GIGI SurgerySurgery (Small(Small IntestineIntestine && Appendix)Appendix) SmallSmall IntestineIntestine ObstructionObstruction Historically,Historically, nonoperativenonoperative managementmanagement ruledruled Reduction of hernias Laxatives Ingestion of heavy metals Leeches LateLate 1800s1800s whenwhen antisepsisantisepsis andand asepticaseptic surgicalsurgical techniquetechnique developeddeveloped surgicalsurgical interventionintervention becamebecame safersafer SmallSmall IntestineIntestine -- ObstructionObstruction UnderstandingUnderstanding thethe pathophysiologypathophysiology ofof SBOSBO withwith thethe useuse ofof thethe followingfollowing hashas greatlygreatly reducedreduced mortalitymortality ofof ptspts withwith mechanicalmechanical SBOSBO IsotonicIsotonic fluidfluid resuscitationresuscitation IntestinalIntestinal tubetube decompressiondecompression AntibioticsAntibiotics SBOSBO EtiologyEtiology ObstructionObstruction arisingarising fromfrom extraluminalextraluminal causescauses (adhesions,(adhesions, hernias,hernias, carcinomas,carcinomas, andand abscesses)abscesses) ObstructionObstruction intrinsicintrinsic toto thethe bowelbowel wallwall (primary(primary tumors)tumors) IntraluminalIntraluminal obstructionobstruction (gallstones,(gallstones, enteroliths,enteroliths, FB,FB, bezoars)bezoars) SBOSBO AtAt turnturn ofof 2020th century,century, herniashernias accountedaccounted forfor >50%>50% ofof mechanicalmechanical SBOSBO NowNow withwith electiveelective herniahernia repairs,repairs, itit isis thethe 33rd mostmost commoncommon causecause ofof SBOSBO ADHESIONSADHESIONS areare byby farfar thethe MCCMCC ofof SBO!SBO! SBOSBO AdhesionsAdhesions MainlyMainly afterafter pelvicpelvic operationsoperations (gynecologic(gynecologic procedures,procedures, appendectomy,appendectomy, andand colorectalcolorectal resection)resection) MoreMore thanthan 60%60% ofof allall causescauses ofof bowelbowel obstructionobstruction inin thethe U.S.U.S. LikelyLikely duedue toto thethe increasedincreased mobilitymobility ofof thethe bowelbowel inin thethe pelvispelvis asas comparedcompared toto thethe moremore tetheredtethered statestate inin thethe upperupper abdomenabdomen SBOSBO MalignantMalignant tumorstumors 20%20% ofof casescases MajorityMajority areare metastaticmetastatic lesionslesions secondarysecondary toto peritonealperitoneal implantsimplants thatthat havehave spreadspread fromfrom anan intraintra--abdominalabdominal primaryprimary tumortumor suchsuch asas ovarian,ovarian, pancreatic,pancreatic, gastric,gastric, oror coloniccolonic PrimaryPrimary coloniccolonic cancerscancers (cecal(cecal oror ascendingascending colon)colon) maymay causecause extrinsicextrinsic compressioncompression PrimaryPrimary SBSB tumorstumors areare extremelyextremely rarerare SBOSBO HerniasHernias 10%10% ofof casescases (3(3rd MCC)MCC) VentralVentral oror inguinalinguinal InternalInternal herniashernias –– usuallyusually relatedrelated toto priorprior abdominalabdominal surgerysurgery SBOSBO CrohnCrohn’’ss diseasedisease 44th MCCMCC (approximately(approximately 5%)5%) ObstructionObstruction resultsresults fromfrom acuteacute inflammationinflammation andand edemaedema thatthat sometimessometimes resolvesresolves withwith conservativeconservative managementmanagement LongstandingLongstanding CrohnCrohn’’ss diseasedisease cancan leadlead toto stricturesstrictures thatthat maymay requirerequire resectionresection andand reanastomosisreanastomosis versusversus strictureplastystrictureplasty SBOSBO PathophysiologyPathophysiology Early in an obstruction, intestinal motility and contractile activity increase to propel luminal contents past the obstructing point Early on this increase in peristalsis is present both proximal and distal to the point of obstruction Later in the course, the intestine becomes fatigued and dilates With dilation, water and electrolytes accumulate both intraluminally and within the bowel wall SBOSBO PathophysiologyPathophysiology Massive 3rd-space fluid loss dehydration and hypovolemia Can lead to hypotension, shock, IAP, ↓venous return, elevation of the diaphragm, ↓ ventilation Proximal obstruction Dehydration + hypochloremia + hypokalemia + metabolic alkalosis + vomiting Distal obstruction Less dramatic electrolyte abnormalities Dehydration + oliguria + azotemia + hemoconcentration SBOSBO PathophysiologyPathophysiology AsAs thethe intraluminalintraluminal pressurepressure ↑↑,, thethe mucosalmucosal bloodblood flowflow ↓↓ ConcernConcern forfor bowelbowel perforationperforation andand peritonitisperitonitis InIn absenceabsence ofof obstruction,obstruction, jejunumjejunum && ileumileum virtuallyvirtually sterile;sterile; however,however, withwith