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Background: When performing a craniotomy involving the orbital bar, the supraorbital notch is a potential landmark to localize the lateral extent of the frontal sinus. Avoidance of the frontal sinus is important to reduce the risk of postoperative surgical site infection, epidural abscess formation, and mucocele development., Objective: To determine the reliability of the supraorbital notch as a marker of the lateral location of the frontal sinus., Methods: Cadaveric dissections were used with image guidance software to define the relationship between the frontal sinus and supraorbital foramen., Results: The supraorbital notch was located 2.54 cm from midline and the lateral extent of the frontal sinus extended 2.84 mm lateral to the supraorbital notch. When performing a craniotomy extending medially to the supraorbital notch at a perpendicular angle, the frontal sinus was breached in 65% of craniotomies. When the craniotomy ended 10 mm lateral to the supraorbital notch, the rate of frontal sinus breach decreased to 10%., Conclusion: When performing a craniotomy involving the supraorbital notch, a lateral to medial trajectory that ends 15 mm to the supraorbital notch will minimize the risk of frontal sinus violation., (Copyright © 2018 by the Congress of Neurological Surgeons.)

Background: Open transcranial approaches to the anterior skull base remain an integral component of current skull base practice. Evolution of these and other techniques has resulted in revisions of standard, tried-and-true methods in attempts to improve patient outcomes and cosmesis, while still providing the best combination of surgical exposure and ergonomics., Objective: To describe a modified approach for midline tumors of the anterior skull base., Methods: We describe the anatomy and techniques of a modified extended bifrontal craniotomy for anterior skull base tumors. Case examples and a postoperative 3-dimensional computed tomographic reconstruction of the craniotomy are provided., Results: The technique has been employed with success in 3 tuberculum sellae meningiomas where the anterior limit of the tumor is several centimeters back from the inner table of the frontal bone. The mean distance from the tumor to inner table was 2.8 cm (range 1.3-3.8 cm). Mean tumor dimensions were 3.0 cm (transverse), 3.5 cm (anterior-posterior), and 2.2 cm (craniocaudal). Average operative time was 557 min. No cases had new T2/fluid-attenuated inversion recovery magnetic resonance imaging signal of the inferior frontal lobe to indicate retraction injury., Conclusion: The tailored extended bifrontal craniotomy for anterior skull base tumors provides adequate access to the anterior cranial fossa and has replaced our standard extended bifrontal approach. Keeping the osteotomy cut lines outside of the orbit reduces orbital swelling and mechanical disruption of conjugate eye movements in the early postoperative period, while allowing for minimal frontal lobe retraction and providing sufficient surgical exposure along the anterior skull base.

Background: Fronto-orbital advancement is a procedure commonly performed in craniofacial centers for coronal and metopic suture synostosis. Several variations of the technique have been reported., Objective: To describe our modifications to the anterior cranioplasty procedure and the results of our surgical series., Methods: Using our craniofacial database, we retrospectively analyzed the records of all patients undergoing fronto-orbital advancement for craniosynostosis. The same team of neurosurgeons and plastic surgeons performed all procedures. Demographic data, operative time, blood loss, length of stay, and clinical outcome were analyzed., Results: Of 248 patients treated for craniosynostosis, a total of 70 patients underwent fronto-orbital advancement. Nineteen presented with metopic, 26 with unilateral coronal, 17 with bilateral coronal, and 8 with multiple synostosis. Median age at surgery was 6.5 months. Mean operative time was 210 minutes; mean blood loss was 167 mL; and length of stay was 4.5 days. A positive correlation was found between operative time and blood loss (r = 0.1, P < .01) and age at surgery and blood loss (r = 0.3, P < .0001). There was a minor morbidity rate of 2.9%. A good reconstruction was obtained in all patients using our en bloc fronto-orbital advancement without any midline osteotomies at a mean follow-up of 15 months., Conclusion: A team approach and the application of a standardized surgical technique should make it safer to operate in young children, shorten the surgical time, and lead to a reduction in blood loss. Reconstructing the frontal bone as an entire unit yielded excellent correction for coronal and metopic synostosis.

