Posterior Cranial Vault Research Articles

Posterior Cranial Vault Distractor Osteogenesis for the Treatment of Chiari Malformation Type 1: A Systematic Review of the Literature.

Although posterior cranial vault distraction osteogenesis (PVDO) is utilized routinely now for the treatment of craniosynostosis, its use as a treatment option for Chiari type 1 malformation (CM1) is limited to case reports and small retrospective case series. The authors conducted a systematic review of the published literature for PVDO as a treatment for CM1. The primary outcomes were reported complications, symptom improvement, and reoperation rates in patients that had PVDO surgery for CM1. The authors further investigated differences between patients with CM1 with an associated genetic syndrome and craniosynostosis. In total, 42 patients with an average age of 41.1 months were used in our analysis. A total of 38.1% of the patients had a diagnosed syndrome, 78.6% of patients had associated craniosynostosis, and 26/42 (61.9%) total patients-reported symptom improvement. Of 26 patients that reported symptom improvement, 20 (76.9%) had associated syndromes and 6 (23.1%) did not (P=0.011). In addition, of these 26 symptom improved patients, 17 (65.4%) were associated with craniosynostosis while 9 (36.4%) did not have craniosynostosis (P=0.008). Posterior cranial vault distraction osteogenesis seems to be a promising new surgical intervention for treatment of CM1. Most patients saw symptom improvement after treatment (61.9%). There was a clinically and statistically significant difference in symptom improvement for patients with syndromic CM1 when compared with nonsyndromic CM1 patients.

Posterior cranial vault distraction osteogenesis: a literature review

Introduction:Craniosynostosis is a congenital condition where one or more cranial sutures close prematurely, limiting skull growth and causing cranial deformities. Posterior cranial vault distraction (PCVD) is used to relieve intracranial pressure and improve cranial aesthetics. Its incidence is about 1 in 2000–2500 live births. Methods:This systematic review followed PRISMA guidelines. We searched PubMed, Scielo, and Lilacs for studies on PCVD in craniosynostosis, focusing on success, morbidity, and mortality. Six articles were included in the final review. Data were extracted and risk of bias was assessed using the ROBINS-I tool. Results:The included studies reported significant increases in intracranial volume (144 mL to 281 mL) post-PCVD. Most patients showed stable results without recurrence. Complications included wound infection (29%) and cerebrospinal fluid leaks, though few required re-operations. PCVD improved intracranial pressure symptoms in most cases. Conclusion:PCVD is an effective technique for treating craniosynostosis, increasing intracranial volume and improving symptoms of intracranial hypertension. Despite some complications, it remains a reliable and stable alternative for cranial expansion.

The Use of Resorbable Fixation for Posterior Cranial Vault Distraction Osteogenesis

Summary: Posterior vault distraction osteogenesis (PVDO) traditionally relies on the use of cranial distractors affixed with titanium screws to the posterior cranial vault transport segment to allow for expansion of intracranial volume. We describe a novel technique using the Synthes RAPIDSORB IPS resorbable fixation system for stable fixation of the distraction hardware for PVDO. In a retrospective review of our experience with the IPS system, there was no instance of hardware or fixation failure. This off-label use of the IPS system results in a significant reduction in operative time for hardware removal while allowing for a more limited dissection, which can help reduce devascularization of the bony regenerate, bony relapse, and other complications.

Posterior cranial vault distraction in children with syndromic craniosynostosis: the era of biodegradable materials-a comprehensive review of the literature and proposed novel global application.

