Value of intravascular ultrasound for endovascular stent-graft placement in aortic dissection and aneurysm

BACKGROUND: Endovascular stent-graft placement is a new concept for the treatment of aortic dissection and aneurysm. Intravascular ultrasound (IVUS) with established diagnostic features may be instrumental in guiding endovascular procedures. METHODS: We performed IVUS and digital angiography before, during, and after implantation of 47 stent grafts in 40 patients with Stanford type B dissection (26 patients, 28 stent grafts), thoracic aneurysm (9 patients, 11 stent grafts), and abdominal aneurysm (5 patients, 8 stent grafts). RESULTS: IVUS could clearly identify the aortic anatomy and differentiate between true and false lumen in all cases of dissection. In four patients with type B dissection extending from the thoracic to the abdominal aorta the true lumen was exclusively identified by IVUS, and thus, essential for safe execution of the procedure. In another patient stent-graft placement in the aorta was optimized by covering a second entry detected by IVUS, but undetected by angiography. The site of stent implantation, the true and false lumen, as well as entry and reentry were always identified in both thoracic and abdominal aorta. In comparison with angiography, IVUS information led to additional balloon molding due to incomplete stent apposition in seven cases. CONCLUSIONS: As an adjunctive imaging modality IVUS is likely to improve stent-graft placement in aortic type B dissection, especially in patients with abdominal extension.     

Follow-up of stented carotid arteries by Doppler ultrasound

OBJECTIVE: Blood flow velocity (BFV) in the carotid artery is altered by stent placement. The significance of these alterations is unknown. In our experience, both standard BFV criteria for stenosis and customized criteria recommended by other authors have led to high rates of false-positive studies. We reviewed our experience with Doppler ultrasonography immediately after extracranial carotid artery stent placement to define criteria for restenosis by BFV. METHODS: Complete carotid angiograms and BFV results were available for 114 patients treated between January 1998 and December 1999. Angiographic images obtained immediately after stent placement and at follow-up were measured for residual or recurrent stenosis by a blinded reviewer according to the North American Symptomatic Carotid Endarterectomy Trial method. Results of BFV studies obtained within 1 week of stent placement were interpreted by using two standard criteria (A, peak in-stent systolic velocity greater than 125 cm/s; B, internal carotid artery-to-common carotid artery ratio greater than 3.0) and two customized criteria (C, peak in-stent velocity greater than 170 cm/s; D, internal carotid artery-to-common carotid artery ratio greater than 2.0). The results of follow-up angiography and the most recent Doppler study were compared for nine patients. RESULTS: On the basis of an examination of Doppler studies obtained immediately after stent placement, 36 patients met Criterion A for stenosis according to measured BFV (corresponding mean angiographic stenosis, 14.73 +/- 18.45%), 3 patients met Criterion B (mean stenosis, 1.67 +/- 2.89%), 8 patients met Criterion C (mean stenosis, 12.61 +/- 13.18%), and 14 met Criterion D (mean stenosis, 7.98 +/- 21.74%). No patient with Doppler criteria for significant stenosis had more than 50% residual stenosis. Three of nine patients who underwent follow-up angiography had stenosis of 50% or more; of these three patients, two underwent second angioplasty procedures. The peak in-stent systolic velocity or internal carotid artery-to-common carotid artery BFV ratio for each of the three patients with restenosis, but not for the six other patients, had increased by more than 80% since the immediate post-stenting Doppler study. CONCLUSION: Strict BFV criteria for restenosis after carotid artery stenting are less reliable than change in BFV over time. An immediate post-stenting Doppler study must be obtained to serve as a reference value for future follow-up evaluation.     

