Posterior Vault Distraction With Midface Distraction Without Osteotomy as a First Stage for Syndromic Craniosynostosis

Transfacial Two-pin External Mandibular Distraction Osteogenesis: A Technique for Neonatal Airway Obstruction from Robin Sequence

Surgical management in those with moderate-to-severe airway obstruction includes tongue-lip adhesion, tracheostomy, and/or mandibular distraction osteogenesis. This article describes a transfacial two-pin external device technique for mandibular distraction osteogenesis, utilizing minimal dissection.

Methods

The first percutaneous pin is transcutaneously placed just inferior to the sigmoid notch parallel to the interpupillary line. The pin is then advanced through the pterygoid musculature at the base of the pterygoid plates, toward the contralateral ramus, and exits the skin. A second parallel pin is placed spanning the bilateral mandibular parasymphysis distal to the region of the future canine. With the pins in place, bilateral high ramus transverse corticotomies are performed. Using univector distractor devices, the length of activation varies, with the goal of overdistraction to achieve a class III relationship of the alveolar ridges. Consolidation is limited to a 1:1 period with the activation phase, and removal is performed by cutting and pulling the pins out of the face.

Results

To guide optimal transcutaneous pin placement, transfacial pins were then placed through twenty segmented mandibles. Mean upper pin (UP) distance was 20.7 ± 1.1 mm from the tragus. The distance between the cutaneous entry of the UP and lower pin was 23.5 ± 0.9 mm, and the tragion-UP-lower pin angle was 118.7 ± 2.9°.

Conclusions

The two-pin technique has potential advantages regarding nerve injury and mandibular growth, given an intraoral approach with limited dissection. It may safely be performed on neonates whose small size may preclude the use of internal distractor devices.

"Ten Years of Posterior Cranial Vault Expansion via Distraction Osteogenesis: An Update and Critical Evaluation"

PURPOSE

The goal of this study was to describe the 10-year evolution of our surgical technique and institutional perioperative outcomes using posterior vault distraction osteogenesis (PVDO) in patients with syndromic and multi-suture craniosynostosis.

METHODS

We performed a retrospective cohort study of patients who underwent PVDO for treatment of syndromic and multi-suture craniosynostosis at a single institution over a 10-year period. Demographic data, perioperative outcomes, distraction patterns, and complications were analyzed. Outcomes for patients in the first 5 years ("early cohort") were compared to those of the latter 5 years ("late cohort").

RESULTS

110 patients underwent a total of 118 PVDO procedures. Syndromic patients represented 83.6% of the cohort (n=92) and were significantly younger than non-syndromic patients at the time of first PVDO (median 14.1 [6.6, 40.1] vs 42.7 [15.2, 59.6] months, p=0.014). Mean distraction distance in the anterior-posterior direction was 30.8 mm (SD=7.4). Compared to the early cohort, PVDO in the late cohort had faster median operative times (144.0min [123.0, 189.0] vs 161.0min [138.0, 199.0], p=0.038), lower estimated blood loss as a percent of blood volume (28.5 [20.6, 45.3] vs 50.0 [31.1, 95.8], p<0.001), and lower blood replacement as percent of blood volume (39.5 [23.8, 59.1] vs 56.3 [37.8, 110.1], p=0.009).

CONCLUSIONS

Our 10-year experience with PVDO demonstrates continued overall safety and efficacy with improved perioperative outcomes over time. While it has become our first line of expansion in syndromic craniosynostosis, shortcomings such as need for device removal, infectious concerns, and potential for CSF leak merit attention by the craniofacial community.

Robot-assisted frontofacial correction in very young children with craniofacial dysostosis syndromes: a technical note and early functional outcome

OBJECTIVE

In this study, the authors aimed to 1) retrospectively analyze the early functional outcomes in a cohort of very young children with craniofacial dysostoses who underwent robot-assisted frontofacial advancement (RAFFA) or robot-assisted midface distraction (RAMD), and 2) analyze the utility of robotic assistance in improving the accuracy and safety of performing transfacial pin insertion for RAFFA or RAMD.

