Transjugular intrahepatic portosystemic shunt in a patient with cavernomatous portal vein occlusion

A 23-year-old woman with liver cirrhosis secondary to primary sclerosing cholangitis was referred to us for the treatment of recurrent bleeding from esophageal varices that had been refractory to endoscopic sclerotherapy. Her portal vein was occluded, associated with cavernous transformation. A transjugular intrahepatic portosystemic shunt (TIPS) was performed after a preprocedural three-dimensional computed tomographic angiography evaluation to determine feasibility. The portal vein system was recanalized and portal blood flow increased markedly after TIPS. Esophageal varices disappeared 3 weeks after TIPS. Re-bleeding and hepatic encephalopathy were absent for 3 years after the procedure. We conclude that with adequate preprocedural evaluation, TIPS can be performed safely even in patients with portal vein occlusion associated with cavernous transformation.     

Are Covered Stents Really Effective at Closing Esophagotracheal Fistulas? Results of an Animal Study

Purpose: To determine whether covered self-expanding metal stents successfully exclude experimentally created esophagotracheal fistulas. Methods: Esophagotracheal fistulas were surgically created in the upper third of the esophagus in 12 minipigs and immediately sealed by implantation of a covered self-expanding metal stent (20 mm expanded diameter) in the esophagus. Before the animals were killed, after 3, 7, 14, 28, 30, and 36 days, the position of the stent and the sealing of the fistula were monitored fluoroscopically. The esophagus, trachea, and both lungs were examined histologically. Results: Creation of an esophagotracheal fistula was successful in all cases. All fistulas were widely patent at autopsy. The technical success rate for stent deployment and initial sealing of the fistula was 100%. During follow-up, five stents migrated distally, but none into the stomach. Therefore, the fistula was no longer excluded in five animals. In seven animals the stent sealed the fistula until the death of the animal. Tracheal narrowing necessitated additional tracheal stenting in three animals. Two minipigs died due to aspiration of food. Histologic examination showed signs of aspiration in all animals with stents in place for longer than 2 weeks. Conclusion: This experimental animal study revealed worse results for sealing of esophagotracheal fistulas with covered self-expanding metal stents than have been reported for the clinical use of these devices.     

An Experimental Study of Endovascular Stenting with Special Reference to the Effects on the Aortic Vasa Vasorum

Purpose: To evaluate the effects of bare stents and covered stents on the aortic wall, especially the vasa vasorum. Methods: Eight bare stents and nine covered stents were placed in the infrarenal aorta of nine dogs. The dogs were euthanized at 4–45 weeks after stent placement. The vasa vasorum was evaluated by microstereoscopy with vascular casting, and the histopathology of the aortic wall was examined by light microscopy. Results: In the unstented normal aorta, vasa vasorum nourished the adventitia and the outer media, and the intima and inner media were avascular. In the stented segment, vascular dilatation and proliferation of vasa vasorum, medial atrophy, and intimal hyperplasia were observed, more prominent for covered stents than for bare stents. Conclusion: Intravascular stent placement caused not only medial atrophy and intimal hyperplasia but also proliferation of the vasa vasorum, probably due to hypoxia in the aortic wall. Received: 0/00/00/Accepted: 0/00/00     

Palliative Treatment of Malignant Colorectal Strictures with Metallic Stents

Purpose: To assess the effectiveness and safety of self-expanding metallic stents as a primary palliative treatment for inoperable malignant colorectal strictures. Methods: Under radiological guidance 20 self-expanding metallic Wallstents were implanted in 16 consecutive patients with colorectal stenoses caused by malignant neoplasms, when surgical treatment of the condition had been ruled out. The patients were followed up clinically for 1–44 months, until death or termination of this study. Results: The stents were successfully implanted in all cases and resolved the clinical obstruction in all the patients except one, who underwent subsequent colostomy. During follow-up of the remaining 15 patients, clinical complications arising from the procedure were pain (two patients), minor rectal bleeding (one patient), and severe rectal bleeding (one patient) (26%). There were three cases of stent migration and three cases of stent occlusion, and reintervention by us was necessary in 20% of cases (3/15). The mean life span following the procedure was 130 days, and none of the patients exhibited clinical symptoms of obstruction at the time of death (12 patients) or termination of the study (3 patients). Conclusion: Deployment of metallic stents under radiologic guidance is an effective alternative as a primary palliative measure in malignant colorectal obstruction, though the possible clinical complications and need for repeat intervention during follow-up should be taken into account.     

