Transclival Approach Research Articles

Pons herniation after skull base chondrosarcoma surgery: A rare complication after transclival endoscopic endonasal approach

Background: Intracranial chondrosarcomas are malignant tumors that most commonly affect the clivus region. For tumors in this location, the extended endoscopic endonasal approach could offer an alternative route. We present a case of pons herniation after this technique. Case Description: A 55-year-old female presented with a 6-month history of difficulty walking. The neurological evaluation showed asymmetric tetra paresis and involvement of the IX cranial nerve on the right side. Imaging exams showed a lesion at the upper clivus, with a possible diagnosis of chondrosarcoma. An extended transclival approach with partial resection and a multilayer closure were performed. The patient had a slight immediate improvement in muscle strength, and she was discharged home 5 days after surgery. Four weeks later, she evolved with worsening strength on the left side. A new image examination revealed an atypical protrusion of the pontine tissue through the bone defect at the opening of the clivus; a surgical revision was proposed, but the patient chose conservative management. Conclusion: Pontine herniation is a rare complication with no defined cause. The use of a rigid material for closure could reduce the chances of this complication, but futher studies are necessary to reinforce that hypothesis.

Preservation of Olfactory Function After Pediatric Endoscopic Endonasal Skull Base Surgery with Nasoseptal Flap Reconstruction

ObjectiveEndoscopic endonasal surgery is a feasible approach to lesions of the pediatric skull base. Olfactory outcomes following endoscopic endonasal approach (EEA) have been reported in the adult literature, but pediatric outcome data is lacking. The purpose of this preliminary study is to evaluate post-operative olfactory outcomes in pediatric patients who underwent EEA through transsphenoidal and/or transclival corridors. MethodsRetrospective chart review of patients < 18 years of age who underwent EEA with nasoseptal flap skull base reconstruction between March 2019-January 2022. Following their first post-operative debridement and 6 months following surgery, patients were administered the University of Pennsylvania Smell Identification Test (UPSIT) to assess olfactory function. ResultsFifteen patients (7 female, 8 male) with a mean age of 14.9 years met inclusion criteria. Thirteen (86.7%) patients required a transsphenoidal approach and 2 (13.3%) patients underwent a combined transsphenoidal and transclival approach. Mean time between surgical resection and first olfactory testing was 6.3 weeks (range 4.6-7.3 weeks). Nine patients (60.0%) had normosmia following EEA while 3 (20.0%) had mild microsmia, and 3 (20.0%) had moderate microsmia at 6 weeks following surgery. Results improved at their 6 month follow up visits. No patients experienced post-operative severe microsmia or anosmia. ConclusionsOlfactory preservation is possible following pediatric EEA, though 40% of patients will develop some degree of microsmia in the immediate post-operative period and 20% will have some persistent dysfunction at 6 months. Long-term data is necessary to determine if microsmia continues to improve over time.

Endoscopic Transclival Approach for Evacuation of Retroclival Hematoma: 2-Dimensional Operative Video.

Retroclival hematomas are a rare entity, presenting anteriorly to the brainstem in the epidural, subdural, or subarachnoid space. Although those that develop in the epidural space often arise from trauma, subdural retroclival hematomas frequently occur spontaneously in the setting of coagulopathy, aneurysm rupture, or pituitary apoplexy, with many cases having an unknown etiology.1-4 Although most are treated with conservative management, surgical intervention is preferred for those presenting with evidence of brainstem compression, hydrocephalus, worsening neurological deficits, and clinical deterioration.5 In this report, we present the case of a 75-year-old woman with a medical history of mitral regurgitation, nonischemic cardiomyopathy, and atrial fibrillation on warfarin presenting with 4 days of temporoparietal headaches and double vision. On examination, the patient demonstrated right abducens and hypoglossal nerve palsies. Computed tomography revealed a subdural hemorrhage within the retroclival cistern, extending into the dorsal inferior aspect of the C2 vertebral body, resulting in posterior displacement of the pons, medulla, and proximal cervical spinal cord. Spinal and cerebral angiograms did not show evidence of any vascular malformation. An endoscopic transclival approach was selected for hematoma evacuation. Key surgical steps included harvesting of nasoseptal flap, endoscopic transnasal approach to the sellar/subsellar space, transclival drilling, retroclival hematoma evacuation, and clival reconstruction. The patient tolerated the procedure well and was discharged 15 days postoperatively with resolution of prior cranial nerve deficits. Postoperative computed tomography imaging revealed complete retroclival hematoma evacuation. At her 3-month follow-up, the patient remained neurologically intact with imaging confirming no residual subdural hematoma. Institutional Review Board approval was obtained for this submission (2018-9379). Patient consent was not obtained as personal identifying information was kept confidential, following guidelines set forth by Institutional Review Board requirements.

