简介：AbstractObjective:To describe and assess the repair technique and perioperative management for cerebrospinal fluid (CSF) leak resulting from extensive anterior skull base fracture via extradural anterior skull base approach.Methods:This was a retrospective review conducted at the Department of Neurosurgery of the Shanghai Tenth People's Hospital from January 2015 to April 2020. Patients with traumatic CSF rhinorrhea resulting from extensive anterior skull base fracture treated surgically via extended extradural anterior skull base approach were included in this study. The data of medical and radiological records, surgical approaches, repair techniques, peritoperative management, surgical outcome and postoperative follow-up were analyzed. Surgical repair techniques were tailored to the condition of associated injuries of the scalp, bony and dura injuries and associated intracranial lesions. Patients were followed up for the outcome of CSF leak and surgical complications. Data were presented as frequency and percent.Results:Thirty-five patients were included in this series. The patients’ mean age was 33 years (range 11-71 years). Eight patients were treated surgically within 2 weeks; while the other 27 patients, with prolonged or recurrent CSF rhinorrhea, received the repair surgery at 17 days to 10 years after the initial trauma. The mean overall length of follow-up was 23 months (range 3-65 months). All the patients suffered from frontobasal multiple fractures. The basic repair tenet was to achieve watertight seal of the dura. The frontal pericranial flap alone was used in 20 patients, combined with temporalis muscle and/or its facia in 10 patients. Free fascia lata graft was used instead in the rest 5 patients. No CSF leak was found in all the patients at discharge. There was no surgical mortality in this series. Bilateral anosmia was the most common complication. At follow-up, no recurrent CSF leak or meningitis occurred. No patients developed mucoceles, epidural abscess or osteomyelitis. One patient ultimately required ventriculoperitoneal shunt because of progressive hydrocephalus.Conclusion:Traumatic CSF rhinorrhea associated with extensive anterior skull base fractures often requires aggressive treatment via extended intracranial extradural approach. Vascularized tissue flaps are ideal grafts for cranial base reconstruction, either alone or in combination with temporalis muscle and its fascia—fascia lata sometimes can be opted as free autologous graft. The approach is usually reserved for patients with traumatic CSF rhinorrhea in complex frontobasal injuries.

简介：AbstractMany patients develop a variety of bowel dysfunction after sphincter preserving surgeries (SPS) for rectal cancer. The bowel dysfunction usually manifests in the form of low anterior resection syndrome (LARS), which has a negative impact on the patients' quality of life. This study reviewed the LARS after SPS, its mechanism, risk factors, diagnosis, prevention, and treatment based on previously published studies. Adequate history taking, physical examination of the patients, using validated questionnaires and other diagnostic tools are important for assessment of LARS severity. Treatment of LARS should be tailored to each patient. Multimodal therapy is usually needed for patients with major LARS with acceptable results. The treatment includes conservative management in the form of medical, pelvic floor rehabilitation and transanal irrigation and invasive procedures including neuromodulation. If this treatment failed, fecal diversion may be needed. In conclusion, Initial meticulous dissection with preservation of nerves and creation of a neorectal reservoir during anastomosis and proper Kegel exercise of the anal sphincter can minimize the occurrence of LARS. Pre-treatment counseling is an essential step for patients who have risk factors for developing LARS.

