The sucker-like end-to-side arterial anastomosis for free flap in extremities reconstruction: a retrospective study of 78 cases

BACKGROUND

The application of end-to-side (ETS) anastomosis for flap transfer poses challenges, particularly in cases of significant size discrepancy between the donor and flap arteries. Herein, a novel ETS anastomosis technique, termed "sucker-like ETS anastomosis", is developed to mitigate and rectify such vessel discrepancies. This study aims to evaluate the efficacy of this technique in tissue defect reconstruction through free flap transfer.

METHODS

Between September 2018 and March 2023, the medical records and follow-up data of 78 patients who underwent free flap transfer using sucker-like ETS anastomosis for significant artery size discrepancies were collected and retrospectively analyzed.

RESULTS

Among the 78 cases that received free flap transfer, the range of artery size discrepancy (flap artery vs donor artery) was 1:1.6-1:4 (mean: 1:2.5). Following anastomosis with the sucker-like ETS technique, 75 cases achieved flap survival without requiring additional surgical intervention, yielding a one-stage success rate of 96.2%. Three cases experienced post-operative venous crises, with two cases surviving after vein exploration and one case undergoing flap necrosis, necessitating a secondary skin graft. Seven cases faced delayed wound healing but eventually achieved complete healing following dressing changes. No arterial crisis was observed during hospitalization. With an average follow-up of 13 months, the surviving flaps exhibited excellent vitality without flap necrosis or pigment deposition. Overall, the application of sucker-like ETS arterial anastomosis for flap transfer resulted in a high overall surgical success rate of 98.7% (77/78).

CONCLUSION

The application of sucker-like ETS anastomosis for free flap transfer is highly effective, particularly in cases with significant size discrepancy between the recipient and donor arteries.

Arterialization of plantar venous system via vein graft: A novel technique for reconstruction of heel pad degloving injuries

BACKGROUND

Patients with heel pad degloving injury frequently develop ischemic necrosis of the area, necessitating soft-tissue reconstruction surgery. We have developed a technique for arterialization of the plantar venous system via vein graft (APV) as the primary revascularization treatment. The objective of this study was to clarify both the utility of APV for the preservation of degloved heel pads and the impact of this preservation on clinical outcomes.

METHODS

Ten consecutive cases of degloving injury with devascularized heel pad were treated at a single trauma center from 2008 to 2018. Five cases underwent APV and five underwent conventional primary suture (PS) as the initial treatment. We evaluated the course according to the frequency of heel pad preservation, additional intervention after heel pad necrosis, post-operative complications, and outcomes using the Foot and Ankle Disability Index score (FADI) at the time of last follow-up.

RESULTS

Among the five cases that underwent APV, the heel pad was preserved in three cases and flap surgery was required in two cases. All cases that underwent PS developed necrosis of the heel pad, requiring skin graft in one case and flap surgery in four. One skin graft case and one free flap case after PS developed plantar ulcers. The three cases with preserved heel pads exhibited higher FADI than the seven cases that developed necrosis.

CONCLUSION

APV showed a relatively high frequency of heel pad preservation, which otherwise was uniformly lacking. Functional outcomes were improved in cases with preserved heel pad compared to those that developed necrosis and underwent additional tissue reconstruction.

Tissue-engineered Minimalistic Reconstruction of a Severely Crushed Fingertip

The goals of treatment for fingertip injuries are maximising digital length, tactile sensation, pulp padding, and fingertip appearance while minimising complications like infection and amputation. Currently, terminalisation, healing by secondary intention, and flap surgeries are widely used for crushing fingertip injuries, but they have their own set of issues and limitations. We present a tissue-engineered method by combining platelet-rich fibrin injections with stacked-up layers of synthetic biodegradable temporising matrix to treat a severely crushed fingertip. This novel therapy minimised reconstructions while successfully regenerating new soft-tissues. Soft-tissue regeneration within the stacked-up biodegradable matrix achieved adequate volume, sensation, function, and mobility of the newly reconstructed fingertip while maintaining its skeletal length. Notably, the regenerated fingertip allowed the patient to resume work normally as a busy software engineer. Thus, minimalistic fingertip reconstruction not only prevented a disability, but also served as a viable alternative to major reconstructive surgeries.

Adhesive cryogel particles for bridging confined and irregular tissue defects

BACKGROUND

Reconstruction of damaged tissues requires both surface hemostasis and tissue bridging. Tissues with damage resulting from physical trauma or surgical treatments may have arbitrary surface topographies, making tissue bridging challenging.

