Volume changes in aortic true and false lumen after the "PETTICOAT" procedure for type B aortic dissection

The PETTICOAT (Provisional ExTension to Induce COmplete ATtachment) technique may be employed during endovascular treatment of type B aortic dissection (TBD) using self-expandable bare stents distal to the covered stent graft placed over the proximal entry tear. The aim of this study is to evaluate the volume changes of the true (TL) and false lumen (FL) on computed tomography (CT) scans.

Since 2005, 25 selected patients received endovascular treatment for complicated TBD with the PETTICOAT technique employing the Zenith Dissection Endovascular System (William Cook Europe, Bjaerverskov, Denmark). Indications to the use of the PETTICOAT technique were the evidence of clinical manifest dynamic malperfusion in five cases (20%) and/or radiologic evidence of TL collapse in 20 cases (80%). Five patients were treated within 2 weeks from onset, 13 patients between 2 weeks and 3 months, and seven patients over 3 months after the initial acute event. The volumetric analysis of the changes of TL and FL obtained from CT scan performed before endovascular treatment of TBD, postoperatively and yearly thereafter were analyzed using the OsiriX software v 3.9 (Pixmeo sarl, Bernex, Switzerland).

Initial clinical (30 days) and midterm clinical success was observed in 21 cases (84%) and in 23 cases (92%), respectively. The volumes of the aortic TL and FL were evaluated at 30 days and midterm follow-up (mean, 38 ± 17 months). The following TL volumes were recorded: baseline 84 ± 29 cm(3), postoperative 167 ± 31 cm(3) (+98%), 1 year 193 ± 46 cm(3) (+131%), and 2 years 216 ± 54 cm(3) (+140%). The following FL volumes were recorded: baseline 332 ± 86 cm(3), postoperative 286 ± 85 cm(3) (-14%), 1 year 233 ± 81 cm(3) (-30%), and 2 years 248 ± 112 cm(3) (-32%). Progressive remodeling of the TL was recorded over time in both thoracic and abdominal segments with shrinkage of the FL mainly in the thoracic segment.

These data provide insight into potential therapeutic benefit of the PETTICOAT technique. A significant immediate increase in TL could be achieved with resolution of all cases of dynamic malperfusion and TL collapse. A different behavior of volumes in the thoracic and abdominal segments was observed.