Stent Misplacement Research Articles

Metallic Full-Length Ureteral Stents: Does Urinary Tract Infection Cause Obstruction?

Metallic ureteral stents promise to offer superior upper urinary tract drainage with extended exchange intervals and freedom from extrinsic compression in patients with advanced malignancy or other significant obstructing retroperitoneal or pelvic processes. Existing literature indicates a variable experience with these relatively new devices, with some investigators reporting excellent results and long problem-free intervals, and others reporting less enthusiastic outcomes. We report a retrospective review of a series of five sequential patients undergoing placement of Resonance® (Cook Medical, Bloomington, IN) metallic ureteral stents for extrinsic ureteral compression refractory to placement of traditional (polymer) ureteral stents. Of five patients reviewed, three (60%) required additional operative intervention for stent migration or malposition. Four patients (80%) died of their primary malignancy <12 months after metallic stent placement. Four (80%) of five patients had obstruction of their stents demonstrated with nuclear renography and/or other imaging, and three (60%) required removal and alternative means of urinary tract drainage within 4 months of placement due to obstruction, intractable pain, or migration. Four patients (80%) had urinary tract infections (UTIs) within 4 months of stent placement. No obstruction was seen due to extrinsic ureteral compression after stent placement. Metallic ureteral stents may have utility for patients with pathological processes causing extrinsic ureteral compression refractory to the use of traditional polymer ureteral stents. However, metallic ureteral stents are not immune to obstruction, migration, and associated discomfort. Stent obstruction appears to be increased in patients with postoperative UTI.

Coexistent Primary Open-Angle Glaucoma and Cataract: Interim Analysis of a Trabecular Micro-Bypass Stent and Concurrent Cataract Surgery

To evaluate the safety and efficacy of the iStent Trabecular Micro-bypass Stent in patients undergoing concurrent cataract and glaucoma surgery. Prospective, 24-month, uncontrolled, multicenter, multicountry evaluation of 58 patients with uncontrolled primary open-angle glaucoma (including pseudoexfoliation and pigmentary) and cataract. Patients underwent clear cornea phacoemulsification followed by ab interno gonioscopically guided implantation of the iStent. Of the 48 per protocol population, 42 patients completed 12 months of the 24-month study, and their data are included in this interim analysis. At baseline, mean (+/-SD) intraocular pressure (IOP) was 21.7+/-3.98 mmHg. At 12 months, mean IOP was reduced to 17.4+/-2.99 mmHg, a mean IOP reduction of 4.4+/-4.54 mmHg (p<0.001, 18.3%). At baseline, patients were taking a mean 1.6+/-0.8 medications. By 12 months, the mean number of medications was reduced to 0.4+/-0.62 (p<0.001). Half the patients achieved an IOP < or =18 mmHg and were able to discontinue hypotensive medication by the 12-month visit. The most commonly reported device-related adverse events were the appearance of stent lumen obstruction (7 eyes) and stent malposition (6 eyes). None of the adverse events were deemed serious. In patients undergoing concurrent cataract and glaucoma surgery, the iStent was safe and efficacious for the reduction of IOP and medication therapy.

Self-Expanding Nitinol Stent Implantation for Treatment of Aortic Coarctation

To prospectively assess the efficacy of self-expanding nitinol aortic stents in the treatment of coarctation of the aorta (CoA). Between July 2005 and July 2008, 21 patients (14 men; mean age 19.2+/-5.5 years, range 11-34) with CoA were treated with self-expanding Sinus-Aorta stents. The predilation balloon was selected to be <5 times the stenosis diameter. The stent diameter was selected to be 20% to 30% greater than the diameter of the undiseased aorta at the level of the diaphragm. All procedures were successfully performed without any major complications. Predilation (mean balloon diameter 12.3 mm) and postdilation (mean balloon diameter 15.4 mm) were performed in 12 and 14 procedures, respectively. The mean diameter of the stents was 21.6+/-2.3 mm (range 18-26). The mean peak transcoarctation pressure gradient decreased from 57.4+/-19.5 mmHg (range 30-100) before the procedure to 1.2+/-2.2 mmHg (range 0-7; p<0.001). Cephalad stent dislodgement with the first-generation device occurred in 3 of 12 patients; 2 were treated with a second stent overlapping the first, and the third received 3 overlapped stents after the second stent migrated distally. No stent dislodgement occurred in the subsequent 9 patients treated with longer second-generation stents with anti-jump markers. None of the patients had dissection, arterial rupture, or other complications. On follow-up, 1 (5%) patient had recoarctation and minor stent migration after 18 months; another stent was deployed successfully. No evidence of aneurysm formation was seen in 7 patients undergoing arch imaging. CoA can be successfully and safely managed with self-expanding nitinol aortic stents without aortic wall complications. Stent malpositioning can be overcome using oversized stents with anti-jump markers.

