Saphenous Vessels Research Articles

Medial saphenous fasciocutaneous and myocutaneous free flap transfer in eight dogs.

Skin defects on the distal extremity (n = 7) or face (n = 1) of eight dogs were repaired using a medial saphenous fasciocutaneous or myocutaneous flap. The cause of the wounds were ablative oncological surgery (n = 4), trauma (n = 3), or radiation burn (n = 1). The flap was removed from the medial femorotibial region, and transferred to the wound bed. The vascular supply to the flap was reestablished via microvascular anastomosis of the medial saphenous vessels of the flap to recipient vessels isolated adjacent to the wound. Three flaps incorporated the distal half of the caudal head of the sartorius muscle to form a myocutaneous free flap. All flaps survived completely. The medial saphenous fasciocutaneous and myocutaneous free flaps were found to be reliable and cosmetically acceptable for repair of skin defects in dogs.

Prevascularized bone graft cultured in sintered porous β-Ca 2P 2O 7 with 5 wt% Na 4P 2O 7·10H 2O addition ceramic chamber

Autogenous bone transfer is an important part of reconstructive plastic surgery. Presently available techniques have the disadvantages of limitation of available donor site, loss of donor tissue and the possibility of donor defect or deformity. In the present study, a vascularized bone graft was created and cultured in the groin area of the New Zealand rabbit. The cylindrical ceramic chambers, 15mm in length, 6mm in outer diameter and 3mm in inner diameter, were prepared by the addition of sintered porous β-Ca 2P 2O 7 with 5 wt% Na 4P 2O 7-10H 2O. In the first group, the chambers impregnated with autogenous bone fragments and allogenous demineralized bone matrix with volume ratio 1:1 were cultured in the rabbit's groin area with saphenous vessels passing through. In the second group, the chambers were treated by the same procedures as the first group but without saphenous vessels passing through. In the third group, the chambers were not impregnated, and were cultured in the groin area with saphenous vessels. After 2, 4, 6, 8 and 12 wk of operation, the animals were killed with an overdose of intravenous pentobarbital. The viability of the osseous tissue in the chamber was evaluated by histological examination, microangiograms and fluorochrome incorporation for the three groups. The autogenous bone chips could survive and retain their osteogenic properties while packed into the sintered porous β-Ca 2P 2O 7 (with 5 wt% Na 4P 2O 7 · 10H 2O addition) ceramic chamber and implanted in the rabbit groin area up to 12 wk. However, even at the longest time periods, considerable amounts of dead bone were present in the chambers. In addition, we observed bone resorption in the three groups up to 12 wk, which might be attributed to lack of physiological stress. There were significant differences in new bone formation and osseous cell viability among the three groups. The prevascularized vessels and autogenous bone chips were both necessary for the formation of new bone and osteogenic property in the chamber under these heterotopic circumstances. The biodegradable ceramic used in this study was gradually absorbed and dissolved in the physiological environment. However, the degradation debris of the ceramic caused no injury to the new bone formation. These findings support the concept of creating a preformed vascularized bone graft to reconstruct segmental bone defects.

The rat saphenous flap: a fasciocutaneous free flap model without panniculus carnosus.

The rat saphenous flap is described as a new experimental model for free flap studies. This is a fasciocutaneous free flap based on the saphenofemoral vascular pedicle. The flap may include the entire medial aspect of the lower leg between the knee and ankle. Thirty flaps were harvested from 15 inbred rats. Each flap was transferred to the anterior neck of a recipient rat of the same inbred strain so that 15 flaps were vascularized free flaps using the standard end-to-end microvascular technique and the other 15 flaps were nonvascularized free grafts. All but two (technical failure) of the vascularized flaps showed complete survival, whereas all nonvascularized flaps completely necrosed 2 weeks after transfer. It was concluded that the rat saphenous flap has several advantages such as a long and consistent vascular pedicle, ease of harvest, and an all-or-none survival pattern. Furthermore, as a unique feature of this flap, histological analysis revealed that the rat saphenous flap is composed of the skin and underlying fascia without panniculus carnosus. We therefore suggest that the rat saphenous flap is the first true fasciocutaneous free flap model in the rat. In this paper, in addition to illustrating the anatomy of the saphenous vessels and describing a new fasciocutaneous free flap model based on these vessels, we have documented some anatomical details of the rat leg that have never been described in the literature related to the rat anatomy.

Pre-formed vascularized bone grafts using polyethelyne chambers.

