Adjunctive Arteriovenous Fistula Research Articles

Preemptive Femoral-Femoral Crossover Grafting of Artery and Vein Before Pelvic Exenterative Surgery for Locally Advanced and Recurrent Pelvic Malignancy Involving the Aortoiliac Axis.

Achieving a negative resection through a pelvic exenteration for a recurrent or an advanced pelvic malignancy offers the potential for cure. Exenterative surgical units have expanded the boundaries and redefined what constitutes resectable disease through improved surgical technique. In selected cases, contiguous tumor involvement of the aortoiliac axis requires en bloc resection and subsequent vessel reconstruction. However, vascular reconstruction can be challenging in a contaminated field during an extended radical resection. The aim of this Technical Note is to describe a novel method in the management of patients with recurrent or advanced pelvic malignancy involving the aortoiliac axis by performing preemptive femoral-femoral arterial and venous crossover grafts, with adjunctive arteriovenous loop fistula formation before undergoing an extended radical pelvic resection 4 weeks later. Four patients have undergone preemptive femoral-femoral arterial and venous crossover grafts at our institution (median age = 60 y (range, 47-66 y); 2 women). There were no early complications, and all of the patients subsequently underwent extended radical pelvic resections for a pelvic malignancy. Preemptive vascular reconstruction before major pelvic surgery reduces the risk of graft infection because this method avoids the wounds being contaminated by GI or genitourinary organisms. Other advantages to this technique include a reduction in the overall operating time for the pelvic exenteration, a significant reduction in the ischemia time to the lower limbs, and ensuring that the grafts are patent before embarking on major intra-abdominal surgery.

Comprehensive surgical management of the competitive athlete with effort thrombosis of the subclavian vein (Paget-Schroetter syndrome)

The results of treatment for subclavian vein effort thrombosis were assessed in a series of competitive athletes. A retrospective review was conducted of high-performance athletes who underwent multidisciplinary management for venous thoracic outlet syndrome in a specialized referral center. The overall time required to return to athletic activity was assessed with respect to the timing and methods of diagnosis, initial treatment, operative management, and postoperative care. Between January 1997 and January 2007, 32 competitive athletes (29 male and 3 female) were treated for venous thoracic outlet syndrome, of which 31% were in high school, 47% were in college, and 22% were professional. The median age was 20.3 years (range, 16-26 years). Venous duplex ultrasound examination in 21 patients had a diagnostic sensitivity of 71%, and the mean interval between symptoms and definitive venographic diagnosis was 20.2 +/- 5.6 days (range, 1-120 days). Catheter-directed subclavian vein thrombolysis was performed in 26 (81%), with balloon angioplasty in 12 and stent placement in one. Paraclavicular thoracic outlet decompression was performed with circumferential external venolysis alone (56%) or direct axillary-subclavian vein reconstruction (44%), using saphenous vein panel graft bypass (n = 8), reversed saphenous vein graft bypass (n = 3), and saphenous vein patch angioplasty (n = 3). In 19 patients (59%), simultaneous creation of a temporary (12 weeks) adjunctive radiocephalic arteriovenous fistula was done. The mean hospital stay was 5.2 +/- 0.4 days (range, 2-11 days). Seven patients required secondary procedures. Anticoagulation was maintained for 12 weeks. All 32 patients resumed unrestricted use of the upper extremity, with a median interval of 3.5 months between operation and the return to participation in competitive athletics (range, 2-10 months). The overall duration of management from symptoms to full athletic activity was significantly correlated with the time interval from venographic diagnosis to operation (r = 0.820, P < .001) and was longer in patients with persistent symptoms (P < .05) or rethrombosis before referral (P < .01). Successful outcomes were achieved for the management of effort thrombosis in a series of 32 competitive athletes using a multidisciplinary approach based on (1) early diagnostic venography, thrombolysis, and tertiary referral; (2) paraclavicular thoracic outlet decompression with external venolysis and frequent use of subclavian vein reconstruction; and (3) temporary postoperative anticoagulation, with or without an adjunctive arteriovenous fistula. Optimal outcomes for venous thoracic outlet syndrome depend on early recognition by treating physicians and prompt referral for comprehensive surgical management.

