One-step orbit reconstruction using PMMA implants following hyperostotic sphenoid wing meningioma removal: Evolution of the technique in short clinical series

Purpose

To report our experience with patient specific implants for one-step orbit reconstruction following hyperostotic SWM removal and to describe the evolution of the technique through three surgical cases. Methods: Three cases of one-step SWM removal and orbit reconstruction are described. All cases are given consecutively to describe the evolution of the technique. Hyperostotic bone resection was facilitated by electromagnetic navigation and cutting guides (templates). Based on a 3D model, silicone molds were made using CAD/CAM. Then PMMA implant was fabricated from these molds. The implant was adjusted and fixed to the cranium with titanium screws after tumor removal. Results: Following steps of the procedure changed over these series: hyperostotic bone resection, implant thickness control, implant overlay features, anatomic adjustments, implant fixation. The proptosis resolved in all cases. In one patient the progressive visual acuity deterioration was recognized during the follow-up. No oculomotor disturbances and no tumor regrowth were found at the follow-up.

Conclusion

CAD/CAM technologies enable creation of implants of any size and configuration, and thereby, to increase the extent of bony resection and lower the risk of tumor progression. The procedure is performed in one step which decreases the risk of postoperative morbidity.

Modified orbitozygomatic craniotomy with a single burr hole in the alternative sphenoid ridge keyhole

BACKGROUND

One-piece modified orbitozygomatic approach (OZA) is an extended version of the pterional approach that also includes orbital walls and frontal process of the zygomatic bone. For this craniotomy one burr hole must be placed in MacCarty keyhole and another - in the temporal region.

OBJECTIVE

To develop a technique of the one-piece modified OZA with single a burr hole in the alternative sphenoid ridge keyhole that allows access to orbit, anterior cranial fossa and middle cranial fossa and apply it intraoperatively.

METHODS

A single human head specimen was used. The dissection was performed using standard surgical instruments high-speed Stryker drill. Every stage of the approach was photographed. We also report a surgical case of a patient with orbital cavernous hemangioma that was resected using the described technique.

RESULTS

The technique of the one-piece modified OZA with a single burr hole in the alternative sphenoid ridge keyhole is described, and its advantages and limitations are analyzed. The technique is used to totally resect an orbital cavernous hemangioma with good functional and cosmetic result.

CONCLUSION

Modified OZA with a single burr hole in the sphenoid ridge keyhole is possible and may be an alternative to the classic technique. The advantages of this variation are the placement of just one burr hole and the preservation of a larger portion of the orbital roof. The latter facilitates better bone reconstruction and better cosmetic outcome. Disadvantages are the difficulty of identifying the location of the sphenoid ridge keyhole and risk of damaging the dura.

Predictive model for preoperative risk calculation of cerebrospinal fluid leak after resection of midline craniofacial mass lesions

Background

Complex anterior skull base defects produced by resection of mass lesions vary in size and configuration and may be extensive. We analyzed the largest single-center series of midline craniofacial lesions extending intra- and extracranially. The study aims at the development of a predictive model for preoperative measurement of the risk of the postoperative cerebrospinal fluid (CSF) leak based on patients' characteristics and surgical plans.

Methods

166 male and 149 female patients with mean age 40,5 years (1 year and - 81 years) operated for benign and tumor-like midline craniofacial mass lesions were retrospectively analyzed using logistic regression method (Ridge regression algorithm was selected). The overall CSF leak rate was 9.6%. The ROSE algorithm and 'glmnet' software suite in R were used to overcome the cohort's disbalance and avoid overtraining the model.

Results

The most influential modifiable negative predictor of the postoperative CSF leak was the use of extracranial and combined approaches. Use of transbasal approaches, gross total resection, utilization of one or two vascularized flaps for skull base reconstruction were the foremost modifiable predictors of a good outcome. Criterium of elevated risk was established at 50% with a specificity of the model as high as 0.83.

Conclusions

The performed study has allowed for identifying the most significant predictors of postoperative CSF leak and developing an effective formula to estimate the risk of this complication using data known for each patient. We believe that the suggested web-based online calculator can be helpful for decision making support in off-pattern clinical situations.

[Molecular genetic features of meningiomas]

Meningioma is the most common primary tumor of the central nervous system. Traditional classification is based on histological properties of tumors and distinguishes different grades of meningioma malignancy. However, knowledge about different molecular mechanisms of tumor provided new data on genetic features of meningiomas. The authors analyze current available data on the main driver mutations, new classifications based on molecular genetic characteristics and potential targets for therapy.