Preliminary Results from a Multicenter, European, Prospective Evaluation of the New, Double Flare, Duodenal Evolution Stent

Background: Malignant gastric outlet obstruction is a secondary complication of cancers in an advanced state. Palliation of the symptoms is the primary aim of the treatment in these patients. Enteral stent have recently emerged as a safe and effective alternative to surgery in patients with gastric outlet obstruction. Aims: to evaluate, in a prospective multicenter european study, the safety and the short-term clinical success of a new enteral, nitinol stent with flares at proximal and distal ends (Evolution Duodenal, Cook Medical, Winston Salem, NC, USA). Patients and Methods: From September 2008 to November 2008, 23 consecutive patients (12 men; mean age 67.2 years, range 51-78) presenting with symptoms of gastric outlet obstruction due to a malignant stricture of the distal stomach or duodenum were enrolled into the study. Evolution stents were deployed under fluoroscopic and endoscopic control. Prospective data were collected through a dedicated Case Report Form. The gastric outlet obstruction scoring system (GOOSS) was used to grade the patients' ability to eat. Results: A total of 26 enteral stents were placed in 23 patients. Etiology of the stricture was: pancreatic cancer in 14 (60.8%), gastric cancer in 7 (30.4%), ampullary cancer in 1 (4.3%) and primary duodenal cancer in 1. The site of obstruction was pyloric-duodenal in 7 pts (30.4%), duodenal bulb in 6 (26%), second portion of duodenum in 2 (8.6%), third portion of duodenum in 3 (13%), second and third portion in 5 (21.7%). The median length of the stricture was 5.8+1.88 cm. Mean duration of procedure was 30+8.60 minutes. Stent misplacement occurred in 2 patients (8.6%) who were successfully treated by placement of a second stent. In 13 patients the proximal end of the stent extended proximal to the pylorus while in 10 the whole stent was opening with both ends in different portions of the duodenum. No early (within 7 days) or late complications were recorded after a median follow-up of 8.8 weeks (range 2-12 weeks). Twenty-one patients (91.3%) were able to tolerate oral intake with a significant improvement of GOSS score (from 0.8+0.26 to 2.6+0.44). One patient with no symptomatic relief underwent gastrojejunostomy 3 weeks after stenting. Two patients died during follow-up period due to disease progression. Conclusions: The new, double flared Evolution duodenal stent provided in this preliminary evaluation a safe and effective palliation of malignant gastric outlet obstruction. A larger study with longer follow-up is required to confirm these promising preliminary results.

Retrieval of a Misplaced Double-J Ureteral Stent in the Renal Pelvis

Double-J ureteral stents are widely used in endourologic surgery. To insert a ureteral stent is usually a simple and uncomplicated task. However, the stent can be misplaced when a surgeon advances it too far up the ureter. We report a novel technique to remove a misplaced stent in the renal pelvis.

Editorial Comment

Pyeloplasty, a common procedure for the pediatric urologist, has evolved from a procedure that was performed uniformly as an open technique to an operation that is now commonly performed laparoscopically. Stenting after pyeloplasty has been a debatable issue for the open and laparoscopic techniques. Traditionally, the definitive method to confirm proper intraoperative antegrade placement of a double-J stent within the bladder has been fluoroscopic assistance. Of course, this exposes the patient to radiation, which is of a greater concern in the child and adolescent than in the adult. A simple alternative method is the instillation of either methylthioninium chloride or indigo carmine into the bladder and then visualization of the refluxed colored fluid from the proximal end of the stent before closure of the upper urinary tract. One of the limitations of this technique is the discoloration of the tissue, which can be problematic when closing the upper tract. ReplyUrologyVol. 73Issue 2PreviewWe appreciate the reviewer's comments and agree that urologists should be quite facile at ultrasonography because we review ultrasound scans daily. A portable ultrasound device allows for immediate intraoperative evaluation of stent placement by the surgeon, enabling correction of a malpositioned stent so that each patient leaves the operating room with a radiographically confirmed well-positioned stent. These adjuncts improve efficiency, procedural time, and, most importantly, patient outcomes. Full-Text PDF Intraoperative Ultrasound: Application in Pediatric PyeloplastyUrologyVol. 73Issue 2PreviewTo describe a simple method of using a readily available portable ultrasound device to confirm distal stent placement for antegrade placed stents. Antegrade placement of internal double-J ureteral stents during open or laparoscopic pyeloplasty has become an alternative to retrograde placement but might be less reliable owing to the lack of confirmation of the distal stent position. Full-Text PDF

