小肠疾病英文-PPT.ppt

AnatomyThe jejunal mucosa is relatively thick with prominent plicae circulares;the mesenteric vessels form only one or two arcades with long vasa recta.The ileum is smaller in circumference and has thinner walls;the mesenteric vessels form multiple vascular arcades with short vasa recta.Blood supply to the jejunoileum and distal duodenum is entirely from the superior mesenteric artery,which courses anterior to the third portion of the duodenum.The celiac artery supplies the proximal duodenum.PhysiologyMotility:Peristalsis consists of intestinal contractions passing aborally at a rate of 1 to 2 cm/seccontractions initiated by the migrating myoelectric complex(MMC)under the control of both neural and humoral pathwaysENDOCRINE FUNCTIONObstructionEtiology:Common causes of small bowel obstruction in industrialized countries:Clinical Manifestations and DiagnosisCardinal symptoms:colicky abdominal pain nausea vomiting abdominal distention failure to pass flatus and fecesPhysical Examdistended abdomenperistaltic wavesminimal or no bowel soundsMild abdominal tenderness with/without a palpable massExam to rule out incarcerated herniasRectal examRadiologic and Laboratory ExaminationsPlain abdominal radiographs:accuracy60%-dilated loops of small intestine without evidence of colonic distention -multiple air-fluid levels,often in a stepwise pattern -demonstrate the cause of the obstructionCT:for more complex casesPlain abdominal film shows complete bowel obstruction caused by a large radiopaque gallstone(arrow)obstructing the distal ileum.CT scan of the abdomen of a patient with a mechanical bowel obstruction secondary to an abscess in the right lower quadrant(arrow).Multiple dilated and fluid-filledloops of small bowel are noted.Simple Vs Strangulating Obstruction“Classic”signs of strangulation:-tachycardia-fever-Leukocytosis-a constant,noncramping abdominal painDifferentiation of partial from complete SBOPartial SBO:pass flatus or liquid stoolsComplete SBO:obstipation Differentiation of Proximal /distal SBOpain:epigastric/periumbilical area vomiting:prominent/later onsetdistention:no/predominateTreatmentMedical and surgical managementThe overlapping sequence:investigation resuscitation operationThe timing of operation depends on three factors:-duration -opportunity of vital organ function -risk of strangulationMedical ManagementNasointestinal /nasogastric intubation Intravenous fluids/blood plasma administrationBroad-spectrum antibiotics administrationSurgical principlesThe nature of problem determines approach to management of SBO.The criteria of determining bowel viability:color,motility,arterial pulsationIf questionable,released and placed,re-examined