The dragonfly technique for trachea closure in temporary tracheostomies. Surgical steps and clinical results.

PURPOSE: To assess the effectiveness of a new suturing technique called Dragonfly for the closure of temporary tracheotomies. This technique involves placing two sutures during the tracheotomy procedure and leaving them loose and unknotted until the day of skin closure. METHODS: Retrospective case control study. Monocentric study at a department of Otolaryngology and head and neck surgery at a tertiary centre in Italy. A total of 50 patients who underwent temporary tracheotomy between January 2017 and December 2021. Patients were divided into two groups based on the trachea closure method: traditional closure with sutures placed during the skin closure procedure (Group A) and the Dragonfly technique (Group B). The incidence of tracheal stenosis by Computed Tomography (CT), granulation tissue formation, bleeding, procedure duration, patient discomfort were evaluated. RESULTS: The incidence of tracheal complications and tracheal stenosis was reduced in Group B (6%) compared to Group A (24%). Procedure times (3 min vs. 6 min) durations was significantly shorter. No patients had symptoms of tracheal stenosis at the end of the procedures. CONCLUSION: The Dragonfly suturing technique is effective and safe for tracheotomy closure, reducing the incidence of tracheal stenosis and shortening hospitalization duration compared to the traditional method.

Involvement of Catechols in Acteoside in the Activation of Promatrix Metalloproteinase-2 and Membrane Type-1-Matrix Metalloproteinase Expression via a Phosphatidylinositol-3-Kinase Pathway in Human Dermal Fibroblasts.

Granulation tissue formation during skin wound healing requires the migration and proliferation of dermal fibroblasts in the wound site, where a subsequent remodeling of extracellular matrices (ECM) occurs. An abnormality of ECM remodeling within the healing wound leads to fibrosis and a contracted scar. To evaluate whether acteoside, a phenylethanoid glycoside isolated from the leaves of Rehmannia glutinosa LIBOSCH., exhibits wound-healing actions, we examined the effect of acteoside on the expression of matrix metalloproteinases (MMPs) in normal human dermal fibroblasts (NHDF). Acteoside dose- and time-dependently augmented the activation of the precursor of MMP-2 (proMMP-2/progelatinase A) in untreated- and interleukin-1ß-treated NHDF, while the alteration of the MMP-2 gene expression was negligible. The acteoside-induced proMMP-2 activation was associated with the augmented membrane-type 1 MMP (MT1-MMP) expression in the NHDF. In addition, the proMMP-2 activation was enhanced by two aglycones in acteoside: caffeic acid and 3,4-dihydroxyphenylethanol, which consist of catechol. However, there was no change in the proMMP-2 activation in other catechol derivatives: homovanillyl alcohol- and homovanillic acid-treated NHDF, indicating that catechols in acteoside were requisite for the regulation of the MMP activation and expression in NHDF. Furthermore, the proMMP-2 activation by acteoside was selectively inhibited by LY294002, a potent phosphatidylinositol-3-kinase (PI3K) inhibitor. These results provide novel evidence that acteoside augments proMMP-2 activation along with an increase in MT1-MMP expression through a PI3K signal pathway in NHDF. Thus, acteoside is likely to be an attractive candidate that facilitates ECM remodeling in the skin wound repair process.

Effects of a topical aqueous oxygen emulsion on collagen deposition and angiogenesis in a porcine deep partial-thickness wound model.

A porcine deep partial-thickness wound model was used to evaluate the effects of a newly developed topical aqueous oxygen emulsion (TOE) on wound repair. The wounds were treated with TOE, which contains super-saturated oxygen or vehicle control. Semiquantitative immunofluorescent staining was performed to examine protein production for type I and type III collagen and vascular endothelial growth factor (VEGF). Immunofluorescent staining revealed higher protein levels of type I and type III collagen and VEGF in the TOE treatment group. Histological analysis also revealed improved angiogenesis and granulation tissue formation with topical TOE treatment and was consistent with the protein expression. In addition, the histology examination demonstrated faster epithelialization in wounds treated with TOE. The study suggests that sustained high levels of oxygen released by TOE may promote the process of wound repair through increasing collagen deposition and angiogenesis as well as stimulating epithelialization.

P311 promotes type II transforming growth factor-ß receptor mediated fibroblast activation and granulation tissue formation in wound healing.

Background: P311, a highly conserved 8 kDa intracellular protein, has recently been reported to play an important role in aggravating hypertrophic scaring by promoting the differentiation and secretion of fibroblasts. Nevertheless, how P311 regulates the differentiation and function of fibroblasts to affect granulation tissue formation remains unclear. In this work, we studied the underlying mechanisms via which P311 affects fibroblasts and promotes acute skin wound repair. Methods: To explore the role of P311, both in vitro and in vivo wound-healing models were used. Full-thickness skin excisional wounds were made in wild-type and P311-/- C57 adult mice. Wound healing rate, re-epithelialization, granulation tissue formation and collagen deposition were measured at days 3, 6 and 9 after skin injury. The biological phenotypes of fibroblasts, the expression of target proteins and relevant signaling pathways were examined both in vitro and in vivo. Results: P311 could promote the proliferation and differentiation of fibroblasts, enhance the ability of myofibroblasts to secrete extracellular matrix and promote cell contraction, and then facilitate the formation of granulation tissue and eventually accelerate skin wound closure. Importantly, we discovered that P311 acts via up-regulating the expression of type II transforming growth factor-ß receptor (TGF-ßRII) in fibroblasts and promoting the activation of the TGF-ßRII-Smad signaling pathway. Mechanistically, the mammalian target of rapamycin signaling pathway is closely implicated in the regulation of the TGF-ßRII-Smad pathway in fibroblasts mediated by P311. Conclusions: P311 plays a critical role in activation of the TGF-ßRII-Smad pathway to promote fibroblast proliferation and differentiation as well as granulation tissue formation in the process of skin wound repair.

