Correction: Efficacy of intraoperative indocyanine green videoangiography (ICG-VA) and FLOW 800 in the surgical management of intracranial aneurysms: a systematic review and meta-analysis (Acta Neurochirurgica, (2026), 168, 1, (24), 10.1007/s00701-026-06779-6)

Turpo-Peqqueña A.G.; Santos‑Vargas S.A.; Loza‑Chipa H.R.; Lamas F.M.; Espinoza‑Laura G.A.; Núñez‑Basurco C.S.; Medina‑Neira D.N.; Benites‑Bustamante V.A.; Osorio‑Pacheco R.R.; Turpo‑Peqqueña J.R.; Huanca‑Quispe G.; Vizcarra‑Vizcarra C.A.; Gómez B.; Rivillas J.A.; Hernández‑Mayori R. · Acta Neurochirurgica (2026) · DOI: 10.1007/s00701-026-06990-5

Resumen

The authors regret that after publication of the article entitled “Efficacy of intraoperative indocyanine green videoangiography (ICG-VA) and FLOW 800 in the surgical management of intracranial aneurysms: a systematic review and meta-analysis”, several methodological inconsistencies, numerical discrepancies, and interpretative statements requiring clarification were identified. These issues involved wording that could imply comparative or causal interpretations beyond the descriptive nature of the included studies, inconsistencies in study classification and denominators, as well as incomplete reporting in the methodological quality assessment. These corrections were made to improve methodological precision, internal consistency, and alignment between the study design and interpretation of the findings. These corrections primarily address methodological wording, study classification consistency, denominator harmonization, and interpretative precision. Importantly, the pooled quantitative estimates, statistical analyses, and overall descriptive intraoperative findings of the study were not materially altered by these corrections. The principal pooled intraoperative findings and overall conclusions of the study remain unchanged. However, this led to several clarifying corrections throughout the manuscript as follows: In the Abstract, Background section, the sentence: “FLOW 800 is a semi quantitative analysis tool that enhances blood flow evaluation.” should read: “FLOW 800 is a semi quantitative analysis tool that may assist intraoperative blood flow evaluation.” In the Abstract, Background section, the sentence: “This meta-analysis aims to evaluate the combined diagnostic efficacy of ICG-VA and FLOW 800” should read: “This meta-analysis aims to evaluate intraoperative outcomes reported with the combined use of ICG-VA and FLOW 800”. In the Abstract, Conclusions section, the sentence:“The combined use of ICG-VA and FLOW 800 enhances the intraoperative detection of misclipping, residual aneurysm, and flow disturbances not evident with ICG-VA alone” should read: “The combined use of ICG-VA and FLOW 800 may serve as a complementary intraoperative tool for the assessment of misclipping, residual aneurysm, and flow disturbances reported during aneurysm surgery” The statement: “not evident with ICG-VA alone” has been removed to avoid unsupported comparative interpretation. The statement: “encourage broader adoption” has also been removed. The following sentence was added to emphasize the need for future validation: “Further prospective comparative studies are warranted to validate these findings against angiographic standards and better define its intraoperative role in neurosurgical practice.” In the Introduction section, the sentence: “FLOW 800 (Zeiss Meditec, Oberkochen, Germany), a software that transforms fluorescence signals into color-coded maps, has been introduced, allowing real-time interpretation of cerebral flow dynamics” should read: “FLOW 800 (Zeiss Meditec, Oberkochen, Germany), a software that transforms fluorescence signals into color-coded maps, has been introduced, allowing semi-quantitative intraoperative assessment of cerebral flow dynamics.” The phrase: “allowing semi-quantitative intraoperative assessment of cerebral flow dynamics” was added to better clarify the descriptive and semi-quantitative nature of FLOW 800 analysis. Also, in the Introduction section, the sentence: “Therefore, this meta-analysis aims to evaluate the combined efficacy of ICG-VA and FLOW 800” should read: “Therefore, this meta-analysis aims to evaluate intraoperative findings reported with the combined use of ICG-VA and FLOW 800”. The phrase:“combined efficacy”was replaced by:“reported intraoperative findings” to avoid causal or comparative interpretation inconsistent with the observational design of the included studies. Additionally, the following clarification was added: “reported with the combined use” to emphasize the descriptive nature of the