Comparative Analysis on Surgical Operability and Degree of Exposure of Microsurgical Approaches to Intraforaminal Lumbar Disk Herniations.

BACKGROUND: Intraforaminal lumbar disk herniations (IFDHs) represent a heterogeneous and relatively uncommon disease; their treatment is technically demanding due to the anatomical relationships with nerve roots and vertebral joints. Over time, several approaches have been developed without reaching a consensus about the best treatment strategy. MATERIALS AND METHODS: Authors comparatively analyze surgical operability and exposure in terms of quantitative variables between the different microsurgical approaches to IFDHs, defining the impact of each approach on surgical maneuverability and exposure on specific targets.A comparative microanatomical laboratory investigation was conducted. The operability score (OS) was applied for quantitative analysis of surgical operability. RESULTS: Transarticular and combined translaminar-trans-pars-interarticularis approaches result in providing the best surgical exposure and maneuverability on all targets with surgical controls on both nerve roots, at the expense of a higher risk of iatrogenic instability. Trans-pars-interarticularis approach reaches comparable levels of operability, even limited to the pure foraminal area (lateral compartment); similar findings were recorded for partial facetectomy on the medial compartment. The contralateral interlaminar approach provides good visualization of the foramen without consensual favorable maneuverability, which should be considered the main drawback. CONCLUSIONS: Approach selection has to consider disease location, the possible migration of disk fragments, the degree of nerve root involvement, and risk of iatrogenic instability. According to the findings, authors propose an operative algorithm to tailor the surgical strategy, based both on the precise definition of anatomic boundaries of exposure of each approach and on surgical maneuverability on specific targets.

Anterior selective scalenectomy for periforaminal exposure in the ventral supraclavicular approach.

Aims and Objectives: Route of choice to access cervical paravertebral lesions with foraminal involvement is the anterolateral corridor with its variants. Main limitation of these techniques is represented by the limited surgical access to periforaminal area due to the bulk generated by the anterior scalene muscle (ASM). Over the years, alternative techniques for ASM surgical management have been developed, which are still today a matter of debate. Most popular include ASM scalene complete section (SCS) and ASM medial detachment (SMD). Authors describe an innovative, minimally invasive muscle section technique, the anterior selective scalenectomy (ASS), which reduces the risk of iatrogenic morbidity and optimizes exposure of periforaminal area in anterolateral cervical routes. Materials and Methods: A laboratory investigation was conducted. Technique was applied in a surgical setting, and an illustrative case was reported. Results: ASS is a quick and easy technique to perform. It allows optimization of surgical visibility and control on the periforaminal area in the cervical anterolateral corridor. It respects muscle anatomy and vascularization, favoring functional recovery and management of peri-operative pain; it reduces the risk of morbidity on phrenic nerve and pleura. Considering the minimally invasive nature of the technique, it allows for a slightly more limited exposure compared to traditional techniques while ensuring optimal surgical maneuverability on the target area. Conclusions: ASS represents an effective and safe alternative to traditional ASM section techniques for the exposure of periforaminal area in anterolateral cervical routes. It is indicated in case of lesions with paravertebral development and minimal intraforaminal component in the C3-C6 segment.

Meningioma and Other Meningeal Tumors.