obstruction,obstruction, microfloramicroflora changeschanges E. coli, S. faecalis, Klebsiella (up to 109-1010/ml) SBOSBO –– ClinicalClinical ManifestationsManifestations SymptomsSymptoms Colicky abdominal pain Nausea Vomiting Have patient describe bilious, nonbilious, or feculent Failure to pass flatus/feces (obstipation) Develops later Pts may report diarrhea early on due to increased peristalsis Abdominal distention SBOSBO –– ClinicalClinical ManifestationsManifestations PhysicalPhysical ExamExam +/- tachycardia +/- hypotension suggestive of severe dehydration Fever (possible strangulation) Distended abdomen Rushes/tinkles Localized tenderness, rebound, guarding concern for peritonitis and strangulated bowel ALWAYS check for incarcerated inguinal hernias!!! Rectal exam – perform hemoccult SBOSBO –– ClinicalClinical ManifestationsManifestations XX--RayRay AASAAS usuallyusually confirmconfirm H&PH&P 60%60% accurateaccurate UprightUpright multiplemultiple AFLAFL SBOSBO –– ClinicalClinical ManifestationsManifestations CompleteComplete bowelbowel obstructionobstruction secondarysecondary toto largelarge radiopaqueradiopaque gallstonegallstone SBOSBO –– ClinicalClinical ManifestationsManifestations CTCT scanscan BeneficialBeneficial whenwhen diagnosisdiagnosis uncertainuncertain SensitiveSensitive forfor diagnosingdiagnosing completecomplete oror HGHG SBOSBO andand forfor determiningdetermining locationlocation andand etiologyetiology LessLess sensitivesensitive inin PSBOPSBO HelpfulHelpful forfor extrinsicextrinsic causescauses SBOSBO –– ClinicalClinical ManifestationsManifestations SBOSBO –– ClinicalClinical ManifestationsManifestations Barium/Enteroclysis Enteroclysis – oral insertion of tube into duodenum to instill air and barium directly into small intestine Definitive study in pts in whom diagnosis of LG intermittent SBO is clinically uncertain Disadvantages of enteroclysis NGT Slow transit of contrast in pts with SBO Expertise required SBOSBO –– ClinicalClinical ManifestationsManifestations U/SU/S PregnantPregnant ptspts MRIMRI NoNo betterbetter thanthan CTCT SBOSBO –– ClinicalClinical ManifestationsManifestations LabLab workwork NotNot helpfulhelpful inin diagnosisdiagnosis EssentialEssential inin assessingassessing degreedegree ofof dehydrationdehydration PtsPts withwith SBOSBO needneed serialserial electrolyteelectrolyte checkschecks toto assessassess effectivenesseffectiveness ofof resuscitationresuscitation FollowFollow HctHct secondarysecondary toto resuscitationresuscitation onon hemoconcentrationhemoconcentration associatedassociated withwith SBOSBO LeukocytosisLeukocytosis maymay bebe associatedassociated withwith strangulationstrangulation SimpleSimple vs.vs. StrangulatingStrangulating SBOSBO StrangulatingStrangulating SBOSBO usuallyusually involvesinvolves closedclosed--looploop obstructionobstruction AssociatedAssociated withwith increasedincreased morbidity/mortalitymorbidity/mortality ““ClassicClassic signssigns”” Tachycardia Fever Leukocytosis Constant noncramping abdominal pain SimpleSimple vs.vs. StrangulatingStrangulating SBOSBO CTCT usefuluseful onlyonly inin latelate stagesstages ofof irreversibleirreversible ischemiaischemia LDH,LDH, amylase,amylase, alkalk phos,phos, ammoniaammonia levelslevels notnot beneficialbeneficial LactateLactate andand CPKCPK limitedlimited successsuccess BOTTOMLINE:BOTTOMLINE: Bowel ischemia and strangulation cannot be reliably diagnosed or excluded preoperatively in all cases by any known clinical parameter. SBOSBO –– TreatmentTreatment FluidFluid ResuscitationResuscitation LRLR –– IVFIVF ofof choicechoice UOPUOP monitoringmonitoring viavia foleyfoley AfterAfter potassiumpotassium andand chloridechloride levelslevels normalizenormalize andand UOPUOP adequate,adequate, IVFIVF cancan bebe changedchanged toto maintenancemaintenance withwith KClKCl replacementreplacement DueDue toto oftenoften largelarge fluidfluid requirements,requirements, centralcentral venousvenous assessmentassessment maymay bebe necessarynecessary SBOSBO –– TreatmentTreatment BroadBroad--spectrumspectrum antibioticsantibiotics ProphylacticallyProphylactically givengiven duedue toto somesome reportedreported datadata onon bacterialbacterial translocationtranslocation AlsoAlso givengiven asas prophylaxisprophylaxis forfor possiblepossible resectionresection oror inadvertentinadvertent enterotomyenterotomy atat timetime ofof surgerysurgery SBOSBO –– TreatmentTreatment NGTNGT EmptiesEmpties stomachstomach NoNo benefitbenefit givengiven fromfrom longerlonger intestinalintestinal tubestubes PSBOPSBO cancan bebe managedmanaged conservativelyconservatively (IVF(IVF && NGT)NGT) inin 6060--85%85% ofof patientspatients SBOSBO –– OperativeOperative ManagementManagement