Safety and efficacy of the endoscopic transsphenoidal transclival approach performed using direct cortical stimulation for pontine cavernous malformations.

Surgical treatment of brainstem cavernous malformations (CMs) is challenging. Surgery using the endoscopic transsphenoidal transclival approach (eTSTCA) is reported as a useful alternative for ventral brainstem CMs. However, CMs located in the ventral midline of the brainstem are rare, and only a small number of case reports on these CMs treated with the eTSTCA exist. The efficacy and safety of the eTSTCA have not yet been fully examined. A retrospective analysis was performed for 5 consecutive patients who underwent surgery via the eTSTCA for treating ventral pontine CMs. The average maximum CM diameter was 26.0 mm (18-38 mm). All patients underwent MR-diffusion tensor imaging, which confirmed that the corticospinal tract (CST) deviated posteriorly or laterally to the CM. Direct brainstem cortical stimulation was performed to localize the CST before making the cortical incision. After the excision of the CM, the cavity was filled with artificial CSF to make an aqueous surgical field (wet-field technique) for observing the tumor cavity and confirming complete hemostasis and resection. Total removal was achieved in all patients. The preoperative modified Rankin Scale score was 3 in 3 patients and 4 in 2 patients, whereas it was 1 in 2 patients and 0 in 3 patients 3 months after surgery. Postoperative CSF leakage was observed in 1 patient, and transient abducens nerve palsy was observed in 1 patient. No other intra- or postoperative complications were observed. MR-diffusion tensor imaging and direct brainstem cortical stimulation were useful to ascertain the proximity of the CST to the CM. The endoscope provides a clear view even underwater, and it was safe and effective to observe the entire CM cavity and confirm complete hemostasis without additional retraction of the brainstem parenchyma, including the CST. The eTSTCA provides a direct access point to the lesion and may be a safer alternative treatment for patients whose CST deviates laterally or posteriorly to the CM.

Endoscopic endonasal transclival clipping of a cerebellar arteriovenous malformation feeding vessel and associated aneurysm; a 2D operative video

Positioned along the ventral surface of the pons, proximal superior cerebellar artery (SCA) aneurysms account for only 1.7% of all intracranial aneurysms [1]. Unlike more commonly encountered basilar artery aneurysms, patients often experience good outcomes when treated via endovascular coiling or surgical clipping [1,2]. These lesions frequently have a lateral projection and paucity of perforator arteries [2]. With further development of endoscopic endonasal techniques, access to this region is possible via a direct frontal exposure to the ventral brainstem, basilar artery and branching vessels. To date, there are only a limited number of reports describing an endoscopic endonasal transclival (EETC) approach for surgical clipping [3–5]. In this operative video, we detail the surgical clipping of a cerebellar arteriovenous malformation feeding vessel and an associated aneurysm using the EETC approach in a 59-year-old woman who presented with sudden onset of a severe headache. The feeding vessel and aneurysm’s midline location, just below the take-off of the SCA made it a good candidate for this surgery. Major steps included in this video include 1) transsphenoidal exposure of and subsequent drilling of the clivus, 2) dural opening into the pre-pontine cistern and dissection of the aneurysm, 3) clipping of the aneurysm, and 4) multi-layered closure of the skull base defect. Overall, the patient tolerated the procedure well and was found to have no residual filling of the aneurysm or the AVM feeding vessel at 2-year follow-up. EETC is a viable surgical option for the treatment of aneurysm located along the midline of the pre-pontine cistern.

A rare case of multifocal chordoma involving the lower clivus and multiple spine levels: illustrative case.

