Helical EndoStaples enhance endograft fixation in an experimental model using human cadaveric aortas

ObjectiveThis study evaluated the contribution of Aptus EndoStaples (Aptus Endosystems, Sunnyvale, Calif) in the proximal fixation of eight endografts used in the endovascular repair of abdominal aortic aneurysms (EVAR).MethodsNine human cadaveric aortas were exposed, left in situ, and transected to serve as fixation zones. The Zenith (Cook, Bloomington, Ind), Anaconda (Vascutek, Inchinnan, Scotland, UK), Endurant (Medtronic, Minneapolis, Minn), Excluder (W. L. Gore and Associates, Flagstaff, Ariz), Aptus (Aptus Endosystems), Aorfix (Lombard Medical, Didcot, UK), Talent (Medtronic), and AneuRx (Medtronic) stent grafts were proximally deployed and caudal displacement force (DF) was applied via a force gauge, recording the DF required to dislocate each device ≥20 mm from the infrarenal neck. Measurements were repeated after four and six EndoStaples were applied at the proximal fixation zone, as well as after a Dacron graft was sutured at the proximal neck in standard fashion. Finally, a silicone tube was used as a control fixation zone to test the DF of grafts with EndoStaples in a material that exceeded the integrity of a typical human cadaveric aorta and provided a consistent substrate to examine the differential effect of variable degrees of EndoStaple implantation using zero, two, four, and six EndoStaples.ResultsIn the cadaveric model, the mean DF required to dislocate the endografts without the application of EndoStaples was 19.73 ± 12.52 N; this increased to 49.72 ± 12.53 N (P < .0001) when four EndoStaples where applied and to 79.77 ± 28.04 N when six EndoStaples were applied (P = .003). The DF necessary to separate the conventionally hand-sutured Dacron graft from the aorta was 56 N. In the silicone tube model, the Aptus endograft without EndoStaples withstood 3.2 N of DF. The DF increased to 39 ± 3 N when two EndoStaples were added, to 71 ± 6 N when four were added, and to 98 ± 5 N when six were added. In eight of the 13 cadaver experiments conducted with four and six EndoStaples, the displacement occurred as a result of complete aortic transection proximal to the fixation site, indicating that aortic tissue integrity was the limiting factor in these experiments.ConclusionsThe fixation of eight different endografts was increased by a mean of 30 N with four Aptus EndoStaples and by a mean of 57 N with six EndoStaples in this model. Endostaples can increase endograft fixation to levels equivalent or superior to that of a hand-sewn anastomosis. The application of six EndoStaples results in aortic tissue failure above the fixation zone, demonstrating fixation strength that exceeds inherent aortic integrity in these cadavers.Clinical RelevanceThe proximal fixation of an endovascular device in the endovascular repair of abdominal aortic aneurysms (EVAR) is of crucial importance to avoid complications such as kinking, migration, and endoleak. This study represents the first attempt to quantify the effect of a new innovative device (Aptus EndoStaples) aimed to enhance endograft fixation. A cadaveric model, which resembles the forces applied onto the endovascular devices in vivo, was chosen to test the effect of the EndoStaples. The results suggest that endograft fixation is significantly better after the application of the EndoStaples, to an extent where it surpasses the inherent durability of the vessel wall