Distraction osteogenesis is utilized to increase intracranial volume in the treatment of restrictive pathologies, most commonly syndromic synostosis. Children too young for open calvarial vault expansion or other systemic or local contraindications to a direct reconstructive approach benefit greatly from distraction osteogenesis, typically addressing posterior vault expansion. Wound infection, cerebrospinal fluid (CSF) leak, device failure, need for a second surgery for removal, and cost, are issues that can limit the use of this approach. These challenges are more pronounced in low- and middle-income countries (LMICs) due to lack of access to the device, the financial burden of the need for a second surgery, and the severity of the implications of infection and CSF leak. Over the last five decades, there has been an increased acceptance of bioresorbable instrumentation in craniofacial surgery. Poly L-lactic acid, polyglycolic acid, and polydioxanone are the most commonly used polymers. New resorbable fixation tools such as ultrasound-activated pins and heat-activated pins are superior to conventional bioresorbable screws in allowing attachment to thinner bone plates. In this paper, we present a review of the literature on cranial vault distraction and the use of bioresorbable materials and propose a novel design of a fully absorbable cranial distractor system using external magnetic distraction control, eliminating the need for external activation ports and a second surgery to remove the hardware. The application of this technology in LMIC settings could advance access to care and treatment options for patients with syndromic synostosis.

Morphometric analysis and outcomes following posterior cranial vault distraction in syndromic and multisuture craniosynostosis

Turribrachycephaly is a common feature in many syndromic and multisuture craniosynostoses and is traditionally treated with total cranial vault reshaping and fronto-orbital advancement. A staged approach with posterior cranial vault distraction as a primary procedure followed by anterior cranial vault reshaping has the advantage of reducing the vertical dimension of the skull in a controlled and gradual manner while expanding the cranial volume. The purpose of this study was to evaluate outcomes following posterior cranial vault expansion using distraction osteogenesis at a single tertiary pediatric center. This retrospective review included all cases of posterior cranial vault distraction at a single institution from 2008 to 2022 performed by one surgeon. Morphometric outcomes such as Turricephaly Index (TI) and posterior cranial volume (PCV) were assessed from pre- and postoperative computerized tomography scans for patients who underwent posterior cranial vault distraction as a primary first-stage operation. Clinical outcomes and complications were collated. A total of 41 patients (25 females, 16 males; mean age 11 months) with syndromic craniosynostosis (n=32) and nonsyndromic craniosynostosis (n=9) were included. The main indication for posterior cranial vault distraction in this cohort was turricephaly (63%). The mean distraction distance was 25.9mm and the mean decrease in TI was 18%. The estimated increase in PCV from distraction in this cohort was 19.7%. In this cohort of patients, 13 patients (32%) experienced complications but there were no mortalities. Posterior cranial vault distraction osteogenesis is an effective surgical procedure to increase intracranial volume and correct turricephaly in children with syndromic and nonsyndromic craniosynostosis. This procedure is considered a safe and effective first-stage cranial operation in children with syndromic craniosynostosis with increased intracranial pressure and or turricephaly.

Re-imagining early cloverleaf skull deformity management from front to back approach-30years on.

The cloverleaf skull deformity remains among the most complicated craniofacial conditions to successfully manage. Many cases achieve largely unsatisfactory outcomes due to the requirement for frequent reoperation on the cranial vault and failure to deal with all the elements of the craniofaciostenosis in a timely fashion. Early cranial vault surgery without addressing the cranial base deformity and its attendant cerebrospinal fluid flow changes is invariably challenging and disappointing. A recent focus on the expansion of the posterior cranial vault as a primary procedure with the greater volume change allows a delay in fronto-orbital advancement and reduced need for repeat surgery. We herein describe three cases of complex multisuture craniosynostosis with cloverleaf skull deformity who underwent neonatal posterior cranial vault decompression along with foramen magnum decompression. Our report examines the safety and rationale for this pre-emptive surgical approach to simultaneously deal with the cranial vault and craniocervical junction abnormalities and thus change the early trajectory of these complex cases.

Comparison of Morphometric Outcomes following Open Posterior Expansion versus Endoscopic Strip Craniectomy for Sagittal Synostosis.

