Self-expanding metallic stents drainage for acute proximal colon obstruction

AIM: To clarify the usefulness of the self-expanding metallic stents (SEMS) in the management of acute proximal colon obstruction due to colon carcinoma before curative surgery.METHODS: Eighty-one colon (proximal to spleen flex) carcinoma patients (47 males and 34 females,aged 18-94 years,mean = 66.2 years) treated between September 2004 and June 2010 for acute colon obstruction were enrolled to this study,and their clinical and radiological features were reviewed.After a cleaning enema was administered,urgent colonoscopy was performed.Subsequently,endoscopic decompression using SEMS placement was attempted.RESULTS: Endoscopic decompression using SEMS placement was technically successful in 78 (96.3%) of 81 patients.Three patients’ symptoms could not be relieved after SEMS placement and emergent operation was performed 1 d later.The site of obstruction was transverse colon in 18 patients,the hepatic flex in 42,and the ascending colon in 21.Following adequate cleansing of the colon,patients’ abdominal girth was decreased from 88 ± 3 cm before drainage to 72 ± 6 cm 7 d later,and one-stage surgery after 8 ± 1 d (range,7-10 d) was performed.No anastomotic leakage or postoperative stenosis occurred after operation.CONCLUSION: SEMS placement is effective and safe in the management of acute proximal colon obstruction due to colon carcinoma,and is considered as a bridged method before curative surgery.

Drug-eluting fully covered self-expanding metal stent for dissolution of bile duct stones in vitro

BACKGROUND The treatment of difficult common bile duct stones(CBDS)remains a big challenge around the world.Biliary stenting is a widely accepted rescue method in patients with failed stone extraction under endoscopic retrograde cholangiopancreatography.Fully covered self-expanding metal stent(FCSEMS)has gained increasing attention in the management of difficult CBDS.AIM To manufacture a drug-eluting FCSEMS,which can achieve controlled release of stone-dissolving agents and speed up the dissolution of CBDS.METHODS Customized covered nitinol stents were adopted.Sodium cholate(SC)and disodium ethylene diamine tetraacetic acid(EDTA disodium,EDTA for short)were used as stone-dissolving agents.Three different types of drug-eluting stents were manufactured by dip coating(Stent I),coaxial electrospinning(Stent II),and dip coating combined with electrospinning(Stent III),respectively.The drugrelease behavior and stone-dissolving efficacy of these stents were evaluated in vitro to sort out the best manufacturing method.And the selected stonedissolving stents were further put into porcine CBD to evaluate their biosecurity.RESULTS Stent I and Stent II had obvious burst release of drugs in the first 5 d while Stent III presented controlled and sustainable drug release for 30 d.In still buffer,the final stone mass-loss rate of each group was 5.19%±0.69%for naked FCSEMS,20.37%±2.13%for Stent I,24.57%±1.45%for Stent II,and 33.72%±0.67%for Stent III.In flowing bile,the final stone mass-loss rate of each group was 5.87%±0.25%for naked FCSEMS,6.36%±0.48%for Stent I,6.38%±0.37%for Stent II,and 8.15%±0.27%for Stent III.Stent III caused the most stone mass-loss no matter in still buffer or in flowing bile,which was significantly higher than those of other groups(P<0.05).In vivo,Stent III made no difference from naked FCSEMS in serological analysis(P>0.05)and histopathological examination(P>0.05).CONCLUSION The novel SC and EDTA-eluting FCSEMS is efficient in diminishing CBDS in vitro.When conventional endoscopic techniques fail to remove difficult CBDS,SC and EDTA-eluting FCSEMS implantation may be considered a promising alternative.