Background: Precise placement of the MacCarty keyhole, a burr hole simultaneously exposing the anterior cranial fossa floor and orbit, provides accurate, efficient entry for orbitozygomatic and supraorbital craniotomies. To locate the optimal keyhole site, previous studies have used superficial landmarks that, in our experience, are not always visible or consistent on older crania., Objective: Therefore, we present a technique for accurate keyhole placement using landmarks that are easily visible across age ranges., Methods: From inside the cranium, 1-mm burr holes were placed along the anterior junction of the floor and lateral wall of the anterior cranial fossa in 50 adult skulls (100 sides, with calvaria removed). Additionally, from inside the orbit, 1-mm burr holes were placed into the lateral orbital roof. Exit sites of intracranial and intraorbital burr holes were referenced to the frontozygomatic suture. The center of the site between the exiting intracranial and intraorbital holes was deemed the best location for the keyhole., Results: The keyhole center was 6.8 mm (mean) superior and 4.5 mm (mean) posterior to the frontozygomatic suture, which was easily identified on all specimens. Although this keyhole center was slightly more superior on right sides than left, this was not statistically significant. In a minority of specimens, the keyhole was located near the meningo-orbital foramen (22%) and the lateral extent of the frontal sinus (2%)., Conclusions: We defined an alternative method for locating the MacCarty keyhole, based on a reliable external landmark, approximately 7 mm superior and 5 mm posterior to the frontozygomatic suture.

Background: The transciliary supraorbital approach (TCSO) provides an anterior view for visualizing sellar, parasellar, and suprasellar structures. Whether an orbital osteotomy adds to this exposure has not been quantified., Objective: We quantitatively evaluated the TCSO and benefits of an additional orbital osteotomy for exposing common sites of anterior circulation aneurysms., Methods: Under image guidance, TCSO and orbital osteotomy were performed on 10 sides of 5 cadaver heads to quantify exposures of 4 surgical targets: (1) the junction of the anterior cerebral and anterior communicating arteries (ACoA); (2) the internal carotid artery (ICA) at the level of the posterior communicating artery (PCoA); (3) the bifurcation of the ICA; and (4) the middle cerebral artery (MCA) bifurcation. Horizontal and vertical angles of attack and surgical freedom for instrument manipulation were measured before and after the orbital rim and roof were removed., Results: An orbital osteotomy significantly increased surgical freedom to the ACoA (from 471.15 +/- 182.14 mm2 to 683.35 +/- 283.78 mm2, P = .021); PCoA (from 746.58 +/- 242.78 mm2 to 966.23 +/- 360.22 mm2, P = .007); ICA bifurcation (from 616.08 +/- 310.95 mm2 to 922.38 +/- 374.88 mm2, P = .002); and MCA bifurcation (from 1160.77 +/- 412.03 mm2 to 1597.71 +/- 733.18 mm2, P = .004). There were no significant differences in horizontal angles of attack. The vertical angles of attack were significantly greater after orbital osteotomy, principally with the ACoA and ICA bifurcation as targets., Conclusion: TCSO combined with orbital osteotomy improves exposure. Removing the orbital rim and roof increases the area for instrument use and improves the vertical angle of attack to common sites in the anterior circulation involving aneurysms.

Objective: We introduce a technique for performing a selective amygdalohippocampectomy (AH) through a minisupraorbital approach., Methods: A minisupraorbital craniotomy and an anterior selective AH were performed in 8 cadaver heads (16 sides). The anatomic specimens were analyzed, and the extent of resection of the hippocampus and amygdala was evaluated. Surgically relevant measurements were performed using anatomic specimens. An image-guided system was used to document the extent of the anterior AH. Laboratory data were used to support the clinical application of the technique., Results: The anterior route allowed removal of the amygdala and hippocampus, as confirmed by anatomic assessment. The image-guided system and anatomic evaluation confirmed that the amygdala and hippocampus can be accessed and removed through this route. The mean distance between the anterior aspect of the uncus and the tip of the temporal horn was 17.0 +/- 4.6 mm; the mean distance from the head of the hippocampus to the posterior border of the cerebral peduncles was 26.0 +/- 3.2 mm. Clinical application resulted in satisfactory removal of the amygdala and hippocampus., Conclusion: The anterior route for selective AH is a logical and straightforward approach to the mesial temporal lobe. Compared with other variations, it is less invasive and destructive, especially in terms of the fibers of the optic pathway, temporal stem, and lateral temporal neocortex.