Meningiomas develop from meningothelial cells and approximately account for more than 30 percent of central nervous system (CNS) tumors. They can occur anywhere in the dura, most often intracranially and at dural reflection sites. Half of the cases are usually at parasagittal/falcine and convexity locations; other common sites are sphenoid ridge, suprasellar, posterior fossa, and olfactory groove. The female-to-male ratio is approximately 2 or 3-1, and the median age at diagnosis is 65 years. Meningiomas are generally extremely slow-growing tumors; many are asymptomatic or paucisymptomatic at diagnosis and are discovered incidentally. Clinical manifestations, when present, are influenced by the tumor site and by the time course over which it develops. Meningiomas are divided into three grades. Grade I represents the vast majority of cases; they are considered typical or benign, although their CNS location can still lead to severe morbidity or mortality, resulting in a reported ten-year net survival of over 80%. Atypical (WHO grade II) meningiomas are considered "intermediate grade" malignancies and represent 5-7% of cases. They show a tendency for recurrence and malignant degeneration with a relevant increase in tumor cell migration and surrounding tissue infiltration; ten-year net survival is reported over 60%. The anaplastic subtype (WHO III) represents only 1-3% of cases, and it is characterized by a poor prognosis (ten-year net survival of 15%). The treatment of choice for these tumors stands on complete microsurgical resection in case the subsequent morbidities are assumed minimal. On the other hand, and in case the tumor is located in critical regions such as the skull base, or the patient may have accompanied comorbidities, or it is aimed to avoid intensive treatment, some other approaches, including stereotactic radiosurgery and radiotherapy, were recommended as safe and effective choices to be considered as a primary treatment option or complementary to surgery. Adjuvant radiosurgery/radiotherapy should be considered in the case of atypical and anaplastic histology, especially when a residual tumor is identifiable in postoperative imaging. A "watchful waiting" strategy appears reasonable for extremely old individuals and those with substantial comorbidities or low-performance status, while there is a reduced threshold for therapeutic intervention for relatively healthy younger individuals due to the expectation that tumor progression will inevitably necessitate proactive treatment. To treat and manage meningioma efficiently, the assessments of both neurosurgeons and radiation oncologists are essential. The possibility of other rarer tumors, including hemangiopericytomas, solitary fibrous tumors, lymphomas, metastases, melanocytic tumors, and fibrous histiocytoma, must be considered when a meningeal lesion is diagnosed, especially because the ideal diagnostic and therapeutic approaches might differ significantly in every tumor type.

Craniopharyngioma in Pediatrics and Adults.

Craniopharyngiomas are rare malignancies of dysembryogenic origin, involving the sellar and parasellar areas. These low-grade, epithelial tumors account for two main histological patterns (adamantinomatous craniopharyngioma and papillary craniopharyngioma), which differ in epidemiology, pathogenesis, and histomorphological appearance. Adamantinomatous craniopharyngiomas typically show a bimodal age distribution (5-15 years and 45-60 years), while papillary craniopharyngiomas are limited to adult patients, especially in the fifth and sixth decades of life. Recently, craniopharyngioma histological subtypes have been demonstrated to harbor distinct biomolecular signatures. Somatic mutations in CTNNB1 gene encoding ß-catenin have been exclusively detected in adamantinomatous craniopharyngiomas, which predominantly manifest as cystic lesions, while papillary craniopharyngiomas are driven by BRAF V600E mutations in up to 95% of cases and are typically solid masses. Despite the benign histological nature (grade I according to the World Health Organization classification), craniopharyngiomas may heavily affect long-term survival and quality of life, due to their growth pattern in a critical region for the presence of eloquent neurovascular structures and possible neurological sequelae following their treatment. Clinical manifestations are mostly related to the involvement of hypothalamic-pituitary axis, optic pathways, ventricular system, and major blood vessels of the circle of Willis. Symptoms and signs referable to intracranial hypertension, visual disturbance, and endocrine deficiencies should promptly raise the clinical suspicion for sellar and suprasellar pathologies, advocating further neuroimaging investigations, especially brain MRI. The optimal therapeutic management of craniopharyngiomas is still a matter of debate. Over the last decades, the surgical strategy for craniopharyngiomas, especially in younger patients, has shifted from the aggressive attempt of radical resection to a more conservative and individualized approach via a planned subtotal resection followed by adjuvant radiotherapy, aimed at preserving functional outcomes and minimizing surgery-related morbidity. Whenever gross total removal is not safely feasible, adjuvant radiotherapy (RT) and stereotactic radiosurgery (SRS) have gained an increasingly important role to manage tumor residual or recurrence. The role of intracavitary therapies, including antineoplastic drugs or sealed radioactive sources, is predominantly limited to monocystic craniopharyngiomas as secondary therapeutic option. Novel findings in genetic profiling of craniopharyngiomas have unfold new scenarios in the development of targeted therapies based on brand-new biomolecular markers, advancing the hypothesis of introducing neoadjuvant chemotherapy regimens in order to reduce tumor burden prior to resection. Indeed, the rarity of these neoplasms requires a multispecialty approach involving an expert team of endocrinologists, neurosurgeons, neuro-ophthalmologists, neuroradiologists, radiotherapists, and neuro-oncologists, in order to pursue a significant impact on postoperative outcomes and long-term prognosis.