获得性动-静脉瘘的介入微创治疗

目的 评价用介入微创技术治疗获得性动一静脉瘘(AVF)的安全性和疗效。方法 对10例不适宜传统外科治疗的AVF患者进行介入治疗,包括肾动-静脉瘘4例、髂动-静脉瘘3例、锁骨下动-静脉瘘3例。致病原因为穿通性损伤5例、医源性损伤3例、恶性肿瘤和小肠Crohn病各1例。就诊时临床表现有肢体肿胀-静脉显露6例、局部血管杂音10例、心脏负荷增加10例、右心功能衰竭2例、血尿4例。3例用经导管超选择性栓塞,7例用被覆膜支架置人封闭瘘口。结果 10例患者均治疗成功,治疗结束时复查血管造影显示瘘口被封闭。轻微并发症3例,无严重并发症。术后患者局部肿胀、静脉充血、心脏负荷过度等症状迅速改善,血管杂音消失;肾脏AVF患者,术后肾功能测定属于正常,其中2例肾动脉被覆膜支架置入患者同位素肾扫描显示患侧肾脏形态-功能正常。术后随访6个月至6年。3例患者分别于术后6、9、14个月死于与AVF无关的疾病;2例于术后3周、2个月因AVF复发,在原支架区再次置入一个被覆膜支架后残留瘘口闭塞;2例于术后6、8个月复查造影显示支架区存在轻度狭窄。7例患者仍然生存,未再针对AVF进行外科或介人治疗。结论 介入微创技术,包括超选择性栓塞和被覆膜支架置入术,是治疗获得性、复杂型AVF安全有效的方法。     

Transesophageal echocardiography-guided algorithm for stent-graft implantation in aortic dissection

OBJECTIVE: Endovascular stent-graft placement is replacing traditional surgery in type B aortic dissection. Usually stent-graft implantation is performed under fluoroscopic and angiographic guidance, but this relatively new procedure is still burdened with some complications. We investigated the value of a developed algorithm based on transesophageal echocardiography (TEE) for guiding stent-graft implantation in type B aortic dissection. METHODS: Forty-two patients with type B aortic dissection (chronic in 28 patients with aneurysmal dilatation of the false lumen, and acute complicated in 14 patients) underwent endovascular stent-graft reconstruction of the descending thoracic aorta. TEE was always performed after angiography. TEE-induced variations of the procedure, based on the algorithm, were compared with initial angiography-based decisions. RESULTS: TEE was decisive for guidewire repositioning (not possible with fluoroscopy) from the false to the true lumen in 3 patients and for correct guidewire entrance in an elephant trunk prosthesis in another patient. After stent-graft implantation color Doppler TEE enabled detection of proximal peri-stent leaks in 13 patients, whereas only 6 (46%) of the 13 leaks were detectable at angiography (P = .008). Most leaks were subsequently eliminated with balloon dilation or further stent grafting. Pulsed Doppler TEE was also useful for differentiating true leaks (13 patients) from Dacron porosity (7 patients). A pulsed-Doppler velocity cutoff value of 50 cm/s enabled differentiation of Dacron porosity (characterized by slow blood flow) from true peri-stent leak (fast flow). After stent-graft implantation TEE demonstrated new intimal tears in the thoracic aorta in 7 patients, whereas only 2 of the 7 new tears were detectable at angiography (P = .024); in 6 of 7 patients the new distal tears were subsequently resolved with placement of additional stents, whereas in a patient with Marfan syndrome new proximal tears determined a type I endoleak, which could not be resolved. Overall, TEE furnished decisive information additional to angiography in determining successful procedural changes in 16 of 42 patients (38%). There were no in-hospital deaths, and pre-discharge spiral computed tomograms showed a good outcome of stent-graft implantation in 37 of 42 patients (88%), with 5 residual type I endoleaks, all previously detected with TEE but impossible to eliminate with either balloon molding or further stent implantation. All but 2 patients (95%) are currently alive at mean follow-up of 30 +/- 18 months. CONCLUSIONS: TEE algorithm is an easy and useful tool in the operating room to guide correct stent-graft positioning in type B aortic dissection.     

