UNIVERSITE MOHAMMED V DE RABAT
FACULTE DE MEDECINE ET DE PHARMACIE - RABAT
DOYENS HONORAIRES :
1962 – 1969 : Professeur Abdelmalek FARAJ 1969 – 1974 : Professeur Abdellatif BERBICH
1974 – 1981 : Professeur Bachir LAZRAK
1981 – 1989 : Professeur Taieb CHKILI
1989 – 1997 : Professeur Mohamed Tahar ALAOUI
1997 – 2003 : Professeur Abdelmajid BELMAHI
2003 - 2013 : Professeur Najia HAJJAJ – HASSOUNI
ADMINISTRATION: Doyen
Professeur Mohamed ADNAOUI
Vice-Doyen chargé des Affaires Académiques et estudiantines Professeur Brahim LEKEHAL
Vice-Doyen chargé de la Recherche et de la Coopération Professeur Toufiq DAKKA
Vice-Doyen chargé des Affaires Spécifiques à la Pharmacie Professeur Younes RAHALI
PROFESSEURSDEL'ENSEIGNEMENTSUP2RIEUR:
Décembre 1984
Pr.MMOUNIAbdelaziz MédecineInterne-Cl i nique Rovale
Pr. MAAZOUZIAhmedWajdi Anesthésie-Réanimation Pr.SETTAFAbdellatif PathologieChirurgicale Janvier, Février et Décembre 1987
Pr. LA..CHKAR Hassan MédecineInterne
Décembre 1988
Pr.DAFIRIRachida Radiologie
Décembre 1989
Pr.ADNAOUIMohamed MédecineInterne-Doyen de l a FMPR
Pr.OUAZZANITaïbiMohamedRéda Neurologie
Janvier et Novembre 1 990
Pr.KHARBACHAîcha Gynécologie.Obstétrique Pr. TAZISaoudAnas AnesthésieRéanimation
Février Avril Juillet et Décembre 1991
Pr.AZZOUZIAbderrahim AnesthésieRéanimation-Doven de FMPQ
Pr.BAYAHIARabéa Néphrologie
Pr.BELKOUCHI Abdelkader ChirurgieGénérale Pr.BENCHEKROUNBelabbesAbdellatif ChirurgieGénérale Pr. BENSOUDAYahia Pharmaciegalénique
Pr.BERRAHO Amina Ophtalmologie
Pr.BEZADRachid GynécologieObstétriqueMéd. C hef M;1ternité des O rangers
Pr.CHERRAH Yahia Pharmacologie
Pr.CHOKAIRIOmar Histologie Embryologie
Pr. KHATTAB Mohamed Pédiatrie
Pr.SOUIAYMANIRachida Pharmacologie·Di r. du Centre Nati o mil PV Rabat
Pr.TAOUFIKJamal Chimiethérapeutique
Décembre 1992
Pr.AHALIATMohamed ChirurgieGénéraleDoyen de FMPT
Pr.BENSOUDA Adil AnesthésieRéanimation Pr.CHAHEDOUAZZANILaaziza Gastro·Entérologie Pr.CHRAIBI Chafiq GynécologieObstétrique
Pr.JIDDANEMohamed Anatomie
Pr.TAGHYAhmed ChirurgieGénérale
Pr. ZOUHDI Mimoun Microbiologie
Mars 1994
Pr.BENJAAFARNoureddine Radiothérapie
Pr.BENRAISNozha Biophysique
Pr.CAOUIMalika Biophysique
Pr.CHRAIBI Abdelmjid EndocrinologieetMaladiesMétaboliquesDoven de l à FMPA
Pr.ELAMRANISabah GynécologieObstétrique
Pr.ELBARDOUNIAhmed Traumato-Orthopédie
Pr.ELHASSANIMyRachid Radiologie
Pr.ERROUGANIAbdelkader ChirurgieGénérale-Di recteur du C HIS
Pr.ESSAKALIMalika Immunologie
Pr.ETTAYEBIFouad ChirurgiePédiatrique
Pr.IFRINELahssan ChirurgieGénérale
Pr. MAHFOUDMustapha Traumatologie-Orthopédie
Pr. RHRABBrahim Gynécologie –Obstétrique
Pr.SENOUCIKarima Dermatologie
Mars 1994
Pr.ABBARMohamed* UrologieInspect eur du SSM
Pr.BENTAHIIA Abdelali Pédiatrie
Pr.BERRADAMohamedSaleh Traumatologie-Orthopédie
Pr.CHERKAOUILallaOuafae Ophtalmologie Pr.IAKHDARAmina GynécologieObstétrique Pr.MOUANENezha Pédiatrie Mars 1995 Pr.ABOUQUALRedouane RéanimationMédicale Pr.AMRAOUIMohamed ChirurgieGénérale Pr.BAIDADAAbdelaziz GynécologieObstétrique Pr.BARGACHSamir GynécologieObstétrique Pr. ELMESNAOUIAbbes ChirurgieGénérale Pr.ESSAKALIHOUSSYNILeila Oto-Rhino-Laryngologie Pr.IBENATIYAANDALOUSSIAhmed Urologie Pr.OUAZZANICHAHDIBahia Ophtalmologie
Décembre 1996 Pr.BELKACEMRachid ChirurgiePédiatrie Pr.BOUIANOUARAbdelkrim Ophtalmologie Pr.ELAIAMIELFARICHAELHassan ChirurgieGénérale Pr.GAOUZIAhmed Pédiatrie Pr. OUZEDDOUNNaima Néphrologie
Pr.ZBIRELMehdi* CardiologieDi rect eur HMI Mohammed V
Novembre 1997
Pr.ALAMIMohamedHassan Gynécologie-Obstétrique
Pr.BEN SLIMANELounis Urologie
Pr.BIROUKNazha Neurologie
Pr.ERREIMINaima Pédiatrie
Pr.FELIATNadia Cardiologie
Pr.KADDOURINoureddine ChirurgiePédiatrique
Pr.KOUTANIAbdellatif Urologie
Pr.I.AHLOUMohamedKhalid ChirurgieGénérale
Pr.MAHRAOUICHAFIQ Pédiatrie
Pr.TOUFIQJallal Psychiatrie Di recteur Hôp•.Ar.-razi Salé Pr.YOUSFIMALKI Mounia GynécologieObstétrique
Pr.BOUGTAB Ahdesslam ChirurgieGénérale Pr.ERRIHANI Hassan OncologieMédicale
Pr.BENKIRANEMajid* Hématologie
Janvier 2000
Pr.ABIDAhmed* Pneumo-phtisiologie
Pr.AIT OUAMARHassan Pédiatrie
Pr.BENJELLOUN DakhamaBadr.Sououd Pédiatrie
Pr.BOURKADIJamal-Eddine Pneumo-phtisiologie Directeur Hôp. My Youssef
Pr.CHARIFCHEFCHAOUNIAlMontacer ChirurgieGénérale Pr.ECHARRABElMahjoub ChirurgieGénérale Pr.ELFTOUHMustapha Pneumo-phtisiologie Pr.ELMOSTARCHIDBrahim* Neurochirurgie
Pr.TACHINANTERajae Anesthésie-Réanimation Pr.TAZIMEZALEKZoub_ida Médecine Interne
Novembre 2000
Pr.AIDISaadia Neurologie
Pr.AJANAFatimaZohra Gastro·Entérologie
Pr.BENAMR Said ChirurgieGénérale
Pr.CHERTIMohammed Cardiologie
Pr.ECH.CHERIFELKETTANISelma Anesthésie-Réanimation
Pr.EL HASSANIAmine Pédiatrie•Di rect eur Hôp. Chei kh Zaid
Pr.ELKHADER Khalid Urologie
Pr.GHARBIMohamedElHassan EndocrinologieetMaladiesMétaboliques Pr.MDAGHRIALAOUIAsmae Pédiatrie
Décembre 2001
Pr.BALKHIHicham* AnesthésieRéanimation Pr. BENABDELJLIL Maria Neurologie
Pr.BENAMARLoubna Néphrologie Pr. BENAMORJouda Pneumo-phtisiologi e Pr.BENELBARHDADIlmane Gastro-Entérologie Pr.BENNANIRajae Cardiologie Pr.BENOUACHANEThami Pédiatrie Pr.BEZZAAhmed* Rhumatologie Pr.BOUCHIKHIIDRISSIMedLarbi Anatomie Pr.BOUMDINElHassane* Radiologie Pr.CHATLatifa Radiologie
Pr.DAALIMustapha* Chirurgie Générale
Pr.ELHIJRIAhmed AnesthésieRéanimation
Pr.ELMAAQILIMoulay Rachid Neuro-Chirurgie Pr.ELMADHITarik Chirurgie-Pédiatrique Pr.ELOUNANIMohamed ChirurgieGénérale
Pr.ETTAIRSaid Pédiatrie•Directeur Hôp. d1Enlants Rabat
Pr.GAZZAZMiloudi* Neuro-Chirurgie
Pr.HRORAAbdelmalek ChirurgieGénéraleDirecteur Hôpital Ibn Sina
Pr.KABIRIELHassane* ChirurgieThoracique
Pr.MIKDAMEMohammed* HématologieClinique
Pr.MOHSINERaouf ChirurgieGénérale
Pr.NOUINIYassine Urologie
Pr.SABBAHFarid ChirurgieGénérale
Pr.SEFIANIYasser ChirurgieVasculairePériphérique Pr.TAOUFIQBENCHEKROUN Sournia Pédiatrie
Décembre 2002
Pr. AL BOUZIDI Abderrahmane* AnatomiePathologique
Pr.AMEURAhmed* Urologie
Pr.AMRIRachida Cardiologie
Pr.AOURARHAziz* Gastro-Entérologie
Pr.BAMOU Youssef* Biochimie-Chimie
Pr.BELMEJDOUBGhizlene* Endocrinologie et Maladies Métaboliques
Pr.BENZEKRI Laila Dermatologie
Pr.BENZZOUBEIRNadia Gastro-Entérologie
Pr.BERNOUSSIZakiya Anatomie Pathologique
Pr.CHOHOAbdelkrim * Chirurgie Générale
Pr.CHKIRATEBouchra
PédiatriePr.ELAlAMIELFellousSidiZouhair Chirurgie Pédiatrique
Pr.ELHAOURIMohamed* Dermatologie
Pr.·FILALIADIBAbdelhai Gynécologie Obstétrique
Pr.HAJJIZakia Ophtalmologie
Pr.JAAFARAbdeloihab* Traumatologie Orthopédie
Pr.KRIOUILE
Yamina
PédiatriePr.MOUSSAOUIRAHALIDriss* Gynécologie Obstétrique
Pr.OUJILAL Abdelilah Oto-Rhino-Laryngologie
Pr.RAISSMohamed Chirurgie Générale
Pr.SIAHSamir* Anesthésie Réanimation
Pr.THIMOU
Amal
PédiatriePr.ZENTARAziz*
Chirurgie GénéraleJanvier 2004
Pr
.
