European Journal of Vascular & Endovascular Surgery
Volume 33, Issue 6 , Pages 679-683, June 2007

The Amsterdam Acute Aneurysm Trial: Suitability and Application Rate for Endovascular Repair of Ruptured Abdominal Aortic Aneurysms

  • L.L. Hoornweg

      Affiliations

    • Department of Vascular Surgery, Academic Medical Center, Amsterdam, The Netherlands
    • ,
  • W. Wisselink

      Affiliations

    • Department of Vascular Surgery, Vrije Universiteit Medical Center, Amsterdam, The Netherlands
    • ,
  • A. Vahl

      Affiliations

    • Department of Vascular Surgery, Onze Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands
    • ,
  • R. Balm

      Affiliations

    • Department of Vascular Surgery, Academic Medical Center, Amsterdam, The Netherlands
    • Corresponding Author InformationCorresponding author. R. Balm, MD, PhD, Department of Vascular Surgery, G4-107, Academic Medical Center, Meibergdreef 9, 1105, P.O. Box 22700, 1100 DD Amsterdam, The Netherlands.
    • ,
  • On behalf of the Amsterdam Acute Aneurysm Trial Collaborators

Accepted 6 December 2006. published online 06 February 2007.

Article Outline

Purpose

To evaluate anatomical suitability and application rate for endovascular repair of patients with a ruptured abdominal aortic aneurysm (RAAA).

Methods

The Amsterdam Acute Aneurysm trial is a multicenter randomised trial comparing open with endovascular treatment in patients with a RAAA (International Standard Randomized Controlled Trial Number (ISRCTN) 66212637). Between April 2004 and January 2006, all consecutive patients with clinical suspicion of a RAAA at presentation were assessed prospectively. Anatomical suitability for endovascular repair was based on use of an aorto-uni-iliac endovascular graft and assessed in patients with a proven aortic rupture on CT angiography (CTA).

Results

In 128/256 patients, presenting with clinical suspicion of a ruptured aneurysm, RAAA was diagnosed. 105 patients were brought to a trial center and CTA confirmed RAAA in 83 patients. In 38 of 83 patients (45.8%) with positive CTA, the anatomy of the aorta and iliac arteries was considered suitable for endovascular repair. Exclusion from endovascular repair was due to unsuitable infrarenal neck or iliac anatomy (37 and 8 patients respectively). Overall, endovascular treatment was applicable in 38/128 patients (29.7%) with a RAAA in the Amsterdam region and in 38 out of 105 patients (35.5%) admitted to the trial centers.

Conclusion

In this prospective cohort of all patients with a RAAA in the Amsterdam Acute Aneurysm Trial region, the suitability for endovascular repair in patients with a RAAA confirmed on CTA is 45.8%, but the application rate was lower.

Keywords: Ruptured aortic aneurysms, Endovascular repair, Suitability

 

Back to Article Outline

Introduction 

The mortality rate for open surgical repair in patients with a ruptured abdominal aortic aneurysm (RAAA) who reach the hospital alive is approximately 40 to 55%.1, 2, 3, 4, 5 Despite improved peri- and postoperative care, Bown et al.6 report in their meta-analysis a very limited improvement in outcome for open surgical repair during the last 5 decades.

Endovascular repair might improve the outcome of patients with RAAA. Initial reports of endovascular repair for RAAA are promising, although to date no results from completed randomised trails are available.7, 8, 9, 10 A recent report on an aborted randomized trial that compared open and endovascular repair concluded that there was no superiority of one technique over the other. Therefore, it continues to be ethical to randomize patients between the two techniques.11

The option of either open surgical or endovascular repair is only possible in a selected group of patients. The feasibility of endovascular repair for RAAA depends on distinctive anatomical criteria such as size of the infrarenal neck and iliac arteries and haemodynamic stability sufficient to perform pre interventional CT-angiography (CTA).

The purpose of the present study is to evaluate anatomical suitability and application rate for endovascular repair in a prospective cohort of patients with a RAAA.