Efficacy of ultrasound scan contrast agents in the noninvasive follow-up of aortic stent grafts

OBJECTIVE: Computed tomographic angiography (CTA) is currently the most commonly used technique for postoperative surveillance to detect endoleaks after endovascular stent graft repair of abdominal aortic aneurysms. We have evaluated the efficacy of duplex ultrasound scan with the addition of an ultrasound scan contrast agent in documenting endoleaks and compared these results with CTA. METHODS: Conventional duplex ultrasound scan with color Doppler imaging (CDI) was first done as part of routine postoperative surveillance. After the CDI study, a 1-mL bolus of ultrasound scan contrast was given via an antecubital vein, followed by a 5-mL flush with normal saline solution. The duplex ultrasound scan evaluation of the stent graft was repeated once the contrast agent was circulating throughout the blood pool, with tissue harmonic imaging to optimize visualization of the contrast agent. Status of the stent graft, the presence or absence of any endoleak, and whether these endoleaks were graft related (group I) or arterial branch related (group II) were recorded. Findings were compared with CTA studies done within a 2-week period of the ultrasound scan examination. RESULTS: Twenty patients were evaluated, 18 with modular stent grafts and two with unibody bifurcated stent grafts. Patients had a mean age of 74.5 +/- 7.6 years; 19 were male, with only one female. All stent grafts remained widely patent with normal aortoiliac flow hemodynamics. Duplex ultrasound scan with contrast identified all eight of the endoleaks seen with CTA and was able to determine whether they were group I or group II leaks. In two patients, ultrasound scan with contrast detected small endoleaks at the proximal graft attachment site, with extravasation of contrast into the aneurysm sac during systole. These endoleaks were not seen with CTA but were confirmed with conventional angiography at the time of endovascular closure. Standard duplex ultrasound scan with CDI failed to identify four of the 10 endoleaks in patients with technically difficult conditions. CONCLUSION: Duplex ultrasound scan, when used with an intravenously administered ultrasound scan contrast agent in the noninvasive follow-up of patients with aortic stent grafts, appears to provide good sensitivity to the presence and type of endoleaks, even in patients with technically difficult conditions not amenable to conventional duplex ultrasound scan with CDI.     

Preoperative imaging diagnosis of carotid body tumors

Carotid body tumors (CBTs) are relatively frequent lesions encountered at high altitudes, such in as the Andean Mountains. A correct preoperative diagnosis is essential for surgical planning and performance. For this reason, we have reviewed the evolution of our experience in the imaging diagnosis of these tumors. Between 1980 and June 2008, 160 CBTs were diagnosed. A total of 138 tumors were operated on, 4 are waiting for surgery, and 18 were not operated on because of age, medical conditions, or patient refusal. We have reviewed retrospectively the modalities of imaging diagnosis in our patients who underwent operation. Among the 138 tumors operated on, a correct preoperative diagnosis was done in 127 cases (92%). The preoperative diagnosis of the remaining 11 patients was unspecified benign tumor for 6 patients and neck lymph node for 5 patients. The imaging methods performed by different radiologists were conventional ultrasound, color Doppler ultrasound, carotid conventional angiography (CA), axial tomography, magnetic resonance and magnetic resonance angiography, and computed tomographic angiography (CTA). Most patients had more than one image study. Review of radiologist reports revealed a correct diagnosis in all carotid CA, magnetic resonance studies, and CTA. Additionally, CTA appeared to be a valuable method to predict the Shamblin group. Clinical suspicion and current image techniques permit a correct diagnosis in practically all cases of CBT.     

Dynamic aortic changes in patients with thoracic aortic aneurysms evaluated with electrocardiography-triggered computed tomographic angiography before and after thoracic endovascular aneurysm repair: preliminary results

The purpose of this study was to utilize dynamic computed tomographic angiography (CTA) on pre- and postoperative thoracic endovascular aneurysm repair (TEVAR) patients to characterize cardiac pulsatility-induced aortic motion on essential TEVAR proximal sealing zones and to study the influence of endograft placement. Six pre- and six postoperative dynamic CTA studies were obtained in six patients with thoracic aortic aneurysms (TAAs) undergoing TEVAR. Data were acquired using a retrospective electrocardiography-triggered dynamic CTA scan, with eight reconstructed phases over the cardiac cycle. Scans were acquired during a single breath hold. Multiplanar reconstructions were made perpendicular to the aorta at five surgically relevant anatomical thoracic landmarks: 1 cm proximal to the innominate trunk, 1 cm proximal and 1 cm distal to the left subclavian artery, and 1 cm proximal and 3 cm distal to the proximal end of the stent. After segmentation of the aortic lumen in the images, diameter change and area change over the cardiac cycle were measured. Diameter change was measured through the center of mass of the aortic lumen, and the average change over 180 axis is presented. We found significant distention of the thoracic aortic arch and descending thoracic aorta during the cardiac cycle before and after TEVAR. Distention ranged 3-12% in diameter and 2-20% in area. This distention was preserved after TEVAR. Patients with TAA experience aortic diameter and area changes during the cardiac cycle. The magnitude, and hence the clinical importance, of this aortic distention varies among patients. After stent-graft placement, aortic distention throughout the cardiac cycle is preserved. This may have major implications for correct sizing of the endograft as well as for stent-graft design and durability as the forces on the stents may be much larger after implantation than initially anticipated by stent manufacturers.     

