Less is more: does the addition of barrel staves improve results in endoscopic strip craniectomy for sagittal craniosynostosis?

Evaluating mechanical benefit of wedge osteotomies in endoscopic surgery for sagittal synostosis using patient-specific 3D-printed models

PURPOSE

Endoscopically assisted sagittal strip craniotomy with subsequent cranial orthosis is a frequently used surgical approach for non-syndromic sagittal synostosis. Originally, this technique involved a wide sagittal strip craniectomy with bilateral wedge osteotomies. More recent studies suggest omitting wedge osteotomies, achieving similar outcomes. The controversy surrounding wedge osteotomies and our efforts to refine our technique led us to create models and evaluate the mechanical impact of wedge osteotomies.

METHODS

We conducted a 3D-print study involving preoperative CT scans of non-syndromic scaphocephaly patients undergoing minimally invasive-assisted remodelation (MEAR) surgery. The sagittal strip collected during surgery underwent thickness measurement, along with a 3-point bending test. These results were used to determine printing parameters for accurately replicating the skull model. Model testing simulated gravitational forces during the postoperative course and assessed lateral expansion under various wedge osteotomy conditions.

RESULTS

The median sagittal strip thickness was 2.00 mm (range 1.35-3.46 mm) and significantly positively correlated (p = 0.037) with the median force (21.05 N) of the 3-point bending test. Model testing involving 40 models demonstrated that biparietal wedge osteotomies significantly reduced the force required for lateral bone shift, with a trend up to 5-cm-long cuts (p = 0.007). Additional cuts beyond this length or adding the occipital cut did not provide further significant advantage (p = 0.1643; p = 9.6381).

CONCLUSION

Biparietal wedge osteotomies reduce the force needed for lateral expansion, provide circumstances for accelerated head shape correction, and potentially reduce the duration of cranial orthosis therapy.

Cognitive Outcomes of Children With Sagittal Craniosynostosis Treated With Either Endoscopic or Open Calvarial Vault Surgery

Importance

Several studies have reported a higher incidence of neurodevelopmental delays and cognitive deficits in patients with single-suture craniosynostosis; however, there are few studies examining the associations of repair type with cognitive outcomes.

Objective

To measure differences in neuropsychological outcomes between school-age children who were treated for sagittal craniosynostosis and unaffected controls and explore differences in cognitive function among children with sagittal craniosynostosis who were previously treated with either endoscopic strip craniectomy or open calvarial vault surgery.

Design, Setting, and Participants

This cohort study was performed between 2018 and 2022. Eligible participants included patients aged 5 to 17 years who had previously been seen as infants or toddlers (<3 years) at 1 of 3 surgical centers for craniosynostosis repair with either endoscopic surgery or open calvarial vault surgery. A separate cohort of unaffected controls were included for comparison. Data analysis was conducted from November 2023 to February 2024.

Exposures

Open calvarial vault surgery or endoscopic repair for single-suture craniosynostosis.

Main Outcomes and Measures

The primary outcome was the Differential Ability Scales-II (DAS-II) General Conceptual Ability (GCA) score, an index for overall intellectual ability. Secondary outcomes included DAS-II subscale scores (Verbal Ability, Nonverbal Reasoning, Spatial Ability, Working Memory, and Processing Speed), and Patient-Reported Outcomes Measurement Information System (PROMIS) cognitive function scores.

Results

A total of 81 patients with sagittal craniosynostosis (59 male [73%]; 22 female [27%]) and 141 controls (81 male [57%]; 60 female [43%]) were included. Of the 81 participants with sagittal craniosynostosis, 46 underwent endoscopic repair and 35 underwent open repair. Median (range) age at time of follow-up assessment was 7.7 (5.0-14.8) years for children with sagittal craniosynostosis and median age at assessment was 8.5 (7.7-10.5) years for controls. After controlling for age at assessment, sex, and socioeconomic status, there was no statistically significant or clinically meaningful difference in GCA scores between children who underwent endoscopic repair (adjusted mean score, 100; 95% CI, 96-104) and open repair (adjusted mean score, 103; 95% CI, 98-108) (P > .99). We found no significant difference in PROMIS scores between repair types (median [range] for endoscopic repair 54 [31-68] vs median [range] for open repair 50 [32-63]; P = .14). When comparing the treatment groups with the unaffected controls, differences in subscale scores for GCA and working memory were observed but were within normal range.

Conclusions and Relevance

In this cohort study, there were no statistically or clinically significant differences in cognitive outcomes among school-age children by and type of surgical procedure used to repair nonsyndromic sagittal craniosynostosis. These findings suggest primary care clinicians should be educated about different options for craniosynostosis surgery to ensure early referral of these patients so that all treatment options remain viable.

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.

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.

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.

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.

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.

Long-term 3D CT follow-up after endoscopic sagittal craniosynostosis repair

OBJECTIVE

Surgical treatment of sagittal synostosis involves various surgical modalities. Long-term follow-up issues include increased intracranial pressure, secondary sutural fusion, incomplete reossification, and suboptimal cosmetic appearance. The authors' objective in this study was to review their long-term endoscopic surgical results in children with sagittal synostosis using 3D CT.

