The management of early in situ saphenous vein bypass occlusions

To determine the causes and optimum management of early in situ bypass occlusions, we reviewed our experience of 13 thromboses occurring within the first 30 postoperative days in 148 in situ saphenous vein reconstructions. All early thrombosed bypasses were performed for limb salvage, with 31% of bypasses to the popliteal level and 69% to infrapopliteal vessels. The median time to occlusion was 24 hours. All patients underwent reoperation. Graft failure was due to retained venous valves in 31% of the procedures, other technical problems in 38%, and inadequate outflow in 31%. Reoperative surgery was individualized. In grafts explored for thrombosis, the one-year graft patency rate was 46%, and the limb salvage rate was 54%. Graft patency did not appear to correlate with the presumed cause of initial graft occlusion. Our results indicate that an aggressive surgical approach is appropriate in early in situ graft thrombosis.     

Hemodynamics of in situ saphenous vein arterial bypass

Doppler-derived blood flow velocity and limb blood pressure measurements were used to characterize the hemodynamics of 128 in situ saphenous vein arterial bypasses. The magnitude and configuration of the graft velocity waveform was the best predictor of clinical outcome. Successful bypasses had antegrade flow throughout the pulse cycle and a blood flow velocity above 40 cm/s. A low graft blood flow velocity (less than 40 cm/s) was associated with technical error or early graft failure due to poor runoff. The return of normal limb blood pressure correlated with a technically satisfactory bypass but was measured in only 50% of limbs on the first day after surgery. In 28 bypasses with high blood flow velocity (mean +/- SD) in systole (102 +/- 20 cm/s) and diastole (35 +/- 11 cm/s), postoperative limb blood pressure was initially low (mean ankle-brachial pressure index = 0.68) due to restriction of blood flow through small-diameter (less than 4-mm) venous conduits. As revascularization hyperemia abated, diastolic blood flow velocity decreased and limb blood pressure normalized. Despite the high blood flow velocity and pressure gradient associated with flow-restrictive venous conduits, limb ischemic symptoms resolved, and graft patency was not decreased. An understanding of graft and limb hemodynamics after in situ bypass grafting is critical when noninvasive diagnostic techniques are used to document technical adequacy and for postoperative surveillance.     

The lesser saphenous vein: an underappreciated source of autogenous vein.

Use of the ipsilateral greater saphenous vein for arterial bypass procedures is frequently limited by previous stripping, bypass operations, or anatomic unsuitability. In such cases the contralateral greater saphenous vein or arm veins are often used. However, over the past 5 years we have used the lesser saphenous vein as a preferred alternative autogenous vein. Duplex scanning has been used in 311 cases for preoperative mapping and assessment with excellent correlation with actual anatomy found at operation. Harvest of the lesser saphenous vein has been facilitated by the use of a medial subfascial approach not requiring special positioning of the leg. A total of 91 lesser saphenous veins have been used for arterial bypass procedures; 66 of these were repeat cases. Vein use was 90.2%. In 40 of these cases the lesser saphenous vein was used as the entire conduit, including 10 in situ, 20 reversed vein (including 18 for coronary artery bypass), and 10 orthograde vein bypasses. In the remaining 33 cases the lesser saphenous vein was spliced to another vein to complete a bypass procedure. In the entire group, patency was 77% at 2 years. These data suggest that the lesser saphenous vein should be a principal alternative to ipsilateral greater saphenous vein for arterial bypass because of its ready availability, high use rate, ease of harvesting and preparation, and ideal handling characteristics.     

