Metallic biliary stents for malignant obstructive jaundice: a review

Short-term clinical outcomes of percutaneous biliary tract interventions: analysis of success and complication rates

INTRODUCTION

Obstructive jaundice is a clinical syndrome that is commonly seen in gastroenterology. Endoscopic retrograde cholangiopancreatography (ERCP) has been recognized as a first-choice therapeutic approach, with percutaneous biliary interventions (PBIs) being a viable alternative. Recent data questions the performance and safety profile of PBIs.

Jailbreaking a metal biliary stent through a duodenal stent

Video 1.

In vivo and in situ evaluation of a wireless magnetoelastic sensor array for plastic biliary stent monitoring

This paper presents the in vivo and in situ evaluation of a system that wirelessly monitors the accumulation of biliary sludge in a plastic biliary stent. The sensing element, located within the stent, is a passive array of magnetoelastic resonators that is queried by a wireless electromagnetic signal. The in vivo and in situ testing uses commercially-available plastic biliary stents, each enhanced with an array of ribbon sensors (formed from Metglas™ 2826 MB). The sensor array is approximately 70 mm long and contains individual resonators that are 1 mm in width and have lengths of 10 mm, 14 mm, and 20 mm. The array is anchored into the 2.8 mm inner-diameter stent using a thermal staking technique. For the in situ testing, an instrumented stent is placed in various locations within the abdominal cavity of a female domestic swine carcass to evaluate the wireless range of the system; these results show that a wireless signal can be obtained from a range of at least 7.5 cm from a sensor array covered in bile. The in vivo testing includes the endoscopic implantation of an instrumented stent into the bile duct of a swine. After implantation, the swine was housed for a period of 4 weeks, during which the animal showed no ill effects and followed the expected growth curve from 29 kg to 42 kg. At the conclusion of the in vivo test, the animal was euthanized, and the instrumented stent explanted and examined. The results presented in this paper indicate that the monitoring system does not adversely affect the health of the animal and can feasibly provide sufficient wireless range after implantation.

One-step percutaneous transhepatic insertion of a balloon-expanding metallic stent for obstructive jaundice

BACKGROUND AND AIM

The aim of this study was to evaluate the efficacy and safety of one-step percutaneous transhepatic insertion of the Express LD stent, a balloon-expanding stainless steel stent used for the management of distal artery stenosis in the treatment of obstructive jaundice caused by various inoperable malignancies.

METHODS

Seventy-one consecutive patients with unresectable malignant biliary obstruction who underwent Express LD stent placement between 2007 and 2010 at our institute were reviewed.

RESULTS

Mean stent patency was 165 ± 144 days and mean patient survival was 180 ± 156 days, while the cumulative stent patency rate and patient survival rate at 6 and 12 months were 79% and 65%, and 38% and 16%, respectively. Stents were successfully placed in all cases without any stent migration or misplacement. Stent failure occurred in 14 patients (20%), and 16 complications were observed, including 12 cholangitis (17%), two cholecysitis (3%), and two pancreatitis (3%). Y-configuration stenting for hilar bile duct obstruction was the only independent prognostic factor for stent failure.

CONCLUSIONS

One-step percutaneous transhepatic insertion of the Express LD stent is effective and safe for the management of obstructive jaundice caused by inoperable malignancies.

In situ and ex vivo evaluation of a wireless magnetoelastic biliary stent monitoring system

This paper presents the in situ and ex vivo evaluation of a system that wirelessly monitors the accumulation of intimal tissue and sludge in a biliary stent. The sensing element, located within the stent, is a magnetoelastic resonator that is queried by a wireless radio frequency signal. The in situ testing uses a commercially-available self-expanding biliary stent enhanced with a 1 mm x 25 mm magnetoelastic ribbon sensor (formed from Metglas 2605SA1). The stent has a conformal magnetic layer (consisting of strontium ferrite particles suspended in polydimethylsiloxane) that biases the sensor. The external interrogation module is able to acquire a signal from the sensor from a distance of at least 5 cm while the sensor is implanted in a porcine carcass and loaded with biological fluids. The ex vivo testing uses bile harvested from the porcine carcass. The response of a 1 mm x 25 mm magnetoelastic ribbon sensor is first calibrated with fluids of known density and viscosity, and the calibrated sensor is used to estimate that the viscosity of the harvested bile is 2.7-3.7 cP. The test results presented in this paper illustrate the fundamental usability of the system when the sensor is implanted, loaded by biological fluids, and interrogated in a surgical setup.

Clinical experience and applications of drug-eluting stents in the noncoronary vasculature, bile duct and esophagus

OBJECTIVE

To review the use of drug-eluting stents outside the coronary artery.

FINDINGS

The vast majority of research and clinical data on drug-eluting stents are from their use in coronary artery atherosclerosis; however, these devices can be used outside the coronary circulation in both vascular and nonvascular structures. In noncoronary arteries the principle indication for drug-eluting vascular stents is the same as in the coronary circulation, prevention of restenosis. Human experience has been essentially limited to trials or compassionate use; two small controlled studies and a number of small observational single center reports have been published, and there are trials in progress. To date the data have not been as compelling as in the coronary circulation. The physical characteristics of each vascular bed such as external compressive forces, blood flow rates, wall thickness relative to lumen size, and vessel wall composition differ significantly from the coronary circulation and each presents unique challenges to local drug delivery. Outside the vascular bed, the principle expected use is the prevention of tissue ingrowth after stent insertion in tubular structures such as the trachea, esophagus or bile ducts.

CONCLUSIONS

Considerable further study of drug-eluting stents will be required in each anatomic region to determine the ideal stent/drug combination and clinical appropriateness.

Early diagnosis and treatment of severe acute cholangitis

AIM: To investigate the diagnostic standard for early identification of severe acute cholangitis in order to lower the incidence of morbidity and mortality rate.

METHODS: A diagnostic standard was proposed in this study as follows: documented biliary duct obstruction by ultrasound or computerized tomography or other imaging tools with the manifestation of systemic inflammatory response syndrome (SIRS). The surgical procedures included emergency common bile duct exploration with T tube insertion or cholecystostomy with secondary common bile duct exploration. And incidence of postoperative multiple organ dysfunction syndrome (MODS), duration of systemic inflammatory response and hospital mortality were analyzed.

RESULTS: Fourty-three patients conforming to the diagnostic standard described above were employed in this study. 1 patient was admitted in acutely ill condition and complicated with acute relapse of chronic bronchitis, cholecystostomy procedure was performed but the patient was complicated with postoperative acute lung injury which was treated by assisted mechanical ventilation for 5 d; 2 wk later, two-stage common bile duct Exploration and T tube insertion were performed. The remaining 42 patients underwent primary common bile duct exploration and T tube insertion, 1 developed acute lung injury and recovered 3 d later, 2 patients developed acute renal dysfunction, 1 of which recovered 2 d later and the other died on d 4. For all patients, the postoperative systemic inflammatory response persisted for 2 to 8 d with median of 3 d.

CONCLUSION: Early diagnosis of severe acute cholangitis can be made using this diagnostic standard, further development of systemic inflammatory response could be prevented and incidence of MODS as well as hospital mortality decreased.