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A Review of the Endovascular Management of Thoracic Aortic Pathology
ORIGINAL ARTICLE
Heart, Lung and Circulation (2015) 24, 1211–1215 1443-9506/04/$36.00 http://dx.doi.org/10.1016/j.hlc.2015.05.008
A Review of the Endovascular Management of Thoracic Aortic Pathology David Bell, MBBS *, Levi Bassin, MBBS, Michael Neale, MBBS, FRACS, Peter Brady, MBBS, FRACS Department of Cardiothoracic and Vascular Surgery, Royal North Shore Hospital, Sydney, NSW, Australia Received 24 February 2015; received in revised form 2 May 2015; accepted 6 May 2015; online published-ahead-of-print 10 June 2015
Background
Thoracic endovascular aortic repair (TEVAR) has recently gained popularity, but there is ongoing debate surrounding its safety and efficacy. We present 13 years of TEVAR experience at our institution.
Methods
Data from procedures performed between September 2000 and October 2013 were sourced. Eighty-one TEVARs were performed in 72 patients for various disorders of the thoracic aorta.
Results
The mean duration of follow-up was 62 months (range, 2–140 months). One-month, one-year, and five-year survival rates were 93%, 88%, and 63%, respectively. Five mortalities occurred within 30 days of operation (7%), three of which were related to vascular complications. There were 12 episodes of postoperative endoleak (12.5%). The left subclavian artery was covered without revascularisation in nine cases resulting in two episodes of subclavian steal syndrome and one episode of left arm claudication. Three patients had perioperative strokes, and one patient spinal cord ischaemia.
Conclusions
We demonstrated low rates of reintervention after TEVAR and a low risk of complications, particularly neurological. We therefore advocate an endovascular approach for thoracic pathology involving the aortic arch and descending aorta, particularly in elderly patients. Coverage of the LSCA is often necessary, but where possible, prophylactic revascularisation should be performed.
Keywords
Endovascular Thoracic aorta Aneurysm Dissection Endoleak Subclavian artery
Introduction In 1994, Dake et al. published the first series of thoracic endovascular aortic repairs (TEVAR) [1]. TEVAR offers a less invasive alternative to the traditional open thoracic aortic repair, providing a new option to patients who were previously deemed unsuitable for open operation. In the late 1990s, the development of aortic arch debranching in combination with endovascular grafting further broadened the scope of TEVAR to enable endovascular treatment of aortic arch, or near-arch pathology [2]. TEVAR has rapidly gained popularity, but there is ongoing debate surrounding its safety and efficacy. Whilst a wealth of data have suggested that TEVAR is superior to open repair
with respect to early mortality and major complications, including spinal cord ischaemia, postoperative bleeding, and renal impairment, no randomised controlled trials that compare TEVAR with open repair have been performed to date [3]. In addition, a long-term survival benefit of TEVAR is yet to be demonstrated [4,5]. Little has been reported on the Australian experience with TEVAR. We aimed to present 13 years of experience with TEVAR at the Royal North Shore Hospital (RNSH).
Materials and Methods Ethics approval of this study was obtained from the RNSH ethics committee.
*Corresponding author at: Department of Cardiothoracic Surgery, Royal North Shore Hospital, Reserve Rd, St Leonard, NSW 2065. Tel.: +0412212807, Email: [email protected] Crown Copyright © 2015 Published by Elsevier Inc on behalf of Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). All rights reserved.
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Data were sourced from private and public hospital medical records, medical imaging reports, and correspondence from general practitioners and other specialists. The most recent patient status with respect to quality of life was ascertained by liaising with general practitioners. Where relevant, the date of death was sourced from the Ryerson index [6]. Between September 2000 and October 2013, 81 endovascular procedures were performed in 72 patients for various disorders of the thoracic aorta at RNSH public and private hospitals. Nine repeat endovascular procedures were performed for postoperative endoleak. Three ascending aortic replacements for type A aortic dissections were performed prior to TEVAR. The endoluminal approach alone was used for 48 primary procedures. In 24 cases, the procedures were performed in a hybrid manner. In 14 of the 24 cases, debranching and stenting were performed as part of the same procedure, whereas in 10 cases, these were performed as separate procedures. The series consisted of 49 men and 23 women, with a mean age at operation of 70 years (range, 17–89 years). The indications for operation included 37 atherosclerotic aneurysms (26 elective and 11 emergency presentations); nine traumatic disruptions of the thoracic aorta; six penetrating aortic ulcers; five false aneurysms, one of which was mycotic; five chronic type B dissections with either persistent pain or ongoing expansion of the false lumen; three acute type B dissections with significant pseudocoarctation; three chronic sequelae of previously treated type A dissections; one acute type A dissection in a 92-year-old woman; one coarctation of the aorta; and one case of an infected sinus related to a previous open ascending aorta repair.