Reply

We appreciate the reviewer's comments and agree that urologists should be quite facile at ultrasonography because we review ultrasound scans daily. A portable ultrasound device allows for immediate intraoperative evaluation of stent placement by the surgeon, enabling correction of a malpositioned stent so that each patient leaves the operating room with a radiographically confirmed well-positioned stent. These adjuncts improve efficiency, procedural time, and, most importantly, patient outcomes. We have not used ultrasonography for tapered reimplants, but we welcome the suggestion and will use it in the future. Editorial CommentUrologyVol. 73Issue 2PreviewPyeloplasty, a common procedure for the pediatric urologist, has evolved from a procedure that was performed uniformly as an open technique to an operation that is now commonly performed laparoscopically. Stenting after pyeloplasty has been a debatable issue for the open and laparoscopic techniques. Traditionally, the definitive method to confirm proper intraoperative antegrade placement of a double-J stent within the bladder has been fluoroscopic assistance. Of course, this exposes the patient to radiation, which is of a greater concern in the child and adolescent than in the adult. Full-Text PDF Intraoperative Ultrasound: Application in Pediatric PyeloplastyUrologyVol. 73Issue 2PreviewTo describe a simple method of using a readily available portable ultrasound device to confirm distal stent placement for antegrade placed stents. Antegrade placement of internal double-J ureteral stents during open or laparoscopic pyeloplasty has become an alternative to retrograde placement but might be less reliable owing to the lack of confirmation of the distal stent position. Full-Text PDF

Balloon-Expandable Covered Stent Therapy of Complex Endovascular Pathology

The current study was designed to investigate our hypotheses that balloon-expandable covered stents display acceptable function over longitudinal follow-up in patients with complex vascular pathology and provide a suitable alternative for the treatment of recurrent in-stent restenosis. All stents were Atrium iCast, which is a balloon-mounted, polytetrafluoroethylene-covered stent with a 6F/7F delivery system. A retrospective review was performed of 49 patients with 66 stented lesions. Data were analyzed with life tables and t-tests. The most commonly treated vessels were the iliac (61%) and renal (24%) arteries. Indications for covered stent placement were unstable atheromatous lesions (50%), recurrent in-stent restenosis (24%), aneurysm (8%), aortic bifurcation reconstruction (7.5%), dissection (4.5%), endovascular aneurysm repair-related (4.5%), and stent fracture (1.5%). Patency was assessed by angiogram or duplex ultrasonography. The primary end point was patency and secondary end points were technical success and access-site complications. Mean follow-up was 13 months (range 1.5-25). The technical success rate was 97%. Unsuccessful outcomes were due to deployment error (n=1) and stent malpositioning (n=1). The cohort (n=64) 6- and 12-month primary patency rates were 96% and 84%, respectively. Twelve-month assisted primary patency was 98%. Iliac artery stents (n=38) had a primary patency of 97% at 6 months and 84% at 12 months with an assisted primary patency of 100% at 12 months. Renal artery stents (n=16) had a primary patency of 92% at 6 months and 72% at 12 months with an assisted primary patency of 92% at 6 and 12 months. Stents placed for recurrent in-stent restenosis (n=16) had a primary patency of 85%, assisted primary patency of 93%, and a 15% restenosis rate at 12 months. Specifically, stents placed for renal artery recurrent in-stent restenosis (n=10) had a primary patency of 73%, assisted primary patency of 82%, and a restenosis rate of 27%. The restenosis rate included two renal artery occlusions in patients noncompliant with clopidogrel use and resulted in ipsilateral kidney loss in both patients. In-stent peak systolic velocities decreased significantly (p<0.05) from preoperation to 12 months in iliac stents and to 18 months in renal stents. Ankle-brachial index increased significantly in iliac stents from preoperation (0.62+/-0.18) to 18 months (0.86+/-0.16). Successful exclusion of atheromatous lesions and aneurysm/dissection/endoleak was 100%. Access-site complications occurred in 6%: pseudoaneurysm (n=2), dissection (n=1), and bleeding (n=1). Balloon-expandable covered stents have an acceptable primary patency with an excellent assisted patency after salvage angioplasty. The clinical utility of this technology is broad for the treatment of aneurysms, extravasation, unstable atheromatous lesions, and recurrent in-stent restenosis.