Back to Article Outline

Methods 

The Amsterdam Acute Aneurysm trial is a multicenter randomized trial comparing open with endovascular treatment in patients with a RAAA (ISRCTN 66212637).12 Collaborating centres and trial centres are listed in the Appendix. Background, design and methods of this trial have been described previously and patient enrolment continues.13

An important aspect of the trial is close cooperation between 10 hospitals in the Amsterdam region and the regional ambulance services, serving 1.3 million inhabitants. Part of this cooperation is installation of an acute aneurysm rotation in which the 3 trial centres alternate on a weekly basis. All patients with clinical suspicion of a RAAA are sent to the trial centre on call. For inclusion into the randomized trial, there must be proof of aneurysm rupture. We defined rupture as an acute haemorrhage from the infrarenal aneurysm outside the true aortic wall with the presence of intraperitoneal and/or retroperitoneal blood at CTA. If patients are considered suitable for either open or endovascular treatment, patients are randomized by computer and patients treated immediately after randomization. The study is performed according the World Medical Association's declaration of Helsinki and the study protocol was approved by the Central Committee on Research on humans in the Netherlands and the ethical committees of all the trial centres involved.

For this study on suitability and application rate for endovascular repair of RAAA, we registered prospectively all consecutive patients in the Amsterdam region between April 2004 and January 2006, with clinical suspicion of a RAAA at presentation in the ambulance or on arrival in the emergency room. All haemodynamically stable patients who could be brought to one of the 3 trial centres and, in which the diagnosis RAAA was not rejected at presentation, underwent immediate CT-scanning for firm diagnosis of RAAA and assessment of anatomical suitability for endovascular repair. In the Amsterdam region all ambulance and hospital protocols are based on controlled hypotension.9 If the low blood pressure in controlled hypotension could not be maintained, patients were declared hemodynamically unstable and brought to the operating theatre for acute open repair.

Immediately after CT scanning was performed an experienced endovascular team, consisting of a vascular surgeon and an interventional radiologist, evaluated suitability for endovascular repair. Anatomical suitability was assessed in all patients with a proven aortic rupture on CTA and based on use of a standard set of aorto-uni-iliac endovascular grafts14 (Talent®, Medtronic, Santa Rosa, CA). The following anatomical guidelines were used: the infrarenal aortic neck cranial to the aneurysm must have a diameter between 20 and 32mm and a length of at least 10mm; at least one iliac artery should be able to accommodate the endovascular graft and have a diameter of 8 to 18mm; the contra-lateral common iliac artery diameter should have a diameter between 8 and 20mm. The vascular surgeon in charge made the ultimate decision on suitability. Emergency endovascular aorto-uni-iliac grafts were available in all trial centres. Application rate was defined as the percentage of all patients with a RAAA that could be treated with an endovascular graft.

Patient characteristics and CTA data were recorded in a database with use of SPSS 11.0 data editor (Microsoft Corporation, USA) and continuous data were expressed in mean±standard deviation.

Back to Article Outline

Results 

During the study period a total of 256 patients with clinical signs of aneurysm rupture presented in the Amsterdam region. These patients mainly were referred by general practitioners (101) and by ambulance staff (79). The diagnosis of RAAA was confirmed in 128 out of a total of 256 patients with clinical signs suggestive of an aneurysm rupture. Twenty-three patients with RAAA could not be brought to one of the trial centres due to haemodynamic instability. Of the 105 patients (mean age 75.1 yrs (range 55–93), 89 male) admitted at the trial centres, 3 patients could not be evaluated for treatment by CTA and rupture was diagnosed by ultrasound: 2 because of severe co morbidities and 1 died in the emergency room. CTA confirmed RAAA in 83 of the remaining 102 patients. In 19 patients no CTA data were available due to hemodynamic instability: RAAA was confirmed at open repair.

Among the 83 patients whose CTA data could be analysed, we found anatomy suitable for endovascular repair of the aorta and iliac arteries in 38 patients (45.8%). Mean age was 72.7 years SD 10.5 and 32 were men. Thirty seven patients were unfit for endovascular repair due to unsuitable infrenal neck and 8 due to iliac anatomy. (Fig. 1)

Overall, endovascular treatment was applicable in 38/128 patients (29.7%) with a RAAA in the Amsterdam region. Considering only the 105 patients with a RAAA admitted at the trial centres, the application rate was 35.5% (38/105).