Results Thirty-one patients presented with chest or thoracic back pain, and an additional nine with post-traumatic chest pain. Twenty-four cases were detected incidentally. Two cases presented with acute haemoptysis; two, with a new cerebrovascular accident in conjunction with chest pain; and two, with syncope and chest pain. Two presentations were attributable to aneurysmal compression of surrounding structures: one case presented with shortness of breath due to bronchial compression; and the other with dysphonia related to compression of the recurrent laryngeal nerve. One patient presented with poorly controlled hypertension and was found to have a juxtaductal coarctation of the aorta. Four patients were haemodynamically unstable at presentation. For the purposes of this study, the ascending aorta was defined as extending from the aortic root to the origin right brachiocephalic artery; the aortic arch, as extending from the right brachiocephalic artery to the attachment of the ligamentum arteriosum; and the descending aorta as the segment of the aorta distal to this. Disease was most commonly localised to the proximal descending aorta (32 cases) and aortic arch (15 cases). In 11 cases disease spanned the thoracoabdominal aorta (Crawford classification: three, type 1; one, type 2; three, type 3; none, type 4; four, type 5) [19]. In
D. Bell et al.
eight cases, the disease was localised to the distal descending thoracic aorta; and in six cases, the disease was confined to the mid descending thoracic aorta. The mean aneurysm size at operation was 63 mm (21 [saccular] to 90 mm). The mean patient follow-up duration was 62 months (range, 2–140 months). One-month, one-year, and five-year survival rates were 93%, 88%, and 63% respectively. The following stent grafts were used: Valiant/Talent (37 cases), Zenith (17 cases), Gore (13 cases), Talent (eight cases), Cook (three cases), Relay (two cases), Aneurx (one case), and Palmaz (one case). Stent size varied in diameter from 26 to 42 mm. The median stent width was 34 mm. Smaller widths were predominantly utilised in the distal thoracic aorta, and larger widths, in the proximal descending thoracic aorta. Relevant patient comorbidities included hypertension (40 cases), chronic kidney disease defined by an estimated glomerular filtration rate < 60 mL/min (15 cases), ischaemic heart disease (14 cases), chronic obstructive pulmonary disease (10 cases), obesity (seven cases), and diabetes (six cases). A preoperative spinal drain was inserted in 23 patients for spinal cord protection. The decision to insert a drain was based on the risk of spinal cord ischaemia predicted by the extent of aortic coverage required, a history of previous abdominal aortic aneurysm (AAA) repair, and whether or not the left subclavian artery (LSCA) was to be covered. One patient required urgent conversion to an open procedure for a complication related to vascular access. The patient recovered well and later underwent an uncomplicated TEVAR.
Thirty-Day Mortality Five mortalities occurred within 30 days of operation, three of which were related to vascular complications. Early death occurred in three patients who underwent elective operation and in two patients who presented as emergencies. A 73-year-old woman died after an extensive bowel infarction secondary to hypoperfusion after a hybrid repair of a thoracoabdominal aneurysm. An 80-year-old woman died of ischaemic bowel related to hypoperfusion following hybrid repair of a large type 1b endoleak. A 79-year-old man died from pneumonia after a TEVAR eroded into his oesophagus. Another two patients died of extravascular complications. A 21-year-old man presented with a traumatic aortic tear after a motor vehicle accident. A TEVAR was performed with successful exclusion of the defect, but the patient died one week later due to head injuries. An 80-year-old man with multiple comorbidities presented with a large thoracoabdominal aneurysm at risk of imminent rupture. He was unsuitable for an open procedure because of respiratory disease. An endoluminal repair with a custom-made fenestrated graft was performed. The patient could not be extubated and died from type 2 respiratory failure secondary to pneumonia.
Endoleak Table 1 summarises 12 episodes of postoperative endoleak. Two type 2 endoleaks were small enough to be managed conservatively and closed without intervention after
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Long Term Outcomes of TEVAR
Table 1 Postoperative endoleak. Pathology
Location
Endoleak
Management
Outcome
Saccular aneurysm Aneurysm
Distal arch Distal arch-descending
Type 2 via LSCA Type 1b
Embolisation of LSCA Thoracotomy and banding
No further endoleak Persistent endoleak,
of the proximal end of the stent
not suitable for further
aorta
intervention Aneurysm
Descending aorta
Type 1b
Abdominal aortic debranching,
Died, ischaemic gut
extension TEVAR/EVAR Descending aorta
Type 2 via LSCA
Debranching and graft extension
No further endoleak
False aneurysm
Proximal descending aorta
Type 1b
Formal open repair
No further endoleak
Traumatic disruption
Proximal
Type 1b
Open repair under DHCA
No further endoleak
Type 2 via LSCA
Embolisation LSCA
No further endoleak
Aortic arch debranching,
No further endoleak
Chronic type B dissection
descending aorta Aneurysm
Proximal descending aorta
Type A dissection, previous Bentall’s
Aortic arch- distal
Type 1a
descending aorta
Previous arch repair complicated by
TEVAR, Amplatz plug to LSCA Type 2 via LSCA
Managed conservatively
No further endoleak
Type 2 via LSCA
Embolisation LSCA
No further endoleak
Type 2 via LSCA
Managed conservatively
No further endoleak
infected sinus Diverticulum of Kommerell Aneurysm
Proximal descending aorta Proximal descending aorta
TEVAR- thoracic endovascular aortic repair, EVAR- endovascular aortic repair, LSCA- left subclavian artery, DHCA- deep hypothermic circulatory arrest.