Primary implantation of polyester-covered stent-grafts for transjugular intrahepatic portosystemic stent shunts (TIPSS): A pilot study

Purpose: To investigate whether placement of a polyester-covered stent-graft increases the primary patency of transjugular intrahepatic portosystemic stent shunts (TIPSS). Methods: Between 1995 and 1997 Cragg Endopro or Passager MIBS stent-grafts were used for the creation of TIPSS in eight male patients, 35–59 years of age (mean 48 years). All patients suffered from recurrent variceal bleeding and/or refractory ascites due to liver cirrhosis. Seven stent-grafts were dilated to a diameter of 10 mm, one to 12 mm. Follow-up was performed with duplex ultrasound, clinical assessment, and angiography. Results: The technical success rate for creation of a TIPSS was 100%. The mean portosystemic pressure gradient decreased from 25 mmHg to 12 mmHg. In seven of eight patients TIPSS dysfunction occurred between 2 days and 3 years after stent-graft placement. In one patient the TIPSS is still primarily patent (224 days after creation). The secondary patency rates are 31 days to 3 years. Conclusion: The primary use of polyester-covered stent-grafts for TIPSS did not increase primary patency rates in our small series.     

Retrospective Comparison of the Patency of Wallstents and Palmaz Long-Medium Stents Used for TIPS

Purpose: To compare patency rates of transjugular intrahepatic portosystemic shunts (TIPS) after placement of long-medium Palmaz stents or Wallstents. Methods: We performed a retrospective review of TIPS performed at our institution between December 1997 and December 1998. During this time period we placed long-medium Palmaz stents for TIPS procedures in 17 patients and Wallstents in 20 patients as the initial stent. Patency was determined on follow-up by ultrasound, angiography, or pathologic examination in the event of transplant. Results: Primary patency in the Palmaz stent group was 70.6% (12/17 patients) (follow-up 1–399 days, mean 127 days). Both primary assisted and secondary patency in the Palmaz group was 100% (17/17 patients) (follow up 1–399 days, mean 154 days). Primary patency in the Wallstent group was 50% (10/20 patients) (follow up 1–370 days, mean 65 days). Primary assisted patency in the Wallstent group was 80% (16/20 patients) (follow up 1–601 days, mean 141 days). Secondary patency in the Wallstent group was 100% (20/20 patients) (follow up 2–601 days, mean 142 days). Kaplan-Meier analysis of the two groups of patients yielded a primary patency of 266 days (standard error 45 days) for TIPS with the Palmaz stent and 139 days (standard error 45 days) for the Wallstent (p = .04). The 3, 6, and 12-month primary patency rates were .84, .63, and .42 respectively for the Palmaz stents and .36, .36, and .18 respectively for the Wallstent. There was no significant difference in primary assisted or secondary patency between the two stent groups. The mean tract curvature in the patients with Palmaz stents was 23.5° (SD 18.2°, range 0–69.0°) compared with 57° (SD 34.5°, range 7.0–144.0°) in patients with Wallstents (p = .01). Conclusions: Our nonprospective, nonrandomized study suggests that TIPS created with the long-medium Palmaz stent have a higher primary patency than those created with the Wallstent in tracts that are relatively straight.     

Pneumoperitoneum Caused by Transhepatic Air Leak After Metallic Biliary Stent Placement

A self-expanding metallic biliary stent was placed for palliation of a common bile duct obstruction in a 68-year-old male with unresectable pancreatic head cancer 3 days after initial percutaneous right transhepatic catheter decompression. The stent crossed the ampulla of Vater. Three days later, the stent was balloon-dilated and the percutaneous access was removed. At removal, a small contrast leak from the transhepatic tract was seen. Three days later, pneumoperitoneum was found with symptoms of peritoneal irritation and fever. A widely open sphincter of Oddi caused by the metallic stent, accompanied by delayed sealing of the transhepatic tract, may have caused the air and bile leakage into the peritoneal space. This case shows that pneumoperitoneum may occur without ductal tear or bowel injury, with a biliary stent crossing the ampulla of Vater.     