Back to Article Outline

Discussion 

Implementing endovascular management of patients with a RAAA is a complex process. First there is the logistic challenge of offering an endovascular service 24 hr per day and 7 days per week. This was solved by the introduction of a RAAA rotation in 3 centres. Nevertheless 23 patients could not be transported to the trial centres. Twenty-one patients were hemodynamically unstable and the ambulance staff decided to bring the patients to the nearest hospital. In 2 patients the trial centre on call was busy with another major vascular procedure resulting in unavailability of the vascular surgeon. These 2 patients received open repair at the referring hospitals.

Second patients need pre-operative CTA examination to confirm rupture of the aneurysm and more importantly to assess anatomical suitability. This potentially introduces a delay. Lloyd et al.15 described that 12.5% of the patients who did not undergo repair of their ruptured aneurysm due to severe co-morbidity died within 2 hours after admission. In a recent report Hinchcliffe et al. concluded that the concerns that CT scanning prior to surgery caused detriment to the patients appeared to be misplaced.11 This implies that in most patients who reach the hospital alive anatomical suitability can be assessed by CTA. In all patients with a possible RAAA we applied the principles of hypotensive resuscitation.16 Nevertheless 19 patients (18%) could not undergo CTA because the surgeon decided that the patient was too unstable to justify further delay of surgery. One patient died immediately after admission before CTA.

Peppelenbosch et al.17 concluded that even if moderate and severe hemodynamic instability are defined in advance, different surgeons tend to respond differently to a patient with hypovolemic shock. These variations in haemodynamic thresholds will lead to varying suitability rates among different studies.8, 14

In our study, the suitability rate for patients with RAAA was 45.8%. Reichart et al. reported a potential 42% suitability rate, also using the Talent® aorto-uni-iliac emergency set.18 Peppelenbosch et al. recently published a 49% suitability rate, but patients with a neck length less than 10mm were included in his study.13

The debate on whether to use a bi-furcated or an aorta-uni-iliac stent continues. The choice of an aorto-uni-iliac endovascular graft was made for several reasons. First the technical ease results in a shorter learning curve which makes this technique accessible for a broader range of vascular surgeons. A study reporting on elective endovascular repair showed a significant increase in suitability rate using an aorta-uni-iliac stent because an unilateral iliac access problem did not prevent endovascular repair.19 Second it can be deployed quickly, resulting in a rapid control of the intra-abdominal bleeding. Third only a minimal supply of stent-grafts is needed to treat most patients.

Complications of the femoro-femoral bypass such as thrombosis and infection are often mentioned as a possible disadvantages of the aorta-uni-iliac stent but the literature indicates a similar perioperative morbidity to bifurcated endovascular stentgrafts and acceptable long term patency of femoro-femoral bypasses after aorta-uni-iliac endovascular aneurysm repair.20, 21

In our study, like previous studies,12, 18, 21, 22, 23, 24, 25 most patients deemed unfit for endovascular repair had an unsuitable infrarenal aortic neck (37/45 patients (82%)). In contrast to intact aneurysms, patients with ruptured aneurysms appear to have a larger aneurysm diameter and shorter and narrower proximal necks.26

Finally we want to emphasise that the literature on this subject mostly describes selected patient series.

Back to Article Outline

Conclusion 

In this study, suitability for endovascular repair in patients with a RAAA, confirmed by CTA, was 45.8%, the application rate in all identified RAAA patients in the Amsterdam region was 29.7%, but 35.5% for patients admitted to the specialist trial centres.

Back to Article Outline

Acknowledgement 

The study was supported by the Dutch Heart Foundation.

Back to Article Outline

Appendix. 

Trial collaborators; R. Balm, D.A. Legemate, M.M. Idu, C. Kox, J.A. Reekers, K.P. van Lienden, O.M. van Delden (Academic Medical Center), W. Wisselink, J.A. Rauwerda, F.G. van den Berg (Vrije Universiteit Medical Center), A.C. Vahl, M.J.T. Visser, F.H.W.M van der Heijden, C. de Vries, V.P.M. van der Hulst, A.D. Montauban van Swijndregt (Onze Lieve Vrouwe Gasthuis).

Trial coordinator; L.L. Hoornweg (Academic Medical Center).

Trial centers, Amsterdam, The Netherlands; Academic Medical Center, Vrije Universiteit Medical Center, Onze Lieve Vrouwe Gasthuis.

Safety committee, J.P. Tijssen (clinical epidemiologist of cardio vascular diseases), B.A.J.M. de Mol (cardio thoracic surgeon and safety expert), B.C. Eikelboom (vascular surgeon).

