The effects of 5-fluorouracil on flexor tendon healing by using a biodegradable gelatin, slow releasing system: experimental study in a hen model.

This study investigated the effects of 5-fluorouracil in a slow-release biodegradable gelatin system on tendon healing. Gelatin blocks prepared in a size of 10 × 20 × 1 mm were loaded with 10, 20, and 30 mg of 5-fluorouracil, and 30 adult white Leghorn chickens were used. The tendons to the third and fourth toes were severed and repaired. The extremities were casted for three weeks. After sacrifice, the tendons were examined histologically and biomechanically for adhesion formation. The 10 mg-loaded gelatin group showed a decrease in adhesion formation when compared with the operative control group; the 20 and 30 mg groups showed signs of severe inflammation. Low doses of 5-fluorouracil applied via a slow-release gelatin system reduced adhesion formation in flexor tendon healing.

Correlation between the dermatoscopic and histopathological features of pigmented basal cell carcinoma.

BACKGROUND: Dermatoscopy has a great value in the diagnosis of pigmented basal cell carcinoma (BCC), which is a clinical variant of BCC. The precise definitions of histopathological correlates of dermatoscopic features observed in pigmented BCC have not been established yet. OBJECTIVE: The present study aimed to investigate the correlation between the dermatoscopic features of pigmented BCC and their histopathological counterparts to provide clear histopathological definitions of each dermatoscopic feature. METHODS: In this case series that comprised a methodological component, after the orientation of dermatoscopic features was determined by placing sutures in the lesions, the histopathological counterparts of each were examined and definitions were made accordingly. RESULTS: Although the most common histopathological subtype of BCC is the solid type, the most common histopathological subtype observed in the pigmented BCC lesions in the present study was the superficial multifocal type (72.5%). Blue-whitish veil was observed in 57.5% (n=23) of the lesions, a percentage higher than that reported in the literature. In addition to confirming the previously histopathologically defined dermatoscopic features of pigmented BCC, we identified three histopathologically undefined features of pigmented BCC that are spoke-wheel areas, large blue-grey ovoid nests and multiple blue-grey globules. CONCLUSION: Dermatoscopy facilitates prediction of the corresponding histopathological findings in pigmented BCC, based on specific dermatoscopic features.

Long-term effects of extraluminal dilatation with a rigid circle on arteriovenous anastomotic line in venous grafts transposed into arterial defects.

Postanastomotic narrowing resulting from subintimal hyperplasia is a well-known phenomenon. In the current study the authors compared a metallic circle and conventional suture technique in anastomoses performed in two ends of external jugular vein grafts interposed in carotid arteries of rabbits. They recorded the patency rates, fluid flow rates, and histological effects of the circle on the anastomotic line and compared them with conventional suture anastomoses. In 16 rabbits (experimental group) a standard suture was used in both ends of the jugular vein graft transposed to the carotid arteries on one side. On the other side, circle anastomoses were performed on both ends of the vein graft. In an additional 8 rabbits (control group), the anterior jugular veins and carotid arteries were dissected on both sides and left. During postoperative week 12, in 8 rabbits of the experimental group, the flow rates of carotid arteries were measured in vitro, and intraluminal silicone casts were prepared. In the remaining 8 experimental rabbits, carotid angiographies were performed and anastomotic segments were harvested for histological examination. Flow rates were also measured in the control group, and artery and vein segments were harvested. The patency rates of the vein grafts with metallic circle anastomoses were 100%, whereas conventional suture patency was 75% at week 12. Flow rates were significantly higher in the metallic circle-anastomosed vein grafts (74 ml per minute vs. 123 ml per minute, mean values; p < 0.05). Histological examination revealed reduced intimal thickness in the metallic circle anastomoses compared with conventional suture anastomoses. Dilatation of the arteriovenous end-to-end anastomotic line by a rigid circle prevents anastomotic narrowing in the long term.

A new flap model in rats: iliac osteomusculocutaneous flap.

Although osteomusculocutaneous flaps are used frequently in clinical practice to repair defects involving soft tissue and bone, there are still many questions that remain to be answered regarding their basic physiology. To accomplish such basic science studies, simple and reliable animal osteomusculocutaneous flap models are needed. The purpose of this study was to describe a new flap model in rats--namely, the iliac osteomusculocutaneous flap. Thirty adult Wistar rats weighing 200 to 250 g were used in this experiment. In 15 rats, the vascular anatomy of the iliolumbar vessels and their relation with adjacent soft tissues and the iliac bone was determined by anatomic dissection. Based on this anatomic study, the iliac osteomusculocutaneous flap model was created in rats. The flap is comprised of a skin island (3 x 3 cm) in the flank region, a 1 x 1-cm segment of iliac bone, and an abdominal wall muscle cuff. In 10 rats, the flap was raised as an island flap based on its vascular pedicle of iliolumbar vessels, and was replaced in situ. In the remaining 5 rats, the flap was transferred to the groin region as a free flap. Direct observation on postoperative day 7 revealed that the skin island of all the flaps was completely viable. Bone scintigraphy performed on postoperative day 3 in free flaps demonstrated radionuclide uptake, indicating viability of the bony segment. The dye injection study revealed ink staining within blood vessels of the bone, confirming its viability. Microangiography of the flap demonstrated vascularity of each component of the flap by the iliolumbar vessels, including a distinct branch to the iliac bone. The authors conclude that the iliac osteomusculocutaneous flap of the rat is a simple and reliable flap model that offers the following advantages: (1) It is a true osteomusculocutaneous flap, (2) it can be used as a free flap without the need for an isogeneic rat, (3) the vascular pedicle is consistent, and (4) it is harvested from a small-animal species.

