SNARE‐OVER‐THE‐WIRE TECHNIQUE FOR SAFE EXCHANGE OF A STENT FOLLOWING ENDOSONOGRAPHY‐GUIDED BILIARY DRAINAGE

Endosonography‐guided biliary drainage (ESBD) is a new option that allows establishment of biliary drainage. Due to the diameter of the working channel of an echoendoscope, it is necessary to replace a small caliber stent with a larger one to lessen the risk of stent occlusion. However, insertion of a guidewire into the bile duct via the hole of the sinus tract following direct removal of a previously placed stent is not always possible, resulting in guidewire passage outside the fistula and bile leakage. Cannulation of the previously deployed stent, guidewire insertion into the bile duct via the cannula and the stent, and removal of the stent with the snare over the guidewire leaving the guidewire in place (the snare‐over‐the‐wire technique [SOW]) for stent exchange following ESBD was attempted. Four patients who required stent exchange following ESBD were included in the present study to evaluate the feasibility and usefulness of SOW. SOW was successful in all the cases. A new stent was also successfully deployed over the guidewire in all the cases. No complications were encountered. The snare‐over‐the‐wire technique is feasible and useful in stent exchange following ESBD for the reduction of the risk of guidewire migration.     

A novel approach to facilitate dilation of complex non-traversable esophageal strictures by efficient wire exchange using a stent pusher

BACKGROUND: Dilation of non-traversable complex strictures is frequently difficult. For a tight stricture, over-the-wire dilation is difficult using a flexible biliary guidewire as opposed to a more rigid guidewire with a spring tip made for use with polyvinyl over-the-wire dilators (Savary). However, passage of the more rigid, spring-tipped wire is not always possible. A new method is discussed here whereby a biliary guidewire is exchanged consistently with a rigid, spring-tipped wire to facilitate dilation of complex strictures. METHODS: The wire exchange was carried out using a 10F stent pusher. The latter is readily available and semi-rigid, and its large lumen easily accommodates a Savary guidewire. Furthermore, because it can be passed through an endoscope, it can be passed without difficulty through an extremely tight stricture because the device does not buckle in the proximal esophagus or mouth. RESULTS: Dilation was successful in 6 patients using this technique with no complications. Four patients required placement of the stent pusher through a therapeutic endoscope. CONCLUSION: A method is described that facilitates dilation of complex, tight esophageal strictures by exchange of a flexible biliary guidewire with a more rigid Savary wire using a stent pusher.     

Balloon deflection technique: A method to facilitate entry of a balloon catheter into a deployed stent.

The entry of an angioplasty balloon into a coronary stent is occasionally difficult due to poorly expanded stent struts or calcified tissue blocking balloon passage. We describe a simple technique using a second guidewire and balloon to facilitate entry into the stent. Cathet. Cardiovasc. Intervent. 51:312-313, 2000.     

A unique pitfall in percutaneous coronary angioplasty of in-stent restenosis: guidewire passage out of the stent.

Three cases of in-stent restenosis are narrated, wherein, during balloon angioplasty of the lesion, the guidewire inadvertently exited out of the stent. The forward balloon progress was halted in this region. In the first case, the situation could only be realized when dilatation of a forcefully pushed small balloon avulsed the well-embedded stent. The mishap was averted in the subsequent two cases by reintroduction of a new guidewire. Some suggestions to avoid this eventuality are offered. Though the cases pertain to in-stent restenosis, the observations may be applicable to the procedures in general that entail passage of a guidewire through a stented area.     

Intravascular ultrasound evaluation of a pseudolesion created by stent placement in the right artery

The creation of a pseudolesion after guidewire placement in tortuous arterial segments is a well recognized phenomenon. Intravascular ultrasound has been useful in assessing deployment of intracoronary stents and equivocal angiographic findings. We present a case in which a pseudolesion was not observed until after placement of an intracoronary stent. Intravascular ultrasound demonstrated no dissection or significant lesion; however, there was focal calcification just distal to the stent providing a substrate for the distorted vessel architecture. The lesion resolved with removal of the guidewire.     