Collaborating centers, The Netherlands; Slotervaartziekenhuis Amsterdam (T.O.M. Nagy), Boven IJ ziekenhuis, Amsterdam (A.M. Wiersema), Sint Lucas Andreas ziekenhuis, Amsterdam (A. Voorwinde), Ziekenhuis Amstelveen (J.A. Lawson), Waterlandziekenhuis, Purmerend (Th.A.A. van der Broek), Zaans Medisch Centrum, Zaandam (R.A. Cohen), Spaarneziekenhuis, Hoofddorp (D. Nio).

This work is being funded by a research grant (grant 2002B197) from the Dutch Heart Foundation, The Hague, the Netherlands.

Scan protocols. 

Academic Medical Center

Siemens® Somatom Sensation 4, Erlangen, Germany

slice thickness 5mm, collimation 10mm, reconstruction increment 2.5mm, pitch 1.5

Contrast protocol: power injection 100ml Visipaque 320, 3ml/s, bolus tracking

Vrije Universiteit Medical Center

Siemens® Somatom Sensation 64, Erlangen, Germany

slice thickness 1.5mm, collimation 6mm, reconstruction increment 1mm, pitch 1.2

Contrast protocol: power injection 100ml Ultravist 300, 5ml/s, bolus tracking

Onze Lieve Vrouwe Gasthuis

Philips® Tomoscan AVE 1, Philips Medical Systems, Eindhoven, The Netherlands

slice thickness 7mm, collimation 7mm, reconstruction increment 5mm, pitch 1.4

Contrast protocol: power injection 100ml Omnipaque 300, 2ml/s, delay 50sec

Back to Article Outline

References 

  1. Akkersdijk GJ, van der GY, van Bockel JH, de Vries AC, Eikelboom BC. Mortality rates associated with operative treatment of infrarenal abdominal aortic aneurysm in The Netherlands. Br J Surg. 1994;81(5):706–709
  2. Dardik A, Burleyson GP, Bowman H, Gordon TA, Williams GM, Webb TH, et al. Surgical repair of ruptured abdominal aortic aneurysms in the state of Maryland: factors influencing outcome among 527 recent cases. J Vasc Surg. 1998;28(3):413–420
  3. Gloviczki P, Pairolero PC, Mucha P, Farnell MB, Hallett JW, Ilstrup DM, et al. Ruptured abdominal aortic aneurysms: repair should not be denied. J Vasc Surg. 1992;15(5):851–857
  4. Marty-Ane CH, Alric P, Picot MC, Picard E, Colson P, Mary H. Ruptured abdominal aortic aneurysm: influence of intraoperative management on surgical outcome. J Vasc Surg. 1995;22(6):780–786
  5. Wen SW, Simunovic M, Williams JI, Johnston KW, Naylor CD. Hospital volume, calendar age, and short term outcomes in patients undergoing repair of abdominal aortic aneurysms: the Ontario experience, 1988–92. J Epidemiol Community Health. 1996;50(2):207–213
  6. Bown MJ, Sutton AJ, Bell PR, Sayers RD. A meta-analysis of 50 years of ruptured abdominal aortic aneurysm repair. Br J Surg. 2002;89(6):714–730
  7. Hinchliffe RJ, Braithwaite BD, Hopkinson BR. The endovascular management of ruptured abdominal aortic aneurysms. Eur J Vasc Endovasc Surg. 2003;25(3):191–201
  8. Lachat ML, Pfammatter T, Witzke HJ, Bettex D, Kunzli A, Wolfensberger U, et al. Endovascular repair with bifurcated stent-grafts under local anaesthesia to improve outcome of ruptured aortoiliac aneurysms. Eur J Vasc Endovasc Surg. 2002;23(6):528–536
  9. Ohki T, Veith FJ. Endovascular grafts and other image-guided catheter-based adjuncts to improve the treatment of ruptured aortoiliac aneurysms. Ann Surg. 2000;232(4):466–479
  10. Yusuf SW, Whitaker SC, Chuter TA, Wenham PW, Hopkinson BR. Emergency endovascular repair of leaking aortic aneurysm. Lancet. 1994;344(8937):1645