[Complicated course of the postoperative period with the development of epidural hygroma and intracranial hypotension after removal of cranio-orbital meningioma. Clinical case and literature review]

Surgical removal of cranio-orbital meningiomas is an effective method of treating this pathology. Modern surgical techniques and technologies make it possible to perform operations with a low risk of complications. Lumbar drainage or repeated lumbar punctures are often used intraoperatively or in the early postoperative period to prevent nasal CSF leak; this rarely leads to the development of significant neurological symptoms. We present a case of the development of severe intracranial hypotension with the formation of a subdural hygroma in the early postoperative period after removal of a cranio-orbital meningioma in a 41-year-old patient. The operation was performed using an individual model and molds for simultaneous reconstruction of the bone defect with an implant made of polymethyl methacrylate. On the 1st and 2nd days after surgery, lumbar punctures were performed. From the 2nd day there was a progressive deterioration with the development of symptoms characteristic of intracranial hypotension. Computed tomography revealed an increasing displacement of the midline structures of the brain and an increasing volume of epidural fluid accumulation in the area of surgical intervention. Magnetic resonance imaging revealed characteristic signs of intracranial hypotension. Conservative treatment (bed rest, active hydration) had no effect. On the 6th day after surgery, an epidural blood patch procedure was performed and closed external drainage of the epidural hygroma was performed, and a rapid regression of neurological symptoms was noted. Our experience and literature data indicate that it is necessary to remember the possibility of developing clinically significant intracranial hypotension even after a single lumbar puncture. The formation of hygromas in the surgical area is characteristic of intracranial hypotension, but in most cases does not require additional surgical intervention and does not have a negative impact on the outcome of treatment. Conservative treatment of intracranial hypotension is the first choice and often sufficient. If there is no effect and the patient's condition worsens, it is necessary to perform an epidural blood patch procedure.

[Bone defect closure after resection of sphenoorbital meningioma]

Sphenoorbital meningiomas (SOM) are a subgroup of skull base tumors with soft tissue component in the orbit and anterior and/or middle cranial fossa. According to different authors, SOMs account for 2-12% of all intracranial meningiomas. Reconstruction of bone defects after resection of SOM has own nuances. Along with cranial vault repair, patients encounter with cosmetic defects following facial skull lesion, ophthalmic symptoms due to orbital defects, dental and functional problems associated with opening of the mouth in case of damage to maxilla and mandible. Predominant infiltrative growth of tumor and common large bone defects involving various anatomical regions require multiple implants or implants with complex shape. Moreover, contact of implantation area with nasal cavity and paranasal sinuses requires additional impermeability of soft tissue reconstruction and inertness of materials.

OBJECTIVE

To summarize available modern data on bone defect closure after resection of SOM.

MATERIAL AND METHODS

The authors reviewed available data on bone defect closure after resection of SOM. Effectiveness of modern methods of reconstruction and safety of materials were assessed.

RESULTS

We analyzed 96 available references. Technical features of tumor resection, materials used for bone defect closure and modern possibilities of 3D technologies in reconstructive surgery were described. The authors proposed the algorithms for selecting the materials for bone defect closure after resection of SOM.

CONCLUSION

Improvement of surgical technique and development of new materials and technologies significantly improve cosmetic and functional results. A large percentage of negative ophthalmologic outcomes and high risk of complications in SOM surgery require further studies and elaboration of modern techniques.

[Quantitative analysis of orbit volume and eyeball position after resection of hyperostotic sphenoid wing meningioma and simultaneous orbital wall reconstruction using individual technologies]

OBJECTIVE

To conduct a quantitative analysis of orbit volume at different stages of preparation and surgical treatment of patients with cranio-orbital meningiomas undergoing resection with simultaneous orbital wall reconstruction using 3D modeling and 3D printing technologies.

MATERIAL AND METHODS

A prospective cohort non-randomized study included 24 patients with cranio-orbital meningiomas. The volumes were measured by segmenting the orbital structures using the planimetric method in the Inobitec PRO software package. Three expert neurosurgeons independently performed these measurements. The implants were modeled in Blender software. We used the intraclass correlation coefficient (ICC) and global similarity index (GSI) to analyze interrater agreement and ensure reproducibility of analysis.

RESULTS

Interrater agreement on orbital markings was very high for both metrics (ICC and GSI). The ICC (A,3) for intact orbit volume was 0.99 (95% CI 0.981; 0.996, p=1.9962018^{-33}), 0.99 (95% CI 0.983; 0.996, p=1.903203^{-34}) for damaged orbit volume at the preoperative stage, 0.99 (95% CI 0.979; 0.995, p=3.5939828^{-32}) for damaged orbit volume at the stage of modeling of resection and reconstruction, 0.99 (95% CI 0.978; 0.995, p=1.1048941^{-30}) for damaged orbit volume in postoperative period. The ICC for measurements related to EI was 0.94-0.97 (very high). This analysis revealed a strong inverse relationship between EI and volume index at the preoperative stage (rho= -0.55, p=0.004987), as well as between dynamics of EI and volume indexes in perioperative period (rho= -0.59, p=0.003). We found significant relationship (p=0.006757) between implant displacement in the area of lateral orbital wall and differences of actual and theoretical volumes.