Open middle and posterior cranial vault expansion (OPVE) or endoscopic (ES) strip craniectomy are two surgical techniques for normalization of head shape in isolated sagittal synostosis. This study aims to compare 2-year cranial morphometrics after these two approaches. The authors performed morphometric analysis on preoperative [time (T) 0], immediately postoperative (T1), and 2-year (T2) postoperative computed tomographic scans of patients who underwent OPVE or ES before 4 months of age. Perioperative data and morphometrics were compared between the two groups and age-matched controls. Nineteen patients were included in the ES cohort, 19 age-matched patients were included in the OPVE cohort, and 57 were included as controls. Median surgery time and blood transfusion volume were less for the ES approach (118 minutes and 0 cc, respectively) compared with OPVE (204 minutes and 250 cc, respectively). Anthropometric measurements after OPVE were closer in normal controls at T1 compared with ES, but the skull shapes were comparable at T2. In the midsagittal plane, anterior vault was higher after OPVE at T2 compared with both ES and controls, but the posterior length was shorter and closer to controls than in the ES cohort. Cranial volumes were like controls for both cohorts at T2. There was no difference in complication rate. Both OPVE and ES techniques result in normalization of cranial shape in patients with isolated sagittal synostosis after 2 years with minimal morphometric differences. Family decision-making between the two approaches should be based on age at presentation, avoidance of blood transfusion, scar pattern, and availability of helmet molding and not on expected outcome. Therapeutic, III.

Surgical Management of Craniosynostosis—Between the Past and the Future: A Comprehensive Review of the Literature

AbstractCranial sutures are fibrous joints between the bones of the cranial vault, acting as centers of osteogenesis of the embryonic mesenchyme. Skull growth is a strictly regulated process, controlled by several genetic pathways. A minor perturbation of these pathways may lead to premature fusion of the cranial sutures. Craniosynostosis occurs as a result of the premature fusion of the cranial sutures. The incidence of craniosynostosis is approximately 1 in 2,500 live births. Syndromic craniosynostoses such as Apert, Crouzon, and Pfeiffer comprise 15% of patients, while nonsyndromic craniosynostosis represents 85% of all patients. By the late 1800s, Lannelongue (Paris, 1890) and Lane (San Francisco, 1892) attempted the first surgical intervention (strip craniectomy) for the management of craniosynostosis. The inadequacy of simple suturectomies and strip craniectomies in the management of craniosynostosis led to the innovation of more complex procedures such as frontoorbital advancement and posterior cranial vault distraction. However, these extensive surgical interventions are lengthy procedures and associated with more blood volume loss which requires blood transfusion. These limitations led to the modern era of minimally invasive endoscopic techniques. In this paper, we reviewed the body of the literature on the evolution of surgical management of craniosynostosis over the last century and the possible future directions.

Perioperative Comparison Between Open Cranial Vault Remodeling and Distraction Osteogenesis for Unilateral Lambdoid Craniosynostosis.

There are multiple treatment options for unilateral lambdoid craniosynostosis (ULS) including open posterior cranial vault remodeling (OCVR) and distraction osteogenesis (DO). There is a paucity of data comparing these techniques in the treatment of ULS. This study compared the perioperative characteristics of these interventions for patients with ULS. An IRB-approved chart review was performed from January 1999 to November 2018 at a single institution. Inclusion criteria included the diagnosis of ULS, treatment with either OCVR or DO using a posterior rotational flap technique, and a minimum 1-year follow-up. Seventeen patients met the inclusion criteria (12 OCVR and 5 DO). Patients in each cohort were found to have a similar distribution in sex, age at the time of surgery, synostosis laterality, weight, and length of follow-up. There was no significant difference in mean estimated blood loss/kg, surgical time, or transfusion requirements between cohorts. Distraction osteogenesis patients had a longer mean hospital length of stay (3.4 +/- 0.6d versus 2.0 +/- 0.6d, P = 0.0004). All patients were admitted to the surgical ward postoperatively. In the OCVR cohort, complications included 1 dural tear, 1 surgical site infection, and 2 reoperations. In the DO cohort, 1 patient had a distraction site infection, treated with antibiotics. There was no significant difference in estimated blood loss, volume of blood transfusion, or surgical time between OCVR and DO. Patients who underwent OCVR had a higher incidence of postoperative complications and the need for reoperation. This data provides insight into the perioperative differences between OCVR and DO in patients with ULS.

