34
Treatment
6.1.2.3.3. Loeys-Dietz Syndrome Surgical Interventions:
Replacement of the Aorta in Patients With Loeys-Dietz
Syndrome
COR LOE
Recommendations
1 C-LD 1. In patients with Loeys-Dietz syndrome and aortic dilation, the
surgical threshold for prophylactic aortic root and ascending
aortic replacement should be informed by the specific genetic
variant, aortic diameter, aortic growth rate, extra-aortic
features, family history, patient age and sex, and physician and
patient preferences (see Table 11).
2b C-EO 2. In patients with Loeys-Dietz syndrome attributable to a
pathogenic variant in TGFBR1, TGFBR2, or SMAD3,
surgery to replace the intact aortic arch, descending aorta, or
abdominal aorta at a diameter of ≥4.5 cm may be considered,
with the specific genetic variant, patient age, aortic growth
rate, family history, presence of high-risk features (see Table
11), and surgical risk informing the decision.
Table 11. Surgical Thresholds for Prophylactic Aortic Root
and Ascending Aortic Replacement in Loeys-Dietz
Syndrome Based on Genetic Variant
COR
LOE
(references)
Genetic
Variant
Presence of
High-Risk Features*
Aortic
Diameter (cm)
1 C-LD TGFBR1 No ≥4.5
1 C-LD TGFBR2 No ≥4.5
2b C-EO TGFBR1 Yes ≥4.0
2a C-LD TGFBR2 Yes ≥4.0
2a C-EO SMAD3 —
≥4.5
†
2b C-EO
TGFB2
‡
—
≥4.5
†
2b C-EO TGFB3 —
≥5.0
†
* Aortic surgery may be recommended at smaller aortic diameters in Loeys-Dietz syndrome
attributable to TGFBR1 and TGFBR2 pathogenic variants when there are features that
associate with a higher risk of aortic dissection, including : certain specific pathogenic
variants; women with TGFBR2 and small body size; severe extra-aortic features (ie,
craniosynostosis, cle palate, hypertelorism, bifid uvula, marked arterial tortuosity, widened
scars, and translucent skin); family history of aortic dissection (especially at young age or
relatively small aortic diameter); and aortic growth rate >0.3 cm/y.
†
Family history, age, and aortic growth rate also inform surgical thresholds.
‡
Pathogenic variants in the TGFB2 gene are different than variants in the TGFBR2 gene.
