Long-Term Outcomes of Spring-Assisted Surgery for Sagittal Craniosynostosis

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.

Posterior Cranial Distraction in Craniosynostosis: A Systematic Review of the Literature

OBJECTIVE

Posterior cranial distraction (PCD) is a surgical technique to address craniosynostosis, especially in syndromic patients. The technique has the ability to significantly expand the cranium, while requiring minimal dural dissection, compared to cranial remodeling. Our goals were to determine the patient characteristics and surgical outcomes of PCD. The two questions that we sought to answer were: 1) What is the average published complication rate and the most common complications of PCD? and 2) How much intracranial volume expansion can one expect with PCD?

DESIGN

A PubMed database search of articles on PCD was performed. Case reports and articles with overlapping patients were excluded. A systematic review was performed using the remaining articles.

MAIN OUTCOME MEASURES

Patient data were extracted in order to determine the total number of patients, patients with a syndrome, types of syndromes, mean age at surgery, mean distraction distance, mean increase in intracranial volume, and complications.

RESULTS

18 articles representing 325 patients were analyzed. A syndrome was present in 68.6% of patients. The mean age at time of surgery was 22.1 months. Mean distraction amount was 24.7 mm. Mean increase in intracranial volume was 253.2 cm3. The overall complication rate was 32.2%, with the most common complications being surgical-site infection, hardware-related complications and delayed wound healing.

CONCLUSIONS

PCD is a powerful technique in the management of syndromic craniosynostosis, although complication rates are significantly higher than traditional remodeling techniques. Future studies should compare the effects of supratorcular and infratorcular osteotomies on intracranial volume, cosmesis and complications.

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.

Sagittal Craniosynostosis: Treatment and Outcomes According to Age at Intervention

The purpose of this study is to describe the treatment strategies and outcomes of nonsyndromic single-suture sagittal craniosynostosis based on the patient's age at intervention. Studies from MEDLINE, Scopus, and Cochrane Central Register of Controlled Trials were systematically searched for patients with nonsyndromic single-suture sagittal craniosynostosis. Inclusion criteria encompassed studies with follow-up of at least 12 months, minimum of 25 patients per cohort, and first-time surgical intervention. The risk of bias in nonrandomized studies of intervention tool [Risk Of Bias In Non-randomized Studies-of Interventions (ROBINS-I)] was applied. A total of 49 manuscripts with 3316 patients met criteria. Articles were categorized based on age at intervention; 0 to 6, older than 6 to 12, and older than 12 months. Fifteen of the manuscripts described interventions in more than 1 age group. From the 49 articles, 39 (n=2141) included patients 0 to 6 months old, 15 (n=669) discussed patients older than 6 to 12 months old, and 9 (n=506) evaluated patients older than 12 months old. Follow-up ranged from 12 to 144 months. Over 8 types of open surgical techniques were identified and 5 different minimally invasive procedures were described. Minimally invasive procedures were exclusively seen in the youngest patient cohort, while open cranial vault reconstructions were often seen in the 2 older cohorts. Endoscopic surgery and open conservative procedures are indicated for younger patients, while complex open cranial vault reconstructions are common in older patients. However, there is no consensus on one approach over the other. Even with the analysis of this review, we cannot factor a strong conclusion on a specific technique.

Shared Decision-Making: Process for Design and Implementation of a Decision Aid for Patients With Craniosynostosis

To describe the process of developing a craniosynostosis decision aid.

We conducted a mixed-methods exploratory study between August 2019 and March 2020 to develop a decision aid about surgical treatment for single suture craniosynostosis.

A single tertiary care academic children's hospital.

The decision aid development team consisted of surgeons, research fellows, a clinical nurse practitioner, clinical researchers with expertise in decision science, and a university-affiliated design school. Qualitative interviews (N = 5) were performed with families, clinicians (N = 2), and a helmeting orthotist to provide feedback on decision aid content, format, and usability.

After cycles of revisions and iterations, 3 related decision aids were designed and approved by the marketing arm of our institution. Distinct booklets were created to enable focused discussion of treatment options for the 3 major types of single suture craniosynostosis (sagittal, metopic, unicoronal).

Three decision aids representing the 3 most common forms of single suture craniosynostosis were developed. Clinicians found the decision aids could help facilitate discussions about families' treatment preferences, goals, and concerns.

We developed a customizable decision aid for single suture craniosynostosis treatment options. This tool lays the foundation for shared decision-making by assessing family preferences and providing clear, concise, and credible information regarding surgical treatment. Future research can evaluate this tool's impact on patient-clinician discussions about families' goals and preferences for treatment.

