Treatment of malignant dysphagia with nitinol stents

Self-expanding nitinol stents were used in 22 patients for palliative treatment of malignant esophagogastric strictures. All patients but 5 were men (age range 47–75 years). The strictures were caused by squamous cell carcinoma (n = 12), adenocarcinoma (n = 8), and recurrent anastomotic carcinoma (n = 2). No technical failure or procedural complications occurred. After the procedure, the severity of dysphagia decreased at least one grade in all patients. Tumor ingrowth into the stent was seen in 7 patients of 22 (32%). Four of these patients were treated with additional stents, and in 3 patients, due to refusal, only balloon dilations were performed, which caused temporary relief. Tumor ingrowth into the stent was noted from 10 days to 7 months (mean 3 months). This seems to be a disadvantage of nitinol stents. At the end of the study 10 patients had died dead with a mean survival of 3 months (range 1 week to 6 months) and 12 patients were still alive with a mean follow-up of 4 months (range 1–8 months). It is concluded that nitinol stents provide satisfactory palliation in patients with malignant dysphagia with neglectable procedural morbidity and mortality rates.     

表面改性在介入器械上的应用

论述赋予介入器械的材料表面润滑性、抗菌性、抗凝血性及抗组织增生等性能的各种表面改性技术的现状，讨论这些技术的一些应用的实例，提出需要进一步研究的问题。     

经左颈静脉肝内门腔静脉支架分流术（附12例报告）

为解决肝硬变门脉高压患者在经颈静脉肝内门腔静脉支架分流术中右颈静脉窄或闭的难题，我们做了经左颈静脉途径完成肝内门腔分流术的尝试。自１９９３年７月至１９９５年８月，共１７８例ＴＩＰＳＳ操作中发现１２例右颈静脉狭窄或闭塞。其方法为经左颈内静脉穿刺、插管入路。     

MR monitoring of MR-guided radiofrequency thermal ablation of normal liver in an animal model

The purpose of this study was to determine the suitability of MRI to accurately detect radiofrequency (RF) thermoablative lesions created under MR guidance. In vivo RF lesions were created in the livers of six New Zealand White rabbits using a 2-mm-diameter titanium alloy RF electrode with a 20-mm exposed tip and a 50-W RF generator. This was performed using a 0.2T clinical C-arm MR imager for guidance and monitoring. Each animal was sacrificed and gross evaluation was performed. Histologic correlation was performed on the first two animals. The MR-compatible RF electrode was easily identified on rapid gradient-echo images used to guide electrode placement. A single lesion was created in each rabbit liver. Lesions ranged from approximately 10 to 17 mm in diameter (mean, 13.5 mm). T2-weighted and short T1 inversion recovery (STIR) images demonstrated lesions ranging in diameter from 12 to 18 mm (mean, 14.6 mm). Lesion dimensions determined from images closely correlated with those determined at gross examination with the discrepancy never exceeding 2 mm, for an r² value of .87. MRI performed at the time of MR-guided RF ablation accurately demonstrated created lesions. This modality may provide a new option for the treatment of local and regional neoplastic disease.     

Management of abdominal sepsis

Introduction: Today the management of the different forms of peritonitis is generally standardised. The classification of primary and secondary peritonitis is well accepted. From a pathophysiological point of view, postoperative and post-traumatic peritonitis should be considered as independent entities. The bacteriological isolates from the inflamed peritoneal cavity do not correlate with the clinical course, and the occurrence of enterococci and bacteroides may be slightly related to ongoing infectious complications. Classification: Valuable scoring systems mainly rely on systemic signs of the septic disease and seem to better differentiate the prognosis of the disease than more surgically oriented scores do. Although the scoring systems did not allow any clinical decision, they should be used to help better compare patients treated in different institutions. The observation of the minor relevance of bacteriology and the superiority of general sepsis scores agrees with the fact that pre-existing septic organ dysfunction and pre-existing comorbidity are the main determinants of mortality. Treatment: Surgical therapy focuses on the control of the source of infection because it has been clearly shown that, without resolving the source of infection, the prognosis remains poor. Adjuvant surgical measures aim at the further reduction of the bacterial load in the peritoneal cavity. Planned relaparotomy, relaparotomy on demand, and continuous closed peritoneal lavage are used. Results: Clinical results proved these methods to be equally effective although pathophysiological considerations favour closed peritoneal lavage. Conclusion: Summarising the available data, we need a more sophisticated understanding of the pathophysiology of the peritonitis, and well-designed clinical studies are necessary to define the optimal surgical treatment modalities. Received: 27 November 1997     

Intestinal plethora: An early sign of acute posttraumatic hepatic artery-portal vein arteriovenous fistula

Traumatic communications between the hepatic artery or its branches and the portal vein or its tributaries usually are clinically occult until the late sequelae of portal hypertension, such as esophageal and mesenteric varices, ascites, or congestive heart failure, become manifest. The authors describe the early diagnosis of such a lesion by computed tomography. The CT findings included a hepatic hematoma and, more significantly, diffuse thickening of the small and large bowel wall. This thickening represents vascular congestion of the bowel caused by acute portal hypertension prior to the development of decompressing portal collateral circuits. When this CT finding is not associated with other signs of intestinal ischemia or infarction, it should suggest portal hypertension and lead to arteriography for diagnosis and therapy of arterioportal fistula.     

