graft in the treatment of gangrene

Transcription

1 Annals of the Royal College of Surgeons of England (I974) vol 54 Use of the reversed saphenous vein graft in the treatment of gangrene R E Horton MBE MS FRCS Consultant Surgeon, United Bristol Hospitals Summary The use of the reversed long saphenous vein graft in the treatment of rest pain or gangrene of the lower limb is described. The essential features for primary success are the use of systemic heparin and a special suture technique designed to prevent the formation of an intimal flap. The long-term follow-up shows a high mortality from oncological disease and complications of atherosclerosis. Only 25% of subjects with patent grafts survive for 5 years. The grafts show thickening of the intima and collagenous replacement of the muscle within a few months. Introduction Nearly i8 years have passed since I first reported on the treatment of peripheral vascular disease by grafting at the meeting of the BMA in Toronto in At that time I only attempted to graft short occlusions in patients with otherwise reasonably healthy-looking arteries. The operation was confined to patients suffering from intermittent claudication as I considered that in those with gangrene the disease was too advanced. These grafts were homografts and they were inserted by an endto-end technique following excision of the occluded segment. The results were so poor that I did not feel justified in going on with the work. More than half the operations were initially unsuccessful and in those which were initially satisfactory about half the patients got recurrent intermittent claudication within a single year. In addition to the poor results of the operation I feared the possibility of rejection of the homografts. With degeneration of the media, extensive aneurysmal dilatation of some homografts which remained patent took place (Fig. i), and these had to be treated by ligation of the graft to prevent rupture. The introduction of the long saphenouis vein graft was a very important step forward. Although a number of surgeons had usedl pieces of vein from time to time, it was Robert Linton2'3 who firmly established the long saphenous vein as the ideal material for grafting in papers published in I955 and later in i962, when he reported 23 long saphenous vein grafts which had been followed up for 2-6 years without evidence of graft occlusion in any case. Most of the papers which have appeared concern the use of vein grafts in a mixed group of cases but predominantly in patients with intermittent claudication. In recent years I have attempted to treat all cases of gangrene with this operation. The present study is concerned with 58 long saphenous vein grafts performed on 53 patients during the past 8 years. The patients were all candidates for a major amputation Hunterian Lecture delivered on 8th November 1973

2 I66 R E Horton 'run-in' is vital, and in the absence of a strong femoral pulse a proximal operation must always be done as a primary procedure unless it i, possible to take the vein from the external iliac artery above the site of obstruction. FIG. I Aneurysmal dilatation of a homograft 6 years after its insertion. on account of rest pain, usually accompanied by gangrene. About 36% of the patients presenting for treatment were inoperable because of the lack of any distal vessel to which a graft could be joined, or occasionally because the vein was inadequate in size or absent following a stripping operation for varicose veins. But 64% of the patients were saved from a major amputation by a vein graft operation, although in patients with severe diabetes there was often considerable delay in lhealing even in a revascularized limb. The incidence of salvage is probably rising, and successful grafts to arteries below the popliteal give hope for improvement in the futiure. Primary failure has been practically eliminated as a result of technical developments. 'Run-off' is not so important a consideration in success as I used to think, but Indications All the patients were in need of amputation because of rest pain, with or without gangrene, if the circulation could not be restored. My experience with the treatment of intermittent claudication has been disappointing. Thrombosis of the graft or advancing disease in the arteries below the knee causes recurrence of symptoms. In cases of gangrene, on the other hand, the alternative to a successful graft is amputation. Even if the graft should subsequently thrombose or other circulatory deterioration occur, amputation is not always necessary, presumably because of the gradual development of additional collateral circulation; if amputation should be necessary following closure of a graft it may be delayed for a considerable time. The general condition of the patient is not particularly significant as a properly conducted graft is less shocking than a major amputation and blood loss is minimal. The ages of the patients treated ranged from 44 to 88 years. The man of 88 retained his leg after a successful graft and lived for another 3 years at home with the help of a housekeeper before dying from a heart attack at the age of 9I. There is considerable variation in the arteriographic appearances in cases of gangrene, which may depend on the rapiditv of the onset of the occlusion and the extent of the collateral circulation. John Hunter4 observed, '- but in general when large vessels are obliterated their office is vicariously performed by the enlargement of others which had previously existed'. Gangrene may occur

