ΔΙΠΛΩΜΑΤΙΚΗ ΕΡΓΑΣΙΑ
ΔΙΠΛΩΜΑΤΙΚΗ ΕΡΓΑΣΙΑ
ΘΕΜΑ: THE USE OF THE TRI-MODULAR, ULTRA LOW PROFILE STENT GRAFT WITH POLYMER-FILLED SEALING RINGS BEYOND CURRENT INDICATIONS FOR ABDOMINAL
AORTA ANEURYSM REPAIR
ΜΕΤΑΠΤYXΙΑΚΟΣ ΦΟΙΤΗΤΗΣ:
Γεώργιος Ιωακείμ Παπαδόπουλος Ειδικευόμενος Αγγειοχειρουργικής Πανεπιστημιακό Νοσοκομείο Ηρακλείου
ΑΘΗΝΑ Ιούνιος, 2016
2 ΕΘΝΙΚΟ ΚΑΙ ΚΑΠΟΔΙΣΤΡΙΑΚΟ
ΠΑΝΕΠΙΣΤΗΜΙΟ ΑΘΗΝΩΝ
ΔΙΑΚΡΑΤΙΚΟ ΜΕΤΑΠΤΥΧΙΑΚΟ ΠΡΟΓΡΑΜΜΑ ΣΠΟΥΔΩΝ
«Ενδαγγειακές Τεχνικές»
ΠΡΑΚΤΙΚΟ ΚΡΙΣΕΩΣ
ΤΗΣ ΣΥΝΕΔΡΙΑΣΗΣ ΤΗΣ ΤΡΙΜΕΛΟΥΣ ΕΞΕΤΑΣΤΙΚΗΣ ΕΠΙΤΡΟΠΗΣ ΓΙΑ ΤΗΝ ΑΞΙΟΛΟΓΗΣΗ ΤΗΣ ΔΙΠΛΩΜΑΤΙΚΗΣ ΕΡΓΑΣΙΑΣ
Του Μεταπτυχιακού Φοιτητή Γεώργιου Ιωακείμ Παπαδόπουλου
Εξεταστική Επιτροπή
Καθηγητής Γεώργιος Γερουλάκος Επιβλέπων
Αν. Καθηγητής Ιωάννης Κακίσης
Αν. Καθηγητής Χρήστος Κλωνάρης
H Tριμελής Εξεταστική Επιτροπή η οποία ορίσθηκε απο την ΓΣΕΣ της Ιατρικής Σχολής του Παν. Αθηνών Συνεδρίαση της ...ης ... 201... για την αξιολόγηση και εξέταση του υποψηφίου κου Γεώργιου Παπαδόπουλου, συνεδρίασε σήμερα ../…/20….
H Eπιτροπή διαπίστωσε ότι η Διπλωματική Εργασία του Κ Γεώργιου Ιωακείμ Παπαδόπουλου με τίτλο 'The use of the tri-modular, ultra low profile stent graft with polymer-filled sealing rings beyond current indications for Abdominal Aorta Aneurysm repair', είναι πρωτότυπη, επιστημονικά και τεχνικά άρτια και η βιβλιογραφική πληροφορία ολοκληρωμένη και εμπεριστατωμένη.
Η εξεταστική επιτροπή αφού έλαβε υπ’ όψιν το περιεχόμενο της εργασίας και τη συμβολή της στην επιστήμη, με ψήφους ... προτείνει την απονομή στον παραπάνω Μεταπτυχιακό Φοιτητή την απονομή του Μεταπτυχιακού Διπλώματος Ειδίκευσης (Μaster's).
Στην ψηφοφορία για την βαθμολογία ο υποψήφιος έλαβε για τον βαθμό «ΑΡΙΣΤΑ»
ψήφους ..., για τον βαθμό «ΛΙΑΝ ΚΑΛΩΣ» ψήφους ..., και για τον βαθμό «ΚΑΛΩΣ» ψήφους ... Κατά συνέπεια, απονέμεται ο βαθμός
«...».
Tα Μέλη της Εξεταστικής Επιτροπής
Καθηγητής Γεώργιος Γερουλάκος Επιβλέπων (Υπογραφή)
Αν. Καθηγητής Ιωάννης Κακίσης (Υπογραφή)
Αν. Καθηγητής Χρήστος Κλωνάρης (Υπογραφή)
3 Dedications
To the teachers, the students and the pioneers
To the mothers, the fathers and the children
4 Thanks
Thanks Professor Thanks Boss Thanks honey Thanks God
5 CONTENTS
Page Introduction
...
7 PART 1 – SHORT REVIEW1. Current knowledge on Endovascular Aneurysm Repair with the tri-modular, ultra low profile stent graft with polymer-filled sealing rings …... 7 1.1 Endovascular aneurysm repair with the Ovation TriVascular Stent Graft System utilizing a
predominantly percutaneous approach under local anaesthesia...7 1.2 Ultra-low profile polymer-filled stent graft for abdominal aortic aneurysm treatment: a two-year follow-up...7 1.3 One-year outcomes from an international study of the Ovation abdominal stent graft
system for endovascular aneurysm repair...7 1.4 Current knowledge on EVAR with the ultra-low profile Ovation abdominal stent-graft system....8 1.5 Graft inflow stenosis induced by the inflatable ring fixation mechanism of the Ovation stent-graft system: hemodynamic and clinical implications...8 1.6 Anaphylactic reaction during implantation of the ovation stent graft in a patient with abdominal aortic aneurysm...8 2. The use of the tri-modular, ultra low profile stent graft with polymer-filled sealing rings and
other endografts in challenging aorto-iliac anatomies...8 2.1 Initial single center experience with the ovation stent graft system in the treatment of abdominal aortic aneurysms: application to challenging iliac access anatomies...9 2.2 Pushing forward the limits of evar: new therapeutic solutions for extremely challenging aaas
using the ovation stent graft...8 2.3 Initial single-site experience with the Ovation abdominal stent-graft system in patients with
challenging aorto-iliac anatomy...8
2.4 Practical points of attention beyond instructions for use with the Zenith fenestrated stent graft....9 2.5 Performance of the Endurant stent graft in patients with abdominal aortic aneurysms independent
of their morphologic suitability for endovascular aneurysm repair based on instruction for use...9 3. The use of the tri-modular, ultra low profile stent graft with polymer-filled sealing rings and other endografts in the treatment of para-anastomotic aneurysms...9 3.1 On-label use of commercially available abdominal endografts for para-anastomotic aneurysms
and pseudoaneurysms after infrarenal abdominal aortic aneurysm repair...9
6
3.2 The durability of endovascular repair of para-anastomotic aneurysms after previous open
aortic reconstruction...10
3.3 Endovascular Repair of Para-anastomotic Aneurysms after Aortic Reconstruction...10
3.4 Endovascular repair of para-anastomotic aortic aneurysms. …...10
3.5 Endovascular repair of proximal para-anastomotic aneurysms after previous open abdominal aneurysm reconstruction...10
3.6 Endovascular repair of para-anastomotic aortoiliac aneurusms...10
3.7 Endovascular treatment of a ruptured para-anastomotic aneurysm of the abdominal aorta...10
3.8 Combined endovascular/surgical management of a ruptured para-anastomotic aneurysm of the left common iliac artery...10
PART 2 – SPECIAL PART Aim...11
Methodology...11
Results...13
Tables...15
Discussion...16
Conclusions...17
ABSTRACT English... 17
Greek... 18
References...19
Appendix...23
Figures...23
7 Introduction
Even though the study of the past is essential to face the present and get prepared for the future, a vascular surgeon, unlike a history researcher, needs not only to preserve his observational objectivity, but also to face his patients needs, based every time on the amenities provided and his experience.
