Nasolabial Aesthetics Following Cleft Repair: An Objective Evaluation of Subjective Assessment

OBJECTIVE

Assess the weight and contribution of each of the parameters of the Asher-McDade Scale to overall subjective assessment of nasolabial aesthetics following cleft lip repair.

DESIGN

Retrospective cohort evaluation.

SETTING

Cleft and craniofacial center.

PARTICIPANTS

Forty-one patients who underwent unilateral cleft lip repair.

INTERVENTIONS

Unilateral cleft lip repair.

MAIN OUTCOME MEASURES

Nasolabial rating using the Asher-McDade scale and overall subjective assessment of nasolabial aesthetics using a rank score following unilateral cleft lip repair.

RESULTS

Strong interrater reliability was observed between the 3 raters. Significant association was determined on bivariate analysis between nasal form score (β = 27.06; P < .001), nasal symmetry score (β = 26.41; P < .001), nasal profile score (β = 28.75; P < .001), vermilion border score (β = 13.40; P = .012), and the ranking score. Adjusted β coefficients obtained from multivariate regression analysis were used to develop a modified nasolabial appearance score (over 5), that is, weighted for each of the 4 parameters: nasal form (over 8, adjusted β = 14.33), nasal symmetry (over 5, adjusted β = 7.96), nasal profile (over 5, adjusted β = 9.44), and vermilion (over 2, adjusted β = 3.31). Regression analysis between our modified nasolabial appearance score and patient ranking score demonstrated superior goodness of fit when compared to the Asher-McDade overall nasolabial appearance score (R² = .80; P < .001 vs R² = .69; P < .001).

CONCLUSION

The parameters evaluated in the Asher-McDade scale have different weights and contribute differently to overall subjective assessment of nasolabial aesthetic outcomes following cleft lip repair. Adjusting for their weights results in a modified score that demonstrates superior correlation with overall subjective assessment of nasolabial aesthetic outcomes.

In-House Manufacture of Sterilizable, Scaled, Patient-Specific 3D-Printed Models for Rhinoplasty

BACKGROUND

Rhinoplasty relies on clear patient communication and precise execution of a three-dimensional (3D) plan to achieve optimal results. As 3D imaging and printing continue to grow in popularity within the medical field, rhinoplasty surgeons have begun to leverage these resources as an aid to preoperative planning, patient communication, and the technical performance of this challenging operation.

OBJECTIVES

Utilizing departmentally available resources and open-access 3D imaging platforms, we have developed an affordable, reproducible protocol for rapid in-house virtual surgical planning (VSP) and subsequent manufacture of 3D-printed rhinoplasty models.

METHODS

Preoperative 3D photographic images underwent virtual rhinoplasty using a freely available 3D imaging and sculpting program (BlenderTM [Version 2.78, Amsterdam, The Netherlands]). Once the ideal postoperative result was digitally achieved, scaled, sterilizable, and patient-specific 3D models of the preoperative and ideal postoperative result were manufactured in-house using a departmentally owned 3D printer.

RESULTS

3D-printed models have successfully been manufactured and employed for 12 patients undergoing rhinoplasty. The average time to prepare a set of pre- and postoperative models was 3 hours, while the printing process required 18 to 24 hours per model. Each set of surgical models can be manufactured at a total materials cost of approximately $5.00.

CONCLUSIONS

We describe an affordable means to construct sterilizable, scaled, patient-specific 3D-printed models for rhinoplasty. This technique may become of increasing interest to academic and cosmetic centers as hardware costs of 3D printers continue to fall.

LEVEL OF EVIDENCE: 4

The Role of Adenosine Receptor Activation in Attenuating Cartilaginous Inflammation

Adenosine receptor activation has been explored as a modulator of the inflammatory process that propagates osteoarthritis. It has been reported that cartilage has enhanced regenerative potential when influenced by adenosine receptor activation. As adenosine's role in maintaining chondrocyte homeostasis at the cellular and molecular levels is explored, successful in vivo applications of adenosine delivery for cartilage repair continue to be reported. This review summarizes the role adenosine receptor ligation plays in chondrocyte homeostasis and regeneration of articular cartilage damaged in osteoarthritis. It also reports on all the modalities reported for delivery of adenosine through in vivo applications.

Haptic, Physical, and Web-Based Simulators: Are They Underused in Maxillofacial Surgery Training?