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简介：Background:Apreviousstudyhasreporteda50%reductionindisuseatrophyofthequadricepsduringthefirst14daysafteranteriorcruciateligament(ACL)reconstruction.Afollow-uptrialisneededtoconfirmthesepromisingresults.ThepresentstudyaimstoinvestigatetheeffectofanocclusionstimulusonquadricepsatrophyafterACLreconstruction.Methods:Atotalof24subjectsparticipatedinthestudy.Theywererandomizedintotwogroups.Startingthe2nddayaftersurgery,theocclusiongroupreceivedanocclusionstimulusfor5min,followedbyremovaloftheocclusivepressurefor3min.Thiswasrepeatedfivetimesinonetrainingsession,twicedaily.Duringtheperiodofocclusivestimulus,thesubjectsperformed20lowloadexercisesforthequadriceps.Thecontrolgroupfollowedthesameexerciseprotocol,butwithouttheocclusionstimulus.Changesinquadricepsanatomicalcrosssectionarea(ACSA)weremeasuredusingaxialmagneticresonance(MR)imagesat40%and50%ofthelengthofthefemur.Results:BothgroupshadasignificantreductionofquadricepsACSAfrom2daysbeforesurgeryto16daysaftersurgery.Duringtheinterventionperiod,theocclusiongrouplost13.8%±1.1%(mean±SEM)andthecontrolgrouplost13.1%±1.0%oftheirquadricepsACSA,respectively.Therewasnosignificantdifferencebetweentheocclusionandcontrolgroupswithregardstoatrophyofthequadricepsmuscles.Conclusion:Inconflictwithotherstudiesusingasimilarprotocol,applicationofbloodflowrestrictionthefirst14daysafterACLreconstructiondidnotreducequadricepsACSAmuscleatrophymeasuredbyMRinapopulationofathletes.

简介：AIM:Tocomparetheanteriorandposteriorcornealparametersbeforeandaftercollagencross-linkingtherapyforkeratoconus.METHODS:Collagencross-linkingwasperformedin31eyesof31keratoconuspatients(meanage30.6±8.9y).Priortotreatmentandanaverage7moaftertherapy,ScheimpfluganalysiswasperformedusingPentacamHR.Inadditiontocornealthicknessassessments,cornealradius,elevation,andaberrometricmeasurementswereperformedbothonanteriorandposteriorcornealsurfaces.Dataobtainedbeforeandaftersurgerywerestatisticallyanalyzed.RESULTS:Intermsofhorizontalandverticalcornealradius,andcentralcornealthicknessnodeviationswereobservedanaverage7moafteroperation.Cornealhigherorderaberrationshowednodifferenceneitheronanteriornoronposteriorcornealsurfaces.Duringfollow-upperiod,nosignificantdeviationwasdetectedregardingelevationvaluesobtainedbymeasurementinmmunitsbetweenthe3.0-8.0mm-zones.CONCLUSION:Cornealstabilizationcouldbeobservedintermsofanteriorandposteriorcornealsurfaces,elevationandhigherorderaberrationvalues7moaftercollagencross-linkingtherapyforkeratoconus.

简介：AIMTo在一年后续上分析并且比较五个不同变量(1wk，1，3，6并且12mo)：线性测密度术珍视的前面的囊(交流)，和以后的囊(PC)区域测密度术值，交流和PC，和交流洞在femtosecond以后的区域减小比率帮助激光的奔流surgery.METHODSThis是未来的比较级学习。71个病人经历了femtosecond在2014年6月和2015年12月之间的单个眼睛上的帮助激光的奔流外科。5.0公里直径激光帮助了前面的capsulotomy在所有眼睛上被执行。在每外科以后的评估，交流opacificaction(ACO)和密度铺平的PCopacification(PCO)被OculusPentacam?HR使用区域和线性测密度术方法。数字图象与一个裂缝灯Topcon摄影照相机和IMAGEnet?被捕获5软件。数字图象上的交流洞区域用Sketchandcalc区域计算器被测量并且变换成减小比率levels.RESULTSUsing皮尔森关联系数(PCC)，我们没发现关联(r=-0.091，P=0.46)在在ACO的进化之间的第12个月评价，区域测密度术珍视，PCO区域测密度术珍视看作了独立变量。我们没发现关联，用PCC(r=-0.096，P=0.43)在ACO线性测密度术价值和PCO的进化之间，线性测密度术珍视在第12月访问，作为独立变量两个都工作。交流线性测密度术层次和交流区域测密度术层次继续从第六强烈成长到第12个月。交流空缺区域减小比率的价值的分析(1wk，1，3，6，12mo)揭示了连续考试的价值之间的统计上重要的差别，但是变化的大小减少了。在在六和12之间监视月的最后的时期，变化的大小是结果显示出的low.CONCLUSIONOur当capsulorhexis区域减小比率铺平时，ACO测密度术从第六珍视到第12个月的Scheimpflug的猛烈增加显示了可观的减少。我们没发现在ACO区域和PCO区域和线性测密度术价值之间的关联，在第12月考试，作为独立变量工作。

