Dihydromyricetin regulates KEAP1-Nrf2 pathways to enhance the survival of ischemic flap.

In clinical flap practice, there are a lot of studies being done on how to promote the survival of distal random flap necrosis in the hypoxic and ischemic state. As a traditional Chinese medicine, dihydromyricetin (DHM) is crucial in preventing oxidative stress and apoptosis in a number of disorders. In this work, we examined the impact of DHM on the ability to survive of ischemia flaps and looked into its fundamental mechanism. Our results showed that DHM significantly increased the ischemic flaps' survival area, encouraged angiogenesis and blood flow, reduced oxidative stress and apoptosis, and stimulated KEAP1-Nrf2 (Kelch-like ECH-associated protein 1-nuclear factor erythroid 2-related factor) signaling pathways. Adeno-associated virus (AAV) upregulation of KEAP1 expression also negated the favorable effects of DHM on flap survival. By activating KEAP1-Nrf2 signaling pathways, DHM therapy promotes angiogenesis while reducing oxidative stress and apoptosis.

Effects of pharmacological delay with roxadustat on multi-territory perforator flap survival in rats.

Roxadustat (FG-4592) is a specific hypoxia-inducible factor (HIF) prolyl hydroxylase inhibitor. We investigated the effects of FG-4592 pretreatment on survival and second choke vessels of multi-territory perforator flaps in rats. In total, 72 rats were divided into two groups (n = 36 each): the experimental (FG-4592) group and the control group. FG-4592 was administered orally as a single dose of 60 mg/kg every other day; the first drug solution was administered to the animals 7 days before the surgical procedure. On postoperative day 7, the surviving flap area was calculated. At 12 h post-surgery, in the second choke zone in the flaps, macrovascular hinges were compared by angiography and imaging, and microvascular changes were assessed by histology. Laser Doppler imaging was used to evaluate flap perfusion at the second choke zone at 12 h and 7 days after surgery. At 7 days after surgery, the flap survival area and perfusion were significantly greater in rats given FG-4592 compared with controls. At 12 h after surgery, the diameter of macrovascular and microvascular vessels, nitric oxide content, perfusion, and the protein levels of HIF-1α and inducible nitric oxide synthase were also significantly greater in FG-4592-treated rats than controls. In conclusion, pretreatment with roxadustat may improve initial flap survival and dilate the second choke zone vessels in a multi-territory perforator flap.

Functional and aesthetic recovery of the second toe defect using a wrap-around pedicled flap from the great toe.

We report the results of using a fibula-sided digital artery pedicled flap from the great toe to cover the second toe free flap donor site, which avoids delayed wound healing, and prevents pain and skin ulceration. This study included 15 patients who had second toe wrap-around free flaps to reconstruct thumb and finger defects. All 15 pedicled flaps used to cover the defect healed uneventfully. All patients were able to stand and walk and were satisfied with the postoperative aesthetic outcome at the 6-month follow-up. We conclude that this an effective procedure for preventing donor site defects after second toe wrap-around free flap transfer.Level of evidence: IV.

Sequential posterior interosseous artery perforator flap for reconstruction of dorsal hand defects.

Dorsal hand defects accompanied by exposure of bones and tendons remain a huge challenge for plastic surgeons. The pedicled perforator flaps have unique advantages in resurfacing the defects. This study aimed to investigate the clinical efficacy of the sequential posterior interosseous artery perforator flap for repairing dorsal hand defects. This study was composed of an anatomical study and clinical application. Anatomically, 30 adult upper limb specimens injected with red latex were dissected, the perforators from the branches of the posterior interosseous artery were observed in the dorsal forearm, and the sequential flap based on them was designed based on the anatomical characteristics. Clinically, nine cases of soft tissue defects on the dorsum of the hand were treated by this flap. Anatomically, the posterior interosseous artery divided into an ascending branch and a descending branch, and the descending branch traveled 1.0 ± 0.3 cm down to divide into the ulnar and radial terminal branches. The ulnar terminal branch presented constantly, and the radial terminal branch had an occurrence rate of 93.33%. Clinically, all flaps survived completely and possessed a soft texture and satisfactory appearance, as well as a nonbloated pedicle, and the donor region had a natural color and appearance with only a linear scar left behind. The sequential posterior interosseous artery perforator flap could become a useful option for repairing dorsal hand defects, as it has the advantages of being easy to perform without sacrificing the main vessels and avoiding donor area skin grafting.

Effects of pedicle torsion on dynamic perforasome survival in a multiterritory perforator flap model: An experimental study.

