Objective To introduce an improved method of continuous intradermal suture,and to evaluate its clinical efficacy for the closure of surgical incisions.Methods Eighty-two patients were enrolled in this study,including 37 cases of nevus,10 cases of basal cell carcinoma,16 cases of sebaceous cyst,6 cases of lipoma,8 cases of seborrheic keratosis,3 cases of dermatofibroma and 2 cases of depressed scar.All the patients were managed by simple surgical excision with the shortest length of postoperative incisions being 0.8 cm and the longest length being 12 cm.An improved method of continuous intradermal suture was used for the closure of all the postoperative incisions.Specifically,an absorbable thread with a small triangle needle in both ends was inserted through and pulled out from the dermal layer at one side of the incision,and then inserted through and pulled out from the dermal layer at the opposite side of the incision,which was repeated until the incision was entirely closed.Results Among the 82 patients,80 achieved primary healing,and 2 developed erythematous painful swelling at the incision site 2 days after the operation,which disappeared after symptomatic treatment for 5 days.During 3-6 months of follow-up,the incisions closed leaving a flat and smooth surface in 78 patients,and proliferative scar formed in 4 patients,which was obviously improved after local injection with glucocorticoids.No disruption of incisions was observed.Conclusion The improved method of continuous intradermal suture can be applied to the closure of skin defects in the face,neck,trunk and extremities with a favorable healing outcome and cosmetic result.

Objective To compare the effects of two skin sampling methods (negative pressure suction blister and skin shaving) on the physical status of autologous epidermal keratinocytes transplanted to patients with vitiligo. Methods Skin samples were obtained from the normal skin of 32 patients with stable vitiligo by suction blister under negative pressure and skin shaving alone or in combination. Immunohistochemistry was performed to examine the expression of proliferating cell nuclear antigen (PCNA) and caspase-3 in these samples.Skin tissues resected from 15 normal human subjects served as the control. Results There was an expression of PCNA and caspase-3 at different degrees in all the skin tissues obtained by the two sampling methods from the 32 patients. Most PCNA-positive cells were focally distributed at the basal layer in epidermis obtained from suction blisters, and a few PCNA-positive cells were observed in the middle and lower part of the prickle cell layer of epidermis from shaved skin. There was a significant difference in the percentage of PCNA-positive cells between the epidermis from suction blisters and shaved skin as well as between the epidermis from suction blisters and normal control skin (x2 = 10.99, 14.08, both P < 0.05), but not between the epidermis from shaved skin and normal control skin (x2 = 1.31, P > 0.05). The expression of caspase-3 was predominantly located in the cytoplasm of keratinocytes in the basal layer as well as middle and lower part of prick cell layer, and no difference was observed in the percentage of caspase-3-expressing keratinocytes between the epidermis from shaved skin, suction blisters and normal control skin (x2 = 1.41, 2.89, 1.91, all P > 0.05). Conclusions The proliferation activity of epidermal cells seems important to the survival of grafted skin, and compared to the suction blister technique, skin shaving appears to have less influence on the proliferation of keratinocytes.