简介：AbstractPurpose:To retrospectively analyze the clinical outcomes of meniscus repair with simultaneous anterior cruciate ligament (ACL) reconstruction and explore the causes of failure of meniscus repair.Methods:From May 2013 to July 2018, the clinical data of 165 patients who were treated with meniscus surgery and simultaneous ACL reconstruction, including 69 cases of meniscus repair (repair group) and 96 cases of partial meniscectomy (partial meniscectomy group) were retrospectively analyzed. The exclusion criteria were as follows: (1) ACL rupture associated with fracture, collateral ligament injury, or complex ligament injury; (2) a history of knee surgery; or (3) a significant degree of osteoarthritis. The 69 patients in the repair group were divided into the non-failure group (62 cases) and the failure group (7 cases) depending on the repair effect. Postoperative outcomes of the repair group and the partial meniscectomy group were compared. General conditions and postoperative outcomes of the failure group and the non-failure group were compared. During the median follow-up period of 28 months (range, 4 - 65 months) after the second arthroscopy, postoperative outcomes of seven patients in the failure group were summarized. SPSS 25.0 statistical software was used for statistical analysis. A p value less than 0.05 was considered statistically significant.Results:Seven patients in the failure group who underwent the second arthroscopy were followed up for (30 ± 17.4) months and their postoperative outcomes were summarized. Compared with the partial meniscectomy group, the International Knee Documentation Committee scores of patients in the repair group improved significantly (p = 0.031). Compared with the non-failure group, more patients in the failure group were younger than 24 years (p = 0.030). The median follow-up period was 39.5 months. All patients recovered well after subsequent partial meniscectomy and relieved clinical symptoms. Visual analog scale scores decreased significantly (p = 0.026), and the International Knee Documentation Committee and Lysholm scores improved significantly (p = 0.046 for both).Conclusion:The failure rate of meniscus repair in this study was 10.1% (7/69), all of which were medial meniscus tears. However, the surgical outcomes of ACL reconstruction were not affected, and there might be a role for graft protection. Therefore, meniscus retears can be successful treated by performing subsequent partial meniscectomy in patients with repair failure.

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简介：AbstractPurpose:To avoid potential problems of double-bundle anterior cruciate ligament reconstruction (ACLR), various modifications have been reported. This study analyzed a novel technique of modified double-bundle (MDB) ACLR without implant on tibial side in comparison to single-bundle (SB) ACLR.Methods:Eighty cases of isolated anterior cruciate ligament tear (40 each in SB group or MDB group) were included. SB ACLR was performed by outside in technique with quadrupled hamstring graft fixed with interference screws. In MDB group, ACLR harvested tendons were looped over each other at the center and free ends whipstitched. Femoral tunnel was created by outside in technique. Anteromedial tibial tunnel was created with tibial guide at 55°. The anatomic posterolateral aiming guide (Smith-Nephew) was used to create posterolateral tunnel. With the help of shuttle sutures, the free end of gracillis was passed through posterolateral tunnel to femoral tunnel followed by semitendinosus graft through anteromedial tunnel to femoral tunnel. On tibial side the graft was looped over bone-bridge between external apertures of anteromedial and posterolateral tunnel. Graft was fixed with interference screw on femoral side in 10° knee flexion. International Knee Documentation Committee (IKDC), Tegner score, Pivot shift and knee laxity test (KLT, Karl-Storz) were recorded pre- and post-surgery. At one year magnetic resonance imaging (MRI) was done. Statistical analysis was done by SPSS software.Results:Mean preoperative KLT reading of (10.00 ± 1.17) mm in MDB group improved to (4.10 ± 0.56) mm and in SB group it improved from (10.00 ± 0.91) mm to (4.80 ± 0.46) mm. The mean preoperative IKDC score in MDB group improved from (49.49 ± 8.00) to (92.5 ± 1.5) at one year and that in SB group improved from (52.5 ± 6.9) to (88.4 ± 2.6). At one-year 92.5% cases in MDB group achieved their preinjury Tegner activity level as compared to 60% in SB group. The improvement in IKDC, KLT and Tegner scale of MDB group was superior to SB group. MRI confirmed graft integrity at one year and clinically at 2 years.Conclusion:MDB ACLR has shown better outcome than SB ACLR. It is a simple technique that does not require fixation on tibial side and resultant graft is close to native ACL.