12 months. Four type 2 endoleaks persisted for longer than 12 months and required further intervention. In three of these cases, the LSCA was successfully embolised. In the other case, the aortic arch was debranched and the previously placed TEVAR was extended. Six type 1 endoleaks developed postoperatively. Two of these cases developed after treatment of thoracoabdominal aneurysms with poorly defined end points. All type 1 endoleaks required further intervention with either arch debranching and stent extension or formal open repair (one case). As mentioned earlier, one patient died from ischaemic bowel after the treatment of a type 1b endoleak. In addition, one case of type 1b endoleak was unsuccessfully treated because of a diffusely enlarged aorta with poor proximal and distal aortic end points. An anterior thoracotomy and banding of the proximal endoleak was performed. Some initial improvement was observed, but soon after, a distal endoleak developed. The patient died two years later from respiratory disease.
Coverage of the LSCA The LSCA was covered in 25 cases. In 16 cases, the LSCA was debranched and reperfused via a bypass graft. The LSCA was not revascularised in nine cases. Complications related to the coverage of the LSCA without revascularisation included two episodes of subclavian steal
syndrome, both requiring left common carotid artery (LCCA)-to-LSCA bypass, and one episode of left arm claudication that required a LCCA-to-left axillary artery bypass.
Additional Vascular Complications There was one case of graft dislodgement and aortooesophageal fistula formation in a 36-year-old man with high cervical quadriplegia. He had previously undergone a TEVAR for a traumatic aortic disruption after a motor vehicle accident. Two years postoperatively, he presented with an episode of massive, terminal haemoptysis but opted for no further intervention. There was one case of graft related dissection. A 77-yearold woman with a previous TEVAR presented post fall with back pain and was found to have a dissection at the distal end of the graft. This was managed conservatively. The patient died six years later from unknown causes.
Other Postoperative Complications Two patients returned to theatre for postoperative bleeding after hybrid procedures. One patient required an emergency laminectomy and evacuation of a spinal subdural haematoma related to the placement of a spinal drain. Three patients had perioperative strokes. Two of the patients achieved complete neurological recoveries, whereas one patient had mild ongoing right leg weakness.
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Table 2 Postoperative complications. Complication
Number (%)
Endoleak requiring reintervention Other graft related complications
10 (12.5%) 2 (2.5%)
(dissection, dislodgement) Pneumonia
6 (7.4%)
Acute kidney injury
6 (7.4%)
30 day mortality (all cause)
5 (6.2%)
30 day mortality (vascular cause)
3 (3.7%)
Bleeding
2 (2.5%)
Stroke (neurological recovery) Stroke (permanent neurological deficit)
2 (2.5%) 1 (1.2%)
Spinal cord ischaemia
1 (1.2%)
Myocardial infarction
1 (1.2%)
One patient had spinal cord ischaemia that manifested as Brown-Sequard syndrome. This occurred after a LCCALSCA bypass and TEVAR in a patient with a right-sided aortic arch and Kommerell’s diverticulum. A spinal drain was inserted after evidence of spinal cord ischaemia. The patient recovered well with minimal left leg weakness and only minor persistent sensory change in the right leg. Six patients had postoperative acute kidney injury, defined by a percentage increase in serum creatinine of more than 50% or the need for renal replacement therapy [9]. Only one patient required temporary postoperative haemofiltration. All of the patients experienced significant renal recovery to within 30 mmol/L of their preoperative serum creatinine. All postoperative complications are summarised in Table 2.
