Morphology of the left subclavian artery: implications for single-branched endovascular aortic arch repair

OBJECTIVES

Our goal was to evaluate the morphology of the aortic arch, focusing on the left subclavian artery (LSA), and to anticipate implications for single-branched endovascular aortic arch repair.

METHODS

We performed a morphological analysis of computed tomography angiography scans of 322 patients between January 2002 and December 2018. Arch type and distance between arch vessels on the convexity were evaluated. We defined 3 morphological types: U-type distance between the left common carotid artery (LCCA) and LSA offspring >10 mm; V-type distance between the LCCA and LSA offspring <10 mm and W-type isolated left vertebral artery offspring from the aortic arch.

RESULTS

Most patients presented a type III arch [50% (n = 161)]. The median distance from the brachiocephalic trunk offspring to the LCCA offspring measured 2.5 mm (2.0-3.0 mm) and that between the LCCA offspring and the LSA offspring was 6.5 mm (4.0-11.0 mm). We observed no significant difference based on the morphological type (V versus U versus W) in the brachiocephalic trunk-LCCA distance, but there were significant differences in the LCCA-LSA distance between types V and U (P < 0.001) and between types V and W (P < 0.001). Interestingly, we found no significant difference in the LCCA-LSA distance between types U and W. We noted a significant difference in the median diameter of the LSA according to U, V and W types: V type versus U type, 12.5 vs 13.5 mm (P = 0.033) as well as U type versus W type, 13.5 vs 10.5 mm (P < 0.001) and V type versus W type, 12.5 vs 10.5 mm (P < 0.002). The distances between the LSA offspring and left vertebral artery offspring between types U and V did not differ significantly.

CONCLUSIONS

Our categorization of the U, V and W types of the LSA can help us anticipate shapes and distances and thereby function as an initial evaluation tool for predicting single branched endovascular aortic arch repair involving the LSA.

Subsequent open-cardiac surgery after transcatheter aortic valve implantation-indications and outcomes

Background

Transcatheter aortic valve implantation (TAVI) has been historically done in high-risk patients or patients who are deemed unfit for open-heart surgery. Despite high procedural success rates subsequent open surgery remains an issue, immediately after TAVI implantation or during follow-up as bailout strategy.

Purpose

Aim of this study was to report on indications and clinical outcomes of patients who underwent open-cardiac surgery following TAVI.

Methods

Between 01/2011 and 12/2020 our centre performed 3131 TAVI procedures. Twenty-seven patients (including patients in whom TAVI was performed in other centres) underwent subsequent open-heart surgery via cardiopulmonary bypass after previous TAVI. Demographic, intraprocedural data and indications for surgery were evaluated. The VARC-2 criteria were applied to report on clinical outcomes.

Results

Twenty-seven patients (aged 79 [IQR 76–84]; 59.3% male) were operated on for endocarditis (n=11; 40.7%), 3 patients for annular rupture, severe paravalvular leak and severe stenosis, respectively as well as 1 patient each for severe tricuspidal valve regurgitation, valve thrombosis, malpositioning, valve migration, ostial right coronary artery obstruction, left ventricular rupture and type A aortic dissection. The interval between the index TAVI procedure to open surgery was 3 months (IQR 0–26 months). Eight patients underwent emergency subsequent surgery on the same day immediately after TAVI. The surgical data including the procedures are shown in Figure 1. Four patients died intraoperatively due to uncontrolled bleeding. Immediate procedural and procedural mortality was 25.9% and 40.7%, respectively and all-cause mortality was 51.9% (11/12 died for cardiovascular reasons). Figure 2 shows the Kaplan-Meier estimator for survival. Intraoperative, immediate, procedural and all-cause mortality in patients operated on immediately after TAVI was 25.0%, 25.0%, 37.5%, and 50% respectively. No disabling stroke was observed while a non-disabling stroke occurred in 1 patient. New permanent pacemaker implantation was needed in 3 patients (11.1%). One patient required an additional, second operation to remove a left ventricular thrombus as bailout procedure. One patient suffered from a persisting endocarditis and was discharged on permanent antibiotic intake.