Brain Tumors Affecting the Orbit Globe and Orbit Tumors Affecting the Brain.

Brain tumors affecting the orbit and orbital tumors affecting the brain are a heterogeneous group of lesions, with histological features, behaviors, diagnostic criteria, and treatments varying from each other. Dermoid cyst and cavernous hemangiomas are considered the most frequent benign lesions, while non-Hodgkin lymphoma is the most common malignant tumor in this region. Sharing the same anatomical region, clinical manifestations of orbital lesions may be often common to different types of lesions. Imaging studies are useful in the differential diagnosis of orbital lesions and the planning of their management. Lesions can be classified into ocular or extra-ocular ones: the latter can be further differentiated into extraconal or intraconal, based on the relationship with the extraocular muscles. Surgical therapy is the treatment of choice for most orbital lesions; however, based on the degree of removal, their histology and extension, other treatments, such as chemotherapy and radiotherapy, are indicated for the management of orbital lesions. In selected cases, chemotherapy and radiotherapy are the primary treatments. This chapter aimed to discuss the orbital anatomy, the clinical manifestations, the clinical testing and the imaging studies for orbital lesions, and the principal pathological entities affecting the orbit together with the principles of orbital surgery.

Hemorrhagic Suprasellar Central Nervous System Embryonal Tumor in an Adult: Uncommon Features of an Extremely Rare Neoplasm.

BACKGROUND: Occurrences of suprasellar central nervous system (CNS) embryonal tumors in adults are extremely rare. Hemorrhagic onset is further uncommon, with only anecdotic cases reported in the literature. The authors describe the case of a 57-year-old man affected by a suprasellar CNS embryonal tumor, with hemorrhagic onset and a unique diffusion pattern along the optic pathways. MATERIAL AND METHODS: A 57-year-old man presenting with acute visual acuity worsening and left homonymous hemianopia was referred to our hospital. Neuroradiologic studies demonstrated an infiltrating, high-grade lesion involving the optic chiasm and right retrochiasmatic pathways with a hemorrhagic area in the ipsilateral pulvinar. RESULTS: The patient underwent microsurgical biopsy. Pathologic assessment confirmed the diagnosis of CNS embryonal tumor, not otherwise specified (NOS) according to the 2016 World Health Organization (WHO) classification of CNS tumors. The patient was referred to a multimodal adjuvant treatment; he eventually died 4 months after surgery. Competent literature has been systematically reviewed in the light of the relevant changes made in the last version of the WHO classification. CONCLUSION: Embryonal tumors should be considered in the differential diagnosis for sellar and suprasellar space-occupying lesions, despite the rarity of the disease and the uncommon features at time of presentation. As per our knowledge, this is the first case ever described of hemorrhagic suprasellar embryonal tumor with a diffusion pattern along white matter fibers. Histogenesis, biomolecular and neuroradiologic features, and classification of embryonal tumors are an open field of research, with considerable implications for the definition of better diagnostic pitfalls and therapeutic regimens.

Temporal Flaps in Head and Neck Reconstructive Surgery: A Systematic Review of Surgical Techniques.

The temporal region is a great source of vascularized flap, providing extremely variable and versatile options for reconstruction in head and neck surgery. Its popularity has led to the conception of a large variety of different flaps, in terms of contents and design. Temporal flaps are highly pliable and flexible, providing adequate bulk to obliterate dead spaces and improving engraftment, thus facilitating wound healing. The need to access different anatomical compartments, often far from the original flap anatomical site, has led surgeons to develop techniques to enlarge pedicles and bulk, by reverting and splitting flaps' contents, as well as through partial mandibular and zygomatic resection. To further increase versatility, a multilayered combination of different regional tissues and muscle segmentation techniques has been described. Historically, each flap has had its own proponents and opponents, but a pointy review systematizing techniques and comparatively analyzing different flaps was still missing in the literature. The field of use of some flaps has been progressively limited by the increasing relevance of free tissue transfers, which nowadays may provide success rates up to 95% with a constrained morbidity, thus offering an effective alternative, when available. Given the wide range of reconstructive strategies based on temporal flaps, there is still a great debate on nomenclature and surgical techniques. The present study systematizes the topic, classifying regional flaps according to contents and indications. Harvesting techniques are described stepwise and schematically illustrated, thus offering an indispensable tool to the armamentarium of reconstructive surgeons.

