SMART stent for salvage of hemodialysis access grafts

PURPOSE: To evaluate the SMART stent for treating angioplasty-resistant hemodialysis access venous stenoses. MATERIALS AND METHODS: A retrospective study of 64 patients with polytetrafluoroethylene grafts who were treated with the SMART stent at 69 locations in the venous outflow tract was undertaken. Stents were used for elastic recoil after percutaneous transluminal angioplasty, venous rupture, or recurrent stenosis less than 3 months after angioplasty. When angiographic follow-up was available, the degree of in-stent restenosis was measured. Primary patency was determined, and, when applicable, compared with that of previous angioplasty treatments of the same lesion. RESULTS: The SMART stent was placed in 15 central veins and 54 peripheral veins, with a 98% technical success rate and a 97% clinical success rate. The mean primary access patency times were 14.9 months and 8.9 months in patients who received central and peripheral stents, respectively. In 19 patients whose central or peripheral venous stenoses were previously treated with angioplasty, the mean primary access patency was increased from 2.5 months to 10.6 months after placement of the SMART stent (P = .0003). Angiography in 29 patients after an average of 348 days showed 55% mean in-stent stenosis. The only stent-related complication occurred in a patient who had venous dissection associated with the edge of a SMART stent placed at the elbow. CONCLUSION: The SMART stent is safe and effective for treating dialysis access venous stenoses that are resistant to standard angioplasty.     

Early detection and treatment of hemodialysis access dysfunction

Purpose: To assess the usefulness of a program for the early detection of hemodialysis graft dysfunction and the impact on graft survival of percutaneous transluminal angioplasty (PTA) and stent implantation to correct venous stenosis. Methods: A program for the early detection of hemodialysis access graft dysfunction was carried out in 110 patients over a period of 80 months. Detection was based on physical examination, flow rate measurements, venous pressure, and analytical determinations performed at dialysis. The stenoses detected were treated by PTA or PTA plus stent deployment. Survival curves compared primary and assisted patency rates for the different graft types. Results: The most important indicators of dysfunction were increased venous pressure and difficulty in cannulation of the graft. Significant stenoses were revealed by 227 (92.2%) of the 246 fistulography procedures performed. PTA results were satisfactory in 100% of the Thomas grafts, 74% of the Brescia-Cimino (BC) grafts, and 53% of the polytetrafluoroethylene (PTFE) grafts. Technical success rates for stent deployment were 92% for BC grafts and 100% for PTFE grafts, while functional success rates were 96% and 97%, respectively. The difference in the primary patency (P1) and assisted patency (AP) values was statistically significant for all three graft types. There was no significant difference in the patency rates for grafts treated by PTA alone or by PTA and stent deployment. Conclusion: A surveillance program helped prevent graft thrombosis, and intervention as required achieved excellent primary and assisted patency rates. Stent deployment salvaged a considerable number of accesses but did not significantly extend access survival time.     

A comparison study of self-expandable stents vs balloon angioplasty alone in femoropopliteal artery occlusions

In a group of 26 patients percutaneous transluminal (balloon) angioplasty (PTA) and stents (Wallstents) were applied and in another 26 matched patients PTA alone was used as primary treatment for femoropopliteal occlusions of 3 cm or longer. Five patients with stents showed early thrombosis necessitating catheter thrombolysis and/or thrombus aspiration. Ten patients had recurrent stenoses within 12 months, mostly due to neointimal hyperplasia. Following three late catheter reinterventions, a cumulative secondary patency rate of 69% was achieved after 12 months. The group of patients treated by PTA alone showed a 12 months patency rate of 65% without reinterventions. In 8 other patients, stents were inserted for recurrent obstructive or PTA-resistant lesions, and similar results as with the stents above were obtained. Thus, these stents do not improve primary results of PTA in femoropopliteal occlusions but may be useful secondarily after unsuccessful PTA.     