Initial experience with the first generation of the Ovation tri-modular, low profile stent graft with polymer- filled sealing rings has been presented with excellent results emphasizing on the totally percutaneous procedure under local anesthesia on the grounds of the faced shortage of anesthesiologists 1-4, 10-35.
This paper aims to present overall mid-term experience including the second generation Ovation Prime, in which the limbs are attached at the distal end to facilitate easier catheterization of the contralateral limb.
After accumulating experience, the idea to deal with more difficult anatomies and aortic pathologies other than primary aneurysmal disease became reality. There are cases of on- and off- label use that are proved to utilize safe and effective alternative options for patients, who otherwise would have to undergo open or more complex procedures, such as cuffs, chimney and fenestrated stent grafting.
Besides, there has already begun some discussion on narrow and tortuous iliac arteries, short and angulated necks 8,9,36-43 and ways of isolating anastomotic pseudoaneurysms after previous aortoiliac reconstructive surgery 48-67. Such use of few widely used endografts has been reported 44,45,46, but this paper contains some of the first results regarding the Ovation and Ovation Prime endograft.
PART 1 – SHORT REVIEW
In the present review, we discuss the use of the tri-modular, ultra low profile stent graft with polymer-filled sealing rings beyond current indications for Abdominal Aorta Aneurysm repair.
We searched PubMed up to 30 May 2016 using combinations of the following keywords: EVAR, tri- modular, ultra low profile, stent graft with polymer-filled sealing rings, instructions for use, indications, para-anastomotic aneurysm, off-label. Randomized controlled trials, original papers and review articles were included. References of these articles were scrutinized for relevant articles.
1. Current knowledge on Endovascular Aneurysm Repair with the tri-modular, ultra low profile stent graft with polymer-filled sealing rings1-4, 10-35
Herein we focus on the most relevant and interesting references - among some dozens - regarding the on-label use of the endograft studied. Comparative results are shown on Table I.
1.1 Ioannou CV, Kontopodis Ν, El Kehagias, Αl Papaioannou, Al Kafetzakis, G Papadopoulos, D Pantidis, D Tsetis. Endovascular aneurysm repair with the Ovation TriVascular Stent Graft System utilizing a predominantly percutaneous approach under local anesthesia. Br J Radiol.
2015;88(1051):20140735
This paper presents the initial experience from 66 patients treated with excellent results in our department in the University Hospital of Heraklion, Crete, Greece. It actually consists the base of our methodology that encouraged us to expand our series and gave the inspiration for the further study of the endograft' s off-label use.
1.2 Ierardi AM, Tsetis D, Ioannou CV, Lagana D, Floridi C, Pinto A, Piffaretti G, Carrafiello G.
Ultra-low profile polymer-filled stent graft for abdominal aortic aneurysm treatment: a two-year follow-up. Radiol Med. 2015;120: 542-8
One could account the results from this Greek-Italian cooperation as an intermediate step for the present study, since the conclusions confirm the safety on 36 selected cases treated under the same protocol and exploiting the endograft' s limits on approved instructions for use.
1.3Manish Mehta, Francisco Valdes, Thomas Noite, Gregory Mishkel, William Jordan, Bruce Gray, Mark Eskandari, Charles Botti. One-year outcomes from an international study of the Ovation abdominal stent graft system for endovascular aneurysm repair. J Vasc Surg. 2014 Jan 59(1):65- 73
8
Undoubtly this prospective, multicenter, single-arm trial conducted at 36 sites in the United States, Germany and Chile establishes the safety and effectiveness of the Ovation stent graft, as it presents 99.3% success rate and no stent graft migration or type I,III or IV endoleak among 161 patients.
1.4 Moulakakis KG, Dalainas I, Kakisis J, Giannakopoulos TG, Liapis CD. Current knowledge on EVAR with the ultra-low profile Ovation abdominal stent-graft system. J Cardiovasc Surg(Torino). 2012 Aug;53(4):427-32
Looking back in the year 2012, just one year after the FDA's approval for the Ovation endograft, we notice a pioneer report in Greece by the University of Athens.
1.5 Ioannou CV, Kontopodis N, Metaxa E, Papaharilaou Y, Georgakarakos E, Kafetzakis A,
Kehagias E, Tsetis D. Graft inflow stenosis induced by the inflatable ring fixation mechanism of the Ovation stent-graft system: hemodynamic and clinical implications. J Endovasc Ther.
2014;21:829-38
An objective evaluation of an endograft commands further study not only of the advantages, but also of the disadvantages. The observation of a graft stenosis having occasionally been met in our department was studied in the Bioengineering department of the Foundation of Research and Technology in Heraklion, Crete to finally prove no significant clinical consequences. Anyway, it seems the producing Industry was moved to include further instructions regarding balloning of the sealing rings.
1.6 Sfyroeras GS, Moulakakis KG, Antonopoulos CN, Manikis D, Vasdekis SN. Anaphylactic reaction during implantation of the ovation stent graft in a patient with abdominal aortic aneurysm. J Endovasc Ther 2015 Aug; 22(4):620-2
Another against the motion argument should one find in this paper, from the University of Athens again, that also raised concerns to surgeons and producing Industry about precautions on the deployment procedure.
