Long-term results of endoscopic balloon dilatation of lower gastrointestinal tract strictures in Crohn's disease:A prospective study

AIM:To examine the long-term results of endoscopic treatment in a prospective study conducted over a period of 10 years,1997 to January 2007.METHODS:A total of 25 patients(20 female and five male:aged 18-75 years),with at least one symptom of stricture not passable with the standard colonoscope and with a confirmed scarred Crohn's stricture of the lower gastrointestinal tract,were included in the study.The main symptom was abdominal pain.The endoscopic balloon dilatation was performed with an 18 mm balloon under endoscopic and radiological control.RESULTS:Eleven strictures were located in the colon,13 at the anastomosis after ileocecal resection,three at the Bauhin valve and four in the ileum.Four patients had two strictures and one patient had three strictures.Of the 31 strictures,in 30 was balloon dilatation successful in a single endoscopic session,so that eventually the strictures could be passed easily with the standard colonoscope.In one patient with a long stricture of the ileum involving the Bauhin valve and an additional stricture of the ileum which were 15 cm apart,sufficient dilatation was not possible.This patient therefore required surgery.Improvement of abdominal symptoms was achieved in all cases which had technically successful balloon dilatation,althoughin one case perforation occurred after dilatation of a recurrent stricture.Available follow-up was in the range of 54-118 mo(mean of 81 mo).The relapse rate over this period was 46%,but 64% of relapsing strictures could be successfully dilated again.Only in four patients was surgery required during this follow-up period.CONCLUSION:We conclude from these initial results that endoscopic balloon dilatation,especially for short strictures in Crohn's disease,can be performed with reliable success.Perforation is a rare complication.It is our opinion that in the long-term,the relapse rate is probably higher than after surgery,but usually a second endoscopic treatment can be performed successfully,leading to a considerable success rate of the endoscopic procedure.

Short and long-term outcomes of endoscopic balloon dilatation for Crohn's disease strictures

AIM:To investigate the short and long-term outcomes of endoscopic balloon dilatation(EBD) for Crohn's disease(CD) strictures.METHODS:Between January 1995 and December 2011,47 EBD procedures were performed in 30 patients(8 females and 22 males) with CD.All patients had strictures through which an endoscope could not pass,and symptoms of these strictures included abdominal pain,abdominal fullness,nausea,and/or vomiting.The 47 strictures included 17 anastomotic and 30 de novo strictures.Endoscopy and dilatation were performed under conscious sedation with intravenous diazepam or flunitrazepam.The dilatations were all performed using through-the-scope balloons with diameters from 8 mm to 20 mm on inflation and lengths of 30-80 mm.Each dilatation session consisted of two to four,3-min multistep inflations of the balloon,repeated at intervals of 1 wk until adequate dilatation(up to 15-20 mm in diameter) was achieved.The follow-up data were collected from medical records and analyzed retrospectively.Primary success was defined as passage of the scope through the stricture after EBD.Longterm outcomes were analyzed focusing on interventionfree survival and surgery-free survival demonstrated by the Kaplan-Meier method.(Intervention-free meant cases in which neither endoscopic balloon re-dilatation nor surgery was needed after the first dilatation during the observation period).The log rank test was used to evaluate the difference in long-term outcomes between anastomotic and de novo stricture cases.RESULTS:Primary success was achieved in 44 of the 47 strictures(93.6%).Balloon dilatations failed in 3 cases(6.4%).In 1 case,EBD was a technical failure because the guide-wire could not be passed through the stricture which showed severe adhesion and was a flexural lesion of the intestine.In 2 cases,unexpected perforations occurred immediately after balloon dilatation.Of the 47 treatments,complications occurred in 5(10.6%).All 5 patients had de novo strictures.One suffered bleeding,two high fever and there were colorectal perforations.One of the patients with a colorectal perforation was treated surgically,the other was managed conservatively.These 2 cases correspond to the two aforementioned EBD failures.Long-term outcomes were evaluated for the 44 successfully-treated strictures after a median follow-up of 26 mo(range,2-172 mo).During the observation period,re-strictures after EBDs occurred in 26 cases(60.5%).Fourteen of these 26 re-stricture cases underwent EBD again,but in two EBD failed and surgery was ultimately performed in both cases.Twelve of the 26 re-stricture cases were initially treated surgically when the re-strictures occurred.Finally,30 of the 47 strictures(63.8%) were successfully managed with EBD,allowing surgery to be avoided.Intervention-free survival evaluated by the Kaplan-Meier method was 75% at 12 mo,58% at 24 mo,and 43% at 36 mo.There was no significant difference between the anastomotic strictures(n = 16) and de novo strictures(n = 28) in the intervention-free survival as evaluated by the log-rank test.Surgery-free survival evaluated by the Kaplan-Meier method was 90% at 12 mo,75% at 24 mo,and 53% at 36 mo.The 16 anastomotic strictures were associated with significantly better surgery-free survivals than the 28 de novo strictures(log-rank test:P < 0.05).CONCLUSION:Anastomotic strictures were associated with better long-term outcomes than de novo strictures,indicating that stricture type might be useful for predicting the long-term outcomes of EBD.