3 Use of the reversed saphenous vein graft in the treatment of gangrene 1:,:0'm ';9' ::;' d';.-.k'"'.:;:~ R:`i F,:; ca..;. +i>:,:i,:. ::Y:':':F':-;:;,: - ::..;.-:;::,:.:;,;:, FIG. 2 Illustrating the wide variety of grafts which have been used to meet varying circumstances. in a patient with comparatively healthy arteries and a single short femoral artery occlusion. More often a femoral occlusion is associated with a second occlusion of the arteries in the leg before gangrene occurs, and a single femoral artery occlusion generally gives rise to intermittent claudication or may even be symptomless. Planng the graft The bypass does not follow any predetermined plan but is decided in each individuial case. The two factors which require to be judged are the length of the occlusion and any severe adjacent disease, and the length of available vein. The vein may have been stripped or may be totally inadequate. If this is the case the operation must be abandoned. However, the vein is usually of adequate calibre for the length required to bypass the occlusion, although not necessarily for a routine graft from the common femoral to the distal popliteal artery, which I I67 consider quite unnecessary. It is important to keep the length of the graft to good-calibre vein. This eclectic approach has resulted in a great variety of graft operations (Fig. 2). However, nearly 6o% of the operations fell into two categories. One was from the common femoral artery to the proximal popliteal just beyond the adductor magnus. The other, which was slightly more commonlv performed, was from the superficial femoral to the distal popliteal artery under cover of the medial head of the gastrocnemius. The proximal anastomosis must be made to the femoral artery at a site where there is a strong pulse. When the femoral pulse is not present a proximal operation is usually needed, but it may be possible to attach a vein graft to the external iliac artery, as in a patient treated with a 45-cm graft from the external iliac artery, which was approached extraperitoneally, to the proximal popliteal artery (Fig. 3). The distal anastomosis has to be made to an artery of sufficient size below the occlusion. This is generally the popliteal artery, but in 2 cases the distal anastomosis was made to the posterior tibial, in one to the peroneal, and in one to the tibioperoneal trunk. In most cases 'run-off' was poor, and this must be accepted as usual when gangrene is present and is certainly not a contraindication to a graft. In fact, I believe that 'run-in' is more important than 'run-off'. Success cannot be assured if there is aortoiliac disease, and gangrene may even recur without occlusion of the graft if proximnal disease later develops. When the graft is Joined to a more

4 i68 R E Horton caused by the increased head of pressure in the isolated segment. A very wide range of arteriographic appearances may be associated with gangrene. Poor 'run-off' is not important, and a successful graft can be performed in cases which were once thought to be quite inoperable. Proximal as well as distal disease contributes to reduction of the flow to the foot, and this needs to be dealt with when it is present. - The operation So that the operation can be completed in FIG. 3 A 45-cm graft taken from the external iliac artery to the popliteal. The external iliac artery was approached extraperitoneally. or less isolated segment of popliteal artery (Fig. 4) the extra flow through the collateral branches is enough to enable a successful local amputation to be accomplished with primary healing. Linton5 also has observed that a successful graft could be performed in the presence of poor outflow provided an adequate inflow was present, and Koontz and Stansel' showed that distal arterial patency was not a significant factor in late failure. Manick et al.7, working in Boston, agreed that a graft to an isolated segment would remain open even when the initial flow rate FIG. 4 'Isolated' popliteal artery. A vein was very low. They attributed the later in- graft sutured to this caused sufficient increase crease in flow to the opening up of collaterals in circulation to avoid amputation.

