Diagnosis and surgical treatment for a rare cause of arterial tortuosity

Surgical, imaging, and histologic findings after aortic and arch reconstruction.

Central Message.

Restoring laminar flow in arterial tortuosity reduces wall shear stress, potentially slowing progression; early diagnosis and close follow-up enable timely, comprehensive intervention.

Arterial tortuosity (AT) disrupts laminar blood flow and predisposes to creation of helical vortices that increase arterial wall shear stress (WSS),¹ leading to aneurysm formation, ischemic events, or arterial dissections.^2,3

One of the rare causes of AT is autosomal recessive cutis laxa type 1B (ARCL1B), which is a connective tissue disorder resulting from EFEMP2 mutation, leading to reduced fibulin-4 protein levels and influencing collagen and elastin cross-linking.⁴

We present the case of a 40-day-old girl with no family history of connective tissue disease who presented with an incidental systolic murmur, computed tomography (CT) scan revealing tortuosity of the whole aorta, ascending aortic aneurysm, pseudoaortic coarctation, and postisthmus aneurysm. Asymptomatic, she received conservative treatment with regular follow-ups, aiming to defer surgery until implantation of an adult-sized tube graft is possible. At age 8 years, she developed dysphagia due to a rapidly enlarging aortic aneurysm, reaching a z score of +17.6 requiring surgical intervention.

Investigations

Pulsations and blood pressure were symmetrical across all limbs; physical examination revealed joint hypermobility. Initial echocardiography identified an ascending aortic aneurysm, AT, and mild aortic regurgitation. Also, mildly tortuous pulmonary artery branches without a significant pressure gradient or right ventricular hypertrophy were noted. CT aortography clearly illustrated the tortuosity of the whole aorta, the dilated ascending aorta, pseudoaortic coarctation, and postisthmus aneurysm. Serial CT scans illustrated the progressive course of her disease (Figure 1, A). Four-dimensional-flow magnetic resonance imaging showed flow aliasing at the proximal ascending aorta creating a large vortex. A second vortex was found at the proximal descending aortic aneurysm (Figure 1, B). Peak velocities were reduced across all aortic segments (Figure 1, C) whereas the aortic WSS was increased, peaking at the ascending aorta (Figure 1, D). Furthermore, molecular genetic testing through whole exome sequencing identified pathogenic variants in the EFEMP2 gene, confirming the diagnosis of ARCL1B.

Figure 1.

Preoperative imaging. A, Aortic 3-dimensional models with their respective z score diameters across 5 planes at different age milestones. B, Four-dimensional-flow magnetic resonance imaging scan showing flow aliasing at the proximal ascending aorta creating a large vortex. A second vortex was found at the proximal descending aortic aneurysm. C, Peak velocities reduced at different aortic segments (m/second). D, Increased aortic wall shear stress, peaking at the ascending aorta.

Operative Details

At age 8 years, she developed dysphagia due to a rapidly enlarging aneurysm (z score +17.6) requiring surgical intervention. Surgery was performed to replace the ascending aorta and arch with uncurling and realignment of the arch branches.

A median sternotomy was performed followed by direct cannulation of the brachiocephalic artery, bicaval venous cannulation, and left ventricular venting. The aortic segments were mobilized while cooling the core temperature to 24 °C. After crossclamping and administering antegrade cardioplegia, the ascending aorta was excised and the aortic root and valve were inspected and found to be of adequate size and healthy cusp morphology.

Deep hypothermic circulatory arrest with antegrade cerebral perfusion was initiated. During arrest, the entire aortic arch was excised and its branches were harvested individually. Arch branches were individually released and stretched slightly. Extra length causing tortuosity was trimmed. Tissue biopsies from the ascending aorta, aortic arch, and brachiocephalic artery were sent to the histology lab.

The distal arch aneurysm, adherent to the chest wall at the apex of the left pleural cavity was excluded but not resected, leaving the native aortic wall in its place to avoid raw surface bleeding. A 20-mm polyethylene terephthalate tube was anastomosed distally to the descending aorta, reinforced with a circumferential pericardial strip.