A 10-Year Experience with Complementary Distal Arteriovenous Fistula and Deep Vein Interposition for Infrapopliteal Prosthetic Bypasses

Since up to 20% of patients undergoing lower extremity revascularization do not have an adequate venous conduit, some authors have explored the use of prosthetic grafts with adjunctive techniques for lower extremity revascularization. However, the long-term graft patency of those procedures has not been well documented. The purpose of this study was to examine the long-term patency of polytetrafluoroethylene (PTFE) bypass with adjunctive arteriovenous fistula and venous interposition (AVF/VI) for infrapopliteal revascularization. Over a 10-year period, 246 lower extremity reconstructions were performed in 176 (71.5% men) patients with critical ischemia in whom a totally autogenous vein bypass was not feasible. Seventy-six limbs had undergone 1 or more failed ipsilateral infrainguinal bypasses. Indications for surgery were chronic critical limb-threatening ischemia (86%) (rest pain, ischemic ulcer, or gangrene) or acute ischemia (14%). Ages ranged from 46 to 91 years (mean 74 +/-0.6 [SD] years). Risk factors such as diabetes, hypertension, coronary artery disease, end-stage renal disease, and use of tobacco were present in 49%, 49%, 52%, 8%, and 67% of the patients, respectively. During the follow-up, 112 cases (45%) required reinterventions. Twenty-seven patients (15%) required bypass revision twice. During the follow up, 56 limbs (23%) were amputated (above-the-knee amputation 25 (10%); below-the-knee amputation 31 (13%). To date, 150 (85%) patients of a total of 176 are deceased. The primary graft patency rates were as follows: at 1 year, 51%; at 2 years, 41%; 3 years, 35%; and 5 years, 24%. Limb salvage rates were as follows: 1 year, 79%; 2 years, 76%; 3 years 76%; and 5 years, 74%. Patient survival rates were as follows: 1 year, 69%; 2 years, 60%; 3 years, 54%; and 5 years, 40%. Amputation-free patient survival rates were as follows: 1 year, 66%; 2 years, 57%, 3 years, 51%, and 5 years, 30%. This technique appears to offer reasonable patency and limb salvage rates in patients in whom autogenous bypass grafts are not feasible.

Should Duplex Ultrasonography Be Performed for Surveillance of Femoropopliteal and Femorotibial Arterial Prosthetic Bypasses?

Duplex ultrasonography (DU) has been shown to be beneficial for surveillance of lower extremity vein bypasses. However, DU as part of surveillance program for prosthetic grafts is not widely accepted. The purpose of this report was to determine if DU could reliably detect failing prosthetic infrainguinal arterial bypasses and if there were differences in predictability between femoropopliteal (FP) and femorotibial (FT) prosthetic grafts. Between January 1992 and December 1997, 89 infrainguinal grafts in 66 patients were entered into our postoperative prosthetic graft surveillance protocol, which included clinical evaluation, segmental pressures, pulse volume recordings, and DU performed every 3 months. Patients with follow-up of less than 3 months were excluded unless the graft thrombosed. An abnormal DU considered predictive of graft failure included (1) peak systolic velocity (PSV) > 300 cms/sec at inflow or outflow arteries, in the graft or at an anastomosis (unless an adjunctive arteriovenous fistula had been performed); (2) adjacent PSV ratio > 3.0; (3) uniform PSVs < 45 cms/sec; or (4) monophasic signals throughout the graft. DU was considered to have correctly diagnosed a failing graft if a stenosis > 75% the luminal diameter of the graft, at an anastomosis, or in an inflow/outflow artery was confirmed by operative or arteriographic findings or if the graft thrombosed after an abnormal DU but before intervention. Our results support the routine use of DU as a part of a graft surveillance protocol for femorotibial, but not femoropopliteal, prosthetic grafts.

Improved method to create the common ostium variant of the distal arteriovenous fistula for enhancing crural prosthetic graft patency.

