New end-to-end microvascular anastomosis with geometrically adaptable ends technique: an experimental study on rats.

OBJECTIVE: The aim of this study was to develop an effective arterial anastomosis model with a high patency rate and low operation time. We introduced a new end-to-end microvascular anastomosis with geometrically adaptable ends. METHODOLOGY: In this technique, two triangular flaps were prepared at the end of the vessels and four stitches applied on the tip of those flaps. During this study, 15 new technique anastomoses were compared to 15 conventional 8 stitches anastomoses in 30 rat femoral arteries. Operating time, patency rates and number of stitches with consequential effects on the vessel wall were analyzed statistically. The anastomotic patency of both groups was assessed by: (1) in vivo observation using the milking test under the operating microscope and (2) flow study using laser Doppler ultrasound. Healing was assessed by the light and electron microscopy. RESULTS: According to statistical results and compared to the conventional method, the new technique was associated with a significant time savings (mean 18 vs 26 minutes, p < 0.001). The patency rates were equivalent to the conventional technique by observation and laser Doppler ultrasound (p > 0.05). Histological evaluation of both techniques showed that rats operated with the new technique healed faster and with less endothelial damage. CONCLUSIONS: This new "Geometrically Adaptable Ends Technique" is faster, easier to perform and a reliable method with patency and flow characteristics similar to those of the conventional end-to-end anastomoses (Fig. 7, Ref. 20).

Effects of polyglycolic acid bioabsorbable membrane and oxidised cellulose on the osteogenesis in bone defects: an experimental study.

BACKGROUND: The purpose of the present study was to determine the effects of polyglycolic acid bioabsorbable membrane and oxidised cellulose on the osteogenesis in bone defects. MATERIALS AND METHODS: Fifty-four male adult New Zealand White rabbits weighing 3.0 to 3.5 kg were used. The rabbits were randomly divided into three groups of eighteen rabbits: the control group (n = 18), the polyglycolic acid bioabsorbable membrane group (biofix group, n = 18), and the oxidised cellulose group (Surgicel group, n = 18). Each experimental group was also randomly subdivided into two subgroups of nine rabbits, one with periosteum and the other without periosteum. A rectangular transosseous calvarial bone defect, 16 x 20 mm in size, was created. In the control group, the calvarial bone defect was not filled. Polyglycolic acid bioabsorbable membrane (Biofix, Bioscience, Tampere Finland) was implanted over the bone defect area in the biofix group, and oxidised cellulose (Surgicel, Ethicone, London, United Kingdom) in the Surgicel group. The calvarial bone defects were evaluated-histopathologically in the second, sixth, and tenth weeks. RESULTS: As for the results of sequential bone regeneration, macroscopical and histological aspects were observed. Bone formation was significantly enhanced by oxidised cellulose in the calvarial bone defects covered with periosteum, whereas cartilage formation was observed in bare calvarial bone defects. CONCLUSION: We believe that oxidised cellulose has osteogenic potential, and that polyglycolic acid bioabsorbable membrane inhibits osteoinductive effect and retards osteogenesis.

Viability of diced, crushed cartilage grafts and the effects of Surgicel (oxidized regenerated cellulose) on cartilage grafts.

The viability of cartilage grafts has been well documented; however, controversy still exists about the viability of crushed cartilage. Recently, there has been a tendency to use diced cartilage grafts wrapped with oxidized regenerated cellulose (Surgicel) sheets for improving dorsal contour in rhinoplasty. The viability of diced cartilage grafts and the effect of Surgicel on cartilage grafts are not well known. In this study, we used ear cartilage from 18 New Zealand rabbits. Cartilage grafts were transplanted to surgically created subcutaneous pockets on the back of the rabbits on both the left and right sides. There were three groups: (1) intact cartilage grafts, (2) crushed cartilage grafts, and (3) diced cartilage grafts. The grafts that were transplanted to the right side were wrapped with Surgicel. Cartilage grafts in all groups were viable. In grafts that were wrapped with Surgicel, a marked increase in the collagen content was investigated. Grafts that were wrapped with Surgicel demonstrated no evidence of proliferation, whereas the bare cartilage grafts demonstrated significant amounts of proliferation.

The fate of neurotization techniques on reinnervation after denervation of the gastrocnemius muscle: an experimental study.