ABDELIAH
El
Hassan
OphtalmologiePr.AMRANIMariam Anatomie Pathologique
Pr.BENBOUZIDMohammedAnas Ota-Rhine-Laryngologie
Pr.BENKIRANEAhmed* Gastro-Entérologie
Pr.BOUI.AADAS Malik Stomatologie et Chirurgie Maxille-faciale
Pr.BOURAZZA
Ahmed*
NeurologiePr.CHAGARBelkacem* TraumatologieOrthopédie
Pr.CHERRADINadia AnatomiePathologique
Pr.ELFENNIJamal* Radiologie
Pr.ELHANCHIZAKI GynécologieObstétrique
Pr.ELKHORASSANIMohamed Pédiatrie
Pr. HACH!Hafid ChirurgieGénérale
Pr.JABOUIRIKFatima Pédiatrie
Pr.TARIBAbdelilah* PharmacieClinique Pr.TIJAMIFouad ChirurgieGénérale Pr.ZARZURJamila Cardiologie Janvier 2005 Pr.ABBASSIAbdellah ChirurgieRéparatriceetPlastique Pr.ALKANDRYSifEddine* ChirurgieGénérale Pr.ALLALIFadoua Rhumatologie Pr.AMAZOUZIAbdellah Ophtalmologie
Pr.BAHIRIRachid Rhumatologie Di rect eur Hôp. Al Avachi Salé
Pr.BARKA.TAmina Pédiatrie
Pr.BENYASSAatif Cardiologie
Pr.DOUDOUHAbderrahim* Biophysique
Pr.HAJJILeila Cardiologie (mise endisponibilité)
Pr.HESSISSENLeila Pédiatrie
Pr. JIDALMohamed* Radiologie
Pr.LAAROUSSIMohamed Chirurgie Cardio-vasculaire
Pr.LYAGOUBIMohammed Parasitologie
Pr.SBIHISouad Histo-Embryologie Cytogénétique
Pr.ZERAIDINajia Gynécologie Obstétrique
AVRIL 2006
Pr.ACHEMLALLahsen* Rhumatologie
Pr.BELMEKKIAbdelkader* Hématologie
Pr.BENCHEIKHRazika O.R.L Pr.BIYIAbdelhamid* Biophysique
Pr.BOUHAFSMohamedElAmine Chirurgie ·Pédiatrique
Pr.BOULAHYAAbdellatif* ChirurgieCardio-Vasculaire.Di rect eur Hôpi t al Ibn Si na M Pr.CHENGUETIANSARIAnas Gynécologie Obstétrique
Pr.DOGHMINawal Cardiologie Pr.FELIATIbtissam Cardiologie
Pr.FAROUDYMamoun Anesthésie Réanimation
Pr.HARMOUCHE Hicham Médecine Interne
Pr.IDRISSLAHLOUAmine* Microbiologie
Pr.JROUNDILaila Radiologie
Pr.KARMOUNITariq Urologie
Pr.KILIAmina Pédiatrie Pr.KISRAHassan Psychiatrie
Pr.KISRAMounir Chirurgie - Pédiatrique
Pr.LAATIRISAbdelkader* Pharmacie Galénique
Pr.LMIMOUNIBadreddine* Parasitologie
Pr.MANSOURIHamid* Radiothérapie
Pr.OUANASSAbderrazzak Psychiatrie Pr.SAFISoumaya* Endocrinologie
Pr.SEKKATFatima Zahra Psychiatrie
Pr.SOUALHI Mouna Pneumo - Phtisiologie
Pr.TELLALSaida* Biochimie
Pr.ACHOURAbdessamad* Chirurgie générale
Pr.AITHOUSSAMahdi* Chirurgie cardia vasculaire
Pr.AMHAJJILarbi* Traumatologie orthopédie
Pr.AOUFISarra Parasitologie
Pr.BAITEAbdelouahed* Anesthésie réanimation
Pr.BALOUCHLhousaine* Biochimie-chimie
Pr.BENZIANEHamid* Pharmacie clinique
Pr.BOUTIMZINENourdine Ophtalmologie
Pr.CHERKAOUINaoual* Pharmacie galénique
Pr.EHIRCHIOUAbdelkader* Chirurgie générale
Pr.ELBEKKALIYoussef* Chirurgie cardio-vasculaire
Pr.ELABSIMohamed Chirurgie générale
Pr.ELMOUSSAOUIRachid Anesthésie réanimation
Pr.ELOMARIFatima Psychiatrie
Pr.GHARIBNoureddine Chirurgie plastique et réparatrice
Pr.HADADIKhalid* Radiothérapie
Pr.ICHOUMohamed* Oncologie médicale
Pr.ISMAILINadia Dermatologie
Pr.KEBDANITayeb Radiothérapie
Pr.LOUZI Lhoussain* Microbiologie
Pr.MADANINaoufel Réanimation médicale
Pr.MAHIMohamed* Radiologie
Pr.MARCKarima Pneumo phtisiologie
Pr.MASRARAzlarab Hématologie biologique
Pr.MRANISaad* Virologie
Pr.OUZZIFEzzohra Biochimie-chimie
Pr.RABHIMonsef* Médecine interne
Pr.RADOUANEBouchaib* Radiologie
Pr.SEFFARMyriame Microbiologie
Pr.SEKHSOKHYessine* Microbiologie
Pr.SIFATHassan* Radiothérapie
Pr.TABERKANETMustafa"* Chirurgie vasculaire périphérique
Pr.TACHFOUTI Samira Ophtalmologie
Pr.TAJDINEMohammedTariq* Chirurgie générale
Pr.TANANEMansour* Traumatologie-orthopédie
Pr. TLIGUIHoussain Parasitologie
Pr.TOUATIZakia Cardiologie
Mars 2009
Pr.ABOUZAHIRAli * Médecine interne
Pr.AGADRAomar* Pédiatrie
Pr.AITAIJAbdelmounaim* Chirurgie Générale
Pr.AITBENHADDOU ElHachmia Neurologie
Pr.AKHADDARAli * Neuro-chirurgie
Pr.ALLALINazik Radiologie
Pr.AMINEBouchra Rhumatologie
Pr.BOUHSAINSanae* Biochimie-chimie
Pr.BOUIMohammed* Dermatologie
Pr.BOUNAIMAhmed* Chirurgie Générale Pr.BOUSSOUGAMostapha* Traumatologie-orthopédie Pr.CHTATAHassanToufù.<* Chirurgie Vasculaire Périphérique Pr.DOGHMIKamal * Hématologie clinique
Pr.ELMALKIHadjOmar Chirurgie Générale Pr.ELOUENNASSMostapha* Microbiologie Pr.ENNIBIKhalid* Médecine interne
Pr.FATHIKhalid Gynécologie obstétrique
Pr.HASSIKOUHasna* Rhumatologie
Pr.KABBAJNawa Gastro-entérologie
Pr.KABIRIMeryem Pédiatrie
Pr.KARBOUBILamya Pédiatrie
Pr.IAMSAOURIJamal* Chimie Thérapeutique Pr.MARMADELahcen Chirurgie Cardio-vasculaire
Pr.MESKINIToufik Pédiatrie
Pr.MESSAOUDINezha* Hématologie biologique
Pr.MSSROURIRahal Chirurgie Générale
Pr.NASSARlttimade Radiologie
Pr.OUKERRAJLatifa Cardiologie