Objective: To describe the technical details of a 3-piece orbitozygomatic approach., Introduction: In a 3-piece orbitozygomatic approach, soft tissue exposure is mostly comparable to the classic frontopterional approach. Osseous resection is a 3-piece operation that consists of first performing anterior and posterior cuts along the zygomatic arch, reflecting it down, attached to the masseter. This is followed by a classic frontotemporosphenoidal craniotomy, and finally, an osteotomy of the orbital rim, roof, and lateral wall of the orbit., Results: When compared with its 1- and 2-piece counterparts, 3-piece orbitozygomatic craniotomy, as described here, is a relatively simple operation and is thus advisable when considering an anterior or middle fossa approach. Brain exposure is wide, whereas cerebral retraction is minimal. We recommend avoiding orbit sectioning as deep as the superior orbital fissure., Conclusion: The modifications described herein show the technical features of the 3-piece orbitozygomatic approach, which provides excellent brain exposure with less retraction and a good cosmetic result.

Objective: The lateral supraorbital approach for safely and completely removing olfactory groove meningiomas was assessed., Methods: Between September 1997 and June 2008, a total of 656 meningiomas were operated on by the senior author (JH) at the Department of Neurosurgery, Helsinki University Central Hospital; 66 were olfactory meningiomas. We retrospectively analyze the clinical data, radiological findings, surgical treatment, histology, and outcome of all the olfactory groove meningioma patients and discuss the operative techniques used., Results: Sixty-six patients were operated on by the lateral supraorbital approach. The median preoperative Karnofsky Performance Scale score was 80 (range, 40-100). Three patients were redo cases in which the primary operation had been performed elsewhere. Seemingly complete tumor removal was achieved in 60 patients (91%); there was no surgical mortality. Postoperatively, 6 patients (9%) had cerebrospinal fluid leakage, 5 (8%) had new visual deficits, 4 (6%) had wound infections, 4 (6%) had cotton granulomas, and 1 (2%) had a postoperative hematoma. The median Karnofsky score at discharge was 80 (range, 40-100). Six patients had recurrent tumors; 3 underwent reoperations after an average of 21 months (range, 1-41 months); 1 was treated with radiosurgery, and 2 were only followed. During the median follow-up time of 45 months (range, 2-128 months), there were 4 recurrences (6%) diagnosed on average 32 months (range, 17-59 months) after surgery., Conclusion: The lateral supraorbital approach can be used safely for olfactory groove meningiomas of all sizes with no mortality and relatively low morbidity. Surgical results and tumor recurrence with this fast and simple approach are similar to those obtained with more extensive, complex, and time-consuming approaches.

Objective: Several variations on the supraorbital craniotomy via a forehead or eyebrow incision have been described in the literature in recent years. A modification of this approach, the transciliary orbitofrontozygomatic approach, has been used by the authors as a minimally invasive method of approaching certain intracranial pathologies. The authors present their experience with this technique in 105 consecutive patients with tumors or aneurysms of the anterior cranial fossa., Methods: A transciliary keyhole approach was used in all cases. From June 1998 to June 2005, 37 tumors, 1 cavernous malformation, and 77 anterior circulation aneurysms were treated (67 females, 38 males; age range, 8-77 years) with an orbitofrontozygomatic approach via an eyebrow incision. Patients were followed by the authors at a single institution for 1 year postoperatively., Results: Of the 105 patients treated with a transciliary orbitofrontozygomatic approach, 2 (1.9%) developed a cerebrospinal leak. Two other patients (1.9%) very early in the series had persistent forehead asymmetry at 1 year postoperatively. Two patients who underwent surgery for a ruptured aneurysm experienced an intraoperative rupture, which was thought to be unrelated to the exposure. None of the operations had to be converted to a pterional craniotomy., Conclusion: This approach was used in 105 consecutive patients who underwent operation for either tumors or aneurysms via an eyebrow incision. The transciliary orbitofrontozygomatic approach is associated with low surgical morbidity. Although experience with this technique is still limited, it is a viable alternative in cases in which the pathology resides in the midline or anterior fossa.

