Tracheal Replacement Techniques and Associated Mortality: A Systematic Review.

OBJECTIVE: Tracheal replacement is a crucial operation to enhance the quality of life for patients with extensive tracheal lesions. The most suitable surgical techniques for different clinical conditions remain a topic of debate. Through a reviewing of the relevant literature, this study investigated the association between surgical techniques and mortality rate. DATA SOURCES: Studies were collected from PubMed, Embase, the Web of Science, the Cochrane Center Register of Controlled Trials, and ClinicalTrials.gov. METHODS: This systematic review encompassed literature from the inception of each database to May 10, 2023, focusing on tracheal replacement for patients who underwent circumferential resection of the trachea or partial resection with preservation of the posterior membranous wall. Non-human and non-clinical studies were excluded. RESULTS: About 31 studies were included in the assessment comprising a combination of case reports and case series, and 118 patients underwent tracheal replacement through four underlying methodologies, including tracheal allotransplantation, autologous tissue reconstruction, bioprosthetic reconstruction, or tissue engineering surgery. Each modality exhibits unique advantages and disadvantages, leading to variable outcomes in clinical application. CONCLUSION: Tracheal replacement is challenging due to the absence of an ideal substitution or graft material. Despite limited clinical successes observed across various modalities, we believe autologous tissue reconstruction for tracheal replacement has the advantage of broadest indications, low rejection rate, and avoidance of immunosuppressive agents. Future research should focus on achieving tracheal replacement that preserves mucociliary clearance, lateral rigidity, and longitudinal flexibility. LEVEL OF EVIDENCE: NA Laryngoscope, 134:1517-1522, 2024.

The Synergistic Effect of Electrical Stimulation and Dermal Fibroblast Cells-Laden 3D Conductive Hydrogel for Full-Thickness Wound Healing.

Clinically, most patients with poor wound healing suffer from generalized skin damage, usually accompanied by other complications, so developing therapeutic strategies for difficult wound healing has remained extremely challenging until now. Current studies have indicated that electrical stimulation (ES) to cutaneous lesions enhances skin regeneration by activating intracellular signaling cascades and secreting skin regeneration-related cytokine. In this study, we designed different concentrations of graphene in gelatin-methacrylate (GelMa) to form the conductive composite commonly used in wound healing because of its efficiency compared to other conductive thermo-elastic materials. The results demonstrated the successful addition of graphene to GelMa while retaining the original physicochemical properties of the GelMa bioink. In addition, the incorporation of graphene increased the interactions between these two biomaterials, leading to an increase in mechanical properties, improvement in the swelling ratio, and the regulation of degradation characteristics of the biocomposite scaffolds. Moreover, the scaffolds exhibited excellent electrical conductivity, increasing proliferation and wound healing-related growth factor secretion from human dermal fibroblasts. Overall, the HDF-laden 3D electroconductive GelMa/graphene-based hydrogels developed in this study are ideal biomaterials for skin regeneration applications in the future.

Prognostic Factors of Marjolin Ulcers: A Meta-Analysis and Systematic Review Assisted by Machine Learning Techniques.

BACKGROUND: Marjolin ulcers (MUs) are malignant tumors arising from previously injured skin, including burn wounds, scars, chronic ulcers, and other chronic nonhealing inflammatory conditions. They have a potentially long latent period. The authors aimed to establish the prognostic factors for recurrence, metastasis, and disease-specific death related to MU. METHODS: The authors performed a comprehensive search of PubMed, Embase, and the Cochrane Library. After assessing the methodologic quality of case series, they performed a meta-analysis and systematic review. Furthermore, the authors used machine learning to predict patient survival time. RESULTS: MUs on the upper limbs, head, and neck had a higher risk of recurrence. Contrastingly, lower grade lesions, absence of lymph node metastasis, and a tumor diameter of less than 10 cm were associated with lower recurrence risk. The risks were unrelated to age and latent period. In addition, patients without lymph node metastasis had a lower risk of developing distant metastasis. Furthermore, the risk of disease-specific death was lower in patients with a lower tumor grade, absent lymph node metastasis, small tumor diameter (<10 cm), and tumors located in regions other than the head and neck. Correlation analysis showed that the age at initial injury was negatively correlated with the latent period of MU. CONCLUSIONS: The authors found that tumor grade, tumor site, lymph node status, and tumor size are important predictors of a worse prognosis. To integrate these predictors, the authors created an equation to predict the survival time for individual patients by means of machine learning processes. Moreover, the authors found that MU developed more quickly in older individuals with injuries.

