Resection Of Skull Base Tumors Research Articles

Early experience of radiofrequency ablation-assisted resection of skull base tumor through an endoscopic endonasal approach

To describe the early experience of resecting skull base tumor via a radiofrequency ablation-assisted endoscopic endonasal approach, investigate the safety and feasibility of the technique, and to assess its preliminary treatment outcomes. Ten patients with skull base tumor who were admitted between September and November 2013 were operated on through a radiofrequency ablation-assisted endoscopic endonasal approach in Xuanwu hospital of capital medical university. In this study, the operative technique was described, and the degree of resection, complications and the early clinical outcomes was presented. Complete resection was achieved in all patients using this technique. No patient in the series experienced a new neurological deficit, cerebrospinal fluid leak or meningitis after surgery. No recurrence and death related to skull base tumor were found in the follow-up period (16-18 months). The volume of intraoperative blood loss was 60 to 1 000 ml (medium 285 ml). The duration of operations was from 42 to 150 min (medium 95 min). The hospital stay was from 14 to 19 d (average 15.7 d). Our limited experience indicates that this technique is feasible and safe for the complete resection of some skull base tumors in selected cases.

Endoscopic versus Open Approaches in Management of Sinonasal Melanoma

Background: Sinonasal melanoma (SNM) accounts for 5% of all malignant neoplasms of the nasal cavity and paranasal sinuses. It is an aggressive malignancy with a high rate of metastasis and 2-year overall survival rate of 30%. Although rare, the overall incidence of SNM is on the rise. Knowing this and considering the increased utilization of nasal endoscopy in the resection of anterior skull base tumors, comparison of traditional open craniofacial resections to endoscopic resections in SNM is warranted.

Fascia patchwork closure for endoscopic endonasal skull base surgery.

With the development of endoscopic technology and surgery, resection of midline skull base tumors has been achieved using endoscopic endonasal skull base (EESB) approaches. EESB approaches reportedly have a greater risk of postoperative cerebrospinal fluid (CSF) leakage. Recently, the introduction of the nasoseptal flap (NSF) decreased dramatically the incidence of CSF leakage, but the use of an NSF increases the risk of disturbing the function of the nose. Here, we report our new technique called "fascia patchwork closure" for closure after EESB surgery and its outcome. All 48 cases involved midline skull base tumors resected via EESB approaches. Of them, 32 cases were closed by the fascia patchwork technique after tumor resection, and there was no incidence of CSF leakage. Moreover, 6 of the 32 cases were closed without the use of an NSF, indicating that the fascia patchwork closure approach is effective as part of a multilayer closure for the prevention of CSF leakage. The establishment and popularization of this technique might result in the further development of EESB surgery and also an improvement of postoperative nasal function.

Multimodal navigated skull base tumor resection using image-based vascular and cranial nerve segmentation: A prospective pilot study.

Background:Skull base tumors frequently encase or invade adjacent normal neurovascular structures. For this reason, optimal tumor resection with incomplete knowledge of patient anatomy remains a challenge.Methods:To determine the accuracy and utility of image-based preoperative segmentation in skull base tumor resections, we performed a prospective study. Ten patients with skull base tumors underwent preoperative 3T magnetic resonance imaging, which included thin section three-dimensional (3D) space T2, 3D time of flight, and magnetization-prepared rapid acquisition gradient echo sequences. Imaging sequences were loaded in the neuronavigation system for segmentation and preoperative planning. Five different neurovascular landmarks were identified in each case and measured for accuracy using the neuronavigation system. Each segmented neurovascular element was validated by manual placement of the navigation probe, and errors of localization were measured.Results:Strong correspondence between image-based segmentation and microscopic view was found at the surface of the tumor and tumor-normal brain interfaces in all cases. The accuracy of the measurements was 0.45 ± 0.21 mm (mean ± standard deviation). This information reassured the surgeon and prevented vascular injury intraoperatively. Preoperative segmentation of the related cranial nerves was possible in 80% of cases and helped the surgeon localize involved cranial nerves in all cases.Conclusion:Image-based preoperative vascular and neural element segmentation with 3D reconstruction is highly informative preoperatively and could increase the vigilance of neurosurgeons for preventing neurovascular injury during skull base surgeries. Additionally, the accuracy found in this study is superior to previously reported measurements. This novel preliminary study is encouraging for future validation with larger numbers of patients.

Surgical technique for repair of complex anterior skull base defects.

