Cutting balloon angioplasty for resistant venous anastomotic stenoses

Conventional angioplasty of stenoses at the venous anastomosis has been demonstrated to be an important endovascular adjunct to mechanical thrombectomy of clotted arteriovenous dialysis grafts. In some cases, however, severe venous anastomosis stenosis is resistant to angioplasty. Cutting balloon angioplasty may have an advantageous role in these difficult situations in order to avoid surgical revision. In this series of 350 patients receiving percutaneous, endovascular declotting procedures, 9 patients had high-grade venous anastomotic stenoses (opening less than 2 mm) that could not be remedied with either conventional or high-pressure noncompliant peripheral angioplasty balloons. These nine patients had the lesions opened with the use of 4 mm x 10 mm cutting balloons and placement of self-expanding nitinol stents at the venous anastomosis during the same angiography procedure. Patients were followed for patency and functionality of the graft. In all cases, immediate technical success occurred. Among these patients, the vessels have remained patent for as long as 20 months of follow-up and grafts have remained functional. Cutting balloon angioplasty may have a potential therapeutic role in resistant venous anastomotic stenoses.     

Outcomes of thrombosed arteriovenous grafts: comparison of stents vs angioplasty

The usual radiologic approach to thrombosed grafts is a combination of thrombectomy and angioplasty of the underlying lesion. However, the primary (unassisted) graft patency after thrombectomy is quite poor. We evaluated whether graft patency following thrombectomy is improved by placement of a stent in the stenotic lesion. Using a prospective, computerized vascular access database, we identified 14 patients with thrombosed arteriovenous (A-V) grafts treated with a stent at the venous anastomosis (stent group). The outcomes of these grafts was compared to those observed in 34 sex, age-, and date-matched control patients whose thrombosed A-V grafts were angioplastied (control group). Both groups were comparable in age, sex, race, diabetic status, graft age, and number of previous graft interventions. The immediate technical success, as indicated by the post-procedure graft to systemic pressure ratio, was similar in the stent and control groups (0.33+/-0.16 vs 0.41+/-0.17, P=0.14). The primary graft patency (time from thrombectomy to next intervention) was significantly longer for the stent group (median survival, 85 vs 27 days, P=0.02). Assisted or secondary patency (time from thrombectomy to permanent graft failure) was also longer for the stent group (median survival, 1215 vs 46 days, P=0.049). In conclusion, treatment of thrombosed grafts with a stenosis at the venous anastomosis with a stent results in longer primary and secondary graft survival, as compared to treatment with angioplasty. Stent placement may be a useful treatment modality in a subset of patients with thrombosed A-V grafts and stenosis at the venous anastomosis.     

The use of covered nitinol stents to salvage dialysis grafts after multiple failures

The increasing number of patients requiring hemodialysis and the limited number of access sites have resulted in an increase in multiple graft revisions to maintain access for hemodialysis. Venous outflow or anastomotic stenoses in vascular grafts tend to recur and contribute to the difficulty in maintaining a functioning graft. Thus, extending the life of a failed graft becomes an important objective of this study, which was to assess the use of covered nitinol stents to salvage expanded polytetrafluoroethylene (ePTFE) grafts with venous anastomotic or outflow stenosis that have failed after multiple revisions. This is a review of 8 failed non-autogenous ePTFE grafts with isolated venous anastomotic or proximal outflow stenoses that had undergone multiple previous revisions, had failed percutaneous transluminal angioplasty (PTA), and required placement of a covered nitinol stent. Graft locations were forearm (2), upper arm (4), and femoral (2). The mean number of interventions per patient before stent placement was 5.87 thrombectomies (range 2-28) and 3.38 balloon angioplasties (range 2-19). Five patients had 0.62 interposition grafting and 3 had patch angioplasty. All 8 patients (100%) underwent successful dialysis after thrombectomy and stenting. The primary and secondary patency rates after stent placement were 50% and 75%, and 25% and 75%, at 3 and 6 months, respectively. Percutaneous thrombectomy, balloon angioplasty, and concomitant covered nitinol stent placement extend the function of hemodialysis access grafts that have previously failed multiple times.     