Gamma Knife radiosurgery as primary treatment of low-grade brainstem gliomas: A systematic review and metanalysis of current evidence and predictive factors.

The current standard of care for surgically inaccessible low-grade brainstem gliomas (BS-LLGs) is external-beam radiotherapy (RT). Developments toward more innovative conformal techniques have focused on decreasing morbidity, by limiting radiation to surrounding tissues. Among these Gamma Knife radiosurgery (SRS-GK) has recently gained an increasingly important role in the treatment of these tumors. Although SRS-GK has not yet been compared with conventional RT in patients harboring focal BS-LGGs, clinical practice has been deeply influenced by trials performed on other tumors. This is the first meta-analysis on the topic, systematically reviewing the most relevant available evidence, comparing RT and SRS-GK as primary treatments of BS-LGGs, focusing on survival, clinical outcome, oncological control, and complications. Predictive factors have been systematically evaluated and analyzed according to statistical significance and clinical relevance.

Impact of C-shaped skin incision on surgical operability in the retrosigmoid approach: when a good start is half of the job.

BACKGROUND: The retrosigmoid approach (RSA) is one of the routes of choice to approach tumors and vascular lesions of the cerebellopontine angle. Among different types of skin incisions and soft tissue dissection techniques, the most widely used variants comprise the straight/lazy S-shaped and the C-shaped incisions. Several reports discuss advantages in terms of functional and clinical outcomes of the C-shaped incision, but scientific considerations about the critical impact of this kind of incision on surgical operability are still extremely limited. OBJECT: Authors comparatively analyze the advantage provided by C-shaped incision in RSA in terms of anatomic exposure and surgical operability, compared with straight/lazy S-shaped one. METHODS: A comparative microanatomical laboratory investigation was conducted. The operability score (OS) was applied for quantitative analysis of surgical operability. RESULTS: C-shaped incision, providing a significant reduction of the overall working distance (-13%) together with an overall increase of the maneuverability area (+ 204.9%), did improve the conizing effect on the surgical corridor. It optimized overall maneuverability of surgical instruments, in terms of angle of attack (+ 27.7%), as well as maneuverability arc (+ 122%), on the entire surgical field. C-shaped incision ensured good operability on all surgical targets (OS ranging from 2 to 3), most significantly improving surgical maneuverability at the porus trigeminus and internal acoustic meatus. CONCLUSION: C-shaped incision in the RSA significantly improves anatomic exposure and surgical operability as compared with straight/lazy S-shaped incision.

Resection of Intracranial Tumors with a Robotic-Assisted Digital Microscope: A Preliminary Experience with Robotic Scope.

BACKGROUND: Magnified intraoperative visualization is of paramount importance during microsurgical procedures. Although the introduction of the operating microscope represented one of the most relevant innovations in modern neurosurgery, surgical vision and maneuverability can be limited in cases with unfavorable angles of attack. In such cases, the placement of the operating microscope can be difficult and result in significant discomfort to the surgeon. In previous decades, exoscopes were introduced as alternative tools to provide optimal ergonomics by decoupling the line of sight of the surgeon from the binocular lenses. However, exoscopic platforms entail interim manual adjustments of the camera position and setting. To overcome this limitation, robotic-assisted digital microscopy was developed. We have reported our preliminary experience with the RoboticScope to investigate the feasibility and safety of this novel digital system for intraoperative magnification. METHODS: In September 2020, the RoboticScope was used to perform 3 cranial procedures for the resection of brain tumors. The surgeon's opinion was recorded to evaluate the quality of the intraoperative vision, the safety and efficacy of the surgical maneuverability, and the surgeon's personal comfort. RESULTS: RoboticScope provided remarkable advantages in terms of enhanced workflow efficacy and increased comfort of the surgeon during the microsurgical phase of the cranial procedures. The overall quality of the intraoperative digital imaging was rated not inferior to that of traditional optical microscopes. CONCLUSIONS: The RoboticScope is a promising device that might represent a valuable alternative to conventional tools for intraoperative visualization in the resection of intracranial tumors.

Endoscope-Assisted Neuroportal Transcerebellar Approach to the Fourth Ventricle: An Anatomical Study.

