Measuring the greater curvature length of virtual stent graft can provide accurate prediction of stent graft position for thoracic endovascular aortic repair

Prognostic impact of early aortic volume changes at hospital discharge in patients with acute type B aortic dissection

BACKGROUND

Early prediction of aorta-related events is important for determining subsequent treatment strategies in patients with acute aortic dissection. However, most studies evaluated long-term aortic growth rates by annual assessment. The purpose of our study was to determine whether the in-hospital growth rate of aortic volume was associated with aorta-related events.

METHODS

We studied 116 patients with uncomplicated type B acute aortic dissection. We analyzed whether changes in aortic volume were associated with aorta-related events during a 5-year follow-up. According to the growth rate from admission to discharge, patients were divided into two groups: Increase >0 (aortic volume: n = 59, aortic diameter: n = 43) and Reduction ≤0 (aortic volume: n = 57, aortic diameter: n = 73) in maximum aortic diameter or aortic volume. The primary endpoint was the discriminative ability of the growth rate of aortic volume for aorta-related events.

RESULTS

According to the evaluation of aortic volume changes, the Increase group had significantly higher aorta-related event rates than those in the Reduction group (49.2 % vs. 3.5 %, respectively; p < 0.001). Receiver operating characteristics analysis showed that the growth rate of aortic volume had a clearly useful discrimination, with an area under the curve of 0.84, whereas the discriminative ability of the growth rate of maximum aortic diameter was poor (area under the curve: 0.53). Multivariate analysis showed that the growth rate of aortic volume from admission to discharge was an independent predictor of aorta-related events (hazard ratio, 26.3; 95 % confidence interval, 2.04-286.49; p = 0.001).

CONCLUSIONS

In-hospital evaluation of aortic volume was helpful to predict long-term aorta-related events in patients with uncomplicated type B acute aortic dissection.

Stent-Graft Migration Post-Endovascular Repair of Thoracic Aorta: A Retrospective Cohort Study

Background Migration of the stent-graft post-thoracic endovascular aortic repair (TEVAR) is not uncommon; however, it is sparsely reported. The objective of this study was to assess the incidence, risk factors, and complications of stent-graft migration post-TEVAR.

Materials and Methods Thirty-one patients who underwent TEVAR were retrospectively analyzed. The demographic, anatomical, and procedure-related factors were assessed. The measurements were done along the greater curvature of aorta around two fixed anatomic landmarks, that is, left common carotid artery or neoinnominate artery (hybrid repair) proximally and celiac artery distally. Aortic elongation and migration at proximal, distal, as well as at overlapping zone were measured. More than 10 mm of migration was considered significant.

Results Significant migration was observed in six (19%) patients. No significant migration was observed in the overlapping zone. The proximal landing zone 3 (odds ratio [OR] 12.78, p 0.01) was a significant risk factor, whereas landing zone 2 was a protective factor against the migration (OR 0.08, p 0.02). The odds for migration were more in segments I/3 and II/3 compared with I/2 and II/2, respectively, as per Modified Arch Landing Areas Nomenclature. A single complication was seen in the migration group which was treated by an overlapping stent graft.

Conclusion The stent-graft migration after TEVAR is not uncommon. Type 3 proximal landing zone was a significant risk factor for migration with an increased risk toward I/3 and II/3. Proximal landing zone 2 as well as adequate overlapping distance in multiple stent grafts can prevent migration.

Ethical Approval No IECPG-227/24.06.2020

Greater Curvature, Centerline or Straightened Centerline Length - Which length is Most Accurate for Preprocedural Planning in Thoracic Endovascular Aortic Repair?

BACKGROUND

Automated centerline (CL) measurements have been conventionally used for stent-graft length estimation during thoracic endovascular aortic repair (TEVAR). The purpose of this study was to assess the accuracy of greater curvature length (GL), semiautomated CL and straightened centerline length (SCL) for preprocedural planning in TEVAR.

METHODS

Immediate postprocedural CT Angiographies of 30 patients (22 males, age-49.2 ± 10.1years) who underwent TEVAR between 2015 and 2017 were retrospectively analyzed. CL, GL, SCL and the straightline length(SL) were measured between proximal and distal ends of the stent-graft and results were compared with the true length of the stent-graft (TL). Tortuosity index (TI = CL/SL) was calculated.

RESULTS

GL (17.92 ± 4.78 cm) was the closest in predicting the TL (17.75 ± 4.29 cm) (P = 0.414) overall, as well as in both dissection and aneurysm subgroups (P= 0.9). There was a significant difference between CL (16.67 ± 4.07 cm) and TL (P< 0.0001) as well as between SCL (16.86 ± 4.16 cm) and TL (P= 0.001). These differences were greater in dissection subgroup than in the aneurysm group (P< 0.0001 and P= 0.03 for TL-CL and TL-SCL, respectively). The extent of mismatch between GL or CL and TL did not correlate with tortuosity, but the difference between TL and SCL had a significant positive correlation with tortuosity (r = 0.375, P= 0.04). TL-GL had a negative linear correlation with the stent-graft length (TL) in the dissection group (r = 0.50, P= 0.03).

CONCLUSIONS

The greater curvature length predicts the actual total length of the deployed stent-graft more accurately than centerline or straightened centerline lengths. Hence, it should be used in planning for the length of stent-graft required for TEVAR.