In nerve injuries, if it is not possible to reinnervate muscle by using neurorrhaphy and nerve grafting technique, reinnervation should be provided by the use of neuroization-directly implanting motor nerve into muscle. A comparative study of three techniques of neurotization is presented in rabbits. In this experimental study, a total of 40 white New Zealand rabbits were used and divided into four groups, each including 10 rabbits. In the first group (control--Group 1), only surgical exposure of the gastrocnemius muscle, main muscle nerve (tibial nerve), and peroneal nerve was done, without any injury to the nerves. In the second group (direct neurotization group--Group 2), the tibial nerve was transected, and the peroneal nerve, which had already been divided into fascicles, was implanted into the lateral head of the gastrocnemius muscle aneural zone. In the third group (dual neurotization group--Group 3), the tibial nerve which had been transected and re-anastomosed, and the peroneal nerve were implanted into the lateral head of the gastrocnemius muscle. In the last experimental group (hyperneurotization group--Group 4), fascicles of the peroneal nerve were implanted into the lateral head of the gastrocnemius, preserving the tibial nerve. Six months later, changes in the histologic pattern and the functional recovery of the gastrocnemius muscle were investigated. It was found that functional recovery was achieved in all neurotization groups. Groups with the tibial nerve transected had less muscular weights than those of groups with the tibial nerve intact. EMG recordings showed that polyphasic and late potentials were frequently seen in groups with the tibial nerve transected. Degeneration and regeneration of myofibrils was observed in such groups as well. New motor end-plates, including vesicles, were formed in a scattered manner in all neurotization groups. As a result, the authors conclude that direct and dual neurotization techniques are useful in peripheral nerve injuries, if it is not possible to reinnervate muscle by using neurorraphy and nerve grafting, and that there is no suggested superiority among these techniques.

Exposure of high-density porous polyethylene (Medpor) used for contour restoration and treatment.

Porous high-density polyethylene (Medpor) is a biocompatible large-pore, high-density polyethylene implant. It is well tolerated by surrounding tissue, and its porous structure is rapidly infiltrated by host tissue. It is a highly stable and somewhat flexible porous alloplast that has rapid tissue ingrowth into its pores. However, when the implant is placed under a thin cover of skin, there is a risk of exposure. A total of 52 Medpor implants were placed in 31 patients over a four-year period. The implants were used for the chin, malar area, nasal reconstruction, ear reconstruction, orbital reconstruction, and the correction of mandibular contour deformities. Many of these implants were placed in areas considered problematic, such as those with thin or atrophic soft-tissue coverage and extensive scarring. There were nine complications, including three patients in whom the implant was exposed; these are presented here.

Tissue engineering of high density porous polyethylene implant for three-dimensional reconstruction: an experimental study.

Three-dimensional defects have been reconstructed with carved and remodelled frameworks wrapped within vascular carriers. If sufficient vascular penetration can be established without any change in the size and shape of an implant, it will be possible to cover it with a skin graft and aesthetically important fine details can be obtained. To achieve this, we first prefabricated high-density porous polyethylene implant in rabbits. Secondly, we applied full-thickness skin grafts over the anterior surface of the prefabricated implant. The implants were placed and anchored underneath the superficial inferior epigastric artery and vein pedicle bilaterally. A total of 10 implants were prefabricated and then grafted in five rabbits. The implants were evaluated by perfusion scintigraphy and histological examination. Results showed that the implants were invaded by fibroneo-vascular tissue, and that this tissue, which can be transferred as a pedicled or a free flap, was sufficient to sustain a skin graft.

Island V-Y tensor fasciae latae fasciocutaneous flap for coverage of trochanteric pressure sores.

The distal fasciocutaneous portion of the lateral thigh is supplied by the direct cutaneous branch of the lateral descending branch of the lateral circumflex femoral artery and the third perforating artery of the deep femoral artery. This consistent vascular anatomy allows raising a distal skin island based on both arteries on the lateral thigh, and this flap can be advanced into a trochanteric defect according to the V-Y technique. Based on anatomic and clinical study, a new design has been developed of the tensor fasciae latae fasciocutaneous flap, which is supplied by two pedicles. Seven island V-Y tensor fasciae latae fasciocutaneous flaps have been used for the coverage of trochanteric pressure sores in six patients. It is believed that the island V-Y tensor fasciae latae fasciocutaneous flap could overcome the traditional drawbacks of the conventional tensor fasciae latae flap and its modifications, and this is an ideal flap for covering trochanteric pressure sores without any donor site deformity and morbidity, which greatly improves the aesthetic result.

The effects of L-arginine and iloprost on the viability of random skin flaps in rats.

The effects of an intravenous infusion of L-arginine as a physiological precursor of endothelium-derived relaxing factor/nitric oxide (EDRF/NO), iloprost (a stable prostacyclin (PGI2) analogue), and L-arginine combined with iloprost on skin viability were studied in 9 x 3 cm random pattern skin flaps in rats. Intravenous infusion of all drugs was started at the beginning of the operation and continued for 60 minutes. At the end of infusion period the depth of fluorescein dye penetration in the skin flap was assessed visually from photographic records, and the flap survival area was measured by the grid method at the seventh postoperative day. There was a significant reduction in distal necrosis of random skin flaps after intravenous infusion of L-arginine, iloprost, and L-arginine combined with iloprost (p < 0.01). Possible mechanisms that may be responsible for impairment of endothelium-dependent vasodilation and vasospasm in the microvasculature of random skin flap and their prevention with L-arginine and iloprost include restoration of the depleted stores of NO which in turn causes vasodilatation and has an antithrombotic effect.

