We performed this study to investigate the role of perivascular areolar tissue for the survival of single-ended venous flap using rat inferior epigastric pedicle. Five models of flap were studied ; Group A-flap based on an inferior epigastrie vien and areolar tissue ; Group B-flap with skeltonized vein ; Group C-flap based on an inferior epigastric artery and areolar tissue ; Grup D-flap with skeletonized artery ; Group E-flap based on perivascular areolar tissue alone. Each group included 40 flaps in 20 rats. Group A showed 25 totally survived flaps and 9 partially survived flaps, but other groups showed almost all necrotic flaps. Histological examination of the survived pedicle showed many small vascular channels around the inferior epigastric artery and vein. We belive that these vascular channels may play an important role for the survival of single-ended venous flap.

The proper management of parotid gland tumors demands through knowledge of the anatomy of the involved region, a good understanding of the histopathology of all types of parotid gland tumors. and a thorough. well-planned operative technique.

Author reviewed a total of 78 patients of parotid gland tumors who had been admitted and treated in Ewha Medical Center during the period from 1985 to 1990.

The following results were obtained.

1) Female was affected 1.52 times more than males, and the most frequent age group was 4th and 5th decades.

2) The most common tumor of the parotid gland was pleomorphic adenoma(begin mixed tumor) with the incidence of 87.2% of all parotid gland tumors.

3) The benign tumors had slightly longer than malignant tumors.

4) The most frequent type of surgery performed for all parotid gland tumors was superficial parotidectomy.

5) Postoperative complications included facial nerve palsy that was 33.3% of all parotid gland tumor surgery.

6) The recurrence rate was 2.6%.

This study examines the extent of endothelial damage following a period of irrigation with various crystalloid irrigation fluds. Both arteries and veins were evaluated after irrigation with normal saline, lactated Ringer's. balanced salt solution (BSS), and balanced salt solution plus(BSS⁺). The arterial and venous endothelia were examined with the scanning electron microscope. Using a randomized blind observer scoring system. micrographs were evaluated for changes in nuclear shape, cell junction integrity, cytoplasm changes, and sloughing of the endothelial cell layer. BSS⁺ and BSS produced stastically significant(p<.001) improvement over the other two irrigation fluids in the arteries. BSS⁺ and BSS were stastically superior(P<.00l) in the venous vessels. The compositions of BSS and BSS⁺ tend to maintain a physiologic environment in the presence of ischemia. These maintained a morphologic appearance closer to that of perfusion-fixed controls The data suggest a protective effect of such physiologic preparations on the endothelium. The preservation of intact endothelium may play a role in decreased platelet activation. continued production of prostacyclin, and maintenance of and intact barrier between the intra-cellular and extracellular spaces. This could enhance the survival of transplanted or transferred tissue, by helping to maintain nearly normal endothelium during surgery.

Since the anastomosis by suture, most widely used in microvascular surgery, has two major disadvantage in that it may inflict considerable damage on the vessel ends and that the suture material may function as a thrombogenic agent, much effort has been spent in developing methods of anastomosis in which the number of suture is reduced to minimum. As one of such efforts, we performed the following experiment using fibrin glue leaving out any suture material. First we divided the femoral artery of the rat and telescoped the proximal end into distal end by traction of two U-shaped guide sutures. Next, we removed the guide sutures and dropped the fibrinogen and thrombin solution dissolved in the distilled water and calcium chloride respectively on the telescoped area. After waiting for 5 minutes, vascular clamps were released. The result we got from the gross and histological examination showed that this method has advantage as follows; 1)This method is easier and speedier than suture technique. 2)Suture material was not exposed into the lumen. 3)There was less vessel trauma owing to fewer sutures and less manipulation of the vessel end. 4)Blood leakage from the anastomosal site was prevented. 5)There was no aneurysm.

