ORIGINAL ARTICLE

The Use of Brainlab Navigation in Le Fort III Osteotomy Jeyhan S. Wood, MD, Adam Purzycki, MD,y Jim Thompson, MD,y Lisa R. David, MD,y and Louis C. Argenta, MDy Abstract: Le Fort III osteotomy is commonly used in the surgical correction of midface hypoplasia, specifically in patients with syndromic craniosynostosis. These osteotomies can be associated with significant complications, which are often the result of incomplete or inaccurate osteotomies. Brainlab, a technology first developed for neurosurgery, has been applied to numerous surgical subspecialties. The aim of this study was to report our initial experience using the Brainlab VectorVision2 and Brainlab Curve (Brainlab, Westchester, IL) as an intraoperative guidance system for osteotomy placement during Le Fort III advancement. Three pediatric patients with syndromic craniosynostosis and midface hypoplasia scheduled to undergo Le Fort III advancement were scanned preoperatively with 0.6-mm computed tomography cuts, which were then uploaded to the Brainlab system. All surgeries commenced with rigid fixation of the Brainlab registration device to the patient’s skull. The navigation system was used intraoperatively to accurately determine osteotomy sites and trajectories. External distractors were placed without complication. Mean length of surgery was 331 minutes, and mean estimated blood loss was 500 mL. No transfusion was required with a mean postoperative hemoglobin of 8.3 g/dL. The application of Brainlab technology to Le Fort III advancement proved useful in establishing precise osteotomy lines and trajectories. Looking forward, this technology could be applied to a minimal dissection technique in order to avoid extensive blood loss. Further study would be needed to determine possible benefits such as reduced complications or operative time when using an intraoperative navigation system for image-guided osteotomy placement during Le Fort III advancement. Key Words: Brainlab, image guidance, navigated surgery, Le Fort III, osteotomy (J Craniofac Surg 2015;26: 616–619) What Is This Box? A QR Code is a matrix barcode readable by QR scanners, mobile phones with cameras, and smartphones. The QR Code links to the online version of the article.

From the Division of Plastic Surgery, University of North Carolina, Chapel Hill, Chapel Hill; and yDepartment of Plastic & Reconstructive Surgery, Wake Forest Baptist Health, Winston-Salem, NC. Received July 25, 2014. Accepted for publication January 15, 2015. Address correspondence and reprint requests to Lisa R. David, MD, Wake Forest Baptist Health, Department of Plastic & Reconstructive Surgery, Medical Center Blvd, Winston-Salem, NC 27157; E-mail: ldavid@ wakehealth.edu The authors report no conflict of interest. Copyright # 2015 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000001573

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e Fort III osteotomy is commonly used in the surgical management of patients with midface hypoplasia associated with syndromic craniosynostosis, such as those with Crouzon syndrome or Pfeiffer syndrome. Midface hypoplasia has multiple potential effects on the growing child, including upper airway obstruction, malocclusion, proptosis, and aesthetic appearance.1,2 These patients are at risk for sleep disordered breathing, such as obstructive sleep apnea, which can result in symptoms such as learning difficulties and memory loss in the short term.3 Untreated, obstructive sleep apnea can result in feeding difficulties, cognitive issues, and developmental delay. Ocular proptosis may lead to corneal ulceration, vision loss, and ocular subluxation in the most severe cases.1 Le Fort III midface advancement has been shown to decrease the risks of obstructive sleep apnea,4 proptosis, dental-skeletal malocclusions, and aesthetic problems associated with midface hypoplasia.5 Le Fort osteotomies can be associated with significant complications, which are often the result of incomplete or inaccurate osteotomies. Complications may involve infraorbital nerve injury, anosmia, localized infections, and eyelid ptosis.1 Major complications may include respiratory compromise, generalized infection, intracranial or extracranial hemorrhage, arteriovenous fistula formation,6,7 cerebrospinal fluid (CSF) leak secondary to fracture of the cribriform plate,8 and ophthalmic complications secondary to fractures involving the optic canal.1 One main precipitating factor for these potential complications is related to nasofrontal and pterygomaxillary dysjunction and the force required for downfracturing. Incomplete osteotomy of the pterygomaxillary junction is common, as this area is anatomically challenging to adequately visualize. If incomplete osteotomies are performed, significant force is required for pterygomaxillary separation, which can subsequently lead to significant hemorrhage from the internal maxillary artery or its branches. Matsumoto et al6 have reported a skull base fracture during Le Fort III osteotomy resulting in a massive subarachnoid hemorrhage causing a fatality, which was attributed to this forceful down-fracturing. Le Fort III advancement is not an inconsequential procedure, with a mean operative time of just under 5 hours and a mean estimated blood loss of just over 1 liter cited by Meling et al.2 Brainlab (Brainlab, Westchester, IL), a technology first developed to improve neurosurgical planning and navigation, has been applied to numerous surgical subspecialties, including trauma, head and neck, neurosurgery, orthopedic, and vascular surgery. Intraoperative navigation system use in neurosurgery is considered the criterion standard for craniotomy size and location determination of deep lesions to estimate extent of resection.9 The Brainlab navigation system has been shown to improve outcomes in orbital reconstruction surgery, reducing the need for repeat procedures and minimizing complications.10 It has also been shown to allow for accurate placement of pedicle screws for thoracolumbar spine fracture fixation.11 Intraoperative navigation has been used extensively in head and neck surgery, becoming an imperative technology for functional endoscopic sinus surgery.12 Brainlab has even been applied to the retrieval of traumatic foreign bodies in the maxillofacial region, in which minimally invasive techniques are optimal.13 Specifically, this technology has been shown to decrease