Stenoses in dialysis fistulas: treatment with percutaneous angioplasty

Percutaneous transluminal angioplasty (PTA) was performed on 30 stenotic lesions in 25 dialysis access fistulas. The fistulas were in 23 patients with a mean age of 53 years. Lesions were detected with angiography within a few days after poor flow or increased venous pressure was documented during dialysis. Twenty-two lesions were in patients with polytetrafluoroethylene graft fistulas, five were in patients with bovine carotid fistulas, and three were in patients with endogenous arteriovenous fistulas. There were 28 venous stenoses (20 at the anastomotic site and eight more proximally) and two arterial stenoses. The overall success rate was 80%, with a 6-month patency of 76% and a mean patency after PTA of 9.4 months. Among the venous lesions, the success was 100% for proximal lesions and 71% for anastomotic lesions. There were two technical failures, which required surgery for revision of the fistulas, and four self-limited hematomas. PTA is a safe and effective treatment for stenoses in dialysis fistulas, particularly for lesions remote from the anastomotic sites.     

Metallic stents deployed in synthetic arteriovenous hemodialysis grafts

OBJECTIVE: The purpose of our study was to review the success of metallic stent treatment of intragraft stenoses in patients with synthetic arteriovenous hemodialysis grafts. MATERIALS AND METHODS: Between May 1993 and May 1997, 19 metallic stents were placed in 11 patients (seven women, four men; age range, 41-83 years) to treat elastic intragraft stenoses or graft dissections. Before stent placement, all patients had experienced multiple episodes of graft thrombosis, had very limited vascular access for hemodialysis, and were considered poor surgical candidates. RESULTS: The technical success rate was 100%, and there were no procedural complications. Using life-table analysis, we found primary patency to be 36% at 6 months after stent placement, 12% at 12 months, and 12% at 18 months. Secondary patency was 91% at 6 months after stent placement, 71% at 12 months, and 47% at 18 months. The mean and median patencies per intervention were 4.2 and 3.6 months, respectively. Mean and median secondary graft patencies were both 14 months (range, 3 days-32 months). Puncture through the stents occurred during dialysis, causing stent distortion and fracture. Eight stents had a linear fracture suggesting compression contributed to the stent distortion. No clinically evident complications related to stent placement occurred. CONCLUSION: Metallic stent deployment can salvage access in synthetic arteriovenous grafts by alleviating intragraft stenoses. Patency of intragraft stents is similar to venous stents used to treat other hemodialysis-related stenoses; however, fracture of Wall-stents occurs with prolonged graft use, especially in areas of needle punctures.     

Peripheral venous stenoses of hemodialysis shunts: improved long-term patency rates with stent placement

PURPOSE: The purpose of this study was to evaluate the effectiveness of endovascular stents placed in the peripheral veins of hemodialysis shunts. MATERIALS AND METHODS: 156 endovascular stents were placed in the peripheral veins of 155 hemodialysis shunts with 220 stenoses. Among these, 106 stenoses of 93 hemodialysis shunts had been treated by percutaneous transluminal angioplasty (PTA) before stent placement. RESULTS: The initial success rate was 97.7%. Primary radiologic patency rates of the stents at 6 months, 1 year, and 2 years were 69.8%, 49.1%, and 45.8%, respectively. Secondary radiologic patency rates at 1 year, 2 years, and 3 years were 94.0%, 91.8%, and 88.0%, respectively. Primary clinical patency rates at 6 months, 1 year, and 2 years were 64.4%, 43.4%, and 27.3%; while secondary clinical patency rates at 1 year, 2 years, and 3 years were 93.5%, 86.5%, and 73.4%, respectively. Radiologic and clinical primary patency rates of 106 stenoses and 93 hemodialysis shunts were significantly higher than those of PTA that had been performed before stents were placed. CONCLUSION: Stent placement for stenoses of the peripheral veins of hemodialysis shunts recurring in three months and treated by PTA alone can improve long-term patency.     