简介：Objective:Toanalyzethehistologicalresultsandthebiologicalremodelingofligamentousinsertionafterthereconstructionofanteriorcruciateligament(ACL)withautograftorallografttendon.Methods:ExtensordigitorumtendonwasharvestedfromhindlimbasgraftmaterialandtransplantedtoreconstructtheresectedACLin12mongreldogs.Eachfreetendonendwassecuredbyholdingsuturesandthenthesuturesweretiedtothepostscrewatthefemoralandtibialbonytunneloutletaftertransplantationrespectively.Autograftwasrandomlyperformedononesideofkneewhileallograftontheothersideofknee.Aftertransplantation,thehistologicalanalysiswasundertakenatthe6th,12thweeksandthe6thmonthusinghematoxylin-eosin(HE)stainunderlightmicroscope.Results:TheinsertionstructureofnormalACLtypicallyconsistedoffourlayers,i.e.,denseconnectivetissue,fibrocartilage,mineralizedfibrocartilageandbone.Therewasadistinctregulartidemarklinebetweenfibrocartilageandmineralizedfibrocartilage.Atthe6thweekpostoperativcly,looseconnectivetissuepresentedintheinterspacebetweengraftandbonytunnelwallinbothautograftandallograftgroups.Atthe12thweekpostoperatively,thecollagenousfibersbetweenautograftandtunnelwallbecamewellorganizedandthefourlayersofinsertionwithdiscontinuoustidemarklineweredemonstratedindistinctlyinautograftgroupbutnotinallograftgroup.Atthe6thmonthpostoperatively,bothofaclearandcontinuoustidemarklineanddistinctfourlayerscouldbeseeninautograftgroup.Inallograftgroup,onlyawaveddiscontinuoustidemarklinewasshownandeithertheanatomicmorphologyorthematurityofinsertionwasinferiortothatofautograftgroup.Conclusions:Atthe6thmonthpostoperatively,althoughtheligament-cartilageinsertionisprimarilyformedafterACLreconstructionwithautograftorallografttendon,thehistologicalmorphologyandthematurationofinsertionofautografttendonar

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简介：AbstractBackground:Recently, adjustable-loop devices (ALDs) have been widely used, and their reliability has always been the focus of attention. This study compared loop length changes under pull stress caused by flexion and extension of the cadaver knee between ALDs and fixed-loop devices (FLDs) in terms of femoral fixation after anterior cruciate ligament (ACL) reconstruction.Methods:ACL reconstruction in cadaveric knee joints was performed under arthroscopy with femoral suspension devices and tibial fixation by tying sutures on staples. The knee joint was repeatedly flexed and extended 30 times after fixation. According to the femoral fixation device used (Endobutton or Ultrabutton), the knee joints were divided into two groups: the ALD group (12 specimens) and the FLD group (ten specimens). The length of the loop before and after fixation was measured, and the loop length of the ALD group was re-measured 1 day after reconstruction.Results:There was no significant difference in the length of the loop between the two groups (t = 0.579, P = 0.569). One day later, the loop length of the ALDs retracted by 0.29 ± 0.33 (0-1.1) mm, and there was no retraction in three specimens.Conclusion:There was no significant difference in the loop length under flexion and extension stress after ACL reconstruction between ALDs and FLDs.

