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76. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie

Prof. Dr. med.

Vorsitz | Chair

PD Dr.

The mini-combined transpetrosal approach for petroclival tumors: indications and surgical outcomes

Schädelbasis

Der minikombinierte transpetrosale Ansatz für petroclivale Tumoren: Indikationen und chirurgische Ergebnisse

The mini-combined transpetrosal approach (mini-CTPA) is a modification of the standard one developed to reduce soft tissue trauma, cosmetic issues, time-consuming bony work, and neurological risks. Here we reported our experience with the mini-CTPA applied to different skull base tumors.A retrospective study of skull base tumors surgically treated with mini-CTPA from 2020 to 2023 was conducted. Preoperative characteristics, postoperative results, and clinical outcomes were analyzed. The surgical technique was detailed.A total of 32 skull base tumors were treated using the mini-CTPA: 16 (50%) sphenocavernous-petroclival meningiomas, 8 (25%) petroclival meningiomas, 4 (12.5%) epidermoid cysts, 2 (6.3%) chordomas, 1 (3.1%) chondrosarcoma, and 1 trochlear nerve schwannoma. The mean age at surgery was 50 years (range 23–69), and the mean preoperative tumor volume was 29.5 cm³ (10.5–60.4 cm³). The mean extent of resection was 91% (45–100%). Gross total (GTR), near-total (NTR), and subtotal resection (STR) rates were as follow: for sphenocavernous-petroclival meningiomas, 13% GTR, 31% NTR, and 56% STR; petroclival meningiomas, 25% GTR, 63% NTR, and 13% STR; epidermoid cysts, 100% GTR; chordomas, 50% GTR and 50% STR; chondrosarcoma, NTR (1 case); trochlear nerve schwannoma, GTR (1).Postoperative complications included pseudomeningocele in 3 patients (9%). New permanent deficits were observed in some cases, including trochlear nerve palsy in 3 patients, facial hypoesthesia in 3, abducens nerve palsy in 3, and hypoacusia in 2 patients.The Mini-CTPA offers adequate exposure for a variety of skull base lesions centered in the petroclival region. This approach is designed to reduce invasiveness, shorten surgical time, and minimize approach-related morbidities, making it a more accessible and practical technique for skull base surgeons.

Abstractvortrag | Abstract talk

Prof. Dr.

Dural Venous Sinus Thrombosis (DVST) After Surgery with the Retrosigmoid Approach: Literature Review and Case Series of Hemorrhagic DVST

Sinusthrombose nach Operationen mit retrosigmoidalem Zugang: Literaturübersicht und Fallserie von hämorrhagischen Sinusthrombosen

This study aims to explore the incidence, presentation, and management of dural venous sinus thrombosis (DVST) following surgery via a retrosigmoid approach, as documented in the literature, while also presenting three cases of DVST with subsequent cerebellar hemorrhage treated at our institution.Among over 3,000 patients who underwent surgery via the retrosigmoid approach at our clinic since 2000, we retrospectively analyzed three cases involving female patients aged 27, 51, and 54 years. These patients developed cerebellar hemorrhagic infarction in the context of DVST following retrosigmoid surgery. The primary pathologies included petroclival meningioma, a prepontine and premedullary neuroenteric cyst, and vestibular schwannoma. All patients underwent uneventful tumor resections without intraoperative injury to any significant venous structures. Neurological condition and imaging findings were reviewed both pre- and postoperatively, along with the surgical and medical interventions and associated outcomes.All three patients were promptly extubated post-surgery without new neurological deficits. However, within half a day, they exhibited significant neurological deterioration and reduced levels of consciousness. Cranial imaging revealed hemorrhagic cerebellar infarctions due to DVST involving the transverse or sigmoid sinuses, accompanied by hydrocephalus and brainstem compression. Surgical interventions included hematoma evacuation, external ventricular drainage, and, in one case, decompressive craniectomy. Despite these severe complications, two patients achieved full recovery, while the third experienced only mild residual impairments.Based on the reviewed literature, DVST is a less rare complication of retrosigmoid approach surgery than previously assumed. It often remains asymptomatic and does not require specific treatment. However, when associated with cerebellar hematoma, it can lead to severe postoperative morbidity. At our institute, the incidence of cerebellar hemorrhage associated with DVST was below 0.1%. Further research is necessary to identify risk factors and refine perioperative prevention strategies.

