# Assessment of Computed Tomography Imaging for Isolated Type 1 Bicuspid Aortic Valve Repair: A Comparison between Internal and External Suture Annuloplasty Techniques

## TL;DR

This study compares internal and external suture annuloplasty techniques for repairing bicuspid aortic valves using CT imaging to determine their effectiveness.

## Contribution

The study provides new insights into the anatomical positioning and effectiveness of internal versus external suture annuloplasty for bicuspid aortic valve repair.

## Key findings

- Internal suture annuloplasty showed less area discrepancy between the VBR and Hegar dilator compared to the external group.
- Postoperative annular area expansibility decreased in the internal group but not in the external group.
- Internal annuloplasty results in better positioning relative to the VBR due to less VAJ interference.

## Abstract

The ideal position of suture annuloplasty relative to the
aortic annulus (internal or external) remains unclear. This study aimed to
investigate the effectiveness of internal and external suture annuloplasty for
isolated type 1 bicuspid aortic valve (BAV) repair. Electrocardiogram (ECG)-gated
computed tomography (CT) was used to compare the two techniques and analyze their
impact on the aortic annulus.

We retrospectively analyzed 20
patients who underwent isolated type 1 BAV repair with either internal or
external suture annuloplasty. Each group included 10 patients with comparable
clinical features. Preoperative and postoperative ECG-gated CT scans were
performed to assess the anatomical relationship between the ventricular-aortic
junction (VAJ) and virtual basal ring (VBR), and to measure the height of
annuloplasty from the VBR at predefined landmarks in both groups. Perioperative
annular geometries, including annular area and perimeter, were measured to
quantify the impact of annuloplasty on annular expansibility. The discrepancy
between the postoperative annular dimension and size of the Hegar dilator were
compared between groups to evaluate the effectiveness of annuloplasty.

In both groups, VAJ was higher than VBR at the right coronary
(RC) ostium (7.7 ± 3.3 mm) and the raphe (7.9 ± 1.5 mm). The height
from the VBR to the external suture annuloplasty shared a similar pattern at the
RC ostium and raphe (5.3 ± 1.1 mm and 4.8 ± 1.0 mm, respectively). In
contrast, the height differences were minimal for these landmarks in the internal
group. Postoperative annular area expansibility decreased in the internal group
compared to preoperative levels (4.9 ± 2.3% vs. 8.9 ±
5.5%, p = 0.038), while no significant change was found in the external
group (7.6 ± 4.1% vs. 6.5 ± 2.8%, p = 0.473). The
internal group showed less area discrepancy between the VBR and the Hegar dilator
both at systole (10.1 ± 3.7% vs. 30.1 ± 16.6%, p
= 0.004) and diastole (5.7 ± 4.9% vs. 20.9 ± 14.5%,
p = 0.009) compared to the external group.

Internal suture annuloplasty results in better positioning relative to the VBR
than external suture annuloplasty due to the absence of VAJ interference. While
this results in more precise annular reduction and less expansibility in the
short term, a long-term follow-up evaluation is necessary to assess its
effectiveness.