Delayed stenosis following placement of a polyethylene terephthalate endograft in the cervical carotid artery. Report of three cases

Three patients with carotid artery (CA) pseudoaneurysms were treated using four polyethylene terephthalate endografts (Wallgraft endoprostheses). Two patients received a single graft and one patient with bilateral pseudoaneurysms received two grafts. Complete occlusion of the pseudoaneurysm with patency of the arterial lumen was achieved following endograft placement in all patients. The clinical follow-up interval ranged from 12 to 18 months and included angiography or ultrasonography studies or both. One patient experienced neurological symptoms, and in-graft stenosis ranging from 50 to 100% occurred in three of the four grafts. Although the Wallgraft endoprosthesis produced good initial results for the treatment of cervical CA pseudoaneurysms, as demonstrated on radiography, it was associated with a high rate of stenosis or occlusion in all three patients.     

Large vertebral arteriovenous fistula treated with stent-grafts--case report

A 24-year-old woman presented with neck bruit and thrill. Neurological examination revealed no focal abnormality. Angiography and magnetic resonance imaging showed an arteriovenous fistula (AVF) at the C4-5 levels of the right vertebral artery (VA). The fistula had a single orifice that drained into the epidural veins via the C4-5 intervertebral foramen. A stent-graft was made of a 3.9 cm balloon-expandable stent and an expandable polytetrafluoroethylene graft sutured outside the stent. The stent-graft was advanced through the femoral artery up to the VA but did not pass far enough distally to seal the entire fistula because of the high friction between the bulky device and the small vessel. Another 2 cm stent-graft was delivered and successfully positioned across the fistula. The AVF completely disappeared and the right VA was well preserved. Follow-up angiography at 3 weeks and 5 months after the treatment showed no fistula and no stenosis inside the stent-grafts. Stent-grafts are useful to treat AVF with a large orifice. The stent-graft is a promising technology to treat neurovascular diseases, although improvement is required for use in smaller vessels.     

Serious complications that require surgical interventions after endoluminal stent-graft placement for the treatment of infrarenal aortic aneurysms

BACKGROUND: Endoluminal stent-graft placement for the treatment of infrarenal abdominal aortic aneurysms has gained widespread acceptance because it is associated with lower peri-interventional morbidity than conventional transabdominal surgery. In this study the long-term morbidity of the procedure was evaluated. METHODS AND RESULTS: Between September 1994 and December 1998, 150 patients (age, 69.6 +/- 8.49 years; 142 men, 8 women) with abdominal aortic aneurysms were treated with the placement of an intravascular nitinol stent-graft (Stentor [55] and Vanguard-System [95]); there were eight tubular grafts and 142 bifurcated grafts. Initial placement of the stent-graft was successful in 144 patients. Mean follow-up was 49 +/- 25 months. In 13.3% of stent-graft placements we encountered the following complications: 4 cases of migration or dislocation of the prosthesis (30.5 +/- 7.4 months after placement); 2 ruptures of the aorta (26.7 and 15.0 months after placement); 3 recurrent thromboses of the stent-graft (25.5 +/- 5.3 months after placement); 3 endoleaks (27.5 +/- 15.7 months after placement); and 5 infections of the prosthesis (26.6 +/- 16.5 months after placement). There was no correlation between the complications and the type of stent used. All of these patients were treated by surgical replacement of the prosthesis with a Dacron graft. CONCLUSIONS: (1) The results suggest that most complications are due to a continuation of the disease process leading to loosening of the prosthesis. (2) Explantation of the prosthesis and surgical repair is feasible but bears additional risks. (3) Because the onset of reperfusion of the excluded aneurysm cannot be predicted, all patients with infrarenal aortic stent-grafts require frequent computer tomographic follow-up. (4) Finally, the results call for further improvements in the design of the stent-graft.     

