Posterior Vault Reconstruction Research Articles

Frontofacial Features of Unilateral Lambdoid Craniosynostosis: A Multicenter Assessment

Background: Unilateral lambdoid craniosynostosis is differentiated from deformational plagiocephaly primarily by assessing the cranium from posterior and bird’s-eye views. Findings include posterior displacement of the ipsilateral ear, ipsilateral occipitomastoid bossing, ipsilateral occipitoparietal flattening, contralateral parietal bossing, and contralateral frontal bossing. Diagnosis based off facial morphology may be an easier approach because the face is less obstructed by hair and head-coverings, and can easily be assessed when supine. However, frontofacial characteristics of unilateral lambdoid craniosynostosis are not well described. Methods: A retrospective cohort review of patients with isolated, unilateral lambdoid craniosynostosis from the Children’s Hospital of Pittsburgh and the Children’s Hospital of Philadelphia was performed. Preoperative frontal and profile photographs were reviewed for salient characteristics. Results: Nineteen patients met inclusion criteria. Eleven patients had left lambdoid craniosynostosis, and eight had right lambdoid craniosynostosis. All patients were nonsyndromic. Patients demonstrated contralateral parietal bossing and greater visibility of the ipsilateral ear. Contralateral frontal bossing was mild. The orbits were tall and turricephaly was present in varying severity. Facial scoliosis as a C-shaped deformity was present in varying severity. The nasal root and chin pointed to the contralateral side. Conclusions: The combination of greater visibility of the ipsilateral ear, contralateral parietal bossing, and C-shaped convex ipsilateral facial scoliosis are hallmark frontofacial features of unilateral lambdoid craniosynostosis. Although the ipsilateral ear is more posterior, the greater visibility may be attributed to lateral displacement from the mastoid bulge. Evaluation of long-term postoperative results is needed to assess if this pathognomonic facial morphology is corrected following posterior vault reconstruction.

How Low Should We Go? Safety and Craniometric Impact of the Low Occipital Osteotomy in Posterior Vault Remodeling.

A larger volume cranial vault expansion is likely facilitated by a low posterior cranial osteotomy beneath the torcula; however, this may impart an increased risk of venous bleeding. The authors compared the safety of infratorcular versus supratorcular osteotomy in patients undergoing posterior vault reconstruction or posterior vault distraction osteogenesis and analyzed volumetric changes. Patients undergoing initial posterior vault reconstruction or distraction osteogenesis between 2009 and 2021 at the authors' institution were grouped by occipital osteotomy location and analyzed retrospectively. Craniometric analysis was performed if patients had high-resolution computed tomography scans available within 180 days preoperatively and postoperatively. A total of 187 patients were included: 106 (57 percent) who underwent posterior vault distraction osteogenesis and 81 (43 percent) who underwent posterior vault reconstruction. Infratorcular osteotomy was more common in reconstruction [ n = 65 (80 percent)] than in distraction osteogenesis [ n = 61 (58 percent); p < 0.002]. Blood transfused was similar between low and high osteotomy cohorts in the distraction osteogenesis ( p = 0.285) and reconstruction ( p = 0.342) groups. However, median transfused blood volume per kilogram of patient weight was greater in the low versus high osteotomy distraction osteogenesis ( p = 0.010) and reconstruction ( p = 0.041) cohorts. Intraoperative venous sinus injury was rare. In the distraction osteogenesis cohort, there was increased median intracranial volumetric gain in the low (263 ml) compared with the high osteotomy cohort (127 ml; p = 0.043); however, when controlled for distraction distance, only a trend was observed ( p = 0.221). Patients undergoing distraction osteogenesis showed a larger median intracranial volume increase (168 ml) compared with those undergoing reconstruction (73 ml; p < 0.001). Infratorcular osteotomy can be performed safely in most patients undergoing cranial vault remodeling and does not appear to be associated with greater hemodynamic instability or sinus injury. Therapeutic, III.

The Road to Transfusion-free Craniosynostosis Repair in Children Less Than 24 Months Old: A Quality Improvement Initiative.