Evaluation of IScore validity in a Greek cohort of patients with type 2 diabetes

BACKGROUND: Diabetes constitutes a risk factor for stroke that also aggravates stroke prognosis. Several prognostic models have been developed for the evaluation of neurologic status, severity, short-term functional outcome and mortality of stroke patients. IScore is a novel tool recently developed in order to predict mortality rates within 30 days and 1 year after ischemic stroke and diabetes is not included in the scoring scale of IScore. The aim of the present study was to evaluate and compare IScore validity in ischemic stroke patients with and without diabetes. METHODS: This prospective study included 312 consecutive Caucasian patients with type 2 diabetes and 222 Caucasian patients without diabetes admitted for ischemic stroke in a tertiary Greek hospital. Thirty-day and 1-year IScores were individually calculated for each patient and actual mortality was monitored at the same time intervals. IScore’s predictive ability and calibration was evaluated and compared for ischemic stroke patients with and without diabetes. The performance of IScore for predicting 30 and 1-year mortality between patients with and without diabetes was assessed by determining the calibration and discrimination of the score. The area under the receiver operating characteristic curve was used to evaluate the discriminative ability of IScore for patients with and without diabetes, whereas the calibration of IScore was assessed by the Hosmer–Lemeshow goodness-of fit statistic. RESULTS: Baseline population characteristics and mortality rates did not differ significantly for both cohorts. IScore values were significantly higher for patients with diabetes at 30 days and 1 year after ischemic stroke and patients with diabetes presented more frequently with lacunar strokes. Based on ROC curves analysis IScore’s predictive ability for 30 day mortality was excellent, without statistically significant difference, for both cohorts. Predictive ability for 1 year mortality was also excellent for both groups with significantly better ability for patients with diabetes especially at high score values. Calibration of the model was good for both groups of patients. CONCLUSIONS: IScore accurately predicts mortality in acute ischemic stroke Caucasian patients with and without diabetes with higher efficacy in predicting 1 year mortality in patients with diabetes especially with high scores

Endovascular repair of abdominal aortic aneurism: mechanical parameters influencing endograft fixation