Pancreatic stent insertion: consequences of failure and results of a modified technique to maximize success

BACKGROUND: Increasingly, pancreatic stents are being placed to prevent post-ERCP pancreatitis. However, guidewire and stent placement may fail if the duct is small or tortuous, potentially exacerbating the risk. This study assessed the impact of unsuccessful pancreatic stent placement on complications and the efficacy of a modified technique for stent insertion when pancreatic ductal anatomy makes stent insertion technically difficult. METHODS: Technical variables and 30-day complications of consecutive therapeutic ERCPs, including attempted major papilla pancreatic stent insertion were prospectively studied. Success rates for pancreatic stent placement were compared for a 1-year period during which conventional deep guidewire insertion was used and another 1-year period in which a modified technique was used as needed in patients with ductal anatomy that made stent placement technically difficult. In the modified technique, a short (2-3 cm) small diameter (3F-5F) stent was placed over a 0.018-in nitinol-tipped guidewire, passed as little as 1 to 2 cm beyond the pancreatic sphincter. RESULTS: In 225 high-risk therapeutic ERCPs, pancreatitis occurred after the procedure in two of 3 (66.7%) patients in whom pancreatic stent insertion failed vs. 32 of 222 (14.4%) patients with successful insertion (p=0.06). Severe pancreatitis occurred only after unsuccessful stent insertion. Significant multivariate risk factors for post-ERCP pancreatitis were unsuccessful pancreatic stent insertion (odds ratio 16.1: 95% CI[1.3, 200]), sphincter of Oddi dysfunction (odds ratio 3.2: 95% CI[1.4, 7.5]), and prior post-ERCP pancreatitis (odds ratio 3.2: 95% CI[1.4, 7.1]). The following were not risk factors: performance of pancreatic, biliary, or needle-knife pre-cut sphincterotomy; number of pancreatic contrast injections; and difficult cannulation. Stent placement was unsuccessful in 3 (3.2%) of 93 attempts during the 1-year period in which a conventional technique was used vs. none of 132 attempts in a subsequent year in which the modified technique was used. CONCLUSIONS: Failed attempts at pancreatic stent placement are associated with an extremely high risk of post-ERCP pancreatitis. Success can be consistently achieved by use of a modified technique.     

Report of an undeployed stent causing the unraveling of a coronary artery guidewire being used for sidebranch protection

We report a case of a 70-year-old male who was undergoing elective angioplasty of the left anterior descending coronary artery. During the procedure, a coronary guidewire became unraveled after positioning an undeployed stent; we describe its successful retrieval by removal of the undeployed stent. Although sidebranch protection and placement of a stent with the guidewire left in place is commonly performed without complication, it should be realized that this practice is not without hazard because of the unusual, but serious consequences that could ensue if the entrapped wire were to unravel.     

Use of a temporary plastic stent to facilitate the placement of multiple self-expanding metal stents in malignant biliary hilar strictures

BACKGROUND: Although endoscopic palliation of malignant biliary hilar obstruction is preferable to surgery or percutaneous drainage, it remains technically challenging. This is especially true when multiple self-expanding metal stents (SEMS) are placed, because difficulty is commonly encountered in passing the second SEMS at the level of the previously deployed initial stent. We have devised a method of deploying multiple metal stents by using a temporary plastic stent, which makes deployment of the second stent much easier. METHODS: After guidewire placement, a plastic stent is deployed in a subhilar position. The initial SEMS is deployed, with the plastic stent maintaining a passage for the second SEMS. After the second SEMS is deployed, the plastic stent is retrieved. OBSERVATIONS: This technique has been used successfully in 7/8 patients, all of whom presented with symptomatic jaundice secondary to malignant hilar obstruction of various etiologies (cholangiocarcinoma, n=4; metastatic disease, n=3; and hepatocellular carcinoma, n=1). Drainage was successful in all cases, with significant improvement in symptoms and cholestasis. CONCLUSIONS: This simple technique lessens the technical difficulty of placing bilateral hilar SEMS.     