Early posttransplant hepatic venous outflow obstruction: Long-term efficacy of primary stent placement

Although balloon angioplasty has been accepted as the safe and effective initial treatment to manage hepatic venous outflow abnormalities, it may induce rupture of the fresh anastomosis but also may be ineffective to eliminate various etiologies of venous outflow abnormalities in the early post-transplant period. Therefore, we performed primary stent placement in 108 patients to treat early-onset (</=4 weeks) post-transplant hepatic venous outflow abnormality. The following parameters were documented retrospectively: technical success and complications: clinical success; recurrence; and patency of stent-inserted hepatic veins.Technical success was achieved in 166 (97.6%) of 170 anastomoses (107 patients). Major complications occurred in 5 (4.6%) patients: partial stent migration (n = 2) and stent malposition (n = 3). Clinical success was achieved in 83 (82.2%) of 101 patients who had abnormal liver enzymes or clinical symptoms. Seven patients without initial clinical symptoms have remained healthy. Restenosis or occlusion of the stent-inserted hepatic veins was documented in 22 patients at a mean of 9.6 +/- 8.6 months after stent placement. Four of them underwent stent replacement or retransplantation due to liver function deterioration. Overall 1-, 3-, and 5-year primary patency rates were 82.3 +/- 0.3%, 75.0 +/- 0.4%, and 72.4 +/- 0.5%, respectively. Multivariate Cox regression analysis showed that diameter of stents was an independent factor associated with patency of stents (p = 0.001).Primary stent placement seems to be an effective treatment modality with an acceptable long-term patency to treat early post-transplant hepatic venous outflow obstruction.

Endoscopic management of pancreatic fistula after distal pancreatectomy and enucleation

Background Preoperative endoscopic pancreatic sphincterotomy (EPS) has been proposed to prevent postoperative pancreatic fistula (POPF) after distal pancreatectomy (DP) or enucleation (EN). The use of EPS as a curative treatment for POPF has been scarcely reported. We reported 10 consecutive patients who were successfully treated by EPS for a prolonged POPF. Study design Ten patients underwent EPS for prolonged POPF (median duration = 40 days, range 20–114; median daily output = 80 mL, range 50–250) after 6 DPs, 2 ENs, and 2 medial pancreatectomies. Results EPS was performed in all patients, with stent insertion in 4. No patient developed a specific complication because of EPS. POPF healed within a median delay of 4 days (range 1–12). One patient underwent a repeated endoscopy to treat stent malposition. The median delay of discharge after EPS was 13 days (range 8–15). With a 20-month median follow up, 1 patient developed early transient POPF recurrence because of spontaneous stent migration. Conclusions EPS is indicated for prolonged POPF after DP or EN because it is highly feasible, shortens healing, and is well tolerated.

A technique for increased accuracy in the placement of the “giant” Palmaz stent for treatment of type IA endoleak after endovascular abdominal aneurysm repair

We report a deployment technique that eliminates "watermelon seeding" of the "giant" Palmaz stent in the treatment of type IA endoleak after endovascular abdominal aneurysm repair. A 5010 Palmaz stent (Cordis Corp, Miami Lakes, Fla) is asymmetrically hand-crimped on an appropriately sized valvuloplasty balloon that assures that the proximal (cranial) aspect will deploy first. A long 16 to 20F sheath is placed distal to the target area. Once the balloon and stent assembly is in position, the sheath is partially retracted to allow only the proximal (cranial) half of the balloon to expand, flaring the unsheathed proximal stent. The expanded proximal balloon prevents cranial stent migration. The sheath prevents distal (caudal) stent migration. Full retraction of the sheath allows the distal balloon and stent to expand, completing the stent deployment.