METHODS

A retrospective analysis of a cohort of 18 children (age range 1-42 months at presentation), who underwent RAFFA or RAMD from February 2015 to February 2021 in the craniofacial unit at Amrita Institute of Medical Sciences and Research Centre in Kochi, India, was performed. Inclusion criteria were patients who had undergone RAFFA in a single stage or RAMD where the cranial vault had been addressed earlier, had been addressed on follow-up, or had not been addressed and had follow-up of at least 6 months.

RESULTS

Overall, 18 children with syndromic craniosynostosis underwent LeFort level III midface distraction, with or without RAFFA, from February 2015 to February 2021 at a single center in India. The patients' ages ranged from 6 to 47 months at the time of the procedure. All patients had significant obstructive sleep apnea (OSA), significant ocular issues, and disturbed sleep as determined by the authors' preoperative protocol. Clinically significant intracranial pressure issues were present in 17 patients. None of the patients had injury due to the transfacial pin trajectory such as globe injury, damage to the tooth buds, or the loss of purchase during the active distraction phase. The mean distraction achieved was 23 mm (range 18-30 mm) (n = 16/18). Of the 18 patients, 10 (56%) had an excellent outcome and 6 (33%) had a satisfactory outcome. In all cases, the degree of OSA had significantly reduced after surgery. Eye closure improved in all patients, and complete closure was seen in 11 patients. On follow-up, the functional gain remained in 14 of 16 patients at the final follow-up visit. The distraction results were stable during the follow-up period (mean 36 months [range 6-72 months]).

CONCLUSIONS

The early RAFFA and RAMD protocols investigated in this study gave a significant functional advantage in very young patients with craniofacial dysostoses. The results have demonstrated the accuracy and safety of robotic assistance in performing transfacial pin insertion for RAFFA or RAMD.

Complete posterior cranial vault distraction osteogenesis to correct Chiari malformation type I associated with craniosynostosis

OBJECTIVE

Posterior vault distraction osteogenesis (PVDO) is an effective tool to increase intracranial volume and expand the posterior cranial fossa. During PVDO, the authors extended osteotomy posterior to the foramen magnum to fully expand the posterior cranial fossa. The aim of this study was to investigate the efficacy of complete PVDO in posterior fossa expansion and treatment of Chiari malformation type I (CM-I) in patients with craniosynostosis.

METHODS

Patients with craniosynostosis who had undergone complete PVDO between January 2012 and May 2020 were reviewed retrospectively. A coronal osteotomy extending to the foramen magnum was performed and the foramen magnum was decompressed by removing its posterior rim with a 1-mm Kerrison rongeur. Four distractor devices were placed and the vector of distraction was controlled from the posterior to the inferior-posterior direction, depending on the deformity. Changes in the intracranial volume, posterior cranial fossa area, and cerebellar tonsillar descent were measured after complete PVDO by using CT and MRI.

RESULTS

A total of 11 patients with craniosynostosis and concurrent CM-I were included in the study. The mean age was 34.6 ± 24.0 months (continuous variables are expressed as the mean ± SD throughout). One patient had sleep apnea, which was consistent with CM-I, and another patient had a headache, which was nonspecific. The intracranial volume increased from 1179.6 ± 180.2 cm3 to 1440.6 ± 251.5 cm3 (p = 0.003; 24.5% increase compared to the preoperative volume). The posterior skull base area increased from 44.9 ± 19.3 cm2 to 72.7 ± 18.1 cm2 (p = 0.004). Cerebellar tonsillar descent decreased in all 11 patients after complete PVDO (preoperative: 10.8 ± 3.7 mm, postoperative: 2.7 ± 3.0 mm; p = 0.003). Among the 11 patients, 5 showed complete resolution of cerebellar tonsillar herniation.

CONCLUSIONS

Complete PVDO can more efficiently expand the posterior cranial fossa, unlike conventional methods. Moreover, it helps to relieve cerebellar tonsillar herniation. Complete PVDO is a powerful tool to increase the intracranial and posterior fossa volumes in patients with craniosynostosis and concurrent CM-I.

