The Evolving Role of Springs in Craniofacial Surgery: The First 100 Clinical Cases:

Multimodal Outcomes of Early Open Extended Midline Strip Craniectomy With Bilateral Microbarrel Staving for Correction of Isolated Nonsyndromic Sagittal Synostosis

AIM

Sagittal synostosis is the most common craniosynostosis. The aim of surgery is to preserve cognitive function and to correct the morphologic changes. In our unit, the authors offer strip craniectomy and microbarrel staving (SMB) performed at 16 to 22 weeks. This study aims to ascertain the 7-year outcome of scaphocephaly correction by SMB. The authors investigate whether the improvement in cranial index (CI) is sustained over time, and report speech and language and neurodevelopmental outcomes.

METHODS

All nonsyndromic patients with sagittal synostosis who underwent SMB between 2009 and 2012 were identified from a prospectively created database that recorded anthropometric measurements, quality metrics, and neurodevelopmental outcomes.

RESULTS

A total of 27 patients were analyzed. The mean CI preoperatively was 67.5% (±3.5), and at 7 years 78% (±4.8). Regarding neurodevelopmental outcomes at 7 years, SDQ responses did not highlight any concerns for social, emotional, or behavioral outcomes. The vast majority of those who completed a WASI-II assessment performed within the average ranges in terms of cognitive ability. In terms of speech and language 70% of subjects demonstrated receptive language within normal level (WNL). Seventy-seven percent of subjects demonstrated expressive language WNL.

CONCLUSIONS

In conclusion, after 7 years of follow-up, early open extended SMB is a safe and effective method for correction of isolated nonsyndromic isolated sagittal synostosis. Across the neurodevelopmental measures and assessments, the children in the current study appeared to perform within expected ranges. Speech and language problems are more prevalent than in the general population.

Spring-assisted posterior vault expansion in children over 2 years of age with craniosynostosis

BACKGROUND

This study evaluated spring-assisted posterior vault expansion (SA-PVE) in children aged > 2 years with craniosynostosis and signs of high intracranial pressure (ICP).

METHODS

We retrospectively analysed all consecutive patients aged > 2 years and operated with SA-PVE between 2018 and 2020 at the Craniofacial Center at Sahlgrenska University Hospital, Sweden. During the procedure, a circumferent occipital bone flap extending below the torcula was created and remained attached to the dura. Intracranial volumes (ICVs) were calculated from computed tomography (CT) images, and demographic data and information regarding symptoms and signs of high ICP were collected.

RESULTS

The study included eight patients [Crouzon/Pfeiffer (n = 4), multiple craniosynostosis (n = 3), and secondary synostosis (n = 1)]. Median age at SA-PVE was 3.8 years (range: 2.5-12.8 years), and springs were removed after a median of 5.5 months (range: 2.3-8.3 months). The median operating time was 164 min (range: 102-221 min), and estimated blood loss was 4.5 mL/kg body weight (range: 1.4-59.1 mL/kg body weight), with 50% of patients receiving a blood transfusion. The median increase in ICV was 206 cm3 (range: 122-344 cm3) representing an 18.7% increase (range: 7.9-24.1%; p = 0.01). We observed no major perioperative complications, and symptoms related to high ICP were improved or absent at clinical follow-up.

CONCLUSION

These results demonstrated that SA-PVE involving creation of a large occipital bone flap including the torcula as a safe and effective surgical treatment in children aged >2 years with craniosynostosis and elevated ICP.

The Incidence and Morphology of Deformational Plagiocephaly in Unicoronal Synostosis

It has been our observation that unicoronal synostosis and deformational plagiocephaly (DP) are not mutually exclusive. The incidence and phenotypical manifestations of a patient presenting with both conditions have not been studied previously. The authors performed a retrospective review of patients presenting with unicoronal synostosis, examining their 3DCT scans for the presence of DP and assessing their endocranial and orbital morphology. The authors found that 38.4% of patients with unicoronal synostosis also have DP. Ipsilateral DP is less common than contralateral DP, but these patients tend to have a delayed presentation due to a reduction in forehead asymmetry corresponding to the parallelogram deformity. Regardless, DP has no impact on the endocranial nor orbital morphology in unicoronal synostosis.

Metopic craniosynostosis: Dynamic cranioplasty for trigonocephaly versus fronto-orbital remodeling and advancement - A retrospective study

The aim of this study was to compare a traditional fronto-orbital remodeling and advancement (FORA) with the dynamic cranioplasty for trigonocephaly (DCT). The authors analyzed patients who underwent surgery for trigonocephaly. Perioperative data were compared. Parents were asked to use a visual analog scale to evaluate the pre- and postoperative distance between the eyes, the forehead shape, and the global appearance of the face. A panel of observers was asked to grade pre- and postoperative photographs using a similar visual analog scale. Pre- and postoperative anthropometric data were collected and analyzed in a subset of the study population aged 9 years or older. The total sample size was 51 patients (DCT n = 39; FORA n = 12). Durations of surgery and anesthesia were shorter in the DCT group (115 vs 194 min, p = 0.001; 226 vs 289 min, p = 0.001). Patients in the DCT group received similar preoperative ratings to those in the FORA group, but significantly higher postoperative ratings by parents for all three questions. There were no significant differences in postoperative ratings by the panel or postoperative anthropometric data. DCT is safe and effective. It is preferred over FORA because it is associated with shorter durations of surgery and anesthesia, while providing higher degrees of parental satisfaction and similar aesthetic and anthropometric outcomes.

A coddling of the sagittal suture: inequality in spring-assisted expansion

PURPOSE

We examined differences in long-term morphometric outcomes of spring-mediated cranioplasty (SMC) for various forms of isolated nonsyndromic sagittal craniosynostosis.

METHODS

A retrospective review was performed of children who underwent SMC from 2011 to 2020 at the Children's Hospital of Philadelphia. Cephalic indices (CI), Whitaker grades, parietal bone thickness, and degree of suture fusion were assessed. Frontal bossing and vertex-nasion-opisthocranion (VNO) angles were compared to a normal control group.

RESULTS

Fifty-four subjects underwent surgery at age 3.6 ± 1.0 months with follow-up of 6.3 ± 1.8 years. Mean CI was 75.2 ± 4.1 at 5.9 ± 2.0 years postoperatively. Mean CI were 75.8 ± 4.1 (n = 32), 76.4 ± 4.0 (n = 22), and 77.1 ± 4.8 (n = 11) at 5, 7, and 9+ years postoperatively, respectively. Three (5.6%) required reoperation for persistent scaphocephalic cranial deformity. Fifty-one (94.4%) were Whitaker Grade I. On physical examination, 12 (22.2%) demonstrated craniofacial abnormalities. At long-term follow-up, there were no differences in frontal bossing angle (102.7 ± 5.2 degrees versus 100.7 ± 5.6 degrees, p = .052) and VNO angle (44.9 ± 3.3 degrees versus 43.9 ± 2.2 degrees, p = .063) between study and control groups. Younger age at surgery predicted a lower Whitaker grade, more normalized VNO angle, and greater change in CI during active expansion. Increased percentage fused of the posterior sagittal suture predicted a higher Whitaker grade, while decreased anterior fusion was associated with frontal bossing and temporal hollowing.

CONCLUSIONS

Overall, children undergoing spring-mediated cranioplasty for sagittal craniosynostosis demonstrated maintenance of CI, favorable cosmetic outcomes, and a low reoperation rate at mid-term follow-up. Early intervention is associated with improved aesthetic outcomes, and regional fusion patterns may influence long-term craniofacial dysmorphology.

Springs Produce Favorable Morphologic Outcomes Relative to H-Craniectomy According to a Two-Center Comparison of Matched Cases

BACKGROUND

Sagittal synostosis is the most common type of premature suture closure, and many surgical techniques are used to correct scaphocephalic skull shape. Given the rarity of direct comparisons of different surgical techniques for correcting craniosynostosis, this study compared outcomes of craniotomy combined with springs and H-craniectomy for nonsyndromic sagittal synostosis.