Endotracheal Stent Granulation Stenosis Resolution after Colchicine Therapy in a Dog

Endotracheal Stent Granulation Stenosis Resolution after Colchicine Therapy in a Dog

Percutaneous Coronary Interventions without On-Site Cardiac Surgery: A Remote Australian Experience

The current American College of Cardiology (ACC) guidelines recommend that elective percutaneous coronary interventions (PCI) should not be performed in institutions without on-site cardiac surgery. We sought to determine the safety of PCI without cardiac surgical support on-site and specifically the safety of complex elective procedures. The results of the first 1000 procedures performed at our institution, which is a rural centre 80 km from the nearest cardiac surgical facility, are reported. Between September 2002 and April 2006 a total of 1000 procedures were performed in 893 patients at our institution. Patients included both high and low risk cohorts. Clinical and procedural outcomes were recorded and analysed. Of the 921 elective and 79 emergency primary PCI procedures performed, 1138 vessels were treated and 1429 stents deployed. A 95% procedural success rate was recorded. Complex PCI was performed with multi-vessel PCI in 13%, bifurcation PCI in 8%, chronic total occlusions (CTO) in 5%, saphenous vein graft interventions in 5%, unprotected left main interventions in 0.8% and rotational atherectomy in 0.8% of all procedures performed. Of the cohort, 75.3% of the lesions treated were either American College of Cardiology (ACC)/American Heart Association (AHA) type B or C lesions. In the primary PCI group, three deaths and three sub-acute stent occlusions occurred. In the elective group, the following major complications occurred: one death, three sub-acute stent occlusions, one case of contrast nephropathy requiring short-term dialysis, two cases of cardiac tamponade, two significant femoral pseudo-aneurysms and one misplaced stent. Acute myocardial infarction occurred in 21 patients. There were no urgent transfers for CABG surgery to salvage a complication of PCI. PCI including high risk elective procedures can safely be performed without on-site cardiac surgery by experienced high volume operators.

Comparison of Wallstent and Ultraflex stents for palliation of malignant left-sided colon obstruction: a retrospective, case-matched analysis

Self-expandable metal stents (SEMSs) are accepted palliation for malignant colon obstruction. Outcomes of different stent types is unknown. Our purpose was to compare outcomes after palliative placement of the Enteral Wallstent (EW) and the Precision Colonic Ultraflex (PCU) stent. Retrospective study of all SEMS placement during a 7-year period. Tertiary care academic medical center. Malignant left-sided colon obstruction in which through-the-scope (TTS) or non-TTS stent placement was possible. Technical and clinical success rates, stent-related complications, reintervention. Demographics, degree, site, and cause of obstruction were comparable. Technical difficulties were more frequent with EW than PCU (16% vs 9%, P not significant), insufficient stent expansion and stent misplacement being most common. Relief of obstruction occurred in all patients when placement was technically successful. Mean follow-up was 93 days (range 7-691 days). Early (<7 days) stent occlusion (6% vs 0%, P not significant) and migration (4% vs 0%, P not significant) occurred more frequently in the EW group. Self-limited hematochezia was more common with PCU (20% vs 2%, P = .002). Delayed complications (perforation, stent occlusion, migration, and erosion) occurred significantly more often in the EW group (38% vs 20%). Reintervention was needed more frequently for EW, endoscopic (40% vs 17%, P = .01) and operative (46% vs 26%, P = .03). Enteral Wallstents and Precision Ultraflex Colonic stents adequately relieve colonic obstruction. Stent dysfunction, stent-related complications, and need for reintervention are higher after EW placement. Precision Colonic Ultraflex stents appear better suited for palliation of left-sided malignant colon obstruction.

Application of self-expanding enteral metal stents for the palliative treatment of malignant gastrointestinal obstructions