Table I
n Percutaneous access (%)
Local anesthesia
(%)
Technical success
(%)
Open Conversion
(%)
LOS (days)
Endoleak type I
(%)
Endoleak type II
(%)
Ioannou 66 76 66 95 3 3 0 13
Mehta 161 43 34 100 0 1 0 34
Ierardi 36 43 24 100 0 1 0 33.3
2. The use of the tri-modular, ultra low profile stent graft with polymer-filled sealing rings and other endografts in challenging aorto-iliac anatomies 36-43,44,45,46
Even though this chapter challenges more interest for the certain study, it unfortunately contains only a few references one can find in the current literature. Comparative results are shown on Table II.
2.1 Trellopoulos G, Georgakarakos E, Pelekas D, Papachristodoulou A, Kalaitzi A, Asteri T. Initial single center experience with the ovation stent graft system in the treatment of abdominal aortic aneurysms: application to challenging iliac access anatomies. Ann Vasc Surg. 2015
Jul;29(5):913-9
Sirignano P, Menna D, Capoccia L, Mansour W, Speziale F. Not only the proximal neck.
Comment on 'initial single center experience with the ovation stent-graft system in the
treatment of abdominal aortic aneurysms: application to challenging iliac access anatomies.
Ann Vasc Surg 2015 Oct;29(7):1480-2
Here one can follow an interesting debate on the discussion regarding narrow (<7mm) or severely angulated (90°-120°) iliac arteries and the special maneuvers to avoid or deal with limb occlusion.
This study is made on 42 patients that 45% of them presented narrow iliac arteries and half of them had at least one iliac artery angulated.
9
2.2Sirignano P, Capoccia L, Menna D, Mansour W, Speziale F. Pushing forward the limits of evar:
new therapeutic solutions for extremely challenging aaas using the ovation stent graft. J Cardiovasc Surg(Torino). 2015 Feb 6
In 2015 Sirignano's team from Rome publishes a retrospective single center study including 21 patients that underwent EVAR with OVATION stent graft achieving 100% technical success. In
66.7% of the patients the neck length was <10mm, 42.8% had severe tortuosity at least on one iliac access and 71.4 % a non-cylindrical neck was present. At a mean follow up of 9 months, only one patient presented an iliac leg thrombosis.
2.3Irace L, Venosi S, Gattuso R, Laurito A, Pompa V, Pasinati G, Bresadola L. Initial single-site experience with the Ovation abdominal stent-graft system in patients with challenging aortoiliac anatomy. J Cardiovasc Surg (Torino). 2014 Jan 16
One year earlier than Sirignano, Irace's team in Rome again had published a smaller series of 14 patients. Concluding, he takes for promising their results including 1 type I endoleak, 1 type II endoleak and 1 case of iliac axis occlusion, all treated endovascularly with success.
2.4Verhoeven EL, Katsargyris A, Fernandes e Fernandes R, Bracale UM, Houthoofd S, Maleux G.
Practical points of attention beyond instructions for use with the Zenith fenestrated stent graft. J Vasc Surg 2014 Jul, 60(1):246-52
This is an interesting expert's opinion on dealing with short or absent infrarenal necks using in an off-label way the Zenith fenestrated stent graft. Anyway, he admits F-EVAR remains a relatively complex procedure.
2.5 Donas KP, Torsello G, Weiss K, Bisdas T, Eisenack M, Austermann M. Performance of the Endurant stent graft in patients with abdominal aortic aneurysms independent of their morphologic suitability for endovascular aneurysm repair based on instruction for use. J Vasc Surg. 2015 Oct;62(4):848-54
Of course we could not ignore this last but definitely not least paper, which Donas, who is by the way a Greek vascular surgeon, published from St Franziskus Hospital in Munster, Germany, The 712 included patients were consecutive (all comers) and treated independently from their morphologic eligibility for use of the Endurant device based in the instructions for use. In 7 years this team takes as good their results, including 14% overall mortality, 93% overall freedom from reintervention and 0.7 % surgical conversion and explantation of the device.
Table II
n Off-label cases (%) Endoleak type I,II,IV (%)
Endoleak type II (%) Trellopoulos 42 Angulated iliacs 54
narrow iliacs 45
0 11.9
Sirignano 21 Angulated iliacs 42.8 neck <10mm 66.7
0 na
Irace 14 100 7 7
Donnas 517 27 <1 <1
3. The use of the tri-modular, ultra low profile stent graft with polymer-filled sealing rings and other endografts in the treatment of para-anastomotic aneurysms 48-67
Our search on this topic gave more results, but still too heterogenous to compare. Comparative results are shown on Table III.
3.1Y. Tsomba, A.Kahlberg, E.M. Marone, G.Melissano, R.Chiesa. On-label use of commercially available abdominal endografts for para-anastomotic aneurysms and pseudoaneurysms after infrarenal abdominal aortic aneurysm repair. EJVES Dec 2013, 46(6):657-666
10
This one is of the biggest series and more thorough investigations, coming from Milan, Italy.
Through 13 years
58
patients underwent on-label EVAR and were followed-up for 1-144 months thereafter (mean 67 months). 25 aorto-uniiliac and 11 bifurcated implants were performed, single proximal aortic cuffs were used in 10 patients and iliac extension in 12. These writers conclude to low rates of feasibility, 19% for proximal aortic anastomosis, 71% for distal aortic anastomosis and 80% for iliac arteries. Additionally, concern is raised on high rates of late complications (aneurysm related mortality 7%, endograft migration 7% and re-interventions 17%).3.2 Jan A.Ten Bosch, Evert J.Waasdorp, Jean-Paul de Vries, Frans L. Moll, Joep Teijink, Joost van Herwaarden. The durability of endovascular repair of para-anastomotic aneurysms after previous open aortic reconstruction. J Vasc Surg 2011;54:1571-9
This is a 10 year study from 4 centers in The Netherlands including 32 bifurcated stent grafts, 8 tube grafts, 7 aorto-uniiliac stent grafts and 11 iliac extensions. Median follow-up was 41 months (0-106).
