2024
Optimizing hospital length of stay after infrainguinal bypass: Should ultrashort set the bar?
Said S, Ochoa Chaar C. Optimizing hospital length of stay after infrainguinal bypass: Should ultrashort set the bar? Journal Of Vascular Surgery 2024, 80: 1191. PMID: 39306445, DOI: 10.1016/j.jvs.2024.05.006.Peer-Reviewed Original Research
2020
Regional Anesthesia is Underutilized for Carotid Endarterectomy Despite Improved Perioperative Outcomes Compared with General Anesthesia
Lumas S, Hsiang W, Akhtar S, Ochoa Chaar CI. Regional Anesthesia is Underutilized for Carotid Endarterectomy Despite Improved Perioperative Outcomes Compared with General Anesthesia. Annals Of Vascular Surgery 2020, 73: 336-343. PMID: 33373769, DOI: 10.1016/j.avsg.2020.11.035.Peer-Reviewed Original ResearchConceptsNational Surgical Quality Improvement ProgramCarotid endarterectomyGeneral anesthesiaRegional anesthesiaImproved outcomesSurgeons National Surgical Quality Improvement ProgramChronic obstructive pulmonary diseaseOutcomes of CEASurgical Quality Improvement ProgramCombined end pointObstructive pulmonary diseaseChoice of anestheticQuality Improvement ProgramAnesthesia typeHospital lengthPerioperative outcomesBaseline characteristicsPatient characteristicsCarotid surgeryHeart failurePropensity matchingPulmonary diseaseGA patientsMyocardial infarctionAmerican CollegeMultiple Reinterventions for Claudication are Associated with Progression to Chronic Limb-Threatening Ischemia
Kim TI, Kiwan G, Mohamedali A, Zhang Y, Dardik A, Guzman RJ, Ochoa Chaar CI. Multiple Reinterventions for Claudication are Associated with Progression to Chronic Limb-Threatening Ischemia. Annals Of Vascular Surgery 2020, 72: 166-174. PMID: 33227462, DOI: 10.1016/j.avsg.2020.10.004.Peer-Reviewed Original ResearchConceptsChronic limb-threatening ischemiaLower extremity revascularizationCongestive heart failureHeart failureOpen revascularizationMultiple reinterventionsSingle-center retrospective reviewChronic limb threatening ischemiaLimb threatening ischemiaLimb-threatening ischemiaNumber of reinterventionsLong-term outcomesMultivariable logistic regressionRate of progressionBenign natural historyIndex revascularizationMajor amputationRest painPerioperative complicationsExtremity revascularizationRetrospective reviewRisk factorsDisease progressionOpen procedureClaudicationOutcomes of treatment with paclitaxel-coated devices for peripheral arterial disease
Kim TI, Kiwan G, Mohamedali A, Zhang Y, Mena-Hurtado C, Mojibian H, Guzman RJ, Ochoa Chaar CI. Outcomes of treatment with paclitaxel-coated devices for peripheral arterial disease. Journal Of Vascular Surgery 2020, 73: 911-917. PMID: 33038480, DOI: 10.1016/j.jvs.2020.08.146.Peer-Reviewed Original ResearchMeSH KeywordsAgedAged, 80 and overAmputation, SurgicalCardiovascular AgentsCoated Materials, BiocompatibleDrug-Eluting StentsEndovascular ProceduresFemaleHumansLimb SalvageMaleMiddle AgedPaclitaxelPeripheral Arterial DiseaseProsthesis DesignRetreatmentRetrospective StudiesRisk AssessmentRisk FactorsTime FactorsTreatment OutcomeVascular PatencyConceptsPaclitaxel-coated devicesPeripheral artery diseaseCause of mortalityPCD useRisk of mortalityCumulative doseFemoropopliteal peripheral artery diseaseKaplan-Meier survival curvesLong-term mortalityPeripheral arterial diseaseCox regression analysisDrug-coated balloonsOutcome of treatmentDrug-eluting stentsMajor amputationPrimary patencyReintervention rateArtery diseaseArterial diseaseRandomized trialsOpen surgeryPresent studySingle institutionEndovascular interventionPatientsLower Extremity Revascularization for Chronic Limb-Threatening Ischemia among Patients at the Extremes of Age
