Endovascular treatment of obstructive iliac artery dissections

Purpose: To report our results from a study of the endovascular treatment of flow restricting chronic atherosclerotic or catheter-induced segmental iliac artery dissections with bare stents.

Material and Methods: Thirty symptomatic patients with 32 lesions, including chronic atherosclerotic (n = 21) and catheter-induced (n = 11) segmental arterial dissections, were treated with primary stenting. The common iliac artery was involved in 19 lesions and the external iliac artery in the remaining 13. Two patients had two lesions in the same vessel. Technical success was defined as restoration of the smooth contoured luminal patency with no more than 20% residual stenosis in diameter in atherosclerotic dissections associated with plaque formation or total obliteration of the false lumen in catheter-induced dissections. Complete relief of, or marked improvements in, presenting symptoms, or at least single category improvement, was assessed for clinical success.

Results: Technical success rate was 100%. No procedure-related complications such as distal emboli or early occlusions were observed. Complete symptom relief was achieved in all patients with catheter-induced dissection and in all but three cases with chronic spontaneous atherosclerotic dissection. In two cases, occlusion of the stents occurred during the follow-up period. Clinical and radiological mean follow-up for 24 months (range 3-55) revealed patency of all other stented segments. Cumulative primary patency rate was 97% over 12 months and 90% over 24 months.

Conclusion: Endovascular treatment of chronic atherosclerotic and catheter-induced short obstructive iliac arterial dissections with bare stents is safe and effective. Patency of the diseased arterial segment with a smooth lumen can be sustained for an extensive period.     

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.     

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.     

Intraarterial pressure gradients after randomized angioplasty or stenting of iliac artery lesions

Purpose To determine initial technical results of percutaneous transluminal angioplasty (PTA) and stent procedures in the iliac artery, mean intraarterial pressure gradients were recorded before and after each procedure. Methods We randomly assigned 213 patients with typical intermittent claudication to primary stent placement (n=107) or primary PTA (n=106), with subsequent stenting in the case of a residual mean pressure gradient of >10 mmHg (n=45). Eligibility criteria included angiographic iliac artery stenosis (>50% diameter reduction) and/or a peak systolic velocity ratio >2.5 on duplex examination. Mean intraarterial pressures were simultaneously recorded above and below the lesion, at rest and also durign vasodilatation in the case of a resting gradient ≤10 mmHg. Results Pressure gradients in the primary stent group were 14.9±10.4 mmHg before and 2.9±3.5 mmHg after stenting. Pressure gradients in the primary PTA group were 17.3±11.3 mmHg pre-PTA, 4.2±5.4 mmHg post-PTA, and 2.5±2.8 mmHg after selective stenting. Compared with primary stent placement, PTA plus selective stent placement avoided application of a stent in 63% (86/137) of cases, resulting in a considerable cost saving. Conclusion Technical results of primary stenting and PTA plus selective stenting are similar in terms of residual pressure gradients.     

Percutaneous endoluminal stent and stent-graft placement for the treatment of femoropopliteal aneurysms: Early experience

Purpose: To determine the efficacy of percutaneous endoluminal stents and stent-grafts for the treatment of isolated femorpopliteal aneurysms. Methods: Seven men (age 51–69 years) with femorpopliteal occlusions (n=6) related to aneurysms and a patent femoropopliteal aneurysm (n=1) were treated percutaneously. In two patients uncovered Wallstents and in five patients polyestercovered nitinol stents were implanted. Assessment was performed with Doppler ultrasound and duplex ultrasonography 24 hr, 1, 3, 6, 12, and 24 months after the intervention. Additionally, intraarterial angiography was performed at 6 months. Results: Stent placement succeeded in all cases. No immediate adjunctive surgical treatment was necessary. Ankle-brachial index (ABI) improved from 0.29±0.29 (SD) before to 0.78±0.23 (SD) 24 hr after the intervention. One patient was lost to follow-up. Stent-graft occlusion occurred in four patients: after 2 days (n=1), 1 month (n=2), and 3 months (n=1). One of the patients, whose stent occluded at 1 month, underwent successful recanalization with local fibrinolysis therapy. Three of the seven, all with three-vessel run-off, demonstrated patency of the stent, which was assessed by duplex ultrasonography at 29, 31, and 34 months. Breaking of the stent struts or significant stent migration was not observed. Conclusions: These results in a small number of patients warrant further investigation to evaluate the role of percutaneous stents in femoropopliteal aneurysms. Until further data of clinical studies are available, this method cannot be recommended, and it cannot replace surgical treatment.     