Discussion Whilst many retrospective reviews of thoracic aortic stenting have been reported from large American centres [3], little has been reported of the Australian experience with TEVAR in smaller, non-centralised centres. The 30-day mortality rate for patients in this study was 7% (13% for emergency presentations and 4% for elective procedures). This is similar to rates of perioperative survival reported in large North American-based survival studies [4]. The only two elective postoperative mortalities occurred after the management of thoracoabdominal pathology with hybrid procedures, which are recognised as having a higher complication rate compared with isolated thoracic aortic stenting [20]. The rate of stroke in this series was 4.2%, with only one patient having a permanent neurological deficit. These results compare favourably with published rates of stroke post open and endovascular thoracic aortic repair [3,10,11]. All three episodes of stroke in this study occurred in patients with pathology involving the distal aortic arch or proximal
descending thoracic aorta. This is consistent with previous studies that demonstrated that the most notable risk factor for stroke associated with TEVAR is arch involvement [10]. Rates of spinal cord complications in this series compared favourably with those reported from large international centres. Whilst only one episode of spinal cord ischaemia occurred in this series, a meta-analysis showed that the incidence of paraplegia post TEVAR was over 3% [3]. Rates of endoleak post-TEVAR requiring intervention vary widely in the literature but are usually reported to be between 10% and 20% [12,13]. The 12.5% rate of reintervention required for postoperative endoleak in this series compares well with those in previous series. As demonstrated, pathology involving the thoracic aorta often occurs in the proximity of aortic arch branches, particularly in the region of the LSCA. Successful and stable treatment with TEVAR necessitates adequate proximal and distal graft landing zones, ideally requiring at least 2 cm of normal aortic wall [14,15]. In instances where aortic arch branches are involved the involved branches may be covered, treated with a branched endograft or debranched, and revascularised. In the case of the LSCA, the most commonly performed procedures include either transposition of the LSCA to the LCCA or a bypass from the LCCA to the LSCA. Whilst symptoms are only reported in 20% of cases, coverage of the LSCA without debranching and revascularisation poses many potential problems, including vertebrobasilar ischaemia, left arm claudication, type 2 endoleak, and spinal cord injury [16]. This series consisted of 25 cases of LSCA coverage. In all but nine cases, the LSCA was revascularised. No major complications related to coverage of the LSCA were encountered, including stroke or spinal cord ischaemia. However, two cases of vertebrobasilar ischaemia, one case of left arm claudication, and four cases of type two endoleak were noted. Prophylactic aortic arch debranching has potential drawbacks. However, results in this series demonstrate that it may be performed with relatively few complications, with no operative deaths or strokes and only one return to theatre for postoperative bleeding in 16 cases. There are absolute contraindications to coverage of the LSCA without revascularisation. These include patients with in situ left internal mammary artery grafts and a hypoplastic right vertebral artery [17]. In addition, it is advisable to revascularise the LSCA in cases where the descending aorta will be covered below T6 and where there is a history of previous AAA repair due to the increased risk of spinal cord ischaemia. Our current recommendation based on our results is for prophylactic debranching prior to TEVAR where possible. Preoperative imaging, particularly of the right vertebral artery, is an important step in planning these procedures, although we have not routinely screened for the artery of Adamkiewicz. The only reason to cover the LSCA without revascularisation may be in an emergency situation or where the patient may be deemed unfit for an extended open surgical procedure [18].
Long Term Outcomes of TEVAR
Conclusion We demonstrated low rates of reintervention post thoracic aortic stenting, good long-term outcomes, and a low risk of complications, particularly neurological. We therefore advocate an endovascular approach for thoracic pathology involving the aortic arch and descending aorta where possible, based on low morbidity and mortality and, to a large extent, on improved and faster functional recovery, particularly in elderly patients. In addition, we demonstrated that thoracic aortic stenting can be performed in smaller, non-centralised centres, with comparable rates of procedure-related mortality and morbidity with those in larger centres. Coverage of the LSCA is often necessary, but where possible, prophylactic revascularisation should be performed.
Acknowledgements No grants, financial support, or technical assistance was required for this project.
References [1] Dake MD, Miller C, Semba CP, Mitchell RS, Walker PJ, Liddell RP. Transluminal placement of endovascular stent grafts for the treatment of descending thoracic aortic aneurysms. N Engl J Med 1994;331: 1729–34. [2] Quin˜ones-Baldrich WJ, Panetta TF, Vescera CL, Kashyap VS. Repair of type IV thoracoabdominal aneurysm with a combined endovascular and surgical approach. J Vasc Surg 1999;30(3):555–60. [3] Cheng D, Martin J, Shennib H, Dunning J, Muneretto C, Schueler S, et al. Endovascular aortic repair versus open surgical repair for descending thoracic aortic disease a systematic review and meta-analysis of comparative studies. J Am Coll Cardiol 2010;55(10):986–1001. [4] Goodney PP, Travis L, Lucas FL, Fillinger MF, Goodman DC, Cronenwett JL, et al. Survival after open versus endovascular thoracic aortic aneurysm repair in an observational study of the Medicare population. Circulation 2011;124(24):2661–9. [5] Cao CQ, Bannon PG, Shee R, Yan TD. Thoracic endovascular aortic repair: indications and evidence. Ann Thorac Cardiovasc Surg 2011;17 (1):1–6.