Kim TI, Aboian E, Fischer U, Zhang Y, Guzman RJ, Ochoa Chaar CI. Lower Extremity Revascularization for Chronic Limb-Threatening Ischemia among Patients at the Extremes of Age. Annals Of Vascular Surgery 2020, 72: 517-528. PMID: 32927042, DOI: 10.1016/j.avsg.2020.08.135.Peer-Reviewed Original ResearchMeSH KeywordsAge of OnsetAgedAged, 80 and overAgingAmputation, SurgicalChronic DiseaseDatabases, FactualEndovascular ProceduresFemaleHumansIschemiaLimb SalvageLower ExtremityMaleMiddle AgedPeripheral Arterial DiseaseRisk AssessmentRisk FactorsTime FactorsTreatment OutcomeVascular Surgical ProceduresConceptsChronic limb-threatening ischemiaLower extremity revascularizationExtremes of ageRisk factor profileMajor amputationPatients 51Extremity revascularizationFactor profileDistinct risk factor profilesAge groupsChronic limb threatening ischemiaLimb threatening ischemiaLimb-threatening ischemiaMajor amputation ratePeripheral artery diseaseGroup of patientsInsulin-dependent diabetesExtreme age groupsSuprainguinal bypassAmputation rateElderly patientsInfrainguinal bypassActive smokersArtery diseaseMultivariable analysisTrends and outcomes of thoracic endovascular aortic repair with open concomitant cervical debranching
Bellamkonda KS, Yousef S, Nassiri N, Dardik A, Guzman RJ, Geirsson A, Ochoa Chaar CI. Trends and outcomes of thoracic endovascular aortic repair with open concomitant cervical debranching. Journal Of Vascular Surgery 2020, 73: 1205-1212.e3. PMID: 32861861, DOI: 10.1016/j.jvs.2020.07.103.Peer-Reviewed Original ResearchMeSH KeywordsAdolescentAdultAgedAged, 80 and overAorta, ThoracicAortic DiseasesBlood Vessel Prosthesis ImplantationCarotid ArteriesDatabases, FactualEndovascular ProceduresFemaleHumansMaleMiddle AgedPostoperative ComplicationsRetrospective StudiesRisk AssessmentRisk FactorsSubclavian ArteryTime FactorsTreatment OutcomeYoung AdultConceptsCarotid-carotid bypassEndovascular aortic repairCervical debranchingPerioperative outcomesAortic repairAortic pathologyMultivariable analysisThoracic endovascular aortic repairSurgeons National Surgical Quality Improvement Program filesCarotid-subclavian bypassDependent functional statusOpen surgical debranchingUse of TEVARLonger hospital stayCurrent Procedural Terminology codesUrgency of surgeryComplex aortic pathologiesThoracic aortic pathologyCommon surgical procedureProcedural Terminology codesSignificant differencesNumber of bypassesAdvanced endovascular technologySurgical debranchingDebranching proceduresEndograft type and anesthesia mode are associated with mortality of endovascular aneurysm repair for ruptured abdominal aortic aneurysms
Bellamkonda KS, Yousef S, Zhang Y, Dardik A, Geirsson A, Chaar CIO. Endograft type and anesthesia mode are associated with mortality of endovascular aneurysm repair for ruptured abdominal aortic aneurysms. Vascular 2020, 29: 155-162. PMID: 32787557, DOI: 10.1177/1708538120947859.Peer-Reviewed Original ResearchMeSH KeywordsAdolescentAdultAgedAged, 80 and overAnesthesia, GeneralAortic Aneurysm, AbdominalAortic RuptureBlood Vessel ProsthesisBlood Vessel Prosthesis ImplantationDatabases, FactualEndovascular ProceduresFemaleHumansMaleMiddle AgedProsthesis DesignRisk AssessmentRisk FactorsTime FactorsTreatment OutcomeYoung AdultConceptsInfrarenal abdominal aortic aneurysmAbdominal aortic aneurysmEndovascular aneurysm repairBody mass indexAortic aneurysmEndograft typeAneurysm repairOverall mortalityMass indexSurgeons National Surgical Quality Improvement Program databaseNational Surgical Quality Improvement Program databaseRuptured infrarenal abdominal aortic aneurysmQuality Improvement Program databaseRuptured abdominal aortic aneurysmLower body mass indexAbdominal aortic aneurysm diameterAneurysmal iliac arteriesDependent functional statusCharacteristics of patientsImprovement Program databasePrimary treatment modalityOpen abdominal surgeryAortic aneurysm diameterSignificant differencesConcomitant stentingCosts and complications of hospital admissions for inferior vena cava filter malfunction