PTA versus Stent in der femoropoplitealen Strombahn

PURPOSE: To evaluate whether primary stenting is superior to balloon angioplasty (PTA) alone in the treatment of femoropopliteal obstructive disease. MATERIALS AND METHODS: Sixty-two patients, 24 female and 38 male, mean age 67 years (39-87) years, were randomized to PTA alone (n = 37) or balloon angioplasty followed by implantation of Palmaz stents (n = 33). Follow-up included clinical assessment, ankle-brachial index (ABI), color duplex ultrasound at 1, 3, 6 and 12 months after intervention and intravenous angiography at 6 or 12 months. RESULTS: We had four cases of primary PTA failures (10.8%) and no early (< 30 days) thrombosis compared to one primary stent failure (3.0%) and three early thromboses (9.0%) in the stent group. Cumulative primary angiographic patency rates (life-table analysis) for PTA alone were 82% and 72% (6 and 12 months, respectively) compared to 81% and 60% for primary stent placement. The secondary angiographic patency were 97% and 88% for PTA and 88% and 72% for stent implantation, respectively. However, there was no significant difference in patency rates. CONCLUSIONS: Despite fewer primary technical failures, mid-term angiographic and clinical patency were not improved by primary stent placement compared to PTA alone.     

Use of the Wallstent in the venous system including hemodialysis-related stenoses

Eighteen patients with a total of 23 venous stenoses or occlusions were treated with the Wallstent. In 5 patients treated for malignant stenosis there was one primary failure due to insufficient stent expansion. The other 4 patients showed rapid relief of their inflow obstruction, all remaining asymptomatic despite later stent occlusion in 1 patient. Four patients were treated for benign postoperative stenoses of the iliac or femoral vein. All stents remained patent for a period of 6 weeks-58 months. Nine patients were treated for one or multiple stenoses along the venous outflow tract of hemodialysis fistulas. Of 14 lesions that were eventually stented, 12 are still patent after 3–27 months (mean 19). However, 10 secondary interventions (eight percutaneous transluminal angioplasty (PTA), two stents) and three additional stent procedures for new lesions were necessary. Although our experience is limited, we believe that patients with tumor compression or postoperative strictures of large veins benefit from treatment with stents. Stenting of venous outflow stenoses in hemodialysis fistulas can significantly prolong stent function, however, PTA should always be the first treatment of choice.     

Treatment of venous outflow stenoses in thigh grafts with Wallstents.

OBJECTIVE: We studied the effectiveness of Wallstent deployment to treat elastic femoral and iliac vein stenoses in patients with lower extremity hemodialysis grafts. MATERIALS AND METHODS: Between August 31, 1992, and October 13, 1997, 44 metallic stents were deployed in 20 patients to treat stenoses exhibiting immediate, significant elastic recoil after angioplasty. Twenty-four stents were placed in the femoral and saphenous veins, and the remaining 20 stents were placed in the iliac veins. Follow-up was provided by the nephrology and surgical service at our institution and by electronic review of patients' charts. The follow-up period was from August 31, 1992, until October 1, 1998. RESULTS: Stents were successfully inserted and stenotic lesions dilated in 100% of procedures. Each patient successfully completed at least one session of dialysis after the procedure. The primary patency rate of stents was 87% 60 days after the procedure, 51% 180 days after, 39% 1 year after, and 20% 2 years after. The secondary patency rate was 95% 60 days after the procedure, 92% 180 days after, 81% 1 year after, and 62% 2 years after. Complications were limited to two graft infections that developed 5 and 7 days after stent placement. CONCLUSION: Treatment of elastic venous stenoses is effective in patients with lower extremity dialysis grafts using metallic stents. The patency rates of these devices placed in the iliac and femoral veins are comparable with those of metallic stents placed in upper extremity and central veins.     

