Objective To investigate the effects of botulinum toxin type A (BTXA) on the excessive expansion speed and blood supply of myocutaneous flap. Methods Seven adult Guizhou minipigs of clean grade were included, female or male and weighing 16-20 kg. The 2.4 mL BTXA solution (96 U) was injected in cutaneous muscle (24 points) of one side as experimental group (n=7), the 2.4 mL saline in the other side as control group (n=7). Two expanders (200mL) were implanted beneath the cutaneous muscle on the bilateral flank of each pig symmertrically at 3 days after injection. One week later, the expanders were filled with saline every 4 days with an intracapsular pressure of 11.97 kPa, and accumulative total amounted to 400 mL for 3 weeks in control group and 5 weeks in experimental group. Then the expanders were taken out; the myocutaneous flaps formed and were sutured in situ. The myocutaneous flaps were cut for histological examination and capillary count. The expansion speed of the myocutaneous flap were recorded. The blood supply of the myocutaneous flap were observed by infrared thermography at 1 week after implantation expanders, before removing the expanders, and at 5 days after myocutaneous flap suture in situ. Results All the animals survived to the end of the experiment. The total expansion time was (54.0 ± 3.1) days in experimental group and (67.0 ± 3.9) days in control group, showing significant difference (t= —8.107, P=0.000). All myocutaneous flaps survived after being sutured in situ. Infrared thermograhy revealed that the temperature of the distal myocutaneous flap in experimental group was significantly higher than that in control group at 1 week after implantation of expanders (P lt; 0.05); at 5 days after myocutaneous flap suture in situ, the temperature of the central flap in experimental group was significantly higher than that in control group (P lt; 0.05); and there was no significant difference between 2 groups at the other time points (P gt; 0.05). The histological observation showed that the blood vessel density of the dermal layer and tissue between the capsule and the muscle layer in experimental group was significantly higher than those in control group (P lt; 0.05). Conclusion When excessive expansion is performed, BTXA can accelerate the expansion rate and improve the blood supply of expanded myocutaneous flaps.
Objective To explore an improved method of reconstructing the scalp soft tissue defect with the expanded skin soft tissue and treating and preventing the related complication. Methods From October 2002 toJune 2005, 32 patients (20 males and 12 females, aged 5-48 years) underwent reconstruction of the scalp soft tissue defects with the expanded scalp soft tissue in thetwo-stage operation. In the first stage, a tissue expander (cylindrical form, 50-250 ml) was inplanted into the skin to achieve a skin soft tissue expansion. After a sufficient skin expansion (8 cm×5 cm to 25 cm×23 cm) was made by the routine water affusion for 6-16 weeks, a properly-designed skin flap was taken and transferred to reconstruct the scalp soft tissue defect in the second-stage of the operation. All the scalp defects were left after the resections of the scalp lesions, which ranged in size from 7 cm×5 cm to 20 cm×20 cm.Results After operation, all the 32 patients had their scalp defects repaired and reconstructed well.The expanded skin flaps of all the 32 patients survived except 1 patient who had a necrosis of the distal epidermis of the flap, which healed after the dressings of the wound. The hair grew well and the scars were hidden with a satisfactory appearance. Four patients developed complications (necrosis of the distal flapin 1 patient, hematoma in 1, expander exposure in 1, and wound rupture in 1).Conclusion Reconstruction of the scalp soft tissue defect with the skin soft tissue expansion is an ideal method.
Objective To summarize the prevention and treatment of postoperative complications after the skin soft tissue expansion for scar alopecia. Methods From January 1995 to June 2005, 57 patients with scar alopecia were admitted to our department for treatment. Of the patients, 25 were males and 32 were females with their ages ranging from 5 to 55 years. The causes were burn in 33 patients, trauma in 14, alopecia after head surgery in 8, and other causes in 2. Their disease courses ranged from 6 months to 15 years. Fortreatment, 89 therapeutic expanders were utilized in 57 patients. The retrospective analysis on the complications and their prevention and treatment were performed. Results The follow-up for 3-12 months averaged 6 monthsrevealed that 81 areas undergoing the expander insertion healed well and the hair grew well, too. Eight areas undergoing the expander insertions had complications, including expander exposure in 2 patients, infection in 2, hematoma in 1, expander rupture in 1, necrosis of the flap tip in 1, and scar necrosis at the injection port in 1. The results also revealed that there was a significantly increased rate of complications in the patients aged 5-10 years and the patients older than 50 years （Plt;0.05）. The complication rate in the patients who received 2 expanders at one time was significantly higher than that in the patients whoreceived only 1 expander（Plt;0.05）. However, there was no significant difference in the complication rate in the other kinds of patients. All the complicationswere effectively treated with a satisfactory therapeutic result. Conclusion The skin soft tissue expansion for scar alopecia can effectively prevent and treat postoperative complications. If the complications are identified early and treated properly, the therapeutic results will be satisfactory.