Temporary self-expanding metallic stents for achalasia: A prospective study with a long-term follow-up

AIM: To compare the efficacy of self-expanding metallic stents (SEMSs) for the long-term clinical treatment of achalasia. METHODS: Ninety achalasic patients were treated with a temporary SEMS with a diameter of 20 mm (n = 30, group A), 25 mm (n = 30, group B) or 30 mm (n = 30, group C). Data on clinical symptoms, complications and treatment outcomes were collected, and follow-up was made at 6 mo and at 1, 3-5, 5-8, 8-10 and > 10 years, postoperatively.RESULTS: Stent placement was successful in all patients. Although chest pain occurrence was high, stent migration was less in group C than in groups A and B. The clinical remission rate at 5-8, 8-10 and > 10 years in group C was higher than that in the other two groups. The treatment failure rate was lower in group C (13%) than in groups A (53%) and B (27%). SEMSs in group C resulted in reduced dysphagia scores and lowered esophageal sphincter pressures, as well as normal levels of barium height and width during all the follow-up time periods. Conversely, these parameters increased over time in groups A and B. The primary patency in group C was longer than in groups A and B. CONCLUSION: A temporary SEMS with a diameter of 30 mm is associated with a superior long-term clinical efficacy in the treatment of achalasia compared with a SEMS with a diameter of 20 mm or 25 mm.

A temporary self-expanding metallic stent for malignant colorectal obstruction

AIM:To investigate the clinical safety and efficacy of a temporary self-expanding metallic stent(SEMS) for malignant colorectal obstruction.METHODS:From September 2007 to June 2012,33 patients with malignant colorectal obstruction were treated with a temporary SEMS.The stent had a tubular configuration with a retrieval lasso attached inside the proximal end of the stent to facilitate its removal.The SEMS was removed one week after placement.Clinical examination,abdominal X-ray and a contrast study were prospectively performed and both initial and follow-up data before and at 1 d,1 wk,and 1 mo,3 mo,6 mo and 12 mo after stent placement were obtained.Data collected on the technical and clinical success of the procedures,complications,need for reinsertion and survival were analyzed.RESULTS:Stent placement and removal were technically successful in all patients with no procedurerelated complications.Post-procedural complications included stent migration(n = 2) and anal pain(n = 2).Clinical success was achieved in 31(93.9%) of 33 patients with resolution of bowel obstruction within 3 d of stent removal.Eleven of the 33 patients died 73.81 ± 23.66 d(range 42-121 d) after removal of the stent without colonic re-obstruction.Clinical success was achieved in another 8 patients without symptoms of obstruction during the follow-up period.Reinsertion of the stent was performed in the remaining 12 patients with re-obstruction after 84.33 ± 51.80 d of follow-up.The mean and median periods of relief of obstructive symptoms were 97.25 ± 9.56 d and 105 ± 17.43 d,respectively,using Kaplan-Meier analysis.CONCLUSION:Temporary SEMS is a safe and effective approach in patients with malignant colorectal obstruction due to low complication rates and good medium-term outcomes.

Use of fully covered self-expanding metal stents in benign biliary diseases

Biliary fully covered self-expanding metal stents (FCSEMS) are now being used to treat several benign biliary conditions. Advantages include small predeployment and large postexpansion diameters in addition to an easy insertion technique. Lack of imbedding of the metal into the bile duct wall enables removability. In benign biliary strictures that usually require multiple procedures, despite the substantially higher cost of FCSEMS compared with plastic stents, the use of FCSEMS is offset by the reduced number of endoscopic retrograde cholangiopancreatography interventions required to achieve stricture resolution. In the same way, FCSEMS have also been employed to treat complex bile leaks, perforation and bleeding after endoscopic biliary sphincterotomy and as an aid to maintain permanent drainage tracts obtained by means of Endoscopic Ultrasound-guided biliary drainage. Good success rates have been achieved in all these conditions with an acceptable number of complications. FCSEMS were successfully removed in all patients. Comparative studies of FCSEMS and plastic stents are needed to demonstrate efficacy and cost-effectiveness

Self-expanding metal stents for the palliation of malignant gastric outlet obstruction in patients with peritoneal carcinomatosis