Transluminally Placed Endovascular Grafts for Venous Lesions in Patients on Hemodialysis

This report summarizes a feasibility study of transluminally placed endovascular grafts (TPEG) using pre-expanded polytetrafluoroethylene (PTFE) to treat venous abnormalities in patients on hemodialysis. Seventeen patients with peripheral (n = 11) or central (n = 6) venous lesions were treated with TPEG devices. Covered Gianturco stents were used for the peripheral lesions and covered Palmaz stents were used for central lesions. Venous abnormalities included vascular rupture after balloon angioplasty or surgical thrombectomy (n = 4), stenosis associated with an aneurysm (n = 2) and occlusive disease and central stenoses not responsive to balloon angioplasty (n = 11). The mean primary patency period was 37 days. The mean secondary patency period was 215 days. At 60, 180, and 360 days the primary and secondary patency rates were 40%, 32%, and 32%, and 70%, 55%, and 39%, respectively. Follow-up studies have shown various outcomes of the implanted TPEG devices, which have included stenoses within the TPEG (n = 2), stenoses central to the TPEG (n = 1), stenoses peripheral to the TPEG (n = 3), acute thrombosis extending to the TPEG without a stenosis (n = 1), graft abandoned with patent TPEG (n = 6), and TPEG patent within primary patency period at last follow-up (n = 4). The TPEG devices, made with pre-expanded PTFE, appear safe in the short term, do not prevent progressive dialysis access site failure, and need to be compared to PTA and endovascular stenting in a randomized prospective trial.     

External beam irradiation as an adjunctive treatment in failing dialysis shunts

PURPOSE: To evaluate the utility of low-dose irradiation as adjunctive treatment for failing dialysis shunts related to stenoses. MATERIALS AND METHODS: Thirty-one patients with 41 lesions in their dialysis shunts were successfully enrolled for this study. After imaging of the shunt and calculation of venous stenoses, each patient was randomized into one of two segments of the protocol: (i) angioplasty and/or stent placement alone, and (ii) angioplasty and/or stent placement followed by external beam irradiation. All patients with significant venous stenoses (> or =50%) were treated with appropriately sized PTA (percutaneous transluminal angioplasty) and Wallstents. Patients randomized to the external irradiation segment underwent localized irradiation via a Theratron cobalt unit of 7 Gy 0-24 hours and 24-48 hours after intervention. Those patients randomized to the control group received no additional treatment. Clinical follow-up included resumption of successful dialysis with appropriate hemodynamic parameters. Two follow-up shunt images were obtained, follow-up 1 (fu-1) from 90 to 179 days and follow-up 2 (fu-2) from 180 to 365 days. Percentages of significant recurrent stenoses, defined as greater than 50%, were recorded and re-treated as needed. RESULTS: Sixteen of the 31 patients underwent external beam irradiation. There were 21 lesions in the test group that underwent irradiation after intervention, and 20 lesions were treated with intervention alone. There were seven native arteriovenous fistulas and 24 Gore-tex grafts. All stenoses were either venous outflow stenoses (68%) or central stenoses (32%). The authors utilized chi2 analysis to compare restenoses rates between the control and irradiated groups at fu-1 (P<.99) and fu-2 (P<.10). CONCLUSIONS: Although the results show that external beam irradiation has minimal effects on the restenoses of dialysis grafts when used in conjunction with PTA and stent placement, further studies with a larger, more homogenous population are needed to assess the trend of improving patency rates after external beam irradiation.     

血管成形术和内支架置入术对放射治疗后动脉损伤的治疗

目的评价经皮穿刺血管成形术和内支架置入术在放射治疗（简称放疗）后所致动脉疾病的治疗,及靶血管和内支架的长期支撑开放作用。方法１４例患者,因为放疗所致１８处动脉性病变,而给予血管球囊成形术治疗。并将１３个内支架置入于８例患者,分别治疗血管闭塞３例,动脉瘤１例,残存狭窄２例,多发狭窄１例,球囊成形术后再发狭窄１例。所有病例均用ＣＴ扫描和（或）多普勒超声检查,观察内支架及其靶血管内的血流情况。结果血管成形术成功治疗１４例,其中８例患者在动脉病变处置入内支架。随访８个月至５年,１１例动脉病变基本消失,血管造影示狭窄＜２０％,临床症状完全解除,３例狭窄＜３０％,临床症状改善。结论单一的血管成形术以及多技术综合运用,可有效治疗放疗所致的动脉性病变,应考虑其为动脉损伤性病变的首选治疗方法     