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[6] The Ryerson Index. Available at: http://www.ryersonindex.org/. June 1 2014. [7] Shah AA, Barfield ME, Andersen ND, Williams JB, Shah JA, Hanna JM, et al. Results of thoracic endovascular aortic repair 6 years after United States Food and Drug Administration approval. Ann Thorac Surg 2012;94(5):1394–9. [8] Desai ND, Pochettino A, Szeto WY, Moser GW, Moeller PJ, Sodhi N, et al. Thoracic endovascular aortic repair: evolution of therapy, patterns of use, and results in a 10-year experience. J Thorac Cardiovasc Surg 2011;142 (3):587–94. [9] Mehta RL, Kellum JA, Shah SV, Molitoris BA, Ronco C, Warnock DG, et al. Acute Kidney Injury Network: report of an initiative to improve outcomes in acute kidney injury. Crit Care (Lond) 2007;11(2):R31. [10] Melissano G, Tshomba Y, Bertoglio L, Rinaldi E, Chiesa R. Analysis of stroke after TEVAR involving the aortic arch. Eur J Vasc Endovasc Surg 2012;43(3):269–75. [11] Lee WA, Daniels MJ, Beaver TM, Klodell CT, Raghinaru DE, Hess Jr PJ. Late outcomes of a single-center experience of 400 consecutive thoracic endovascular aortic repairs. Circulation 2011;123(25):2938–45. [12] Morales JP, Greenberg RK, Lu Q, Cury M, Hernandez AV, Mohabbat W, et al. Endoleaks following endovascular repair of thoracic aortic aneurysm: etiology and outcomes. J Endovasc Ther 2008;15(6):631–8. [13] Parmer SS, Carpenter JP, Stavropoulos SW, Fairman RM, Pochettino A, Woo EY, et al. Endoleaks after endovascular repair of thoracic aortic aneurysms. J Vasc Surg 2006;44(3):447–52. [14] Caronno R, Piffaretti G, Tozzi M, Lomazzi C, Rivolta N, Castelli P. Intentional coverage of the left subclavian artery during endovascular stent graft repair for thoracic aortic disease. Surg Endosc 2006;20:915–8. [15] Peterson BG, Eskandari MK, Gleason TG, Morasch MD. Utility of left subclavian artery revascularisation in association with endoluminal repair of acute and chronic thoracic aortic pathology. J Vasc Surg 2006;43:433–9. [16] Hausegger KA, Oberwalder P, Tiesenhausen K, Tauss J, Stanger O, Schedlbauer P, et al. Mortality involved with debranching: intentional left subclavian artery occlusion by thoracic aortic stent-grafts without surgical transposition. J Endovasc Ther 2001;8:472–6. [17] Antoniou GA, El Sakka K, Hamady M, Wolfe JH. Hybrid treatment of complex aortic arch disease with supra-aortic debranching and endovascular stent graft repair. Eur J Vasc Endovasc Surg 2010;39(6):683e90. [18] Weigang E, Parker JA, Czerny M, Lonn L, Bonser RS, Carrel TP, et al. Should intentional endovascular stent graft coverage of the left subclavian artery be preceded by prophylactic revascularization. Eur J Cardiothorac Surg 2011;40:858–68. [19] Crawford ES, Crawford JL, Safi HJ, Coselli JS, Hess KR, Brooks B, et al. Thoracoabdominal aortic aneurysms: preoperative and intraoperative factors determining immediate and long-term results of operations in 605 patients. J Vasc Surg 1986;3:389–404. [20] Conrad MF, Crawford RS, Davison JK, Cambria RP. Thoracoabdominal aneurysm repair: a 20-year perspective. Ann Thorac Surg 2007;83:S856– 61. discussion S890-2.
Heart, Lung and Circulation (2015) 24, 1211–1215 1443-9506/04/$36.00 http://dx.doi.org/10.1016/j.hlc.2015.05.008
A Review of the Endovascular Management of Thoracic Aortic Pathology David Bell, MBBS *, Levi Bassin, MBBS, Michael Neale, MBBS, FRACS, Peter Brady, MBBS, FRACS Department of Cardiothoracic and Vascular Surgery, Royal North Shore Hospital, Sydney, NSW, Australia Received 24 February 2015; received in revised form 2 May 2015; accepted 6 May 2015; online published-ahead-of-print 10 June 2015
Background
Thoracic endovascular aortic repair (TEVAR) has recently gained popularity, but there is ongoing debate surrounding its safety and efficacy. We present 13 years of TEVAR experience at our institution.
Methods
Data from procedures performed between September 2000 and October 2013 were sourced. Eighty-one TEVARs were performed in 72 patients for various disorders of the thoracic aorta.
Results
The mean duration of follow-up was 62 months (range, 2–140 months). One-month, one-year, and five-year survival rates were 93%, 88%, and 63%, respectively. Five mortalities occurred within 30 days of operation (7%), three of which were related to vascular complications. There were 12 episodes of postoperative endoleak (12.5%). The left subclavian artery was covered without revascularisation in nine cases resulting in two episodes of subclavian steal syndrome and one episode of left arm claudication. Three patients had perioperative strokes, and one patient spinal cord ischaemia.
Conclusions
We demonstrated low rates of reintervention after TEVAR and a low risk of complications, particularly neurological. We therefore advocate an endovascular approach for thoracic pathology involving the aortic arch and descending aorta, particularly in elderly patients. Coverage of the LSCA is often necessary, but where possible, prophylactic revascularisation should be performed.
Keywords
Endovascular Thoracic aorta Aneurysm Dissection Endoleak Subclavian artery
Introduction In 1994, Dake et al. published the first series of thoracic endovascular aortic repairs (TEVAR) [1]. TEVAR offers a less invasive alternative to the traditional open thoracic aortic repair, providing a new option to patients who were previously deemed unsuitable for open operation. In the late 1990s, the development of aortic arch debranching in combination with endovascular grafting further broadened the scope of TEVAR to enable endovascular treatment of aortic arch, or near-arch pathology [2]. TEVAR has rapidly gained popularity, but there is ongoing debate surrounding its safety and efficacy. Whilst a wealth of data have suggested that TEVAR is superior to open repair
with respect to early mortality and major complications, including spinal cord ischaemia, postoperative bleeding, and renal impairment, no randomised controlled trials that compare TEVAR with open repair have been performed to date [3]. In addition, a long-term survival benefit of TEVAR is yet to be demonstrated [4,5]. Little has been reported on the Australian experience with TEVAR. We aimed to present 13 years of experience with TEVAR at the Royal North Shore Hospital (RNSH).