METHODS

Comparisons were performed using available preoperative and postoperative imaging and follow-up data from the 2 craniofacial national referral centers in Sweden, which perform 2 different surgical techniques: craniotomy combined with springs and H-craniectomy (the Renier technique). The study included 23 pairs of patients matched for sex, preoperative cephalic index, and age. Cephalic index, total intracranial volume (ICV), and partial ICV were measured before surgery and at 3 years of age, with volume measurements compared against those of preoperative and postoperative controls. Perioperative data included operation time, blood loss, volume of transfused blood, and length of hospital stay.

RESULTS

Craniotomy combined with springs resulted in less bleeding and lower transfusion rates than H-craniectomy. Although the spring technique requires 2 operations, the mean total operation time was similar for the methods. Of the 3 complications that occurred in the group treated with springs, 2 were spring-related. The compiled analysis of changes in cephalic index and partial volume distribution revealed that craniotomy combined with springs resulted in superior morphologic correction.

CONCLUSION

The findings showed that craniotomy combined with springs normalized cranial morphology to a greater extent than H-craniectomy based on changes in cephalic index and total and partial ICVs over time.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Nonsyndromic Craniosynostosis Correlation Between Ethnicity, Race, and Pattern of Affected Suture Type: Meta-Analysis

BACKGROUND

Previous studies have sought to analyze risk factors associated with craniosynostosis and while syndromic craniosynostosis is often linked to genetic mutations, the factors impacting nonsyndromic cases are less investigated. The aim of current meta-analysis is to evaluate the relationship between ethnicity and suture type in nonsyndromic craniosynostosis patients.

METHODS

The search term "craniosynostosis [Title/Abstract] AND (race [Title/Abstract] OR ethnicity [Title/Abstract])) NOT (syndrome [Title/Abstract])" was used to search the PubMed, Cochrane, and MEDLINE databases. Analyses were conducted separately for each racial and ethnic group for each suture type cohort. Odds ratios were conducted for each suture cohort and confounders were adjusted using linear mixed-effect models. Because of the homogeneity of the populations and categorical nature of the classification, binary logistic regression was run on aggregate data.

RESULTS

The literature search yielded 165 articles. After reviewing titles, abstracts, and manuscript contents of these articles, 5 studies were ultimately included in a meta-analysis. Studies with missing data for a particular cohort or variable were excluded from the respective analysis. Hispanic children had higher odds of sagittal suture involvement (OR: 1.53, P <0.001), whereas Asian had coronal suture (OR: 2.47, P <0.001). Both Asian and African American children had significantly lower odds of sagittal suture involvement (OR: 0.50, P <0.001 and OR: 0.7, P =0.04, respectively).

CONCLUSION

The relationship between ethnicity and craniosynostosis has been suggested as a risk factor, but without definitive conclusion. Present meta-analysis findings demonstrated association between ethnicity and suture type, however further research with larger scale and geographically varied data is warranted.

The Top 100 Most-Cited Publications in Clinical Craniofacial Research

INTRODUCTION

Craniosynostosis is a birth defect defined as premature closure of sutures leading to possible neurological deficits and cosmetic deformities. Most of the current literature to date focuses on craniosynostosis etiology by analyzing genetics. This paper is a bibliometric analysis of the most influential works related to the clinical management of craniosynostosis to help guide clinicians in their decision-making.

METHODS AND MATERIALS

Clarivate Web of Science database was used to identify the top 100 most-cited articles addressing the clinical management of craniosynostosis. A bibliometric review was performed to analyze publication metrics and track research trends.

RESULTS

The 100 most-cited publications pertaining to craniosynostosis management were cited a cumulative 12,779 times. The highest cited article was Shillito and colleagues' "Craniosynostosis: A Review Of 519 Surgical Patients" with 352 citations. The oldest clinical craniosynostosis article dates back to 1948, and the most recent was published in 2016. The year with the most clinical-focused publications was 2011. The most prolific author was Renier, D. The United States produced 56 of the 100 articles. Most articles (n=52) were level 3 evidence.

DISCUSSION

This bibliometric evaluation of craniosynostosis provides insight into the most impactful literature on this topic. The highest cited articles retrospectively analyze large sample sizes, outline proper evaluation, discuss intervention timelines, and highlight specific treatment plans for this birth defect. By filtering through existing literature, this analysis can guide clinicians on the management of craniosynostosis to maximize patient outcomes.

Long-term results of minimally invasive strip craniectomy without helmet therapy for scaphocephaly - a single-centre experience

Scaphocephaly is the most common type of craniosynostosis and various surgical techniques are used for treatment. Due to late postoperative changes of the head shape, long-term outcome data is important for evaluating any new surgical technique. At our institution, minimally invasive strip craniectomy without regular helmet therapy is the standard treatment in scaphocephalic patients. Between October 2021 and February 2023, we retrospectively examined the skull shape of patients who underwent minimally invasive strip craniectomy for scaphocephaly using a 3D surface scan technique. The cephalic index (CI), the need for helmet therapy and additional cosmetic outcome parameters were investigated. We included 70 patients (72.5% male). The mean follow-up time was 46 (10-125) months and the mean CI was 75.7 (66.7-85.2). In 58 patients, the final cosmetic result was rated as "excellent/good" (mean CI: 76.3; 70.4-85.0), in 11 as "intermediate" (mean CI: 73.3; 66.7-77.6), and in one case as "unsatisfactory" (CI 69.3). The presence of a suboccipital protrusion was associated with a "less than good" outcome. The CI correlated significantly with the overall outcome, the presence of frontal bossing, and the interval between scan and surgery (age at scan). Minimally invasive strip craniectomy is an elegant and safe method to correct scaphocephaly. Our data show good cosmetic results in the long term even without regular postoperative helmet therapy.

Isolated Sagittal Craniosynostosis: A Comprehensive Review

Sagittal craniosynostosis, a rare but fascinating craniofacial anomaly, presents a unique challenge for both diagnosis and treatment. This condition involves premature fusion of the sagittal suture, which alters the normal growth pattern of the skull and can affect neurological development. Sagittal craniosynostosis is characterised by a pronounced head shape, often referred to as scaphocephaly. Asymmetry of the face and head, protrusion of the fontanel, and increased intracranial pressure are common clinical manifestations. Early recognition of these features is crucial for early intervention, and understanding the aetiology is, therefore, essential. Although the exact cause remains unclear, genetic factors are thought to play an important role. Mutations in genes such as FGFR2 and FGFR3, which disrupt the normal development of the skull, are suspected. Environmental factors and various insults during pregnancy can also contribute to the occurrence of the disease. An accurate diagnosis is crucial for treatment. Imaging studies such as ultrasound, computed tomography, magnetic resonance imaging, and three-dimensional reconstructions play a crucial role in visualising the prematurely fused sagittal suture. Clinicians also rely on a physical examination and medical history to confirm the diagnosis. Early detection allows for quick intervention and better treatment outcomes. The treatment of sagittal craniosynostosis requires a multidisciplinary approach that includes neurosurgery, craniofacial surgery, and paediatric care. Traditional treatment consists of an open reconstruction of the cranial vault, where the fused suture is surgically released to allow normal growth of the skull. However, advances in minimally invasive techniques, such as endoscopic strip craniectomy, are becoming increasingly popular due to their lower morbidity and shorter recovery times. This review aims to provide a comprehensive overview of sagittal craniosynostosis, highlighting the aetiology, clinical presentation, diagnostic methods, and current treatment options.

Craniometric and Aesthetic Outcomes in Craniosynostosis Surgery: A Systematic Review and Meta-Analysis

OBJECTIVE

To systematically review the published comparative aesthetic outcomes, and its determinants, for craniosynostoses surgically treated by minimally-invasive cranial procedures and open cranial vault remodeling (CVR).