Kim TI, Abougergi MS, Guzman RJ, Ochoa Chaar CI. Costs and complications of hospital admissions for inferior vena cava filter malfunction. Journal Of Vascular Surgery Venous And Lymphatic Disorders 2020, 9: 315-320.e4. PMID: 32791305, DOI: 10.1016/j.jvsv.2020.08.002.Peer-Reviewed Original ResearchMeSH KeywordsCost SavingsCost-Benefit AnalysisDatabases, FactualDevice RemovalEndovascular ProceduresFemaleForeign-Body MigrationHospital CostsHumansInpatientsLength of StayMaleMiddle AgedPatient AdmissionProsthesis DesignProsthesis FailureProsthesis ImplantationRetrospective StudiesTime FactorsTreatment OutcomeUnited StatesVena Cava FiltersConceptsIVCF retrievalEndovascular retrievalOpen retrievalMost patientsHospital admissionEndovascular removalNational Inpatient Sample databaseHigher infectious complicationsNational hospital admissionMean hospital lengthDeep venous thrombosisTenth Revision codesHigher hospital costsCost of hospitalizationSpecific ICD-10 codesUrban teaching hospitalICD-10 codesInfectious complicationsOverall complicationsHospital lengthInpatient mortalityAbdominal surgeryInstitutional seriesPatient characteristicsPulmonary embolismComparison of Atherectomy to Balloon Angioplasty and Stenting for Isolated Femoropopliteal Revascularization
Bai H, Fereydooni A, Zhuo H, Zhang Y, Tonnessen B, Guzman RJ, Ochoa Chaar CI. Comparison of Atherectomy to Balloon Angioplasty and Stenting for Isolated Femoropopliteal Revascularization. Annals Of Vascular Surgery 2020, 69: 261-273. PMID: 32512112, DOI: 10.1016/j.avsg.2020.05.019.Peer-Reviewed Original ResearchConceptsPercutaneous transluminal angioplastyMajor ipsilateral amputationIpsilateral amputationPrimary patencyDistal embolizationFemoropopliteal diseaseBalloon angioplastyTechnical successStatus improvementAnkle-brachial index improvementSignificant additional clinical benefitSociety Consensus (TASC) II classificationChronic obstructive pulmonary diseaseConcomitant open surgeryLower ratesOutcomes of atherectomyUse of atherectomyAcute limb ischemiaOne-year outcomesVascular Quality InitiativeCongestive heart failureHigher reintervention rateLower extremity revascularizationObstructive pulmonary diseaseAdditional clinical benefitThe Reintervention Index: A New Outcome Measure for Comparative Effectiveness of Lower Extremity Revascularization
Ochoa Chaar CI, Gholitabar N, DeTrani M, Jorshery S, Zhuo H, Zhang Y, Dardik A. The Reintervention Index: A New Outcome Measure for Comparative Effectiveness of Lower Extremity Revascularization. Annals Of Vascular Surgery 2020, 69: 52-61. PMID: 32474144, DOI: 10.1016/j.avsg.2020.05.040.Peer-Reviewed Original ResearchMeSH KeywordsAgedAged, 80 and overAmputation, SurgicalComparative Effectiveness ResearchEndarterectomyEndovascular ProceduresFemaleHumansLimb SalvageLower ExtremityMaleMiddle AgedPeripheral Arterial DiseasePostoperative ComplicationsRetreatmentRetrospective StudiesRisk AssessmentRisk FactorsTime FactorsTreatment OutcomeVascular GraftingConceptsOpen lower extremity revascularizationLower extremity revascularizationPeripheral artery diseaseEndovascular groupExtremity revascularizationOutcome measuresEndovascular lower extremity revascularizationFrequency of reinterventionsTertiary care centerCurrent outcome measuresNew outcome measureType of procedureCardiovascular comorbiditiesMajor amputationEndovascular revascularizationReintervention ratePatient characteristicsArtery diseaseConsecutive patientsMultivariable analysisRetrospective reviewOpen groupCare centerEndovascular proceduresReinterventionPostcontrast Acute Kidney Injury after Peripheral Vascular Interventions in Kidney Transplant Recipients