Overall re-intervention rate was 26.9% and conversion rate was 6.9%. Procedural related mortality was 10%. Major conclusions are safety and durability in patients with appropriate anatomy, while bifurcated stent grafts show fewer complications than tube grafts.
3.3 James H. Mitchell, MD Kathryn G. Dougherty Neil E. Strickman, MD Ali Mortazavi, MD Zvonimir Krajcer, MD. Endovascular Repair of Paraanastomotic Aneurysms after Aortic Reconstruction. Tex Heart Inst J 2007;34:148-53
During 5 years 8 patients were recorded to have undergone percutaneous exclusion of 10 para-anastomotic aneurysms with 100% technical success. No in-hospital mortality and no endoleak was recorded. They regard that endovascular exclusion is a viable alternative to open surgical repair that greatly reduces most risks.
3.4Ulka Sachdev, Donald Baril, Nicholas Morrissey, Daniel Silverberg, Tikva Jacobs, Alfio Carroccio, Sharif Ellozy, Michael Marin. Endovascular repair of para-anastomotic aortic aneurysms. J Vasc Surg 2007;46:636-41
This team reports 98 % initial technical success after treating 53 patients in 9 years. Overall mortality within a mean follow-up of 18 months was 49%, while they identified 11% endoleaks in <1month of surgery. Closer follow-up is their proposal.
3.5 Wu Z, Xu L, Raithel D, Qu L. Endovascular repair of proximal para-anastomotic aneurysms after previous open abdominal aneurysm reconstruction. Vascular, 2015 Jun 25. pii:
1708538115593194
The most recent publication comes from China and Germany, that presents 24 patients with proximal para-anastomotic aneurysms. These writers found during a median follow-up of 43
months 16.7% endoleaks type Ia and cumulative mortality rate of 12.5%. Significant difference was found in freedom from re-intervention between treatment with tube and unibody bifurcated stent graft.
3.6 Tsang JS, Naughton PA, Wang TT, Keeling AN, Moneley DS, Lee MJ, Kelly CJ, Leahy SL.
Endovascular repair of para-anastomotic aorto-iliac aneurusms. Cardiovasc Intervent Radiol, 2009 Nov, 32(6):1165-70
Dublin, Ireland suggests that endovascular repair is the treatment of choice for
para-anastomotic aneurysms, since they deployed 7 aorto-uniiliac and 4 bifurcated stent grafts among 148 patients that underwent EVAR in 9 years, with 100% technical success and no perioperative mortality.
3.7 Sfyroeras GS, Lioupis C, Bessias N, Maras D, Pomoni M, Andrikopoulos V. Endovascular treatment of a ruptured para-anastomotic aneurysm of the abdominal aorta. Cardiovasc Intervent Radiol 2008 Jul;31suppl 2:79-83
This is a relatively early greek report from Athens about a ruptured PAA treated with a bifurcated stent graft through an end-to-side anastomosed old aortobifemoral graft.
3.8Dimitrios Maras, Theofanis T. Papas, Christos D. Gekas, Chrisovalantis Psathas, Ioannis Kotsikoris, Achilleas Nikolaou, Polyvios Pavlidis and Vassilios Andrikopoulos. Combined endovascular/surgical management of a ruptured para-anastomotic aneurysm of the left common iliac artery. The Open Cardiovascular Medicine Journal, 2009, 3, 143-146
11
Another interesting report from Athens, Greece came up one year later regarding a patient with a rupture in 1 from 3 PAAs, who was treated with an aorto-uniiliac Cook Zenith and a traditional open surgical femoral-femoral bypass.
Table III
n LOS
(days)
Technical success (%)
Type I endoleak
(%)
Type II endoleak
(%)
Perioperative mortality
Open Conversion
Overall mortality
Tsomba 65 2 98 5 1.7 0 17 15
Bosch 58 3 91 5 10 10 6.9 19
Mitchel 8 1.1 100 0 0 0 0 na
Sachdev 53 na 98 7.5 7.5 3.8 5.6 49
Wu 24 6.7 100 16.7 0 0 4.2 12.5
Tsang 11 na 100 na na 0 9 na
PART 2 – SPECIAL PART Aim
This study aims to present and evaluate overall mid-term experience from the use of the Ovation endograft beyond current indications for Abdominal Aorta Aneurysm.
Patients and methods
Study Design – Patient population
We conducted a single-center retrospective study which included all AAA patients treated by endovascular means with the Ovation and Ovation Prime endograft from January 2011 till December 2015.
Indications to treat an AAA were according to current SVS and ESVS guidelines 5-6.
Aneurysm diameters were obtained along the centerline axis to acquire precise measurements 7. Device description
The Ovation endograft has a tri-modular design consisting of the main body and two iliac
limbs. The main body includes a suprarenal nitilol stent with anchors to achieve active fixation to the aortic wall and a low-permeability polytetrafluoroethylene (PTFE) graft which unlike other devices is not supported by a metallic endo-skeleton but contains a network of inflatable channels and sealing rings that are filled during deployment with a low-viscosity, radiopaque fill polymer. The main body is 80mm long and designed as one 50mm long cylinder which splits into two 30mm long legs. Sealing at the proximal infrarenal aortic neck is performed by a unique mechanism of two inflatable O-rings which cure in situ and conform to the patient-specific neck anatomy. The iliac limbs consist of highly flexible nitinol stents encapsulated in low-permeability PTFE.
Due to the unique concept of separation of the endograft’s fabric and metal portions delivery is achieved through ultra-low profile delivery system. Moreover, the original sealing mechanism allows sealing
in infrarenal necks as short as 7mm which makes this device the only that has been approved to treat aneurysms with aortic neck < 10mm.
Procedures / Anesthetic techniques
During initial experience with the Ovation endograft the procedure was conducted under general or 12
regional anesthesia (RGA). All patients were monitored with ECG, pulse oximetry and the left radial artery was cannulated under local anesthesia for invasive measurement of the blood pressure.
General anesthesia was induced with propofol 1mgKg-1, fentanyl 1-2 mcg/kg and cis atracurium to facilitate endotracheal intubation. The patient was intubated and maintenance of anesthesia was achieved with propofol infusion and supplemental doses of fentanyl according to patients’ needs.
For regional anesthesia, the combined spinal /epidural technique was preferred using the two-level approach. The epidural space was first located in the standard manner at the L1-2 level with a 18G Tuohy needle and a 20G catheter was inserted. After a negative test dose for intrathecal or intravenous placement of the epidural catheter ensuring that the epidural catheter was placed properly, a standard spinal was performed at L3-L4 with 10mg of levobupivacaine and 20 mcg fentanyl.