Pr.RHORFIIsmailAbderrahmani* Pneumo-Phtisiologie
Octobre 2010
Pr.ALILOUMustapha Anesthésie réanimation
Pr.AMEZIANETaoufiq* MédecineInterne DirecteurERSSM Pr.BEIAGUIDAbdelaziz Physiologie
Pr.CHADLIMariama* Microbiologie
Pr.CHEMSIMohamed* Médecine Aéronautique Pr.DAMIAbdellah* Biochimie, Chimie P r.DARBIAbdellatif* Radiologie
Pr.DENDANEMohammedAnouar Chirurgie Pédiatrique
Pr.ELHAFIDINaima Pédiatrie
Pr.ELKHARRASAbdennasser* Radiologie
Pr.ELMAZOUZSamir Chirurgie Plastique et Réparatrice
Pr.ELSAYEGHHachem Urologie
Pr.ERRABIHlkram Gastro-Entérologie
Pr.LAMALMINajat Anatomie Pathologique Pr.MOSADIKAhlam Anesthésie Réanimation Pr.MOUJAHIDMountassir* Chirurgie Générale
Pr. NAZIH Mouna* Hématologie
Mai 2012
Pr.AMRANIAbdelouahed Chirurgie pédiatrique Pr.ABOUEWAA Khalil * Anesthésie Réanimation Pr.BENCHEBBADriss * Traumatologie-orthopédie Pr.DRISSIMohamed* Anesthésie Réanimation Pr.ELAIAOUIMHAMDI Mouna Chirurgie Générale Pr.EL KHATIABIAbdessadek* Médecine Interne Pr.ELOUAZZANIHanane * Pneumophtisiologie Pr.ER-RAJIMounir Chirurgie Pédiatrique
Pr.JAHIDAhmed Anatomie Pathologique
Pr.RAISSOUNIMaha* Cardiologie *EnseignantsMilitaires Février 2013 Pr.AHIDSamir Pharmacologie Pr.AITELCADIMina Toxicologie Pr.AMRANIHANCHILaila Gastro-Entérologie Pr.AMORMourad Anesthésie Réanimation
PrAWABAlmahdi Anesthésie Réanimation
Pr.BEIAYACHIJihane Réanimation Médicale Pr.BELKHADIR ZakariaHoussain Anesthésie Réanimation Pr.BENCHEKROUNLaila Biochimie-Chimie
Pr.BENKIRANESouad Hématologie
Pr.BENNANAAhmed* Informatique Pharmaceutique Pr.BENSGHIRMustapha* Anesthésie Réanimation Pr.BENYAHIAMohammed* Néphrologie
Pr.BOUATIAMustapha Chimie Analytique et Bromatologie Pr.BOUABIDAhmedSalim* Traumatologie orthopédie
PrBOUTARBOUCHMahjouba Anatomie
Pr. CHAIBAli* Cardiologie
Pr. DENDANETarek Réanimation Médicale
Pr.DININouzha * Pédiatrie
Pr.ECH-CHERIFELKEITANIMohamed Ali Anesthésie Réanimation Pr.ECH-CHERIFELKEITANINajwa Radiologie
Pr.ELFATEMINIZARE Neure-chirurgie Pr.ELGUERROUJHasnae Médecine Nucléaire Pr.ELHARTI Jaouad Chimie Thérapeutique Pr.ELJAOUDIRachid* Toxicologie
Pr.ELKABABRIMaria Pédiatrie
Pr. ELKHANNOUSSIBasma Anatomie Pathologique
Pr.ELKHLOUFISamir Anatomie
Pr.ELKORAICHIAlae Anesthésie Réanimation Pr.EN-NOUAL!Hassane* Radiologie
Pr.ERRGUIGLaila Physiologie
Pr.FIKRIMeryern Radiologie
Pr.KABBAJHakima Microbiologie Pr.KADIRIMohamed* Psychiatrie
Pr.LATIBRachida Radiologie
Pr.MAAMARMounaFatimaZahra Médecine Interne
Pr.MEDDAH Bouchra Pharmacologie
Pr.MELHAOUIAdyl Neuro-chirurgie
Pr.MRABTIHind Oncologie Médicale
Pr.NEJJARIRachid Pharmacognosie
Pr.OUBEJJAHouda Chirugie Pédiatrique Pr.OUKABLIMohamed* Anatomie Pathologique
Pr. RAHALIYounes PharmacieGalénique Vice-DoyenàlaPharmacie
Pr.RATBIIlham Génétique Pr.RAHMAN!Mounia Neurologie Pr.REDAKarim* Ophtalmologie Pr.REGRAGUI'X'afa Neurologie Pr.RKAINHanan Physiologie Pr.ROSTOMSamira Rhumatologie
Pr.ROUAS Lamiaa Anatomie Pathologique Pr.ROUIBAAFedoua * Gastro-Entérologie
PrSALIHOUNMouna Gastro-Entérologie
Pr.SAYAH Rochde Chirurgie Cardio-Vasculaire Pr.SEDDIKHassan * Gastro-Entérologie
Pr.ZERHOUNIHicham Chirurgie Pédiatrique
Pr.ZINEAli * Traumatologie Orthopédie
• Enseignants Militaires
AVRIL 2013
Pr.ELKHATIBMOHAMEDKARIM* Stomatologie et Chirurgie Maxillo-faciale
MARS 2014
Pr.ACHIRAbdellah Chirurgie Thoracique Pr.BENCHAKROUNMohammedT Traumatologie- Orthopédie Pr.BOUCHIKH Mohammed Chirurgie Thoracique
Pr.ELKABBAJDriss* Néphrologie Pr.ELMACHTANIIDRISSISamira" Biochimie-Chimie Pr.HARDIZIHouyam Histologie·Embryologie.Cytogénétique Pr.HASSAN!Amale* Pédiatrie Pr.HERRAKLaila Pneumologie Pr.JANANEAbdellah• Urologie
Pr.JEA.IDIAnass* Hématologie Biologique Pr.KOUACHJaouad* Génycologie-Obstétrique Pr.LEMNOUERAbdelhay* Microbiologie
Pr.MAKRAMSanaa* Pharmacologie
Pr.OUIAHYANERachid* Chirurgie Pédiatrique Pr.RHISSASSIMohamedJaafar CCV
Pr.ABILKACEMRachid* Pédiatrie
Pr.AITBOUGHIMA Fadila Médecine Légale
Pr.BEKKALIHicham* Anesthésie-Réanimation
Pr.BENAZZOUSalma Chirurgie Maxillo-Faciale
Pr.BOUABDELIAHMounya Biochimie-Chimie
Pr.BOUCHRIKMourad* Parasitologie
Pr.DERRAJISoufiane* Pharmacie Clinique
Pr.DOBLALI Taoufik Microbiologie
Pr.ELAYOUB!ELIDRISSIAli Anatomie
Pr.ELGHADBANE AbdedaimHatim* Anesthésie-Réanimation
Pr.ELMARJANYMohammed* Radiothérapie
Pr.FEJJALNawfal Chirurgie Réparatrice et Plastique
Pr.JAHIDIMohamed* O.R.L
Pr.lAKHALZouhair* Cardiologie
Pr.OUDGHIRI NEZHA Anesthésie-Réanimation
Pr.RAMIMohamed Chirurgie Pédiatrique
Pr.SABIR Maria Psychiatrie
Pr.SBAIIDRISSIKarim* Médecine préventive, santé publique et Hyg.
