Benign Tumors of the Anterior Cranial Base.

ABSTRACTBACKGROUND: Endoscopic transnasal surgery has gained rapid global acceptance over the last two decades. The growing literature and understanding of anterior skull base endoscopic anatomy, in addition to new dedicated endoscopic instruments and tools, have helped to expand the use of the transnasal route in skull base surgery.OBJECTIVE: Report our early experience in expanded endoscopic transnasal surgery (EETS) and approach to skull base neoplasms.DESIGN: Descriptive, retrospective case series.SETTING: Major tertiary care center.PATIENTS AND METHODS: A retrospective case review was conducted at King Saud University Medical City between December 2014 and August 2019. Cases with skull base neoplasms that underwent EETS were included. EETS was defined as endoscopic surgical exposure that extended beyond the sellar margins (prechiasmatic sulcus superiorly, clival recess inferiorly, cavernous carotid lines laterally). Routine transsphenoidal pituitary neoplasms, neoplasms of sinonasal origin and meningoencephaloceles were excluded.MAIN OUTCOME MEASURES: Preoperative clinical assessment, imaging results, surgical approach, and hospital course were all retrieved from the patient electronic charts. Clinical follow-up, perioperative complications, and gross residual tumor rates were documented and reviewed.SAMPLE SIZE AND CHARACTERISTICS: 45 cases of EETS, 13 males and 32 females with mean age of 39.0 (17.7) years (range 2–70 years).RESULTS: The series comprised a wide range of pathologies, including giant pituitary adenoma (8 cases), meningioma (23 cases), craniopharyngioma (4 cases), chordoma (4 cases), optic pathway glioma (2 cases), epidermoid neoplasms (2 cases), astrocytoma (1 case), and teratoma (1 case). For the entire series, gross total resection was achieved in 25/45 operations (55.5%). Postoperative cerebrospinal fluid leak was the most common complication observed in 9 patients (20%) which were all managed endoscopically. Major vascular complications occurred in 2 patients (4.4%) and are described. Other complications are outlined as well. No mortality was observed.CONCLUSIONS: EETS to the skull base can be done with results comparable to traditional approaches. More work is needed to expand our experience, improve outcomes, and educate the public and medical community in our region about the usefulness of this approach.LIMITATIONS: Sample size and study design.CONFLICT OF INTEREST: None.

Objective: To investigate the cause and urgent management of internal carotid artery injury during transnasal endoscopic skull base surgery. Methods: Five cases of internal carotid artery injury encountered during transnasal endoscopic skull base surgery in Department of Otorhinolaryngology Head and Neck Surgery, the First Affiliated Hospital of University of Science of Technology of China, Anhui Provincial Hospital from December 2010 to July 2017 were analysed retrospectively. There were 2 cases of adenoid cystic carcinoma, 1 case of salivary gland-type adenocarcinoma, 1 case of petrous apex cholesterol granulomas and 1 case of squamous carcinoma. The cause of internal carotid artery injury and subsequent treatment were analysed, in order to prevent internal carotid artery injury during transnasal endoscopic surgery. Results: Intraoperatively, all these 5 cases were packed with vaseline strip successfully. Two cases underwent subsequent intravascular covered stent graft implantation; 1 case underwent replacement of packing with muscle fascia graft; 1 case was packed with vaseline strip in nasal and nasopharyngeal cavity; 1 case accepted ligation of common carotid artery after failure of nasal packing. Four cases were successfully treated without craniocerebral or ocular complications. Otherwise, 1 case demonstrated with extremity paralysis after ligation. Follow up ranged from 6 to 84 months, no patient died. Conclusion: The injury of internal carotid artery is related with improper operative procedures and anatomic localization, which should be treated properly with emergent hemostasis, and an experienced multidisciplinary team to repair vascular damage is very important.

The present study investigates the indications for transnasal endoscopic surgery in treating post-operative maxillary cysts. In this retrospective study, the records of 118 patients with post-operative maxillary cysts (88 unilateral and 30 bilateral) consisting of 148 procedures were reviewed. A transnasal endoscopic approach was performed in 144 lesions (97.3 per cent). A combined endonasal endoscopic and canine fossa (external) approach was performed in 4 of 148 lesions, because the cysts were located distant from the nasal cavity and had a thick bony wall. A ventilation stent was placed in four patients (four cysts) to avoid post-operative meatal antrostomy stenosis. Recurrence was observed in five patients (4.2 per cent), all of whom subsequently underwent transnasal endoscopic revision surgery. Transnasal endoscopic surgery is an effective treatment for post-operative maxillary cyst with the exception of cysts located distant from the nasal cavity.