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Copyright © 2015 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.

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Volume 26, Number 3, May 2015

Le Fort III Osteotomy

FIGURE 1. Application of the skull reference base directly to the patient’s skull after raising the anterior skin flap.

overall operative time as well as intraoperative and postoperative complication rates.13 The aim of this study is to report our initial experience using the Brainlab VectorVision2 system and the Brainlab Curve system as an intraoperative guidance system for osteotomy placement during Le Fort III advancement.

MATERIALS AND METHODS Three pediatric patients with syndromic craniosynostosis and midface hypoplasia scheduled to undergo Le Fort III advancement were scanned preoperatively using a computed tomography (CT) scanner with 0.6-mm cuts. Brainlab CT scan protocol requires a slice thickness maximum of 2 mm. At our institution, a pediatric lowdose radiation protocol is used. All 3 patients had undergone previous frontal orbital advancement. These scans were uploaded to the Brainlab system preoperatively. The first 2 surgeries were performed with the guidance of the Brainlab VectorVision2, and the third surgery was performed with the Brainlab Curve, which offers an additional three-dimensional reconstruction view of the skull. On the day of surgery, the Brainlab machine is set up preoperatively by the technician in the operating room, with the patient’s preoperative maxillofacial CT uploaded and with the machine placed at the head of the patient’s bed. This process is complete by the time the patient is prepared and draped. The machine does not require additional time for warming up or for acquiring images. The patient is placed on a neuro-headrest in order to optimize access to the posterolateral scalp for registration device fixation. An oral RAE (Ring-Adair-Elwyn) tube is used for intubation. After induction of general anesthesia, the bed is turned 180 degrees. The head and face are prepared in their entirety with povidone-iodine (Betadine). For the first 2 surgeries, a small stab incision was made with a no. 15 blade in the posterolateral scalp posterior to the planned coronal incision. The Brainlab skull reference base was then rigidly secured to the calvarium with a single 1.8-mm self-tapping titanium screw. The hair was not shaved. For the third surgery, the skull registration device was rigidly fixated directly to the skull after raising the skin flaps anteriorly and slightly posteriorly (Fig. 1). The reference array is then secured to the base, being sure to strategically place this device with an unobstructed view of the Brainlab system. By placement of the skull registration base directly on the skull versus through the scalp, the device could be placed farther away from the edge of the bed, allowing more mobility of the head during surgery without impeding the required clear view of the device to the Brainlab tracking system. The Brainlab system is then calibrated to the specific patient using a specialized pointer tool. The available sagittal, coronal, axial, and three-dimensional reconstruction images displayed by the navigation system are used intraoperatively to accurately determine the osteotomy sites as well as the correct osteotomy trajectory (Fig. 2). Briefly, osteotomies #

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FIGURE 2. Intraoperative surgeon’s view of the patient’s images displayed on the Brainlab Curve monitor.

were made at the anterior zygomatic arch; at the pterygomaxillary junction; across the medial orbital wall, orbital floor, and lateral orbital wall; at the nasofrontal junction; and down the vomer. Any instrument, including an osteotome, is able to be registered to the Brainlab system by attaching a specialized device to the end of the chosen instrument that is then tracked and processed by the navigation system. After completion of the Le Fort III osteotomies by mallet and chisel as well as oscillating saw and midface advancement, the external distractor (BLUE Device; W. Lorenz Surgical, Jacksonville, FL) is applied in standard fashion. The skull reference base is removed simply by unscrewing the single screw. The stab incision through the scalp, when made, was closed with a single interrupted absorbable suture. The coronal incision was closed with absorbable suture in layered fashion after the placement of a 15F Blake drain.