The 3D printed conductive grooved topography hydrogel combined with electrical stimulation for synergistically enhancing wound healing of dermal fibroblast cells.

Patients with extensive cutaneous damage resulting from poor wound healing often have other comorbidities such as diabetes that may lead to impaired skin functions and scar formation. Many recent studies have shown that the application of electrical stimulation (ES) to cutaneous lesions significantly improves skin regeneration via activation of AKT intracellular signaling cascades and secretion of regeneration-related growth factors. In this study, we fabricated varying concentrations of gelatin-methacrylate (GelMa) hydrogels with poly(3,4-ethylenedioxythiophene) (PEDOT): polystyrene sulfonate (PSS), which is a conductive material commonly used in tissue engineering due to its efficiency among conductive thermo-elastic materials. The results showed successful modification of PEDOT:PSS with GelMa while retaining the original structural characteristics of the GelMa hydrogels. In addition, the incorporation of PEDOT:PSS increased the interactions between both the materials, thus leading to enhanced mechanical strength, improved swelling ratio, and decreased hydrophilicity of the scaffolds. Our GelMa/PEDOT:PSS scaffolds were designed to have micro-grooves on the surfaces of the scaffolds for the purpose of directional guiding. In addition, our scaffolds were shown to have excellent electrical conductivity, thus leading to enhanced cellular proliferation and directional migration and orientation of human dermal fibroblasts. In vivo studies revealed that the GelMa/PEDOT:PSS scaffolds with electrical stimulation were able to induce full skin thickness regeneration, as seen from the various stainings. These results indicate the potential of GelMa/PEDOT:PSS as an electro-conductive biomaterial for future skin regeneration applications.

Soft Tissue Damage in Patients With Hemifacial Microsomia.

OBJECTIVE: The aim of this study was to evaluate the extent of the damage to soft tissues on the affected side in patients with hemifacial microsomia (HFM). MATERIALS AND METHODS: Nine patients with HFM were included in this study and underwent computed tomography (CT) examination in the craniofacial area. The axial and coronal CT images were used for evaluating the damage to related soft tissues. RESULTS: The results showed that the masseter muscle, temporal muscle, pterygoid muscles, and parotid gland were damaged on the affected side in all 9 patients with HFM. However, the extent of the damage to the pterygoid muscles was less than that to the masseter muscle, temporal muscle, and parotid gland. CONCLUSIONS: These findings indirectly support the crucial role of hemorrhage in the development of HFM, and the extent of damage to soft tissues may depend on the distance and barrier effect of the mandible between the hemorrhage and the affected tissues.

Ileocecal vascularized lymph node transfer for the treatment of extremity lymphedema: A case report.

Vascularized lymph node (VLN) transfer has been of high interest in the past decade for the treatment of lymphedema, since it has been shown to be effective in reducing limb volumes, decreasing infectious episodes and improving quality of life. Multiple donor sites have been described in the quest for the optimal one. Herein, we describe a novel lymph node flap option based on the ileocolic artery and vein. The ileocecal vascularized lymph node (IC-VLN) flap was used in the management of a 33-year-old male patient with lower extremity lymphedema secondary to left inguinal trauma. The patient had previously underwent a pedicled omentum flap transposition with minimal improvement in limb size and persistent episodes of infection. At 15 month follow-up, the IC-VLN flap improved the lymphatic drainage in the affected limb with a mean limb circumference reduction rate of 26.3%. No donor site complications or further episodes of infection were noted. According to our findings, the IC-VLN flap may be another option for VLN transfer in very selected cases. Nevertheless, larger series with a longer follow-up are required to analyze the efficacy and long-term results of this flap.

