Distal aortic surgery following arch replacement with a frozen elephant trunk☆

Expert opinion: How to treat type IA endoleakage

Type Ia endoleaks due to failed sealing or loss of landing zone and the adequate management thereof remain crucial for long-term therapeutic success following TEVAR. This expert opinion summarizes our institutional experience with endovascular, open surgical, and hybrid techniques in the context of recent scientific publications. The rapid turnover of technical innovations, but most importantly outcome data demonstrate the requirement for increasingly patient-tailored treatment strategies and the need for specialized aortic centers. The latter should offer a complete range of treatment options, an adequate perioperative management, and the highest level of multidisciplinary expertise.

Outcomes of Secondary Endovascular Aortic Repair After Frozen Elephant Trunk

OBJECTIVE

The aim of this study was to evaluate the midterm outcomes of secondary extension of frozen elephant trunk (FET) by means of thoracic endovascular aortic repair (TEVAR).

METHODS

This single-center prospective study was conducted in a tertiary aortic center on consecutive patients having undergone TEVAR with an endograft covering most of the 10 cm FET module with 2 to 4 mm oversizing. All patients were monitored by computerized tomography angiography (CTA) at sixth month and yearly thereafter.

RESULTS

From January 2015 to July 2022, among 159 patients who received FET, 30 patients (18.8%) underwent a TEVAR procedure (13 for a thoracoabdominal aneurysm, 11 for a chronic aortic dissection and 6 for an emergency procedure). All connections were successfully achieved with 2 postoperative deaths (6.6%) and 1 paraplegia (3.3%). At a median follow-up of 21 months (interquartile range [IQR], 4.2-34.7), 5 patients (25%) required a fenestrated-branched endovascular aortic repair (F-BEVAR) extension followed by 4 patients with 5 reinterventions, 3 for a Type 3 endoleak due to disconnection between FET and TEVAR endograft, and 2 unrelated to the FET for a secondary Type 1C endoleak. All reinterventions were successful, without mortality or morbidity.

CONCLUSIONS

In this series, FET connection with a TEVAR endograft was effective with low postoperative morbidity but with a risk of aortic reintervention related to disconnection between the FET and TEVAR endograft. These results suggest the need for annual CTA monitoring with no time limit in patients following connection of the FET with a TEVAR endograft.

CLINICAL IMPACT

In this series of 30 patients, midterm outcomes of secondary extension of frozen elephant trunk (FET) by thoracic endovascular repair (TEVAR) showed 3 disconnections (10%) with a Type 3 endoleak between FET and TEVAR. These findings suggest the need for annual CTA monitoring with no time limit. But so far, only a few studies provide some information after one year while the risk of disconnection increases over time and becomes a concern after 3 years. This is the new message brought by our study.

Fenestrated-branched endovascular repair for distal thoraco-abdominal aortic pathology after total aortic arch replacement with frozen elephant trunk

OBJECTIVE

To report the outcomes of fenestrated-branched endovascular repair (FBEVAR) for thoracoabdominal aortic pathology after total aortic arch replacement with frozen elephant trunk (TAR+FET).

METHODS

Interrogation of prospectively-maintained databases from four high volume aortic centres identified consecutive patients treated with distal FBEVAR after prior TAR+FET between August 2013 and September 2020. Primary endpoint was 30-day/in-hospital mortality. Secondary end points were technical success, early clinical success, mid-term survival and freedom from re-intervention. Data are presented as median (IQR).

RESULTS

39 patients [21 men; median age, 73 years (67-75)] with degenerative (n=22) and post-dissection TAAAs (n=17) [median diameter 71 mm (61-78)] were identified. Distal FBEVAR was intended in 27 patients [median interval 9.8 months (6.2-16.6)], anticipated in seven and unexpected in five. 31 patients had a two (n=24) or three (n=7) stage distal FBEVAR. Reno-visceral target vessel preservation was 99.3% (145 of 146). Early primary and secondary technical success was 92% and 97%, respectively. 30-day mortality was 2.6% [n=1; respiratory failure and spinal cord ischaemia (SCI)]. Six survivors also developed SCI which was associated with complete (n=4), or partial recovery (n=2) at hospital discharge. No patients required renal replacement therapy or suffered a stroke. Early clinical success was 95%. Median follow-up was 30.5 months (23.7-49.7). Eleven patients required 16 late re-interventions. Estimated 3-year survival and freedom from re-intervention were 84±6% and 63±10%, respectively.