RESULTS Three female patients underwent a Le Fort III osteotomy and placement of an external distractor at the average age of 12 years (range, 9–14 years). Two patients had Pfeiffer syndrome and the third Crouzon syndrome. Using the axial, sagittal, and coronal views of the patient, as well as the three-dimensional reconstruction offered on the Brainlab screen, Brainlab was used intraoperatively to help determine osteotomy trajectories. All surgeries were completed without complication. Mean length of surgery was 331 minutes (range, 304–379 minutes), with a mean estimated blood loss of 500 mL. No transfusion was required with a mean postoperative hemoglobin of 8.3 g/dL. Patients stayed in the hospital an average of 7.3 days (range, 5–10 days).

DISCUSSION Le Fort III osteotomies are needed in cases of severe dysmorphology that is both congenital and a result of previous surgery such as fronto-orbital advancement. Abnormal osseous structure, previously created osseous defects, and abnormal growth patterns combined with abnormal anatomy lead to difficult visualization and localization for surgery, which increases complication risk. Many complications associated with Le Fort osteotomies have been reported in the literature,6,8,14–16 the best documented being with Le Fort I osteotomy with an incidence of 6% to 9%.6,17 The complications associated with Le Fort osteotomies may include hemorrhage,18 arteriovenous fistula formation, ophthalmic symptoms including blindness,14,17 vision impairment19 and cranial nerve palsies, dural tears leading to CSF leak,8 and even death.1,6 These complications are primarily attributed to unexpected skull

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base fractures, which are often related to forceful down-fracture manipulation with incomplete or malpositioned osteotomies. Morbidity is most frequently reported with the osteotomy at the pterygomaxillary junction. This region is highly vascularized, and the main trunk of the maxillary artery and its branches are at risk of injury, given their close approximation to the osteotomy site. In a cadaver study, Apinhasmit et al20 found that the margin of safety from the superior cutting edge of a 15-mm osteotome to the maxillary artery is 8 mm in adults. In addition, because of the intimate anatomic relationship that exists between the pterygoids, palatine bones, sphenoid bones, and optic canal, visual symptoms may result not only from a small amount of hemorrhage or edema in the area, but also from the propagation of force from aggressive down-fracturing of the maxilla to the optic canal, leading to possible injury of the optic nerve’s perineural circulation.17 In a cadaver study, Herford et al21 found the tensile force required to separate the pterygomaxillary junction with complete Le Fort III osteotomies was 28 lb, which increased to an average of 75 lb with incomplete osteotomies. Precise placement and correct orientation of the osteotome are key for minimizing collateral damage. Several modified techniques for obtaining ideal separation at the pterygomaxillary junction have been described in the literature, using different surgical approaches and different instruments.6,22 Despite these advances, unfavorable dysjunction leading to unpredictable fracture of the pterygoid plate can occur. In a study by Renick and Symington22 looking at 12 consecutive patients undergoing Le Fort I osteotomy, an unintentional high- or low-level pterygoid plate fracture occurred in 62.5%, which were identified by postoperative CT. While none of the fractures in this study resulted in a postoperative complication, these unfavorable fractures of the pterygoid plate, particularly the high-level fractures, have the potential to cause untoward fractures that may be associated with devastating complications by extending through the sphenoid bone and skull base.6,17,23 Patients with syndromic craniosynostoses have been found to be at a particularly high risk of these skull base fractures because they have a well-described dysmorphic cranial base.1,6,8,19,24 These patients have an inferiorly displaced anterior cranial base and often short nasal bones, which must be accounted for when planning the nasofrontal dysjunction.1,8 Otherwise, unintentional fracture of the cribriform plate with resultant CSF leak or even meningoencephalocele may occur.8 In addition, dysmorphic patients may have an expanded middle cranial fossa affecting the anatomic position of the sphenoid bones and a small posterior fossa.24 As seen in our cohort of patients, many patients with syndromic craniosynostoses undergoing midface advancement have undergone previous reconstructive procedures, including frontal orbital advancement, which also alters the expected anatomy of the anterior cranial base surrounding the nasofrontal suture. Using Brainlab, the appropriate positioning and trajectory of the nasofrontoethmoidal osteotomy to avoid the inferiorly displaced fovea ethmoidalis, cribriform plate, and anterior cranial base can be determined under direct visual guidance (Fig. 3). Brainlab is also useful in performing osteotomies within the malformed orbit, particularly behind the nasolacrimal apparatus. Positioning of the chisel saw is greatly facilitated using Brainlab while avoiding extensive disruptive exposure in this difficult area. Osteotomies of the posterior lateral maxillary wall can be positioned more accurately. Retro displacement of the maxilla results in compression and distortion of this area, which is difficult to visualize even with extensive dissection. Chisels can be advanced in the posterior lateral maxillary wall more accurately with Brainlab, thus minimizing potential soft tissue bleeding. Although this study was not designed to assess the effect of an intraoperative navigation system on operative time, one could

