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.

Revision of bilateral self-expandable metallic stents placed using the stent-in-stent technique for malignant hilar biliary obstruction

Background: Endoscopic biliary decompression using bilateral self-expandable metallic stent(SEMS) placed using the stent-in-stent(SIS) technique is considered favorable for unresectable malignant hilar biliary obstruction(MHBO). However, occlusion of the bilateral SIS placement is frequent and revision can be challenging. This study was performed to investigate the efficacy, the long-term patency and the appropriate approach for revision of occluded bilateral SIS placement in unresectable MHBO. Methods: From January 2011 to July 2016, thirty-eight patients with unresectable MHBO underwent revision of occluded bilateral SIS placement. Clinical data including success rates and patency of revision, were retrospectively analyzed. Results: The technical success rate of revision was 76.3%. The clinical success rate of revision was 51.7% and mean patency of revision was 49.1 days. No significant predictive factor for clinical failure of revision was observed. The cell size of SEMS was not found to have significant effects on clinical success rates or revision patency. Conclusions: Revision of occluded bilateral SIS placement for MHBO showed fair patency and clinical success rate. Revision method and cell size of SEMS were not found to influence clinical outcomes.

Efficacy of uncovered self-expandable metallic stent for colorectal obstruction by extracolonic malignancy

BACKGROUND Self-expandable metallic stent(SEMS)is widely used for malignant colorectal obstruction.Recently,SEMS has been used for palliative option for colorectal obstruction caused by extracolonic malignancy(ECM).AIM To evaluate the efficacy of SEMS for colorectal obstruction caused by ECM,and to identify the factors associated with stent occlusion.METHODS Seventy-two patients who were treated with uncovered SEMS insertion for malignant colorectal obstructions caused by colorectal metastasis or peritoneal seeding of ECM at Samsung Medical Center between April 2012 to March 2016 were enrolled.We analyzed technical and clinical outcomes of stent insertion,the factors associated with stent occlusion and long term outcomes after stent insertion.RESULTS Technical success rate was determined as 90.3%with a clinical success rate of 87.7%.Stent occlusion developed in 28.1%,with a median duration of 51 d.Further,81.3%with stent occlusion could be treated with secondary stent insertion.Clinical failure was observed to be related to the male sex(P=0.020)and right colon obstruction(P=0.017).Stent length≤10 cm was found to be associated with stent occlusion(P=0.003).Median survival time after stent insertion was 4.7 mo and 40.4%were able to receive their oncological treatments after stent insertion without surgery.CONCLUSION Uncovered SEMS is effective for the treatment of colorectal obstruction caused by ECM,considering life expectancy of patients with ECM.

Effect of external beam radiotherapy on patency of uncovered metallic stents in patients with inoperable bile duct cancer

BACKGROUND： Although biliary decompression with metallic stenting is the preferred treatment for inoperable bile duct cancer（BDC）, maintenance of patency is still unsatisfactory.We tried to assess the effectiveness and safety of external beam radiotherapy（EBRT） for prolonging stent patency in patients having uncovered metallic stents.METHOD： We retrospectively reviewed 50 patients who received endoscopic stenting, of whom 18 received EBRT（RT group） and 32 did not（non-RT group）.RESULTS： No difference was found in baseline characteristics between the two groups. Although stent patency was longer in the RT group than that in the non-RT group（140.7±51.3 vs136.4±34.9 days, P=0.94）, the difference was not statistically significant. There were a lower rate of stent occlusion（27.8% vs50.0% of patients, P=0.12） and a longer overall survival（420.1 ±73.2 vs 269.1±41.7 days, P=0.11） in the RT group than in the non-RT group, and the difference again was not statistically significant. The development of adverse reactions did not differ（55.6% vs 53.1% of patients, P=0.91）. There was no serious adverse reaction in both groups（P=0.99）.CONCLUSIONS： EBRT did not significantly improve stent patency in patients with inoperable BDC having uncovered metallic stents. However, EBRT was safe. Future trials withrefined protocols for better efficacy are expected.

