Characteristics Of Small Intestinal Strictures Under Single Balloon Enteroscopy

BackgroundSmall intestinal strictures are not rare in clinical practice and often associated with severe symptoms,such as intestinal obstruction,acute or chronic abdominal pain or gastrointestinal bleeding,which require rapid diagnosis and treatments.However,it is important to note that small intestine is located in the middle of digestive tract and deep,and it is about 5-7 meters,accounting for 75%of the length of alimentary tract as well as crooked,therefore the conventional examinations(full gastrointestinal barium meal,small intestinal barium,angiography and radionuclide scanning and routine gastroenteroscopy,etc.)have a poor diagnostic efficiency,which make the small intestine considered by clinicians as a "Dark Continent" for a long time.Capsule Endoscopy(CE)and Balloon-assisted enteroscopy(BAE)contributed to the diagnosis and treatment of small intestinal diseases.CE,as a non-invasive examination,is easy to operate and can fully observe the mucosa of small intestinal,which achieved the diagnosis of small intestinal disorders.However,CE can not allow tissue biopsy and endoscopic treatments.In addition,patients with suspected or existing small intestinal strictures are at a risk of CE retention during CE examination,which to some extent limits the widespread application of CE in patients with small intestinal strictures.BAE,including Double-balloon enteroscopy(DBE)and Single-balloon enteroscopy(SBE),overcome the deficiency of CE and can observe the small intestine directly,take biopsies as well as conduct endoscopic treatments(Endoscopic balloon dilation,stent placement,polypectomy,hemostasis and removal of foreign bodies,etc.),having become an important tool for the diagnosis and treatment of small intestinal strictures.DBE was first invented by Yamamoto and colleagues in 2001.It consists of an enteroscopy and an overtube,each with a balloon at the distal end,but its preoperative preparation and operation are complex,time-consuming and laborious;In 2008,SBE came into being,which eliminated the balloon at the distal end of the enteroscopy and only reserved the balloon of the overtube,making the operation simpler and time-saving.There was no significant difference in the diagnostic rate of small intestinal diseases between DBE and SBE.Although BAE is an invasive examination,the incidence of complications is very low.In clinical practice,CE examination is usually the first choice,but if the lesion is located beyond the Treitz ligament,deep enteroscopy(DE)is an ideal examination method.In fact,BAE can also be used as the first-line treatment for small intestinal strictures,after all,CE may have a risk of retention in the intestinal lumen.In a word,BAE enables more and more small intestinal diseases to be timely diagnosed and treated,including the small intestinal strictures.In clinical practice,the etiology of small intestinal strictures is various and can be divided into primary and secondary small intestinal strictures.The former is caused by primary small intestinal diseases,such as various neoplastic and inflammatory diseases,etc,while the latter is mostly secondary intestinal strictures caused by parenteral diseases,such as foreign body,adhesion intestinal obstruction or metastatic carcinoma,etc.The clinical features and enteroscopic manifestations of strictures caused by each disease have both similarities and differences,which require careful identification by the clinical and endoscopic doctors,so as not to delay the diagnosis and treatment of diseases.Chron's disease(CD),primary intestinal lymphoma(PIL)and intestinal tuberculosis(ITB)are similar in clinical symptoms,laboratory indicators,imaging and endoscopic manifestations,histopathological results and other aspects,which make the differential diagnosis extremely difficult.In addition,in recent years,the incidence of CD in China has been increasing,which further make clinicians attach great importance to the diagnosis and treatment of the three.A large number of previous studies focused on the value of DBE or SBE in the diagnosis and treatment of small intestinal diseases,but there were few literatures about small intestinal strictures.Therefore,this study emphasized on the characteristics of small intestinal strictures under SBE.Objectives1.To analyze the etiology of small intestinal strictures;2.To describe the enteroscopic characteristics of small intestinal strictures caused by various etiologies;3.To propose the enteroscopic classification of small intestinal strictures after summarization;4.To compare CD and ITB,CD and PIL by means of the proposed enteroscopic classification and related clinical indicators so as to facilitate the differential diagnosis.Research objects and Methods1.Cases collectedClinical data of 176 patients with small intestinal strictures confirmed by SBE examinations in Qilu Hospital of Shandong University from January 2012 to November 2018 were collected retrospectively,including demographic data,clinical symptoms,related laboratory indicators,imaging and enteroscopic manifestations,histopathological results and final diagnosis.There were 106 males and 70 females,with an average age of 51.4±16.4 years.2.SBE examinations(1)Preoperative preparation:Patients were fully informed of the necessity and risks of SBE examination and informed consents were signed.Contraindications should be excluded in all patients before SBE.Patients who underwent oral SBE needed to fast for 8-12 hours and water deprivation for 4-6 hours.Patients who underwent anal SBE began to take polyethylene glycol electrolyte powder 4-6 hours before examination and finished within 2 hours.