Spring-assisted surgery in the treatment of sagittal synostosis: A systematic review

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.

Correction of Unicoronal Synostosis With Springs: Two Patients With Improved Facial Symmetry

OBJECTIVE

Surgical correction of unicoronal synostosis (UCS) entails extensive cranioplasties which do not address facial scoliosis. This paper presents the first results with springs that motivated the shift from extensive cranioplasties to dynamic techniques for surgical correction of UCS.

METHODS

Two cases of UCS were operated with a linear osteotomy combined with springs. The deviation in facial symmetry (orbital dystopia angle) and skull base angles were measured on pre and postoperative computed tomography scans until 3 years of age.

RESULTS

The facial scoliosis was corrected. At spring removal, the orbital dystopia angle had gone from a 9.2 to 13.2-degree deviation preoperatively to a 0.5 to 0.9-degree overcorrection compared with the ideal 0-degree deviation. Also, the skull base deviation improved.

CONCLUSION

Linear osteotomy combined with springs corrects the facial scoliosis in UCS. These cases indicate that dynamic methods may be beneficial for improving the results of surgical correction of UCS.

Ethical Considerations in Surgery for Single-suture Craniosynostosis

Singe-suture craniosynostosis (SSC) describes the premature fusion of one cranial suture, which restricts cranial growth and consequently results in unaffected regions presenting a compensatory expansion. Surgery can redistribute intracranial volume, reduce the risk of elevated intracranial pressure, and improve head shape, potentially leading to improved neurocognitive function and social acceptance. However, there is limited evidence that surgery for SSC improves neurocognitive function and social acceptance. Given the inherent surgical risks and uncertainty of outcomes, the conditions under which this surgery should be allowed remain uncertain. Here, we discuss ethical questions regarding the permissibility of surgery, value of neurocognitive function and social acceptance, research ethics associated with SSC, patient autonomy and parental roles, and the process of recommending surgery and obtaining consent. Because surgery for SSC has become a routine procedure, its practice now presents a relatively low risk of complications. Furthermore, having acquired an understanding of the risks associated with this surgery, such knowledge fulfils the principle of non-maleficence although not beneficence. Thus, we advocate that surgery should only be offered within Institutional Review Board-approved research projects. In these situations, decisions concerning enrollment in scientific research involves health care providers and parents or guardians of the child, with the former acting as gate-keepers upon recognition of a lack of coping skills on the part of the parent or guardian in dealing with unforeseen outcomes. To minimize associated surgical risks and maximize its benefits, there exists a moral obligation to refer patients only to highly specialized centers.

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.

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.

Improved cephalic index following early cranial vault remodeling in patients with isolated nonsyndromic sagittal synostosis

OBJECTIVE

Isolated nonsyndromic sagittal synostosis (SS) is the most common form of craniosynostosis in children, accounting for approximately 60% of all craniosynostoses. The typical cranial measurement used to define and follow SS is the cephalic index (CI). Several surgical techniques have been suggested, but agreement on type and timing of surgery is lacking. This study aimed to evaluate the authors' institutional experience of surgically treating SS using a modified subtotal cranial vault remodeling technique in a population-based cohort. Special attention was directed toward the effect of patient age at time of surgery on long-term CI outcome.

METHODS

A retrospective analysis was conducted on all patients with isolated nonsyndromic SS who were surgically treated from 2003 to 2011. Data from electronic medical records were gathered. Eighty-two patients with SS were identified, 77 fulfilled inclusion criteria, and 72 had sufficient follow-up data and were included. CI during follow-up after surgery was investigated with ANOVA and a linear mixed model.

RESULTS

In total, 72 patients were analyzed, consisting of 16 females (22%) and 56 males (78%). The mean ± SD age at surgery was 4.1 ± 3.1 months. Blood transfusions were received by 81% of patients (26% intraoperatively, 64% postoperatively, 9% both). The mean ± SD time in the pediatric ICU was 1.1 ± 0.25 days, and the mean ± SD total hospital length of stay was 4.6 ± 2.0 days. No patient required reoperation. The mean ± SD CI increased from 69 ± 3 to 87 ± 5 for patients who underwent surgery before 45 days of age. Surgery resulted in a larger increase in CI for patients who underwent surgery at a younger age compared with older patients (p < 0.05, Tukey's HSD test). In the comparison of patients who underwent surgery before 45 days of age with patients who underwent surgery at 45-90, 90-180, and more than 180 days of age, the linear mixed model estimated a long-term loss of CI of 3.0, 5.5, and 7.4 points, respectively.