Sagittal Synostectomy With Tension Band Sutures for Correction of Sagittal Craniosynostosis

BACKGROUND AND OBJECTIVES

Premature fusion of the sagittal suture is the most common form of craniosynostosis and can be treated using a variety of open or endoscopic approaches. Existing approaches have varying degrees of effectiveness. Open approaches, whether performed early or late, can be associated with significant blood loss and the need for transfusion. Endoscope-assisted approaches are minimally invasive but require months of postoperative helmet therapy to help remodel the skull. Implantation of springs or distractors requires a second operation for removal of the devices. Here, we present an alternative technique for early correction of sagittal craniosynostosis combining sagittal synostectomy with tension band sutures to remodel the skull without need for transfusion or helmet therapy.

METHODS

We retrospectively reviewed the medical records of all patients treated for sagittal craniosynostosis using a synostectomy with tension band sutures at a single tertiary care institution. Data on patient demographics, operative factors, and postoperative course were collected.

RESULTS

Thirty-four patients underwent the novel procedure. The median preoperative cephalic index was 68 and improved to 76 immediately postoperatively. The median blood loss was 10 mL while the operative duration was 112 minutes. No blood transfusions were needed. One small dural laceration was encountered that was promptly repaired. There were no postoperative complications. Patients presenting for follow-up visits showed continued improvement in head shape and cephalic index.

CONCLUSION

A modified sagittal craniectomy with tension band sutures to remodel the skull is effective in achieving immediate correction of sagittal craniosynostosis. The correction remains durable over long-term follow-up. Importantly, the technique can be performed with minimal blood loss and reduces transfusion risk, operative time, and overall morbidity compared with traditional open approaches while avoiding the need for helmet therapy necessitated by endoscopic approaches.

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.

Sagittal Craniosynostosis: Comparing Surgical Techniques Using 3D Photogrammetry

BACKGROUND

The aim of this study was to compare three surgical interventions for correction of sagittal synostosis-frontobiparietal remodeling (FBR), extended strip craniotomy (ESC), and spring-assisted correction (SAC)-based on three-dimensional (3D) photogrammetry and operation characteristics.

METHODS

Patients who were born between 1991 and 2019 and diagnosed with nonsyndromic sagittal synostosis who underwent FBR, ESC, or SAC and had at least one postoperative 3D photogrammetry image taken during one of six follow-up appointments until age 6 were considered for this study. Operative characteristics, postoperative complications, reinterventions, and presence of intracranial hypertension were collected. To assess cranial growth, orthogonal cranial slices and 3D photocephalometric measurements were extracted automatically and evaluated from 3D photogrammetry images.

RESULTS

A total of 322 postoperative 3D images from 218 patients were included. After correcting for age and sex, no significant differences were observed in 3D photocephalometric measurements. Mean cranial shapes suggested that postoperative growth and shape gradually normalized with higher occipitofrontal head circumference and intracranial volume values compared with normal values, regardless of type of surgery. Flattening of the vertex seems to persist after surgical correction. The authors' cranial 3D mesh processing tool has been made publicly available as a part of this study.

CONCLUSIONS

The findings suggest that until age 6, there are no significant differences among the FBR, ESC, and SAC in their ability to correct sagittal synostosis with regard to 3D photocephalometric measurements. Therefore, efforts should be made to ensure early diagnosis so that minimally invasive surgery is a viable treatment option.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Spring forces and calvarial thickness predict cephalic index changes following spring-mediated cranioplasty for sagittal craniosynostosis

BACKGROUND

Variables interacting to predict outcomes following spring-mediated cranioplasty (SMC) for non-syndromic craniosynostosis, including spring parameters and calvarial thickness, are poorly understood. This study assessed interactions between spring parameters and calvarial thickness to predict changes in cephalic index (CI) following SMC.

METHODS

Patients undergoing SMC for non-syndromic sagittal craniosynostosis at our institution between 2014 and 2021 were included. Calvarial thickness was determined from patient preoperative CTs using Materalise Mimics at 27 points in relation to the sagittal suture. Linear mixed effects models were used to determine interactions between anterior, middle, and posterior calvarial thickness with spring force and length.

RESULTS

Sixty-nine patients undergoing surgery at mean age 3.7 months were included in this study. Stronger posterior spring force interacted with thinner posterior calvarial thickness to predict greater changes in CI at 3 months postoperatively (p = 0.022). When evaluating spring force and calvarial thickness set distances from the sagittal suture, stronger posterior spring force interacted with thinner posterior calvarial thickness 5 mm (p = 0.043) and 10 mm (p = 0.036) from the sagittal suture to predict changes in CI. Interactions between spring parameters and calvarial thickness in the anterior and middle positions did not significantly predict changes in CI.