METHODS

The authors reviewed the long-term results of their first 38 patients who underwent endoscopic sagittal synostosis repair at age 16 weeks or younger. A standard vertex craniectomy with biparietal wedges was done in each case. After surgery, the children were fitted with a helmet, which they wore until 8 months of age. Patients were followed up for 5 years or longer, at which point a 3D CT scan was obtained. The authors examined data on the cranial index, area of bony defect, presence or absence of secondary sutural fusion, neosuture formation, and scalloping of the inner table of the skull.

RESULTS

Thirty-two of 38 children met inclusion criteria. There was a small but significant recession of the cranial index after the completion of helmeting (from 0.772 after completion of helmeting to 0.755 at 5 years). Of 32 children, 14 had a bony defect area > 4 cm2. Three children had secondary sutural fusion (two unilateral coronal, one bicoronal). Ten of 32 patients had partial neosuture formation.

CONCLUSIONS

The authors report their experience with 32 of their first 38 children who underwent endoscopic sagittal synostosis repair at 16 weeks of age or younger. With a minimum duration of 5 years, this is the longest clinicoradiological follow-up utilizing 3D CT to date in children with sagittal synostosis treated with endoscopic surgery. The authors report detailed measurements of bony loss, adjacent sutural fusion, and neosuture formation.

A comparison of endoscopic strip craniectomy and pi craniectomy for treatment of sagittal craniosynostosis

OBJECTIVE

Sagittal craniosynostosis is managed with a wide variety of operative strategies. The current investigation compares the clinical outcomes of two widely performed techniques: pi craniectomy and minimally invasive endoscopic strip craniectomy (ESC) followed by helmet therapy.

METHODS

This IRB-approved retrospective study examined patients diagnosed with nonsyndromic, single-suture sagittal craniosynostosis treated with either pi craniectomy or ESC. Included patients had a minimum postoperative follow-up of 5 months.

RESULTS

Fifty-one patients met the inclusion criteria (pi 21 patients, ESC 30 patients). Compared to patients who underwent ESC, the pi patients were older at the time of surgery (mean age 5.06 vs 3.11 months). The mean follow-up time was 23.2 months for ESC patients and 31.4 months for pi patients. Initial cranial index (CI) was similar between the groups, but postoperatively the ESC patients experienced a 12.3% mean increase in CI (from 0.685 to 0.767) compared to a 5.34% increase for the pi patients (from 0.684 to 0.719), and this difference was statistically significant (p < 0.001). Median hospital length of stay (1 vs 2 days) and operative duration (69.5 vs 93.3 minutes) were significantly less for ESC (p < 0.001 for both). The ESC patients showed a trend toward better results when surgery was done at younger ages. Craniectomy width in ESC cases was positively associated with CI improvement (slope of linear regression = 0.69, p = 0.026).

CONCLUSIONS

While both techniques effectively treated sagittal craniosynostosis, ESC showed superior results compared to pi craniectomy. ESC showed a trend for better outcomes when done at younger ages, although the trend did not reach statistical significance. A wider craniectomy width (up to 2 cm) was associated with better outcomes than smaller craniectomy widths among the ESC patients.

Optimal duration of postoperative helmet therapy following endoscopic strip craniectomy for sagittal craniosynostosis

OBJECTIVEMany infants with sagittal craniosynostosis undergo effective surgical correction with endoscopic strip craniectomy (ESC) and postoperative helmet therapy (PHT). While PHT is essential to achieving optimal cosmesis following ESC, there has been little comprehensive analysis of the ideal PHT duration needed to attain this goal.METHODSThe authors retrospectively reviewed the charts of infants undergoing ESC and PHT for sagittal synostosis at our institution between 2008 and 2015. Data collected included age at surgery, follow-up duration, and PHT duration. Cephalic index (CI) was evaluated preoperatively (CIpre), at its peak level (CImax), at termination of helmet therapy (CIoff), and at last follow-up (CIfinal). A multivariate regression analysis was performed to determine factors influencing CIfinal.RESULTSThirty-one patients (27 male, 4 female) were treated in the studied time period. The median age at surgery was 2.7 months (range 1.6 to 3.2) and the median duration of PHT was 10.4 months (range 8.4 to 14.4). The mean CImax was 0.83 (SD 0.01), which was attained an average of 8.4 months (SD 1.2) following PHT initiation. At last follow-up, there was an average retraction of CIfinal among all patients to 0.78 (SD 0.01). Longer helmet duration after achieving CImax did not correlate with higher CIfinal values. While CImax was a significant predictor of CIfinal, neither age at surgery nor CIpre were found to be predictive of final outcome.CONCLUSIONSPatients undergoing ESC and PHT for sagittal synostosis reach a peak CI around 7 to 9 months after surgery. PHT beyond CImax does not improve final anthropometric outcomes. CIfinal is significantly dependent on CImax, but not on age, nor CIpre. These results imply that helmet removal at CImax may be appropriate for ESC patients, while helmeting beyond the peak does not change final outcome.