Decoupling coefficients of dilatational wave for Biot's dynamic equation and its Green's functions in frequency domain

Green＇s functions for Blot＇s dynamic equation in the frequency domain can be a highly useful tool for the investigation of dynamic responses of a saturated porous medium. Its applications are found in soil dynamics, seismology, earthquake engineering, rock mechanics, geophysics, and acoustics. However, the mathematical work for deriving it can be daunting. Green＇s functions have been presented utilizing an analogy between the dynamic thermoelasticity and the dynamic poroelasticity in the frequency domain using the u-p formulation. In this work, a special term ＂decoupling coefficient＂ for the decomposition of the fast and slow dilatational waves is proposed and expressed to present a new methodology for deriving the poroelastodynamic Green＇s functions. The correct- ness of the solution is demonstrated by numerically comparing the current solution with Cheng＇s previous solution. The separation of the two waves in the present methodology allows the more accurate evaluation of Green＇s functions, particularly the solution of the slow dilatational wave. This can be advantageous for the numerical implementation of the boundary element method （BEM） and other applications.

Short- and long-term efficacy of endoscopic balloon dilation in Crohn's disease strictures

AIM:To evaluate short- and long-term efficacy of endoscopic balloon dilation in a cohort of consecutive patients with symptomatic Crohn's disease (CD)-related strictures. METHODS:Twenty-six CD patients (11 men; median age 36.8 year, range 11-65 years) with 27 symptomatic strictures underwent endoscopic balloon dilation (EBD).Both naive and post-operative strictures, of any length and diameter, with or without associated fistula were included. After a clinical and radiological assessment, EBD was performed with a Microvasive Rigiflex through the scope balloon system. The procedure was considered successful if no symptom reoccurred in the following 6 mo. The long-term clinical outcome was to avoid surgery. RESULTS:The mean follow-up time was 40.7 ± 5.7 mo (range 10-94 mo). In this period, forty-six EBD were performed with a technical success of 100%. No procedure-related complication was reported. Surgery was avoided in 92.6% of the patients during the entire follow-up. Two patients, both presenting ileocecal strictures associated with fistula, failed to respond to the treatment and underwent surgical strictures resection. Of the 24 patients who did not undergo surgery, 11 patients received 1 EBD, and 13 required further dilations over time for the treatment of relapsing strictures (7 patients underwent 2 dilations, 5 patients 3 dilations, and 1 patient 4 dilations). Overall, the EBD success rate after the first dilation was 81.5%. No difference was observed between the EBD success rate for naive (n = 12) and post-operative (n = 15) CD related strictures (P > 0.05). CONCLUSION:EBD appears to be a safe and effective procedure in the therapeutic management of CD-related strictures of any origin and dimension in order to prevent surgery.

Endoscopic balloon dilation for management of stricturing Crohn’s disease in children