CONCLUSIONS

The modified subtotal cranial vault remodeling technique used in this study significantly improved CI in patients with SS. The best results were achieved when surgery was performed early in life.

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.

Cranial bone structure in children with sagittal craniosynostosis: Relationship with surgical outcomes

BACKGROUND

While spring-assisted cranioplasty has become a widespread technique to correct scaphocephaly in children with sagittal synostosis, predicting head shape changes induced by the gradual opening of the springs remains challenging. This study aimed to explore the role of cranial bone structure on surgical outcomes.

METHODS

Patients with isolated sagittal synostosis undergoing spring-assisted cranioplasty at GOSH (London, UK) were recruited (n = 18, age: 3-8 months). Surgical outcome was assessed by the change in cephalic index measured on 3D head scans acquired before spring insertion and after their removal using a 3D handheld scanner. Parietal bone samples routinely discarded during spring-assisted cranioplasty were collected and scanned using micro-computed tomography. From visual assessment of such scans, bone structure was classified into one- or three-layered, the latter indicating the existence of a diploë cavity. Bone average thickness, volume fraction and surface density were computed and correlated with changes in cephalic index.

RESULTS

Cephalic index increased for all patients (p < 0.001), but individual improvement varied. Although the patient age and treatment duration were not significantly correlated with changes in cephalic index, bone structural parameters were. The increase of cephalic index was smaller with increasing bone thickness (Pearson's r = -0.79, p < 0.001) and decreasing bone surface density (r = 0.77, p < 0.001), associated with the three-layered bone structure.

CONCLUSIONS

Variation in parietal bone micro-structure was associated with the magnitude of head shape changes induced by spring-assisted cranioplasty. This suggests that bone structure analysis could be a valuable adjunct in designing surgical strategies that yield optimal patient-specific outcomes.

Does Receiving a Blood Transfusion Predict for Length of Stay in Children Undergoing Cranial Vault Remodeling for Craniosynostosis? Outcomes Using the Pediatric National Surgical Quality Improvement Program Dataset

PURPOSE

Recent interventions have aimed at reducing the need for blood transfusions in the perioperative period in patients with craniosynostosis undergoing cranial vault remodeling. However, little is known regarding whether the receipt of a blood transfusion influences the length of hospital stay. The purpose of this study was to assess whether the receipt of a blood transfusion in patients undergoing cranial vault remodeling is associated with an increased length of stay.

MATERIALS AND METHODS

To address the research purposes, we designed a retrospective cohort study using the 2014 Pediatric National Surgical Quality Improvement Program (NSQIP Peds) dataset. The primary predictor variable was whether patients received a blood transfusion during cranial vault remodeling. The primary outcome variable was length of hospital stay after the operation. The association between the receipt of blood transfusions and length of stay was assessed using the Student t test. The association between other covariates and the outcome variable was assessed using linear regression, analysis of variance, and the Tukey test for post hoc pair-wise comparisons.

RESULTS

The sample was composed of 756 patients who underwent cranial vault remodeling: 503 who received blood transfusions and 253 who did not. The primary predictor variable of blood transfusion was associated with an increased length of stay (4.1 days vs 3.0 days, P = .03). Other covariates associated with an increased length of stay included race, American Society of Anesthesiologists status, premature birth, presence of a congenital malformation, and number of sutures involved in craniosynostosis.

CONCLUSIONS

The receipt of a blood transfusion in the perioperative period in patients with craniosynostosis undergoing cranial vault remodeling was associated with an increased length of stay.

Reconstruction of gluteal deformities: a systematic review and experience of four cases

BACKGROUND

The reconstruction of gluteal deformities remains a major challenge. The aim of this article is to provide a systematic review of the literature concerned, and to present a case series with representative defects from various zones.