AOUT 2015
Pr.MEZIANEMeryem Dermatologie
Pr.TAHIRILatifa Rhumatologie
PROFESSEURSAGREGES 1
JANVIER 2016
Pr.BENKABBOUAmine Chirurgie Générale
Pr.ELASRIFouad* Ophtalmologie Pr.ERRAMINoureddine* O.R.L Pr. NITASSISophia O.R.L JUIN 2017 Pr.ABIRachid* Microbiologie Pr.ASFALOUIlyasse* Cardiologie
Pr.BOUAYTIElArbi* Médecine préventive, santé publique et Hyg.
Pr.BOUTAYEBSaber Oncologie Médicale
Pr.ELGHISSASSIIbrahim Oncologie Médicale
Pr.HAFIDIJawad Anatomie
Pr.OURAINISaloua* 0. R.L
Pr.RAZINERachid Médecine préventive, santé publique et Hyg.
Pr.ZRARA Abdelhamid* Immunologie
NOVEMBRE 2018
Pr.AMELLALMina Anatomie
Pr.SOULYKarim Microbiologie
Pr.TAHRIRjae Histologie-Embryologie-Cytogénétique
PROFEURS/Prs. HABILITES
Pr.ABOUDRARSaadia Physiologie
Pr. AlAMIOUHABINaima Biochimie-chimie
Pr.AIAOUIKATIM Pharmacologie
Pr.AIAOUISLIMANILallaNaïma Histologie-Embryologie
Pr. ANSARM'hammed ChimieOrganiqueetPharmacie Chimique Pr.BARKIYOUMalika Histologie-Embryologie
Pr.BOUHOUCHEAhmed GénétiqueHumaine
Pr.BOUKLOUZEAbdelaziz ApplicationsPharmaceutiques Pr.CHAHEDOUAZZANILallaChadia Biochimie-chimie
Pr.DAKKATaoufiq Physiologie
Pr.FAOUZIMoulayElAbbes Pharmacologie
Pr.IBRAHIMIAzeddine Biologiemoléculaire/Biotechnologie
Pr.KHANFRIJamalEddine Biologie Pr.OUIADBOUYAHYAIDRISSIMed ChimieOrganique Pr.REDHAAhlam Chimie Pr.TOUATIDriss Pharmacognosie Pr.ZAHIDIAhmed Pharmacologie Mise à jour le 04/02/2020 Khaled Abdellah
Chef du Service des Ressources Humaines FMPR
To my parents Khadija Oussalem and Abderrahim Naji
Special thanks to my lovely parents for your hard work, love and support
throughout my entire life. You have been great inspiration to me,
my role models and my best companions.
Mum thaught me to always go after what I deserve and Dad always thaught me to
be patient. The combinaison of the both of you is very weird but somehow it works. I
can never thank you enough or repay you. I love you.
For my sisters Hala Zineb and Sahar
You are annoying , spoiled and make me mad but that’s how sisters are and I love
you. Somehow whenever I need help you are there to deliver. You are not only my
sisters but my companions,
cheerleaders and I will presume you are my number one fans (you better be).
I wish you all luck in life.
To the rest of my family, dead or alive
Thank you always and forever.
To my awesome friends and second family
To my small circle: Imane Katir, Saad Ait El Borj, Mehdi Ajji, Mehdi Farina.
You have thought me so much in life.
With you Imane, I learned so much about the importance of communication and that
love no matter how great, it needs communication. Thank you for being like me and
making me feel understood when sometimes no one could.
Saad, with you I learned to not care. Well, I am still learning. But you thought me
that some things are so simple and it all lays in the perception of things.Thank you for
that.
Mehdi Ajji, you are one of the few people that will always hold a special part in my
heart. You helped me be me and at the same time less me if that makes sense. Thank
you for that.
Mehdi Farina, you are a tricky one. You thaught me how to be an adult, and how to
take responsibility for my actions. Somehow, you were the person who knew how my
brain worked the most. One or two hellish (for you) years together does that.
Thank you all for all the love and patience you showed me.
To my mini donut, thank you for being next to me and I hope we are never the reason
we make each other cry cry cry.
To my other friends and colleagues
I can’t thank all of you. But you know the place you hold in my heart. I drifted apart
from some of you but I won’t forget our moments shared together.
My words of gratitude go to you for bring a constant source of support when things
would get a bit discouraging. May we continue this beautiful journey that is life
together and I thank you for all the beautiful memories and the unforgettable
moments.
To myself
I am lamely awesome.
Times got tough but somehow you managed to get through it. You always do. You are
thoughtful, gentle, and think of others before yourself. Those are qualities that I hope
you will learn to manage but also keep throughout your life.
To Pr. AMRANI Abdelouahed
I would like to start by thanking Pr Amrani Abdelouahed for all the devoted help and
guidance of my research subject. You pushed me to give the best in me. To work more and
to persevere.You were an inspiration and an amazing source of constant motivation and
encouragement. You made this work possible.
To Pr. BELKACEM Chagar
I would like to thank my thesis president Pr. B. Chagar, a person that I will forever be
grateful for. Your words of encouragement and support will always be with me. Thank
you for showing me all the opportunities ahead of me and for being a mentor during my
To Pr. El HAFIDI Naima
A special thanks to Pr. N. El Hafidi for accepting to be one of the members of my thesis
jury.Her kind words were a motivation for me to work harder and never give up.
To Pr. TlIGUI Houssain
I would also like to thank Pr. H. Tligui for accepting to read and improve my thesis with
his great remarks and comments.
To Pr. KRIOUILE Yamna
A special thanks to Pr. Kriouile Y. foragreeing to be one of the members of my thesis
jury.I am thankful to the positive encouragement you provided me.
AD‑MSC : Adipose tissue derived mesenchymal stem cells ADSC : Adipose derived stem cells
AFP : alpha-fetoprotein
ANAs : Acellular nerve allografts
ASC : Adipose stem cells
AT : Adipose tissue
ATDSCs : Amniotic Tissue-Derived Stem Cells ATMSCs : adipose tissue mesenchymental stem cells BDNF : Brain-derived neurotrophic factor
bFGF : basic fibroblast growth factor
BM : Bone marrow
BMMNCs : Bone marrow-derived mononuclear cells BMRC : British Medical Research Council BMSC : Bone Marrow derived stem cells BNB : Blood nerve barrier
BPBP : Brachial plexus birth palsy BPI : Brachial plexus Injury
cAMP : cyclic adénosine monophosphate CDNF : Ciliary-derived neurotrophic factor CEA : Carcinoembryonic antigen
CFU- F : Fibroblast colony forming unit
CL : Cord lining
CLEC : Cord lining epithelial cells CLMC : Cord lining mesenchymal cells CMAP : compound muscle action potential CMR : Center for Regenerative Medicine CMRL : connaught medical research laboratories CNS : Central nervous system
CT : myelography
CT : Computed Tomography
dASC : Differentiated adipose-derived stem cell
DC : Dendritic cells
DMEM : Dulbecco’s Modified Eagle’s Medium DMSO : dimethyl sulphoxide
DPSCs : Dental pulp stem cells DRG : Dorsal root ganglion ECM : extracellular matrix
EFRT : estimated functional regeneration time EGC : Embryonic germ cells
EMG : Electromyography
EMG‑NCV : Electromyography nerve conduction velocity EMSCs : Endometrium Derived Stem Cells
epiSC : Epiblast stem cells
ERK : extracellular signal regulated kinases
ESC : Embryonic stem cells
FBS : Fetal bovine serum
FSK : Forskolin
GFAP : Glial fibrillary acid protein GFAP : glial fibrillary acidic protein GMSCs : gingival tissue stem cells GVHD : Graft-versus-Host disease hAECs : Human amniotic epithelial cells hASC : Harvested adipose stem cells HGF : hepatocyte growth factor
HRG : heregulin
HSC : Hematopoietic stem cells Hsc : hematopoietic stem cells HUCB : Human umbilical cord blood ICM : Inner cell mass
INR : International normalized ratio iPSC : Induced pluripotent stem cells IRB : institutional review board IVF : In vitro fertilization
MAPCs : Multipotent adult progenitor cells MBP : Myelin basic protein
MHC : major histocompatibility complex MMD : Mean myofiber diameter MNC : mononuclear cells
MRC : Medical Research Council MRI : Magnetic Resonance Imaging MSC : Mesenchymal stem cells MUPs : Motor unit potentials MUPs : Motor unit action potential NCV : nerve conduction velocity
NF : Neurofilmanent
NGF : Nerve growth factor
NGF : nerve growth factor
NSCs : Neural stem cells NSE : Neuron-specific enolase
Nt : neurotrophin
OBPP : obstetrical brachial plexus palsy
PB : plexus brachial