A well-preserved cranium from the Judith River Formation (Montana, USA) reveals the inner ear and neuroanatomy of a Campanian baenid turtle.

A cranium belonging to a baenid turtle was recently recovered from the lower half of the Judith River Formation, Montana. Badlands Dinosaur Museum (BDM) 004 is a well-preserved partial cranium that includes the posterior cranial vault, cranial base, and otic capsules. Based on diagnostic characters, the skull can be attributed to Plesiobaena antiqua, which has been previously reported from the Judith River Formation. It also shares with palatobaenines projecting posterior processes of the tubercula basioccipitale and a prominent condylus occipitalis with a deep central pit, demonstrating variation within the Pl. antiqua hypodigm. In a phylogenetic analysis, an operational taxonomic unit of BDM 004 was positioned within Baenodda in an unresolved polytomy with Pl. antiqua, Edowa zuniensis, Palatobaeninae, and Eubaeninae. Microcomputed tomographic (μCT) scans revealed morphology of the middle and inner ear and endocast that are largely unknown in baenids. Semicircular canals of BDM 004 are virtually identical to those of Eubaena cephalica and consistent in dimensions to those of other turtle taxa, including anterior and posterior semicircular canals that are robust and taller than the common crus and diverge from each other at an angle of approximately 90°. The digital endocast reveals a moderately flexed brain with rounded cerebral hemispheres and minimal separation between the metencephalon and myelencephalon. Its well-preserved columella auris (stapes) is gracile with a posterodorsally flared basis columella. It arcs across the middle ear and flattens near its terminus. This study adds to the understanding of baenid middle and inner ear and neuroanatomical morphology and expands the morphological understanding of Pl. antiqua.

Posterior Cranial Retraction Combined With Bilateral Parietal Distraction for Children With Nonsyndromic Craniosynostosis.

The nonsyndromic craniosynostosis is the most common of craniosynostoses in childhood. There are many treatments. We aim to treat 12 cases of nonsyndromic craniosynostosis via posterior cranial vault distraction osteogenesis combined with bilateral parietal distraction. Data of a total of 12 patients (7 boys and 5 girls) with nonsyndromic sagittal synostosis who underwent distraction osteogenesis between January 2015 and August 2020 were retrospectively analyzed. Bilateral parietal bone flaps and posterior occipital flaps were designed and cut. Then, distraction device was placed, which was distracted at 5 days after surgery (twice per day, 0.4-0.6 mm/d, and lasting for 10-15 days). After 6 months of fixation, the secondary surgery was performed to remove the device. The scaphocephaly was corrected, and the appearance was satisfactory. Postoperative follow-up time was 6 to 14 months, with an average of 10 months, and the mean CI was 63.2 and 78.25 before and after surgery, respectively; the mean anterior-posterior skull diameter was shortened (12.63 ± 3.47) mm, the transverse diameter of both temporal regions was lengthened (15.4 ± 4.18) mm, and the scaphocephalic deformity was significantly improved. There was no detachment or rupture of the extender postoperatively. No severe complications, such as radiation necrosis or intracranial infection, were observed. Posterior cranial retraction combined with bilateral parietal distraction in children with nonsyndromic craniosynostosis, in which the proposed technique did not exhibit severe complications, and it is worthy of further promotion and application in clinical practice.

COVID19-induced immunosuppression and aggressive progression of primary cranial vault lymphoma presenting as a management challenge, a case report, and a literature review

BackgroundWe needs to study Primary Large cell Non-Hodgkin’s Lymphoma of the cranial vault, which is rare, and its association with COVID19 has not been reported, which may have an immunosuppressive effect to aggravate its progression.Patient detailsOur patient, a 53-year-old male, noticed fast growth of posterior cranial vault lesion from 2 to 10 cm size in last 6 months after COVID 19 affliction. MRI brain with contrast revealed lesions suggesting meningioma. The whole-body PET scan was normal. Following Subtotal excision of the mass, histopathology revealed large B-cell Non-Hodgkin’s lymphoma (DLBCL). Immunohistochemistry showed positive results for CD10, CD20, CD45 (LCA), ALK, and BCL-VE with a Ki-67 index of 90–95%. Following radiotherapy and chemotherapy patient is disease-free on imaging and doing well at 5 months of follow-up.ConclusionsEarly intervention with excisional biopsy and timely chemo and radiotherapy in favorable immunostaining may add survival benefits even in malignant features induced by immunosuppressing diseases such as COVID19 in diffuse large B-cell lymphoma (DLBCL) of the scalp.