Successful use of the distal adjunctive arteriovenous fistula (dAVF) for the enhancement of prosthetic graft patency rates in the crural position is critically dependent on the qualitative and quantitative aspects of the arterial and venous runoff. Precise technical performance of the fistula is equally vital to secure optimal results. The purpose of this study was to determine current prosthetic graft patency and limb salvage rates using a modified version of the common ostium dAVF. The standard method to create the common ostium variant of dAVF has been modified to improve apposition of the "otomy" sites of the artery and vein, avoid twisting and stenosis by terminating the fistula suture line at the artery-vein junctures, reshaping the ovoid ostium to a rectangular shape, and finally, use of multiple interrupted heel-toe sutures. Since 1979 we have created 290 fistulas in 281 patients who required leg revascularization procedures. In different time periods we have documented improving graft patency and limb salvage rates. Fistula patency, reflected by annual attrition rates of 13% to 26% per year, continues as a challenge for long-term results. Current 3-year secondary cumulative graft patency and limb salvage rates by life table analysis are 61% and 74%, respectively. The conduit material may play a role with regard to steal phenomena and the need for banding techniques. Configuration of the adjunctive dAVF may impact on prosthetic graft patency in the crural position. In addition, the type of graft material used for bypass may be instrumental in preventing or precipitating the steal phenomenon. These issues require further study to better understand flow dynamics, patterns of intimal hyperplasia, and blood distribution as a function of conduit material and impedance of the arterial and venous runoff.

Analysis of the Hemodynamics of a Bypass with Adjunctive Arterio–Venous Fistula Using a Direct Electrical Circuit Model

Background: The purpose of this work was to study, in a theoretical electric model the effect that an adjunctive arterio–venous fistula (AVF) produces on the flow patterns of a distal infrapopliteal bypass. Method: A theoretical electric model that mimics a femoro–infrapopliteal bypass with an adjunctive AVF was designed. Based on Thevenin's Theorem, flows in different areas of the circuit (bypass, collaterals, AVF, segment of artery distal to bypass anastomosis, arteriolar system) were calculated at different resistance values for AVF, collaterals, and bypass. Results: This model demonstrated the following: (1) An adjunctive AVF with large resistance (smaller vein diameter) maintains distal flow, as opposed to a low-resistance AVF. (2) Good collateral flow, in addition to low-resistance AVF, can produce retrograde flow in the segment of the artery distal to the AVF. (3) True distal flow (arteriolar flow) in the presence of high collateral resistance can decrease with decreasing resistance of the AVF, but it will never become retrograde. Conclusion: The effect of an adjunctive AVF on the hemodynamics of a bypass and its distal runoff vessels depends on the resistance of the AVF and the collateral vessels. The presence of AVF always increases the bypass flow and in this respect it may promote graft patency. However, Bypass grafting in the face of a low collateral resistance is of dubious value and the addition of a fistula in this situation is detrimental.

Pantaloon vein graft technique in tibial revascularization with arteriovenous fistula for limb salvage

Graft patency and limb salvage in 91 successive patients operated upon between April 1989 and April 1994 with a human umbilical vein graft combined with an adjunctive arteriovenous fistula at the distal anastomosis of the prosthetic graft in a single limb were evaluated. All the patients operated on were in the ‘limb salvage’ category. On discharge from hospital 91% of the revascularized limbs were salvaged. Secondary cumulative patency at 57 months was 57.3% with a 61.5% limb salvage rate. This technique, which has anatomical and haemodynamic advantages, results in improved graft patency and foot salvage rates in patients with critical leg ischaemia and poor distal run-off when autologous saphenous vein is absent or cannot be used.

Pantaloon Vein Graft Technique in Tibial Revascularization with Arteriovenous Fistula for Limb Salvage

Graft patency and limb salvage in 91 successive patients operated upon between April 1989 and April 1994 with a human umbilical vein graft combined with an adjunctive arteriovenous fistula at the distal anastomosis of the prosthetic graft in a single limb were evaluated. All the patients operated on were in the ‘limb salvage’ category. On discharge from hospital 91% of the revascularized limbs were salvaged. Secondary cumulative patency at 57 months was 57.3% with a 61.5% limb salvage rate. This technique, which has anatomical and haemodynamic advantages, results in improved graft patency and foot salvage rates in patients with critical leg ischaemia and poor distal run-off when autologous saphenous vein is absent or cannot be used. Copyright © 1996 The International Society for Cardiovascular Surgery.

