This study aims to investigate whether displacement force on stents can accurately represents the displacement of the stent after endovascular aneurysm repair (EVAR) by comparing the measured stent displacement with the displacement forces calculated by computational fluid dynamics (CFD). And the effect of cross-limb and parallel-limb EVAR on stent displacements is further studied. Based on our objective, in this study, ten cross-limb EVAR patients and ten parallel-limb EVAR patients in West China Hospital of Sichuan University were enrolled. Patient-specific models were first reconstructed based on the computed tomography angiography images, then the stent displacements were measured, and the displacement forces acting on the stents were calculated by CFD. Finally, the cosα value of the angle between the displacement force and the displacement vector was used to analyze the matching degree between the displacement and the displacement force. The results showed that the displacement forces on cross-limb stents and parallel-limb stents were (2.67 ± 2.14) N and (1.36 ± 0.48) N, respectively. Displacements of stent gravity center, stent displacements relative to vessel, and vessel displacements of cross-limb and parallel-limb stents were (4.43 ± 2.81) mm and (6.39 ± 2.62) mm, (0.88 ± 0.67) mm and (1.11 ± 0.71) mm, (3.55 ± 2.88) mm and (5.28 ± 2.52) mm, respectively. The mean cosα for cross-limb and parallel-limb stents were 0.02 ± 0.66 and - 0.10 ± 0.73, respectively. This study indicates that the displacement force on the stent can't accurately represent the displacement of the stent after EVAR. In addition, the cross-limb EVAR is probably safer and more stable than the parallel-limb EVAR.
Aortic Aneurysm, Abdominal/surgery* ; Blood Vessel Prosthesis ; Blood Vessel Prosthesis Implantation ; Endovascular Procedures/methods* ; Humans ; Prosthesis Design ; Retrospective Studies ; Stents ; Treatment Outcome

OBJECTIVETo discuss the availability of endovascular stent-graft exclusion in giant and long-segment thoracic aortic aneurysms.

METHODSEndovascular stent-graft exclusion was performed on 3 male patients with giant and long-segment thoracic aortic aneurysm. Multiple stent-grafts were connected as a long stent-graft to repair these thoracic aortic aneurysms, of which one with 28 cm in length and 7.3 cm in maximum diameter was excluded by 4 stent-grafts with different diameters and same length of 130 mm. The preliminary bypass between right common carotid artery and left common carotid artery or left common carotid artery and left subclavian artery was performed on 2 patients.

RESULTSThree patients underwent the operation successfully, and achieved the good results. There was no endoleak at the conjunction of stent-grafts in 2 cases, and a little endoleak in 1 case, which disappeared 1 year after operation. One case presented temporal cerebral ischemia, which disappeared after 1 month.

CONCLUSIONSThe endovascular deployment with multiple stent-grafts connection is a safe, mini-invasive and effective therapeutic method for giant and long-segment thoracic aortic aneurysm, but long-term outcomes will be gotten after the follow-up study.

Aged ; Aortic Aneurysm, Thoracic ; surgery ; Blood Vessel Prosthesis ; Blood Vessel Prosthesis Implantation ; instrumentation ; methods ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Stents ; Treatment Outcome

OBJECTIVETo discuss the safety, feasibility, efficacy and problem of endovascular repair (EVR) for ruptured aortic aneurysm (RAA).

METHODSFourteen patients with RAA were obtained diagnosis and anatomic data of proximal and distal neck through magnetic resonance imaging and CT. The patients with hypotension were accepted anti-shock treatment. Stent-grafts were deployed in proper position of RAA under X-ray fluoroscopic.

RESULTSThe time from rupture to operation was 50 min to 21 d. Three cases had plenty of blood in left pleural cavity and 2 cases were done under bleeding shock condition. Five cases with RAA were fixed by bifurcated stent-grafts and others by straight stent-grafts. Follow-up term was 1 month to 38 months. One with ruptured thoracic aortic aneurysm died 4 h later after operation, another one died of left thoracic cavity infection 9 months later, and others lived well without complication.

CONCLUSIONThe EVR is a safe, efficient and feasible method. It will be a potential alternative to treat RAA in future, but more suitable for RAA with better proximal and distal landing zones.