BACKGROUND: Necrosis of propeller flaps is a problem in clinical practice. This study was performed to investigate the effects of pedicle torsion on dynamic perforasome survival using a multiterritory perforator flap model in rats. METHODS: Intercostal artery perforator flaps (IC flaps) containing two adjacent dynamic perforasomes were applied to both sides of the dorsum in 15 rats. The IC vessels were dissected carefully under 10 × magnification. A 360° arc of pedicle torsion was applied to the right IC flaps, which comprised the rotary group. Left IC flaps were used as controls. Flap perfusion, viability, and angiography were compared between the two groups. RESULTS: Sodium fluorescein angiography showed that there was blood supply to the flap in both groups on postoperative day (POD) 1, and laser Doppler images indicated that flap perfusion increased daily after surgery. The differences in perfusion of dynamic perforasomes between the two groups were not significant. The mean survival rate of the rotary group was not significantly different from that of the control group (98.94 ±â€¯1.24% versus 99.03 ±â€¯1.86%, respectively, p > 0.05) on POD 7. Angiography showed that dilated choke vessels connected the three perforasomes in both groups. CONCLUSIONS: The 360° arc of pedicle torsion had no detrimental effect on dynamic perforasome perfusion or survival in a multiterritory perforator flap model after meticulous surgical dissection of the pedicle in this study. The dilated choke vessel connected adjacent perforasomes, and the dynamic perforasome survival still adhered to the perforasome theory after pedicle torsion.

Comparison of a Small Central versus a Large Peripheral Perforator in a Rat Model of Extended Dorsal Three-Vascular Territory Perforator Flap.

BACKGROUND: Selection of suitable perforators is critical for satisfactory postreconstructive surgery outcome. This study aims to compare a small central versus a large peripheral perforator flap in a rat extended dorsal three-vascular territory perforator flap model. METHODS: An extended intercostal artery perforator flap with three vascular territories was used to model a small central perforator flap. An extended deep circumflex iliac artery flap with three vascular territories was used to model a large peripheral perforator flap. Flap viability, angiography, and perfusion were compared. RESULTS: Intercostal artery flaps showed significantly higher relative viable area than deep circumflex iliac artery flaps (98.5 ± 3.2 percent versus 87.1 ± 7.3 percent; p < 0.01). Angiography revealed that the anatomical and the first adjacent territories were perfused successfully in both types of flap, but the second adjacent territory of deep circumflex iliac artery flaps was not perfused sufficiently, thus ultimately leading to flap necrosis. Perfusion at the anatomical and the first adjacent territories of both types of flap increased significantly for 3 days (p < 0.05) and became stable 5 to 7 days after surgery. Perfusion at the second adjacent territory of deep circumflex iliac artery flaps diminished continuously. CONCLUSIONS: A small central perforator may supply a larger vascular territory than a large peripheral perforator. Both the size and the location of a perforator should be considered for optimizing the design of an extended perforator flap.

Vasculature Characterization of a Multiterritory Perforator Flap: An Experimental Study.

Background Tip necrosis in the perforator flap is a significant problem in clinical practice. This study aimed to characterize the vasculature of a multiterritory perforator flap using a rat model and to investigate the impact of the vasculature on flap survival. Methods In total, 105 Sprague Dawley rats were divided into seven groups, including the control, 3 hours postoperative (PO), 12 hours PO, 1 day PO, 3 days PO, 5 days PO, and 7 days PO. A perforator flap with three territories based on the deep iliac circumflex artery was performed. Flaps with only skin incisions and vessel exposure were performed in the control group. The first choke zone (FCZ) was located between the anatomical and dynamic territories, and the second choke zone (SCZ) was located between the dynamic and potential territories. Sodium fluorescein and lead oxide-gelatin angiography and histological examination were performed in each group. Results Sodium fluorescein angiography revealed delayed staining in the perforator flap PO, particularly in the FCZ and SCZ. The delay phenomenon disappeared after 12 hours PO in the FCZ and after 1 day PO in the SCZ. Nonfluorescein-stained areas were found distal to the potential territory. In the FCZ PO, the choke vessels were dilated, while the number of microvessels was increased in the SCZ without choke vessel dilation. Conclusions The remodeling of choke vessels and increase in microvessel number represent arteriogenesis and angiogenesis, respectively. This neovascularization was responsible for flap survival in the entire dynamic territory and part of the potential territory.

Postoperative Growth in Radial Polydactyly: A Clinical Study.

PURPOSE: This study was designed to evaluate thumb growth after surgical management of a duplicate thumb and investigate its developmental pattern. METHODS: We compared the thumbs and index fingers of 486 normal children (aged 1-18 y) (group A) with 15 children showing radial polydactyly (group B). All duplicate thumbs were treated with excision of the radial thumb and reconstruction of the ulnar thumb. Radiographs of groups A and B were used to compute the thumb-to-index finger length ratio and width ratio, and the thumb-to-index finger phalanx length ratio and phalanx width ratio. RESULTS: In group A, the length ratio, width ratio, phalanx length ratio, and phalanx width ratio did not change with age, and remained constant in males and females. In group B, after an average follow-up period of 41.0 months, the original findings were also similar to the final ratios. In group B, only the phalanx width ratio was obviously smaller than normal. CONCLUSIONS: A permanent developmental stability exists between the thumb and the index finger, even in patients with radial polydactyly. The development of the retained digit is not influenced by the ablation of the extra digit. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

The Effect of Inducible Nitric Oxide Synthase on Multiterritory Perforator Flap Survival in Rats.