After accumulating experience with this endograft, completion of the procedure under local anesthesia (LA) was found to be feasible and well tolerated by the patients. This practice was finally adapted as routine except in cases with relative contraindications as described by Verhoven et al.
These mainly were:
• Patient’s anxiety or unwillingness to undergo local anesthesia.
• Need for cut-down to prepare femoral arteries.
• Previous groin incision.
• Patient obesity (body mass index > 30 kg/m2).
If LA was not performed, the choice between regional and general was left to the patient’s and anesthesiologist’s preference.
Local anesthesia protocol included preoperative administration of p.o. bromazepam 1.5 – 3mg as well as intravenous non-steroidal drugs (usually Parecoxib 40mg) and 75-100mg of pethidine intramuscularly, administered 30 - 60 minutes before the procedure. Furthermore, anesthetic cream (25 mg lidocaine and 25 mg prilocaine per 1 gr of cream) was also locally applied preoperatively at the femoral puncture sites. LA was achieved using infiltration with lidocaine 1% (maximum safe dose 4 mg/kg) or bupivacaine 0.5% (maximum safe dose 2 mg/kg). Intravenous sedation was not used. Operative monitoring included continuous electrocardiography, pulse oxymetry, and invasive arterial blood pressure measured through a radial intra-arterial line. A urinary catheter was always used.
Procedures / Surgical techniques
Femoral access was generally achieved percutaneously whenever possible (Figure 1). Two Perclose Proglide (Abbott Vascular, Illinois, USA) vascular closure devices were pre-deployed after femoral catheterization of each artery to achieve hemostasis upon completion of the procedure. In cases of excessive femoral artery calcification, presence of intramural thrombus, or previous groin incision, the common femoral artery was dissected and controlled through a short incision parallel to the inguinal ligament just above the inguinal crease. Following femoral access, the main body and the limbs of the endograft were deployed according to the manufacturer’s instructions for use while the inflatable O-rings were filled with the radiopaque polymer to achieve proximal sealing (see: www.trivascular.com/images/files/810-0012-01- 01rD_IFU_PMA_Ovation_Prime.pdf).
After accumulating experience with this stent graft, we have previously reported the need to dilate the graft at the ring site with a compliant balloon to dilate and mold the rings and to avoid any
inflow stenosis caused by possible inward expansion of the rings (Figure 2). We now perform this technique on a routine basis.
Completion angiography was always performed to evaluate good functioning, patency of renal arteries and the absence of endoleaks (Figure 3).
Follow-up protocol
Patients were evaluated during regular follow-up visits, with abdominal X-rays (face/profile) and contrast-enhanced CT scans performed at 1, 6 and 12 months after the intervention (Figure 4). Annual
follow up thereafter was performed using ultrasound scans of the aorta to evaluate sac size and possible intrasac flow.
There was a slice thickness of 1 mm to retrieve required accuracy and all CT scans were reviewed by an interventional radiologist and a vascular surgeon. Migration, endoleaks and AAA dimensions were recorded at that time.
13 Outcomes
For the current analysis 30-day mortality was used as the primary outcome to be evaluated.
Secondary outcome measures regarded
• Pre-operative measures (patients age, sex, comorbidities, anatomic variables of AAAs),
• Peri-operative measures (technical success, percutaneous vs cut-down femoral access, operative time),
• Immediate post-operative information (requirement for intensive care, postoperative systematic and local complications, hospital length of stay).
• Follow-up (clinical success, migration, endoleak, increase in AAA size).
Technical success is determined taking into account the SVS Reporting standards for endovascular aneurysm repair which relate the former with periprocedural events that occur from the initiation of the procedure and extend through the first 24-hour postoperative period. Primary technical success is defined as successful deployment of the device in the intended location in the absence of surgical conversion or mortality, type I or III endoleaks, or graft limb obstruction, while assisted primary and secondary success refer to endovascular and surgical means respectively, used to achieve technical success.
Operative time is reported as anesthesia time plus procedural time. Anesthesia time refers to the time from the beginning of anesthesia administration (either local, regional or general) till the beginning of the operation and procedural time refers to the time from that point upon completion of the procedure.
For short- and mid-term results, clinical success is evaluated which requires the absence of mortality as a result of aneurysm-related treatment, type I or III endoleak, graft infection or thrombosis, aneurysm expansion (diameter > 5 mm, or volume > 5%), aneurysm rupture, or conversion to open repair. Moreover, clinical failure is defined as the presence of graft dilatation of 20% or more by diameter, graft migration, or a failure of device integrity. Clinical success can be claimed for those cases with a type II endoleak only in the absence of aneurysm expansion. Assisted primary clinical success is reported when additional endovascular procedures are needed whereas secondary clinical success for additional surgical procedures are required to preserve clinical outcome.
In the current analysis, above mentioned endpoints are reported for the whole study cohort.
RESULTS
Pre-procedural data
During a 60-months period (01/2011 – 12/2015) 106 patients underwent EVAR with the Ovation Trivascular Stent Graft system in our center. Median follow-up time was 35 (range 5-60) months. Median age of patients was 68 (range 54-88) years. The great majority of subjects treated were male(104 male, 2 female). Among 106 patients, none had an American Society of Anesthesiologists (ASA) score of 1, 43 subjects had a score of 2, 47 patients presented an ASA score of 3 and finally 16 patients had an ASA score of 4.
Median maximum diameter of the AAAs treated was 64 mm (Range 52 mm- 100 mm).
In 17 (16%) cases at least one of the external iliac arteries had a diameter of less than or equal to 6mm making these patients unsuitable to endografts with large caliber delivery systems.
EVAR was performed in 10 (9.4%) patients with off-label indications.
These included a short proximal neck of less than 10mm in 4 (3.8%) cases and extensive proximal neck angulation (>60°) in another 3 (2.8%) cases.
In 3 (30 / 2.8%) patients the indication for EVAR was a para–anastomotic pseudo-aneurysm after previous open abdominal aortic repair.
Anatomic variables of AAAs treated are summarized in Table I.