PBS : Phosphate-buffered saline PDGF : platelet-derived growth factor PDLSCs : Periodontal ligament stem cells PET : Positron Emission Tomography PNI : peripheral nerve injury
PNS : peripheral nerve system RA : Alltransretinoic acid ROM : range of movement RTA : Road traffic accident SCAPs : Apical papilla stem cells SCI : spinal cord injury
SCs : Schwann cells
SDF-1/CXCR4 : Stromal cell-derived factor-1/C–X–C chemokine receptor 4
SEm : scanning electron microscopy
SPECT : Single Photo Emission Computed Tomography SSC : spermatogonial stem cell
Tem : transmitting electron microscopy TENG : tissue engineered nerve grafts
tMSCs : transdifferentiated Schwann cell-like
UC : Umbilical cord
UCB : Umbilical cord blood
UC-MSCs : Umbilical Cord Mesenchymal Stem Cells
UL : Upper limb
US : Ultrasonography
USG : ultrasonography
VEGF : Vascular endothelial growth factor β-ME : β-mercaptoethanol
LIST of
List of figures
Figure 1 : BPBP treatment decision tree during the first year . ... 7 Figure 2 : Stages of peripheral nerve regeneration following a transaction . ... 9 Figure 3 : Suggested management tree after peripheral nerve injury . ... 10 Figure 4 : Peripheral nerve gap repair options ... 15 Figure 5 : Peripheral nerve reconstructive algorithm, differentiated by nerve defect
characteristics and repair modality ... 17 Figure 6 : The hierarchy of stem cells ... 19 Figure 7 : Origin of stem cells . ... 21 Figure 8 : Therapeutic imminence index of stem cells isolated from various sources. ... 23 Figure 9 : Neonatal stromal cells ... 26 Figure 10 :Sources of stem cells for peripheral nerve repair ... 32 Figure 11 : Articles published from 2009 to 2019 using PubMed database. Keywords: stem cells, peripheral nerve regeneration. ... 39 Figure 12 : Clinical trials December 2019. ... 44 Figure 13 : Clinical trials in phase III-IV. ... 44 Figure 14 : Clinical trials July 2015 ... 45 Figure 15 : Mechanism of stem cell transplantation for peripheral nerve injury regeneration ... 71 Figure 16 : Neural stem cell repair of peripheral nerve damage ... 76
List of table
Table 1 : Functional impairment by level of injury . ... 5 Table 2 : Neurosensory impairment classification according to Sunderland and Seddon ... 8 Table 3 : Mesenchymal stem cells characteristic ... 23 Table 4 : Immunophenotype of UCB derived stem cells ... 24 Table 5 : Immunophenotype of adipose tissue-derived stem cells ... 27 Table 6 : Immunophenotype of bone marrow- derived stem cells . ... 28 Table 7 : Immunophenotype of dental stem cells ... 29 Table 8: Immunophenotype of dermis – derived stem cells ... 30 Table 9 : Immunophenotype of amniotic fluid-derived stem cells ... 31 Table 10 : Immunophenotype of endometrium-derived stem cells ... 31 Table 11 : Comparison of stem cells from different sources in peripheral nerve regeneration ... 34 Table 12 : Extraction, discrimination, and culture of MSCs derived from various tissues .... 37 Table 13 : Number of articles published in the last 10 years (2009-2019) in each different research data base. (updated in December 2019). ... 40 Table 14 : Effect of human amniotic epithelial cells(hAECs) transplantation on the rabbit forepaw motor functions after brachial plexus injury ... 48 Table 15 :The comparison of the affected limb neurological examination ... 60 Table 16 : Electromyography and radial nerve conduction studies ... 61 Table 17 : Improvement in the muscle strength through manual muscle testing grading before and after the cell transplantation ... 62 Table 18 : Electromyography findings observed 7 months after the first cell transplantation ... 63 Table 19 : Baseline patient and injected mononuclear cell characteristic in groups A,B and C (MRC,Medical Research Council) ... 66 Table 20 : Mean myofibre diameter, centro-nuclear myofibre, fibrosis, Pax7+myofibres , vWF per myofibre and CD56+myofibres of muscle biopsies of the injured biceps muscle before MNC injection and at three months follow-up . ... 68 Table 21 : Elbow flexion range of movement (ROM) and strength of the injured elbow together with the Short-From 36 and Disabilities of the arm shoulder and Hand (DASH, dutch language version) questionnaires and visual analogue scale (VAS) for pain before mononuclear cell (MNC) injection and after three and six months ... 69 Table 22 : Comparison of the clinical trials. ... 70 Table 23 : Summary of the secretion of neurotrophic factors ... 74 Table 24 : Stem cells delivery in peripheral nerve regeneration ... 83
I. Introduction ... 1 II. Prerequisites ... 3 1. Nerve injury ... 3
1.1. Brachial plexus injury... 3 1.2. Nerve regeneration ... 8 1.3. Nerve surgery ... 10 2. Stem cells ... 17 2.1. History of stem cell research ... 17 2.2. Stem cells categories ... 18 2.3. Types of stem cells ... 19 2.3.1. Totipotent cells ... 19 2.3.2. Pluripotent Cells ... 20 2.3.3. Oligopotent Cells ... 20 2.3.4. Unipotent Cells ... 20 2.3.5. Multipotent Cells ... 21 2.4. Mesenchymal Stem cell ... 22 2.4.1. Umbilical cord ... 24 2.4.2. Adipose derived stem cells. ... 26 2.4.3. Bone Marrow derived stem cells... 27 2.4.4. Dental derived stem cells ... 28 2.4.5. Skin derived stem cells ... 29 2.4.6. Other sources ... 30 2.5. Comparison of MSCs ... 32 2.6. Isolation of MSCs ... 34 2.7. Stem cell culture ... 35 2.8. Stem Cell preservation: cryopreservation ... 37 III. Research Methodology ... 38
1. Research ... 38 2. Clinical trials: Translation of Stem Cells; Insights for Peripheral Nerve Repair ... 44 3. Results of the research ... 46
3.1. Experimental ... 46 3.2. Clinical ... 60 IV. Stem cells in clinical practice ... 71
1. Mechanisms of stem cell promotion of peripheral nerve regeneration ... 71 2. Administration ... 76 3. Biomaterials and Scaffolds for Stem Cell Therapy ... 81 4. Strategies To Improve The Efficacy Of Regeneration Therapy For Nerve Damage... 83 5. Assessing nerve recovery ... 83 6. Risks ... 86 V. In Morocco ... 89 VI. Conclusion ... 92 SUMMARIES ... 97 REFERENCES ... 101
1
I. Introduction
Injuries of peripheral nerves are common, affecting nearly 3% of trauma patients, and often result in long-term disability. The functional recovery is correlated to the severity of the injury, the anatomical site of the injury and the delay before any kind of intervention(1).
These injuries are mainly caused by severe trauma, usually accompanied by bone fracture and vascular damage. Autologous nerve grafting is the gold standard for peripheral nerve repair; however, limited donor nerve resources and other issues preclude the search for new therapeutic strategies.
In the brachial plexus injury (BPI), the upper brachial plexus (C5-C6) is commonly affected, resulting in paresis of shoulder function and elbow flexion(2). The aim of nerve surgery is to restore innervation of the biceps muscle, however often times a deficit in the functionality of the arm remains.
The current management of brachial plexus injury (BPI) aims at improving movement and muscle strength to attain functional independence.
Complete functional recovery is infrequent as the regeneration of the normal number of axons occurs only after relatively minor injuries(3) .
Due to the slow rate of nerve regeneration that occurs gradually at approximately 1 mm/day, recovery from a BPI takes time, and patients may not experience results for several months(4) .
As for the brachial plexus birth palsy (BPBP), defined as a partial or total paralysis of the upper limb, it affects the nerve roots C5 and C6 (80% cases) and less frequently C7, C8 and T1. This complication occurs at the time of birth, most often after a difficult delivery, but could also be during a c-section.
2
In addition, its prevalence remains relatively frequent (1-3/1000 live births) despite advances in obstetrics(5). It remains difficult to predict or even prevent obstetrical brachial plexus palsy, even if many risk factors have been identified: poorly balanced maternal diabetes, macrosomia, shoulder dystocia, breech presentation, and uterus abnormalities among others.