Objective: Endonasal and supraorbital "eyebrow" craniotomies are increasingly being used to remove craniopharyngiomas and tuberculum sellae meningiomas. Herein, we assess the relative advantages, disadvantages, and selection criteria of these 2 keyhole approaches., Methods: All consecutive patients who had endonasal or supraorbital removal of a craniopharyngioma or tuberculum sellae meningioma were analyzed., Results: Of 43 patients, 22 had a craniopharyngioma (18 endonasal, 4 supraorbital), and 21 had a meningioma (12 endonasal, 7 supraorbital, 2 both routes); 33% had prior surgery. Craniopharyngiomas were primarily retrochiasmal in location in 78% of endonasal cases versus 25% of supraorbital cases (P = 0.08). Meningiomas were larger when approached by the supraorbital route versus the endonasal route (33 +/- 10 versus 25 +/- 8 mm, respectively; P = 0.008). Endoscopy was used in 84% of endonasal approaches and in 31% of supraorbital approaches (P = 0.001). Of patients having first-time surgery for a craniopharyngioma (n = 14) or meningioma (n = 15), total/near total removal was achieved in 83% and 80% of patients by the endonasal route and in 50% and 80% of patients by the supraorbital route, respectively. Vision improved in 87% and 70% of patients who had surgery by an endonasal versus supraorbital route, respectively (P = 0.3). Visual deterioration occurred in 2 patients with meningiomas, 1 by endonasal (7%), and 1 by supraorbital (11%) removal. The endonasal approach was associated with a higher rate of postoperative cerebrospinal fluid leaks (16 versus 0%; P = 0.3), 4 of 5 of which occurred in patients with meningioma., Conclusion: The endonasal route is preferred for removal of most retrochiasmal craniopharyngiomas, whereas the supraorbital route is recommended for meningiomas larger than 30 to 35 mm or with growth beyond the supraclinoid carotid arteries. For smaller midline tumors, either approach can be used, depending on surgeon experience and tumor anatomy. Compared with traditional craniotomies, the major limitation of both approaches is a narrow surgical corridor. The endonasal approach has the added challenges of restricted lateral suprasellar access, a greater need for endoscopy, and a more demanding cranial base repair.

Objective: Olfactory groove meningiomas account for 8 to 13% of all intracranial meningiomas. Surgical removal is often performed through the bifrontal, unilateral subfrontal (frontolateral), or pterional approach. We report on the clinical outcome and recurrence rate after surgical treatment of olfactory groove meningiomas in our neurosurgical department., Methods: A retrospective study was conducted by analyzing the charts of the patients, including surgical records, discharge letters, histological records, follow-up records, and imaging studies., Results: A total of 1800 meningiomas were operated on between 1978 and 2002 in our department. There were 82 patients with olfactory groove meningiomas, including 63 women and 19 men with a mean age of 57.8 years (age range, 33-91 yr). Most patients presented with mental disturbance. Tumors were operated through the bifrontal (n = 46), frontolateral (n = 34), and pterional (n = 2) approaches. Total tumor removal (Simpson Grade 1 or 2) was achieved in most cases (91.2% frontolateral, 93.5% bifrontal). Perioperative mortality was 4.9% (four out of 82 patients, all operated through the bifrontal approach). The overall recurrence rate was 4.9%, with four patients requiring surgery. The mean follow-up period was 63.4 months (range, 4-270 mo)., Conclusion: Olfactory groove meningiomas were removed mainly through two different surgical approaches. Even in large tumors, high rates of total tumor resection could also be achieved with low recurrence rates using the simple and minimally invasive frontolateral approach. In recent years, we have preferred to use the frontolateral approach, which provides quick access to the tumor with less brain exposure while still enabling total tumor removal with a low morbidity rate and no mortality.