BACKGROUND Crohn’s disease(CD)has a multitude of complications including intestinal strictures from fibrostenotic disease.Fibrostenotic disease has been reported in 10%-17%of children at presentation and leads to surgery in 20%-50%of cases within ten years of diagnosis.When symptoms develop from these strictures,the treatment in children has primarily been surgical resection.Endoscopic balloon dilation(EBD)has been shown to be a safe and efficacious alternative to surgery in adults,but evidence is poor in the literature regarding its safety and efficacy in children.AIM To evaluate the outcomes of children with fibrostenosing CD who underwent EBD vs surgery as a treatment.METHODS In a single-center retrospective study,we looked at pediatric patients(ages 0-18)who carry the diagnosis of CD,who were diagnosed after opening a dedicated Inflammatory Bowel Disease clinic on July 1,2012 through May 1,2019.We used diagnostic codes through our electronic medical record to identify patients with CD with a stricturing phenotype.The type of intervention for patients’strictures was then identified through procedural and surgical billing codes.We evaluated their demographics,clinical variables,whether they underwent EBD vs surgery or both,and their clinical outcomes.RESULTS Of the 139 patients with CD,25(18%)developed strictures.The initial intervention for a stricture was surgical resection in 12 patients(48%)and EBD in 13 patients(52%).However,4(33%)patients whom initially had surgical resection required follow up EBD,and thus 17 total patients(68%)underwent EBD at some point in their treatment process.For those 8 patients who underwent successful surgical resection alone,4 of these patients(50%)had a fistula present near the stricture site and 4(50%)had strictures greater than 5 cm in length.All patients who underwent EBD had no procedural complications,such as a perforation.Twenty-two(88%)of the treated strictures were successfully managed by EBD and did not require any further surgical intervention during our follow up period.CONCLUSION EBD is safe and efficacious as an alternative to surgery for palliative management of strictures in selected pediatric patients with CD.

Endoscopic balloon dilation of crohn's disease stricturessafety,efficacy and clinical impact

AIM To evaluate the incidence of anastomotic strictures after intestinal resection in Crohn's disease(CD), demonstrate long-term efficacy and safety of endoscopic balloon dilation(EBD) in CD strictures and its impact on the diagnosis of subclinical postoperative endoscopic recurrence. METHODS Retrospective single tertiary center study based on prospectively collected data between 2010 and 2015including anastomotic and non-anastomotic strictures. RESULTS29% of 162 CD patients included developed an anastomotic stricture. 43 patients with anastomotic strictures and 37 with non-anastomotic strictures underwent EBD; technical success was 97.7% and 100%, respectively, however, 63% and 41% needed repeat dilation during the 4.4-year follow-up. Longer periods between surgery and index colonoscopy and higher lactoferrin levels were associated with the presence of stricture after surgery. Calprotectin levels > 83.35 μg/g and current or past history of smoking were associated with a shorter time until need for dilation(HR = 3.877, 95%CI: 1.480-10.152 and HR = 3.041, 95%CI: 1.213-7.627). Anastomotic strictures had a greater need for repeat dilation(63% vs 41%, P = 0.047). No differences were found between asymptomatic and symptomatic cohorts. Disease recurrence diagnosis was only possible after EBD in a third of patients. CONCLUSION EBD is an effective and safe alternative to surgery, with a good short and long-term outcome, postponing or even avoiding further surgery. EBD may allow to diagnose disease recurrence in patients with no clinical signs/biomarkers of disease activity.

Examination of Possible Flow Turbulence during Flow-Mediated Dilation Testing

The validity of the flow-mediated dilation (FMD) test has been doubted due to the lack of normalization to the primary stimulus, shear stress. Shear stress can be calculated using a simplified mathematical model based on Poiseuille’s law. Poiseuille’s law assumes that the blood velocity profile is parabolic. The presence of turbulence will violate this assumption. The Reynolds number (RE) is used to define critical values for the transition from laminar to turbulent flow. Between RE values of 2000 and 4000, flow enters a transitional phase where turbulence is possible. Purpose: To determine whether brachial artery blood flow becomes turbulent during reactive hyperemia following forearm ischemia. Methods: Eleven healthy male subjects (25 ± 5 years) were tested. Brachial artery diameters and blood velocities were measured continuously following 2, 4, 6 and 10 minutes ischemia. The peak post-ischemic RE (REpeak) and RE integrated over 40 seconds (RE40) post-ischemia were calculated. Results: There was a significant change in REpeak (F4,7 = 98.573, p = ≤ 0.001) and RE40) (F4,7) = 50.613, p = ≤ 0.001) in response to ischemia. Within-subjects contrasts revealed a significant increase in REpeak and RE40 for each duration of ischemia versus baseline (p = ≤ 0.001). Following 4 minutes of ischemia there was approximately 12 seconds of potentially turbulent flow. Conclusion: Blood flow transitions between laminar and turbulent flow during ischemia-induced reactive hyperemia. This may limit the efficacy of estimating shear stress when using the standard FMD test protocol.

