Virtual Surgical Planning for Correction of Delayed Presentation Scaphocephaly Using a Modified Melbourne Technique:

Efficacy and safety of sagittal synostosis surgery in older (> 12 months) patients: a systematic review and meta-analysis

PURPOSE

Sagittal synostosis is the most common isolated craniosynostosis. Surgical treatment of this synostosis has been extensively described in the global literature, with promising outcomes when it is performed in the first 12 months of life. However, in some cases, patients older than 12 months arrive at the craniofacial center with this synostosis. A comprehensive study on efficacy and perioperative outcomes has yet to be fully explored in this population. This systematic review and meta-analysis aimed to assess the available evidence of surgical outcomes for the treatment of sagittal synostosis among older patients to analyze the efficacy and safety of synostosis surgery in this unique population.

METHODS

PubMed, Embase, and Scopus were searched for studies published from inception to March 2024 reporting surgical outcomes of synostosis surgery in older patients (> 12 months) with isolated sagittal synostosis. The main outcome was the reoperation rate, with secondary endpoints including transfusion rates, aesthetic outcomes, and surgical complications.

RESULTS

Nine studies were included in the final analysis. The pooled proportion of the reoperation rate was 1%. The rate of excellent aesthetic results was 95%. The need for transfusion associated with the procedures was 86%, and finally, surgical complications attained a pooled ratio of 2%, indicating minimal morbidity associated with the surgical repair.

CONCLUSION

Sagittal synostosis surgery is a safe and effective procedure to perform in older patients; this meta-analysis suggests that open surgery confers a significant rate of excellent aesthetic results with a low reoperation rate and minimal complications associated with the intervention. Future research with direct comparisons among different techniques will validate the findings of this study, which will all contribute to the rigor of synostosis management.

The Role of Virtual Surgical Planning in Surgery for Complex Craniosynostosis

Background

Virtual surgical planning (VSP) decreases reliance on intraoperative subjective assessment of aesthetic and functional outcomes in craniofacial surgery. Here, we describe our experience of using VSP for complex craniosynostosis surgery to inform preoperative decision making and optimize postoperative outcomes.

Methods

Chart review was performed for children treated with craniosynostosis at our institution from 2015 to 2021. Eight VSP maneuvers were defined and assigned to each patient when applicable: (1) complex cranioplasty: combined autologous and synthetic; (2) autologous cranioplasty; (3) synthetic cranioplasty; (4) vector analysis and distractor placement; (5) complex osteotomies; (6) multilayered intraoperative plans; (7) volume analysis; and (8) communication with parents. Outcomes between VSP and non-VSP cohorts were compared.

Results

Of 166 total cases, 32 were considered complex, defined by multisutural craniosynostosis, syndromic craniosynostosis, or revision status. Of these complex cases, 20 underwent VSP and 12 did not. There was no difference in mean operative time between the VSP and non-VSP groups (541 versus 532 min, P = 0.82) or in unexpected return to operating room (10.5% versus 8.3%, P = 0.84). VSP was most often used to communicate the surgical plan with parents (90%) and plan complex osteotomies (85%).

Conclusions

In this cohort, VSP was most often used to communicate the surgical plan with families and plan complex osteotomies. Our results indicate that VSP may improve intraoperative efficiency and safety for complex craniosynostosis surgery. This tool can be considered a useful adjunct to plan and guide intraoperative decisions in complex cases, reducing variability and guiding parental expectations.

The Esthetic Perception of Morphological Severity in Scaphocephalic Patients is Correlated With Specific Head Geometrical Features

OBJECTIVE

To investigate the relationship between perception of craniofacial deformity, geometric head features, and 3D head shape analyzed by statistical shape modeling (SSM).

PATIENTS

A total of 18 unoperated patients with scaphocephaly (age  =  5.2  ±  1.1m)-6 were followed-up after spring-assisted cranioplasty (SAC) (age  =  9.6  ±  1.5m)-and 6 controls (age  =  6.7  ±  2.5m).

MAIN OUTCOME MEASURES

3D head shapes were retrieved from 3D scans or computed tomography (CTs). Various geometrical features were measured: anterior and posterior prominence, take-off angle, average anterior and posterior lateral and horizontal curvatures, cranial index (CI) (cranial width over length), and turricephaly index (TI) (cranial height over length). SSM and principal component analysis (PCA) described shape variability. All models were 3D printed; the perception of deformity was blindly scored by 9 surgeons and 1 radiologist in terms of frontal bossing (FB), occipital bulleting (OB), biparietal narrowing (BN), low posterior vertex (LPV), and overall head shape (OHS).