Long-term outcome following coronary stent embolization or misdeployment

Twenty-three patients were identified as having either coronary stent embolization or misdeployment at our center over a 4-year period. They were matched to an equal number of controls who underwent a stenting procedure but in whom embolization or misdeployment did not occur. Baseline demographic characteristics were similar between the 2 groups. The embolization group required higher mean predilation pressure than the control group and more of the embolization group required a predilation pressure >10 atm before attempted stent placement (7 vs 1, p = 0.02). Total procedure and fluoroscopy time as well as dye volume were dramatically higher in the embolization group compared with the control group. Lesion angulation >45 degrees was predictive of stent embolization and 6 of 23 (23%) stents embolized during passage through a previously deployed stent. Sixteen cases of stent embolization and/or misdeployment occurred within the coronary circulation, 8 of which were retrieved, and 7 stents embolized to the central and/or peripheral circulation. A total of 23 major adverse coronary events occurred in the case group versus 7 events in the control group (p = 0.04) over a mean follow-up of 36 +/- 13 months. Fifteen of the events (65%) in the case group occurred in those 8 patients in whom the stent remained in the coronary circulation, including 3 bypass surgeries, 2 myocardial infarctions, 5 repeat percutaneous interventions, and 1 death after hospital discharge. Only 1 patient in whom the stent embolized outside the coronary circulation demonstrated possible evidence for peripheral vascular insufficiency. Intracoronary stent embolization in which the stent remains misdeployed in the coronary circulation is associated with poor long-term outcomes. Extracoronary stent embolization is associated with minimal long-term sequelae.     

Entrapment of guidewire in the coronary stent during percutaneous coronary intervention

A 76-year-old man presented with chest discomfort. On coronary angiography, subtotal occlusion in the mid-right coronary artery (RCA) and 60 % tubular stenosis in the distal RCA were revealed. Two intracoronary stents could be placed in the RCA without any difficulty. However, the guidewire could not be removed. The intraoperative finding showed that the guidewire had become entrapped in the coronary stent. The guidewire was successfully removed and emergency coronary bypass grafting was performed.     

Temporary endosonography-guided biliary drainage for transgastrointestinal deployment of a self-expandable metallic stent

Endosonography-guided biliary drainage (ESBD) is now gaining acceptance as a useful alternative for the management of obstructive jaundice.(1) At present, ESBD is used mainly to establish an anastomosis between the biliary tree and the duodenum, stomach, jejunum, or esophagus by placing a stent so as to bridge the bile duct and alimentary tract. We herein report a new application of ESBD, that is, its temporary use for gaining access to the bile duct in order to deploy a self-expandable metallic stent (SEMS) via the transhepatic route. In a patient with pylorus stenosis due to advanced gastric cancer with extrahepatic bile duct obstruction caused by nodal metastasis, a plastic stent was placed temporarily by ESBD to bridge the esophagus and the left hepatic duct. Ten days later, the stent was retrieved, leaving a guidewire in the bile duct, and a delivery unit of a SEMS was introduced into the bile duct over the guidewire via the sinus tract. The SEMS was then successfully deployed through the stenosis. No stent was left in the sinus tract. This procedure yields a mature fistula through which a delivery unit can be safely introduced into the bile duct followed by uneventful deployment of a SEMS.     

Ping-pong snaring of a totally dislodged stent across left main ostium: “All is not lost”

Undeployed stent loss is a rare but potentially serious complication of percutaneous coronary intervention. Its management is not assisted by well-defined guidelines, and it is made even more difficult when the dislodged stent is not protected by in situ guidewire. In this work, we present the case of a total stent loss with a crushed device protruding out of the left main. In this hopeless circumstance, an innovative ping-pong technique was used to contralaterally perform a successful stent retrieval.     

Dislodged stent: a simple retrieval technique.

We report a technique for retrieval of a dislodged coronary stent using a stiff angioplasty wire positioned beside the initial stent guidewire. This two-wire technique provides a better platform to move and position the snare device without moving the dislodged stent and thus lessens the risk of embolization. If a larger femoral sheath is needed for stent removal, this method facilitates sheath exchange. Cathet. Cardiovasc. Intervent. 47:323-324, 1999.     

Side-strut stenting technique for the treatment of aorto-ostial in-stent restenosis and deformed stent struts

Percutaneous coronary intervention for the treatment of aorto-ostial in-stent restenosis poses unique technical challenges not offered by other lesion subtypes. These difficulties are further enhanced when encountered with a case of deformed stent struts preventing coaxial guiding catheter engagement and introduction of guidewire through the true stent lumen. In this report, we describe a method of stenting through stent struts side-strut stenting for treating aorto-ostial in-stent restenosis associated with deformed stent struts resulting in good long-term outcome.     

