Quantization of extraoral free flap monitoring for venous congestion with deep learning integrated iOS applications on smartphones: a diagnostic study.

BACKGROUND: Free flap monitoring is essential for postmicrosurgical management and outcomes but traditionally relies on human observers; the process is subjective and qualitative and imposes a heavy burden on staffing. To scientifically monitor and quantify the condition of free flaps in a clinical scenario, we developed and validated a successful clinical transitional deep learning (DL) model integrated application. MATERIAL AND METHODS: Patients from a single microsurgical intensive care unit between 1 April 2021 and 31 March 2022, were retrospectively analyzed for DL model development, validation, clinical transition, and quantification of free flap monitoring. An iOS application that predicted the probability of flap congestion based on computer vision was developed. The application calculated probability distribution that indicates the flap congestion risks. Accuracy, discrimination, and calibration tests were assessed for model performance evaluations. RESULTS: From a total of 1761 photographs of 642 patients, 122 patients were included during the clinical application period. Development (photographs =328), external validation (photographs =512), and clinical application (photographs =921) cohorts were assigned to corresponding time periods. The performance measurements of the DL model indicate a 92.2% training and a 92.3% validation accuracy. The discrimination (area under the receiver operating characteristic curve) was 0.99 (95% CI: 0.98-1.0) during internal validation and 0.98 (95% CI: 0.97-0.99) under external validation. Among clinical application periods, the application demonstrates 95.3% accuracy, 95.2% sensitivity, and 95.3% specificity. The probabilities of flap congestion were significantly higher in the congested group than in the normal group (78.3 (17.1)% versus 13.2 (18.1)%; 0.8%; 95% CI, P <0.001). CONCLUSION: The DL integrated smartphone application can accurately reflect and quantify flap condition; it is a convenient, accurate, and economical device that can improve patient safety and management and assist in monitoring flap physiology.

Reconstruction of nasal airway in patients of class IIId maxillary defect with vastus lateralis muscle-chimeric double skin paddle ALT flap.

BACKGROUND: A reconstructive challenge in patients with class IIId maxillary defect is how to obliterate the defect and restore a patent nasal airway. The current strategy using the single anterolateral thigh (ALT) fasciocutaneous flap for reconstruction may result in permanent mouth breathing. As the ALT flap was a common option in reconstruction processes, this study aimed to evaluate the benefits of vastus lateralis (VL) muscle-chimeric double skin paddle ALT flap in simultaneous defect and nasal airway reconstruction. METHODS: This study included 21 patients with class IIId maxillary defect who underwent free ALT flap reconstruction (n = 11, single ALT flap group; n = 10, VL muscle-chimeric double skin paddle ALT flap (chimeric ALT flap) group) at the China Medical University Hospital from August 2015 to September 2019. Associated parameters collected for analysis included gender, age, body mass index (BMI), operative time, hospitalization, clinical stage, preoperative treatment, flap/defect size, comorbidities, postoperative RT, mouth breathing and short/long term complications. RESULTS: No significant differences were observed in age, BMI, hospitalization, clinical stage, preoperative treatment, defect size, comorbidities, and postoperative RT between the two groups; however, the chimeric ALT flap group as dominated by male patients (p = 0.009), and had longer operative times (12.1 h vs. 10.1 h, p = 0.002) and larger flap sizes (180 cm2 vs. 96.7 cm2, p = 0.013). Compared with the chimeric ALT flap group, the single ALT flap group suffered from permanent mouth breathing. CONCLUSION: Nasal airway reconstruction should be considered in patients with class IIId maxillary defect. Compared to the single ALT flap, the chimeric ALT flap is a superior reconstructive option for patients with class IIId maxillary defect, although a longer surgical duration and larger flap size are required.

Risk of diaphragmatic hernia in patients with spontaneous pneumothorax.