Objective: Many approaches have been recommended for the surgical treatment of anterior and middle cranial fossa lesions. The frontobasal approach and its many modifications have been proposed and developed for such situated lesions. An alternative approach is the frontolateral craniotomy through a supraciliary skin incision., Methods: This minimally invasive technique, a 2.5 x 3.0 cm craniotomy, just above the eyebrow through a supraciliary incision, is a simple but elegant modification of the traditional approach to the anterior cranial fossa., Results: A step-by-step description of the approach is offered in this report to facilitate a clear understanding of the lesions treatable with this minimally invasive technique., Conclusion: The supraciliary frontolateral keyhole craniotomy is a minimally invasive cosmetic approach that provides excellent exposure to a variety of intracranial lesions. This approach cannot be used for all intracranial pathologies, but is recommended for many anterior and middle cranial fossa lesions.

Objective: To evaluate the efficacy of the combination of an extensive surgical debridement and simultaneous free flap repair in case of troublesome cranial osteomyelitis., Methods: Five patients with persistent, frontal bone osteomyelitis were treated with surgical debridement of the infected bone and reconstruction with a free flap. In all patients, osteomyelitis occurred after neurosurgical procedures and lasted from 1 to 7 years. A latissimus dorsi muscle flap with a split skin graft has been performed., Results: No flap failure occurred and donor site morbidity was negligible. No signs of osteomyelitis or soft tissue infection were observed during the mean follow-up period of 3.2 years. Furthermore, the contour of the cranium could be preserved without a need for bone grafts or implants., Conclusion: In our experience, the combination of an extensive surgical debridement and a free flap transfer is demonstrated to be an effective treatment for "chronic" osteomyelitis of the cranium.

Objective and Importance: Aneurysms of the paraclinoid segment arising from the anterolateral wall of the proximal internal carotid artery (ICA) are usually located in the intradural space, and the proximal neck of the aneurysm is closely adjacent to the dural ring. Although most of these aneurysms can be identified by cerebral angiography, the top of the aneurysm can be flattened because of its relationship to the undersurface of the clinoid process. We report a rare case of a ruptured ICA anterolateral wall aneurysm that was not identified by initial angiography but was clearly observed at the time of vasospasm., Clinical Presentation: A 59-year-old female patient was transferred to our hospital because of sudden loss of consciousness. Initial angiography failed to disclose any aneurysm except for one projecting to the right at the C3-C4 portion of the left ICA. A left frontotemporal craniotomy with drilling of the anterior clinoid process was performed 1 day after the onset of subarachnoid hemorrhage. Within the operative field, however, no hemorrhage was detected near the C3-C4 portion of the left ICA. Subsequent angiography performed during vasospasm clearly demonstrated a ruptured aneurysm in the anterior paraclinoid segment of the right ICA., Intervention: After drilling the anterior clinoid process and cutting the dural ring, we successfully clipped the aneurysm. The aneurysm was saccular, with a broad neck that extended below the dural ring. Intraoperative inspection demonstrated that the dome of the aneurysm was in a subclinoid location, suggesting that most of the aneurysm might have been flattened by the dural ring at the time of initial angiography but before the onset of vasospasm., Conclusion: The presented case suggests that this type of aneurysm may be missed by routine angiography performed before and after vasospasm. If initial angiography fails to reveal the origin of the subarachnoid hemorrhage but computed tomography still discloses hemorrhage from an ICA aneurysm, repeated angiography should be considered within 14 days after the onset of subarachnoid hemorrhage to confirm whether the aneurysm has arisen from the anterior clinoid segment of the ICA.

Objective: To describe the advantages of a modification of the standard fronto-orbitotemporozygomatic (FOTZ) approach, consisting of the forced opening of the patient's mouth (open-mouth FOTZ), for the treatment of benign tumors massively involving the splanchnocranium and neurocranium., Methods: The modified FOTZ approach obtained by forced mouth opening is described. Such a procedure was introduced with the aim of obtaining a minimally invasive access to lesions involving both the infratemporal-parapharyngeal spaces and the anteromedial cranial fossae. The forced opening of the mouth allows the surgeon to keep the coronoid process of the mandible away from the operating field, producing a wide exposure of the infratemporal space like that of the posterior wall of the maxillary sinus, which can be penetrated from behind without adding destructive procedures on the mandibular bone., Results: From a series of 45 patients affected by cranial base lesions operated on during an 8-year time period, three patients affected by juvenile nasopharyngeal angiofibromas were selected for an open-mouth FOTZ approach. In all cases, a complete eradication of both the intracranial and extracranial components of the tumor was possible by this approach. The same procedure was then used in four patients affected by extensive meningiomas and two patients harboring Vth cranial nerve schwannomas, with complete tumor removal., Conclusion: In our experience, the open-mouth FOTZ approach seems particularly suited for extensive benign tumors (including juvenile nasopharyngeal angiofibromas) with splanchnocranial and neurocranial involvement. No indication exists for the use of this approach in malignant tumors, in which total eradication with large tumor-free margins is required.