review. In the Methods section, Study Selection subsection, the sentence: “We included 12 studies in the qualitative synthesis (344 aneurysms).” was removed due to inconsistency with the corrected total number of included patients and aneurysms reported in the Results section. The Study Selection subsection was retained as follows: “Five reviewers independently screened titles and abstracts. Full-text articles of potentially eligible studies were then assessed based on the predefined inclusion criteria. Any discrepancies were resolved by consensus or, when necessary, through consultation with the senior author.” In the Results section, Study characteristics subsection, the total number of included patients and aneurysms was corrected. The sentence: “The 12 included studies comprised 344 aneurysms in 341 patients” should read: “A total of 335 patients and 384 aneurysms were analyzed.” In the Results section, Study characteristics subsection, study design classifications were harmonized between the narrative text and Table 1. The sentence: “Nine studies had a retrospective design [3, 10, 18, 19, 23, 25, 27, 36, 41], while three were prospective [24, 32, 43].” should read: “Nine studies had a retrospective design [3, 10, 18, 23, 25, 27, 32, 36, 41], while three were prospective [19, 24, 43].” This correction was made to ensure consistency between the narrative text and Table 1 regarding the classification of Kırış 2024 and Rennert 2019 study designs. In the Results section, several interpretative statements were revised to reduce unsupported superiority claims and replace them with descriptive wording consistent with the observational design of the included studies. The expression “the greatest utility of the combined use of ICG-VA + FLOW 800 occurs in anterior circulation aneurysms” was replaced by “several included studies descriptively reported potential utility of the combined use of ICG-VA + FLOW 800 in anterior circulation aneurysms.” The phrase “FLOW 800 allowed for objective assessment of perfusion” was replaced by “FLOW 800 was used for intraoperative perfusion assessment,” while “improving intraoperative accuracy” was replaced by “supporting intraoperative assessment and surgical decision-making.” The statement “Its utility was also evident in posterior circulation aneurysms” was modified to “Some studies also reported its application in posterior circulation aneurysms.” Likewise, the sentence “the combination with FLOW 800 corrected these inconsistencies by differentiating real flow from residual fluorescence and detecting incomplete clipping” was replaced by “several included studies reported that FLOW 800 helped differentiate real flow from residual fluorescence and assisted in the identification of incomplete clipping.” The statement “its clinical value is greater in ruptured aneurysms” was modified to “some studies reported potential clinical utility in ruptured aneurysms,” and the expression “the FLOW 800 combination proved essential” was replaced by “the combined use of ICG-VA and FLOW 800 was considered useful.” Additionally, the following sentence was added: “However, due to limited subgroup-specific reporting and the absence of formal comparative subgroup analyses, these observations should be interpreted cautiously.” A corrected version of Figure 1 showing “Records excluded (n = 1001)”. (Figure presented.) PRISMA flow diagram. PRISMA, preferred reporting items for systematic reviews and meta-analysis. ICG-VA: Indocyanine Green Videoangiography In the Quality Assessment section and Fig. 6, the previously omitted study Rennert 2019 was added to the QUADAS-2 assessment panel. Figure 6 was updated accordingly to include all 12 studies consistently across the risk-of-bias analysis. Consequently, the percentage of studies classified as having “some methodological concerns” was corrected from “63.6%” to “66.7%,” ensuring consistency between Fig. 6 and the total number of included studies. In Table 3, discrepancies involving denominators in the meta-regression analysis were corrected and harmonized. Specifically, the total number of aneurysms analyzed for the “Aneurysm remnant – Study design” predictor was corrected to “206” to ensure consistency across the meta-regression analyses and corresponding pooled outcomes. (Figure presented.) (Table presented.) Risk of bias assessment using the QUADAS-2 tool. Panel A shows the risk of bias per study across four domains: patient selection, index test, reference standard, and flow & timing. Panel B summarizes the percentage of judgments across all studies. Green indicates low risk; yellow indicates