Treatment of traumatic aneurysms and arteriovenous fistulas of the skull base by using endovascular stents

OBJECT: The authors describe their preliminary clinical experience with the use of endovascular stents in the treatment of traumatic vascular lesions of the skull base region. Because adequate distal exposure and direct surgical repair of these lesions are not often possible, conventional treatment has been deliberate arterial occlusion. The purpose of this report is to demonstrate the safety and efficacy as well as limitations of endovascular stent placement in the management of craniocervical arterial injuries. METHODS: Six patients with vascular injuries were treated using endovascular stents. There were two arteriovenous fistulas and two pseudoaneurysms of the distal extracranial internal carotid or vertebral arteries resulting from penetrating trauma, and two petrous carotid pseudoaneurysms associated with basal skull fractures. In one patient a porous stent placement procedure was undertaken as well as coil occlusion of an aneurysm, whereas in the remaining five patients covered stent grafts were used as definitive treatment. There were no procedural complications. One patient in whom there was extensive traumatic arterial dissection was found to have asymptomatic stent thrombosis when angiography was repeated 1 week postoperatively. This was the only patient whose associated injuries precluded routine antithrombotic or antiplatelet therapy. Follow-up examinations in the remaining five patients included standard angiography (four patients) or computerized tomography angiography (one patient), which were performed 3 to 6 months postoperatively, and clinical assessments ranging from 3 months to 1 year in duration (mean 9 months). In all five cases the vascular injury was successfully treated and the parent artery remained widely patent. No patient experienced aneurysm recurrence or hemorrhage, and there were no thromboembolic complications. CONCLUSIONS: The authors' experience demonstrates that endovascular treatment of traumatic vascular lesions of the skull base region is both feasible and safe. The advantages of minimally invasive stent placement and parent artery preservation make this procedure for repair of neurovascular injuries a potentially important addition to existing methods.     

Double-barrel technique for preservation of aortic arch branches during thoracic endovascular aortic repair

Thoracic endovascular aortic repair (TEVAR) may involve either planned or inadvertent coverage of aortic branch vessels when stent grafts are implanted into the aortic arch. Vital branch vessels may be preserved by surgical debranching techniques or by placement of additional stents to maintain vessel patency. We report our experience with a double-barrel stent technique used to maintain aortic arch branch vessel patency during TEVAR. Seven patients underwent TEVAR using the double-barrel technique, with placement of branch stents into the innominate (n = 3), left common carotid (n = 3), and left subclavian (n = 1) arteries alongside an aortic stent graft. Gore TAG endografts were used in all cases, and either self-expanding stents (n = 6) or balloon-expandable (n = 1) stents were utilized to maintain patency of the arch branch vessels. In three cases the double-barrel stent technique was used to restore patency of an inadvertently covered left common carotid artery. Four planned cases involved endograft deployment proximally into the ascending aorta with placement of an innominate artery stent (n = 3) and coverage of the left subclavian artery with placement of a subclavian artery stent (n = 1). TEVAR using a double-barrel stent was technically successful with maintenance of branch vessel patency and absence of type I endoleak in all seven cases. One case of zone 0 endograft placement with an innominate stent was complicated by a left hemispheric stroke that was attributed to a technical problem with the carotid-carotid bypass. On follow-up of 2-18 months, all double-barrel branch stents and aortic endografts remained patent without endoleak, migration, or loss of device integrity. The double-barrel stent technique maintains aortic branch patency and provides additional stent-graft fixation length during TEVAR to treat aneurysms involving the aortic arch. Moreover, the technique uses commercially available devices and permits complete aortic arch coverage (zone 0) without a sternotomy. Although initial outcomes are encouraging, long-term durability remains unknown.     

