University of Groningen
Advances in complex endovascular aortic surgery
Dijkstra, Martijn Leander
IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite from
it. Please check the document version below.
Document Version
Publisher's PDF, also known as Version of record
Publication date:
2018
Link to publication in University of Groningen/UMCG research database
Citation for published version (APA):
Dijkstra, M. L. (2018). Advances in complex endovascular aortic surgery. University of Groningen.
Copyright
Other than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).
Take-down policy
If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum.
chapter 9
Summary & future perspectives
151
9
The endovascular treatment of aortic pathology is rapidly advancing and now allows for the treatment of majority of both aneurysmal and occlusive disease1–4
and has become the preferred treatment method for the majority of these patients.5 This thesis focused on the advances in complex endovascular aortic
surgery, including advanced imaging, novel devices and techniques, improve-ments in peri-operative care and management of complications.
One of the major concerns with EVAR is durability. There is a relatively high need for re-intervention and long term complications do occur.6
In chapter two the use of peri-operative cone-beam CT (CBCT) was evaluated. CBCT was found to accurately detect endoleaks peri-operatively when compared to post-operative multi-slice CT (MDCT). Also, the use of a peri-operative roadmap using fusion technology resulted in significantly lower contrast dosage and a trend toward lower fluoroscopy and operative times.7 The routine use of CBCT could therefore
potentially result in reduces re-intervention rates and undoubtedly has value, especially in more complex endovascular aortic surgery. Given the costs, using CBCT for standard endovascular procedures might not be cost beneficial. Fenestrated endografts allow for the treatment of the majority of complex aortic juxta- and supra-renal aneurysms. The majority of the accumulated experience has been with the Zenith fenestrated endograft (Cook Medical Australia, Brisbane, Queensland, Australia).8 The results with this endograft are good,
however there are some drawbacks in terms of anatomical constrains. Also, the lack of alternative endografts is not optimal given the lack of competition. In chapters three and four the results and possible advantages of a recently introduced Fenestrated Anaconda endograft (Vascutek, Renfrewshire, Scotland) were explored.9, 10 High technical success and low re-intervention, morbidity and
mortality rates attributed to good short- and mid-term results. Early Type IA endoleak is of concern and occurred relatively frequent, although all resolved spontaneously. It was hypothesized this is due to increased embedding in time which occurs as the stent material temperature increases to body temperature following deployment. Given the relatively small number of patients (n = 60), the results should be interpreted with caution and larger studies are needed to confirm the ‘benign’ aspect of these type IA endoleaks. In general, having multiple options for the treatment of more complex aneurysms is beneficial. For instance, the anatomic constraints of the fenestrated anaconda are a more favorable compared to the Zenith endograft (due to more flexibility in terms of fenestration placement). Ultimately the patient will benefit most if the treating physician can select the best endograft to match the patients’ anatomy from a number of commercially available grafts. Future research is now largely focused on so called ‘of-the-shelf’ fenestrated devices, which deal with the problems of
152
Chapter 9
manufacturing time (6–8 weeks on average) and prohibit FEVAR in acute cases. Until such devices become commercially available and comparable results are achieved, the endograft manufacturers should keep refining current endografts in the pursuit of the developing of the optimal endograft. Another promising alternative is the use of ChEVAR. This technique can be technically challenging, but shows promising short- and mid-term results.11 The only commercially
avail-able endograft currently registered for use with chimney grafts is the Endurant II (Medtronic Vascular, Santa Rosa, CA, USA). Meanwhile, the fenestrated anaconda is a valuable and viable alternative for the treatment of patients with juxta- and supra-renal aortic aneurysms.
The combined use of the Nellix device (Endologix, Irvine, CA, USA) with chimney grafts (Chimney-Nellix) to preserve flow to major visceral branches is another pos-sible solution for acute patients. The technical feasibility of this novel technique was explored in chapter five.12 Two patients were treated using this technique
with technical success of 100 %. One case was complicated by a retro-peritoneal bleed from a right lower pole renal artery which was not visible on completion angiography. Given the 100 % technical success rate the technique is deemed feasible and might offer an alternative to open surgery for patients presenting with an acute juxta-renal aneurysms. There is a possible role for this technique in non-acute patients that are deemed unfit for open surgery, although FEVAR has been proven safe and remains the preferred option. It is to be seen whether ‘bail-out’ options such as Chimney-Nellix will remain if ‘off-the-shelf’ devices are introduced.
