Rotational ablation of coronary artery lesions using single,large burrs

Previous clinical use of the Rotablator^(TM) In coronary artery disease has involved a sequential increase in burr sizes up to 2 mm in diameter and has often utilized balloon adjunct to achieve an optimal result. We report our experience and describe our technique using a single, large burr (2.25, 2.5, or 2.75 mm diameter) without balloon assistance. The burr size was selected to approximate 70–90 percent of the apparent normal lumen diameter. Thirty-one patients with 36 lesions of complex morphology (eccentric, irregular, calcified, ulcerated, at bends, at bifurcations, completely occluded, as well as balloon failures) were successfully treated with the Rotablator^(TM). Results were assessed by computerized quantitative angiography. The percent diameter stenosis (mean ± SD) for the group was reduced from 69.8 ± 11.3% to 30.9 ± 10% (p < 0.001). The mean absolute diameter stenosis increased from 0.9 ± 0.3 mm to 2.2 ± 0.3 mm (p < 0.001). Angiographically visible dissections were seen in 4 patients and were uncomplicated in 2. One patient had a non-Q-wave myocardial infarction. A fourth patient had a presumed acute occlusion 36 hr after the procedure, necessitating emergency bypass surgery, but without Q waves on the electrocardiogram or wall-motion abnormalities on the echocar-diogram. Nitroglycerin was infused through the Rotablator^(TM) catheter and has considerably lowered the degree and frequency of spasm. No other acute complications occurred. The mean procedure time using a single burr was shorter than when multiple burrs were used: 56.5 vs. 97.3 min, respectively (p < 0.05). The use of a single, large-size Rotablator^(TM) burr is an effective method of treating complex coronary stenoses without balloon assistance and has an encouragingly low complication rate and short procedure time. © 1992 Wiley-Liss, Inc.     

Percutaneous transluminal rotational atherectomy in the treatment of peripheral vascular disease using a transluminal endatherectomy catheter (TEC): Initial results and angiographic follow-up

Purpose To evaluate the clinical results of percutaneous transluminal rotational atherectomy in the treatment of peripheral vascular disease. Methods Rotational atherectomy was performed in 39 patients aged 39–87 years (mean 66.6 years). A total of 71 lesions (43 stenoses and 28 occlusions) were treated in 40 limbs. Additional balloon angioplasty was required in 54% of lesions. Fifteen patients (37.5%) presented in Fontaine stage II, 10 patients (25%) in Fontaine stage III and 15 patients (37.5%) in Fontaine stage IV. Rotational atherectomy at 750 rpm was carried out over a 0.014-inch guidewire with continuous aspiration into a vacuum, bottle. Follow-up angiography and color flow Doppler examinations were performed in 22 patients (23 limbs) after a mean period of 6 months (range 2–14 months) Results There was one primary technical failure. In 36 of 40 lesions there was a good angiographic result with residual stenoses in less than 30%. In 70 lesions treated by rotational atherectomy, however, 54% showed residual stenoses of 30%–50% and these cases required additional balloon angioplasty. The mean ankle-brachial index improved significantly (p<0.001), from 0.49 before the procedure to 1.01 after the procedure. A single distal embolus, related to primary recanalization, occurred and there were two large inguinal hematomas. Cumulative clinical patency after 6 months was 83.8% and cumulative angiographic patency after 6 months was 79.1%. Conclusion Percutaneous rotational atherectomy is a promising approach for the treatment of chronic peripheral vascular disease. Further prospective, randomized studies are necessary to compare percutaneous transluminal angioplasty with this new technical approach.     