Materials and Methods Ethics approval of this study was obtained from the RNSH ethics committee.
*Corresponding author at: Department of Cardiothoracic Surgery, Royal North Shore Hospital, Reserve Rd, St Leonard, NSW 2065. Tel.: +0412212807, Email: [email protected] Crown Copyright © 2015 Published by Elsevier Inc on behalf of Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). All rights reserved.
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Data were sourced from private and public hospital medical records, medical imaging reports, and correspondence from general practitioners and other specialists. The most recent patient status with respect to quality of life was ascertained by liaising with general practitioners. Where relevant, the date of death was sourced from the Ryerson index [6]. Between September 2000 and October 2013, 81 endovascular procedures were performed in 72 patients for various disorders of the thoracic aorta at RNSH public and private hospitals. Nine repeat endovascular procedures were performed for postoperative endoleak. Three ascending aortic replacements for type A aortic dissections were performed prior to TEVAR. The endoluminal approach alone was used for 48 primary procedures. In 24 cases, the procedures were performed in a hybrid manner. In 14 of the 24 cases, debranching and stenting were performed as part of the same procedure, whereas in 10 cases, these were performed as separate procedures. The series consisted of 49 men and 23 women, with a mean age at operation of 70 years (range, 17–89 years). The indications for operation included 37 atherosclerotic aneurysms (26 elective and 11 emergency presentations); nine traumatic disruptions of the thoracic aorta; six penetrating aortic ulcers; five false aneurysms, one of which was mycotic; five chronic type B dissections with either persistent pain or ongoing expansion of the false lumen; three acute type B dissections with significant pseudocoarctation; three chronic sequelae of previously treated type A dissections; one acute type A dissection in a 92-year-old woman; one coarctation of the aorta; and one case of an infected sinus related to a previous open ascending aorta repair.
Results Thirty-one patients presented with chest or thoracic back pain, and an additional nine with post-traumatic chest pain. Twenty-four cases were detected incidentally. Two cases presented with acute haemoptysis; two, with a new cerebrovascular accident in conjunction with chest pain; and two, with syncope and chest pain. Two presentations were attributable to aneurysmal compression of surrounding structures: one case presented with shortness of breath due to bronchial compression; and the other with dysphonia related to compression of the recurrent laryngeal nerve. One patient presented with poorly controlled hypertension and was found to have a juxtaductal coarctation of the aorta. Four patients were haemodynamically unstable at presentation. For the purposes of this study, the ascending aorta was defined as extending from the aortic root to the origin right brachiocephalic artery; the aortic arch, as extending from the right brachiocephalic artery to the attachment of the ligamentum arteriosum; and the descending aorta as the segment of the aorta distal to this. Disease was most commonly localised to the proximal descending aorta (32 cases) and aortic arch (15 cases). In 11 cases disease spanned the thoracoabdominal aorta (Crawford classification: three, type 1; one, type 2; three, type 3; none, type 4; four, type 5) [19]. In
D. Bell et al.
eight cases, the disease was localised to the distal descending thoracic aorta; and in six cases, the disease was confined to the mid descending thoracic aorta. The mean aneurysm size at operation was 63 mm (21 [saccular] to 90 mm). The mean patient follow-up duration was 62 months (range, 2–140 months). One-month, one-year, and five-year survival rates were 93%, 88%, and 63% respectively. The following stent grafts were used: Valiant/Talent (37 cases), Zenith (17 cases), Gore (13 cases), Talent (eight cases), Cook (three cases), Relay (two cases), Aneurx (one case), and Palmaz (one case). Stent size varied in diameter from 26 to 42 mm. The median stent width was 34 mm. Smaller widths were predominantly utilised in the distal thoracic aorta, and larger widths, in the proximal descending thoracic aorta. Relevant patient comorbidities included hypertension (40 cases), chronic kidney disease defined by an estimated glomerular filtration rate < 60 mL/min (15 cases), ischaemic heart disease (14 cases), chronic obstructive pulmonary disease (10 cases), obesity (seven cases), and diabetes (six cases). A preoperative spinal drain was inserted in 23 patients for spinal cord protection. The decision to insert a drain was based on the risk of spinal cord ischaemia predicted by the extent of aortic coverage required, a history of previous abdominal aortic aneurysm (AAA) repair, and whether or not the left subclavian artery (LSCA) was to be covered. One patient required urgent conversion to an open procedure for a complication related to vascular access. The patient recovered well and later underwent an uncomplicated TEVAR.
