Tibial cortex transverse transport promotes ischemic diabetic foot ulcer healing via enhanced angiogenesis and inflammation modulation in a novel rat model.

BACKGROUND: Tibial Cortex Transverse Transport (TTT) represents an innovative surgical method for treating lower extremity diabetic foot ulcers (DFUs), yet its underlying mechanisms remain elusive. Establishing an animal model that closely mirrors clinical scenarios is both critical and novel for elucidating the mechanisms of TTT. METHODS: We established a diabetic rat model with induced hindlimb ischemia to mimic the clinical manifestation of DFUs. TTT was applied using an external fixator for regulated bone movement. Treatment efficacy was evaluated through wound healing assessments, histological analyses, and immunohistochemical techniques to elucidate biological processes. RESULTS: The TTT group demonstrated expedited wound healing, improved skin tissue regeneration, and diminished inflammation relative to controls. Marked neovascularization and upregulation of angiogenic factors were observed, with the HIF-1α/SDF-1/CXCR4 pathway and an increase in EPCs being pivotal in these processes. A transition toward anti-inflammatory M2 macrophages indicated TTT's immunomodulatory capacity. CONCLUSION: Our innovative rat model effectively demonstrates the therapeutic potential of TTT in treating DFUs. We identified TTT's roles in promoting angiogenesis and modulating the immune system. This paves the way for further in-depth research and potential clinical applications to improve DFU management strategies.

Application of computed tomography angiography-assisted classification of arterial branches in the first web space of the foot for thumb reconstruction.

BACKGROUND: Computed tomography angiography (CTA) has become a widely used imaging modality in vascular surgery. The first web arterial branches of the foot are significant for surgical planning of the donor site for thumb reconstruction. METHODS: We retrospectively analysed 30 thumb reconstructions with free second toe/great toe wrap-around flap transfer, performed between January 2016 and January 2019. The mean patient age was 30 (2-45) years. The causes of hand injury were: 20 machine strangulation injuries, 6 heavy weight smash injuries, and 4 crush injuries. Patients with iodine allergy were excluded preoperatively. We evaluated the effectiveness of CTA in visualizing first web arterial branches and compared it with intraoperative findings. Surgical plan for donor sites was prepared based on the classification of the first web arterial branches. RESULTS: The arterial branches of the patients were classified based on CTA findings as follows: (1) fork type: 24 patients (48 feet, 80%); (2) main trunk type: four patients (8 feet, 13.33%); and (3) side branch type: one patient (2 feet, 3.33%). One case of poor vascular continuity and artifacts in CTA underwent thumb reconstruction with free great toe wrap-around flap transfer. Tissue survival was achieved in all reconstructed thumbs. During the follow-up period (average, 12 months), all reconstructed thumbs exhibited good outcomes. The donor sites on the feet of all patients recovered well. CONCLUSION: CTA allows preoperative assessment of blood supply and planning of donor site. Our results can serve as a reference for surgical planning of the donor site while reducing the occurrence of adverse events.

Computed Tomography Angiography Allows the Classification of the First Dorsal Metatarsal Arteries.

Background Conventional angiography is an invasive technique. Submillimeter computed tomography angiography (CTA) has been shown to be an effective alternative for peripheral artery branches. This study aimed to assess the use of CTA to guide the choice and design of foot donor area for finger or thumb reconstruction. Methods This was a retrospective study of 79 patients who underwent finger or thumb reconstruction between January, 2011 and March, 2014. All these patients underwent preoperative CTA to determine the exact blood supply at the donor site. Preoperative imaging and intraoperative findings at the donor site were compared. Results Among the 79 patients (158 feet), 474 artery segments (dorsalis pedis artery [DPA], first dorsal metatarsal artery [FDMA], and toe web artery [TWA]) were evaluated using CTA. Image satisfaction rates of the vessels were 100.0 ± 0.0%, 89.2 ± 3.2%, and 60.1 ± 5.0% for DPA, FDMA, and TWA, respectively. Among the 158 feet, 90 were Gilbert type I (57.0%), 52 were Gilbert type II (32.9%), 13 were Gilbert type III (8.2%), and 3 were with poor visibility and could not be classified (1.9%). In all 79 patients, the CTA image of the FDMA was consistent with the intraoperative observations. All reconstructed fingers survived. Follow-up was available for 69 patients. After a 6- to 18-month follow-up, the reconstructed fingers and donor area recovered well, and the reconstructed fingers had strong holding power, without pain. Conclusion CTA can produce three-dimensional images for extremity arteries, allowing the preoperative assessment of blood supply and planning of donor site.

[Preliminary study on appropriate concentration gradient of nerve growth factor in promoting fracture healing].

OBJECTIVE: To study the effect of local application of different concentrations of nerve growth factor (NGF) on fracture healing, and to further search for the appropriate concentration gradient of NGF to promote fracture healing. METHODS: Seventy-five adult male Sprague Dawley rats, weighing (220.0 +/- 2.5) g, were made the right tibia fracture model at 1 cm distal from the tibial tubercle and randomly divided into 5 groups (groups A, B, C, D, and E, n=15). Fractures were treated with 0.3 mL normal saline containing different concentration of NGF (0.00648 x 10(-2), 0.032 40 x 10(-1), 0.16200 x 10(-2), and 0.81000 x 10(-2) microg/g) in groups A, B, C, and D, respectively, and the same amount of normal saline in group E. After 2, 4, and 6 weeks, the specimens were harvested from 5 rats of each group to perform the biochemical test and histological observation. Before the rats were sacrificed, the arteriovenous blood was taken from the eye-ball to test the alkaline phosphatase (ALP) activity. RESULTS: After 2, 4, and 6 weeks, the gross observation showed that the size and hardness of bone tissue and callus tissue growth gradually increased in groups A, B, C, and D, and group D was higher than groups A, B, C, and E. The X-ray films showed that the calcified area gradually increased in groups A, B, C, and D, and group D was higher than groups A, B, C, and E. The histological observation showed that the trabecular quality and maturity in group D were better than those in groups A, B, C, and E. Group D was significantly higher than groups A, B, C, and E (P < 0.05) in the gray values of callus tissue and the calcium content of callus tissue at 4 and 6 weeks, in the wet weight of callus tissue at 2 and 4 weeks, and in the ALP content of serum at 2 weeks. The trabecula surface index of osteoblast, the trabecular volume, and the trabecular width decreased as time in the order of groups A, B, C, and D, which were higher than those of group E; group D was the highest, showing significant differences when compared with the other groups (P < 0.05). CONCLUSION: The local application of NGF can promote fracture healing in rats. The high concentration gradient of NGF (0.81000 x 10(-2) microg/g) has an obvious promotion role on fracture healing.