Alterations in brain cytokines during internal carotid artery clamping with or without using indwelling shunt

Carotid endarterectomy (CEA) is the “golden standard” in the treatment of either symptomatic internal carotid artery stenosis > 50% or asymptomatic stenosis > 70% for prevention of stroke. However, 2-6% of the patients that undergo CEA are likely to have a periprocedural stroke. Intropeative embolism and/or cerebral hypoperfusion are the major causes of stroke and are due to carotid clamping. The use of indwelling endoluminal shunt during the CEA is a very efficient method of preventing cerebral hypoperfusion caused by the carotid artery clamping. Nevertheless, due to potential complications attributed to the insertion technique of the shunt, the standard use of the shunt is still controversial. Objective: The objective of this experiment is to elucidate the nessecity of the use of an indwelling shunt based on the induction of oxidant stress during carotid artery clamping of a rabbit depending on the patency of the contralateral carotid artery. Materials and Methods: The changes of the oxidant (rate of accumulation) and antioxidant (Lag time and Total Antioxidant Status - TAS) stress in the brain of the rabbit were evaluated as the most sensitive markers of cerebral ischemia. New Zealand White Rabbits were randomized into 4 groups: 1. shunt ipsilateraly and patent contralateral carotid artery, 2. shunt ipsilateraly and occlusion of the contralateral carotid artery, 3. no shunt ipsilateraly and patent contralateral carotid artery, 4. no shunt ipsilateraly and occlusion of the contralateral carotid artery. Blood was collected from the site of ipsilateral clamping : at the beginning of the procedure (level 0) and then, 5 – 10 – 15 – 30 and 60 min after level 0. Results: The production of free radicals (rate of accumulation) and the concetration of the antioxidants in the serum (lagtime and TAS) are increased during arterial clamping regardless of the insertion of an indwelling shunt or the patency of the contralateral carotid artery. However the animals with no shunt at the ipsilateral and occlusion of the contralateral carotid artery, were found to have statistically significant increased production of free radicals (rate of accumulation: group 1vs4 60min, 5.7vs6.8 ΟD/ sec X 10-5 p=0.050, group 2vs4 60min, 1.17vs6.8 ΟD/ sec X 10-5 p=0.031, group 3vs4 60min 3.42vs6.8 ΟD/ sec X 10-5 Παπαπέτρου Α. Διδακτορική Διατριβή 17 p=0.046) and statistically significant decreased concentration of antioxidants (lagtime: : group 1vs4 60min, 2182vs414 sec p=0.057, group 2vs4 60min, 4024vs414 sec p=0.049, group 3vs4 60min 2672vs414 sec p=0.048) & (total antioxidant status: : group 1vs4 60min, 1.38vs0.61 mM p=0.034, group 2vs4 60min, 0.85vs0.61 mM p=0.057, group 3vs4 60min 0.95vs0.61 mM p=0.050) The reduced values of tLag and TAS (total antioxidant status) (p50% και ασυμπτωτική στένωση >70%.40 Ωστόσο, κατά μέσο όρο 2-6% των ασθενών που υποβάλλονται σε ΕΚΑ μπορεί να εκδηλώσει ΑΕΕ κατά την περιεγχειρητική περίοδο. 