Acute Colonic Pseudo-Obstruction (ACPO): An Expanding Colon with Unusual Risk Factors

The distention of the colon without mechanical or anatomical obstruction, Acute Colonic Pseudo-obstruction (ACPO), is a common condition occurring in the critically ill. ACPO in the setting of an acute pulmonary embolism and embolic stroke is a rarity. A 76-year-old female with shortness of breath, left hemiparesis and right-sided paresthesias presented with acute pulmonary embolism and acute infarcts of the left caudate nucleus, thalamus and occipital lobe. Her hospitalization was complicated with persistent distention of the large bowel without dilation of the small bowel. Empiric antibiotics were initiated without improvement and laboratory studies including Clostridium difficile were negative. She underwent nasogastric decompression and two decompressive colonoscopies with a resolution of her symptoms. This case illustrates an example of acute abdominal distension, without underlying etiology, in the setting of acute embolism of the pulmonary and cerebral vasculature. Early identification and action with decompressive colonoscopy were key to preventing further bowel damage or rupture.

CS(K)上的S-粗集特征

对CS(K)(概念格)上的概念结点进行等价类划分,分析了概念格的粗集特征和S-粗集特征,给出了概念格上粗集和S-粗集的定义及其相应定理,找出概念格与粗集、S-粗集之间的关系,并通过实例说明了CS(K)上的S-粗集特征.

一种新型“S”型尿道扩张器联合等离子双极电切治疗男性单纯性尿道狭窄(附10例回访)

目的介绍一种新型S型尿道扩张器联合等离子双极电切治疗男性单纯性尿道狭窄的方法,以提高腔内手术治疗尿道狭窄的治疗效果。方法总结2009年10月～2010年6月,我科利用S型尿道扩张器联合等离子双极电切治疗成功的尿道狭窄患者10例。结果 10例患者均获成功,随访12～20个月无1例术后复发。结论在等离子镜下置导丝,S型尿道扩张器逐级扩张,再联合等离子电切治疗男性单纯性尿道狭窄是一种创伤小,安全有效的方法,值得临床应用。

空气/水界面上大豆11S球蛋白吸附膜的膨胀特性

采用轴对称滴形分析法检测了不同体相蛋白含量和pH值条件下,空气/水界面上大豆11S球蛋白吸附膜的表面膨胀特征参数随吸附时间的变化.结果表明:随着吸附时间的延长,吸附膜的表面膨胀模量增大,相角减小;膨胀弹性明显高于膨胀粘性,因此,从流变学的角度分析,空气/水界面上大豆11S球蛋白吸附膜的粘弹性实际上是弹性的;表面膨胀模量随体相蛋白浓度的增加而增大,受pH值的影响更为明显.

输尿管镜联合S形尿道扩张器治疗男性尿道狭窄的临床观察

目的分析输尿管镜联合S形尿道扩张器治疗男性尿道狭窄的效果。方法回顾性分析输尿管镜联合S形尿道扩张器治疗21例男性尿道狭窄患者的临床资料。结果本组21例患者术后均获随访6~12个月。拔除尿管后,排尿情况得到显著缓解。术后尿道扩张治疗时间为4~25周,其间患者排尿顺利,无明显并发症出现。结论输尿管镜联合S形尿道扩张器治疗男性尿道狭窄,操作简单易行,安全性高,疗效显著,尤其适于在基层医院应用。

不同流体界面上大豆11S球蛋白吸附膜膨胀黏弹性的比较研究

采用轴对称滴形分析法（ADSA）检测了空气／水、正十二烷／水和大豆油／水界面上不同浓度（0．00l％-0．1％）的大豆11S球蛋白吸附膜的表面膨胀黏弹性随吸附时间的变化。研究表明，在体相蛋白溶液pH8．0和离子强度0．05mol／L的恒定条件下，随着吸附时间的延长，表面膨胀弹性增大，膨胀弹性明显大于膨胀黏性。从表面流变学的角度分析，空气／水和大豆油／水界面上大豆11S球蛋白吸附膜实际上是弹性的，膨胀弹性随液滴体相蛋白浓度的增加而增大，受界面类型的影响很大。空气／水界面上吸附膜的膨胀黏弹性最大，而大豆油／水界面上吸附膜的膨胀黏弹性最小。