BACKGROUND AND STUDY AIMS: Minimally invasive approaches to deep-seated lesions still represent a fundamental issue in modern neurosurgery. Tubular retractors allow to enhance the operability of intraventricular lesions, minimizing the risk of damages to brain parenchyma. Increasing interest for portal devices has been mainly focused on supratentorial pathologies, while transportal approaches in the posterior cranial fossa have been rarely described. In the present study, the authors aimed to investigate the surgical exposure and operability obtained with a microsurgical neuroportal transcerebellar approach targeting the fourth ventricle, assisted by endoscopic exploration. MATERIAL AND METHODS: Six cadaveric specimens were provided for anatomical microsurgical dissection and Vycor ViewSite Brain Access System was used as tubular retractor. Surgical feasibility of the neuroportal transcerebellar approach was demonstrated through a definable and measurable parameter, the operability score. RESULTS: The neuroport provided a surgical corridor away from eloquent structures to target the whole fourth ventricle cavity, preventing injury to cerebellar nuclei and white matter pathways and, potentially, minimizing the risk of surgical morbidity. Maximal operability was reached in the pontomedullary junction and medullary area of the ventricular floor. Transportal endoscopic assistance contributed to a further extension of surgical exposure in blind spots, corresponding to the ipsilateral lateral recess, the uppermost part of the fourth ventricle, and the obex. CONCLUSION: The neuroportal transcerebellar approach represents a viable alternative route to the fourth ventricle, avoiding vermian splitting or subarachnoid dissection of the cerebellomedullary cistern. Endoscopic assistance enhances the exposure of the surgical field and accomplishes a valid instrument for intraventricular orientation to ease microsurgical procedures.

Combined, Rib-Sparing, Bilateral Approach to the Ventral Mid and Low Thoracic Spine: Study on Comparative Anatomy and Surgical Feasibility.

BACKGROUND: Pathologies of the ventral thoracic spine represent a challenge, igniting arguments about which should be the ideal surgical approach to access this area. Anterior transthoracic thoracotomy and a number of posterolateral routes have been developed. Among the latter, costotransversectomy has demonstrated to provide good ventral exposure with a lower, but not negligible, morbidity. The optimal approach should be the one minimizing surgical morbidity on both neural and extraneural structures while optimizing exposure. METHODS: The authors described the combined, rib-sparing, bilateral approach (CRBA) to the ventral mid/low-thoracic spine. The technique combines a transfacet pedicle partially sparing approach on one side and a transpedicular with transverse process resection on the contralateral one. A laboratory investigation was conducted. The technique was applied in a surgical setting, and a case was reported. RESULTS: CRBA is rib-sparing, completely extracavitary, and does not require pleural exposure and paraspinal muscle splitting, thus minimizing potential morbidity. The combination of 2 corridors ensures the greatest exposure compared with standard posterolateral approaches. The only blind corner is limited to a small area just in front of the dural sac. A bimanual approach optimizes control during surgical manipulation, even if the area of maneuverability and cross-section areas of surgical corridors are slightly limited compared to traditional costotransversectomy due to the minimally invasive nature of the procedure. CONCLUSIONS: CRBA represents a safe and effective option to access the ventral mid/low thoracic spine. It provides great exposure and bimanual manipulation of the surgical target, minimizes potential morbidity, and avoids entrance into the thoracic cavity and paraspinal muscle splitting.

Combined Technique of Temporal Muscle Augmentation for Muscle Reconstruction in Case of Small to Medium Anatomic Defects.

Inadequate temporal muscle (TM) reconstruction after surgery may hesitate in potentially severe functional and aesthetic sequelae, making it of paramount importance to carefully consider TM reconstruction even in case of small deformities.The authors describe the combined temporal muscle augmentation technique (CTMA), an innovative technique for TM augmentation for muscle reconstruction in case of small to medium substance loss.A cadaver study was conducted as preclinical validation of the technique for the assessment of CTMA coverage capability. CTMA consists in a combination of 2 techniques for muscle surface coverage (MSC) increase: the radial (RA) and the longitudinal augmentation (LA), which enables to harvest a radial (RF) and a longitudinal flap (LF), respectively.Each flap derives from a different muscle-bundle, spearing TM segmentation and functional performance, and are supplied by a specific neuro-vascular peduncle, which makes flaps functionally independent.A surgical case is reported to demonstrate the feasibility of the technique.Combined temporal muscle augmentation technique provides an overall coverage surface of 6.5 ± 0.6 cm, which corresponds to a gap distance of 2.5 ± 0.2 cm, with RF providing a statistically significant larger surface of coverage compared to LF (×2.1; P = 0.0001).Combined temporal muscle augmentation technique is easy and fast to perform displaying a good reconstructive capability with complete preservation of temporal muscle anatomic compartmentalization and segmental vasculature. It might be considered as a safe and effective alternative in the reconstruction of small-to medium TM defects.