CONCLUSION

The proposed method of planimetric contouring and segmentation of orbital volumes is highly accurate and reproducible. Significant patterns allow us to develop predictive models for preliminary calculation of target volume of the damaged orbit.

[Domestic software, medical devices and materials in surgery for hyperostotic craniofacial meningiomas]

OBJECTIVE

The modern concept of resection of hyperostotic craniofacial meningiomas involves the desire for one-stage surgery with excision of tumor and simultaneous extensive skull defect closure.

MATERIAL AND METHODS

The authors present skull defect closure with an individual implant after resection of cranioorbital meningioma in a 61-year-old man. The neoplasm was accompanied by exophthalmos and eyelid edema. The patient underwent simultaneous microsurgical resection and skull reconstruction with an individual implant. At discharge (7 days after surgery), exophthalmos regressed to 3 mm. After 3 months, ophthalmologist revealed complete regression of exophthalmos.

RESULTS

Domestic software and 3D printers were used for implant modeling and preparing the necessary physical models and molds. We intraoperatively used domestic polymer and titanium fixation systems for manufacturing and fixation of implant.

CONCLUSION

This clinical case confirms that resection of hyperostotic craniofacial meningioma with simultaneous bone defect closure using domestic analogues of software, technical equipment, materials and methods is possible at all stages of this procedure.

[Dural defect closure after resection of cranioorbital meningiomas]

Dural defect closure after resection of cranioorbital meningiomas has its own specifics. Extended malignant lesions and common large bone defects involving various anatomical regions require multiple implants or implants with complex geometry. The features of this stage of reconstruction were described in the previous issue of the Burdenko Journal of Neurosurgery. At the same time, contact of implant with nasal cavity and paranasal sinuses dictates additional requirements for tightness of soft tissue reconstruction and inertness of material. In this review, we describe modern and historically interesting methods of reconstruction of soft tissue defects following resection of cranioorbital meningioma.

OBJECTIVE

To summarize and analyze available literature data on reconstruction of soft tissue defects following resection of cranioorbital meningioma.

MATERIAL AND METHODS

The authors reviewed available data on reconstruction of soft tissue defects after resection of cranioorbital meningiomas. Effectiveness of reconstruction techniques and safety of materials were analyzed.

RESULTS

The authors analyzed 42 available full-text articles. Features of growth and natural course of cranioorbital meningioma, methods of soft tissue defects closure, modern materials and sealing compositions are described. Considering these data, the authors proposed the algorithms for selecting materials for dural reconstruction after resection of cranioorbital meningioma.

CONCLUSION

Improvement of surgical technique, development of new materials and technologies increase the efficiency and safety of dural defect closure. Nevertheless, high incidence of complications associated with dura mater repair necessitates further research in this area.

Assessing the reliability of zygomatic bone landmarks as guides to reach the inferior orbital fissure in orbitozygomatic osteotomy: anatomical study of 83 human skulls

To perform an adequate orbitozygomatic craniotomy, it is very important that the bone cut which passes through the body of the zygoma reaches the inferior orbital fissure (IOF). To reach the IOF, two surface landmarks on the body of the zygoma are described: a point located directly superior to the malar eminence and the zygomaticofacial foramen. The article explores the reliability of these landmarks and three other alternative points to reach the IOF. Eighty-three adult skulls were used in this study. The IOF dimensions and the relationship with the malar eminence, the point superior to the malar eminence, the zygomaticofacial foramen, and 3 alternative points (E, C, F) were analyzed. The malar eminence was unacceptable for use as a guide to the IOF. The point superior to the malar eminence was also unacceptable as a guide as only 9.4% and 10.9% were in the projection of the IOF on the right and left, respectively. 59.7% of the total zygomaticofacial foramina fell in the IOF projection. The point F fell in the projection of the IOF in 98.8% and 100.0% on the right and left, respectively. The use of the malar eminence as a guide to reach the IOF is unreliable in one third of cases as it is not easily identified intraoperatively in these cases. The zygomaticofacial foramen cannot be considered a reliable surgical landmark to reach the IOF. The authors recommend using a novel landmark which may be identified as a midpoint between intersections of the anterior and posterior margins of the zygomatic frontal process on a line extending from the inferior margin of the zygomatic arc. This point is reliable in 98.8-100% of cases.

