The Effects of Negative Pressure Therapy on Hair Growth of Mouse Models

Negative pressure therapy (NPT) has been shown to facilitate wound healing and promote hair growth in a porcine model. However, there is a paucity of research on the impact of negative pressure on hair growth in murine models. Despite the ability of nude mice to develop hair follicles, the hair they produce is often flawed towing to genetically induced keratin disorders, rendering them a pertinent animal model for assessing hair regeneration. Therefore, this study aims to investigate the effects of negative pressure on hair follicle growth in a nude mouse model. To achieve this, a customized external tissue expansion device was developed to apply negative pressure to the dorsum of nude mice. The mice were subjected to several treatment courses consisting of 15 and 30 min of continuous negative pressure at 10 mmHg, which were repeated 5 and 10 times every other day until sacrifice. Dorsal skin samples were subsequently extracted from the suction and nonsuction areas. The sections were stained with various antibodies to assess the expression of SOX-9, LHX-2, Keratin-15, β-catenin, CD31, and vascular endothelial growth factor-A, and a TUNEL assay was used to analyze cell apoptosis. The results showed that the number of hair follicles and angiogenesis were significantly higher in the suction area than in the nonsuction area in all groups. Moreover, mice that received NPT for 15 min for 10 times had a higher hair follicle density than the other three groups. Immunofluorescence staining for LHX-2 and Keratin 15 further validated the results of these findings. In conclusion, this study demonstrated that negative pressure effectively promotes hair follicle growth and angiogenesis in nude mice through SOX-9- and LHX-2-mediated follicular regeneration and β-catenin-mediated hair follicle morphogenesis.

3D-Bioprinted GelMA Scaffold with ASCs and HUVECs for Engineering Vascularized Adipose Tissue

The purpose of tissue engineering is to reconstruct parts of injured tissues and to resolve the shortage of organ donations. However, the main concern is the limited size of engineered tissue due to insufficient oxygen and nutrition distribution in large three-dimensional (3D) tissue constructs. To provide better support for cells inside the scaffolds, the vascularization of blood vessels within the scaffold could be a solution. This study compared the effects of different culturing systems using human adipose tissue-derived stem/stromal cells (ASCs), human umbilical vein endothelial cells (HUVECs), and coculture of ASCs and HUVECs in 3D-bioprinted gelatin methacrylate (GelMA) hydrogel constructs. The in vitro results showed that the number of live cells was highest in the coculture of ASCs and HUVECs in the GelMA hydrogel after culturing for 21 days. Additionally, the tubular structure was the most abundant in the GelMA hydrogel, containing both ASCs and HUVECs. In the in vivo test, blood vessels were present in both the HUVECs and the coculture of ASCs and HUVECs hydrogels implanted in mice. However, the blood vessel density was the highest in the HUVEC and ASC coculture groups. These findings indicate that the 3D-bioprinted GelMA hydrogel coculture system could be a promising biomaterial for large tissue engineering applications.

Safety and efficacy of intracranial vascularized submental lymph node transfer for treating hydrocephalus

Hydrocephalus is routinely treated with ventriculoperitoneal shunt drainage of cerebrospinal fluid (CSF), a procedure plagued by high morbidity and frequent revisions. Vascularized submental lymph node (VSLN) transplants act as lymphatic pumps to drain interstitial fluid (ISF) from lymphedematous extremities. As the field of neuro-lymphatics comes to fruition, we hypothesize the efficacy of VSLN in the drainage of intracranial CSF-ISF. We report novel placement of VSLN in the temporal subdural space in two patients diagnosed with symptomatic communicating hydrocephalus. At a minimum follow-up of 1 month postoperatively, both experienced radiological and clinical improvements.

Temporal and geographical prevalence of carbapenem-resistant Pseudomonas aeruginosa and the in vitro activity of ceftolozane/tazobactam and comparators in Taiwan-SMART 2012-2021

OBJECTIVES

To determine the in vitro activities of ceftolozane/tazobactam (C/T) and comparators against Pseudomonas aeruginosa isolates cultured from hospitalised patient samples in Taiwan from 2012 to 2021 with an additional focus on the temporal and geographical prevalence of carbapenem-resistant P. aeruginosa (CRPA).

METHODS

P. aeruginosa isolates (n = 3013) were collected annually by clinical laboratories in northern (two medical centres), central (three medical centres), and southern Taiwan (four medical centres) as part of the SMART global surveillance program. MICs were determined by CLSI broth microdilution and interpreted using 2022 CLSI breakpoints. Molecular β-lactamase gene identification was performed on selected non-susceptible isolate subsets in 2015 and later.