Homologous pairing activities of Arabidopsis thaliana RAD51 and DMC1.

In eukaryotes, homologous recombination plays a pivotal role in both genome maintenance and generation of genetic diversity. Eukaryotic RecA homologues, RAD51 and DMC1, are key proteins in homologous recombination that promote pairing between homologous DNA sequences. Arabidopsis thaliana is a prominent model plant for studying eukaryotic homologous recombination. However, A. thaliana RAD51 and DMC1 have not been biochemically characterized. In the present study, we purified A. thaliana RAD51 (AtRAD51) and DMC1 (AtDMC1). Biochemical analyses revealed that both AtRAD51 and AtDMC1 possess ATP hydrolyzing activity, filament formation activity and homologous pairing activity in vitro. We then compared the homologous pairing activities of AtRAD51 and AtDMC1 with those of the Oryza sativa and Homo sapiens RAD51 and DMC1 proteins.

The deregulation of miR-133b is associated with poor prognosis in bladder cancer.

BACKGROUND: MicroRNAs (miRNAs) are single-stranded, endogenous, non-coding RNAs that are increased or decreased in almost all cancer types, and they paly crucial roles in the tumorigenesis as well as development. MATERIALS AND METHODS: 90 patients diagnosed with bladder cancer were enrolled in the present study. The bladder cancer tissues or adjacent normal tissues were obtained from the tumor area or adjacent normal zone. The expression level of miR-133b was examined by quantitative real-time polymerase chain reaction assay (qRT-PCR). Survival curves were displayed by the Kaplan-Meier method, and differences between two survival curves were calculated by the log-rank test. RESULTS: The expression levels of miR-133b in bladder tissues were significantly decreased when compared with the matched adjacent normal bladder tissues (P < 0.05). Moreover, miR-133b expression levels are significantly associated with lymphatic invasion (P = 0.026), distant metastasis (P = 0.025), tumor grade (P = 0.038), as well as the muscle invasion status (P < 0.001). The log-rank test indicated that patients with decreased miR-133b expression underwent poorer overall survival (P = 0.007). Furthermore, multivariate Cox regression analysis showed that the expression level of miR-133b (P = 0.024) was an independent factor for predicting the overall survival in patients with bladder cancer. CONCLUSIONS: The present study showed that miR-133b might be associated with bladder cancer progression, and its down-regulation might be a biomarker for poor prognosis of bladder cancer.

A 'silent' skull metastatic follicular thyroid carcinoma mimicking as a benign scalp tumor in a pregnant woman.

Thyroid cancer with cranial metastasis in a pregnant woman is very rare. In the literature, most cases are diagnosed early from neurogenic signs or symptomatic thyroid gland. Pregnancy also contributes to a hesitation toward early surgical and medical treatments. We reported a scalp tumor in a physically healthy 37-year-old pregnant female with a follicular thyroid carcinoma (FTC) with lung, bone and cranial metastasis in initial presentation. Silent neurogenic and physical examinations make an early diagnosis very challenging. Resection of scalp and intracranial tumor, a thyroidectomy, post-operative radioactive iodine therapy and tyrosine kinase inhibitors were employed as treatment. The scalp tumor was confirmed as a metastatic follicular thyroid carcinoma via positive immunoreactivity for thyroglobulin and thyroid transcription factor 1 in tumor cells. Blood examination revealed an elevated thyroglobulin level (>5335 ng/mL). The patient was discharged without any neurological deficit. An asymptomatic scalp tumor in a pregnant woman with a normal thyroid disease history needs differential diagnosis from intracranial origin. Rapid progression and an elevated thyroglobulin level are the indicators that further image study is needed. Aggressive surgical excision of resectable thyroid gland and metastatic tumor are essential for a longer survival rate. There is nothing to indicate that a post-partum operation will worsen prognosis. LEARNING POINTS: Follicular thyroid cancer with cranial metastasis in initial presentation can be asymptomatic.Follicular thyroid cancer with cranial metastasis in a pregnant woman can be treated after delivery.Rapid enlargement of scalp tumor is indicated for further image study even in a patient without any neurological deficit.