Peri-procedural data
Median anesthesia time in our series was 14 (Range 4-60) minutes while median procedural time was 90 (Range: 65-280) minutes. In 81 (76.4%) patients a total percutaneous access was achieved while in
25 (23.6%) at least one femoral artery was surgically prepared via cut-down. RGA was administered in 32 (30%) patients while in 74 (70%), procedure was completed under local anesthesia. Technical success (including primary, primary assisted and secondary technical success) was achieved in 103/106 patients (97.2%). In two patients catheterization of the controlateral leg of the aortic main body was not possible due to its collapse and/or twisting. In both patients an additional brachial approach was employed in order to facilitate contralateral limb catheterization which were unsuccesfull. The third patient had too small diameter external iliac arteries (of about 4mm) and extensive angulation which were preoperatively deemed as
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passable but turned out that the passing of the endograft was not feasible. Two of these patients were subjected to conversion to open surgical repair (2/106 patients, 1.8%). In one patient with bilateral common iliac occlusions which were endovascularly recanalized, a complete left graft limb collapse and occlusion due to a very tight distal aortic lumen (12mm diameter) complicated the procedure. This was managed by inserting an ipsilateral reverse “U” internal to external iliac artery stent-graft to insure that a left type Ib endoleak would not occur and essentially the graft was converted into a aorto-uni-iliac graft. Since the patient had an occluded common iliac artery before the procedure, the arterial perfusion of the left lower limb remained unchanged and therefore no additional surgery was required.
Additional endovascular interventions (primary assisted technical success) were required in two cases where a type Ia endoleak was observed upon completion angiography which resolved after balloon angioplasty with a compliant aortic balloon (35mm diameter) at the sealing zone of the inflatable O-rings.
Moreover in one case, thrombosis of the superficial femoral artery (access site) resulted in acute limb ischemia which required immediate surgical exploration and thrombectomy (secondary technical success).
Concomitant brachial access was required in two additional cases to achieve contralateral catheterization which were successful in both instances.
No additional complex procedures such as cuffs, tube, aorto-uniiliac, chimney, periscope or branched grafts were needed regarding the off-label cases. Interestingly, no Type I, III or IV endoleaks were observed in this patient subgroup, whereas, a type II endoleak was observed in 2 (20%) cases.
Post-procedural data and follow-up
Immediate and mid-term aneurysm related mortality rate was 0% whereas 2 (1.9%) patients died 1 and 4 months post-operatively due to non-aneurysm related causes. Unilateral graft limb thrombosis was observed in 3 (2.8%) cases, offering a cumulative graft patency rate of 97.2%. Postoperatively, ICU was necessary for 1 patient receiving regional anesthesia. Median length of stay in the hospital was 2 days (Range 1-16). In total, 15/106 patients (14.1%) presented any kind of morbidity (systemic and/or local complications). There was a 6.6% (7/106) systemic complication rate (2 cardiovascular event, 2 respiratory infection, 2 renal dysfunction and 1 case of DVT and PE) and a 7.5% (8/106) local complication rate (3 pseudoaneurysms, 2 case of wound infection and 3 cases of lymphorrhea). Clinical success was achieved in 103/106 (97.2%) patients. Clinical failure was attributed to the 3 cases where successful endograft
deployment was not achieved and an additional case of a type II endoleak in which sac enlargement was observed but due to comorbidities no further therapeutic actions were taken. In 4 cases, endovascular procedures were undertaken to correct limb stenosis (primary assisted clinical success) whereas 3 patients underwent surgical intervention to maintain good outcome (1 surgical debridement due to wound infection, 1 femoro-femoral bypass due to graft limb occlusion, 1 resection of a femoral artery pseudoaneurysm:
secondary clinical success). Three (2.8%) type-Ia endoleaks were found on the 1st postoperative CT
examination which spontaneously resolved by the 2nd CT scan and no additional procedures were necessary.
In our series no migration and no type III or IV endoleaks were observed. There were 18/106 (17%) type II endoleaks and sac enlargement was observed in one case as already mentioned. Additional endovascular procedures were required in 7 (6.6%) while concomitant open surgery was performed in 4 (3.8%) patients.
Patients’ characteristics as well as peri- and post-procedural data for our study population are summarized in Table II.
No additional complex procedures such as cuffs, tube, aorto-uniiliac, chimney, periscope or branched grafts were needed regarding the off-label cases. Mean follow-up of the off-label cases was 18.1 (range: 6- 32) months. Interestingly, no Type I, III or IV endoleaks were observed in this patient subgroup, whereas, a type II endoleak was observed in 2 (20%) cases.
15 TABLES
Table I: Anatomic variables of AAAs in our study population. Median values and range are reported. L1 represents the distance between the origin of the most caudal renal artery and the aortic bifurcation. L2 and L3 are the distances between the lowest renal artery to the right and left internal iliac artery origin respectively. LCIA and RCIA stand for left and right common iliac artery respectively.
Anatomic Variable Median (Range)
Neck Length (mm) 22 (6-55)
Neck Angle (°)
31 (0-77)Neck Diameter (mm) (Lowest renal artery)
24 (11-29) Neck Diameter (mm)
(Lowest renal artery+13mm)
25 (16-31)
L1 (mm) 111 (80-140)
L2 (mm) 175 (132-240)
L3 (mm) 176 (120-240)
AAA Dmax (mm) 58 (54-85)
RCIA diameter (mm 13 (7-58)
LCIA diameter (mm 13 (10-100)
REIA diameter (mm 6.5 (5.2-11)
LEIA diameter (mm 7.7 (5.5-12.5)
Table I
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Table II: Overall patients’ characteristics as well as peri- and post-procedural data are reported. Additional surgical and endovascular procedures include those that
were performed both immediately after EVAR but also during follow-up.
Conversion to open surgery is recorded separately. ASA: American Society of anesthesiologists, LOS: Length of stay, OSR: Open surgical repair, ICU:
Intensive care unit.
Variable Overall
(n=106)
Age (years) [range] 68 [54-88]
Gender (male : female) 104 - 2
ASA 3,4 63 (59%)
Dmax (mm) [range] 64 [52-100]
Anesthesia time (min) [range] 14 [4-60]
Procedural time (min) [range] 90 [65-280]
Percutaneous access 81 (76%)
Technical success 103 (97%)
Conversion to OSR 3 (2.8%)
ICU 1 (0.9%)
LOS (days) 2 (1-16)
Morbidity 10 (9.4%)
Systemic complications 7 (6.6%)
Local complications 8 (7.5%)
Clinical success 102 (96.2%)
Additional endovascular procedures 9 (8.4%)
Additional surgical procedures 6 (5.6%)
Table II Discussion
Following the tested concept of patiently accumulating experience and with no prejudice adopting new-generation endografts' benefits, we see our wish coming true : mid-term results come to confirm and moreover improve initial results. This is a valid fact regarding not only our single-center study, but also other contemporary single- and multi- center studies, applying for the same and various other endografts as well. Perhaps careful patient selection and detailed planning lead to low morbidity and low endoleaks rates.