RESULTS

Overall, 520 (17.3%) CRPA isolates were identified. The prevalence of CRPA increased from 11.5%-12.3% (2012-2015) to 19.4%-22.8% (2018-2021) (P ≤ 0.0001). Medical centres in northern Taiwan reported the highest percentages of CRPA. C/T, first tested in the SMART program in 2016, was highly active against all P. aeruginosa (97% susceptible), with annual susceptibility rates ranging from 94% (2017) to 99% (2020). Against CRPA, C/T inhibited >90% of isolates each year, with the exception of 2017 (79.4% susceptible). Most CRPA isolates (83%) were molecularly characterised, and only 2.1% (9/433) carried a carbapenemase (most commonly, VIM); all nine carbapenemase-positive isolates were from northern and central Taiwan.

CONCLUSION

The prevalence of CRPA increased significantly in Taiwan from 2012 to 2021 and warrants continued monitoring. In 2021, 97% of all P. aeruginosa and 92% of CRPA in Taiwan were C/T susceptible. Routine in vitro susceptibility testing of clinical isolates of P. aeruginosa against C/T, and other newer β-lactam/β-lactamase inhibitor combinations, appears prudent.

Conjugation of bone grafts with NO-delivery dinitrosyl iron complexes promotes synergistic osteogenesis and angiogenesis in rat calvaria bone defects

Craniofacial/jawbone deformities remain a significant clinical challenge in restoring facial/dental functions and esthetics. Despite the reported therapeutics for clinical bone tissue regeneration, the bioavailability issue of autografts and limited regeneration efficacy of xenografts/synthetic bone substitutes, however, inspire continued efforts towards functional conjugation and improvement of bioactive bone graft materials. Regarding the potential of nitric oxide (NO) in tissue engineering, herein, functional conjugation of NO-delivery dinitrosyl iron complex (DNIC) and osteoconductive bone graft materials was performed to optimize the spatiotemporal control over the delivery of NO and to activate synergistic osteogenesis and angiogenesis in rat calvaria bone defects. Among three types of biomimetic DNICs, [Fe2(μ-SCH2CH2COOH)2(NO)4] (DNIC-COOH) features a steady kinetics for cellular uptake by MC3T3-E1 osteoblast cells followed by intracellular assembly of protein-bound DNICs and release of NO. This steady kinetics for intracellular delivery of NO by DNIC-COOH rationalizes its biocompatibility and wide-spectrum cell proliferation effects on MC3T3-E1 osteoblast cells and human umbilical vein endothelial cells (HUVECs). Moreover, the bridging [SCH2CH2COOH]- thiolate ligands in DNIC-COOH facilitate its chemisorption to deproteinized bovine bone mineral (DBBM) and physisorption onto TCP (β-tricalcium phosphate), respectively, which provides a mechanism to control the kinetics for the local release of loaded DNIC-COOH. Using rats with calvaria bone defects as an in vivo model, DNIC-DBBM/DNIC-TCP promotes the osteogenic and angiogenic activity ascribed to functional conjugation of osteoconductive bone graft materials and NO-delivery DNIC-COOH. Of importance, the therapeutic efficacy of DNIC-DBBM/DNIC-TCP on enhanced compact bone formation after treatment for 4 and 12 weeks supports the potential for clinical application to regenerative medicine.

Development of a rat model of lymphedema and the implantation of a collagen-based medical device for therapeutic intervention

Secondary lymphedema is a common condition among cancer survivors, and treatment strategies to prevent or treat lymphedema are in high demand. The development of novel strategies to diagnose or treat lymphedema would benefit from a robust experimental animal model of secondary lymphedema. The purpose of this methods paper is to describe and summarize our experience in developing and characterizing a rat hindlimb model of lymphedema. Here we describe a protocol to induce secondary lymphedema that takes advantage of micro computed tomography imaging for limb volume measurements and visualization of lymph drainage with near infrared imaging. To demonstrate the utility of this preclinical model for studying the therapeutic benefit of novel devices, we apply this animal model to test the efficacy of a biomaterials-based implantable medical device.

Factors associated with health-related quality of life in gynaecologic cancer survivors with lower limb lymphedema: a cross-sectional study in Taiwan

BACKGROUNDS

Gynaecological cancer survivors may develop lower limb lymphoedema after surgery, which negatively impacts quality of life. The purposes of this study were (1) to assess the levels of symptom distress, depression, body image, and health-related quality of life (HRQoL); (2) to recognize factors associated with HRQoL related in gynaecologic cancer survivors with lower limb lymphoedema.