Prof

Repeated Gammaknife radiosurgery for vestibular schwannomas

Gammaknife radiosurgery (GKRS) is a well recognized treatment for vestibular schwannomas (VS) with high tumour control rate and low morbidity. When failure occasionally occurs, additional treatment is required and can either be performed by surgical resection or by repeated GKRS depending on the size of the tumour and clinical condition.From 1992 to 2018, 4,530 VS were treated in our institution. Of these, 110 (2.4%) patients underwent a second treatment because of tumour progression. Forty-nine (1.1%) patients including 47 patients with sporadic VS and 2 patients suffering from neurofibromatosis underwent repeated GKRS. Mean tumour volume was 0.6 cm3 and 1.8 cm3 at initial and second GKRS treatment, respectively. Mean delay between treatments was 61 months (range: 27-203; median: 55 months). Mean prescription dose was 12 Gy for both interventions.Mean radiological follow-up after repeated GKRS was 54 months (range: 4-132; median: 53 months). Tumour regression was achieved in 63.2% of cases. No additional treatment was required. Useful hearing ability was preserved in 7/13 (53.8%) patients who had serviceable hearing at the time of the second GKRS with a mean audiometric follow-up of 48 months (range: 6-132; median: 47 months). Mean clinical follow-up was 54 months (range: 3-132; median: 55 months). One patient experienced transient (6th-24th months) facial palsy and 2 patients transient hemifacial spasm. One patient reported transient (36th-60th months) facial hypoesthesia. No patient developed symptomatic adverse radiation effects.Repeated GKRS is safe and effective for VS, and should be systematically considered before salvage surgical resection.

Prof.

A standardized protocol for performance and outcome evaluation in auditory brainstem implants

Standardisiertes Protokoll zu Vorgehen und Analyse bei Auitorischen Hirnstammimplantaten

In view of the high outcome variability in auditory brainstem implants (ABI) , tools for intra- and post-surgical evaluation are highly needed. Here we apply and present a protocol for implantation, intra-operative control and post-surgical evaluation of patients' benefits in auditory perception.In 46 patients with deafness due to tumorous nerve destruction (NF2 associated schwannomatosis) tumor resectiopns were performed with meticulous preservation of the brainstem vascularization, clear anatomical exposure of the dorsal cochlear nucleus and extensive electrophsiolgical testing of electrically evoked auditory brainstem responses EABR, classified for the presence and number of vertex positive peaks. ABI were implanted and secured under ongoing monitoring control. The cooperation centers were applying the same principles also at postsurgical activation and ABI programming. Clinical ABI Outcome was analyzed for continuous communication without or with specific measures such as lip-reading or written notes.Under standardized conditions in experienced teams, ABI surgery does not expose the patients to any critical risk. The intraoperative presence of EABR can predict positive auditory rehabilitation outcome correctly in 90%. The EABR waveform deformations did not seem to correspond to the clinical outcome. Auditory outcome was useful for 88% of patients with over 60% being able to fluent communication without or with lip reading.For completely deaf patients with destroyed auditory nerves, the functional outcome in hearing rehabilitation by ABI has been greatly improved. The importance of EABR waveform variability is not yet clearly understood. Techniques like E-ABR and a practical guide to analyze patients' levels of communication by fluency and dependance/ independance of further tools may facilitate the evaluation and documentation.

Dr. med.

Assessing ischemic stroke risk in cavernous sinus meningiomas: The role of cavernous carotid involvement

Korreliert die Beteiligung der A. carotis interna mit dem Schlaganfallrisiko bei Sinus-cavernosus Meningiomen?

