Objective To investigate the clinical effect of intensepulsed light depilation combined with bigger skin expander in auricular reconstruction. Methods From January 2000 to January 2006, seventythree patients suffering congenital microtia of one side were treated. Among them, 32 patients were reconstructedby the intense pulsed light depilation combining with bigger skin expander(new method group), and 41 patients were reconstructed by traditional auricular reconstruction method(traditional method group). In the new method group, there were12 males and 20 females, aging 6-45 years. The typing of congenital microtia weredegree Ⅰ in 6 cases, degree Ⅱ in 20 cases and degree Ⅲ in 6 cases. The size of flap ranged from 9 cm×5 cm to 11 cm×6 cm. And the size of fascial flap ranged from 7 cm×5 cm to 9 cm×6 cm.In the traditional method group, there were 13 males and 28 females, aging 6-42 years. The typing of congenital microtia were degree Ⅰ in 8 cases, degree Ⅱ in 27 casesand degree Ⅲ in 6 cases. The size of flap ranged from 8 cm×5 cm to 10 cm×6 cm. And the size of fascial flap ranged from 7 cm×5 cm to 9 cm×6 cm. The skin sizeand scar size were measured. The complications and the satisfactory rate were compared between two groups after operation to assess the value of these methods. Results After 6-12 months of second operation, all patients were given thirdstage auricular reconstruction and followed up. In the new method group, the flap and skin grafting survived and the wound healed by the first intension. The crus of helix, helix,concha and scapha could be found clearly. There was no hair on the surface of helix. In the traditional method group, the framework exposure occured in one patients because of local flap necrosis. The wound cured by the temporal superficial fascia flaps combined with split skin grafts transplantation. The other flap and skin grafting survived and the wound healed by the first intension. The helix, concha and scapha could be found, but there was some hair on the surface of 35 patients’ helix. There were significant differences in the skin graft, scar size and the satisfactory rate between two groups (Plt;0.05). There was no significant difference in the complications(Pgt;0.05). Conclusion There is less scar and skin grafts in this new method. And the hair can be depilated in the reconstructed auricle completely. So it can achieve more satisfactory appearance.
OBJECTIVE To investigate the effect of the endoexpander pressure of continuous and constant pressure expansion on the drug permeability. METHODS The expanders were divided into two groups, the normal expansion and the continuous and constant pressure expansion (4.6 kPa). Each expander was filled with 0.2% Metronidazole, then the expanders were immersed wholly in normal saline and sealed totally. At several intervals over 72 hours, the surrounding saline was sampled and the drug concentration of the sample was measured respectively. RESULTS Both groups were permeable to the Metronidazole and the concentration outside the expander would reach the effective concentration in 48 hours. The drug concentration of the continuous and constant pressure expansion was higher than that of the normal one and there was significant difference between the two groups (P lt; 0.01). CONCLUSIO The endoexpander pressure in continuous and constant pressure expansion can enhance the drug permeability. In view of this, in the course of continuous and constant pressure expansion, 0.2% Metronidazole can be used to prevent and control the infection.
An in vitro experiment showed that the skin expanders were permeable to metronidazole and procaine. Twenty kidney shaped skin expanders were divided into four groups. Group 1. 100ml 0.2% metronidazole solution was injected into the expanders and the expenders were immersed in a flask filled with 100ml saline solution, and then were placed in a hermetically sealed glass chamber; Group 2.the whole procedure was the same as that of Group 1 except the expander was previously boiled in water for 30 minutes; Group 3. 100 ml 2% procaine was injected instead of metronidazole, other step was the same as that ofgroup I; and Group 4. the whole procedure was the same as that of Group 2 except the solutioninjected was 2% procaine. The concentration of metronidazole and procaine in the surrounding saline was measured at 1st, 2nd, 4th, 16th, 24th, 48th, 72nd 120th hours. The rate of diffusion of a drug was highest at 2 and 4 hous. The rate of diffusion was inversely proportional to its molecular weight, i.e., the smaller the molecular weight the greater the permeability. In view of this, during the process of expansion, metronidazole and procaine would diffuse out of the expander which might be beneficial for preventing infection and controlling pain.