Stent-grafts for de novo TIPS: technique and early results

PURPOSE

To evaluate the potential benefits of placing a polytetrafluoroethylene (PTFE)-covered stent-graft during initial creation of a transjugular intrahepatic portosystemic shunt (TIPS) in clinical practice.

MATERIALS AND METHODS

De novo TIPS were created with a PTFE stent-graft in four male and four female patients with symptomatic portal hypertension awaiting liver transplant. Their ages ranged from 35 to 62 (mean, 47) years. Patients were followed with TIPS ultrasound (US) and/or venography until liver transplantation or death; one remains under active study. Six recovered specimens underwent gross and microscopic evaluation.

RESULTS

All TIPS placements were successful. Six shunts were primarily patent, with a mean patency of 289 days, through completion of the study. Five were found to be patent at transplant and one was found to be patent at autopsy. Explant evaluation revealed a smooth, thin layer of neointima and exclusion of biliary secretions. Three patients developed a total of four stenoses (one tandem lesion) during follow-up, leading to revision in two patients. Mean primary and total patency in these patients was achieved after 279 and 463 days, respectively. A previously occult moderate stenosis was detected after explant in another patient. Only one (nonsignificant) stenosis clearly developed in an area covered by PTFE.

CONCLUSION

Placement of a de novo PTFE stent-graft during TIPS creation is feasible and may extend primary shunt patency. Appropriate positioning of the stent-graft is critical.

Hepatic allograft abscess with hepatic arterial thrombosis

BACKGROUND

Intrahepatic abscess (IA) is an uncommon complication after liver transplantation (OLTx) usually found in the setting of hepatic arterial thrombosis (HAT) often with associated biliary tree necrosis and/or stricture. Conventional treatment of IA in this setting has required retransplantation.

METHODS

A retrospective review of 274 patients (287 OLTx) from September 1991 through September 1996 was performed. Median follow-up was 3.6 years. Diagnosis of HAT was confirmed by arteriography and IA was documented by computerized tomography. Percutaneous drainage of the abscess and stenting of biliary strictures, if present, was achieved using conventional interventional radiology techniques.

RESULTS

The diagnosis of hepatic artery complication was made in 14 patients (5.1%), 2 of whom required retransplantation. Hepatic artery thrombosis associated with solitary IA was found in 3 patients (1%) who were transplanted in our center and in 1 additional patient followed up at our center but transplanted elsewhere. All 4 patients had complete resolution of IA using this approach. Three of the 4 patients are alive and well, with the fourth patient succumbing to recurrent hepatitis B infection resulting in allograft failure.

CONCLUSIONS

Solitary hepatic allograft abscesses associated with HAT respond to percutaneous drainage and antibiotics, obviating the need for retransplantation in this setting.

Bleeding ileal conduit stomal varices: diagnosis and management using transjugular transhepatic angiography and embolization

An uncommon complication of ileal conduit urinary diversion is bleeding varices at the stoma site. Variceal formation is a complication of portal hypertension, which is most commonly due to intrinsic liver disease. Problematic recurrent bleeding is usually managed locally or by portosystemic shunt. We report a case of recurrent, massive ileal conduit variceal hemorrhage in a patient without a significantly elevated portosystemic gradient. Therefore, this patient was not a candidate for a shunt procedure. Using a transjugular transhepatic approach to the portal vein, the varices were embolized to stasis without any complications. The patient has subsequently experienced no further bleeding episodes.

Transjugular intrahepatic portosystemic shunt with silicone-covered Wallstents: results in a swine model

PURPOSE

To evaluate the use of impermeable silicone-covered Wallstents for transjugular intrahepatic portosystemic shunt creation.

MATERIALS AND METHODS

A transjugular intrahepatic portosystemic shunt was created in 14 young swine (weight, 20-32 kg) by using impermeable silicone-covered Wallstents. In eight animals, the silicone covering extended from the portal vein to the inferior vena cava. In two swine, the silicone covering ended short of the inferior vena cava, in two it ended short of the portal vein wall, and in two it ended short at each end. Follow-up transhepatic portal venography was performed weekly for 6 weeks or until the shunt was occluded. Animals were then sacrificed for gross and histologic evaluation.

