Pancreatic and biliary stents

Biocompatible Polymer Materials with Antimicrobial Properties for Preparation of Stents

Biodegradable polymers are promising materials for use in medical applications such as stents. Their properties are comparable to commercially available resistant metal and polymeric stents, which have several major problems, such as stent migration and stent clogging due to microbial biofilm. Consequently, conventional stents have to be removed operatively from the patient's body, which presents a number of complications and can also endanger the patient's life. Biodegradable stents disintegrate into basic substances that decompose in the human body, and no surgery is required. This review focuses on the specific use of stents in the human body, the problems of microbial biofilm, and possibilities of preventing microbial growth by modifying polymers with antimicrobial agents.

Identification of research trends concerning application of stent implantation in the treatment of pancreatic diseases by quantitative and biclustering analysis: a bibliometric analysis

OBJECTIVES

In recent years, with the development of biological materials, the types and clinical applications of stents have been increasing in pancreatic diseases. However, relevant problems are also constantly emerging. Our purpose was to summarize current hotspots and explore potential topics in the fields of the application of stent implantation in the treatment of pancreatic diseases for future scientific research.

METHODS

Publications on the application of stents in pancreatic diseases were retrieved from PubMed without language limits. High-frequency Medical Subject Headings (MeSH) terms were identified through Bibliographic Item Co-Occurrence Matrix Builder (BICOMB). Biclustering analysis results were visualized utilizing the gCLUTO software. Finally, we plotted a strategic diagram.

RESULTS

A total of 4,087 relevant publications were obtained from PubMed until May 15th, 2018. Eighty-three high-frequency MeSH terms were identified. Biclustering analysis revealed that these high-frequency MeSH terms were classified into eight clusters. After calculating the density and concentricity of each cluster, strategy diagram was presented. The cluster 5 "complications such as pancreatitis associated with stent implantation" was located at the fourth quadrant with high centricity and low density.

CONCLUSIONS

In our study, we found eight topics concerning the application of stent implantation in the treatment of pancreatic diseases. How to reduce the incidence of postoperative complications and improve the prognosis of patients with pancreatic diseases by stent implantation could become potential hotspots in the future research.

Post-Cholecystectomy Mirizzi Syndrome: A Case Report and Review of the Literature

Patient: Female, 44

Final Diagnosis: Post-cholecystectomy Mirizzi syndrome

Symptoms: Abdominal pain • nausea • vomiting

Medication: Tramadol • hydromorphone • prochlorperazine

Clinical Procedure: US • MRCP • ERCP• choledochoscopy

Specialty: Gastroenterology and Hepatology

Partially Covered Versus Uncovered Self-Expandable Metal Stents: Coating Nor Diameter Affect Clinical Outcomes

INTRODUCTION

Jaundice is a common initial presentation of malignant biliary stricture. In patients with life expectancies that are greater than 3 months, self-expanding metal stents (SEMS) offer a larger diameter stent with longer patency and fewer complications compared to plastic stents. There have been conflicting results in the published literature as to efficacy and safety between the various SEMS types and diameters. We compared stent coating (PCSEMS vs USEMS) and diameter on clinical outcomes regarding management of malignant biliary obstruction.

METHODS

A retrospective cohort study was conducted using a database of consecutive patients who underwent an ERCP with biliary SEMS placement (only 8 and 10 mm) between 2009 and 2017.

RESULTS

In total, 278 patients who had SEMS at ERCP for malignant biliary obstruction were included (213 PCSEMS vs 65 USEMS). The groups were demographically evenly matched. Clinical success rates and patency duration were not statistically significant between PCSEMS and USEMS (98.1% vs 95.5%, P = 0.36, and 302.5 vs 225.5 days, P = 0.72, respectively). Adverse event rates were similar between both PCSEMS and USEMS with regard to overall adverse events. Stent diameter did not have an impact on overall clinical success (98.9% vs 95.3%, P = 0.11) or patency duration (239 days vs 336 days, P = 0.51).

CONCLUSIONS

Our comparison of PCSEMS versus USEMS and 8 mm versus 10 mm showed no difference in clinical efficacy or adverse events between the two SEMS coatings and diameter, illustrating that coating and size do not matter in regard to stent choice, despite prior suggestive data.

Risk Factors for the Development of Stent-Associated Cholangitis Following Endoscopic Biliary Stent Placement

BACKGROUND AND AIM

To elucidate the overall risk and risk factors for developing cholangitis following biliary stent placement by endoscopic retrograde cholangiopancreatography (ERCP) and to determine the clinical outcomes of these individuals.

METHODS

We performed a retrospective review of 796 patients who had undergone 1127 ERCPs with biliary stent placement between 2007 and 2015 at a single tertiary care center. There were 91 episodes of stent-associated cholangitis (SAC) during the study period. Data obtained through the medical records included ERCP indication, patient factors (biliary anatomy, demographics, and comorbidities), stent characteristics (material, length, and design), change in serum bilirubin, stent indwelling time, rates and etiologies of bacteremia, and the mortality rate.

RESULTS

Those with SAC were more likely to have an anatomic biliary stricture (13.1% vs. 2.3%, p < .0001), with hilar and multiple strictures having the highest risk (19.1% vs. 11.6%, p = .04). The ERCP indication of malignant biliary obstruction was associated with higher rates of SAC (15.6% vs. 3.4%, p = < .0001). Rates of SAC were higher in those who failed to normalize total bilirubin (16.9% vs. 7.8%, p = .0005), and these episodes occurred earlier compared to those who normalized total bilirubin (median 30.5 days vs. 140.5 days, p < .0001).

CONCLUSIONS

Patients at increased risk of SAC include those with an anatomic stricture, malignant biliary obstruction, and those who fail to normalize total bilirubin after biliary stent placement. Future protocols should be designed to reduce the risk of cholangitis in these populations.