Angle of covered self-expandable metallic stents after placement is a risk factor for recurrent biliary obstruction

BACKGROUND Studies have shown that covered self-expandable metallic stents(CSEMS)with a low axial forces after placement can cause early recurrent biliary obstruction(RBO)due to precipitating sludge formation.AIM To ascertain whether the angle of CSEMS after placement is a risk factor for RBO in unresectable distal malignant biliary obstruction(MBO).METHODS Between January 2010 and March 2019,261 consecutive patients underwent selfexpandable metallic stent insertion by endoscopic retrograde cholangiopancreatography at our facility,and 87 patients were included in this study.We evaluated the risk factors for RBO,including the angle of CSEMS after placement as the primary outcome.We measured the obtuse angle of CSEMS after placement on an abdominal radiograph using the SYNAPSE PACS system.We also evaluated technical and functional success,adverse events,time to RBO(TRBO),non-RBO rate,survival time,cause of RBO,and reintervention procedure as secondary outcomes.RESULTS We divided the patients into two cohorts based on the presence or absence of RBO.The angle of CSEMS after placement(per 1°and per 10°)was evaluated using the multivariate Cox proportional hazard analysis,which was an independent risk factor for RBO in unresectable distal MBO[hazard ratio,0.97 and 0.71;95%confidence interval(CI):0.94-0.99 and 0.54-0.92;P=0.01 and 0.01,respectively].For early diagnosis of RBO,the cut-off value of the angle of CSEMS after placement using the receiver operating characteristic curve was 130°[sensitivity,50.0%;specificity 85.5%;area under the curve 0.70(95%CI:0.57-0.84)].TRBO in the<130°angle group was significantly shorter than that in the≥130°angle group(P<0.01).CONCLUSION This study suggests that the angle of the CSEMS after placement for unresectable distal MBO is a risk factor for RBO.These novel results provide pertinent information for future stent management.

Palliation of Malignant Esophageal Obstruction and Fistulas with Metallic Stents: A Tertiary Center Experience

Background: To determine the usefulness of metallic stent in advanced oesophageal malignancies. Methods: In a retrospective study conducted at the Endoscopy Unit of King Abdulaziz University Hospital, patients underwent stent placement, with or without palliative radiotherapy for inoperable esophageal cancer, during the period spanning January 2010 through December 2014. Ethical approval for this study was granted by the King Abdulaziz University Research Ethics Committee. Data were collected from the electronic database of the hospital. All patients underwent OGD before stenting to know site of tumor, length of tumor and degree of stricture. Barium meal and CT scan was also done in some cases to know exact characteristics of tumor. Stent was selected more than 2 cm longer than the length of tumor. Self expanding metallic stents were used in all cases. Confirmation of proper placement of stent was done using fluoroscopy. Complications post stenting were analysed. Results: A total of 15 cases were studied. Males were 53.3% while females were 46.7%. Youngest patient was 39 yr old and eldest was 79 years with mean 64.93 years. Mean height was 159.73 cm and mean weight 54.98 kilogram. Co-morbidities like DM was 20%, DM with HTN was 6.7%, bronchial asthma 13.3% and DM with HTN with IHD and Renal implant in 6.7%. Diagnosis at admission was esophageal squamous cell carcinoma in 33.3%, esophageal adeno-carcinoma in 53.3%, gastric cancer in 6.7%, tracho-esophageal fistula in 6.7%. Stage 3 was 13.3%, and stage 4 was 86.7%. Surgical resection and palliation was done in14.2%, and only palliation was done in 92.9% of cases. SEMS were used in all patients and majority had Niti-S stent placed in 73.3% and Wallflex in 13.3% and Ultraflex in 6.7% and Boston in 6.7% cases. Dysphagia was Indication of stenting in 100% of cases and stricture in 57.1% and stricture and recurrent aspiration in 42.9%. Post stenting complications were early in 20% and late in 40%. Tumor ingrowth was in 20%, GERD in 20%, Mild chest pain and discomfort in 10%, stent migration in 10%, fistula formation in 10%, chest pain and GERD in 10%, and aspiration and pneumonia in 20%. Conclusions: Self expanding metallic stents are invaluable in advanced oesophageal cancer for palliation and alleviation of symptoms and better quality of life. Patients prior to chemoradiotherapy may get benefit of stenting making oesophageal passage patent which may otherwise get occluded by edema caused by radiotherapy.

