Executive Summary
This week's digest highlights: Adopting standardized perioperative protocols in Cushing disease may significantly reduce length of stay and readmission rates. Consider using synthetic implants for cranioplasty after decompressive craniectomy to lower reoperation rates due to bone resorption. For interlaminar endoscopic lumbar discectomy, administering mg of intrathecal ropivacaine is recommended for optimal...
Owen briefs you on what matters in this week's digest.
Think chief-resident chalk talk: what matters, what changes practice, and where to spend your reading time.
Tumor / Skull Base
Standardized Perioperative Protocols Are Associated With Reduced Length of Stay and Readmission in Cushing Disease: Results From the Multicenter RAPID Study.
Research • Tumor / Skull Base • Neurosurgery • 2026-04-21
Consider adopting standardized perioperative protocols to potentially reduce LOS and readmission in Cushing disease.
OAdopting standardized perioperative protocols may help reduce length of stay and readmission rates in Cushing disease patients, but further high-quality studies are needed to confirm these findings.
Study snapshot
Design
Multicenter retrospective study
Population
Patients with Cushing disease undergoing transsphenoidal resection at 13 US centers
Intervention
Standardized perioperative protocols
Comparator
No protocol or less formalized protocols
Primary outcome
Length of stay and 90-day unplanned readmission
Why it matters
Perioperative protocols reduce length of stay in nonfunctioning pituitary adenomas, but their impact on Cushing disease was unknown. This multicenter retrospective study of 832 patients suggests that institutions with standardized protocols have significantly shorter LOS and reduced readmission rates. Clinicians may consider adopting formal perioperative protocols, including intraoperative checklists and non-narcotic pain regimens, to improve outcomes in Cushing disease.
Practice change
May support the implementation of perioperative protocols in Cushing disease to improve outcomes.
More context
Key details
- Retrospective analysis of RAPID consortium data from 13 US academic pituitary centers.
- 76.9% of institutions had a postoperative protocol; 69.2% used a formal document; 23.1% had hospital policy.
High-yield
Standardized perioperative protocols are associated with reduced length of stay and readmission in Cushing disease patients undergoing transsphenoidal surgery.
Clinical context
Perioperative protocols improve outcomes in nonfunctioning pituitary adenomas, but evidence in Cushing disease is lacking.
Limitations
Retrospective design limits causal inference.Survey-based protocol characterization may not capture all practice variations.
Methodological critique
Retrospective design with potential for selection bias and unmeasured confounders.
Teaching pearl
Implementing a formal perioperative protocol with an intraoperative checklist and non-narcotic pain regimen can reduce both LOS and readmission in Cushing disease patients.
Funding and COI
Not stated
Spine
The Optimal Effective Concentration of Spinal Anesthesia for Interlaminar Endoscopic Lumbar Discectomy: An Approach Based on the Biased Coin Design.
Research • Spine • Drug design, development and therapy • 2026-04-18
Use mg intrathecal ropivacaine for spinal anesthesia in interlaminar endoscopic lumbar discectomy.
OTarget a spinal anesthesia dose of 7.5 mg of intrathecal ropivacaine for interlaminar endoscopic lumbar discectomy to achieve effective anesthesia in 90% of patients while minimizing motor blockade and complications.
Study snapshot
Design
Prospective dose-finding study using biased coin design
Population
Adults 18-65 years, ASA I-III, undergoing IELD for lumbar disc herniation at L4/5 or L5/S1
Intervention
Intrathecal ropivacaine at varying concentrations
Comparator
None (dose-finding study)
Primary outcome
MEC90 of ropivacaine for effective spinal anesthesia (VASpain=0)
Why it matters
The optimal dose of spinal ropivacaine for interlaminar endoscopic lumbar discectomy was unknown. This study using a biased coin design determined the MEC90 of intrathecal ropivacaine to be 7.5 mg (95% CI 6.75-8.25 mg), providing a precise target for effective anesthesia in 90% of patients. Clinicians can use this concentration to balance efficacy and safety, minimizing motor blockade and complications.
Practice change
May support using 7.5 mg ropivacaine as the standard dose for spinal anesthesia in IELD.
More context
Key details
- Biased coin design up-and-down sequential method used to determine MEC90.