Comparative anatomical study on the role of zygomatic osteotomy in the extradural subtemporal approach to the clival region, when less is more.

PURPOSE: A great concern in performing the extradural subtemporal approach (ESTA) is the evaluation of the actual advantage provided by zygomatic osteotomy (ZO). Complications related to zygomatic dissection have been widely reported in the literature, making it of paramount importance to balance the actual need to perform it, against the risk of maneuver-related morbidity. Authors comparatively analyze the putative advantage provided by ZO in the ESTA in terms of anatomic exposure and surgical operability. Technical limits and potentials are critically revised and discussed. METHODS: A comparative microanatomical laboratory investigation was conducted. The operability score (OS) was applied for quantitative analysis of surgical operability. RESULTS: ZO was found to provide a weakly significant improvement in the surgical angle of attack (p value 0.01) (mean increase 3°). Maneuverability arch (MAC) increase related to ZO did not reach statistical significance (p value 0.09) (mean increase 2°). The variations provided by MAC increase on the conizing effect (CE) did not lead to an actual advantage in the real surgical scenario, modifying the vision area (VA) in terms of reduction of central vision area (CA) in favor of an increase of peripheral vision area (PA) only in the most caudal part of the surgical field. Ultimately, ZO did not influence the overall OS, scoring both ESTA-ZO+ and ESTA-ZO- 2 out of 3. CONCLUSION: In the ESTA, ZO does not provide an actual significant advantage in terms of surgical operability on clival and paraclival areas.

Temporal Galeofascial Flap for Reconstruction After Transmaxillary Approaches to the Clival Region.

BACKGROUND: A paramount concern after transmaxillary approaches has been skull base reconstruction. Regional pedicled flaps represent the best reconstructive option. We have described a technique to harvest a lateral-based multilayered vascularized flap for skull base reconstruction after resection of large tumors using the transmaxillary transpterygoid approach (TMTPA). METHODS: We performed a cadaver study using the TMTPA to harvest the combined temporal galeofascial flap (CTGF). The first layer, with major sealing capabilities, is composed by a temporoparietal galeal-pericranial flap. The second layer is composed by temporal muscle fascia to provide mechanical support for flap dural engrafting. RESULTS: The CTGF provides excellent coverage of both the clival dural lining and the ipsilateral pterygopalatine fossa structures (×1.6). The CTGF is pliable and easy to harvest. It offers great flexibility in flap content and design, providing a large quantity of vascularized tissue. The vascular pedicle derives from the superficial temporal vessels, which can ensure flap trophism. CONCLUSIONS: CTGF represents an effective option as a regional multilayered pedicled flap for skull base reconstruction after resection of clival tumors using the TMTPA. The flap pedicle, owing to its anatomical location, will often be preserved even after repeated microsurgical or endoscopic procedures, providing a technical alternative for reconstruction even in patients who have undergone multiple surgeries with low residual availability of regional flaps.

Temporal myofascial segmentation for multilayer reconstruction of middle cranial fossa floor after extradural subtemporal approach to the clival and paraclival region.

BACKGROUND: Skull-base reconstruction represents a concern after resection of middle fossa (MF) tumors by the extradural subtemporal transzygomatic approach (ESTZ). Regional pedicled flaps appear to be the best option. This study describes a technique for temporal myofascial segmentation to harvest a multilayered vascularized flap for MF reconstruction, which might preserve temporal muscle (TM) function and its blood supply. METHODS: The technique to harvest a combined segmented temporal myofascial flap (CSTMF) is described. The flap consists in a temporal fascial (TFF) and a muscle flap (TMF), composed by TM anterior-medial bundle (AMB). RESULTS: CSTMF provides wide coverage of dural lining, through the TFF, and of dead-space, through the TMF. The possibility to tailor TMF according to the need, anatomically preserving the blood supply, enables to significantly increase its volume. CONCLUSION: CSTMF represents an effective option as regional multilayered pedicled flap for MF reconstruction, potentially preserving TM function and minimizing the cosmetic impact.