Conclusions

Subsequent open-heart surgery after TAVI is rare, but may urgently become necessary due to TAVI related complications or progressing other cardiac pathologies. Despite a substantial early attrition rate clinical outcome is acceptable and a relevant number of patients can be discharged after surgery for immediate life-threatening TAVI complications. The option of subsequent surgical conversion remains an indispensable tool in the setting of a modern heart team-based approach. These results substantiate recommendations regarding both, having a cardiac surgical service on site and performing TAVI as an interdisciplinary team.

Funding Acknowledgement

Type of funding sources: None. Surgical detailsKaplan-Meier estimator for survival

Coronary angiography in patients with native or prosthetic aortic-valve endocarditis: outcomes and implications for myocardial revascularisation

Background

Coronary angiography (CA) remains the cornerstone of the preoperative assessments before open-heart surgery to detect or rule out coronary artery disease (CAD). Preoperative CA is currently not recommended in patients with active infective aortic valve endocarditis, but may help to reduce the risk of perioperative myocardial infarction.

Purpose

This study aimed to evaluate the risks and benefits of preoperative CA in selected patients before aortic valve replacement to treat active infective endocarditis of the aortic valve and to assess the incidence and relevance of CAD.

Methods

Sixty-five patients with native or prosthetic aortic-valve endocarditis underwent preoperative diagnostic CA between 03/2008 and 09/2020. We collected their baseline characteristics, including the neurological status, previous cardiac surgical procedures, and reviewed the preoperative echocardiograms and the CA data. We evaluated the intraoperative data, and clinical outcomes after CA and after surgery. Patients were selected according to the site, size and mobility of vegetations of the underlying active infective process.

Results

CA revealed CAD in the majority of patients (n=34; 52%): one-vessel disease n=17 (26%), two-vessel disease n=6 (9%), and three-vessel disease n=11 (17%). Coronary sclerosis without hemodynamic significance were detected in 23 patients (35%). Sixteen patients had a previous history of CAD. We observed no adverse events following preoperative diagnostic CA, particularly no thromboembolic complications, including stroke, visceral, or lower body ischaemia. Surgery was performed 3 [IQR 1; 5] days after CA. During surgical aortic-valve replacement, concomitant coronary artery bypass grafting was performed in 19 patients (29%). Postoperative in-hospital mortality was 12% (n=8) and the new-onset disabling-stroke incidence was 2% (n=1). Neither stroke nor visceral or lower body ischemia due to embolism were observed in any patient after surgery.

Conclusions

By weighing risks and benefits of CA together as a team, no adverse clinical outcomes but significant clinical implications could be identified in patients with active infective aortic valve endocarditis. Concomitant surgical myocardial revascularization was frequent and may well have contributed to favorable clinical outcome. Therefore, active infective endocarditis of the aortic valve per se should not be regarded as an absolute contraindication for CA.

Funding Acknowledgement

Type of funding sources: None.

Efficacy of Vascular Closure Devices in Closing Large-Bore Sheath Arterial Sites after Treatment with Extracorporeal Life Support System

BACKGROUND

 We retrospectively evaluated vascular complications and wound infections after surgical or percutaneous transfemoral removal of temporary extracorporeal life support systems (ECLSs).

METHODS

 A total of 83 patients were weaned from ECLS between August 2015 and September 2020. We analyzed for a composite endpoint of vascular complications and wound infections requiring negative-pressure wound therapy. Patients were divided into two groups: percutaneous group using the MANTA vascular occlusion system (VCD; Teleflex, Morrisville, North Carolina, United States) (n = 23) and surgical group (n = 60).

RESULTS

 The median age in the entire cohort was 67 years. Vascular complications were seen in 20% (n = 12) in the surgical group and in 13% (n = 3) in the percutaneous group (p = 0.72). A total of 32% (n = 19) in the surgical group and 9% (n = 2) in the percutaneous group (p = 0.031) had wound infections. A composite endpoint of vascular complications and wound infections showed significantly more complications in the surgical group (52%, n = 31) as compared with the percutaneous group (22%, n = 5) (p = 0.020). The median duration in the intensive care unit was 13 days for the surgical group and 12 days for the percutaneous group without any significant difference in both groups (p = 0.93).

CONCLUSIONS

 Using the MANTA VCD for percutaneous removal of ECLS cannulas after weaning from ECLS is safe and reproducible. A composite endpoint of vascular complications and wound infections was significantly lower in the percutaneous removal group as compared with the surgical group.