Evaluation of aortoiliac aneurysm before endovascular repair: comparison of contrast-enhanced magnetic resonance angiography with multidetector row computed tomographic angiography with an automated analysis software tool

PURPOSE: The purpose of this study was to assess accuracy and reliability of a volumetric analysis of abdominal aneurysms on the basis of multidetector row computed tomographic angiography (CTA) and magnetic resonance angiography (MRA) with a commercially available automated vessel analysis software program. MATERIALS AND METHODS: Twenty patients with abdominal aortic aneurysms underwent preoperative CTA and MRA before endovascular repair. Postdeployment CTA was performed in 15 of these 20 patients (75%). All preoperative CTA and MRA and postdeployment CTA data sets were analyzed with an automated software tool. The length of the stent grafts on postdeployment CTA was measured and compared with the true length of the primary component. Two readers independently evaluated 13 vessel parameters on preoperative CTA and MRA, which are considered to be important in planning stent graft deployment. RESULTS: With the automated analysis software tool, all measurements could be performed on either CTA or MRA data sets. There was no statistically significant difference between postdeployment measurements of stent graft length on CTA and the true dimensions of the implanted stent grafts. Interobserver agreement for all of the measurements with either CTA or MRA was good to excellent (interclass coefficient, 0.71 to 0.99) with only minimal mean differences of measured dimensions between both readers (range, -2.0 to +2.3 mm, Bland-Altman). Intermodality agreement between CTA and MRA was good to excellent (interclass coefficient, 0.62 to 0.98) with small mean differences of measured dimensions between both methods (range, -4.1 to +2.1 mm, Bland-Altman). CONCLUSION: Volumetric measurement with an automated analysis software tool allows a fast, precise, and reliable noninvasive preoperative determination of all aortic dimensions on the basis of either CTA or MRA data sets.     

Packing Technique for Endovascular Coil Embolisation of Peripheral Arterial Pseudo-aneurysms with Preservation of the Parent Artery: Safety,Efficacy and Outcomes

ObjectivesTo evaluate the endovascular treatment of pseudo-aneurysms (PAs) with super-selective coil embolisation using the 3D packing technique.DesignRetrospective study of consecutive patients in one academic centre.MaterialsFrom 2002 to 2009, 16 patients (mean age 51.6 years, range 24–82) underwent PA sac packing with coils. Four patients were asymptomatic, nine had PA rupture, and three had other symptoms. Lesion location was as follows: splenic artery (8), carotid artery (2), hepatic artery (2), superior mesenteric artery (1), cystic artery (1), uterine artery (1), and hypogastric artery (1).MethodsThe sac was packed with 0.018-inch controlled-detachable microcoils, preserving the parent artery. Magnetic resonance angiography was done within 6 months, at 12 months then yearly.ResultsTechnical success rate was 100%. Complete definitive PA exclusion was achieved with a single procedure in 15 (93.8%) patients. One patient with a secondary bleeding arterio-digestive fistula underwent successful surgery. No major complications or late recanalisations occurred during follow-up (mean, 24.7 months; range 6–49).ConclusionsCoil PA embolisation by 3D sac packing is safe and effective and may induce less morbidity than complete parent vessel occlusion, stent placement, or open surgery. This procedure should be used whenever possible, as it preserves parent artery patency.     

Traumatic pseudoaneurysms of the head and neck: early endovascular intervention

BACKGROUND: Trauma to the head and neck with military munitions often presents with complex multisystem injury patterns. Vascular evaluation typically focuses on the carotid and vertebral arteries; however, trauma to branches of the external carotid artery may also result in devastating complications. Pseudoaneurysms are the most frequent finding on delayed evaluation and can result in life-threatening episodes of rebleeding. METHODS: Patients evacuated from the Afghanistan and Iraq conflicts with penetrating injury to the face and neck were evaluated by the vascular surgery service to determine the potential for unsuspected vascular injury. Patients with significant penetrating injury underwent computed tomography angiography (CTA) as the initial evaluation and subsequent arteriography in cases where injuries were suspected or metallic fragments produced artifacts obscuring the vasculature. Data on all vascular evaluations were entered prospectively into a database and retrospectively reviewed. RESULTS: Between February 2003 and March 2007, 124 patients were evaluated for significant penetrating trauma to the head and neck. Thirteen pseudoaneurysms of the head and neck were found in 11 patients: two in the internal carotid artery, one of the vertebral artery, and 10 involving branches of the external carotid. Seven pseudoaneurysms were symptomatic, of which two presented with episodes of massive bleeding and airway compromise. Seven pseudoaneurysms were treated with coil embolization, 1 with Gelfoam (Upjohn, Kalamazoo, Mich) embolization, 2 with stent grafts, 2 with open repair, and 1 with observation alone. None of the patients undergoing embolization had complications; however, a stent graft of the internal carotid artery occluded early, without stroke. All of the pseudoaneurysms had resolved on follow-up CTA or angiogram. CONCLUSIONS: Pseudoaneurysms are a common finding in patients with high-velocity gunshot wounds or blast injuries to the head and neck. Most involve branches of the external carotid artery and can be treated by embolization. CTA should be performed on all patients with high-velocity gunshot wounds or in cases of blast trauma with fragmentation injuries of the head and neck.     