5 Use of the reversed saphenous vein graft in the treatment of gangrene I 2-2 hours the work is divided between two surgeons, each with one assistant. In addition to shortening the time of the operation this technique affords useful supervised experience for a registrar or experienced senior house surgeon. The first step in the operation is removal of the saphenous vein graft, which I believe is best done through a longitudinal incision over it. The length of graft necessary may be judged from the arteriogram, but it is always wise to take considerably more than is expected to be necessary. The graft is then taken to a sterile trolley and inflated with saline to identify any leaks. When these have been secured it is left inflated with saline to overcome spasm in its wall. While this is being done the other surgeon is exposing the artery at the sites of the proposed anastomoses. Location and exposure of a site suitable for the proximal anastomosis does not present any problems and is judged from the arteriogram. The popliteal artery is accessible for an anastomosis in its proximal or distal part. Generally the lower end is healthier, but when atheroma is severe the artery must be explored until a piece suitable for an anastomosis is found. To isolate the proximal part of the popliteal artery the sartorius muscle is identified and retracted backwards, exposing the fascia of the popliteal fossa. If this is incised just below the adductor magnus the popliteal artery will be easily found, and this site is anatomically quite suitable for an anastomosis (Fig. 5a). The adductor magnus tendon should never be divided. It is unnecessary and may result in injury to large collaterals and the popliteal vein. If it is necessary to expose the distal end of the popliteal artery, the fascia is incised more distally and the sartorius, gracilis, and semitendinosus fully mobilized to their attachments. The key to the exposure is the division of the musculotendinous attachment I 69 of the medial head of the gastrocnemius (Fig. 5b). It is usually necessary to divide the tendon of the semimembranosus to gain access to this. Once the medial head is seen the index finger is inserted under its distal border to come out proximally in the popliteal fossa. The musculotendinous origin can then FIG. 5 Exposure of popliteal artery. (a) The sartorius muscle is retracted backwards and the underlying popliteal fascia incised distal to the attachment of the adductor magnus. (b) To expose the distal half of the popliteal artery it is necessary to divide the medial head of the gastrocnemius close to its origin.

6 170 R E Horton be divided with scissors and the blood vessels immediately come into full view. Selfretaining retractors are important as, with two surgeons vorking together, there is no room for additional assistants with retractors. Access to the posterior tibial or peroneal artery is gained by detaching the origin of the soleus muscle from the oblique line of the tibia. The incision extends from the tendinous tunnel through which the neurovascular bundle passes. When the dissection is completed and suitable sites for the anastomoses have been located the anaesthetist is asked to heparinize the patient. The dose given is 6,ooo-8,ooo units intravenously, according to the weight of the patient. The use of a small dose of dilute heparin below the distal clamp is equivalent to not using heparin at all. Suture technique (Fig. 6) Unless the anastomoses are too close they are completed synchronously. The most common cause of immediate thrombosis is undoubtedly the failure of a suture, particularly at the distal end, to take up and hold out the atheromatous intima, which will then dissect away and lift up as an occluding flap when the clamps are removed. For a time, some years ago, I eliminated this complication by the use of interrupted sutures, placing all the sutures correctly and then tying them as in a conservative resection of the rectum. However, this was somewhat time-consuming and the present technique is a compromise. The artery is incised for about I 2 mm and the vein bevelled to give a length which is marginally longer. A single suture of 5/o silk is then placed at each end and these are carefully tied. All sutures pass from within out on the arterial side so that the intima is not lifted by the needle. Attention is then given to one side of the anastomosis. It will be noted that there is a suture with an atraumatic needle at each end. If one of these is taken down to the other end as a continuous suture as in the standard technique it becomes impossible to see inside the artery for the last few sutures, and it is at this point that the suture may fail to pick up the intima, allowing it to form a flap. To overcome this difficulty 2 or 3 interrupted FIG. 6 Suture technique. Top. Key sutures inserted. Middle. Interrupted sutures inserted at one end and continuous suture brought from opposite end before tying interrupted sutures. Lower. Anastomosis complete. j r