肝动脉化疗,栓塞与肝静脉暂时闭塞治疗肝癌

本文报道在10例肝癌患者中运用肝静脉暂时闭塞和肝动脉内灌注化疗、栓塞的方法治疗取得较好疗效。7例甲胎蛋白阳性患者5例下降大于50%,2例转阴。4例肿瘤缩小>50%。2例合并肝动-静脉瘘者成功实行碘油栓塞,1例经治疗后肝动-静脉瘘消失。对肝功能的影响与普通介入治疗相同。消化道反应相对较轻。并可提高肿瘤局部药物浓度,延长药物作用时间。配合肝段动脉或靶血管的插管可进一步提高疗效,减少并发症。     

前列地尔Lipo-PGE1干预肝脏血流灌注的实验研究

目的： 探讨前列地尔脂微球(liposome prostaglandin E₁,Lipo-PGE₁) 不同用药时间和途径对肝脏血流灌注的作用机制。方法: 选取健康成年犬12只，经左小隐静脉注射Lipo-PGE₁₁ μg/kg，速度均为0.05 μg·kg^-1·min^-1。分别于0 min、5 min、15 min、30 min后行肝脏CT灌注成像（computed tomography perfusion imaging，CTPI）扫描，计算肝动脉灌注量(hepatic arterial perfusion,HAP)、门静脉灌注量 (portal vein perfusion,PVP)、总肝灌注量（total liver perfusion,TLP），对照分析不同时间Lipo-PGE1对肝脏血流灌注的影响。选取健康成年犬24只，随机平均分成4组：对照组、外周静脉用药组、肝动脉组、肠系膜上动脉组。Lipo-PGE₁的用药量均为1 μg/kg、用药速度均为0.05 μg·kg^-1·min^-1，0.9%生理盐水用量为20 mL。各组用药5 min后行肝脏CTPI，比较分析不同途径给予Lipo-PGE₁对肝脏血流灌注的影响。结果: 经外周静脉注射Lipo-PGE10 min、5 min、15 min、30 min后CTPI测量的HAP(mL·min^-1·mL^-1)分别为：0.22 ±0.65、0.24±0.65、0.22±0.69、0.22±0.06；PVP (mL·min^-1·mL^-1)：1.22±0.40、1.88±0.59、1.55±0.55、1.29 ±0.57；TLP (mL·min^-1·mL^-1)分别为：1.44±0.42、2.12±0.61、1.77±0.56、1.51±0.58。方差分析显示HAP组间比较无显著差异（F=0.249，P>0.05），而PVP、TLP组间比较有显著差异（F=3.812，P<0.05）、（F=3.805，P<0.05）。5 min组PVP、TLP增加最为显著，15 min、30 min时两者仍处于高值水平。对照组和外周静脉组、肝动脉组、肠系膜上动脉组的HAP (mL·min^-1·mL^-1)分别为：0.22±0.06、0.24±0.06、0.31±0.07、0.26±0.05；PVP (mL·min^-1·mL^-1)分别为1.28±0.38、2.33±0.41、2.37±0.55、2.83±0.94；TLP (mL·min^-1·mL^-1)分别为：1.50±0.40、2.57±0.42、2.67±0.58、3.09±0.94。方差分析显示HAP组间比较无显著差异（F=2.248，P>0.05），而PVP、TLP组间比较有显著差异（F=6.892，P<0.01）、（F=7.802，P<0.01）。经肠系膜上动脉给药较其它途径给药PVP、TLP增加趋势更为显著。结论: Lipo-PGE₁能显著增强肝脏血流灌注，且主要影响门静脉灌注分量，介入技术可为快速改善肝血流灌注提供有效途径。     

Fluid and solid mechanical implications of vascular stenting

Vascular stents have emerged as an effective treatment for occlusive vascular disease. Despite their success and widespread use, outcomes for patients receiving stents are still hampered by thrombosis and restensosis. As arteries attempt to adapt to the mechanical changes created by stents, they may in fact create a new flow-limiting situation similar to that which they were intended to correct. In vitro fluid mechanics and solid mechanics studies of stented vessels have revealed important information about how stents alter the mechanical environment in the arteries into which they are placed. Adverse nonlaminar flow patterns have been demonstrated as well as remarkably high stress concentrations in the vessel wall. In vivo studies of stented vessels have also shown a strong relationship between stent design and their dynamic performance within arteries. Alterations in pressure and flow pulses distal to the stent have been observed, as well as regional changes in vascular compliance. Considering the influence of flow and stress on the vascular response and the suboptimal clinical outcomes associated with stenting, knowledge gained from stent/artery mechanics studies should play an increasingly important role in improving the long-term patency of these devices. © 2002 Biomedical Engineering Society. PAC2002: 8719Rr, 8780-y, 8719Uv