Introduction: Self-expanding metal stents (SEMSs) are currnetly the best treatment for inoperable and lumen obstructive cancers of the GI tract. Although this type of endoscopic therapy is not reimbursed in Hungary, we had the privilege (thanks to OMCH) to apply these stents in all current indications to the benefit of our patients. The aims of our current study were to summarise our initial experience with enteral stenting and to assess the outcome and complications of this procedure. Methods: In the period from November 2005 to January 2007 we deployed 26 enteral SEMSs in 22 patients. All procedures were performed in the fluoroscopy/ERCP unit. After positioning the endoscope above stricture, we first localize the extent of the stricture by contrast filling. Then a guide-wire positioned over the stricture that was followed by fluoroscopy. Finally the SEMS was pushed over the wire through the stricture, and the opening was monitored with fluoroscopy and sometimes also with endoscopy too. Endoscopic follow-up procedures were performed 3 days later and we routinely entering and passing the stent inside to check the complete opening and the optimal position. Results: 21 patients had malignant and 1 patient had benign stricture. Out of 26 stenting procedure, 20 esophageal, 3 colorectal, 1 gastric, 1 duodenal and 1 oesophago-jejunal SEMS application were completed. The mean age was 67 years (35–86), with a male vs. female ratio of 2,6:1. Mean length of patient survival was 120 days (4 months) and 12 patients are still alive. The primary technical success rate was 18/22 (81%), failure was due to early stent migration and malposition (in proximal esophageal tumors) in 2–2 patients. No early complication occurred. Late complications were tumor expansion (2), stent fracture (1), and tracheomalatia (1). Conclusion: SEMS application is a relatively easy, safe and definitive therapy of patients with malignant GI obstruction. In comparison to palliative surgery SEMSs are more cost effective and less invasive, therefore it must be supported by the health care financial system.

Influence of a Paclitaxel-Eluting Covered Metallic Stent On Tissue Hyperplasia: An Experimental Study in a Canine Biliary Model

Aim: The aim was to evaluate safety of a paclitaxel-eluting covered metallic stent in a canine biliary model by comparing histologic tissue reaction. Methods: Six paclitaxel-eluting covered metallic stents were endoscopically placed in the bile ducts of six mongrel dogs, and five covered metallic stents were placed in five dogs as controls. The dogs were sacrificed at six weeks after stent placement and gross and histopathologic examinations were done. Degree of inflammation was graded as follows: 0, none; 1, mild; 2, moderate; 3, severe. Results: All 11 dogs survived until the sacrifice without evidence of jaundice. All the stents except for two drug-eluting stents were placed within the canine bile duct successfully. Two malpositioned stents were excluded from histologic analysis. There was no migration or perforation. In the control stent group, there was no tissue ingrowth. Both proximal and distal ends of all the control stents showed minimal tissue overgrowth except for distal end obstruction in one and 20% narrowing of proximal end in another. In the drug-eluting stent group, tissue ingrowth was found in three animals. Two were malpositioned stents. Minimal tissue overgrowth was noted in both ends of three animals. One dog without malpositioned stent showed ingrowth at both ends. Microscopic examination demonstrated increased thickness of epithelial layers in middle and distal ends of canine bile ducts in contact with drug-eluting stents (575.00 ± 301.39 μm vs. 180.00 ± 109.55 μm, P = 0.022; 1150.00 ± 100.00 μm vs. 430.00 ± 323.27 μm, P = 0.012, respectively). Proximal ends of bile ducts showed no significant difference in thickness of epithelial layers, but there was tendency for increased thickness in the drug-eluting stent group (800.00 ± 282.84 μm vs. 530.00 ± 272.95 μm, P = 0.260). Canine bile duct in contact with drug-eluting stents showed less severe inflammatory reaction in the proximal and distal ends (2 vs. 2.80 ± 0.45, P = 0.024; 1.50 ± 0.58 vs. 2.60 ± 0.55, P = 0.036, respectively). In the middle of canine bile duct in contact with drug-eluting stents, there was tendency for less severe inflammation although not statistically significant (1.50 ± 1.00 vs. 1.80 ± 0.84, P = 0.498). Conclusion: Placement of paclitaxel-eluting covered metallic stents in normal canine bile duct was without significant complications despite significant histologic changes from local drug delivery. The results provide a basis for extending the use of a paclitaxel-eluting covered metallic stent in clinical trials. Further studies in patients with malignant biliary obstruction are needed to establish the role of this stent in the palliation of obstructive jaundice.

Carotid Stent Failure: Results of Surgical Rescue

Little data is available on surgical "rescue" of failed carotid stents (CAS). We have analyzed a series of CAS failures treated by conventional open surgery. Five patients underwent surgery after CAS failure, either electively (4) or as an emergency (1). Elective surgical "rescue" was for stent restenosis (2 cases) or stent misplacement (2 cases). Emergency surgery was performed for entrapment of the protection system in the stent. Surgical rescue was accomplished by perimedial endarterectomy and "en bloc" plaque and stent extraction in 3 cases, and by vein bypass in 2 cases, with no neurological complications. Surgical rescue of failed CAS is effective.

