This Week in Neurosurgery — Sep 9, 2026

Welcome to This Week in Neurosurgery. This week we're covering 10 notable papers spanning skull base and tumour surgery, vascular and functional neurosurgery, and perioperative pain and anaesthesia strategy. Let's dive in.

We start with the largest single contribution of the week, a three-part prospective multicentre cohort published in Neurosurgery that revisits one of the most entrenched compromises in skull base surgery: how much of a large vestibular schwannoma to leave behind. The Acoustic Neuroma Subtotal Resection Study followed 126 patients with tumours of at least two and a half centimetres, mean diameter three point three centimetres, for an average of five years, sorting them by what the postoperative MRI actually showed — gross total, near-total with a remnant under half a cubic centimetre, or subtotal. In the first paper, Monfared and colleagues report that the extent of resection did not predict facial nerve function, either immediately or in the long term [1]. What did predict a good outcome was a smaller tumour to begin with, and what predicted a bad one was surgical failure: patients who ultimately needed radiosurgery or revision surgery had roughly four and a half times the odds of fair-to-poor facial nerve function at last follow-up. The second paper explains why that matters, because subtotal resection carried about a threefold higher regrowth risk than gross total resection — around a quarter of subtotal patients regrew, versus roughly one in twelve after gross total — and the regrowth came sooner, at a median of two years rather than four [2]. The authors identified a residual volume of zero point seven cubic centimetres, or about twelve percent of the original tumour, as the practical ceiling for a near-total resection that behaves like a cure. The third paper closes the argument by removing the presumed perioperative payoff: operative time, length of stay and complication rates were no different across the three groups, and at one year the gross total and near-total patients had significant improvement in headache severity while the subtotal patients did not, with larger residual volumes tracking with worse dizziness handicap and worse balance testing [3]. Taken together, this is a coherent challenge to the reflex of planned debulking. If you can safely achieve a gross total or near-total resection, the data here say the facial nerve does not thank you for leaving tumour behind, and the patient's headache, balance and reoperation risk all get worse if you do.

Staying with tumours but moving to the population level, World Neurosurgery published an age-stratified analysis of nearly forty-nine thousand adults with nonmalignant intracranial meningioma from the United States Surveillance, Epidemiology, and End Results database [10]. Three quarters of the cohort were women, and female sex was independently associated with better survival at every age band, though the advantage narrowed in the oldest patients. The striking gradient is in treatment: resection rates fell from about thirty-nine percent in patients under fifty to under six percent in those eighty and older, yet surgery was associated with improved survival in every age group. The benefit was not uniform — the largest absolute ten-year survival gains, on the order of ten to twenty percentage points, were in patients with tumours of forty millimetres or more, whereas in patients in their seventies with small tumours under twenty millimetres the difference was negligible and not statistically significant. Tumour size of forty millimetres or greater was the strongest independent predictor of mortality. This is registry data with all the confounding by selection that implies, so it cannot tell you that an eighty-year-old should be operated on. What it does suggest is that large tumours in older patients may be an under-treated group, and that small tumours in the elderly are reasonably left alone. The paper also flags higher mortality among Black patients compared with White patients in every age band below eighty, a disparity signal that deserves attention rather than a footnote.

On the vascular and functional side, three papers deal with lesions where the right answer is rarely all-or-nothing. Neurosurgery reports a two-decade single-centre series of feeder artery aneurysms associated with arteriovenous malformations — 81 patients, 132 aneurysms, with about seventy percent presenting with haemorrhage [7]. Of the aneurysms treated directly, ninety-five percent achieved complete occlusion, with microsurgical clipping and cyanoacrylate embolisation both at one hundred percent and coiling at eighty percent, and the symptomatic complication rate was around five percent with no deaths. The more useful finding for planning is what happened to the aneurysms left alone: of eighteen untreated feeder aneurysms with follow-up, twelve regressed after the arteriovenous malformation itself was treated and six stayed stable, and none enlarged or ruptured. That supports treating the nidus first and reassessing, rather than reflexively securing every feeder aneurysm. In Operative Neurosurgery, a multicentre retrospective cohort across six institutions reports on magnetic resonance-guided laser interstitial thermal therapy for epileptogenic cavernous malformations in 23 adults, with seizure outcomes in the 19 who had at least a year of follow-up [6]. Just under sixty percent achieved Engel class one seizure freedom at one year, and all of those remained seizure free at a median of just over two years; favourable Engel one or two outcomes reached about three quarters at last follow-up. Perioperative haemorrhage occurred in three patients but was asymptomatic in all of them, and one patient had a persistent deficit. Shorter epilepsy duration before treatment and a fully concordant presurgical workup both predicted better outcomes — an argument for referring these patients earlier rather than after two decades of medication trials. And World Neurosurgery offers a narrative review of 88 articles on revascularisation for paediatric moyamoya, concluding that direct, indirect and combined bypass all beat conservative management but that no approach is universally superior [9]. Indirect bypass delivered comparable clinical and neurocognitive outcomes with lower technical complexity and operative risk, which means the choice should turn on the individual child and on the operator's own experience.