Dose perturbation by metallic biliary stent in external beam radiotherapy of pancreato-biliary cancers

This study aims to investigate dose perturbations caused by a metallic biliary stent (MBS) in patients undergoing external beam radiotherapy for cancers in the pancreato-biliary region. Four MBSs with nitinol mesh were examined in the EasyCube^® phantom including a custom stent holder fabricated by a 3D printer. For experimental models, three-dimensional conformal radiotherapy plans using a single anterior-posterior (AP) and four-field box (4FB) as well as volumetric modulated arc therapy (VMAT) plan were prepared to deliver the photon beam of 8 Gy to the stent holder. EBT3 film was used to measure dose distributions at four sides surrounding MBS. All MBSs in the AP beam demonstrated mean dose enhancements of 2.3-8.2% at the proximal, left, and right sides. Maximum dose enhancements of 12.3-19.5% appeared at regions surrounding the radiopaque markers. At the location distal to the source, there were mean dose reductions of - 3.6 to - 10.9% and minimum doses of - 11.1 to - 9.5%. The mean and maximum doses with the 4FB plan were in the ranges of - 0.1 to 3.6% and 6.7-14.9%, respectively. The VMAT produced mean doses of - 0.9 to 4.8% and maximum doses of 6.0-15.3%. Dose perturbations were observed with maximum and minimum spots near the stent surface. The use of multiple beams including parallel-opposed pairs reduced dose perturbations caused by the nitinol and radiopaque components within the stent. Special attention is required for patients in whom the radiopaque markers are closely located near critical structures or the target volume.

Risk Factors for Pancreatitis and Cholecystitis after Endoscopic Biliary Stenting in Patients with Malignant Extrahepatic Bile Duct Obstruction

Background/Aims:

For the treatment of malignant biliary obstruction, endoscopic retrograde biliary drainage (ERBD) has been widely accepted as a standard procedure. However, post-ERBD complications can affect the lives of patients. The purpose of this study was to identify the predictive factors for these complications, including the patient’s status, cancer status, and stent type.

Methods:

This was a retrospective analysis conducted in a single tertiary hospital from January 2007 to July 2017. The following variables were evaluated: sex, age, body mass index, cancer type, history of pancreatitis, gallbladder stone, previous biliary stenting, precut papillotomy, stent type, contrast injection into the pancreatic duct or gallbladder, cystic duct invasion by the tumor, and occlusion of the cystic duct orifice by a metal stent.

Results:

Multivariate analysis showed that contrast injection into the pancreatic duct was a risk factor for pancreatitis. Patients with a history of bile drainage showed a lower risk of pancreatitis. For cholecystitis, the analysis revealed contrast injection into the gallbladder and cystic duct invasion by the tumor as important predictive factors. Metal stents showed a greater risk of post-procedure pancreatitis than plastic stents, but did not affect the incidence of cholecystitis.

Conclusions:

Considering that contrast injection is the most important factor for both complications, a careful approach by the physician is essential in preventing the occurrence of any complications. Further, choosing the type of stent is an important factor for patients at a risk of post-procedure pancreatitis.

Endoscopic palliation of biliary obstruction

Advanced pancreaticobiliary malignancy tends to be uncurable at presentation and causes significant morbidity for patients. Palliation for malignant biliary obstruction should be minimally invasive, cost-effective, and aim to improve quality of life of patients. Strategies of endoscopic palliation of malignant biliary obstruction can differ based on sites and degree of biliary obstruction with complex decisions of optimal stent type and placement that involve conscientious planning by a multidisciplinary team.

Stenting for Benign and Malignant Biliary Strictures

Benign and malignant biliary strictures are common indications for endoscopic retrograde cholangiopancreatography. Diagnosis involves high-quality cross-sectional imaging and cholangiography with various endoscopic sampling techniques. Treatment options include placement of plastic biliary stents and self-expanding metal stents, which differ in patency duration and cost effectiveness. Whether the etiology is benign or malignant, a multidisciplinary strategy should be implemented. This article will discuss general principles of biliary stenting in both benign and malignant conditions.

A Review on the Management of Biliary Complications after Orthotopic Liver Transplantation

Orthotopic liver transplantation is the definitive treatment for end-stage liver disease and hepatocellular carcinomas. Biliary complications are the most common complications seen after transplantation, with an incidence of 10-25%. These complications are seen both in deceased donor liver transplant and living donor liver transplant. Endoscopic treatment of biliary complications with endoscopic retrograde cholangiopancreatography (commonly known as ERCP) has become a mainstay in the management post-transplantation. The success rate has reached 80% in an experienced endoscopist's hands. If unsuccessful with ERCP, percutaneous transhepatic cholangiography can be an alternative therapy. Early recognition and treatment has been shown to improve morbidity and mortality in post-liver transplant patients. The focus of this review will be a learned discussion on the types, diagnosis, and treatment of biliary complications post-orthotopic liver transplantation.

Encapsulation Approaches for In-Stent Wireless Magnetoelastic Sensors

Wireless magnetoelastic sensors offer significant potential for measuring the accumulation of biomass within stents - enabling early detection prior to stent occlusion - but the encapsulation of these sensors remains a critical challenge. The encapsulation must allow the sensors to navigate the curvature and accommodate the contact forces imparted during and after the implantation procedure, while also leaving the sensor open to mechanical interaction with the biomass during the extended period of deployment. This paper is focused on the encapsulation of ribbon-like magnetoelastic sensors (12.5 mm x 1 mm x 60 μm) within plastic biliary stents (inner diameter of 2.54 mm). The compromise between two polymer-based package designs - one mechanically flexible (Type F) and one mechanically stiff (Type S) - is evaluated. The primary advantage of the Type F package is the flexibility during the delivery process while that of the Type S package is in maintaining a strong signal even when the stent is in a curved bile duct. The maximum thicknesses of the Type F and S packages are 0.53 mm and 0.74 mm, respectively. Mechanical tests show that both types protect the sensors from forces imparted by a standard introducer, and allow the encapsulated sensors to accommodate bending with a radius of curvature as small as 3 cm. The Type F package has also been tested in situ, in the bile duct of a porcine carcass. The signal is measurable with a wireless range of 10 cm, at a resonant frequency of 159 kHz and a quality factor of 397.

Management of anastomotic biliary stricture after liver transplantation: metal versus plastic stent

Background

Post-transplant anastomotic biliary strictures remain refractory to endoscopic therapy in a considerable number of cases. The aim of this meta-analysis was to compare fully-covered self-expandable metal and plastic stents in the management of post-transplant biliary strictures.

Methods

A meta-analysis was performed using a random effects model; results were expressed as odds ratio (OR) and mean standardized difference. The primary outcome was stricture resolution, while recurrence rate after stent placement, treatment time, and safety of the procedure were the secondary outcomes.

Results

Through a systematic literature review until October 2017, we identified 7 studies, of which 4 were randomized controlled trials. Stricture resolution was slightly higher with metal stents, with no statistical difference between the two procedures (OR 1.38, 95% confidence interval [CI] 0.60-3.15; P=0.45) and low heterogeneity (I²=6%). Stricture recurrence showed a non-significant trend in favor of plastic stents (OR 1.82, 95%CI 0.52-6.31, P=0.35). Endoscopic retrograde cholangiopancreatography with placement of metal stents offered a significant improvement in terms of reduced treatment time (mean standardized difference: -3.58 months, 95%CI -6.23 to -0.93; P=0.008), but with more frequent complications, although not significantly so (OR 2.34, 95%CI 0.75-7.25; P=0.14). Sensitivity analysis confirmed all the findings.

