Strategic perspectives on open thoracoabdominal repair following frozen elephant trunk: distal shifting, technical caveats, and the role of stepwise interventions

Introduction

The surgical management of complex thoracoabdominal aortic aneurysms (TAAA) following the frozen elephant trunk (FET) procedure remains one of the most challenging frontiers in cardiovascular surgery. In a recent issue of the Annals of Cardiothoracic Surgery, the authors presented a sophisticated surgical video demonstrating an open TAAA repair after FET using the Thoraflex hybrid graft (1). Their technique—specifically the use of the Siena graft’s collar for anastomosis to the Thoraflex stent-graft and the reconstruction of visceral branches using a four-branched graft—is both elegant and instructive. However, while their approach highlights the technical feasibility of this reconstruction, several critical aspects regarding the “distal shifting” concept, device-specific safety, mechanical durability, and the pitfalls of staged repairs warrant further discussion.

The evolution of invasiveness: distal shifting and the Marfan context

The authors utilized a left thoracotomy to clamp the Thoraflex stent-graft and perform the visceral reconstruction. This approach aligns with the contemporary “distal shifting” concept of the anastomosis, which is increasingly advocated in recent European guidelines to reduce surgical morbidity (2). The fundamental idea of distal shifting is to move the site of the distal anastomosis further downstream, thereby potentially avoiding a high, extensive thoracotomy.

We propose that this concept can be extended further to achieve even lower invasiveness. By performing thoracic endovascular aortic repair (TEVAR) after the initial FET to extend the landing zone more distally, surgeons can shift the subsequent open thoracotomy from a high or mid-intercostal space to a significantly lower level, such as the 7th to 9th intercostal space. This approach transforms a major thoracic insult into a more localized abdominal-focused procedure.

A key debate in this strategy is the sacrifice of intercostal arteries. The original article emphasizes the advantage of being able to reconstruct these arteries via open repair to prevent spinal cord ischemia (SCI). Nevertheless, in the context of Marfan syndrome—a frequent underlying pathology in these cases—clinical observation suggests that the incidence of SCI is lower than in non-Marfan patients (3). In these high-risk cohorts, we believe the benefit of reducing surgical trauma through “distal shifting” and a lower thoracotomy likely outweighs the potential risk associated with sacrificing more proximal intercostal segments.

Technical caveats: the reality of stent clamping and suture fracture

A critical point of discussion is the intraoperative clamping of the Thoraflex stent-graft. While many surgeons routinely clamp the stent-bearing portion of the FET during distal reconstruction without immediate catastrophe, we must acknowledge the inherent risks. Clamping a metal stent carries the potential for structural damage to the framework, including metal fatigue or strut fracture. It is imperative for the surgical community to recognize that Terumo’s “instructions for use” (IFU) for the Thoraflex Hybrid does not approve or recommend clamping the stent-bearing segment.

To mitigate this risk, it is preferable to use devices specifically designed for such interventions. For instance, the Frozenix partial (Japan Lifeline, Tokyo, Japan) features a “non-stented” portion specifically designed for safe clamping. Recent clinical data have demonstrated the technical success and favorable initial outcomes of this partial FET design across various aortic arch pathologies, allowing for a safer transition to distal staged repairs (4). Utilizing such specialized devices or extending the non-stented vascular graft portion distal to the FET may provide a more robust and IFU-compliant surgical strategy.

Furthermore, we must address the mechanical interaction between the prosthetic graft and the FET stent struts at the anastomosis. When anastomosing a new graft to a stent-bearing segment, the constant pulsatile friction between the metal struts and the polypropylene sutures can lead to late-term suture fracture. Indeed, cases of pseudoaneurysm formation due to failure at the stentgraft-graft anastomosis have been reported, underscoring the potential for mechanical wear at the suture line (5). Even the “covering technique”—sleeving the new graft over the external surface of the FET—cannot entirely eliminate this risk. Surgeons must anticipate potential late-term complications and maintain lifelong, rigorous radiologic surveillance.