TIPSS技术在门脉癌栓性门脉高压中的应用

目的 探讨TIPSS技术在治疗门静脉癌栓合并门脉高压中的技术特点及禁忌证。方法 16例门静脉癌栓合并门脉高压症患者，9例门静脉主干完全堵塞，7例门静脉主干及分支有不同程度栓塞；6例合并门脉海绵样变；1例单纯上消化道大出血；4例单纯顽固性腹水；11例上消化道大出血合并顽固性腹水。结果 16例中11例患者成功行TIPSS治疗，技术成功率约68.8%，门脉压力从术前4.9kPa降至2.4kPa，平均降低2.5kPa，腹水减少或消失，症状缓解。平均生存136d。5例失败。结论 TIPSS是治疗门脉癌栓引起的上消化道大出血和顽固性腹水的有效方法，门脉海绵样变是该术的禁忌证。     

Treatment of Complete and Partial Obstruction of the Nasolacrimal System with Polyurethane Stents: Initial Experience

Purpose: To present our experience in the treatment of nasolacrimal occlusion by means of polyurethane stents. Methods: Forty polyurethane stents were placed under fluoroscopic guidance in 35 consecutive patients with epiphora due to total or partial obstruction of the nasolacrimal system. The set designed by Song was used in all patients. The procedure was performed by introducing a guidewire through the superior punctum into the canaliculus and advancing it across the obstruction into the inferior meatus of the nasal cavity. After pulling out the guidewire, the stent was advanced in retrograde fashion and released into the sac and the nasolacrimal duct. Results: The technical success rate was 100%. The average time for the procedure was 25 min (range 10–60 min). Immediate complications were: mild pain (n= 5), severe pain (n= 1), minimal epistaxis (n= 7), and moderate epistaxis (n= 1). No major complications occurred. The last clinical control revealed complete resolution of epiphora in 35 eyes and partial resolution in four; one patient did not improve. Conclusion: This technique for treatment of obstruction of the nasolacrimal system is simple and safe, and may obviate the use of more invasive procedures. Received: 0/00/00/Accepted: 0/00/00     

Percutaneous Endovascular Stent-Graft for Iliac Pseudoaneurysm Following Lumbar Discectomy

In a 24-year-old woman, an iliac pseudoaneurysm following lumbar discectomy was successfully treated by percutaneous placement of a self-expanding stent-graft. A postprocedural angiogram demonstrated complete exclusion of the pseudoaneurysm without leakage of contrast agent.     

Interventional radiologic treatment for idiopathic portal hypertension

Purpose: To evaluate the usefulness of interventional radiological treatment for idiopathic portal hypertension. Methods: Between 1995 and 1998, we performed an interventional radiological treatment in five patients with idiopathic portal hypertension, four of whom had refused surgery and one of whom had undergone surgery. Three patients with gastroesophageal varices (GEV) were treated by partial splenic embolization (PSE), one patient with esophageal varices (EV) and massive ascites by transjugular intrahepatic portosytemic shunt (TIPS) and PSE, and one patient with GEV by percutaneous transhepatic obliteration (PTO). Midterm results were analyzed in terms of the effect on esophageal and/or gastric varices. Results: In one woman with severe GEV who underwent three sessions of PSE, there was endoscopic confirmation that the GEV had disappeared. In one man his EV shrunk markedly after two sessions of PSE. In two patients slight reduction of the EV was obtained with one application of PSE combined with endoscopic variceal ligation therapy. PTO for GV in one patient resulted in good control of the varices. All patients have survived for 16–42 months since the first interventional treatment, and varices are well controlled. Conclusion: Interventional radiological treatment is effective for patients with idiopathic portal hypertension, whether or not they have undergone surgery.     

Single and tandem stents in sheep iliac arteries: Is there a difference in patency?