Endoscopy in inflammatory bowel disease: Role in diagnosis, management, and treatment

Endoscopy plays a fundamental role in the diagnosis, management, and treatment of inflammatory bowel dis-ease(IBD). Colonoscopy, flexible sigmoidoscopy, and esophagogastroduodenoscopy have long been used in the care of patients with IBD. As endoscopic technologies have progressed, tools such as endoscopic ultrasound, capsule endoscopy, and balloon-assisted enteroscopy have expanded the role of endoscopy in IBD. Furthermore, chromoendoscopy has enhanced our ability to detect dys-plasia in IBD. In this review article, we will focus on the roles, indications, and limitations of these tools in IBD. We will also discuss the most commonly used endoscopic scoring systems, as well as special considerations in post-surgical patients. Lastly, we will discuss the role of endoscopy in the diagnosis and management of fistulae and strictures.

Endoscopic management of Crohn's strictures

Symptomatic intestinal strictures develop in more than one third of patients with Crohn's disease(CD) within 10 years of disease onset. Strictures can be inflammatory, fibrotic or mixed and result in a significant decline in quality of life, frequently requiring surgery for palliation of symptoms. Patients under the age of 40 with perianal disease are more likely to suffer from disabling ileocolonic disease thus may have a greater risk for fibrostenotic strictures. Treatment options for fibrostenotic strictures are limited to endoscopic and surgical therapy. Endoscopic balloon dilatation(EBD) appears to be a safe, less invasive and effective alternative modality to replace or defer surgery. Serious complications are rare and occur in less than 3% of procedures. For non-complex strictures without adjacent fistulizaation or perforation that are less than 5 cm in length, EBD should be considered as first-line therapy. The aim of this review is to present the current literature on the endoscopic management of small bowel and colonic strictures in CD, which includes balloon dilatation, adjuvant techniques of intralesional injection of steroids and anti-tumor necrosis factor, and metal stent insertion. Short and long-term outcomes, complications and safety of EBD will be discussed.

Endoscopic management of inflammatory bowel disease strictures

Stricture formation is a common complication of Crohn’s disease, occurring in approximately one third of all patients with this condition. While the traditional management of such strictures has been largely surgical, there have been case series going back three decades high-lighting the potential role of endoscopic balloon dilation in this clinical setting. This review article summarizes the stricture pathogenesis, focusing on known clinical and genetic risk factors. It then highlights the endo-scopic balloon dilation research to date, with particular emphasis on three large recent case series. It concludes by describing the literature consensus regarding specific methodology and presenting avenues for future investigations.

Comparison of different intervention procedures in benign stricture of gastrointestinal tract

AIM:To determine the most effective intervention procedure by evaluation of mid and long-term therapeutic efficacy in patients of stricture of the gastrointestinal tract (GTT). METHODS:Different intervention procedures were used to treat benign stricture of GIT in 180 patients including pneumatic dilation (group A,n=80),permanent (group B, n=25) and temporary (group C,n=75) placement of expandable metallic stents. RESULTS:The diameters of the strictured GIT were significantly greater after the treatment of all procedures employed (P<0.01).For the 80 patients in group A,160 dilations were performed (mean,2.0 times per patient). Complications in group A included chest pain (n=20),reflux (n=16),and bleeding (n=6).Dysphagia relapse occurred in 24(30%) and 48 (60%) patients respectively during 6-and- 12 momth follow-up periods in group A.In group B,25 uncovered or partially covered or antireflux covered expandable metallic stents were placed permantly, complications included chest pain (n=10),reflux (n=15), bleeding (n=3),and stent migration (n=4),and dysphagia relapse occurred in 5 (20%) and 3 patients (25%) during the 6-and-12 month follow-up periods,respectively.In group C,the partially covered expandable metallic stents were temporarily placed in 75 patients and removed after 3 to 7 days via gastroscope,complications including chest pain (n=30),reflux (n=9),and bleeding (n=12),and dysphagia relapse occurred in 9 (12%) and 8 patients (16%) during the 6-and-12 month follow-up periods,respectively.The placement and withdrawal of stents were all successfully performed.The follow-up of all patients lasted for 6 to 96 months (mean 45.3±18.6 months). CONCLUSION:The effective procedures for benign GIT stricture are pneumatic dilation and temporary placement of partially-covered expandable metallic stents.Temporary placement of partially-covered expandable metallic stents is one of the best methods for benign GIT strictures in mid and long-term therapeutic efficacy.