Endoscopic therapy using a self-expandable metallic stent with an anti-migration system for postorthotopic liver transplantation anastomotic biliary stricture

BACKGROUND Endoscopic therapy using multiple plastic stents(MPSs)is the standard therapy for postorthotopic liver transplantation(p-OLT)anastomotic biliary stricture(ABS).However,this approach demands repeated procedures.Recent studies us-ing fully covered self-expandable metallic stents(FCSEMS)have shown en-couraging results,but migration occurs in 10%to 40%of cases.The objective of this retrospective study was to evaluate the efficacy of endoscopic treatment using FCSEMS with an anti-migration system(Am-FCSEMS)in patients with p-OLT ABS.AIM To evaluate the efficacy of endoscopic treatment using an Am-FCSEMS in patients with p-OLT ABS.METHODS This study was conducted in a private tertiary care centre in S?o Paulo,Brazil and was approved by our institution's Human Research Committee.From April 2018 to October 2020,regardless of previous endoscopic treatment(MPS or FCSEMS),17 patients with p-OLT ABS and indications for endoscopic therapy were included in this study.The exclusion criteria were pregnancy,nonanastomotic biliary or hilar stricture,hepatic artery stenosis/thrombosis,isolated biliary fistulae,a distance shorter than 2 cm from the stricture to the hepatic hilum,and patient refusal.The primary endpoint was the efficacy of p-OLT ABS endoscopic treatment using an Am-FCSEMS that re-mained in place for a 12-mo period.Biliary sphincterotomy was performed in patients with native papilla,and an Am-FCSEMS(10 mm in final diameter and 60 or 80 mm in length)was placed(Hanarostent TM MI Tech,Co).Balloon stricture dilation was performed only if necessary to introduce the stent.RESULTS Three patients were excluded due to loss to follow-up before stent removal.Among the 14 patients included and followed,7 were women,and the average age was 56 years(range:28-76).The average period of Am-FCSEMS placement was 362±109 d.Technical success occurred in all 14 patients(100%).There were no cases of distal stent migration.Complete resolution of the stricture occurred in 13/14 patients(92.85%).Adverse events occurred in 3/14 patients(21.42%):2 patients with mild acute pancreatitis(14.28%)and 1 patient(7.14%)with stent dysfunction(occlusion by biliary sludge and stones,which was treated endoscopically without the need for stent removal).No deaths occurred related to therapy.All stents were removed using foreign body forceps or snares without difficulty.After Am-FCSEMS removal,all 13 patients who had ABS resolution were followed-up for an average of 411±172 d,and there was no stricture recurrence or need for further endoscopic therapy.CONCLUSION In this retrospective study,endoscopy therapy using an Am-FCSEMS for p-OLT ABS was safe and effective,with a high stricture re-solution rate that was probably due to the absence of stent migration.

Efficacy and complications of inoperable malignant distal biliary obstruction treatment by metallic stents:fully covered or uncovered?

Obstructive jaundice caused by malignant distal biliary obstruction is a common clinical symptom in patients with inoperable biliary–pancreatic cancer.Endoscopic retrograde cholangiopancreatography(ERCP)-guided stent implantation is an effective treatment for obstructive jaundice.Internal stent drainage is more physiologic and associated with a better quality of life than external stent drainage methods such as percutaneous transhepatic gallbladder drainage or percutaneous transhepatic cholangiodrainage.Selfexpanding metallic stents,which may be covered and uncovered,are commonly used.However,some uncertainties remain regarding the selection of metallic stents,including drainage patency time,clinical effect,stent migration,and post-operative complications such as pancreatitis,bleeding,and cholecystitis.This review aims to summarize the current progress and controversies surrounding the use of covered or uncovered metallic stents in inoperable common biliary obstruction via ERCP.