Treatment of infectious aortic disease with bovine pericardial tube grafts

OBJECTIVES

Our aim was to evaluate the mid-term outcomes of bovine pericardial tube graft repair for infectious aortic disease in any aortic segment.

METHODS

Between May 2015 and July 2020, 45 patients were treated for infectious aortic disease of the native (n = 9) aorta or after (endo-)graft (n = 36) implantation with bovine pericardial tube grafts. Clinical, infectious details, outcomes and follow-up data were evaluated.

RESULTS

All aortic segments underwent pericardial tube graft or bifurcational replacement: the aortic root (n = 12, 27%), ascending aorta (n = 18, 40%), aortic arch (n = 7, 16%), descending aorta (n = 5, 11%), thoraco-abdominal aorta (n = 6, 13%) and abdominal aorta (n = 18, 40%) including the iliac arteries (n = 14, 31%). Organ fistulation (n = 15, 33%) was the most common underlying pathology. Seven patients (16%) expired in-hospital secondary to ongoing sepsis (n = 5, 11%), respiratory failure (n = 1, 2%) and unknown cause (n = 1, 2%). A fungal infection was predictive for in-hospital mortality (P = 0.026, odds ratio: 19.470). After a median follow-up of 11 [first quartile: 2, third quartile 26] months, 9 additional patients (20%) expired and 1 patient developed a postoperative spondylodiscitis at the level of the aortic tube graft. Hence, freedom from proven aortic graft re-infection was 98%.

CONCLUSIONS

Orthotopic aortic reconstruction using bovine pericardial tube grafts to treat infectious aortic disease is possible in any aortic segment. Organ fistulation is a frequently observed disease mechanism requiring concomitant treatment. Granted, the early attrition rate is substantial, but after the initial period, both survival and freedom from re-infection appear encouraging.

The frozen elephant trunk technique for aortic dissection is safe after previous aortic repair

OBJECTIVES

The goal of this study was to evaluate outcomes of aortic arch replacement using the frozen elephant trunk (FET) technique after previous proximal and/or distal open or endovascular thoracic aortic repair.

METHODS

Sixty-three patients [median age: 63 (55-74) years; 65% men] were operated on for acute or chronic aortic dissection after previous proximal and/or distal open or endovascular thoracic aortic repair. Intraoperative details, clinical outcome and follow-up results were evaluated.

RESULTS

The median time between the index and the FET procedure was 81 (40-113) months. Fifty-eight (92%) patients had already undergone proximal aortic surgery; supracoronary ascending aortic replacement was the most frequent index procedure [n = 25 (40%)]. Distal aortic interventions had been done in 8 (13%) patients including endovascular thoracic aortic repair in 6 patients (10%). In-hospital mortality was 3% (n = 2). Postoperative strokes occurred in 5 patients (8%); of those, 1 stroke was dissection-related (2%). Subsequent aortic reinterventions after the FET procedure had to be done in 33% (n = 21).

CONCLUSIONS

Outcomes of aortic arch replacement using the FET technique after previous proximal and/or distal open or endovascular thoracic aortic repair are associated with low mortality and morbidity. Still, postoperative stroke remains an issue. After the successful accomplishments, the approach serves as an ideal platform for the secondary surgical or endovascular downstream aortic procedures, which are frequently needed.

Results of endovascular aortic arch repair using the Relay Branch system

OBJECTIVES

Our goal was to evaluate results of endovascular aortic arch repair using the Relay Branch system.

METHODS

Forty-three patients with thoracic aortic pathology involving the aortic arch have been treated with the Relay Branch system (Terumo Aortic, Sunrise, FL, USA) in 10 centres. We assessed in-hospital mortality, neurological injury, treatment success according to current reporting standards and the need for secondary interventions. In addition, outcome was analysed according to the underlying pathology: non-dissective disease versus residual aortic dissection (RAD) (defined as remaining dissection after previous type A repair, chronic type B aortic dissections).

RESULTS

In-hospital mortality was 9% (0% in patients with RAD). Disabling stroke occurred in 7% (0% in patients with RAD); non-disabling stroke occurred in 19% (7% in patients with RAD). Early type IA and B endoleak formation occurred in 4%. Median follow-up was 16 ± 18 months. During the follow-up period, 23% of the patients died. Aortic-related deaths were low (3% in patients with RAD).