(2)Approach of insertion:Endoscopists evaluated the general location of the lesion according to the clinical symptoms and relevant auxiliary examinations of patients,and empirically selected the oral,anal or combined approach.(3)Operative procedure:"Push and pull" method was conducted.(4)All SBE procedures were performed by 3 experienced endoscopists.Results1.Basic clinical characteristics of small intestinal strictures:Main clinical symptoms:Intestinal obstruction in 79 cases(44.9%,79/176),abdominal pain and abdominal distension in 56 cases(31.8%,56/176),obscure gastrointestinal bleeding(OGIB)in 34 cases(19.3%,34/176),nausea and vomiting in 5 cases(2.8%,5/176)as well as diarrhea in 2 cases(1.1%,2/176).Course of disease:90 cases were less than 6 months(51.1%,90/176),26 cases from 6 to 12 months(14.8%,26/176),and 60 cases were more than 12 months(34.1%,60/176).Computed tomography(CT),CT enterography(CTE)or Magnetic resonance enterography(MRE)examinations were performed in 146 patients before SBE,and only 114 patients were suspected with small intestinal strictures(78.1%,114/146).Twenty-eight patients underwent CE before SBE,and 7 of them with capsule retention were confirmed to have severe strictures under enteroscopy.2.Etiologies and locations of small intestinal strictures:There were more than 30 etiologies of small intestinal strictures in 176 patients,mainly including inflammatory diseases(42.0%,74/176),such as CD,ITB,Nonsteroid anti-inflammatory drugs-induced enteritis(NSAIDs-induced enteritis),radiation enteritis,ischemic bowel disease and so on,and neoplastic diseases(33.5%,59/176),such as primary small intestinal adenocarcinoma,PIL,leimyoma,small bowel stromal tumors(SBSTs),lipomyoma,neuroendocrine neoplasm etc.Ileum(67.8%,101/149)was the most common site of inflammatory diseases and jejunum(43.5%,30/69)was the most common site of neoplastic diseases.Among inflammatory diseases,strictures caused by CD(95.6%,43/45),ITB(72.7%,8/11)and BD(75%,3/4)occurred in the ileum.Primary small intestinal adenocarcinoma was more common in the jejunum(48.3%,14/29),while PIL was more common in the ileum(53.3%,8/15).3.Enteroscopic characteristics of small intestinal strictures under SBE(1)Inflammatory diseases:In general,inflammatory diseases tended to present as single or multiple,irregular and mild strictures accompanied by various shapes of ulceration.(2)Neoplastic diseases:Most were lateral or circumferential protrusion which blocked the small intestinal cavity and often caused single,moderate or severe strictures,which may or not be accompanied by formation of superficial ulceration.(3)Secondary small intestinal strictures:Severe strictures resulted from external pressure or deformation of the intestinal lumen and often were accompanied by congestion and edema of mucosa.Normal mucosa could also be seen,but mucosal ulceration was rare.4.Enteroscopic classification of small bowel stricturesThe classification contained three types:Protruded-associated type(Type ?),Ulcer-associated type(Type ?)and Simple type(Type ?).Each type was divided into two subtypes:Lateral-protruded type(Type ? a),Circumferential-protruded type(Type ? b),Circular ulcer-associated type(Type ? a),Irregular ulcer-associated type(Type ?b),Simple diagram type(Type ?a)and Simple hypertrophic type(Type?b).5.Comparison between CD and ITB:The age of onset was similar(P>0.05)and the location of small intestinal strictures was both common in the ileum(P>0.05).Imaging examination suggesting small intestinal strictures was more common in ITB(P=0.042),while ? b was more often seen in CD(P=0.03 1).6.Comparison between CD and PIL:Patients in PIL were older than patients in CD(P=0.014).Abdominal masses were mostly found in PIL(P=0.O11).The course of the two was statistically significant(P=0.002).The course of CD was often more than 12 months,while the course of PIL was often less than 6 months.The elevation of CRP was more often seen in PIL(P=0.002).Strictures in CD were mostly found in the ileum(P=0.007).There was a statistically significant difference in severity of strictures between the two groups(P=0.001).Mild strictures were mostly found in CD,while severe strictures were mostly found in PIL.?b was more common in CD(P<0.001),while I b(P<0.001)and III b(P=0.011)were more common in PIL.Conclusion1.Inflammatory diseases and neoplastic diseases were the main etiologies of small intestinal strictures,with CD and ITB as the former as well as primary intestinal adenocarcinoma and PIL as the latter.2.Under SBE,inflammatory diseases tended to present as single or multiple,irregular and mild strictures accompanied by various shapes of ulceration.Most neoplastic diseases were lateral or circumferential protrusion which blocked the small intestinal cavity and often caused single,moderate or severe strictures,which may or not be accompanied by formation of superficial ulceration.For secondary small intestinal strictures,severe strictures resulted from external pressure or deformation of the intestinal lumen and were often accompanied by congestion and edema of mucosa.Normal mucosa could also be seen,but mucosal ulceration was rare.3.Enteroscopic classification of small bowel strictures contained three types:Protruded-associated type(Type ?),Ulcer-associated type(Type ?)and Simple type(Type ?).Each type was divided into two subtypes:Lateral-protruded type(Type ?a),Circumferential-protruded type(Type ?b),Circular ulcer-associated type(Type ?a),Irregular ulcer-associated type(Type ?b),Simple diagram type(Type ?a)and Simple hypertrophic type(Type ?b).4.Comparing CD with ITB,?b was more common in CD.Comparing CD with PIL,?b was more common in CD,while ? b and ?b were more common in PIL.