RESULTS

Only two of 14 shunts were patent after 3 weeks; both were stenosed with luminal narrowing of more than 50% in the middle of the shunt. By 6 weeks, all shunts were occluded. At histologic evaluation, a marked foreign-body reaction with superimposed thrombosis was demonstrated.

CONCLUSION

In comparison with uncovered Wallstents, impermeable silicone-covered Wallstents are associated with decreased patency at transjugular intrahepatic portosystemic shunt creation. This is likely due to increased thrombogenicity and a foreign-body reaction.

Diagnosis and management of ureteroiliac artery fistula: value of provocative arteriography followed by common iliac artery embolization and extraanatomic arterial bypass grafting

PURPOSE

We describe an effective multidisciplinary approach to the diagnosis and management of ureteroarterial fistulas that reduces morbidity and mortality.

MATERIALS AND METHODS

Five ureteroarterial fistulas in 4 patients were studied with standard and provocative arteriography (arteriography combined with ureteral manipulation). After establishing the diagnosis, each lesion was treated with percutaneous embolic occlusion of the common iliac artery followed by extraanatomic arterial bypass grafting. All patients had chronic ureteral stenting, prior pelvic irradiation, prior pelvic surgery and intrapelvic malignancy, and all fistulas presented with urinary tract hemorrhage.

RESULTS

Standard arteriography was nondiagnostic but provocative arteriography demonstrated the fistula in each case. Successful embolization of the common iliac artery followed by extraanatomic arterial bypass grafting precluded the need for laparotomy and preserved ipsilateral renal function.

CONCLUSIONS

Provocative arteriography followed by arteriographic common iliac artery embolization and extraanatomic bypass grafting was successful for the diagnosis and treatment of ureteroarterial fistulas. There was no mortality, limb loss or renal loss.

Stent-grafts for revision of TIPS stenoses and occlusions: a clinical pilot study

PURPOSE

To assess the clinical and technical results of stent-graft placement for revision of transjugular intrahepatic portosystemic shunt (TIPS) stenoses and occlusions.

MATERIALS AND METHODS

Six patients who developed recurrent TIPS stenosis or occlusion of the parenchymal tract underwent shunt revision with use of polytetrafluoroethylene (PTFE) stent-grafts anchored at both ends by Z stents and centrally supported by Wallstents.

RESULTS

Before graft placement, mean primary patency was 50 days (range, 9-100 days). Patients underwent one to eight revisions with angioplasty or stent placement (mean, 3.2). Three patients had biliary-TIPS fistulas documented with use of a prototype double occlusion balloon catheter. Stent-grafts were successfully placed within the obstructed shunt, creating an excellent lumen in all cases. The portosystemic gradient was decreased from a mean of 24.3 mm Hg (range, 12-35 mm Hg) to a mean of 10.3 mm Hg (range, 7-16 mm Hg). Five of six patients were asymptomatic and no complications occurred (median clinical follow-up, 331 days). One patient died of pre-existing multi-organ system failure. The duration of primary patency after stent-grafting was improved (mean, 229 days; range, 27-324 days) and the difference approached statistical significance despite the small sample size (P = .056, paired t test). Three patients remained primarily patent at a mean venographic follow-up of 315 days. One shunt occluded at 1 month from residual thrombus in the portal vein, and one stenosis occurred that was secondary to misplacement of the original stent-graft. Patency was re-established in each of these patients.

CONCLUSION

PTFE covered stent-grafts are effective for shunt revision in patients with tract stenosis or occlusion and appear to improve TIPS patency.

Experimental TIPS with spiral Z-stents in swine with and without induced portal hypertension

PURPOSE

To assess the suitability of spiral Z-stents for transjugular intrahepatic portosystemic shunt (TIPS) and the influence of portal hypertension on shunt patency in young swine.

METHODS

TIPS were established using spiral Z-stents in 14 domestic swine. In 7 animals, the portal venous pressure was normal; in the other 7, acute portal hypertension was induced by embolization of portal vein branches. Follow-up portal venography and histologic evaluations were done from 1 hr to 12 weeks after TIPS.