AIM To evaluate the efficacy of self-expanding metal stents(SEMS) for the palliation of malignant gastric outlet obstruction in patients with and without peritoneal carcinomatosis(PC).METHODS We performed a retrospective analysis of 62 patients who underwent SEMS placement for treatment of malignant gastroduodenal obstruction at our hospital over a six-year period. Stents were deployed through the scope under combined fluoroscopic and endoscopic guidance. Technical success was defined as successful stent placement and expansion. Clinical success was defined as an improvement in the obstructive symptoms and discharge from hospital without additional parenteral nutrition. According to carcinomatosis status, patients were assigned into groups with or without evidence of peritoneal disease.RESULTS In most cases, obstruction was caused by pancreatic(47%) or gastric cancer(23%). Technical success was achieved in 96.8%(60/62), clinical success in 79%(49/62) of all patients. Signs of carcinomatosis were identified in 27 patients(43.5%). The diagnosis was confirmed by pathology or previous operation in 7 patients(11.2%) and suspected by CT, MRI or ultrasound in 20 patients(32.2%). Presence of carcinomatosis was associated with a significantly lower clinical success rate compared to patients with no evidence of peritoneal disease(66.7% vs 88.6%, P = 0.036). There was no significant difference in overall survival between patients with or without PC(median 48 d vs 70 d, P = 0.21), but patients showed significantly longer survival after clinical success of SEMS placement compared to those experiencing clinical failure(median 14.5 d vs 75 d, P = 0.0003).CONCLUSION Given the limited therapeutic options and a clinical success rate of at least 66.7%, we believe that SEMS are a reasonable treatment option in patients with malignant gastric outlet obstruction with peritoneal carcinomatosis.

Management of occluded self-expanding biliary metal stents in malignant biliary disease

Background: Occlusion of self-expanding metal stents(SEMS) in malignant biliary obstruction occurs in up to 40% of patients. This study aimed to compare the different techniques to resolve stent occlusion in our collective of patients.Methods: Patients with malignant biliary obstruction and occlusion of biliary metal stent at a tertiary referral endoscopic center were retrospectively identified between April 1, 1994 and May 31, 2014. The clinical records were further analyzed regarding the characteristics of patients, malignant strictures, SEMS,management strategies, stent patency, subsequent interventions, survival time and case charges.Results: A total of 108 patients with biliary metal stent occlusion were identified. Seventy-nine of these patients were eligible for further analysis. Favored management was plastic stent insertion in 73.4% patients. Second SEMS were inserted in 12.7% patients. Percutaneous transhepatic biliary drainage and mechanical cleansing were conducted in a minority of patients. Further analysis showed no statistically significant difference in median overall secondary stent patency(88 vs. 143 days, P = 0.069), median survival time(95 vs. 192 days, P = 0.116), median subsequent intervention rate(53.4% vs. 40.0%, P = 0.501)and median case charge(€5145 vs. €3473, P = 0.803) for the treatment with a second metal stent insertion compared to plastic stent insertion. In patients with survival time of more than three months,significantly more patients treated with plastic stents needed re-interventions than patients treated with second SEMS(93.3% vs. 57.1%, P = 0.037).Conclusions: In malignant biliary strictures, both plastic and metal stent insertions are feasible strategies for the treatment of occluded SEMS. Our data suggest that in palliative biliary stenting, patients especially those with longer expected survival might benefit from second SEMS insertion. Careful patient selection is important to ensure a proper decision for either management strategy.

Self-expanding metallic esophageal stents:A long way to go before a particular stent can be recommended

We agree that the covered self-expanding metal stents (SEMSs) fare better than the uncovered stents as recurrent dysphagia due to tumor ingrowth is common with uncovered stent. Recent American College of Gastroenterology Practice Guideline on the Role of Esophageal Stents in Benign and Malignant Diseases concludes that SEMSs cannot be routinely recommended in conjunction with chemo-radiation. The comparison of ultraflex and choostent in the Italian study found no difference in the palliation of dysphagia, rate of complications and survival rate.