Safety and efficacy of Kaffes intraductal self-expanding metal stents in the management of post-liver transplant anastomotic strictures

BACKGROUND Endoscopic management is the first-line therapy for post-liver-transplant anas-tomotic strictures.Although the optimal duration of treatment with plastic stents has been reported to be 8-12 months,data on safety and duration for metal stents in this setting is scarce.Due to limited access to endoscopic retrograde cholan-giopancreatography(ERCP)during the coronavirus disease 2019 pandemic in our centre,there was a change in practice towards increased usage and length-of-stay of the Kaffes biliary intraductal self-expanding stent in patients with suitable anatomy.This was mainly due to the theoretical benefit of Kaffes stents allowing for longer indwelling periods compared to the traditional plastic stents.METHODS Adult liver transplant recipients aged 18 years and above who underwent ERCP were retrospectively identified during a 10-year period through a database query.Unplanned admissions post-Kaffes stent insertion were identified manually through electronic and scanned medical records.The main outcome was the incidence of complications when stents were left indwelling for 3 months vs 6 months.Stent efficacy was calculated via rates of stricture recurrence between patients that had stenting courses for≤120 d or>120 d.RESULTS During the study period,a total of 66 ERCPs with Kaffes insertion were performed in 54 patients throughout their stenting course.In 33 ERCPs,the stent was removed or exchanged on a 3-month interval.No pancreatitis,perfor-ations or deaths occurred.Minor post-ERCP complications were similar between the 3-month(abdominal pain and intraductal migration)and 6-month(abdominal pain,septic shower and embedded stent)groups-6.1%vs 9.1%respectively,P=0.40.All strictures resolved at the end of the stenting course,but the stenting course was variable from 3 to 22 months.The recurrence rate for stenting courses lasting for up to 120 d was 71.4%and 21.4%for stenting courses of 121 d or over(P=0.03).There were 28 patients that were treated with a single ERCP with Kaffes,21 with removal after 120 d and 7 within 120 d.There was a significant improvement in stricture recurrence when the Kaffes was removed after 120 d when a single ERCP was used for the entire stenting course(71.0%vs 10.0%,P=0.01).CONCLUSION Utilising a single Kaffes intraductal fully-covered metal stent for at least 4 months is safe and efficacious for the management of post-transplant anastomotic strictures.

Understanding the corrosion of Mg alloys in in vitro urinary tract conditions: A step forward towards a biodegradable metallic ureteral stent

Ureteral stents play a fundamental role in modern time urology. However, following the deployment, stent-related symptoms are frequent and affect patient health and quality of life. Using biodegradable metals as ureteral stent materials have emerged as a promising strategy, mainly due to the improved radial force and slower degradation rate expected. Therefore, this study aimed to characterize different biodegradable metals in urinary tract environment to understand their propensity for future utilization as base materials for ureteral stents. The corrosion of 5 Mg alloys - AZ31, Mg-1Zn, Mg-1Y, pure Mg, and Mg-4Ag - under simulated urinary tract conditions was accessed. The corrosion layer of the different alloys presented common elements, such as Mg(OH)_(2), MgO, and phosphate-containing products, but slight variations in their chemical compositions were detected. The corrosion rate of the different metals varied, which was expected given the differences in the corrosion layers. On top of this, the findings of this study highlighted the significant differences in the samples' corrosion and corrosion layers when in stagnant and flowing conditions. With the results of this study, we concluded that Mg-1Zn and Mg-4Ag presented a higher propensity for localized corrosion, probably due to a less protective corrosion layer;Mg-4Ag corroded faster than all the other four alloys,and Mg-1Y stood out due to its distinct corrosion pattern, that showed to be more homogeneous than all the other four samples, making this one more attractive for the future studies on biodegradable metals.

Endoscopic-ultrasound-guided biliary drainage with placement of electrocautery-enhanced lumen-apposing metal stent for palliation of malignant biliary obstruction:Updated meta-analysis