Previous work has shown that corticocancellous bone chips placed in a titanium chamber with an arteriovenous vascular pedicle will result in a pre-formed vascularized bone graft. The present study was designed to determine whether these grafts can be transferred as an island or free vascularized bone graft, and to examine the material properties of these grafts. Thirty-two male, New Zealand white rabbits were divided into four groups based on the time of sacrifice following the initial chamber implantation. Injected molded cylindrical polyethelyne chambers, measuring 22 mm long and with an 8-mm inner diameter, were used. Corticocancellous bone chips were placed in the chambers and each chamber was implanted in the mid-thigh, with saphenous vessels running through the chamber. The chambers were implanted into the right and left thigh of each animal. To test the hypothesis of the possibility of transferring this graft as an island or free vascularized graft, ligation of the distal vascular pedicle on one side was achieved at re-exploration at 3, 6, 9, and 12 weeks. The contralateral side served as a control in which the vascular pedicle was not ligated. In the controls, bony bridging between the corticocancellous bone chips was observed after 7 weeks. A solid bone graft was present within the chamber by 10 weeks. However, histomorphometric evaluation indicated significant bone resorption. By 13 weeks, resorption progressed to the point where only small islands of bone remained. Ligation of the distal vessels resulted in thrombosis of the vessels within the chamber. Necrosis of newly-formed bone was observed in the area adjacent to the vascular thrombosis.(ABSTRACT TRUNCATED AT 250 WORDS)

The isolated perfused equine skin flap. Preparation and metabolic parameters.

A model for the study of equine cutaneous physiology, pharmacology, and toxicology was developed. Four 4 x 12 cm and twenty-one 6 x 12 cm single-pedicle axial pattern skin flaps based on the caudal superficial epigastric artery, and eight 6 x 12 cm flaps based on the saphenous artery and medial saphenous vein, were raised and sutured in a tubed configuration. On day 2, each flap was removed, the artery was cannulated, and the flap was perfused with a modified Krebs-Ringer's albumin-based medium for at least 6 hours. Flap viability was assessed by glucose use, lactate production, and histologic examination at the end of the perfusion period. The 4 x 12 cm flaps had evidence of skin necrosis, but the 6 x 12 cm flaps remained histologically viable. Results were compared to those previously reported from perfusion of porcine skin flaps based on the caudal superficial epigastric artery. While the ratios of glucose use to lactate production were similar, equine flaps used less glucose and produced less lactate per gram of tissue than similar pig flaps. Equine skin flaps perfused by saphenous vessels used more glucose and produced more lactate than flaps perfused by caudal superficial epigastric vessels. These results indicate that conclusions drawn from cutaneous physiology studies should not be extrapolated across species lines and that site-specific skin should be used for cutaneous physiology, pharmacology, and toxicology studies. The identified skin flaps may have applications in equine reconstructive surgery.

Perivascular sympathectomy does not remove adrenergic nerves from distal vessels. The effect of various denervations on the rat saphenous bundle: A histochemical study

It has been claimed earlier that perivascular sympathectomy removes distal adrenergic innervation of the vessels. Based on preliminary results suggesting the contrary, the purpose of this work was to reconsider the denervation effect of perivascular sympathectomy. We operated on 40 rats using different denervation methods mainly to test the effects of perivascular sympathectomy on the distal saphenous vessels of the leg. The operations were performed on the right leg, while the left leg was used as a control. Samples were taken 2 days after the operations for glyoxylic acid-induced fluorescence examination for the histochemical demonstration of adrenergic nerves. Perivascular sympathectomy seemed to remove the adrenergic innervation only from the operated segment of the vessel. There was a short segment of diminished innervation a few millimeters in length just distal to the perivascular sympathectomy while the more distal adrenergic nerves around the vessels appeared to be normal. When the saphenous nerve was cut the adrenergic innervation seemed to disappear for 1 cm and to continue to be diminished at the medial malleolus site. Lumbar sympathectomy did not seem to remove the distal adrenergic nerves around the vessels, but caused only a slight decrease in innervation. It can be concluded that the peripheral adrenergic innervation is apparently normal after perivascular sympathectomy and that the operation does not have the previously assumed denervation effects.

Perivascular Sympathectomy of the Metacarpal Artery of the Rabbit Paw Fails to Remove Distal Adrenergic Innervation

Though vasospastic disorders of the hand are commonly treated by perivascular sympathectomy, which is believed to remove distal adrenergic innervation, our earlier experimental studies with rat saphenous vessels and rabbit ear vessels gave the opposite results. We therefore operated on 12 rabbits, carrying out perivascular sympathectomy of a metacarpal artery in the left forepaw, the right paw serving as a control. Six rabbits were killed after one week and the other six after three weeks, and the adrenergic nerves were examined by glyoxylic acid-induced fluorescence. Adrenergic innervation seemed to be normal in the distal vasculature after perivascular sympathectomy, and seemed to be missing only from the site of the operation.