Use of stents and stent grafts to salvage angioplasty failures in patients with hemodialysis grafts

To determine the efficacy of using stents and stent grafts for treatment of hemodialysis graft-related stenoses which have failed angioplasty. This retrospective study was composed of 51 patients with polytetrafluoroethylene hemodialysis grafts who underwent angioplasty of a graft-related stenosis but subsequently required insertion of a stent or stent graft. The study group included 40 patients with >30% residual stenosis and 11 patients with angioplasty-induced venous ruptures. The patient's medical records and radiology reports were reviewed. Patient demographics, indication for stent placement, and the type of stent were recorded. Stent patency was determined using Kaplan-Meier analysis. A total of 70 stents were used; most (57.7%) were deployed across the venous anastomosis. A variety of different types of stents and stent grafts were used including 26 SMART, 18 Viabahn, 13 aSpire, and 13 other stents. The technical success rate for insertion of the device was 100%. Following insertion of the device the primary patency of the vascular access was 81%, 70%, and 54% at 1, 3, and 6 months, respectively. The secondary patency of the vascular access was 89%, 82%, and 74% at 3, 6, and 12 months, respectively. The primary patency of the stent or stent graft was 96%, 93%, 87%, and 47% at 1, 3, 6, and 12 months, respectively. Stents and stent grafts are useful for salvaging failed angioplasty procedures and thereby maintaining patency of the hemodialysis graft. By inserting a stent, the resultant patency rates are similar to those following a successful angioplasty procedure. Importantly, the primary patency of the stent was substantially better than the primary patency of the entire vascular access.     

Salvaging prosthetic dialysis fistulas with stents: forearm versus upper arm grafts

OBJECTIVE: We compared results of angioplasty with those of concomitant stent placement to treat thrombosed forearm hemodialysis grafts with results for upper arm grafts. MATERIAL AND METHODS: Between October 1998 and July 2002, stents were deployed in 61 patients undergoing balloon angioplasty because of venous anastomotic stenosis causing graft thrombosis. Stents were used only in cases of inadequate angioplasty results. Twenty-three forearm grafts and 38 upper arm grafts were treated. All procedures were performed in an endovascular operating suite, with fistulography. Primary and secondary patency rates were analyzed and compared for graft location with the life table method. RESULTS: Grafts had undergone a mean of 1.56 previous revisions because of thrombosis (forearm: 1.52, upper arm: 1.58; P = NS). Excluding early thrombosis, a single graft infection was the only procedural complication. Cumulative primary patency rate at 3, 6, and 12 months (from stent placement) was 36.4%, 15.6%, and 0%, respectively, for forearm grafts, which was inferior to the 59.5%, 34.0%, and 17.0% primary patency rate observed for upper arm grafts (P =.0307) Secondary patency rate was 40.9%, 40.9%, and 30.7%, respectively, for forearm grafts, and 64.9%, 42.3%, and 19.7% for upper arm grafts (P = NS). CONCLUSION: Stent deployment can salvage thrombosed dialysis grafts. However, sustained patency occurs infrequently, with better results for upper arm grafts than for forearm grafts. Inasmuch as surgical revision of forearm grafts is usually straightforward, stenting should be reserved for use in high axillary grafts and other sites where surgical repair is difficult.     

A comparison of patch angioplasty and stenting for axillary venous stenoses of thrombosed hemodialysis grafts

The efficacy of balloon angioplasty with stent placement is compared to surgical patch angioplasty for thrombosed upper arm hemodialysis grafts with stenotic lesions at the venous anastomosis. Patients with thrombosed hemodialysis grafts terminating at the axillary vein were reviewed. Thirty-eight stents were placed after thrombectomy and venous balloon angioplasty in 26 patients. Fifteen case-matched controls underwent 23 polytetrafluoroethylene patch angioplasties for similar lesions. Kaplan-Meier survival analysis was used for statistical comparison. Primary patency for stent placement compared with patch angioplasty was not statistically different at any time through 1-year follow-up (37% vs 55% at 3 months, 25% vs 45% at 6 months, and 25% vs 15% at 12 months, respectively; p = 0.37). Secondary patency rates were slightly better for patch angioplasty compared with stent placement (78% vs 59% at 3 months, 78% vs 48% at 6 months, and 54% vs 32% at 12 months, respectively) however these differences were not statistically significant (p = 0.13). There was no difference in complication rates between groups. Sustained patency is poor for both angioplasty with stent placement and surgical patch angioplasty when revising thrombosed dialysis grafts with anastomotic axillary vein stenosis. These data suggest slightly better patency for the routine use of patch angioplasty for these lesions. However, the endovascular approach appears to be a reasonable alternative when surgical exposure is difficult.     