[Transcranial microsurgical decompression of the optic canal in surgical treatment of meningiomas of the sellar region]

RATIONALE

When removing the meningiomas of the sellar region, there is always a risk of visual impairment for various reasons, in particular, as a result of traction damage to the optic nerve. Decompression of the optic canal increases nerve mobility during tumor manipulation. In cases of meningioma growing into the canal, its decompression often seems necessary.

AIM

Evaluation of the effectiveness and risks of performing decompression of the optic canal.

MATERIALS AND METHODS

The study included patients with meningiomas of the parasellar location, who underwent surgical treatment at the Burdenko Neurosurgical Center for the period from 2001 to 2017. They were divided into two groups - main and control. The main group consisted of 129 patients who underwent decompression of the optic nerve canals when the tumor was removed. The tumor matrix in this group was most often located in the region of the tuberum sellae, supradiaphragmally, in the region of the anterior clinoid process and the optic canal. In 31 cases, decompression was bilateral - during one operation and using one access in 27 patients; in 4 cases, the decompression of the second canal was delayed for 1.5-3 months after the first operation. 160 decompressions were performed by the intradural and 7 - by extradural methods. During intradural decompression, the roof of the optic canal was resected, and during extradural decompression, the lateral wall of the canal was trephined. The control group consisted of 308 patients who did not undergo canal decompression when the tumor was removed. It included meningiomas with a predominant location of the matrix in the area of the tuberclum and diaphragm of the sella. Tumors in both groups were removed according to the same principles (matrix coagulation, mainly the gradual removal of the tumor, the use of ultrasonic aspirator, a situational decision on the radicality of the operation, etc.). The main difference between operations in these two groups was only canal related algorithms (with or without its trepanation), as well as the probable prevalence of significant lateral tumor growth in cases with canal trepanation. Visual functions in the «primary» group were evaluated before and after operations with trepanation of the canal depending on various factors - the initial state of vision and the radicality of the tumor excision, including removal from the canal. The differences in the postoperative dynamics of vision in the main and control groups were studied. The primary data processing was carried out using the program MSExcel. Secondary statistical processing was carried out using the program Statistica. To assess the statistical significance of differences in the results obtained in the compared patient groups, the Chi-square test was used, and in the case of small groups - the exact Fisher test was applied.

RESULTS

In the main group postoperative vision improvement of varying degrees on the side of trepanation was registered in 36.9% (59 out of 160) cases, no vision changes were found in 36.9% (59 out of 160), and in 26,2% (42 out of 160) the eyesight deteriorated. If preserving vision is attributed to a satisfactory result, then in general the results of these operations should be considered good. A comparative study of the results of removal of meningiomas with trepanation of the canals (main group) or without it (control group) was carried out among patients with the most critical vision situation (visual acuity 0.1 and below, up to only light perception). These groups are comparable in the number of observations - 62 and 73 respectively. The predominance of cases with improved vision in the main group compared with the control group (50.0% versus 38.36%) and a lower incidence of vision impairment (22.58% versus 34.25%) were found. However, the revealed differences are statistically unreliable and make it possible for us to talk only about the trend. The complications associated with trepanation of the canal include mechanical damage to the nerve by the drill. In our series of observations, there was only 1 case of abrasion of the nerve surface with the burr, which did not lead to a significant visual impairment. With the intradural method of trepanation in the area of the medial wall of the canal, the sphenoid sinus may open (in our series, in 34 cases out of 160 trepanations). Immediately closure of these defects was performed by various auto- and allomaterials in various combinations (pericranium, fascia, muscle fragment, hemostatic materials, and fibrin-thrombin glue). A true complication - CSF rhinorrhea liquorrhea developed in only one case, which required transnasal plastic surgery of the CSF fistula using a mucoperiostal flap.

CONCLUSIONS

1. Trepanation of the optic canal in cases of meningiomas of parasellar localization is a relatively safe procedure in the hands of a trained neurosurgeon and does not worsen the results of operations compared with the excision of the same tumors without trepanation of the canal. 2. The literature data and the results of our study make it possible to consider the decompression of the optic canal as an optional, but in many cases, useful option that facilitates the transcranial removal of some meningiomas of the sellar region.

[Results of surgical treatment of skull-base primary malignant tumors with intracranial invasion]

OBJECTIVE

Analysis of factors affecting life expectancy at patients with primary malignant tumors of anterior and middle parts of the skull base with intracranial invasion.