CONCLUSIONS

Distal FBEVAR after prior TAR+FET is associated with high technical success and low early mortality. The risk of SCI is significant although the majority of patients demonstrate full or partial recovery before hospital discharge. Mid-term patient survival is favourable but there remains a high requirement for late re-intervention. FBEVAR represents an acceptable alternative to distal open TAAA repair.

TEVAR Following FET: Current Outcomes of Rendezvous Procedures in Clinical Practice

BACKGROUND

 The treatment of extensive thoracic/thoracoabdominal aortic pathologies with arch involvement remains a challenging task in aortic surgery. The introduction of the frozen elephant trunk (FET) technique offered a link between open surgery and thoracic endovascular aortic repair (TEVAR). Despite a decade of experience, data on the complementary use of these techniques are scant. The aim of this study was to evaluate TEVAR following FET in clinical reality.

METHODS

 Between November 2006 and June 2018, 20 patients (9 females; median age of 69 years) underwent endovascular second-stage completion after FET. The clinical outcomes, technical feasibility, and morphological findings were analyzed retrospectively.

RESULTS

 Eleven of the 20 interventions were intended "rendezvous procedures" in a multistage approach; 4 were elective reinterventions, and 5 were emergency complication repairs. The median interval between FET and TEVAR was 231 days (11 days-7.4 years). The technical success rate was 100%. During a median follow-up (FU) period of 58.3 months, the overall survival rate was 95%, with one in-hospital death. Neurological complications occurred in three cases (spinal cord injury: n = 1; stroke: n = 2). Computed tomography angiography showed overall regression in the median diameter of the proximal descending aorta (from 57 to 48.5 mm).

CONCLUSION

 TEVAR as a second-stage intervention after FET is a feasible option, with satisfactory results at medium-term FU. In extensive thoracoabdominal aortic disease without proximal landing zones, the complementary use of both techniques in a multistage approach should be considered.

Modified Distal Aortic Arch Occlusion During Aortic Arch Replacement

BACKGROUND

Circulatory arrest has been identified as an independent risk factor related to postoperative mortality in patients with Stanford type A aortic dissection. This study described a modified technique for distal aortic arch occlusion that markedly shortened the circulatory arrest time. The early results are encouraging.

METHODS

From May 2016 to September 2018, 51 patients with Stanford type A aortic dissection underwent the modified procedure for aortic arch replacement. All operations were performed via transitory circulatory arrest by clamping the distal aorta between the left common carotid artery and the left subclavian artery. The in-hospital and follow-up data of the treated patients were investigated.

RESULTS

Successful repair of the involved vasculature was achieved in all patients. One (1) patient died due to postoperative aspiration and infection, and three patients required continuous renal replacement therapy due to poor preoperative renal function. The remaining patients were successfully discharged. The median average circulatory arrest time was 5.0 (3.0-6.0) minutes. No cases of tracheotomy, delayed closure, secondary thoracotomy, or other complications occurred. During the follow-up period of 2.4-18.6 months, the implanted grafts and stented elephant trunks were all fully open and not kinked.

CONCLUSIONS

A modified distal aortic arch occlusion can considerably shorten the duration of circulatory arrest. Current experience suggests that this approach can serve as a feasible alternative for patients during aortic arch replacement because of its simplicity and satisfactory clinical effects.

Redo Descending Aortic Replacement via Direct Anastomosis to J Graft Open Stent Graft

A 64-year-old man with prior history of total arch replacement with frozen elephant trunk was admitted for an enlarging descending thoracic aortic aneurysm. Preoperative computed tomography revealed previously implanted J graft open stent graft, a frozen elephant trunk device approved in Japan, with enlarged dissected aortic aneurysm from distal anastomosis site to the level of the diaphragm. The patient underwent descending aortic replacement. Proximal anastomosis was directly performed at the distal end of the previously implanted J graft open stent graft. Hemostasis at the anastomosis site was uneventful and the patient was discharged from the hospital without any aneurysm-related complication.

Long-term experience with the E-vita Open hybrid graft in complex thoracic aortic disease†

OBJECTIVES

The E-vita Open hybrid stent graft is intended to achieve one-stage treatment of the proximal and distal thoracic aorta down to the mid-thoracic level in cases of acute (AAD) or chronic (CAD) type I aortic dissection and complex thoracic aortic aneurysm (TAA). We report our long-term results up to 10-year experience.

METHODS

From February 2005 until March 2015, 178 consecutive patients (mean age 59 ± 11 years) underwent surgery using the E-vita Open hybrid graft for AAD ( n  = 96), CAD ( n  = 43) or TAA ( n  = 39). Pre-, intra- and postoperative variables, influential procedural improvements and follow-up data including aortic remodelling analyses are presented.

