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Updated: Apr 20, 2026
Microsurgical Clip Obliteration of Middle Cerebral Aneurysm Using Intraoperative Flow Assessment
Published on: September 25, 2009
Structured mentorship enables novice surgeons to achieve acceptable outcomes in microsurgical aneurysm clipping: an
Harsh Deora1, Mohammed Nadeem1, Sarthak Mehta1
1Department of Neurosurgery, National Institute of Mental Health and Neurosciences, (NIMHANS), Bengaluru, Karnataka, India.
Objective:
To evaluate the impact of surgeon experience on microsurgical aneurysm clipping outcomes and assess whether structured training enables novice surgeons to achieve technical and clinical parity with experts despite declining open surgical exposure in the endovascular era.
Methods:
A 5-year retrospective cohort study (2019-2024) analyzed 402 intracranial aneurysm clippings performed by two expert (>300 lifetime clippings) and two novice surgeons (<30 lifetime clippings), whom the experts directly trained. Primary outcomes included intraoperative rupture, temporary clipping duration, and residual aneurysm. Secondary outcomes encompassed functional status, ICU stay, and mortality-multivariable regression adjusted for age, aneurysm complexity (multiplicity, neck width), and surgical timing.
Results:
Experts managed more complex cases, including higher rates of multiple aneurysms (12.9% vs. 4.1%; p 0.008) and wider necks (2.94 ± 1.53 mm vs. 2.48 ± 1.11 mm; p 0.008). Despite this, intraoperative safety metrics were comparable: rupture rates (experts 13.6% vs. novices 9.8%; p 0.297) and temporary clip times (317.9 ± 403.4 s vs. 265.1 ± 253.0 s; p = 0.894). Discharge functional outcomes were comparable, with nearly 70% achieving good recovery (mRS 0-2) in both cohorts (p = 0.975). Residual aneurysm rates were identical (10.5%; p > 0.05). After adjustment, experts had higher ICU admission odds (OR 2.2, 95% CI 1.43-3.65; p = 0.0005), reflecting case complexity, but no differences in mortality, rupture, or functional outcomes emerged. Novices demonstrated a non-significant improvement in good outcomes during their latter 61 cases (63.9% vs. 73.8%; p = 0.69), aligning with a typical learning curve.
Conclusions:
Within the constraints of this single-centre, retrospective, non-randomised study conducted at a high-volume microsurgical centre with direct expert supervision and structured case allocation, novice surgeons achieved short-term outcomes that were non-inferior to expert surgeons for the cases assigned to them. These findings support the narrower inference that a structured, mentorship-driven training framework can facilitate safe operative performance among carefully supervised trainees operating on appropriately selected cases, and should not be generalised beyond this specific training context.