Randomized study to compare PTA alone versus PTA with Palmaz stent placement for femoropopliteal lesions

PURPOSE: The purpose of this study was to evaluate whether percutaneous transluminal angioplasty (PTA) combined with Palmaz stent placement provides long-term advantages compared to PTA alone after 34 months of follow-up in the femoropopliteal region. MATERIALS AND METHODS: Thirty patients randomized to undergo PTA in combination with stent placement and 23 patients randomized to undergo PTA alone were evaluated. RESULTS: Mean follow-up (+/-SD) for the PTA group was 33.8 months (+/- 8.7) and for the Palmaz group 29.1 months (+/- 6.2), with a maximum follow-up period of 39 months for both groups. No significant differences in primary or secondary patency rates could be observed at 12 or 39 months. After 39 months, the primary patency rate for PTA alone was 68.4% and the secondary patency rate was 89.5%; the primary patency rate for PTA with stent placement was 62% and the secondary patency rate was 90%. CONCLUSIONS: The results of this study show that even after a long-term follow up of more than 3 years, PTA with stent placement in the femoropopliteal artery does not produce better results than PTA alone, although it does provide better initial luminal gain after the procedure.     

Percutaneous transluminal angioplasty (PTA) alone versus PTA with balloon-expandable stent placement for short-segment femoropopliteal artery disease: a metaanalysis of randomized trials

PURPOSE: To evaluate and compare the results of percutaneous transluminal angioplasty (PTA) and stent placement to treat femoropopliteal artery occlusive disease. MATERIALS AND METHODS: Published data of randomized clinical trials comparing the results of PTA and stent placement for femoropopliteal artery occlusive disease were analyzed. Proportions were combined, and the odds ratio (OR) with its 95% CI was used as the effect size estimate. RESULTS: Seven studies published in 1999 or later (614 limbs in 519 patients) were included in this metaanalysis, in which 323 limbs underwent PTA and 291 limbs underwent PTA followed by balloon-expandable stent placement. In the combined results of PTA versus PTA plus stent placement, a significant difference in primary patency at 6 months (OR, 0.47; 95% CI, 0.27-0.84; P < .05) was found, but no significant difference could be found in primary patency at 12 months (OR, 1.27; 95% CI, 0.87-1.86; P > .05) or 24 months (OR, 1.22; 95% CI, 0.81-1.82; P > .05) or in secondary patency at 12 months (OR, 1.34; 95% CI, 0.78-2.30; P > .05). CONCLUSIONS: In the treatment of femoropopliteal artery occlusive disease (< or =10 cm), higher primary patency rates can be expected at 6 months with PTA followed by implantation of balloon-expandable stents versus PTA alone, but PTA with stent placement does not produce better long-term primary results and secondary patency rates than PTA alone.     

Stent Grafts for Central Venous Occlusive Disease in Patients with Ipsilateral Hemodialysis Access

PurposeTo assess long-term outcomes of stent grafts in patients with symptomatic central venous stenoses and occlusions ipsilateral to hemodialysis grafts or fistulas.Materials and MethodsThe study included 52 of 55 consecutive patients with symptomatic stenoses of the central veins draining upper limb dialysis access grafts or fistulas treated with stent grafts. Indications for stent grafts were poor angioplasty results, rapid recurrence, or total occlusion. Endpoints were lesion patency and access patency following intervention. Mean follow-up was 25 months with a median of 24 months and 1.25 additional procedures per patient year. Patency rates were calculated using Kaplan-Meier analysis.ResultsAll stent grafts were successfully deployed. The lesion patency rates at 6, 12, 24, and 36 months after intervention were 60%, 40%, 28%, and 28%. The access patency rates at 6, 12, 24, and 36 months after intervention were 96%, 94%, 85%, and 72%. There was one major complication and no minor complications. In 40 patients (77%), the internal jugular vein confluence was covered by the stent graft. In five patients, the dialysis circuits became occluded, with no clinical sequelae in four; one patient was lost to follow-up. The contralateral brachiocephalic vein was covered in three patients (6%), preventing contralateral access construction in one patient.ConclusionsCentral vein stent graft placement in patients with hemodialysis access is associated with prolonged access patency. Coverage of major vein confluences, which occurred in 83% of the patients in this series, can compromise future access and should be avoided whenever possible by careful technique.     