End-to-side neurorrhaphies of the ulnar and median nerves at the wrist: report of two cases without sensory or motor improvement.

The authors present two unsuccessful clinical cases of end-to-side neurorrhaphy. In the first patient the distal median nerve was coapted in an end-to-side manner to the intact ulnar nerve. In the other patient four cables of sural nerve graft were used to bridge the ulnar nerve and the intact median nerve by two end-to-side coaptations. Neurorrhaphies were performed via epineural sutures through epineural windows. Both of the cases failed to demonstrate any signs of regeneration either clinically or as evidenced by electromyography, Semmes-Weinstein monofilament test, or 256-Hz vibration tests at 18 and 21 months' follow-up respectively.

Two new intramedullary implant designs for phalanx fixation in digital replantation: an experimental study.

Bone fixation in digital replantation must provide adequate rigidity, and must be applied in a fast and easy manner. Various fixation methods have been used so far with certain advantages and disadvantages. The authors report two new intramedullary proximal phalangeal implant designs to secure two amputated bone segments tightly. They compare their intramedullary implants with commonly applied K-wire fixation methods and plate fixation via biomechanical analysis in terms of bending rigidity and distraction strength. Their two-sided asymmetrical screw provided the highest rigidity and distraction strength, whereas the hook-trap system was nearly equal to cross-K-wire fixation. Intramedullary bone fixation may be a feasible method of bone fixation, and resorbable implant materials and different implant configurations deserve further investigation.

Crossover replantation and fillet flap coverage of the stump after ectopic implantation: a case of bilateral leg amputation.

A successful case of crossover replantation of the left foot to the stump of the right leg and temporary ectopic implantation of the right amputated foot on the forearm is described. The ectopically implanted right foot was used as a free fillet flap for the late reconstruction of the left leg stump. At the latest follow-up examination, 18 months after the accident, the patient was able to walk independently with a prosthesis on the stump of the left leg. Both the cross-replanted foot and the free filleted foot flap, used for the reconstruction of the left leg stump, have maintained adequate protective sensation. The importance of utilization of amputated parts for functional reconstruction is stressed. Crossover replantations and ectopic implantations should be considered in bilateral amputations for the salvage of at least one extremity.

End-to-side microvascular anastomosis using an external metal ring.

Enthusiasm for developing safer and faster anastomotic techniques and complementary devices continues. We report on a new microvascular end-to-side anastomosis technique using a silver ring around the anastomotic circumference. The purpose of this study was to compare the effectiveness of this technique with conventional end-to-side vessel anastomosis. Forty Sprague-Dawley rats were divided into two groups. Twenty rats were used to assess the external ring method in end-to-side anastomosis between carotid arteries and anterior jugular veins and the remaining 20 formed the control group with conventional end-to-end anastomosis. The anastomosis time was 26.4 min for standard suture anastomosis and 18.4 min for the external ring technique (P< 0.01). Patency was 95% with standard technique and 100% using the external ring (P> 0.05). The external ring technique of end-to-side microvascular anastomosis is a safe and reliable method and may reduce the operation time. Its clinical applicability should be further evaluated.

Comparison of immune response to nerve allograft segments in fetal and adult rabbits: a histological study.

Fetuses, as opposed to adults, are immature immunologically and it has been proved that they can tolerate allograft materials much better than adults. In this study the rejection phenomenon of nerve allografts was compared histologically in fetuses and adults. The study was performed in 60 New Zealand rabbits (30 pregnant and 30 nonpregnant), and allograft nerve segments were obtained from Chinchilla rabbits. The animals were divided into fetal and adult groups. Each group was studied at various time periods. Nerve allografts were placed under the panniculus carnosus in the interscapular region of the fetuses and adults. In both fetal and adult groups, the nerve allograft segments were assessed histologically after 1, 7, and 30 days. The criteria used during the evaluation were the degenerative findings in the myelinated axons (large, medium, and small axons), changes in Schwann's cells, and the quantity of infiltrating cells. The changes were graded microscopically from 0 (no change) to 3 (severe destruction and cellular infiltration). Cellular infiltration was more extensive in the adult groups than in the fetal groups. Earlier fetal groups showed minimal infiltration, but the response became more extensive in the later fetal groups. This is probably related to the removal of the fetuses from their intrauterine environment. When comparing fetal and adult groups, the results were significant (p < 0.05). The fetuses tolerated the nerve allograft segments better than the adults. This may be related to the immature immune system of the fetuses.

Intrasphenoidal migration of a premaxillary Kirschner wire.

OBJECTIVE: The use of Kirschner wire for the fixation of premaxilla is a well-known method in bilateral cleft lip surgery. We report a case in which the Kirschner wire of the premaxillary fixation had migrated intrasphenoidally. RESULTS AND CONCLUSIONS: The foreign body was accidentally discovered during a cephalometric analysis and was taken out surgically through an upper lip sulcus incision. Although the wire remained asymptomatic for 10 years, it constituted a potential danger for intracranial migration.