Chordomas are rare bone tumors originating from notochord remnants with a predilection for the median axis of the body, primarily in the sacrococcygeal spine, skull base, and cervical spine. This paper presents the first reported case of simultaneous multilevel chordomas with various enhancements. A 40-year-old woman presented with right-sided otalgia, headache, nasal obstruction, and facial pressure. The patient's head and spinal magnetic resonance imaging (MRI) demonstrated a midline lesion in the clivus, C2, and T1-5 spinal levels. All lesions were T1 isointense and T2 hyperintense, consistent with chordoma. Interestingly, the clivus lesion was enhancing, whereas the C2 lesion was only slightly enhancing, and the rest of the lesions showed no enhancement. The patient underwent endoscopic endonasal transclival approach surgery for the clival lesion, followed by radiation to the surgical bed and the C2 lesion. The remaining lesions were monitored. Follow-up imaging showed stable disease in the C2 lesion and other lower lesions. The patient's severe pain in the posterior cervical spine was managed with cervical fusion, pain management, and physical therapy. This case underscores the importance of comprehensive spinal MRI in patients with chordomas, as multiple concurrent primaries may be present. The article summarizes the fundamental distinctions between ecchordosis physaliphora and chordoma and casts doubt on the capacity to always differentiate them.

Anatomical Step-by-Step Dissection of Complex Skull Base Approaches for Trainees: Surgical Anatomy of the Endoscopic Endonasal Middle-Inferior Clivectomy, Odontoidectomy, and Far-Medial Approach.

Introduction The clival, paraclival, and craniocervical junction regions are challenging surgical targets. To approach these areas, endoscopic endonasal transclival approaches (EETCAs) and their extensions (far-medial approach and odontoidectomy) have gained popularity as they obviate manipulating and working between neurovascular structures. Although several cadaveric studies have further refined these contemporary approaches, few provide a detailed step-by-step description. Thus, we aim to didactically describe the steps of the EETCAs and their extensions for trainees. Methods Six formalin-fixed cadaveric head specimens were dissected. All specimens were latex-injected using a six-vessel technique. Endoscopic endonasal middle and inferior clivectomies, far-medial approaches, and odontoidectomy were performed. Results Using angled endoscopes and surgical instruments, an endoscopic endonasal midclivectomy and partial inferior clivectomy were performed without nasopharyngeal tissue disruption. To complete the inferior clivectomy, far-medial approach, and partially remove the anterior arch of C1 and odontoid process, anteroinferior transposition of the Eustachian-nasopharynx complex was required by transecting pterygosphenoidal fissure tissue, but incision in the nasopharynx was not necessary. Full exposure of the craniocervical junction necessitated bilateral sharp incision and additional inferior mobilization of the posterior nasopharynx. Unobstructed access to neurovascular anatomy of the ventral posterior fossa and craniocervical junction was provided. Conclusion EETCAs are a powerful tool for the skull-base surgeon as they offer a direct corridor to the ventral posterior fossa and craniocervical junction unobstructed by eloquent neurovasculature. To facilitate easier understanding of the EETCAs and their extensions for trainees, we described the anatomy and surgical nuances in a didactic and step-by-step fashion.

The anterolateral triangle as window on the foramen lacerum from transorbital corridor: anatomical study and technical nuances

ObjectiveNeurosurgical indications for the superior eyelid transorbital endoscopic approach (SETOA) are rapidly expanding over the last years. Nevertheless, as any new technique, a detailed knowledge of the anatomy of the surgical target area, the operative corridor, and the specific surgical landmark from this different perspective is required for a safest and successful surgery. Therefore, the aim of this study is to provide, through anatomical dissections, a detailed investigation of the surgical anatomy revealed by SETOA via anterolateral triangle of the middle cranial fossa. We also sought to define the relevant surgical landmarks of this operative corridor.MethodsEight embalmed and injected adult cadaveric specimens (16 sides) underwent dissection and exposure of the cavernous sinus and middle cranial fossa via superior eyelid endoscopic transorbital approach. The anterolateral triangle was opened and its content exposed. An extended endoscopic endonasal trans-clival approach (EEEA) with exposure of the cavernous sinus content and skeletonization of the paraclival and parasellar segments of the internal carotid artery (ICA) was also performed, and the anterolateral triangle was exposed. Measurements of the surface area of this triangle from both surgical corridors were calculated in three head specimens using coordinates of its borders under image-guide navigation.ResultsThe drilling of the anterolateral triangle via SETOA unfolds a space that can be divided by the course of the vidian nerve into two windows, a wider “supravidian” and a narrower “infravidian,” which reveal different anatomical corridors: a “medial supravidian” and a “lateral supravidian,” divided by the lacerum segment of the ICA, leading to the lower clivus, and to the medial aspect of the Meckel’s cave and terminal part of the horizontal petrous ICA, respectively. The infravidian corridor leads medially into the sphenoid sinus. The arithmetic means of the accessible surface area of the anterolateral triangle were 45.48 ± 3.31 and 42.32 ± 2.17 mm2 through transorbital approach and endonasal approach, respectively.ConclusionSETOA can be considered a minimally invasive route complementary to the extended endoscopic endonasal approach to the anteromedial aspect of the Meckel’s cave and the foramen lacerum. The lateral loop of the trigeminal nerve represents a reliable surgical landmark to localize the lacerum segment of the ICA from this corridor. Nevertheless, as any new technique, a learning curve is needed, and the clinical feasibility should be proven.