BACKGROUND Endoscopic ultrasound-guided biliary drainage using electrocautery-enhanced(ECE)delivery of lumen-apposing metal stent(LAMS)is gradually being re-cognized as a viable palliative technique for malignant biliary obstruction after endoscopic retrograde cholangiopancreatography(ERCP)failure.However,most of the studies that have assessed its efficacy and safety were small and hetero-geneous.Prior meta-analyses of six or fewer studies that were published 2 years ago were therefore underpowered to yield convincing evidence.AIM To update the efficacy and safety of ECE-LAMS for treatment of biliary ob-struction after ERCP failure.METHODS We searched PubMed,EMBASE,and Scopus databases from the inception of the ECE technique to May 13,2022.Primary outcome measure was pooled technical success rate,and secondary outcomes were pooled rates of clinical success,re-intervention,and adverse events.Meta-analysis was performed using a random-effects model following Freeman-Tukey double-arcsine transformation in R soft-ware(version 4.1.3).RESULTS Fourteen eligible studies involving 620 participants were ultimately included.The pooled rate of technical success was 96.7%,and clinical success was 91.0%.Adverse events were reported in 17.5%of patients.Overall reinter-vention rate was 7.3%.Subgroup analyses showed results were generally consistent.CONCLUSION ECE-LAMS has favorable success with acceptable adverse events in relieving biliary obstruction when ERCP is impossible.The consistency of results across most subgroups suggested that this is a generalizable approach.

Acute left-sided malignant colonic obstruction:Is there a role for endoscopic stenting?

The therapy of left-sided malignant colonic obstruction continues to be one of the largest problems in clinical practice.Numerous studies on colonic stenting for neoplastic colonic obstruction have been reported in the last decades.Thereby the role of self-expandable metal stents(SEMS)in the treatment of malignant colonic obstruction has become better defined.However,numerous prospective and retrospective investigations have highlighted serious concerns about a possible worse outcome after endoscopic colorectal stenting as a bridge to surgery,particularly in case of perforation.This review analyzes the most recent evidence in order to highlight pros and cons of SEMS placement in left-sided malignant colonic obstruction.

Successful resection of colonic metastasis of lung cancer after colonic stent placement:A case report and review of the literature

BACKGROUND Lung cancer is the leading cause of cancer deaths worldwide.Although lung cancer can metastasize to various organs such as the liver,lymph nodes,adrenal gland,bone,and brain,metastases to the digestive organs,especially the colon,are rare.CASE SUMMARY An 83-year-old man diagnosed with lung cancer received radiation and chemoimmunotherapy,resulting in a complete clinical response.One year after the initial lung cancer diagnosis,the patient presented with obstructive ileus caused by a tumor in the descending colon.An elective left hemicolectomy was successfully performed after the endoscopic placement of a self-expandable metallic stent(SEMS).Pathologically,the tumor of the descending colon was diagnosed as lung cancer metastasis.The postoperative course was uneventful,and the patient is in good condition 13 mo after surgery,with no signs of recurrence.The previous 23 cases of surgical resection of colonic metastasis from lung cancer were reviewed using PubMed to characterize their clinicopathological features and outcomes.CONCLUSION SEMS is useful for obstructive colonic metastasis as a bridge to surgery to avoid emergency operations.

Metallic ureteral stent in restoring kidney function: Nine case reports

BACKGROUND Retroperitoneal fibrosis is an exceptionally rare disease characterized by proliferation of fibrous tissue and inflammation in the retroperitoneum.It features many symptoms in the kidneys and in other organs and usually leads to ureteral obstruction.CASE SUMMARY Here we present 9 consecutive cases of idiopathic retroperitoneal fibrosis(IRPF)in patients who presented to the Department of Nephrology or Department of Rheumatology,Xuanwu Hospital,Capital Medical University,Beijing,China,between January 2012 and June 2017 with ureteral obstruction due to external compression of the ureter that led to hydronephrosis and kidney dysfunction.Computed tomography imaging was used to identify hydronephrosis and ureteral obstruction and to evaluate kidney function.Each patient was diagnosed with IRPF based on clinical observation and computed tomography examination results.To restore kidney function,a retrograde metallic stent was placed in the ureter under X-ray guidance 2 d after each patient’s admission.No perioperative complications occurred in any patient,but postoperative complications occurred in two patients as follows:Patient 2 had stent migration and repeated metallic stent infections that resolved with treatment;and patient 4 had postoperative hematuria because he resumed normal activities too soon after stent placement(contrary to instruction).Placement of the metallic ureteral stents provided relief from ureteral obstruction and restored kidney function in all patients.CONCLUSION Our 9-case series underscores the utility and efficacy of applying the Resonance®metallic ureteral stent to treat ureteral obstruction in patients with IRPF.For all retroperitoneal fibrosis cases in our series,ureteral stents provided effective relief and were shown to reduce the incidence rate of perioperative and postoperative complications.