Objective: To evaluate the orbitopterional approach to anterior communicating artery (AComA) aneurysms, on the basis of the quantification of this surgical exposure, compared with the pterional approach, in a cadaveric study and a retrospective review of data for 40 patients who underwent clipping of AComA aneurysms via the orbitopterional approach., Methods: In an anatomic study, four cadaveric heads underwent pterional craniotomies on the left side and orbitopterional craniotomies on the right side. A fifth head was initially subjected to bilateral pterional craniotomies and then underwent bilateral orbital osteotomies, for direct comparison of these approaches. Using frameless stereotaxy, we quantified the angles of exposure and surgical field depths provided by the pterional and orbitopterional craniotomies. In a clinical study, 40 patients who underwent clipping of AComA aneurysms via orbitopterional approaches were evaluated for basal brain injury, the need for resection of the gyrus rectus, dissection of the sylvian fissure, and approach-related complications. The incidence of postoperative hydrocephalus among patients with subarachnoid hemorrhage who underwent lamina terminalis fenestration was also reviewed., Results: The angles of observation were increased 46% in the axial plane (orbitopterional, 72.92 +/- 6.57 degrees; pterional, 49.75 +/- 2.27 degrees; P < 0.01) and 137.5% in the projection plane (orbitopterional, 8 +/- 2.19 degrees; pterional, 19 +/- 1.78 degrees; P < 0.01). The surgical window depth was decreased 13% with the orbitopterional approach (P < 0.05). Clinically, there was no incidence of frontobasal hypodensities on postoperative computed tomographic scans. Three patients (7.5%) required resection of the gyrus rectus. No patient required sylvian fissure dissection for aneurysm exposure. Two of 29 patients (6.9%) who survived subarachnoid hemorrhage required ventriculoperitoneal shunts despite lamina terminalis fenestration. No approach-related complications were recognized., Conclusion: The orbitopterional approach improved the observation of the AComA complex and seemed to decrease the risk of intraoperative brain damage.

Objective and Importance: Desmoplastic fibroma is a benign bone tumor that can be locally aggressive. It usually occurs in the long bones and mandible. We report on a patient with a desmoplastic fibroma arising in the temporal bone and review previously published cases of desmoplastic fibroma originating within the cranium., Clinical Presentation: A 43-year-old woman presented with a 12-year history of progressively worsening head asymmetry. Magnetic resonance imaging and computed tomography demonstrated a mass originating from the bone and involving the adjacent soft tissues., Intervention: A temporal parietal craniectomy was performed with excision of a large tumor involving the bone. An acrylic cranioplasty was used to replace the bone. Pathological examination of the lesion identified desmoplastic fibroma of the cranium. After surgery, the patient's cranial asymmetry was corrected., Conclusion: Desmoplastic fibroma of the cranium is rare. Surgical resection is the treatment of choice.

Objective: We have developed a simple and easy modification of the orbitozygomatic approach using one-piece pedunculated craniotomy. This modification prevents atrophy of the temporal muscle, resulting in temporal fossa depression and atrophy of the free bone graft resulting in the occurrence of bone pits along the line of the craniotomy., Methods: The key points of this modification are as follows. The scalp flap is elevated in the plane between the superficial and deep layers of the temporal fascia. The temporal muscle is dissected from the temporal plane by performing subperiosteal elevation with intact insertion to the superior temporal line of the temporal muscle, which results in the creation of a subperiosteal tunnel beneath the temporal muscle. The one-piece fronto-orbitozygomatic bone flap is hinged on the temporal muscle., Results: After the surgeons had received full training in the procedures and anatomic findings related to this craniotomy in 10 cadaveric heads, surgery was performed for paraclinoid or parasellar tumors in five patients. Although temporary pulsatile exophthalmos occurred after surgery in one patient, no craniotomy-related complications occurred during or after surgery. Because the bone flap is fragile at the frontozygomatic suture, fixation with a small titanium plate was required in three of five patients at the end of the operation. All patients were pleased with the cosmetic results of surgery during a minimum follow-up period of 6 months., Conclusion: The modifications described in this article reduce the risk of atrophy of the temporal muscle and improve the cosmetic results without limitation of operative exposure.