Objective: To evaluate the differences of proximal, distal and overall fixation mechanisms within 8 commercially available endografts and compare their fixation ability to each other. Moreover various parameters were validated concerning their influence upon fixation. Methods: 20 human cadaveric aortas were surgically dissected from renals to iliac bifurcations, left in situ and transected 2 cm below the renals and above aortic bifurcation, to mimic AAAs’ proximal and distal landing zones. The mean proximal infrarenal aortic diameter was 20,5 mm (range 19,2-21,9). 8 stent grafts were implanted (Anaconda, Excluder, Talent, AUI Endofit, Zenith, Endurant, Powerlink Endologix and VI Extender Cuff) from the femoral arteries, according to manufacturers’ guidelines. In addition a PTFE graft was anastomosed to the aorta or iliac artery with running PTFE suture. Distal force was applied to the flow divider of each graft, either fully or only proximally deployed, via a sensitive force gauge. Minimum displacement force (DF) needed to dislodge the stent graft from the infrarenal neck was recorded. Measurements were repeated after molding balloon dilatation at the proximal neck. Iliac legs were measured as well, for chephalad displacement, either after minimum or maximum iliac fixation and before and after balloon dilatation. Results: Within the self expanding endografts, Zenith recorded the highest proximal DF 34.50 N (31.35-37.50), Anaconda showed the 2nd highest proximal DF 28.75 Ν (26.50 -31.05), Endurant recorded the 3rd highest DF 26.75 Ν (24.60-28.70), Excluder was measured 17.90 Ν (17.30-18.85), Talent recorded DF 14.90 Ν (14.40-15.30), Powerlink needed a DF of 13.65 Ν (12.50-14.90), Endofit recorded DF was 12.15 Ν (11.00-13.40). ΒΕ VI Extender cuff, proximally deployed, needed DF was 27.70 Ν. PTFE anastomosis recorded the highest proximal DF 76.20 Ν (66.40-79.00). Molding balloon dilatation produced a significant DF increase in “hooked” grafts but an insignificant in “hookless”. Increased length of iliac landing zone increases distal fixation ability. Hooks and barbs significantly enhance proximal and total fixation. Suprarenal stent does not significantly affect fixation. When columnar strength was incorporated, full deployment (body and limbs) caused significant increase in DF compared to proximal deployment only. When columnar support was unavailable, full deployment caused marginal increase in DF compared to proximal deployment only. Balloon expandable VI Extender cuff recorded significant DF that was higher than the mean DF of self expanding endografts. Conclusions: Hooks and barbs and balloon dilatation significantly enhance proximal and total fixation. Suprarenal stent does not significantly affect fixation. Length of iliac landing zone increases fixation ability.Σκοπός: Κάθε ενδοπρόθεση φέρει ιδιαίτερα μηχανικά χαρακτηριστικά με τα οποία επιτυγχάνει την κεντρική και περιφερική της στήριξη. (Μεταλλικές ακίδες-άγκιστρα-γάντζοι, η τριβή από την ασκούμενη ακτινική τάση στο αορτικό τοίχωμα, ο ελεύθερος υπερνεφρικός ενδονάρθηκας, η πλάγια επιμήκης μεταλλική μπάρα και η στήριξη στον αορτικό διχασμό). Σκοπός μας, είναι να μελετήσουμε τη στήριξη όλων των εμπορικά διαθέσιμων ενδομοσχευμάτων στο τοίχωμα πτωματικών αορτών. Μέθοδος: Για να το επιτύχουμε μετρήσαμε τη δύναμη μετακίνησης (Displacement force - DF) που χρειάζεται να εφαρμοστεί σε αυτά κατά τον επιμήκη άξονά τους ώστε να μετακινηθούν περιφερικά περισσότερο από 20 mm. Χρησιμοποιήσαμε 20 πτωματικές αορτές. Η μέση διάμετρος των υπό εξέταση αορτών ήταν 20,5 mm (διακύμανση 19,2 – 21,9). Χρησιμοποιήσαμε 8 είδη ενδομοσχευμάτων (Anaconda Vascutek, Excluder Gore, Talent Medtronic, αορτομονολαγόνια ενδοπρόθεση Unifit AUI LeMaitre, Zenith Cook, Endurant Medtronic, Powerlink Endologix, VI Extender Cuff και κλασσική πρόθεση PTFE). Με αυτόν τον τρόπο μετρήθηκε η απόλυτη τιμή δύναμης (DF) σε Newton που πρέπει να ασκηθεί στην ενδοπρόθεση για να την μετακινήσει κατά 20 mm δηλ. να της προκαλέσει αντίστοιχη μετανάστευση. Το ίδιο εφαρμόστηκε και στα λαγόνια σκέλη, όπου μετρήθηκε η απόλυτη τιμή δύναμης που πρέπει να ασκηθεί στο σκέλος για να το μετακινήσει κατά 20 ή 50 mm. Αποτελέσματα: Από τα αυτοδιατεινόμενα ενδομοσχεύματα, το Zenith κατέγραψε την υψηλότερη DF 34,5Ν (31.35-37.50), το Anaconda 28,75 Ν (26.50 - 31.05), το Endurant 26.75 Ν (24.60-28.70), το Excluder 17.90 Ν (17.30-18.85), το Talent 14.90 Ν (14.40-15.30), το Powerlink 13.65 Ν (14.90-12.50) και το Unifit 12.15 Ν (11.00-13.40). Το VI Extender Cuff ως διατεινόμενο με αεροθάλαμο μετρήθηκε ξεχωριστά και κατέγραψε DF 27.70 N. Η κλασσική πρόθεση PTFE χρειάστηκε 76.20 Ν (66.40-79.00) για να μετακινηθεί. Η διαστολή με αεροθάλαμο διαμόρφωσης στον κεντρικό αυχένα αύξησε την απαιτούμενη DF σε όλες τις ενδοπροθέσεις και μάλιστα σε αυτές με γάντζους ή ακίδες η διαφορά ήταν στατιστικά σημαντική. Επιπλέον η τοποθέτηση των λαγονίων σκελών 2 ή 5 cm ως ζώνη περιφερικής στήριξης επηρεάζει την DF και μάλιστα η διαφορά είναι στατιστικά σημαντική. Τα ενδομοσχεύματα με γάντζους ή ακίδες χρειάζονται στατιστικώς σημαντικά μεγαλύτερη δύναμη για να μετακινηθούν. Τα ενδομοσχεύματα με ελεύθερο υπερνεφρικό ενδονάρθηκα, ανεξαρτήτως του τρόπου έκπτυξης, κατέγραψαν ελαφρώς μεγαλύτερη στατιστικά μη σημαντική DF και άρα στηρικτική ικανότητα από τα ενδομοσχεύματα που δεν έχουν υπερνεφρικό ενδονάρθηκα. Στα ενδομοσχεύματα με επιμήκη μπάρα ή ενιαίο σκελετό η πλήρης έκπτυξή τους αυξάνει σημαντικά τη στηρικτική ικανότητα σε σχέση με την μερική τους έκπτυξη. Στα ενδομοσχεύματα χωρίς επιμήκη μπάρα ή ενιαίο σκελετό η πλήρης έκπτυξή τους αυξάνει οριακά την απαιτούμενη δύναμη μετακίνησης DF και άρα τη στηρικτική ικανότητα σε σχέση με την μερική τους έκπτυξη. Το ΒΕ VI Extender cuff εμφανίζει κεντρικά και περιφερικά DF μεγαλύτερη του μέσου όρου των Self Expanding ενδομοσχευμάτων. Συμπεράσματα: Οι ακίδες-γάντζοι και η διαστολή με αεροθάλαμο αυξάνουν τη στηρικτική ικανότητα. Το υπερνεφρικό stent δεν επηρεάζει από μόνο του τη στηρικτική ικανότητα. Το ικανό μήκος περιφερικής στήριξης (5cm) στις λαγόνιες αυξάνει σημαντικά την περιφερική στηρικτική ικανότητα