7 Use of the reversed saphenous vein graft in the treatmenlt of gangrene ' 17 I suturcs are placed at the distal end and left sibility of gangrene of the second leg is a untied. The continuous suture is taken down telling indication for conservative surgery on to these interrupted sutures, which are then the first leg. tied and the continuous suture tied to the first interrupted suture. Cases with occluded popliteal artery When the popliteal artery is occluded it may be possible to use a more distal artery for the anastomosis. I have been able to do this on only 4 occasions. One patient had a graft from the femoral to the peroneal artery and a Syme's amputation. He remains well and wvorking to this day. Two patients had grafts joined to the posterior tibial artery (Fig. 7). One had a tarsal amputation which healed well, but she died from a coronary thrombosis 31 months later. A second with gangrene of a toe died of lung cancer within a year. The fourth patient, who had a graft joined to the tibioperoneal trunk, is alive and well wvith a patent graft nearly 5 years after the operation. Bilateral gangrene Bilateral amputation in an elderly patient is a disaster of the first magnitude. Ten of the patients seen (i 8%) were candidates for a bilateral amputation. Four had alrcady lost a limb at the level of the knee or higher. In one of these the amputation had followed an unsuccessful endarterectomy for gangrene. Each of these patients was extremely concerned about the likely loss, in their opinion, of the second leg, but in all but one it was saved by a long saphenous vein graft. Five patients have had successful grafts on each leg. In one other patient a graft done at the age of 85 was still functioning when he developed gangrene of the second leg at the age of 89. Unfortunately he was considered to be too old for further surgery and was not seen until the gangrene had reached above the malleoli. Nothing could be gained by a graft, FIG. 7 Arteriogram showing patent graft to and the second leg was amputated. The pos- posterior tibial artery. 0

8 1 72 R EA Hortonl Early thrombectomy It is obvious that once a plaque of atheroma so narrows the femoral artery that a thrombus forms, this will extend throughout the length of the artery with a poor flow and will stop where the flow is re-established by collateral vessels. Equally, if a patient is seen immediately after this has happened it should be possible to remove the propagated thrombus with a Fogarty catheter and greatly reduce the length of graft needed to overcome the atheromatous occlusion. Although theoretically possible, this has been a practical proposition in only one case. This was in a 66-year-old man who was admitted within 3 hours of the onset of acute ischaemia of the leg. It was already anaesthetic and paralysed and had the clinical appearance of having suffered an embolism at the femoral bifurcation. However, there was no obvious source for an embolus and an arteriogram showed almost complete occlusion at the level of the profunda femoris, with loose clot in the whole of the superficial femoral artery. The leg was explored and the obstruction found to be caused by a plaque of atheroma. Longitudinal arteriotomies were made above and below the plaque of atheroma, which could then be seen to be reducing the lumen to a chink less than i mm across. After extraction of thrombus from the artery distal to the occlusion with a Fogarty catheter a 5-cm saphenous graft vas used to join the arteriotomies. Had this patient not been treated urgently it seems likely he would have lost the leg. Had the circulation recovered sufficiently to save most of the leg he would have needed a graft from the common femoral to the popliteal artery. He remains well with a strong dorsalis pedis pulse 4 years later but has had a cardiac infarct. Immediate results There was no operative mortality. There were 2 primary failures resulting in Stokes-Gritti amputations. In one early case it was not possible to get a good flow of blood into the graft and it is clear in retrospect that I made an error of judgement and that attention should have been directed to the proximal arteries. In the second case failure was due to the fact that the graft was inadequate in the length necessary. The occlusion extended from the external iliac to the distal popliteal artery and the vein graft was too narrow in part of its length to carry an adequate flow of blood. A third patient was a woman of 65 who had a I 7-cm graft in I968. Initially the flow was satisfactory, but 48 hours later the limb became cold and painful. An arteriogram showed the graft to be patent but there was an obstruction at the lower anastomosis. Exploration showed that this was due to a small flap of intima which had escaped the continuous suture. After resuture the flow was restored and has remained satisfactory. This was an important case as it caused me to change to the technique which I have described, and this complication has not been seen again. In one other case a perfectly satisfactory graft thrombosed after 48 hours. Exploration showed that there was a thrombus at the proximal anastomosis. After the thrombus had been cleared an ellipse of artery wall was excised before the anastomosis was re-made. When the artery is particularly rigid this is an essential step if a slit-like anastomosis is to be avoided. About half the patients have suffered from some degree of oedema of the leg, but this has never been troublesome and usually disappears in 6-8 weeks. One patient was re-explored for continued bleeding. The source was found to be an artery in the muscle, which now had a good flow because it was below the level of the graft.