Cavernous sinus meningiomas (CSMs) are among the most challenging skull base tumors to treat due to their tendency to involve the internal carotid artery (ICA), which, in rare cases, can lead to ischemic symptoms. However, data on the long-term risk of ischemic stroke remain limited. This study aims to analyze the long-term risk of ischemic stroke in patients with previously treated CSMs.We reviewed the database of our skull base center for cases of histologically confirmed primary CSMs treated between 2006 and 2022. Included patients underwent tailored microsurgical resection of the extracavernous tumor portion followed by fractionated stereotactic radiation therapy (FSRT) as a standard departmental procedure for symptomatic CSM. Medical records and neuroimaging were analyzed to collect clinical information and identify symptoms or radiological evidence of ischemic strokes during follow-up. Cavernous carotid artery involvement was classified according to the Hirsch grading system as partially encased, completely encased (with or without narrowing), or completely encased with obliteration.A total of 33 patients were identified, with a mean age of 55 years (range 22–77). The median clinical and radiological follow-up after FSRT was 102 months (range 12–212) and 88 months (range 12–209) respectively. At initial imaging, narrowing of the ICA was observed in 20 patients (60.6%), while occlusion was evident in 3 cases (9.1%). 14/33 patients (42.4%) exhibited subcortical arteriosclerotic leucencephalopathy, which did not progress during follow-up. None of the patients received prophylactic antiplatelet or anticoagulation therapy specifically for tumoral ICA involvement. In one case in which a benign CSM occluded the ipsilateral ICA, protective stent implantation on the contralateral side was performed prior salvage irradiation. Only one patient experienced an acute ischemic thalamic stroke ipsilateral to the CSM 8 years after FSRT, but this event was unrelated to the CSM.Our study demonstrates that despite the high prevalence of ICA stenosis in patients with CSMs, the long-term risk of ischemic stroke is not increased, even after FSRT. Importantly, the absence of ischemic events directly attributable to tumoral ICA involvement suggests that prophylactic antiplatelet or anticoagulation therapies may not be necessary in this patient population.

Rapid communication

Safety and feasibility of protective stenting with flow diversion devices for resection of complex skull base tumors involving the internal carotid artery

Schutzstenting der Arteria carotis interna mit "Flow Diverter" bei der Resektion komplexer Schädelbasistumoren

Skull base tumors involving the internal carotid artery (ICA) pose significant surgical challenges due to their complex anatomical relationships and the critical need to preserve cerebral blood flow. Vascular injuries, particularly of the ICA, can result in catastrophic consequences with severe morbidity or mortality. Flow diversion devices have emerged as an innovative strategy in the interventional treatment of various neurovascular diseases. This study is the first worldwide to investigate the safety, feasibility, and outcomes of protective stenting using flow diversion devices prior to the resection of skull base tumors encasing the ICA.A retrospective analysis was conducted on five patients treated at our departments between 2022 and 2024. The cohort consisted of five patients with complex skull base tumors encasing the ICA. All patients underwent preoperative protective stenting with flow diversion devices to reinforce the ICA (four patients with Pipeline Vantage™ from Medtronic and one with FRED X™ from Terumo Neuro). Data on procedural safety, complications, and surgical outcomes were collected and analyzed.The study included four women and one man, aged between 18 and 60 years. Four patients had paragangliomas, and one had a neurofibroma associated with Neurofibromatosis Type II. Protective stenting was successfully performed in all five patients before surgery. There were no intraoperative vascular injuries, stent-related complications (such as thrombosis or hemorrhage), or postoperative neurological deficits. Complete tumor resection was achieved in all patients. One patient died during follow-up due to a pulmonary embolism unrelated to the primary tumor or the surgical procedureProtective stenting using flow diversion devices is a safe and effective adjunct in the management of complex skull base tumors involving the ICA. This technique facilitated complete tumor resection in all patients without vascular injury. These findings underscore the significant potential of flow diverters in complex skull base surgeries. Further studies with larger patient cohorts are necessary to validate these results and expand the clinical applications of this approach.

Session 26
Schädelbasis 3

Termin

Vorsitz | Chair

Thema

Programm

Session 26Schädelbasis 3

Termin

Vorsitz | Chair

Thema

Programm

Session 26
Schädelbasis 3