1、2018/9/2,small intestine disease,1,SMALL INTESTINE DISEASE,2018/9/2,small intestine disease,2,The length of whole small intestine is about 2.5-2.8m in vitro. All can be divided into 3 parts : Duodenum Jejunum ileum,Anatomy,2018/9/2,small intestine disease,3,2018/9/2,small intestine disease,4,2018/9/
2、2,small intestine disease,5,Jejunum and ileum,The jejunum is 2/5 of the whole small intestine The ileum is 3/5 of the whole small intestine distally. The mesentery extends from the ligament of Treitz In the base, it is only 15cmWhile in the margin, it can extend as long as the length of small bowel,
3、2018/9/2,small intestine disease,6,Histology,The wall of small intestine Mucosa Submucosa Muscles Serosa Epithelium is the inner lining of mucosa and increases the surface area of mucosa with multiple villi,2018/9/2,small intestine disease,7,Small Intestine: Duodenum, Jejunum, Ileum,2018/9/2,small i
4、ntestine disease,8,2018/9/2,small intestine disease,9,It consists of 3 kinds of cells:,The absorptive cells are columnar cell with microvilli The exocrine cells include Goblet cells secreting mucin Paneth cells containing lysosomal enzymes The endocrine cells,2018/9/2,small intestine disease,10,Phys
5、iology,The functions of the small intestine: Digestion Absorption Secretion of gut hormones Barrier for microbes and toxins of lumen passing into the system Motility that can push chyme into distal portion,2018/9/2,small intestine disease,11,Barrier:,Both nonimmunologic and immunologic processes pro
6、vide protection. Non-immunologic defenses consist of Gastric Acidity and Enteric Proteolytic Enzymes, Mucin, Peristalsis, Rapid epithelium turnover, and bacterial Competitive Inhibition. Immunologic components include Gut-Associated Lymphoid Tissue (Peyer Patches, Lymphoid Follicles, Mesenteric Lymp
7、h Nodes), Migratory Pathways, and Secretory IgA.,2018/9/2,small intestine disease,12,Intestinal Obstruction 肠梗阻,2018/9/2,small intestine disease,13,Defination,A blockade of the flow of intestinal content. Anatomic, functional changes but also systemically physiologic disorders. Intestine obstruction
8、 is a syndrome consisting of many diseases with the same symptoms.,2018/9/2,small intestine disease,14,2018/9/2,small intestine disease,15,2018/9/2,small intestine disease,16,Etiology and classification 1.According to its basic causes: mechanical, dynamic obstruction,and obstruction of vascular supp
9、ly origin 1). Mechanical obstruction from lesions within the wall of the intestine, intrinsic from extra-intestinal lesions , extrinsic from obstructing intra-luminal substances. congenital, inflammatory, neoplastic, or traumatic origin. Adhesions of postoperative, congenital origin, Hernias Intra-l
10、uminal foreign bodies,2018/9/2,small intestine disease,17,Causes of mechanical obstruction: 1hernia 2Adhesive obstruction 3Tumor in intestine 4Tumor outside intestine 5.congenital intestinal narrow 6 Intestine retortion 7Intestine narrow 8intussusception,2018/9/2,small intestine disease,18,from lesi
11、ons within the wall of the intestine, intrinsic Inflammation Tumor in intestine,2018/9/2,small intestine disease,19,Tumor in colon,2018/9/2,small intestine disease,20,from extra-intestinal lesions , extrinsic Incarcerated hernia Adhesive obstruction,2018/9/2,small intestine disease,21,from obstructi
12、ng intra-luminal substances: obstruction caused by ascarids,2018/9/2,small intestine disease,22,2). Dynamic obstruction Paralytic obstruction: Nerval reflex or toxin stimulation, acute diffuse peritonitis, abdominal operation, retroperitoneal hematoma and infection. Spastic obstruction in intestinal
13、 functional disorder or toxication. 3). Obstruction of blood supply origin thrombosis or embolism, then intestinal paralysis.,2018/9/2,small intestine disease,23,2.According to whether the vascular supply to intestinal wall is compromised, Simple and strangulation obstruction. Simple obstruction, wi
14、thout threat to the viability of the intestinal wall. Strangulation obstruction, the vascular supply is compromised.,2018/9/2,small intestine disease,24,3.According to obstruction level or site. Proximal, distal intestinal, or large bowel obstruction, or high and low obstruction 4.According to the e
15、xtent of obstruction Incomplete and complete obstruction, 5.According to mode of onset and progression of obstruction. Acute and chronic obstruction,2018/9/2,small intestine disease,25,6. Open-loop Obstruction: It is the most common type in which only a single site results in obstruction. Closed-loo
16、p Obstruction: It results when both limbs of the gut loop are obstructed or just one loop are obstructed but there is a valve in the proximal lumen. In this type of obstruction, the proximal gut could not decompression effectively such as colon obstruction.,2018/9/2,small intestine disease,26,7.Psud
17、oobstruction: It is the rare paralytic obstuction of the intestine.,2018/9/2,small intestine disease,27,Pathology,The proximal gut of the obstructive site appears distention and hyperpressure due to accumulation of the gas and fluid in lumen. The wall in this portion thins in acute obstruction, whic