BACKGROUND: Few studies have implied the incidence of diaphragmatic hernia (DH) after spontaneous pneumothorax (SP) with unknown mechanisms. The current study aimed to identify whether there is an association between the DH and SP. METHODS: We selected 46,897 patients with SP (SP cohort) and 46,897 without SP (non-SP matched cohort) from the National Health Insurance Database. Patients were frequency matched according to age, sex, and index year. The incidence of DH and its association with SP were assessed after stratifying different characteristics and comorbidities. Statistical analysis including chi-square test, t-test, cox proportional hazard model, and Kaplan-Meier method were used. RESULTS: The results suggested there were significant associations between SP and DH, especially in the subgroup of patients with older age (aged 40-64 years: 2.61-fold in adjusted hazard ratio (aHR), 95% confidence interval (CI): 1.27-5.36; aged > 65 years: 1.97-fold in aHR, 95% CI 1.43-2.71), male sex (2.11-fold in aHR, 95% CI 1.56-2.85), hypertension (2.05-fold in aHR, 95% CI 1.30-3.23), diabetes mellitus (2.58-fold in aHR, 95% CI 1.37-4.86), and smoking-related disease (1.86-fold in aHR, 95% CI 1.28-2.71). The SP cohort has significantly correlated with DH within 5-year follow-up (< 2 years: 3.22-fold in aHR, 95% CI 2.10-4.94; 2-5 years: 1.70-fold in aHR, 95% CI 1.05-2.75). CONCLUSIONS: The SP cohort had a higher incidence of DH than the non-SP matched cohort. A prospective study of indications based on the findings of the current research should be performed.

Free extended anterolateral thigh myocutaneous flap versus combined pedicled pectoralis major-latissimus dorsi myocutaneous flaps in deep and extensive sternal wound reconstruction.

BACKGROUND: The combined pedicled pectoralis major-latissimus dorsi (PM-LD) and free extended anterolateral thigh (ALT) myocutaneous flaps provide well-vascularized tissues for extensive sternal wound reconstruction. However, the outcomes and postoperative complications between the two surgical techniques are different. Thus, the aim of this study is to evaluate the feasibility of these two reconstructive options. METHODS: This single-center, retrospective study was conducted between August 2011 and May 2019. Forty-four patients diagnosed with deep sternal wound infection (DSWI) and presented with grade four complications (sternal instability and necrotic bone tissue) were enrolled. Two reconstructive strategies, namely, combined pedicled PM-LD (n = 24) and free extended ALT (n = 20) myocutaneous flaps, were used according to the patients' hemodynamics. Data including age, gender, body mass index (BMI), hospital stay, follow-up, defect/flap size, number of surgical procedures before reconstruction, duration from the last debridement to flap coverage, comorbidities, and postoperative complications, were obtained for statistical analysis. RESULTS: The mean defect size in the combined PM-LD myocutaneous flap group was 188.4 (5*17-10*23) cm2 , and the mean flap size was 150.0 (8*12-15*15) cm2 and 205.0 (8*15-10*25) cm2 in PM and LD flap, respectively. The mean defect size in the free extended ALT myocutaneus flap group was 202.5 (6*16-10*21) cm2 , and the mean flap size was 285.2 (9*30-12*25) cm2 . No significant differences were observed between the free extended ALT and the combined pedicled PM-LD myocutaneous flaps in relation to age, gender, BMI, hospital days, follow-up, defect size, preoperative procedures, and comorbidities, except for the average operative time (443.2 ± 31.2 vs. 321.3 ± 54.3 mins, p = .048). The combined pedicled PM-LD myocutaneous flap had significantly more donor site complications, including seroma (21% vs. 0%, p = .030), bilateral nipple-areolar complex asymmetry (100% vs. 0%, p < .0001), and skin graft loss with infection (33% vs. 0%; p = .044) than the free extended ALT myocutaneous flap. CONCLUSION: The free extended ALT and the combined pedicled PM-LD myocutaneous flaps were both feasible and effective options for sternal wound reconstruction. Our findings suggested that the free extended ALT myocutaneous flap may be a better alternative for a comprehensive and extensive reconstruction of sternal wounds. Further studies based on these findings can be conducted.