大隐静脉原位转流术重建下肢血液循环

目的:评价大隐静脉原位转流术治疗下肢动脉硬化闭塞症的疗效.方法:运用自制瓣膜切除器开展大隐静脉原位转流术治疗下肢动脉硬化闭塞症38例共40例肢体.患者术前踝肱指数(ABI)为0-0.58(平均0.29),均经动脉造影证实.术后移植物均可扪及搏动,有28条肢体足背或胫后动脉搏动恢复,17例同时行输入输出道动脉重建术,溃疡清创术6例,4例于术后3天内出现移植物搏动消失,行第2次重建术,结果:ABI平均值同术前0.29上升至0.84,严惩缺血肢体挽救率为100%,经寿命表统计分析,1-5年的血管累积通畅率分别为92%,87%,82%,72%和65%,结论:大隐静脉原位转流术是治疗下肢动脉硬化闭塞症的理想方法之一,同时行输入功输出道动脉重建术,对保证移植血管的通畅有着重要的意义.     

Popliteal-crural bypass through the posterior approach with lesser saphenous vein for limb salvage

PURPOSE: A review of popliteal-crural bypasses via the posterior approach was done to evaluate the results of this technique. METHODS: During a period of 36 months, 21 patients with limb-threatening ischemia underwent 21 popliteal-crural bypasses via the posterior approach in the prone position with reversed lesser saphenous vein. All patients had limb-threatening ischemia, with rest pain in five patients, ulceration in nine patients, and gangrene in seven patients. Diabetes mellitus was present in 17 patients. RESULTS: The inflow site was the supragenicular popliteal artery in 12 patients and the infragenicular popliteal artery in nine patients. The outflow sites were the tibioperoneal trunk in five patients, the posterior tibial artery in six patients, the peroneal artery in eight patients, and the anterior tibial artery in two patients. Of the seven patients with gangrene, three patients underwent transmetatarsal amputation and four underwent toe amputation. The limb salvage rate for the entire group was 100% at 24 months. No early graft failures were seen, and the 12-month and 24-month primary graft patency rates were 89% and 77%, respectively, with life-table analysis. The primary assisted patency rate was 95% at 12 and 24 months. Patency was determined with duplex scan graft surveillance. CONCLUSION: The posterior approach to popliteal-distal bypass is an acceptable alternative to traditional bypass procedure with excellent early patency and limb salvage results. The approach has the advantage of better utilization of lesser saphenous vein and easier operative exposure in patients with short segment infrapopliteal occlusive disease.     

The short saphenous vein: an alternative to the long saphenous vein for aortocoronary bypass.

The long saphenous vein and internal mammary artery are considered at present to be the best grafts available for coronary artery bypass. Patients who have had bilateral long saphenous vein stripping and who require multiple aortocoronary bypass grafts present a challenge to the cardiac surgeon. The short saphenous vein appears to be a suitable alterative.     

Lessons learned in adopting the in situ saphenous vein bypass

A 3-year experience with in situ saphenous vein bypasses was analyzed to evaluate the suitability of the conduit, the effect on vein utilization rate, the ease of valve ablation, the incidence of persistent arteriovenous (AV) fistula, the duration of the operation, and the nature of the learning curve to become adept at this technique. From 1981 through 1983, 74 patients underwent 55 femoral-tibial and 23 femoral-popliteal in situ saphenous vein bypasses. The operative indications were threatened limb loss in 76 (97%) and disabling claudication in 2 (3%); 35 of 74 patients (48%) were diabetic. In the last year pulsed Doppler spectrum analysis was added to arteriography for intraoperative graft assessment. For 55 femoral-tibial grafts measured by life-table patency rates at 30 days, only one femoral-popliteal graft failed (1 1/2 years). Complete vein utilization was accomplished in 91% of the bypasses attempted. In 41 of the 78 (51%) grafts, vein diameter was 3.5 mm or less. Operative time decreased with experience. Pulsed Doppler spectral analysis has proved useful for intraoperative graft evaluation. The in situ saphenous vein has become the conduit of choice for infrageniculate bypass.     

Popliteal-to-tibial in situ saphenous vein bypass for limb salvage in diabetic patients

This study has summarized our results with popliteal-tibial in situ saphenous vein bypass in 26 patients, 25 of whom were diabetic, over a 2 year period. Both above- and below-knee popliteal inflow sites were used for bypass of limb-threatening ischemia. Distal calf or pedal outflow sites were required in all but two patients who had sequential bypass performed to tibial sites. Postoperative ankle-brackial indices were calculated. Eleven patients had transcutaneous mapping surrounding the pedal skin envelope injuries. The mean lowest and highest transcutaneous oxygen values have been reported as a guide to successful healing.     