CONCLUSIONS

The results of endovascular aortic arch repair using the Relay Branch system in a selected patient population with regard to technical success are good. In-hospital mortality is acceptable, the number of disabling strokes is low and technical success is high. Non-disabling stroke is a major concern, and every effort has to be taken to reduce this to a minimum. The best outcome is seen in patients with underlying RAD. Finally, more data are needed.

Aortic Arch Anatomy in Candidates for Aortic Arch Repair

Detailed knowledge of aortic anatomy is necessary before new prostheses can be developed. Our aim was to provide a thorough analysis of aortic arch anatomy in patients who are potential candidates for arch repair. Patients' charts were screened between 2001 and 2019 for all those with a dissection or aneurysm involving aortic arch. Aortic diameters, segmental lengths, aortic arch type, tortuosity, diameters and length of supraaortic vessels were analyzed via computed tomography angiography. We included 558 patients who underwent thoracic aortic treatment for type A, B, non-A non-B dissection, or aortic arch aneurysm. Incidence of all three arch types was similar in patients with type A dissection. In type B dissection and arch aneurysm patients, arch type III was most commonly observed (47% and 52%, respectively). The left vertebral artery offspring from aortic arch was observed in 6.6%. The mid-ascending aorta and aortic arch were not dilated in type B and non-A non-B dissection patients. The innominate, left common carotid and left subclavian arteries median diameters were 16 (14; 18), 8 (7; 9) and 11 (10; 12) mm, respectively. The median innominate artery length was 37 (30; 44) mm. The median left subclavian artery length was 40 (34; 46) mm. Arch types are distributed differently among patients with various arch pathologies. Patients with aortic dissection type B and non-A non-B have a non-dilated ascending aorta and aortic arch. Aortic arch tortuosity, innominate and left subclavian artery lengths do not differ among aortic pathologies.

The 3-step approach for the treatment of multisegmental thoraco-abdominal aortic pathologies

OBJECTIVES

The goal of this study was to describe our 3-step approach to treat multisegmental thoraco-abdominal aortic disease due to aortic dissection and to present our initial clinical results.

METHODS

Nine patients with multisegmental thoraco-abdominal aortic pathology due to aortic dissection underwent our 3-step approach, which consisted of total aortic arch replacement via the frozen elephant trunk technique, thoracic endovascular aortic repair for distal extension down to the level of the thoraco-abdominal transition and, finally, open thoraco-abdominal aortic replacement for the remaining downstream aortic segments. We assessed their baseline and aortic characteristics, previous aortic procedures, intraoperative details, clinical outcomes and follow-up data.

RESULTS

The median age was 58 (42-66) years; 4 patients (44%) presented connective tissue disease. Eight patients (89%) had undergone previous aortic surgery for aortic dissection. In-hospital mortality was 0% (n = 0). None suffered symptomatic spinal cord injury or disabling stroke. During the follow-up period, 1 patient died of acute biliary septic shock 6 months after thoraco-abdominal aortic replacement.

CONCLUSIONS

The 3-step approach to treat multisegmental thoraco-abdominal aortic pathology due to aortic dissection, which involves applying both open and endovascular techniques, is associated with an excellent clinical outcome and low perioperative risk. Distal shifting of the disease process through the thoracic endovascular aortic repair extension-and thereby necessitating limited open thoraco-abdominal aortic repair-seems to be the major factor enabling these favourable results.

IRB APPROVAL

IRB approval was obtained (No. 425/15) from the institutional review board of the University of Freiburg.

Direct Versus Side Graft Cannulation From the Right Axillary Artery in Thoracic Aortic Surgery

BACKGROUND

The axillary artery can be cannulated for antegrade cerebral perfusion directly or by employing a prosthetic vascular graft anastomosed to the artery.

METHODS

From 2008 until 2019, 688 patients underwent axillary artery cannulation. Of those, 287 underwent direct cannulation and 401 cannulation through a side graft. We identified risk factors for cannulation-related complications, and after propensity score matching, we compared the 2 matched cohorts' cannulation-related and postoperative outcomes.