Heparin-induced thrombocytopenia and thrombosis in primary lymphedema patients who underwent vascularized lymph node transplantations.

BACKGROUND: Heparin-induced thrombocytopenia and thrombosis (HITT) may result in microsurgical flap failure. This study investigated the outcomes of HITT in primary lymphedema patients who underwent vascularized lymph node transplantations (VLNT). METHODS: Between 2012 and 2019, primary lymphedema patients who underwent VLNTs were retrospectively included. The 4Ts score was used to categorize patients into HITT (scores of 5-7) and non-HITT (score < 5) groups. Outcome evaluations included the re-exploration rate, success rate, circumferential differences, cellulitis episodes, and Lymphedema Specific Quality of Life Questionnaire (LYMQoL) scores. RESULTS: Twenty-six and 15 patients with 31 and 16 VLNTs were included in the HITT and non-HITT groups, respectively. The HITT group had significantly greater first, second and third re-exploration rates of 38.7% (12/31), 25.7% (8/31), and 6.5% (2/31) than the non-HITT group (6.3%, 0%, and 0%, all p < 0.01), respectively. The platelet counts significantly decreased by 21.0% in the HITT group compared with the non-HITT group (14%) on postoperative Day one (p < 0.01) with a cutoff value of 17% and AUC = 0.88. CONCLUSIONS: HITT may cause a high re-exploration rate of VLNTs in primary lymphedema patients. The 17% reduction in platelets on postoperative day one was an early sign for detecting HITT.

The Correlation between Lower Extremity Fracture and Subsequent Arterial Embolism and Thrombosis-A National Population Cohort Study.

The hazard of subsequent arterial embolism and thrombosis (SAET) in patients with lower leg fractures is not yet well demonstrated. The purpose of this study is to determine the correlation between lower leg fracture and SAET in Taiwan. A total of 134,844 patients with lower leg fractures (ICD-9-CM: 823) and chronological diagnosis as SAET (ICD-9-CM: 444.22) was matched (1:1) to the non-fracture cohort according to their propensity score (data coming from the National Health Insurance database between January 2000 to December 2012). Patients were matched by age, gender, and comorbidities. The incidence of SAET and correlation between SAET development and lower leg fracture was statistically analyzed, and subgroup analysis categorized by characteristics and comorbidities was conducted as well. The cumulative incidence of SAET was calculated by Kaplan-Meier analysis. Kaplan-Meier analysis plot showed that, by the end of the ten-year follow-up period, the cumulative incidence of SAET was significantly higher for the lower leg fracture cohort than for the non-fracture cohort (log-rank test: p < 0.001). The lower leg fracture, male, elder age (45-64-year-old; ≥65-year-old), hypertension, diabetes mellitus, and gout were significantly associated with lower extremity SAET risk compared with the matched group. There was an inseparable correlation between the lower leg fracture group and the risks of SAET; subgroup analysis by gender (male, female), age (age < 40 years, age 40-64 years, and age > 65 years) and comorbidities (hypertension, diabetes mellitus, and gout) show compatible results as well. Patients with lower leg fracture have a significantly increased risk of SAET since then two years after the fracture. The hazard of SAET was significantly higher in patients with lower leg fracture than in the non-fracture cohort, and the high incidence was found since then two years after fracture. Further studies are warranted.

Associations between Zygoma Fracture and Post-Traumatic Headache: A Study among Taiwanese Population.

