Irving I. Dardik

A decade of experience with the glutaraldehyde-tanned human umbilical cord vein graft for revascularization of the lower limb

Between October 1975 and November 1985, 907 lower limb bypasses were constructed in 715 patients (799 limbs) with glutaraldehyde-stabilized umbilical veins (UV-G) used as the predominant, or sole, graft material. Each reconstruction was classified in one of eight categories depending on the site of the distal anastomosis: above- and below-knee popliteal, anterior and posterior tibial, peroneal, trifurcation, sequential, and crural (tibial or peroneal) bypasses with adjunctive distal arteriovenous fistulas. Primary and secondary cumulative graft patency rates were determined for each category as well as cumulative actual palliation that combines end points of graft failure, amputation, and death. Half-life patencies for popliteal, tibial, and peroneal bypasses were 6.5, 2.3, and 1.7 years, respectively. Perioperative graft thrombosis occurred in 11% of popliteal reconstructions compared with 22% for the crural group. Nonocclusive graft failure caused by infection, aneurysm, or progressive foot gangrene occurred in 87 grafts (8%). The overall infection rate was 4.3%. Anastomotic aneurysms (1.4%) and strictures (2.1%) occurred infrequently as isolated phenomena. The incidence of graft dilatation and aneurysms assumed significant proportion after 5 years (36% aneurysms and 21% dilation); the diagnosis was particularly facilitated by B-mode imaging. Nevertheless, the overall clinical impact of graft degradation remained minimal (6% after 5 years). Twenty-two of 26 graft aneurysms were excised with successful graft replacement achieved in 10. During this 10-year period, our attitudes did change with regard to the indication for UV-Gs in relation to the maturation of infrapopliteal reconstructive surgery, appreciation of the superior results attainable with in situ saphenous vein, recognition of morphologic changes in long-term UV-G implants, and the growing documentation of poor results with polytetrafluorethylene in the crural position. We believe that UV-G is an acceptable alternative to the absent or deficient autologous vein, particularly in patients with limited life expectancy and where expediency may be a critical factor.

Successful arterial substitution with modified human umbilical vein.

Human umbilical veins were prepared as vascular grafts by tanning with dialdehyde starch or gluteraldehyde and by structural re-inforcement with an outer polyester fiber mesh. These grafts were implanted in baboons in the aortoiliac position for periods of 3 days to 9 months. There was no aneurysm formation and there was an excellent maintenance of patency as well as function. Histologic evaluation of the graft materials showed a dense collagen layer within the encircling polyester fiber mesh. A multicellular subintimal layer formed a discrete inner capsule. The inflammatory response within the umbilical component was insignificant. There was no evidence of rejection. This study suggests that the modified umbilical vein can serve as a satisfactory blood conduit. Experience with three short-term clinical implants supports the applicability and potential for this new vascular graft.

Biodegradation and aneurysm formation in umbilical vein grafts. Observations and a realistic strategy.

In a series of 756 glutaraldehyde-stabilized umbilical vein grafts implanted over a 7 1/2-year period, aneurysms were identified in seven cases. The earliest aneurysm was seen at 31 months after implantation and the remainder between 43 and 79 months after surgery. Corrective surgery was performed in five cases and succeeded in four. Although definite mechanisms have not been identified, mechanical fatigue, reversal of aldehyde crosslinks, and immunologic factors may be operative. The pathologic changes include: (1) actual dilation of both graft and mesh with or without intraluminal thrombus and, (2) maintenance of graft diameter with erosion of the umbilical vein and polyester mesh rupture leading to perigraft hematoma and false aneurysm formation. Microscopic examination and infrared spectral analysis confirmed the presence of host-contributed lipid in some specimens. Although this is a low incidence of aneurysm formation, umbilical vein grafts should be selected primarily for patients with limited life expectancy or for whom alternative materials with comparable or superior patency rates are not available or acceptable. Periodic angiography, particularly after 3 or 4 years, is recommended as a routine part of follow-up examinations. Improved graft materials and control of host environmental factors are potential means to reduce the noted degradation.

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.

The role of the peroneal artery for limb salvage.