简介：Inanerawhencardiactransplantpatientsaresurvivingmoreimmediateissuesofrejectionandinfection,theprevalenceofmorechronicissuessuchascardiacallograftvasculopathy(CAV)isrising.Thiscasedescribesaman20yearsaftercardiactransplantwithhisfirstpresentationofCAV.Acutemyocardialinfarctionwasdiagnosedonthebasisofsymptomsandbiochemicalmarkersandoncoronaryangiography,andhewasfoundtohaveacriticalstenosisofthemidportionoftheleftanteriordescendingartery.Itwaselectedtotreatthispercutaneouslywithafullybioresorbablevascularscaffold(BVS)becauseofthediffusenatureofthediseaseprocess.Thiswassuccessfullyperformedwithopticalcoherencetomographyguidance.TheuseofBVSinCAVhasnotbeenwellstudied.ThisisoneoffewcasereportsdescribingtheuseofBVSinCAV.

简介：Ourpreviousstudieshaveconfirmedthatduringnervetranspositionrepairtoinjuredperipheralnerves,theregeneratednervefibersofmotorneuronsintheanteriorhornofthespinalcordcaneffectivelyrepairdistalnerveandtargetmuscletissueandrestoremusclemotorfunction.Toobservetheeffectofnerveregenerationandmotorfunctionrecoveryafterseveraltypesofnervetranspositionformediannervedefect(2mm),30Sprague-Dawleyratswererandomlydividedintoshamoperationgroup,epineurialneurorrhaphygroup,musculocutaneousnervetranspositiongroup,medialpectoralnervetranspositiongroup,andradialnervemuscularbranchtranspositiongroup.Threemonthsafternerverepair,thewristflexiontestwasusedtoevaluatetherecoveryofwristflexionafterregenerationofmediannerveintheaffectedlimbsofrats.Thenumberofmyelinatednervefibers,thethicknessofmyelinsheath,thediameterofaxonsandthecross-sectionalareaofaxonsintheproximalanddistalsegmentsoftherepairednervesweremeasuredbyosmicacidstaining.Theratioofnewlyproduceddistalmyelinatednervefiberstothenumberofproximalmyelinatednervefiberswascalculated.Wetweightsoftheflexordigitorumsuperficialismusclesweremeasured.Musclefibermorphologywasdetectedusinghematoxylin-eosinstaining.Thecross-sectionalareaofmusclefiberswascalculatedtoassesstherecoveryofmuscles.Resultsshowedthatwristflexionfunctionwasrestored,andthenervegrewintothedistaleffectorinallthreenervetranspositiongroupsandtheepineurialneurorrhaphygroup.Thereweredifferencesinthenumberofmyelinatednervefibersineachgroup.Themagnificationofproximaltodistalnerveswas1.80,3.00,2.50,and3.12inepineurialneurorrhaphygroup,musculocutaneousnervetranspositiongroup,medialpectoralnervetranspositiongroup,andradialnervemuscularbranchtranspositiongroup,respectively.Nevertheless,axondiametersofnewnervefibers,cross-sectionalareasofaxons,thicknessesofmyelinsheath,wet

简介：AbstractPurpose:Recurrent dislocation of shoulder (RDS) is a common injury in high demand professionals, like athletes and military personnel. The treatment for the patients with Bankart lesion is the arthroscopic repair. This present study compares the outcomes of two different techniques of arthroscopic Bankart repair i.e. a standard two anterior portals technique and a single anterior portal technique in patients with RDS.Methods:Patients with traumatic RDS met the inclusion criteria were managed with Bankart repair using either two anterior portals (Group A) or a single anterior portal (Group B) technique. Patients were evaluated before the intervention and at the mean follow-up of approximately two years using Rowe score, Oxford shoulder score and Tegner activity scale.Results:The mean age of the patients in Groups A (n = 34) and B (n = 37) was 29.64 years and 29.05 years respectively (p = 0.66). The dominant shoulder was involved in 27 patients in Group A and 22 patients in Group B (p = 0.069). The operative time in Group A and B was 68.52 min and 46.35 min, respectively (p < 0.001). The complications at follow-up, the mean Rowe score and Oxford score improved significantly in both groups compared with the pre-operative values. However, the final outcome scores were not significantly different between the both groups. The median Tegner's score preoperatively and at follow-up was 7 and 6, respectively in Groups A and B.Conclusions:Single anterior portal technique is an effective treatment modality, yielding a similar outcome as two anterior portals technique in the management of RDS.