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FIGURE 3. Use of a registered osteotome for the nasofrontal dysjunction (top) projects the planned trajectory of the osteotomy in all 3 views as well as on the three-dimensional model (bottom).

hypothesize that once the learning curve was completed, then using Brainlab would decrease operative time. This has been reported in the trauma literature.13 Grobe et al13 found that by using Brainlab for the localization of foreign bodies after gunshot wounds in the maxillofacial region, operative time was decreased consistently during the 32 navigated procedures versus the 18 non-navigated procedures. Furthermore, there was a significant correlation between navigated surgery and non-navigated surgery and complication rate and a significant correlation between operative time and postoperative complications.13 For our 3 patients, average operative time was 331 minutes. Prior to Brainlab, our average operating time for these cases was 324 minutes. One could assume we have not completed the learning curve with only 3 patients. In addition, a different Brainlab system was introduced for the third case. Considering the average hospital operating room fee, including the average anesthesiologist professional fee, is $66 per minute,25 and the cost of using the Brainlab system is fixed to the patient at our institution at $1253.75, this could lead to a substantial savings once the learning curve has been completed. The learning curve for this technology as applied to craniofacial surgery has not yet been defined. Radiation exposure in children is a very important topic. Our institution utilizes a pediatric low-dose radiation CT scan protocol. A pediatric protocol is advocated in order to minimize ionizing radiation exposure to the child,26 as high cumulative radiation doses have been associated with an increased risk of leukemia and brain tumor development.27 The use of Brainlab for intraoperative #

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guidance does not expose the patient to any additional radiation; a single craniomaxillofacial CT scan is required.

CONCLUSIONS Complications from Le Fort III osteotomies, although uncommon, can be devastating and are well described in the literature. Application of Brainlab technology to determine correct osteotome positioning and trajectory during Le Fort osteotomy is an adjunct to the craniofacial surgeon’s armamentarium of techniques to potentially improve safety and precision of this widely practiced procedure, especially in those patients with syndromic craniosynostoses with a dysmorphic cranial base. We found this to be most useful at the pterygomaxillary junction, nasofrontal junction, and within the lacrimal fossa. Looking forward, this technology could be applied to a minimal dissection technique in order to avoid extensive blood loss. Long-term potentials of surgical techniques with accurate positioning devices such as Brainlab are many. With appropriate endoscopes, osteotomies in combination with the Brainlab may facilitate Le Fort III procedures by minimizing extensive time consuming exposure techniques. This would also minimize bleeding, postoperative dead space, and infection risk. Further study would be needed to determine possible benefits such as reduced complications or operative time when using an intraoperative navigation system for image-guided osteotomy placement during Le Fort III advancement.

REFERENCES 1. Nout E, Cesteleyn LL, van der Wal KG, et al. Advancement of the midface, from conventional Le Fort III osteotomy to Le Fort III distraction: review of the literature. Int J Oral Maxillofac Surg 2008;37:781–789 2. Meling TR, Hogevold HE, Due-Tonnessen BJ, et al. Comparison of perioperative morbidity after Le Fort III and monobloc distraction osteogenesis. Br J Oral and Maxillofac Surg 2011;49:131–134 3. Sinha D, Guilleminault C. Sleep disordered breathing in children. Indian J Med Res 2010;131:311–320 4. Bouchard C, Troulis MJ, Kaban LB. Management of obstructive sleep apnea: role of distraction osteogenesis. Oral Maxillofac Surg Clin North Am 2009;21:459–475 5. Iannetti G, Fadda T, Agrillo A, et al. Le Fort III advancement with and without osteogenesis distraction. J Craniofac Surg 2006;17:536–543 6. Matsumoto K, Nakanishi H, Seike T, et al. Intracranial hemorrhage resulting from skull base fracture as a complication of Le Fort III osteotomy. J Craniofac Surg 2003;14:545–548 7. Lanigan DT, Hey JH, West RA. Major vascular complications of orthognathic surgery: false aneurysms and arteriovenous fistulas following orthognathic surgery. J Oral Maxillofac Surg 1991;49:571– 577 8. Ridgway E, Robson C, Padwa B, et al. Meningoencephalocele and other dural disruptions: complications of Le Fort III midfacial osteotomies and distraction. J Craniofac Surg 2011;22:182–186 9. Kockro RA, Reisch R, Serra L, et al. Image-guided neurosurgery with 3dimensional multimodal imaging data on a stereoscopic monitor. Neurosurgery 2013;72 (suppl 1:):78–88