- First patient received 7.5 mg ropivacaine; dose adjusted by 0.75 mg based on response.
- Positive outcome defined as VASpain = 0; negative as VASpain ≥ 1.
- MEC90 estimated via isotonic regression and validated with Probit regression.
- Study included 55 patients; minimum 45 positive outcomes required.
High-yield
See source article for primary outcome data.
Clinical context
Spinal anesthesia is preferred for IELD, but optimal ropivacaine dose to balance efficacy and safety is unknown.
Limitations
Single-center study with relatively small sample size.Results may not generalize to other populations or surgical techniques.
Methodological critique
Biased coin design efficiently estimates MEC90 but requires careful validation.
Teaching pearl
For spinal anesthesia in IELD, target a ropivacaine dose of 7.5 mg to achieve effective anesthesia in 90% of patients while minimizing motor block.
Funding and COI
Not stated
General Neurosurgery
Cranioplasty outcomes after decompressive craniectomy: a near-nationwide population-based study based on 15 years of cranial reconstructions in Sweden.
Research • General Neurosurgery • Journal of neurosurgery • 2026-01-16
Consider synthetic implants for cranioplasty, especially in patients under, to reduce reoperation rates due to bone resorption.
OIn cranioplasty following decompressive craniectomy, synthetic implants may be preferable to autologous bone in younger patients due to a significant risk of reoperation from bone resorption, as evidenced by a 31% reoperation rate in a large Swedish cohort.
Study snapshot
Design
Multicenter retrospective cohort study
Population
Patients undergoing primary cranioplasty after decompressive craniectomy in Sweden (2008-2022)
Intervention
Cranioplasty (autologous bone or synthetic implant)
Comparator
Autologous vs synthetic implants
Primary outcome
Reoperation rate, functional recovery (modified Rankin Scale)
Why it matters
Before this study, cranioplasty outcomes were based on heterogeneous cohorts with limited follow-up. This near-nationwide Swedish study with median 80-month follow-up provides robust benchmarks: 31% reoperation rate, 15% revision due to bone resorption with autografts. Surgeons should consider synthetic implants preferentially, especially in younger patients, to reduce reoperation rates.
Practice change
May support a shift from autograft-first to alloplast-first strategy for cranioplasty, particularly in younger patients.
More context
Key details
- Multicenter near-nationwide study in Sweden over 15 years (2008-2022).
- 725 patients included; median age 49 years; autologous bone used in 74%.
- Median follow-up 80 months.
- Resorption most pronounced in patients <40 years; infection rates comparable across materials.
- 14% received permanent shunt; functional improvement more frequent in younger, healthier patients with earlier cranioplasty.
High-yield
31% of patients underwent at least one reoperation after cranioplasty.
Clinical context
Cranioplasty after decompressive craniectomy has high complication rates. Autologous bone grafts are commonly used but may resorb.
Limitations
Retrospective design with potential selection bias.Functional recovery assessed only at 6 months, not long-term.
Methodological critique
Retrospective design with potential unmeasured confounders.
Teaching pearl
When planning cranioplasty after decompressive craniectomy, remember that autologous bone has a high resorption rate in younger patients. Consider synthetic implants to reduce reoperation risk.
Funding and COI
Not stated
Basic Science
Exploring the immune environment of glioblastoma in humanized mouse models.
Research • Basic Science • Neuro-oncology • 2026-03-30
Preclinical evidence; no immediate practice change pending clinical validation.
OHumanized mouse models of glioblastoma may enhance understanding of immune interactions and therapy resistance, but their clinical applicability remains unvalidated and should be approached with caution.
Study snapshot
Design
Basic science (preclinical)
Population
Immunodeficient mice humanized with human CD34+ hematopoietic stem cells, then xenografted with radiation-resistant patient-derived glioblastoma xenografts.
Intervention
Humanized mouse model of glioblastoma using patient-derived xenografts.
Comparator
Conventional xenograft models and human recurrent GBM scRNA-seq data.
Primary outcome
Characterization of immune cell infiltration and gene expression profiles in tumors.