Conclusion

Metal stents appear to be a promising tool that can decrease treatment time, although there is still no clear evidence of their superiority over plastic stents in terms of efficacy.

Endoscopic management of difficult benign biliary and pancreatic strictures using a wire-guided cystotome: experience with 25 cases

BACKGROUND AND STUDY AIMS

Endoscopic management using standard accessories is the preferred modality for treatment of benign biliary strictures. However, with difficult strictures, there is frequently failure of endoscopic therapy. We are reporting our experience regarding use of a standard diathermic dilator (cystotome) to aid in stricture dilatation and stent placement in patients with difficult strictures.

PATIENTS AND METHODS

Data were analyzed from January 2014 to January 2017 at a single tertiary care center in North India. Total 25 patients were included.

RESULTS

The mean age was 45 years (varying from 38 - 55 years). Of the 25 patients with difficult strictures, 14 (56 %) were male and 11 (44 %) were female. Further, of these, 19 had biliary and 6 had pancreatic strictures. The average time of diathermic current application was 3.5 seconds (ranging 3 - 5 seconds). Technical and clinical success were achieved in 100 % of cases. None of the patients had any procedure-related (early or delayed) major complications.

CONCLUSION

The cystotome is an extremely safe and useful accessory in benign biliary and pancreatic strictures, whereas conventional methods to negotiate stricture have failed.

Association of covered metallic stents with cholecystitis and stent migration in malignant biliary stricture

BACKGROUND AND AIMS

ERCP with self-expandable metallic stent (SEMS) placement provides reliable and durable relief of malignant biliary obstruction. Our objective was to compare efficacy and adverse outcomes between uncovered SEMSs (USEMSs) and covered SEMSs (CSEMSs).

METHODS

A retrospective cohort study was performed of all consecutive patients who underwent ERCP with SEMS placement for the management of a malignant bile duct stricture. Comparative analyses on clinical success, patency duration, stent dysfunction, and adverse outcomes were performed. Univariate and multivariable analyses were performed to identify factors associated with stent dysfunction.

RESULTS

Six hundred forty-five patients underwent SEMS placement for the management of malignant bile duct stricture from 2008 to 2016. CSEMSs and USEMSs had similar rates of clinical success in relief of bile duct obstruction (93.0% vs 92.1%, respectively; P = .69) and patency duration (546.7 vs 557.9 days, P = .14). Among those with an intact gallbladder, the incidence of acute cholecystitis was higher in the CSEMS group compared with the USEMS group (7.8% vs 1.2%; P < .001). In the multivariable analysis, CSEMS use was associated with increased risk of stent migration (hazard ratio, 10.7; 95% confidence interval, 4.1-27.7).

CONCLUSIONS

CSEMSs and USEMSs have similar clinical success rates and patency durations in management of malignant bile duct stricture. CSEMSs, however, are associated with increased rates of migration and cholecystitis. Comparable efficacy and superior safety profile of USEMSs render a compelling argument for its place as the preferred choice of SEMSs in the management of malignant biliary stricture.

Mechanisms and Management of Acute Pancreatitis

Acute pancreatitis represents a disorder characterized by acute necroinflammatory changes of the pancreas and is histologically characterized by acinar cell destruction. Diagnosed clinically with the Revised Atlanta Criteria, and with alcohol and cholelithiasis/choledocholithiasis as the two most prominent antecedents, acute pancreatitis ranks first amongst gastrointestinal diagnoses requiring admission and 21st amongst all diagnoses requiring hospitalization with estimated costs approximating 2.6 billion dollars annually. Complications arising from acute pancreatitis follow a progression from pancreatic/peripancreatic fluid collections to pseudocysts and from pancreatic/peripancreatic necrosis to walled-off necrosis that typically occur over the course of a 4-week interval. Treatment relies heavily on fluid resuscitation and nutrition with advanced endoscopic techniques and cholecystectomy utilized in the setting of gallstone pancreatitis. When necessity dictates a drainage procedure (persistent abdominal pain, gastric or duodenal outlet obstruction, biliary obstruction, and infection), an endoscopic ultrasound with advanced endoscopic techniques and technology rather than surgical intervention is increasingly being utilized to manage symptomatic pseudocysts and walled-off pancreatic necrosis by performing a cystogastrostomy.

Management of endoscopic biliary stenting for choledocholithiasis: Evaluation of stent-exchange intervals

AIM

To evaluate the best management of plastic stents in patients with choledocholithiasis who were unfit for endoscopic stone removal or surgery.

METHODS

Between April 2007 and September 2017, 87 patients (median age 83.7 years) with symptomatic choledocholithiasis were treated with insertion of 7-Fr plastic stents because complete endoscopic stone retrieval was difficult, and their general condition was not suitable for surgery. Seventy of these patients agreed to regular stent management and stent exchange was carried out at every 6 mo (Group A, n = 35) or every 12 mo (Group B, n = 35). The remaining 17 patients did not accept regular stent exchange, and stents were replaced when clinical symptoms appeared (Group C). We evaluated the frequency of biliary complication and stent patency rate during follow-up periods.

RESULTS

The patency rate of biliary plastic stents was 91.4% at 6 mo (Group A) and 88.6% at 12 mo (Group B), respectively. Acute cholangitis occurred in 2.9% of Group A patients and in 8.6% of Group B patients. In Group C, median stent patency was 16.3 mo, and stent exchange was carried out in 70.6% of cases because of acute cholangitis or obstructive jaundice. Although a high incidence of acute cholangitis occurred, there was no biliary-related mortality.

CONCLUSION

Plastic stent exchange at 12-mo intervals is considered a safe procedure for patients with choledocholithiasis. Long-term biliary stenting increases biliary complications, but it can be an acceptable option for select patients who are medically unfit for further invasive procedures.

Characterization of biofilms in biliary stents and potential factors involved in occlusion

AIM

To quantify the components in biofilms and analyze the predisposing factors involved in occlusion of biliary stents.

METHODS

In a prospective study conducted from April 2011 to March 2014 at a tertiary care hospital, all consecutive patients who required endoscopic biliary stent exchange/removal were included. Etiology of the biliary disease was diagnosed by imaging, cytology and on follow-up. Clinical details of patients with biliary stent retrieval were noted. All extracted stents were collected in sterile containers and immediately processed for quantification of biofilm proteins and polysaccharides. Molecular identification of commonly known and unknown bacteria was performed by polymerase chain reaction and density gradient gel electrophoresis methods.