Objective: Postoperative pterional depression is a minor but unpleasant sequela of frontotemporal craniotomy. We developed a simple method for repair of this condition with the use of an endoscope and calcium phosphate cement., Methods: The cranial defect was approached by means of endoscopic visualization through a small incision within the hairline. The defect was repaired with an injectable calcium phosphate cement., Results: The bone defect was easily accessed and readily repaired in all five patients. No adverse reactions to the implant were observed. Satisfactory cosmetic results were obtained in all patients treated with the use of this method., Conclusion: This minimally invasive cranioplasty technique proved to be effective for the repair of the postoperative pterional defect.

Objective and Importance: Hydroxyapatite cement, a new biomaterial that is being marketed as a method for reconstructing cranial defects, offers many advantages. We document, herein, the complete dissolution and failure of this material to set in a surgically dry field, under optimal conditions, an occurrence that has not been previously reported., Clinical Presentation: Hydroxyapatite cement was used for reconstruction of a frontal bone defect secondary to a traumatic depressed cranial fracture in a 9-year-old male patient. At the time of suture removal on postoperative Day 6, we observed serous discharge from the wound, a reappearance of the cranial defect, and brain pulsations visible subcutaneously., Intervention: The patient was returned to the operating room, at which time we learned that the hydroxyapatite cement had migrated out of the defect; small concretions of the cement were scattered throughout the subgaleal space. The concretions of cement in the subgaleal space and the small amount of cement remaining in the defect were removed, and titanium mesh was used. An excellent cosmetic result was achieved., Conclusion: Although offering many advantages, hydroxyapatite cement does carry a risk of failure to set, despite optimal technique. Causes for failure to set, as well as possible modifications in the use of material and technique, are discussed.

Objective and Importance: Osteolytic lesions can be seen in various diseases, and they also resemble the markings normally found on the cranium. We present a rare case of symptomatic hypertrophic pacchionian granulation mimicking bone tumor in the calvaria., Clinical Presentation: A 46-year-old woman suffered from a small hump accompanied by pain in the right frontoparietal region. A plain radiograph revealed two punched-out lesions. Precontrast-enhanced computed tomographic scans demonstrated hypodense masses, with partial defect of the outer table of the cranium. Magnetic resonance imaging demonstrated hypointense masses in the T1-weighted image and hyperintense masses in the T2-weighted image, with capsule-like contrast enhancement by gadolinium diethylenetriamine penta-acetic acid., Intervention: The masses were totally resected with attached bone and dura. One of them had destroyed the outer table of the cranium. The affected portions of the masses lacked the dura and partially adhered to the brain surface. Histologically, hypertrophic pacchionian granulation was diagnosed., Conclusion: The patient has had no recurrence for 2 years. This case suggests the need to include hypertrophic pacchionian granulation in the differential diagnosis of punched-out lesions.

We report a case of ossifying fibroma involving the paranasal sinuses, orbit, and anterior cranial fossa. Ossifying fibroma is a benign fibro-osseous tumor, rarely involving the anterior cranial base. The patient was admitted because of exophthalmos and diplopia. The lesion was totally removed surgically. Grossly, it had a thin osseous capsule. The microscopic examination showed mainly fibrous tissues and lamellar bone trabeculae rimmed by osteoblasts and myxomatous areas in some parts. The histopathological aspect of this entity is discussed with reference to the differential diagnosis from monostotic fibrous dysplasia.