Two trials this week attack perioperative physiology and pain from different directions, both in the Journal of Clinical Neuroscience. Ramadurai and colleagues randomised 150 adults undergoing emergency decompressive craniectomy for acute traumatic subdural haematoma to subanaesthetic ketamine, lidocaine, or placebo as adjuncts to propofol-based total intravenous anaesthesia [4]. Ketamine cut mean propofol consumption by roughly a quarter compared with placebo, more than halved intraoperative fentanyl requirements, and modestly reduced vasopressor boluses. Importantly for the old concern about ketamine and intracranial pressure, intracranial pressure, cerebral perfusion pressure and brain relaxation scores were comparable across all three arms, and there were no differences in Glasgow Outcome Scale-Extended scores. The authors are appropriately careful: because propofol was titrated to haemodynamics rather than processed EEG, they cannot separate a true propofol-sparing effect from ketamine's sympathomimetic action. Lidocaine showed a smaller propofol-sparing effect and no adverse intracranial signal. The second paper is a small retrospective series of 50 consecutive patients undergoing venous sinus stenting for idiopathic intracranial hypertension, in which seven received bilateral middle meningeal artery infusion of fifty milligrams of one percent lidocaine immediately after stent deployment [5]. First-day headache burden was roughly halved compared with controls, and in-hospital opioid consumption fell substantially, with no infusion-related complications and all infused arteries remaining patent. With only seven treated patients this is hypothesis-generating and nothing more, but it is a low-cost idea worth watching as prospective data emerge. Rounding out the week, a meta-analysis of eight studies and 281 patients compared standalone lateral or oblique cages against posterior approaches for lumbar adjacent segment disease [8]. Standalone constructs meant markedly less blood loss, operative times shorter by well over an hour, hospital stays about three days shorter, greater disc height restoration, and lower overall complication odds — but roughly four to five times the odds of cage subsidence on follow-up. That is a genuine trade-off to put in front of the patient during consent.

If you only have time for one paper this week, make it the second part of the Acoustic Neuroma Subtotal Resection Study on tumour regrowth [2]. Combined with its companion papers, it directly undercuts the rationale for planned subtotal resection in large vestibular schwannomas and gives you concrete residual-volume thresholds you can apply on the postoperative MRI.

Here are the key takeaways from this week in Neurosurgery. First, in large vestibular schwannomas, leaving tumour behind did not protect the facial nerve, did tripple the regrowth risk, and was linked to worse headache, dizziness and balance at one year — aim for gross total or near-total resection when it is safe, and treat a residual above roughly zero point seven cubic centimetres as high risk. Second, in meningioma registry data, surgery was associated with better survival at every age, with the biggest gains in tumours of forty millimetres or more and essentially none in small tumours in older patients. Third, feeder artery aneurysms on arteriovenous malformations do not all need direct treatment — many regressed after the malformation was addressed, and none of the untreated ones ruptured in this series. Fourth, subanaesthetic ketamine reduced propofol, opioid and vasopressor requirements during decompressive craniectomy without any detectable harm to intracranial pressure or perfusion, though outcomes were unchanged. And fifth, standalone lateral and oblique cages for adjacent segment disease buy you a faster, less morbid operation at the cost of substantially higher subsidence risk.

That's your roundup for This Week in Neurosurgery. The full transcript and references are available on the episode page in your AudioScholar library. This is an AI-curated summary — for clinical decisions, always consult primary sources and current guidelines. See you next week.

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