A Newly Designed Nitinol Stent: Early Clinical Experience in the Treatment of Iliac Artery Stenoses and Occlusions

Objective

To investigate the effectiveness of the newly designed Niti-S stent in the management of iliac arterial stenoses and occlusions.

Materials and Methods

Stenoses (n=25) or occlusions (n=5) in the iliac arteries of 25 patients (30 limbs) were treated. The site of the lesions was the common (n=15) or external (n=11) iliac artery, or both (n=4). Eight limbs were treated for diffuse disease, six for highly eccentric lesion, five for occlusive lesion, and 11 for failed angioplasty.

Results

In all patients, technical success was achieved without major complications. One death, not procedure-related, occurred within 30 days. Ankle-brachial indexes improved from 0.63±0.30 to 0.99±0.21, and ischemic symptoms showed improvement in 22 patients (88%). Fontaine classifications before stenting, namely IIa(n=3), IIb(n=16), III(n=2), and IV(n=4) improved to I(n=17), IIa(n=5), and IV(n=3). Follow-up over a 27 (mean, 19.8±8)-month period showed that cumulative patency rates were 95.8% at 1 year and 86.2% at 2 and 3 years. No significant decrease in the mean ankle-brachial index was observed.

Conclusion

The Niti-S stent appears to be a safe and effective device for the treatment of iliac stenoses and occlusions. These preliminary results require confirmation with a larger series.     

The Efficacy of Metallic Stent Placement in the Treatment of Colorectal Obstruction

Objective

To evaluate the efficacy of newly designed covered and non-covered coated colorectal stents for colonic decompression.

Materials and Methods

Twenty-six patients, (15 palliative cases and 11 preoperative) underwent treatment for the relief of colorectal obstruction using metallic stents positioned under fluoroscopic guidance. In 24 of the 26, primary colorectal carcinoma was diagnosed, and in the remaining two, recurrent colorectal carcinoma. Twenty-one patients were randomly selected to receive either a type A or type B stent; for the remaining five, type C was used. Type A, an uncovered nitinol wire stent, was lightly coated to ensure structural integrity. Type B (flare type) and C (shoulder type) stents were polyurethane covered and their diameter was 24 and 26mm, respectively. The rates of technical success, clinical success, and complications were analyzed using the chi-square test, and to analyse the mean period of patency, the Kaplan-Meier method was used.

Results

Thirty of 31 attempted placements in 26 patients were successful, with a technical success rate of 96.8% (30/31) and a clinical success rate of 80.0% (24/30). After clinically successful stent placement, bowel decompression occurred within 1-4 (mean, 1.58 ± 0.9) days. Five of six clinical failures involved stent migration and one stent did not expand after successful placement. In the preoperative group, 11 stents, one of which migrated, were placed in ten patients, in all of whom bowel preparation was successful. In the palliative group, 19 stents were placed in 15 patients. The mean period of patency was 96.25 ± 105.12 days: 146.25 ± 112.93 for type-A, 78.82 ± 112.26 for type-B, and 94.25 ± 84.21 for type-C. Complications associated with this procedure were migration (n=6, 20%), pain (n=4, 13.3%), minor bleeding (n=5, 16.7%), incomplete expansion (n=1, 3.3%), and tumor ingrowth (n=1, 3.3%). The migration rate was significantly higher in the type-B group than in other groups (p=0.038).

Conclusion

Newly designed covered and non-covered metallic stents of a larger diameter are effective for the treatment of colorectal obstruction. The migration rate of covered stents with flaring is higher than that of other types. For evaluation of the ideal stent configuration for the relief of colorectal obstruction, a clinical study involving a larger patient group is warranted.     

Pancreatitis-Induced Extrahepatic Portal Vein Stenosis Treated by Percutaneous Transhepatic Stent Placement: a Case Report

One month after onset of an acute biliary pancreatitis, a 75-year-old man developed refractory ascites. Duplex ultrasound and CT scan revealed a focal stenosis of the extrahepatic portal vein as confirmed by transhepatic direct portography. In the same session, this stenosis, responsible for symptomatic prehepatic portal hypertension, was successfully dilated and stented and afterwards a residual pressure gradient of 1 mmHg over the stented segment was measured. One week after the stenting procedure the patient was free of ascites and control physical and biochemical examination one year later is completely normal.     