RESULTS

Follow-up transhepatic portal venograms showed progressive narrowing of the shunt, most prominent in the midportion of the tract. Ingrowth of liver parenchyma between the stent wires found after 3 weeks led to progressive shunt narrowing and shunt occlusion by 12 weeks. A pseudointima grew rapidly inside the stent, peaked in thickness around 4 weeks, and decreased later. Acutely created portal hypertension rapidly returned to normal and there was no difference in TIPS patency between the two groups of animals.

CONCLUSION

Although the spiral Z-stent can be used as a device for creation of TIPS in patients with cirrhotic livers, it is associated with extensive liver ingrowth in swine that leads to rapid shunt occlusion. Portal hypertension was only transient in this model.

Malignant esophageal obstruction and esophagorespiratory fistula: palliation with a polyethylene-covered Z-stent

PURPOSE

To prospectively evaluate the clinical efficacy of polyethylene-covered metallic Z-stents in treatment of dysphagia secondary to malignant esophageal obstruction and esophagorespiratory fistula.

MATERIALS AND METHODS

Thirty-five patients with dysphagia due to malignant esophageal obstruction (n = 32) and esophagorespiratory fistula (n = 3) were treated with polyethylene-covered Gianturco-Rösch Z-stents.

RESULTS

Thirty-nine stents were placed in 35 patients. Stent placement was technically successful in all patients. Improvement in dysphagia was achieved in 34 of 35 patients. The average dysphagia score decreased from 3.1 (dysphagia to liquids) to 0.6 (essentially normal diet). An esophagorespiratory fistula was completely sealed in two of three patients. All 35 patients were followed up clinically at 1 day and 1 week and at 3-month intervals (range, 1 week to 18 1/2 months; mean, 4.8 months). Recurrent dysphagia or aspiration occurred in only three of 34 (9%) patients whose disease was initially palliated and was easily treated in all cases. Nine complications occurred in eight patients (23%) and included chest pain that required analgesia (n = 3), food impaction (n = 1), stent migration (n = 2), and upper gastrointestinal tract hemorrhage (n = 3).

CONCLUSION

Polyethylene-covered stents are a relatively safe and effective means of long-term palliation in patients with severe malignant esophageal obstruction and esophagorespiratory fistula. These stents are easily deployed, and the rate of stent migration is relatively low.

Attempted induction of chronic portal venous hypertension with polyvinyl alcohol particles in swine

PURPOSE

Creation of presinusoidal chronic portal venous hypertension by means of repeated portal vein (PV) embolization was explored in an attempt to improve a porcine model of transjugular intrahepatic portosystemic shunt (TIPS) patency.

MATERIALS AND METHODS

Six microswine underwent weekly PV embolization for 5 weeks with a total of 10.4-12.6 g of polyvinyl alcohol (PVA) particles (0.149-0.250 mm in size). Portography, liver function tests, pressure measurement in the PV and inferior vena cava (IVC) before and after PV embolization, and histopathologic evaluation of the livers were performed.

RESULTS

Transhepatic portal venography performed after each embolization demonstrated diffuse PV branch occlusion in all cases. At weekly follow-up, reconstitution of flow was demonstrated in these branches; permanent occlusion of PV branches was not achieved. The mean PV pressure elevated acutely from 17.3 mm Hg +/- 0.9 to 24.5 mm Hg +/- 4.2 (P < .01) after each embolization. However, the pressure always returned to baseline on the follow-up studies 1 week later. Liver function tests were normal. Histopathologic evaluation of the liver showed, in multiple PV branches, central plugs of PVA with peripheral recanalization. The liver parenchyma was otherwise normal.

CONCLUSION

Massive embolizations of PV with PVA at weekly intervals failed to create permanent portal hypertension or induce hepatic fibrosis.

Bile duct injury as a major cause of stenosis and occlusion in transjugular intrahepatic portosystemic shunts: comparative histopathologic analysis in humans and swine

PURPOSE

A comparative histologic analysis of human and swine transjugular intrahepatic portosystemic shunts (TIPS) was performed to investigate factors limiting TIPS patency and to further develop an animal model for TIPS.

