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Obstructive lymphoedema, an accumulation of protein-rich fluid in interstitial spaces, was created in five dogs by a combination of the irradiation of one groin and subsequent surgical ablation of any remaining lymphatics. The lymphoedema was stable for up to 2 years. The aim was to test the efficacy of intra-arterial injection of autologous lymphocytes as a therapy for lymphoedema. The hypothesis was that cytokines produced by lymphocytes mediate proteolysis by macrophage proteinases in the lymphoedematous limb to remove the excess protein and relieve the oedema. A concentrated lymphocyte-rich preparation was isolated from blood by the Ficoll-Paque method. These preparations were injected into the femoral artery four times at approximately 4 weekly intervals. Three months after the first injection of lymphocytes, lymphoedematous limbs showed a marked 69% reduction in the mean excess circumferences compared with opposite control limbs. After treatment, skin thickness and hydroxyproline content (both measures of fibrosis) as well as water content (a measure of oedema) had reduced significantly. In specimens of interstitial fluid and in skin homogenates acidic proteinase activity increased and the protein concentration decreased significantly compared with controls. It is concluded that increased proteolysis, possibly due to activated macrophages recruited to the lymphoedematous limb, may partly explain these results.

Multi-digit hand injuries require assessment of possible methods of repair and consideration of long-term function to determine the most appropriate management for the individual patient. A case is presented in which an amputated non-replantable digit was used as a source of a free flap to cover a large defect on another injured digit.

The harmful effects of ischaemia or skin flaps were modified using the thromboxane synthetase inhibitor UK-38,485. The epigastric island flaps of Sprague-Dawley rats (n = 288) were subjected to 10, 12 or 14 h of total pedicle occlusion, or 3, 5 or 7 h of venous occlusion of the sole vascular pedicle. Within each time period, rats received intravenous doses of either physiological saline (controls) or UK-38,485 at the beginning or end of the ischaemic episode. Flaps treated with UK-38,485 overall had a higher survival rate than control ischaemic flaps (P less than 0.001). This applied both to total (arterial) ischaemia (P less than 0.001) and partial (venous) ischaemia (P less than 0.01). There was no significant difference between treatment given at the beginning or at the end of the ischaemic episode. These results may be explained by reduced platelet aggregation and thrombosis in the microvasculature due to the lower thromboxane/prostacyclin ratios for treated flaps. The possible inter-relationship of the prostanoids with free radical mechanisms in the no-reflow phenomenon is also discussed.

An evaluation of the effect of ischaemia upon the intraluminal pH of microvascular free jejunal autografts was undertaken with a view to developing a monitoring system to be used clinically. Employing a canine model, the intraluminal pH of isolated jejunal segments was measured during normal perfusion and under conditions of arterial and venous occlusion. Ischaemia induced a rapid, easily measured fall in intraluminal pH reversible after 1 h of normothermic ischaemia. The most rapid pH change occurred within the first 10 min. It is felt that continuous intraluminal pH measurement may form a reliable method of monitoring the postoperative vascular perfusion of clinical free jejunal transfers.

Histopathological studies are described on 30 biopsy specimens of lymphaticovenous anastomoses ranging from two days to eight months following operation. Sixteen were patent and 14 were occluded. It was observed that in the non-patent specimens occlusion stemmed from the venous component. The prime determining factor in the success of the anastomosis was the achievement of correct apposition of the cut edges of the vessels, and this was directly dependent on the number and spacing of the sutures as well as the tension applied at their insertion. Correct apposition is more easily achieved with these delicate thin-walled vessels by better visualization afforded by the use of the operating microscope and appropriate instrumentation. The slow rate of repair in this situation is emphasized.

Five centimetres long segments of 3 mm internal diameter synthetic expanded polytetrafluorethylene (E-PTFE) vascular graft (Gore-Tex) were implanted into the femoral arteries, proximal to the origin of the saphenous artery, of 10 mongrel dogs. In five cases saphenous island flaps were raised and the femoral artery was ligated distal to the saphenous origin so that a low flow system was created through the graft. In 10 femoral vessels the Gore-Tex graft was inserted without raising a flap and the distal femoral artery not ligated so that the graft acted purely as a conduit for blood flow to the distal limb. This created a high flow rate model compared to the reduced flow in the former group. In the first group flap survival was evaluated daily by direct observation of the flaps and graft patency was assessed every 48 h by means of Doppler ultrasound. None of these flaps survived longer then 48 h. In the second group, graft patency was monitored every 48 h with Doppler ultrasound and exploration of Gore-Tex grafts at 3 weeks showed that all had thrombosed.