Treatment of extracranial and intracranial aneurysms and arteriovenous fistulae using stent grafts

OBJECTIVE: Treatment of 11 patients with aneurysms or arteriovenous fistulae of the craniocervical arteries with stent grafts. METHODS: Peripheral stent grafts were deployed in two extracranial internal carotid arteries. Coronary stent grafts were used to treat two giant aneurysms, five direct carotid-cavernous fistulae, one vertebrojugular fistula, and two dissecting aneurysms of the vertebral artery (V2 and V4). RESULTS: Stent grafts were used successfully in two extracranial internal carotid and two extracranial vertebral arteries, one dissecting aneurysm of the intracranial vertebral artery, one giant aneurysm and one pseudoaneurysm of the cavernous internal carotid artery, and five direct carotid-cavernous sinus fistulae. Angiographic follow-up examinations (available in nine patients; obtained at 3 mo to 5 yr; average, 24 mo) revealed normal vessel caliber, and the stent grafts in all 9 of 11 initial patients were patent. There was a recurrent saccular aneurysm adjacent to the stent graft in the patient with the intracranial vertebral artery aneurysm. The following five complications were encountered: transient hemiparesis (n = 2), increased hemiparesis, postprocedural management-related fatality, and ICA dissection. In six patients, stent graft deployment was accomplished without any technical or clinical complication. There were no permanent neurological deficits consequent to stent graft placement. CONCLUSION: Stent grafts are a useful tool for the endovascular treatment of head and neck aneurysms and direct arteriovenous fistulae in selected patients. The major disadvantage of the currently available stent grafts is their lack of mechanical flexibility. Maneuvering stent grafts in the intracranial arteries carries the risk of iatrogenic vessel dissection and may require supportive measures and protection of the target site by conventional stents.     

Midterm results of stent-graft repair for thoracic aortic aneurysms: computed tomographic evaluation

Midterm observation of endovascular surgery using a fabric-covered stent graft for thoracic aortic aneurysms is discussed with postoperative follow-up findings based on regularly performed thoracic computed tomography (CT). From 1996 to 1999, 20 patients with thoracic aortic aneurysm underwent stent-graft placement in our hospital. One year follow-up CT results after placement were obtained for 17 patients. The CT scans found that there were both thrombosis and size reduction of aneurysm in 8 patients (46%), thrombosis without size reduction in 2 (13%), a new ulcerlike projection (ULP) in 3 (19%), persistent minor endoleakage in 2 (13%), a new endoleak in 1 (6%), and a recurrent endoleak from intercostal arteries in 1 (6%). The new ULP formation seemed to be a peculiar problem stemming from an intimal injury caused by edges of the stent. Therefore, we recently adopted a new spiral stent instead of the previous stent to avoid the injury. The new endoleak suggested that aneurysmal thrombosis without size reduction could cause the aneurysm to develop recurrent endoleaks. From these findings, we concluded that midterm observation of stent-graft repair for thoracic aortic aneurysms did not give satisfactory results. In order to improve the results of endovascular surgery using stent-grafts, we need to develop safer stent grafts with a reliable design to prevent endoleaks and to avoid intimal injury of the aorta. We also hope to develop effective technologies that can accelerate organization of thrombus in the aortic aneurysm after stent-graft placement.     

