Clinical Outcomes of Subarachnoid Hemorrhage in Patients With Nicotine Dependence

Neurosurgery 98:1095–1102, 2026

This retrospective, population-based study analyzes clinical outcomes after nontraumatic subarachnoid hemorrhage (SAH) among 43,315 patients with documented nicotine dependence versus patients without substance use disorders. Using the TriNetX network with propensity score matching, primary endpoints included mortality, vasospasm, hydrocephalus, and delayed cerebral ischemia (DCI), with nicotine dependence associated with significantly higher hazards for all outcomes.

The manuscript details methods, matching variables, statistical analyses, mechanistic discussion of nicotine’s vascular effects, and limitations inherent to large electronic health record databases. Conclusions emphasize that nicotine dependence predicts worse SAH outcomes and support prioritizing smoking cessation counseling as part of long-term patient management.

Study focus: Clinical outcomes after nontraumatic subarachnoid hemorrhage (SAH) in adults with nicotine dependence versus those with no substance use disorder diagnoses.

Data source & cohort: TriNetX electronic medical record network analysis of adults (≥18) with ICD-10 I60 (nontraumatic SAH) from 2004–2024; 43,315 had nicotine dependence (F17) out of ~210k+ SAH patients.

Methods: Used 1:1 propensity score matching to balance demographics, comorbidities, lab/substance testing, and SAH severity (NIS-SAH Severity Score elements), then applied Cox proportional hazards and Kaplan–Meier survival analyses.

Mortality risk: Nicotine dependence associated with higher post-SAH mortality hazard (HR ≈ 1.24–1.25, statistically significant).

Vasospasm risk: Nicotine dependence associated with higher hazard of vasospasm (HR ≈ 1.47–1.49, statistically significant).

DCI risk: Nicotine dependence associated with higher hazard of delayed cerebral ischemia (DCI) (HR reported ≈ 1.30–1.35, statistically significant).

Hydrocephalus risk: Nicotine dependence associated with higher hazard of newly diagnosed hydrocephalus (HR ≈ 1.27, statistically significant).

Clinical implication: Elevated risks linked to nicotine dependence underscore the importance of smoking cessation counseling for long-term management after SAH.

Venous sacrifice in neurosurgery: new insights from venous indocyanine green videoangiography

J Neurosurg 115:18–23, 2011. DOI: 10.3171/2011.3.JNS10620

The purpose of this paper is to evaluate whether venous indocyanine green (ICG) videoangiography has any potential for predicting the presence of a safe collateral circulation for veins that are at risk for intentional or unintentional damage during surgery.

Methods. The authors performed venous ICG videoangiography during 153 consecutive neurosurgical procedures. On those occasions in which a venous sacrifice occurred during surgery, whether that sacrifice was preplanned (intended) or unintended, venous ICG videoangiography was repeated so as to allow us to study the effect of venous sacrifice. A specific test to predict the presence of venous collateral circulation was also applied in 8 of these cases.

Results. Venous ICG videoangiography allowed for an intraoperative real-time flow assessment of the exposed veins with excellent image quality and resolution in all cases. The veins observed in this study were found to be extremely different with respect to flow dynamics and could be divided in 3 groups: 1) arterialized veins; 2) fast-draining veins with uniform filling and clear flow direction; and 3) slow-draining veins with nonuniform filling. Temporary clipping was found to be a simple and reversible way to test for the presence of potential anastomotic circulation.

Conclusions. Venous ICG videoangiography is able to reveal substantial variability in the venous flow dynamics. “Slow veins,” when they are tributaries of bridging veins, might hide a potential for anastomotic circulation that deserve further investigation.