Achalasia is a primary esophageal motility disorder, with the main symptom of dysphagia; and caused by the tonus increase and abnormal relaxation of the lower esophageal sphincter(LES). The etiology remains unclear, the objective of the current treatment approaches for achalasia containing the reduction of the LES tone and obstruction to relieve the patients' symptoms; including pharmacologic treatment, botulinum toxin treatment, surgical myotomy, pneumatic dilatation and cardia stent dilatation. The temporary cardia stent dilatation possesses some better advantages and effects; and ought to be the first choice of minimal invasive interventional management for achalasia.

For patients unable to get the necessary nutrition orally,a variety of techniques,including surgical way,to make gastrostomy with tube placement have been employed.For recent years,gastrostomy and tube placement with the help of endoscopic guidance or percutaneous interventional management has been developed,which is superior to surgical procedure in minimizing injuries,decreasing cost and reducing complications.In certain clinical situations,both endoscopic method and interventional method can be employed.This paper aims to make a comprehensive review of the indications,techniques and skills,advantages and disadvantages of both the endoscopy-guided and the imaging-guided percutaneous gastrojejunostomy for the establishment of enteral nutrition.

Objective To retrospectively a nalyze and think the original papers o f gastrointestinal(GI) imageology for 46 years in Chinese Journal of Radiology(C JR), meeting a huge challenge of Chinese GI imageology in alternation of generat ions. Methods From October 1953 to October 1999, a review of o riginal articles of GI imageology in CJR was conducted. Results Within 46 years of GI imageol ogy evolution, 211 published original articles of CJR included 79 original paper s of radiography and single contrast radiography, 73 original papers of double co ntrast radiography, 21 original papers of interventional radiology, 15 original papers of CT and MR and CR (computed radiograpy), 9 original papers of experim e nt study, and 4 original papers of comprehensive imaging applications. There wer e different dominant imaging applications at different times, radiography and si ngle contrast radiography in fifties and sixties, double contrast radiography an d CT diagnosis in seventies and eighties, and comprehensive applications of CT a nd MR and CR and interventional radiology in nineties. Conclusion In GI imageol ogy for 46 years, double contrast radiography in X-ray diagnosis was the main m e thod of imaging diagnosis, CT and MR and CR diagnosis were important means of re cruit; interventional radiology was an important section of GI imageology in nin eties.

Objective To evaluate the effects and methods of interventional therapy of the atherosclerotic renal artery stenosis(ARAS).Methods 28 cases of ARAS were implanted with stents by guiding catheter or guidewire exchanging, 31 stents were implanted (Palmaz stent in 22, Wallstent in 4, and Symphony stent in 5). Follow up was undertaken for 6 months to 1 year, together with recording the blood pressure, creatinine, the effective number of antihypertensive medication and comparing with those before the procedure. Results Stents were implanted successfully in all cases. Complication of renal arterial embolism happened in 2 cases with recanalization by guidewire exchanging. Restenosis happened in 4 cases.Conclusion Stent implantation for renal artery stenosis by guiding catheter is an ideal method or probably the chief interventional therapy to preserve the renal function.

Objective To assess the effectiveness and safety and biocompatibility of balloon-expanding stainless steel stents (SSS) covered with polyurethane membrane (PUM), expanding poly teflon ester membrane(ePTFEM)and biomembrane (BM) in the treatment of experimental saccular aneurysms of carotid arteries in canine models.Methods 36 experimental saccular aneurysms of carotid arteries in 20 canines were created successfully by sugery. Experimental aneurysms were treated with covered stents including twelve PUM-SSS, twelve ePTFEM-SSS and twelve BM-SSS for each twelve canines repectively. They were placed endovascularly in the common carotid arteries covering the orifice of aneurysms. Follow up angiography was performed immediately after the procedure and 2, 4 and 12 weeks afterwards under the control of conventional anticoagulation. The animals were then sacrificed for histopathologic and statistical investigation. Results 36 stents were placed successfully in the target arteries. The complete patency rates of PUM-SSS, ePTFEM-SSS and BM-SSS were 25.0%, 41.7% and 91.7% respectively. Histological analysis indicated that all treated aneurysmal pouches were filled with thrombus. Stent wires were found to be located deep within the vessel wall and encased by extension of the tunica intima. Endothelialization of BM-SSS groups already began at the 2nd week which was earlier than that of PUM-SSS and ePTFEM-SSS. Various degrees of degenerative cells were seen under the transmission electron microscopy without surface erosion of stents. Conclusion Placement of covered stent endovascularly is expedient, safe, and effective. BM-SSS provides the best mechanical behavior, physiochemical stability, anticoagulative ability and biocompatibility.

