The Transcrusal Approach
Bibliographic record
Abstract
In Brief OBJECTIVE This study reviewed the experience and outcomes of 1 surgical team (L.S.P., S.P.L.) using the transcrusal approach. METHODS Ten-year retrospective review of 17 consecutive patients requiring transcrusal exposure of the petrous apex and upper brainstem was performed. The main outcome measures included hearing and facial nerve preservation as measured by standard audiography and postoperative assessment using the House-Brackmann scale. RESULTS Operative indications included meningioma (5 patients), epidermoid/dermoid cyst (3 patients), trigeminal schwannoma (3 patients), giant or large upper basilar artery aneurysm (3 patients), pontine cavernoma (1 patient), chondrosarcoma (1 patient), and clival melanocytoma (1 patient). Average tumor size was 3.6 cm. Complete resection was achieved in 50% of patients with petroclival tumors. Follow-up data were obtained for 14 patients at 20 ± 4 months. Serviceable hearing was preserved in 58%. Sixty-four percent of patients demonstrated House-Brackmann stage I facial nerve function. Two patients died perioperatively (brainstem infarction). Two patients became hemiparetic, with 1 improving substantially. CSF leaks developed in 3 patients. Forty-seven percent of patients demonstrated cranial nerve V deficits. Forty-one percent of patients demonstrated deficits of cranial nerve III, IV, or VI. Vertigo, vestibular disturbance, hydrocephalus, temporal lobe contusion, or hematoma did not develop in any patients. CONCLUSION The transcrusal approach provides adequate exposure for most petroclival lesions and giant aneurysms of the upper basilar artery while offering the possibility of hearing preservation. Like all approaches to large tumors and aneurysms in this region, there is a significant risk of morbidity and mortality. However, this approach is an excellent alternative to other techniques that necessitate deliberate sacrifice of ipsilateral hearing. OBJECTIVE: This study reviewed the experience and outcomes of one surgical team using the transcrusal approach. METHODS: A ten-year retrospective review of 17 consecutive patients requiring transcrusal exposure of the petrous apex and upper brainstem was performed. The main outcome measures included hearing and facial nerve preservation measured by standard audiography and postoperative assessment using the House-Brackmann scale. RESULTS: Operative indications included meningioma, epidermoid/dermoid cyst, trigeminal schwannoma, giant or large upper basilar artery aneurysm, pontine cavernoma, chondrosarcoma, and clival melanocytoma. Average tumor size was 3.6 cm. Complete resection was achieved in 50% of patients with petroclival tumors. Follow-up data were obtained for 14 patients at 20 [±] 4 months. Serviceable hearing was preserved in 58%. Sixty-four percent of patients demonstrated House-Brackmann stage I facial nerve function. Two patients died perioperatively (brainstem infarction). Two patients became hemiparetic, with 1 improving substantially. CSF leaks developed in 3 patients. Forty-seven percent of patients had cranial nerve V deficits. Forty-one percent of patients had deficits of cranial nerve III, IV, or VI. CONCLUSION: The transcrusal approach provides adequate exposure for most petroclival lesions and giant aneurysms of the upper basilar artery and offers the possibility of hearing preservation. While there is potential risk, the approach to an excellent alternative is technique that acquires deliberate sacrifice of ipsilateral hearing.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".