Purpose: To compare patency and neointima formation of single and tandem arterial stents. Methods: In each of six sheep, two Memotherm nitinol stents (tandem stents) were inserted into the external iliac artery on one side and a single stent into the artery on the opposite side. The size of the iliac lumen was assessed in the proximal, middle, and distal segments of the stents by intravascular ultrasound (IVUS) before, immediately after, and 1 month after implantation when the sheep were killed. Neointimal thickness was determined in the proximal, middle, and distal segments of each stent by light microscopy. Results: All stents remained patent. There was no significant difference in lumen and neointimal thickness between single and tandem stents. Cranial tandem stents showed a significantly wider lumen and smaller neointimal thickness than caudal tandem stents. In the proximal and distal segments, the lumen of the stents was significantly smaller and the neointimal thickness greater than in the middle segment; differences in neointimal thickness were significant only between the proximal and the middle segment. Conclusion: In an experimental setting, tandem stents did not interfere with one another with regard to patency and neointima formation when compared with a single contralateral stent. Neointimal thickening after stent insertion seems to be inversely related to the original arterial diameter.     

Endovascular Conversion Procedure for Failed Primary Endovascular Aortic Stent-Grafts

Initial failure of successful deployment of endovascular aortic stent-grafts can be due to a variety of factors and frequently requires surgical intervention. We describe an endovascular technique for salvaging initially failed tubular aortic and bifurcated aortoiliac stent-grafts with reference to three cases. Received: 0/00/00/Accepted: 0/00/00     

Patency and reintervention rates during routine TIPSS surveillance

Purpose: To assess the medium-term outcome of transjugular intrahepatic portosystemic stent shunts (TIPSS) by measuring the incidence of shunt obstruction or failure during routine surveillance and the number of interventions performed. Methods:This is a retrospective study covering a 4-year period, from 1992 to 1996, during which 102 TIPSS procedures were performed. Indications for treatment were variceal bleeding (76%) and refractory ascites (24%). Follow-up protocol after TIPSS included transfemoral or transjugular portal venography and measurement of portosystemic pressure gradient (PPG) at 3 months, 12 months, and then at yearly intervals. The results of the first 155 venograms on 62 patients (mean follow-up 14 months) have been reviewed and Kaplan-Meier analysis performed. Results: One hundred and thirty-seven of 155 (88%) examinations showed patent shunts. Fifty-six of 137 (41%) of the patent TIPSS had elevated PPG with signs of stenosis. The majority (41/56) of shunt stenoses with elevated pressure gradients were related to neointimal hyperplasia in the hepatic venous aspect of the shunt. Interventions used to reduce the pressure gradient or to restore patency included: angioplasty (62/102 interventions), additional stents (21/102), a second TIPSS procedure (2/102), and thrombolysis or thrombectomy (4/102). The primary patency rate was 66% at 1 year (52% at 2 years). Primary assisted patency was 72% at 1 year (58% at 2 years). Secondary patency was 86% at 1 year (63% at 2 years). Conclusion: The majority of TIPSS shunts will remain patent when regular portal venography, with appropriate intervention, is undertaken. Although there is a high reintervention rate this mainly takes the form of balloon angioplasty.     

Percutaneous Endoluminal Bypass of Iliac Aneurysms with a Covered Stent

To evaluate the feasibility of percutaneous treatment of iliac aneurysms, a covered stent was inserted in nine men suffering from common iliac artery aneurysms (six cases), external iliac aneurysms (one case), or pseudoaneurysms (two cases). Placement of the stent was successful in all patients. In one patient, an endoprosthesis thrombosed after 15 days, but was successfully treated by thrombolysis and additional stent placement. At the follow-up examinations (mean period 22 months) all stent-grafts had remained patent. No late leakage or stenosis was observed.     