Transportation of Immunosuppressive Substances Produced at the Site of Burn Injury Into the Systemic Circulation: The Role of Lymphatics

Serum of patients with severe burns has the ability to suppress mitogen-induced lymphocyte proliferation. Edema fluid collected from the site of injury during resuscitation and at the time of fascial excision has also been shown to suppress this response. An animal model was designed to identify the onset time of the formation of suppressive factors, their potential site(s) of origin, and their route of entry into the systemic circulation. Femoral artery, saphenous vein, and lateral saphenous lymphatic vessels were cannulated in an anesthetized dog. Baseline samples were collected, the hind paw was subjected to scald injury, and samples were collected serially for up to 6 hours after burn injury. Tissue fluid beneath the scald injury was harvested at the end of the experiments. In the absence of significant serologic evidence for inhibition, lymph and tissue fluid exhibited early and prolonged suppression of mitogen-induced lymphocyte proliferation. We concluded that edema fluid capable of cell-mediated immune suppression forms early after thermal injury and that lymph generated from the site of burn injury is immunosuppressive.

A new experimental model of lymphedema in rats' hind lower legs

In this study, a simple and reliable experimental model for lymphedema is described. In the middle portion of albino rats' hind lower leg, leaving the saphenous vessels and the accompanying lymphatics intact, all other soft tissues are incised circularly. After retraction of the cut ends of muscles, the skin edge of the ventral side is sutured to that of the dorsal side to envelope the muscles of both cut ends and the saphenous vessels and lymphatics. Resection of lymphatics or circular strip of soft tissues is not performed. In 48 of 50 rats' legs, measurements were made of leg circumference and the diameter of the lymphatics; in addition changes of lymphatic contractility were observed. These measurements, observations and histopathological studies showed a consistent picture of lymphedema. The clinical implication of this observation is that a small number of lymphaticovenous anastomoses will not correct lymphedema and that the quality of the results will correlate with the number of anastomoses. In studying the findings of experimental lymphedema, some other clinical phenomena are explained and modifications of the operative procedure of microlymphaticovenous anastomosis for treating lymphedema are suggested.

Reverse flow saphenous island flap in the patient with below-knee amputation

Three reverse flow island flaps based on the saphenous vessels were successfully transferred. The reverse flow saphenous island flap is harvested on the medial aspect of the lower half of the thigh. This flap is reliable, it can cover the knee and upper half of the leg and is most effective when covering the stump in through-knee or below-knee amputations.

Molded Vascularized Osteoneogenesis

The clinical application of free vascularized bone grafting techniques in reconstructive surgery has limitations with respect to available donor sites and configuration of the graft. In this study, we were able to produce a vascularized bone graft with a predetermined size and shape by the use of titanium chambers implanted into the groins of rabbits. Forty adult New Zealand white rabbits were included in this study. In all animals, bone fragments were harvested from the iliac crests and placed within a titanium chamber. The chamber was positioned in the groin with the saphenous vessels passing through the chamber longitudinally in contact with the bony fragments. In half the animals, a segment of periosteum was harvested from the tibia and sutured around the vessels with the cambium layer facing the bone fragments. Sacrifices were performed at 4, 8, 12, and 16 weeks to examine the chamber contents. At all time periods, the contents completely filled the chamber, and the saphenous vessels remained patent. Histologic evaluation showed remodeling of the bone fragments as early as 4 weeks concomitant with a sprouting vascular network demonstrable with microangiography. Fluorochrome bone labels documented new bone formation within the chamber. These changes were progressive to week 12, but the 16-week specimens appeared to be undergoing resorption.

Pedicle Graft Epiphysis Transplantation

Transfer of a graft taken from the iliac crest apophysis of 48 immature dogs was studied as a means of repairing an epiphysiodesis constituting more than 50% of the growth plate area. Four groups of dogs were studied. In Group I the graft was pedicled on the superficial circumflex iliac vessels and reimplanted in situ. In Group II the pedicled graft was transferred to the groin area as an island graft. These two control groups demonstrate the conservation of growth activity when the graft is pedicled on its epiphyseal vessels. In Group III the graft was transferred to the distal epiphyseal area of the femur after resection of the portion of the growth plate (approximately 2/3) located inside the perichondrial ring, with conservation of 80% of the outer portion of the cylinder. Microsurgical revascularization was achieved by using the saphenous vessels. In Group IV (the control group for Group III) the latter technique was used without revascularization. Roentgenography was performed for nine months after operation. The specimens were studied by tetracycline labeling and histologic and histochemical examinations. Results indicate that a well vascularized graft functions as a dynamic catalyst for regeneration of the resected portion of the growth plate and prevents the formation of bony bridges between the epiphysis and metaphysis by possible activation of the peripheral groove of Ranvier.

Perfusion of Isolated Dog Skin

Perfusion of Isolated Dog Skin