Adult ; Aged ; Aortic Rupture ; diagnosis ; surgery ; Blood Vessel Prosthesis ; Blood Vessel Prosthesis Implantation ; instrumentation ; methods ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Stents ; Treatment Outcome

OBJECTIVETo discuss the safety, feasibility, efficacy and problems of endovascular repair for aortic dissection.

METHODSFrom June, 1998 to Dec, 2004, 178 aortic dissections were treated by stent-grafts, including 76 acute cases and 102 chronic cases, 19 cases with Stanford A and 159 cases with Stanford B. Under local or general anesthesia, every stent-graft was deployed at the proper position of first tear entry through femoral artery under X-ray fluoroscopic. The changes of hemodynamic in true and false lumen, visceral and limbs blood supply were investigated after operation.

RESULTS10 cases combined with left common carotid artery or left subclavian artery or hepatic artery and superior mesenteric artery bypass. 36 left subclavian arteries were covered simultaneously without bypass and the average blood pressure of left brachial artery was (61.6 +/- 23.7) mm Hg. The stent-grafts were deployed above thoracic 8 in 159 cases and below thoracic 8 in 19 cases. This group included 3.4% 30-day death rate, 12.9% endoleak rate after deployment, and without misplace of stent grafts, migration, rupture, conversion to open surgery and paraplegia complication. The average operation time 1.5 h (0.5-4.3 h), blood loss 140 ml (30-500 ml), movement recover time 1.8 d (0.5-21.0 d), food recover time 1.5 d (0.5-9.0 d). The true lumen blood supply in most of damaged visceral arteries were improved. Follow up between 1 month to 76 months, the endoleak rate was 6.4% one month later.

CONCLUSIONThe endovascular repair is a safe, efficacy and feasible method to aortic dissection. The long term results keep in follow up.

Adult ; Aged ; Aneurysm, Dissecting ; surgery ; Aortic Aneurysm, Thoracic ; surgery ; Blood Vessel Prosthesis ; Blood Vessel Prosthesis Implantation ; methods ; Catheterization, Peripheral ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Treatment Outcome

OBJECTIVETo evaluate the results of a variety of alternative endovascular techniques applied to patients with complicated abdominal aortic aneurysm complex abdominal aortic aneurysm (cAAA) and unsuitable for open surgery.

METHODSFrom January 2001 to December 2010, charts of all patients having an abdominal aortic aneurysm (AAA) were reviewed. Endovascular aneurysm repair (EVAR) was done in 138 patients, in which 9 patients were defined as cAAA such as juxta-renal AAA, short or angulated AAA neck, AAA with bilateral iliac artery aneurysms. There were 8 male and 1 female patients, aged from 26 to 87 years with a mean of 67 years. All these patients at high risk for open surgery were offered a modified EVAR technique including fenestrated technique, scallop technique, chimney technique, balloon assisted U-turn stenting and reverse-U stent-graft in 2, 5, 1 and 1 patients respectively.

RESULTSAll techniques were successful and without severe postoperative complications. An intraoperative endoleak was found in 4 patients and was corrected immediately. One patient with type I and III endoleaks underwent dilatation with a compliant balloon. Two patients with type I endoleak underwent coil embolization (1 patient) and bare stent (1 patient). During follow-up, one patient with a type II endoleak who demonstrated no increase in sac diameter during follow-up was observed. Mean follow-up was 25.9 months (ranging from 4 to 79 months). No rupture occurred and 8 aneurysms shrink significantly. In 7 patients, critical vessels (renal and mesenteric arteries) were protected during the initial procedure and remained patent except in one patient who was performed reverse "U" stent graft with thrombosis in hypogastric artery.

CONCLUSIONHigh-risk patients with cAAA inappropriate for traditional EVAR can be successfully treated by using simple ancillary endovascular techniques with acceptable short or mid-term results.

Aged ; Aged, 80 and over ; Aortic Aneurysm, Abdominal ; surgery ; Blood Vessel Prosthesis ; Blood Vessel Prosthesis Implantation ; methods ; Female ; Humans ; Male ; Middle Aged ; Stents ; Treatment Outcome

OBJECTIVETo evaluate the initial and long-term results of endovascular aneurysm repair (EVAR) in high-surgical-risk abdominal aortic aneurysm (AAA) patients.