RESULTS

A smaller axillary-artery diameter (odds ratio = 0.70; 95% confidence interval, 0.56-0.87) and emergency surgery (odds ratio = 2.23; 95% confidence interval, 1.27-3.92) were identified as risk factors for cannulation-associated complications. In the propensity score-matched cohorts (n = 266 in each), the number of patients experiencing cannulation-related complications was significantly higher in the direct cannulation group than in the side-graft group (n = 33 [12.4%] versus n = 15 [5.6%]; P = .01). The direct group's incidence of iatrogenic axillary artery dissection was significantly higher (n = 17 [6.4%] versus n = 4 [1.5%] P = .008); their incidence of postoperative stroke was also significantly higher (n = 39 [14.7%] versus n = 21 [7.9%]; P = .025). Patients cannulated with a side graft needed more transfusions of blood products (median [IQR]: 3.0 [1.0-6.0] versus 4.0 [2.0-7.0;] P = .009).

CONCLUSIONS

Cannulating the right axillary through a vascular prosthetic graft reduces cannulation-related complications such as iatrogenic axillary artery dissection and lowers stroke rates. To help prevent cannulation-related complications and stroke, we recommend the routine use of a side graft when cannulating the axillary artery.

Can a trainee perform endovascular aortic repair as effectively and safely as an experienced specialist?

OBJECTIVES

Endovascular aortic repair (EVAR) is a technically demanding procedure usually carried out by highly experienced surgeons. However, in this era of modern endovascular surgery with growing numbers of patients qualifying for the procedure, the need to enhance surgical training has emerged. Our aim was to compare the technical results of EVAR in patients operated on by trainees to that of those operated on by an endovascular expert.

METHODS

Between 2016 and 2018, a total of 119 patients diagnosed with an abdominal aorta disease requiring EVAR were admitted to our clinic. Overall, we included 96 patients who underwent preoperative and postoperative computed tomography angiography and EVAR performed either by an endovascular expert (N = 51) or a trainee (N = 45).

RESULTS

We detected no difference in the baseline characteristics, indication for EVAR and preoperative anatomy between patients operated on by trainees and our endovascular expert. We noted the same incidence of endoleak type Ia occurrence (n = 2 vs n = 2, P = 1.00), reintervention rate (n = 0 vs n = 0, P = 1.00) and in-hospital mortality (n = 0 vs n = 1, P = 1.00) for operations done by trainees and the expert, respectively. There was no difference in X-ray doses or time between the 2 groups. Despite longer median operation times [112 (first quartile: 84; third quartile: 129) vs 89 (75-104) min; P = 0.03] and in-hospital stays [10 (8-13) vs 8 (7-10) days, P = 0.007] of the patients operated on by trainees, the overall clinical success of EVAR was satisfactory in both groups.

CONCLUSIONS

An EVAR planned and performed by a trainee need not raise the cumulative risk of the procedure. Trainees who have undergone both mind and hand skills training can therefore carry out EVAR under the supervision of an experienced specialist as effectively and safely as experts do.

The Frozen Elephant Trunk Technique for the Treatment of Type B and Type Non-A Non-B Aortic Dissection

OBJECTIVE

To evaluate outcomes of patients with acute complicated or chronic Type B or non-A non-B aortic dissection who underwent the frozen elephant trunk (FET) technique.

METHODS

Between April 2013 and July 2019, 41 patients presenting with acute complicated (n = 29) or chronic (n = 12) descending thoracic aortic dissection were treated by the FET technique, which was the treatment of choice when supra-aortic vessel transposition would not suffice to create a satisfactory proximal landing zone for endovascular aortic repair, when a concomitant ascending or arch aneurysm was present, or in patients with connective tissue diseases.

RESULTS

One patient (2%) died intra-operatively secondary to an aortic rupture in dwnstream aortic segments. No post-operative deaths occurred. Four patients (10%) suffered a non-disabling posto-operative stroke and were discharged with no clinical symptoms (modified Rankin Scale [mRS] 0, n = 1), no significant disability (mRS 1, n = 2), or with slight disability (mRS 2, n = 1). No spinal cord ischaemia was observed. The primary entry tear was either surgically resected or excluded from circulation in all patients. During follow up, one patient (2%) died after two years (not aorta related) and 16 patients (39%) underwent an aortic re-intervention after 7.7 [interquartile range 0.7, 15.8] months (endovascular aortic repair: n = 14; open thoraco-abdominal aortic replacement: n = 1, hybrid approach: n = 1).