Thirty-Day Mortality Five mortalities occurred within 30 days of operation, three of which were related to vascular complications. Early death occurred in three patients who underwent elective operation and in two patients who presented as emergencies. A 73-year-old woman died after an extensive bowel infarction secondary to hypoperfusion after a hybrid repair of a thoracoabdominal aneurysm. An 80-year-old woman died of ischaemic bowel related to hypoperfusion following hybrid repair of a large type 1b endoleak. A 79-year-old man died from pneumonia after a TEVAR eroded into his oesophagus. Another two patients died of extravascular complications. A 21-year-old man presented with a traumatic aortic tear after a motor vehicle accident. A TEVAR was performed with successful exclusion of the defect, but the patient died one week later due to head injuries. An 80-year-old man with multiple comorbidities presented with a large thoracoabdominal aneurysm at risk of imminent rupture. He was unsuitable for an open procedure because of respiratory disease. An endoluminal repair with a custom-made fenestrated graft was performed. The patient could not be extubated and died from type 2 respiratory failure secondary to pneumonia.
Endoleak Table 1 summarises 12 episodes of postoperative endoleak. Two type 2 endoleaks were small enough to be managed conservatively and closed without intervention after
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Long Term Outcomes of TEVAR
Table 1 Postoperative endoleak. Pathology
Location
Endoleak
Management
Outcome
Saccular aneurysm Aneurysm
Distal arch Distal arch-descending
Type 2 via LSCA Type 1b
Embolisation of LSCA Thoracotomy and banding
No further endoleak Persistent endoleak,
of the proximal end of the stent
not suitable for further
aorta
intervention Aneurysm
Descending aorta
Type 1b
Abdominal aortic debranching,
Died, ischaemic gut
extension TEVAR/EVAR Descending aorta
Type 2 via LSCA
Debranching and graft extension
No further endoleak
False aneurysm
Proximal descending aorta
Type 1b
Formal open repair
No further endoleak
Traumatic disruption
Proximal
Type 1b
Open repair under DHCA
No further endoleak
Type 2 via LSCA
Embolisation LSCA
No further endoleak
Aortic arch debranching,
No further endoleak
Chronic type B dissection
descending aorta Aneurysm
Proximal descending aorta
Type A dissection, previous Bentall’s
Aortic arch- distal
Type 1a
descending aorta
Previous arch repair complicated by
TEVAR, Amplatz plug to LSCA Type 2 via LSCA
Managed conservatively
No further endoleak
Type 2 via LSCA
Embolisation LSCA
No further endoleak
Type 2 via LSCA
Managed conservatively
No further endoleak
infected sinus Diverticulum of Kommerell Aneurysm
Proximal descending aorta Proximal descending aorta
TEVAR- thoracic endovascular aortic repair, EVAR- endovascular aortic repair, LSCA- left subclavian artery, DHCA- deep hypothermic circulatory arrest.
12 months. Four type 2 endoleaks persisted for longer than 12 months and required further intervention. In three of these cases, the LSCA was successfully embolised. In the other case, the aortic arch was debranched and the previously placed TEVAR was extended. Six type 1 endoleaks developed postoperatively. Two of these cases developed after treatment of thoracoabdominal aneurysms with poorly defined end points. All type 1 endoleaks required further intervention with either arch debranching and stent extension or formal open repair (one case). As mentioned earlier, one patient died from ischaemic bowel after the treatment of a type 1b endoleak. In addition, one case of type 1b endoleak was unsuccessfully treated because of a diffusely enlarged aorta with poor proximal and distal aortic end points. An anterior thoracotomy and banding of the proximal endoleak was performed. Some initial improvement was observed, but soon after, a distal endoleak developed. The patient died two years later from respiratory disease.
Coverage of the LSCA The LSCA was covered in 25 cases. In 16 cases, the LSCA was debranched and reperfused via a bypass graft. The LSCA was not revascularised in nine cases. Complications related to the coverage of the LSCA without revascularisation included two episodes of subclavian steal
syndrome, both requiring left common carotid artery (LCCA)-to-LSCA bypass, and one episode of left arm claudication that required a LCCA-to-left axillary artery bypass.
Additional Vascular Complications There was one case of graft dislodgement and aortooesophageal fistula formation in a 36-year-old man with high cervical quadriplegia. He had previously undergone a TEVAR for a traumatic aortic disruption after a motor vehicle accident. Two years postoperatively, he presented with an episode of massive, terminal haemoptysis but opted for no further intervention. There was one case of graft related dissection. A 77-yearold woman with a previous TEVAR presented post fall with back pain and was found to have a dissection at the distal end of the graft. This was managed conservatively. The patient died six years later from unknown causes.
Other Postoperative Complications Two patients returned to theatre for postoperative bleeding after hybrid procedures. One patient required an emergency laminectomy and evacuation of a spinal subdural haematoma related to the placement of a spinal drain. Three patients had perioperative strokes. Two of the patients achieved complete neurological recoveries, whereas one patient had mild ongoing right leg weakness.
