Treatment of external carotid arteriovenous fistula with detachable balloon

Summary A simple fistula between the external carotid artery and the internal jugular vein was treated for the first time using Debrun's technique with a detachable balloon catheter. The nature of the fistulous connection makes the release of the balloon inflated with silicone completely harmless. The occlusion of the fistula, while maintaining the patency of the remaining branches of the external carotid artery, proves this technique to be the most appropriate for the treatment of arteriovenous fistulae in the neck.     

Design of gradient coils for permanent magnets

Designing gradient coils for permanent magnets requires modeling the interaction between the currents and the ferromagnetic material. We have developed and tested an iterative design approach based on the boundary element method. The power dissipated by the gradient coil is treated as a constraint of the minimization problem. The technique is illustrated on a magnet with a rectangular prismatic cavity and two ferromagnetic plates adjacent to the coil. The procedure improved the linearity of the field from 10.5% to 3.4% and reduced the power dissipation to 63% of the power of the unoptimized coil. The optimized distribution of currents has been transformed to variable locations of coil windings without loss of gradient uniformity. The new approach significantly reduces computation time and memory storage and yields practical designs of gradient coils for permanent magnets.     

Newly designed “pieced” stent in a rabbit model of benign esophageal stricture

AIM: To investigate a newly designed stent and its dilatation effect in a rabbit model of benign esophageal stricture.METHODS: Thirty-four New Zealand white rabbits underwent a corrosive injury in the middle esophagus for esophageal stricture formation. Thirty rabbits with a successful formation of esophageal strictures were randomly allocated into two groups. The control group (n = 15) was implanted with a conventional stent, and the study group (n = 15) was implanted with a detachable “pieced” stent. The study stent (30 mm in length, 10 mm in diameter) was composed of three covered metallic pieces connected by surgical suture lines. The stent was collapsed by pulling the suture lines out of the mesh. Two weeks after stricture formation, endoscopic placement of a conventional stent or the new stent was performed. Endoscopic extraction was carried out four weeks later. The extraction rate, ease of extraction, migration, complications, and survival were evaluated.RESULTS: Stent migration occurred in 3/15 (20%) animals in the control group and 2/15 (13%) animals in the study group; the difference between the two groups was not statistically significant. At the end of four weeks, the remaining stents were successfully extracted with the endoscope in 100% (11/11) of the animals in the study group, and 60% (6/10) of the animals in the control group; this difference was statistically significant (P < 0.05). There was no difference in the mean number of follow-up days between the control and study groups (25.33 vs 25.85). Minor bleeding was reported in five cases in the study group and four in the control group. There were no severe complications directly associated with stent implantation or extraction in either of the two groups.CONCLUSION: In this experimental protocol of benign esophageal strictures, the novel “pieced” stent demonstrated a superior removal rate with a similar migration rate compared to a conventional stent.     

血管内栓塞治疗颅内动脉瘤

目的探讨血管内栓塞治疗颅内动脉瘤的临床价值。方法选择不同血管内栓塞治疗方案,对27例33个颅内动脉瘤进行栓塞,并总结分析其临床资料。结果 （1）弹簧圈栓塞22例27个动脉瘤,术中动脉瘤破裂出血1例。（2）支架辅助栓塞2例2个动脉瘤,无神经功能缺失。（3）球囊及支架辅助栓塞1例2个动脉瘤,无神经功能缺失。（4）载瘤动脉闭塞2例2个动脉瘤：术后出现神经功能损害1例。结论血管内栓塞治疗颅内动脉瘤是一种微创、安全、有效的治疗方法。     

非接触磁感应脑阻抗断层成像系统设计

针对脑组织电阻抗的研究，本文设计了工作频率在10MHz的单通道硬件电路和试验台，可以分辨电导率介于0．001s/m到6s/m的四种不同浓度的NaCl盐溶液，并对模拟正常人脑组织（0．375s/m）的0．195％NaCl盐溶液目标，给出了初步成像结果。     

经血管内途径栓塞治疗颈动脉海绵窦瘘(附216例报告)

目的　探讨颈动脉海绵窦瘘 (CCF)的治疗方法选择、栓塞技术要点及随访意义。方法　对 2 16例CCF病人共行 2 2 0次栓塞 ,其中 ,经股动脉入路 2 0 2例 ,经股静脉入路 9例 ,经眼上静脉入路 5例 ;以球囊栓塞瘘口 188例 ,以微弹簧圈栓塞 2 3例 ,球囊并用弹簧圈 5例。术后 6～ 10 8个月随访 110例 ,其中行影像学复查 3 5例。结果　 2 12例 1次栓塞成功 ,4例于第一次栓塞后球囊泄漏复发 ,经再次栓塞治愈 ,总治愈率 10 0 %。颈内动脉通畅率 94 4% (2 0 4/2 16) ,无并发症及死亡 ,随访显示疗效可靠。结论　CCF一般经股动脉入路用可脱性球囊栓塞瘘口 ,栓塞时球囊应稳步前进 ,一旦扩充 ,决不轻易后拉。小瘘口CCF选择微弹簧圈栓塞 ;若颈内动脉结扎或闭塞 ,可经静脉入路栓塞瘘口。正确选择栓塞途径及栓塞材料是手术成功的关键。