Lessons from a high-volume unit: the efficacy and risks of staged repair

The safety of staged repairs is well-documented, yet the period between stages is fraught with hidden dangers. Between October 2021 and March 2025, our unit performed staged multiple aortic surgeries for 20 patients with chronic aortic dissection (10 type A and 10 type B). The inclusion criteria are patients with the diagnosis of aortic dissection who have undergone multiple open or endovascular surgeries. Indication of the primary surgery is emergency entry resection in type A acute aortic dissection (N=10), progressive aneurysmal dilatation in type B dissection (N=10). Their mean age is 58.1 years (type A 54.1, type B 62.3, respectively).

Our fundamental strategy was to prioritize entry resection either by open surgery or endovascular repair, followed by stepwise extensions to the arch, descending, and thoracoabdominal aorta when operative indication arises, to minimize single-stage invasiveness. All patients underwent CT monitoring every 6 months. We investigated the mortality and secondary interventions of this study cohort.

Notably, there is no mortality both in-hospital and during the follow-up among these 20 patients. In type A cohort (n=10): Initial surgeries included four non-arch procedures (root + ascending: 2, ascending: 2) and six FET-arch repairs. All four patients who initially had non-arch procedures subsequently required FET-arch replacement (median interval: 99 months). Following arch treatment, nine patients underwent TEVAR (median interval: 15 months). Eight of these remained stable, while one required an additional descending aorta replacement. One other patient required a root replacement 22 months later. Remarkably, all patients in the Type A group are surviving without any instances of stroke, SCI, or unplanned emergency surgeries.

In our chronic type B cohort (n=10): one patient received TEVAR in the acute phase, while others were managed conservatively with anti-hypertensive therapy. All patients eventually underwent staged arch repair and TEVAR (median interval: 3 months). Two patients required TAAA replacement; one was performed electively at 8 months, while the other was performed urgently at 15 months for impending rupture. Both TAAA operations were performed as the third operation through left thoracotomy via low intercostal space and proximal anastomoses of stentgraft-TAAA graft were achieved by clamping the thoracic endografts implanted on FETs. The clinical outcome of these 2 patients was excellent as well, without any mortality and morbidity, including stroke and SCI.

The diameter of the thoracic aorta at the celiac axis increased in 2, did not change in 6 and decreased in 12 patients. Therefore, the rate of negative remodeling after the procedures were 60% (12/20). While the survival and neurological outcomes were excellent, the chronic Type B cohort revealed a more complex reality. We encountered three unplanned emergency surgeries. Notably, two of these were due to impending rupture caused by stent-graft induced new entry (SINE) after the FET procedure—one occurring at 1 month and another at 19 months post-operatively. The size of the FET with distal SINE (dSINE) was 26 mm thoraflex of the SINE post-operative day (POD) 1 month and 25 mm Frozenix of the SINE POD 18 months. In both cases, the FET was used for type A acute aortic dissection. The size of the FET was determined as 90% of the whole aortic diameter at the landing zone in the acute setting. Therefore, there is no notable oversizing in this study cohort. These findings suggest that while the staged approach is valid for reducing initial surgical insult, FET-induced SINE is a critical concern in chronic B dissections, and if needed, TAAA repair should be performed, hopefully via low intercostal space as a result of distal shifting.

Conclusions

Our institutional data confirms that a staged approach is effective in preventing mortality and neurological complications by distributing the surgical insult. However, the occurrence of unplanned surgeries in the Type B group serves as a stark reminder: the interval between staged procedures is not a “period of safety” but a “period of risk”.

While the technique presented in the original article provides an excellent framework for TAAA repair after FET, we advocate for the integration of TEVAR to further distalize the anastomosis when possible, particularly in patients with Marfan syndrome. Surgeons must remain mindful of the mechanical limitations of stent-to-graft suturing, respect device-specific limitations regarding stent clamping, and maintain a high index of suspicion for FET-related complications like SINE during the staged journey.

Acknowledgments

None.

Footnote

Provenance and Peer Review: This article was commissioned by the editorial office, Journal of Visualized Surgery. The article has undergone external peer review.

Peer Review File: Available at https://jovs.amegroups.com/article/view/10.21037/jovs-2026-1-0002/prf

Funding: None.

Conflicts of Interest: The author has completed the ICMJE uniform disclosure form (available at https://jovs.amegroups.com/article/view/10.21037/jovs-2026-1-0002/coif). The author has no conflicts of interest to declare.

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