MATERIAL AND METHODS

139 patients (47 women and 92 men) with primary malignant tumors of the anterior and middle parts of the skull base with intracranial invasion (stage T4 according to TNM classification or stage C according to Kadish classification for estesioneuroblast ) were treated at the NMRCN Burdenko for the period from 2004 till 2018. The study was conducted by the method of total sampling. The observations are divided into 2 groups: primarily operated (group I) and repeatedly operated (group II).

RESULTS

The average age in both groups was 50 years. In most (64.7%) cases, the tumor affected the medial sections of the base of anterior and middle cranial fossae, and in 35.3% of cases it was localized laterally. All tumors were classified to T4 stage according to TNM classification or (9 olfactory neuroblastomas) to stage C according to Kadish classification.

DISCUSSION

The impact on life expectancy was largely provided by postoperative radiation therapy, the repeated nature of operation, and the presence of brain infiltration. In the total cohort of patients 5-year OS, 5-year RVS, 5-year-old IDF and 5-year LC were 50.7, 35, 54.2 and 36.4%, respectively. In group I, the medians OS and IDF were equal and amounted to 138.3 months. The median RVS was 43.8 months. 5-year OS equal to 63.6%, 5-year RVS - 40.8%, 5-year-IDF - 64.8%, 5-year LC was up to 65.7%. The survival rate in the analyzed cohort for 1, 2, 3 years was 81.4, 71.8 and 67.8%, respectively. In group II, the treatment results for the group of repeatedly treated patients were significantly worse. There were no cases of 5-year survival. The 1-, 2-, and 3-year survival rates were 59.3, 50.8 and 31.8%, respectively. The median OS was 27.1 months, IDF was 27.1 months, RVS was 18.2 months, and LC was 9.1 months.

CONCLUSION

The results and analysis of literature justify the feasibility of surgical treatment of patients with malignant tumors of craniofacial localization at T4 stage. The purpose of surgical intervention should be: elimination of the immediate threat to the patient's life due to edema and dislocation of the brain; the maximum possible removal of tumor tissue (cytoreduction); if possible, the elimination of the most significant symptoms for the patient (pain, nasal breathing disorders, cosmetic defect). If there are special reserves, it is obligatory to include radiation and chemotherapy in the treatment process.

[Individual preoperative 3D modeling of vascular brain pathology]

The possibility of segmenting three-dimensional objects by DICOM-series is well known and available both on specialized workstations and on personal computers. The technique, however, is relatively rarely used in clinical practice, and we believe that the benefits of preoperative preparation using segmented 3D models are underestimated. The article is devoted to our experience in using segmentation of anatomical structures based on CT and MRI for preoperative preparation for surgical operations performed in neurosurgical departments on patients with vascular pathology. The paper discusses the types and possibilities of segmentation, provides some examples describing the clinical use of the technique.

[An anatomical study on the applicability of direct endoscopic exclusion of the ethmoid arteries for devascularization of the anterior skull base structures]

The anterior skull base structures are the site of initial growth of histologically different tumors. The difficulties in their removal are often associated with significant vascularization, which may limit the amount of resection due to abundant intraoperative blood loss. Midline tumors are primarily fed by the ethmoid arteries that are not accessible to embolization. The aim of this work was a comparative experimental study of various direct approaches to the ethmoid arteries.

MATERIAL AND METHODS

The study was conducted on anatomical specimens of 12 cadaveric heads of deceased people without pathology of the anterior skull base structures, orbits, nasal cavity, and paranasal sinuses (24 sides). In all specimens, the internal and external carotid arteries were stained with silicone. During anatomical dissection, four surgical approaches for exclusion of the ethmoid arteries were studied: 1) transorbital approach to the arteries using a bicoronal incision; 2) endoscopic retro-caruncular approach; 3) endoscopic endonasal transethmoidal approach to the ethmoid artery canals; 4) endoscopic endonasal transethmoidal transorbital approach to the ethmoid arteries in the orbit.

RESULTS

We described a surgical technique for exclusion of the ethmoid arteries using the approaches and analyzed their advantages and disadvantages. We formulated an algorithm for choosing the method for direct endoscopic exclusion of the ethmoid arteries, depending on the surgical approach chosen for removal of the tumor and features of the tumor extracranial spread.

CONCLUSION

The decision on tumor devascularization is based on assessment of tumor blood supply (CT angiography or MR angiography data). Our study demonstrated the advantages and disadvantages of various approaches to the ethmoid arteries for their exclusion in order to early devascularize anterior skull base tumors. All these approaches are less traumatic and characterized by a good cosmetic and functional outcome.