Lumen-apposing-metal stent misdeployment in endoscopic ultrasound-guided drainages:A systematic review focusing on issues and rescue management

BACKGROUND The introduction of lumen-apposing metal stents(LAMS)for endoscopic ultrasound(EUS)-guided drainages has marked a turning point in the field of interventional ultrasound and it is gathering worldwide diffusion in different clinical settings.Nevertheless,the procedure may conceal unexpected pitfalls.LAMS misdeployment is the most frequent cause of technical failure and it can be considered a procedure-related adverse event when it hampers the conclusion of the planned procedure or results in significant clinical consequences.Stent misdeployment can be managed successfully by endoscopic rescue maneuvers to allow the completion of the procedure.To date,no standardized indication is available to guide an appropriate rescue strategy depending on the type of procedure or of misdeployment.AIM To evaluate the incidence of LAMS misdeployment during EUS-guided choledochoduodenostomy(EUS-CDS),gallbladder drainage(EUS-GBD)and pancreatic fluid collections drainage(EUS-PFC)and to describe the endoscopic rescue strategies adopted under the circumstance.METHODS We conducted a systematic review of the literature on PubMed by searching for studies published up to October 2022.The search was carried out using the exploded medical subject heading terms“lumen apposing metal stent”,“LAMS”,“endoscopic ultrasound”and“choledochoduodenostomy”or“gallbladder”or“pancreatic fluid collections”.We included in the review on-label EUS-guided procedures namely EUS-CDS,EUS-GBD and EUS-PFC.Only those publications reporting EUS-guided LAMS positioning were considered.The studies reporting a technical success rate of 100%and other procedure-related adverse events were considered to calculate the overall rate of LAMS misdeployment,while studies not reporting the causes of technical failure were excluded.Case reports were considered only for the extraction of data regarding the issues of misdeployment and rescue techniques.The following data were collected from each study:Author,year of publication,study design,study population,clinical indication,technical success,reported number of misdeployment,stent type and size,flange misdeployed and type of rescue strategy.RESULTS The overall technical success rate of EUS-CDS,EUS-GBD and EUS-PFC was 93.7%,96.1%,and 98.1%respectively.Significant rates of LAMS misdeployment have been reported for EUS-CDS,EUS-GBD and EUS-PFC drainage,respectively 5.8%,3.4%,and 2.0%.Endoscopic rescue treatment was feasible in 86.8%,80%,and 96.8%of cases.Non endoscopic rescue strategies were required only in 10.3%,16%and 3.2%for EUS-CDS,EUS-GBD,and EUS-PFC.The endoscopic rescue techniques described were over-the-wire deployment of a new stent through the created fistula tract in 44.1%,8%and 64.5%and stent-in-stent in 23.5%,60%,and 12.9%,respectively for EUSCDS,EUS-GBD,and EUS-PFC.Further therapeutic option were endoscopic rendezvous in 11.8%of EUS-CDS and repeated procedure of EUS-guided drainage in 16.1%of EUS-PFC.CONCLUSION LAMS misdeployment is a relatively common adverse event in EUS-guided drainages.There is no consensus on the best rescue approach in these cases and the choice is often made by the endoscopist relying upon the clinical scenario,anatomical characteristics,and local expertise.In this review,we investigated the misdeployment of LAMS for each of the on-label indications focusing on the rescue therapies used,with the aim of providing useful data for endoscopists and to improve patient outcomes.

Outcomes of colon self-expandable metal stents for malignant vs benign indications at a tertiary care center and review of literature