DESIGN

PRISMA-compliant systematic review.

SETTING

Not-applicable.

PATIENTS/PARTICIPANTS

Articles were included if they compared spring cranioplasty, strip minimally-invasive craniectomy or CVR for outcomes related to aesthetics or head shape. Forty-two studies were included, comprising 2402 patients.

INTERVENTIONS

None.

MAIN OUTCOME MEASURE(S)

The craniometric and PROM used to determine surgical outcomes.

RESULTS

Twenty-five studies (59%) evaluated sagittal craniosynostosis, with metopic (7;17%) and unicoronal (4;10%) the next most prevalent. Thirty-eight studies (90%) included CVR, 24 (57%) included strip craniectomy with helmeting, 9 (22%) included strip craniectomy without helmeting, 11 (26%) included spring cranioplasty, and 3 (7%) included vault distraction. A majority of studies only used 1 (43%) or 2 (14%) craniometric measures to compare techniques. In sagittal synostosis, 13 (59%) studies showed no difference in craniometric outcomes, 5 (23%) showed better results with CVR, 3 (14%) with strip craniectomy, and 1 (5%) with springs. In studies describing other synostoses, 10/14 (71%) were equivocal. Subjective outcome measures followed similar trends. Meta-analysis shows no significant difference in cranial index (CI) outcomes between CVR and less invasive procedures in patients with sagittal synostosis.

CONCLUSIONS

There is no difference in CI outcomes between CVR and less invasive procedures. The majority of literature comparing craniometric and aesthetic outcomes between CVR and less invasive procedures shows equivocal results for sagittal synostosis. However, the heterogeneity of data for other craniosynostoses did not allow meta-analysis.

Spring-Assisted Cranial Expansion for Multisuture Craniosynostosis: First Case Report from the Indian Subcontinent

We present a first use case report from the Indian subcontinent of a 5-month-old child with multisuture craniosynostosis with raised intracranial pressure managed by spring-assisted cranial expansion followed by traditional fronto-orbital advancement and cranial vault remodeling. We emphasize the advantages of spring-assisted cranial expansion in extremely young infants with raised intracranial pressure over posterior vault distraction osteogenesis and open posterior vault remodeling.

Combined Dynamic Osteotomies for Craniosynostosis

Background

In primary craniosynostosis, the premature fusion of one or more sutures prevents the perpendicular expansion of brain tissue (primary defect). Providing space for the brain to expand, the compensatory growth of unaffected sutures causes progressive skull deformation (secondary defect). Understanding the need to treat the osteogenic matrix responsible for the cranial vault's shape was essential to develop a novel surgical concept known as dynamic osteotomy. It uses springs to activate stenotic sutures and trigger dura-mater distension while flexibilizing compensatory osseous defects via helicoid osteotomy (nautilus technique), allowing for efficient bone expansion and remodeling in craniosynostosis.

Method

This case series describes patients with craniosynostosis treated with dynamic osteotomy utilizing structural transformation inductors such as springs and helicoid osteotomy (nautilus technique), operated on between July 2004 and January 2020 at a single center in Brazil.

Result

Dynamic osteotomy longitudinally achieved stable osseous remodeling during growth period while maintaining good vitality and continuity of the osteotomized cranial vault.

Conclusion

Dynamic osteotomy utilizing springs and nautilus technique, alone or in combination, is a successful treatment of craniosynostosis regardless of patient's age.

Two-Center Review of Posterior Vault Expansion following a Staged or Expectant Treatment of Crouzon and Apert Craniosynostosis

BACKGROUND

The timing of posterior cranial expansion for the management of intracranial pressure can be "staged" by age and dysmorphology or "expectant" by pressure monitoring. The authors report shared outcome measures from one center performing posterior vault remodeling (PCVR) or distraction (PVDO) following a staged approach and another performing spring-assisted expansion (SAPVE) following an expectant protocol.

METHODS

Apert or Crouzon syndrome patients who underwent posterior expansion younger than 2 years were included. Perioperative outcomes and subsequent cranial operations were recorded up to last follow-up and intracranial volume changes measured and adjusted using growth curves.

RESULTS

Thirty-eight patients were included. Following the expectant protocol, Apert patients underwent SAPVE at a younger age (8 months) than Crouzon patients (16 months). The initial surgery time was shorter but total operative time, including device removal, was longer for PVDO (3 hours 52 minutes) and SAPVE (4 hours 34 minutes) than for PCVR (3 hours 24 minutes). Growth-adjusted volume increase was significant and comparable. Fourteen percent of PCVR, 33% of PVDO, and 11% of SAPVE cases had complications, but without long-term deficits. Following the staged approach, 5% underwent only PVDO, 85% had a staged posterior followed by anterior surgery, and 10% required a third expansion. Following the expectant approach, 42% of patients had only posterior expansion at last follow-up, 32% had a secondary cranial surgery, and 26% had a third cranial expansion.

CONCLUSION

Two approaches involving posterior vault expansion in young syndromic patients using three techniques resulted in comparable early volume expansion and complication profiles.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Moderne Behandlung von Kraniosynostosen

Hintergrund

Bei 13–48 % aller Lebendgeborenen treten Auffälligkeiten der Schädelform auf. Meistens ist ein lagerungsbedingter Plagiozephalus ursächlich. Bei vorzeitigem Verschluss von Schädelnähten resultieren pathognomische Deformitäten durch das kompensatorische Wachstum der umgebenden Schädelknochen. Es muss zwischen Einzelnahtsynostosen und Kraniosynostosen im Rahmen syndromaler Erkrankungen unterschieden werden.

Ziel

Diese Arbeit soll einen Überblick über Diagnostik, konservative und chirurgische Therapie von Kraniosynostosen geben.

Methoden

Narratives Review.

Ergebnis

Bei Verdacht auf eine Kraniosynostose erfolgt zunächst die klinische Beurteilung und Einschätzung durch erfahrene Untersucher. Die pathognomische Schädelform ergibt die Arbeitsdiagnose. Bestätigt wird diese durch Verfahren wie 3D-Stereofotografie und Sonographie. In komplexen Fällen können CT oder MRT notwendig sein.

Die Indikation für eine Therapie ergibt sich aus ästhetischen Gesichtspunkten und der Vorbeugung psychosozialer Folgen. Bei syndromalen Formen besteht diese insbesondere zur Vermeidung möglicher Folgen eines erhöhten Hirndrucks.

Besteht die Indikation zur Operation muss zwischen endoskopischer und offener Technik unterschieden werden. Unterschiede bestehen hier hinsichtlich Invasivität und möglichem Korrekturausmaß. Im Anschluss an die operative Behandlung schließt sich häufig eine Helmtherapie an, um das bestmögliche Ergebnis zu erreichen. Die anschließende Follow-up-Periode erstreckt sich mindestens bis zum 12. Lebensjahr. Insgesamt sollte die Behandlung im Team mit Neurochirurgen, Mund‑, Kiefer‑, Gesichtschirurgen, Kinderärzten, Augenärzten und Humangenetikern stattfinden.

Introduction of Spring-Assisted Cranioplasty for Sagittal Craniosynostosis in a Craniofacial Service: A Report of Early Experience

Spring-assisted cranioplasty (SAC) for the treatment of craniosynostosis uses internal springs to produce dynamic changes in cranial shape over several months before its removal. The purpose of this study was to report the first Egyptian experiences with SAC in the treatment of children with sagittal synostosis and evaluate the preliminary outcome. A total of 17 consecutive patients with scaphocephaly underwent SAC with a midline osteotomy along the fused sagittal suture and insertion of 3 springs with bayonet-shaped ends across the opened suture. Operative time, blood transfusion requirements and length of ICU, total hospital stay, and complications graded according to Oxford protocol classification were recorded. Spring removal was performed once re-ossification of the cranial defect occurred. All patients successfully underwent SAC without significant complications. The mean age at surgery was 6.8 months. The mean time of the spring insertion surgery was 63 minutes (SD 9.7). Blood transfusion was needed in less than half of the patients (41.2%).The mean duration of hospital stay was 3.2 days. The mean timing of spring removal was 5.5 months (SD 0.4). The mean time of the second surgery (spring removal) was 22.8 minutes (SD 3.6). In conclusion, SAC can easily be incorporated into the treatment armamentarium of craniofacial surgeons. The technique offers a safe and minimally invasive option for the treatment of sagittal craniosynostosis with the benefit of limited dural undermining, minimal blood loss, operative time, anesthetic time, ICU stay, and hospital stay.