RESULTS

A moderate correlation was found between FB and anterior prominence (r  =  0.56, P < .01) and take-off angle (r  =  - 0.57, P < .01). OB correlated with average posterior lateral curvature (r  =  0.43, P < 0.01) similarly to BPN (r  =  0.55, P < .01) and LPV (r  =  0.43, P < .01). OHS showed strong correlation with CI (r  =   - 0.68, P < .01) and TI (r  =  0.63, P< .01). SSM Mode 1 correlated with OHS (r  =  0.66, p < .01) while Mode 3 correlated with FB (r  =   - 0.58, P < .01).

CONCLUSIONS

Esthetic cranial appearance in craniofacial patients is correlated to specific geometric parameters and could be estimated using automated methods such as SSM.

Conformity of the Virtual Surgical Plan to the Actual Result Comparing Five Craniofacial Procedure Types

BACKGROUND

The "accuracy" of virtual surgical planning across multiple procedure types is not known. The authors aimed to compare the planned outcome from virtual surgical planning to the actual postoperative outcome for five craniofacial procedure types performed by a single surgeon: implant cranioplasty, cranial vault remodeling, orthognathic surgery, mandible reconstruction, and mandibular distraction.

METHODS

Stereolithography formats were obtained from virtual surgical planning and compared to postoperative computed tomographic scans for consecutive patients who underwent one of the five procedure types. Volumetric renderings of the operated bony region of interest were overlaid and compared using a Boolean operation to compute conformity (as a percentage of the region of interest). Conformity across procedure type was analyzed using analysis of variance and post hoc Bonferroni analysis, where appropriate.

RESULTS

One hundred thirty patients were included (51.5 percent male and 49.5 percent female; mean age, 27 years; 59 orthognathic surgery, 32 cranial vault remodeling, 16 mandible reconstruction, 12 mandibular distraction, and 11 implant cranioplasty patients). The highest tier of conformity was obtained for implant cranioplasty (median, 76.8 ± 10.3 percent) and mandible reconstruction (mean, 69.4 ± 11.2 percent), followed by orthognathic surgery (mean, 55.0 ± 7.3 percent) and mandibular distraction (median, 41.9 ± 20.3 percent), followed by cranial vault remodeling (mean, 22.2 ± 12.1 percent) (p < 0.001 between tiers and p > 0.05 among tiers).

CONCLUSIONS

Virtual surgical planning resulting in custom permanent implants and intraoperative guides provides more predictable results compared to virtual surgical planning used for procedures involving higher degrees of skeletal repositioning and postoperative movement (i.e., mandibular distraction and nonrigid cranial vault remodeling). In cases with expectedly lower conformity, excellent outcomes can be achieved with sound intraoperative judgment.

Modeling and simulation of cochlear perimodiolar electrode based on composite spring-mass model

This paper proposes, a method for the physical modeling of the perimodiolar electrode, particularly for the process of recovering its preset shape with the guide wire drawn out, based on the composite spring-mass model by employing the virtual-volumetric spring inspired from the traditional spring-mass model. Simulation experiments of modeling and virtual insertion of perimodiolar electrode were carried out. The results indicated that the mean and standard deviation of the difference between the local deformation angles of the simulated and measured sets of mass points, (1, 2, 3), (2, 3, 4), …, (13, 14, 15), were 6.34° and 5.98°, respectively. Additionally, the physical model of the perimodiolar electrode can reflect the overall morphological changes of the real perimodiolar electrode.

Advanced Three-Dimensional Technologies in Craniofacial Reconstruction

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Describe the evolution of three-dimensional computer-aided reconstruction and its current applications in craniofacial surgery. 2. Recapitulate virtual surgical planning, or computer-assisted surgical simulation, workflow in craniofacial surgery. 3. Summarize the principles of computer-aided design techniques, such as mirror-imaging and postoperative verification of results. 4. Report the capabilities of computer-aided manufacturing, such as rapid prototyping of three-dimensional models and patient-specific custom implants. 5. Evaluate the advantages and disadvantages of using three-dimensional technology in craniofacial surgery. 6. Critique evidence on advanced three-dimensional technology in craniofacial surgery and identify opportunities for future investigation.