Lee SR, Dardik A, Ochoa Chaar CI. Postcontrast Acute Kidney Injury after Peripheral Vascular Interventions in Kidney Transplant Recipients. Annals Of Vascular Surgery 2020, 68: 8-14. PMID: 32428641, DOI: 10.1016/j.avsg.2020.04.057.Peer-Reviewed Original ResearchConceptsKidney transplant recipientsPeripheral vascular interventionsPostcontrast acute kidney injuryPC-AKIAcute kidney injuryKidney transplantKidney injuryTransplant recipientsRisk factorsVascular interventionsNew dialysis requirementPoor allograft functionPropensity-matched patientsPeripheral artery diseaseVascular Quality InitiativeGroup of patientsKaplan-Meier analysisMultivariable logistic regressionLong-term survivalAllograft functionBaseline warfarinHospital mortalityDialysis requirementPerioperative outcomesFeared complicationTrends of hospital-based surgery for varicose veins in the elderly
Kim TI, Zhang Y, Guzman RJ, Ochoa Chaar CI. Trends of hospital-based surgery for varicose veins in the elderly. Journal Of Vascular Surgery Venous And Lymphatic Disorders 2020, 9: 146-153.e2. PMID: 32360785, DOI: 10.1016/j.jvsv.2020.04.016.Peer-Reviewed Original ResearchMeSH KeywordsAblation TechniquesAge FactorsAgedAged, 80 and overAnesthesia, GeneralDatabases, FactualFemaleHospitalizationHumansMaleMiddle AgedPostoperative ComplicationsRetrospective StudiesRisk AssessmentRisk FactorsTime FactorsTreatment OutcomeUnited StatesVaricose VeinsVascular Surgical ProceduresVenous InsufficiencyConceptsProportion of patientsAdverse eventsVenous ablationGeneral anesthesiaVaricose veinsAge groupsVein ablationVein surgeryHospital-based surgeryCurrent Procedural Terminology codesHigh-risk patientsVaricose vein surgeryProcedural Terminology codesLarge national databaseYounger age groupsPaucity of dataMore comorbiditiesAnesthesiologists classificationOverall morbidityVenous surgeryDialysis populationVenous insufficiencyOpen surgeryConservative measuresOperative characteristicsVariations in the Management of Claudication in a Tertiary Care Center
Ochoa Chaar CI, Gholitabar N, Detrani M, Jorshery SD, Kim TI, Zhuo H, Zhang Y, Dardik A. Variations in the Management of Claudication in a Tertiary Care Center. Annals Of Vascular Surgery 2020, 67: 395-402. PMID: 32179142, DOI: 10.1016/j.avsg.2020.02.015.Peer-Reviewed Original ResearchMeSH KeywordsAgedConservative TreatmentElectronic Health RecordsEndovascular ProceduresFemaleGuideline AdherenceHealthcare DisparitiesHumansIntermittent ClaudicationLower ExtremityMaleMiddle AgedPeripheral Arterial DiseasePractice Guidelines as TopicPractice Patterns, Physicians'Retrospective StudiesRisk FactorsRisk Reduction BehaviorTertiary Care CentersTime FactorsTreatment OutcomeVascular Surgical ProceduresConceptsLower extremity revascularizationAnkle-brachial indexVascular surgeonsConservative therapyWalking exercisesSmoking cessationMean ankle-brachial indexManagement of claudicationTertiary care centerRecords of patientsCoronary artery diseaseStandard of carePattern of symptomsQuality of lifeMajor amputationVascular claudicationMedical optimizationStatin medicationExtremity revascularizationArtery diseaseOpen revascularizationMedical managementSingle centerEndovascular interventionInstitutional protocolRapid increase in hybrid surgery for the treatment of peripheral artery disease in the Vascular Quality Initiative database
