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Comparison of the association of sac growth and coil compaction with recurrence in coil embolized cerebral aneurysms.

Hoppe AL, Raghavan ML, Hasan DM - PLoS ONE (2015)

Bottom Line: In recurrent cerebral aneurysms treated by coil embolization, coil compaction is regarded as the presumptive mechanism.The translation of the coil mass center at follow-up was computed.Aneurysm sac growth, not coil compaction, was the primary mechanism of recurrence following successful coil embolization.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, United States of America.

ABSTRACT

Background and purpose: In recurrent cerebral aneurysms treated by coil embolization, coil compaction is regarded as the presumptive mechanism. We test the hypothesis that aneurysm growth is the primary recurrence mechanism. We also test the hypothesis that the coil mass will translate a measurable extent when recurrence occurs.

Methods: An objective, quantitative image analysis protocol was developed to determine the volumes of aneurysms and coil masses during initial and follow-up visits from 3D rotational angiograms. The population consisted of 15 recurrence and 12 non-recurrence control aneurysms initially completely coiled at a single center. An investigator sensitivity study was performed to assess the objectivity of the methods. Paired Wilcoxon tests (p<0.05, one-tailed) were performed to assess for aneurysm and coil growth. The translation of the coil mass center at follow-up was computed. A Mann Whitney U-Test (p<0.05, one-tailed) was used to compare translation of coil mass centers between recurrence and control subjects.

Results: Image analysis protocol was found to be insensitive to the investigator. Aneurysm growth was evident in the recurrence cohort (p=0.003) but not the control (p=0.136). There was no evidence of coil compaction in either the recurrence or control cohorts (recurrence: p=0.339; control: p=0.429). The translation of the coil mass centers was found to be significantly larger in the recurrence cohort than the control cohort (p=0.047).

Conclusion: Aneurysm sac growth, not coil compaction, was the primary mechanism of recurrence following successful coil embolization. The coil mass likely translates to a measurable extent when recurrence occurs and has the potential to serve as a non-angiographic recurrence marker.

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(A) Coil mass center translation, δ, in the recurrence (N = 9) and control cohorts (N = 9). The box and whisker plots show quartiles and the p-values are from one-tail Mann-Whitney U test for hypothesizing that δ will be higher in the recurrence cohort than in control ( hypothesis, H0: δRECR ≤ δCTRL; alternative hypothesis, HA: δRECR > δCTRL). The triangles indicate raw data values. (B) Receiver operator curve showing the predictability of δ in recurrence (N = 9) and control (N = 9) aneurysms. δ is a better predictor of recurrence than clinically measured sac size, as it has a larger area under the curve or AUC (AUC = 0.74). Optimal sensitivity and specificity in differentiating recurrence aneurysms from control was found at δ = 1.1 mm.
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pone.0123017.g004: (A) Coil mass center translation, δ, in the recurrence (N = 9) and control cohorts (N = 9). The box and whisker plots show quartiles and the p-values are from one-tail Mann-Whitney U test for hypothesizing that δ will be higher in the recurrence cohort than in control ( hypothesis, H0: δRECR ≤ δCTRL; alternative hypothesis, HA: δRECR > δCTRL). The triangles indicate raw data values. (B) Receiver operator curve showing the predictability of δ in recurrence (N = 9) and control (N = 9) aneurysms. δ is a better predictor of recurrence than clinically measured sac size, as it has a larger area under the curve or AUC (AUC = 0.74). Optimal sensitivity and specificity in differentiating recurrence aneurysms from control was found at δ = 1.1 mm.

Mentions: Demographic and procedural study subject information is given in Table 1. The aneurysm sac and coil mass volumes estimated by the two blinded users agreed quite strongly (see Fig 2) with coefficients of determination for the aneurysm sac and coil mass volumes of 0.998 and 0.999 respectively. Imaging data was available to calculate VSG in all 15 subjects within the recurrence cohort (11 from VSG1, 1 from VSG2, 2 from VSG3, and 1 from VSG4) and all 12 subjects in the control cohort (all 12 from VSG3). However imaging data was only available to calculate VCG in 9 of 15 aneurysms in the recurrence cohort and 9 of 12 aneurysms in the control cohort. Aneurysm sac growth was found to exist with statistical significance in the recurrence cohort (min, median, max VSG = -0.044, +0.083, +0.580 cc; p = 0.003; see Fig 3). In contrast, sac growth was not found to exist with statistical significance in the control cohort (min, median, max VSG = -0.009, +0.001, +0.024 cc; p = 0.136; see Fig 3). Coil mass compaction was not found to occur with statistical significance in either the recurrence (min, median, max VCG = -0.265, +0.004, +0.359 cc; p = 0.339; see Fig 3) or control cohorts (min, median, max VCG = -0.013, 0.000, +0.008 cc; p = 0.429; see Fig 3). Translation of a coil mass center (δ) in the recurrence cohort was significantly larger than in the control cohort (min, median, max δ = 0.21, 1.97, 5.64 mm versus 0.32, 0.99, 2.06 mm; p = 0.047). It is noteworthy that the control cohort had smaller aneurysms at initial presentation compared to the recurrence cohort (sac size median = 10 versus 6.5 mm; 2p = 0.004 by Mann-Whitney U-test). A receiver operating characteristic (ROC) curve was plotted for δ and was found to have an area under the curve (AUC) of 0.74. Therefore δ is a better predictor of recurrence than clinically measured sac size, which had an AUC = 0.65 (see Fig 4). Sac size (height x width) of all aneurysms was measured by a single neurosurgical specialist on angiograms, the largest dimension of which was labeled as clinically measured sac size. According to the ROC curve, δ = 1.1 mm had optimal sensitivity and specificity to distinguish recurrence from control aneurysms.