SUMMARY

Increasingly used in craniofacial surgery, virtual surgical planning is applied to analyze and simulate surgical interventions. Computer-aided design and manufacturing generates models, cutting guides, and custom implants for use in craniofacial surgery. Three-dimensional computer-aided reconstruction may improve results, increase safety, enhance efficiency, augment surgical education, and aid surgeons' ability to execute complex craniofacial operations. Subtopics include image analysis, surgical planning, virtual simulation, custom guides, model or implant generation, and verification of results. Clinical settings for the use of modern three-dimensional technologies include acquired and congenital conditions in both the acute and the elective settings. The aim of these techniques is to achieve superior functional and aesthetic outcomes compared to conventional surgery. Surgeons should understand this evolving technology, its indications, limitations, and future direction to use it optimally for patient care. This article summarizes advanced three-dimensional techniques in craniofacial surgery with cases highlighting clinical concepts.

Analysis of Actual Versus Predicated Intracranial Volume Changes for Distraction Osteogenesis Using Virtual Surgical Planning in Patients With Craniosynostosis

INTRODUCTION

The primary outcome metric in patients with craniosynostosis are changes in intracranial volumes (ICVs). In patients who undergo distraction osteogenesis (DO) to treat craniosynostosis, changes are also dependent on the length of distraction. Virtual surgical planning (VSP) has been used to predict anticipated changes in ICV during cranial vault reconstruction. The purpose of this study is to analyze the actual versus predicted ICV changes using VSP in patients who undergo DO for craniosynostosis management.

METHODS

All patients with craniosynostosis treated with DO at a single institution, Rady Children's Hospital, between December 2013 and May 2019 were identified. Inclusion criteria are as follows: VSP planning with predicted postoperative ICV values and preoperative and postdistraction CT scans to quantify ICV. Postoperative ICV and VSP-estimated ICV were adjusted for age-related ICV growth. The primary outcome measure calculated was age-adjusted percent volume change per millimeter distraction (PVCPD), and results were analyzed using paired Wilcoxon signed rank tests.

RESULTS

Twenty-seven patients underwent DO for cranial vault remodeling. Nineteen patients were nonsyndromic, and 8 patients were syndromic. The median postoperative PVCPD was 0.30%/mm, and the median VSP-estimated PVCPD was 0.36% per millimeter (P < 0.001). A subanalysis of nonsyndromic patients showed a median postoperative PVCPD of 0.29%/mm in nonsyndromic patients that differed significantly from the VSP estimate of 0.34%/mm (P = 0.003). There was also a significant difference in syndromic patients' observed PVCPD of 0.41%/mm versus VSP estimate of 0.79%/mm (P = 0.012).

CONCLUSIONS

Virtual surgical planning overestimates the change in ICV attributable to DO in both syndromic and nonsyndromic patients.

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.

Traditional Versus Virtual Surgery Planning of the Fronto-Orbital Unit in Anterior Cranial Vault Remodeling Surgery

BACKGROUND

Craniosynostosis correction surgery is a complex procedure, which involves complete dismantling and reassembly of the cranial vault components. The traditional planning method for these surgeries results in increased intra-operative time owing to its highly subjective nature. The advent of virtual surgical planning (VSP) platform has lead to a greater pre-operative insight and precision outcome in calvarial remodeling surgeries. The purpose of this paper is to evaluate intra-operative time and blood loss difference as a measure of surgical efficiency between VSP based template guided Anterior Cranial Vault Reconstruction (ACVR) with Fronto-Orbital Unit Advancement (FOUA) and the traditional surgeries.

METHODS

Data were collected from patients who underwent ACVR with FOUA in our unit. Patients were divided into 2 groups, Template Fronto-Orbital Unit (TFOU) group and Non-template Fronto-Orbital Unit (NFOU) group. In TFOU group, Virtual planning along with fabrication of Template guide was carried out. Patients undergoing ACVR using traditional techniques were categorized as NFOU group. A comparative prospective analysis was carried out in terms of Intra-operative time duration and blood loss. Student 't' test was used to compare the means of the 2 groups.

RESULTS

A total of 10 patients were included in the present study. There were 5 control (NFOU) and 5 TFOU cases. There was a significant decrease in the operating time in TFOU group compared to the NFOU group. TFOU group also showed reduced intra-operative bleed compared to the NFOU group.