CONCLUSIONS

Stronger posterior spring force interacted with thinner posterior calvaria to predict greater changes in CI 3 months following SMC for non-syndromic sagittal craniosynostosis. These results suggest dynamic interactions between several variables may impact outcomes following SMC.

Sagittal synostosis: does choice of intervention and its timing affect the long-term aesthetic and neurodevelopmental outcome? A single-institution study of 167 children

OBJECTIVE

Sagittal craniosynostosis (SC) is the most commonly encountered form of craniosynostosis. Despite its relative frequency, there remains significant heterogeneity in both operative management and follow-up between centers and a relative paucity of long-term outcome data in the literature. At the authors' institution, families of children presenting with SC are offered the following options: 1) conservative management with ophthalmic surveillance, 2) minimally invasive surgery at < 6 months of age (spring-assisted cranioplasty [SAC]) or 3) calvarial vault remodeling at any age (CVR). The authors reviewed outcomes for all children presenting with SC during a 5-year period, regardless of the treatment received.

METHODS

Consecutive children born between January 1, 2008, and December 31, 2012, presenting with SC were identified, and detailed chart reviews were undertaken. Demographic, surgical, perioperative, head shape, scar, and neurodevelopmental (behavioral, education, speech, and language) data were analyzed. The cohort was divided by type of surgery (none, SAC, or CVR) and by age at surgery (early, defined as ≤ 6 months; or late, defined as > 6 months) for comparison purposes.

RESULTS

A total of 167 children were identified, 129 boys and 38 girls, with a median age at presentation of 5.0 (range 0.4-135) months. Three families opted for conservative management. Of the 164 children who underwent surgery, 83 underwent SAC, 76 underwent CVR, and 5 underwent a "hybrid" procedure (CVR with springs). At a median age of 7.0 (range 0.5-12.3) years, there was no significant difference in concerns regarding head shape, scar, or neurodevelopmental outcomes between the early and late intervention groups over all procedures performed, or between the early or late SAC and CVR cohorts. There were more head shape concerns in the SAC group than in the CVR group overall (25.7% vs 11.8%, respectively; p = 0.026), although most of these concerns were minor and did not require revision.

CONCLUSIONS

In this cohort, regardless of operative intervention and timing of intervention, infants achieved similar neurodevelopmental outcomes. Minimally invasive surgery (SAC) appears to result in less complete correction of head shape than CVR, but this may be balanced by advantages in reduced operative time, hospitalization, and blood loss. SAC was equal to CVR in neuropsychological outcomes.

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.

Update in Management of Craniosynostosis

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand the craniofacial dysmorphology of craniosynostosis, and the variation of each type. 2. Identify the functional concerns and learn the rationale behind timing of operative intervention. 3. Approach each dysmorphology critically and identify the operative intervention needed to improve form and function 4. Understand and address the specific issues related to syndromic craniosynostosis and be able to delineate management plan.

SUMMARY

Craniosynostosis is a condition in which premature fusion of one or more cranial sutures lead to abnormal head shape and growth restriction of the brain. Nonsyndromic craniosynostosis occurs in isolation, and usually involves a single suture, whereas syndromic craniosynostosis may involve multiple sutures and is associated with extracraniofacial findings. Although surgical management can be similar, the treatment plan must take into consideration issues specific to the syndromes. This article aims to provide a concise overview of the authors' current understanding regarding the presentation, treatment principle, surgical option, and debates in craniosynostosis.

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.

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

Statistical shape modelling for the analysis of head shape variations

The aim of this study is, firstly, to create a population-based 3D head shape model for the 0 to 2-year-old subjects to describe head shape variability within a normal population and, secondly, to test a combined normal and sagittal craniosynostosis (SAG) population model, able to provide surgical outcome assessment. 3D head shapes of patients affected by non-cranial related pathologies and of SAG patients (pre- and post-op) were extracted either from head CTs or 3D stereophotography scans, and processed. Statistical shape modelling (SSM) was used to describe shape variability using two models - a normal population model (MODEL1) and a combined normal and SAG population model (MODEL2). Head shape variability was described via principal components analysis (PCA) which calculates shape modes describing specific shape features. MODEL1 (n = 65) mode 1 showed statistical correlation (p < 0.001) with width (125.8 ± 13.6 mm), length (151.3 ± 17.4 mm) and height (112.5 ± 11.1 mm) whilst mode 2 showed correlation with cranial index (83.5 mm ± 6.3 mm, p < 0.001). The remaining 9 modes showed more subtle head shape variability. MODEL2 (n = 159) revealed that post-operative head shape still did not achieve full shape normalization with either spring cranioplasty or total calvarial remodelling. This study proves that SSM has the potential to describe detailed anatomical variations in a paediatric population.