Special maneuvers and boulder corrections might also contribute to hold them low.
Simultaneously, another plan luckily finds no overwhelming obstacles to fulfill the continuous
expectation of embracing more difficult anatomies. Comparatively, our results have been shown as better or worse from previous series. Of course, it is not a fair comparison, when a single center presents results from one hundrend elective cases and a referral center presents seven hundrend cases including urgent ones too.
''Pulling and not pushing the technology'', anastomotic aneurysms appear here as a secondary indication for the deployment of the Ovation endograft for the first time, utilizing an idea already tried with widely used endografts leading to various results so far. Apparently long series published by
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high-volume centers advantage on statistic importance, but there have not been reported so positive results with bifurcated stent-grafts, comparatively to other alternative options, like aorto-uniiliac grafts and cuffs.
There are always, of course the alternative options of difficult open redo and laparoscopic procedures, or additional complex procedures, such as chimney, periscope or branched grafting, but with no guaranty of more hopeful results68-69.
Study Limitations
The present findings should be evaluated with the perspective that they have arisen from a
retrospective analysis. Such a design is well known to be susceptible to confounding factors due to the lack of randomization between groups. Moreover, recall bias is a well known factor which may limit reliability of obtained results in a retrospective study.
Conclusion
Midterm results of the Ovation Abdominal endograft demonstrate excellent safety and effectiveness during EVAR, particularly in cases with challenging anatomical characteristics such as short proximal necks, necks with extensive angulation or narrow access vessels. Furthermore, interior lining of a graft after open aortic repair with this aortic endograft in order to isolate a pseudo-aneurysm also seems to be applicable and safe.
We consider the tri- modular, ultra low profile stent graft with polymer -filled sealing rings as a safe and feasible option in aneurysms with short proximal necks <1cm, wide proximal neck angles >60 degrees, highly tortuous and narrow iliac arteries <8mm, or even in para -anastomotic aneurysms after previous open repair.
Funding: None
Abstract
Introduction: Endovascular Aneurysm Repair (EVAR) has evolved over the years and according to the individual patient needs and the surgeon's armamentarium, training, perception and initiative, current indications have been expanded to include more difficult anatomies and aortic pathologies other than
primary aneurysmal disease. The purpose of this study is to present our initial overall experience with the use of the Ovation tri-modular, low profile stent graft with polymer-filled sealing rings in patients with
abdominal aortic aneurysms according to the graft’s “instructions for use” as well as in off-label cases.
Methods: We conducted a single-center retrospective study between 01/2011-12/2015, including patients that underwent EVAR using the Ovation and Ovation Prime tri-modular, ultra low profile endograft with polymer-filled sealing rings. Outcome was evaluated regarding pre-, peri-, immediate post-operative and follow-up measures. Overall results are reported and any off-label use of the graft was documented and further studied.
Results: During the study period, the stent graft was deployed in 106 patients. Regional anesthesia was utilized in 25 (23.6%) patients, while the remaining 81 (76.4%) cases were performed through a totally percutaneous procedure under local anesthesia. Technical success was achieved in 97.2% (103/106) of the patients. Mean follow-up time was 35 (range: 5-60) months. Immediate and mid-term aneurysm related mortality rate was 0% whereas 2 (1.9%) patients died 1 and 4 months post-operatively due to non-aneurysm related causes. Unilateral graft limb thrombosis was observed in 3 (2.8%) cases, offering a cumulative graft
patency rate of 97.2%. Three (2.8%) type-Ia endoleaks were found on the 1st postoperative CT examination which spontaneously resolved by the 2nd CT scan and no additional procedures were necessary. No
endoleak type III, IV or stent migration was observed. There were 18 (17%) type-II endoleaks. Additional endovascular procedures were required in 7 (6.6%) while concomitant open surgery was performed in 4 (3.8%) patients. In 17 (16%) cases at least one of the external iliac arteries had a diameter of less than or equal to 6mm making these patients unsuitable to endografts with large caliber delivery systems. EVAR was performed in 10 (9.4%) patients with off-label indications. These included a short proximal neck of less than 10mm in 4 (3.8%) cases and extensive proximal neck angulation (>60°) in another 3 (2.8%) cases. In 3 (30 / 2.8%) patients the indication for EVAR was a para–anastomotic pseudo-aneurysm after previous open
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abdominal aortic repair. No additional complex procedures such as cuffs, tube, aorto-uniiliac, chimney, periscope or branched grafts were needed. Mean follow-up of these off-label cases was 18.1 (range: 6-32) months. Interestingly, no Type I, III or IV endoleaks were observed in this patient subgroup, whereas, a type II endoleak was observed in 2 (20%) cases.
Conclusion: Midterm results of the Ovation Abdominal endograft demonstrate excellent safety and effectiveness during EVAR, particularly in cases with challenging anatomical characteristics such as short proximal necks, necks with extensive angulation or narrow access vessels. Furthermore, interior lining of a graft after open aortic repair with this aortic endograft in order to isolate a pseudo-aneurysm also seems to be applicable and safe.
Key words: EVAR, tri-modular, ultra low profile, stent graft with polymer-filled sealing rings, instructions for use, indications, para-anastomotic aneurysm, off-label
Περίληψη
Εισαγωγή: H ενδαγγειακή αποκατάσταση των ανευρυσμάτων της κοιλιακής αορτής εξελίσσεται με την πάροδο του χρόνου και σύμφωνα με τις ανάγκες του κάθε ασθενούς και του χειρουργού το οπλοστάσιο, την εκπαίδευση, την αντίληψη και την πρωτοβουλία, οι τρέχουσες ενδείξεις έχουν επεκταθεί για να συμπεριλάβουν πιο δύσκολες ανατομίες και αορτικές παθολογίες από την πρωτοπαθή ανευρυσματική νόσο.