Posterior Cranial Vault Distraction for Treating Syndromic Brachyturricephaly: A 2-Dimensional Operative Video.

De Schlichting, Emmanuel MD*; Pech-Gourg, Grégoire MD‡; Jecko, Vincent MD§,‖; Lechanoine, François MD¶; Gimbert, Edouard MD§; Zaldivar-Jolissaint, Julien Francisco MD*; Coll, Guillaume MD, PhD# Author Information

Morphometric Outcomes of Nonsyndromic Sagittal Synostosis following Open Middle and Posterior Cranial Vault Expansion.

This study aimed to quantify the change in three-dimensional skull morphometrics for patients with sagittal synostosis at presentation, after surgery, and at 2-year follow-up. Computed tomography scans from 91 patients with isolated SS were age-, sex-, and race-matched with those from 273 controls. The authors performed vector analysis with linear regressions to model the effect of open middle and posterior cranial vault remodeling on cranial shape and growth. Anterior cranial volume, bossing angle, and frontal shape were not changed by surgery but normalized without surgical intervention by 2 years. Biparietal narrowing and middle cranial volume were corrected after surgery and maintained at 2 years. Occipital protuberance was improved after surgery and normalized at 2 years. Posterior cranial volume was decreased by occipital remodeling and remained slightly lower than control volumes at 2 years, whereas middle vault volume was larger than in controls. Residual deformities that persisted at 2 years were decreased superolateral width at the level of opisthion and increased anterosuperior height (vertex bulge). Linear models suggested older age at surgery resulted in more scaphocephaly and enlarged posterior cranial vault volumes at 2 years but did not affect other volume outcomes. Preoperative severity was the variable most predictive of 2-year morphometrics. Initial severity of sagittal synostosis deformity was the best predictor of 2-year morphometric outcomes. Upper posterior cranial width decreases with time after surgery and an anterior vertex bulge can persist after open surgery, but frontal dysmorphology self-corrects without surgical intervention. Therapeutic, IV.

Posterior cranial vault distraction osteogenesis: A systematic review.

Posterior cranial vault distraction osteogenesis (PCVDO) has become the treatment of choice in specific indications within 12 years since its introduction in 2009. It is used to treat or prevent Intracranial hypertension secondary to craniosynostosis. However, there is still a lack of evidence describing this procedure's safety concerning the osteotomy line being close to the torcula. This systematic review aims to generate evidence regarding the safety of this new technique. A systematic search of Pubmed and Embase database were done without any time limit until the last search date of July 31, 2021. Articles focused on posterior cranial vault distraction osteogenesis were shortlisted using defined inclusion criteria. In addition, complications, volume gain, and distraction protocols in patients with craniosynostosis were assessed. The review included 11 articles from 11 different centres. Of the Total 241 patients, 51 were non-syndromic patients, and 190 were syndromic patients. There were 242 procedures done on 241 patients. The proportion of patients with complications was 30%. Wound infection was the most commonly reported complication. PCVDO resulted in 20-25% volume gain and successfully prevented increased intracranial pressure (ICP). The systematic review has significantly identified a 30.606% incidence of complications in PCVDO. No mortality was linked directly to the Posterior cranial vault distraction osteogenesis procedure (PCVDO). The authors identified the evolution of many unique vectors and osteotomy designs customized for patients and practices for safe surgery. The effects of PCVDO on the anterior cranial fossa remain a topic of interest and require observational studies for better understanding.

Determination of Novel, Cranium-Based Relationships for Construct Placement in Microtia Reconstruction for Hemifacial Microsomia Patients.