Fluoroscopic removal of fractured,retained,embedded Z self-expanding metal stent using a guidewire lasso technique:A case report

BACKGROUND There are few reports of a fractured esophageal self-expanding metallic stent(SEMS)and the lasso retrieval technique,forming a guidewire loop by directing the guidewire back up the external stent for retrieval.CASE SUMMARY A 74-year-old man complained of dysphagia approximately 6 mo after radical resection of esophageal cancer.Benign anastomotic stenosis was diagnosed,and a 20 mm in diameter and 60 mm in length esophageal covered SEMS was inserted after repeated balloon dilatation.About 13.5 mo after stenting,dysphagia recurred and esophagography showed severe stenosis above the proximal stent and stent removal was performed.One-third of the stent was removed and the fractured stent remained in the proximal esophagus.A suction tube was introduced through the guidewire and then the guidewire was grabbed,acting like a“lasso”on tightening.The remaining fractured stent was successfully removed by slowly pulling back the guidewire,with no fragments of stent wires retained.CONCLUSION The guidewire lasso technique is a simple,effective method of removing esophageal SEMS in rare cases of stent fracture.

Self-Expanding Metal Stenting for Malignant Colonic Tumours: A Prospective Study

Background: Self-expanding metal stents (SEMS) have been used in the management of malignant colorectal obstruction for palliation or as a bridging tool to single-stage surgery. We present the clinical results of a series of patients with colonic cancer in whom SEMS were inserted endoscopically under radiological guidance. Methods: Between September 2007 and January 2010, prospectively collected data from 21 patients who underwent SEMS insertion was analysed. This data includes demographics, indication for stenting, stent size, technical success, clinical success, complications, survival and duration of hospitalisation. Results: 14 male and 7 female patients with malignant colonic obstruction underwent SEMS insertion: 19 requiring palliation and 2 bridging to surgery. The rate of technical success was 100% and of initial clinical success was 100%. In 16/19 (84.2%) of the palliation group, clinical success was maintained at mean follow up of 3.4 months (1-6 months), while 3/19 (15.8%) died, two with functioning stents and one with stent occlusion. The two patients with operable tumours were successfully bridged to one-stage elective surgery at 1 month and 4 months following stenting. Post-procedure complications occurred in 5 patients: 1 perforation, 2 pain, 1 migration and 1 stent occlusion. All patients were discharged alive and the median hospital stay was 1 day (range: 1 to 13 days). Conclusion: SEMS provides an effective and safe option in the palliation of malignant colorectal obstruction. In operable patients, it provides a useful option to avoid colostomy, by facilitating safer single-stage surgery. In this prospective study of SEMS insertion, high rates of technical and initial clinical success were achieved. This could be attributed to performing the procedure under combined endoscopic and radiological guidance.

Preliminary feasibility and hemodynamic performance of a newlydeveloped self-expanding bioprosthesis and 16-F delivery system in transcatheter aortic valve implantation in sheep

We sought to evaluate the feasibility and hemodynamic performance of a new self-expanding bioprosthesis and 16-F delivery system in sheep. A 23-mm new self-expanding aortic bioprosthesis was implanted in sheep （n = 10） with a 16-F catheter via the right common carotid artery, Each sheep underwent angiography and coronary angiography before intervention, immediately and 1 h after stent implantation. Electrocardiographic monitoring was carded out during and 2 h after the procedure. Transthoracic echocardiography was employed to detect he- modynamic performance before intervention, immediately and 1 and 2 h after stent implantation. All sheep were euthanized 2 h after successful implantation for macroscopic inspection. In all cases, the new self-expanding aortic bioprosthesis was successfully delivered to the aortic root and released with a 16-F catheter. Successful implantation was achieved in 8 of 10 sheep. Hemodynamic performance and device position of successful implantation were stable 2 h after device deployment. Atrioventricular block was not observed. We conclude that it is feasible to implant the new self-expanding aortic valve with a 16-F delivery system into sheep hearts via the retrograde route.

Successful endoscopic removal of three embedded esophageal self-expanding metal stents

In the report,we describe a case of refractory benign esophageal strictures from esophageal cancer after an operation for the placement of three partially covered self-expanding metal stents (SEMSs),which were all embedded in the esophageal wall.Using the stentin-stent technique,the three embedded SEMSs were successfully removed without significant complications.To the best of our knowledge,few cases of the successful removal of multiple embedded esophageal SEMSs have been reported in the literature.This case also highlights that the stent-in-stent technique is effective for removing multiple embedded esophageal SEMSs.

