Sizing for endovascular aneurysm repair: clinical evaluation of a new automated three-dimensional software.
BACKGROUND
To assess the reproducibility and accuracy of the sizing procedure before aortic endograft implantation using new sizing automated software as compared with standard radiological procedures.


METHODS
On the basis of original spiral-computed tomography images, the sizing of 32 patients with abdominal aortic aneurysm treated by endovascular aneurysm repair (EVAR) was retrospectively compared. The first sizing was performed by a radiologist using a standard workstation (General electrics) and software (Advanced vessel analysis). The second was performed twice by two surgeons using a personal computer with automatic three-dimensional sizing software (Endosize; Therenva, Rennes, France). All diameters and lengths required before EVAR were measured (17 items). Moreover, 13 qualitative criteria regarding EVAR feasibility, including neck length, were compared. Intra- and interobserver variability with Endosize, as well as the variability between the two measurement methods were analyzed using the intraclass correlation coefficient (ICC) and Bland and Altman's method. Qualitative variables were analyzed using Fischer's exact test and kappa coefficient.


RESULTS
Intraobserver variability with Endosize proved to be efficient. None of the ICCs were lower than 0.9, and more than 90% of the absolute differences between two measurements were less than 2 mm. Interobserver variability with Endosize was assessed in a similar manner. Measurement variability of vessel diameters was less marked than that of vessel lengths. This trend was observed for all datasets. Comparison of the two measurement methods demonstrated a good correlation (minimum ICC = 0.697; maximum ICC = 0.974), although less so than that observed using Endosize. Mean time consumption using Endosize was 13.1 ± 4.53 minutes (range: 7.2-32.7). Analysis of the alarm sets demonstrated a high agreement between observers (kappa coefficient = 0.81).


CONCLUSIONS
Sizing using the Endosize software is as reliable as conventional radiological procedures. Sizing by surgeons using an automated, user-friendly, and mobile tool appears to be reproducible.
Kaladji
Adrien
A
Vascular Surgery Unit, Pontchaillou Hospital, Rennes, France. kaladrien@hotmail.fr
Lucas
Antoine
A
Kervio
Gaëlle
G
Haigron
Pascal
P
Cardon
Alain
A
D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging* / Q000601:surgery*; D001027:Aortography / Q000379:methods*; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000295:instrumentation*; D017076:Computer-Aided Design; D005240:Feasibility Studies; D005260:Female; D005602:France; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D011300:Preoperative Care; D011474:Prosthesis Design; D011857:Radiographic Image Interpretation, Computer-Assisted; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012984:Software; D036542:Tomography, Spiral Computed