RESULTS

Overall 30-day mortality was 10%, 10% for AAD, 7% for CAD and 13% for TAA. Univariable analysis identified low left ventricular ejection fraction, peripheral arterial disease, chronic obstructive pulmonary disease and severely compromised haemodynamics as risk factors for in-hospital death. Logistic regression analysis defined compromised haemodynamics and duration of cardiopulmonary bypass as significant. After 7 years, estimated survival was 55% for AAD, 74% for CAD and 73% for TAA patients. Freedom from aorta-related late death was 94%, 91% in AAD, 100% in CAD and 97% in TAA. Positive or stable aortic remodelling down to the stent graft end was achieved in 92% AAD, 82% in CAD and full aneurysmal exclusion in 88%. Further downstream, negative remodelling was observed in 27% of the AAD, 41% of the CAD and 22% of the TAA patients. Freedom from endovascular intervention downstream was 96% in AAD, 75% in CAD and 74% in TAA patients. Freedom from thoraco-abdominal surgery was 97%, 65% and 93%, respectively.

CONCLUSIONS

The E-vita Open hybrid stent graft renders durable long-term performance without any proximal endoleakage or graft failure over time and represents the ideal landing or docking zone for either thoracic endovascular thoracic repair or thoraco-abdominal surgery, if required. No reinterventions were necessary down to the end of the stent graft, proving that the disease is overcome along the hybrid graft down to mid-thoracic level.

Endovascular repair of residual intimal tear or distal new entry after frozen elephant trunk for type A aortic dissection

BACKGROUND

In patients with type A dissection, residual dissection and new distal entry tears following the frozen elephant trunk (FET) procedure adversely affect long-term prognosis. Management include open and endovascular repair, while clinical experience is limited. We evaluate the efficacy of thoracic endovascular aortic repair (TEVAR) in management of residual intimal tear or distal new entry tear following FET in patients with type A aortic dissection (TAAD).

METHODS

Between May 2003 and April 2013, we performed FET and total arch replacement for 1,003 patients with TAAD. Among these, 23 patients (2.3%) required TEVAR for distal new entry (n=2) or residual intimal tear (n=21) at a mean of 2.0±1.6 years after FET. Mean age was 50.1±11.5 years. Marfan syndrome was seen in 2 patients (8.7%).

RESULTS

Procedural success was 100%. The distal landing zone was above the 11th thoracic vertebra (T11) in 86.9% (20/23). Neither death nor any paraplegia or stroke occurred early after TEVAR. Follow-up was complete in 100% averaging 2.8±1.7 years (0.3-6.4). One non-Marfan patient died of distal aortic rupture at 4 months after TEVAR. No late stroke or paraplegia occurred. Survival was 95.7% (95% CI, 72.9-99.4%) at 3 and 5 years, respectively. CTA detected false lumen obliteration by thrombus around the endograft in the descending aorta in 91.3% (21/23) of patients.

CONCLUSIONS

These early and midterm outcomes show the efficacy of TEVAR in obliterating the residual intimal tear or distal new entry after FET in patients with TAAD. TEVAR may be an alternative approach to distal new entry or residual intimal tear following FET for patients with TAAD.

Surgical treatment of complex aneurysms and thoracic aortic dissections with the Frozen Elephant Trunk technique

OBJECTIVE

Report initial experience with the Frozen Elephant Trunk technique.

METHODS

From July 2009 to October 2013, Frozen Elephant Trunk technique was performed in 21 patients (66% male, mean age 56 ± 11 years). They had type A aortic dissection (acute 9.6%, chronic 57.3%), type B (14.3%, all chronic) and complex aneurysms (19%). It was 9.5% of reoperations and 38% of associated procedures (25.3% miocardial revascularization, 25.3% replacement of aortic valve and 49.4% aortic valved graft). Aortic remodeling was evaluated comparing preoperative and most recent computed tomography scans. One hundred per cent of complete follow-up, mean time of 28 months.

RESULTS

In-hospital mortality of 14.2%, being 50% in acute type A aortic dissection, 8.3% in chronic type A aortic dissection, 33.3% in chronic type B aortic dissection and 0% in complex aneurysms. Mean times of cardiopulmonary bypass (152 ± 24 min), myocardial ischemia (115 ± 31 min) and selective cerebral perfusion (60 ± 15 min). Main complications were bleeding (14.2%), spinal cord injury (9.5%), stroke (4.7%), prolonged mechanical ventilation (4.7%) and acute renal failure (4.7%). The need for second-stage operation was 19%. False-lumen thrombosis was obtained in 80%.