Back-up procedures following complicated gastric pull-up procedure for esophageal reconstruction: Salvage with intestinal flaps.

BACKGROUND: Gastric pull-up (GPU) is the most common procedure for restoring the continuity of the alimentary tract. Yet, complications because of anastomotic problems are reported to be as high as 25% after this procedure. Managing the neck with anastomotic leakage or stricture following failed GPU and/or radiotherapy is formidable. We report our method, basic algorithm and results with the complicated GPU procedure management with intestinal transfers . PATIENTS AND METHODS: Nineteen cases referred to our department with complicated esophageal reconstruction following GPU procedure were included in this report. Of the19 patients, 18 had undergone GPU procedure for reconstruction after cancer resection (mean age 55 years) and one for idiopathic esophagitis (mean age 45years). Fifteen patients presented with severe stricture formation and 4 patients with leakage from the anastomotic site. Average time between the GPU and salvage procedures was 7.3 months for patients with stricture formation and 15.5 days for patients with leakage. Pedicled colon interposition (n = 8) was used when the upper end of the gastric tube was located below the sternoclavicular junction. A free jejunal flap (n = 11) was utilized when defects were located at the neck (above the sternoclavicular junction). RESULTS: In all patients salvage procedures with intestinal flap transfer were successful with complete flap survival. Post-operative period was uneventful except of two patients with pedicled colon interposition who presented minor leakage post-operatively (10.5%). This was treated with conservative means, leading to spontaneous healing. The average follow-up for the patients with tumor resection was 11.8 months (range: 6 to 30) after the salvage procedure. All patients resumed smooth oral intake eventually. There were 16 patients who could feed with solid diet, whereas three patients were able to tolerate only soft diet. CONCLUSION: Intestinal tissues can be safely and successfully transferred as salvage procedures, with meticulous technique, careful patient selection and individual flap design. While gastric pull-up remains a good procedure for esophageal reconstruction, the methods described in this report are useful as back-up armaments in complicated cases. © 2015 Wiley Periodicals, Inc. Microsurgery 36:567-572, 2016.

Efficacy and Safety of Povidone-Iodine Irrigation in Reducing the Risk of Capsular Contracture in Aesthetic Breast Augmentation: A Systematic Review and Meta-Analysis.

BACKGROUND: Capsular contracture is common and distressing after aesthetic breast augmentation. The precise cause of capsular contracture is not well established. This systematic review investigates current available evidence regarding perioperative povidone-iodine irrigation safety and efficacy in reducing capsular contracture. METHODS: PubMed/MEDLINE, Embase, and Scopus databases were searched for publications through December of 2014. Studies with the following criteria were included: (1) primary breast augmentation with implants; (2) perioperative povidone-iodine use; and (3) documentation of capsular contracture. Our primary outcome was incidence of Baker class III/IV capsular contracture. The methodologic quality of included studies was assessed independently. Trials were meta-analyzed to obtain a pooled odds ratio describing the effect of povidone-iodine irrigation on Baker class III/IV capsular contracture. RESULTS: Nine studies with a total of 5153 patients undergoing aesthetic breast augmentation with implants were included. Only three comparative studies achieved high methodologic quality. The meta-analysis included four studies, with 1191 patients receiving povidone-iodine irrigation and 595 patients receiving saline irrigation. The meta-analysis favored povidone-iodine irrigation for decreasing Baker class III/IV capsular contracture (2.7 percent versus 8.9 percent; OR, 0.30; 95 percent CI, 0.18 to 0.50; p < 0.00001; I = 0 percent). The reported implant rupture rates for both saline implants and silicone implants were less than 1 percent. CONCLUSIONS: Perioperative povidone-iodine irrigation reduces Baker class III/IV capsular contracture and is not associated with implant rupture. Low methodologic quality of included studies limits recommendations for perioperative povidone-iodine irrigation as the standard of practice. Additional high-quality trials are warranted to corroborate the findings of this meta-analysis. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.