In chapter six known endovascular techniques used routinely for aneurysmal disease were adapted for the treatment of aorto-iliac occlusive disease (AIOD).13
In more severe AIOD (TASC C and D) there has been a shift to a more endovas-cular approach.14
The preservation of major visceral branches may limit the use of endovascular techniques. Adding chimney grafts during covered endovascu-lar repair of the aortic bifurcation (CERAB) could solve this. Fourteen patients with either disabling claudication or critical limb ischemiae due to AIOD were treated using Chimney-CERAB. In total, 15 chimney grafts were used (inferior mesenteric artery (n = 8), the right renal artery (n = 4), and the left renal artery (n = 3). Technical success was achieved in all cases. During follow up (mean 12 months, rage 6–24) one CERAB limb and one chimney graft occluded. Based on these finding Chimney-CERAB is deemed a feasible alternative to open surgery in patients with severe AIOD (TASC C and D). Future research should focus on a larger number of patients and longer term patency. For the superior mesenteric, as well as both renal arteries, preservation of flow is usually vital. For the inferior
Summary & future perspectives
153
9
mesenteric artery there are no clear indications which patients benefit from flow preservation and there are currently no guidelines available.
With extending endovascular options, a growing number of patients that would have not been treated by open surgery are being offered treatment. As a consequence, more and more patients with extensive co-morbid conditions undergo EVAR. In chapter seven the outcomes and survival of patients with extensive co-morbid conditions were evaluated.15 A total of 1263 patients were
included. The SVS/AAVS classification is a useful tool for predicting survival after EVAR, in contrast to the ASA classification. Overall, the 30-day all-cause mortal-ity rates were low, the highest being 1.9 % in the SVS/AAVS III group. As to be expected, 1-year all-cause mortality significantly increased with the SVS/AAVS score to 11.3 % in the SVS/AAVS 3 group. This is in contrast to early reports showing much higher peri-operative mortality rates.16, 17 Notably, these were
randomized controlled trials. Nevertheless it was concluded that endovascular aneurysm repair has evolved and good peri-operative results can be achieved even in high-risk patients. When treating patients with extensive co-morbid conditions the benefits should always be weighted to the expected gains. For instance, if a patients with extensive co-morbid conditions presents with an aneurysm < 6.0 cm and the annual risk of rupture is deemed less than 10 %. In this case a conservative strategy might still be warranted given the all-cause mortality rate of 11.3 at 1-year, even if a 2.0 % 30-day mortality rate can be achieved in this cohort. Given the widespread use of EVAR the chances of a future randomized controlled trial to give more insight are slim. Therefore, future prospective registries should ideally include all patients, both treated and man-aged conservatively.
Beside the more frequent complications, one of the most dreaded complications during endovascular aortic repair is spinal cord ischemia (SCI). SCI after EVAR is rare,18 but this increasingly becomes a problem in more complex thoracic and
thoraco-abdominal repairs where a larger portion of the aorta is covered.19 This
has been the scope of extensive research, but to date no definitive preventive strategy has been established. Chapter eight reviews the current literature on SCI preventive measures.20 In total 43 studies (including 7168 patients) were
included in the final analysis. Transient SCI occurred in 5.7 % (450/7168, 95 % CI 4.5–6.9 %, range 0.3–30.6 %), and permanent SCI in 2.2 % (232/7168, 95 % CI 1.6–2.8 %, range 0.3–20.8 %). A trend is observed towards a higher SCI incidence in ‘high risk’ patients. In regard to the preventive measures, interest-ingly, the different spinal fluid drainage protocols did not significantly reduce SCI incidence. Of the remaining preventive measures, the avoidance of peri-operative hypotension and mild hypotension resulted in lower permanent SCI
154
Chapter 9
rates (1.8 % and 0.4 %, respectively). Counter-intuitively, the use of permissive endoleak resulted in quite high SCI rates (transient SCI estimate (15.4 %) and a permanent SCI estimate of 4.8 %), possibly due to selection bias (high risk patients). The remaining preventive measures did not have a significant impact on the occurrence of either transient or permanent SCI. Therefore, low overall transient SCI rates are achieved during endovascular thoraco-abdominal aortic repair. In high risk cohorts however, permanent SCI rates up to 21 % are being reported. Current SCI protocols vary widely. Based on the available data, the use selective spinal fluid drainage, avoidance of hypotension and mild hypothermia are advocated. There is no evidence for the use of any of the other proposed pre-ventive measures. There are some new developments in the prevention of SCI. For instance, sequential embolization of intercostal arteries is being performed ahead of endograft placement. This would pre-condition and protect the my-elum for ischemia-reperfusion injury and would allow for collateral vasculature to adapt. No data has been reported and this is purely hypothetical. Given the low incidence of SCI and very large number of variables a future prospective international multi-center database should be instated to accumulate quality data and work towards an optimal treatment strategy.