Comparison of the association of sac growth and coil compaction with recurrence in coil embolized cerebral aneurysms.

Hoppe AL, Raghavan ML, Hasan DM - PLoS ONE (2015)

(A) Coil mass center translation, δ, in the recurrence (N = 9) and control cohorts (N = 9). The box and whisker plots show quartiles and the p-values are from one-tail Mann-Whitney U test for hypothesizing that δ will be higher in the recurrence cohort than in control ( hypothesis, H0: δRECR ≤ δCTRL; alternative hypothesis, HA: δRECR > δCTRL). The triangles indicate raw data values. (B) Receiver operator curve showing the predictability of δ in recurrence (N = 9) and control (N = 9) aneurysms. δ is a better predictor of recurrence than clinically measured sac size, as it has a larger area under the curve or AUC (AUC = 0.74). Optimal sensitivity and specificity in differentiating recurrence aneurysms from control was found at δ = 1.1 mm.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4404091&req=5

pone.0123017.g004: (A) Coil mass center translation, δ, in the recurrence (N = 9) and control cohorts (N = 9). The box and whisker plots show quartiles and the p-values are from one-tail Mann-Whitney U test for hypothesizing that δ will be higher in the recurrence cohort than in control ( hypothesis, H0: δRECR ≤ δCTRL; alternative hypothesis, HA: δRECR > δCTRL). The triangles indicate raw data values. (B) Receiver operator curve showing the predictability of δ in recurrence (N = 9) and control (N = 9) aneurysms. δ is a better predictor of recurrence than clinically measured sac size, as it has a larger area under the curve or AUC (AUC = 0.74). Optimal sensitivity and specificity in differentiating recurrence aneurysms from control was found at δ = 1.1 mm.
Mentions: Demographic and procedural study subject information is given in Table 1. The aneurysm sac and coil mass volumes estimated by the two blinded users agreed quite strongly (see Fig 2) with coefficients of determination for the aneurysm sac and coil mass volumes of 0.998 and 0.999 respectively. Imaging data was available to calculate VSG in all 15 subjects within the recurrence cohort (11 from VSG1, 1 from VSG2, 2 from VSG3, and 1 from VSG4) and all 12 subjects in the control cohort (all 12 from VSG3). However imaging data was only available to calculate VCG in 9 of 15 aneurysms in the recurrence cohort and 9 of 12 aneurysms in the control cohort. Aneurysm sac growth was found to exist with statistical significance in the recurrence cohort (min, median, max VSG = -0.044, +0.083, +0.580 cc; p = 0.003; see Fig 3). In contrast, sac growth was not found to exist with statistical significance in the control cohort (min, median, max VSG = -0.009, +0.001, +0.024 cc; p = 0.136; see Fig 3). Coil mass compaction was not found to occur with statistical significance in either the recurrence (min, median, max VCG = -0.265, +0.004, +0.359 cc; p = 0.339; see Fig 3) or control cohorts (min, median, max VCG = -0.013, 0.000, +0.008 cc; p = 0.429; see Fig 3). Translation of a coil mass center (δ) in the recurrence cohort was significantly larger than in the control cohort (min, median, max δ = 0.21, 1.97, 5.64 mm versus 0.32, 0.99, 2.06 mm; p = 0.047). It is noteworthy that the control cohort had smaller aneurysms at initial presentation compared to the recurrence cohort (sac size median = 10 versus 6.5 mm; 2p = 0.004 by Mann-Whitney U-test). A receiver operating characteristic (ROC) curve was plotted for δ and was found to have an area under the curve (AUC) of 0.74. Therefore δ is a better predictor of recurrence than clinically measured sac size, which had an AUC = 0.65 (see Fig 4). Sac size (height x width) of all aneurysms was measured by a single neurosurgical specialist on angiograms, the largest dimension of which was labeled as clinically measured sac size. According to the ROC curve, δ = 1.1 mm had optimal sensitivity and specificity to distinguish recurrence from control aneurysms.

Bottom Line: In recurrent cerebral aneurysms treated by coil embolization, coil compaction is regarded as the presumptive mechanism.The translation of the coil mass center at follow-up was computed.Aneurysm sac growth, not coil compaction, was the primary mechanism of recurrence following successful coil embolization.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, United States of America.

ABSTRACT

Background and purpose: In recurrent cerebral aneurysms treated by coil embolization, coil compaction is regarded as the presumptive mechanism. We test the hypothesis that aneurysm growth is the primary recurrence mechanism. We also test the hypothesis that the coil mass will translate a measurable extent when recurrence occurs.

Methods: An objective, quantitative image analysis protocol was developed to determine the volumes of aneurysms and coil masses during initial and follow-up visits from 3D rotational angiograms. The population consisted of 15 recurrence and 12 non-recurrence control aneurysms initially completely coiled at a single center. An investigator sensitivity study was performed to assess the objectivity of the methods. Paired Wilcoxon tests (p<0.05, one-tailed) were performed to assess for aneurysm and coil growth. The translation of the coil mass center at follow-up was computed. A Mann Whitney U-Test (p<0.05, one-tailed) was used to compare translation of coil mass centers between recurrence and control subjects.

Results: Image analysis protocol was found to be insensitive to the investigator. Aneurysm growth was evident in the recurrence cohort (p=0.003) but not the control (p=0.136). There was no evidence of coil compaction in either the recurrence or control cohorts (recurrence: p=0.339; control: p=0.429). The translation of the coil mass centers was found to be significantly larger in the recurrence cohort than the control cohort (p=0.047).

Conclusion: Aneurysm sac growth, not coil compaction, was the primary mechanism of recurrence following successful coil embolization. The coil mass likely translates to a measurable extent when recurrence occurs and has the potential to serve as a non-angiographic recurrence marker.

Show MeSH
Related in: MedlinePlus