145 Διεγχειρητική εμβολή ή/και εγκεφαλική υποάρδευση αποτελούν τα κύρια αίτια ΑΕΕ, κύρια λόγω του καρωτιδικού αποκλεισμού. Η τοποθέτηση ενδοαυλικής παράκαμψης (shunt) θεωρείται η πιο αποτελεσματική μέθοδος στην πρόληψη της εγκεφαλικής ισχαιμίας λόγω υποάρδευσης κατά τον αποκλεισμό της καρωτίδας στην ΕΚΑ74. Παρά ταύτα και λόγω του ότι είναι επεμβατική τεχνική με δυνητικές επιπλοκές η χρήση του αποτελεί ένα από τα πιο αμφισβητούμενα ζητήματα στην ΕΚΑ75, 76. Υπολογίζεται ότι περίπου 15% των ασθενών που υποβάλλονται σε ΕΚΑ θα εμφανίσουν ευρήματα, κλινικά ή εργαστηριακά, υποάρδευσης και σε αυτούς κρίνεται απαραίτητη η τοποθέτηση shunt. Τρεις είναι οι απόψεις που υπάρχουν: τοποθέτηση shunt ως πρακτική ρουτίνας σε όλους τους ασθενείς76, 77, εκλεκτική τοποθέτηση78, 79 με βάση τις διεγχειρητικές μεθόδους εγκεφαλικής παρακολούθησης όπως αναφέρθηκαν παραπάνω ή άλλα κριτήρια όπως π.χ αγγειογραφικά80 και, τέλος, μη τοποθέτηση shunt σε κανένα ασθενή. Ορισμένοι χειρουργοί προτείνουν τη συστηματική χρήση του shunt σε όλες τις καρωτιδικές ενδαρτηρεκτομές διότι είναι απλό και ασφαλές. Άλλοι επισημαίνουν ότι οι κίνδυνοι ορισμένων εγκεφαλικών μπορεί να αυξάνονται με τη χρήση των shunt και διαφωνούν εντελώς στη χρησιμοποίησή τους. Η αλήθεια είναι πως μπορεί να συνοδεύονται από συγκεκριμένες επιπλοκές και η ενδαρτηρεκτομή γίνεται πιο εύκολα, με περισσότερη ασφάλεια όσον αφορά το τελικό περιφερικό τμήμα της πλάκας και ίσως γρηγορότερα επί απουσίας shunt. Η μεγιστοποίηση του οφέλους και η ελαχιστοποίηση του κινδύνου όσον αφορά τη χρήση του shunt φαίνεται να επιτυγχάνεται με την επιλεκτική χρήση τους, που βασίζεται στην διεγχειρητική διάγνωση της εγκεφαλικής ισχαιμίας (βάσει Α. Παπαπέτρου – Διδακτορική Διατριβή ηλεκτοεγκεφαλογραφήματος, ανάστροφης πίεση περιφερικού τμήματος έσω καρωτίδας και με τοπική αναισθησία σε ξύπνιο ασθενή), ποικίλλει όμως ευρέως από χώρα σε χώρα και κέντρο σε κέντρο. Με την παρούσα διατριβή, διευκρινίζεται σε βιοχημικό/μοριακό επίπεδο, δια της μέτρησης της επαγωγής οξειδωτικού στρες, η βαρύτητα της εγκεφαλικής ισχαιμίας με βάση την χρήση ή μη διεγχειρητικής ενδαυλικής παράκαμψης και την παρουσία ή μη απόφραξης της ετερόπλευρης καρωτιδικής κυκλοφορίας. Η οξειδωτική κατάσταση μελετάται τα τελευταία χρόνια σε όλα τα βιολογικά μοντέλα ισχαιμίας επαναιμάτωσης (στεφανιαία ισχαιμία, περιφερική ισχαιμία, εντερική ισχαιμία κλπ) ώς ο πλέον ευαίσθητος δείκτης βλάβης του προσβεβλημένου οργάνου. Το οξειδωτικό stress που αναπαράγεται κατά τη διάρκεια της εγκεφαλικής ισχαιμίας που συνοδεύει την καρωτιδική ενδαρτηρεκτομή δεν είχε μελετηθεί μέχρι σήμερα. Με τη μελέτη μας, διαφωτίζεται ο αμφιλεγόμενος ρόλος της διεγχειρητικής ενδαυλικής παράκαμψης ως μέσο προστασίας του εγκεφάλου από τη διεγχειρητική ισχαιμία..