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10. Cai EZ, Koh YP, Hing EC, et al. Computer-assisted navigational surgery improves outcomes in orbital reconstructive surgery. J Craniofac Surg 2012;23:1567–1573 11. Fan Chiang CY, Tsai TT, Chen LH, et al. Computed tomography–based navigation-assisted pedicle screw insertion for thoracic and lumbar spine fractures. Chang Gung Med J 2012;35:332–338 12. Stelter K, Andratschke M, Leunig A, et al. Computer-assisted surgery of the paranasal sinuses: technical and clinical experience with 368 patients, using the Vector Vision Compact( system. J Laryngol Otol 2006;120:1026–1032 13. Grobe A, Weber C, Schmelzle R, et al. The use of navigation (BrainLAB Vector vision2) and intraoperative 3D imaging system (Siemens Arcadis Orbic 3D) in the treatment of gunshot wounds of the maxillofacial region. Oral Maxillofac Surg 2009;13:153–158 14. Lo LJ, Hung KF, Chen YR. Blindness as a complication of Le Fort I osteotomy for maxillary distraction. Plast Reconstr Surg 2002;109: 688–698 15. Cruz AA, Santos AC. Blindness after Le Fort I osteotomy: a possible complication associated with pterygomaxillary separation. J Craniomaxillofac Surg 2006;34:210–216 16. Kim JW, Chin BR, Park HS, et al. Cranial nerve injury after Le Fort I osteotomy. Int J Oral Maxillofac Surg 2011;40:327–338 17. Girotto JA, Davidson J, Wheatly M, et al. Blindness as a complication of Le Fort osteotomies: role of atypical fracture patterns and distortion of the optic canal. Plast Reconstr Surg 1998;102:1409–1421 18. Lanigan DT, Hey JH, West RA. Major vascular complications of orthognathic surgery: hemorrhage associated with Le Fort I osteotomies. J Oral Maxillofac Surg 1990;48:561–573 19. Vyas RM, Keagle JN, Wexler A, et al. Unilateral vision impairment from a carotid-cavernous fistula after a monobloc osteotomy in a patient with Apert syndrome. J Craniofac Surg 2007;18:960–965 20. Apinhasmit W, Methathrathip D, Ploytubtim S, et al. Anatomical study of the maxillary artery at the pterygomaxillary fissure in a Thai population: its relationship to maxillary osteotomy. J Med Assoc Thai 2004;87:1212–1217 21. Herford AS, Finn R, Tharanon W, et al. Anatomical studies: tension forces in relation to Le Fort III osteotomies. J Craniofac Surg 2000;11:197–202 22. Renick BM, Symington JM. Postoperative computed tomography study of pterygomaxillary separation during the Le Fort I osteotomy. J Oral Maxillofac Surg 1991;49:1061–1065 23. Akita S, Mitsukawa N, Komiyama M, et al. Anatomical study using cadavers for imaging of life-threatening complications in Le Fort III distraction. Plast Reconstr Surg 2013;131:19e–27e 24. Tokumaru AM, Barkovich AJ, Ciricillo SF, et al. Skull base and calvarial deformities: association with intracranial changes in craniofacial syndromes. Am J Neuroradiol 1996;17:619–630 25. Shippert RD. A study of time-dependent operating room fees and how to save $100,000 by using time-saving products. Am J Cosmet Surg 2005;22:25–34 26. Morton RP, Reynolds RM, Ramakrishna R, et al. Low-dose head computed tomography in children: a single institutional experience in pediatric radiation risk reduction. J Neurosurg Pediatrics 2013;12:406–410 27. Pearce MS, Salotti JA, Little MP, et al. Radiation exposure from CT scans in childhood and subsequent risk of leukaemia and brain tumours: a retrospective cohort study. Lancet 2012;380:499–505

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The Use of Brainlab Navigation in Le Fort III Osteotomy.

Le Fort III osteotomy is commonly used in the surgical correction of midface hypoplasia, specifically in patients with syndromic craniosynostosis. The...
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