Objective To study the availability by making experimental saccular aneurysm models of carotid arteries in canine similar to human intracranial aneurysms.Methods Twenty healthy canines with experimental saccular side-wall aneurysms of carotid arteries were created successfully by surgery. Results Forty experimental saccular side-wall aneurysms of carotid arteries were created successfully with 36 aneurysms and parent arteries maintaining patency with each other and four spontaneously occluded confirmed by angiography.Model successfurll rate reached 90%.Conclusions Experimental saccular side-wall aneurysms of carotid arteries in canines were one of best models created for simulating human intracranial aneurysms.

Stent implantation plays an significant role in the interventional therapy, mainly with permanent stent, possessing many disadvantages such as restenosis and inflammatory hyperplasia and can thus hardly be used in children and nonmalignant stenosis. Biodegradable stent has theoretical capability to solve these problems and acquires a bright future. Nowadays, with the development of material industry and manufacture craft, biodegradable stent technique has turned up to be mature in last decades. Through the strict animal experiments and prophase of clinic application, satisfactory result has been acquired. We believe that bioabsorbable stent will be widely used in many benign diseases which would be a good supplement for permanent stent in the near future.

Objective To evaluate the application value of detachable balloon in today's interventional neuroradiology. Methods 38 cases with vascular lesion in the area of cranial cervical region ( 26 cases with CCF, 3 with giant aneurysm in the cavernous segment of internal carotid artery, one with fusiform aneurysm in internal carotid artery, and 8 with AVF in the area of cranial cervical) were treated by detachable balloon for embolizing the shunt or scrificing the lesion ipsilateral internal carotid artery. Results All 38 cases were cured without complication and sequeulae. Of them, anatomical cure was aquired in 21 cases, lesion cure in 17 cases. Conclusions Detachable balloon is still the first choice of embolization material in today's endovascular therapy of some vascular lesions in the area of cranial cervical region.

Objective Experimental study of the mechanism in esophageal restenosis after balloon dilation of benign stricture.Methods Esophageal stenosis model of the rats was created by 5ml of 50% NaOH solution burn with double balloon method, and esophageal restenosis (RS) model was developed by esophageal stenosis with dilation of PTCA balloon catheter. Quantitative and quanlitative analysis of esophageal stenosis and RS formation in the rats were observed and recorded by analytic measurements imaging and immunohistologic chemistry respectively. Results Esophageal benign stricture and RS model of 49 rats were developed. Cross section area and perimeter of esophageal mucosa layer, muscule layer and the whole layer had increased in experimental group. Comparing to control group, it had remarkable significance in statistics ( P

Objective To observed the long-term follow-up of the two types of interventional procedure for achalasia. Methods The study cohort was comprised of 140 patients of achalasia including 70 patients treated under fluoroscopy with pneumatic dilation (group A) and 70 with temporary partially covered metal stent dilation (group B). Results One hundred and forty dilations were performed on the 70 patients of group A with complications of chest pain (n=35), reflux (n=18), and bleeding (n=8); 38 atients of relapsing dysphagia during a 12-month follow-up, and 50 patients out of 60 of recurrent dysphagia during a 36-month follow-up. Seventy partially covered expandable metal stents were temporarily placed in the 70 patients of group B and withdrawn after 3-7 days via gastroscopy with complications of chest pain (n=28), reflux (n=15), and bleeding (n=9); 7 patients out of 70 exhibited dysphagia relapse during a 12-month follow-up, and 9 out of 58 patients exhibited dysphagia relapse during a 36-month follow-up. All the stents were inserted and withdrawn successfully. The follow-up in groups A-B lasted for 12-96 months. Conclusion Temporary partially covered metal stent dilation is one of the best methods of interventional procedure for achalasia in long-term follow-up. (J Intervent Radiol,2005,14:171-174)