PURPOSE

Surgical residencies have increasingly incorporated both digital and mannequin simulation into their training programs. The aim of our review was to identify all digital and mannequin maxillofacial simulators available for education and training, highlight their benefit, and critically assess the evidence in support of these educational resources.

MATERIALS AND METHODS

We performed a comprehensive literature review of all peer-reviewed publications of digital and mannequin simulators that met the inclusion criteria, defined as any simulator used in education or training. All simulators used in surgical planning were excluded. Before the query, it was hypothesized that most studies would be descriptive in nature and supported by low levels of evidence. Literature search strategies included the use of multiple combinations of key search terms, review of titles and abstracts, and precise identification of the use of the simulator described. All statistics were descriptive.

RESULTS

The primary search yielded 259 results, from which 22 total simulators published on from 2001 to 2016 were identified using the inclusion and exclusion criteria: 10 virtual reality haptic-based simulators, 6 physical model simulators, and 6 Web-based simulators used for a variety of procedures such as dental skills, instrument handling, orthognathic surgery (Le Fort I osteotomy, vertical ramus osteotomy, bilateral sagittal split ramus osteotomy), genioplasty, bone grafting, sinus surgery, cleft lip repair, orbital floor repair, and oral biopsy. Only 9 formalized studies were completed; these were classified as low-level evidence-based cohort studies (Levels IV and V). All other simulator reports were descriptive in nature. There were no studies with high levels of evidence completed (Level I to III).

CONCLUSIONS

The results of this review suggest that, although seemingly beneficial to the trainee in maxillofacial surgery, simulation in education in this field is an underused commodity because of the significant lack of scientific and validated study designs reported on in the literature thus far. The maxillofacial and simulation communities would benefit from studies on utility and efficacy with higher levels of evidence.

Internet-Based Digital Simulation for Cleft Surgery Education: A 5-Year Assessment of Demographics, Usage, and Global Effect

BACKGROUND

In October 2012, a freely available, internet-based cleft simulator was created in partnership between academic, nonprofit, and industry sectors. The purpose of this educational resource was to address global disparities in cleft surgery education. This report assesses demographics, usage, and global effect of our simulator, in its fifth year since inception.

OBJECTIVE

Evaluate the global effect, usage, and demographics of an internet-based educational digital simulation cleft surgery software.

SETTING AND PARTICIPANTS

Simulator modules, available in five languages demonstrate surgical anatomy, markings, detailed procedures, and intraoperative footage to supplement digital animation. Available data regarding number of users, sessions, countries reached, and content access were recorded. Surveys evaluating the demographic characteristics of registered users and simulator use were collected by direct e-mail.

RESULTS

The total number of simulator new and active users reached 2865 and 4086 in June 2017, respectively. By June 2017, users from 136 countries had accessed the simulator. From 2015 to 2017, the number of sessions was 11,176 with a monthly average of 399.0 ± 190.0. Developing countries accounted for 35% of sessions and the average session duration was 9.0 ± 7.3 minutes. This yields a total simulator screen time of 100,584 minutes (1676 hours). Most survey respondents were surgeons or trainees (87%) specializing in plastic, maxillofacial, or general surgery (89%). Most users found the simulator to be useful (88%), at least equivalent or more useful than other resources (83%), and used it for teaching (58%).

CONCLUSIONS

Our internet-based interactive cleft surgery platform reaches its intended target audience, is not restricted by socioeconomic barriers to access, and is judged to be useful by surgeons. More than 4000 active users have been reached since inception. The total screen time over approximately 2 years exceeded 1600 hours. This suggests that future surgical simulators of this kind may be sustainable by stakeholders interested in reaching this target audience.

