Evaluation of a rabbit rectal VX2 carcinoma model using computed tomography and magnetic resonance imaging

AIM: To establish a rabbit rectal VX2 carcinoma model for the study of rectal carcinoma. METHODS: A suspension of VX2 cells was injected into the rectum wall under the guidance of X-ray fluoroscopy. Computed tomography (CT) and magnetic resonance imaging (MRI) were used to observe tumor growth and metastasis at different phases. Pathological changes and spontaneous survival time of the rabbits were recorded. RESULTS: Two weeks after VX2 cell implantation, the tumor diameter ranged 4.1-5.8 mm and the success implantation rate was 81.8%. CT scanning showed low-density foci of the tumor in the rectum wall, while enhanced CT scanning demonstrated asymmetrical intensification in tumor foci. MRI scanning showed a low signal of the tumor on T1-weighted imaging and a high signal of the tumor on T2-weighted imaging. Both types of signals were intensified with enhanced MRI. Metastases to the liver and lung could be observed 6 wk after VX2 cell implantation, and a large area of necrosis appeared in the primary tumor. The spontaneous survival time of rabbits with cachexia and multiple organ failure was about 7 wk after VX2 cell implantation. CONCLUSION: The rabbit rectal VX2 carcinoma model we established has a high stability, and can be used in the study of rectal carcinoma.

Primary hepatic neuroendocrine tumor with multiple liver metastases:A case report with review of the literature

We herein present a case involving a 41-year-old woman in whom ultrasound examination revealed multiple liver hemangiomas more than 3 years ago.Follow-up ultrasound examination revealed that the masses had significantly increased;the largest was located in the right lobe(about 8.2 cm×7.4 cm×6.0cm).Abdominal multidetector computed tomographyrevealed multiple well-circumscribed,heterogeneous,hypodense masses(largest,6.4 cm×6.3 cm×5.0cm)with significant contrast enhancement during the arterial and portal phases and with contrast washout and peripheral enhancement during the delayed phases.Magnetic resonance images demonstrated multiple well-circumscribed,heterogeneous,hypointense hepatic masses with significant contrast enhancement(largest,6.4 cm×6.5 cm×5.1 cm);multiple enlarged porta lymph nodes;and multiple s l i g h t l y e n l a rg e d re t ro p e r i t o n e a l l y m p h n o d e s.Histological and immunohistochemical examination of the right mass biopsy specimen suggested a malignant neoplasm that had originated from a neuroendocrine cell type(grade 2 well-differentiated neuroendocrine carcinoma).After performing a systemic examination to exclude metastasis from an extrahepatic primary site,we considered that the masses had arisen from a primary hepatic neuroendocrine tumor with multiple liver metastases.The patient underwent transcatheter arterial chemoembolization using a combination of oxaliplatin(150 mg)mixed with one bottle of gelatin sponge particles(560-710μm)and lipiodol(6 m L).Primary neuroendocrine tumors of the liver are extremely rare.This case is interesting because of the rarity of this neoplasm and previous misdiagnosis as multiple liver hemangiomas.Previously reported cases in the literature are also reviewed.

Temporary self-expanding metallic stents for achalasia: A prospective study with a long-term follow-up

AIM: To compare the efficacy of self-expanding metallic stents (SEMSs) for the long-term clinical treatment of achalasia. METHODS: Ninety achalasic patients were treated with a temporary SEMS with a diameter of 20 mm (n = 30, group A), 25 mm (n = 30, group B) or 30 mm (n = 30, group C). Data on clinical symptoms, complications and treatment outcomes were collected, and follow-up was made at 6 mo and at 1, 3-5, 5-8, 8-10 and > 10 years, postoperatively.RESULTS: Stent placement was successful in all patients. Although chest pain occurrence was high, stent migration was less in group C than in groups A and B. The clinical remission rate at 5-8, 8-10 and > 10 years in group C was higher than that in the other two groups. The treatment failure rate was lower in group C (13%) than in groups A (53%) and B (27%). SEMSs in group C resulted in reduced dysphagia scores and lowered esophageal sphincter pressures, as well as normal levels of barium height and width during all the follow-up time periods. Conversely, these parameters increased over time in groups A and B. The primary patency in group C was longer than in groups A and B. CONCLUSION: A temporary SEMS with a diameter of 30 mm is associated with a superior long-term clinical efficacy in the treatment of achalasia compared with a SEMS with a diameter of 20 mm or 25 mm.