Outcome of endovascular intervention for infrainguinal vein graft stenosis

Assisted graft patency rate following revision of a graft stenosis is far better than that following thrombectomy of an occluded graft. Graft revision by endovascular means has been proposed as a suitable alternative to more invasive surgery. This study reports our experience with endovascular treatment of vein graft stenosis. Between December 1992 and September 2000, percutaneous transluminal balloon angioplasty (PTA) was performed on 90 vein graft stenoses in 87 infrainguinal vein bypass grafts identified by routine graft duplex scan (peak systolic velocity, PSV > 300 cm/sec). All 90 stenoses treated by PTA were retrospectively analysed for stenosis-free patency rate (life-table analysis). Re-stenosis was defined by PSV exceeding 300 cm/sec at the same site of the vein graft where a stenosis was dilated.Ninety vein graft stenoses (72 primary stenoses and 18 recurrent stenoses) in 33 femoropopliteal (above knee), 30 femoropopliteal (below knee) and 24 femorotibial vein bypass grafts were treated by PTA. The timing of PTA ranged from one to 252 months (mean, 23.9 months) from the initial surgery. Cumulative stenosis-free patency rate after PTA was 55.8% at 6 months, 54.0% at one year and 45.0% at three years. Stenosis-free patency rate at six months was significantly lower for revision of recurrent stenosis (25.9%) than for primary stenosis (61.6%) (P = 0.01). The revision of duplex scan detected vein graft stenosis with endovascular intervention was associated with an acceptable stenosis-free patency rate. However, recurrent stenosis treated by PTA had a significantly inferior outcome. Direct surgical revision would be more appropriate for recurrent lesions.     

球囊扩张联合覆膜支架植入治疗人造血管动静脉内瘘狭窄

目的 探讨球囊扩张联合覆膜支架植入治疗人造血管动静脉内瘘(AVG)狭窄的临床疗效.方法 前瞻性选取15例经皮腔内血管成型术(PTA)疗效欠佳的AVG狭窄患者,且具备以下特点:狭窄长度不超过7 cm,狭窄程度大于50％;PTA后3个月内狭窄复发2次或以上;扩张后残余狭窄＞30％或狭窄部位立即弹性回缩.所有患者在数字减影血管造影(DSA)下行球囊扩张后植入不同内径的聚四氟乙烯覆膜支架.结果 男3例,女12例,平均年龄(66±12)岁.支架植入前内瘘平均使用时间为(19.5±15.0)个月.共植入支架16枚,技术成功率100％,植入部位为静脉吻合口9例(9/15);静脉流出道6例(6/15),其中头静脉3例,肱静脉2例,腋静脉1例.首次开通率3个月为40％,6个月为19％,12个月为13％.再次开通率3个月为93％,6个月为88％,12个月为87％.术后平均随访时间为(14.9±5.3)个月,再窄狭率为87％(13/15).术后PTA 36例次,支架内狭窄36％ (13/36);支架远端狭窄8％ (3/36);支架近端狭窄22％(8/36);与支架无关的狭窄33％ (12/36).AVG中位生存时间为25个月.结论 球囊扩张联合覆膜支架植入治疗AVG狭窄技术成功率高,并发症少,首次开通率不高,但再次开通率令人满意.     