The quality of life achieved in patients with brachial plexus injury after conventional treatment is also worrisome as it is not satisfactory (6–8).
Despite advances in microsurgical techniques and a progressive understanding of patho-physiological mechanisms, peripheral nerve repair continues to be a major clinical challenge. These peripheral injuries are often accompanied by loss of sensation, partial or complete apraxia, chronic pain, and occasionally permanent disability.
The search for a more efficient treatment led to the tryout of regenerative medicine through stem cells.
It was appreciated long ago that within a given tissue there is a cellular heterogeneity: in some tissues, such as the blood, skin and intestinal epithelium, the differentiated cells have a short lifespan and are unable to self-renew. This led to the concept that such tissues are maintained by stem cells, defined as cells with extensive renewal capacity and the ability to generate daughter cells that undergo further differentiation(9). The National academy of medicine (2018) states that the therapeutic use of stem cells began with human medullary and cord blood hematopoietic stem cells (HSC) in the treatment of aplasias, leukemias and hematological genetic diseases. It developed with the mesenchymal stem cells (MSC) produced in small quantities by the bone marrow, but also other tissues, and utilized after isolation and culture. Therapeutic successes were obtained in various cardiac and cutaneous diseases (among others) due to their secretory properties of growth factors.
Adult mesenchymal Stem Cells (MSCs), primarily isolated from bone marrow, were identified to be multipotent stem cells with the potential to differentiate into cells of mesodermal (osteocytes, chondrocytes, and adipocytes), ectodermal (neurons) and endodermal origins . Other eminent sources of adult MSCs include the placenta , umbilical cord , amniotic fluid , adipose tissue, dental pulp , breast milk , and synovium .
3
Through this thesis, we will try to answer the following questions: What place do stem cells occupy in the treatment of nerve injury? Are there any existing trials whether clinical or experimental? And is their use possible in Obstetrical brachial plexus injury?
The following thesis will be divided into two main parts: the first one is a prerequisite on both nerve injuries and stem cells; the second one treats the research methodology and discusses the results of our main question Stem cells in nerve injury especially brachial plexus injury.
II. Prerequisites
1. Nerve injury
1.1. Brachial plexus injury
Brachial plexus birth palsy (BPBP) is a common injury affecting 1 to 4 children per 1000 live births(10).
A 10 year study made in Nigeria showed a persistent high prevalence of children with BPBP averaging 15.3% per year with associated problems such as birth asphyxia, humeral fracture, clavicular fracture and shoulder dislocation(11). Hamzat and colleagues (12) also reported the prevalence of BPBP in Accra, Ghana to be 27%, the results of the study further indicated that birth weight exceeding 4.0 kg, vertex presentation and vaginal delivery were the noticeable co-existing factors for BPBP in Accra.
The incidence of BPBP seems to be increasing, due to increasing birth weights, despite advancements in obstetric care(13,14). Fortunately, most affected infants have spontaneous recovery within the first 6 to 8 weeks of life and therefore progress to obtain normal or near normal range of motion and strength(15,16).
However, if substantial recovery is not present by 3 months of age, permanent range of motion limitations, decreased strength, and decreased size and girth of the affected limb will be present(17).
4
with an increased risk of shoulder dystocia and prolonged labor. Prolonged labor and shoulder dystocia are complications directly related to the Increasing mothers' age. Studies show that both nulliparous and multiparous mothers' are at risk for delivering babies who may suffer birth injuries as the average birth weight of children is the same for both groups of women. Increased risk of shoulder dystocia, high birth weight (macrosomia) and prolonged labour in mothers above 34 years are also risk factors for BPBP.
Despite progress in obstetrics, the incidence of BPBP has remained stable over the last few decades. This may be essentially related to the unpredictability of shoulder dystocia and the increase in mean birth weight (18).
Types of lesions
Most authors agree that plexus brachial (PB) lesions are most often transitory, with 75– 95% of cases advancing to complete recuperation(15). The most recent studies report a lower rate of 66%, with a residual deficit in 20–30% and considerable alteration of function in 10– 15% of cases(19–21). The final prognosis of BPBP is directly related to the type of initial nerve lesions. Although the extent of the lesions can be assessed clinically, today no exam can specify the type of lesion (simple elongation, rupture, or avulsion). The prognostic assessment at birth is based only on clinical criteria. A poor prognosis is confirmed when mainly total paralysis occurs and the Horner syndrome is present (19).
All in all, the combination of these three factors (the type and extent of the lesions, Horner syndrome, and the speed of recuperation) will provide the assessment of the patient’s progression and guide the therapeutic indications.
We may encounter:
paralysis of the upper roots with C5C6 ± C7 involvement: this accounts for more than 75% of BPBPs with most often post-ganglion lesions
total paralysis: this accounts for approximately 20% of cases. Its diagnosis is even easier when an upper limb is completely inert and dangling . There are sensory problems and no active range of movement is possible beyond the presence of a few
5
shoulder movements at the scapulothoracic joint and flessum of the fingers’ distal interphalangea
distal paralysis (Klumpke palsy): this is exceptional and accounts for less than 2% of cases(18) .The lesional mechanism is direct traction on the upper limb, with the shoulder in abduction. This situation can be encountered in cephalic presentations with the hand first and in certain caesarian deliveries. Clinically, the wrist and the hand are inert, whereas the elbow and shoulder retain normal function.
Table 1 : Functional impairment by level of injury (22).
Assessment tool
To determine the severity of the problem, it is important to distinguish two types of lesions :
the pre-ganglion or avulsion lesion, located upstream of the dorsal root ganglion, is a veritable tearing of the rootlet at the spinal cord. This lesion, which most often involves the C8 and D1 roots, is particularly serious because it cannot be repaired by direct surgery. It should be systematically sought on MRI or CT-myelography for better surgical planning;
the post-ganglion lesion is located downstream of the dorsal root ganglion. Three types are described in the Sunderland classification (23):
type 1 or Seddon neurapraxia: a simple elongation of the PB without interrupting the nerve continuity, leading to transitory paralysis that is
6 spontaneously resolved,
type 2 or axonotmesis: partial nerve rupture touching the axon but keeping the nerve sheath intact. Spontaneous recuperation is possible but with a risk of a “switching” error,
type 3 or neurotmesis: complete nerve rupture with neuroma formation. Spontaneous recuperation is impossible but the lesion remains accessible to nerve repair.
Radiology
Not many reports exist regarding the use of ultrasonography (US) in BPBP. US has been used preoperatively and compared to the preoperative CT-Myelography (CTM) or MRI. The utility of US is complementary to that of CTM or MRI as US can give information on the muscles and the location of the brachial plexus neuroma to facilitate the formation of strategies for nerve reconstruction. Furthermore, US can be used to assess for diaphragmatic movement and avoid radiation from x-rays(phrenic nerve function)(24).
In cases in which function is not recuperated by the 3rd month, two complementary exams can be requested : electromyography (EMG), an exam that is difficult to perform and to interpret in the newborn or the infant, currently plays a very limited role in the diagnosis of BPBP. It is often describe as “overly optimistic” because of the frequent underestimation of the severity of the nerve lesions but can be requested in the preoperative workup as a surgical exploration of BP (when necessary), with an essentially medical–legal goal;
MRI of the cervical spine is a very useful exam in preoperative planning. Compared to the CT-myelography, it has the advantage of direct visualization of the spinal cord and in certain cases the BP itself. The presence on MRI of a pseudo-meningocele is highly suggestive of radicular avulsion. It can significantly influence the nerve repair strategy. False-positive and false-negative results are found in 10–15% of cases. However, its reliability remains close to that of the CT-myelography (24).
However, the disadvantages of CT-myelography are the need for general anesthesia and lumbar puncture for intrathecal contrast introduction, as well as radiation exposure. Other difficulties include the inability to determine the correct spinal level.
7
MRI has the advantage of being a direct, non-invasive exam that is increasingly easy to perform with simple sedation, whereas CT-myelography always requires general anesthesia.
Figure 1 : BPBP treatment decision tree during the first year (19).
The incidence of traumatic injuries is estimated as > 500,000 new patients annually in the world(25). Post‑traumatic brachial plexus injury can result in complete sensory and motor function loss which is challenging for reversal of the damage, but not untreatable.
8 1.2. Nerve regeneration
Peripheral nerve injuries include a variety of conditions in which one or more peripheral nerves are damaged, leading to neurological deficits distal to the level of the lesion. Peripheral nerve injuries may occur as isolated neurological conditions or, more commonly, in association with soft tissue, vascular, and/or skeletal damage. Patients with peripheral nerve injury may present with sensory deficits, loss of motor function, or a combination of both.
