Flap surgery and its survival is a major interest of the plastic surgeon. There have been numerous investigations concerned with finding a safe and effective method for increasing the area of skin flap survival. As the delay phenomenon theory, that is vascular smooth muscle relaxation auguments the blood flow to the capillary bed of the skin flap, experimental study using the Sprague-Dawley rats was perforned with the calcium antagonists which cause the dilatation of vascular smooth muscle by blocking the calcium influx into the cells.

The experimental results were as followings :

Survival area increased up to 72.7% with verapamil treatment and 81.22% with nimodipine treatment compared to 58.62% in the control. There was no significant difference between verapamil and nimodipine treatment groups.

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%.

Since Willam Harvery had proposed the concepts of circulation in 1628. the anatomy and physiology of circulation has been intensively studied. Venous drainage of a musculocutaneous flap was shown to be of importance for the prevention of necrosis and successful flap taken.

We created an experimental model in rats in which the illiolumbar veins were used as the draining veins, and the following experiment was performed.

The experimental models were divided into 3 groups ;

Group I: bilateral illiolumbar neurovascular bundles of the grafts were not preserved as a control.

Group II: preserving the bilateral illiolumbar veins as the draining veins.

Group III: silastic sheet was placed between the musculocutaneous flap and the underlying bed. In this study, it was demonstrated that

1) Necrosis could be prevented by draining veins.

2) Group II with draining veins : it indicated that the number and size of the draining veins were critical for the survival of the flap.

3) Group III with silastic sheet protection of plasmatic circulation was showed that flap could not survived.

The search for a superior absorbable surgical suture has been underway for years. The synthetic materials have been shown to have certain advantages over the use of the familiar natural absorbable gut sutures. Specially, since synthtic absorbable sutures are degraded by simple hydrosis rather than by phagocytosis. they elicit a minimal tissue reaction.

A newly-developed absorbable monofilament, poly-dioxanone(PDS, Ethicon) has certain adventages : it passes easily through tissues retains its tensile strength for a long time, and produces minimal tissue reaction.

9-0 absorbable polydioxanone(PDS) has been compared to 9-0 nonabsorbable Ethilon in order to evaluate any advantages of either suture in microvascular surgery. In each of 45 rats, one femoral artery was anastomosed end-to-end with PDS and the other with Ethilon. Specimen were harvested 48hr. 14day and two months post operatively. Histologic analysis of inflammation, fibrosis, and medial necrosis of the anastomoses revealed no significant differences between the two materials. There was no difference as regards stenosis and aneurysm formation, when evaluated independently by the two methods.

It can be concluded that the amount of inflammation and fibrosis leading to stenosis is related to the amount of trauma at the time of surgery and not to the type of suturing material used.

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.

Human adipose tissue transplantation was first attempted in 1983 by Neuber and subsequently it was used widely as a surgical method to correct surface depression or to augment soft tissue during the period of the 20th century. But the fat grafts lost about the 50% of their weight and volume and complication has been discovered. Recently, with introduction of the suction-associated lipectomy and the minced free fat injection technique, there has been revived interest in using suctioned adipose tissue for transplantation to correct contour deficiences.

The purpose of this study is to evaluate adipocyte survival in pigs under 3 different conditions as follows ;

1) Type of grafts : Lump (Excised) & minced(libposuctioned).

2) Beneficial effects of insulin : the addition to the specimens and not.

3) State of Donor site ; old scar bed and fresh bed.

The biopsy specimens from 8 groups were taken after 4 and 8 weeks and routinely measured their survival weights and prepared for microscopic examination.

The results shows ;

1) The differences between the specimens of 4 weeks and those of 8 weeks were revealed in the survival weights and histologic findings.

2) While the survival adipocytes in lump and minced groups did not differ histoligically, there was statiscally significant increasing of survival weights in minced groups(2.3±0.34, 2.0±0.26) compared with the lump groups.

3) Insulin did not show any effects on survival weights and histology.

4) There was no statiscally significant differences between specimens of scar bed groups and those of non-scar bed groups(P-value>0.05).

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.