Access-Related venous stenoses and occlusions: Treatment with percutaneous transluminal angioplasty and dacron-covered stents

Purpose: To determine the effectiveness of using Dacron-covered stents to treat access-related venous stenoses and occlusions. Methods: Twenty-two Dacron-covered stents were placed in 20 patients: in the basilic or axillary vein (n = 2), cephalic vein (n = 3), subclavian vein (n = 5), and at the venous anastomosis of the polytetrafluoroethylene (PTFE) implant graft (n = 10). Results: Initial technical success was 100%. The cumulative primary and secondary patency rates were 57% and 83% at 6 months, 29% and 64% at 12 months, and 29% and 53% at 18 months. A statistically significant difference in the stent patency was revealed by comparing the patients with stents in the subclavian vein and patients with upper arm stents. The secondary patency rates of the upper arm stents were 73% after 6, 12, and 18 months. Conclusions: Percutaneous placement of Dacron-covered stents is a safe and effective procedure for salvage of a dialysis fistula. First results are promising, with a tendency to prolongation of the time interval between reinterventions.     

Using pullback pressure measurements to identify venous stenoses persisting after successful angioplasty in failing hemodialysis grafts

OBJECTIVE: We used pullback pressure measurements to identify venous stenoses persisting after angioplasty of failing hemodialysis grafts. MATERIALS AND METHODS: Fifty angioplasty procedures were performed in 32 patients with elevated venous pressures at dialysis. Grafts were initially evaluated on digital subtraction angiography, and all stenoses measuring greater than 50% on angiography underwent angioplasty. In successful cases (residual stenosis < 30%), pullback pressure measurements were obtained from the superior vena cava to the graft to identify hemodynamically significant (> 10 mm Hg) stenoses. These lesions were then treated with repeated angioplasty. RESULTS: Hemodynamically significant stenoses with a gradient range of 10-27 mm Hg (mean, 16 mm Hg) were found in nine (18%) of 50 procedures. All gradients occurred at sites of previous angioplasty. Repeated angioplasty of these stenoses performed with larger angioplasty balloons reduced gradients to less than 3 mm Hg in six stenoses and to 5 mm Hg in three stenoses. In this subgroup, primary patency was eight (89%) of nine stenoses at 1 month and 2 months and five (56%) of nine stenoses at 6 months. Using life table analysis, we found that primary patency of the entire population was 84% at 1 month, 66% at 2 months, and 47% at 6 months. The mean time between interventions was 6 months, and the thrombosis rate was 0.32 per year. CONCLUSION: Pullback pressure measurements are a useful adjunct to angiography to evaluate the hemodynamic results of angioplasty in patients with failing hemodialysis grafts.     

Angioplasty with or without Stent Placement in the Brachiocephalic Artery: Feasible and Durable? A Retrospective Cohort Study

