Frozen elephant trunk with straight vascular prosthesis

Three-Dimensional-Evaluation of Aortic Changes after Frozen Elephant Trunk (FET) in Zone 0 vs. Zone 2 in Acute Type A Aortic Dissection

Introduction: The management of aortic dissection has evolved significantly over the decades, with the frozen elephant trunk (FET) procedure emerging as a key technique for treating complex aortic pathologies. Recent practices involve deploying the FET prosthesis more proximally in the aorta (Zone 0) to reduce complications, leading to questions about its impact on long-term aortic remodeling compared to traditional Zone 2 deployment. Methods: This retrospective analysis utilized 3D segmentation software to assess the volumetric changes in aortic remodeling after acute Type A aortic dissections, comparing FET stent graft deployment in Zone 0 and Zone 2. The study included 27 patients operated on between 2020 and 2022, with volumetric measurements taken from postoperative and 6-month follow-up CT scans. Statistical analyses were performed to evaluate the differences in the aortic true lumen (TL) and the perfused false lumen (PFL) between the two groups. Results: Both Zone 0 and Zone 2 deployments resulted in significant true lumen (TL) increases (Z0 p = 0.001, Z2 p < 0.001) and perfused false lumen (PFL) decreases (Z0 p = 0.02, Z2 p = 0.04), with no significant differences in volumetric changes between the groups (p = 0.7 post op and p = 0.9 after 6 months). The distal anastomosis in Zone 0 did not compromise the aortic remodeling outcomes and was associated with reduced distal ischemia and cerebral perfusion times (p = 0.041). The angle measurements in Zone 0 did not show any significant changes after the 6-month control (p = 0.2). However, in Zone 2, a significant change was detected. (p = 0.022). The part comparison analyses did not indicate significant differences in aortic deviation between the groups (p = 0.62), suggesting comparable effectiveness in aortic remodeling. Conclusions: Performing the distal anastomosis more proximally in Zone 0 offers technical advantages without compromising the effectiveness of aortic remodeling compared to the traditional Zone 2 deployment. This finding supports the continued recommendation of Zone 0 deployment in the management of acute Type A aortic dissections, with ongoing studies being needed to confirm the long-term outcomes and survival benefits.

Frozen Elephant Trunk for Acute Type A Dissection: Is Risk from Procedure or Patient Characteristics?

BACKGROUND

 The initial goal of acute Type A aortic dissection (ATAAD) repair remains to get the patient off the table safely. More extensive repair is being pushed at the index operation with the frozen elephant trunk (FET) operation, but outcomes are suggested to be worse. However, we hypothesize that the risk associated with the FET in ATAAD is from the patient presenting factors rather than the operation itself.

METHODS

 A retrospective review of a single institution prospective database from 2015 to 2021 was performed. Two cohorts were created based on the indication for FET: evidence of radiographic malperfusion (n = 44) or clinical malperfusion (n = 31). Data were analyzed for preoperative characteristics, intraoperative characteristics, and postoperative outcomes. Statistical univariate analysis was performed with chi-square analysis and t-tests with significance determined at an alpha level of 0.05.

RESULTS

 Preoperative characteristics were similar in each group, independent of malperfusion markers. The intraoperative characteristics were similar, except the clinical malperfusion group had more packed red blood cells and cryoprecipitate given. The clinical malperfusion group had longer intensive care unit length of stay (p < 0.001), more postoperative strokes (p < 0.001), more reoperations (p <0.0001), and higher mortality rate (p = 0.0003).

CONCLUSION

 These data suggest that clinical malperfusion increases the risk of major complications and death. However, full arch replacement with FET in the absence of clinical malperfusion does not appear to add risk to the operation for ATAAD. Patients with increased risk of distal degeneration should be considered for more aggressive replacement to avoid subsequent arch replacement.

Frozen elephant trunk in acute type A aortic dissections: frontiers and challenges

Acute type A aortic dissection (ATAAD), a surgical emergency, has high mortality and morbidity. More than half of the patients die within 2 weeks and the 30-day mortality is 90%. Frozen elephant trunk in ATAAD addresses the primary and secondary goals - resection of the primary tear in the ascending aorta and promoting remodelling in the downstream aorta. Though the literature supports this fact, in reality these literatures emerge from high-volume centres. But in the "real world" most of the ATAAD are operated on in the low-volume centres. Furthermore, in India, there are unique challenges including the financial burden, transport, emergent availability of the hybrid prosthesis and aortic supercentres.