Surgical Thrombectomy and Transluminal Balloon Angioplasty for Failed Above-knee Femoropopliteal Polytetrafluoroethylene Bypass Grafts

Endovascular therapy offers an alternative to redo bypass or surgical graft revision for failed above-knee femoropopliteal PTFE bypass grafts. We evaluated the outcome of surgical thrombectomy and balloon angioplasty for the treatment of thrombosed bypass grafts. Thirty selected patients with thrombosed above-knee femoropopliteal PTFE bypass grafts were treated. Under local anesthesia, a surgical thrombectomy followed by bypass graft angiography and balloon angioplasty of perianastomotic stenoses was performed. Stents were used selectively for suboptimal angioplasty results. Patients underwent duplex scanning of the bypass graft postoperatively and at 6-month intervals. Life-table analysis and log-rank (Mantel-Cox) comparisons were performed. Patients were categorized into two groups on the basis of time elapsed from initial bypass graft construction to graft failure. Group 1 included 21 patients with a mean time to graft failure of 10 months (range, 0-20). Surgical thrombectomy was successful in 20 grafts (95%) and 17 patients had a stent placed after angioplasty. Rethrombosis occurred within 30 days in seven grafts (33%) in group 1 and major amputations were performed in six patients (28%). Group 2 included nine patients with a mean time to initial bypass graft failure of 48 months (range, 29-96). All patients in group 2 had a successful surgical thrombectomy and all received a stent. None of the grafts treated in group 2 reoccluded within 30 days of intervention and one patient (11%) went on to require a major amputation. By life-table analysis, the 6- and 12-month patency for group 1 was 15.3% and 5.1%, compared to 58.3% and 38.9% for group 2 (p = 0.027). Surgical thrombectomy along with balloon angioplasty has an unacceptably high rate of failure and limb loss in patients treated for early (<2 years) femoropopliteal PTFE bypass graft thrombosis. Surgical graft revision or redo bypass is recommended to achieve successful revascularization in these patients. Treatment with surgical thrombectomy and balloon angioplasty achieves significantly greater short-term patency results in patients with late (>2 years) bypass graft failure and may be a reasonable alternative for patients who cannot tolerate reoperation or lack autogenous conduit.Presented at the Twenty-eighth Annual Meeting of the Peripheral Vascular Surgery Society, Chicago, IL, June 7, 2003.     

Recurrent stenosis of common carotid-intracranial internal carotid interposition saphenous vein bypass graft caused by intimal hyperplasia and treated with endovascular stent placement. Case report and review of the literature

Intimal hyperplasia is a well-known cause of delayed stenosis in vein bypass grafts in all types of vascular surgery. Options for treatment of stenosis in peripheral and coronary artery bypass grafts include revision surgery and the application of endovascular techniques such as balloon angioplasty and stent placement. The authors present a case of stenosis caused by intimal hyperplasia in a high-flow common carotid artery-intracranial internal carotid artery (IICA) saphenous vein interposition bypass graft that had been constructed to treat a traumatic pseudoaneurysm of the intracavernous ICA. The stenosis recurred after revision surgery and was successfully treated by endovascular stent placement in the vein graft. The literature on stent placement for vein graft stenoses is reviewed, and the authors add a report of its application to external carotid-internal carotid bypass grafts. Further study is required to define the role of endovascular techniques in the management of stenotic cerebrovascular disease.     

Balloon angioplasty as a treatment of failing infrainguinal autologous vein bypass grafts

PURPOSE: The purpose of this study was to evaluate the role of balloon angioplasty in the treatment of failing infrainguinal vein bypass (IVB) grafts. METHODS: A retrospective chart review of patients undergoing revision of a failing IVB graft by vascular surgeons at a tertiary care center from 1990 to 2001 was performed. Failing bypass grafts were identified by routine duplex scan surveillance and physical examination. The criteria for endovascular intervention varied on the basis of surgeon preferences and time period; factors considered when choosing balloon angioplasty included significant comorbidities that precluded operative intervention, the lack of adequate conduit for surgical revision, or poor accessibility of the stenotic lesion. Data recorded included demographic patient data, type of IVB graft, patency status, further procedures performed, and all complications and mortalities. Cumulative primary and assisted patency rates were calculated by using Kaplan-Meier life-table analysis. RESULTS: A total of 45 balloon angioplasties were performed in 36 patients. There were 36 angioplasties of vein bypass grafts, and additional balloon angioplasties were performed on nine of these patients. Locations of IVB grafts included femoropopliteal (13 patients), femorodistal (13), and popliteal to distal (10). Initial success was achieved in 33 of 36 vein bypass grafts (91.7%). In these bypass grafts, the stenotic lesions were identified and treated at the proximal anastomosis (3 patients), mid-bypass graft (6 patients), and distal anastomosis (27 patients). Autogenous vein was used for all bypass grafts. Cumulative vein bypass graft (life-table analysis) primary patency rates (those free of occlusion or bypass graft threatening stenosis) were 74.2% at 6 months, 62.7% at 12 months, and 58.2% at 24 months. Repeat interventions included surgical thrombectomy with vein patch angioplasty or bypass graft revision, as well as repeat balloon angioplasty with or without thrombolysis. Cumulative assisted vein bypass graft patency rates (those free of occlusion or bypass graft threatening stenosis) were 87.0%, 83.2%, and 78.9% at 6, 12, and 24 months, respectively. Two patients (4%) developed thigh hematomas; no other procedure-related complications were noted, and there were no deaths in the perioperative period. CONCLUSION: Balloon angioplasty of failing infrainguinal vein bypass grafts can be successfully performed with a low rate of complications. Acceptable short-term patency can be achieved. This procedure should be considered as an initial option in failing IVB grafts.     