冠脉内旋磨术联合低压球囊扩张治疗支架内再狭窄

对 3例冠状动脉支架内再狭窄的病人先行冠状动脉旋磨术 ,然后以 4 0 5.2～ 60 7.8kPa的低压力行球囊扩张 ,探讨了其对治疗再狭窄的安全性及有效性。结果显示 :3例病人手术皆获成功 ,围术期无并发症 ,术后随访 6～ 1 2个月无死亡或出现心绞痛、心肌梗死及其他冠心病事件。提示 :冠状动脉旋磨术与球囊扩张联合应用是一种安全有效的治疗支架内再狭窄的方法。     

The mechanism of directional coronary atherectomy

An attempt was made to assess the mechanism of directional coronaryatherectomy using different methods of analysis. Quantitativecoronary angiography was used as the gold standard to assessthe immediate results of atherectomy, and a comparative quantitativeanalysis of atherectomy and balloon angioplasty was made. Todetermine whether the post-atherectomy cross-sectional areais close to a circle, we compared the area measurements obtainedby edge detection with those obtained by videodensitometry.Finally, the extent of a ‘Dotter’ effect was establishedby quantitative angiography following crossing the stenosiswith the atherectomy device. For the purpose of this study,the results of the first 113 successful atherectomy procedureswere reviewed. In matched lesions, directional atherectomy induceda greater increase in minimal luminal diameter than balloonangioplasty (1.6 mm vs 0.8 mm; P < 0.0001 However, this luminalimprovement is due to a substantial ‘Dotter’ effectinduced by the bulky atherectomy device. Following atherectomy,only a slight difference in cross-sectional area measurementsbetween edge detection and videodensitometry (mean difference:0.28 mm² was found. Histologic examination of an atherectomizedcoronary artery showed a near-circular post atherectomy areageometry. In conclusion, directional atherectomy is a very effectivedevice with a substantially better initial result than balloonangioplasty. However, insertion of this bulky device itselfcauses an important ‘Dotter’effect.     

Molecular Motion of Drugs in Hydrocolloids Measured by Electron Paramagnetic Resonance

The effects of a polymer, the Li-salt copolymer of methyl-methacrylic acid, and its methyl ester on the motion of drug molecules in hydrocolloids were studied. The investigation was carried out by means of electron paramagnetic resonance (EPR) using the model nitroxide tempol, and the spin-labeled drugs lidocaine (si-lid) and dexamethasone (sl-dex). Synthesis of sl-dex was performed. Spin-labeled molecules dissolved in hydrocolloids undergo a fast reorientation motion. The decreasing order of rotational correlation times () —sl-dex > si-lid > tempol—suggests that the size and the shape of the molecules strongly affect their motion. The inhibition of motion of larger molecules depends also on their flexibility. The values indicate proportionality of the microviscosity of hydrocolloids to the polymer concentration. Rotational motion is dependent on the local environment conditioned by the free spaces between polymer molecules.     

创新人才培养模式加强临床医学本科生培养与管理

论述了温州医学院附属第一医院以办“社会化住院医师轮训班”为契机,创建新型人才培养模式,加强对临床医学本科毕业生的培养与管理的具体做法;总结了医院通过做好毕业后医学教育工作,在提高临床医学本科毕业生的业务素质、职业道德水平、参与市场竞争能力,以及通过二次分配提高基层的医疗服务水平等方面取得的成效。     

Fetal striatal transplants reinstate the electrophysiological response of pallidal neurons to systemic apomorphine challenge in rats with excitotoxic striatal lesions

Previous studies with single-unit recording and 2-[14C]deoxyglucose quantitative autoradiography have shown that systemic administration of apomorphine increases the functional activity of pallidal neurons, and that the enhancement in the globus pallidus (GP) activity is abolished by striatal lesions. The present study employing electrophysiological techniques tested whether embryonic striatal tissue implanted in the excitotoxically damaged striatum of rats may affect the lesion-induced alteration in the neuronal response of GP to apomorphine. Systemically administered apomorphine significantly increased spontaneously firing rates of GP cells. The blockade of dopamine receptors with haloperidol reversed the increased rate to baseline levels. Quinolinate-induced striatal lesions attenuated the rate-increasing effect of apomorphine. Embryonic striatal grafts placed in the lesioned striatum restored the response of GP cells to systemic apomorphine. The graft-mediated restoration of the GP neuron response to apomorphine were accompanied by an improvement in the motor asymmetry induced by this drug. Considering previous anatomical data to demonstrate extensive innervation of the GP by embryonic striatal grafts, the present results suggest that the grafts reconstruct the functional striatopallidal pathway which is capable of transmitting apomorphine-induced changes in the neuronal activity.