Late renal artery occlusion following endovascular repair of abdominal aortic aneurysm: a possible complication of mural thrombus formation within aortic endografts

Mural thrombus formation within aortic endoprostheses has been described to occur in up to one-third of aortic endografts depending on the device type. Data regarding the clinical significance of such a phenomenon are scarce, but in most cases it is considered to be clinically innocent. The authors describe a rare case of late renal artery occlusion due to intraprosthetic thrombus formation and extension into the right renal orifice 30 months after endovascular abdominal aortic aneurysm repair. Additionally, a brief literature review regarding the incidence and natural history of mural thrombotic deposits within aortic endografts is also conducted

Unilateral Iliac Artery Stenting Improves Perfusion and Symptoms in Both Limbs in Patients With Bilateral Iliac Lesions

Purpose: To test the hypothesis that unilateral dilation of a common (CIA) or internal iliac artery (IIA) stenosis in selected patients with contralateral chronic iliac artery occlusion is adequate to offer clinical benefit to the untreated chronically occluded limb. Methods: Sixteen patients (11 men; mean age 66.7 +/- 4.9 years) with chronic occlusion of one CIA [with or without extension to the external iliac artery (EA)] and CIA stenosis (n=11), IIA stenosis (n=3), CIA and IIA stenoses (n=1), or IIA and EIA stenoses (n=1) on the contralateral side were treated with unilateral angioplasty/stenting of the iliac artery stenosis as sole treatment for both limbs. Clinical and hemodynamic success of this approach was assessed for both limbs. Results: Eleven patients were treated with stenting of the stenosed CIA, 2 with IIA dilation, one with IIA stenting, one with stenting of both the CIA and IIA, and the last with IIA and EIA stenting. Technical success was obtained in all. Immediate hemodynamic success was also 100% for both limbs: the mean resting ankle-brachial index increased from 0.67 +/- 0.06 to 0.88 +/- 0.04 on the stenosis side and from to 0.53 +/- 0.06 to 0.69 +/- 0.07 in the contralateral occluded limb (p<0.001). Clinical success was 100% for the treated limb immediately after the procedure and 93.8% for the contralateral limb. One patient with ischemic rest pain in the occluded limb continued to experience severe symptoms after contralateral CIA stenting despite hemodynamic improvement; he had a femorofemoral graft implanted 2 months after the initial intervention and was considered the only clinical failure. During a mean 24-month follow-up (range 12-54), all stented arteries remained patent. Conclusion: In selected patients with CIA or IIA stenosis and long chronic occlusion of the contralateral iliac axis, unilateral dilation/stenting of the stenosis alone increases blood flow and improves clinical symptoms to both limbs. J Endovasc Ther. 2013;20:106-11

Should The Size Threshold for Elective Abdominal Aortic Aneurysm Repair be Lowered in The Endovascular Era? No

According to the current international guidelines, patients with infrarenal or juxtarenal abdominal aortic aneurysms (AAAs) measuring >= 5.5 cm should undergo repair to reduce the risk of rupture. The 5.5-cm-diameter threshold is the size when the AAA rupture rate balances the mortality rates of elective open surgical AAA repair (3%). Endovascular AAA repair (EVAR) is associated with lower perioperative mortality and complication rates compared with open surgical repair. This debate addresses the issue whether the current size threshold for elective AAA repair needs to be lowered in the endovascular era. This article supports the position that the size threshold for AAA repair should not be lowered

Balloon angioplasty vs nitinol stent placement in the treatment of venous anastomotic stenoses of hemodialysis grafts after surgical thrombectomy

Objective: Most arteriovenous hemodialysis grafts fail <= 18 months after implantation, most commonly due to intimal hyperplasia at the venous anastomosis. This open prospective study compared balloon angioplasty vs nitinol stent placement in the treatment of venous anastomotic stenosis after thrombectomy of prosthetic brachial-axillary accesses. Methods: Between February 2007 and December 2010, 61 patients with an initial thrombosis of a prosthetic brachial-axillary access were admitted to our hospital. Of these patients, 28 (46%), treated before June 2008, underwent thrombectomy plus balloon angioplasty of the venous anastomosis (group A), whereas the remaining 33 (54%) patients, who were treated after July 2008, underwent graft thrombectomy plus angioplasty with self-expanding nitinol stent placement (group B). Primary, primary-assisted, and secondary patency rates were calculated using Kaplan-Meier analysis and compared between the two groups with the log-rank test. Results: Primary patency was 32% at 3 months, 24% at 6 months, and 14% at 12 months in group A, and the respective values were 85%, 63% and 49% in group B. Primary patency was significantly better in group B than in group A (P < .001; log-rank test). Cumulative median patency was 60 days in group A and 260 days in group B. Patient age, sex, comorbidities, graft material, and graft age did not have prognostic significance. Primary-assisted and secondary patency rates were significantly higher in group B. Conclusions: Graft thrombectomy plus angioplasty with self-expanding nitinol stent placement provides significantly higher patency rates compared with thrombectomy plus plain balloon angioplasty of the venous anastomosis. (J Vase Surg 2012;55:472-8.