Few studies have discussed the development of post-traumatic headache (PTH) after zygoma fracture. This research aimed to examine the association between zygoma fracture and PTH and its other associated factors. A total of 3043 patients with zygoma fracture and 3043 patients with non-fracture were included in this analysis. They were matched to a non-fracture cohort from the National Health Insurance database according to age, sex, and index year. The incidence of PTH and its association with zygoma fracture were assessed. The zygoma fracture cohort had a significantly higher cumulative incidence of PTH than the non-fracture cohort in a 10-year follow-up. The confounding risk factors of PTH included zygoma fracture, female sex, and comorbidities, including obesity and depression. Female patients under 40 years old who had zygoma fractures had a higher incidence of PTH than the non-fracture group. Moreover, patients with zygoma fractures commonly developed PTH within three months after injury. Female patients under 40 years old with precedent zygoma fractures had a higher incidence rate of PTH than those without fractures. Moreover, patients with zygoma fractures commonly developed PTH within three months after injury. Nevertheless, before widely applying our results, a prospective study must be conducted to verify the risk factors found in this study.

Feasibility of a craniometry in a comminuted zygomaticomaxillary complex fracture.

Few studies have reported on using craniometry for comminuted zygomaticomaxillary complex (ZMC) fracture management. We present our experiences with this procedure and a review of the related literature.From September 2011 to October 2018, 43 patients with comminuted ZMC fracture receiving open reduction internal fixation under coronal incision were enrolled. Data on gender, age, operation time, hospital stay, duration of follow-up, vertical/horizontal differences, and complications were collected. Between-group differences (C-arm imaging vs craniometry) were evaluated using nonparametric Mann-Whitney test for continuous data and chi-square test for categorical data.No significant difference were found between the groups regarding gender, age, hospital duration, follow-up duration, and postoperative complications, except for operation time. The averaged operation time was significantly shorter in the C-arm imaging group (4.217 h) than in the craniometry group (6.193 h). The C-arm imaging group had two cases with horizontal differences >3 mm and one case with vertical differences >3 mm. The craniometry group had four cases with horizontal differences >3 mm and four cases with vertical differences >3 mm. There were no significant differences between the two groups in horizontal differences and vertical differences.Craniometry may achieve the same outcomes as C-arm imaging in comminuted ZMC fracture management; however, the former requires more time than the latter.

Anterograde injection of low-dose urokinase salvages free anterolateral thigh flap: A case report of safe and effective treatment.

RATIONALE: A 54-year-old Taiwanese male came to our hospital presented with right retromolar mucoepidermoid carcinoma. Composite resection and right modified radical neck dissection were performed. We then use free anteral lateral thigh flap to reconstruct the defect. However, venous congestion was found 32 h after the surgery. PATIENT CONCERNS: The main concerns of the patient is complete salvage of the free flap, and avoiding the secondary free flap harvesting and reconstruction surgeries. DIAGNOSES: Right retromolar mucoepidermoid carcinoma. INTERVENTIONS: We report the case of a patient with an anterolateral thigh flap with venous perianastomosis thrombosis and intraflap microvascular thrombosis successfully salvaged using anterograde intra-arterial injection of low-dose urokinase (60,000 U), without administering intravenous anticoagulation heparin during the postoperative period. OUTCOMES: The flap was completely salvaged 3 days after treatment. No other flap-associated or bleeding complications were noted. The intra-oral wounds around the flap completely healed without any post-ischemic complications. LESSONS SUBSECTIONS: Although the ideal urokinase doses and delivery procedures for free flap salvage have not been developed thus far, our method maximizes the urokinase gradient in the flap, minimizes the total dose required for flap salvage, and ensures no systemic spread. Thus, compared with other thrombolytic agents, urokinase may be more effective and safe for free flap salvage. With more experience, a standardized dosage and procedure can be developed.

A Simple Technical Modification for the Creation of an External Monitoring Skin Paddle for Tubed ALT Flap Reconstruction after Circumferential Hypopharyngeal Resection.

Supplemental Digital Content is available in the text.

A comprehensive study of long-term skeletal changes after spinal cord injury in adult rats.