Durability of vein graft revision: the outcome of secondary procedures

Occlusive lesions that reduced graft blood flow and ankle systolic pressure were identified in 83 femorodistal saphenous vein bypasses by use of duplex scanning or arteriography. Sites of stenosis included vein conduit (n = 41), anastomoses (n = 20), outflow arteries (n = 15), or inflow (n = 9) arteries. One hundred three secondary procedures consisting of vein-patch angioplasty (n = 31), sequential (n = 21) or interposition (n = 17) graft placement, percutaneous transluminal balloon angioplasty (n = 17), or excision of the lesion and primary anastomosis (n = 16) were performed to correct primary (n = 85) or recurrent (n = 18) graft stenoses. Cumulative graft patency after reintervention was 96% at 1 year, and 85% at 5 years. Stenosis or occlusion of revision sites was less after excision (0 of 16) or replacement (1 of 17) of abnormal segments compared to vein-patch angioplasty (8 of 31) or balloon angioplasty (9 of 18). Sequential or jump grafts constructed to improve graft outflow impaired by either myointimal or atherosclerotic occlusive lesions were the least durable secondary procedures. Five of eight graft failures in this series resulted from sequential/jump graft occlusion. All categories of secondary procedures normalized graft and limb hemodynamics, although only one third of patients reported symptoms of limb ischemia before revision. Surveillance of infrainguinal vein bypasses for occlusive lesions is a valid concept to salvage patent but hemodynamically-failing grafts. Secondary procedures that excised the lesion, used autologous tissue reconstruction, and normalized hemodynamics at the revision site and in the vein bypass were associated with a low incidence of restenosis and prolonged graft patency.     

Results of aggressive graft surveillance and endovascular treatment on secondary patency rates of Vectra Vascular Access Grafts

OBJECTIVE: The aim of the present study was to determine the effect of an aggressive graft surveillance and endovascular treatment protocol on secondary patency rates of a polyetherurethaneurea vascular access graft, specially designed to provide early access and rapid hemostasis. METHODS: One hundred and ninety Vectra Vascular Access Grafts (C. R. Bard, Inc, Murray Hill, NJ) were placed in 176 patients (78 females and 98 males, mean age 61.7 years). There were 41 forearm grafts, 145 upper arm grafts and four thigh grafts. Graft surveillance was performed by using clinical and hemodialysis parameters to detect a failing/failed graft and followed by endovascular treatment, rheolytic thrombectomy (AngioJet, Possis Medical Inc, Minneapolis, Minn) and/or angioplasty +/- stenting of the anatomical lesion (arterial anastomosis, graft, venous outflow, draining or central veins). RESULTS: Hemodialysis started after a median of 15.5 days, as soon as from the day of the operation in some cases. Bleeding complications occurred in six patients (3.2%), venous hypertension in seven (3.7%), steal syndrome in two (1.1%), neurological complications in two (1.1%), while late infection (range 2.7-14.6 months) was seen in six patients (3.2%). Thrombectomy and angioplasty (median number of sessions 1, interquartile range 1-2) was performed in 43 grafts. Isolated angioplasty, not associated with thrombosis (median number of sessions 1, interquartile range 1-2), was performed in 50 grafts. These interventions increased primary assisted patency from 69% and 63% at 12 and 18 months, respectively to a secondary patency rate of 86%. Taking into account grafts removed for late infection, functional secondary patency rate dropped to 83% and 81%, at 12 and 18 months, respectively. Arterial anastomosis angioplasty was performed more frequently in thrombosed grafts (28.6%) than failing grafts (6.7%), P < .001 and had a significant negative predictive value on secondary patency rates at 12 and 18 months, which were 60.5% compared with 89% for grafts that had no interventions performed (P = .007) and 90.9% for grafts that had any intra-graft, venous outflow, or draining or central vein stenosis treated with angioplasty at any stage (P = .002). Multivariate analysis identified the presence of arterial anastomosis stenosis as the single predictor of secondary patency (relative risk 0.247, P = .002). CONCLUSIONS: Aggressive graft surveillance and endovascular treatment increases significantly secondary patency rates of Vectra Vascular Access Grafts. Longer follow-up will determine the effectiveness of this policy. The role of inflow stenosis on graft longevity and alternative treatment options warrant further investigation.     

