Endovascular repair of radiation-induced bilateral common carotid artery stenosis and pseudoaneurysms: a case report

BACKGROUND

Radiation-induced damage to small and medium-sized vessels has been observed in both animals and humans. Changes may appear in the immediate postradiation period or many years later. In this case, we report an unusual presentation of bilateral radiation-induced carotid artery stenoses associated with pseudoaneurysms, and a previously unreported application of a recently established treatment.

CASE DESCRIPTION

A 72-year-old African-American male presented with recurrent right hemispheric transient ischemic attacks (TIA) and neck pain. Thirteen years previously, the patient had received radiation therapy for laryngeal carcinoma. Diagnostic carotid angiography demonstrated moderate radiation-induced bilateral carotid artery stenosis and associated common carotid pseudoaneurysms. The patient was treated with bilateral endovascular stents and electrolytically detachable coils in staged procedures. At his most recent follow-up, there is no evidence of re-stenosis and the patient remains asymptomatic.

CONCLUSIONS

This case illustrates a novel and successful treatment for the endovascular repair of post-radiation bilateral carotid artery stenosis and pseudoaneurysms. In our practice, we have seen three such cases of radiation-induced vasculopathy. Therefore, patients with a previous history of radiation therapy for head and neck neoplasms merit cautious monitoring and judicious use of stents and secondary coils, when necessary.     

Transarterial intravenous coil embolization of dural arteriovenous fistula involving the superior sagittal sinus

BACKGROUND

We report a rare case of traumatic dural arteriovenous fistula involving the superior sagittal sinus successfully treated by transarterial intravenous coil embolization.

CASE PRESENTATION

A 38-year-old woman presented with tension headache. She had a past history of severe head injury at the age of three. Computed tomography scanning showed a heterogenous low-density area in the right frontal lobe, and magnetic resonance imaging demonstrated abnormal vascular structures in the same area. Angiography revealed a dural arteriovenous fistula involving the lateral wall of the fully patent superior sagittal sinus. The fistula was fed by scalp, meningeal, and cortical arteries, and drained into a cortical vein leading to the superior sagittal sinus. Femoral transarterial intravenous embolization with microcoils completely occluded the dural arteriovenous fistula.

CONCLUSION

Severe head injury may lead to asymptomatic dural arteriovenous fistulas after a long time. Transarterial intravenous coil embolization can be effective in the treatment of dural arteriovenous fistulas involving the superior sagittal sinus.     

Acute endovascular treatment of ruptured aneurysms in poor-grade patients

We reviewed the 6-month outcome of 45 consecutive patients in poor grade treated acutely by coiling after subarachnoid haemorrhage (SAH). About half had a favourable outcome, a promising result in accordance with some surgical and endovascular reports proposing early aggressive treatment of an aneurysm causing SAH. The poor clinical grade, due to parenchyma damage from the SAH, remains the main prognostic factor, rebleeding from the untreated aneurysm being only one cause of poor outcome. It is therefore difficult to isolate the impact of any treatment of the aneurysm on outcome, and unavoidable selection bias may strongly influence favourable results. Nevertheless, available evidence and the limited invasiveness suggest that acute endovascular treatment is reasonable in these patients.Presented in part at the XVII Symposium Neuroradiologicum, Paris, 2002     

Analytical approach to noncircular section birdcage coil design: verification with a Cassinian oval coil.

A general analytical framework is presented for the design of birdcage radiofrequency resonators on cylindrical formers having arbitrary cross-sectional shape. The primary objective of such shapes would be to improve the sensitivity of the NMR experiment to noncircular regions of the human anatomy while maintaining field homogeneity and quadrature polarization comparable to those of standard circular birdcage coils. The shape of the corresponding radiofrequency screen, which is required to decouple the coil from the rest of the NMR system and which is key to the performance, is also provided by this methodology. The theory was tested by constructing a 3-T, quadrature, proton coil on a shape conforming to the anthropomorphic mean of the human head, namely, the oval of Cassini. Both bench tests (Q) and in vivo spectral and imaging comparisons of the Cassinian coil with an equivalently dimensioned and constructed circular birdcage coil, respectively, predicted and demonstrated in vivo an improvement in SNR of approximately 24% over the circular section coil. The experimental RF field homogeneity and quadrature performance were comparable for both coil geometries, with the circular coil being marginally superior.     