Background:Modern microsurgical techniques enable en bloc resection of complex skull base tumors. Anterior cranial base surgery, particularly, has been associated with a high rate of postoperative cerebrospinal fluid (CSF) leak, meningitis, intracranial abscess, and pneumocephalus. We introduce simple modifications to already existing surgical strategies designed to minimize the incidence of postoperative CSF leak and associated morbidity and mortality.Methods:Medical records from 1995 to 2013 were reviewed in accordance with the Institutional Review Board. We identified 21 patients who underwent operations for repair of large anterior skull base defects following removal of sinonasal or intracranial pathology using standard craniofacial procedures. Patient charts were screened for CSF leak, meningitis, or intracranial abscess formation.Results:A total of 15 male and 6 female patients with an age range of 26–89 years were included. All patients were managed with the same operative technique for reconstruction of the frontal dura and skull base defect. Spinal drainage was used intraoperatively in all cases but the lumbar drain was removed at the end of each case in all patients. Only one patient required re-operation for repair of persistent CSF leak. None of the patients developed meningitis or intracranial abscess. There were no perioperative mortalities. Median follow-up was 10 months.Conclusion:The layered reconstruction of large anterior cranial fossa defects resulted in postoperative CSF leak in only 5% of the patients and represents a simple and effective closure option for skull base surgeons.

Transfacial Surgical Approaches to Secure Wide Exposure of the Skull Base

BackgroundTreatment of skull base tumors is challenging due to limited access and presence of important neurovascular structures nearby. The success of a complete tumor resection depends on the extent of tumor exposure and secure field of view. While these tumors are often removed by transcranial endoscopic access, transfacial approach is sometimes required depending on the location and size of the tumor. This study describes various transfacial approaches in patients undergoing skull base tumor resection.MethodsFrom March to November 2013, 15 patients underwent skull base tumor resection via transfacial accesses at a tertiary institution. Data were reviewed for patient demographics, type of access used, completeness of tumor resection, surgical outcome, and postoperative complications.ResultsTwo clivus tumor patients underwent transmaxillary approach; three tuberculum- sellae and suprasellar-hypothalamus tumor patients underwent transbasal approach; three clinoid and retrobulbar intraconal orbital tumor patients underwent orbitozygomatic approach; and seven petroclival-area, pons, cavernous sinus, and lateral-sphenoid-wing tumor patients underwent zygomatic approach. In all cases, the upper and lower margins of the tumor were visible. Complete tumor removal consisted of 10 cases, and partial tumor removal in 5. There were no immediate major complications observed for the transfacial portion of the operations. The overall cosmetic results were satisfactory.ConclusionPlastic surgeons can use various transfacial approaches according to the location and size of skull base tumors to secure a sufficient field of view for neurosurgeons.

NI-17 * MULTIMODAL NAVIGATED SKULL BASE TUMOR RESECTION USING IMAGE-BASED VASCULAR AND CRANIAL NERVE SEGMENTATION: A PROSPECTIVE VALIDATION STUDY

INTRODUCTION: Skull base tumors frequently encase or invade adjacent normal neural and vascular structures. Preoperative segmentation and planning to identify these anatomical landmarks are essentially important in complex skull base tumor resection for minimizing surgical morbidities. METHODS: Ten patients with skull base tumors underwent preoperative 3TMRI, which included thin sectioned 3D space T2, 3D Time of Flight and MPRAGE sequences. Images were reviewed by an expert independent neuroradiologist. Imaging sequences were loaded in BrainLab iPlanNet (8/10) and Stryker (2/10) for segmentation and pre-operative planning. After patient registration to the intra-op neuronavigation system and surgical exposure, each segmented neural or vascular element was validated by manual placement of the navigation probe. RESULTS: Perfect correspondence between image-based segmentation and microscopic view was found at the surface of the tumor and tumor-normal brain interfaces in all cases. Pre-operative segmentation of the major arteries, veins, and venous sinuses matched with the intra-operative microscopic findings in all cases (Dice-coefficient =1). This information reassured the surgeon and prevented vascular tearing during different stages of tumor resection. This also helped in preventing major intra-operative arterial or venous bleeding. Preoperative segmentation of the related cranial nerves was technically possible in only 80% of cases. However, Image-guidance helped the surgeon to localize the involved cranial nerves in all cases. CONCLUSION: Image-based pre-operative vascular and neural element segmentation, especially with 3D reconstruction, is highly informative preoperatively and could increase the vigilance of neurosurgeons for preventing vascular and neural injury during skull base surgeries. This novel preliminary study is encouraging for future prospective intraoperative validation with larger numbers of patients.