CONCLUSION

Frozen Elephant Trunk is a feasible technique and should be considered. The severity of the underlying disease justifies high mortality rates. The learning curve is a reality. This approach allows treatment of more than two segments at once. Nonetheless, if a second stage is made necessary, it is facilitated.

Repair of Distal Aortic Arch Aneurysms by Left Subclavian Artery Transposition with Stented Elephant Trunk Implantation

BACKGROUND

Repair of distal aortic arch aneurysms remains technically challenging using conventional open surgery due to its location. Several techniques, including a conventional prosthetic graft replacement and a hybrid technique, were introduced to manipulate this lesion. We retrospectively reviewed our experience with left subclavian artery (LSCA) transposition with stented elephant trunk implantation for repair of distal aortic arch aneurysms.

METHODS

From May 2009 to December 2014, 9 men (mean age 55 ± 16 years) with distal aortic arch aneurysms underwent LSCA transposition with stented elephant trunk implantation under hypothermic cardiopulmonary bypass with antegrade selective cerebral perfusion via a median sternotomy. One case had a history of endovascular abdominal aortic repair.

RESULTS

There was no in-hospital death. The mean time of mechanical ventilation and intensive care unit stay was 22 ± 9 and 53 ± 17 hr, respectively. No severe complications occurred in this group. All patients survived and were discharged. No patient died during the follow-up period. Postoperative computed tomography revealed good patency of the anastomotic site between the LSCA and the left common carotid artery.

CONCLUSIONS

Satisfactory surgical results and follow-up outcomes were achieved by simultaneous repair of proximal aortic lesions and complete seal of the lesion involving the distal aortic arch and proximal descending aorta using LSCA transposition with implantation of a stented elephant trunk. Encouraging outcomes favor this technique for distal aortic arch aneurysm.

Stented elephant trunk procedure with left subclavian artery transposition for acute type B dissection with distal arch involvement

OBJECTIVE

Complete or partial supra-aortic debranching, after thoracic endovascular aortic repair, is appealing treatment for complicated acute type B dissection (ABAD) with aortic arch involvement (AAI) because of reduced surgical trauma. However, unsatisfactory outcomes have been reported. We retrospectively reviewed our experience of left subclavian artery (LSCA) transposition with stented elephant trunk (SET) implantation for complicated ABAD with distal AAI.

METHODS

From April 2011 to December 2014, 19 patients (all men; mean age: 44 years) who had complicated ABAD and distal AAI underwent LSCA transposition with SET implantation via a median sternotomy under hypothermic cardiopulmonary bypass with selective cerebral perfusion. Preoperative renal dysfunction was observed in 3 patients, visceral ischemia in 2 patients, and lower-limb ischemia in 1 patient.

RESULTS

No in-hospital deaths occurred. Seventeen patients required mechanical ventilation for <24 hours, and 2 cases for <48 hours. The mean time of mechanical ventilation and duration of stay in the intensive care unit was 18 ± 6 hours and 44 ± 16 hours, respectively. Ischemia of the viscera and lower limbs after surgery was ameliorated. Continuous renal replacement therapy was not required in 3 patients who had preoperative renal dysfunction. Complete thrombosis of the false lumen at the distal end of the SET was observed in 17 of 18 (94.4%) patients during follow-up.

CONCLUSIONS

This method preserves autologous brachiocephalic vessels, excludes the false lumen, promotes thrombosis and remodeling of the distal aorta, and repairs proximal aortic lesions simultaneously. Satisfactory surgical outcomes and follow-up results were achieved using LSCA transposition with SET implantation.

Repair of complicated type B dissection with an isolated left vertebral artery using the stented elephant trunk technique

OBJECTIVES

The presence of an isolated left vertebral artery (ILVA) remains a challenging issue for thoracic endovascular aortic repair (TEVAR) of type B dissection if the proximal landing zones are inadequate. We retrospectively reviewed our experience of the surgical management of complicated type B dissection with an ILVA using the stented elephant trunk technique.

METHODS

Between February 2009 and May 2013, 7 patients with complicated type B dissection (acute = 2 and chronic = 5) underwent the stented elephant trunk procedure under hypothermic cardiopulmonary bypass with selective antegrade cerebral perfusion. All the patients were males with a median age of 53 ± 6 (range 42-59) years. Preoperative lower limb ischaemia was observed in 1 patient, renal dysfunction in 1 patient and visceral ischaemia in 1 patient.