Endoscopic strip craniectomy with molding helmet therapy versus spring-assisted cranioplasty for nonsyndromic single-suture sagittal craniosynostosis: a systematic review

OBJECTIVE

Endoscopic strip craniectomy with postoperative molding helmet therapy (ESC-H) and spring-assisted cranioplasty (SAC) are commonly used minimally invasive techniques for correction of nonsyndromic sagittal craniosynostosis, but it is unclear which, if either, is superior. Therefore, the authors undertook a systematic review to compare ESC-H with SAC for the surgical management of nonsyndromic single-suture sagittal craniosynostosis.

METHODS

Studies were identified through a systematic and comprehensive search of four databases (Embase, MEDLINE, and two databases in the Cochrane Library). Databases were searched from inception until February 19, 2021. Pediatric patients undergoing either ESC-H or SAC for the management of nonsyndromic single-suture sagittal craniosynostosis were included. Systematic reviews and meta-analyses, single-patient case reports, mixed cohorts of nonsyndromic and syndromic patients, mixed cohorts of different craniosynostosis types, and studies in which no outcomes of interest were reported were excluded. Outcomes of interest included reoperations, blood transfusion, complications, postoperative intensive care unit (ICU) admission, operative time, estimated blood loss, length of hospital stay, and cephalic index. Pooled summary cohort characteristics were calculated for each outcome of interest. Methodological quality was assessed using the Newcastle-Ottawa Scale. The study was reported in accordance with the 2020 PRISMA statement.

RESULTS

Twenty-two studies were eligible for inclusion in the review, including 1094 patients, of whom 605 (55.3%) underwent ESC-H and 489 (44.7%) underwent SAC for nonsyndromic sagittal craniosynostosis. There was no difference between the pooled estimates of the ESC-H and SAC groups for operative time, length of stay, estimated blood loss, and cephalic index. There was no difference between the groups for reoperation rate and complication rate. However, ESC-H was associated with a higher blood transfusion rate and higher postoperative ICU admission.

CONCLUSIONS

The available literature does not demonstrate superiority of either ESC-H or SAC, and outcomes are broadly similar for the treatment of nonsyndromic sagittal craniosynostosis. However, the evidence is limited by single-center retrospective studies with low methodological quality. There is a need for international multicenter randomized controlled trials comparing both techniques to gain definitive and generalizable data.

Management of Sagittal and Lambdoid Craniosynostosis: Minimally Invasive Approaches

The resurgence of strip craniectomies began in the mid-1990s with advances in surgical technique and anesthesia coupled with the critical observation that earlier interventions benefitted from an easily molded skull. Jimenez and Barone's pioneering introduction of endoscopic approaches to strip craniectomies coupled with postoperative helmeting in newborns and young infants and Claes Lauritzen's introduction of spring-mediated cranioplasty began the era of minimally invasive approaches in the surgical correction of craniosynostosis. This article provides technical descriptions of these treatment modalities, a comparative literature review, and our institutional algorithms for the correction of sagittal craniosynostosis and unilambdoid craniosynostosis.

Predicting Changes in Cephalic Index Following Spring-mediated Cranioplasty for Nonsyndromic Sagittal Craniosynostosis: A Stepwise and Machine Learning Algorithm Approach

BACKGROUND

Spring-mediated cranioplasty (SMC) is an increasingly utilized technique to treat patients with nonsyndromic sagittal craniosynostosis, but variables impacting outcomes are incompletely understood. The purpose of this study was to determine variables most predictive of outcomes following SMC, primarily changes in cephalic index (CI).

METHODS

Patients with nonsyndromic sagittal craniosynostosis undergoing SMC at our institution between 2014 and 2021 were included. Cephalic index was measured from patient computed tomography scans, x-rays, or by caliper-based methods. Parietal bone thickness was determined from patient preoperative computed tomography. Stepwise multiple regression analysis, least absolute shrinkage and selection operator, and random forest machine learning methods were used to determine variables most predictive of changes in CI.

RESULTS

One hundred twenty-four patients were included. Stepwise multiple regression analysis identified duration of spring placement (P=0.007), anterior spring force (P=0.034), and anterior spring length (P=0.043) as statistically significant predictors for changes in CI. Least absolute shrinkage and selection operator analysis identified maximum spring force (β=0.035), anterior spring length (β=0.005), posterior spring length (β=0.004), and duration of spring placement (β=0.0008) as the most predictive variables for changes in CI. Random forest machine learning identified variables with greatest increase in mean squared error as maximum spring force (0.0101), anterior spring length (0.0090), and posterior spring length (0.0056).

CONCLUSIONS

Maximum and total spring forces, anterior and posterior spring lengths, and duration of spring placement were the most predictive variables for changes in CI following SMC. Age at surgery and other demographic variables were inferior predictors in these models.

Fronto-Orbital Advancement for Metopic and Unilateral Coronal Craniosynostoses

Fronto-orbital advancement remains a powerful technique for the correction of anterior cranial vault differences related to metopic (trigonocephaly) or unilateral coronal (anterior plagiocephaly) craniosynostoses. Traditional fronto-orbital advancement requires access to the forehead and superior 2/3 of the orbit via a coronal incision. The frontal bone and orbital segment (bandeau) are then separated from the skull and reshaped. In patients with metopic craniosynostosis, the bandeau and frontal bone will need to be advanced and widened. In patients with unilateral coronal craniosynostosis, the bandeau will need to be "untwisted" to address the supraorbital retrusion on the affected side, the affected orbit will need to be shortened and widened, and the frontal bone flap will need to be proportionately advanced on the affected side. Overcorrection of the affected dimension should be undertaken to account for growth and relapse.

Syndromic Craniosynostosis: Cranial Vault Expansion in Infancy

Syndromic craniosynostosis (CS) represents a relatively uncommon disease process that poses significant reconstructive challenges for the craniofacial surgeon. Although there is considerable overlap in clinical features associated with various forms of syndromic CS, key extracranial features and close examination of the extremities help to distinguish the subtypes. While Virchow's law can easily guide the diagnosis of single suture, nonsyndromic CS, syndromic CS traditionally results in atypical presentations inherent to multiple suture fusion. Coronal ring involvement in isolation or associated with additional suture fusion is the most common pattern in syndromic CS often resulting in turribrachycephaly.

Endoscopic treatment of sagittal suture synostosis - a critical analysis of current management strategies

While many centers nowadays offer minimally invasive techniques for the treatment of single suture synostosis, surgical techniques and patient management vary significantly. We provide an overview of how scaphocephaly treated with endoscopic techniques is managed in the reported series and analyze the crucial steps that need to be dealt with during the management process. We performed a review of the published literature including all articles that examined sagittal-suture synostosis treated with endoscopic techniques as part of single- or multicenter studies. Fourteen studies reporting results of 885 patients were included. We identified 5 key steps in the management of patients. A total of 188 patients were female and 537 male (sex was only specified in 10 articles, for 725 included patients, respectively). Median age at surgery was between 2.6 and 3.9 months with a total range from 1.5 to 7.0 months. Preoperative diagnostics included clinical and ophthalmologic examinations as well as neuropsychological and genetic consultations if needed. In 5 publications, a CT scan was routinely performed. Several groups used anthropometric measurements, mostly the cephalic index. All groups analyzed equally recommended to perform endoscopically assisted craniosynostosis surgery with postoperative helmet therapy in children < 3 months of age, at least for non-syndromic cases. There exist significant variations in surgical techniques and patient management for children treated endoscopically for single suture sagittal synostosis. This heterogeneity constitutes a major problem in terms of comparability between different strategies.