Peroneal artery revascularization was performed in 61 cases for limb salvage and compared to a comparable group of 89 tibial artery reconstructions. Preoperative arteriography is essential to define runoff quality and pedal arch integrity. Intraoperative arteriography and flow determinations minimize failures due to technical error and provide some indication of the prognosis for graft patency. Failure to augment flow by at least 50% suggests pedal arch deficiency and is predictive for early graft closure. Cumulative patency for peroneal bypass was 55 ± 8% at 1 year and 38 ± 10% at 30 months compared to 63 ± 6 and 59 ± 7% for tibial reconstructions at the same time intervals. Most graft failures occurred within the first six months. Nineteen peroneals have been followed for more than one year with only three failures occurring. Improved criteria for case selection resulted in an 80% decrease in the number of failed grafts for the second half of this series. A similar reduction was noted for secondary operations. Results obtained with good quality saphenous veins (37 ± 13% at 30 months) and glutaraldehyde tanned umbilical veins (53 ± 11%) depend more on technical, pathologic and biologic factors than on the particular graft material employed. The mortality rate at 30 days was 3.3% and compared favorably with other limb salvage procedures and with primary amputations. Cumulative patient survival with functional limbs was 79 ± 9% at 30 months and was distinctly superior to reported data on survival of amputees. A cumulative limb salvage rate of 79 ± 6% at 30 months for the peroneal group makes such reconstructions definitely favorable to uniform limb ablation.

Clinical use of polyglycolic acid polymer as a new absorbable synthetic suture

Abstract The use of polyglycolic acid sutures was evaluated in 126 operations performed upon 118 unselected patients. The material appears to compare favorably with other sutures with respect to handling, tensile strength, knot security, lack of toxicity, and minimal tissue reaction. PGA did not interfere with wound healing, and the material was well tolerated in both clean and contaminated operations, including thirty-five operations in which PGA was used skin to skin. We believe PGA is the first practicable synthetic absorbable suture material. It is a nonproteinaceous, polymeric fiber which is predictably absorbed in vivo , and approaches the requirements of a “universal” suture material.

Glutaraldehyde-stabilized umbilical vein prosthesis for revascularization of the legs: Three year results by life table analysis

Abstract Three hundred sixty-one vascular reconstructions for salvage of the leg were performed from 1975 to 1978 employing glutaraldehyde-stabilized umbilical veins. These included 183 bypasses to the popliteal segment, 108 to either of the tibial arteries and 70 to the peroneal artery. One hundred forty-one (77 per cent) of the popliteal reconstructions were below the knee. Operative mortality rates were 2.7,2.8, and 4.3 per cent for popliteal, tibial, and peroneal reconstructions, respectively. The cumulative patency rates at 36 months for each of the three types of reconstructions were 76.4 (popliteal), 63.4 (tibial), and 39.8 per cent (peroneal). The latter figure was statistically insignificant because of the small number of patients between 24 and 36 months. The cumulative patency rate for peroneal reconstructions at 2 years was 55.7 ± 6.2 per cent. Failures were usually due to inappropriate case selection or progressive disease, particularly in the distal circulation. Two grafts were removed because of wound infection and secondary graft infection. There were no instances of aneurysm formation or myointimal proliferation in the graft. These data support the continued use of the glutaraldehyde-stabilized umbilical vein as a suitable alternative to the autologous saphenous vein. The graft provides a reliable material for reconstruction of the leg that is nonantigenic, mechanically equivalent to normal vascular structures, and biocompatible as determined by physical and chemical modalities. The durability of these grafts is based on the thromboresistance of the flow surface and the cross-links established by aldehyde processing. In appropriately selected cases and with expert surgical technique, long-term graft function with limb salvage can be obtained.

Femoral tibial-peroneal bypass: the lateral approach and use of glutaraldehyde-tanned umbilical vein.

Access to the peroneal artery as well as to the anterior tibial artery can be accomplished by a lateral approach with fibular resection. The technic is described as well as the use of the glutaraldehyde-tanned human umbilical cord vein as a vascular prosthesis. The results using the latter have been extremely gratifying.

Arterial Reconstruction with a Modified Collagen Tube: A Clinical Experience

Twenty-one modified bovine grafts were implanted in a variety of arterial reconstructions. Successful clinical results were obtained in 60% of the survivors. Attention is directed, however, to the problems of difficulty in reexplorations, the lack of elasticity, and aneurysm development indigenous to the bovine graft. One infection in this series required graft removal and extra-anatomic bypass. The modified bovine graft represents a major advance in vascular reconstruction, but should not be accepted as the ideal arterial prosthesis.

Clinical and Morphologic Assessment of Long-Term Human Umbilical Cord Vein Implants Employed as Vascular Conduits

Clinical experience employing glutaraldehyde-stabilized human umbilical cord veins as vascular prostheses for popliteal, tibial, and peroneal recon structions continues to show promise and remarkable morphologic stability for periods exceeding 4 years. Cumulative graft patency rates are similar to those achieved with autologous saphenous vein. Angiographic studies as well as analysis of explant specimens by microscopy and biophysical techniques demonstrate the durability of these protheses. Although some changes do occur, such as lipid imbibition, these may reflect the metabolic status of the host more than the graft itself.