Discrepancy between the nonautomatic

Transcription

1 Discrepancy between the nonautomatic and semiautomatic measurements of AAA diameter-does it influence outcome? Joy Roy Department of Vascular Surgery Karolinska University Hospital / Karolinska Institutet Stockholm, Sweden

2 Disclosure of Interest Speaker name: JOY ROY I have the following potential conflicts of interest to report: Consulting Employment in industry Shareholder in a healthcare company Owner of a healthcare company Other(s) I do not have any potential conflict of interest

3 Background Maximum Diameter is the only robust parameter clinically used to determine AAA intervention. - Imaging modality Ultrasound? CT? - lack of consistency on AAA diameter measurements The UKSAT Participants, 1998, Lancet

4 Background Large numbers of AAA patients are on surveillance unpredictable to determine which patients will require Intervention Expensive patient anxiety Small AAAs rupture 30% of raaa in Stockholm were known AAA patients, 44% - small diameters or lost during follow up Zommorodi et al, 2016, J Vasc Surg Skibba, 2015, J Vasc Surg

5 Hypothesis 3D analysis of AAAs (Geometric and Biomechanical) improves prediction for the need of intervention compared to the.

6 Method -Radiologist vs Semi-automatic 3D segmentation och finite-element-analys (FEA) A4 Clinics Software

7 Retrospective Longitudinal Study Undergoing surveillance at Our Department ( ) CT Clinical diameter mm at baseline 95 patients included Clinical Maximum Diameter Semi-automatic 3D-segmentation och FEA Diameters Volumes Biomechanical Rupture risk, PWRI Growth Rate 4 yr FU after the first CT Clinical Diameter n = 55: Intervention Group Surgery or 55 mm diameter n = 40: Stable Not intervened and < 55 mm diameter

8 Results Stable, n = 40 Intervention, n = 55 p 33 (82%) 39 (71%) 0.29 Age 70.5 ( ) 70 (67-77) 0.69 Heredity (First degree relative with 4 (12%) 12 (26%) 0.31 AAA) Missing data 8 (20%) 9 (16%) Smoking Ongoing Earlier Never Missing data: 13 (33%) 16 (41%) 10 (26%) 1 (2.5%) 21 (38%) 22 (40%) 12 (22%) 0.86 MAP (mmhg) Missing data: BMI (kg/m2) Missing data: 100 ( ) 1 (2%) 26.2 ( ) 4 (10%) ( ) 4 (7%) 25.8 ( ) 0 at Baseline 42 (40-45) 46 (44-49) <0.001 Growth Rate (mm/yr) 1.1 ( ) 3.8 ( ) <0.001 Missing data 0 2 (4%)

9 Results Need for intervention p = Stable Surgery Indication PWRI [ratio] PWRI p = 2.6e Stable Surgery Indication Diameter [mm] p = 3e Stable Surgery Indication Diameter [mm] Semiautomatic External Diameter

10 Prediction of Need for Intervention Semi-automatic external diameter + PWRI Results Need for intervention Stable Surgery Indication Clinical diameter [mm] Prediction by PWRI and semiautomatic external diameter FALSE TRUE

11 Random Forest och Ridge 10-fold Cross validation Semi-automatic External Diameter PWRI AAA volume Lumen volume Sensitivity D Segmentation 3D segmentation+pwri + PWRI + Clinical Diam + AUC ( ) AUC 0.85 ( ) p = p= AUC 0.75 ( ) AUC 0.75 ( ) Specificity 1.00 Lasso 10-fold Cross validation 0.75 Semi-automatic External Diameter PWRI Sensitivity D 3D segmentation+pwri Segmentation + PWRI + Clinical Diam + AUC 0.83 ( ) 0.83 ( ) p = p=0.047 AUC 0.75 ( ) AUC 0.75 ( ) Specificity

12 r = 0,17, p = 0,1 r = 0,41 p = 4,2e-05 r = 0,27 p = 0,0096 r = 0,25 p = 0,014 Results Growth Rate r = 0.27, p = Annual Growth Rate [mm/year] PWRI [ratio] PWRI r = 0.17, p = Annual Growth Rate [mm/year] Diameter [mm] r = 0.41, p = 4.2e Annual Growth Rate [mm/year] Diameter [mm] Semiautomatic External Diameter r=0.27, p= r=0.17, p=0.1 r=0.41, p=4.2e-05

13 Results Prediction of Growth Rate Multiple linear regression Growth Rate as the Dependent Variable Coefficient P Semi-automatic External Diameter *** Semi-automatic Luminal Diameter Max Thrombus Thickness * AAA Volume Lumen volume Thrombus volume PWS PWRI ILT Stress

14 Conclusions 3D analysis Semi-automatic diameter and the Peak Wall Rupture risk are better predictors of the Need for Intervention Growth rate correlates better to Semiautomatic Diameter and PWRI vs Clinical Diameter Supports the Concept of 3D Imaging during Surveillance Prospective Studies planned and underway for 3D- och Biomechanical analysis using MRI and Ultrasound

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