METHODS

A review of the literature was performed using PubMed, EMBASE, and The Cochrane Library, in accordance with the PRISMA statement. Quality of evidence was rated according to GRADE. Patients with various buttock deformities were included and, depending on the defect, the reconstructive techniques applied consisted of lipoinjection, local fasciocutaneous flap, or pedicled gracilis muscle flap. Complications, patient's pain assessment, impairment in everyday-life activities, aesthetic outcome, objective assessment of sensitivity, and recurrence were considered.

RESULTS

A total of 498 records were identified in the literature search. Of those, 12 studies met the PICOS (participants, interventions, comparators, outcomes, and study design) criteria. Overall, 41 patients were analysed, the evidence of which was of low quality. In this study, four patients (three female and one male) with a mean age of 44 ± 15 years were operated on between 2010-2014. The mean operation time was 83 ± 30 minutes. One patient required revision due to persistent seroma and recurrence, and one patient required neurolysis and gracilis denervation due to neuroma and scarring. After a mean follow-up of 40 ± 21 months, the results were functionally and cosmetically satisfactory.

CONCLUSIONS

Reconstruction of buttock deformities using an integrated approach can lead to a long-lasting, functionally and aesthetically satisfactory result. However, evidence is limited due to the lack of good-quality studies.

The Management of Nonsyndromic, Isolated Sagittal Synostosis

AIM

Isolated sagittal synostosis is the commonest form of craniosynostosis. The reasons for surgery are to normalize the head shape and to increase the cranial volume, thus reducing the risk of raised intracranial pressure and allowing for normal brain development. It has been suggested that sagittal synostosis may impair neuropsychological development. This systematic review appraised the literature on the management of sagittal synostosis.

METHODS

A literature search was performed with the assistance of a professional librarian. Studies selected had to satisfy the criteria set by PICO (patients, intervention, comparison, and outcome). Cranial index and neuropsychological outcome were used as outcome measures. MINORS was used to assess the methodological quality of the selected articles. A score of 75% was deemed to be of satisfactory quality, and the quality of the evidence from the selected studies was graded using the GRADE system.

RESULTS

One hundred forty-eight articles were initially identified. Only 6 articles fulfilled the PICO criteria and scored a minimum of 75% on MINORS. Four studies compared 1 technique to another with documented cranial indices. Two studies compared 1 group to another and assessed the neuropsychological development. According to GRADE, the quality of evidence was deemed to be very low.

CONCLUSIONS

This systematic review assessed cranial index and neuropsychological outcome following surgery for isolated, nonsyndromic sagittal synostosis. The quality of the evidence in the published literature was noted to be of very low quality. There is a need for better-designed, prospective studies to guide surgeons involved in management of sagittal synostosis.

Comparison Between Two Different Isolated Craniosynostosis Techniques: Does It Affect Cranial Bone Growth?

INTRODUCTION

Craniosynostosis is a premature closure of a cranial suture. Cranioplasty is indicated to correct skull deformity, relieve increased intracranial pressure, and promote homogenous cranial growth. Different techniques have been adopted to achieve optimal outcomes. Although surgical benefits are widely accepted, this intervention might also affect cranial skeletal growth.

METHODS

The authors conducted a retrospective case-control study including patients operated for isolated metopic or sagittal synostosis. These patients had undergone a computed tomography (CT) scan before surgery and/or at 3 years of age postoperatively. These were operated between 2002 and 2012. Intracranial volume was measured using a MATLAB application. The control group was age and sex-matched individuals who had CT scans for trauma or neurological indications. All results with P value <0.05 were considered statistically significant.

RESULTS

A total of 185 patients were included in the study with a preoperative CT scan (143 sagittal synostosis and 42 metopic synostosis). Postoperatively 160 patients were identified including 103 sagittal synostosis and 57 metopic synostosis. These patients were compared to 414 controls. There was a statistically significant reduction in intracranial volume (ICV) in patients operated for metopic synostosis with both techniques. It also demonstrated a statistically significant difference in ICV in patients with sagittal synostosis operated with Pi-plasty and a nonsignificant difference in ICV in patients operated with strip craniotomy and springs.

CONCLUSION

In conclusion, these measurements of ICV have revealed that extensive cranioplasties for premature craniosynostosis can lead to minor but significant growth restriction and reduced ICV at long-term follow-up.