18、h diminishes the gut barrel resulting in bacterial translocation. If the blood supply is impaired, the necrosis or perforation can appear in the intestinal wall while the secondary peritonitis will happen.,2018/9/2,small intestine disease,28,The wall thickens due to edema or compensating hyperplasia
19、 in chronic obstruction. The distal gut of the obstructive site is empty and collapse. The joined point is just the portion of obstruction.,2018/9/2,small intestine disease,29,Pathophysiology A.Local Effects,Intestinal gas increases with gas swallowed and produced by gastrointestinal contents. Intes
20、tinal fluid accumulates due to the decreasing flux from the lumen to the blood (absorption) and the increasing flux from the blood to the lumen (secretion). Intestinal flora is abnormal because of stasis within the intestinal segments. Intestinal motility (peristalsis) is strongly stimulated by pres
21、sure within the bowel lumen,2018/9/2,small intestine disease,30,B. Systemic Effects,Water and electrolyte losing: extracorporeal losing (vomiting) intracorporeal losing (accumulation of gas and fluid in lumen) edema of the involved intestinal wall and free peritoneal fluid exuding from the serosal s
22、urface of gut,2018/9/2,small intestine disease,31,Gut original endotoxemia Intestinal flora are abnormal and germ increasing because of stasis of the gut. The gut barrier decreases resulting from the distention of intestinal lumen in order that bacteria enter bodys system. both of two reasons can ma
23、ke the bacterial translocation to happen.,2018/9/2,small intestine disease,32,Intestinal gangrene and perforation can result in the secondary suppurative peritonitis. All of these could induce a systemic inflammatory response syndrome (SIRS) and multiple organs dysfunction syndrome (MODS).,2018/9/2,
24、small intestine disease,33,Cardiopumonary dysfunction Abdominal distention with elevated pressure in peritoneal cavity decreases the returning blood through inferior vena cava. Simultaneously, elevated diaphragm limits respiration.,2018/9/2,small intestine disease,34,Shock and other organs insuffici
25、ency prolonged hypovolemia with dehydration electrolytes disturbance acidosis or alkalosis infection in the system or peritoneal cavity All of those reasons can also lead to organ insufficiencies acute renal dysfunction acute respiratory dysfunction cardiopumonary dysfunction,2018/9/2,small intestin
26、e disease,35,Clinical manifestations Abdominal pain Nausea and vomiting Constipation Abdominal distention. Their onset varies not only with the duration of established obstruction but also with its anatomic site.,2018/9/2,small intestine disease,36,A.Pain:,Pain is the earliest and most suggestive sy
27、mptom In the early stage of obstruction, is poorly localized or diffusion The persistent severe pain represents the stage of obstruction with strangulation, perforation and peritonitis.,2018/9/2,small intestine disease,37,腹痛，伴有肠鸣,2018/9/2,small intestine disease,38,B.Vomiting:,It is an effective way
28、 that the gastro-intestinal tract could be decompressed, especially in high obstruction, and makes temporary improvement in the patient.,2018/9/2,small intestine disease,39,呕吐：部位越高呕吐越早且频繁,2018/9/2,small intestine disease,40,C.Constipation:,It is a valuable diagnostic symptom that the patient must be
29、 failure in passing flatus and feces through the anus. Still pass flatus: the distal, unobstructed intestine empties. partial or incomplete obstruction,2018/9/2,small intestine disease,41,D.Abdominal Distention:,Abdominal distention is another important symptom in the later stage of intestinal obstr
30、uction. The onset time of distention relates with obstructive site, duration, and completeness or uncompleteness.,2018/9/2,small intestine disease,42,1)not prominent in proximal intestinal obstruction, 2)prominent and diffuse in distal intestinal obstruction and paralytic obstruction. 3)colon is obs
31、tructed, abdominal distention is often round abdomen 4)Abdominal distention of intestinal torsion, is asymmetrical.,Characters of distention,2018/9/2,small intestine disease,43,腹胀：程度与梗阻部位有关,2018/9/2,small intestine disease,44,Physical Examination the signs of dehydration: dry mucous membranes, loss
32、of skin elasticity Vital Signs: In the cases with strangulated obstruction, these items are difficult to control.,2018/9/2,small intestine disease,45,B.Abdominal Findings,a.Inspection: It is the first step of physical examination. The contour of abdomen, visible peristalsis, distending gut, external
33、 hernias, and incisions of previous surgery would be observed carefully.,2018/9/2,small intestine disease,46,b.Palpation: Localized tenderness or a tender, palpable mass Signs of localized or generalized peritonitis Some items should be attend when the palpation was operated: such as, the mass in ab
