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 evaluate the safety and efficacy of botulinum toxin type A injection around internal anal sphincter and sector resection combined with epluchage and drainage by a small incision in treatment for stage Ⅱ and Ⅲ anal fissure，explore its surgical procedures and key points，and introduce a new surgical treatment for anal fissure. Methods The patients according to the inclusive criteria were divided into trial group and control group in randomized，parallel，controlled clinical trial method．The botulinum toxin type A injection around internal anal sphincter and sector resection combined with epluchage and drainage by a small incision was performed in the trial group, the anal fissure resection and part internal anal sphinctor latero-resection was perfermed in the control group. The safety index （including anal stenosis，incontinence，acute urinary retention，postoperative pain，and rectal anal tube pressure） and validity indicators （including cure rate，operation time，wound healing，wound healing grade，and scar size） were compared before and after operation between two groups．Results No anal stenosis and acute urinary retention occurred in the two groups. The anal incontinence score was not significantly different between two groups （P＞0.05）．The postoperative pain score in the trial group was significantly lower than that in the control group （24 h，the first defecation，and on week one after operation，all P＜0.01）．The difference of rectal anal canal pressure was not statistically significant between two groups （P＞0.05）．The cure rate was higher （P＜0.05），operation time and wound healing time were shorter （P＜0.01），wound healing was better （P＜0.05），scar area was smaller （P＜0.01） in the trial group as compared with the control group．Conclusions Comparing with the control group，high cure rate，short wound healing time，small size of scar，short operation time and minimal invasion are seen in the trial group．The shape and function of the anus are better reserved than that of the control group，this technique has a good clinical efficacy and safety．