Introduction:Pediatric craniofacial reconstruction has historically resulted in extensive blood loss necessitating transfusion. This single-center quality improvement initiative evaluates the impact of perioperative practice changes on the allogeneic transfusion rate for children 24 months and younger of age undergoing craniofacial reconstruction.Methods:At project initiation, an appointed core group of anesthesiologists provided all intraoperative anesthetic care for patients undergoing craniofacial reconstruction. Standardized anesthetic guidelines established consistency between providers. Using the Plan-do-check-act methodology, practice changes had been implemented and studied over a 5-year period. Improvement initiatives included developing a temperature-management protocol, using a postoperative transfusion protocol, administering intraoperative tranexamic acid, and a preincisional injection of 0.25% lidocaine with epinephrine. For each year of the project, we acquired data for intraoperative and postoperative allogeneic transfusion rates.Results:A cohort of 119 pediatric patients, ages 4–24 months, underwent anterior or posterior vault reconstruction for craniosynostosis at a tertiary children’s hospital between March 2013 and November 2018. Intraoperative and postoperative transfusion of allogeneic blood products in this cohort decreased from 100% preintervention to 22.7% postintervention.Conclusions:Interdepartmental collaboration and practice modifications using sequential Plan-do-check-act cycles resulted in a bundle of care that leads to a sustainable decrease in the rate of intraoperative and postoperative allogeneic blood transfusions in patients less than 24 months of age undergoing craniosynostosis repair. This bundle decreases the risk of transfusion-related morbidity for these patients. Other institutions looking to achieve similar outcomes can implement this project.

Ventricular shunt complications in patients undergoing posterior vault distraction osteogenesis.

The primary objective of this study is to investigate post-operative morbidity and shunt revision rates of patients with shunt-dependent hydrocephalus (SDH) undergoing posterior vault distraction osteogenesis (PVDO) compared to patients undergoing conventional posterior vault reconstruction (PVR). A retrospective case-controlled cohort analysis of all patients with SDH undergoing PVDO and PVR for syndromic or complex craniosynostosis was performed. Demographic information, perioperative variables, distraction protocols, and shunt-related complications-infection, surgical revision of shunt, increased length of stay (LOS), and readmission within 90 days of surgery-were compared using the appropriate statistical tests. Fourteen patients with ventricular shunts who underwent PVDO and eight patients with shunts who underwent PVR were identified. Shunt-related complication rates were significantly higher with PVDO (n = 5) compared to PVR (n = 0), p = 0.0093. Among the five patients who suffered complications, the most common were shunt infection (n = 4), shunt malfunction (n = 4), and wound infections (n = 3). All patients with complications required additional operations for shunt revision and/or replacement; four patients required multiple takebacks for such procedures, with an average of three additional procedures per patient. In complex or syndromic craniosynostosis patients who have previously undergone ventricular shunting, PVDO is associated with higher shunt-related complications and need for additional procedures when compared to traditional PVR. While the benefits of PVDO in the treatment of syndromic craniosynostosis are well documented, the risks of PVDO in the face of a VP shunt must be considered. Further investigation into patient-specific risk factors and risk reduction strategies is warranted.

Intraoperative intracranial pressure monitoring in the pediatric craniosynostosis population.

OBJECTIVEEvaluation of increased intracranial pressure (ICP) in the pediatric craniosynostosis population based solely on ophthalmological, clinical, and radiographic data is subjective, insensitive, and inconsistent. The aim of this study was to examine the intraoperative ICP before and after craniectomy in this patient population.METHODSThe authors measured the ICP before and after craniectomy using a subdural ICP monitor in 45 children. They regulated end-tidal carbon dioxide and the monitoring site under general anesthesia to record consistent ICP readings.RESULTSThe average age of the patient population was 29 months (range 3.8-180.5 months). Thirty-seven patients (82.2%) were undergoing initial craniosynostosis procedures. All craniosynostosis procedures were categorized as one of the following: frontoorbital advancement (n = 24), frontoorbital advancement with distraction osteogenesis (n = 1), posterior vault distraction osteogenesis (n = 10), and posterior vault reconstruction (n = 10). Nineteen of 45 patients (42.2%) had syndromic or multisuture craniosynostosis. The mean postcraniectomy ICP (8.8 mm Hg, range 2-18 mm Hg) was significantly lower than the precraniectomy ICP (16.5 mm Hg, range 6-35 mm Hg) (p < 0.001). Twenty-four patients (53%) had elevated ICP prior to craniectomy, defined as ≥ 15 mm Hg. Only 4 (8.9%) children had papilledema on preoperative funduscopic examination (sensitivity 17%, specificity 100%, negative predictive value 51%, and positive predictive value 100%). There were no significant differences in elevated precraniectomy ICP based on type of craniosynostosis (syndromic/multisuture or nonsyndromic) or age at the time of surgery. Patients undergoing initial surgery in the first 12 months of life were significantly less likely to have elevated precraniectomy ICP compared with patients older than 12 months (26.3% vs 73.1%, p = 0.005).CONCLUSIONSIn this study, the authors report the largest cohort of syndromic and nonsyndromic craniosynostosis patients (n = 45) who underwent precraniectomy and postcraniectomy ICP evaluation. A craniectomy or completed craniotomy cuts for distractors effectively reduced ICP in 43/45 patients. The authors' findings support the notion that papilledema on funduscopy is a highly specific, however poorly sensitive, indicator of increased ICP, and thus is not a reliable screening method. These findings indicate that even nonsyndromic patients with craniosynostosis are at risk for increased ICP. Furthermore, patients who present prior to 12 months of age appear less likely to have elevated ICP on presentation. Further studies with other noninvasive imaging of the retina may be useful as an adjunct tool for determining elevated ICP.