Anatomic Study on Neuroendoportal Transcortical Approach to Lateral Ventricles.

BACKGROUND: Resection of intraventricular lesions remains a challenge for modern neurosurgery. Endoscopy has provided great advantages in ventricular surgery, even if limited in terms of operability, due to the restricted working channel and impossibility for bimanual surgical manipulation. Tubular approaches have been considered as an option, enabling the use of microsurgical techniques, minimizing violation of brain tissue. The aim of our study was to describe and critically evaluate the use of portal surgery to access lateral ventricles in terms of surgical exposure and operability. METHODS: A microanatomic laboratory cadaver study was conducted with a stepwise description of the surgical technique. The operability score was applied for quantitative analysis of surgical operability, and an illustrative case is reported. RESULTS: Through the anterior approach, the neuroport provides maximal operability at the foramen of Monro and the posterior aspect of the frontal horn, while through the posterior approach maximal operability is achieved in the paratrigonal area. Endoscopic assistance does not affect operability but provides adjunctive exposure in blind spots, as the roof of the frontal horn, the most anterior aspect of the temporal and occipital horn. CONCLUSIONS: Ventricular tubular systems provide adequate visualization, with minimal brain retraction, improving operability as compared with endoscopy. Endoscopic assistance critically widens surgical exposure in blind spots without providing concomitant significant advantage in terms of surgical operability.

Bilateral Temporal Myofascial Flap for the Reconstruction of Frontal Sinus Defects.

BACKGROUND: A frontal sinus infection, following a transsinus skull base procedure, portends potentially life-threatening complications, making surgical revision mandatory in refractory infections. The authors describe the application of the bilateral temporal myofascial flap (BTMF) as a valuable option for frontal sinus reconstruction, when pericranial or galeal-frontalis myofascial flap (GFMF) is no longer available. METHODS: A microanatomic laboratory cadaver investigation was conducted to obtain anthropometric measurements. Surgical technique is described, and intraoperative images are provided. RESULTS: The surgical steps of this technique and the related intraoperative images are reported. One case illustration regarding frontal sinus reconstruction following a postoperative infection, as a complication after a transsinus procedure, is reported. CONCLUSION: The BTMF should be considered as a valuable option for frontal sinus reconstruction after transsinus skull base procedures when GFMF is not available.

Gamma Knife Radiosurgery for Residual and Recurrent Vestibular Schwannomas After Previous Surgery: Clinical Results in a Series of 90 Patients and Review of the Literature.

OBJECTIVE: Complete removal of vestibular schwannomas (VS) is not always achievable without any risk of disabling postoperative complications, especially in terms of facial nerve function. Moreover, even after gross total removal, a relevant rate of recurrence has been reported. The aim of this study is to validate Gamma Knife radiosurgery (GKRS) as an effective strategy to treat tumor regrowth after previous surgery. METHODS: Ninety patients treated with GKRS for VS after previous microsurgery were included in the present study. GKRS was performed at a median of 31 months (range, 4-174 months) postoperatively. Mean tumor volume was 3.35 cm3 (median, 2.5 cm3; range, 0.027-13 cm3) and median marginal dose was 13 Gy. RESULTS: At a mean follow-up of 77.2 months, tumor control was achieved in 90% of patients: 2 patients underwent repeated GKRS, and 7 patients underwent further microsurgery. Tumor shrinkage at last follow-up was recorded in 80.3% of cases. The complication rate was low and many consisted of a transient worsening of preexisting symptoms. The overall incidence of persisting facial nerve deficit and trigeminal nerve impairment was, in both cases, 3.3%. Two of 5 patients (40%) preserved functional hearing at last follow-up. One patient (1.1%) underwent ventriculoperitoneal shunting 12 months after GKRS. CONCLUSIONS: GKRS is a safe and effective treatment for growing residual and recurrent VSs, with tumor control obtained in 90% of cases and a low morbidity rate. Moreover, the possibility of treating patients with major medical comorbidities constitutes a significant advantage over repeated surgery.