Background Inducible nitric oxide synthase (iNOS) plays an important role in vasodilation, angiogenesis, and ischemia-reperfusion injury. We investigated the effects of iNOS on the survival and choke vessels of multiterritory perforator flaps in rats. Methods In this study, 84 rats were divided into two groups of 42 rats each and subjected to multiterritory perforator flap operations. Rats in group A received daily intraperitoneal doses of 100 mg per kg of aminoguanidine (AG) and rats in group B received daily intraperitoneal injections of the same volume of saline solution. On postoperative day 7, the surviving flap area was calculated as a percentage of the total flap dimensions using DP2-BSW software. The diameter and density of microvessels in the second choke zone of the flap were calculated from histology studies. The nitric oxide (NO) content was measured using NO concentration assay kits, and the levels of vascular endothelial growth factor (VEGF) and iNOS were assessed using western blotting. Superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were measured using test kits. Laser Doppler imaging was used to evaluate flap perfusion in the second choke zone for 7 days after surgery. Results The flap survival area, diameter and density of microvessels, iNOS and VEGF levels, NO content, blood perfusion, and MDA content were significantly higher in the control group compared with the AG group, whereas SOD activity was significantly lower in the control group. Conclusions iNOS has a beneficial effect on the survival of multiterritory perforator flaps.

Effects of calcitriol on random skin flap survival in rats.

Calcitriol, a metabolite of vitamin D, is often used in osteoporosis clinics. However, the material has other bioactivities; for example, it accelerates angiogenesis, has anti-inflammatory properties, and inhibits oxidative stress. We investigated the effects of calcitriol in a random skin flap rat model. "McFarlane flap" models were established in 84 male Sprague Dawley rats, divided into two groups. One group received intraperitoneal injections of calcitriol (2 µg/kg/day) whereas control rats received intraperitoneal injections of saline. The percentage flap survival area and tissue water content were measured 7 days later, which showed that calcitriol improved flap survival area and reduced tissue edema. It also increased the mean vessel density and upregulated levels of VEGF mRNA/protein, both of which promote flap angiogenesis. Moreover, it decreased leukocyte and macrophage infiltration, reduced the inflammatory proteins IL1ß and IL6, increased SOD activity, decreased MDA content, and upregulated the level of autophagy. Overall, our results suggest that calcitriol promotes skin flap survival by accelerating angiogenesis, having anti-inflammatory effects, reducing oxidative stress, and promoting autophagy.

[EFFECTIVENESS OF DORSAL PENTAGONAL FLAP FOR RECONSTRUCTION OF THE WEB SPACE IN CONGENITAL TOE SYNDACTYLY].

OBJECTIVE: To investigate the effectiveness of dorsal pentagonal flap for reconstruction of the web space in congenital toe syndactyly. METHODS: Between January 2009 and June 2014, 10 patients with congenital toe syndactyly were treated for web space reconstruction with dorsal pentagonal flap. There were 6 boys and 4 girls with the average age of 42 months (range, 8 months to 9 years). The congenital toe syndactyly located at the left foot in 5 cases, the right foot in 4 cases, and both feet in 1 case; 7 patients had polydactyly and 1 patient had brachydactylia. During follow-up, the toe function and web space appearance, web space depth, and web space gradient were observed to evaluate the effectiveness. RESULTS: All 13 flaps survived and incisions healed by first intention. Ten patients were followed up 6-50 months (mean, 26 months). The skin color and texture in 13 reconstructed web spaces were close to normal web space. in 9 patients undergoing web spaces reconstruction of single foot, the abduction angle of toes was (42.879±3.703) at the injured side, showing no significant difference when compared with the normal side [(45.922±2.657)°] (t= -2.004, P=0.062); the web space depth was (1.881±0.266) cm at the injured side and was (1.631±0.202) cm at the normal side, showing significant difference (t=2.248, P=0.039); and the web space gradient was (42.733±3.421)° at the injured side and was (41.189±5.593)° at the normal side, showing no significant difference (t=0.707, P=0.490). The web space appearance, web space depth, and web space gradient were close to those of the normal web space in 1 patient undergoing bilateral web spaces reconstruction. CONCLUSION: Web space reconstruction with dorsal pentagonal flap is easy to perform with reliable blood supply and low re-operated rate. The cosmetic and functional results are satisfactory.