In conclusion, due to improvements in imaging, devices, endovascular tech-niques, peri-operative care and management of complications, vascular surgery is moving towards a solely endovascular approach. This holds true for almost all vascular pathology, including venous (although not discussed in this thesis), occlusive and aneurysmal disease, with increasing complexity. Device advances in conformability, flexibility, lower profile and fewer anatomical restraints will further expand the applicability of the endovascular techniques. Since, the only way is usually up, the first attempts of a total endovascular repair of the (very anatomically complex) aortic arch have been made.21 This could in term result in
more extensive aortic coverage, for which more insight in the exact mechanisms of collateral flow is needed. This in term will lead to the optimal preventive and revascularization strategies, as well as peri-operative anesthetic management needed to minimize complication and morbidity risks. In order to do so, an inter-national multi-center prospective registry should be instated. However, for the foreseeable future, given the limitations of the currently available endovascular techniques and devices, there will be a (small) subgroup of patients that will still need open surgical treatment. This subgroup will become smaller in the upcoming decades. One of the future challenges for these, usually complex, patients will be getting a surgeon skilled in open surgery, as these will become harder to find.
Summary & future perspectives
155
9
references
1. Norgren L, Hiatt WR, Dormandy JA, Nehler MR, Harris KA, Fowkes FG, et al. Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II). J Vasc Surg. 2007; 45 Suppl S: S5-67.
2. Chaikof EL, Brewster DC, Dalman RL, Makaroun MS, Illig KA, Sicard GA, et al. The care of patients with an abdominal aortic aneurysm: the Society for Vascular Surgery practice guidelines. J Vasc Surg. 2009; 50(4 Suppl): S2-49.
3. Moll FL, Powell JT, Fraedrich G, Verzini F, Haulon S, Waltham M, et al. Management of abdominal aortic aneurysms clinical practice guidelines of the European society for vascular surgery. Eur J Vasc Endovasc Surg. 2011; 41 Suppl 1: S1-S58.
4. Erbel R, Aboyans V, Boileau C, Bossone E, Bartolomeo RD, Eggebrecht H, et al. 2014 ESC Guidelines on the diagnosis and treatment of aortic diseases: Document covering acute and chronic aortic diseases of the thoracic and abdominal aorta of the adult. The Task Force for the Diagnosis and Treatment of Aortic Diseases of the European Society of Cardiology (ESC). Eur Heart J. 2014; 35(41): 2873-926. 5. Schwarze ML, Shen Y, Hemmerich J, Dale W. Age-related trends in utilization and
outcome of open and endovascular repair for abdominal aortic aneurysm in the United States, 2001-2006. J Vasc Surg. 2009; 50(4): 722-9 e2.
6. Nordon IM, Karthikesalingam A, Hinchliffe RJ, Holt PJ, Loftus IM, Thompson MM. Secondary interventions following endovascular aneurysm repair (EVAR) and the enduring value of graft surveillance. Eur J Vasc Endovasc Surg. 2010; 39(5): 547-54. 7. Dijkstra ML, Eagleton MJ, Greenberg RK, Mastracci T, Hernandez A. Intraoperative
C-arm cone-beam computed tomography in fenestrated/branched aortic endo-grafting. J Vasc Surg. 2011; 53(3): 583-90.