BACKGROUND Endoscopic placement of a self-expandable metal stent(SEMS)is a minimally invasive treatment for use in malignant and benign colonic obstruction.However,their widespread use is still limited with a nationwide analysis showing only 5.4%of patients with colon obstruction undergoing stent placement.This underutilization could be due to perceived increase risk of complications with stent placement.AIM To review long-and short-term clinical success of SEMS use for colonic obstruction at our center.METHODS We retrospectively reviewed all the patients who underwent colonic SEMS placement over aeighteen year period (August 2004 through August 2022) at our academic center. Demographicsincluding age, gender, indication (malignant and benign), technical success, clinical success,complications (perforation, stent migration), mortality, and outcomes were recorded.RESULTSSixty three patients underwent colon SEMS over an 18-year period. Fifty-five cases were formalignant indications, 8 were for benign conditions. The benign strictures included diverticulardisease stricturing (n = 4), fistula closure (n = 2), extrinsic fibroid compression (n = 1), and ischemicstricture (n = 1). Forty-three of the malignant cases were due to intrinsic obstruction from primaryor recurrent colon cancer;12 were from extrinsic compression. Fifty-four strictures occurred on theleft side, 3 occurred on the right and the rest in transverse colon. The total malignant case (n = 55)procedural success rate was 95% vs 100% for benign cases (P = 1.0, NS). Overall complication ratewas significantly higher for benign group: Four complications were observed in the malignantgroup (stent migration, restenosis) vs 2 of 8 (25%) for benign obstruction (1-perforation, 1-stentmigration) (P = 0.02). When stratifying complications of perforation and stent migration there wasno significant difference between the two groups (P = 0.14, NS).CONCLUSIONColon SEMS remains a worthwhile option for colonic obstruction related to malignancy and has ahigh procedural and clinical success rate. Benign indications for SEMS placement appear to havesimilar success to malignant. While there appears to be a higher overall complication rate inbenign cases, our study is limited by sample size. When evaluating for perforation alone theredoes not appear to be any significant difference between the two groups. SEMS placement may bea practical option for indications other that malignant obstruction. Interventional endoscopistsshould be aware and discuss the risk for complications in setting of benign conditions. Indicationsin these cases should be discussed in a multi-disciplinary fashion with colorectal surgery.

Stent fracture after transjugular intrahepatic portosystemic shunt placement using the bare metal stent/stent-graft combination technique

BACKGROUND A transjugular intrahepatic portosystemic shunt(TIPS)is widely placed to treat portal hypertension.Because the Viatorr®stent(W.L.Gore and Associates,Flagstaff,AZ,United States)is not available in all hospitals in China,the bare metal stent(BMS)/stent-graft combination technique is still popular for TIPS construction.Stent fracture is a complication after TIPS placement using this technique,with limited available literature focusing on it.AIM To assess the incidence of stent fracture after TIPS placement using the BMS/stent-graft combination technique and to identify the risk factors for stent fracture.We proposed technique modifications to improve the clinical results of TIPS placement with the BMS/stent-graft combination technique.METHODS We retrospectively analyzed the computed tomography(CT)data of all patients with portal hypertension who underwent the TIPS procedure between June 2011 and December 2021 in a single center.Patients implanted with the BMS/stent graft and had follow-up imaging data available were included.We identified patients with stent fracture and analyzed their characteristics.Multivariable logistic regression was applied to identify the potential predictors of stent fracture.RESULTS Of the 68 included patients,stent fracture occurred in seven(10.3%)patients.Based on CT images,the stent fractures were categorized into three types.Our study consisted of four(57.1%)type I fractures,one(14.3%)type II fracture,one(14.3%)type IIIa fracture,and one(14.3%)type IIIb fracture.After adjusting for covariates,multivariable logistic regression revealed that the risk factors for stent fracture were the implantation of a greater number of stents[adjusted odds ratio(aOR)=22.2,95%confidence interval(CI):1.2-415.4,P=0.038]and a larger proximal sagittal stent bending angle(aOR=1.1,95%CI:1.0-1.3,P=0.020).CONCLUSION Stent fracture occurred in approximately 10%of patients with portal hypertension who underwent TIPS with the BMS/stent-graft combination technique.The number of implanted stents and stent bending angle at the inferior vena cava end were predictors of stent fracture,which suggests that the incidence of stent fracture could potentially be reduced by procedural modifications.