“How Much Is Enough?” Endonasal Surgery for Olfactory Neuroblastoma

Endoscopic Transnasal Resection of Solitary Fibrous Tumor in the Optic Canal

Recent advancements in endoscopic transnasal surgery(ETS)have expanded the application of this technique to meningiomas in the central skull base area, offering a less invasive alternative with a potentially lower physical burden on patients than conventional microscopic skull base surgery. Notably, while ETS allows surgeons to reach tumors without traversing the brain and nerves, thus theoretically reducing the risk of cranial nerve damage, it requires a high level of proficiency to avoid inadequate resection and tumor recurrence. In this article, we discuss the various surgical considerations, including preoperative imaging, surgical setting, nasal cavity expansion, skull base opening, tumor removal, and skull base reconstruction, as general procedures for specific meningiomas. We further describe the concept and details of our multi-layer fascial closure technique for dural repair in ETS, underlining the importance of skilled dural reconstruction in preventing postoperative complications. In conclusion, while ETS for skull base meningiomas presents a promising and less invasive treatment option, its success relies heavily on the surgeon's experience and understanding of the skull base anatomy, stressing the need for careful approach selection.

Transnasal Endoscopic Surgery for Resection of Angiofibroma With and Without Arterial Embolization

OBJECTIVE Skull base chondrosarcoma is one of the most intractable tumors because of its aggressive biological behavior and involvement of the internal carotid artery and cranial nerves (CNs). One of the most accepted treatment strategies for skull base chondrosarcoma has been surgical removal of the tumor in conjunction with proactive extensive radiation therapy (RT) to the original tumor bed. However, the optimal strategy has not been determined. The goal of this study was to evaluate the early results of endoscopic transnasal surgery (ETS). METHODS The authors retrospectively analyzed 19 consecutive patients who underwent ETS at their institution since 2010. Adjuvant stereotactic radiosurgery (SRS) was performed only for the small residual tumors that were not resected to avoid critical neurological complications. Histological confirmation and evaluation of the MIB-1 index was performed in all cases. The Kaplan-Meier method was used to determine the actuarial rate of tumor-free survival. RESULTS The median tumor volume and maximal diameter were 14.5 cm3 (range 1.4-88.4 cm3) and 3.8 cm (range 1.5-6.7 cm), respectively. Nine patients (47%) had intradural extension of the tumor. Gross-total resection was achieved in 15 (78.9%) of the 19 patients, without any disabling complications. In 4 patients, the surgery resulted in subtotal (n = 2, 11%) or partial (n = 2, 11%) resection because the tumors involved critical structures, including the basilar artery or the lower CNs. These 4 patients were additionally treated with SRS. The median follow-up duration was 47, 28, and 27 months after the diagnosis, ETS, and SRS, respectively. In 1 patient with an anterior skull base chondrosarcoma, the tumor relapsed in the optic canal 1 year later and was treated with a second ETS. Favorable tumor control was achieved in all other patients. The actuarial tumor control rate was 93% at 5 years. At the final follow-up, all patients were alive and able to perform independent activities of daily living without continuous neurological sequelae. CONCLUSIONS These preliminary results suggest that ETS can achieve sufficient radical tumor removal, resulting in comparative resection rates with fewer neurological complications to those in previous reports. Although the follow-up periods of these cases were relatively short, elective SRS to the small tumor remnant may be rational, achieving successful tumor control in some cases, instead of using proactive extensive RT. Thus, the addition of RT should be discussed with each patient, after due consideration of histological grading and biological behavior. To determine the efficacy of this strategy, a larger case series with a longer follow-up period is essential. However, this strategy may be able to establish evidence in the management of skull base chondrosarcoma, providing less-invasive and effective options as an initial step of treatment.

Three-Dimensional Printed Skull Base Simulation for Transnasal Endoscopic Surgical Training.