Endovascular repair of abdominal aortic aneurism: mechanical parameters influencing endograft fixation

Objective: To evaluate the differences of proximal, distal and overall fixation mechanisms within 8 commercially available endografts and compare their fixation ability to each other. Moreover various parameters were validated concerning their influence upon fixation. Methods: 20 human cadaveric aortas were surgically dissected from renals to iliac bifurcations, left in situ and transected 2 cm below the renals and above aortic bifurcation, to mimic AAAs’ proximal and distal landing zones. The mean proximal infrarenal aortic diameter was 20,5 mm (range 19,2-21,9). 8 stent grafts were implanted (Anaconda, Excluder, Talent, AUI Endofit, Zenith, Endurant, Powerlink Endologix and VI Extender Cuff) from the femoral arteries, according to manufacturers’ guidelines. In addition a PTFE graft was anastomosed to the aorta or iliac artery with running PTFE suture. Distal force was applied to the flow divider of each graft, either fully or only proximally deployed, via a sensitive force gauge. Minimum displacement force (DF) needed to dislodge the stent graft from the infrarenal neck was recorded. Measurements were repeated after molding balloon dilatation at the proximal neck. Iliac legs were measured as well, for chephalad displacement, either after minimum or maximum iliac fixation and before and after balloon dilatation. Results: Within the self expanding endografts, Zenith recorded the highest proximal DF 34.50 N (31.35-37.50), Anaconda showed the 2nd highest proximal DF 28.75 Ν (26.50 -31.05), Endurant recorded the 3rd highest DF 26.75 Ν (24.60-28.70), Excluder was measured 17.90 Ν (17.30-18.85), Talent recorded DF 14.90 Ν (14.40-15.30), Powerlink needed a DF of 13.65 Ν (12.50-14.90), Endofit recorded DF was 12.15 Ν (11.00-13.40). ΒΕ VI Extender cuff, proximally deployed, needed DF was 27.70 Ν. PTFE anastomosis recorded the highest proximal DF 76.20 Ν (66.40-79.00). Molding balloon dilatation produced a significant DF increase in “hooked” grafts but an insignificant in “hookless”. Increased length of iliac landing zone increases distal fixation ability. Hooks and barbs significantly enhance proximal and total fixation. Suprarenal stent does not significantly affect fixation. When columnar strength was incorporated, full deployment (body and limbs) caused significant increase in DF compared to proximal deployment only. When columnar support was unavailable, full deployment caused marginal increase in DF compared to proximal deployment only. Balloon expandable VI Extender cuff recorded significant DF that was higher than the mean DF of self expanding endografts. Conclusions: Hooks and barbs and balloon dilatation significantly enhance proximal and total fixation. Suprarenal stent does not significantly affect fixation. Length of iliac landing zone increases fixation ability.