Stone extraction balloon-guided repeat self-expanding metal stent placement

Self-expanding metal stent (SEMS) placement offers safe and effective palliation in patients with upper gastrointestinal obstruction due to a malignancy. Well described complications of SEMS placement include tumor growth, obstruction, and stent migration. SEMS occlusions are treated by SEMS redeployment, argon plasma coagulation application, balloon dilation, and surgical bypass. At our center, we usually place the second SEMS into the first SEMS if there is complete occlusion by the tumor. We discovered an unusual complication during SEMS redeployment. The guide-wire passed through the mesh of the first SEMS and caused the second SEMS to become entangled with the first SEMS. This led to the distortion and malfunction of the second SEMS, which worsened the gastric outlet obstruction. For lowering the risk of entanglement, we studied stone extraction balloon-guided repeat SEMS placement. This is the first report of a SEMS entangled by the mesh of the first SEMS and stone extraction balloon-guided repeat SEMS placement for lowering the risk of this complication.

Iatrogenic Oesophageal Perforations in Neoplastic Lesions: Management with Covered Self-Expanding Prostheses

Background:Perforation of the oesophagus is a serious condition. Most of them are iatrogenic and are associated with significant morbidity and mortality, especially with late diagnosis. Aim: To prospectively analyse the results of the endoscopic management of iatrogenic perforations in oesophageal neoplasia, through the immediate insertion of a covered self-expanding prosthesis (CSES). Materials and Methods: Between 01.01.2006 and 12.30.2016, a series of 19 consecutive patients attended the Teaching Unit of Endoscopic Surgery of the Regional de Concepción Hospital, Chile, with the diagnosis of oesophageal neoplasia confirmed by biopsy were prospectively studied. All were subjected to a prior evaluation by the oncology team and subsequently referred for endoscopic palliative management of dysphagia. The average age was 77 ± 9.3 years, 8 (42.1%) were female and 11 (57.9%) were male. In 17 patients (89.5%) the stenosis compromised the oesophagus, in 2 (10.5%) the gastro-oesophageal junction, 16 had a squamous carcinoma (84.2%) and 3 an adenocarcinoma (15.8%). Results: Perforation was diagnosed during the procedure in 18 patients (94.7%) and in 1 (5.3%) 22 hours later. Follow-up was done for a minimum of 90 days or until death. The prostheses were inserted successfully in all cases. The immediate evolution was satisfactory in 12 patients (63.2%). In the rest (36.8%), 18 complications appeared. The most frequent were retrosternal pain, subcutaneous emphysema and fever. The early evolution was satisfactory in 12/19 cases (63.2%). Complication was evidenced in 7 (36.8%), the most frequent was retrosternal pain (36.8%). Fever occurred in 3 (15.8%), pleural effusion in 3 (15.8%) and mediastinitis in 2 of these. The prosthesis was kept in situ as a definitive palliation method for neoplastic dysphagia. In 10 of the 18 cases that survived more than a month, there were late complications (55.6%), none of them associated with the perforation itself. The only death (5.3%) was due to an oesophagus-pleural fistula, associated with an early prosthetic migration. Recovery of the oral intake occurred, on average, at 3.7 days. The hospital stay averaged 9.6 days. Conclusion: The use of CSES for the treatment of iatrogenic oesophageal perforations in the context of neoplasia, is a safe and effective method, with low morbidity, adequate recovery of the oral intake and prompt discharge from hospital.

Endoscopic removal of a self-expanding metallic airway stent: A case report

Self-expanding metallic stents are sometimes placed for the management of obstructing airway lesions or conditions such as airway wall malacia or tracheal stenosis. However, endoscopic removal of these devices from the airway can pose extreme challenges for both clinical airway management as well as for the administration of general anesthesia. We report on a 61-yearold man with a complex cardiac history presenting for endoscopic stent removal necessitated by the formation of extensive granulation tissue. Comorbidities included a history of myocardial infarction, an ischemic cardiomyopathy with severe left heart failure(ejection fraction of 25%), mild right heart failure, 2+ tricuspid regurgitation status post tricuspid valve repair, and atrial fibrillation. An automatic external(wearable) cardiac defibrillator(Zoll Life Vest) was also in place. Induction of anesthesia was carried out using etomidate, with maintenance of anesthesia carried out with a propofol infusion(total intravenous anesthesia). Rocuronium was used for neuromuscular blockade. A size 4 i Gel supraglottic airway and, later, rigid bronchoscopy formed the basis for airway management. Stable conditions were met through the 2-h procedure, and the patient recovered uneventfully. Our successful experience in this case leads us to propose further use of a supraglottic airway in conjunction with total intravenous anesthesia for these procedures.