some concerns and red indicates high risk of bias Predictors of outcome identified on meta-regression Outcome Predictor No. of studies reporting outcome Total no. of aneurysm analyzed P value Significant R2 (%) I2 (%) τ2 Misclipping Publication year 8 277 0.7486 No 0.0 62.72 0.8291 Median patient age 7 245 0.0679 No 48.37 42.11 0.2985 Study design 8 277 <.0001 Yes 0.0 40.84 0.3016 Aneurysm remnant Publication year 6 206 0.5755 No 0.0 32.62 0.3538 Median patient age 5 174 0.0247 Yes 100 0.0 0.0 Study design 6 206 <.0001 Yes 0.0 0.0 0.0 Vascular stenosis/occlusion Publication year 6 197 0.2835 No 1.30 84.43 3.9216 Median patient age 6 197 0.6625 No 0.00 42.49 0.4343 Study design 6 197 <.0001 Yes 0.0 27.26 0.2251 Clip repositioning Publication year 7 245 0.9562 No 0.0 56.18 0.7113 Median patient age 7 245 0.0073 Yes 100 0.0 0.0 Study design 7 245 <.0001 Yes 0.0 37.85 0.3050 In the Discussion section, several interpretative statements were revised to reduce unsupported causal or comparative claims and replace them with more descriptive wording consistent with the observational nature of the included studies. The sentence “our results showed 9.36% which reinforces the idea of using complementary methods to optimize results” was modified to “our results showed 9.36%, which supports the use of complementary intraoperative assessment methods.” The phrase “with no visible evidence in ICG-VA” was replaced by “with no clear abnormalities reported on standard ICG-VA assessment” to avoid unsupported direct comparative inference. The sentence: “Similarly, Goertz et al. [10] demonstrated intraoperative hypoperfusion that led to corrections not identified by other techniques.” was revised to: “Similarly, Goertz et al. [10] reported intraoperative hypoperfusion findings that prompted surgical adjustments during aneurysm clipping.” This modification was made to avoid unsupported comparative interpretation regarding other intraoperative techniques. Finally, the statement “Together, these findings support the value of FLOW 800 as a supplementary tool to optimize intraoperative decisions in aneurysm surgery.” was revised to: “Together, these findings suggest that FLOW 800 may provide complementary intraoperative hemodynamic information during aneurysm surgery.” This modification was made to adopt more cautious and descriptive wording consistent with the observational nature of the included studies. In the Limitations section, the following statement was added: “Because this study was based on a single-arm proportional meta-analysis without direct comparative groups, causal inferences regarding superiority of the combined ICG-VA and FLOW 800 approach over isolated ICG-VA should be interpreted cautiously.” In the Conclusion section, the sentence “The combined use of ICG-VA and FLOW 800 could enhance intraoperative detection of misclipping, remnants, and vascular compromise in aneurysm surgery” was revised to “The combined use of ICG-VA and FLOW 800 may serve as a complementary intraoperative tool for the assessment of misclipping, aneurysm remnants, and vascular compromise during aneurysm surgery.” Additionally, the sentence “These techniques show promise as complementary tools, particularly in resource-limited settings” was replaced by “These findings summarize the pooled intraoperative detection rates reported with the combined use of ICG-VA and FLOW 800 in aneurysm surgery.” The following sentence was also added: “Future high-quality prospective studies are essential to confirm these descriptive intraoperative findings in larger prospective comparative studies.” Finally, the Data Availability Statement “No datasets were generated or analysed during the current study” was revised to “All data analyzed during this study are included in this published article and its supplementary information files.” Furthermore, the name of the first and corresponding author was incorrectly presented in the published manuscript. The correct name is Albert Gabriel Turpo-Peqqueña. Additionally, the author has removed his affiliations with the Faculty of Biology, National University of San Agustín (Arequipa, Peru), and the Center for Molecular Engineering Research (CIIM), Universidad Católica de Santa María (Arequipa, Peru). Finally, the corresponding author’s ORCID iD was previously incomplete or incorrect and has been updated to: https://orcid.org/0000-0002-9020-7659. The authors would like to apologise for any inconvenience caused. © The Author(s) 2026.

Instituciones: Universidad de San Martín de Porres; Universidad Nacional de San Agustín de Arequipa; Universidad Católica de Santa María