Long-Term Outcomes after Multimodal Treatment for Clival Chordoma: Efficacy of the Endonasal Transclival Approach with Early Adjuvant Radiation Therapy

This study investigates the long-term outcomes of clival chordoma patients treated with the endonasal transclival approach (ETCA) and early adjuvant radiation therapy. A retrospective review of 17 patients (2002–2013) showed a 10-year progression-free survival (PFS) rate of 67.4%, with the ETCA group showing fewer progressions and cranial neuropathies than those treated with combined approaches. The ETCA, a minimally invasive technique, provided a similar extent of resection compared to conventional skull-base approaches and enabled safe delivery of high-dose adjuvant radiotherapy. The findings suggest that ETCA is an effective treatment for centrally located clival chordomas.

Endoscopic Endonasal Approach for Trigeminal Schwannomas: Tailored Approaches Based on Lesion Traits.

To describe four endoscopic endonasal subapproaches, namely, the trans-lamina papyracea, trans-prelacrimal recess, trans-Meckel's cave, and transclival approaches for trigeminal schwannomas (TSs). This retrospective study reviewed the medical records and intraoperative videos of 38 patients with TSs who underwent endoscopic endonasal approach (EEA) between Jan 2013 and Dec 2021. According to Jeong's classification, for TS equally in middle and posterior fossae (MP), a purely trans-Meckel's cave approach was carried out in 2 cases, and a combined transclival approach was carried out in 4 cases. The four tumors that involved infratemporal fossa (two E3, one mE3, and one Mpe3) were performed via a trans-prelacrimal recess approach, and type Mpe3 was also assisted by the trans-Meckel's cave approach. One patient with type E1 was treated with a trans-lamina papyracea approach. The other 27 cases, including type M, Mp, ME2, and MpE2, were all removed by a purely trans-Meckel's cave approach. Thirty-six patients (97.4%) received total resection under a purely EEA. The functional abilities and preoperative symptoms of 31 patients (88.6%) improved. Eight (21.1%) patients experienced permanent neurological function deficits. Postoperative cerebrospinal fluid and intraoperative internal carotid artery injury occurred in 1 (2.6%) patient. According to the specific endoscopic endonasal subapproaches corresponding to the different TS locations, satisfactory results can be obtained for most types of tumors. It represents an effective alternative to the open transcranial approach and can also be properly used in most types of TS with experienced hands. 4 Laryngoscope, 2023.

How I do it: the endoscopic endonasal transclival approach for clipping of the ruptured vertebral artery aneurysm.

Vertebral artery aneurysms account for less than 5% of all cerebral aneurysms. They have a high risk of rupture and are associated with threatening clinical outcomes compared with anterior circulation aneurysms. The endoscopic endonasal transclival approach (EETA) was used. During the temporary clipping, the neck of the aneurysm was dissected, and a permanent clip was applied. The repair of the skull base defect was carried out with the nasoseptal mucoperiosteal flap on the vascular pedicle. The EETA is a feasible alternative for the clipping of the medially located ruptured vertebral artery aneurysm. EETA can be recommended for centers with a large volume of cerebrovascular and endoscopic neurosurgical procedures.