Endoscopic trans-nasal surgery has evolved a long way from the days of narrow corridors with high rates of cerebrospinal fluid (CSF) leak to the present state of HD optics with better tissue differentiation, extended approaches, and use of vascularized flaps for defect closure. Trans-nasal approach is an established technique for pituitary tumors practiced worldwide. However, trans-nasal endoscopic excision of suprasellar meningiomas provides a tougher challenge in terms of instrument manipulation, tumor excision with good visual outcome, and a robust defect closure to prevent CSF leaks. Out of 83 cases of midline anterior cranial fossa meningiomas operated over 14 years, our experience in 12 cases of suprasellar meningiomas for radical resection via the trans-nasal endoscopic route is discussed. Amongst these, six were excised via primary extended endoscopic trans-sphenoidal surgery, four cases had a residual lesion or recurrence after primary transcranial surgery, and two cases involved a combined transcranial and extended endoscopic approach. Visual improvement along with resolution of headache was seen in all patients postoperatively. None of the patients had CSF leak requiring further repair. Syndrome of inappropriate antidiuretic hormone was found in one patient, which was transient and easily corrected. Trans-nasal endoscopic surgery for suprasellar meningiomas is an effective technique that provides results of tumor excision comparable to the transcranial approach in suitable cases. Visual outcome was found to be superior, and rates of CSF leak were remarkably reduced with vascularized flap. However, each case must be assessed individually and lateral extension beyond the optic canals with internal carotid artery encasement must be considered before planning surgery.

Today, endoscopic endonasal approach is considered the gold standard in skull base surgery of the chiasmosellar region. Advances in transnasal endoscopic skull base surgery allow conducting more extensive interventions via wider approaches which requires more complicated plastic closure of the skull base defect. In 2006, G. Haddad et al. suggested using a vascularized nasoseptal flap to reconstruct a skull base defect. This method is generally accepted at present due to its reliability and low frequency of postoperative complications. The purpose of this article is to analyze publications on possible complications and pathological conditions of the nasal cavity when using a vascularized nasoseptal flap for skull base surgery after removal of neoplasms of the chiasmo-sellar region. The study included articles found in the Pubmed database (2006–2020) which described frequency and character of complications caused by skull base defect reconstruction by a nasoseptal flap after transnasal removal of chiasmo-sellar neoplasms. According to the literature review, the following complications are reported: cerebrospinal fluid leak, flap necrosis and infectious complications, pathological changes in the nasal cavity: prolonged crusting, synechiae, epistaxis, septum perforation, sinusitis, subatrophic changes of mucosae, nasolacrimal duct obstruction, olfactory dysfunction. The authors conclude that the nasoseptal flap is, undoubtedly, an effective material for reconstruction of dural defects by endoscopic endonasal skull base surgery, because of its good viability due to the preserved blood supply and high tightness of the plasty. However, there is a risk of complications in the nasal cavity. For these reasons, development of effective methods for prevention of nasal complications after using a vascularized flap in endoscopic endonasal surgery is an important issue today.

Dural suturing is an effective adjunct to skull base dural repair in endoscopic transnasal surgery, although it is technically cumbersome. Here, we presented a novel surgical suture "Kashimé" (Kono Seisakusho) that can be tightened without tying. To examine the efficacy of Kashimé for skull base dural repair in endoscopic transnasal surgery. Kashimé was used in 8 patients with skull base dural defects during nonpedicled flap-based multilayered skull base reconstruction to close or approximate the gaps between the dural edges or secure a free fascial graft. The time required for each dural stitch (passing a needle through the dura, pulling out the thread, and tightening it) and the incidence of postoperative cerebrospinal fluid leakage were the study end points. Based on our preliminary experiences with 12 stitches used, no postoperative cerebrospinal fluid leakage was observed. The learning curve was steep, and the mean (±SD) time was 127 (±44) seconds for a single stitching procedure, except for the first case. Regarding the metal artifact, although a beam hardening artifact was not observed on computed tomography, a 4- to 9-mm diameter image defect was observed on magnetic resonance imaging. Kashimé can help surgeons to complete a single dural stitch in endoscopic transnasal surgery for approximately 2 minutes. It may be an optimal tool for skull base reconstruction, but the efficacy and safety need to be investigated.

Transnasal endoscopic cranial base surgery is a novel minimal-access method for reaching the midline cranial base. Postoperative cerebrospinal fluid leak remains a persistent challenge. A new method for watertight closure of the anterior cranial base is presented. To achieve watertight closure of the anterior cranial base, autologous fascia lata was used to create a "gasket seal" around a bone buttress, followed by application of a tissue sealant such as DuraSeal (Confluent Surgical, Inc., Waltham, MA). The gasket-seal closure was used to seal the anterior cranial base in a series of 10 patients with intradural surgery for suprasellar craniopharyngiomas (n = 5), planum meningiomas (n = 3), clival chordoma (n = 1), and recurrent iatrogenic cerebrospinal fluid leak (n = 1). Lumbar drains were placed intraoperatively in five patients and remained in place for 3 days postoperatively. After a mean follow-up period of 12 months, there were no cerebrospinal fluid leaks. The gasket-seal closure is an effective method for achieving watertight closure of the anterior cranial base after endoscopic intradural surgery.