CONCLUSION

Virtual surgical planning (VSP) and 3D modeling with prefabricated template guide augurs reliable outcomes and portends the possibility of lesser intra-operative time. It is a valuable tool, which offers enormous benefits in terms of precise pre-surgical planning with predictive results.

Total Cranial Reconstruction for the Treatment of Sagittal Craniosynostosis in Children

OBJECTIVE

To study the effect of total cranial reconstruction for sagittal synostosis (scaphocephaly) deformity in Chinese children.

METHODS

A retrospective analysis was performed involving 23 children with isolated non-syndromic sagittal synostosis who were treated by total calvarial vault remodeling after 1 year of age from May 2015 to June 2019 in the Department of Neurosurgery, Children's Hospital of Nanjing Medical University. The authors reconstruct patients' pre- and post-operative cranial thin-section CT scan images and those of the control group. The cephalic index (traditional, normative), intracranial volume, horizontal point of maximum width (H-PMW), vertical point of maximum width (V-PMW), frontal to head height ratio and occipital to head height ratio data were analyzed using a paired t test or Wilcoxon signed-rank test.

RESULTS

Twenty-three patients met the inclusion criteria, including 19 males and 4 females. The ratio of males to females was 4.7:1. All patients underwent total cranial reconstruction. The average age was 26.52 months (13-48 months), the average operation time was 214.13 minutes (150-265 minutes), and the average amount of suspended erythrocytes was 200 ml (100-400 ml). The cranial morphology of all patients improved significantly after the operation. The traditional cephalic index (pre-operative: 0.70 (0.04); post-operative: 0.78 (0.02)) and normative cephalic index (pre-operative: 0.68 (0.03); post-operative: 0.77 (0.02)) were significantly increased (P < 0.0001). The mean horizontal point of maximum width improved from 0.54 to 0.56 (P = 0.0043), the mean vertical point of maximum width decreased from 0.59 to 0.54 (P = 0.0006), the frontal height decreased from 0.89 to 0.77 (P < 0.0001), and the occipital height improved from 0.78 to 0.88 (P < 0.0001). The intracranial volume increased from 1287.35 to 1426.90 cm3 (P < 0.0001). All of the children had a good skull shape and no recurrence of deformity.

CONCLUSIONS

Total calvarial reconstruction can effectively correct scaphocephaly in Chinese children, expand cranial volume, reduce cranial height, shorten fronto-occipital diameters and enlarge biparietal diameters.

Computer-Assisted Design and Manufacturing Assists Less Experienced Surgeons in Achieving Equivalent Outcomes in Cranial Vault Reconstruction

PURPOSE

The purpose of this study was to assess whether long-term outcomes were equivalent between computer-assisted design and manufacturing (CAD/CAM) -assisted cranial vault reconstruction performed by an inexperienced surgeon, with fewer years of surgical experience, and traditional reconstruction performed by senior surgeons with many decades of experience.

METHODS

An Institutional Review Board-approved retrospective cohort study was performed for all patients with nonsyndromic craniosynostosis between the ages of 1 month to 18 years who received primary, open calvarial vault reconstruction at the Johns Hopkins Hospital between 1990 and 2017. The primary outcome variable was the Whitaker category (I-IV) for level of required revision at the 2-year follow-up visit. Secondary outcomes included estimated blood loss, length of stay, operative time, and postoperative complications. CAD/CAM-assisted surgery was considered noninferior if the proportion of cases requiring any revision (Whitaker II, III, or IV) was no more than 10% greater than the proportion in the traditional surgery group with multivariate logistic regression analysis. t tests and fisher exact tests were used for secondary outcomes.

RESULTS

A total of 335 patients were included, with 35 CAD/CAM-assisted reconstructions. CAD/CAM-assisted reconstruction was noninferior to traditional after accounting for patient demographics, type of surgery, and experience level of the plastic surgeon. The traditional group required revision more frequently at 29.0% compared to CAD/CAM at 14.3%. Secondary outcomes were not significantly different between groups, but CAD/CAM had significantly longer average operative times (5.7 hours for CAD/CAM, 4.3 hours for traditional, P < 0.01).

CONCLUSION

CAD/CAM technology may lower the learning curve and assist less experienced plastic surgeons in achieving equivalent long-term outcomes in craniofacial reconstruction.