Σκοπός: Κάθε ενδοπρόθεση φέρει ιδιαίτερα μηχανικά χαρακτηριστικά με τα οποία επιτυγχάνει την κεντρική και περιφερική της στήριξη. (Μεταλλικές ακίδες-άγκιστρα-γάντζοι, η τριβή από την ασκούμενη ακτινική τάση στο αορτικό τοίχωμα, ο ελεύθερος υπερνεφρικός ενδονάρθηκας, η πλάγια επιμήκης μεταλλική μπάρα και η στήριξη στον αορτικό διχασμό). Σκοπός μας, είναι να μελετήσουμε τη στήριξη όλων των εμπορικά διαθέσιμων ενδομοσχευμάτων στο τοίχωμα πτωματικών αορτών. Μέθοδος: Για να το επιτύχουμε μετρήσαμε τη δύναμη μετακίνησης (Displacement force - DF) που χρειάζεται να εφαρμοστεί σε αυτά κατά τον επιμήκη άξονά τους ώστε να μετακινηθούν περιφερικά περισσότερο από 20 mm. Χρησιμοποιήσαμε 20 πτωματικές αορτές. Η μέση διάμετρος των υπό εξέταση αορτών ήταν 20,5 mm (διακύμανση 19,2 – 21,9). Χρησιμοποιήσαμε 8 είδη ενδομοσχευμάτων (Anaconda Vascutek, Excluder Gore, Talent Medtronic, αορτομονολαγόνια ενδοπρόθεση Unifit AUI LeMaitre, Zenith Cook, Endurant Medtronic, Powerlink Endologix, VI Extender Cuff και κλασσική πρόθεση PTFE). Με αυτόν τον τρόπο μετρήθηκε η απόλυτη τιμή δύναμης (DF) σε Newton που πρέπει να ασκηθεί στην ενδοπρόθεση για να την μετακινήσει κατά 20 mm δηλ. να της προκαλέσει αντίστοιχη μετανάστευση. Το ίδιο εφαρμόστηκε και στα λαγόνια σκέλη, όπου μετρήθηκε η απόλυτη τιμή δύναμης που πρέπει να ασκηθεί στο σκέλος για να το μετακινήσει κατά 20 ή 50 mm. Αποτελέσματα: Από τα αυτοδιατεινόμενα ενδομοσχεύματα, το Zenith κατέγραψε την υψηλότερη DF 34,5Ν (31.35-37.50), το Anaconda 28,75 Ν (26.50 - 31.05), το Endurant 26.75 Ν (24.60-28.70), το Excluder 17.90 Ν (17.30-18.85), το Talent 14.90 Ν (14.40-15.30), το Powerlink 13.65 Ν (14.90-12.50) και το Unifit 12.15 Ν (11.00-13.40). Το VI Extender Cuff ως διατεινόμενο με αεροθάλαμο μετρήθηκε ξεχωριστά και κατέγραψε DF 27.70 N. Η κλασσική πρόθεση PTFE χρειάστηκε 76.20 Ν (66.40-79.00) για να μετακινηθεί. Η διαστολή με αεροθάλαμο διαμόρφωσης στον κεντρικό αυχένα αύξησε την απαιτούμενη DF σε όλες τις ενδοπροθέσεις και μάλιστα σε αυτές με γάντζους ή ακίδες η διαφορά ήταν στατιστικά σημαντική. Επιπλέον η τοποθέτηση των λαγονίων σκελών 2 ή 5 cm ως ζώνη περιφερικής στήριξης επηρεάζει την DF και μάλιστα η διαφορά είναι στατιστικά σημαντική. Τα ενδομοσχεύματα με γάντζους ή ακίδες χρειάζονται στατιστικώς σημαντικά μεγαλύτερη δύναμη για να μετακινηθούν. Τα ενδομοσχεύματα με ελεύθερο υπερνεφρικό ενδονάρθηκα, ανεξαρτήτως του τρόπου έκπτυξης, κατέγραψαν ελαφρώς μεγαλύτερη στατιστικά μη σημαντική DF και άρα στηρικτική ικανότητα από τα ενδομοσχεύματα που δεν έχουν υπερνεφρικό ενδονάρθηκα. Στα ενδομοσχεύματα με επιμήκη μπάρα ή ενιαίο σκελετό η πλήρης έκπτυξή τους αυξάνει σημαντικά τη στηρικτική ικανότητα σε σχέση με την μερική τους έκπτυξη. Στα ενδομοσχεύματα χωρίς επιμήκη μπάρα ή ενιαίο σκελετό η πλήρης έκπτυξή τους αυξάνει οριακά την απαιτούμενη δύναμη μετακίνησης DF και άρα τη στηρικτική ικανότητα σε σχέση με την μερική τους έκπτυξη. Το ΒΕ VI Extender cuff εμφανίζει κεντρικά και περιφερικά DF μεγαλύτερη του μέσου όρου των Self Expanding ενδομοσχευμάτων. Συμπεράσματα: Οι ακίδες-γάντζοι και η διαστολή με αεροθάλαμο αυξάνουν τη στηρικτική ικανότητα. Το υπερνεφρικό stent δεν επηρεάζει από μόνο του τη στηρικτική ικανότητα. Το ικανό μήκος περιφερικής στήριξης (5cm) στις λαγόνιες αυξάνει σημαντικά την περιφερική στηρικτική ικανότητα