METHODS

A cross-sectional study was conducted with convenience sampling of gynaecologic cancer survivors with lower limb lymphoedema. Gynaecologic cancer survivors were assessed for symptom distress, depression, body image, and HRQoL. Multiple regression analysis was conducted to recognize the factors associated with HRQoL. Independent-samples t-test was used to compare symptom distress, depression, body image, and HRQoL by grade of lymphoedema.

RESULTS

The most common distressing symptoms of lower limb lymphoedema were lower extremity oedema, lower extremity tightness, and lower extremity stiffness. Worse HRQoL was associated with more symptom distress, less satisfaction with body image, a high grade of lymphoedema, and a longer duration of lower limb lymphoedema. These factors explained 76.5% of the variance in HRQoL. Gynaecologic cancer survivors with late grade lymphoedema experienced lower HRQoL and higher levels of symptom distress, depression, and greater dissatisfaction with body image than those who had early grade lymphoedema.

CONCLUSIONS

Symptom distress had the strongest association with overall HRQoL and with all individual domains of HRQoL, except mental function. These results suggest that educating gynaecologic cancer survivors to assess lower limb lymphoedema-related problems, providing symptom management, and guiding survivors in physical activity to relieve lower extremity discomfort can improve HRQoL.

Retroauricular lymph node flap: An anatomic and surgical feasibility study

BACKGROUND

The study investigated the anatomy of the retroauricular lymph node (LN) flap and evaluate its surgical feasibility as a new donor site for a free LN flap in lymphedema surgery.

METHODS

Twelve adult cadavers were examined. The course and perfusion of the anterior auricular artery (AAA) and the location and sizes of the retroauricular LNs were studied.

RESULTS

The AAA was available in 87% and absent in 13% specimens. The AAA's origin had a mean vertical distance of 12.2 ± 6.9 mm and a mean horizontal distance of 19.1 ± 4.2 mm from the superior attachment of the ear. The mean diameter of the AAA was 0.8 ± 0.2 mm. The mean number of LN per region was 7.7 ± 2.3, with an average LN size of 4.1 ± 1.9 × 3.2 ± 1.7 mm. The LN were categorized into anterior (G1) and posterior (G2) groups, with a total of 59 and 10 LN, respectively. In a cluster analysis, three LN clusters could be detected across the anterior group (G1).

CONCLUSIONS

The retroauricular LN flap is a delicate but feasible flap with reliable anatomy, containing a mean of 7.7 LNs.

Postpartum Spinal Cord Infarction: A Case Report and Review of the Literature

Background: Postpartum spinal cord infarction is a very rare disease. Only two cases have been reported in the English literature. Methods: We reported a 26 year old female who received second doses of the mRNA-1273 vaccine 52 days before delivery. She presented as sudden onset of paraplegia, sensory level, and sphincter incontinence at postpartum period. No history of heparin exposure was noted. Imaging findings confirmed the T10-11 level infarction and her anti-human heparin platelet factor 4 (anti-PF4) antibody was positive. After 7 days of dexamethasone therapy, her paraplegia and urinary incontinence gradually improved. Results: The CT angiography (CTA) of the artery of Adamkiewicz (Aka) showed tandem narrowing, most conspicuous at the T10-11 level, which was presumably due to partial occlusion of the arteriolar lumen. The thoracolumbar spine magnetic resonance imaging with contrast medium showed owl's eyes sign at the T10 and T11 levels. We compared our case with two other case reports from the literature. Conclusions: Post-partum spinal cord infarction with positive anti-PF4 antibody and relatively thrombocytopenia are the characteristics of our case.

Curbing COVID-19 progression and mortality with traditional Chinese medicine among hospitalized patients with COVID-19: A propensity score-matched analysis

Background

Viral- and host-targeted traditional Chinese medicine (TCM) formulae NRICM101 and NRICM102 were administered to hospitalized patients with COVID-19 during the mid-2021 outbreak in Taiwan. We report the outcomes by measuring the risks of intubation or admission to intensive care unit (ICU) for patients requiring no oxygen support, and death for those requiring oxygen therapy.

Methods

This multicenter retrospective study retrieved data of 840 patients admitted to 9 hospitals between May 1 and July 26, 2021. After propensity score matching, 302 patients (151 received NRICM101 and 151 did not) and 246 patients (123 received NRICM102 and 123 did not) were included in the analysis to assess relative risks.