9 Use of the reversed saphenious vein graft in1 the treatmenit of gyanlgrene In a very obese woman a part of the skin flap became necrotic and had to be excised on the I2th day. The wound was resuttured without adverse effect on the graft or on the convalescence apart from about one week's delay. Late graft closure The problems of this work today do not very much concern the operation or anything immediately following it. Nearly all the difficulties come later. It is easy to say that a graft is patent if it can be felt pulsating. In the presence of a femoral pulse absence of graft pulsation has been considered to mean thrombosis of the graft. However, a saphenous vein graft lhas a strong tendency to remain patent, and in many patients it is by far the healthiest 'artery' they possess. In a patient who developed recurrent gangrene 5 years after a successful vein graft an aortogram showed a patent and healthy vein graft notwithstanding severe occlusive disease of the iliac arteries and aorta. It was possible to take a Dacron graft from the aorta and to suture it to the vein graft in the thigh (Fig. 8). The vein looked perfectly healthy at this time, 5 years after its insertion, and no diffictulties were encountered in its dissection or in sutturing the Dacron graft to it. The Dacron and saphenous vein have remained patent for a further I8 months so far with complete relief of pain in the foot, and the dorsalis pedis pulse is easily palpable. Ten of the 58 grafts have closed during the period of follow-up. In 4 the closure was followed by recurrent gangrene requiring ampuitation, but in 2 others which closed after 3 years of patency the circulation was initially sufficient to retain a viable leg. However, with gradual deterioration an amputation was necessary in each case about 2 years later. In 4 cases the sequel of closure has been intermittent claudication rather than gangrene, presumably because of the development of an improved collateral circulation. Rather more of the closures were in grafts which crossed the knee joint, and it is often said that this is a factor leading to late closure. In this series the majority of the grafts crossed the knee, and in the presence of such variable and indefinable disease above and below the graft I wotuld not like to be dogmatic on this point. However, it is significant that 7 of tlle Io grafts closed within one year and the FIG. 8 Dacron graft taken from the aorta to a patent saphenous vein graft. Aortoiliac occlusion had developed 5 years after placement of graft but the saphenous vein graft remained patent.