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??Endovascular repair of Stanford B dissection with branched stent-graft??An analysis of 11 cases YANG Jue??FU Wei-guo??XU Xin??et al. Department of Vascular surgery??Zhongshan Hospital??Fudan University??Shanghai 200032??China
Corresponding author??FU Wei-guo??E-mail??fu.weiguo@zs-hospital.sh.sn
Abstract Objective To summarize experience of thoracic endovascular aortic repair (TEVAR) in patients with proximal short landing zone with branched stent-graft. Methods A total of 11 patients with Stanford B dissection who underwent TEVAR with left subclavian artery ??LSA?? revascularization by single-branched stent-graft from July 2013 to February 2014 were retrospectively reviewed. Routine postoperative follow-up with computed tomography angiography (CTA) was performed to assess TEVAR and LSA patency??endoleak??dissection exclusion and complications in 1 and 6 months. Results TEVAR with single-branched stent-graft was successfully performed in 10 patients??and 1 patients failed by unsuccessful deployment of branched stent and replaced by another stent-graft with coverage of LSA. The mean operative time was??130.0±36.0??minutes. No major complications occurred. All patients were followed up in 1 and 6 months postoperatively. Type ?? endoleak was noted in 1 patient and 1 patient had an asymptomic LSA stent occlusion by CTA. Thrombosis formed in the aortic false lumen of the graft exclusion segment in all the patients??and the average diminution was 12mm. Conclusion Branched stent-graft is a feasible and effective option for LSA revascularization with proximal landing zone ??20 mm during TEVAR.     

Emergency stent placement for symptomatic acute carotid artery occlusion after endarterectomy. Case report

The authors report a case of emergency carotid artery (CA) stent placement for a symptomatic acute CA occlusion following carotid endarterectomy (CEA). This 43-year-old man underwent a right-sided CEA for an asymptomatic 80% CA stenosis detected using duplex ultrasound testing. The patient experienced hypotension and possibly a myocardial infarction intraoperatively and a left hemiplegia immediately postoperatively. He was referred to the authors' institution for consideration of emergency coronary intervention and evaluation of stroke. A computerized tomography scan of the head demonstrated subtle early ischemic changes in the right posterior parietal region. Cerebral angiography revealed occlusion of the right common CA (CCA) at the CA bifurcation. Two coronary stents (Magic Wall; Boston Scientific Scimed, Maple Grove, MN) were placed in tandem in the right CCA and internal CA (ICA), overlapping at the proximal cervical ICA. Complete recanalization of the CA was achieved, and the patient made a clinically significant recovery. Diagnostic angiography can provide important information about CA and intracranial circulation that will aid in the evaluation of postoperative stroke after CEA. Stent placement should be considered as an alternative method of treatment for acute CA occlusion or dissection following CEA.     

Long-term outcome and reintervention after endovascular abdominal aortic aneurysm repair using the Zenith stent graft

OBJECTIVE: To assess the long-term performance of the bifurcated Zenith stent graft. METHODS: A total of 325 patients (300 men and 25 women) underwent elective endovascular abdominal aortic aneurysm repair with bifurcated Zenith stent grafts between October 1998 and December 2005. Follow-up included routine contrast-enhanced computed tomography and multiview abdominal radiographs at 1, 6, and 12 months and yearly thereafter. Data on late-occurring (>30 days after stent-graft implantation) complications and interventions were collected prospectively. RESULTS: Of the original 325 patients, 92 have since died, resulting in a mean follow-up of 2.3 years (range, 1 month to 7.0 years). Nine (2.8%) of 325 patients required reintervention to treat or prevent endoleak (type I or III) or graft occlusion at an average of 1.4 years after stent-graft placement (range, 40 days to 4.0 years). Three (0.9%) of these patients died from causes related to malfunction of the stent graft: one each from aneurysm rupture, stent-graft infection, and infection of a femoral-femoral bypass graft placed after limb occlusion. Nineteen additional patients (5.8%) required treatment for type II endoleak, for a total reintervention rate of 8.6%. CONCLUSIONS: Late failures of Zenith stent-graft attachment, structure, or function are rare. In the absence of known endoleak, routine follow-up imaging plays a limited role in the identification and prevention of impending failure.