简介：AbstractPurpose:The purpose of this study was to review the microsurgical anatomy and clipping of ruptured anterior communicating artery (AComA) aneurysms and to plan and avoid complications before operation.Methods:A total of 523 cases of cerebral aneurysms admitted to the neurosurgery department of the Third Affiliated Hospital of Sun Yat-Sen University from September 2010 to October 2018 were analyzed retrospectively. Among them, 85 patients had ruptured AComA aneurysms. This study was limited to 85 of these cases, whose satisfactory preoperative angiographic diagnostic films can be retrieved from the hospital database system because of the need for detailed review.Results:We performed supraorbital eyebrow keyhole approach (SOEK) craniotomy in 85 patients to clip 85 AComA aneurysms, in the setting of subarachnoid hemorrhage (SAH). Patients’ mean age was (52.69 ± 9.94) years (range, 28-78 years). The proportions of small, medium and large aneurysms were 83.5%, 15.3%, and 1.2%, respectively. The average size of the aneurysms was (5.07 ± 2.36) mm. There were 77.8% of patients with inferior aneurysms and 81.3% of patients with superior aneurysms achieved good results. There was a significant correlation between A1 dominance and operation method (p < 0.001). There was no significant relationship between surgical approach and aneurysm projection or A2 plane (p = 0.157 & p = 0.318).Conclusion:Regardless of whether the A2 plane is open or closed, the A1 dominant side is still a better choice for accessing AComA aneurysms to avoid dangerous premature bleeding.

简介：AbstractPurpose:The majority of acute anterior shoulder dislocations are sustained during sports and wilderness activities. The management of acute dislocations in the pre-hospital setting is currently without guidelines based on the evidence. The study aims to assess the risk of acute complications in pre-hospital shoulder reduction and identify which pre-hospital reduction technique has the highest success rate in the published literature.Methods:The involved databases were Allied and Complementary Medicine, CENTRAL, CINAHL, Cochrane Database of Systematic Reviews, Embase, Europe PMC, Ovid MEDLINE®, Pedro, Proquest, Trip, and World Health Organization International Clinical Trials Registry platform. Only original research of high methodological quality was included, which was defined by the recently developed assessment tool-assessing the methodological quality of published papers (AMQPP) and investigated the management of acute anterior shoulder dislocations in the pre-hospital setting.Results:Two hundred and ninety-eight articles were identified and screened. A full text review was performed on 40 articles. Four articles published between 2015 and 2018 met the inclusion criteria. A total of 181 patients were included with the study duration ranging from 6 to 60 months. All studies reported zero immediate complication following pre-hospital reduction and there were no documented subsequent adverse events regardless of the technique used. Prompt resolution of neurological symptoms was observed following the early and successful pre-hospital reduction. First attempt success rate, when performed by skilled practitioners, ranged from 72.3% to 94.9%.Conclusion:Pre-hospital shoulder reduction appears to be a safe and feasible option when carried out with the appropriate expertise. A novel reduction technique adapted from the mountain medicine diploma course at the University of Paris North was found to have the highest first attempt reduction success rate of 94.9%. Other techniques described in the literature included Hippocratic, Stimson's, Counter-traction and external rotation with the success rates ranging from 54% to 71.7%.