MATERIALS AND METHODS

Twenty-one human and 13 porcine shunts were evaluated by means of gross inspection, histologic evaluation, and electron microscopy.

RESULTS

Severe stenosis (> 75% narrowing) or occlusion was detected with portal venography in nine of the 21 human shunts (48%) and in 10 of 13 porcine shunts (77%). Gross or histologic evidence of a substantial biliary fistula was observed in seven of nine porcine shunts and in seven of eight human shunts with severe parenchymal tract stenosis or occlusion. No evidence of substantial bile duct injury was identified in the 13 human shunts or two swine shunts with patent, nonstenotic parenchymal tracts (P < .01, Fisher exact). Histologic findings in porcine shunts mimicked human tissue responses, including a metaplastic proliferation of bile duct epithelium at sites of bile duct transection.

CONCLUSION

Bile duct transection and bile leak are significantly associated with TIPS parenchymal tract abnormalities in patients and swine. TIPS in swine created with the Wallstent faithfully reproduce gross morphologic and histologic changes observed in patients.

Treatment of esophageal obstruction from mediastinal compressive tumor with covered, self-expanding metallic Z-stents

BACKGROUND

Mediastinal malignancies may involve the esophagus, leading to esophageal stenosis and dysphagia. Rigid and self-expanding esophageal stents have been used for effective palliation, but their use in extrinsic, compressive lesions is controversial.

METHODS

A retrospective review of self-expanding Gianturco-Rösch Z-stents that were successfully placed in 13 patients with malignant esophageal obstruction due to extrinsic lesions.

RESULTS

All patients had an improvement in dysphagia of at least two dysphagia grades. The mean dysphagia grade fell from 3.15 to 0.62. Mean survival was 2.2 months. Early (within 48 hours) procedure-related complications occurred in 4 of 13 patients and consisted of minor, transient chest pain that resolved within 6 hours (3 patients) and endoscopic stent dislodgment into the stomach (1 patient). Late complications (> 48 hours) occurred in 2 patients and consisted of a partial proximal stent migration and the development of a benign stricture proximal to the stent. There was no procedural or stent related mortality.

CONCLUSIONS

Esophageal obstruction and malignant dysphagia from extrinsic, compressive mediastinal malignancies can be effectively and safely palliated with self-expanding Gianturco- Rösch Z-stents.

Prior radiation and chemotherapy increase the risk of life-threatening complications after insertion of metallic stents for esophagogastric malignancy

BACKGROUND

Self-expanding metallic stents (SEMS) are effective in relieving the symptoms of obstructing esophagogastric malignancy. While complications with SEMS have been described, factors influencing such occurrence have not been defined.

METHODS

Self-expanding Gianturco-Rosch Z-stents were placed successfully in 59 patients with obstructing esophagogastric malignancies.

RESULTS

Early procedure-related complications occurred in 6 patients (10%) and were usually minor. Twenty-three late complications occurred in 22 patients (37.5%). Life-threatening complications occurred in 9 patients (15%), including gastrointestinal bleeding (7), perforation (1), and tracheoesophageal fistula (1) and contributed to all five deaths. Eight of 22 patients with prior radiation and/or chemotherapy (36.4%) had life-threatening complications compared to 1 of 37 (2.5%) without prior therapy (p = 0.001). Stent-related mortality occurred in 5 of 22 (23%) patients with prior therapy compared to none of the 37 without prior therapy (p = 0.005). Multivariate analysis confirmed the association between prior radiation and/or chemotherapy and life-threatening complications (p = 0.012; odds ratio, 32.63) and also an association with female gender (p = 0.032; odds ratio, 13.9). There was no association with tumor location or length, histologic type, age, prestent dysphagia grade, or previous surgical resection.

CONCLUSION

Patients with prior radiation and/or chemotherapy have an increased risk of severe complications following placement of SEMS.