Ο σκοπός αυτής της μελέτης είναι να παρουσιάσουμε τη μεσοπρόθεσμη γενική μας εμπειρία από την χρήση του τρισκελούς χαμηλού προφίλ ενδομοσχεύματος με δακτυλίους σφράγισης πληρούμενους με πολυμερές σε ασθενείς με ανεύρυσμα κοιλιακής αορτής σύμφωνα με τις οδηγίες του κατασκευαστή καθώς και σε περιστατικά εκτός ενδείξεων.
Υλικό & Μέθοδοι: Πραγματοποιήσαμε μια μονοκεντρική αναδρομική μελέτη από τον Ιανουάριο 2011 μέχρι τον Δεκέμβρη 2015, συμπεριλαμβάνοντας ασθενείς που υπεβλήθησαν στο τμήμα μας σε ενδαγγειακή αποκατάσταση ανευρύσματος κοιλιακής αορτής με το τρισκελές χαμηλού προφίλ ενδομόσχευμα με
δακτυλίους σφράγισης πληρούμενους με πολυμερές. Τα αποτελέσματα εκτιμήθηκαν αναφορικά με προ-, περι-, άμεσα και μεσοπρόθεσμα μετε- εγχειρητικές μετρήσεις. Τα γενικά αποτελέσματα αναφέρονται και οι εκτός ενδείξεων χρήσεις του ενδομοσχεύματος καταγράφησαν και μελετήθηκαν περαιτέρω.
Αποτελέσματα: Κατά τη διάρκεια της περιόδου μελέτης, το ενδομόσχευμα τοποθετήθηκε σε 106 ασθενείς.
Περιοχική αναισθησία διενεργήθηκε σε 25 (23.6%) ασθενείς, ενώ οι υπόλοιποι 81 (76.4%)
αντιμετωπίσθηκαν με αποκλειστικά διαδερμική προσπέλαση υπό τοπική αναισθησία. Τεχνική επιτυχία επιτεύχθηκε σε 97.2% (103/106) των ασθενών. Ο μέσος χρόνος παρακολούθησης ήταν 35 (εύρος: 5-60) μήνες. Η άμεση και μεσοπρόθεσμη σχετιζόμενη θνησιμότητα ήταν 0%, ενώ 2 (1.9%) ασθενείς κατέληξαν 1 και 4 μήνες μετεγχειρητικά λόγω μη σχετιζόμενων με το ανεύρυσμα αιτιών. Μονόπλευρη θρόμβωση σκέλους του ενδομοσχεύματος παρατηρήθηκε σε 3 (2.8%) περιπτώσεις, προσδίδοντας ένα ποσοστό αθροιστικής βατότητας μοσχεύματος 97.2%. 3 (2.8%) τύπου Ia ενδοδιαφυγές βρέθηκαν στην 1η
μετεγχειρητική αξονική τομογραφία που εξαφανίστηκαν αυτόματα πριν την 2η αξονική και δεν χρειάσθηκαν επιπρόσθετες παρεμβάσεις. Δεν παρατηρήθηκε καμία ενδοδιαφυγή τύπου III, IV ή μετανάστευση
μοσχεύματος. Σημειώθηκαν 18 (17%) τύπου II ενδοδιαφυγές. Επιπρόσθετες ενδαγγειακές παρεμβάσεις απαιτήθηκαν σε 7 (6.6%), ενώ ανοικτή χειρουργική επέμβαση πραγματοποιήθηκε σε 4 (3.8%) ασθενείς. Σε 17 (16%) περιπτώσεις τουλάχιστον μία από τις έξω λαγονίους αρτηρίες είχε διάμετρο μικρότερη ή ίση προς 6mm καθιστώντας αυτούς τους ασθενείς ακατάλληλους για ενδομοσχεύματα με συστήματα προσπέλασης μεγάλου διαμετρήματος. Ενδαγγειακή αποκατάσταση ανευρύσματος κοιλιακής αορτής πραγματοποιήθηκε σε 10 (9.4%) ασθενείς με άτυπες ενδείξεις. Αυτές συμπεριλάμβαναν κοντό εγγύς αυχένα μικρότερο από 10mm σε 4 (3.8%) περιπτώσεις και εκτεταμένη γωνίωση (<60°) εγγύς αυχένα σε άλλες 3 (2.8%). Σε 3 (30%
/ 2.8%) ασθενείς η ένδειξη για ενδαγγειακή αποκατάσταση ήταν παρα-αναστομωτικό ψευδοανεύρυσμα μετά
από προηγούμενη ανοικτή αποκατάσταση αορτής. Δεν χρειάσθηκαν επιπρόσθετες πολύπλοκες διαδικασίες, όπως κολλάρα, σωληνωτά, αορτο-μονολαγόνια, διακλαδούμενα, τύπου καπνοδόχου ή περισκοπίου
μοσχεύματα. Ο μέσος χρόνος παρακολούθησης αυτών των άτυπων περιστατικών ήταν 18.1 μήνες (εύρος: 6- 32). Είναι ενδιαφέρον πως σε αυτήν την υπο-ομάδα των ασθενών δεν παρατηρήθηκαν τύπου Ι, III ή IV ενδοδιαφυγές, ενώ τύπου II ενδοδιαφυγή παρατηρήθηκε σε 2 (20%) περιπτώσεις.
Συμπέρασμα: Τα μεσοπρόθεσμα αποτελέσματα από το τρισκελές χαμηλού προφίλ ενδομόσχευμα με δακτυλίους σφράγισης πληρούμενους με πολυμερές δείχνουν εξαιρετική ασφάλεια και αποτελεσματικότητα
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ειδικά σε περιπτώσεις δύσκολων ανατομικών χαρακτηριστικών, όπως εγγύς αυχένες κοντοί ή με εκτεταμένη γωνίωση και στενές αρτηρίες πρόσβασης. Επιπλέον, το ενδομόσχευμα αυτό δείχνει να απομονώνει με ασφάλεια αναστομωτικά ψευδοανευρύσματα μετά απο προηγούμενη ανοικτή αορτική αποκατάσταση.
Λέξεις κλειδιά: EVAR, τρισκελές, ιδιαίτερα χαμηλού προφίλ, ενδομόσχευμα με πληρούμενους από πολυμερές δακτυλίους σφράγισης, οδηγίες κατασκευαστή, ενδείξεις, παρα- αναστομωτικό ανεύρυσμα
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