[Biopsy and resection of skull base tumors using transorbital endoscopic approaches: primary results]

AIM

Transorbital neuroendoscopic surgery is a new skull base surgery technique that uses the orbit as an artificial corridor to the anterior and middle skull base. The space is created between the periorbita and orbital walls by their additional resection and gentle traction of the orbital contents. Skull base structures are reached using cosmetic incisions. The major advantages of transorbital endoscopic approaches include their variety, possibility of their combination, and access to the central and lateral skull base lesions. The aim of this study was to analyze the primary results of transorbital endoscopic biopsy and resection of skull base lesions, which were performed at the N.N. Burdenko National Medical Research Center for Neurosurgery (Moscow, Russia).

MATERIAL AND METHODS

In 2017-2018, the authors operated on 12 patients with skull base lesions using transorbital endoscopic approaches. The series included ten female and two male patients. The patient's age varied between 24 and 78 years. All patients were admitted for the first time. Half of them underwent biopsy, while the other half underwent tumor resection. The upper-lateral transorbital approach with an eyebrow incision was used in most (8/12) patients; the retrocaruncular approach was used in two cases; the lateral retrocanthal approach was applied in one case; the upper-medial approach with an eyebrow incision was used in one patient.

RESULTS

The histological diagnosis was established in all six biopsies: 3 pseudotumors, 2 WHO Grade I meningiomas, and 1 clear-cell kidney cancer. Tumor resection was successful in 5 out of 6 patients; repeated surgery was required in one patient. In one case, the transorbital approach was combined with the transnasal one for treatment of supraorbital mucocele. One patient developed a persistent neurological deficit (dysfunction of the fifth and sixth nerves) after upper-lateral transorbital surgery. There were no poor cosmetic results in the series.

CONCLUSION

Transorbital neuroendoscopic surgery needs an interdisciplinary approach and a sufficient amount of surgical experience. Surgical skills setting includes microsurgical and endoscopic tumor resection, harvesting and positioning of free and vascularized grafts for skull base reconstruction and prevention of postoperative enophthalmos, and facial incisions and their cosmetic closure. Implementation of new local vascularized flaps may significantly improve the results of transorbital endoscopic procedures and extend the spectrum of indications.

[Severe postoperative intracranial hemorrhagic complications in a neurosurgical patient with von Willebrand disease not diagnosed before surgery (a case report and literature review)]

The article describes a rare clinical case of a patient with previously undiagnosed von Willebrand disease and basal meningioma; an intracranial neurosurgical intervention was complicated by delayed intracranial hematomas, both at the resected tumor site and distantly. The diagnosis of von Willebrand disease was established only after special hematology tests and only after surgery. Despite the use of specific therapy, the patient died due to intracranial hemorrhagic complications in the postoperative period. The paper discusses the problem of preoperative diagnosis of asymptomatic hemostasis disorders in neurosurgical patients and potential ways of its solution.

The Pedicled Buccal Fat Pad: Anatomical Study of the New Flap for Skull Base Defect Reconstruction After Endoscopic Endonasal Transpterygoid Surgery

Objectives To evaluate the efficacy and safety of using a buccal fat pad for endoscopic skull base defect reconstruction. Design Descriptive anatomical study with an illustrative case presentation. Setting Anatomical study was performed on 12 fresh human cadaver specimens with injected arteries (24 sides). Internal carotid artery was exposed in the coronal plane via the endoscopic transpterygoid approach. The pedicled buccal fat pad was used for reconstruction. Participants: 12 human cadaver head specimens; one patient operated using the proposed technique. Main outcome measures: Proximity of the buccal fat pad flap to the defect, compliance of the flap, comfort and safety of harvesting procedure, and compatibility with the Hadad-Bassagasteguy nasoseptal flap. Results: Harvesting procedure was performed using anterior transmaxillary corridor. The pedicled buccal fat pad flap can be used to pack the sphenoid sinus or cover the internal carotid artery from cavernous to upper parapharyngeal segment. Conclusion The buccal fat pad can be safely harvested through the same approach without external incisions and is compliant enough to conform to the skull base defect. The proposed pedicled flap can replace free abdominal fat in central skull base reconstruction. The volume of the buccal fat pad allows obliteration of the sphenoid sinus or upper parapharyngeal space.

[Orbitozygomatic approaches to the skull base]

The paper is written in the lecture format and dedicated to one of the main basal approaches, the orbitozygomatic approach, that has been widely used by neurosurgeons for several decades. The authors describe the historical background of the approach development and the surgical technique features and also analyze the published data about application of the orbitozygomatic approach in surgery for skull base tumors and cerebral aneurysms.