Endoscopic endonasal transclival approach for a ventral brainstem epidermoid cyst: illustrative case.

Intracranial epidermoid cysts are benign, slow-growing malformations that most commonly arise at the skull base. Maximizing resection of the cyst contents and the capsule reduces long-term recurrence but can be made difficult by cyst wall adherence to critical neurovascular structures. Expanded endonasal approaches (EEAs) offer an alternative to traditional open transcranial approaches for accessible epidermoid cysts. In this case report, the authors demonstrate a transclival EEA for a large, ventral brainstem epidermoid cyst. A 41-year-old woman who presented with progressive headaches, diplopia, malaise, and fatigue was found to have a 4.7-cm midline, ventral brainstem epidermoid cyst. She underwent an expanded endonasal transclival approach that exposed the brainstem from the level of the dorsum sella to the tip of the basion. A near-total resection was completed with removal of all cyst contents and most of the capsular wall. Reconstruction was completed with Duragen, an autologous fat graft, and a nasoseptal flap. Postoperatively, she had a partial left cranial nerve VI palsy that remained stable 8 weeks after surgery. The expanded endoscopic transclival approach can facilitate effective resection of midline, ventral epidermoid cysts.

Microsurgical anatomy and the importance of the petrosal process of the sphenoid bone in endonasal surgery.

The petrosal process of the sphenoid bone (PPsb) is a relevant skull base osseous prominence present bilaterally that can be used as a key surgical landmark, especially for identifying the abducens nerve. The authors investigated the surgical anatomy of the PPsb, its relationship with adjacent neurovascular structures, and its practical application in endoscopic endonasal surgery. Twenty-one dried skulls were used to analyze the osseous anatomy of the PPsb. A total of 16 fixed silicone-injected postmortem heads were used to expose the PPsb through both endonasal and transcranial approaches. Dimensions and distances of the PPsb from the foramen lacerum (inferiorly) and top of the posterior clinoid process (PCP; superiorly) were measured. Moreover, anatomical variations and the relationship of the PPsb with the surrounding crucial structures were recorded. Three representative cases were selected to illustrate the clinical applications of the findings. The PPsb presented as a triangular bony prominence, with its base medially adjacent to the dorsum sellae and its apex pointing posterolaterally toward the petrous apex. The mean width of the PPsb was 3.5 ± 1 mm, and the mean distances from the PPsb to the foramen lacerum and the PCP were 5 ± 1 and 11 ± 2.5 mm, respectively. The PPsb is anterior to the petroclival venous confluence, superomedial to the inferior petrosal sinus, and inferomedial to the superior petrosal sinus; constitutes the inferomedial limit of the cavernous sinus; and delimits the upper limit of the paraclival internal carotid artery (ICA) before the artery enters the cavernous sinus. The PPsb is anterior and medial to and below the sixth cranial nerve, forming the floor of Dorello's canal. During surgery, gentle mobilization of the paraclival ICA reveals the petrosal process, serving as an accurate landmark for the location of the abducens nerve. This investigation revealed details of the microsurgical anatomy of the PPsb, its anatomical relationships, and its application as a surgical landmark for identifying the abducens nerve. This novel landmark may help in minimizing the risk of abducens nerve injury during transclival approaches, which extend laterally toward the petrous apex and cavernous sinus region.

The use of three-dimensional endoscope in transnasal skull base surgery: A single-center experience from China.

ObjectiveThe development of skull base surgery in the past decade has been influenced by advances in visualization techniques; recently, due to such improvements, 3D endoscopes have been widely used. Herein, we address its effect for transnasal endoscopic skull base surgery.MethodsA total of 63 patients who under endoscopic endonasal surgery (EES) with 3-D endoscope were retrospectively reviewed, including pituitary adenomas, craniopharyngiomas, meningiomas, Rathke’s cleft cysts, and chordomas. According to different lesions, transsellar approach (24 cases), transsphenoidal–transtuberculum approach (14 cases), transclival approach (6 cases), and transpterygoid approach (19 cases) were selected.ResultsTotal removal of tumors was achieved in 56 patients (88.9%) and subtotal removal in 7 cases (11.1%). Complications included diabetes insipidus in seven patients (11.1%), cerebrospinal fluid (CSF) leakage in two patients (3.2%), major vascular injury occurred in one patient (1.6%), cranial nerve injury in nine patients (14.3%), and meningitis in two patients (3.2%). There was no mortality in the series. All patients recovered and were back to normal daily life, and no tumor recurrence or delayed CSF leakage was detected during the follow-up (2–13 months, mean 7.59 months).ConclusionsVia 3D EES, it improved depth perception and preserved important neurovascular tissue when tumors were removed, which is important for improving the operative prognosis.