Migration of the AVE micro coronary stent

The AVE Micro coronary stent is a balloon-expandable stent with a design that is different from the commonly used slotted tubular or coil stents. The stent delivery system is low in profile and very trackable so that it can negotiate tortuous vessels to reach distal lesions. It also can pass through proximally deployed stents easily. Its moderate radioopacity allows precise stent placement. However, as illustrated in the three case reports presented here, the stent struts did not seem to be firmly embedded into the arterial wall after initial deployment, so that stent migration occurred during subsequent passage of a balloon into the stent for poststenting high pressure balloon dilatation. This new phenomenon of stent migration has not been reported previously with other stents. © 1996 Wiley-Liss, Inc.     

EUS antegrade pancreatography with gastropancreatic duct stent placement: Review of two cases

BACKGROUND: Endoscopic retrograde pancreatography is an established procedure for palliation of patients with pain caused by chronic pancreatitis associated with pancreatic ductal stricture. Some patients may not be candidates for endoscopic retrograde pancreatography because of surgically altered anatomy. Two cases are presented in which endoscopic retrograde pancreatography was unsuccessful and EUS-guided antegrade pancreatography with gastropancreatic stent placement was performed. METHODS: EUS-guided antegrade pancreatography was performed in both patients by creating a gastropancreatic fistula through which dilation and stent placement were performed over a guidewire. RESULTS: Stent insertion was successful in both cases. Both patients experienced rapid improvement in symptoms. CONCLUSIONS: EUS-guided antegrade pancreatography with stent placement may be an alternative to endoscopic retrograde pancreatography when surgical reconstruction precludes access to the major and minor papillae.     

When a stent gets shorty

• Stent with reduced axial force have an increased risk of longitudinal stent deformation (LSD).
• Deep guidewire catheter intubation after ostial stent deployment or attempting to push a device through an already deployed stent are frequently encountered in patients with LSD.
• Optimization of longitudinal strength along with increasing knowledge of LSD will likely reduce the frequency of this complication.

     

New guide wire technique for stent placement through an occluded self-expandable metal stent: The hairpin technique

BACKGROUND AND AIMS: Self-expandable metal stents (SEMS) for malignant biliary strictures sometimes occlude, requiring the insertion of another stent. When a guide wire is advanced conventionally through the proximal portion of an occluded SEMS, the guide wire sometimes penetrates the stent mesh. The present study reports a new guide wire insertion technique that prevents this problem from occurring. METHODS: In this new method of advancing a guide wire, the tip is not straight but bent into a curve. Because the advancing end of the guidewire is rounded like a hairpin, it cannot penetrate the stent mesh. Before cannulation, the flexible tip of the guide wire is extended out of the tip of the cannula in the descending duodenum and then cannulation is carried out as the flexible tip makes a hairpin curve. The guide wire with a maintained hairpin curve is advanced through the proximal end of the SEMS. The hairpin curve pops open and the guide wire straightens out when the guide wire has passed through the SEMS. After that, a second stent can be inserted over the guide wire. This technique has been utilized 14 times for occluded SEMS in 10 patients between June 2001 and September 2003. RESULTS: In all patients the technique served to ensure access to the biliary tree and successful placement of a second stent. CONCLUSIONS: This new hairpin guide wire technique was effective in preventing the guide wire from penetrating the stent mesh and, therefore contributed to successful stent placement within occluded SEMS.     

Intravascular ultrasound in the management of acute coronary artery dissection: A case report

Crossing total occlusions is frequently difficult. The guidewire may enter a false lumen, thereby preventing successful balloon dilatations. We present a case of an acute arterial dissection following attempted angioplasty of a totally occluded right coronary artery. With an intravascular ultrasound probe in the false lumen, we were able to visualize a second guidewire and direct its passage into the true arterial lumen. This allowed for successful balloon dilatation and stent deployment restoring vessel patency.     

Double-wire technique for access into a protruding aorto-ostial stent for treatment of in-stent restenosis.

We report a case of restenosis following ostial stenting of the right coronary artery with protrusion of the stent into the aorta. Treatment was only possible after a guidewire advanced through a lower strut was used to lever the guide, and a second guidewire was advanced through the true lumen.