Polytetrafluoroethylene bypasses to infrapopliteal arteries without cuffs or patches: A better option than amputation in patients without autologous vein

This study was undertaken to evaluate our results of polytetrafluoroethylene (PTFE) tibial and peroneal artery bypasses done for limb salvage. Within a group of patients undergoing infrainguinal limb salvage bypasses at our institution between January 1986 and May 1995, 63 patients faced an immediate amputation, had no autologous vein on duplex examination and operative exploration, and had only a tibial or peroneal artery as an outflow vessel for bypass. Most of these patients (82%) had two or more prior ipsilateral infrainguinal bypasses. These 63 patients underwent 66 PTFE bypasses to a tibial or peroneal artery without a distal anastomotic vein cuff or an adjunctive arteriovenous fistula. Our results were then compared with those reported from infrapopliteal (crural) bypasses performed with alternate autologous vein sources or PTFE in conjunction with various recommended adjuncts. The 3- and 5-year cumulative primary graft patency rates for our PTFE infrapopliteal bypasses were 39%+/-7% and 28%+/-9%, respectively. Secondary graft patency rates were 55%+/-8% and 43%+/-10% at 3 and 5 years, respectively. Limb salvage rates were 71%+/-7% at 3 years and 66%+/-8% at 5 years. Two-year actuarial patient survival rate was only 67%+/-7%. These results indicate that a PTFE bypass to an infrapopliteal artery remains a worthwhile option in patients without usable autologous vein. The secondary patency and limb salvage rates were acceptable in this setting and were not significantly different from the best results reported with prosthetic tibial/peroneal bypasses with distal vein cuffs or patches (74% at 1 year; 58% at 3 years), arteriovenous fistulas (71% at 1 year) or composite arm vein grafts (39% and 29% at 3 and 5 years, respectively).

Long-term results of crural artery bypass with an adjunctive arteriovenous fistula

Long-term results of crural artery bypass with an adjunctive arteriovenous fistula

Creation of a distal arteriovenous fistula improves microcirculatory hemodynamics of prosthetic graft bypass in secondary limb salvage procedures

In patients with critical limb ischemia, poor distal arterial runoff, and absence of autogenous veins, the use of an artificial graft and an arteriovenous fistula might be a valuable option. However, in these patients little information is available regarding preoperative and postoperative microcirculatory hemodynamics after this type of intervention. With the use of intravital capillary microscopy, we studied the effect of distal revascularization on the microcirculation in 26 patients with critical limb ischemia. All patients had had failed vascular reconstructive operations, and artificial grafts were required because of the absence of autogenous veins. Patients were prospectively investigated and divided into two groups: 12 patients received a femorocrural bypass with polytetrafluoroethylene grafts, and 14 patients underwent the same procedure with the creation of an arteriovenous fistula at the site of the distal anastomosis and ligation of the proximal vein. Red blood cell velocity was measured before and after arterial occlusion to determine microcirculatory hemodynamic alterations. Immediate postoperative graft patency was achieved in all 26 patients. The 1-year cumulative graft patency rate was 64% in the group that had creation of an arteriovenous fistula, which was significantly higher (p < 0.01) compared with that in the group in which a fistula was not created (21%). The 1-year cumulative foot salvage rate was 72% in the patients with an arteriovenous fistula and 43% in the patients without a fistula (p < 0.05). Red blood cell velocity increased similarly in both groups after the bypass procedure. Peak and time to peak red blood cell velocity also improved significantly in both groups; however, comparing both groups, peak and time to peak red blood cell velocity were significantly better (p < 0.05) in the patients with an arteriovenous fistula and remained significantly higher during the follow-up period. In conclusion, creation of an adjunctive arteriovenous fistula at the distal anastomosis of a prosthetic graft appears to improve microcirculatory hemodynamics in the nutritional capillary vascular bed. Improved graft patency and foot salvage rates suggest that this procedure benefits patients with critical limb ischemia who have no usable veins.