食管支架治疗食管恶性狭窄的临床应用研究

目的：回顾性分析食管支架放置对恶性食管疾病的治疗并由此带来的生存质量的提高、生存期的延长以及食管支架放置过程中、术后出现的并发症及其相关因素。方法：利多卡因行口腔及咽喉部麻醉，置开口器，透视下将超滑导丝与8F大腔导管送入食管内，撤出导丝，经导管行食管造影标记定位病变区。导丝及导管进入胃内，置换不折导丝，部分病人行预扩张选择合适支架，沿导丝送至病变部位，透视监视下缓慢释放。结果：本组326例食管疾病患者共放置369枚食管支架，343枚支架一次放置成功，所有支架释放后即刻位置满意者337枚。放置支架后患者的一般状况很快得到好转。并发症有疼痛、再狭窄、支架移位、胃内容物反流、出血、支架嵌顿填塞、打嗝，其中l例于放置支架后30h因大出血死亡。结论：对于重度吞咽困难而又失去手术机会或拒绝接受手术治疗的食管癌患者。经口腔放置食管支架是一种操作安全可靠、微创、简单易行、见效快、费用相对低廉的治疗方法。     

Stent Placement for Chronic Iliac Arterial Occlusive Disease: the Results of 10 Years Experience in a Single Institution

Objective

We wanted to retrospectively evaluate the long-term therapeutic results of iliac arterial stent placement that was done in a single institution for 10 years.

Materials and Methods

From May 1994 to April 2004, 206 patients who underwent iliac arterial stent placement (mean age; 64±8.8) were followed up for evaluating the long term stent patency. Combined or subsequent bypass surgery was performed in 72 patients. The follow up period ranged from one month to 120 months (mean; 31±25.2 months). The factors that were analyzed for their effect on the patency of stents were age, the stent type and diameter, the lesion site, lesion shape, lesion length, the Society of Cardiovascular and Interventinal Radiology criteria, the total run off scores, the Fontaine stage and the cardiovascular risk factors (diabetes mellitus, hypertension and smoking). Follow-up included angiography and/or CT angiography, color Doppler sonography and clinical evaluation with the ankle-brachial index.

Results

Two hundred and eighty-four stents were placed in 249 limbs of 203 patients. The technical success rate was 98% (203/206). The primary patency rates of the stents at 3, 5, 7 and 10 year were 87%, 83%, 61% and 49%, respectively. One hundred seventy-seven patients maintained the primary stent patency until the final follow up and 26 patients showed stenosis or obstruction during the follow up. Secondary intervention was performed in thirteen patients. Lesions in the external iliac artery (EIA) or lesions in both the common iliac artery (CIA) and EIA were a poor prognostic factor for stent patency. The run off score and stent diameter also showed statistically significant influence on stent patency. The overall complication rate was 6%.

Conclusion

Iliac arterial stent placement is a safe treatment with favorable long term patency. Lesions in the EIA or lesions in both the EIA and CIA, poor run off vessels and a stent having the same or a larger diameter than 10 mm were the poor prognostic factors for long term stent patency.     

A new catheter configuration for selective antegrade catheterization of the superficial femoral artery: Technical note

A new 5 F catheter configuration is presented with a very short, 90 degrees angled tip that allows safe catheter tip rotation near the puncture site. This facilitates catheterization of the superficial femoral artery and permits easy conversion of a retrograde into an antegrade guidewire placement after puncture of the common femoral artery.     