Self-Expanding Nitinol Stent for Treatment of Tracheal Stenosis Caused by Pulmonary Hypertension:1 case report

A 38 year-old man was admitted because of half a year of recurrent bouts of eough and shortness of breath and 20 days of hemoptysis. He had been apparently healthy until the illness. In the recent 6 months, the dyspnea and fatigue gradually onset and became more severe, the hemoptysis being 100-200 mL per day. Spells of chest pain are associated with coughing. Despite accepting antibiotic and antispasmodic therapy in a hospital, there was no obvious improvement and he was transferred to our hospital. Physical examination on admission: He was in acute distress and anemic face With P 110/min., R 30/min., T36. 8oC and Bp 100/60 mmHg. There were Wheezes, medium and fine

Decompression of Malignant Large-bowel Obstruction with a Self-expanding Metallic Stent or Transanal Drainage Tube

Objective To compare the outcomes after self-expanding metallic stent (SEMS) or transanal drainage tube (TDT) placement in patients with malignant large-bowel obstruction (MLBO). Methods Seventy-three patients with MLBO from the clinical unit underwent SEMS (n = 51) or TDT (n = 22) placement from 2012 to 2017. The success rates of placement, clinical outcomes after decompression, complications, the time to resuming enteral nutrition (EN), Karnofsky performance status (KPS) scoring and the following-up therapeutic options were investigated. Results Technical success were achieved in 100% of patients in both groups. The clinical success rates were 98.0%(50/51) for SEMS and 95.5%(21/22) for TDT. No perforation was found in any group, while 3.9%(2/51) in the SEMS and 18.2%(4/22) in TDT group experienced displacement (P = 0.26). It took 2.1 IQR (0~2) days and 3 IQR (2~5) days to resume EN in the SEMS and TDT groups, respectively (P < 0.001). The KPS scores were significantly higher in patients implanted with SEMS (70, IQR 50~80) than in those with TDT (35, IQR 30~50)(P < 0.001). In the SEMS group, 37.3%(19/51) of patients underwent stenting as a bridge to surgery, 9.8%(5/51) for chemotherapy only and 52.9%(27/51) for palliation, while 40.9%(9/22), 0 and 59.1%(13/22) underwent placement for these reasons in the TDT group, respectively. The majority (6/9) of the patients who underwent TDT placement as a bridge to surgery required stoma creation, while only 31.6%(6/19) of those in the SEMS group needed a stoma (P = 0.080). In addition, anastomotic leakage was only found in the TDT group (2/9)(P = 0.10). Conclusion Both SEMS and TDT placement could provide clinical relief for MLBO. However, SEMS placement is associated with earlier EN, fewer complications, and benefits for the postoperative quality-of-life.

Cellulose fibers-reinforced self-expanding porous composite with multiple hemostatic efficacy and shape adaptability for uncontrollable massive hemorrhage treatment