The role of 3D printing in treating craniomaxillofacial congenital anomalies

Craniomaxillofacial congenital anomalies comprise approximately one third of all congenital birth defects and include deformities such as alveolar clefts, craniosynostosis, and microtia. Current surgical treatments commonly require the use of autogenous graft material which are difficult to shape, limited in supply, associated with donor site morbidity and cannot grow with a maturing skeleton. Our group has demonstrated that 3D printed bio-ceramic scaffolds can generate vascularized bone within large, critical-sized defects (defects too large to heal spontaneously) of the craniomaxillofacial skeleton. Furthermore, these scaffolds are also able to function as a delivery vehicle for a new osteogenic agent with a well-established safety profile. The same 3D printers and imaging software platforms have been leveraged by our team to create sterilizable patient-specific intraoperative models for craniofacial reconstruction. For microtia repair, the current standard of care surgical guide is a two-dimensional drawing taken from the contralateral ear. Our laboratory has used 3D printers and open source software platforms to design personalized microtia surgical models. In this review, we report on the advancements in tissue engineering principles, digital imaging software platforms and 3D printing that have culminated in the application of this technology to repair large bone defects in skeletally immature transitional models and provide in-house manufactured, sterilizable patient-specific models for craniofacial reconstruction.

Three-Dimensional Soft Tissue Nasal Changes After Nasoalveolar Molding and Primary Cheilorhinoplasty in Infants With Unilateral Cleft Lip and Palate

OBJECTIVE

To quantify 3-dimensional (3D) nasal changes in infants with unilateral cleft lip with or without cleft palate (UCL±P) treated by nasoalveolar molding (NAM) and cheilorhinoplasty and compare to noncleft controls.

DESIGN

Retrospective case series of infants treated with NAM and primary cheilorhinoplasty between September, 2012 and July, 2016. Infants were included if they had digital stereophotogrammetric records at initial presentation (T1), completion of NAM (T2), and following primary cheilorhinoplasty (T3). Images were oriented in 3dMD Vultus software, and 16 nasolabial points identified.

PATIENTS

Twenty consecutively treated infants with UCL±P.

INTERVENTIONS

Nasoalveolar molding and primary cheilorhinoplasty.

MAIN OUTCOME MEASURES

Anthropometric measures of nasal symmetry and morphology were compared in the treatment group between time points using paired Student t tests. Postsurgical nasal morphology was compared to noncleft controls.

RESULTS

Nasal tip protrusion increased, and at T3 was 2.64 mm greater than noncleft controls. Nasal base width decreased on the cleft side by 4.01 mm after NAM and by 6.73 mm after cheilorhinoplasty. Columellar length of the noncleft to cleft side decreased from 2:1 to 1:1 following NAM. Significant improvements in subnasale, columella, and nasal tip deviations from midsagittal plane were observed. Treatment improved symmetry of the alar morphology angle and the nasal base-columella angle between cleft and noncleft sides.

CONCLUSIONS

Three-dimensional analysis of UCL±P patients demonstrated significant improvements in nasal projection, columella length, nasal symmetry, and nasal width. Compared to noncleft controls, nasal form was generally corrected, with overcorrection of nasal tip projection, columella angle, and outer nasal widths.

The First Year of Global Cleft Surgery Education Through Digital Simulation: A Proof of Concept

INTRODUCTION

Parallel to worldwide disparities in patient access to health care, the operative opportunities of surgical trainees are increasingly restricted across the globe. Efforts have been directed toward enhancing surgical education outside the operating room and reducing the wide variability in global trainee operative experience. However, high costs and other logistical concerns may limit the reproducibility and sustainability of nonoperative surgical education resources.

METHODS

A partnership between the academic, nonprofit, and industry sectors resulted in the development of an online virtual surgical simulator for cleft repair. First year global access patterns were observed.

RESULTS

The simulator is freely accessible online and includes 5 normal and pathologic anatomy modules, 5 modules demonstrating surgical markings, and 7 step-by-step procedural modules. Procedural modules include high-definition intraoperative footage to supplement the virtual animation in addition to include multiple-choice test questions. In its first year, the simulator was accessed by 849 novel users from 78 countries; 70% of users accessed the simulator from a developing nation.

CONCLUSION

The Internet shows promise as a platform for surgical education and may help address restrictions and reduce disparities in surgical training. The virtual surgical simulator presented may serve as the foundation for the development of a global curriculum in cleft repair.

The Effect of Nasoalveolar Molding on Nasal Airway Anatomy: A 9-Year Follow-up of Patients With Unilateral Cleft Lip and Palate

OBJECTIVE

To determine the effects of nasoalveolar molding (NAM) on nasal airway architecture.

DESIGN

Retrospective case-control study of patients with unilateral cleft lip treated with NAM vs without NAM.

SETTING

Tertiary referral center specializing in cleft and craniofacial care. Patients, Participants, and Interventions: Thirty-six patients with complete unilateral cleft lip and alveolus: 19 with NAM therapy and 17 without NAM therapy.