  11. Hinchliffe RJ, Bruijstens L, MacSweeney ST, Braithwaite BD. A randomised trial of endovascular and open surgery for ruptured abdominal aortic aneurysm - results of a pilot study and lessons learned for future studies. Eur J Vasc Endovasc Surg. 2006;32(5):506–513
  12. Current controlled trials: acute endovascular treatment to improve outcome of ruptured aortoiliac aneurysms: the AJAX-trial. http://www.controlled-trials.com/ISRCTN66212637/662126372005;
  13. Amsterdam Acute Aneurysm Trial Collaborators. Amsterdam acute aneurysm trial; background design and methods. Vascular. 2006;14(3):1–6
  14. Yilmaz N, Peppelenbosch N, Cuypers PW, Tielbeek AV, Duijm LE, Buth J. Emergency treatment of symptomatic or ruptured abdominal aortic aneurysms: the role of endovascular repair. J Endovasc Ther. 2002;9(4):449–457
  15. Lloyd GM, Bown MJ, Norwood MG, Deb R, Fishwick G, Bell PR, et al. Feasibility of preoperative computer tomography in patients with ruptured abdominal aortic aneurysm: a time-to-death study in patients without operation. J Vasc Surg. 2004;39(4):788–791
  16. Roberts K, Revell M, Youssef H, Bradbury AW, Adam DJ. Hypotensive resuscitation in patients with ruptured abdominal aortic aneurysm. Eur J Vasc Endovasc Surg. 2006;31(4):339–344
  17. Peppelenbosch N, Geelkerken RH, Soong C, Cao P, Steinmetz OK, Teijink JA, et al. Endograft treatment of ruptured abdominal aortic aneurysms using the Talent aortouniiliac system: an international multicenter study. J Vasc Surg. 2006;43(6):1111–1123
  18. Reichart M, Geelkerken RH, Huisman AB, van Det RJ, de Smit P, Volker EP. Ruptured abdominal aortic aneurysm: endovascular repair is feasible in 40% of patients. Eur J Vasc Endovasc Surg. 2003;26(5):479–486
  19. Armon MP, Yusuf SW, Latief K, Whitaker SC, Gregson RH, Wenham PW, et al. Anatomical suitability of abdominal aortic aneurysms for endovascular repair. Br J Surg. 1997;84(2):178–180
  20. Hinchliffe RJ, Alric P, Wenham PW, Hopkinson BR. Durability of femorofemoral bypass grafting after aortouniiliac endovascular aneurysm repair. J Vasc Surg. 2003;38(3):498–503
  21. Yilmaz LP, Abraham CZ, Reilly LM, Gordon RL, Schneider DB, Messina LM, et al. Is cross-femoral bypass grafting a disadvantage of aortomonoiliac endovascular aortic aneurysm repair?. J Vasc Surg. 2003;38(4):753–757
  22. Kapma MR, Verhoeven EL, Tielliu IF, Zeebregts CJ, Prins TR, Van der HB, et al. Endovascular treatment of acute abdominal aortic aneurysm with a bifurcated stentgraft. Eur J Vasc Endovasc Surg. 2005;29(5):510–515
  23. Lee WA, Huber TS, Hirneise CM, Berceli SA, Seeger JM. Eligibility rates of ruptured and symptomatic AAA for endovascular repair. J Endovasc Ther. 2002;9(4):436–442
  24. Verhoeven EL, Prins TR, van den Dungen JJ, Tielliu IF, Hulsebos RG, van Schilfgaarde R. Endovascular repair of acute AAAs under local anesthesia with bifurcated endografts: a feasibility study. J Endovasc Ther. 2002;9(6):729–735
  25. Wilson WR, Fishwick G, Sir Peter RFB, Thompson MM. Suitability of ruptured AAA for endovascular repair. J Endovasc Ther. 2004;11(6):635–640
  26. Hinchliffe RJ, Alric P, Rose D, Owen V, Davidson IR, Armon MP, et al. Comparison of morphologic features of intact and ruptured aneurysms of infrarenal abdominal aorta. J Vasc Surg. 2003;38(1):88–92

PII: S1078-5884(07)00004-4

doi:10.1016/j.ejvs.2006.12.011

European Journal of Vascular & Endovascular Surgery
Volume 33, Issue 6 , Pages 679-683, June 2007

Article Tools

* Image Usage & Resolution