Endovascular Stenting of Obstructed Right Ventricle–to–Pulmonary Artery Conduits

The optimal treatment for dysfunctional right ventricle-to-pulmonary artery (RV-PA) conduits is unknown. Limited follow-up data on stenting of RV-PA conduits have been reported. Between 1990 and 2004, deployment of balloon-expandable bare stents was attempted in 242 obstructed RV-PA conduits in 221 patients (median age, 6.7 years). Acute hemodynamic changes after stenting included significantly decreased RV systolic pressure (89+/-18 to 65+/-20 mm Hg, P<0.001) and peak RV-PA gradient (59+/-19 to 27+/-14 mm Hg, P<0.001). There were no deaths, and, aside from 5 malpositioned stents requiring surgical removal, there were no serious procedural complications. During follow-up of 4.0+/-3.2 years, 9 patients died and 2 underwent heart transplantation, none related to catheterization or stent malfunction. During 155 follow-up catheterizations in 126 patients, the stent was redilated in 83 patients and additional stents were placed in 41. Stent fractures were diagnosed in 56 patients (43%) and associated with stent compression and substernal location but did not cause acute hemodynamic consequences. By Kaplan-Meier analysis, median freedom from conduit surgery after stenting was 2.7 years (3.9 years in patients >5 years), with younger age, homograft conduit, conduit diameter < or =10 mm, diagnosis other than tetralogy of Fallot, Genesis stent, higher prestent RV:aortic pressure ratio, and stent malposition associated with shorter freedom from surgery. Tricuspid regurgitation and RV function did not change between stent implantation and subsequent surgery. Conduit stenting is an effective interim treatment for RV-PA conduit obstruction and prolongs conduit lifespan in most patients. Stent fractures were common but not associated with significant complications or earlier conduit reoperation.

Early complications of stenting in patients with congenital heart disease: a multicentre study

Stenting has become an established interventional cardiology procedure for congenital heart disease. Although most stent procedures are completed successfully, complications may occur. This multicentre study evaluated early complications after stenting in patients with congenital heart disease, including potential risk factors. In this combined Dutch-Belgian retrospective study, 309 consecutive patients had undergone 366 catheterizations and received 464 stents in 13 different anatomical positions (418 sites). Seventy-two stenting-related complications (19%) occurred, of which 24 (5.7%) were major. Seven procedure-related deaths were documented (2.3%). Stent malpositioning and embolization were most common (7.7%). The use of non-premounted stents tended to be associated with higher complication rates. Centre inexperience with stenting and stenting of native vs. post-surgical stenosis tended to be associated with increased major complication rates. After stenting, complications are common for congenital heart disease. The vast diversity of stenotic sites combined with relatively small patient populations makes these procedures sensitive to complications. Combining operator experience may reduce the risks of stenting in congenital heart disease. The availability of premounted stents for greater vessel diameters will likely reduce incidences of stent migration and embolization.

Comparison of drug-eluting stent and bare-mental stent in the complex small vessel intervention

现在，冠的干预戏剧性地在 thedrug-eluting stent 时代被改进了。drug-eluting stent 代表它显著地减少的主导的经皮的冠的干预形式 beacause 剩余的合并率与赤裸的心理 stent 相比。如此的利益开始在冠的容器被表明在直径的 3 公里或更多。然而，在冠的 stent 培植以后的休息合并被容器尺寸和长度影响， ands 帐篷吸藏在小容器是更经常的。在 coronarys tenting 以后的休息合并的主要原因是从光滑肌肉的房间以及细胞外的矩阵生产的增长和迁居的 neointimal 增生。很多全身的 pharmacologic 和附属 device-basedapproaches 在进一步在小型机关枪的一种以后降低休息合并的风险是无效的叮当响。最新，打断细胞的复制的代理人的地点特定的交货在禁止 neointimal 增生显示出大诺言。特别地，基于聚合物， sirolimus-eluting andpaclitaxels-eluting stent 证明了在在本国的冠的动脉的以前未经治疗的损害减少休息合并的风险安全、有效。但是小容器和复杂损害干预仍然是争论的。这研究是在小容器(直径 <3 公里) 在复杂损害评估 drug-elutingstent 的申请。