Fereydooni A, Zhou B, Xu Y, Deng Y, Dardik A, Ochoa Chaar CI. Rapid increase in hybrid surgery for the treatment of peripheral artery disease in the Vascular Quality Initiative database. Journal Of Vascular Surgery 2020, 72: 977-986.e1. PMID: 32067877, DOI: 10.1016/j.jvs.2019.11.041.Peer-Reviewed Original ResearchMeSH KeywordsAgedAmputation, SurgicalCombined Modality TherapyDatabases, FactualEndarterectomyEndovascular ProceduresFemaleFemoral ArteryHumansLimb SalvageMaleMiddle AgedPeripheral Arterial DiseasePopliteal ArteryPostoperative ComplicationsRetrospective StudiesRisk AssessmentRisk FactorsTime FactorsTreatment OutcomeVascular GraftingVascular PatencyConceptsLower extremity revascularizationOpen lower extremity revascularizationVascular Quality Initiative databaseFemoropopliteal revascularizationHybrid surgeryAmbulatory statusFemoropopliteal bypassArtery diseaseFemoral endarterectomyChronic obstructive pulmonary diseaseAmputation-free survivalHigh-risk patientsPeripheral artery diseaseVascular Quality InitiativeObstructive pulmonary diseaseCoronary artery diseaseGroup of patientsKaplan-Meier analysisInitiative databaseLength of stayContemporary national trendsBYP groupFemoropopliteal vesselsHYB groupPerioperative advantages
2019
Intraoperative Ultrasound Guidance for Banding of an Arteriovenous Fistula Causing High Cardiac Output Heart Failure
Turner AD, Chen M, Dahl N, Scoutt L, Dardik A, Ochoa Chaar C. Intraoperative Ultrasound Guidance for Banding of an Arteriovenous Fistula Causing High Cardiac Output Heart Failure. Annals Of Vascular Surgery 2019, 66: 665.e5-665.e8. PMID: 31863947, DOI: 10.1016/j.avsg.2019.12.011.Peer-Reviewed Case Reports and Technical NotesConceptsEnd-stage renal diseaseArteriovenous fistulaHigh cardiac output heart failureHigh cardiac output failureHigh-output cardiac failureOutput cardiac failureIntraoperative ultrasound guidanceRare complicationCardiac failureHeart failureRenal diseaseCase reportCardiac functionUltrasound guidanceIntraoperative ultrasoundFlow volumeOutput failureFistulaPatientsGradual declineFailureBandingComplicationsHemodialysisHigh flow volumesPerioperative Outcomes of Lower Extremity Revascularization for Rest Pain and Tissue Loss
Tsay C, Luo J, Zhang Y, Attaran R, Dardik A, Ochoa Chaar CI. Perioperative Outcomes of Lower Extremity Revascularization for Rest Pain and Tissue Loss. Annals Of Vascular Surgery 2019, 66: 493-501. PMID: 31756416, DOI: 10.1016/j.avsg.2019.11.019.Peer-Reviewed Original ResearchMeSH KeywordsAdolescentAdultAgedAged, 80 and overAmputation, SurgicalCritical IllnessDatabases, FactualFemaleGangreneHumansIschemiaLeg UlcerLength of StayLimb SalvageLower ExtremityMaleMiddle AgedPainPatient ReadmissionPeripheral Arterial DiseasePostoperative ComplicationsRetrospective StudiesRisk AssessmentRisk FactorsSeverity of Illness IndexTime FactorsTreatment OutcomeUnited StatesVascular GraftingYoung AdultConceptsCritical limb ischemiaRest painMajor amputationTissue lossPerioperative outcomesTL patientsSurgeons National Surgical Quality Improvement Program databaseNational Surgical Quality Improvement Program databaseSevere peripheral artery diseaseQuality Improvement Program databaseTerms of pneumoniaWorse perioperative outcomesLonger hospital stayHigher American SocietyImprovement Program databasePeripheral artery diseaseCongestive heart failureLower Extremity RevascularizationICD-10 codesAnesthesiologists classUnplanned intubationHospital stayPerioperative mortalityExtremity revascularizationLimb ischemiaA Pilot Study of a Standardized Smoking Cessation Intervention for Patients with Vascular Disease
Rajaee S, Holder T, Indes JE, Muhs B, Sarac T, Sumpio B, Toll BA, Ochoa Chaar CI. A Pilot Study of a Standardized Smoking Cessation Intervention for Patients with Vascular Disease. Annals Of Vascular Surgery 2019, 61: 91-99.e3. PMID: 31449932, DOI: 10.1016/j.avsg.2019.06.017.Peer-Reviewed Original ResearchMeSH KeywordsAneurysmCardiovascular AgentsCholinergic AgentsConnecticutEndovascular ProceduresFemaleHumansMaleMiddle AgedNicotinePatient Education as TopicPeripheral Arterial DiseasePilot ProjectsRisk FactorsRisk Reduction BehaviorSmokersSmokingSmoking CessationTime FactorsTobacco Use Cessation DevicesTransdermal PatchTreatment