Aneurysms of Hemodialysis Access Grafts: Treatment with Covered Stents: A Report of Three Cases

Three patients with dialysis access graft shunts, having a symptomatic pseudoaneurysm and a hemodynamically significant stenosis at the anastomosis between the graft shunt and the subclavian vein, were treated with percutaneous transluminal angioplasty and insertion of a Wallstent. Pseudoaneurysms were excluded by percutaneous insertion of a Cragg Endo-Pro stent-graft with a diameter of 6 mm and a length of 6–10 cm. All three aneurysms were excluded successfully. In two patients, the stent-graft was punctured repeatedly during follow-up and the aneurysms recurred after 7 and 8 months, respectively. The patency of the dialysis shunt after stent-graft insertion was 8 (n= 1) and 9 months (n= 2). Due to the recurrence of the aneurysm (n= 2) or recurrent thrombosis (n= 1) the use of these shunts was discontinued.     

Treatment of a ruptured anastomotic esophageal stricture following bougienage with a dacron-covered nitinol stent

A patient suffering from esophagorespiratory fistula after bougienage of a benign stricture at the site of the anastomosis between a jejunal interposition and the esophagus was referred for interventional treatment. A prototype nitinol stent centrally covered with Dacron was implanted under regional anesthesia and fluoroscopic guidance. The self-expanding prosthesis dilated the stenosis completely and closed the fistula, with consequent improvement in respiratory and nutritional status and thus the general quality of life. The patient was able to eat and drink normally until death 3 months later due to progression of his underlying malignant disease.     

Transluminal Treatment of a Celiac Artery Pseudoaneurysm with a Stent Graft Occlusion Device

This report describes the transluminal placement of a stent graft occlusion device to treat a celiac bypass graft pseudoaneurysm which was causing biliary and duodenal obstruction. Received: 0/00/00/Accepted: 0/00/00     

Popliteal Artery Stenting Using Flexible Tantalum Stents

Purpose: To evaluate the safety and efficacy of stent therapy for the treatment of residual stenoses after percutaneous transluminal angioplasty (PTA) of popliteal stenoses and occlusions. Methods: In a prospective single-center study, flexible tantalum stents were implanted in 32 popliteal arteries for the treatment of residual stenosis greater than 50% after PTA of stenoses (n = 17) or occlusions (n = 15) in the P1 (n = 16), the P2 (n = 13), or both P1 and P2 segment (n = 3). Follow-up patency was assessed by clinical examination, ankle-brachial index, and color Doppler sonography or angiography. Results: Early stent thrombosis (10 days): 1 of 32 arteries (3%). 1-year and 2-year primary patency rate (PPR): 81% ± 7.1% and 74% ± 9.1%, respectively. 1-year PPRs for subgroups: stented stenoses versus stented occlusions: 88% ± 7.8% vs 73% ± 12.0%, p = 0.12; good lower limb runoff versus poor: 84.0% ± 8.7% vs 76.0% ± 12.4; p = 0.09; P1 versus P2: 77.3% ± 9.8% vs 85.7% ± 9.4%, p = 0.38. Recurrent PTA lesions treated with stents showed higher restenosis rate than de novo lesions. Conclusion: The results of stent therapy of residual popliteal stenosis after PTA are encouraging and warrant further investigation.     

Transjugular Intrahepatic Portosystemic Shunt: Histologic and Immunohistochemical Study of Autopsy Cases

Purpose: To assess the histologic findings associated with stenosed and occluded transjugular intrahepatic portosystemic shunt (TIPS) tracts. Methods: Four TIPS tracts within three autopsy livers were histologically studied for vascular components by routine staining and immunohistochemical staining. TIPS had been performed for bleeding from esophageal varices in patients with cirrhosis of the liver. Results: Two TIPS, examined on days 4 and 53, showed occlusion by fibrin thrombus. In the former, no endothelial cells were detected, but coagulative necrosis of hepatocytes was found in the surrounding liver. In the latter, bile pigments were seen on the luminal surface. In the two other TIPS without tract occlusion, examined on days 49 and 293, a layer of endothelial cells, proliferation of smooth muscle cells, and deposition of an extracellular matrix such as collagen were confirmed. In the tract examined on day 293, there was protrusion of hepatocytes into the lumen through the stent wires. Conclusion: Short- and midterm TIPS occlusions were caused by thrombus forming after necrosis of hepatocytes and bile leakage, respectively. Long-term TIPS stenosis was associated with a combination of pseudointimal hyperplasia and ingrowth of hepatocytes. Received: 0/00/00/Accepted: 0/00/00