Infrapopliteal prosthetic graft patency by use of the distal adjunctive arteriovenous fistula

Infrapopliteal prosthetic graft patency by use of the distal adjunctive arteriovenous fistula

Infrapopliteal prosthetic graft patency by use of the distal adjunctive arteriovenous fistula

From November 1979 through December 1989, 210 distal arteriovenous fistulas were constructed as adjuncts to tibial and peroneal vascular reconstructive procedures in 203 patients threatened with limb loss. Two-year cumulative patency rates were calculated by grouping patients on the basis of changing indications in sequential time periods: group 1 (n = 61): 1979 to 1983, 18%; group 2 (n = 80): 1983 to 1986,33%; group 3 (n = 69): 1986 to 1989, 44%. Although the therapeutic results observed in these groups are not statistically comparable, they show a perceptible trend. Postoperative arteriography showed that flow is prograde in the distal vessels beyond the distal arteriovenous fistula. Graft surveillance by duplex ultrasonography also confirmed that flow in the distal arteries is prograde and that “steal” does not occur. Peak systolic velocity (174 ± 38 cm/sec) and mean velocity (92 ± 23) flow rates are increased in grafts with patent distal arteriovenous fistulas compared to those bypasses with closed distal arteriovenous fistulas (p < 0.01). There were no differences in the flow measurements for the arteries beyond the distal anastomoses and distal arteriovenous fistulas, confirming the prograde nature of the distal flow. In 22 patients analysis of graft and fistula patency by duplex sonography showed that one fourth of all grafts were patent without fistulas at 1 and 2 years after operation. Alternatively, 68% of patent grafts at 1 year had patent fistulas and 58% had patent fistulas at 2 years. We conclude that the distal arteriovenous fistula will increase graft flow and simultaneously prevent distal arterial overload without causing “steal.” This technique should be considered whenever a prosthetic graft is necessary for crural reconstruction and only in selected instances of revascularization with autologous veins.

末梢ｒｕｎ‐ｏｆｆ不良例に対する動静脈ろう併設けい骨動脈バイパス移植術の成績 術式改良の工夫

末梢ｒｕｎ‐ｏｆｆ不良例に対する動静脈ろう併設けい骨動脈バイパス移植術の成績 術式改良の工夫

Factors contributing to success and failure of femorotibial bypass grafts.

AbstractFemorodistal bypass grafting is an important technique in the armamentarium of vascular surgeons, and it has been found that the cost of such procedures justifies their performance in patients who have sustained critical ischemia. Graft material remains the most important factor in causation of graft failure, with all prosthetics having disadvantages when compared to the saphenous vein. In attempts to use biological materials, both bovine heterografts and human umbilical vein grafts have been seen to form aneurysms and undergo thrombosis. Meanwhile, many variations on the theme of prosthetic grafts have been tried and found wanting when used as bypasses from the femoral artery to the distal circulation. Among configurations tried have been polytetrafluoroethylene with and without external support; Dacron® in woven and knitted format, with or without internal and external velour; and combinations of these. As patency rates of these reconstructions have proven inferior to others using the saphenous vein, attempts have been made to extend the use of autogenous biologic material. Such attempts have included cephalic vein bypass grafts, short vein bypass grafts originating distal to the femoral artery, deep veins used as grafts, and the in situ bypass. Lately, it has been recognized that the in situ bypass, when compared to concurrent controls, shows no significant advantage to the popliteal level but is the technique of choice when distal anastomoses are at or distal to the midcalf. Compositesequential bypasses represent another technique developed to utilize the autogenous vein as a distal segment. While this has increased the rate of patency of distal bypass grafting, other aids to patency such as use of anticoagulants, antiplatelet agents, and adjunctive arteriovenous fistula have not. Dynamics of the coagulation system show an intrinsic change in patient status toward coagulation in the postoperative period, and although this factor is of some significance in causing early graft thrombosis, technical defects do not seem to play an important part. This review details some of these important causes of graft failure and places them in proper perspective.