A Review on Variability in Treatment Protocols With Posterior Cranial Vault Distraction

BACKGROUND

Prior studies have confirmed the ability of posterior cranial vault distraction osteogenesis (PVDO) to expand the intracranial volume in patients with craniosynostosis. To date, there is scant literature on the optimal distraction protocol for PVDO. The authors sought to review the literature and define a common protocol for posterior cranial vault distraction.

METHODS

The authors performed a systematic review for published PVDO protocols. The data collected from these studies included age at the time of PVDO, number of distraction devices placed, time for latency, rate and rhythm of distraction, distraction length, time for consolidation, and surgical outcomes.

RESULTS

A total of 286 patients were identified within 24 studies from 2011 to 2019. The mean age of patients identified was 25.34 months. After application of distractors, latency period ranged between 1 and 7 days, with most patients undergoing 5 to 7 days of latency. Once distraction was begun, the majority of patients (77.4%) underwent 1 mm of distraction daily. Total lengths of distraction ranged between 13 and 35 mm, with the largest cohort of patients undergoing 26 to 30 mm of total distraction. A total of 60 complications were reported for a total of 212 patients, yielding an overall complication rate of 28.3%.

CONCLUSIONS

Although there is variability in reported PVDO protocols, the majority are similar to distraction osteogenesis protocols described for long bone sites. Increased patient age correlates with selection of a greater latency period and total distraction length, while frequency of complications is also increased.

Craniosynostosis: Posterior Cranial Vault Remodeling

Posterior cranial vault distraction osteogenesis is a powerful, reliable, low-morbidity method to achieve intracranial expansion. It is particularly useful in treating turribrachycephaly seen in syndromic craniosynostosis, allowing for gradual expansion of the bone while stretching the soft tissues over several weeks allowing greater volumetric expansion than conventional techniques. Posterior cranial vault distraction osteogenesis constitutes a more gradual remodeling modality, with infrequent complications. As a first step in intracranial expansion, it preserves the frontal cranium for future frontofacial procedures. A drawback is the need for a second surgery to remove the device, and this must be taken into account during counseling.

Chiari 1 malformation and untreated sagittal synostosis: a new subset of complex Chiari?

PURPOSE

Chiari 1 malformation (CM1) is a well-known association with complex craniosynostosis (CC), while it has been rarely reported in association with monosynostosis. The aim of the present study is to investigate on the association between CM1 and untreated sagittal synostosis (USS).

METHOD

The study included 48 cases of sagittal synostosis (SS), untreated for misdiagnosis and associated with CM1. The children were firstly diagnosed for CM1 by MRI (mean age 9) than for SS (mean age 10.5) by three-dimensional computerized tomography (3D-CT), which documented the absence of the sagittal suture, in the presence of residual indentation of all the other sutures. Syndromic cases were diagnosed by clinical evaluation and molecular studies.

RESULTS

Of the 48 children harboring CM1 plus USS, 21 were asymptomatic for CM1 and are still on follow-up, while 27 children were operated for syringomyelia and scoliosis and/or occurrence of symptoms, three of them had an acute presentation (two papilledema and one sleep apneas) and 11 children had a documented increase of preoperative ICP. Craniovertebral decompression (CVD) was the first-line surgery in 24 children, 16 with duroplasty and five without and eight had also cerebellar (CBL) tonsil coagulation. A cranial vault remodelling was firstly performed in three children. Fifteen percent of children submitted to CVD needed a revision for cerebrospinal fluid (CSF) collection, while two needed both the supra- and infratentorial decompressive procedure and another two needed a treatment for the associated hydrocephalus.

CONCLUSIONS

The present study identified an USS in 27 (15.5%) of 174 CM1 children operated for a symptomatic CM1. We suggest to define this association CM1 plus USS, a new subtype of complex CM1. For the high percentage of complications and multiple procedures needed to solve the CM1, we advise to identify by 3D-CT scan these children before performing CVD. Our finding suggests also that, if left untreated, SS may lead to the delayed occurrence of a challenging subset of CM1.