RESULTS

There were no in-hospital deaths. The median ventilator support time was 16 ± 3 (range 11-20) h. Ischaemia of the lower limb and viscera was ameliorated after surgical stent-graft implantation. Continuous renal replacement therapy was not required in patients with preoperative renal dysfunction after surgery. No neurological deficits were observed in any patients prior to hospital discharge. One patient underwent TEVAR due to distal aortic dilatation within the mean follow-up period, which was 44 ± 19 months.

CONCLUSION

Repair of complicated type B dissection with an ILVA using the stented elephant trunk technique was associated with satisfactory surgical results in patients with inadequate proximal fixation zones. This technique is an alternative to TEVAR for complicated type B dissection with inadequate proximal landing zones.

Elephant trunk technique for hybrid aortic arch repair

The original elephant trunk technique was developed by Borst in 1983 for the treatment of aortic arch aneurysms. This technique reduced operative risks, but was associated with cumulative mortality rates of 6.9 % for the first stage and 7.5 % for the second stage. Patients also waited a long time between two major surgical procedures. Only 50.4 % of patients underwent the second-stage surgery, and there was a significant interval mortality rate of 10.7 %. With the advent of stent-graft techniques, two different hybrid elephant trunk techniques were developed. One technique is first-stage elephant trunk graft placement followed by second-stage endovascular completion. The conventional elephant trunk graft provides a good landing zone for the stent-graft, and endovascular completion is a useful alternative to conventional second-stage surgery. This method has few major complications, and a postoperative paraplegia rate of 1.1 %. The other technique is the frozen elephant trunk technique. This technique eliminates the need for subsequent endovascular completion, and is particularly useful for the treatment of acute type A dissection because it can achieve a secure seal. However, it is associated with a higher rate of spinal cord ischemia than other methods such as the original elephant trunk technique. The left subclavian artery (LSA) is often lost when performing a hybrid elephant trunk procedure. Revascularization of the LSA should be performed to prevent arm ischemia and neurological complications such as paraplegia or stroke, although the level of evidence for this recommendation is low.

Elephant trunks in aortic surgery: fresh and frozen

Aneurysmal diseases are often silent but can cause potentially life-threatening complications in cases of dissection or rupture. Surgical strategies depend on the involved part of the aorta and frequently require extracorporeal circulation and circulatory arrest. From data available from the Centers for Disease Control and Prevention, aneurysm disease is the 18th most common cause of death in all individuals, and the incidence is certain to increase as our population ages. This article discusses different treatment options introduced in the past few decades to address multifocal pathologic conditions of the thoracic aorta. These include the conventional elephant trunk procedure introduced by Hans Borst in 1983, with several modifications, and also hybrid procedures combining open surgical and endovascular techniques: the so-called frozen elephant trunk. Advantages and drawbacks of both techniques will be discussed based on personal and practical perspectives, with specific mention of the elephant trunk procedure in acute aortic dissections.

Total arch replacement combined with stented elephant trunk implantation: a new "standard" therapy for type a dissection involving repair of the aortic arch?

BACKGROUND

Appropriate surgical management of type A dissection is a critical factor for achieving satisfactory outcome, but the choice of optimal procedure is controversial. We retrospectively reviewed our experience with aortic arch replacement for type A dissection involving the arch.

METHODS AND RESULTS

Excluding 14 cases of subtotal or total aortic replacement, 411 of 544 patients with type A dissection (stented elephant trunk=291, conventional surgical repair=120) underwent aortic arch replacement between January 2003 and September 2008. In-hospital mortality was 3.09% (9 of 291) for stented (acute=4.73%, 7 of 148; chronic=1.40%, 2 of 143) and 5.00% (6 of 120) for conventional repairs (acute=6.06%, 4 of 66; chronic=3.70%, 2 of 54). Spinal cord injury was 2.41% (7 of 291) in the stented and 0.83% (1 of 120) in the conventional group. The overall prevalence of stroke was 1.95% (8 of 411) (stented=2.41%, 7 of 291; conventional=0.83, 1 of 120). Secondary intervention was 2.34% (5 of 214) for acute dissection (stented=1 and conventional=4; P=0.031) and 3.05% (6 of 197) for chronic dissection (stented=4 and conventional=2; P=0.661) during follow-up. Obliteration of the false lumen around the stented elephant trunk occurred in 94.2% (130 of 138) of patients with acute dissection and in 92.0% (126 of 137) of patients with chronic dissection.

CONCLUSIONS

Total arch replacement combined with stented elephant trunk implantation demonstrated the superiority of the combination of the surgical and interventional approaches while avoiding the weaknesses associated with the individual methods. The encouraging surgical results could enable this procedure to become the new "standard" therapy for type A dissection involving repair of the aortic arch.