MAIN OUTCOME MEASURES

Cone beam computed tomography (CBCT) scans were compared in multiple coronal sections and were evaluated for linear and angular septal deviation, inferior turbinate hypertrophy, and linear and 2-dimensional airway area.

RESULTS

There were no significant differences in linear or angular septal deviation, inferior turbinate area, linear stenosis, or airway area between NAM- and non-NAM-treated patients.

CONCLUSIONS

NAM effectively molds the external nasal cartilage and structures but may have limited effects on internal nasal structures.

Dipyridamole enhances osteogenesis of three-dimensionally printed bioactive ceramic scaffolds in calvarial defects

PURPOSE

The objective of this study was to test the osteogenic capacity of dipyridamole-loaded, three-dimensionally printed, bioactive ceramic (3DPBC) scaffolds using a translational, skeletally mature, large-animal calvarial defect model.

MATERIALS AND METHODS

Custom 3DPBC scaffolds designed to present lattice-based porosity only towards the dural surface were either coated with collagen (control) or coated with collagen and immersed in a 100 μM concentration dipyridamole (DIPY) solution. Sheep (n = 5) were subjected to 2 ipsilateral trephine-induced (11-mm diameter) calvarial defects. Either a control or a DIPY scaffold was placed in each defect, and the surgery was repeated on the contralateral side 3 weeks later. Following sacrifice, defects were evaluated through microcomputed tomography and histologic analysis for bone, scaffold, and soft tissue quantification throughout the defect. Parametric and non-parametric methods were used to determine statistical significance based on data distribution.

RESULTS

No exuberant or ectopic bone formation was observed, and no histologic evidence of inflammation was noted within the defects. Osteogenesis was higher in DIPY-coated scaffolds compared to controls at 3 weeks (p = 0.013) and 6 weeks (p = 0.046) in vivo. When bone formation was evaluated as a function of defect radius, average bone formation was higher for DIPY relative to control scaffolds at both time points (significant at defect central regions at 3 weeks and at margins at 6 weeks, p = 0.046 and p = 0.031, respectively).

CONCLUSION

Dipyridamole significantly improves the calvarial bone regeneration capacity of 3DPBC scaffolds. The most significant difference in bone regeneration was observed centrally within the interface between the 3DPBC scaffold and the dura mater.

Nasal Septal Anatomy in Skeletally Mature Patients With Cleft Lip and Palate

IMPORTANCE

Septal deviation commonly occurs in patients with cleft lip and palate (CLP); however, the contribution of the cartilaginous and bony septum to airway obstruction in skeletally mature patients is poorly understood.

OBJECTIVES

To describe the internal nasal airway anatomy of skeletally mature patients with CLP and to determine the contributors to airway obstruction.

DESIGN, SETTING, AND PARTICIPANTS

This single-center retrospective review included patients undergoing cone-beam computed tomography (CBCT) from November 1, 2011, to July 6, 2015, at the cleft lip and palate division of a major academic tertiary referral center. Patients met inclusion criteria for the study if they were at least 15 years old at the time of CBCT, and images were used only if they were obtained before Le Fort I osteotomy and/or formal septorhinoplasty. Twenty-four skeletally mature patients with CLP and 16 age-matched control individuals were identified for the study.

MAIN OUTCOMES AND MEASURES

Septal deviation and airway stenosis were measured in the following 3 coronal sections: at the cartilaginous septum (anterior nasal spine), bony septum (posterior nasal spine), and midpoint between the anterior and posterior nasal spine. The perpendicular plate of the ethmoid bone and vomer displacement were measured as angles from the vertical plane at the coronal section of maximal septal deviation. The site of maximal septal deviation was identified.

RESULTS

Among the 40 study participants, 26 were male. The mean (SD) age was 21 (5) and 23 (6) years for patients with CLP and controls, respectively. Septal deviation in patients with CLP was significantly worse than that of controls at the anterior nasal spine (2.1 [0.5] vs 0.8 [0.2] mm; P < .05) and posterior nasal spine (2.9 [0.5] vs 1.0 [0.3] mm; P < .01) and most severe at the midpoint (mean [SD], 4.4 [0.6] vs 2.1 [0.3] mm; P < .01). The point of maximal septal deviation occurred in the bony posterior half of the nasal airway in 27 of 40 patients (68%). The CLP bony angular deviation from the vertical plane was significant in the CLP group compared with the control group (perpendicular plate of the ethmoid bone, 14° [2°] vs 8° [1°]; vomer, 34° [5°] vs 13° [2°]; P < .05 for both), and vomer deviation was significantly associated with anterior nasal airway stenosis (r = -0.61; P < .01).