Upper arm graft fistula for hemodialysis

The repeated failure of forearm hemodialysis access grafts in patients with end-stage renal failure often requires the use of an upper arm graft fistula. During a 7-year period, 20 upper arm graft fistulas were placed in 15 patients. The 5-year patency rate by life-table analysis, including graft fistula salvage by thrombectomy, is 53%. The mean survival from graft insertion until revision or thrombectomy is 36 months. Twenty of the twenty-two thrombectomies performed (91%) were successful in reestablishing graft fistula patency. Six grafts required more than one thrombectomy, and seven grafts required revision of the venous anastomosis. Only one arterial anastomosis required revision. We conclude that the upper arm graft fistula is an acceptable method of hemodialysis access in those patients without suitable forearm access sites. However, an aggressive approach to both graft fistula thrombectomy and the revision of stenotic anastomoses is necessary to maintain a satisfactory patency rate.     

Aggressive approach to late thrombosis of bovine heterografts.

Between January, 1977 and December, 1978, 26 patients presented with delayed thrombosis of bovine heterografts inserted for chronic hemodialysis. Time of presentation ranged from 2-29 months (mean 8.8 months) after insertion. At the time of presentation eight patients were not considered candidates for thrombectomy due to associated infection or physician preference. The remaining eighteen patients underwent thrombectomy, 13 of whom required concomitant revision of the graft (patch angioplasty at the venous anastomosis (6), dilatation (1), resection of intimal hyperplasia (2), resection of stenotic segment with interposition graft (2), resection of false aneurysm (1) and patch graft to mid graft stenosis (1)). Six grafts failed from eight days to seven months after thrombectomy and could not be salvaged. Two grafts functioned until death at three and four months after thrombectomy and the remaining ten grafts remain patent from 4-24 months (mean 13.1 months) after thrombectomy. Critical to success of thrombectomy is an incision over the venous limb with calibration of the venous anastomosis and patch angioplasty when indicated. At completion of thrombectomy arteriograms are mandatory to defect residual thrombosis, defects in the graft and adequacy of venous runoff. This standardized approach has resulted in a significant prolongation of bovine heterograft survival.     