Validation of Outcome Measurements in Surgically Treated Vestibular Schwannomas

Introduction: Surgical resection of benign skull base tumors carries risk of postoperative morbidity. With decrease in morbidity and mortality, concerns and expectations for surgery have changed. In this scenario it is essential to assess risk of postoperative morbidity and incapacity. In the present study, we have validated different outcome tools with preoperative factors. Patients and Methods: A total of 167 patients from a retrospective and a prospective cohort who underwent microsurgical resection for vestibular schwannomas between 2001 and 2010 were surveyed. Preoperative variables such as age, gender, tumor size, and neurological symptoms were assayed against different outcome measures such as QOL work capacity/independency (actual work capacity, Karnovsky, independency), facial function (HB and SB), neurological score (patients and physicians score) in univariate and multivariate analysis. Results: All outcome measures except Eq. 5D showed a significant decrease postoperatively. Only HB grade differed significantly between the cohorts with a better score in the prospective cohort. Patient assessed neurological score correlated significantly to all other outcome measures. Conclusion: Standard QOL instruments may not be sensitive enough to measure outcome after surgery of benign skull base tumors, work capacity is useful in younger patients but patient assessed morbidity may be more useful in all patients.

Impact of Chemoradiotherapy on CSF Leak Repair after Skull Base Surgery.

Background Transnasal endoscopic resection (TER) has become the treatment of choice for many skull base tumors. A major limitation of TER is the management of large dural defects and the need for repair of cerebrospinal fluid (CSF) leaks, particularly among patients who are treated with chemotherapy (CTX) or radiotherapy (RT). The objective of this study is to determine the impact of CTX and RT on the success of CSF leak repair after TER. Methods We performed a retrospective chart review of a single-institution experience of TER from 1992 to 2011. Results We identified 28 patients who had endoscopic CSF leak repair after resection of malignant skull base tumors. Preoperative RT was utilized in 18 patients, and 9 had undergone CTX. All patients required CSF leak repair with rotational flaps after cribriform and/or dural resection. CSF leak repair failed in three patients (11%). A history of RT or CTX was not associated with failed CSF leak repair. Conclusion Adjuvant or neoadjuvant CTX or RT is not associated with failed CSF leak repair. Successful CSF leak repair can be performed in patients with malignant skull base tumors with an acceptable risk profile.

Intraoperative monitoring of the abducens nerve in extended endonasal endoscopic approach: A pilot study technical report

BackgroundTo determine the reliability and usefulness of intraoperative monitoring of the abducens nerve during extended endonasal endoscopic skull base tumor resection. MethodsWe performed abducens nerve intraoperative monitoring in 8 patients with giant clival lesions recording with needle electrodes sutured directly into the lateral rectus muscles of the eye to evaluate spontaneous electromyographic activity and triggered responses following stimulation of the abducens nerves. ResultsA total of 16 abducens nerves were successfully recorded during endoscopic endonasal skull base surgeries. Neurotonic discharges were seen in two patients (12% [2/16] abducens nerves). Compound muscle action potentials of the abducens nerves were evoked with 0.1–4mA and maintained without changes during the neurosurgical procedures. No patient had new neurological deficits or ophthalmological complications post-surgery. ConclusionsIntraoperative monitoring of the abducens nerve during the extended endonasal endoscopic approach to skull base tumors appears to be a safe method with the potential to prevent neural injury through the evaluation of neurotonic discharges and triggered responses.

Applying Free Microvascular Latissimus Dorsi Flaps for Reconstruction of Post-Ablative Defects Affecting the Skull Base

Introduction : Tumors of the head and neck area are complex and pose a significant challenge for radical resection and subsequent reconstruction especially when the skull base is affected. With evolution in surgical reconstructive techniques, better reconstruction of these complex post-ablative defects is now possible and facilitates more aggressive surgical management. The aim of this study was to investigate the course of reconstructive treatment and outcomes with use of free microvascular latissimus dorsi flaps after tumor ablation of skull base penetrating malignancies. Material and methods : All extensive skull base tumor resections with latissimus dorsi free flap reconstruction made in the General University hospital Gregorio MaraA±A³n, between January 2010 and December 2012 were reviewed. Results : Three different types of free latissimus dorsi flaps were used being the grafted muscle flap the most common one. Complications occurred in 44.4 % of patients but no flaps were lost. Two latissimus dorsi donor site seromas were observed (22.2%). Conclusion : For the reconstruction aim of extensive skull base defects, the latissimus dorsi free flap seems to be a reliable option.

