Eric Arnaud

Management of craniosynostoses

Abstractu2002Although it is currently thought that surgery is indicated mainly for cosmetic reasons in isolated craniosynostoses, the functional aspects of the treatment must not be underestimated. Prospective studies on intracranial pressure and mental evolution of these children have shown that there were functional consequences in a significant proportion of cases even of single suture fusion. The frequency of increased intracranial hypertension and the risk of mental impairment depend on the age of the child and the type of craniosynostosis. In nonsyndromic cases, the higher risks are observed in multisutural craniosynostoses (brachycephaly, oxycephaly). In syndromic cases, the risk of intracranial hypertension is higher in Crouzon syndrome, and Apert syndrome carries the higher risk of mental retardation. The study of a personal series of 2,137 craniosynostoses shows that the functional and the cosmetic results are better after early surgery, and that the operative risks are not higher in infants than in older children.

Chiari malformation in craniosynostosis

IntroductionChiari malformation (CM) is a frequent finding in multisutural and syndromic craniosynostosis, occurring in 70% of patients with Crouzon’s syndrome, 75% with oxycephaly, 50% with Pfeiffer’s syndrome and 100% with the Kleeblattschädel deformity. The pathogenesis of this condition and rationale for treatment are still controversial.DiscussionSince its first description in 1972, several factors have been cited to play a role in inducing CM. In the light of recent publications, the roles of premature fusion of cranial vault and cranial base sutures, of congenital anomalies of the cerebellum and brain stem, of raised intracranial pressure, of venous hypertension and of hydrocephalus are reviewed. Evaluation and management of CM are also discussed.ConclusionChiari malformation appears to be an acquired and progressive condition that develops in the first months of life, because of a disproportion between hindbrain growth and an abnormally small posterior fossa, a consequence of the premature fusion of lambdoid and cranial base sutures. Venous hypertension caused by stenosis of the jugular foramen can also be present in these patients, resulting in intracranial hypertension and/or hydrocephalus. Careful MRI evaluation is recommended for the forms of craniosynostosis at a high risk of developing hindbrain herniation. The selection of posterior cranial vault expansion as the first surgical procedure is advocated. In selected cases, treatment of the posterior cranial deformity by occipital vault remodelling and treatment of the Chiari-like deformity by suboccipital decompression can be carried out using the same surgical procedure.

Midface surgery from Tessier to distraction.

Abstractu2002The wall separating the face and the cranium was broken by Paul Tessier and Gérard Guiot in the 1960s, making it possible to perform a combined operation around the orbits and forehead, and opening up close cooperation between plastic surgeons and neurosurgeons, especially for treatment of the major malformations such as hypertelorism of major facial retrusions. The principles of mobilization of the orbits to correct teleorbitism or orbital dystopia are recalled with reference to the different variations and with clinical examples. Facial advancement to correct the retrusions created by faciocraniosynostosis is explained with the many possible variants, combined with a intracranial approach or not, with or without a bipartition. The indications are discussed as is the risk linked to combined advancement of face and forehead. The progressive bone elongation principle introduced by Ilizarov for the limbs has been applied to the face at the mandibular level by McCarthy, with great success. The distraction of bone structures is now also applied at the level of the midface and makes it possible to overcome the retraction of soft tissues and lower the risk of relapse of facial retrusion. Many technical problems have still to be solved, but the results are already very promising. Many other applications of the distraction principle will be developed for the midface level, with other technical improvements such as the use of absorbable mini-plates and screws.

Advances in cranioplasty with osteoinductive biomaterials: summary of experimental studies and clinical prospects.