METHODS

This study proposes a tissue adhesive in the form of adhesive cryogel particles (ACPs) made from chitosan, acrylic acid, 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The adhesion performance was examined by the 180-degree peel test to a collection of tissues including porcine heart, intestine, liver, muscle, and stomach. Cytotoxicity of ACPs was evaluated by cell proliferation of human normal liver cells (LO2) and human intestinal epithelial cells (Caco-2). The degree of inflammation and biodegradability were examined in dorsal subcutaneous rat models. The ability of ACPs to bridge irregular tissue defects was assessed using porcine heart, liver, and kidney as the ex vivo models. Furthermore, a model of repairing liver rupture in rats and an intestinal anastomosis in rabbits were established to verify the effectiveness, biocompatibility, and applicability in clinical surgery.

RESULTS

ACPs are applicable to confined and irregular tissue defects, such as deep herringbone grooves in the parenchyma organs and annular sections in the cavernous organs. ACPs formed tough adhesion between tissues [(670.9 ± 50.1) J/m² for the heart, (607.6 ± 30.0) J/m² for the intestine, (473.7 ± 37.0) J/m² for the liver, (186.1 ± 13.3) J/m² for muscle, and (579.3 ± 32.3) J/m² for the stomach]. ACPs showed considerable cytocompatibility in vitro study, with a high level of cell viability for 3 d [(98.8 ± 1.2) % for LO2 and (98.3 ± 1.6) % for Caco-2]. It has comparable inflammation repair in a ruptured rat liver (P = 0.58 compared with suture closure), the same with intestinal anastomosis in rabbits (P = 0.40 compared with suture anastomosis). Additionally, ACPs-based intestinal anastomosis (less than 30 s) was remarkably faster than the conventional suturing process (more than 10 min). When ACPs degrade after surgery, the tissues heal across the adhesion interface.

CONCLUSIONS

ACPs are promising as the adhesive for clinical operations and battlefield rescue, with the capability to bridge irregular tissue defects rapidly.

Black phosphorous nanomaterials as a new paradigm for postoperative tumor treatment regimens

Surgery is currently a mainstream treatment modality for various solid tumor indications. However, aggressive resection of tumor tissues frequently causes postoperative complications, which severely undermine the well-being of patients. Moreover, the residue tumor cells may substantially increase the risk of local and distant tumor relapse. The recent development in black phosphorus (BP)-based nanomaterials offers a promising opportunity to address these clinical challenges. BP is an emerging nanomaterial with excellent biocompatibility and versatile functionality, which has already demonstrated great potential for a variety of biomedical applications including tumor therapy and tissue engineering. In this review, the recent advances in BP-based nanobiomaterials for the post-surgery treatment of solid tumor have been summarized, while specific emphasis was placed on their capability to continuously inhibit residue tumor growth at the surgery site as well as stimulating various healing mechanisms, aiming to preventing tumor relapse while promoting the healing of surgery-induced traumatic soft/hard tissue injuries. It is anticipated that the nanoengineered BP-based materials may open new avenues to tackle those clinical challenges in surgical treatment of solid tumors.

Experimental Models to Study HIV Latency Reversal from Male Genital Myeloid Cells

HIV reservoirs in tissues are poorly understood and their establishment largely depends on the nature of tissues that interact with the virus. In this chapter, we will describe in vitro and ex vivo models of human urethral mucosal macrophages used in the investigation of the establishment and maintenance of tissue HIV reservoirs. In addition, we will describe how macrophage latent HIV infection was assessed in these models by reverting a nonproductive state of infection back into a productive state. Consequently, infectious particles are released to the macrophage extracellular milieu and detected by adapted viral outgrowth assays. Altogether, these approaches provide invaluable tools for the investigation on tissue-specific pathways that HIV-1 employs to reach host cells and form reservoirs in the genital mucosa. These models will contribute to the development of an efficient and targeted prophylaxis against HIV and of a HIV cure.

In vivo Mouse Mammary Gland Formation

For years, the mammary gland serves as a perfect example to study the self-renew and differentiation of adult stem cells, and the regulatory mechanisms of these processes as well. To assess the function of given genes and/or other factors on stemness of mammary cells, several in vitro assays were developed, such as mammospheres formation assay, detection of stem cell markers by mRNA expression or flow cytometry and so on. However, the capacity of reconstruction of whole mount in the cleared fat pad of recipient female mice is a golden standard to estimate the stemness of the cells. Here we described a step-by-step protocol for in vivo mammary gland formation assay, including preparation of "cleared" recipients and mammary cells for implantation, the surgery process and how to assess the experimental results. Combined with manipulation of mammary cells via gene editing and /or drug treatment, this protocol could be very useful in the researches of mammary stem cells and mammary development.