CONCLUSION

The FET technique is an effective treatment option for acute complicated and chronic Type B or non-A non-B aortic dissection in patients in whom primary endovascular aortic repair is non-feasible. While the post-operative outcome is acceptable with a relatively low incidence of non-disabling strokes, this study also underlines the considerable need for aortic re-interventions. Continuous follow up of all patients undergoing the FET procedure is essential.

How to minimize air embolisms during thoracic endovascular aortic repair with Relay Pro?

The aim of this study was to evaluate the volume of air released from Relay Pro NBS thoracic stent grafts using different de-airing methods. The gas volume was measured in an in vitro experimental setting. Stent grafts were de-aired via (i) standard saline flushing (40 ml), (ii) increased volume saline flushing (120 ml), (iii) carbon dioxide followed by 40 ml saline flushing and (iv) de-airing with 40 ml of saline in an ultrasound bath. The volume of gas released was measured separately while introducing the folded stent graft in the delivery device into the simulated aorta (step 1) and while deploying it outside the delivery device (step 2). Median air volumes released during steps 1 and 2 after flushing with 40 ml of saline were 0.09 (1st-3rd quartile 0.06-0.21) and 0.14 (0.11-0.15) ml, respectively. The volume of air released during step 2 was significantly less [0.09 (0.08-0.10) ml] after de-airing with 120 ml saline (P = 0.049). Neither de-airing with carbon dioxide nor in an ultrasonic bath led to a reduction in the volume of gas released during step 2. Air remaining after de-airing with a standard 40 ml of saline was released partially during stent graft introduction into the aorta and partially during final deployment. The most effective method of reducing air volume was de-airing with increased saline volume.

What Is the Best Method to Achieve Safe and Precise Stent-Graft Deployment in Patients Undergoing TEVAR?

Thoracic endovascular aortic repair (TEVAR) for aortic pathologies requires sufficient landing zone of ideally more than 25 mm for safe anchoring of the stent-graft and prevention of endoleaks. In the aortic arch and at the thoracoabdominal transition, landing zone length is usually limited by the offspring of the major aortic side-branches. Exact deployment of the stent-graft to effectively use the whole length of the landing zone and to prevent occlusion of one of the side-branches is key to successful TEVAR. There are numerous techniques described to lower blood pressure and to reduce or eliminate aortic impulse to facilitate exact deployment of stent-grafts including pharmacologic blood pressure lowering, adenosine-induced asystole, inflow occlusion, and rapid pacing. Aim of this review was to assess the current literature to identify which of the techniques is best suited to prevent displacement and allow for precise placement of the stent-graft and safe balloon-molding.

Landing Zone Remodelling after Endovascular Repair of Dissected Descending Aorta

OBJECTIVE

The aim of this study was to determine geometric changes in the proximal and distal aortic landing zones after thoracic endovascular aortic repair (TEVAR) for acute descending aortic dissection.

METHODS

This was a retrospective analysis of clinical and radiological data. Included are patients who underwent TEVAR for acute descending aortic dissection between 2004 and 2018. Analysed are the proximal and distal landing zones' initial geometries and their change at follow up. Median follow up time was 2.3 (first quartile 0.9, third quartile 4.5) years.

RESULTS

One hundred and one patients were included (93 type B and 8 non-A non-B dissections, aged 65 (57, 74) years old, and 29% female). Dissection extended down to the abdominal aorta in 69% patients. The proximal landing zone was non-dissected in 92 patients. The diameters of non-dissected proximal landing zones increased by 3 (-1, 5; p < .001) mm at follow up. The distal landing zone was dissected in 84% of patients. The diameters of dissected distal landing zones had increased at follow up by 7 (3, 12) mm and 4 (1, 10; both p < .001) mm measured in true lumen and total aorta, respectively, observed one year after TEVAR. Stent grafts reached their nominal diameter at follow up in 22% and 17% of proximal and distal landing zones, respectively. There were seven proximal and 10 distal stent graft induced new entries at follow up. Aortic re-intervention was necessary in 23 patients entailing 19 TEVAR extensions and four open aortic repairs.

CONCLUSION

The distal landing zone in patients undergoing TEVAR for descending aortic dissection is frequently dissected and is associated with the risk of d-SINE at follow up and the need for re-interventions after TEVAR - factors that emphasise the importance of long term follow up.