follow up and had no clinical consequences. No cholangitis, necrosis, abscess, or excessive fibroplasia was found in a hepatoduodenal ligament.

CONCLUSIONS

Our results suggest that polydioxanon biodegradable self-expanding stents seem to be useful for biliary system implantation, offer a good biocompatibility, and completely degrade within 13 wk.