Abstractu2002The surgical repair of large calvarial defects is still a challenge for craniofacial surgeons. Since the discovery of bone growth factors, numerous studies have confirmed the interest of osteoinduction for bone repair. We summarize the findings of experimental and clinical trials carried out with composite bone substitutes. The triple mixture of TGF-β1, fibrin glue, and natural coral has proven effective in repairing rabbit skull defects. The same preparation was also efficient for a cranioplasty in two of three patients, age being a limiting factor. The adjunction of bone morphogenetic protein to autologous bone marrow was shown to be a potentiating factor in a rat cranioplasty model, but the combination of fibrin glue and bone marrow on a natural coral carrier was unable to achieve bone repair in children aged 6 years. Although the series were limited, stability and asepsis were important factors in promoting bony ingrowth. Cranioplasties with osteogenic biomaterials may be good option, but the most adequate dose of growth factor should be determined.

Posterior cranial vault expansion in the treatment of craniosynostosis. Comparison of current techniques

IntroductionSurgical procedures which aim at expanding the posterior cranial vault have come to play an increasingly important role in the treatment of syndromic craniosynostosis. The posterior cranial vault may be expanded by formal cranioplasty or by less invasive methods based on gradual posterior cranial vault expansion or distraction. These procedures share the common goals to prevent intracranial hypertension and progression toward turricephaly by effectively increasing the intracranial volume. They also reduce any local brain compression within the posterior cranial fossa.Patients and MethodsThis review describes the various techniques available for less invasive and gradual posterior cranial vault expansion and their rationale based on our experience on the last 40 cases. Volumetric data for three different surgical techniques have been compared (two cases of posterior cranial vault expansion by free-floating parieto-occipital bone flap, two with springs, and two with internal distractors). The volumetric analysis showed an expansion of 13 and 24xa0% for the free posterior flap, 18 and 25xa0% for the translambdoid springs, and 22 and 29xa0% for the distractors.DiscussionAlthough these figures are not strictly comparable, our data suggest that these three techniques offer a potential for a significant increase in skull volume. The indications for such procedures must, however, be tailored according to the age and condition of the single patient.

Pronostic mental du syndrome d'Apert

Resume Le syndrome dApert est repute saccompagner frequemment dune debilite mentale, a lorigine de laquelle des malformations cerebrales pourraient jouer un role important. Dautres facteurs, tels lâge a loperation, la qualite du millieu sociofamilial pourraient egalement influencer lavenir psycho-intellectual. Population et methodes. - Spixante enfants (32 garcons et 28 filles) ont ete inclus dans letude. Leur QI a eteevalue a laide de tests psychometriques adaptes pour lâge. Lanatomie cerebrale a ete etudiee a laide de limagerie par resonance magnetique (IRM). Une attention particuliere a ete portee sur lâge a lintervention et sur la qualite de lenvironnement familial. Lage a la derniere consultation etait superieur a 3 ans (3 a 28 ans, moyenne 10 ans) pour 38 patients. Resultats. - Le QI etait superieur a 70 chez 12 patients (32%), parmi lesquels cinq (13%) avnient un QI superieur a 90. Le QI moyen etait a 62 (10 a 114). Trente pour cent des enfants avaient une malformation du corps calleux, 43 % des ventricules lateraux et 55 % du septum pellucidum; lIRM ne montrait aucune anomalie dans 28 % des cas. Une ou plusieurs interventions ont ete realisees chez 53 patients, avant lâge de l an pour 37 dentre eux. Dix enfants etaient places en institution ou vivaient dans un milieu familial precaire. Lâge au moment de lintervention apparaissait comme le facteur principal du devenir mental: le QI final etait superieur a 70 chez 50 % des patients operes avant 1 an, contre seulement 8 % chez ceux qui avaient ete operes plus tard (p = 0,01). Parmi les malformations cerebrales observees, seules les anomalies du septum pellucidum paraissaient jouer un role: 50 % des patients sans anomalie du septum avaient un QI superieur a 70, contre 18% dans les cas ou existaient de telles anomalies (p Conclusions. - Une investigation soigneuse comprenant un examen en resonance magnetique nucleaire est necessaire pour rechercher des malformations cerebrales associees. Les patients doivent etre operes tot, idealement avant lâge de 9 mois. La qualite de lenvironnement sociofamilial doit etre optimisee.