A patient who sustained a gunshot wound to the head was successfully treated with acute neurosurgical intervention. Six months after the injury, cranioplasty was used to repair a large skull defect. After cranioplasty, the patient developed significant improvement in motor function in his left upper extremity, which had been plegic after his injury. Although the mechanism of neurological recovery after cranioplasty is controversial, the occurrence of such improvement may be a sufficient indication for cranioplasty in certain patients.

We report the clinical, radiological, and histological features of an 8-year-old boy with an unusual presentation of fronto-orbital sphenoidal fibrous dysplasia. The various forms of fibrous dysplasia are outlined and the differential diagnosis discussed. An approach to surgical management is proposed.

Malignant struma ovarii is a rare type of ovarian teratoma; only 16 cases with distant metastases have been reported previously. We report an extremely rare case of malignant struma ovarii metastatic to the cranial vault, which developed during pregnancy. A 28-year-old woman in the 26th week of pregnancy, who had undergone resection of an ovarian tumor 3 years previously, noticed a mass in her left frontal region that had enlarged gradually in 6 months. Magnetic resonance imaging revealed a massive extradural tumor growing through the cranium. Under fetal heart monitoring, the patient underwent total resection of the tumor, including the adjacent cranial bone and dura, and a healthy infant was delivered at full term. Pathological examination showed that the tumor was a follicular adenocarcinoma. Because there was no abnormality in the patient's thyroid gland, this tumor was considered to be a metastasis from the ovarian tumor, a malignant struma ovarii, resected 3 years previously. The management of brain tumor during pregnancy is also discussed.

An operative technique called the extensive transbasal approach is reported with the operative results of 11 cases. This is an operative mode in which en bloc osteotomy of the orbital roofs and frontal sinus is performed after ordinary bifrontal craniotomy. Through this approach, a far wider operative space than that afforded by conventional operative techniques is possible, and reconstruction of the frontal base can be made securely. We consider this approach of major clinical value.

A 30-month-old Mexican girl with an inclusion subgaleal cyst located over the anterior fontanel is described. This is the first such case ever diagnosed at our institution and, we believe, the first reported from Mexico. Radical excision of the lesion was accomplished. The internal table of the skull was eroded, but no intracranial extension was noticed. As the cyst contained no hair follicles nor any sebaceous or sweat glands, it was histologically classified as an epidermoid cyst. This is another example of such a lesion in an infant of non-African descent.

Giant cell reparative granuloma (GCRG) is an uncommon nonneoplastic lesion of bone. It is even rarer in the bones of the skull, particularly in the calvarial bones. Originally considered to be peculiar to the jawbones, GCRG has been described in some other locations, such as the short tubular bones of the hand and the facial (paranasal) bones. Only one GCRG has been found in the skull, this one in the temporal bone. The authors were unable to find a report of such a lesion in the bones of the calvarium. The etiology of GCRG is unknown, but it is believed to result from a traumatic intraosseous hemorrhage or periosteal reaction. A GCRG was diagnosed in a 31-month-old male infant who presented with a nonpainful, slow-growing, right frontal swelling, apparently related to a head contusion that had occurred 21 months earlier. The lesion was removed surgically. The main differential diagnosis is giant cell tumor.

There are various flaps for bifrontal exposure of the anterior fossa classically described in the neurosurgical literature. This article describes a bifrontal split osteoplastic flap that is characterized by removal of the anterior wall of the frontal sinus without the placement of burr holes on the external surface of the frontal bone. The procedure is safe and rapid, gives the same exposure as other techniques, and allows a superior cosmetic result.

A case of osteogenic sarcoma of the skull in a patient with a long-standing Paget's disease is reported. Osteogenic sarcoma arising within the skull is rare in Paget's disease, although the recent literature emphasizes that it is more common than was realized previously. Intraparenchymal brain invasion, which is rare and present usually only as a preterminal event, was found in this patient who presented initially with minimal neurological findings. Rapid neurological deterioration in this patient was due to macroscopic hemorrhage into tumor. Although microscopic hemorrhage is characteristic of this tumor, gross hemorrhage into osteosarcoma of the skull as a cause of sudden neurological deterioration has not been reported previously. Radical resection is the treatment of choice, although the prognosis for this tumor remains dismal.