PURPOSE: To evaluate the results of percutaneous transluminal angioplasty (PTA) and stent placement in isolated brachiocephalic trunk lesions. MATERIALS AND METHODS: PTA, with or without stent placement, was used to treat 30 patients with isolated clinically significant stenoses (n = 25) or occlusions (n = 5) of the brachiocephalic artery. Initial clinical success was defined as a relief or substantial reduction of the preprocedural symptoms, and initial technical success was defined as a mean translesion pressure gradient of less than 5 mm Hg or a residual stenosis of less than 20%. Clinical evaluation and duplex Doppler ultrasonography of the lesion site were performed at follow-up. Clinical restenosis was defined as recurrent clinical symptoms and a lumen reduction of more than 50%, determining the primary clinical patency. Technical restenosis was defined as more than 50% lumen reduction with or without renewed clinical symptoms, determining the primary technical patency. RESULTS: The initial technical success rate was 83% (occlusions, 60%; stenoses, 88%), and the clinical success rate was 81%. Two patients had major complications, and four experienced minor complications. At a median follow-up of 24 months (4 weeks to 92 months), the primary clinical patency rate was 79% (95% confidence interval [CI]: 57%, 104%), with 83% (95% CI: 60%, 105%) for arteries with stents and 67% (95% CI: 13%, 120%) for those without stents (P = .11). The primary technical patency rate was 50% (95% CI: 24%, 76%). CONCLUSION: PTA with or without stent placement in a stenotic or occlusive brachiocephalic artery is a procedure of tolerable safety with a high initial success rate; however, only moderately rewarding results were obtained after 2 years. Selective stent placement probably improves long-term success. Primary PTA with selective stent placement in an atherosclerotic obstructive brachiocephalic artery should be considered the preferred treatment option.     

Percutaneous transluminal angioplasty (PTA) and venous stenting in hemodialysis patients with vascular access-related venous stenosis or occlusion

Aim of the studyTo present our experience with PTA and venous stenting in hemodialysis patients with vascular access (VA) related venous stenosis or occlusion.Patients – methodsWe studied retrospectively 22 hemodialysis patients with VA-related venous stenosis or occlusions that were treated with PTA and subsequent stenting. The following lesions were detected by digital subtraction venography: occlusion of the brachiocephalic and/or subclavian veins in four patients, stenosis (80–90%) of the same veins in 10 patients, stenosis (80–95%) of the axillary vein in four patients, brachial vein stenosis in two patients, and cephalic vein stenosis in two patients. The follow-up period ranged from 3 to 29 months (mean 15.4 ± 9.8 months). Primary and cumulative stent patency was recorded.ResultsTwenty-two primary venous PTA–stent implantation procedures were performed using 25 stents. The initial deployment of these 25 stents was technically successful, with complete opening (>80%) of the vein's lumen in all but one patient (95.4%). The patency of the vein immediately after the stenting procedure was greater than 90% in 13 patients, 80–90% in eight patients, and less than 40% in the case involving failure. Seventeen episodes of re-obstruction occurred in 13 patients (59%), and all were treated with the same PTA–stent procedures. At the end of the study period 47 stents had been placed in patients. The 3, 6, 12 and 24-month primary patency rates were 88.3%, 65.3%, 45.6% and 25.5%, respectively. Overall cumulative stent patency was 95.4% after 3 months, 79% after 6 months, 74% after 12 months, and 62.8% after 24 months.ConclusionPTA with primary venous stenting is an effective method for the treatment of VA-related stenosis or occlusion. However, repeat and sometimes multiple interventions are usually needed for the treatment of re-stenosis or re-occlusion episodes.     

Iliac and femoral artery stenoses and occlusions: treatment with intravascular stents

Forty-five patients with atherosclerotic stenoses and occlusions of the iliac and superficial femoral arteries were treated with a flexible, self-expanding, metallic intravascular stent. Of these patients, 37 were treated immediately after inadequate angioplasty. At a follow-up period of 2-12 months, intravenous digital subtraction angiograms demonstrated patency of the vessels with stents in 40 of 45 patients. The mean Doppler ankle/arm index increased from 0.60 to 0.92 immediately after treatment and was 0.89 at follow-up. Early thrombotic stent occlusion occurred in two patients. Intimal hyperplasia was a late effect and led to stent stenoses in three patients after 5-9 months and stent occlusion in one patient after 6 months. In three patients, percutaneous recanalization with balloon and Simpson catheters was successful. Intravascular stents proved particularly useful for maintenance of patency after angioplasty in occlusions of the iliac and femoral arteries and in treatment of stenoses due to eccentric and severely ulcerated plaques. The stents also helped manage complications after angioplasty. Long-term results will depend on the degree, frequency, and progression of intimal hyperplasia narrowing the vascular lumen.