Risk Factors in a Pediatric Population for Postoperative Intracranial Infection Following Endoscopic Endonasal Skull Base Surgery and the Role of Antibiotic Prophylaxis.

Endoscopic endonasal skull base surgery (EESBS) is performed through a non-sterile corridor. Intracranial infection rates in a pediatric population have not been extensively studied and the exact effect of antibiotic prophylaxis on rates of infection after EESBS in pediatric patients remains unclear. The purpose of our study is to investigate risk factors for postoperative intracranial infection during EESBS in a pediatric population and help elucidate the role of antibiotic prophylaxis. We conducted a retrospective chart review of 99 consecutive patients under the age of 18 who underwent EESBS at our institution from 2013 to 2021. Centers for Disease Control and Prevention/National Healthcare Safety Network criteria for diagnosis of meningitis were used to identify postoperative intracranial infections. The average age was 12.3 years (range 1.6-18) with 66 male patients and 33 female patients. 49 patients had an intraoperative cerebrospinal fluid (CSF) leak, of which 4 had a postoperative CSF leak. We identified 3 postoperative intracranial infections (3%), which were all meningitis cases. The infection rate was 6% (3/49) among those with intraoperative CSF leaks. All patients with meningitis had a postoperative CSF leak. All infections were transclival approaches (2 chordoma and 1 neurenteric cyst). This investigation represents one of the largest pediatric endoscopic skull base surgery cohorts. EESBS is safe to perform in pediatric populations, but transclival approaches and postoperative CSF leaks are risk factors for postoperative meningitis.

Impact of Radiation Therapy on Outcomes After Spinal Instrumentation for Craniocervical Junction Malignancies.

ObjectiveSpinal reconstruction after resection of invasive craniocervical junction malignancies is fraught with technical and management considerations as well as a paucity of data in the existing literature. In this study, we describe our experience with craniocervical junction malignancies, especially the influence of radiation on the need for revision spinal instrumentation. MethodsWe performed a retrospective chart review of all patients who underwent occipitocervical fixation between 2011 and 2019 at The University of Texas MD Anderson Cancer Center. ResultsTwenty-five patients had primary malignancies and 12 (30%) had metastatic tumors. Thirteen (33%) underwent a staged resection in multiple operations during their hospital stay. Tumor resection was performed in 19 patients (48%), while only stabilization was performed in 21 patients (52%). Nine patients (23%) underwent expanded endoscopic transclival approaches for tumor resection, 10 patients (25%) an extreme lateral approach, and 2 patients (5%) an anterior open approach. Eleven patients underwent early postoperative radiation therapy (within 3 months) and 8 underwent delayed radiation therapy (between 3 months and 1 year in 7 patients). The revision rate was 8%, with a median time to revision surgery of 42 months. The administration and timing of adjuvant radiation therapy relative to surgery had no significant effect on the need for instrumentation revision on log-rank and Cox regression analyses (p < 0.05). ConclusionRevision surgery was needed infrequently in our patients. Postoperative radiation therapy was not associated with hardware failure, indicating that the timing of radiation therapy should be dictated by the diagnosis and can be initiated postoperatively without delay.

Endoscopic endonasal transclival petroclival meningioma resection.

Petroclival meningiomas are surgically challenging due to the surrounding neurovascular structures. Petroclival meningiomas located inferior to the oculomotor nerve and superior or medial to the abducens nerve are ideal for an endoscopic endonasal transclival approach because this prevents the need to work across cranial nerves, limiting operative risk. The authors present a case of a 45-year-old woman with a growing petroclival meningioma that was distorting the pons. In the video they demonstrate the technique and discuss nuances of petroclival meningioma resection via an endoscopic endonasal transclival approach with posterior clinoidectomy.The video can be found here: https://stream.cadmore.media/r10.3171/2022.1.FOCVID21209

Radioanatomical Study of the Skull Base and Septum in Chinese: Implications for Using the HBF for Endoscopic Skull Base Reconstruction.