Excessive oozing through the fabric of the branched Cryolife-Jotec Evita Open NEO hybrid prosthesis

We report 3 cases of excessive oozing after aortic arch replacement using the frozen elephant trunk technique through the fabric of the branched Cryolife-Jotec Evita Open NEO hybrid prosthesis. After weaning from cardiopulmonary bypass, protamine administration as well as standard substitution of plasmatic and cellular coagulation adjusted to thrombelastometry, excessive oozing persisted leading to a complicated postoperative course in all 3 patients.

Aortic proximalization-Zone 0 versus Zone 2: A concept or true challenge?

BACKGROUND

The use of the Frozen Elephant Trunk (FET) device to manage complex surgical pathologies of the aorta (such as acute type A aortic dissection) has gained popularity since its introduction in the early 2000s. Though the distal anastomosis was traditionally performed at aortic Zone 3 (Z-3-FET), preference gradually shifted towards Zone 2 (Z-2-FET) in favor of improved surgical access and clinical outcomes. This review seeks to elucidate whether proximalization of arch repair to Zone 0 (Z-0-FET) would further improve postoperative outcomes.

METHODS

We performed a review of available literature to evaluate the comparative efficacies of Z-2-FET versus Z-0-FET, in terms of surgical technique, clinical outcomes, and incidence of adverse events.

RESULTS

Z-0-FET seems to be associated with a more accessible surgical approach, and shorter cardiopulmonary bypass, antegrade cerebral perfusion, and cardioplegia durations than Z-2-FET. Further, Z-0-FET is could potentially be associated with a lower incidence of neurological, renal, and recurrent laryngeal nerve injury, as well as mortality and reintervention rates than Z-2-FET. This said, Z-0-FET is itself associated with significant challenges, and efficacy in terms of postoperative true lumen integrity and false lumen thrombosis is mixed.

CONCLUSION

Current literature seems to suggest that Z-0-FET procedures are more straightforward and associated with lower rates of certain adverse events, however, the majority of data reviewed is retrospective. This review, therefore, recommends prospective research into the comparative strengths and limitations of Z-0-FET and Z-2-FET to better substantiate whether proximalization of arch repair represents a concept, or a true challenge to advance surgical intervention for arch pathologies.

"Proximalization is Advancement"-Zone 3 Frozen Elephant Trunk vs Zone 2 Frozen Elephant Trunk: A Literature Review

Over the decades, the Frozen Elephant Trunk (FET) technique has gained immense popularity allowing simplified treatment of complex aortic pathologies. FET is frequently used to treat aortic conditions involving the distal aortic arch and the proximal descending aorta in a single stage. Surgical preference has recently changed from FET procedures being performed at Zone 3 to Zone 2. There are several advantages of Zone 2 FET over Zone 3 FET including reduction in spinal cord injury, visceral ischemia, neurological and cardiovascular sequelae. In addition, Zone 2 FET is a technically less complicated procedure. Literature on the comparison between Zone 3 and Zone 2 FET is scarce and primarily observational and anecdotal. Therefore, further research is warranted in this paradigm to substantiate current surgical treatment options for complex aortic pathologies. In this review, we explore literature surrounding FET and the reasons for the shift in surgical preference from Zone 3 to Zone 2.

Left subclavian artery management in frozen elephant trunk: A novel technique

Proximilization of frozen elephant trunk (FET) necessitates the ligation and reimplantation of the left subclavian artery (LSA), the origin of which is distal and posterior, make rerouting difficult and cumbersome. We describe a rather simple technique for subclavian artery exposure and effective anatomical reconstruction in the mediastinum coupled with hybrid FET utilization for aortic aneurysm in elective and nonelective settings. The division of the sternocleidomastoid coupled with the sandbag behind the left shoulder brings the LSA superficial enabling anastomosis without any difficulty.

From E-VITA open plus to E-VITA NEO and E-NOVIA

The first clinical implantation of the "Essen I prosthesis" took place in 2005, which was then followed by E-Vita open plus. With further advancements E-Vita Neo and E-Novia was introduced. These devices enable the surgeons to perform frozen elephant trunk in zone 0/1 which eventually reduce the incidence of paraplegia, recurrent laryngeal nerve palsy and proximalization of supraaortic arch vessels. E-vita open plus and successors alleviate frozen elephant trunk operations rendering more stable results in promoting positive remodelling of the distal aorta.