Flow patterns from metallic vascular endoprostheses: in vitro results

The aim of this study was to determine flow characteristics and pressure gradients of different balloon- and self-expandable stents in an in vitro flow-model. Seven vascular stents (Bridge, Cragg, Memotherm, Palmaz PS 784, Sinus, Symphony, Wallstent), equal in length (60 mm) and diameter (10 mm), were deployed in a closed flow model. The inner diameter of the tube measured 9 mm. Flow at 1.5 and 6 l/min was applied. Flow patterns were visualized by anionic particles illuminated with two helium-neon lasers. Late laminary flow characteristics and pre- /post-stent pressure gradients were determined in either expanded stent, 25 and 50 % tube stenosis. Stent implantation induced a decrease of laminary flow when compared with an unstented tube with and without concentric 25 % stenosis (p < 0.01) at all flow rates and an increase of pressure gradients when compared with an unstented tube for a flow rate of 6 l/min and all stenoses (p < 0.01). At 1.5 l/min most stents revealed no significant change of pressure gradient, the highest gradient measured 4.0 mmHg. Sinus permitted maximum (expanded: 82.1 % and 76.9 % at 25 % stenosis at 1.5 l/min; p < 0.01) and Palmaz minimum of laminary flow at all flow rates and stenoses (70.2 and 52.4 % at 25 % stenosis at 1.5 l/min; p < 0.01). At 6 l/min, when completely expanded, Sinus is equal to Bridge and Memotherm; in 25 % stenosis Sinus is equal to Bridge, Memotherm, and additionally to Cragg and Wall. None of the endoprostheses revealed laminary flow at 50 % stenosis. Inadequate stent deployment bears the risk of creating less laminary flow and pressure gradients. Since flow disturbances and pressure gradients may influence neointimal hyperplasia, stent design and completeness of stent expansion are important factors regarding the appearance of thrombus formation and postinterventional restenosis. Received: 27 April 2000 Revised: 20 July 2000 Accepted: 26 July 2000     

Focal necrosis of the ureter following CT-guided chemical sympathectomy

Focal necrosis of the ureter was observed in our patient 7 days after CT-guided chemical sympathectomy. The injection of phenol was apparently rendered remote from the ureter and still caused ureteric necrosis. Ureteric injury may thus result following chemical sympathectomy, not from direct puncture of the ureter, but from unpredictable individual diffusion pathways.     

Prospective evaluation of peripheral arterial occlusive disease by 2D MR subtraction angiography

The purpose of this study was to assess the diagnostic value of two-dimensional (2D) MR subtraction angiography of lower extremities in patients with symptomatic peripheral arterial occlusive disease with conventional angiography as the standard of reference. Twenty patients were prospectively included. 2D subtraction MR angiography (MRA) consisted of multisection gradient-recalled echo (GRE) acquisitions with the shortest TE available on our machine (4 msec), obtained in the coronal plane before and after intravenous bolus administration of gadolinium chelate. MR images were reconstructed after subtraction with a maximum-pixel-intensity-projection (MIP) algorithm. MRA was performed in all cases 1–4 days before diagnostic angiography. In a prospective blinded analysis, the number and location of significant (ie, >50%) stenoses and occlusions were evaluated for each vascular segment. Sensitivity and specificity were used to evaluate MRA data. Significant stenoses (38 of 46, 83%) and occlusions (66 of 67, 99%) seen at conventional angiography were identified with MRA. The sensitivity and specificity of MRA for determination of stenoses >50% or occlusions was 100% and 97%, respectively. The location and extent of stenoses and/or occlusions on MRA and angiograms were well correlated (kappa values, r = .73, P < .05). Contrast 2D MR subtraction angiography, by providing comparable information to that of conventional angiography, is well suited to evaluate the presence and severity of atherosclerotic lesions of the lower limbs.     