GDC血管内栓塞治疗颅内动脉瘤

目的 探讨电解可脱性弹簧圈（GDC）血管内栓塞治疗颅内动脉瘤的疗效和技术要点。方法 对31例动脉瘤患者应用微导管技术,通过数字减影全脑血管造影,采用GDC作动脉瘤囊内填塞治疗。结果 31例31枚动脉瘤中28枚瘤腔完全闭塞,3枚95％闭塞。术后30例临床痊愈;1例死亡;病死率3．2％。术中并发动脉瘤再破裂出血1例;术后弹簧圈末端逸出1例。术后随访0．5～3年均无再出血。结论 GDC血管内栓塞治疗颅内动脉瘤疗效可靠,早期栓塞及有效的术后处理是提高治愈率的重要方法。     

Use of a three-station phased array coil to improve peripheral contrast-enhanced magnetic resonance angiography

PURPOSE: To explore the imaging capabilities of a new commercially available, three-station, 129-cm long, 12-element phased array coil for contrast-enhanced magnetic resonance angiography (CE-MRA) in patients with symptomatic peripheral arterial occlusive disease. MATERIALS AND METHODS: Nineteen patients, referred for peripheral CE-MRA, were evaluated using the new three-station coil. For each station four coil elements (two anterior and two posterior to the patient) were used. The expected improvements in signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were used to improve spatial resolution and increase anatomic coverage for the distal two stations compared to our previous protocol. Images obtained in the 19 patients imaged with the new coil were compared to those of the last 19 patients scanned without the use of the new coil. Differences in image quality before vs. after the availability of the new coil were compared in terms of SNR and CNR, subjective interpretability score (SIS), degree of venous enhancement, and anatomic coverage. Images were interpreted by two experienced observers, blinded for imaging technique and each other's results. RESULTS: Use of the coil enabled acquisition of high resolution peripheral vasculature images in all cases and allowed for substantially smaller voxel sizes (thighs: 5.3 vs. 8.4 mm(3) [-37%]; legs: 1.8 vs. 8.0 mm3 [-78%]) and much shorter acquisition durations in the aortoiliac and thigh stations (aortoiliac: 16 vs. 27 seconds [-41%]; thighs: 11 vs. 23 seconds [-52%]). Acquisition duration in the leg station was prolonged (68 vs. 29 seconds [+134%]). SNR and CNR were significantly higher only in the aortoiliac station using the three-station coil (both: P < 0.001). There were no significant differences in SIS for the aortoiliac and thigh stations (aortoiliac station: observer 1: P = 0.16, observer 2: P = 0.19; thigh station: both observers: P = 0.27). Images acquired with the new coil had significantly higher SIS for the leg station (both observers: P = 0.004). There were no significant differences in venous enhancement between the two protocols for any of the stations (all P > 0.11). In 12/12 (100%) requested cases the entire pedal arch was depicted using the new coil, whereas this was not possible with the old protocol. CONCLUSION: The new three-station dedicated peripheral vascular coil allows for much higher resolution imaging in the thigh and leg stations with greater anatomic coverage and substantially improves peripheral MRA quality of the lower leg vasculature.     