Internal Thoracic Artery Collateral to the External Iliac Artery in Chronic Aortoiliac Occlusive Disease

Objective

To evaluate the incidence and angiographic findings of the collateral pathway involving the internal thoracic artery in patients with chronic aortoiliac occlusive disease.

Materials and Methods

Between March 2000 and Februrary 2001, 124 patients at our hospital underwent angiographic evaluation of chronic aortoiliac occlusive disease, and in 15 of these complete obstruction or severe stenosis of the aortoiliac artery was identified. The aortograms and collateral arteriograms obtained, including internal thoracic arteriograms, as well as the medical records of the patients involved, were evaluated.

Results

In nine patients there was complete occlusion of the infrarenal aorta, or diffuse stenosis of 75% or more in the descending thoracic aorta, and in the other six, a patent aorta but complete occlusion or stenosis of 75% or more of the common iliac artery was demonstrated. Collateral perfusion via hypertrophied internal thoracic arteries and rich anastomoses between the superior and inferior epigastric arteries, reconstituting the external iliac artery, were noted in all fifteen patients, regardless of symptom duration, which ranged from six months to twelve years.

Conclusion

In patients with chronic aortoiliac occlusive disease, the internal thoracic artery, along with visceral collaterals and those from the contralateral side, is one of the major parietal collateral pathways.     

Placement of a PTFE-covered wallstent through a 12 Fr sheath for the exclusion of a common lliac artery aneurysm

We describe a technique for transfemoral endovascular exclusion of an iliac artery aneurysm with a reconstrained polytetrafluoroethylene (PTFE)-covered Wallstent inserted through a 12 Fr sheath after right femoral artery cutdown. The procedure was successfully performed, with evidence of complete aneurysm exclusion at 4-month follow-up. This technique reduces the caliber of the introducer needed to deploy the covered Wallstent. It should be noted that because of a leak, an additional covered Palmaz stent was also deployed.     

Management of Tracheobronchial Strictures

Recently, the use of tracheobronchial stents has increased greatly sue to the advantages of easy placement and prompt airway relief. in addition, trachebronchial stents provide an alternative to open surgical procedures in select patients with benign tracheobronchial stenosis or obstruction, in particular those with tracheobronchial tuberculosis. This paper review the indications for tracheobronchial stent placement, appropriate stent selection, pre-procedure evaluation, and the results of stent placement for benign and malignant tracheobronchial strictures.phone: 82-2-3010-4370 FAX: 82-2-476-0090 E-mail: hysong@amc.seoul.uk     

Acute Duodenal Obstruction After Percutaneous Placement of Metallic Biliary Stents: Peroral Treatment with Enteral Stents

Three patients with malignant biliary obstruction were treated with placement of metallic biliary stents. Two patients had known partial duodenal stenosis but had no symptoms of gastrointestinal obstruction. The patients developed symptomatic duodenal obstruction early after biliary metallic stent placement. The symptomatic duodenal obstructions were successfully treated with peroral placement of duodenal stents, which obviated the need for surgical intervention.     

Fatal Complications After Self-Expandable Metallic Stent Placement for Inferior Vena Cava Syndrome

We present the case of a 71-year-old man with inferior vena cava syndrome due to metastatic lymph nodes from hepatocellular carcinoma with serious complications that were strongly suspected to result from rapid changes in hemodynamics after self-expandable metallic stent placement.     

Isolated Spontaneous Dissection of the Superior Mesenteric Artery: Percutaneous Stent Placement in Two Patients

Isolated spontaneous dissection of the superior mesenteric artery (SMA) is a rare cause of acute mesenteric ischemia. Two patients were successfully treated by percutaneous stent placement within the main trunk of the SMA. Emphasis is placed on the feasibility of nonsurgical management with percutaneous stent placement of isolated spontaneous dissection of the SMA.     

Percutaneous Stent Placement as Treatment of Renal Vein Obstruction Due to Inferior Vena Caval Thrombosis

A patient who had undergone his third orthotopic liver transplantation nearly 9 years prior to presentation developed worsening hepatic and renal function, as well as severe bilateral lower extremity edema. Magnetic resonance imaging demonstrated vena caval thrombosis from the suprahepatic venous anastomosis to the infrarenal inferior vena cava, obstructing the renal veins. This was treated by percutaneous placement of metallic stents from the renal veins to the right atrium. At 16 months clinical follow-up, the patient continues to do well.     

