Gilberto Goncalves de Souza

Efeitos a curto prazo de "stents" não recobertos e recobertos com politetrafluoroetileno em aorta de suínos: um modelo experimental

PURPOSE: To report an experimental study evaluating, through digital morphometry, the intimal thickening of the arterial wall after the implant of auto-expandable stainless steel stents covered or not with polytetrafluoroethylene (PTFE) in the pig aorta. METHODS: In three groups of pigs a 12 F sheath was inserted in distal abdominal aorta. Group I animals (n=5) served as control. Group II animals (n=10) received an auto-expandable uncovered metallic stent. On group III animals (n=10) an auto-expandable stent covered with PTFE was inserted. After four weeks the animals were killed, the specimens were harvested and the intimal thickening was quantified by morphometric analysis. RESULTS: In the comparison among groups I, II and III referring to intimal, medial area and intimal index, it was not observed statistically significant variation. Differences were identified among groups referring to luminal proximal (p=0,036) and distal areas (p=0,044). Through multiple comparison tests for Kruskal-Wallis it was identified a difference between groups I and II. However, when these variables were controlled by weigh factor (luminal area/weigh relation), this difference was not observed anymore. CONCLUSION: In this short term study, the PTFE covering is not associated to further intimal thickening besides that promoted by the metallic mesh in large arteries and in high flow conditions.

Aortomonoiliac Stent-Grafts for Abdominal Aortic Aneurysm Repair: Association with Iliofemoral Crossover Grafts

Purpose: To analyze the outcome of endovascular exclusion of abdominal aortic aneurysm (AAA) using aortomonoiliac stent-grafts. Methods: Fifty-seven consecutive patients (49 men; median age 70, range 56–89) with AAA >5 cm were treated in a 6-year period with the conical ELLA stent-graft. Forty-two (73.9%) patients were classified ASA (American Society of Anesthesiologists) IV and 6 as ASA V. In the majority of cases, the implantation procedure featured device delivery through the external iliac artery, transrenal placement of a bare stent in selected cases, and an iliofemoral crossover graft through a prevesical tunnel. Results: Successful deployment was achieved in 56 (98.2%) patients. Mean time to discharge was 8.7 days (range 2–125). Two patients died in the 30-day period. Nine endoleaks occurred in 8 (14%) patients; 4 required further intervention. Mean follow-up was 35.3 months (range 1–66), during which 5 patients died from unrelated causes. No late endoleak, graft occlusion, device twisting/migration, or aneurysm rupture was observed. No correlation between type I endoleaks and unfavorable proximal neck or iliac artery anatomical characteristics could be found. Primary technical and clinical success rates were 86.0% and 94.7%, respectively. Conclusions: In this approach, the crossover graft remains in a retropubic space and consequently does not have all the disadvantages of a subcutaneously placed prosthesis. The results achieved in this group of high-risk patients support recommendation of this technique as a simple and safe alternative to bifurcated systems.

Minimally Invasive Surgical Solution in the Treatment of an Unusual Distal Type I Endoleak after Endovascular Abdominal Aortic Aneurysm Repair

Most distal type I endoleaks can be treated by endovascular techniques such as coil embolization of the hypogastric artery and additional stent or extension stent grafts. We report a case of a difficult type I endoleak located in the distal end of a monoiliac conical stent graft used to treat an abdominal aortic aneurysm extensively involving both common iliac arteries. Cranial migration of the endograft and incarceration in the contralateral iliac aneurysm were observed on the computed tomographic scan. The patient was submitted to a procedure that involves endovascular and limited open surgery techniques. A 26 mm balloon catheter was used to secure the proximal implantation site, and through a Gibson incision, the iliac arteries were controlled. An interpositional 8 mm regular Dacron graft was then sutured end to end between the endograft and the external iliac artery.