CONCLUSIONS AND RELEVANCE

Skeletally mature patients with CLP have significant septal deviation involving bone and cartilage. Resection of the bony and cartilaginous septum should be considered at the time of definitive cleft rhinoplasty.

LEVEL OF EVIDENCE

NA.

The technique for 3D printing patient-specific models for auricular reconstruction

PURPOSE

Currently, surgeons approach autogenous microtia repair by creating a two-dimensional (2D) tracing of the unaffected ear to approximate a three-dimensional (3D) construct, a difficult process. To address these shortcomings, this study introduces the fabrication of patient-specific, sterilizable 3D printed auricular model for autogenous auricular reconstruction.

METHODS

A high-resolution 3D digital photograph was captured of the patient's unaffected ear and surrounding anatomic structures. The photographs were exported and uploaded into Amira, for transformation into a digital (.stl) model, which was imported into Blender, an open source software platform for digital modification of data. The unaffected auricle as digitally isolated and inverted to render a model for the contralateral side. The depths of the scapha, triangular fossa, and cymba were deepened to accentuate their contours. Extra relief was added to the helical root to further distinguish this structure. The ear was then digitally deconstructed and separated into its individual auricular components for reconstruction. The completed ear and its individual components were 3D printed using polylactic acid filament and sterilized following manufacturer specifications.

RESULTS

The sterilized models were brought to the operating room to be utilized by the surgeon. The models allowed for more accurate anatomic measurements compared to 2D tracings, which reduced the degree of estimation required by surgeons. Approximately 20 g of the PLA filament were utilized for the construction of these models, yielding a total material cost of approximately $1.

CONCLUSION

Using the methodology detailed in this report, as well as departmentally available resources (3D digital photography and 3D printing), a sterilizable, patient-specific, and inexpensive 3D auricular model was fabricated to be used intraoperatively. This technique of printing customized-to-patient models for surgeons to use as 'guides' shows great promise.

Outcome following Surgical Interventions for Micrognathia in Infants with Pierre Robin Sequence: A Systematic Review of the Literature

Background

Tongue-lip adhesion (TLA), mandibular distraction osteogenesis (MDO), and subperiosteal release of the floor of the mouth (SPRFM) are the most commonly performed surgical procedures to treat severe airway obstruction in infants born with Pierre Robin sequence (PRS).

Objectives

To determine the rate of failure of each type of procedure, in terms of mortality and the need for tracheostomy, and to determine what proportion of infants have significant airway obstruction postoperatively as determined by polysomnography (PSG) and compare the data by procedure type.

Method

A comprehensive literature search (1981 through June 2015) was done of the National Library of Medicine database using PubMed. Extracted data included diagnosis, type of surgery, and outcome including mortality, need for postoperative tracheostomy and details of PSG. Persistence of significant airway obstruction was defined as an apnea-hypopnea index > 15 events/h on PSG.

Results

Both mortality rate and need for tracheostomy were low for all procedures. Many studies lacked sufficient detail to identify significant airway obstruction postoperatively. In studies with sufficient data, MDO was associated with the lowest percentage of significant airway obstruction postprocedure (3.6%) compared to 50% for infants who underwent TLA. Insufficient PSG data was available for patients who were treated with SPRFM.

Conclusions

There is a paucity of objective PSG data to definitively assess postoperative airway outcomes for PRS. MDO appears to be the most effective technique based on the available PSG data. Standardized use of PSG may lead to better identification and treatment of patients at risk for suboptimal airway outcomes postoperatively.

Optimizing Safety of Iliac Bone Harvest Using an Acumed Drill: A Simulated Radiographic Study of 100 Patients

OBJECTIVE

To determine the potential risk of visceral injury during Acumed drill iliac crest cancellous bone graft harvest.

DESIGN

Radiographic iliac crest anatomic analysis with simulated drill course to measure cancellous bone available for harvest and proximity of vulnerable pelvic structures.