Optic nerve decompression in treatment of neoplasms involving optic canal

Neoplasms extending to the optic canal is a diverse group of more than 15 histological types. Elimination of the optic nerve compression is crucial for favorable visual outcome. Material and method. We perform a prospective analysis of 97 patients with different neoplasms with involvement of the optic canal in whom surgery was performed in neurooncological department of Burdenko Neurosurgical Institute during the period from 2010 to 2012. Extent of resection and recurrence rates were determined by pre- and postoperative CT and MRI studies. Results. 97 patients (78 women and 19 men) were involved in the study. Mean age was 49,4 years. Patients were followed for mean of 15.9 months (1-36 month). Total resection was achieved in 54 (55.6%) patients, gross-total resection in 40 (41,2%), partial resection in 3 (3.2%). Underwent postoperative stereotactic radiation therapy 30 patients. There was no recurrence in a series of observations. 4 patients showed extension into both optic canals. Visual disturbances were the main presenting symptoms in 50 (51.5%) patients. 10 (10.3%) patients had normal visual status initially. Visual improvement after surgery was seen in (37%) of 87 patients with visual disturbances. Visual deterioration occurred in 17 (19%) patients. Transient visual deterioration occurred in 1 patient with recovery to the base level over time. The visual outcome was affected by the duration of the symptoms before surgery and the stage of visual disturbances according to the eyeground changes. Conclusions. Involvement of the optic canal is a common phenomenon in craniofacial tumors. Neoplasms extending to the optic canal is a diverse group of both the localization and histology. Decompression of the optic nerves is a crucial step in the surgical management of this neoplasms to optimize visual recovery and prevent tumor recurrence.

Surgery of skull base tumors extending into the orbit, paranasal sinuses, nasal cavity, pterygopalatine and infratemporal fossas: treatment principles in certain types of tumors

Following the paper focused on surgery of skull base tumors invading the orbit, paranasal sinuses, nasal cavities, pterygopalatine and infratemporal fossae, the authors discuss particular issues of surgical treatment of the most common craniofacial mass lesions, including meningiomas, juvenile angiofibromas, trigeminal nerve tumors, chondroid tumors, and others.

Orbitosphenopetroclival meningeomas: clinical and topographic features and results of combined treatment

The aim of the study was to access clinical and topographic features of orbitosphenopetroclival meningeomas and the results of surgical and combined treatment in patients with meningeaomas of that location. Orbitosphenopetroclival meningeomas comprise a peculiar group of tumors and are the result of infiltrative sphenopetroclival meningeomas progression, when the latter extend into the orbit and temporal fossa. Development of neurosurgery, use modern approaches and adjuvant therapies such as stereotaxic radiosurgery and radiotherapy in the past years markedly improve treatment results in these patients. However, difficulties in treatment strategy choice remain. One attempting to excise a tumor radically encounters with the risk of damage to critically important neurovascular structures. When a tumor is excised partially the risk of complication dwindles, however risk of relapse increases. Palliative surgery improve patients' quality of life. Radiosurgery and irradiation of residual tumors allow to establish control on a tumor growth.

MATERIAL AND METHODS

Twenty three patients were studied, of them 20 received surcery, 9 - stereotaxic irradiation, 5 - conventional irradiation. The follow-up interval comprised 8-84 months (median 37 months).

RESULTS

Manifestations of orbitosphenopetroclival meningeomas are combined from signs and symptoms of cranioorbital and petroclival meningeomas, and in many patients include signs of skull base external surface involvemevt, marked cosmetic deficits and psychological distress. Orbitosphenopetroclival meningeomas originate from cavernous sinus and medial parts of sphenoid bone wings. During its progression a tumor extends onto orbit and onto clivus, and then onto infratemporal and sphenopalatine fossae, nasopharynx and posterior cranial fossa.

CONCLUSION

If a residual tumor is present patients with orbitosphenopetroclival meningeomas should undergo adjuvant irradiation after the first surgery.

Tumors of the skull base, extending into the orbit, paranasal sinuses, nasal cavity, pterygopalatine and infratemporal fossa

The first of two papers focusing on surgery of skull base tumors invading orbit, sinonasal cavities, pterygopalatine and infratemporal fossae the authors described foundation and development of craniofacial oncology as a new discipline in skull base surgery, modern approaches to diagnostic evaluation of craniofacial mass lesions and basic principles of surgical management.

The first experience of skull base defect reconstruction using pedicled buccal fat pad after endoscopic endonasal resection of a craniofacial tumor

BACKGROUND

Buccal fat pad (BFP) is widely used in maxillofacial surgery for closure of oroantral and oronasal defects. V.A. Cherekaev et al. were the first who described application of pedicled BFP flap in reconstruction of anterior and middle skull base defects. This article focuses on a novel surgical technique - plastic closure of craniobasal defects via endonasal endoscopic approach.