RESULTS

Eighty one patients (41 males) with age range of 20-86 years were studied. The underlying causes for stent insertion were bile duct stones (n = 46; 56.8%) benign stricture (n = 29; 35.8%) and malignancy (n = 6; 7.4%) with cholangitis in 50 (61.7%) patients. The retrieved stent sizes were 7 Fr (n = 62; 76.5%) and 10 Fr (n = 19; 23.5%) with 65 days median insertion duration. Polybacterial consortia were detected in 90.1% of the stents. The most common bacteria identified by polymerase chain reaction alone and/or sequencing were Pseudomonas (n = 38), Citrobacter (n = 23), Klebsiella (n = 22), Staphylococcus (n = 20), Serratia (n = 16), Escherichia coli (n = 14), Streptococcus (n = 13), Enterococcus (n = 13), Aeromonas (n = 12), Proteus (n = 10) and Enterobacter (n = 9). Protein concentration according to gender (0.547 ± 0.242 mg/mL vs 0.458 ± 0.259 mg/mL; P = 0.115) as well as age > 60 years and < 60 years (0.468 ± 0.295 mg/mL vs 0.386 ± 0.238 mg/mL; P = 0.205) was non-significant. However, polysaccharide concentration was significant both according to gender (0.052 ± 0.021 mg/mL vs 0.049 ± 0.016 mg/mL; P < 0.0001) and age (0.051 ± 0.026 mg/mL vs 0.038 ± 0.016 mg/mL; P < 0.011). Protein concentration in the biofilm was significantly higher (0.555 ± 0.225 mg/mL vs 0.419 ± 0.276 mg/mL; P = 0.018) in patients with cholangitis, lower (0.356 ± 0.252 mg/mL vs 0.541 ± 0.238 mg/mL; P = 0.005) in the 10 Fr group than the 7 Fr group, and significantly higher (0.609 ± 0.240 mg/mL vs 0.476 ± 0.251 mg/mL; P = 0.060) in stents of ≥ 6 mo of indwelling time. However presence/absence of cholangitis, size of stent, indication of stent insertion and indwelling time did not affect the quantity of polysaccharide concentration.

CONCLUSION

Plastic stents retrieved from patients with biliary tract disease showed polymicrobial organisms with higher protein content among patients with cholangitis and those with smaller diameter stents. Longer indwelling duration had more biofilm formation.

Multiple plastic biliary stent placement in the management of large and multiple choledochal stones: single center experience and review of the literature

INTRODUCTION

Endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy is the first step treatment modality of choledocholithiasis. In spite of an extended sphincterotomy, 10-15% of complex choledochal stones (larger than 15 mm and/or more than 3 stones) cannot be removed and recurrent ERCP procedures may be needed.

AIM

To evaluate the role and efficiency of multiple biliary stent application in the treatment of large and multiple choledochal stones.

MATERIAL AND METHODS

Patients with complex choledochal stones and patients with inadequate choledochal clearance during ERCP were included in the study. The study group was divided into 2 groups as the placement of single (n = 27 patients) or multiple stents (n = 58 patients). After a mean time interval of 21 days (10-28), the ERCP procedure was tried for the second time and a stent was placed in case of recurrence.

RESULTS

Successful biliary drainage was provided in both groups. The decrease in the longitudinal or transverse size of the stones after stent placement was found to be statistically significant in both groups (p = 0.001). Cholestatic enzymes (alkaline phosphatase (ALP), γ-glutamyltransferase (GGT)) and bilirubin levels decreased significantly in both groups following stenting (p = 0.001). Additionally, multiple stents functioned as a bridge starting from the first ERCP to full clearance in patients with large and multiple stones which could not be removed at once and saved them from the possible morbidities of an invasive operation.

CONCLUSIONS

Endoscopic multiple biliary stent placement should be preferred in the treatment of patients with complex choledochal stones and high rates of co-morbidity, as a safe alternative to surgery.

Current challenges in optimizing systemic therapy for patients with pancreatic cancer: expert perspectives from the Australasian Gastrointestinal Trials Group (AGITG) with invited international faculty

INTRODUCTION

Despite recent progress, the outlook for most patients with pancreatic cancer remains poor. There is variation in how patients are managed globally due to differing interpretations of the evidence, partly because studies in this disease are challenging to undertake. This article collates the evidence upon which current best practice is based and offers an expert opinion from an international faculty on how latest developments should influence current treatment paradigms. Areas covered: Optimal chemotherapy for first and subsequent lines of therapy; optimal management of locally advanced, non-metastatic cancer including the role of neoadjuvant chemo(radio)therapy, current evidence for adjuvant chemotherapy, major advances in pancreatic cancer genomics and challenges in supportive care particularly relevant to patients with pancreatic cancer. For each section, literature was reviewed by comprehensive search techniques, including clinical trial websites and abstracts from international cancer meetings. Expert commentary: For each section, a commentary is provided. Overall the challenges identified were: difficulties in diagnosing pancreatic cancer early, challenges for performing randomised clinical trials in all stages of the disease, some progress in systemic therapy with new agents and in identifying molecular subtypes that may be clinically relevant and move towards personalized therapy, but still, pancreatic cancer remains a very poor prognosis cancer with significant palliative care needs.

Endoscopic Palliation of Pancreatic Cancer

OPINION STATEMENT

Pancreas cancer is a fourth-leading cause of cancer death in the USA and its incidence is rising as the population is aging. The majority of patients present at an advanced stage due to the silent nature of the disease and treatment have focused more on palliation than curative intent. Gastroenterologists have become integral in the multidisciplinary care of these patients with a focus on providing endoscopic palliation of pancreas cancer. The three most common areas that gastroenterologists palliate endoscopically are biliary obstruction, cancer-related pain, and gastric outlet obstruction. To palliate biliary obstruction, the procedure of choice is to perform endoscopic retrograde cholangiopancreatography (ERCP) with biliary stent placement. We tend to place covered self-expandable metal stents (SEMS) due to their longer patency and removability unless the patient has resectable disease. Pancreas cancer pain is a result of tumor infiltration of the celiac plexus and can be severe and poorly responsive to narcotics. To improve pain control, neurolysis of the celiac plexus has been performed for decades. Since 1996, neurolysis of the celiac area has been performed endoscopically by Endoscopic Ultrasound-Guided Celiac Plexus Neurolysis. This has proven to be as safe and effective as traditional non-endoscopic methods and has allowed the patients to decrease their narcotic use and improve their pain control. This should be done early on in the course of the disease to have maximal effect. Gastric outlet obstruction (GOO) occurs in approximately 15-20% of patients with pancreas cancer. Endoscopic palliation of GOO can be performed by placing uncovered metal enteral stents across the obstruction. This procedure has proven to be very effective in patients who have a short life expectancy (less than two to 6 months) while surgical bypass should be considered for patients with longer life expectancies because it offers better long-term symptom relief. This chapter will review the current literature, latest advancements, and optimal techniques for endoscopic palliation of pancreatic cancer.