Vascular endothelial growth factor receptor 1 (VEGFR1) tyrosine kinase signaling facilitates granulation tissue formation with recruitment of VEGFR1+ cells from bone marrow.

Vascular endothelial growth factor (VEGF)-A facilitates wound healing. VEGF-A binds to VEGF receptor 1 (VEGFR1) and VEGFR2 and induces wound healing through the receptor's tyrosine kinase (TK) domain. During blood flow recovery and lung regeneration, expression of VEGFR1 is elevated. However, the precise mechanism of wound healing, especially granulation formation on VEGFR1, is not well understood. We hypothesized that VEGFR1-TK signaling induces wound healing by promoting granulation tissue formation. A surgical sponge implantation model was made by implanting a sponge disk into dorsal subcutaneous tissue of mice. Granulation formation was estimated from the weight of the sponge and the granulation area from the immunohistochemical analysis of collagen I. The expression of fibroblast markers was estimated from the expression of transforming growth factor-beta (TGF-ß) and cellular fibroblast growth factor-2 (FGF-2) using real-time PCR (polymerase chain reaction) and from the immunohistochemical analysis of S100A4. VEGFR1 TK knockout (TK-/-) mice exhibited suppressed granulation tissue formation compared to that in wild-type (WT) mice. Expression of FGF-2, TGF-ß, and VEGF-A was significantly suppressed in VEGFR1 TK-/- mice, and the accumulation of VEGFR1+ cells in granulation tissue was reduced in VEGFR1 TK-/- mice compared to that in WT mice. The numbers of VEGFR1+ cells and S100A4+ cells derived from bone marrow (BM) were higher in WT mice transplanted with green fluorescent protein (GFP) transgenic WT BM than in VEGFR1 TK-/- mice transplanted with GFP transgenic VEGFR1 TK-/- BM. These results indicated that VEGFR1-TK signaling induced the accumulation of BM-derived VEGFR1+ cells expressing F4/80 and S100A4 and contributed to granulation formation around the surgically implanted sponge area in a mouse model.

Versitality of the Use of Collagen Membrane in Oral Cavity.

INTRODUCTION: Bovine derived collagen membrane is usually and regularly used as a temporary cover or dressing for the extra oral wounds and for the burns on the body. It has wide applications because of its usefulness and biocompatibility. This has provoked us to do a study with the use of collagen membrane even for the intraoral minor surgical defects. AIM: The study was conducted to evaluate the clinical efficacy of collagen membrane as a biological dressing material for intraoral wounds, to check for haemostasis, pain control, granulation tissue formation, rapid re-epithelialization and minimal contracture. MATERIALS AND METHODS: A total of 30 patients 19 male, 11 female were taken for excision of various intraoral lesions like leukoplakia patches, mucocele, epulis growths, irritational fibroma, frenectomy and the surgical defects were closed with collagen membrane. Postoperatively healing was assessed by taking five clinical parameters of Haemostasis, Pain, Granulation tissue, Epithelialization, Contracture. RESULTS: Among 30 patients, haemostasis score was found to be good in 28 cases, fair in two cases. Pain relief score was good in seven cases, fair in 19 cases, poor in four cases. Granulation tissue formation score was good in eight cases, fair in 13 cases, poor in nine cases. Epithelialization score was good in 19 cases, fair in seven cases, poor in four cases. Contracture score was good in six cases, fair in 16 cases, poor in eight cases. Total score of all the five parameters, which was rated as effectiveness score, was calculated by using a standard scale. Final scoring was very effective in six cases, effective in 20 cases, ineffective in four cases. CONCLUSION: Reconstituted bovine derived collagen membrane used in our study was found to be an effective intraoral wound dressing material for faster uneventful healing of intraorally also.

A topical aqueous oxygen emulsion stimulates granulation tissue formation in a porcine second-degree burn wound.

BACKGROUND: Oxygen is an essential substance for wound healing. Limited studies have shown that topical oxygen can influence healing. This study evaluated the effects of a Topical Oxygen Emulsion (TOE) on burn wound healing. METHODS: A porcine second-degree burn wound model was used in the study. Burn wounds were randomly assigned to TOE, vehicle control, and no-treatment (air) groups. Effects of TOE on the granulation tissue formation and angiogenesis were studied using hematoxylin and eosin histological analysis. Protein production and gene expression of types I and III collagen and vascular endothelial growth factor (VEGF) were determined using immunofluorescent staining and Reverse Transcription and Polymerase Chain Reaction (RT-PCR), respectively. RESULTS: The TOE treated wounds exhibited better angiogenesis and granulation tissue formation by histology examination. The immunofluorescence staining and RT-PCR analysis demonstrated that protein production and mRNA expression of VEGF and collagen III were significantly higher in TOE treatment group than vehicle alone and air control groups, while there was no significant difference in the level of collagen I. CONCLUSIONS: Our data demonstrate that TOE enhances burn wound healing via stimulating the expression of VEGF and type III collagen and strongly indicates the potential use of TOE in wounds.