简介：BackgroundAcuteinferiorandanteriormyocardialinfarctionoftenleadstorightventricular(RV)functiondecrease.EstimationofRVfunctionischallengingduetothecomplexRVgeometry.Fewstudieshavebeenconductedtoinvestiogatetheeffectsofacutemyocardialinfarction(AMI)onrightventricularfunctions(RVFs).Two-dimensionSpeckleTrackingImaging(STI)isanovelmethodthatallowsforasegmentbasedmeasurementofmyocardialdeformationandmayhavethepotentialtoquantifyRVdysfunctionmorepreciselythantheconventionalparametersofRVfunction.Therefore,inthisstudyweanalyzedtheRVfunctioninAMIpatientsbyusingthisnoveltechnique.MethodsThirty-fourpatientswithacuteinferiormyocardialinfarction(AIMI),31patientswithacuteanteriormyocardialinfarction(AAMIand30agematchedhealthyindividualswereenrolledforthestudy.2Dspeckletrackingimaging(STI)wasusedtoobtain2Dimagingattheapicalfour-chamberviewunderrestcondition.Peaksystolicstrainsandstrainratesofallsegmentsinrightventricularfreewallwereanalyzed.ResultsComparedtothenormalcontrolgroup,longitudinalpeaksystolicstrain(ε),strainrate(SRs),earlydiastolicstrainrate(SRe)andlatediastolicstrainrate(SRa)inallsegmentsofrightventricularfreewallweresignificantlylowerinAMIpatients.ε,SRs,SReandSRaofeachsegmentofRVintheAIMIgroupweredecreasedsignificantlythanthoseofthenormalcontrolgroup(P<0.05).ε,SRs,SReandSRaofeachsegmentofRVintheAAMIgroupwerelowerthantheseinthecontrolgroup.ExceptforbasalsegmentalSRa,thereweresignificantdifferencesamongotherparameters(P<0.05).ConclusionsRVFsareimpairedinAMIpatients.RVFscouldbeaccuratelyandsensitivelyassessedwithSTI.

简介：AbstractObjective:Endoscopic repair of large anterior skull base (ASB) defects has excellent results when using multilayered repairs with a nasoseptal flap. However, in extensive intranasal tumors, a nasoseptal flap may not always be available. One alternative option is a flexible single-layer ASB repair. Initial studies indicate low cerebrospinal fluid leak rates with a single-layer repair. However, the level of frontal lobe support, particularly the propensity for a significant inferior displacement of the frontal lobe, is not known. The goal of this study is to determine the frontal lobe position after single-layer acellular dermal allograft repair in large ASB defects.Study Design:Retrospective cohort study.Setting:Tertiary care medical center.Subjects and Methods:This cohort study compares the frontal lobe position in adults who underwent endoscopic endonasal ASB tumor resection and single-layer cadaveric dermal matrix repair (ASB cohort) with control subjects without intracranial abnormalities (control cohort). The ASB cohort includes subjects with an ASB defect of ≥5 cm anterior/posterior and ≥1.5 cm wide and who had imaging at least 2 months after surgery. The frontal lobe position is measured on sagittal CT/MRI using a reference line from the base of the sella to the nasion. A value of zero indicates that the inferior-most aspect of the frontal lobe is at the level of the nasion-sellar line. A positive value indicates that the frontal lobe is inferior to the nasion-sellar line. The ASB cohort frontal lobe position is compared with the control cohort using the Mann-Whitney U test. A priori we set an absolute difference of 5 mm as a clinically significant difference.Results:The ASB cohort includes 47 subjects who are 57% male with an average age of 60 years (range: 31-89 years). The most common ASB pathology is esthesioneuroblastoma (n = 21) and 81% of the ASB cohort had postoperative radiation. The control cohort includes 20 subjects who are 60% male, with a mean age of 45 years (range: 19-74 years). The majority of controls underwent imaging for head trauma (n = 13). The ASB mean frontal lobe position is -0.2 mm superior to the nasion-sellar line (range: -9.2 to 10.4 mm), while the control's mean frontal lobe position is 1.1 mm inferior to the nasion-sellar line. This difference is not statistically significant (P= 0.13) and does not reach our a priori definition of clinical significance. The frontal lobe position of ASB subjects who had radiation is closer to the nasion-sellar line as compared with those who did not undergo radiation.Conclusions:Single-layer acellular dermal graft repair maintains frontal lobe support and position in large ASB defects.