Enteroscopy in children and adults with inflammatory bowel disease

Inflammatory bowel disease(IBD)includes Crohn’s disease(CD),ulcerative colitis and unclassified entities.CD commonly involves the terminal ileum and colon but at the time of diagnosis it can be confined to the small bowel(SB)in about 30%of the patients,especially in the young ones.Management of isolated SB-CD can be challenging and objective evaluation of the SB mucosa is essential in differentiating CD from other enteropathies to achieve therapeutic decisions and to plan the follow-up.The introduction of cross-sectional imaging techniques and capsule endoscopy(CE)have significantly expanded the ability to diagnose SB diseases providing a non-invasive test for the visualization of the entire SB mucosa.The main CE limitations are the low specificity,the lack of therapeutic capabilities and the impossibility to take biopsies.Device assisted enteroscopy(DAE)enables histological confirmation when traditional endoscopy,capsule endoscopy and cross-sectional imaging are inconclusive and also allows therapeutic interventions such as balloon stricture dilation,intralesional steroid injection,capsule retrieval and more recently stent insertion.In the current review we will discuss technical aspect,indications and safety profile of DAE in children and adults with IBD.

Enteroscopy in small bowel Crohn's disease: A review

Crohn's disease(CD) is a chronic inflammatory condition of the gastrointestinal tract resulting in inflammation, stricturing and fistulae secondary to transmural inflammation. Diagnosis relies on clinical history, abnormal laboratory parameters, characteristic radiologic and endoscopic changes within the gastrointestinal tract and most importantly a supportive histology. The article is intended mainly for the general gastroenterologist and for other interested physicians. Management of small bowel CD has been suboptimal and limited due to the inaccessibility of the small bowel.Enteroscopy has had a significant renaissance recently, thereby extending the reach of the endoscopist,aiding diagnosis and enabling therapeutic interventions in the small bowel. Radiologic imaging is used as the first line modality to visualise the small bowel. If the clinical suspicion is high, wireless capsule endoscopy(WCE) is used to rule out superficial and early disease, despite the above investigations being normal. This is followed by push enteroscopy or device assisted enteroscopy(DAE) as is appropriate. This approach has been found to be the most cost effective and least invasive. DAE includes balloon-assisted enteroscopy, [double balloon enteroscopy(DBE), single balloon enteroscopy(SBE) and more recently spiral enteroscopy(SE)]. This review is not going to cover the various other indications of enteroscopy, radiological small bowel investigations nor WCE and limited only to enteroscopy in small bowel Crohn's. These excluded topics already have comprehensive reviews.Evidence available from randomized controlled trials comparing the various modalities is limited and at best regarded as Grade C or D(based on expert opinion).The evidence suggests that all three DAE modalities have comparable insertion depths, diagnostic and therapeutic efficacies and complication rates, though most favour DBE due to higher rates of total enteroscopy. SE is quicker than DBE, but lower complete enteroscopy rates. SBE has quicker procedural times and is evolving but the least available DAE today. Larger prospective randomised controlled trial's in the future could help us understand some unanswered areas including the role of BAE in small bowel screening and comparative studies between the main types of enteroscopy in small bowel CD.

Decoupling Conditions for Elasto-plastic Consolidation Question Based on Numerical Modeling Method

Elasto-plastic consolidation is one of the classic coupling questions in geomechanics. To solve this problem, an elasto-plastic constitutive model is derived based on the numerical modeling method. The model is applied to Blot＇s consolidation theory. Incremental governing partial differential equations are established using this method. According to the stress path, the decoupling condition of these equations is discussed. Based on these conditions, an incremental diffusion equation and uncoupling governing equations are presented. The method is then applied to numerical analyses of three examples. The results show that （1） the effect of the stress path should be taken into account in the simulation of the soil consolidation question; （2） this decoupling method can predict the evolvement of pore water pressure; （3） the settlement using cam-clay model is less than that using numerical model because of dilatancy.