Twenty-four thumb mutilations have been repaired by using either whole toe transfers or portions of the big toe for reconstruction. The hallux has many of the properties uniquely suitable for thumb reconstruction. Its total sacrifice, however, leaves a significant defect in the foot, and it is usually too big to look convincing as a thumb. Essential portions of it can be transferred without undue deformity in the foot, and these, in combination with an iliac crest bone graft, can be modelled into a most aesthetic and functional thumb.

Thirteen microvascular free tissue transfers have been used for reconstruction of defects in the head and neck following cancer ablation. These procedures have produced a more rapid repair than conventional techniques and have allowed use of more appropriate tissues than are available locally.

Microsurgical revascularization in the neck has improved the survival rate of free small-bowel grafts used to replace the cervical oesophagus. Colon vessels are larger than those in the jejunum, and even with naked-eye technique good results have been reported following free colon grafting of the oesophagus. The authors thought it might be possible to achieve even better results using microvascular anastomoses in the neck, and in this way replaced the cervical oesophagus in each of 15 dogs with a free transverse colon autotransplant. Four dogs died during operation and four within three days, two of the latter with graft necrosis. The next seven dogs survived eight days or more, and all their colon grafts were viable. Where patent arteries were demonstrated (three cases) the mucosa and myenteric plexuses of the graft survived. In all four dogs where the arteries were thrombosed or not demonstrated, the mucosa was absent, myenteric plexuses were absent in three, and one graft was grossly stenosed. Among these seven dogs there were three fistulae, one where graft arteries were patent and two where they were not; immediate anastomotic healing was not guaranteed by graft survival or arterial patency.

The purpose of this study was to elucidate tissue changes occurring within an ischaemic flap by monitoring the blood biochemistry, and to evaluate these changes in relation to ultimate flap viability. A rabbit epigastric free flap was made ischaemic for 4 days at 6 degrees C, then revascularized by anastomosis of its femoral artery and vein. An identical free flap immediately revascularized in another group of rabbits served as a control. The viability of the free flap, as well as various biochemical parameters studied by drawing blood from a catheter in the ear vein, were observed daily. Immediately after the revascularization of ischaemic flaps, there was a 16-fold increase in the plasma levels of creatine kinase (CK) and a smaller but significant 1.5-fold to 2.0-fold increase in lactate dehydrogenase (LDH) and aspartate aminotransferase (AST). In flaps which ultimately failed by 7 days post-ischaemia, the plasma levels of CK, LDH and AST peaked at day 2 post-ischaemia at 68, 13 and 8 times normal respectively, whereas in flaps which survived, the levels of these enzymes recovered to normal by day 3 post-ischaemia. These enzymic changes are probably due to a combination of ischaemic changes in the flap vasculature, ischaemic changes in the flap muscle, and inflammatory changes in the surrounding abdominal tissue. The plasma levels of CK at any time post-ischaemia, and particularly in the first 24 h, were significantly higher in ischaemic flaps which failed compared with those which survived. This parameter is therefore proposed as a possible means of predicting potential flap failure after ischaemic insult, in time to make appropriate surgical intervention.

An analysis of the first 130 cases of digital revascularization and replantation performed at St Vincent's Hospital, Melbourne, during the period 1970-1977, confirms the long-term functional value of these procedures provided that strict indications for replantation are adhered to. Patient satisfaction has been almost universal, and objective testing shows that the most satisfying aspect of the procedure is the quality of sensory return. Flexor tendon function and the range of joint movement, however, are universally poor, and all patients complain of sensitivity to cold. The thumb has been by far the most satisfactory digit to replant, and avulsion injuries gave the poorest results, from the point of view of both survival and long-term function.

In this series of 35 clinical cases, the versatility of the latissimus dorsal flap is demonstrated. Whilst its width is limited to approximately 10 cm to gain primary closure, its length extends from the axilla almost to the iliac crest. If a larger area of soft tissue cover is required, muscle only may be used covered with a split skin graft. Its safe rapid dissection, reliable blood supply and wide arc of rotation makes it suitable for many of the reconstructive needs in the trunk, head and neck. Its large vascular pedicle makes it particularly suitable for free flap transfer. The commonest indication for use of the flap has been reconstruction of the breast following radical surgery. The secondary morbidity at the donor site is negligible.

The microsurgical techniques used and the results achieved in a series of 27 patients submitted for fallopian tube repair are presented, the majority following elective sterilization.

Obstructive coronary artery disease is in many patients a disease of the proximal arteries. Saphenous vein bypass grafts have been satisfactorily performed into vessels of diameters of 2.5 mm and above. A certain proportion of patients exist, however, in whom the only vessels available for grafting are of diameters of less than 2 mm. The purpose of this study was to test the feasibility of performing internal mammary to coronary artery anastomosis in the dog in vessels of diameters of 1-2 mm, using the operating microscope The study indicates that it is technically possible to perform these anastomoses with an acceptable immediate patency rate.