Pseudoaneurysm of the superficial femoral artery following accidental trauma: result of treatment by percutaneous stent-graft placement

Accidental trauma frequently involves the extremities, and can extend to involve their blood supply, causing exsanguinating hemorrhage and pseudoaneurysm in the involved blood vessel. This is traditionally managed by surgical repair. We report a case in which control of life-threatening hemorrhage and exclusion of a large, post-traumatic pseudoaneurysm in the superficial femoral artery was performed by a commercially available stent-graft, without complication. This treatment method may be a safe and effective alternative to surgery in selected patients. Received: 10 February 1998; Revision received: 31 March 1998; Accepted: 20 April 1998     

Suitability of incorporated vascular stents for surgical patch-plasty: An experimental study

Purpose: Evaluate the feasibility of expanding arterial and venous stents incorporated into the vessel wall by surgical patch-plasty in an experimental study. Methods: An 8-mm Wallstent was percutaneously implanted into the carotid artery of 11 sheep and into the ipsilateral jugular vein in three of them. Three months after implantation, a patch-plasty was performed on the incorporated stents using a 0.4-mm-thick synthetic patch made of polytetrafluoroethylene (PTFE). Stent patency was monitored by color-coded duplex ultrasound and angiography for 6 months after operation. Results: No suture dehiscence or aneurysm formation were observed. Nine of 11 arterial and 2 of 3 venous stents remained fully patent during follow-up. In arteries, complications encountered were a complete stent thrombosis early after surgery, as well as a floating thrombus in the stent, found at final angiography after 6 months. In veins, one partial stent thrombosis was observed. Microradiographic and histological examinations revealed marked intimal hyperplasia in both arterial and venous stents. Intimal hyperplasia was significantly more pronounced in patched than in stented arterial segments (p<0.005). Conclusion: Patch-plasty surgery of previously incorporated vascular stents is technically feasible. Midterm patency rates were acceptable.     

Percutaneous transluminal atherectomy of the superficial femoral and popliteal arteries: Long-term results in 48 patients

Purpose Evaluate retrospectively the long-term primary patency of directional atherectomy (DA) in the femoropopliteal arteries.Materials and Methods DA was used alone in 59 patients (47%) or in combination with predilatation to allow passage of the device (43%) or after thrombolysis (10%) to treat 127 (93%) excentric atherosclerotic stenoses and nine (7%) occlusions of the femoropopliteal arteries. Forty-eight patients were followed by telephone interview, scheduled outpatient visits, color-flow Doppler evaluation, and angiography for 1–36 months (mean 16.9 months).Results Technical success (reduction of the stenosis or occlusion to less than 30% luminal diameter) was achieved in 110 lesions (80.3%) during 48 procedures in 37 patients. Mean luminal diameter was increased 54% with a concomitant increase in mean ankle/brachial indices of 0.33. According to Kaplan-Meier survival curves, patency at 12 and 24 months was 88% and 75%, respectively. When patients who retained patency but developed restenosis were excluded, the probability of patency at 12, 24, and 36 months was 76%, 58%, and 32%, respectively. Major and minor complications occurred in 15 (21.4%) procedures each for a total complication rate of 42.8%.Conclusion Based on our results, DA is an effective method for percutaneous treatment of atherosclerotic disease involving the femoropopliteal arteries. It has similar patency but a relatively high complication rate compared with PTA.     

Infrarenal aortic stents: Initial clinical experience and angiographic follow-up

From March 1990 to May 1991, arterial stents were placed in seven patients because of a tight stenosis (five patients) or a total chronic occlusion (two patients) located in the infrarenal aorta. In one case, the aortic occlusion extended to both common iliac arteries. After balloon dilatation, aortic stents were successfully positioned in all cases. Bilateral common iliac recanalization and stent placement were performed in one case. No complications occurred in any of the patients. Follow-up data were derived from clinical assessments and angiographic results. After a 15.1-month mean follow-up period (range 12–24 months), the seven aortic stents remained patent. Three iliac artery procedures were performed in two of the patients as well. Claudication recurred in three of the seven patients which was related to a common iliac occlusion (one case) or distal progression of atherosclerosis (two cases). Aortic stents seem to be suitable for treating failed angioplasty of aortic lesions but the procedure remains technically difficult when there is associated severe atherosclerosis of the proximal common iliac arteries. Nevertheless, considering the morbidity rate (0%) and the patency rate in this series, this technique could become an alternative to surgical treatment for infrarenal aortic occlusive lesions.     