Efficacy of the Novel Medical Adhesive, MAR-VIVO-107, in an Acute Porcine Liver Resection Model

BACKGROUND

Despite modern surgical techniques, insufficient hemostasis after liver trauma is still a major cause of morbidity and mortality after injury. Therefore, efficient hemostatic agents are indicated. In this study, we evaluated the hemostatic efficacy of a novel synthetic wound adhesive (MAR-VIVO-107) based on polyurethane/polyurea, compared with a widely used fibrin adhesive (Tisseel).

MATERIALS AND METHODS

Twelve German Landrace pigs were randomly assigned to 2 groups. The animals were operated under sterile conditions. A midline laparotomy was performed and the left liver lobe was isolated and resected, using a surgical scissor, in order to induce hepatic trauma. MAR-VIVO-107 or Tisseel was applied to the resected area. The animals were monitored for 60 minutes; thereafter, they were sacrificed under anesthesia. Blood and tissue samples were collected pre- and postresection for biochemical and hematological analyses.

RESULTS

MAR-VIVO-107 versus Tisseel (mean ± SD, P value)-postsurgical survival rate was 100% in both groups. Bleeding time was significantly higher in Tisseel compared with MAR-VIVO-107 (10.3 ± 5.0 vs 3.7 ± 1.5 minutes, P = .0124). In trend, blood loss was less in the MAR-VIVO-107 group (54.3 ± 34.9 vs 105.5 ± 65.8 g, P = .222). Aspartate transaminase levels were significantly lower in the MAR-VIVO-107 group when compared with the Tisseel group (39.0 ± 10.0 vs 72.4 ± 23.4 U/L, P = .0459).

CONCLUSION

The efficacy of MAR-VIVO-107 and comparable performance to the gold standard fibrin have been shown under pre-clinical conditions. MAR-VIVO-107 permits hemorrhage control within seconds, even in wet environment.

Theoretical investigation of transgastric and intraductal approaches for ultrasound-based thermal therapy of the pancreas

Background

The goal of this study was to theoretically investigate the feasibility of intraductal and transgastric approaches to ultrasound-based thermal therapy of pancreatic tumors, and to evaluate possible treatment strategies.

Methods

This study considered ultrasound applicators with 1.2 mm outer diameter tubular transducers, which are inserted into the tissue to be treated by an endoscopic approach, either via insertion through the gastric wall (transgastric) or within the pancreatic duct lumen (intraductal). 8 patient-specific, 3D, transient, biothermal and acoustic finite element models were generated to model hyperthermia (n = 2) and ablation (n = 6), using sectored (210°–270°, n = 4) and 360° (n = 4) transducers for treatment of 3.3–17.0 cm³ tumors in the head (n = 5), body (n = 2), and tail (n = 1) of the pancreas. A parametric study was performed to determine appropriate treatment parameters as a function of tissue attenuation, blood perfusion rates, and distance to sensitive anatomy.

Results

Parametric studies indicated that pancreatic tumors up to 2.5 or 2.7 cm diameter can be ablated within 10 min with the transgastric and intraductal approaches, respectively. Patient-specific simulations demonstrated that 67.1–83.3% of the volumes of four sample 3.3–11.4 cm³ tumors could be ablated within 3–10 min using transgastric or intraductal approaches. 55.3–60.0% of the volume of a large 17.0 cm³ tumor could be ablated using multiple applicator positions within 20–30 min with either transgastric or intraductal approaches. 89.9–94.7% of the volume of two 4.4–11.4 cm³ tumors could be treated with intraductal hyperthermia. Sectored applicators are effective in directing acoustic output away from and preserving sensitive structures. When acoustic energy is directed towards sensitive structures, applicators should be placed at least 13.9–14.8 mm from major vessels like the aorta, 9.4–12.0 mm from other vessels, depending on the vessel size and flow rate, and 14 mm from the duodenum.

Conclusions

This study demonstrated the feasibility of generating shaped or conformal ablative or hyperthermic temperature distributions within pancreatic tumors using transgastric or intraductal ultrasound.

The Stent Patency and Migration Rate of Different Shaped Plastic Stents in Bile Flow Phantom Model and In Vivo Animal Bile Duct Dilation Model

BACKGROUND/AIM

In research and development of biliary plastic stents (PS), continuous efforts have been made to overcome short patency time and high rate of migration. The aim of this study was to evaluate the patency and migration rate of different PS shapes for a given period of time.

METHODS

Using an in vitro bile phantom model, we compared the patency among different shapes of PS (three straight PS, four double-pigtail PS, and a new screw-shaped PS). We performed an analysis of the degree of luminal narrowing by light microscopic examination. Using an in vivo swine model, we compared the patency and migration rate among the three different types of PS.

RESULTS

Eight weeks after the bile exposure in the bile flow phantom model, 80 PS were retrieved and analyzed. The straight PS showed less biofilm formation and luminal narrowing than other types of PS (p < 0.05). Forty-nine PS were inserted into the dilated bile ducts of 10 swine models, and 39 PS were successfully retrieved 8 weeks later. The stent migration occurred less frequently in the double-pigtail PS and the screw-shaped PS than it did in the straight PS (11.1, 10, and 27.3%, respectively). However, there was no statistical difference in stent patency among the different shapes.

CONCLUSIONS

Stent patency may not be significantly different depending on the shape of PS for 8 weeks. The screw-shaped PS showed similar patency and migration rate to the double-pigtail PS. These results may help guiding future PS development and clinical decisions.

Biliary Interventions: Tools and Techniques of the Trade, Access, Cholangiography, Biopsy, Cholangioscopy, Cholangioplasty, Stenting, Stone Extraction, and Brachytherapy

Therapeutic access to the biliary system is generally limited to endoscopic or percutaneous approaches. A variety of percutaneous transhepatic biliary interventions are applicable for the diagnosis and treatment of biliary system pathologies, the majority of which may be performed in conjunction with one another. The backbone of nearly all of these interventions is percutaneous transhepatic cholangiography for opacification of the biliary tree, after which any number of therapeutic or diagnostic modalities may be pursued. We describe an overview of the instrumentation and technical approaches for several fundamental interventional procedures, including percutaneous transhepatic cholangiography and internal/external biliary drainage, endobiliary biopsy techniques, cholangioscopy, cholangioplasty and biliary stenting, biliary stone extraction, and intraluminal brachytherapy.