MATERIAL AND METHODS

We present a case of 12-year old male patient with advanced juvenile angiofibroma who was operated endoscopically using biportal transnasal-transantral approach. After removal of the tumor the defect of anterior cavernous sinus was reconstructed by translocated pedicled BFP flap supported by balloon-catheter.

RESULTS

No postoperative complications such as cerebrospinal fluid nasal leakage were observed after withdrawal of balloon-catheter on the 4th day after surgery. The same day the patient was discharged in good condition.

CONCLUSION

The proposed technique is promising and advantageous as part of complex multilayer skull base defect reconstruction after resection of extra-intracranial mass lesions due to preserved vascular supply of BFP flap. The method is safe and associated with extremely low risk of complications. We hope that the described flap will be appreciated and will take its place within the range of plastic materials for reconstruction of skull base defects in endoscopic endonasal approach.

Breast carcinoma metastasis to the optic nerve: case report and review of literature

Metastatic tumours of the optic nerve are extremely rare. The review of literature revealed only 12 cases of breast carcinoma metastasis to the optic nerve. All patients survived less then 6 month after surgical treatment. We describe a case of metastatic breast carcinoma to the optic nerve that occurred 8 years after radical mastectomy followed by chemotherapy. The metastasis manifested with progressive decrease in visual acuity in the right eye during 3 month. CT and MRI demostrated enhancing lesion in the muscle cone apex of the right orbit with an extension to the optic canal. The presumable diagnosis was optic nerve sheath meningioma, and surgical resection was performed. The tumour involved the optic nerve and has been resected togeher with the nerve. Histology report confirmed metastatic tumour. Postoperatively, the patient received additional stereotactic radiotherapy. Patient died of tumour dissemination 2,5 years after surgery. Breast carcinoma metastases to the optic nerve usually have unfavorable prognosis both for survival and for visual acuity. Isolated metastatic tumors of the optic nerve remain a diagnostic challenge because of their clinical and radiological similarities to more common primary tumors of the optic nerve.

Meningioma challenge: analysis of 80-year experience of Burdenko Neurosurgical institute and future perspectives

The paper describes the history of meningioma surgery at Burdenko Neurosurgical Institute, analyses of accumulated series of patients and assesses effectiveness of different techniques for meningioma diagnosis and treatment of. We analyzed 15413 patients with meningiomas operated in Burdenko Neurosurgical Institute from 1932 to 2011. Mathematical analysis was performed using Statistica 6.0 program. Mortality rate during World War II reached a disastrous level of 45,8%, in 21st century it is below 1%. Temporary and permanent morbidity has also decreased. While in 1961 Karnofsky performance score was 71, in 2011 it became 83. The probability of postoperative tumour recurrence also diminished, from 40% in 1960-s to 29% in 1996 and presumably to 25% nowadays. Independent factors that influence the risk of recurrence are primary gross total resection, grade of anaplasia and radiation therapy. However, unreasonably aggressive surgery leads to significant increase of morbidity. Further improvement of surgical results in patients with meningiomas depends on implementation of new technologies for neurovisualization, abandoning extensive surgical approaches whenever possible, finding the "balance" between radical removal and expected functional outcome, wider application of radiosurgery and three-dimensional conformal radiation therapy.

[Protein malnutrition in patient in the early postoperative period after uncomplicated removal of the brain tumors]

Malnutrition leads to adverse effects and may worsen clinical outcome. Surgery as a stress factor activates pathological reactions changing metabolism structure. The aim of this study was to evaluate changes of protein metabolism in patients after elective neurosurgical operation. 24 patients were prepared for elective surgery and were enrolled in this study. Evaluation of each patient included: measurement of anthropometric indices--height, weight, arm circumference and the triceps skinfold thickness, the definition of protein loss by determining the loss of nitrogen in the urine, assessment of protein catabolism, determining the violations of nutritional status upon the base of laboratory parameters. During the course of the conducted investigation significant (p < 0.05) decrease in the indices of total protein, albumin, transferrin and the absolute numbers of lymphocytes in the postoperative period was revealed. All the patients developed severe protein catabolism. It became clear that uncomplicated elective surgical intervention, together with the adopted scheme of the nutritional therapy leads to severe protein catabolism in all patients.

[Intraosseous cranioorbital hemangiomas]

The authors describe 2 cases of primary intraosseous cavernous hemangioma (PICH). PICH are extremely rare tumors that represent less than 1% of all tumors of the bone. Only 20% of them involve skull. In both cases clinical findings were presented by proptosis, oculomotor disorders and chronic daily headaches. Surgery is the most recommended method of treatment. The best surgical management is gross total resection within intact tissue. In both cases tumor was removed completely.