Biliary metal stents should be placed near the hilar duct in distal malignant biliary stricture patients

BACKGROUND Endoscopic biliary drainage using a self-expandable metallic stent(SEMS)has been widely performed to treat distal malignant biliary obstruction(DMBO).However,the optimal position of the stent remains unclear.AIM To determine the ideal position for SEMS placement.METHODS In total,135 DMBO patients underwent SEMS(uncovered or covered)placement over a ten-year period.A total of 127 patients with biliary obstruction between the junction of the cystic duct and Vater’s papilla were enrolled.An SEMS was placed through the upper common bile duct 2 cm from the biliary hilar duct in 83 patients(Hilar group)or near the top of the biliary obstruction in 44 patients(Lower group).Technical and functional success,adverse events,and risk factors for SEMS dysfunction were evaluated.RESULTS The stent patency period was significantly longer in the Hilar group than in the Lower group(P value<0.01).In multivariate analysis,the only statistically significant risk factor for SEMS dysfunction was being in the Lower group(hazard ratio:9.94,95%confidence interval:2.25–44.0,P<0.01).CONCLUSION A longer patency period was achieved by positioning the SEMS near the biliary hilar duct.

Colorectal stenting for palliation and as a bridge to surgery:A 5-year follow-up study

AIM: To evaluate the long-term effectiveness of colonic stents in colorectal tumors causing large bowel obstruction.METHODS: We retrospectively analyzed data from 49 patients with colorectal cancer who had undergone colorectal stent placement between January 2008 and January 2013. Patients' symptoms,characteristics and clinicopathological data were obtained by reviewing medical records. The obstruction was diagnosed clinically and radiologically. Histopathological diagnosis was achieved endoscopically. Technical success rate(TSR)was defined as the ratio of patients with correctly placed SEMS upon stent deployment across the entire stricture length to total number of patients. Clinical success rate(CSR) was defined as the ratio of patients with technical success and successful maintenance of stent function before elective surgery(regardless of number of SEMS deployed) to total number of patients. The surgical success rate(SSR) of colorectal stent as a bridge to surgery was defined as the ratio of patients with successful surgical procedures. Unsuccessful surgical outcomes were defined as being due to insufficient colonic decompression. The technical,clinical,surgical success rates and complications after stenting were assessed.RESULTS: The median age of patients was 64(36 to 89). 44.9% of patients were male and 55.1% were female. Eighteen patients had the obstruction located in the rectum,15 patients in the rectosigmoid region,10 patients in the sigmoid region,and 6 patients had a tumor causing obstruction in the proximal colon. Each patient was categorized pathologically as stage 2(32.7%,16 patients) or stage 3(42.9%,21 patients) and 12 patients(24.4%) had metastatic disease. None of the patients received chemotherapy before stenting. Stenting was undertaken in 37 patients as a bridge to surgery,and in 12 patients stents were used for palliation. Median time to surgery after stenting was 30 ± 91.9 d. All surgery was completed in one single operation and thus no colostomy with stoma was needed. The median overall survival rate of patients with stage 2-3 colorectal cancer was 53.1 mo and stage 4 was 37.1 mo(P = 0.04). Metastatic colorectal patients who were treated palliatively with stents had backbone chemotherapy with oxaliplatin and/or irinotecan-based regimens plus antiangiogenic therapies,especially bevacizumab. Resolution of the obstruction and clinical improvement was achieved in all patients. The technical,clinical and surgical success rates were 95.9%,100% and 94.6%,respectively.CONCLUSION: The efficacy and safety of colonic stents was demonstrated both as a bridge to surgery and for palliative decompression. In addition,results emphasize the importance of the skills of the endoscopist in colonic stenting.

Treating bilio-duodenal obstruction: Combining new endoscopic technique with 6 Fr stent introducer

Periampullary cancer may cause not only biliary but also duodenal obstructions. In patients with concomitant duodenal obstructions, endoscopic biliary stenting remains technically difficult and may often require percutaneous transhepatic biliary drainage. We describe a method of metal stent placement via a thin forwardviewing endoscope in patients with simultaneous biliary and duodenal obstruction. In two consecutive patients with biliary and duodenal obstruction due to pancreatic cancer, a new biliary metal stent mounted in a slim delivery catheter was placed via a thin forward viewing endoscope after passage across the duodenal stenosis without balloon dilation. In both patients, with our new placement technique, metallic stents were successfully placed in a short time without adverse events. After biliary stenting, one patient received curative resection and the other received duodenal stenting for palliation. Metallic stent placement with a forward-viewing thin endoscope is a beneficial technique, which can avoid percutaneous drainage in patients with bilio-duodenal obstructions due to periampullary cancer.