Primary Self-Expandable Nitinol Stent Placement in Focal Lesions of Infrarenal Abdominal Aorta: Long Term Results

Purpose To evaluate the technical and clinical success, safety and long term results of percutaneous transluminal angioplasty/self-expandable nitinol stent placement of infrarenal abdominal aorta focal lesions. Materials and Methods Eighteen patients underwent PTA of focal atherosclerotic occlusive disease of distal abdominal aorta. Two symptomatic occlusions and 16 stenoses in 10 male and 8 female patients (mean age 68.2 years) were treated with primary self-expandable nitinol stent placement. Results Primary self-expandable nitinol stent placement was technically successful in all 18 procedures; clinical success was achieved in 100% of patients. No complications associated with the procedure occurred. During the 49.4 months of mean follow up (range 3–96, 4 months) all treated aortic segments remained patent. Conclusions Endovascular treatment (primary self-expandable nitinol stent placement) of focal atherosclerotic lesions of distal abdominal aorta is a safe method with excellent primary technical and clinical success rates and favourable Long term results.     

Percutaneous Placement of Self-expandable Metallic Biliary Stents in Malignant Extrahepatic Strictures: Indications of Transpapillary and Suprapapillary Methods

Objective

To compare the efficacy of suprapapillary and transpapillary methods of transhepatic biliary metallic stent placement in malignant biliary strictures and to specify the indications of each method applied.

Materials and Methods

Stents were placed in 59 patients. Strictures were categorized as type A (within 3 cm of the ampulla, n = 27), type B (over 3 cm from ampulla, n = 7), type C (within 3 cm of the bending portion, n = 9), or type D (over 3 cm above the bending portion, n=16). The stenting method was suprapapillary in 34 cases and transpapillary in 25. The rates of initial and long-term patency and of early recurrence were compared.

Results

Initial patency rates for the suprapapillary and transpapillary methods were 1/7 (14.3%) and 20/20 (100%) respectively for type A (p < 0.0001), 4/5 (80.0%) and 2/2 for type B, 3/7 (42.9%) and 2/2 for type C, and 15/16 (93.8%) and 0/0 for type D. Early recurrence rates were 7/30 (23.3%) using the suprapapillary method and 4/29 (13.8%) using the transpapillary method (p = 0.51). The long-term patency rate did not differ significantly according to either type (p = 0.37) or method (p = 0.62).

Conclusion

For good initial patency, the transpapillary method is recommended for strictures of the distal extrahepatic duct near the ampulla and just above the bending portion. Long-term patency is not influenced by the stenting method employed.     

Partially covered Gianturco stent for tracheobronchial stricture caused by intraluminal tumor

Partially covered Gianturco stents were used successfully in two patients to treat tracheobronchial strictures caused by intraluminal tumor growth. The stents were accurately placed without complications. The covered portion of the stent compressed the tumor, and prevented tumor ingrowth until the patients’ deaths. This stent seems to act as effective palliation for tracheobronchial stricture caused by intraluminal tumor.     

Metallic endoprostheses for malignant tracheobronchial obstruction: Initial experience

Purpose To assess the efficacy of the Wallstent endoprosthesis in malignant tracheobronchial obstruction. Methods Seven patients with irresectable carcinoma of the bronchus were treated with nine Wallstent endoprostheses. The procedures were performed under endoscopic and fluoroscopic guidance. Wallstent endoprostheses ranging from 8–16 mm in diameter and 26–49 mm in length were deployed after balloon dilatation of the strictures. Results All stents were successfully deployed in the desired positions. There was one procedural complication and one procedure-related death. Three patients showed significant improvement in respiratory status after stenting. At a mean follow-up of 5.1 months, there has been no stent migration, fracture, or collapse. One patient had proximal tumor overgrowth that was treated with additional stent insertion. One patient died after a bout of massive hemoptysis 3 months poststenting and it was difficult to tell whether this was related to the endoprosthesis. Conclusion The use of the Wallstent endoprosthesis in malignant tracheobronchial obstruction is technically feasible.     

Delayed Colon Perforation after Palliative Treatment for Rectal Carcinoma with Bare Rectal Stent: A Case Report

In order to relieve mechanical obstruction caused by rectal carcinoma, a bare rectal stent was inserted in the sigmoid colon of a 70-year-old female. The procedure was successful, and for one month the patient made good progress. She then complained of abdominal pain, however, and plain radiographs of the chest and abdomen revealed the presence of free gas in the subdiaphragmatic area. Surgical findings showed that a spur at the proximal end of the bare rectal stent had penetrated the rectal mucosal wall. After placing a bare rectal stent for the palliative treatment of colorectal carcinoma, close follow-up to detect possible perforation of the bowel wall is necessary.     