In situ saphenous vein bypass: 1962 to 1987

The historical development of in situ saphenous vein bypass has been traced over the past quarter century. The principal advantage of the in situ vein graft over the conventional reversed vein graft is the increase in flow that occurs in a tapered channel. Both the advantages of this hemodynamic observation in the in situ graft and its disadvantages in the reversed graft are accentuated in longer bypasses as the discrepancy in proximal and distal vein diameter increases. Furthermore, there is new evidence that unusual shear and stress tend to occur at sites of severe vein-artery discrepancy, such as seen in reversed vein grafts but less so in the in situ graft. Experience with the in situ graft has shown that another important advantage is that there is less chance of trauma to the vein from overdistention and rotation, which is inherent in the operation since the vein is not removed from its bed. On the other hand, the overly traumatic disruption of venous valves required in the in situ operation can cause subendothelial damage with resultant fibrosis of the vein. Although it has been demonstrated that equally good results with reversed as with in situ grafts can be obtained by careful attention to detail, this is true only for grafts carried to the popliteal level. The advantages of increased flow and less shear damage because of tapering, physiologic distention under arterial pressure, and finally, decreased handling and manipulation of the vein have become increasingly important as bypass is carried distal to the knee. I believe that the evidence to date indicates that the in situ operation has strong superiority over the conventional reversed graft for reconstructive operations on the lower extremity extending below the knee.     

原位大隐静脉旁路移植术治疗下肢缺血34例

目的：探讨原位大隐静肪房路移植术治疗下肢缺血的疗效。方法：用自制的静脉瓣膜刀为34例患者行原位大隐静脉房路移植术，其中3例做膝上Guo动脉吻合，16例行膝Guo下动脉吻合，11例行胫后动脉吻合，4例行胫前动脉吻合。结果：26例出院时静息痛消失，7例患者间歇跛行消失，平均踝/肱比由术前的0.34(0-0.52)提高到0.78(0.48-1.2)。本组6、12、24、36、48个月的通畅率分别为91.8%、88.14%、84.99%、80.52%、80.52。结论：原位大隐静脉房路移植术能有效地改善或消除肢体缺血，自制静脉瓣膜刀能有效破坏大隐静脉的瓣膜，保证了移植静脉良好的通畅率。     

Rupture of arteriovenous fistula after in situ saphenous vein bypass

Residual saphenous vein tributaries function as arteriovenous fistulas after in-situ lower extremity bypass. Whether or not all of these tributaries need to be ligated at the time of bypass is controversial since many will close spontaneously. Other consequences of retained fistulas range from local skin problems to diminished graft flow and ultimate graft thrombosis. A complication not previously reported is rupture of a retained arteriovenous fistula. This unusual and potentially catastrophic complication should be discoverable at an earlier stage by periodic graft surveillance by means of duplex sonography. The routine policy of selective ligation of saphenous vein tributaries needs to be reexamined.     