Structural pedicled mucochondral‐osteal nasoseptal flap: a novel method for orbital floor reconstruction after sinonasal and skull base tumor resection

Unrepaired orbital floor defects after sinonasal and skull-base tumor resection can lead to herniation of orbital contents into the maxillary or ethmoidal sinuses, possibly resulting in infection and significant cosmetic and functional deficits. Orbital floor defects are usually repaired using prosthetic implants or autogenous material. Nasal septal cartilage has been used previously as a free graft for reconstruction. However, its reliance on local vascular supply can result in ischemia and necrosis in the postoperative period. The vascularized pedicled nasoseptal flap, consisting of mucoperichondrium and mucoperiosteum, is routinely used as an effective reconstruction method for endoscopic repair of cerebrospinal fluid leaks arising from skull base dural defects. However, this flap does not provide rigid structural reconstruction when used alone. We report a case of an orbital floor defect repaired using a pedicled mucochondral-osteal nasoseptal flap. This technique incorporates the structural component of the nasal septal cartilage and bone with the vascularized pedicled nasoseptal flap. This repair technique may be useful in patients requiring postoperative radiotherapy.

Landmark for Medial Extent of Paraclival Carotid Artery at Anterior Genu

The popularity and ability of endonasal techniques for the resection of skull base tumors has increased in recent years leading to more extended resections. The rupture of the internal carotid artery is one of the most feared and devastating complications of the endonasal technique. As endonasal skull base resections have become more extended, the incidence of internal carotid injury has increased. The current surgical technique for localizing the clival portion of the carotid involves an extensive technique of drilling out the pterygoid plate and identifying and following the vidian canal to the carotid artery. The purpose of this study was to identify an intraoperative landmark that consistently marked a location medial to the anterior genu of the ascending paraclival carotid artery. The study looked at 102 CT sinus with 61 females and 41 males all over the age of 18 years old. A trajectory from the nasolacrimal duct to the sphenopalatine foramen consistently ended at the lateral portion of the anterior genu, this line was termed the nasolacrimal-sphenopalatine-carotid line (NSC line). Scans were evaluated and measured to test if 1 cm medial to this landmark was always medial to the carotid.

Sinonasal Quality of Life Outcomes after Minimally Invasive Resection of Sinonasal and Skull Base Tumors

Background: Minimally invasive endoscopic resection (MIER) has emerged as the standard for surgical management of benign and malignant sinonasal and skull base neoplasms. The objective of the present study was to assess sinonasal quality of life (QOL) and to analyze factors that impact symptomatology after surgery. Methods: Single-institution observational cohort study was performed on 94 patients over a 3-year period.

Delayed Complications after Anterior Craniofacial Resection of Malignant Skull Base Tumors

Objective To report complications occurring at least 6 months after completion of treatment for patients with anterior skull base malignancy undergoing anterior craniofacial resection (CFR). Design Retrospective review of medical records of all patients undergoing traditional CFR for treatment of anterior skull base malignancy from 2002 through 2011. Setting Massachusetts General Hospital/Massachusetts Eye and Ear Infirmary Cranial Base Center. Participants Thirty-one consecutive patients who had at least 18 months of follow-up for analysis were reviewed. All patients underwent traditional CFR. A total of 28 patients received postoperative proton beam radiation therapy. Eleven patients received adjuvant chemotherapy. Main Outcome Measures A delayed complication was any complication occurring at least 6 months after the completion of treatment. Results Seventeen patients had delayed complications. Orbital complications were the most common type (13 patients) followed by issues with wound healing (6 patients). The most common orbital complication was epiphora (7 patients). The most common wound complication was a nasocutaneous fistula (5 patients). Conclusions Patients with anterior skull malignancy can develop complications months to years after the completion of treatment. Therefore, it is important to continue to follow and report complications for several years when deciding on the optimal approach for treatment of these patients.

The fallopian canal: a comprehensive review and proposal of a new classification

The facial nerve follows a complex course through the skull base. Understanding its anatomy is crucial during standard skull base approaches and resection of certain skull base tumors closely related to the nerve, especially, tumors at the cerebellopontine angle. Herein, we review the fallopian canal and its implications in surgical approaches to the skull base. Furthermore, we suggest a new classification. Based on the anatomy and literature, we propose that the meatal segment of the facial nerve be included as a component of the fallopian canal. A comprehensive knowledge of the course of the facial nerve is important to those who treat patients with pathology of or near this cranial nerve.