Lower body antegrade perfusion was restored by connecting a second arterial line from the bypass circuit to the proximal end of the polyethylene terephthalate tube, while each neck vessel was trimmed, unfolded, and implanted on the polyethylene terephthalate tube using a C-clamp. Finally, the proximal anastomosis to the sinotubular junction, was performed restoring its diameter (Figure 2, A, and Video 1).

Figure 2.

Results. A, Intraoperative view showing the replaced ascending aorta and aortic arch with the realignment and unfolding of arch vessels. B, Four-dimensional-flow magnetic resonance imaging scan demonstrating restored laminar flow, absence of vortices, and normalized blood velocity. C, Comparison showing the reduction in aortic wall shear stress postoperatively. D, Histological sections from the ascending aorta, arch, and brachiocephalic artery demonstrate altered collagen and elastin. Notably, increased fibrosis was observed in the ascending aorta and arch, the regions of highest wall shear stress.

Results

The intensive care unit course was rapid and uneventful. Postoperatively, imaging demonstrated the restoration of laminar flow across all aortic segments and arch vessels. This was associated with a subsequent reduction in global WSS (Figure 2, B and C). Peak systolic velocities increased across all measured segments: ascending aorta (0.8 to 1.46 m/second), aortic arch (0.5 to 0.7 m/second), and descending aorta (0.4 to 0.8 m/second).

Histological analysis of aortic biopsies revealed varying degrees of collagen and elastin fiber disorganization in the intimal and medial layers compared with the control group. Wall thickness was altered in the ascending aorta (2526.6 ± 409.7 μm), aortic arch (3903.5 ± 1349.6 μm), and innominate artery (1594.9 ± 330.3 μm), relative to normal values (1849.3 ± 89.6 μm). Additionally, the fibrosis index was elevated in the ascending aorta (44.54 ± 5.5) and aortic arch (40.47 ± 8.28) but reduced in the innominate artery (28.4 ± 1.84) compared with normal collagen content (39.7 ± 5.12) (female, age 23 years).⁵ These findings coincided with the areas of increased WSS (Figure 2, D).

Discussion

AT carries significant risks.² Early surgery is indicated for true aortic coarctation or significant pulmonary branch stenosis.³ We opted to delay surgical intervention in this asymptomatic patient to allow for later implantation of an adult-sized aortic graft.² Urgent surgery became necessary at age 8 years due to rapid expansion of the ascending aortic aneurysm causing secondary dysphagia. Given that disturbed laminar flow can exacerbate vascular anomalies,¹ our surgical strategy aimed not only to replace the dilated and tortuous aortic segments but also to unfold and trim the native, twisted arch vessels to optimize flow dynamics. Postoperatively, there was restoration of laminar blood flow and reduced energy loss. This has led to a decrease in global aortic WSS and normalization of blood velocity.

A possible relationship between turbulent flow and the rate of disease progression is suggested by the increased fibrosis observed in the histological specimens of the ascending aorta and arch, areas corresponding to high aortic WSS (Figure 2, D). We recognize the limitation of using adult control tissue as a control reference, which may have had an influence on the extracellular matrix (such as fibrosis levels) and cellular composition.

Finally, AT can present with various connective tissue disorders with abnormalities in elastin and collagen. These include ARCL1B, AT syndrome, Loeys-Dietz syndrome, and Marfan syndrome. Whole exome sequencing can accurately identify the specific mutated gene aiding in precise diagnosis and management.2, 3, 4

Conclusions

AT is a rare vascular anomaly, altering flow dynamics, contributing to histological changes, and accelerating disease progression. Surgical correction, aimed at restoring laminar flow, can decrease WSS, potentially limiting adverse aortic remodeling and lowering the risk of future complications. Institutional review board/ethical review board approval was not required. The patient consented to the publication process with the understanding that their identity will be protected to the best of our ability.

Declaration of Generative AI and AI-Assisted Technologies in the Writing Process

During the preparation of this work the authors used ChatGPT in order to assist with language refinement during manuscript preparation. After using these tools, the authors reviewed and edited the content as needed and takes full responsibility for the content of the publication.

Conflict of Interest Statement

The authors reported no conflicts of interest.

The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest.

Supplementary Data

Video 1

Surgical repair video focusing on the important steps. Video available at: https://www.jtcvs.org/article/S2666-2507(25)00360-8/fulltext.