Resection of midline skull base lesions involve approaches needing extensive neurovascular manipulation. Transnasal endoscopic approach (TEA) is minimally invasive and ideal for certain selected lesions of the anterior skull base. A thorough knowledge of endonasal endoscopic anatomy is essential to be well versed with its surgical applications and this is possible only by dedicated cadaveric dissections. The goal in this study was to understand endoscopic anatomy of the orbital apex, petrous apex and the pterygopalatine fossa. Six cadaveric heads (3 injected and 3 non injected) and 12 sides, were dissected using a TEA outlining systematically, the steps of surgical dissection and the landmarks encountered. Dissection done by the "2 nostril, 4 hands" technique, allows better transnasal instrumentation with two surgeons working in unison with each other. The main surgical landmarks for the orbital apex are the carotid artery protuberance in the lateral sphenoid wall, optic nerve canal, lateral optico-carotid recess, optic strut and the V2 nerve. Orbital apex includes structures passing through the superior and inferior orbital fissure and the optic nerve canal. Vidian nerve canal and the V2 are important landmarks for the petrous apex. Identification of the sphenopalatine artery, V2 and foramen rotundum are important during dissection of the pterygopalatine fossa. In conclusion, the major potential advantage of TEA to the skull base is that it provides a direct anatomical route to the lesion without traversing any major neurovascular structures, as against the open transcranial approaches which involve more neurovascular manipulation and brain retraction. Obviously, these approaches require close cooperation and collaboration between otorhinolaryngologists and neurosurgeons.

In recent years, application of endoscopic transnasal surgery (ETS) has been expanded to orbital lesions, and preliminary results have started to be published for medially located soft mass lesions. However, reports on experience with endoscopic intraorbital surgery aimed at resection of invasive skull base tumors remains quite limited. This report presents the authors' experience with ETS for locally aggressive tumors involving the orbit. ETS was performed for 15 cases of aggressive tumors involving the orbit: 5 meningiomas (meningothelial, n = 3; atypical, n = 1; anaplastic, n = 1), 4 chordomas, 2 chondrosarcomas, and 4 others (metastasis from systemic myxofibrosarcoma, schwannoma, inverted papilloma, and acinic cell carcinoma, n = 1 each). Among these, 9 tumors were located outside the periorbita and 6 inside the periorbita. In 6 intraperiosteal tumors, 5 were intraconal lesions, of which 3 arose in the muscle cone (anaplastic meningioma, optic sheath meningioma, and metastatic myxofibrosarcoma), and 2 meningothelial meningioma had invaded from the sphenoid ridge or the cavernous sinus into the muscle cone through the optic canal and the superior orbital fissure. A case of schwannoma originated around the cavernous sinus and pterygopalatine fossa and extended extraconally into the periorbita. Intraoperatively, ethmoid air cells and the lamina papyracea were removed, and extraperiosteal tumors were safely approached. For intraperiosteal tumors, the periorbita was widely opened, and the tumors were approached through the surgical window between the rectus and oblique muscles. Gross-total resection was achieved for 12 of the 15 tumors, including 2 intraconal lesions. After surgery, exophthalmos resolved in all 8 patients with this symptom, and diplopia resolved in 5 of 6 patients. Improvement of visual symptoms was reported by 4 of 5 patients with loss of visual acuity or constriction of the visual field. Postoperatively, 1 patient showed mild, transient worsening of existing facial dysesthesia, and another showed transient ptosis and mild hypesthesia of the forehead on the affected side. All those symptoms resolved within 3 months. No patients showed enophthalmos, worsening of diplopia or visual function, or impairment of olfaction after surgery. ETS appears acceptable as a less-invasive alternative for treating aggressive tumors involving the orbit. For extraperiosteal tumors, gross-total removal can generally be achieved without neurological complications. For intraperiosteal tumors, surgical indications should be carefully discussed, considering the relationship between the tumor and normal anatomy. Wide opening of the periorbital window is advocated to create a sufficient surgical pathway between the extraocular muscles, allowing a balance between functional preservation and successful tumor resection.