Table 2 : Neurosensory impairment classification according to Sunderland and Seddon(23,26).
Following the severing of a peripheral nerve a complex multicellular response is activated (Figure 2). The axons downstream and upstream the cut go through different paths. The former one degenerate through a process known as the Wallerian degeneration and the latter regrow back towards their targets.
The two nerve stamps are reconnected in a poorly understood process by a section of new tissue known as the bridge composed of inflammatory cells, Perineurial cells fibroblasts and Matrix.
Schwann cells at the tips of the proximal stump and along the length of the distal stamp dedifferentiate to progenitor like cells and together with tissue macrophages and inflammatory cells remodel the environment to make it more conduct for axonal regrowth.
The Schwann cells have a second regenerative function as a guide for actions across the bridge. Emerging from both stamps, Schwann cells encounter fibroblasts that signal a change in Schwann cells Behavior. Resulting in the formation of cellular cords, which transport the
9
accents across the bridge. However, these streams of Schwann cells move along the surface of polarized blood vessels that guide the Schwann cells and accompanying axons as they are enable to migrate directly through the Matrix of the bridge. The hypoxia within the bridge is selectively sensed by macrophages which results in blood vessel formation by the secretion of Vascular endothelial growth factor (VEGF) (27).
Figure 2 : Stages of peripheral nerve regeneration following a transaction (27).
Following the transection of a peripheral nerve, the stumps initially retract (a) but are reconnected by an unknown mechanism by new tissue known as the nerve bridge (b). Initially the bridge, composed of matrix and inflammatory cells, is poorly vascularised and as a result becomes hypoxic. This is specifically sensed by the macrophages, the major cell type of the bridge, which secrete VEGF that promotes angiogenesis. This sensitivity to hypoxia is an intrinsic property of the macrophages, as it can be reproduced in vitro. Downstream of the transection in the distal stump, the axons degenerate in an active process known as Wallerian
10
degeneration. The SCs, sensing the damage, disassociate from the degenerating axons and dedifferentiate to a progenitor-like state that orchestrates many aspects of the regenerative process. This includes the recruitment of macrophages, which together with the SCs, clear the axonal and myelin debris and remodel the environment to create a conducive environment for axonal regrowth. It also involves the formation of the bands of Büngner (c) that result from SCs elongating along the length of their original basement membrane to create directional tubes that provide a sustaining substrate for axonal regrowth back to their original targets. Meanwhile, the bridge has become vascularised in response to the macrophage-induced VEGF signal and SCs migrate along the vasculature, taking the regrowing axons across the bridge and into the distal stump (c). The regeneration process is complete (d), once the axons reinnervate their original targets and the SCs recognising the axons, redifferentiate and the inflammatory response resolves.
1.3. Nerve surgery
11
Two key questions that both patient and physician will ask after a peripheral nerve injury are “how likely is it that at least some function will return?” and “how long is it going to take, before the function starts to return?” Regrettably, none of these factors can be determined with any great accuracy at the time of injury, and this uncertainty is perhaps the real challenge in the management of peripheral nerve injuries.
The most common medical treatments rely largely on reconstructive microsurgery. Although nerve reconstruction has been attempted for centuries, techniques have improved drastically within the past few decades (Siemionow and Brzezicki 2009). Procedural options include nerve autografts, neurolysis, nerve transfers, and direct suture (end to end neurorrhaphy) (Geuna et al. 2013). The nerve transfer method has seen widespread application in recent years and is used in severe nerve trauma, including brachial plexus avulsions (Tung and Mackinnon 2010; Zhang and Gu 2011).
The current “gold standard” includes transplantation of an autologous nerve segment which has been harvested from another healthy, less important nerve such as the sural nerve. The procedure was first developed by Millesi (1981) and later deemed the standard of care (Siemionow and Brzezicki 2009). Although autografts are the “gold standard,” the harvesting of another healthy nerve represents obvious limitations, which is why veins are sometimes used as an alternative (Chiu and Strauch 1990). Although vein autografts may lead to satisfactory return of sensation, comparable to nerve grafting, they are only useful for short distances as longer veins tend to collapse (Chiu 1999).
Conventional Direct Suturing Method
Conventional direct suturing repair without the use of grafted materials may be deployed for short (\5 mm) peripheral nerve gap. Larger gaps repaired by direct suturing exhibit excessive tension over the suture line and offer poor surgical result (29). Although many evidences showed that direct suturing can cause damage and inflammatory reaction that affect nerve regeneration, the practice of direct suturing for peripheral nerve repair continues unchallenged due to the lack of well-controlled human trials for other nerve repair methods(30).
12 Fibrin Glue (30)
Fibrin glue is a sutureless repair for PNI with artificial or biological adhesive. The commercial available product of fibrin sealant, Tisseel, was introduced in 1970s. The potential advantages of adhesives to seal nerve endings are reduced surgical and recovery time, decreased fibrosis and inflammation in addition to providing coaptation of severed nerve fascicles with minimal induced trauma, and neural scar tissue. As a quicker and easier modality to use, fibrin glue is an excellent alternative to suturing for peripheral nerve repair and could be especially beneficial in emergency settings not limited by the lack of experienced staff familiar with specific suture technique. However, a single well-controlled human trial assessing the efficacy of fibrin glue in relation to that of suturing technique is needed for the clinical application of fibrin glue, for the majority of the reviewed studies employed on animal model. So far the results reported about fibrin glue are based on biomechanical, histopathological, electrophysiological and microscopic data. Future studies about fibrin glue should include biomechanics, quantitative histological assessment and electrophysiology.
Nerve Grafts
Autologous nerve grafts are considered the ‘‘gold standard’’ technique for repair of peripheral nerve discontinues.
To date, autologous nerve grafts have offered the best results in nerve regeneration under tension(31). However, the use of autologous nerve grafting is limited by tissue availability, the need of second surgical procedure to harvest graft tissue, donor-site morbidity and loss of function, potential difference in tissue size and structure etc (32,33). An alternative to autologous nerve grafts is the use of cadaveric or donor nerve tissue in the form of allografts(34). Allograft nerve provides guidance and viable donor Schwann Cells, which enable host axons to pass from the proximal to distal stump and reconnect with target organs. Whereas, the patients are required to receive systemic immunosuppression for approximately 18 months for allograft (30). The use of immunosuppression may result in opportunistic infections or even tumor formation (34). Now, there are lots of researches about the development of processed nerve allografts, which has ameliorated some of the limitation for
13
allograft. Processed allografts were made non-immunogenic by some specific processing, including repeated freeze–thaw cycles, exposure to radiation, extended storage in cold University of Wisconsin solution or decellularization with detergents and al.(35) . Processed allografts possess the advantage of providing a biological substrate for nerve regeneration without the requirement of immunosuppression. Now, most research of processed nerve allografts focused on acellular human nerve allografts. The acellular nerve grafts remove the immunoreactive Schwann Cells and myelin but preserve the internal structure of the native nerve and contain important extracellular matrix (ECM) components, such as collagen, laminin and growth factor related to nerve repair and regeneration (36). The function of acellular nerve grafts has been studied in animal and clinical trials. The results showed that acellular nerve allografts could experimentally and clinically be alternative for repairing both sensory and motor peripheral nerve defects. With short acellular nerve grafts, axons, Schwann Cells and inflammatory cells from the host nerve will migrate into and repopulate the graft and restore continuity with the distalnerve stump. However, the regenerative effects of acellular nerve grafts are limited for lacking of Schwann Cells help to produce a basement membrane containing ECM proteins that support axonal growth and form the endoneurial tubes through which regenerating axons grow (37). So supplementing acellular nerve grafts with growth factors or seed cells may improve the outcome of injured nerve repair in large-gap PNI models, and be a highly promising method in clinical application (38).