8. de Niet A, Reijnen MM, Tielliu IF, Lardenoije JW, Zeebregts CJ. Fenestrated En-dografts for Complex Abdominal Aortic Aneurysm Repair. Surgical technology international. 2016; XXIX: 220-30.
9. Dijkstra ML, Tielliu IF, Meerwaldt R, Pierie M, van Brussel J, Schurink GW, et al. Dutch experience with the fenestrated Anaconda endograft for short-neck infra-renal and juxtainfra-renal abdominal aortic aneurysm repair. J Vasc Surg. 2014; 60(2): 301-7.
10. Blankensteijn LL, Dijkstra ML, Tielliu IF, Reijnen MM, Zeebregts CJ, Dutch Fenestrated Anaconda Research G. Midterm results of the fenestrated Anaconda endograft for short-neck infrarenal and juxtarenal abdominal aortic aneurysm repair. J Vasc Surg. 2017; 65(2): 303-10.
11. Lindblad B, Bin Jabr A, Holst J, Malina M. Chimney Grafts in Aortic Stent Grafting: Hazardous or Useful Technique? Systematic Review of Current Data. Eur J Vasc Endovasc Surg. 2015; 50(6): 722-31.
156
Chapter 9
12. Dijkstra ML, Lardenoye JW, van Oostayen JA, Zeebregts CJ, Reijnen MM. Endovas-cular aneurysm sealing for juxtarenal aneurysm using the Nellix device and chimney covered stents. J Endovasc Ther. 2014; 21(4): 541-7.
13. Dijkstra ML, Goverde PC, Holden A, Zeebregts CJ, Reijnen MM. Initial Experience With Covered Endovascular Reconstruction of the Aortic Bifurcation in Conjunction With Chimney Grafts. J Endovasc Ther. 2017; 24(1): 19-24.
14. Pepe RJ, Patel P, Huntress LA, Nassiri N. Endovascular Reconstruction for Chronic Infrarenal Aortoiliac Occlusive Disease. Ann Vasc Surg. 2017.
15. Dijkstra ML, van Sterkenburg SM, Lardenoye JW, Zeebregts CJ, Reijnen MM, In-vestigators E. One-Year Outcomes of Endovascular Aneurysm Repair in High-Risk Patients Using the Endurant Stent-Graft: Comparison of the ASA Classifi cation and SVS/AAVS Medical Comorbidity Grading System for the Prediction of Mortality and Adverse Events. J Endovasc Ther. 2016; 23(4): 574-82.
16. Greenhalgh RM, Brown LC, Powell JT, Thompson SG, Epstein D. Endovascular repair of aortic aneurysm in patients physically ineligible for open repair. N Engl J Med. 2010; 362(20): 1872-80.
17. Prinssen M, Verhoeven EL, Buth J, Cuypers PW, van Sambeek MR, Balm R, et al. A randomized trial comparing conventional and endovascular repair of abdominal aortic aneurysms. N Engl J Med. 2004; 351(16): 1607-18.
18. Freyrie A, Testi G, Gargiulo M, Faggioli G, Mauro R, Stella A. Spinal cord ischemia after endovascular treatment of infrarenal aortic aneurysm. Case report and litera-ture review. J Cardiovasc Surg (Torino). 2011; 52(5): 731-4.
19. Gravereaux EC, Faries PL, Burks JA, Latessa V, Spielvogel D, Hollier LH, et al. Risk of spinal cord ischemia after endograft repair of thoracic aortic aneurysms. J Vasc Surg. 2001; 34(6): 997-1003.
20. Dijkstra ML. Spinal cord ischemia in endovascular thoraco-abdominal aortic repair: review of preventive strategies. Submitted. 2017.
21. Andrasi TB, Grossmann M, Zenker D, Danner BC, Schondube FA. Supra-aortic in-terventions for endovascular exclusion of the entire aortic arch. J Vasc Surg. 2017; 66(1): 281-97 e2.
