Middle ear ventilation status postoperatively after translabyrinthine resection of vestibular schwannoma with mastoid obliteration and Eustachian tube occlusion: Is the Eustachian tube enough to ventilate the middle ear without the mastoid air cell system?
Bibliographic record
Abstract
BACKGROUND: Gas pressure balance is essential for maintaining normal middle ear function. The mucosal surfaces of the middle ear, the mastoid air cell system (MACS), and the Eustachian tube (ET) play a critical role in this process; however, the extent that each of these factors contributes to overall middle ear ventilation is unknown. The objective of this study was to determine if the ET alone can maintain normal middle ear pressure without the MACS. To do this, we reviewed subjects who had their MACS completely removed with translabyrinthine (TL) surgery for vestibular schwannoma. METHODS: A retrospective chart review was done to collect pre and postoperative tympanometry data from patients who underwent resection of vestibular schwannoma. Data from the operative side was compared to the non-operative side at 2 years post-op. RESULTS: Twenty-four patients were included in this study. Of these, 63 % achieved a type A tympanogram at 2 years post-op in the TL resection group, implying an ability to maintain middle ear pressure in the absence of a mastoid cavity. Because some had negative pressures post TL resection, the average change in pre and postoperative pressure was -37.5 daPa for the operative side and 7.8 daPa for the non-operative side. This was significantly different. DISCUSSION: The difference for change in pre and postoperative pressure and compliance between operative and non-operative side might be expected from the ET plugging during TL resection. However, more interesting are those patients in whom the ET presumably reopens, and in these subjects, despite having no mastoid compartment at all, and the space obliterated with fat, they were still able to maintain normal ventilation of the middle ear space. CONCLUSION: Our findings imply that the ET alone is adequate to ventilate at least the reduced middle ear space following TL surgery in most subjects, and perhaps in 100 % if the ET hadn't been plugged during surgery. Hence, the mastoid air cell system, even when healthy, is not needed to maintain air in the middle year cleft.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".