Silicone-covered biodegradable magnesium stent for treating benign esophageal stricture in a rabbit model

BACKGROUND Stent insertion can effective alleviate the symptoms of benign esophageal strictures(BES).Magnesium alloy stents are a good candidate because of biological safety,but show a poor corrosion resistance and a quick loss of mechanical support in vivo.AIM To test the therapeutic and adverse effects of a silicone-covered magnesium alloy biodegradable esophageal stent.METHODS Fifteen rabbits underwent silicone-covered biodegradable magnesium stent insertion into the benign esophageal stricture under fluoroscopic guidance(stent group).The wall reconstruction and tissue reaction of stenotic esophagus in the stent group were compared with those of six esophageal stricture models(control group).Esophagography was performed at 1,2,and 3 weeks.Four,six,and five rabbits in the stent group and two rabbits in the control groups were euthanized,respectively,at each time point for histological examination.RESULTS All stent insertions were well tolerated.The esophageal diameters at immediately,1,2 and 3 wk were 9.8±0.3 mm,9.7±0.7 mm,9.4±0.8 mm,and 9.2±0.5 mm,respectively(vs 4.9±0.3 mm before stent insertion;P<0.05).Magnesium stents migrated in eight rabbits[one at 1 wk(1/15),three at 2 wk(3/11),and four at 3 wk(4/5)].Esophageal wall remodeling(thinner epithelial and smooth muscle layers)was found significantly thinner in the stent group than in the control group(P<0.05).Esophageal injury and collagen deposition following stent insertion were similar and did not differ compared to rabbits with esophageal stricture and normal rabbits(P>0.05).CONCLUSION Esophageal silicone-covered biodegradable magnesium stent insertion is feasible for BES without causing severe injury or tissue reaction.Our study suggests that insertion of silicone-covered magnesium esophageal stent is a promising approach for treating BES.

Clinical application of self-expanding metallic stent in the management of acute left-sided colorectal malignant obstruction

瞄准：在尖锐左边的颜色的管理用自我膨胀的金属性的斯滕特氏印模膏(SEMS ) 的申请总结我们的经验表面的恶意的阻塞。方法：经历在 2000 年 4 月和 2004 年 1 月之间的 SEMS 的放置的所有病人的回顾的图表评论被执行。结果：SEMS 的插入与偶尔的内视镜的帮助在 fluoroscopic 指导下面在 26 个病人被尝试。损害的地点位于二个病人，的结肠左曲七个病人，的左冒号八个病人的 S 字形的冒号和九个病人的直肠。SEMS 的打算的使用为在 7 个病人并且作为到在 19 个病人的选任的外科的一座桥的减轻。在后者组， SEMS 的放置允许外科手术前全身并且肠准备和下列一个阶段吻合。成功的斯滕特氏印模膏放置在 22 被完成(85%) 26 个病人。临床的肠阻塞在 21 在成功的斯滕特氏印模膏放置以后解决了 24 个小时(95%) 病人。三 SEMS 相关的次要的复杂并发症发生了，二 stents 移植了，一个人引起了肛门疼痛。结论：SEMS 在尖锐恶意的颜色的管理代表一个有效、安全的工具表面的阻塞。作为到外科的一座桥， SEMS 能为系统的支持和肠准备提供时间并且排除对烘便的转向或在桌子上洗室年龄的需要。作为一项辩解的措施， SEMS 能为突现的结肠开口术消除需要。

Emergency transcatheter arterial embolization for patients with acute massive duodenal ulcer hemorrhage

IM:To evaluate the efficacy and safety of emergency transcatheter arterial embolization (ETAE) for patients with acute massive duodenal ulcer hemorrhage. METHODS:Twenty-nine consecutive patients with acute massive bleeding of duodenal ulcer were admitted to our hospital from 2006 to 2011. Superselective angiography of the celiac and gastroduodenal arteries was performed to find out the bleeding sites before ETAE, then, embolotherapy was done with gelatin sponge particles or microstrips via a 5 French angio-graphic catheter or 3 French microcatheter. After ETAE, further superior mesenteric arteriography was under-taken in case collateral circulation supplied areas of the duodenal ulcer. Technical and clinical success rates were analyzed. Changes in the mucous membrane were observed using endoscopy following ETAE. RESULTS:Angiography showed active bleeding with extravasation of contrast medium in seven cases with a 24% positive rate of celiac artery bleeding, and in 19 cases with a 65.5% rate of gastroduodenal artery bleeding. There were no angiographic signs of bleeding in three patients who underwent endoscopy prior to ETAE. Twenty-six patients achieved immediate hemostasis and technical success rate reached 90%. No hemostasis was observed in 27 patients within 30 d after ETAE and clinical success rate was 93%. Recurrent hemorrhage occurred in two patients who drank a lot of wine who were treated by a second embolotherapy in the same way. Five patients underwent transient ischem with light abdominal pain under xiphoid, spontaneous restoration without special treatment. No mucous necrosis happened to 29 cases for ischem of gastroduodenal arteries embolized. CONCLUSION:ETAE is an effective and safe measure to control acute massive bleeding of duodenal ulcer.

Super-Flexible Through-the-Scope Self-Expandable Metallic Stent Insertion for the Management of Malignant Tortuous Hepatic or Splenic Flexure Colonic Obstruction

To the Editor： The methods for obstruction of colon cancer include emergency surgery or self-expanding metallic stents （SEMSs）. SEMS insertion was shown to be a safe, easy, and effective treatment for left-sided malignant colon obstruction, for palliative treatment or as bridge to resection. The cases reported of SEMS insertion in the colon proximal to the splenic flexure were 〈5% of all studies. The long distances and the tortuosity of the distal bowel make it difficult to advance and position the stent in the target proximal colon, and obstruction of right colon has traditionally been managed by acute operation.