Interventional Management of Malignant Colorectal Obstruction: Use of Covered and Uncovered Stents

Objective

We wanted to evaluate usefulness of uncovered stent in comparison with covered stent for the palliative treatment of malignant colorectal obstruction.

Materials and Methods

Covered (n = 52, type 1 and type 2) and uncovered (n = 22, type 3) stents were placed in 74 patients with malignant colorectal obstruction. Stent insertion was performed for palliative treatment in 37 patients (covered stent: n = 23 and uncovered stent: n = 14). In the palliative group, the data on the success of the procedure, the stent patency and the complications between the two groups (covered versus uncovered stents) were compared.

Results

The technical success rate was 89% (33/37). Symptomatic improvement was achieved in 86% (18/21) of the covered stent group and in 92% (11/12) of the uncovered stent group patients. The period of follow-up ranged from three to 319 days (mean period: 116±85 days). The mean period of stent patency was 157±33 days in the covered stent group and 165±25 days in the uncovered stent group. In the covered stent group, stent migration (n = 11), stent fracture (n = 2) and poor expansion of the stent (n = 2) were noted. In the uncovered stent group, tumor ingrowth into the stents (n = 3) was noted.

Conclusion

Self-expanding metallic stents are effective for relieving malignant colorectal obstruction. The rate of complications is lower in the uncovered stent group than in the covered stent group.     

Chronic aortic dissection: Stenting of aortic true lumen obliteration with late dynamic variations of both lumens

Percutaneous endovascular techniques were used to treat an arteriovenous fistula (AVF) associated with pancreatic transplantation. A pancreatic transplant superior mesenteric artery-to-superior mesenteric-vein AVF was successfully embolized while flow to the pancreas transplant was preserved. The embolization was aided by the use of Guglielmi detachable coils and a detachable balloon. No complications were encountered. At 23 months follow-up, the patient is doing well with no recurrence.     

Placement of a PTFE-Covered Wallstent Through a 12 Fr Sheath for the Exclusion of a Common Iliac Artery Aneurysm

We describe a technique for transfemoral endovascular exclusion of an iliac artery aneurysm with a reconstrained polytetrafluoroethylene (PTFE)-covered Wallstent inserted through a 12 Fr sheath after right femoral artery cutdown. The procedure was successfully performed, with evidence of complete aneurysm exclusion at 4-month follow-up. This technique reduces the caliber of the introducer needed to deploy the covered Wallstent. It should be noted that because of a leak, an additional covered Palmaz stent was also deployed.     

Cryoplasty for Occlusive Disease of the Femoropopliteal Arteries: 1-Year Follow-Up

Atherosclerosis of femoropopliteal arteries is an important cause of morbidity and mortality. Percutaneous transluminal angioplasty (PTA) has only limited success in treating these arteries, mainly because of the high rate of recurrent stenosis. Cryoplasty has been proposed as a technique which might improve treatment outcome. This study reports our single-center experience with cryoplasty. Thirty-two claudicants, 33 arteries, in whom conservative therapy failed, were consecutively included. Duplex ultrasound (US), angiography, and ankle-brachial index (ABI) measurement were performed before the procedure; ABI and duplex US, 2 weeks and 3, 6, and 12 months after the procedure. Patients’ symptoms were categorized according to the Rutherford classification. Lesions were classified as TASC A, B, or C according to angiographic appearance. Differences in ABI before and after the procedure were defined as significant at p < 0.05 by paired t-test. Patency was evaluated using duplex US by determining the peak systolic velocity ratio. Sixteen TASC A lesions, 13 TASC B lesions, and 4 TASC C lesions were included. ABI improved significantly for TASC A lesions 2 weeks and 3 months postprocedure. Patency after 2 weeks, 6 months, and 12 months was 93%, 67%, and 64% for TASC A lesions, 83%, 31%, and 31% for TASC B lesions, and 100%, 50%, and 33% for TASC C lesions, respectively. In conclusion, cryoplasty has good immediate success rates and patency rates similar to the results of conventional PTA in the literature.