Spring-assisted posterior skull expansion without osteotomies

IntroductionA posterior flatness of the skull vault can be observed in infants with brachycephaly. Such posterior deformation favours the development of turricephaly which is difficult to correct. To reduce the risk of such deformation, an early posterior skull remodelling has been suggested. Translambdoid springs can be used to allow for a distraction through the patent lambdoid sutures and obtain a progressive increase of the posterior skull volume.Surgical techniqueThe procedure consists in a posterior scalp elevation, the patient being on a prone position. Springs made of stainless steel wire (1.5xa0mm in diameter) are bent in a U-type fashion, and strategically positioned across both lambdoid sutures. No drilling is usually necessary, as the lambdoid suture can be gently forced with a subperiosteal elevator in its middle and an indentation can be created with a bony rongeur on each side of the open suture to allow for a self-retention of bayonet-shaped extremity of the spring. Careful attention is addressed to the favoured prone position during the post-operative period. After a delay of 3–6xa0months, the springs can be removed during a second uneventful procedure, with limited incisions, usually as a preliminary step of the subsequent frontal remodelling.ConclusionThe concept of spring-assisted expansion across patent sutures under 6xa0months of age was confirmed in our experience (19 cases). Insertion of the springs allowed for immediate distraction across the suture. A posterior remodelling of the skull could be achieved with minimal morbidity allowing to delay safely a radical anterior surgery.

La « malformation å de Chiari dans le syndrome de Crouzon

Resume La pratique de lIRM laisse penser que lassociation malformation de Chiari et dysostose craniofaciale est beaucoup plus frequente que ce quon aurait pu imaginer. Nous avons donc etudie une population de patients atteints de syndrome de Crouzon pour etablir dune part la reelle incidence de malformation de Chiari dans ce syndrome et, dautre part, pour essayer de comprendre les causes de lassociation dune pathologie du squelette craniofacial avec une malformation du systeme nerveux central. Patients et methode. - Lanatomie de la fosse cerebrale posterieure dans le syndrome de Crouzon a ete retrospectivement etudiee dans une serie de 49 examens en IRM. Resultats. - Un engagement chronique des tonsilles cerebelieuses realisant un aspect de malformation de Chiari a ete retrouve dans 35 cas (71,4 %). Chez 16 sujets il existait une hydrocephalie; tous avaient une malformation de Chiari. En revanche, seulement 19 des 33 patients sans hydrocephalie avaient une malformation de Chiari (57,6 %). Chez les patients porteurs de la malformation de Chiari, la suture lambdoide se synostosait plus precocement que chez les autres, et la difference est statistiquement significative. Conclusion. - La synostose lambdoide prematuree, et la diminution volumetrique concomitante de la fosse cerebrale posterieure, sont probablement a mettre en relation avec lexistence dune malformation de Chiari dans le syndrome de Crouzon. Dans cette hypothese, la malformation de Chiari est a interpreter comme un engagement chronique acquis des tonsilles cerebelleuses plutot que comme une veritable malformation congenitale.

Scaphocephaly correction with retrocoronal and prelambdoid craniotomies (Renier’s “H” technique)

ObjectiveThe aim of this paper is to describe the surgical technique, originally devised by Dr. Renier which is currently used to treat children with scaphocephaly under 6xa0months of age at the Craniofacial Unit of Hopital Necker Enfants Malades (French National Referral Center for Faciocraniosynostosis), focusing on its advantages and limitations.

Crouzon syndrome with acanthosis nigricans: a case-based update.

BackgroundCrouzon syndrome with acanthosis nigricans also named Crouzono-dermo-skeletal is a clinically and genetically distinct entity. It associates a craniofacial phenotype to anomalies of the skin and long bones. This syndrome is due to a specific mutation in FGFR3 gene that can be identified by genetic testing.Illustrative casesAs in our two patients, not all these features might be present and some will be patent only in the infancy or early childhood. Moreover, other organs such as the kidneys might be affected.DiscussionBecause several organs might be affected the recognition of such syndrome is important for a correct management of the patient as well as a proper information and genetic counseling of the families.