Generic and Automated Data Evaluation in Analytical Measurement

In the past year, automation has become more and more important in the field of elemental and structural chemical analysis to reduce the high degree of manual operation and processing time as well as human errors. Thus, a high number of data points are generated, which requires fast and automated data evaluation. To handle the preprocessed export data from different analytical devices with software from various vendors offering a standardized solution without any programming knowledge should be preferred. In modern laboratories, multiple users will use this software on multiple personal computers with different operating systems (e.g., Windows, Macintosh, Linux). Also, mobile devices such as smartphones and tablets have gained growing importance. The developed software, Project Analytical Data Evaluation (ADE), is implemented as a web application. To transmit the preevaluated data from the device software to the Project ADE, the exported XML report files are detected and the included data are imported into the entities database using the Data Upload software. Different calculation types of a sample within one measurement series (e.g., method validation) are identified using information tags inside the sample name. The results are presented in tables and diagrams on different information levels (general, detailed for one analyte or sample).

Cost-effectiveness and clinical efficacy of biliary stents in patients undergoing neoadjuvant therapy for pancreatic adenocarcinoma in a randomized controlled trial

BACKGROUND AND AIMS

The optimal type of stent for the palliation of malignant biliary obstruction in patients with pancreatic adenocarcinoma undergoing neoadjuvant chemoradiotherapy with curative intent is unknown. We performed a prospective trial comparing 3 types of biliary stents-fully covered self-expandable metal (fcSEMS), uncovered self-expandable metal (uSEMS), and plastic-to determine which best optimized cost-effectiveness and important clinical outcomes.

METHODS

In this prospective randomized trial, consecutive patients with malignant biliary obstruction from newly diagnosed pancreatic adenocarcinoma who were to start neoadjuvant chemoradiotherapy were randomized to receive fcSEMSs, uSEMSs, or plastic stents during the index ERCP. The primary outcomes were time to stent occlusion, attempted surgical resection, or death after the initiation of neoadjuvant therapy, and the secondary outcomes were total patient costs associated with the stent, including the index ERCP cost, downstream hospitalization cost due to stent occlusion, and the cost associated with procedural adverse event.

RESULTS

Fifty-four patients were randomized and reached the primary end point: 16 in the fcSEMS group, 17 in the uSEMS group, and 21 in the plastic stent group. No baseline demographic or tumor characteristic differences were noted among the groups. The fcSEMSs had a longer time to stent occlusion compared with uSEMSs and plastic stents (220 vs 74 and 76 days, P < .01), although the groups had equivalent rates of stent occlusion, attempted surgical resection, and death. Although SEMS placement cost more during the index ERCP (uSEMS = $24,874 and fcSEMS = $22,729 vs plastic = $18,701; P < .01), they resulted in higher procedural AE costs per patient (uSEMS = $5522 and fcSEMS = $12,701 vs plastic = $0; P < .01). Conversely, plastic stents resulted in an $11,458 hospitalization cost per patient due to stent occlusion compared with $2301 for uSEMSs and $0 for fcSEMSs (P < .01).

CONCLUSIONS

In a prospective trial comparing fcSEMSs, uSEMSs, and plastic stents for malignant biliary obstruction in patients undergoing neoadjuvant therapy with curative intent for pancreatic adenocarcinoma, no stent type was superior in optimizing cost-effectiveness, although fcSEMSs resulted in fewer days of neoadjuvant treatment delay and a longer time to stent occlusion. (Clincial trial registration number: NCT01038713.).

Effect of mobile phone reminder messages on adherence of stent removal or exchange in patients with benign pancreaticobiliary diseases: a prospectively randomized, controlled study

Background

Plastic and covered metal stents need to be removed or exchanged within appropriate time in case of undesirable complications. However, it is not uncommon that patients do not follow the recommendation for further stent management after Endoscopic Retrograde Cholangiopancreatography (ERCP). The effect of short message service (SMS) intervention monthly on the stent removal/exchange adherence in patients after ERCP is unknown at this time.

Methods

A prospective, randomized controlled study was conducted. After receiving regular instructions, patients were randomly assigned to receive SMS reminding monthly (SMS group) for stent removal/exchange or not (control group). The primary outcome was stent removal/exchange adherence within appropriate time (4 months for plastic stent or 7 months for covered stent). Multivariate analysis was performed to assess factors associated with stent removal/exchange adherence within appropriate time. Intention-to-treat analysis was used.

Results

A total of 48 patients were randomized, 23 to the SMS group and 25 to the control. Adherence to stent removal/exchange was reported in 78.2 % (18/23) of patients receiving the SMS intervention compared with 40 % (10/25) in the control group (RR 1.98, 95 % CI 1.16–3.31; p = 0 · 010). Among patients with plastic stent insertion, the median interval time from stent implantation to stent removal/exchange were 90 days in the SMS group and 136 days in the control respectively (HR 0.36, 95 % CI 0.16–0.84, p = 0.018). No difference was found between the two groups regarding late-stage stent-related complications. The rate of recurrent abdominal pain tended to be lower in SMS group without significant difference (8.7 vs 28 %, p = 0.144). Multivariate logistic regression analyses revealed that SMS reminding was the only factor associated with adherence of stent removal/exchange (OR 6.73, 95 % CI 1.64–27.54, p = 0.008).

Conclusion

This first effectiveness trial demonstrated that SMS reminding monthly could significantly increase the patient adherence to stent removal/exchange after ERCP.

Trial registration

The study was respectively registered on July 10 in 2016 at ClinicalTrials.gov (NCT02831127).

Covered metal stents in endoscopic therapy of biliary complications after liver transplantation

There is growing interest in using covered self-expandable metal stents for the treatment of benign biliary conditions, and the presence of anastomotic biliary strictures and leaks after liver transplantation provide a valuable opportunity for testing them. The performance of the stents is encouraging, and the technical success rate is high. They provide larger diameter dilation and are easily removed, and can potentially limit costs by reducing the number of procedures needed to treat anastomotic biliary strictures. However, drawbacks such as sub-optimal tolerability and migration may affect both patient management and costs. New stent designs are currently being evaluated. Randomized controlled trials and cost-effectiveness analyses comparing covered metal stents with multiple plastic stent endotherapy are warranted in order to define the role of the former as first-line or rescue treatment.