METHODSFrom July 1997 to July 2011, 120 consecutive high-surgical-risk patients with AAA who were treated electively using a bifurcated aortic endograft were entered in a registry. There were 96 male and 24 female patients, aged from 52 to 95 years with a mean of 74 years. Follow-up protocol consisted of computed tomography angiograms or ultrasound performed at 3, 6, 9, 12 months, and annually thereafter. The main goal was evaluation of the operative mortality and the long-term survival of these patients. Secondary goals were determination of the frequency of secondary operations, the outcome of the aneurysm sac, and primary and secondary patency rates after aortic endograft placement.

RESULTSMean aneurysm diameter was (57 ± 8) mm. Thirty-seven patients were operated under local anesthesia and eighty-three under general anesthesia. Five type I endoleaks, twenty-five type II endoleaks and one type III endoleak occurred during the perioperative period. The technical success rate was 95%. Operative mortality was 2.5%. The survival rates at 1-, 3- and 5-year were 92%, 75% and 43% respectively. The mean follow up was (36 ± 3) months. Primary and secondary patency rates at 3 year were respectively 97% and 100%. Secondary intervention rate was 10% (12/120) at 5 year. The reasons included endoleaks for 7 patients, stent-grafts fracture for 2 patients, stent-grafts migration for 2 patients and stent-graft thrombosis for 1 patients.

CONCLUSIONSInitial and long-term results with endograft repair of AAA in high-surgical-risk patients were satisfactory. These results appear to justify endovascular repair for this patient population.

Aged ; Aged, 80 and over ; Aortic Aneurysm, Abdominal ; surgery ; Blood Vessel Prosthesis ; Blood Vessel Prosthesis Implantation ; methods ; Female ; Humans ; Male ; Middle Aged ; Stents ; Treatment Outcome

OBJECTIVETo sum up the experience of performing ascending aorta replacement combined triple-branched stent graft implantation for acute Stanford type A aortic dissection.

METHODSFrom January 2010 to December 2010, 14 patients with acute Stanford type A aortic dissection underwent the procedure of performing ascending aorta replacement combined triple-branched stent graft implantation. Right axillary artery cannulation was used for cardiopulmonary bypass and selected cerebral perfusion. When the body temperature drops below 18°C, the ascending aorta was transected near the base of the innominate artery. From the incision, the triple-branched stent graft was implanted into the true lumen of the arch, descending aorta and the aorta bifurcation vessel. The transected stump of the ascending aorta was anastomosis to the proximal of the branched blood vessel prosthesis.

RESULTSCardiopulmonary bypass time was (186 ± 38) min, cross clamp time was (101 ± 27) min, and average selective cerebral perfusion and lower body arrest time was (39 ± 11) min. The in-hospital mortality was zero. One patient of transient postoperative neurologic dysfunction, one of acute renal failure, one of transient limbs disturbance, one of secondary thoracotomy operation, one of gastrointestinal hemorrhage and one of postoperative chylothorax were observed. CT angiography rechecked showed the position of the vascular stent were satisfactory and the blood flow of arterial branches stents were lucid. The false lumen of the aortic arch and descending aorta closed with thrombus or shrinked.

CONCLUSIONSThe patients required aortic arch to be reconstructed which had no main tearing of intima in the arch may be best candidates for this technique. Open triple-branched stent graft placement combined ascending aorta replacement is an effective means for aortic arch reconstruction in acute Stanford type A aortic dissection.

Adult ; Aged ; Aneurysm, Dissecting ; surgery ; Aorta, Thoracic ; surgery ; Blood Vessel Prosthesis ; Blood Vessel Prosthesis Implantation ; methods ; Female ; Humans ; Male ; Middle Aged ; Treatment Outcome ; Young Adult

OBJECTIVETo evaluate the therapeutic effect and safety of thoracic aortic replacement with concomitant endoluminal stent grafting in the treatment of DeBakey type I aortic dissection.

METHODSFrom September 2007 to January 2010, 6 patients with DeBakey type I aortic dissection (including one with aortic dissection relapse) received ascending aortic (or Bentall) and total aortic arch replacement and simultaneous stent graft implantation into the descending aorta. Multi-slice spiral CT scans (MSCT) were performed in each patient regularly after the surgery. Cardio-pulmonary bypass including deep hypothermic circulatory arrest with selective antegrade cerebral perfusion were used during the surgery.