Vaginal reconstruction with free jejunal flap.

Congenital absence of a vagina is a rare but outstanding anomaly of plastic surgery. Although many methods are described for reconstruction of vaginal agenesis, there is not a method yet to be approved as a perfect solution to this problem. With the aim of solving the problems faced with conventional methods, free jejunal transplantation was planned to construct a neovagina. For this method, we isolated a 15-cm jejunal segment, with its pedicle, transferred it to the preprepared vaginal pouch, and anastomosed the donor vessels of the mesentery to the inferior epigastric vessels. In the postoperative sixth month, problems of intercourse or the need to use any lubricator or stent were still not experienced and reported. In this paper, we judge and compare our approach by reviewing others.

Pilomatrixoma of the earlobe.

BACKGROUND: Pilomatrixoma most commonly occurs in the head and neck region, appearing primarily in the first two decades of life. The lesion is described as a tumor with differentiation toward hair cells and surgical excision is the treatment of choice. OBJECTIVE: We report an uncommon localization of a perforating type pilomatrixoma of 5 x 4 x 4 cm in size that developed from the earlobe. METHODS: Histopathological examination revealed pilomatrixoma. Total resection of the tumor was performed. The earlobe was reconstructed by forming a posterior-superior pedicled skin flap. RESULTS: No recurrence was observed and a good cosmetic result was obtained. CONCLUSION: Local recurrence does not generally occur if the tumor is completely removed. The case we present is of interest in having a history of trauma to the region and a relatively rapid growth with perforation of the overlying skin.

Applications of free scapular flap.

The scapular flap described by Saijo and dos Santos, presents some advantages such as a thin and hairless flap, large vessel diameters, and a long vascular pedicle with a constant anatomy. Furthermore, it provides combined use of skin and vascularized bone tissue from the scapula. Between the years 1988 and 1991, we have successfully used free scapular flaps for the reconstruction of various defects in twelve patients.

Prefabricated microvascular shoulder free flap for forehead reconstruction.

In a case with a large forehead defect following tight scalp bandaging in childhood, a prefabricated microvascular shoulder free flap was used for reconstruction. A free forearm fascial flap, with the radial artery and the concomitant vein as pedicle, was harvested and inserted under a subcutaneous pocket opened in the left shoulder region which served as the future "prefabricated free flap". In addition, a tissue expander was placed in this pocket to provide the necessary tissue expansion to enable primary donor site closure.

Hemimandibular reconstruction with bipedicled scapular osteocutaneous free flap.

A case report is presented on the successful use of a bipedicled scapular osteocutaneous free flap in a young woman, whose hemimandible was resected because of sarcoma, 1 year prior to presentation. The postoperative course was uneventful and donor site morbidity minimal.

Effects of free perichondrial graft replacement of epiphyseal cartilage on bone growth.

An experimental study in 24 lambs was carried out to find an alternative tissue for the distal epiphyseal cartilage of the femur. The animals were divided into three groups. In the first group (n = 12) the left femoral distal epiphyseal cartilage was completely removed and replaced by a free perichondrial graft taken from the distal half of the scapula. In the second group (n = 6) the epiphyseal cartilage was removed and was not replaced by any tissue. The third group (n = 6) was used as control. After six months the legs in the first and third groups were of the same normal length while the legs in the second group were significantly shorter. We conclude that free perichondrial graft seems to be able to replace the epiphyseal cartilage and prevent retardation of growth.

A new surgical approach in genital lymphedema.

A new surgical approach has been used in a case of genital lymphedema. After resection of the lymphedematous mass, U-shaped flaps were made from the suprapubic region anteriorly and the posterior scrotal skin posteriorly. The denuded penis was transposed to its original place by passing it through a buttonhole incision made on the anterior flap. The testicles were placed and fixed in pouches prepared between the anterior and posterior flaps. The patient had an acceptable postoperative outcome both in testicular function and habitual sexual activities.

The cartilaginous potential of the perichondrium in rabbit ear and rib. A comparative study in vivo and in vitro.

In an experimental study the cartilaginous protential of the rabbit ear perichondrium has been compared with that of the rib in vivo and in vitro. Perichondrium was transferred as free autologous grafts to the subcutaneous tissue on the scalp and as loose bodies into the knee joint. The presence of cartilage in the grafts was examined after six weeks. In vitro explants of rabbit perichondrium from the ear and the rib were maintained in an organ culture system. The presence of cartilage was analyzed after one to three weeks. Rabbit perichondrium from the rib appeared to have a greater cartilaginous potential than that from the ear both in vivo and in vitro. Chondrogenesis in perichondrium was demonstrated in vitro.