Migration of Gianturco expandable metallic stents in the upper trachea

Endotracheal expandable metallic stents have been shown to be useful in treating malignant tracheobronchial stenosis. We report two cases of early stent migration in the upper trachea after what appeared to be a successful stent placement. We conclude that care should be taken when placing Gianturco stents across short, extrinsic, stenotic lesions with smooth mucosa located in the upper trachea because they have a tendency to migrate.     

Use of articulated catheters in the treatment of biliary strictures

We have used a single articulated catheter to obviate the need for multiple catheters in patients with complex biliary strictures or strictures associated with small or immature tracts. Two- and three-arm articulated drains (8–14 Fr) made from segments of biliary catheters were placed in 16 patients. Nine were placed transhepatically, 6 transperitoneally through existing T-tube tracts, and 1 through a cystic duct fistula. Six malignant and 10 benign strictures were stented with various catheter configurations through a single tract. Fifteen patients had two catheter components with one articulation and 1 patient had three catheter components with two articulations. The average duration of catheter drainage was 7.0 ± 4.2 months. Routine catheter exchanges were performed; two spontaneous occlusions occurred. In patients where internal stenting may be difficult or undesirable, articulated catheters allow satisfactory external and internal drainage of complex benign and malignant strictures through a single tract, avoiding the need for multiple transhepatic catheters.     

Colonic Anastomotic Stenoses and Memotherm Stent Fracture: A Report of Three Cases

Deployment of a Memotherm colonic stent (Bard, Angiomed, Karlsruhe, Germany) across anastomotic strictures, following anterior resection, is described in three patients. Two patients presented with symptoms of colonic obstruction. Two of the patients had previously undergone unsucessful balloon dilation of the stricture. In the third, in addition to the anastomotic stricture, there was local tumor recurrance. Initially, stenting provided effective relief of symptoms. However, in all three patients, fracture of the stents occurred at intervals of 3-7 months after insertion. This use and complication of colonic stenting has not been reported previously.     

Endovascular Treatment of Femoropopliteal Aneurysms: A Five-Year Experience

Purpose To assess the effectiveness of endovascular treatment of femoropopliteal aneurysms (FPAs). Methods In the last 5 years, we have treated 17 FPAs (diameter 21–75 cm, mean 38.4 cm; length 27–100 cm, mean 72.5 cm) in 15 patients (age 57–80 years, mean 70.9 years). The diagnosis was obtained by color Doppler ultrasound (CDU) and the procedure was planned by CT angiography (CTA) and preprocedural angiography. Eight FPAs were excluded with only one stent-graft; in 8 patients, two stent-grafts were positioned; and in 1 patient, three stent-grafts were used. In 14 cases we used a Wallgraft endoprosthesis, in 2 cases a Hemobahn, and in 1 case an Excluder contralateral leg. The patients were followed up with CDU and occasionally with CTA. Results Immediate technical success was obtained in 17 of 17 cases (100%). One patient died during the first year. During a mean follow-up of 26.9 months (range 3–60 months) we observed 6 of 16 (38%) stent-graft occlusions (3 of which were recanalized with locoregional thrombolysis and 3 with mechanical thrombectomy). Two stent-grafts were patent at 12 and 24 months. Four patients experienced subsequent occlusions and recanalizations until corrected by surgical bypass (1 at 14 months, 2 at 18 months, and 1 at 36 months). Therefore the primary patency was 63% and assisted patency was 73%. Conclusion The endovascular approach is a minimally invasive treatment option for FPAs. Moreover endovascular stent-grafting does not necessarily preclude conventional surgical repair, but it can delay it. Longer follow-up will be needed to determine the long-term patency rate.