Takayasu arteritis: palpable neck mass diagnosed by cross sectional imaging

Takayasu arteritis is a chronic inflammatory disease of unknown origin. The disease is characterized by transmural inflammation and fibrosis; the arterial lesions affect mainly the aorta and great vessels and sometimes involve the pulmonary arteries and visceral vessels. Despite efforts to create criteria for clinical diagnosis, many patients still require angiography for complete evaluation and diagnostic confirmation. We describe a patient with a mass seen on CT and confirmed on MRI; angiography showed changes in the vertebral and carotid arteries. Our case proved to be an atypical presentation of Takayasu arteritis.

Treatment of malignant esophageal obstructions with covered metallic Z stents: long-term results in 52 patients

PURPOSE

To prospectively evaluate the clinical efficacy of silicone-covered Gianturco-Rösch self-expandable Z (GRZ) stents in the treatment of malignant esophageal obstruction.

PATIENTS AND METHODS

GRZ stents were placed in 52 patients (39 men, 13 women) with severe dysphagia due to high-grade malignant esophageal obstruction.

RESULTS

Stent placement was technically successful, and immediate relief of dysphagia was achieved in 50 of 52 patients (96%), with long-term relief in 47 patients (90%). Fifty-one patients (98%) died during follow-up (range, 1 week to 33 months; mean, 4.3 months). Late complications were most prevalent and included stent migration (n = 5), food impaction (n = 2), chest pain (n = 2), membrane disruption with tumor ingrowth (n = 1), granulomatous reaction above the stent (n = 1), esophageal perforation with mediastinitis (n = 1), and upper gastrointestinal hemorrhage (n = 4). Twelve complications were easily managed with medical, endoscopic, or radiologic intervention. Four deaths may have been related to stent placement (early mortality rate, 7.7%).

CONCLUSION

GRZ stents provide relatively safe and effective long-term palliation in patients with severe, malignant esophageal obstruction.

Improved transjugular intrahepatic portosystemic shunt patency with PTFE-covered stent-grafts: experimental results in swine

PURPOSE

To evaluate the ability of stent-grafts made with polytetrafluoroethylene (PTFE) graft material to improve transjugular intrahepatic portosystemic shunt (TIPS) patency.

MATERIALS AND METHODS

TIPS were created in 13 swine by using PTFE-covered stent-grafts. Uncovered TIPS were placed in 13 other swine. Twenty-one of 26 animals were followed up with portal venography for 3 months or until the shunt became severely stenotic. Five animals without severe stenosis were sacrificed before 3 months because of illness.

RESULTS

At 4 weeks after TIPS placement, nine of 13 stent-graft TIPS were patent (< 50% diameter narrowing) compared with only one patent stent in 13 uncovered TIPS. Six of 13 stent-graft TIPS remained patent until the animals were sacrificed. In 11 of 12 uncovered TIPS, stenosis was most prominent in the parenchymal tract. In five of seven stent-graft TIPS, stenosis was most prominent in the hepatic vein above the end of the graft material. Bile leaks were discovered in six occluded uncovered TIPS and in two of the stent-graft TIPS.

CONCLUSION

PTFE-covered stent-grafts significantly improved TIPS patency in swine (P < .01). However, stenosis in the hepatic vein led to late shunt malfunction in selected cases.

Catheter tract hemorrhage during percutaneous biliary intervention: management with use of a retained transhepatic guide wire

PURPOSE

The authors present their experience in managing freely flowing hemorrhage from immature catheter tracts in patients undergoing biliary drainage.

PATIENTS AND METHODS

Transhepatic guide wires were maintained securely whenever catheters were removed from the liver. Six patients among 71 hemorrhaged profusely when drains were manipulated within 4 days of initial catheterization. Management was attempted with use of the transhepatic guide wires.

RESULTS

Maneuvers performed over the retained guide wire controlled bleeding in all six patients. Reintubation constituted definitive therapy in five patients. A biliary-portal venous fistula in the remaining patient was treated with thrombin. The retained guide wire proved necessary in all cases.

CONCLUSION

Hemorrhage from immature catheter tracts can be managed, often definitively, with maneuvers performed over a retained transhepatic guide wire. Accordingly, a secure transhepatic guide wire is essential prior to removal of hepatic catheters and should remain in place until the absence of bleeding is established. These maneuvers may become increasingly important as courses of biliary catheterization become shorter.