Determine if the ideal location of the construct in microtia reconstruction for hemifacial microsomia (HFM) can be more accurately derived from measurements on the cranium. High-resolution computerized tomography (CT) images were analyzed through craniometric linear relationships. Our tertiary care institution from 2000 to 2021. Patients diagnosed with HFM and microtia, who had high-resolution craniofacial CT scans, yielding 36 patients accounting for 44 CT scans. First, the integrity of the posterior cranial vault among HFM patients was determined. If proven to be unaffected, it could be used as a reference in the placement of the construct. Second, the position of the ear in relation to the cranium was assessed in healthy age-matched controls. Third, if proven to be useful, the concordance of these cranium-based relationships could be validated among our HFM cohort. The posterior cranial vault is unaffected in HFM (P > .001). Further, craniometric relationships between the tragus and the Foramen Magnum, as well as between the tragus and the posterior cranium, have been shown to be highly similar and equally precise in predicting tragus position in healthy controls (P > .001). These relationships held true across all age groups (P > .001), and importantly among HFM patients, where the mean absolute difference in predicted tragus position never surpassed 1.5 mm. Relationships between the tragus and the cranium may be used as an alternative to distorted facial anatomy or surgeon's experience to assist in pre-operative planning of construct placement in microtia reconstruction for HFM patients.

Comparing the Increased Intracranial Volume From Different Surgical Methods for Syndromic Craniosynostosis.

Fronto-orbital advancement (FOA) is the traditional surgical method used to increase intracranial volume, but posterior cranial vault distraction osteogenesis (PVDO) has been gaining popularity as an initial treatment option. This study aimed to compare the effects of FOA and PVDO on intracranial volume. Sixteen patients with multiple-suture synostosis and severe intracranial volume restriction were treated with FOA or PVDO at Children's Hospital of Fudan University between January 2016 and December 2019. Data on age at surgery, sex, preoperative intracranial volume, and postoperative intracranial volume were collected. Seven patients underwent FOA and 9 underwent PVDO. All patients underwent surgery for the first time, and the surgeries were performed by the same physician. There was no statistically significant difference in age at surgery or in the intracranial volumes before and after surgery between the 2 groups ( P >0.05). There was a statistically significant difference in the intracranial volume changes between the 2 groups before and after surgery ( P =0.028). Posterior cranial vault distraction osteogenesis provided statistically greater intracranial volume expansion than FOA.

Changes in venous drainage after posterior cranial vault distraction and foramen magnum decompression in syndromic craniosynostosis.

The authors' objective was to measure the effect of posterior cranial vault distraction (PCVD) plus foramen magnum decompression (FMD) on dural sinus volume and venous flow in patients with syndromic craniosynostosis. The volumes of the sagittal, straight, transverse, and sigmoid sinuses of 5 consecutive patients with syndromic craniosynostosis who underwent PCVD+FMD were calculated in cubic centimeters with T2-weighted volumetric MRI sequences before surgery, immediately after surgery, and after the end of the distraction process. Tridimensional reconstructions of phase-contrast magnetic resonance angiography (PC-MRA) images were obtained with multiplanar reconstruction (MPR). The average total volume of all dural sinuses increased immediately after surgery (from 10.06 cm3 to 12.64 cm3) and continued to increase throughout the 30-day distraction period (from 12.64 cm3 to 14.71 cm3) (p = 0.04), except that the right sigmoid sinus remained stable after the initial increase. The most important increases were observed for the left transverse sinus (+113.2%), right transverse sinus (+104.3%), left sigmoid sinus (+91.3%), and sagittal sinus (+41.8%). Less important modifications were evident for the right sigmoid sinus (+33.7%) and straight sinus (+23.4%). Significant improvements in venous flow were noted on the tridimensional reconstructions of the PC-MRA images. Venous obstruction grading score improved in 4 patients (average [range] 2.4 [ 2-5]) (p = 0.023) and remained stable in 1 patient. All patients had chronic tonsillar herniation (CTH) (mean [range] 16.6 [8-26] mm), and 3 had syringomyelia. CTH showed improvement on the last follow-up MRI evaluation in 4 patients (mean [range] 10.5 [0-25] mm) and worsened from 15 mm to 19 mm in 1 patient. Syringomyelia improved in 2 patients and remained unchanged in 1. This study has provided the first radiological evidence of the impact of craniofacial surgery on dural sinus anatomy and venous drainage. The venous anomalies described in patients with syndromic craniosynostosis are not static, and PCVD+FMD triggers a dynamic process that can lead to significant modifications of intracranial venous drainage. The traction exerted by the distracted bone flap onto the occipitoparietal dura mater adherent to the inner calvaria may account for the enlargement of the dural sinus throughout the distraction period. The impact of these modifications on venous pressure, intracranial pressure, CTH, and hydrocephalus remains to be determined.