10 174 R E Horton others much later-2 at about 3 years and one 5 years after the operation. Four patients living 7-8 years after the operation all have easily palpable grafts. It seems likely that technical imperfections causing a gradual build-up of thrombus is the cause of failuitc in the first year, and perhaps thrombus forming on a fibrosing anastomosis may account for later failure. De Weese and Rob8 also observed that graft closure was most likely to occur in the first year. In one patient who developed recurrent rest pain 4 years after a successful operation the vein graft could be felt pulsating strongly. I thought that he must have distal disease and that amputation would be necessary. However, a femoral arteriogram showed that there was narrowing of the graft at the distal anastomosis. This was explored and a small thrombus removed. The anastomosis was then seen to be slightly stenosed and it was widened with a cephalic vein patch with complete relief of symptoms. It was fortunate that I avoided using the opposite saphenous vein as I have recently had to use this to save his second leg. Histology Histological examination shows that there is replacement of the muscle of a graft by collagenous material. In addition to this change in the media there is thickening of the intima, and this was very marked in a biopsy specimen taken 5 years after insertion of a graft which was explored because of a localized thrombus. Grafts examined at 6 and 9 months already showed these changes. The grafts look macroscopically normal up to 7 years after insertion but microscopically shiow evidence of vascularization from outside in addition to the fibrous replacement of muscle and thickening of the intima. No dilatation or calcification, either localized or generalized, has been observed. A graft which had remained patent for 3 years and was then thrombosed for 2 years before it was examined following an amputation showed changes identical with those seen in a patent graft. The continued viability of the graft which is thrombosed is good evidence that it receives a blood supply from the outside. Late results Clearly the operation is palliative and is a local operation on a patient with generalized disease. Also the age group is susceptible to malignant disease and in the follow-up one patient has died of lung cancer and one from carcinoma of the prostate. A third unfortuinate patient survived radiotherapy for carcinoma of the larynx but 21 years later was found to have an inoperable carcinoma of the stomach from which he died nearly 3 years after the vein graft. De Weese and Rob8 observed that diabetic patients had a worse prognosis and in this series the subsequent mortality in diabetics was double that in the non-diabetics. In addition to cardiovascular accidents there were 2 deaths from uraemia in diabetics. The subsequent course was also less easy, and minor trauma in a severe diabetic was liable to be followed by infection and necrosis in the foot in spite of revascularization. Only a quarter of those with patent grafts have survived for 5 years and although a few have lived for 7 or 8 years with patent grafts, I think this must be accepted as exceptional. The fault does not lie with the graft but with the rest of the patient. Three have died from malignant disease, 2 from uraemia complicating diabetes, and the rest from cardiovascular accidents-mainly cardiac infarcts. One may well question whether this surgery is worth while, as I did in I955. The results so far as survival is concerned are, however, quite comparable with much other surgical

11 Use of the reversed saphenous vein graft in the treatment of gangrene 175 work. The South-West Regional Cancer Bureau report a 5-year survival of 34%/0 after resection of cancer of the rectum and i2% after gastrectomy for cancer, so that the results of vascular surgery for gangrene giving a 25% 5-year survival are quite comparable. But one must think not only of survival but of the quality of life, and a man who keeps his leg after a successful vein graft operation is able to lead a comparatively normal life, unlike the elderly amputee who is considerably disabled and lives in dread of losing his other leg. Conclusion I began by referring to my lecture in Toronto in I955. I said this was my first communication on the subject and in fact it was also my last. It has taken nearly 20 years before I felt I was able to make any further contribution. However, I can now say that the technical problems have been largely overcome, that primary failure is virtually unknown so long as there is a good inflow from above, and also that there is no operative mortality. Atherosclerosis remains a progressive and, at present, uncontrollable disease. So it is not surprising that patients die from other manifestations such as coronary thrombosis and also, because of the age group, from oncological diseases and that these two causes together give rise to a considerable mortality. Nevertheless, there is substantial palliation. On the whole a graft which remains patent for a year is likely to remain so until the patient's death, and generally a patient who has a long saphenous graft will die with his legs on. I should like to express my thanks to so many people: to my secretaries, to ward and theatre nurses and sisters, and to many registrars who have helped with the operations. But particularly I should like to express my thanks to Lord Brock and to Professor Milnes Walker, who introduced me to the techniques of vascular surgery and stimulated m' interest in the problems. References I Horton, R E (1956) British Medical Journal, I, 8i. 2 Linton, R R (1955) Surgery 38, Linton, R R, and Darling, R C (i962) Surgery, 5i, Hunter, J (I 835) The Works of John Hunter FRS, Vol. 3, p. 53I. London. 5 Linton, R R (1970) Surgery, 67, Koontz, T J, and Stansel, H C (1972) Surgery, 71, Mannick, J A, Jackson, T, Coffman, J D, and Hume, D M (I967) Surgery, 6i, DeWeese, J A, and Rob, C G (I97I) Annals of Surgery, 174, 346.