Power-Assisted Particulate Bone Grafting Effectively Prevents Osseous Defects After Cranial Vault Reconstruction

Cranial vault reconstruction (CVR) is the gold standard in the operative treatment of craniosynostosis. Full thickness osseous defects (FTOD) of the calvaria have been observed in 5% to 15% patients after CVR, with higher rates cited in the fronto-orbital advancement (FOA) subset. Particulate bone graft (PBG) harvested manually has been shown to decrease FTOD after FOA from 24% to 5.5%. The authors used a modified technique using a powered craniotome, with the hypothesis that the technique would also improve outcomes. A retrospective review was performed of patients who underwent CVR for craniosynostosis between 2004 and 2014. Patient demographics, diagnosis, age, operative details, and postoperative care were reviewed in detail. Categorical, nonparametric variables were compared by Fisher exact tests. A total of 135 patients met inclusion criteria. The most common diagnoses were metopic (n = 41), sagittal (n = 33), and unilateral coronal craniosynostosis (n = 31); 65% (n = 88) underwent FOA, 29% (n = 39) underwent single-stage total vault reconstruction, and 6% (n = 8) had a posterior vault reconstruction. CVR was performed without PBG in 95 patients and with PBG in 40 patients. Without PBG, FTOD were discovered on clinical examination in 18% of patients (n=17): 11 presented with subcentimeter defects, while 6 had larger defects requiring revision cranioplasty (6% operative revision rate). Among those receiving PBG, 1 patient presented a subcentimeter FTOD (2.5% FTOD incidence and 0% operative revision rate). Particulate bone graft harvested with a powered device decreases the rate of FTOD and reoperation rate after CVR for craniosynostosis.

Evaluation of the Safety of Posterior Cranial Vault Reconstruction

Posterior vault reconstruction involves exposure, craniotomy, and reconstruction of the occipital cranium. Although it is commonly performed, the safety and complications associated with posterior vault reconstruction have not been specifically or thoroughly examined. A retrospective chart review was performed for all patients undergoing posterior vault reconstruction at the Children's Hospital of Philadelphia between 1996 and 2006. Diagnosis, operative indication, age and weight at time of surgery, procedure type, intraoperative and postoperative complications, estimated blood loss, blood transfusion volume, and length of surgery and admission were recorded. Fifty posterior vault reconstruction cases were included in the study (17 syndromic and 33 nonsyndromic). Mean estimated blood loss was 53.6 percent (range, 15.9 to 142.9 percent) of total blood volume and was statistically greater in syndromic patients (60.6 percent versus 50.0 percent; p = 0.038). Transfusion volume averaged 66.1 percent of total blood volume but was not statistically significant. Length of surgery and number of intraoperative complications were significantly elevated in the syndromic cohort (p = 0.007 and p = 0.037, respectively), whereas length of admission and number of postoperative complications were not. Complications were intraoperative in seven patients (14 percent) and postoperative in seven (14 percent), for an overall complication rate of 28 percent. This is the largest series to date addressing the safety and complications of posterior vault reconstruction. In the authors' experience, posterior vault reconstruction carries a higher risk of intraoperative complications and blood loss compared with that reported in the literature for other types of cranial vault reconstruction. In addition, syndromic patients were more likely than nonsyndromic patients to encounter intraoperative problems.