支架结合弹簧圈治疗颅内宽颈动脉瘤急性破裂的可行性和安全性

目的　总结血管内支架结合电解可脱卸弹簧圈 (GDC)治疗颅内宽颈动脉瘤急性破裂的临床体会 ,对其可行性和安全性进行初步探讨。方法　 5 7例急性破裂宽颈动脉瘤 ,均先植入冠脉支架覆盖动脉瘤颈 ,再将微导管通过支架网孔超选进入动脉瘤腔内填塞GDC。结果　 1例因血管扭曲不能植入支架 ,5 6例成功 ,均达到 90 %以上栓塞 ,载瘤动脉通畅 ,所有患者无神经功能障碍出现。结论　血管内支架植入结合GDC填塞是治疗急性破裂宽颈动脉瘤的安全、可行的方法     

A 32‐channel lattice transmission line array for parallel transmit and receive MRI at 7 tesla

Transmit and receive RF coil arrays have proven to be particularly beneficial for ultra‐high‐field MR. Transmit coil arrays enable such techniques as B₁⁺ shimming to substantially improve transmit B₁ homogeneity compared to conventional volume coil designs, and receive coil arrays offer enhanced parallel imaging performance and SNR. Concentric coil arrangements hold promise for developing transceiver arrays incorporating large numbers of coil elements. At magnetic field strengths of 7 tesla and higher where the Larmor frequencies of interest can exceed 300 MHz, the coil array design must also overcome the problem of the coil conductor length approaching the RF wavelength. In this study, a novel concentric arrangement of resonance elements built from capacitively‐shortened half‐wavelength transmission lines is presented. This approach was utilized to construct an array with whole‐brain coverage using 16 transceiver elements and 16 receive‐only elements, resulting in a coil with a total of 16 transmit and 32 receive channels. Magn Reson Med 63:1478–1485, 2010. © 2010 Wiley‐Liss, Inc.     

Single-center experience with the Neuroform stent for endovascular treatment of wide-necked intracranial aneurysms

Background

Stent-assisted coiling is an accepted endovascular treatment (EVT) for wide-necked intracranial aneurysms. The Neuroform stent (Target Therapeutics, Fremont, Calif) is a flexible nitinol self-expandable stent that was designed to potentially overcome the limitations of balloon expandable coronary stents in the intracranial circulation. The aim of this study was to reenforce the use of this stent for EVT of wide-necked cerebral aneurysms.

Methods

Between March 2005 and March 2008, 24 patients harboring wide-necked cerebral aneurysms were treated with stent reconstruction of the aneurysm neck. Inclusion criteria restricted the group to adult patients with wide-necked intracranial aneurysms (ruptured and unruptured lesions). Immediate postprocedure angiography studies were performed to determine successful coil occlusion of the aneurysm as well as patency of the parent vessel. We assessed the clinical history, aneurysm dimensions, and technical detail of the procedures, including any difficulties with stent placement and deployment, degree of aneurysm occlusion, and complications. Clinical outcome was assessed with the Glasgow Outcome Scale (GOS).

Results

The stent was easily navigated and precisely positioned in 24 of 26 cases. However, technical difficulties occurred in 9 patients, including difficulties in crossing the stents interstice in 6 cases, inadvertent stent delivery (n = 1), and incapacity of stent delivery (n = 1) and incapacity of crossing the neck (n = 1). These latter 2 cases were classified as failures of the stent-assisted technique. A single procedural complication occurred, involving transient nonocclusive intrastent thrombus formation, which was treated uneventfully with abciximab. Seventeen patients experienced excellent clinical outcomes (GOS 5), with good outcomes (GOS 4) in 5 patients and a poor outcome (GOS 3) in 2 patients. There were no treatment-related deaths or neurologic complications (mean clinical follow-up, 12 months). Angiographic results consisted of 17 complete occlusions, 4 neck remnants, and 3 incomplete occlusions.

Conclusions

The Neuroform stent is very useful for EVT of wide-necked intracranial aneurysms because it is easy to navigate and to deploy accurately. In most cases, the stent can be deployed precisely, even in very tortuous carotid siphons. Although in some cases delivery and deployment was challenging, clinically significant complications were not observed.