A systematic review of therapies for aortobronchial fistulae

Objective: The aim of the study was to summarize epidemiologic data about aortobronchial fistulae and compare outcomes (mortality, recurrence, reoperation) of open, staged, and endovascular repair of aortobronchial fistula. Methods: A systematic literature review was conducted to identify eligible studies published between January 1999 and December 2019. The Cochrane Library, PubMed, and Scopus databases were used as search engines. Eligible studies included articles reporting postoperative outcomes (death/follow-up). Literature review revealed only case reports and small case series, and thus, only descriptive data with data heterogeneity were available. The corresponding authors were contacted to provide additional information or outcome updates (recurrence/reoperation/death). Results: Overall, 214 patients (90 studies) underwent 271 procedures (including redo procedures and staged procedures). Most of the patients were treated by endovascular means (72.42%). Open surgical repair was performed in 21.96% and staged procedures in 5.6%. Aortobronchial fistulae were located most often in the descending thoracic aorta (zone 3 or 4) (64.6%) and in zone 2 (23.8%). Fourteen percent of aortobronchial fistulae developed after thoracic endovascular aneurysm repair. Recurrence or infection occurred in 20% (43) patients. Recurrences were, to some extent, associated with the presence of endoleak. Long-term antibiotic administration (>1 month) was instituted in 63 patients (29.4%), whereas 90 patients (42%) did not receive antibiotics beyond hospitalization. From the remaining 61 patients, 3 received lifelong antibiotics and for 58 patients data were not available. Considering outcomes, the mean follow-up was 25.1 months (0188 months) and not significantly different among treatments. Limitations: Literature review has revealed only case reports and small case series, and thus, only descriptive data were available. Randomized controlled trials are not available due to the rarity of the disease, which significantly decreases the power of the present study. Also, this study reflects significant data heterogeneity due to the nature of the analyzed manuscripts and would benefit from large patient cohort studies that have not been conducted till today. Conclusions: Aortobronchial fistula is a complex disease. Endoleaks may be involved in the development and the recurrence process, and they should not be disregarded. Considering major outcomes (length of follow-up), the available treating strategies are equal, and thus, surgeons should feel confident to apply the treatment of their choice, keeping in mind their experience, patient’s age, and clinical condition

Infected femoral artery pseudoaneurysm in drug addicts: The beneficial use of the internal iliac artery for arterial reconstruction

Background. Infected femoral artery pseudoaneurysm (IFAP) is a severe complication in parenteral drug abusers, with difficult and controversial management. Ligation alone without revascularization is frequently associated with later intermittent claudication and limb amputation. Furthermore, arterial reconstruction with a synthetic or venous conduit is limited because of a contaminated field and, often, unavailability of autologous venous grafts. In this study, we present our experience with the internal iliac artery (IIA) as a graft for arterial reconstruction after IFAP excision in these patients. Methods. Data of 14 consecutive patients who presented with IFAP secondary to parenteral drug abuse from 2001 to 2005 were analyzed. Twelve patients (85.7%) were male. The median age was 27 years (range, 19-42 years). In 13 cases, the IFAP involved the common femoral artery, and in I case it involved the profunda femoris artery (PFA). In nine patients, we used the IIA for arterial reconstruction (five as a patch and four as an interposition graft), whereas in two patients the arterial deficit was repaired with a great saphenous vein patch. In two cases, an extra-anatomic bypass with a synthetic polytetrafluoroethylene graft was performed. In one patient, the pseudoaneurysm involved the PFA and was treated with excision and ligation of the PFA. Results. All nine patients who underwent revascularization with the use of IIA were free of claudication symptoms. None of them experienced any perioperative complications, had signs of reinfection, or required limb amputation during the follow-up period (median, 19 months; range, 4-52 months). Regarding the remaining five patients, one died 25 days after surgery because of multiorgan failure, and one underwent reoperation because of proximal anastornotic rupture of a synthetic graft. The latter patient finally underwent a transmetatarsal amputation. Conclusions. The use of IIA for arterial reconstruction after IFAP excision in drug abusers is safe and effective. These preliminary results indicate that the implementation of this technique offers many advantages compared with traditional treatment options