Flow estimation by DSA in bypasses with or without a distal arterio-venous fistula

Flow of contrast medium in bypasses with or without an arteriovenous fistula (AVF) has been measured using a densitometric technique. Modern digital subtraction angiography (DSA) equipment has the ability to produce images related to the density of the bolus of contrast passing down the vessel and to measure flow from them. Three studies were performed; (1) the method was tested in a model where it was compared with direct flow measurement; (2) A flow study was carried out in four groups of different below knee bypasses; (3) A study to examine the distribution of flow in adjunctive arteriovenous fistula was performed. The first study showed that the method was reliable and highly reproducible; the mean relative variance of DSA measured flow to the real flow being 3.05% and never more than 10%. The second study showed mean flow for various bypasses as shown below: (1) 10 fem.pop. bypasses (61-202 ml/min). 120 ml/min; (2) 10 fem.tib. bypasses (41-190 ml/min). 120 ml/min; (3) 10 fem.tib. bypasses with AVF(243-455 ml/min). 321 ml/min; (4) 10 pop.pedal. bypasses with AVF(112-382 ml/min). 261 ml/min. The differences between group 1 and 2 and group 3 and 4 are significant (P less than 0.005). The third study showed that relatively little of the blood entering an AVF passes distally into the arterial bed (Mean: 11%, 6-19%). In conclusion, DSA flow measurement is a reliable method of flow measurement. An AVF increases graft flow 2-3 times but only about 10% of the blood passes distally into the arterial system.

Surgery of the Veins

Drs Bergan and Yao have provided a truly authoritative, state of the art compendium titled Surgery of the Veins . Within 557 pages the editors have assembled 39 chapters by 73 North American and European authors, each recognized for distinguished contributions to the venous literature. The information is for the most part current and clearly stated, with 224 illustrations in nine sections: basic considerations, diagnostic studies, acute deep vein thrombosis, surgery of chronic venous insufficiency, surgery for inherent venous insufficiency, upper-extremity venous thrombosis, surgery of the vena cava, surgical management of venous thromboembolism, and preventative and supportive measures. Several of the enigmas of venous disease are squarely addressed, including the natural history of the disease, the controversial roles of thrombectomy and adjunctive arteriovenous fistula, and the use of fibrinolytic therapy. The latter discussion is somewhat abbreviated and objective data on the efficacy of this increasingly popular modality are scant. Infrequently performed

Haemodynamics of the adjunctive arteriovenous fistula in femorodistal bypass grafting: an experimental study.

The results of femorotibial bypass for limb salvage vary a great deal. One of the reasons for this might be the discrepancy between potential inflow and run-off into the foot. An arteriovenous fistula at the distal graft anastomosis may improve results but the best anatomical arrangement for the fistula is unknown. Ileofemoral grafts were performed in dogs after the hind limb was rendered ischaemic. The distal end of the graft was anastomosed proximal to, superimposed upon, or distal to an arteriovenous fistula between the femoral artery and its accompanying femoral vein. The effect of the fistula on graft/run-off haemodynamics was then measured. The adjunctive arteriovenous fistula increased inflow by a mean of 900 per cent and reduced systemic pressure by 10 per cent. Peripheral resistance was reduced by 85 per cent. Distal arterial run-off was maximized with respect to total graft flow when the graft was placed distal to the fistula (P less than 0.05). The venous steal of flow and perfusion pressure produced by the fistula was minimized with the same configuration compared to the two other arrangements (P less than 0.01 and P less than 0.05). Placement of the graft distal to the adjunctive arteriovenous fistula maximized distal arterial flow and pressure, and significantly increased graft flow.

Adjunctive arteriovenous fistula with tibial and peroneal reconstruction for limb salvage

Arteriovenous fistulas were constructed as an adjunct to femoral peroneal and tibial bypasses in 13 patients threatened by imminent limb amputation. Previous attempts at conventional vascular reconstructive procedures had failed in nine patients. Deficient or absent pedal arches were noted in all patients, as were poor quality or small crural arteries. Graft patency was achieved in 11 cases and limb salvage in 10. There was no mortality. A steal phenomenon occurred in one patient and was successfully treated by secondary popliteal vein ligation. These preliminary results clearly indicate that an adjunctive arteriovenous fistula can maintain patency in a femoral tibial or peroneal bypass graft while preserving flow into the markedly diseased distal circulation.