Objective Radioanatomy provides surgeons with different choices to prevent the failure of reconstruction caused by improper flap selection and the occurrence of CSF leakage or other severe complications. To establish a radioanatomical model, this study radioanatomically investigated the use of the Hadad–Bassagasteguy nasoseptal flap (HBF) in skull base reconstruction performed via the transethmoidal, transsphenoidal, and transclival approaches to provide preoperative guidance for the selection of approaches for skull base reconstruction and preparation of the HBF. Methods The computed tomography images of 40 Chinese adults were selected for the radioanatomical measurement of data related to the HBF and skull base reconstruction via the transethmoidal, transsphenoidal, and transclival approaches. The results were analyzed using radioanatomy combined with SPSS-based analysis. Results In the 40 patients, the area of the HBF exceeded that of skull base defects reconstructed via the transethmoidal approach by 10.21 ± 1.97 cm2, and the anterior margin width, posterior margin width, upper margin length, and lower margin lengths of the HBF all exceeded the corresponding values of skull base defects requiring reconstruction by at least 8.4 mm. The area of the HBF exceeded that of reconstructed skull base defects by an average of 10.72 ± 2.04 cm2. The area of the HBF exceeded that of skull base defects reconstructed via the transclival approach by 9.01 ± 2.87 cm2. The difference between the anterior margin width of the HBF and the middle width of skull base defects reconstructed via the transclival approach did not exceed 6 mm in only one case (5.4 mm). Conclusion In Chinese adults, the HBF can cover skull base defects reconstructed via the transethmoidal, transsphenoidal, and transclival approaches, permitting its use in skull base reconstruction performed via all three approaches. Radioanatomy can be used for preoperative guidance to plan surgery via the transethmoidal, transsphenoidal, and transclival approaches.

Management of pediatric clival chordoma with extension to the craniocervical junction and occipito-cervical fusion: illustrative case

BACKGROUNDChordomas are rare malignant neoplasms that develop from the primitive notochord with < 5% of the tumors occurring in pediatric patients younger than the age of 20. Of these pediatric chordomas, those affecting the craniocervical junction (C1–C2) are even more rare; therefore, parameters for surgical management of these pediatric tumors are not well characterized.OBSERVATIONSIn this case, a 3-year-old male was found to have a clival chordoma on imaging with extension to the craniocervical junction resulting in spinal cord compression. Endoscopic-assisted transoral transclival approach for clival tumor resection was performed first. As a second stage, the patient underwent a left-sided far lateral craniotomy and cervical laminectomy for resection of the skull base chordoma and instrumented fusion of the occiput to C3. He made excellent improvements in strength and dexterity during rehab and was discharged after 3 weeks.LESSONSIn pediatric patients with chordoma with extension to the craniocervical junction and spinal cord compression, decompression with additional occipito-cervical fusion appears to offer a good clinical outcome. Fusion performed as a separate surgery before or at the same time as the initial tumor resection surgery may lead to better outcomes.

Development of a Cadaveric Multiport Model of Posterior Circulation Aneurysm Clipping for Neurosurgery and Otolaryngology Residents.

Posterior circulation aneurysms are difficult to treat with the current methods of coiling and clipping. To address limitations in training, we developed a cadaveric model to train learners on endoscopic clipping of posterior circulation aneurysms. An endoscopic transclival approach (ETA) and a transorbital precaruncular approach (TOPA) to successfully access and clip aneurysms of the posterior circulation are described. The model has flexibility in that a colored silicone compound can be injected into the cadaveric vessels for the purpose of training learners on vascular anatomy. The other option is that the model could be connected to a vascular perfusion pump allowing real-time appreciation of a pulsatile or ruptured aneurysm. This cadaveric model is the first of its kind for training of endoscopic clipping of posterior circulation aneurysms. Learners will develop proficiency in endoscopic skills, appropriate dissection, and appreciation for relative anatomy while developing an algorithm that can be employed in a real operative arena. Going forward, various clinical scenarios can be developed to enhance the realism, allow learners from different specialties to work together, and emphasize the importance of teamwork and effective communication.