Parietal bone thickness for predicting operative transfusion and blood loss in patients undergoing spring-mediated cranioplasty for nonsyndromic sagittal craniosynostosis

OBJECTIVE

Variables that can predict outcomes in patients with craniosynostosis, including bone thickness, are important for surgical decision-making, yet are incompletely understood. Recent studies have demonstrated relative risks and benefits of surgical techniques for correcting head shape in patients with nonsyndromic sagittal craniosynostosis. The purpose of this study was to characterize the relationships between parietal bone thickness and perioperative outcomes in patients who underwent spring-mediated cranioplasty (SMC) for nonsyndromic sagittal craniosynostosis.

METHODS

Patients who underwent craniectomy and SMC for nonsyndromic sagittal craniosynostosis at a quaternary pediatric hospital between 2011 and 2021 were included. Parietal bone thickness was determined on patient preoperative CT at 27 suture-related points: at the suture line and at 0.5 cm, 1.0 cm, 1.5 cm, and 2.0 cm from the suture at the anterior parietal, midparietal, and posterior parietal bones. Preoperative skull thickness was compared with intraoperative blood loss, need for intraoperative transfusion, and hospital length of stay (LOS).

RESULTS

Overall, 124 patients with a mean age at surgery ± SD of 3.59 ± 0.87 months and mean parietal bone thickness of 1.83 ± 0.38 mm were included in this study. Estimated blood loss (EBL) and EBL per kilogram were associated with parietal bone thickness 0.5 cm (ρ = 0.376, p < 0.001 and ρ = 0.331, p = 0.004; respectively) and 1.0 cm (ρ = 0.324, p = 0.007 and ρ = 0.245, p = 0.033; respectively) from the suture line. Patients with a thicker parietal bone 0.5 cm (OR 18.08, p = 0.007), 1.0 cm (OR 7.16, p = 0.031), and 1.5 cm (OR 7.24, p = 0.046) from the suture line were significantly more likely to have undergone transfusion when controlling for age, sex, and race. Additionally, parietal bone thickness was associated with hospital LOS (β 0.575, p = 0.019) when controlling for age, sex, and race. Patient age at the time of surgery was not independently associated with these perioperative outcomes.

CONCLUSIONS

Parietal bone thickness, but not age at the time of surgery, may predict perioperative outcomes including transfusion, EBL, and LOS. The need for transfusion and EBL were most significant for parietal bone thickness 0.5 cm to 1.5 cm from the suture line, within the anticipated area of suturectomy. For patients undergoing craniofacial surgery, parietal bone thickness may have important implications for anticipating the need for intraoperative transfusion and hospital LOS.

What is the Role of Force in Correcting Scaphocephaly Through Spring-Mediated Cranial Vault Expansion for Sagittal Craniosynostosis?

OBJECTIVES

Spring-mediated cranial vault expansion (SMC) may enable less invasive treatment of sagittal craniosynostosis than conventional methods. The influence of spring characteristics such as force, length, and quantity on cranial vault outcomes are not well understood. Using in vivo and ex vivo models, we evaluate the interaction between spring force, length, and quantity on correction of scaphocephalic deformity in patients undergoing SMC.

METHODS

The authors retrospectively studied subjects with isolated sagittal craniosynostosis who underwent SMC between 2011 and 2019. The primary outcome measure of in vivo analysis was head shape determined by cephalic index (CI). Ex vivo experimentation analyzed the impact of spring length, bend, and thickness on resultant force.

RESULTS

Eighty-nine subjects underwent SMC at median 3.4 months with median preoperative CI 69% (interquartile range: 66, 71%). Twenty-six and 63 subjects underwent SMC with 2 and 3 springs, with mean total force 20.1 and 27.6 N, respectively (P < 0.001).Postoperative CI increased from 71% to 74% and 68% to 77% in subjects undergoing 2- and 3-spring cranioplasty at the 6-month timepoint, respectively (P < 0.001). Total spring force correlated to increased change in CI (P < 0.002). Spring length was inversely related to transverse cranial expansion at Postoperative day 1, however, directly related at 1 and 3 months (P < 0.001). Ex vivo modeling of spring length was inversely related to spring force regardless of spring number (P < 0.0001). Ex vivo analysis demonstrated greater resultant force when utilizing wider, thicker springs independent of spring arm length and degree of compression.

CONCLUSIONS

A dynamic relationship among spring characteristics including length, bend, thickness, and quantity appear to influence SMC outcomes.

Novel Method of Lateral Vault Modification in Scaphocephaly

BACKGROUND

Scaphocephaly is the commonest from of craniosynostosis. There are several surgical methods to correct this and is influenced by the areas affected. A common thread in any of these corrections is an attempt to increase the biparietal diameter by modifying the lateral vault panel (LVP). A simple and novel method is proposed.

MATERIALS AND METHOD

The records of all patients undergoing scaphocephaly correction in the craniofacial unit at the institution were reviewed from 2003 to 2019. There were 106 patients, 57 males, and 49 females. The age ranged from 6 months to 5 years with a mean of 11 months. The method of vault remodeling was LVP only in 36 (34%), subtotal vault remodeling in 59 (56%), and total vault remodeling in 11 (10%). All 106 patients underwent LVP remodeling as part of the procedure. One or 2 wedge excisions was performed to increase the curvature of the LVP and this panel was fixed on the outside of the temporal squame bone.

RESULTS

The patients were followed up for a minimum of 1 year. Satisfactory results were obtained. The mean preoperative cephalic index was 64% and the mean postoperative index was 75%. There were minor complications such as screw visibility in a few patients.

CONCLUSIONS

Wedge excisions of the LVP is a simple and effective maneuver that can be used as strategy when performing scaphocephaly correction.

Predicting and comparing three corrective techniques for sagittal craniosynostosis

Sagittal synostosis is the most occurring form of craniosynostosis, resulting in calvarial deformation and possible long-term neurocognitive deficits. Several surgical techniques have been developed to correct these issues. Debates as to the most optimal approach are still ongoing. Finite element method is a computational tool that's shown to assist with the management of craniosynostosis. The aim of this study was to compare and predict the outcomes of three reconstruction methods for sagittal craniosynostosis. Here, a generic finite element model was developed based on a patient at 4 months of age and was virtually reconstructed under all three different techniques. Calvarial growth was simulated to predict the skull morphology and the impact of different reconstruction techniques on the brain growth up to 60 months of age. Predicted morphology was then compared with in vivo and literature data. Our results show a promising resemblance to morphological outcomes at follow up. Morphological characteristics between considered techniques were also captured in our predictions. Pressure outcomes across the brain highlight the potential impact that different techniques have on growth. This study lays the foundation for further investigation into additional reconstructive techniques for sagittal synostosis with the long-term vision of optimizing the management of craniosynostosis.

Long-Term Neurocognitive Outcomes of Spring-Assisted Surgery versus Cranial Vault Remodeling for Sagittal Synostosis

BACKGROUND

A long-term neurocognitive comparison of patients with sagittal synostosis who underwent spring-assisted surgery or cranial vault remodeling has not been performed.

METHODS

Patients with sagittal synostosis who underwent spring-assisted surgery or cranial vault remodeling were recruited from Wake Forest School of Medicine and Yale School of Medicine, respectively. Cognitive tests administered included an abbreviated intelligence quotient, academic achievement, and visuomotor integration. An analysis of covariance model compared cohorts controlling for demographic variables.