Mechanisms of Biliary Plastic Stent Occlusion and Efforts at Prevention

Biliary stenting via endoscopic retrograde cholangiopancreatography has greatly improved the quality of patient care over the last 30 years. Plastic stent occlusion limits the life span of such stents. Attempts to improve plastic stent patency duration have mostly failed. Metal stents (self-expandable metal stents [SEMSs]) have therefore replaced plastic stents, especially for malignant biliary strictures. SEMS are at least 10 times more expensive than plastic stents. In this focused review, we will discuss basic mechanisms of plastic stent occlusion, along with a systematic summary of previous efforts and related studies to improve stent patency and potential new techniques to overcome existing limitations.

Role of endoscopic retrograde cholangiopancreatography in the management of benign biliary strictures: What’s new?

Benign biliary strictures comprise a heterogeneous group of diseases. The most common strictures amenable to endoscopic treatment are post-cholecystectomy, post-liver transplantation, related to primary sclerosing cholangitis and to chronic pancreatitis. Endoscopic treatment of benign biliary strictures is widely used as first line therapy, since it is effective, safe, noninvasive and repeatable. Endoscopic techniques currently used are dilation, multiple plastic stents insertion and fully covered self-expandable metal stents. The main indication for dilation alone is primary sclerosing cholangitis related strictures. In the vast majority of the remaining cases, temporary placement of multiple plastic stents with/without dilation is considered the treatment of choice. Although this approach is effective, it requires multiple endoscopic sessions due to the short duration of stent patency. Fully covered self-expandable metal stents appear as a good alternative to plastic stents, since they have an increased radial diameter, longer stent patency, easier insertion technique and similar efficacy. Recent advances in endoscopic technique and various devices have allowed successful treatment in most cases. The development of novel endoscopic techniques and devices is still ongoing.

Current Status of Biliary Metal Stents

Many advances have been achieved in biliary stenting over the past 30 years. Endoscopic stent placement has become the primary management therapy to relieve obstruction in patients with benign or malignant biliary tract diseases. Compared with plastic stents, a self-expandable metallic stent (SEMS) has been used for management in patients with malignant strictures because of a larger lumen and longer stent patency. Recently, SEMS has been used for various benign biliary strictures and leaks. In this article, we briefly review the characteristics of SEMS as well as complications of stent placement. We review the current guidelines for managing malignant and benign biliary obstructions. Recent developments in biliary stenting are also discussed.

Covered versus Uncovered Self-Expandable Metal Stents for Managing Malignant Distal Biliary Obstruction: A Meta-Analysis

AIM

To compare the efficacy of using covered self-expandable metal stents (CSEMSs) and uncovered self-expandable metal stents (UCSEMSs) to treat objective jaundice caused by an unresectable malignant tumor.

METHODS

We performed a comprehensive electronic search from 1980 to May 2015. All randomized controlled trials comparing the use of CSEMSs and UCSEMSs to treat malignant distal biliary obstruction were included.

RESULTS

The analysis included 1417 patients enrolled in 14 trials. We did not detect significant differences between the UCSEMS group and the CSEMS group in terms of cumulative stent patency (hazard ratio (HR) 0.93, 95% confidence interval (CI) 0.19-4.53; p = 0.93, I2 = 0%), patient survival (HR 0.77, 95% CI 0.05-10.87; p = 0.85, I2 = 0%), overall stent dysfunction (relative ratio (RR) 0.85, M-H, random, 95% CI 0.57-1.25; p = 0.83, I2 = 63%), the overall complication rate (RR 1.26, M-H, fixed, 95% CI 0.94-1.68; p = 0.12, I2 = 0%) or the change in serum bilirubin (weighted mean difference (WMD) -0.13, IV fixed, 95% CI 0.56-0.3; p = 0.55, I2 = 0%). However, we did detect a significant difference in the main causes of stent dysfunction between the two groups. In particular, the CSEMS group exhibited a lower rate of tumor ingrowth (RR 0.25, M-H, random, 95% CI 0.12-0.52; p = 0.002, I2 = 40%) but a higher rate of tumor overgrowth (RR 1.76, M-H, fixed, 95% CI 1.03-3.02; p = 0.04, I2 = 0%). Patients with CSEMSs also exhibited a higher migration rate (RR 9.33, M-H, fixed, 95% CI 2.54-34.24; p = 0.008, I2 = 0%) and a higher rate of sludge formation (RR 2.47, M-H, fixed, 95% CI 1.36-4.50; p = 0.003, I2 = 0%).

CONCLUSIONS

Our meta-analysis indicates that there is no significant difference in primary stent patency and stent dysfunction between CSEMSs and UCSEMSs during the period from primary stent insertion to primary stent dysfunction or patient death. However, when taking further management for occluded stents into consideration, CSEMSs is a better choice for patients with malignant biliary obstruction due to their removability.

"Thunderstruck": Plasma-Polymer-Coated Porous Silicon Microparticles As a Controlled Drug Delivery System

Controlling the release kinetics from a drug carrier is crucial to maintain a drug's therapeutic window. We report the use of biodegradable porous silicon microparticles (pSi MPs) loaded with the anticancer drug camphothecin, followed by a plasma polymer overcoating using a loudspeaker plasma reactor. Homogenous "Teflon-like" coatings were achieved by tumbling the particles by playing AC/DC's song "Thunderstruck". The overcoating resulted in a markedly slower release of the cytotoxic drug, and this effect correlated positively with the plasma polymer coating times, ranging from 2-fold up to more than 100-fold. Ultimately, upon characterizing and verifying pSi MP production, loading, and coating with analytical methods such as time-of-flight secondary ion mass spectrometry, scanning electron microscopy, thermal gravimetry, water contact angle measurements, and fluorescence microscopy, human neuroblastoma cells were challenged with pSi MPs in an in vitro assay, revealing a significant time delay in cell death onset.

The metamorphosis of vascular stents: passive structures to smart devices

The role of nanotechnology enabled techniques in the evolution of vascular stents.

Outcome of stenting in biliary and pancreatic benign and malignant diseases: A comprehensive review

Endoscopic stenting has become a widely method for the management of various malignant and benign pancreatico-biliary disorders. Biliary and pancreatic stents are devices made of plastic or metal used primarily to establish patency of an obstructed bile or pancreatic duct and may also be used to treat biliary or pancreatic leaks, pancreatic fluid collections and to prevent post-endoscopic retrograde cholangiopancreatography pancreatitis. In this review, relevant literature search and expert opinions have been used to evaluate the outcome of stenting in biliary and pancreatic benign and malignant diseases.