SETTING

Single institution, tertiary care university hospital.

PATIENTS AND PARTICIPANTS

One hundred pelvic computed tomography scans performed on children 8 to 12 years old without traumatic or neoplastic pathology.

INTERVENTIONS

Radiographic simulation of Acumed drill course within iliac bone.

MAIN OUTCOME MEASURES

(1) Potential for pelvic visceral injury. (2) Volume of cancellous bone safely available for harvest.

RESULTS

Superior and medial cortical thickness at the reference point remained stable across age groups; however, lateral cortical thickness increased with age (3.13 to 3.74 mm, P < .001). Cancellous bone width increased with age at all depths measured (P < .001). Through radiographic simulation, the drill could reach the bowel in 4% of cases and only through gross deviation (>30°) from the plane of the ilium. There were no cases of simulated bowel perforation within 3 cm of the reference point. The maximum cancellous volume safely harvested increased with age: 24 cc in 8-year-olds to 36 cc in 12-year-olds (P < .001).

CONCLUSIONS

Acumed assisted iliac crest bone graft harvest is a safe technique in which substantial amount of cancellous bone can be obtained. The low risk of bowel perforation can be further minimized by limiting the depth of drill bit penetration to less than 3 cm.

Epidemiology and cause-specific outcomes of facial fracture in hospitalized children

PURPOSE

Facial fractures in the pediatric population have a significant impact on public health. Although some demographic data exists regarding the overall epidemiology of facial fractures, little attention has been paid to the patterns of facial fractures based on the etiology of the trauma.

MATERIAL AND METHODS

The Kids' Inpatient Database 2000-2009 was utilized to analyze pediatric facial fractures. A total of 21,533 patients were identified. Associations of patient characteristics with outcomes of interest were assessed.

RESULTS

The top three etiologies were motor vehicle accident (MVA), intentional trauma (IT), and falls. There was a decrease in the incidence of facial fractures due to MVAs and an increase in injuries due to IT and falls. Concomitant injuries were present in 58.8% and the mortality rate was 2%. The rate of concomitant injuries increased during study period. Age was significantly associated with concomitant injury, mortality, and LOS.

CONCLUSION

The increasing rate of IT and falls with concomitant injury warrants special consideration to reduce undiagnosed accompanying injuries. Further programs should be put in place to protect children younger than 5 years of age, who have increased risk of concomitant injury and mortality following intentional trauma.

Spring-assisted cranial vault expansion in the setting of multisutural craniosynostosis and anomalous venous drainage: case report

Patients with multisutural craniosynostosis can develop anomalous venous connections between the intracranial sinuses and cutaneous venous system through enlarged emissary veins. Cranial vault remodeling in this subset of patients carries the risk of massive intraoperative blood loss and/or occlusion of collateral draining veins leading to intracranial venous hypertension and raised intracranial pressure, increasing the morbidity of cranial expansion. The authors report the use of spring-mediated expansion as a technique for cranial reconstruction in which the collateral intracranial venous drainage system can be preserved. A patient with bilateral lambdoid, sagittal, and unicoronal synostosis presented for cranial reconstruction. A tracheostomy and ventriculoperitoneal shunt were placed prior to intervention. At the time of reconstruction, a Luckenschadel skull abnormality and Chiari malformation Type I were present. A preoperative CT venogram demonstrated large collateral superficial occipital veins, small bilateral internal jugular veins, and hypoplastic jugular foramina. Collateral flow from the transverse and sigmoid sinuses through large occipital emissary veins was seen. Spring-mediated cranial vault expansion was performed with care to preserve the large collateral veins at the occipital midline. Four springs were placed at each lambdoid and the posterior and anterior sagittal sutures following 1-cm strip suturectomies. Removal of the springs was performed 2 months postoperatively. Cranial vault expansion was performed without disturbing the aberrant intracranial/extracranial venous collateral system. Estimated blood loss was 150 ml. A CT scan obtained 3 months postoperatively showed resolution of the Luckenschadel deformity and a 40% volumetric increase in the skull compared with the preoperative CT. Patients with anomalous venous drainage patterns and multisutural synostosis can undergo spring-mediated cranial vault expansion while preserving the major emissary veins draining the intracranial sinuses. Risks of blood loss, intracranial venous hypertension, and increased intracranial pressure may be decreased compared with traditional techniques of repair.