Spinal cord injury (SCI)-induced bone loss represents the most severe osteoporosis with no effective treatment. Past animal studies have focused primarily on long bones at the acute stage using adolescent rodents. To mimic chronic SCI in human patients, we performed a comprehensive analysis of long-term structural and mechanical changes in axial and appendicular bones in adult rats after SCI. In this experiment, 4-month-old Fischer 344 male rats received a clinically relevant T13 contusion injury. Sixteen weeks later, sublesional femurs, tibiae, and L4 vertebrae, supralesional humeri, and blood were collected from these rats and additional non-surgery rats for micro-computed tomography (µCT), micro-finite element, histology, and serum biochemical analyses. At trabecular sites, extreme losses of bone structure and mechanical competence were detected in the metaphysis of sublesional long bones after SCI, while the subchondral part of the same bones showed much milder damage. Marked reductions in bone mass and strength were also observed in sublesional L4 vertebrae but not in supralesional humeri. At cortical sites, SCI induced structural and strength damage in both sub- and supralesional long bones. These changes were accompanied by diminished osteoblast number and activity and increased osteoclast number and activity. Taken together, our study revealed site-specific effects of SCI on bone and demonstrated sustained inhibition of bone formation and elevation of bone resorption at the chronic stage of SCI.

Transplantation of human umbilical mesenchymal stem cells from Wharton's jelly after complete transection of the rat spinal cord.

BACKGROUND: Human umbilical mesenchymal stem cells (HUMSCs) isolated from Wharton's jelly of the umbilical cord can be easily obtained and processed compared with embryonic or bone marrow stem cells. These cells may be a valuable source in the repair of spinal cord injury. METHODOLOGY/PRINCIPAL FINDINGS: We examine the effects of HUMSC transplantation after complete spinal cord transection in rats. Approximately 5x10(5) HUMSCs were transplanted into the lesion site. Three groups of rats were implanted with either untreated HUMSCs (referred to as the stem cell group), or HUMSCs treated with neuronal conditioned medium (NCM) for either three days or six days (referred to as NCM-3 and NCM-6 days, respectively). The control group received no HUMSCs in the transected spinal cord. Three weeks after transplantation, significant improvements in locomotion were observed in all the three groups receiving HUMSCs (stem cell, NCM-3 and NCM-6 days groups). This recovery was accompanied by increased numbers of regenerated axons in the corticospinal tract and neurofilament-positive fibers around the lesion site. There were fewer microglia and reactive astrocytes in both the rostral and caudal stumps of the spinal cord in the stem cell group than in the control group. Transplanted HUMSCs survived for 16 weeks and produced large amounts of human neutrophil-activating protein-2, neurotrophin-3, basic fibroblast growth factor, glucocorticoid induced tumor necrosis factor receptor, and vascular endothelial growth factor receptor 3 in the host spinal cord, which may help spinal cord repair. CONCLUSIONS/SIGNIFICANCE: Transplantation of HUMSCs is beneficial to wound healing after spinal cord injury in rats.

Tetramethylpyrazine inhibits activities of glioma cells and glutamate neuro-excitotoxicity: potential therapeutic application for treatment of gliomas.

We tested the herbal extract 2,3,5,6-tetramethylpyrazine (TMP) for possible therapeutic efficacy against a glioma cell line and against gliomas transplanted into rat brains. In the cultured glioma cells, 50 muM TMP significantly inhibited glutamate-induced increase in intracellular calcium. Significant cell damage (30%) and proliferation suppression (10%), however, occurred only at higher concentrations (200-400 microM). Gliomaneuronal co-culturing resulted in significant neuronal damage and higher proliferation of the glioma cells (140%) compared with single cultures. Low concentrations of TMP (< or =200 microM) attenuated the neuronal damage, suppressed glioma migration, and decreased glioma proliferation in the neuronal-glioma co-culture. Gliomas transplanted into the frontal cortical area exhibited high proliferation, with untreated rats dying 10-23 days later. TMP treatment inhibited tumor growth and significantly extended survival time. The results indicate that TMP can suppress glioma activity, including growth, and protect neurons against glioma-induced excitotoxicity, suggesting that TMP may have therapeutic potential in the treatment of malignant gliomas.