Self-expandable metal stents versus plastic stents for malignant biliary obstruction: a meta-analysis

BACKGROUND

Malignant biliary obstruction frequently portends a poor prognosis. Palliative treatment with stenting is often required to alleviate symptoms and potentially prevent adverse events.

OBJECTIVES

The aims of our study were (1) to evaluate the clinical difference between self-expandable metal stents (SEMSs) and plastic stents (PSs) in both hilar and distal malignant biliary obstruction on occlusion rate and 30-day mortality rate (primary outcomes) and stent insertion success rate, therapeutic failure, reintervention rate, and adverse events (secondary outcomes); (2) to compare unilateral stenting with bilateral stenting in hilar malignant obstruction in terms of occlusion rate and 30-day mortality rate (primary outcomes) and insertion success rate, therapeutic failure, and adverse events (secondary outcomes).

METHODS

PubMed, Embase, and Cochrane databases were searched for studies that provided data about malignant biliary obstruction and stent therapy. We included randomized, controlled trials (RCT), prospective observational cohort, and retrospective case-control studies. The quality of each included RCT study was assessed by the Jadad scale. Mantel-Haenszel odds ratios (ORs) and mean differences were calculated by using a random-effects model.

RESULTS

Nineteen studies involving 1989 patients (1045 SEMSs and 944 PSs) were included for the comparison of SEMSs and PSs. We also included 7 studies that compared unilateral with bilateral stenting involving 634 patients (346 unilateral and 268 bilateral). Our meta-analysis confirmed that SEMSs are associated with a statistically significant lower risk of occlusion compared with PSs in the short term (OR 0.27; 95% confidence interval [CI], 0.13-0.60) and long term (OR 0.38; 95% CI, 0.28-0.53). SEMSs had a lower 30-day occlusion rate than PSs in both hilar malignant obstruction (OR 0.16; 95% CI, 0.04-0.62) and distal malignant obstruction (OR 0.36; 95% CI, 0.14-0.93). SEMSs had a lower long-term occlusion rate compared with PSs in hilar malignant obstruction (OR 0.28; 95% CI, 0.19-0.39) and distal malignant obstruction (OR 0.42; 95% CI, 0.27-0.64). The 30-day mortality rate was similar with SEMSs and PSs (OR 0.74; 95% CI, 0.47-1.17). Therapeutic failure was more likely when using PSs (13%) compared with SEMSs (7%) (OR 0.43; 95% CI, 0.27-0.67). SEMSs required fewer reinterventions compared with PSs (mean difference, -0.49; 95% CI, -0.8 to -0.19). The incidence of cholangitis was statistically lower with SEMSs (8% vs 21%) (OR 0.41; 95% CI, 0.22-0.76). Bilateral stenting for hilar obstruction was not associated with a lower obstruction rate than unilateral stenting (OR 1.49; 95% CI, 0.77-2.89) or a lower 30-day mortality rate (OR 0.73; 95% CI, 0.29-1.79). There was no statistical difference in therapeutic failure (OR 1.47; 95% CI, 0.77-2.89) or cholangitis incidence (OR 0.61; 95% CI, 0.27-1.38).

CONCLUSION

SEMSs are associated with a statistically significantly lower occlusion rate, less therapeutic failure, less need for reintervention, and lower cholangitis incidence. There was no statistically significant difference in occlusion rate, therapeutic failure, and cholangitis incidence with bilateral stenting. Guideline recommendations may need to be modified to reflect clear and compelling data demonstrating the benefit of SEMSs in patients with malignant biliary obstruction. Bilateral stenting should be avoided because it has no benefit over unilateral stenting in terms of occlusion rate or therapeutic failure.

An Update to Hepatobiliary Stents

Endoscopic stent placement is a common primary management therapy for benign and malignant biliary strictures. However, continuous use of stents is limited by occlusion and migration. Stent technology has evolved significantly over the past two decades to reduce these problems. The purpose of this article is to review current guidelines in managing malignant and benign biliary obstructions, current endoscopic techniques for stent placement, and emerging stent technology. What began as a simple plastic stent technology has evolved significantly to include uncovered, partially covered, and fully covered self-expanding metal stents (SEMS) as well as magnetic, bioabsorbable, drug-eluting, and antireflux stents.(1).

Ultrasonographic measurement of normal common bile duct diameter and its correlation with age, sex and anthropometry

BACKGROUND

Ultrasonography is the diagnostic method of choice for visualization and rational work-up of abdominal organs. The dilatation of the common bile duct helps distinguish obstructive from non-obstructive causes of jaundice. Availability of normal measurements of the common bile duct is therefore important. There exists significant variations in the anthropometric features of various populations, regions and races.

AIM

Study was conducted to obtain data on sonographically measured diameters of common bile duct in a series of normal Rajasthani population and to measure its correlation with age, sex and anthropometry.

SETTING AND DESIGN

Cross-sectional hospital-based study conducted at Mahatma Gandhi Medical College and Hospital, Jaipur, India.

MATERIALS AND METHODS

Study included 200 participants with equal proportion belonging to either sex. Common bile duct was measured at three locations- at the porta hepatis, in the most distal aspect of head of pancreas and mid-way between these points. Anthropometric measurements including height, weight, chest circumference, circumference at transpyloric plane, circumference at umbilicus and circumference at hip were obtained using standard procedures.

STATISTICAL ANALYSIS

Univariable analysis with measures of frequency and standard deviation and bivariable analysis using correlation.

RESULTS

Mean age of study subjects was 34.5 years (Range 18-85 years). Mean diameters of the common bile duct in the three locations were: proximal, 4.0 mm (SD 1.02 mm); middle, 4.1 mm (SD 1.01 mm); and distal, 4.2 mm (SD 1.01 mm) and overall mean for all measures 4.1 mm (SD 1.01 mm). Average diameter ranged from 2.0 mm to 7.9 mm, with 95 percent of the subjects having a diameter of less than 6 mm. We observed a statistically significant relation of common bile duct with age, along with a linear trend. There was no statistically significant difference in common bile duct diameter between male and female subjects. The diameter did not show any statistically significant correlation with any of the anthropometric measurements.

CONCLUSION

Our study reported the upper limit of normality as 7.9 mm. The diameter increased progressively from 3.9 mm among those aged 18-25 years to 4.7 mm among those in the age group more than 55 years. This was found to be statistically significant. Ductal diameters beyond these limits should prompt the need for further investigations.