Why it matters
Before this study, available animal models of glioblastoma lacked human tumor and immune cell interactions, limiting research on therapy resistance and immunotherapies. This study establishes a humanized mouse model using patient-derived xenografts that recapitulates the immune environment of recurrent human GBM. Clinicians can consider this model a valuable preclinical tool for testing novel immunotherapies, though direct clinical application remains preliminary.
Practice change
Does not change current clinical practice but may inform future translational work.
More context
Key details
- Immunodeficient mice expressing human cytokines were used for humanization with CD34+ hematopoietic stem cells.
- Radiation-resistant patient-derived xenografts (PDXs) were implanted after human immune reconstitution.
- Tumor immune infiltration was analyzed by spectral flow cytometry, immunohistochemistry, and scRNA-seq.
- Results were benchmarked against scRNA-seq data from recurrent human GBM patients.
- The model showed enhanced tumor diversity, particularly a high fraction of neural progenitor-like cells.
High-yield
Humanized mouse models of glioblastoma show immune cell infiltration and gene expression profiles similar to recurrent human GBM, providing a platform for immunotherapy research.
Clinical context
Glioblastoma is the deadliest primary brain tumor in adults, and current therapies fail to extend survival meaningfully. Available animal models lack human tumor-immune interactions, hindering immunotherapy research.
Limitations
Preclinical model with limited direct translatability to human patients.Small sample size and lack of quantitative statistical comparisons.
Methodological critique
No quantitative comparisons or statistical tests reported; descriptive study only.
Teaching pearl
When evaluating preclinical GBM models, look for evidence of human immune cell infiltration and gene expression similarity to human tumors—these features increase the model's relevance for immunotherapy testing.
Funding and COI
Not stated
Trials to Know
Deep Brain Stimulation Surgery for Movement Disorders
Trial • Trials to Know • ClinicalTrials.gov • 2026-04-26
Why it matters
This trial evaluates the safety and efficacy of deep brain stimulation (DBS) using the Medtronic Activa Tremor Control System in patients with Parkinson's disease, essential tremor, and dystonia. It addresses the need for standardized outcomes data across multiple movement disorders, which can guide surgical decision-making and patient selection for DBS.
Feasibility of Endosphenoidal Coil Placement for Imaging of the Sella During Transsphenoidal Surgery
Trial • Trials to Know • ClinicalTrials.gov • 2026-04-26
Why it matters
This trial evaluates the feasibility of an endosphenoidal coil (ESC) to improve intraoperative MRI during transsphenoidal surgery for pituitary neoplasms. If successful, it could enhance real-time visualization of residual tumor, potentially improving resection rates and reducing reoperation. For neurosurgeons, this addresses a critical gap in intraoperative imaging quality for sellar lesions.
Multi-omics Research of Idiopathic Normal Pressure Hydrocephalus (iNPH)
Trial • Trials to Know • ClinicalTrials.gov • 2026-04-26
Why it matters
This trial aims to identify multi-omics biomarkers in iNPH patients undergoing ventriculoperitoneal shunting, which could improve patient selection and predict shunt response. For neurosurgeons, better biomarkers would refine surgical decision-making and outcomes in this challenging condition.
Policy & Systems / Advocacy
75 Medical Groups Urge Senate to Protect Medicare Access in Budget Reconciliation Bill
News • Policy & Systems / Advocacy • CNS • 2025-06-25
Why it matters
This coalition letter, including the CNS, signals a critical push to prevent Medicare payment cuts that directly impact neurosurgery reimbursement. Neurosurgeons should monitor this as it could affect practice viability and patient access to surgical care.
More context
Key details
- 75 medical organizations, including the Congress of Neurological Surgeons, signed a letter to Senate leaders.
- The letter urges protection of Medicare access during budget reconciliation, likely opposing cuts or advocating for payment updates.
- Medicare payment reductions have been a persistent issue, with cumulative cuts threatening physician participation.
Conferences & Courses
CNS Annual Meeting 2026
Conference • Conferences & Courses • Event page • 2026-04-26
Why it matters
The 76th CNS Annual Meeting features Olympic champion Lindsey Vonn, Khan Academy founder Sal Khan, and Pulitzer Prize-winning journalist Charles Duhigg as featured speakers, with Gail Rosseau and Ron L. Alterman as honored guests.