RESULTSAll the patients recovered smoothly after the surgical procedure without serious complications. The time of cardiopulmonary bypass ranged from 208 to 291 min (mean 242 min), arrest time of the ascending aortic was 112-194 min (mean 145 min), and selective cerebral perfusion time was 63-102 min (mean 76 min). The patients were followed up for 4-32 months (mean 15.5 months), and MSCT revealed smooth blood flow in the prosthesis, complete thrombus formation in the false lumen in the perigraft space and shrinkage of the distal false lumen without internal fistula or stent dislocation.

CONCLUSIONThoracic aortic replacement with concomitant endoluminal stent grafting is a safe and effective treatment of DeBakey type I dissection.

Adult ; Aneurysm, Dissecting ; classification ; surgery ; Aortic Aneurysm ; classification ; surgery ; Blood Vessel Prosthesis ; Blood Vessel Prosthesis Implantation ; methods ; Female ; Humans ; Male ; Middle Aged ; Stents ; Treatment Outcome

OBJECTIVETo explore the feasibility of utilizing two implantable devices made from modified polyurethane films with antibody tethered replication-defective adenoviruses encoding for green fluorescent protein (AdGFP) as gene delivery platforms.

METHODSIntra-aortic button implants of collagen-coated polyurethane films with antibody tethered AdGFP were sutured into the infrarenal aorta of adult pigs and pulmonary valve leaflet in juvenile sheep was replaced by polyurethane pulmonary valve cusp replacement with antibody-tethered AdGFP. After seven days, the buttons, prosthetic leaflets, and their surrounding tissues were explanted and evaluated for biocompatibility and AdGFP-mediated gene transfer by fluorescent microscopy and PCR analysis.

RESULTSIn vivo analysis of gene transfer from collagen-coated polyurethane films in pig infrarenal aorta implants, one week explants of the collagen-coated polyurethane films demonstrated (14.2 +/- 2.5)% of neointimal cells on the surface of the implant. In sheep pulmonary valve leaflet replacement studies, polyurethane films with antibody tethered AdGFP vector demonstrated (25.1 +/- 5.7)% of cells attached to polyurethane valve leaflets were transduced in one week. PCR analyses showed that GFP DNA was not detectable in blood or distal tissues.

CONCLUSIONSite-specific intravascular delivery of adenoviral vectors for gene therapy can be achieved with these two kinds of polyurethane implants utilizing the antivector antibody tethering mechanism.

Adenoviridae ; genetics ; Animals ; Blood Vessel Prosthesis ; Gene Transfer Techniques ; Genetic Therapy ; methods ; Genetic Vectors ; Green Fluorescent Proteins ; genetics ; Heart Valve Prosthesis ; Male ; Polyurethanes ; chemistry ; Prosthesis Implantation ; Sheep ; Swine

Despite the wide acceptance of endovascular aneurysmal repair in patients with abdominal aortic aneurysm (EVAR), stringent morphologic criteria recommended by manufacturers may preclude this treatment in patients with AAA. The purpose of this study was to investigate how many patients are feasible by Zenith and Excluder stent graft system, which are available in Korea. Eighty-two AAA patients (71 men, mean age 70 yr) who had been treated surgically or medically from January 2005 to December 2006 were included. Criteria for morphologic suitability (MS) were examined to focus on characteristics of aneurysm; proximal and distal landing zone; angulation and involvement of both iliac artery aneurysms. Twenty-eight patients (34.1%) were feasible in Zenith stent graft and 31 patients (37.8%) were feasible in Excluder. The patients who were excluded EVAR had an average of 1.61 exclusion criteria. The main reasons for exclusion were an unfavorable proximal neck (n=34, 41.5%) and problem of distal landing zone (n=25, 30.5%). There was no statistical significance among gender, age or aneurysm size in terms of MS. Only 32 patients (39%) who had AAA were estimated to be suitable for two currently approved grafts by strict criteria. However, even unfavorable AAA patients who have severe co-mobidities will be included in EVAR in the near future. Therefore, more efforts including fine skill and anatomical understanding will be needed to meet these challenging cases.
Aged ; Aged, 80 and over ; Aortic Aneurysm, Abdominal/pathology/*surgery ; *Blood Vessel Prosthesis Implantation/methods ; Female ; Humans ; Male ; Middle Aged