The rationale for the use of vascularized nerve graft is based on the premise that a vascularized graft may provide more demyelination within the graft and subsequently more rapid regrowth of axons down its length followed by remyelination. Free non-vascularized nerve grafts have produced acceptable results if the donor nerves used are relatively thin, whereas thick nerves often develop central necrosis. An experimental technique has been devised to raise a composite neuro-venous graft and by reversing the vein component provide an arterialized composite nerve graft can be safely transferred to different parts of the body. Results have suggested that provided there is a good through in the artery and the vascular bed of the graft is small, venous drainage may not be required provided the artery remains patent. Initial results from light and electron microscopy indicate that in the majority of cases the axons reinnervated the grafts up to twice the distance of the non-vascularized nerve. Experimentally, it is concludred that the vascularized nerve is associated with more rapid axonal regeneration and remyelination than the nonvasularized cable graft.

Skin flap have been developed recently for wide employment in plastic and reconstructive surgery due to advances in microsurgery. After microvascular free flap transfer, the vascular occlusion did not affect flap survival after neovascularization appears to perfuse the flap. But if the flap exclu-de the recipient bed and perimeter, the flap survival depended solely on the axial vessel. This model would enable a clinical assessment of the viability of tissue and the patency of microvascular anastomosis long after the anastomosis is performed. Reexploration would not be necessary. We designed the island flap included the recipient bed and perimeter and the tube flap excluded it in rats. We investigated that the time of neovascularization after the free flap transfer, the assessment of microvascular patency and the importance of the arterial inflow or venous drainage for flap survival. In results, neovascularization appeared to perfuse the flap 4 days after free flap transfer in the island flap. A venous capillary bed developed quickly in the flap bed whereas the arterial capillary bed, sufficient to adequately perfuse the flap, developed much slowly. Therefore, we suggest the possibility that the arterial in-flow in the flap is more important for the flap survival.

The free skin flap transferby microvascular anastomosis has been recently for wide employment in reconstructive surgery. But for the survival of the free skin flap, the blood supplying network obviously is a sine qua non, so the ori-ginal free skin flap requires at least one artery for blood inflow and one vein for drainage. But arteries are not so supeficial as veins, so the flap is very bulky and the sacrifice of the donor artery is the inevitable. And, it is difficult to find an adequate artery in the distal part when a flap is designed, and we can find superficial veins from outside in the most parts of the body. It the arterial inflow is the first prerequisite, author suppose that the arterial inflow through the venous system also can save or nourish the distal part of a flap. So author made the new experimental free flap pattern which arterial inflow through the venous system also can save or nourish the distal part of a flap. So author made the new experimental free flap pattern which arterial inflow through the venous system. And according to the venous drainage pattern, author made the two different groups using rats. In one group, venous anastomosis was done, in the other group, arteriovenous anastomosis was performed which means venous blood drain through arterial system of the flap. And experimental comparisions were done between two different venous drainage patterns.

The free flap and myocutaneous flap transfer by microvascular anastomosis has been developed recently for wide employment in reconstructive surgery and has been used in many clinical applications.

The anatomy of the flap and the specific size, pattern and location of the vessel are important in the wide and varied reconstructive applications of the flap. The mean length and diameter were measured and the course and variation of the dorsalis pedis artery and adjacent area were studied in 44 dissections using 22 Korean cadavers and the vascular pedicles in the latissimus dorsi and adjacent area in 18 dissections using 9 Korean cadavers.

The results are summerized as follows:

1) The mean diameter of the dorsalis pedis artery on the upper limit of the extensor retinaculum is 2.9mm and the mean length of the vascular pedicle from the 1st web space is 13.5cm.

2) The mean diameter of the 1st dorsal metatarsal artery is 1.5mm and the mean length of the vascular pedicle from the 1st web space is 4.5cm.

3) The mean diameter of the thoracodorsal artery and vein before distribution to the latissimus dorsi are 2.1mm and 2.2mm and the mean length of the vascular pedicle from the axillary artery and vein before distribution to the latissimus dorsi is 11.9cm.

4) In the couse and variation of the dorsalis pedis artery, type I, 77%, normal course of the dorsalis pedis artery is most common.

5) There are consistent T-shaped relationship among subscapular, thoracodorsal, circumflex scapular arteries and serratus arterial branch.

6) Vascular structures at the latissimus dorsi are bifurcated into lateral and medial intramuscular bundles.