34、dominal cavity (size, site, surface, soft or hard, fixation or free, tenderness),2018/9/2,small intestine disease,47,In general, the soft and tender abdomen is represent in simple mechanical obstruction while the muscle spasm or rigidity and referred tenderness is demonstrating the strangulated obst
35、ruction.,2018/9/2,small intestine disease,48,c.Percussion: Tympanic resonance refers to the degree of abdominal distention, while the shifting dullness demonstrates ascites.,2018/9/2,small intestine disease,49,d.Auscultation: It is of great value in diagnosis of intestinal obstruction. In simple obs
36、truction loud borborygmi, high-pitch tinkling, gurgling, metallic sound would be heard. If the intestinal sound is absent, it indicates a strangulated obstruction or paralytic obstruction.,2018/9/2,small intestine disease,50,e. Digital Examination of the Rectum: It should be a routine step for intes
37、tinal obstruction, particularly in older patients. If a soft and tender intraabdominal mass is palpated, it suggests an infarcted loop of the gut. Low rectal carcinoma and intussuscepted segment are palpable sometimes,2018/9/2,small intestine disease,51,Laboratory Study,There is no obvious change in
38、 early stage of mechanical intestinal obstruction. Indicate hemoconcentration secondary to intravascular volume depletion: High hematocrit urine volume diminution urine specific gravity elevating,2018/9/2,small intestine disease,52,The leukocyte count shows moderate elevation in simple intestinal ob
39、struction and increasing higher when the vascular supply is impaired. In long-standing intestinal obstruction: plasma concentration of sodium, potassium, chloride are depleted Arterial blood gas analysis indicates disturbance of the acid-base balance (metabolic acidosis by severe dehydration and isc
40、hemic bowel, alkalosis rarely).,2018/9/2,small intestine disease,53,Radiological Examination,A plain abdominal film is the most important procedure in diagnosis of intestinal obstruction When small bowel is obstructed, dilated loops of small intestine multiple air-fluid level When large bowel is obs
41、tructed, the image of dilated colonhaustra of colon Occasionally, reveal the cause.,2018/9/2,small intestine disease,54,2018/9/2,small intestine disease,55,2018/9/2,small intestine disease,56,2018/9/2,small intestine disease,57,Dilated loops of the small bowel and a strangulated left inguinal hernia
42、 (arrow).,2018/9/2,small intestine disease,58,X-ray of small intestine X-ray of ileocecum,2018/9/2,small intestine disease,59,2018/9/2,small intestine disease,60,2018/9/2,small intestine disease,61,Computed tomography in acute bowel obstruction.,Simple SBO: Open ended: Marked discrepancy in caliber
43、of proximal and distal bowel Closed loop: Fixed U-shaped or radial distribution of fluid filled bowel loops Whirl sign: tightly twisted mesentery around a collapsed segment of bowel Beak sign: fusiform tapering of afferent and efferent limbs of bowel leading into site of obstruction. Triangular, rou
44、nd or oval loops due to two adjacent collapsed loops despite proximally dilated loops,2018/9/2,small intestine disease,62,Complicated SBO: Bowel wall thickening ( 3 mm) Focal bowel dilatation Increased density of mesenteric fat Target or halo sign: concentric ring of high and low density of bowel wa
45、ll Pneumatosis intestinalis Changes in the mesentery: increased haziness, blurring of vessels, and obliteration of fat due to hemorrhage Ascites, or localized fluid collection with air bubbles (abscess) Pneumoperitoneum,2018/9/2,small intestine disease,63,A case of small intestinal necrosis due to s
46、upramesenteric vein thrombosis,2018/9/2,small intestine disease,64,An extrinsic mass compressing a loop of small bowel,2018/9/2,small intestine disease,65,A marked mural thickening associated with mucosal irregularity at the hepatic flexure of the colon. At laparotomy, a carcinoma was found.,2018/9/
47、2,small intestine disease,66,Dilated loops of fluid-filled small bowel with a small amount of air,2018/9/2,small intestine disease,67,A dilated loop of air-fluid filled small bowel leading into an incarcerated umbilical hernia,2018/9/2,small intestine disease,68,A dilated loop of small bowel with a
48、beak-shaped cutoff,2018/9/2,small intestine disease,69,A gallstone obstructing the small bowel,2018/9/2,small intestine disease,70,Endoscopy,Early ileal carcinoma demonstrating submucosal invasion,2018/9/2,small intestine disease,71,disposable capsule: 30 x 11 mm,Capsule endoscopy,2018/9/2,small int
49、estine disease,72,Capsule endoscopy,provide more than five hours of real-color images The data is later downloaded to a computer workstation and processed to produce a 20-minute video clip of the images transmitted by the capsule,2018/9/2,small intestine disease,73,Capsule endoscocpy : normal findin
50、gs,2018/9/2,small intestine disease,74,Capsule endoscopy,angiodysplasia, jejunum,bleeding angiodysplasia, ileum,2018/9/2,small intestine disease,75,Diagnosis must make clear the following questions: 1.Whether intestinal obstruction exists: Through symptoms and signs, the diagnosis can be made without difficulty. Abdominal Radiology is much helpful in diagnosis.,