RESULTS

Thirty-nine spring-assisted surgery and 36 cranial vault remodeling patients were included in the study. No significant differences between cohorts were found with respect to age at surgery, sex, race, birth weight, family income, or parental education. The cranial vault cohort had significantly older parental age (p < 0.001), and mean age at testing for the spring cohort was significantly higher (p = 0.001). After adjusting for covariates, the cranial vault cohort had significantly higher verbal intelligence quotient (116.5 versus 104.3; p = 0.0024), performance intelligence quotient (109.2 versus 101.5; p = 0.041), and full-scale intelligence quotient (114.3 versus 103.2; p = 0.0032). When included patients were limited to intelligence quotients from 80 to 120, the cranial vault cohort maintained higher verbal (108.0 versus 100.4; p = 0.036), performance (104.5 versus 97.7; p = 0.016), and full-scale (107.6 versus 101.5; p = 0.038) intelligence quotients. The cranial vault cohort had higher visuomotor integration scores than the surgery group (111.1 versus 98.1; p < 0.001). There were no significant differences in academic achievement.

CONCLUSIONS

Sagittal synostosis patients who underwent cranial vault remodeling had higher intelligence quotient and visuomotor integration scores. There were no differences in academic achievement. Both cohorts had intelligence quotient scores at or above the normal range. Further studies are warranted to identify factors that may contribute to cognitive outcome differences.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

Three-Dimensional Analysis and Surgical Planning for Open Correction of Trigonocephaly

SUMMARY

Metopic craniosynostosis results in trigonocephaly, characterized by a triangular forehead with metopic ridge, bitemporal pinching, and narrow-set eyes with recessed lateral orbital rims. Surgical management is controversial but may include open expansion and vault remodeling, to enhance neurocognitive and aesthetic outcomes. This article and video vignette depict the diagnosis and treatment of metopic craniosynostosis, demonstrating the senior author's open approach, three-dimensional virtual surgical planning, and technical steps.

Comparisons of Intracranial Volume and Cephalic Index After Correction of Sagittal Craniosynostosis With Either Two or Three Springs

ABSTRACT

In this retrospective study, the authors determined changes in intracranial volume (ICV) and cephalic index (CI) in patients with sagittal craniosynostosis and operated with craniotomy combined with either 2 or 3 springs. The authors included patients (n = 112) with complete follow-up that had undergone surgical correction for isolated sagittal craniosynostosis with craniotomy combined with springs between 2008 and 2017. All patients underwent computed tomography examination preoperative, at the time of spring extraction, and at 3 years of age. Intracranial volume was measured using a semiautomatic MATLAB program, and CI was calculated as the width/length of the skull. The authors found that craniotomy combined with 2 springs increased the ICV from a preoperative value of 792 ± 113 mL (mean ± standard deviation) to 1298 ± 181 mL at 3 years of age and increased the CI from 72.1 ± 4.1 to 74.6 ± 4.3, whereas craniotomy combined with 3 springs increased the ICV from 779 ± 128 mL to 1283 ± 136 mL and the CI from 70.7 ± 4.3 to 74.8 ± 3.7. The relative increase in ICV was 65 ± 21% in the two-spring group and 68 ± 34% in the three-spring group (P value = 0.559), and the relative increase in CI was 3.6 ± 3.3% in the two-spring group as compared with 6.0 ± 5.0% in the three-spring group (P = 0.004). These findings demonstrated that use of 3 springs resulted in additional absolute and relative CI-specific effects as compared with 2 springs during the time when the springs were in place, with this effect maintained at 3 years of age.

Using Sensitivity Analysis to Develop a Validated Computational Model of Post-operative Calvarial Growth in Sagittal Craniosynostosis

Craniosynostosis is the premature fusion of one or more sutures across the calvaria, resulting in morphological and health complications that require invasive corrective surgery. Finite element (FE) method is a powerful tool that can aid with preoperative planning and post-operative predictions of craniosynostosis outcomes. However, input factors can influence the prediction of skull growth and the pressure on the growing brain using this approach. Therefore, the aim of this study was to carry out a series of sensitivity studies to understand the effect of various input parameters on predicting the skull morphology of a sagittal synostosis patient post-operatively. Preoperative CT images of a 4-month old patient were used to develop a 3D model of the skull, in which calvarial bones, sutures, cerebrospinal fluid (CSF), and brain were segmented. Calvarial reconstructive surgery was virtually modeled and two intracranial content scenarios labeled “CSF present” and “CSF absent,” were then developed. FE method was used to predict the calvarial morphology up to 76 months of age with intracranial volume-bone contact parameters being established across the models. Sensitivity tests with regards to the choice of material properties, methods of simulating bone formation and the rate of bone formation across the sutures were undertaken. Results were compared to the in vivo data from the same patient. Sensitivity tests to the choice of various material properties highlighted that the defined elastic modulus for the craniotomies appears to have the greatest influence on the predicted overall skull morphology. The bone formation modeling approach across the sutures/craniotomies had a considerable impact on the level of contact pressure across the brain with minimum impact on the overall predicated morphology of the skull. Including the effect of CSF (based on the approach adopted here) displayed only a slight reduction in brain pressure outcomes. The sensitivity tests performed in this study set the foundation for future comparative studies using FE method to compare outcomes of different reconstruction techniques for the management of craniosynostosis.

Spring-assisted minimally invasive repair of sagittal craniosynostosis

Craniosynostosis surgery is intended to repair cranial deformity, reduce the risk of increased intracranial pressure from cephalocranial disproportion, and reduce the risk of developmental delays. In recent years, minimally invasive surgical techniques have been developed to achieve these goals with less tissue disruption, lower rates of transfusion, and shorter recovery time. The operation focuses on unlocking the fused bones, while reshaping relies on an adjunct, most commonly a postoperative cranial molding helmet. As an alternative to the care-intensive helmeting process, reshaping with implanted cranial expander springs has emerged. In this video, the authors demonstrate their technique for spring-assisted minimally invasive repair of sagittal craniosynostosis.

The video can be found here: https://vimeo.com/513923721

Removal of cranial springs after spring-mediated cranioplasty

Cranial spring hardware is generally removed 3 months after placement for spring-mediated cranioplasty. Spring removal is performed as an outpatient procedure under general anesthesia in approximately 15 minutes through the incision locations of the index procedure. Herein, the authors provide a multimedia demonstration of cranial spring hardware removal after spring-mediated cranioplasty for sagittal craniosynostosis.

The video can be found here: https://vimeo.com/511179695

Spring-mediated cranioplasty for sagittal craniosynostosis

Spring-mediated cranioplasty is a useful treatment modality for correcting scaphocephalic head shape in sagittal craniosynostosis because it is less invasive than whole-vault cranioplasty and offers durable morphologic outcomes. Herein, the authors provide a multimedia demonstration of alternative operative approaches for spring-mediated cranioplasty for sagittal craniosynostosis. The video can be found here: https://vimeo.com/511256259.

Craniofacial developmental concepts in dynamic osteotomies and the Nautilus technique: A procedure created in Brazil for the treatment of craniosynostosis

Craniofacial development is the major focus of attention in surgical treatments for craniosynostosis. Growth rate, size, shape, and proportion of soft tissue and bone structures of the skull and face are determinant factors in the establishment of the vital functions of swallowing and breathing, as well as in the aesthetic balance of facial features, so important for the patient's psychological identity. This manuscript revisits the concept of craniosynostosis and reviews the major biological and anatomical factors that come into play in the developmental process of craniofacial structures, especially during infancy and early childhood. It also describes the Nautilus surgical technique, a corrective procedure created and implemented in Brazil in 2011-how it was created and how it has evolved: as we look back into the past 10 years, we shed light onto what was learned, on our contributions to improve treatments over time, and on how much we still have to discover in this fascinating area.

Planning and Osteotomy Designs in the Correction of Single-Suture Craniosynostosis

BACKGROUND

Craniosynostosis is among the abnormalities that are more commonly encountered by craniofacial surgeons. Although the overall concepts for cranial vault remodeling are relatively simple, osteotomy designs and methods for calvarial rearrangement are highly varied. In this work, we present a summary of the known designs for correction of single-suture craniosynostosis.