Recently, microvascular anastomoses has been developed for wide employment in clinical appliance. However, in end-to-end anastomoses of arteries less than 1mm in diameter, the vascular occlusions have been often occured due to suture materal, suture method and aneurysm, thrombosis and infection at the site of repair.

To obtain the more successful microvascuar method and research the histopathology of the vessel wall after repair, We did the experimental comparison of the different methods of microvascular anastomoses in rat femoral artery less than 1mm in diameter.

The experiment was done in 3 different groups. In group 1:6-8 sutures was done. In group 2:6-8 sutures and application of amniotic cuff to the anastomotic site was done. In group 3:4 sutures and application of anastomotic site was done.

The results are summarized as follows.

1) In all each three groups, patency was 90% and thrombosis was 10%.

2) Aneurysm formation was 40% in group 3, 30% in group 1, 2.

3) Infection was 20% in group 2, 3 and the absence in group 1.

4) The histopathology of the microvascular anastomotic site revealed intimal loss, medial necrosis, elastic lamella loss and subintimal hyperplasia in all groups.

5) The histopathologic comparison of the outer surface of the vessel wall in each groups revealed as followed,

(1) group 1 : much neovascularization and a few inflammatory cells.

(2) group 2, 3 : less neovascularization and much inflammatory cells and much fibrosis than group 1.

Recent advances in microsurgery and myocutaneous flaps have induced many surgerns to consider skin flaps from a new point, and this has produced an interest in the fundamentals governing flaps. If the flap is longer and larger, it should be delayed for complete survival,but delay requeires considerable time . Therefore, as a substitute for delay, vascular anastomosis in the distal part of a flap will theoretically give the same effect. In this study, we investigated the importance of arterial inflow in the distal side of a flap in a rat. The experiment was done in 3 groups according to design of flaps and in each group, 3 subgroups was made. In A flap, the superficial epigastric artery was preserved or anastomosis. In B flap, both superficial epigastric artery and vein was preserved or anastomosis. In C flap, both artery and vein was severed. In result, C flap in all 3 groups were completely survived. In conclusion, we suggest the possibility that a large flap may be transposed in oen stage with vascular anastomosis in the distal part - preferably artery and vein, or artery only.

Skin flap necrosis can be a catastrophe in reconstructive surgery. In recent years many attempts have been made clinically and experimentally to improve the blood supply in ischaemic flaps and minimise or prevent completely the impending tissue necrosis. This present study investigates the role heparin in preventing ischaemic flap necrosis experimentally in rabbits.

Odontomas may occur anywhere in the jaws, but they are found most frequently in the third molar and cuspid regions of the mandible. The causes of the odontoma is not known. Although these benign odontogenic tumors grow slowly and are ordinary asymptomatic, they may reach considerable size and should be removed.

Author has been experienced a case of complex odontoma on the hard palate. A 40 year old female who complained protruded mass on left side of hard palate. This hard mass was completely resected and primary closure was carried out in layers.

Pathologic diagnosis was complex composite odontoma. Author reported an experience and reviewed literatures.

The solitary bone cyst is an uncommon lesion of the maxilla. The etiology and pathogenesis of this cyst remain unknown. Several theories have been advanced: the only widely accepted one is the theory of origin from intramedullary hemorrhage after trauma. Author has been experienced a case of solitary bone cyst on the maxilla. A 26-year-old male who complained of protruded mass on right medial aspect of the infraorbital region, this bony mass was completely resected and primary closure was carried out in layers. Pathologic diagnosis was solitary bone cyst. Author reported an experience and reviewed literatures.

Despite the wide use of local anesthetics in surgery, relatively little has been proven about the effects of these agents on skin flaps. The following investigation was undertaken to study the influence of local anesthetic agents, which and without epineprine, on the survival of skin flaps in the rabbits. Infiltration with xylocaine or procaine alone had no influence on the viability of either nondelayed or delayed flaps. However, the addition of 1:100,000 epinephrine, which was not detrimental to survival length in nondelayed flaps, significantly reduced the surviving length in delayed skin flaps.