Early results of endovascular-assisted in situ saphenous vein bypass grafting

Purpose: This study evaluated an endovascular technique for occlusion of arteriovenous fistula when performing saphenous vein in situ bypass grafting.Methods: In 31 limbs femoropopliteal (17) or femorotibial (14) in situ bypass grafting was performed for claudication/aneurysm (4), rest pain (6), or tissue loss (21). A valvulotome was used for valve lysis. Saphenous vein branches were identified with angioscopy in 16 limbs or with fluoroscopy in the remainder. An electronically steerable endovascular catheter was used to deliver platinum coils into the venous tributaries to occlude them.Results: The maximal number of coils placed in any limb was nine. Most operations were performed with only a groin incision (length = 9.8 ± 1.6 cm) and a distal incision (length = 16.8 ± 6.5 cm). Wound complications occurred in four limbs, whereas four limbs developed localized superficial thrombophlebitis. The postoperative ankle-brachial index increased to a mean of 0.91 ± 0.12. Postoperative duplex imaging revealed a missed arteriovenous fistula in 12 limbs. Two were surgically ligated, whereas the remainder were embolized in the radiology suite. Postoperative length of hospitalization was 4 ± 2 days in uncomplicated cases. Follow-up revealed five graft occlusions. Occlusion occurred at 12 hours, 2 weeks, and 6, 14, and 15 months after operation. Although there were no perioperative deaths, two patients have died of unrelated causes.Conclusion: This endovascular technique of arteriovenous fistula embolization decreased the length of the surgical wounds, and patients were discharged 4 ± 2 days in uncomplicated cases. The ultimate test of its efficacy, however, will be long-term functional results. (J VASC SURG 1994;19:778-87.)     

Use of the short saphenous vein in situ for popliteal-to-distal artery bypass

In the absence of a usable greater saphenous vein, the short saphenous vein has been relatively ignored for use as an arterial bypass conduit. In 36 patients, duplex ultrasound scanning was used for preoperative assessment of the short saphenous vein. The internal diameter of the vein ranged from 2.8 to 4.2 mm. The short saphenous vein was harvested for a free vein graft in 31 patients. In the remaining five patients, the short saphenous vein was used in situ for popliteal-to-distal artery bypass. In four patients, the distal anastomosis was performed to the distal anterior tibial artery and in one patient, to the distal posterior tibial artery. Valves were excised with valvulotomes and deep fistulas were easily ligated. A medial incision for vein exposure was the preferred approach. We suggest that the short saphenous vein be considered more often for use as an arterial bypass conduit when the greater saphenous vein is not available, before submitting to nonautogenous bypass or primary amputation.     

Further experience with the saphenous vein used in situ for arterial bypass

Ongoing experience with use of the saphenous vein in situ as an infrainguinal arterial bypass is presented. One hundred eighty-three bypasses were performed for limb-threatening ischemia, 92 of which were to the popliteal artery, either isolated or in continuity with one or more tibial vessels, and 91 bypasses were carried to single tibial vessels below the termination of the popliteal artery. The results were analyzed by the life table method and show an overall patency rate of 89.8 percent at 3 to 4 years. Separate life table analysis of the tibial bypass group showed a patency rate of 83 percent at 3 to 4 years. Special emphasis is placed on the ability to use veins less than 4 mm in diameter, which comprise 40 percent of those used in these procedures. The superior results provided by the in situ method are explained in part by experimental observations which show that endothelial stability is completely preserved by this method but is severely disturbed during the process of vein removal and reversal.     

Early experience with in situ saphenous vein bypass for distal arterial reconstruction

During a 36-month period 74 patients underwent infrainguinal in situ saphenous vein bypass to the popliteal or tibial vessels. The first 54 operations were performed with standard valvulotomes and valve-cutting scissors, while in the last 20 operations a new intraluminal valve-cutting device was used to incise the valves. Ninety-four percent of bypasses were performed for limb salvage, 80% of all operations were done to the tibial vessels, and 31% of bypasses were done to the ankle vessels. The operation was attempted in 81 patients and completed in 74 patients, for a vein utilization rate of 91%. Fifty-five percent of all veins had a distal diameter of less than 4 mm (average 3.6 mm). The patency rates were 92% at 3 months and 90% at 12 and 36 months for all grafts. There were six failed grafts, all within the first 6 months, and eight diabetic patients required reoperation, two for missed valve leaflets, and three needed revision of the distal anastomosis; however, all these grafts were patent at the time of reexploration. There were four perioperative deaths and two patients had nonfatal postoperative myocardial infarctions. This study demonstrates that in situ saphenous vein grafting provides for a high vein utilization rate and suggests that the technique provides for higher graft patency and limb salvage rates than do more traditional types of procedures.