METHODS

A review of the literature was performed of the more frequently used osteotomy designs for single-suture craniosynostosis, as well as their reported results and outcomes. Also reviewed are some of the current available approaches for the diagnosis and surgical planning for single-suture craniosynostosis.

RESULTS

There remains a diversity of techniques available for the reconstruction of each fused cranial suture. Certain osteotomy designs are reported in the literature and are used by craniofacial surgeons more frequently. Each has its own benefits and disadvantages, and there is a growing body of outcome data available to guide surgical decision-making. Regarding diagnosis and surgical planning, computed tomography with 3-dimensional reconstruction remains the diagnostic standard of care, and efforts are ongoing to develop and implement new diagnostic modalities like Black Bone MRI to reduce radiation exposure.

CONCLUSIONS

There has been ongoing evolution of the surgical techniques available to reconstruct single-suture craniosynostosis, leading to ever-improving patient outcomes.

Perioperative Outcomes in the Treatment of Isolated Sagittal Synostosis: Cranial Vault Remodeling Versus Spring Mediated Cranioplasty

BACKGROUND

Patients undergoing cranial expansion including spring-mediated cranioplasty (SMC) and cranial vault remodeling (CVR) receive costly and high acuity post-operative intensive care (ICU) given concerns over neurologic and hemodynamic vulnerability. The authors analyzed perioperative and post-operative events for patients presenting with sagittal craniosynostosis (CS) undergoing SMC and CVR in order to compare complication profiles.

METHODS

The authors performed a single center retrospective cohort study of patients undergoing SMC and CVR for the treatment of nonsyndromic, isolated sagittal CS from 2011 to 2018. Perioperative and post-operative factors were collected, focusing on hemodynamic instability and events necessitating ICU care. Mann-Whitney U and Fisher exact tests were used to compare data with significance defined as P < 0.05.

RESULTS

Among 106 patients, 65 (61%) underwent SMC and 41 (39%) CVR. All CVR patients received prophylactic whole blood transfusion at time of scalp incision. Acute blood loss anemia was the most common post-operative complication, prompting n = 6 (9.2%) and n = 7 (17.1%) blood transfusions in the SMC and CVR cohorts, respectively (P < 0.24). Hemodynamic instability requiring blood transfusion was rare, occurring post-operatively in n = 2 (3.1%) and n = 2 (4.9%) patients in the SMC and CVR cohorts, respectively (P < 0.64). Two patients in the CVR cohort exhibited new neurologic symptoms that self-resolved, compared to no patients in the SMC cohort (P < 0.15).

CONCLUSION

Despite differing degrees of operative invasiveness, post-operative hemodynamic and neurologic decompensation following CVR and SMC for isolated sagittal CS repair remains similarly rare. Indications necessitating post-operative intensive care are infrequent. Post-operative hemoglobin monitoring may enable early prediction for hemodynamic instability.

Anesthetic Considerations for Pediatric Craniofacial Surgery

Anesthetic management of craniosynostosis remains a challenging experience. It requires input and collaboration from multiple specialties to improve patient outcomes. Understanding the surgical corrective techniques and the underlying risks of each is essential to providing the best care to this patient population. The propensity for significant blood loss necessitates fundamental knowledge of pediatric resuscitation and the development of perioperative transfusion protocols that have been shown to reduce transfusion requirements in the peri-operative period.

Spring-assisted posterior vault expansion-a single-centre experience of 200 cases

PURPOSE

Children affected by premature fusion of the cranial sutures due to craniosynostosis can present with raised intracranial pressure and (turri)brachycephalic head shapes that require surgical treatment. Spring-assisted posterior vault expansion (SA-PVE) is the surgical technique of choice at Great Ormond Street Hospital for Children (GOSH), London, UK. This study aims to report the SA-PVE clinical experience of GOSH to date.

METHODS

A retrospective review was carried out including all SA-PVE cases performed at GOSH between 2008 and 2020. Demographic and clinical data were recorded including genetic diagnosis, craniofacial surgical history, surgical indication and assessment, age at time of surgery (spring insertion and removal), operative time, in-patient stay, blood transfusion requirements, additional/secondary (cranio)facial procedures, and complications.

RESULTS

Between 2008 and 2020, 200 SA-PVEs were undertaken in 184 patients (61% male). The study population consisted of patients affected by syndromic (65%) and non-syndromic disorders. Concerns regarding raised intracranial pressure were the surgical driver in 75% of the cases, with the remainder operated for shape correction. Median age for SA-PVE was 19 months (range, 2-131). Average operative time for first SA-PVE was 150 min and 87 for spring removal. Median in-patient stay was 3 nights, and 88 patients received a mean of 204.4 ml of blood transfusion at time of spring insertion. A single SA-PVE sufficed in 156 patients (85%) to date (26 springs still in situ at time of this analysis); 16 patients underwent repeat SA-PVE, whilst 12 underwent rigid redo. A second SA-PVE was needed in significantly more cases when the first SA-PVE was performed before age 1 year. Complications occurred in 26 patients with a total of 32 events, including one death. Forty-one patients underwent fronto-orbital remodelling at spring removal and 22 required additional cranio(maxillo)facial procedures.

CONCLUSIONS

Spring-assisted posterior vault expansion is a safe, efficient, and effective procedure based on our 12-year experience. Those that are treated early in life might require a repeat SA-PVE. Long-term follow-up is recommended as some would require additional craniomaxillofacial correction later in life.

Comparison of Perioperative Outcomes and Parental Satisfaction Outcomes of Strip Craniectomy with Postoperative Helmet versus Spring-Mediated Remodeling in Sagittal Craniosynostosis

INTRODUCTION

We sought to compare outcomes and parental satisfaction between 2 approaches for sagittal craniosynostosis: strip craniectomy with spring-mediated skull remodeling (SMSR) and strip craniectomy with postoperative helmet (SCH).

METHODS

Perioperative and outcome data for SMSR or SCH patients between September 2010 and July 2019 were retrospectively reviewed. A telephone survey was administered to parents of children who underwent both procedures.

RESULTS

A total of 62 children were treated for sagittal craniosynostosis by either SMSR (n = 45) or SCH (n = 17). The SCH group had a lower estimated blood loss (27 vs. 47.06 mL, p = 0.021) and age at surgery (13.0 vs. 19.8 weeks) than the SMSR group. Three patients underwent early springs removal due to trauma or dislodgement, all of whom converted to helmeting. Of the 62 children initially identified, 59 were determined to have an adequate follow-up time to assess long-term outcomes. The mean follow-up time was 30.1 months (n = 16) in the SCH group and 32.0 months in the SMSR group (n = 43, p = 0.39). Two patients in the SCH group and one in the SMSR group converted to open cranial vault reconstruction. Thirty parents agreed to respond to the satisfaction survey (8 SCH, 22 SMSR) based on a Likert scale of responses (0 being most dissatisfied possible, 4 most satisfied possible). Average satisfaction was 3.86/4.0 in the SCH group and 3.45/4.0 in the SMSR group. No parents in the SCH group would change to SMSR, while 3 of the 22 SMSR survey responders would have changed to SCH.

CONCLUSIONS

Perioperative outcomes and average parental satisfaction were similar in both groups. Importance of helmet wear compliance and risk of spring dislodgement should be discussed with parents.

Computational modelling of patient specific spring assisted lambdoid craniosynostosis correction

Lambdoid craniosynostosis (LC) is a rare non-syndromic craniosynostosis characterised by fusion of the lambdoid sutures at the back of the head. Surgical correction including the spring assisted cranioplasty is the only option to correct the asymmetry at the skull in LC. However, the aesthetic outcome from spring assisted cranioplasty may remain suboptimal. The aim of this study is to develop a parametric finite element (FE) model of the LC skulls that could be used in the future to optimise spring surgery. The skull geometries from three different LC patients who underwent spring correction were reconstructed from the pre-operative computed tomography (CT) in Simpleware ScanIP. Initially, the skull growth between the pre-operative CT imaging and surgical intervention was simulated using MSC Marc. The osteotomies and spring implantation were performed to simulate the skull expansion due to the spring forces and skull growth between surgery and post-operative CT imaging in MSC Marc. Surface deviation between the FE models and post-operative skull models reconstructed from CT images changed between ± 5 mm over the skull geometries. Replicating spring assisted cranioplasty in LC patients allow to tune the parameters for surgical planning, which may help to improve outcomes in LC surgeries in the future.