Surgical and endovascular intervention for infrainguinal vein graft stenosis

Purpose: The purpose of this study was to evaluate the stenosis-free patency of open repair (vein-patch angioplasty, interposition, jump grafting) and percutaneous transluminal balloon angioplasty (PTA) of 144 vein graft stenoses that were detected during duplex scan surveillance after infrainguinal vein bypass grafting. Methods: Patients who underwent revision of an infrainguinal vein bypass graft were analyzed for type of vein conduit, vascular laboratory findings leading to revision, repair techniques, assisted graft patency rate, procedure mortality rate, and restenosis of the repair site. Results: The time of postoperative revision ranged from 1 day to 133 months (mean, 13 months). One hundred eighteen primary and 26 recurrent stenoses (peak systolic velocity, >300 cm/s) in 52 tibial and 35 popliteal vein bypass grafts were identified by means of duplex scanning. The repairs consisted of 77 open procedures (vein-patch angioplasty, 28; vein interposition, 33; jump graft, 9; primary repair, 3) and 67 PTAs. No patient died as a result of intervention. Cumulative assisted graft patency rate (life-table analysis) was 91% at 1 year and 80% at 3 years. At 2 years, cumulative assisted graft patency rate was comparable for saphenous vein grafts (reversed, 94%; in situ, 88%; nonreversed, 63%) and alternative vein grafts (89%). Stenosis-free patency rate at 2 years was identical (P = .55) for surgical intervention (63%) and endovascular intervention (63%) but varied with type of surgical revision (P = .04) and time of intervention (<4 months, 45%; >4 months, 71%; P = .006). The use of duplex scan–monitored PTA to treat focal stenoses (<2 cm) and late-appearing stenoses (>3 months) was associated with a stenosis-free patency rate that was 89% at 1 year. After intervention, the alternative vein bypass grafts necessitated twice the reinterventions per month of graft survival (P = .01). Bypass graft to the popliteal versus infrageniculate arteries, site of graft stenosis (vein conduit, anastomotic region), and repair of a primary versus a recurrent stenosis did not influence the outcome after intervention. Conclusion: The revision of duplex scan–detected vein graft stenosis with surgical or endovascular techniques was associated with an excellent patency rate, including when intervention on alternative vein conduits or treatment of restenosis was necessary. When PTA was selected on the basis of clinical and duplex scan selection criteria, the endovascular treatment of focal vein graft stenosis was effective, durable, and comparable with the surgical revision of more extensive lesions. (J Vasc Surg 1999;29:60-71.)     

Equivalent secondary patency rates of upper extremity Vectra Vascular Access Grafts and transposed brachial-basilic fistulas with aggressive access surveillance and endovascular treatment

OBJECTIVES: The 2006 update of the DOQI guidelines has stated that in patients with end-stage renal disease, autogenous radial-cephalic, or brachial-cephalic fistulas are the preferred access modalities, followed by transposed brachial-basilic (TBB) fistulas and prosthetic arteriovenous (AV) grafts. AV grafts are in general least preferred; however, there is very limited data comparing directly the last two modalities. The aim of the present study is to compare outcomes of the TBB fistula and the Vectra Vascular Access Graft. METHODS: Seventy-six patients had a prosthetic brachial-axillary Vectra graft placed, while in 41 patients brachial-basilic upper arm transposition was performed. Graft surveillance to detect a failing/failed access was followed by endovascular treatment, rheolytic thrombectomy (AngioJet, Possis Medical), and/or angioplasty +/- stenting of the responsible anatomical lesion(s). RESULTS: Use of Vectra grafts and TBB fistulas started after a median (interquartile range) of 14 (7-30) and 70 (52-102) days, respectively (P < .001), as early as the operative day in some patients with grafts. Postoperative complications were more frequent in TBB fistulas and late complications (mainly access thrombosis) in Vectra grafts. Total number of thrombectomy sessions performed for graft or fistula occlusion was 45 and 7, respectively (P = .032); total number of isolated angioplasty sessions, performed for failing graft or fistula was 31 and 45, respectively (P = .004). Although primary patency of the two access modalities was equivalent, primary assisted patency was significantly reduced in Vectra grafts (70% at 12 months and 58% at 18 months), compared with TBB fistulas (82% at 12 months and 78% at 18 months, P = .033); however, as a result of endovascular intervention, secondary patency rates at 12 months (87% vs 88%) and 18 months (87% vs 83%) were equivalent (P = .91). Presence of arterial anastomosis stenosis treated with angioplasty at any stage had a significant negative predictive value on secondary patency rates at 12 and 18 months which were 61%, compared with 96% for Vectra grafts that had any intra-graft, venous outflow, draining or central vein stenosis treated with angioplasty at any stage (P = .010). CONCLUSIONS: Aggressive graft surveillance and endovascular treatment methods can yield equivalent long-term secondary patency rates between Vectra graft and TBB fistulas. The advantage of earlier use of Vectra graft must be balanced against the need for more frequent secondary interventions and the risk of graft infection.     