Treatment of malignant esophagorespiratory fistulas with silicone-covered metallic Z stents

PURPOSE

To prospectively evaluate the clinical efficacy of covered metallic Z stents in the treatment of esophagorespiratory fistulas (ERFs).

PATIENTS AND METHODS

Twelve patients with severe aspiration symptoms from malignant ERFs were treated with silicone-covered, metallic, self-expanding Gianturco-Rösch Z (GRZ) stents.

RESULTS

Fluoroscopically guided stent placement was successful and well tolerated in all patients. Immediate postprocedural endoscopy and esophagography showed excellent coverage of the fistulas in all cases. Aspiration symptoms were completely relieved in eight of 12 patients (67%). Four of 12 patients (33%) were improved and able to eat a soft diet. There were no stent-related deaths. Nine patients have died and three patients are alive. Mean follow-up for the entire group was 3.9 months (range, 1 week to 10.5 months). Nonfatal complications occurred in three of 12 patients (25%). Complications included one membrane disruption and one granulomatous reaction with a slight upward stent migration.

CONCLUSION

GRZ stents are an effective and safe means of palliation in patients with malignant esophagorespiratory fistulas.

Silicone-covered self-expanding metallic stents for the palliation of malignant esophageal obstruction and esophagorespiratory fistulas: experience in 32 patients and a review of the literature

Esophagogastric malignancies often are manifested with progressive dysphagia or esophagorespiratory fistulas. Palliative modalities currently available have significant limitations. A modified Gianturco-Rösch silicone-covered self-expanding metallic Z stent was used in 32 consecutive patients with malignant esophageal obstruction (n = 24) or esophagorespiratory fistulas (n = 8). The stent was placed successfully in all patients. Dysphagia improved by at least two grades in 21 of the 24 patients (87.5%); the mean dysphagia grade fell from 3.21 to 1.08. Six of the 8 patients with fistulas were able to resume a normal diet, and the other 2 were able to eat solids without symptoms of aspiration. Complications occurred in 10/32 patients (31%) and included stent migration (4 patients), food impaction (2 patients), membrane disruption with tumor ingrowth (1 patient), tumor overgrowth (1 patient), early pressure necrosis with hemorrhage (1 patient), and late pressure necrosis with sepsis (1 patient). The latter 2 patients died, giving a mortality rate of 6.3%. Many complications were managed with endoscopic or interventional radiologic techniques. Although randomized prospective clinical trials are needed, the silicone-covered Gianturco-Rösch Z stent offers promise for the effective palliation of malignant esophageal obstruction and esophagorespiratory fistulas.

Pathogenesis of pulmonary edema during interleukin-2 therapy: correlation of chest radiographic and clinical findings in 54 patients

The pathogenesis of pulmonary edema that occurs during interleukin-2 therapy has often been attributed to an increase in pulmonary capillary permeability. However, renal insufficiency, fluid overload, and hypotension also develop in many patients. These manifestations of systemic toxicity may contribute to the development of pulmonary edema during therapy. Understanding the cause of pulmonary edema during interleukin-2 therapy could directly affect patients' care. Therefore, we reviewed the chest radiographs and clinical course of 54 patients who received high-dose interleukin-2 therapy and lymphokine-activated killer cells for advanced carcinoma. The type, frequency, and course over time of pulmonary abnormalities were recorded and correlated with clinical measures of renal function, fluid status, and blood pressure. Focal or diffuse parenchymal lung opacities were found on radiographs in 43 (80%) of 54 patients. Findings of interstitial pulmonary edema were most common, occurring in 76% of patients. Weight gain, hypotension, and elevation of the serum creatinine level were not associated statistically with interstitial edema. Diffuse air-space disease developed in 20% of patients. Focal consolidation, which was associated with positive central venous catheter cultures (p less than .03), developed in 28% of patients. Pleural effusion occurred in 48% of patients and was associated with all types of parenchymal disease. These data suggest that the frequent development of pulmonary edema during interleukin-2 therapy is not due to renal insufficiency, fluid overload, or hypotension, but is more likely the result of an interleukin-2-related increase in pulmonary capillary permeability.