Expanded Endonasal Approach using Vascularized Septal Flap Reconstruction for Skull Base Tumors has a Negative Impact on Sinonasal Symptoms and Quality of Life

Endoscopic transsphenoidal surgery is currently the optimal treatment for skull base tumors. This study was designed to assess patient's sinonasal symptoms and quality of life (QoL) after resection of pituitary adenoma or skull base tumors using vascularized septal flap (VSF) reconstruction. Patients with pituitary adenoma underwent the transnasal transsphenoidal endoscopic approach (TTEA; n = 38), and patients with other benign parasellar tumors underwent the expanded endonasal approach (EEA; n = 17) with VSF. Assessment of sinonasal symptoms and QoL by the 36-item Short-Form (SF-36) and the 31-item Rhinosinusitis Outcome Measure (RSOM-31) were performed before and 3 months after surgery. At baseline, the total seven-sinonasal symptom score (T7SSS) was similar between both groups. After surgery, T7SSS significantly increased in EEA but not in TTEA patients. EEA patients reported more smell loss (40.1 ± 26.2; p < 0.05) and posterior nasal discharge (49.3 ± 30.1; p < 0.05) than TTEA patients (21.6 ± 30.9 and 22.5 ± 27.5, respectively). At baseline, both groups had poorer SF-36 compared with the general population. TTEA patients had poorer QoL (on general health, vitality, and mental health) than EEA patients. After surgery, TTEA patients showed impaired physical role and bodily pain compared with baseline, and EEA patients showed impaired physical role and mental health. At baseline, RSOM scores were similar in TTEA and EEA groups. After surgery, EEA but not TTEA patients reported poorer nasal and general symptoms. The EEA with VSF produces more sinonasal symptoms than pituitary surgery, surgery for skull base and pituitary tumors has negative impact on QoL, and functioning tumors have no further negative effect on sinonasal symptoms and QoL.

Outcomes following Microvascular Free Tissue Transfer in Reconstructing Skull Base Defects

Objective Successful resection of complex tumors involving the skull base (SB) depends on the ability to reconstruct the resulting defects. The objective of this study was to assess the outcomes of patients undergoing reconstruction after resection of SB tumors with free flaps. Methods From 1995 to 2010 a retrospective review of cases was undertaken. Demographics, histology, surgical management, complications, locoregional control, and survival were analyzed. Results We performed 62 flaps in 57 patients. There was a preponderance of sinonasal malignancies (45%), and most lesions involved the anterior SB (81%). A total of 94% of patients underwent radiotherapy. Reconstruction was undertaken mainly with anterolateral thigh (37%) or radial forearm (34%) flaps. Complications occurred in 17% of patients, and the flap's success rate was 94%. Conclusion Free flaps are versatile and highly reliable for reconstructing defects resulting from resections of the SB. They should be considered for SB reconstruction of large three-dimensional defects as well as defects involving an irradiated field. Successful reconstruction of the SB can be performed using a small number of highly dependable flaps.

Endoscopic Endonasal Approaches for Benign Tumors Involving the Skull Base

With continued refinements in endoscopic image quality, instrumentation, surgical navigation, skull base closure techniques, anatomical understanding, and advanced neurosurgical and otolaryngological training, the endonasal endoscopic approach has become a well-accepted and widely utilized technique for the resection of most benign midline ventral skull base tumors. While pituitary adenomas and Rathke’s cleft cysts constitute the most common lesions removed via this route, increasing experience has led to its broader utilization for more complex lesions, including craniopharyngiomas, midline meningiomas, and schwannomas. In this article, we review the recent literature published on this topic with an emphasis on the most interesting and important new results and discoveries for each type of benign skull base tumor.

The Use of the Temporoparietal Fascial Flap in Preventing CSF Leak after Lateral Skull Base Surgery

Objective Determine the effectiveness of the temporoparietal fascia flap (TPFF) with adipose tissue in preventing cerebrospinal fluid (CSF) leaks for lateral skull base tumor reconstruction. Design A retrospective chart review from 2005 to 2010 was conducted of patients undergoing skull base tumor resection. Patients with TPFF reconstruction were compared with those with adipose packing alone based on lumbar drain placement, tumor size, extent of dissection, and incidence of CSF leak. Data was analyzed with a Fisher exact test at p < 0.05. Setting Tertiary care institution. Main Outcome Measures Incidence of CSF leak. Results A total of 16 patients had a TPFF reconstruction; 20 had adipose only. Four TPFF patients had lumbar drain placement, as did six in the adipose-only group. Six patients had a CSF leak, all in the adipose-only group (p = 0.02). Patients with a lumbar drain were more likely to have larger tumors (p = 0.01) and to have a CSF leak if they had adipose-only reconstruction (p = 0.07). Conclusions Lateral skull base reconstruction using TPFF with adipose tissue is easily performed and has a low operative morbidity. Early results show a significant decrease in the rate of CSF leak using TPFF, particularly in high-risk patients.