Conduits
During the past few years, studies of peripheral nerve repairing have concentrated on various conduits made of biomaterials, including natural material, non-degradable material and biodegradable synthetic materials. The main characteristic of these conduits is a longitudinal organization mimicking the natural structure of the nerve pathway. Conduits are designed to serve as tubes for axonal elongation and to direct regenerating axons to reconnect with their target neurons. But conduits themselves do not have a profound effect on the outcome of nerve repair. Functional recovery of the injured nerve depends on the slow process of regeneration and correct placement of injured axons(39) . Nerve conduits should be flexible and have sufficient permeability for the exchange of fluids between the regeneration
14
environment and the surrounding tissue. Natural material, such as skeletal muscle tissue or vessels, has been widely investigated as conduit materials. Natural materials offer increased levels of biocompatibility, decreased toxicity and enhanced migration of support cells when compared with synthetic materials(40,41). Studies have indicated that skeletal muscle or vessels grafts can be effective for repairing short nerve gap (\5 mm) in laboratory animals(30). The advantages of these natural devices are numerous donor sites and less induced morbidity when harvesting. However, the efficacy for nerve regeneration of these conduits may progressively reduce in longer nerve defects. Non-degradable materials, such as silicone, elastomer hydrogel or porous stainless steel, have been used for peripheral nerve regeneration. Currently, researches of nerve conduits have focused on biodegradable materials, such as collagen, polyglycolic acid, polylactic acid, polyesters, chitosan (42). These materials may degrade within a reasonable period of time and only manifest mild foreign body reaction. A lot of researches have demonstrated the effectiveness of nerve regeneration with biodegradable conduits in preclinical and clinical experiments. Archibald and al. (43) compared the effective outcome of collagen conduits to that of autograft and direct suturing for median nerve of Macaca fascicularis monkey. The results demonstrated that nerve regeneration using collagen conduit in the nonhuman primate is similar to that of autograft repair. Some nerve conduits made of biodegradable have been commercially available.
15
Figure 4 : Peripheral nerve gap repair options (44).
Traumatic brachial plexus injuries, a clinically severe peripheral nerve injury, cause permanent disability of the body with significant socioeconomic implications(45) . Although nerve transfers including accessory nerve (Songcharoen et al., 1996), phrenic nerve, and intercostal nerve are presently the primary methods to treat brachial plexus injuries, availability of donor nerves remains limited, especially for patients with accessory and phrenic nerve injuries (Krakauer et al., 1994; Flores etal., 2016). Contralateral C7 (CC7) nerve could be a reliable donor for repair of upper trunk injuries, as it could be transferred through a modified pre-spinal approach to improve the recovery of shoulder abduction and elbow flexion (Wang et al., 2012). However, the limited separable length of the CC7 nerve, as
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well as fibrosis and distal retraction of the injured nerve roots, obstruct direct suture to the recipient nerves (Xu et al., 2012). Therefore, nerve grafting is still needed to bridge the nerve gap.
As mentioned above, nerve autograft is regarded as the “gold standard” to treat peripheral nerve defects, but unavoidable complications such as the sacrificing of a functional nerve, dysfunction of the donor site, and limited wide use of autologous nerve grafts (Fansa et al., 2003; Johnson et al., 2005; Battiston et al., 2017). With the rapid development of tissue engineering, an increasing number of animal studies (Gu et al., 2011; Pfister et al., 2011; Cerqueira et al., 2018; Patel et al., 2018) and clinical studies (Cho et al., 2012; He et al.,2015; Hu et al., 2016; Zhu et al., 2017) have confirmed that acellular nerve allografts (ANAs) can yield good results for repair of peripheral nerve defects; moreover they were considered to be ideal peripheral nerve grafts. However, reparative effects of ANAs decrease with increasing length of the nerve graft, potentially as a result of the loss of a normal environment created by living cells for the advancement of nerve regeneration (Walsh et al., 2009).
The exception is a situation where the time from the injury plus the estimated
functional regeneration time EFRT is more than 2 years (¼ time to motor endplates may have disappeared), as the likelihood of functional recovery LFR in this situation is close to zero (28).
Schwann cells (SCs), which can promote nerve regeneration and are a source of trophic factors, remyelinate axons and restore nerve conduction (Bunge et al., 1994). Thus, SCs are the main cell type considered for the seeding of tissue-engineered nerve grafts (Hadlock et al., 2000; Evans et al., 2002). However, SCs cultured in vitro have poor proliferative ability and an insufficient number of cells may delay nerve repair. Moreover, ideal cells for transplantation should be easily obtained, proliferate rapidly, and not elicit an immunological reaction (Tohill et al., 2004).
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Figure 5 : Peripheral nerve reconstructive algorithm, differentiated by nerve defect characteristics and repair modality (44).
2. Stem cells
‘’ Stem cell research must be carried out in an ethical manner in a way that respects the sanctity of human life ‘’John Boehner.
2.1. History of stem cell research: (46)
1908: Alexander Makrisov, Russian scientist ; coined the term Stem cells 1958: First animal created by IVF technique.
1961 + 1963: McCulloch and Till published their accidental findings in radiation research on existence of stem cells (self renewing cells) in bone marrow of mice.
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1968: .Discovery of hematopoietic stem cells .Transplant of bone marrow between two siblings suffering from Severe combined immunodeficiency disease.
1977: concept of tumor stem cells.
1978: Hematopoietic stem cells were discovered in “human cord blood” 1981: Noble prize for the isolation of stem cells from blastocytes of mouse 1992: Adult stem cells identifies in human brain.
1998: Isolation of the first human embryonic stem cells in the lab of James Thomson. 1999: First Successful transplant of insulin making cells from cadavers.
2001: Creation of Embryonic stem cells of mice from nuclear transfer technique. 2006: Nobel Prize on the discovery of induced pluripotent stem cells (iPSCs)
2008: Robert Laaza et al. find first human embryonic stem cells without destruction of embryo
2009: Isolation of stem cells from spinous region of human gingival
2010: Medical treatment of spinal injury from human embryonic stem cells 2014: Generation of insulin producing B-cells from skin cells
2017: Future use of Stem cells to restore hearing and make human blood-brain-barrier 2.2. Stem cells categories
Stem cells can be grouped into 4 broad categories based on their origin: Embronics Stem Cells (ESCs) , induced Pluripotent Stem Cells (iPSC), adult and fetal stem cells [48, 49]
Embryonic stem cells: are grown in the laboratory from cells found in the early embryo ESCs and are pluripotent stem cells derived from the blastocyst stage of embryonic development (47). These cells can either differentiate into tissue of the three primary germ layers or can also be maintained in an undifferentiated state in culture for a prolonged time(48) ;
Induced pluripotent stem cells, also known as ‘reprogrammed’ stem cells: similar to embryonic stem cells but made from adult specialized cells using a laboratory technique discovered in 2006 (49);
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Adult stem cells: scattered in various tissues and organs, and have the capability to produce at least one type of differentiated functional progeny (4,7-10). Although it is thought to have limited differentiation capability previously, recent evidence have shown the capacity of differentiation into the 3 embryonic layers (11);
Fetal stem cells, that are to date the younger stem cells and obtained from amniotic fluid, the umbilical cord (UC), and placenta (4,9,66).
Figure 6 : The hierarchy of stem cells (50).
2.3. Types of stem cells
The ability to differentiate, one of the two main characteristics of stem cells, varies between stem cells depending on their origin and their derivation (50)
Stem cells can be categorized according to their differentiation potential into 5 groups: totipotent or omnipotent, pluripotent, multipotent, oligopotent, and unipotent.
2.3.1. Totipotent cells
Totipotent also called omnipotent cells are viewed as the most undifferentiated cells and are found in early development. A fertilized oocyte and the cells of the first two divisions
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differentiate into both embryonic and extraembryonic tissues which makes them totipotent cells (thereby forming the embryo and the placenta)(51) .
2.3.2. Pluripotent Cells
Pluripotent stem cells are able to differentiate into cells that arise from the 3 germ layers ectoderm, endoderm, and mesoderm – from which all tissues and organs develop (52) . Pluripotent stem cells called embryonic stem cells (ESCs) were first derived from the inner cell mass of the blastocyst (50).
Takahashi and Yamanaka (53) generated pluripotent cells by reprogramming somatic cells that share similar characteristics with ESCs. These cells are named induced pluripotent stem cells (iPSCs). Note that there has been no pluripotent cell population isolated from the lung.
2.3.3. Oligopotent Cells
Oligopotent stem cells are able to form two or more lineages within a specific tissue; for example, the ocular surface of the pig, including the cornea, has been reported to contain oligopotent stem cells that generate individual colonies of corneal and conjunctival cells (54) . Hematopoietic stem cells are a typical example of oligopotent stem cells, as they can differentiate into both myeloid and lymphoid lineages(55) . In the lung, studies suggest that bronchoalveolar duct junction cells may give rise to bronchiolar epithelium and alveolar epithelium (56).
2.3.4. Unipotent Cells
Unipotent stem cells can only self-renew and differentiate into only one specific cell type thereby forming a single lineage such as muscle stem cells, giving rise to mature muscle cells and not any other cells(50) .The type II pneumocytes of the alveoli in the lung give rise to type I pneumocytes.