Comparison of 2 Sagittal Craniosynostosis Repair Techniques: Spring-Assisted Surgery Versus Endoscope-Assisted Craniectomy With Helmet Molding Therapy

INTRODUCTION

This study compares anthropometric outcomes of 2 sagittal synostosis repair techniques: spring-assisted surgery and endoscope-assisted craniectomy with molding helmet therapy.

METHODS

Patients undergoing spring-assisted surgery (n = 27) or endoscope-assisted craniectomy with helmet therapy (n = 40) at separate institutions were retrospectively reviewed. Pre- and 1-year postoperative computed tomography (CT) or laser scans were analyzed for traditional cranial index (CI), adjusted cranial index (aCI), and cranial vault volume (CVV). Nine patient-matched scans were analyzed for measurement consistency.

RESULTS

The spring-assisted group was older at both time points (P < .050) and spring-assisted group CVV was larger preoperatively and postoperatively (P < .01). However, the change in CVV did not differ between the groups (P = .210). There was no difference in preoperative CI (helmet vs spring: 70.1 vs 71.2, P = .368) between the groups. Postoperatively, helmet group CI (77.0 vs 74.3, P = .008) was greater. The helmet group also demonstrated a greater increase in CI (6.9 vs 3.1, P < .001). The proportion of patients achieving CI of 75 or greater was not significantly different between the groups (helmet vs spring: CI, 65% vs 52%, P = .370). There was no detectable bias in CI between matched CT and laser scans. Differences were identified between scan types in aCI and CVV measurements; subsequent analyses used corrected CVV and aCI measures for laser scan measures.

CONCLUSIONS

Both techniques had equivalent proportions of patients achieving normal CI, comparable effects on cranial volume, and similar operative characteristics. The study suggests that there may be greater improvement in CI in the helmet group. However, further research should be performed.

The Science Behind the Springs: Using Biomechanics and Finite Element Modeling to Predict Outcomes in Spring-Assisted Sagittal Synostosis Surgery

Spring-assisted surgery for the correction of scaphocephaly has gained popularity over the past 2 decades. Our unit utilizes standardized torsional springs with a central helix for spring-assisted surgery. This design allows a high degree of accuracy and reproducibility of the force vectors and force distance curves. In this manuscript, we expand on the biomechanical testing and properties of these springs. Standardization of design has enabled us to study the springs on bench and in vivo and a comprehensive repository of calvarial remodeling and spring dynamics has been acquired and analyzed.Finite element modeling is a technique utilized to predict the outcomes of spring-assisted surgery. We have found this to be a useful tool, in planning our surgical strategy and improving outcomes. This technique has also contributed significantly to the process of informed consent preoperatively. In this article, we expand on our spring design and dynamics as well as the finite element modeling used to predict and improve outcomes.In our unit, this practice has led to a significant improvement in patient outcomes and parental satisfaction and we hope to make our techniques available to a wider audience.

Spring Cranioplasty: Incorporation Into Practice

OBJECTIVE

The aim of this paper is to discuss ways to incorporate spring-assisted cranioplasty into the surgical armamentarium for craniosynostosis.

BACKGROUND

Spring-assisted cranioplasty after cranial suturectomy for craniosynostosis was popularized in the literature by Dr Lauritzen in 2008 after reporting the results of the first 100 cases. Since that time, more craniofacial surgeons and neurological surgeons have incorporated this surgical technique for treatment of patients presenting with craniosynostosis. This paper will discuss how the team at Nationwide Children's Hospital has incorporated spring-assisted cranioplasty into the care of patients presenting with sagittal synostosis.

METHODS

In this article, the authors review our previous protocol for the treatment of children with sagittal synostosis prior to the introduction of spring cranioplasty. The authors then describe the impetus for incorporating spring-assisted cranioplasty for sagittal synostosis into our practice, and barriers we encountered during this implementation. The authors then discuss their current, comprehensive protocol for treating children with sagittal craniosynostosis. Finally, the authors review the expected and unexpected advantages that our craniofacial program has experienced as they implemented spring-assisted cranioplasty.

CONCLUSION

Incorporation of spring-assisted cranioplasty for sagittal synostosis offers an additional minimally invasive technique, which presents great advantages for many families, and is rewarding for both craniofacial and neurological surgeons.

Assessment of the Outcome of Calvarial Vault Remodeling and Spring-Mediated Cranioplasty in the Correction of Isolated Sagittal Suture Synostosis

BACKGROUND

Sagittal synostosis is the commonest form of nonsyndromic isolated craniosynostosis. Calvarial vault remodeling (CVR) and spring-mediated cranioplasty (SMC) are the commonly used correction techniques.

AIM OF THE WORK

To study and compare clinical and radiographic outcomes of CVR and SMC in the correction of isolated sagittal suture synostosis.

METHODS

A prospective cohort with the patients were divided into group; I (SMC) and II (CVR), each 15 patients. They were observed to evaluate the outcome and detect complications.

RESULTS

Mean operative time was 59.2 minutes in SMC and 184 minutes in CVR. Mean intraoperative blood loss was 26 mL in SMC and 64.7 mL in CVR. Intraoperative complications in SMC were dural tear in 1 patient and superior sagittal sinus injury in another patient, while in CVR 2 patients with dural tears and a 3rd with superior sagittal sinus injury. Postoperative complications in SMC were exposed spring, gaped wound, and parietal eminence elevation, while in CVR 2 patients needed blood transfusion. The mean hospital stays was 1.4 days in SMC and 4.1 days in CVR. In SMC, the relative increase in cephalic index varied between 5.5% and 8.2%, while for CVR, it varied between 5.1% and 7.9%.

CONCLUSION

The SMC and CVR are safe procedures, with good long-term results and significant objective changes toward normalization of the skull morphology in isolated sagittal craniosynostosis. The SMC is less invasive and associated with reduced hospital stays, decreased blood loss, and can be performed at a younger age than CVR with a lower morbidity.

Three-Dimensional Calvarial Growth in Spring-Assisted Cranioplasty for Correction of Sagittal Synostosis

Spring-assisted cranioplasty (SAC) is a minimally invasive technique for treating sagittal synostosis in young infants. Yet, follow-up data on cranial growth in patients who have undergone SAC are lacking. This project aimed to understand how the cranial shape develops during the postoperative period, from spring insertion to removal. 3D head scans of 30 consecutive infants undergoing SAC for sagittal synostosis were acquired using a handheld scanner pre-operatively, immediately postoperatively, at follow-up and at spring removal; 3D scans of 41 age-matched control subjects were also acquired. Measurements of head length, width, height, circumference, and volume were taken for all subjects; cephalic index (CI) was calculated. Statistical shape modeling was used to compute 3D average head models of sagittal patients at the different time points. SAC was performed at a mean age of 5.2 months (range 3.3-8.0) and springs were removed 4.3 months later. CI increased significantly (P < 0.001) from pre-op (69.5% ± 2.8%) to spring removal (74.4% ± 3.9%), mainly due to the widening of head width, which became as wide as for age-matched controls; however, the CI of controls was not reached (82.3% ± 6.8%). The springs did not constrain volume changes and allowed for natural growth. Population mean shapes showed that the bony prominences seen at the sites of spring engagement settle over time, and that springs affect the overall 3D head shape of the skull. In conclusion, results reaffirmed the effectiveness of SAC as a treatment method for nonsyndromic single suture sagittal synostosis.