OutcomeVascular Surgical ProceduresConceptsSmoking cessation interventionIntervention groupSurgery providersPrimary outcomeCessation interventionsExact testBrief smoking cessation counselingCurrent smoking cessation practicesCarbon monoxide breath testingSmoking cessation counselingSmoking cessation practicesVascular surgery serviceSmoking cessation counseling sessionsTertiary care centerFree nicotine patchesSmoking cessation programOpen surgical proceduresOutpatient smoking cessation programFisher's exact testCessation counselingVascular complicationsStandard careNicotine patchNicotine replacementVascular patientsOne-Year Readmission after Open and Endovascular Revascularization for Critical Limb Ischemia
Ochoa Chaar CI, Gholitabar N, Goodney P, Dardik A, Abougergi MS. One-Year Readmission after Open and Endovascular Revascularization for Critical Limb Ischemia. Annals Of Vascular Surgery 2019, 61: 25-32.e2. PMID: 31376536, DOI: 10.1016/j.avsg.2019.07.003.Peer-Reviewed Original ResearchMeSH KeywordsAgedAmputation, SurgicalCritical IllnessDatabases, FactualEndovascular ProceduresFemaleHospital MortalityHumansIschemiaLower ExtremityMalePatient ReadmissionPeripheral Arterial DiseaseReoperationRetrospective StudiesRisk AssessmentRisk FactorsTime FactorsTreatment OutcomeUnited StatesVascular Surgical ProceduresConceptsEndovascular lower extremity revascularizationLower extremity revascularizationCritical limb ischemiaCharlson Comorbidity IndexNationwide Readmissions DatabaseExtremity revascularizationMajor amputationEndovascular groupLimb ischemiaHigher Charlson comorbidity indexOne-year readmissionCohort of patientsClinical Modification codesHigher readmission ratesRisk-adjusted outcomesCost of careComorbidity indexEndovascular revascularizationInpatient mortalityReadmission ratesSubsequent readmissionPatient characteristicsInitial treatmentOpen revascularizationNinth RevisionNational trends of hybrid lower extremity revascularization in the ACS-NSQIP database
Fereydooni A, Zhou B, Jorshery SD, Deng Y, Dardik A, Chaar CIO. National trends of hybrid lower extremity revascularization in the ACS-NSQIP database. Vascular 2019, 27: 653-662. PMID: 31126228, DOI: 10.1177/1708538119852019.Peer-Reviewed Original ResearchConceptsLower extremity revascularizationExtremity revascularizationPeripheral artery diseaseVascular surgeonsSurgical specialistsPerioperative outcomesArtery diseaseHybrid surgeryHybrid procedureNational Surgical Quality Improvement Project databaseSurgeons National Surgical Quality Improvement Project databaseDisease codes -9Non-vascular surgeonsCurrent Procedural Terminology codesACS-NSQIP databaseProcedural Terminology codesNational trendsContemporary national trendsAnesthesiologists classificationEmergent surgeryOverall morbidityOnly patientsFemoral endarterectomyPropensity matchingHybrid surgery for bilateral lower extremity inflow revascularization
Jorshery SD, Luo J, Zhang Y, Sarac T, Ochoa Chaar CI. Hybrid surgery for bilateral lower extremity inflow revascularization. Journal Of Vascular Surgery 2019, 70: 768-775.e2. PMID: 30837177, DOI: 10.1016/j.jvs.2018.11.037.Peer-Reviewed Original ResearchConceptsABF bypassSurgery patientsHybrid surgeryAmerican CollegeSurgeons National Surgical Quality Improvement Program databaseNational Surgical Quality Improvement Program databaseQuality Improvement Program databaseSurgeons National Surgical Quality Improvement Program filesTotal hospital lengthHigh-risk patientsImprovement Program databasePropensity-matched analysisCritical limb ischemiaLower extremity revascularizationPopulation of patientsAxillobifemoral bypassComposite morbidityFemorofemoral bypassLess pneumoniaUnplanned intubationAortobifemoral bypassMajor amputationHospital lengthPerioperative outcomesBypass patients