National 30-Day Outcomes for Posterior Cranial Vault Distraction

BACKGROUND

Posterior vault distraction (PVD) can rapidly expand calvarial volume in infancy. Limited data exist regarding its perioperative and postoperative safety profile. This study sought to investigate the patient profile, outcomes, and safety of PVD using a national pediatric database.

METHODS

Posterior vault distraction patients between 2012 and 2016 were isolated from the National Surgical Quality Improvement Program Pediatric database. Patient background, perioperative outcomes, and risk factors were analyzed using chi-squared, t test analysis, and multivariate regression.

RESULTS

Ninety-four patients who underwent PVD were isolated with 67 ultimately meeting inclusion criteria for the study. The majority of patients undergoing PVD had limited other documented comorbidities. No patients required reoperation or 30-day readmission. There were no incidences of stroke, surgical site infection, or death. Subdividing outcomes by specialty, plastic surgeons performed PVD on significantly older patients than neurosurgeons (188 days vs 138 days, P = 0.008). Increasing age was associated with increasing operative time (P < 0.001). Furthermore, increasing age is associated with greater absolute transfusion requirements (P = 0.018) and higher, but not significant, risk of requiring any volume of blood transfusion (P = 0.105).

CONCLUSIONS

Posterior vault distraction is a safe procedure to rapidly expand calvarial volume in the setting of craniosynostosis. Increasing patient age is the strongest predictor for prolonged operative time and higher blood transfusion volumes.

Complications in Posterior Cranial Vault Distraction

BACKGROUND

The use of posterior cranial vault distraction for the treatment of elevated intracranial pressure is gaining popularity and is a standard for first-stage cranial expansion in syndromic craniosynostosis at many institutions. However, although the operation is faster and less complex than other cranial vault remodeling procedures, it is not without its own unique set of complications.

METHODS

We surveyed the published literature for case series and case control studies on posterior vault distraction. Complication rates and types for these series were tabulated and grouped by management. When outcomes were unclear, corresponding authors were contacted for clarification and treatment plans.

RESULTS

Eleven reports were found from a search of all the literature on posterior cranial vault distraction with a range of 1 to 22 included patients. The average age at surgery was 16.2 ± 11.8 months. Complication rates ranged from 12.5% to 100%, with the average of 30% of patients across all studies. The most common complications reported were cerebrospinal fluid leak or dural injury, followed by wound infections or device exposures, and device failure. There were no reported patient deaths or long-term morbidities.

CONCLUSIONS

Posterior cranial vault distraction is a relatively safe and effective therapy for the treatment of elevated intracranial pressure in the setting of syndromic craniosynostosis. The majority of described complications center on the interaction of the device with the dura, device extrusion, and infection. Extreme care must be used with the placement of these distraction devices and with handling of the dura at the osteotomy sites to ensure successful outcomes and avoid complications.

LEVELS OF EVIDENCE

III.

Endoscopic craniosynostosis repair

INTRODUCTION

Craniosynostosis is a rare condition that affects approximately one child in every 2,000 live births, and involves pathological fusion of two or more skull bones. Consequences of craniosynostosis include possible limitation of brain growth and cosmetic effects on the appearance of the child. Traditional repairs for these conditions over the past 3-4 decades have involved an open operation with a large skin incision and major manipulations of the skull bones. More recently, minimally invasive endoscopic techniques have been developed to release the skull bones, followed by postoperative treatment with either an external orthosis or internal springs and distractors to achieve the desired correction.

METHODS

In this review minimally invasive endoscopic repair will be reviewed. A general overview of the condition and techniques for correction will be discussed, followed by specific application of these surgeries for different craniosynostosis diagnoses. Attention to the subtleties of each specific condition will be highlighted.

SUMMARY

Over the past two decades clinical experience and a large number of publications have substantiated the benefits of minimally invasive endoscopic techniques for the treatment of craniosynostosis. These techniques have clear benefits for selected patients, and should be part of the standard of care for this condition at craniofacial centers.