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Table 2 Postoperative complications. Complication
Number (%)
Endoleak requiring reintervention Other graft related complications
10 (12.5%) 2 (2.5%)
(dissection, dislodgement) Pneumonia
6 (7.4%)
Acute kidney injury
6 (7.4%)
30 day mortality (all cause)
5 (6.2%)
30 day mortality (vascular cause)
3 (3.7%)
Bleeding
2 (2.5%)
Stroke (neurological recovery) Stroke (permanent neurological deficit)
2 (2.5%) 1 (1.2%)
Spinal cord ischaemia
1 (1.2%)
Myocardial infarction
1 (1.2%)
One patient had spinal cord ischaemia that manifested as Brown-Sequard syndrome. This occurred after a LCCALSCA bypass and TEVAR in a patient with a right-sided aortic arch and Kommerell’s diverticulum. A spinal drain was inserted after evidence of spinal cord ischaemia. The patient recovered well with minimal left leg weakness and only minor persistent sensory change in the right leg. Six patients had postoperative acute kidney injury, defined by a percentage increase in serum creatinine of more than 50% or the need for renal replacement therapy [9]. Only one patient required temporary postoperative haemofiltration. All of the patients experienced significant renal recovery to within 30 mmol/L of their preoperative serum creatinine. All postoperative complications are summarised in Table 2.
Discussion Whilst many retrospective reviews of thoracic aortic stenting have been reported from large American centres [3], little has been reported of the Australian experience with TEVAR in smaller, non-centralised centres. The 30-day mortality rate for patients in this study was 7% (13% for emergency presentations and 4% for elective procedures). This is similar to rates of perioperative survival reported in large North American-based survival studies [4]. The only two elective postoperative mortalities occurred after the management of thoracoabdominal pathology with hybrid procedures, which are recognised as having a higher complication rate compared with isolated thoracic aortic stenting [20]. The rate of stroke in this series was 4.2%, with only one patient having a permanent neurological deficit. These results compare favourably with published rates of stroke post open and endovascular thoracic aortic repair [3,10,11]. All three episodes of stroke in this study occurred in patients with pathology involving the distal aortic arch or proximal
descending thoracic aorta. This is consistent with previous studies that demonstrated that the most notable risk factor for stroke associated with TEVAR is arch involvement [10]. Rates of spinal cord complications in this series compared favourably with those reported from large international centres. Whilst only one episode of spinal cord ischaemia occurred in this series, a meta-analysis showed that the incidence of paraplegia post TEVAR was over 3% [3]. Rates of endoleak post-TEVAR requiring intervention vary widely in the literature but are usually reported to be between 10% and 20% [12,13]. The 12.5% rate of reintervention required for postoperative endoleak in this series compares well with those in previous series. As demonstrated, pathology involving the thoracic aorta often occurs in the proximity of aortic arch branches, particularly in the region of the LSCA. Successful and stable treatment with TEVAR necessitates adequate proximal and distal graft landing zones, ideally requiring at least 2 cm of normal aortic wall [14,15]. In instances where aortic arch branches are involved the involved branches may be covered, treated with a branched endograft or debranched, and revascularised. In the case of the LSCA, the most commonly performed procedures include either transposition of the LSCA to the LCCA or a bypass from the LCCA to the LSCA. Whilst symptoms are only reported in 20% of cases, coverage of the LSCA without debranching and revascularisation poses many potential problems, including vertebrobasilar ischaemia, left arm claudication, type 2 endoleak, and spinal cord injury [16]. This series consisted of 25 cases of LSCA coverage. In all but nine cases, the LSCA was revascularised. No major complications related to coverage of the LSCA were encountered, including stroke or spinal cord ischaemia. However, two cases of vertebrobasilar ischaemia, one case of left arm claudication, and four cases of type two endoleak were noted. Prophylactic aortic arch debranching has potential drawbacks. However, results in this series demonstrate that it may be performed with relatively few complications, with no operative deaths or strokes and only one return to theatre for postoperative bleeding in 16 cases. There are absolute contraindications to coverage of the LSCA without revascularisation. These include patients with in situ left internal mammary artery grafts and a hypoplastic right vertebral artery [17]. In addition, it is advisable to revascularise the LSCA in cases where the descending aorta will be covered below T6 and where there is a history of previous AAA repair due to the increased risk of spinal cord ischaemia. Our current recommendation based on our results is for prophylactic debranching prior to TEVAR where possible. Preoperative imaging, particularly of the right vertebral artery, is an important step in planning these procedures, although we have not routinely screened for the artery of Adamkiewicz. The only reason to cover the LSCA without revascularisation may be in an emergency situation or where the patient may be deemed unfit for an extended open surgical procedure [18].
Long Term Outcomes of TEVAR
Conclusion We demonstrated low rates of reintervention post thoracic aortic stenting, good long-term outcomes, and a low risk of complications, particularly neurological. We therefore advocate an endovascular approach for thoracic pathology involving the aortic arch and descending aorta where possible, based on low morbidity and mortality and, to a large extent, on improved and faster functional recovery, particularly in elderly patients. In addition, we demonstrated that thoracic aortic stenting can be performed in smaller, non-centralised centres, with comparable rates of procedure-related mortality and morbidity with those in larger centres. Coverage of the LSCA is often necessary, but where possible, prophylactic revascularisation should be performed.
Acknowledgements No grants, financial support, or technical assistance was required for this project.
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