Effects of a venous cuff at the venous anastomosis of polytetrafluoroethylene grafts for hemodialysis vascular access

INTRODUCTION AND METHODS: The most frequent complication of polytetrafluoroethylene (PTFE) arteriovenous grafts for hemodialysis is thrombotic occlusion due to stenosis caused by intimal hyperplasia. This complication is also known for peripheral bypass grafts. Because the use of a venous cuff at the distal anastomosis improves the patency of peripheral bypass grafts, we considered that it might also improve the patency of PTFE arteriovenous grafts. Therefore, a randomized multicenter trial was carried out to study the effect of a venous cuff at the venous anastomosis of PTFE arteriovenous grafts on the development of stenoses and the patency rates. RESULTS: Of the 120 included patients, 59 were randomized for a venous cuff. The incidence of thrombotic occlusion was lower in the cuff group (0.68 per patient-year) than in the no-cuff group (0. 88 per patient-year; P =.0007). However, the primary and secondary patency rates were comparable. The cuff group tended to have fewer stenoses at the venous and arterial anastomoses when examined with duplex scan. Graft failure was higher in patients with an initial anastomosing vein diameter smaller than 4 mm (7 of 18 [39%]) than in those with a vein diameter of 4 mm or larger (16 of 88 [18%]; P =. 052). Local edema, skin atrophy, and obesity yielded a higher risk on graft failure (23% vs 11%). CONCLUSION: A venous cuff at the venous anastomosis of PTFE arteriovenous grafts for hemodialysis reduced the incidence of thrombotic occlusions; stenosis at the venous anastomosis was reduced. However, this did not result in a better patency rate. Therefore, the venous cuff should not be used routinely. Initial vein diameter and local problems (edema, obesity, or skin atrophy) appear to be the most important risk factors for graft failure.     

Ischemia from Extrinsic Compression of the Brachial Artery by a Stent in the Venous Outflow of a Brachio‐Basilic Arterio‐Venous Graft

Distal artery embolization is a well‐known complication after mechanical thrombectomy, manifesting as limb ischemia. We describe a case of ischemia that developed after mechanical thrombectomy and stent placement in the venous anastomosis of a brachio‐ basilic arterio‐venous graft. Subsequent investigations revealed that the stent had extrinsically compressed the adjacent brachial artery. Although balloon angioplasty of the artery initially restored flow, the patient needed surgical removal of the graft and stent to prevent persistent ischemia.     

Is surgical thrombectomy to salvage failed autogenous arteriovenous fistulae worthwhile?

The Dialysis Outcomes Quality Initiatives guidelines emphasize placement of autogenous arteriovenous (AV) fistulae for patients on hemodialysis. This recommendation is based on studies that demonstrate enhanced patency for AV fistulae compared with grafts. However, closer review of the data demonstrates that although primary patency of AV fistulae is superior to grafts, the secondary patency rates are equivalent. This suggests that secondary procedures to maintain fistula patency are inferior to those performed on arteriovenous grafts. Surgical thrombectomy of AV fistulae can be challenging. It is often difficult to completely remove thrombus adjacent to the anastomosis of the fistula, and pseudoaneurysms within the fistula can prevent passage of the thrombectomy catheter and complete removal of thrombus from the fistula. Consequently, some surgeons simply abandon thrombosed AV fistulae and place a new access. We have developed a method for completely clearing thrombus from failed AV fistulae by locating the fistulotomy close to the arterial anastomosis and using a technique to manually extract thrombus from the fistula before passing a thrombectomy catheter. The purpose of this study was to review our results with this procedure. Between 2001 and 2004, 10 patients with a previously functioning AV fistula presented with thrombosis. There were seven brachiocephalic fistulae and three radiocephalic fistulae. All patients underwent surgical thrombectomy and fistulography. Five patients underwent balloon angioplasty of a venous stenosis and one patient underwent surgical revision of an arterial stenosis. Technical success, defined as being able to completely clear thrombus from the fistula and treat the cause for fistula failure, was achieved in 70 per cent (7/10) of cases. Technical failure was caused by vein rupture during the balloon angioplasty in two cases and a central venous occlusion that could not be treated in one case. The 6-month primary and secondary patency for cases that were technically successful was 51 and 69 per cent, respectively. Our conclusion was that surgical thrombectomy can significantly extend fistula functionality in patients who present with thrombosis.