Behavioral, Learning Skills, and Visual Improvement in Crouzon Syndrome Patient Following Late Posterior Vault Distraction Osteogenesis.

It is well accepted among craniofacial surgeons that surgery does not improve mental status but does prevent worsening or deterioration of cognitive and mental function. In this report, we describe significant improvement in behavioral, learning skills and visual acuity for a Crouzon patient who underwent late posteriorvault distraction osteogenesis. A 9-year-old Crouzon patient was referred to our hospital, presenting severe intracranial hypertension. The patient had previously undergone a strip craniectomy in early infancy at another medical institution, but there was no subsequent follow-up. Magnetic resonance imaging showed Chiari type I malformation and fundoscopy revealed papilledema. At the time of referral, the patient was not attending a regular school, had not acquired reading skills, was unable to concentrate, and could not accomplish school-related tasks that were standard for children in his age group. The patient underwent posterior vault distraction osteogenesis and showed concentration improvement and acquisition of fluent reading skills. Chiari type I malformation resolved as well as papilledema. visual acuity improved at Snellen test preoperatively from 20/200 to 20/60 at postoperative test. Ventricle size remained unchanged subsequent to performance of the posterior cranial vault distraction. The occipital veins were less visible upon clinical examination and less pronounced when palpated, and the bruit had completely disappeared. Late posterior vault distraction osteogenesis can improve behavioral, learning skills and visual acuity as shown in this 9-year-old Crouzon patient.

Inferiorly Directed Posterior Cranial Vault Distraction for Treatment of Chiari Malformations.

The authors present a case series of patients with Chiari I malformations treated with distraction osteogenesis of the posterior cranial vault, utilizing a vertical distraction vector for appropriate cranial vault expansion while mitigating the risks of scaphocephaly and cerebellar ptosis. Patients with syndromic and nonsyndromic Chiari I malformations treated with vertical-vector distraction osteogenesis of the posterior cranial vault were identified from 2008 to 2014. Demographics, preoperative and postoperative clinical symptoms, and perioperative details were assessed. Long-term esthetic outcomes, complications, and symptomatic improvement were evaluated in conjunction with neurosurgery. Nine patients were identified. Five had known syndromes, 2 likely had unidentified syndromes, and 2 were nonsyndromic. Seven had prior Chiari-related surgeries. Most presented with hydrocephalus, motor symptoms, and developmental delay. Operatively, 2 to 3 internal distraction fixators were applied such that the vector of distraction was along a cephalad-caudad axis. Devices were activated on postoperative day 5 and distracted 1mm per day. Three postoperative complications were found within the first 3 months which included a dislodged distraction arm, a device extrusion, and a local cellulitis. No complications affected the clinical outcome. Radiographic follow-up showed good bone formation, decompression of the posterior fossa, improved cerebrospinal fluid flow, and no cerebellar ptosis. Neurological surveillance showed improvement in intracranial pressure, hydrocephalus, motor symptoms, and behavioral problems. The authors have presented 9 patients with Chiari I malformations treated with distraction osteogenesis, along with a novel technique to safely and effectively expand the posterior fossa while minimizing the risk of cerebellar ptosis. Level II (prognostic/risk studies).