A highly simulated scar model developed by grafting human thin split-thickness skin on back of nude mouse: The remodeling process, histological characteristics of scars

A predictive scar animal model is needed in order to study the mechanism and assess the therapies before its use in humans. However, due to the differences in wound healing patterns and regeneration ability, none of the existing models can fully simulate the characteristics of human scar. The aim of this study was to build a model that recapitulated the developing process and outcomes of human hypertrophic scar (HS). Nude mice were grafted with thin split-thickness human skins. The dynamic changes and final outcomes of the grafts were investigated. The results showed that human skin grafts survived and underwent progressive scarring remodeling in morphology and histology. Scar related markers (α-SMA, CD34, Collage I, TGF-β1) were positive in immunohistology. Protein expressions in TGF-β1/Smad2/3 pathway were increased in accordance with HS during the development process by western blotting. It was finally proved that scar reconstructed by this model matches a real-world human HS. This is a stable, easy to reproduce model for studying the scar formation process and its properties.

Chinese sesame stick-inspired nano-fibrous scaffolds for tumor therapy and skin tissue reconstruction

Surgery is a common treatment to remove the solid skin tumors. It is of great importance to eliminate the remaining tumor cells and achieve the simultaneous tissue reconstruction after surgery for improving life quality of cancer patients. Inspired by the designing strategy and fabrication method of Chinese sesame sticks, a Chinese sesame stick-like scaffold is developed by spin coating of CaCuSi₄O₁₀ nanoparticles (NPs) on the surface of electrospun fibers for tumor therapy and skin tissue reconstruction. The CaCuSi₄O₁₀ NPs can transform near-infrared light energy into heat energy, showing the photothermal conversion efficiency of 33.8%. After coating of the CaCuSi₄O₁₀ NPs on the fibers, the prepared scaffolds exhibit the Chinese sesame stick-like structure and achieve bifunction with both tumor killing and skin tissue reconstruction capacities. The CaCuSi₄O₁₀ NPs endow the scaffolds with photothermal ablation potential to rapidly kill the in vitro tumor cells. Furthermore, Chinese sesame stick-like scaffolds effectively inhibit in vivo tumor growth at the early stage and accelerate healing of cancer surgery-caused wounds at the later stage in tumor-bearing mice. Additionally, the composite scaffolds promote chronic wound healing by stimulating in vivo angiogenesis and re-epithelization, harnessing locally release of bioactive Cu²⁺ and SiO₄^4- ions from the CaCuSi₄O₁₀ NPs. Therefore, the Chinese sesame stick-inspired scaffolds may lay a solid foundation for clinical treatment of cancers and cancer surgery-induced tissue damage.

One-stage Integra coverage for fingertip injuries

BACKGROUND

We hypothesize that one-stage Integra skin coverage is an effective treatment modality for the treatment of fingertip defects.

METHODS

Nine patients who sustained fingertip injuries were treated with one-stage Integra coverage. In all cases, Integra was placed directly on bone. Static two-point discrimination and the Semmes-Weinstein Monofilament Test (SWMFT) were used to determine the sensations of the affected and opposite unaffected digit. The QuickDASH, Cold Intolerance Symptom Severity (CISS), visual analog scale (VAS), and a 0-10-point pain scale were administered to assess patient function, satisfaction, and pain levels.

RESULTS

The mean age was 53.1 years (39-61). There were 8 males and 1 female. The average area covered was 2.3 cm(2) (1.0-3.2). The mean follow-up duration was 16 months (8-46). The median QuickDASH, CISS score, VAS patient satisfaction, and 0-10 pain score were 9.1 (2.3-40.9), 18 (4-30), 10 (most satisfied) (7-10), and 0 (0-3), respectively. Five patients were evaluated for their digital sensory perception. The mean static two-point discrimination was 9.6 mm for the affected digit and 4.6 mm for the opposite unaffected digit. The median SWMFT was 4.31 for the affected digit and 3.61 for the opposite unaffected digit.

CONCLUSION

For small soft tissue and bone defects involving the fingertip, the use of Integra without further skin grafting appears to be effective, avoids the morbidity of the donor site, and avoids a second surgery. Despite mild sensory deficits, patients were satisfied with the results and fully functional during short-term follow-up.