Non-Activated Autologous Platelet-Rich Plasma for the Prevention of Inguinal Wound-Related Complications After Endovascular Repair of Abdominal Aortic Aneurysms

The endovascular repair (EVAR) of abdominal aortic aneurysms (AAAs) usually involves the surgical exposure and catheterization of the femoral arteries. Several inguinal surgical wound-related complications have been reported postoperatively. The aim of this report was to evaluate the safety and efficacy of intraoperative application of autologous platelet-rich plasma (PRP) for the prevention of wound-related complications in AAA EVAR. The authors conducted a patient- and assessor-blinded controlled trial involving 100 subjects undergoing EVAR of an AAA. PRP was produced using an autologous platelet separator and was applied, without prior thrombin activation, in 50 patients eligible for inclusion. The results were compared with a control group of 50 patients who underwent AAA EVAR within the same time period. The primary outcome was the difference in postoperative hospital stay. Secondary outcomes included subjective assessment of wound healing and wound-related complications. Age, sex, and other comorbidities related to wound healing were not significantly different between cases and controls. One patient treated with PRP developed a unilateral wound infection with lymphorrhea, and two patients developed a bi-lateral superficial infection. Twelve patients within the control group developed a wound-related complication. The postoperative hospitalization was significantly lower in the PRP group. The overall surgical wound-related complications rate was also significantly lower in the PRP group. Application of non-thrombin-activated PRP seems to prevent major postoperative wound-related complications (p = .026) and shorten postoperative hospital stay duration after femoral artery exposure and catheterization for AAA EVAR (mean, 4.48 ± 0.48 vs. 6.14 ± 0.39 days)

Impaired renal function is associated with mortality and morbidity after endovascular abdominal aortic aneurysm repair

BackgroundRenal function may be associated with poor outcome following endovascular abdominal aortic aneurysm repair (EVAR), but this relationship has not been adequately investigated. The aim of this study is to evaluate the association of estimated glomerular filtration rate (eGFR) with cardiovascular events and all-cause mortality after EVAR.MethodsProspective cohort study of patients undergoing elective EVAR; eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration formula, and patients were divided in four groups (eGFR ≥90 mL/min/1.73 m2, group 1; 60-89, group 2; 30-59, group 3; <30, group 4). Composite end point consisted of death, nonfatal myocardial infarction, stroke, and vascular complications. Kaplan-Meier curves were constructed, and between-group comparisons were performed adjusted for variables that differed at baseline.ResultsA total of 383 patients (mean age, 69 ± 8 years; mean abdominal aortic aneurysm diameter, 6.2 ± 1.4 cm) were included. Over a mean follow-up of 34 ± 12 months, the following events occurred: 20 deaths (5.2%), 15 nonfatal myocardial infarctions (3.9%), 9 nonfatal strokes (2.3%), and 7 peripheral vascular complications (1.8%). Patients with an eGFR <30 had the highest mortality (35%) and incidence of complications (80%) as per the end point (P = .009 and P < .001, respectively). Adjusted Cox-regression analysis showed that a higher eGFR at baseline by 1 mL/min/1.73 m2 was associated with a 5% lower likelihood of complications as per the end point (P < .001; hazard ratio, 0.95; 95% confidence interval, 0.94-0.97) and a 6% lower likelihood of death (P < .001; hazard ratio, 0.94; 95% confidence interval, 0.92-0.97).ConclusionsImpaired renal function is associated with an increase in cardiovascular events and mortality following elective EVAR