Uncontrollable hemorrhage leads to high mortality and thus effective bleeding control becomes increasingly important in the military field and civilian trauma arena.However,current hemostats not only present limitation when treating major bleeding,but also have various side effects.Here we report a self-expanding porous composites(CMCP)based on novel carboxymethyl cellulose(CMC)fibers and acetalized polyvinyl alcohol(PVA)for lethal hemorrhage control.The CMC fibers with uniform fibrous structure,high liquid absorption and procoagulant ability,are evenly interspersed inside the composite matrix.The obtained composites possess unique fiber-porous network,excellent absorption capacity,fast liquid-triggered self-expanding ability and robust fatigue resistance,and their physicochemical performance can be fine-tuned through varying the CMC content.In vitro tests show that the porous composite exhibits strong blood clotting ability,high adhesion to blood cells and protein,and the ability to activate platelet and the coagulation system.In vivo hemostatic evaluation further confirms that the CMCP presents high hemostatic efficacy and multiple hemostatic effects in swine femoral artery major hemorrhage model.Additionally,the CMCP will not fall off from the injury site,and is also easy to surgically remove from the wound cavity after the hemostasis.Importantly,results of CT tomography and 3D reconstruction indicate that CMCP can achieve shape adaptation to the surrounding tissues and the wound cavities with different depths and shapes,to accelerate hemostasis while protecting wound tissue and preventing infection.

Preclinical study of a self-expanding pulmonary valve for the treatment of pulmonary valve disease

In the past decade,balloon-expandable percutaneous pulmonary valves have been developed and applied in clinical practice.However,all the existing products of pulmonary artery interventional valves in the market have a straight structure design,and they require a preset support frame and balloon expansion.This shape design of the valve limits the application range.In addition,the age of the population with pulmonary artery disease is generally low,and the existing products cannot meet the needs of anti-calcification properties and valve material durability.In this study,through optimization of the support frame and leaflet design,a self-expanding pulmonary valve product with a double bell-shaped frame was designed to improve the match of the valve and the implantation site.A loading and deployment study showed that the biomaterial of the valve was not damaged after being compressed.Pulsatile flow and fatigue in vitro tests showed that the fabricated pulmonary valve met the hydrodynamic requirements after 2108 accelerated fatigue cycles.The safety and efficacy of the pulmonary valve product were demonstrated in studies of pulmonary valve implantation in 11 pigs.Angiography and echocardiography showed that the pulmonary valves were implanted in a good position,and they had normal closure and acceptable valvular regurgitation.The 180 days’implantation results showed that the calcium content was 0.31-1.39 mg/g in the anti-calcification treatment group,which was significantly lower than that in the control valve without anti-calcification treatment(16.69 mg/g).Our new interventional pulmonary valve product was ready for clinical trials and product registration.

Outcomes of a single-step endoscopic ultrasound-guided drainage of pancreatic-fluid collections using an electrocautery-enhanced coaxial lumen-apposing,self-expanding metal stent with and without fluoroscopy

Background:Fluoroscopy is often used during the endoscopic drainage of pancreatic-fluid collections(PFCs).An electrocautery-enhanced coaxial lumen-apposing,self-expanding metal stent(ELAMS)facilitates a single-step procedure and may avoid the need for fluoroscopy.This study compares the treatment outcomes using ELAMS with and without fluoroscopy.Methods:Patients with PFCs who had cystogastrostomy from January 2014 to February 2017 were enrolled.Two groups were studied based on fluoroscopy use.Technical success was defined as uneventful insertion of ELAMS at time of procedure.Clinical success was defined as(i)clinical resolution of symptoms after the procedure and(ii)>75%reduction in cyst size on computed tomography 8 weeks after stent placement.Adverse events including bleeding,stent migration,and infection were recorded.Results:A total of 21 patients(13 males)had PFCs drainage with ELAMS in the study period.The mean age was 51.6614.2 years.Thirteen patients had walled-off necrosis while eight had a pancreatic pseudocyst.The mean size of the PFCs was 11.363.3 cm.Fluoroscopy was used in seven cases(33%)and was associated with a longer procedure time compared to non-fluoroscopy(43.1610.4 vs 33.3610.5 min,P=0.025).This association was independent of the size,location,or type of PFCs.Fluoroscopy had no effect on the technical success rates.In fluoroless procedures,the clinical resolution was 91%as compared to 71%in fluoroscopy procedures(P=0.52)and the radiologic resolution was 57%as compared to 71%in fluoroscopy procedures(P=0.65).Three cases of stent migration/displacement occurred in the fluoroless procedures.Conclusions:ELAMS may avoid the need for fluoroscopy during cystogastrostomy.Procedures without fluoroscopy were significantly shorter and fluoroscopy use had no impact on the technical or clinical success rates.