Results

During the 30-day observation period, no endpoint occurred in the patients receiving NRICM101 plus usual care while 14 (9.27%) in the group receiving only usual care were intubated or admitted to ICU. The numbers of deceased patients were 7 (5.69%) in the group receiving NRICM102 plus usual care and 27 (21.95%) in the usual care group. No patients receiving NRICM101 transitioned to a more severe status; NRICM102 users were 74.07% less likely to die than non-users (relative risk= 25.93%, 95% confidence interval 11.73%-57.29%).

Conclusion

NRICM101 and NRICM102 were significantly associated with a lower risk of intubation/ICU admission or death among patients with mild-to-severe COVID-19. This study provides real-world evidence of adopting broad-spectrum oral therapeutics and shortening the gap between outbreak and effective response. It offers a new vision in our preparation for future pandemics.

Breast cancer-related lymphedema correlated with incidence of cellulitis and mortality

BACKGROUND

This study investigated breast cancer-related lymphedema (BCRL) and its correlation with the incidence of cellulitis and mortality in the National Health Insurance (NHI) database in Taiwan.

METHODS

Between 2004 and 2014, the NHI database of patients with breast cancer who underwent surgical procedures, adjuvant therapies, BCRL, cellulitis, and mortality were retrospectively reviewed. Cox regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for incidence of BCRL and cellulitis in different treatment groups. The associations of BCRL with the incidence of cellulitis and mortality were further analyzed using the Kaplan-Meier curve.

RESULTS

Among 100 301 patients, 5464 (5.4%) developed BCRL with a median onset of 1.3 years. At a mean follow-up of 4.77 years, the incidence of cellulitis in the BCRL group (12.7%, 694/5464 patients) was significantly higher than in the no-BCRL group (2.73%, 2589/94 837 patients) (HR: 3.74; 95% CI: 3.43-4.08; p < 0.0001). At a mean follow-up of 5.77 years, the mortality rate in the cellulitis group (34.21%, 1123/3283 patients) was significantly greater than in the no-cellulitis group (16.29%, 15 804/97 018 patients) (HR: 1.17; 95% CI: 1.1-1.24; p < 0.0001).

CONCLUSIONS

BCRL had a significantly higher incidence of cellulitis and mortality.

Enhancing lymphangiogenesis and lymphatic drainage to vascularized lymph nodes with nanofibrillar collagen scaffolds

BACKGROUND

This study investigated the effect of nanofibrillar collagen scaffold (BioBridge) implantation from the affected limb to the unaffected contralateral femoral vein or lymph node in a rat model.

METHODS

Hind limb lymphedema in Lewis rats was created with lymphadenectomy and inguinal circumcision without radiation. The volumetric difference (greater than 5%) using computed tomography and indocyanine green fluorescence evaluated the progress of lymphedema at 4 weeks. The lymphedema rats have separated into Group I: Controls; Group II: implanted BioBridge to the contralateral femoral vein; and Group III: implanted BioBridge to the contralateral inguinal lymph node.

RESULTS

A total of 14 of 30 (46.7%) rats developed hind limb lymphedema with a mean volume difference of 5.83 ± 0.99% and showed diffuse dermal backflow at 4 weeks postlymphadenectomy. Four weeks postimplantation of BioBridge, the mean volumetric difference was 5.62 ± 2.11%, 4.97 ± 0.59%, and -2.47 ± 2.37% in Group I, II, and III, respectively (p < 0.05). The dermal backflow on the affected limb increased in Groups I and II but decreased in Group III.

CONCLUSIONS

Implantation of BioBridge from the affected limb to the contralateral inguinal lymph node significantly reduced the hind limb lymphedema at 4 weeks.

Distal facial vein catheterization for prevention and management of thrombosis in vascularized lymph node transfers

BACKGROUND

This study investigated the outcomes of the distal facial vein catheterization (DFVC) to manage venous thrombosis in vascularized submental lymph nodes (VSLN) flap transplantations.

METHODS

Between March 2017 and December 2020, patients who underwent VSLN flaps were divided into Group I: combined delayed primary retention sutures (DPRS) with DFVC, and Group II: DPRS alone. Primary outcomes were early (within 72 h) and late venous thrombosis. Secondary outcomes included other nonvascular complications and mechanical factors of the thrombosis.

RESULTS

A total of 105 patients who underwent 106 VSLN flaps, including 37 and 69 flaps in Groups I and II, respectively, were included. There were no statistically significant differences in age, body mass index, Taiwan lymphoscintigraphy staging, and surgical factors between the two groups (all p > 0.05). Early venous thrombosis requiring re-exploration developed in one (2.7%) and three (4.3%) flaps in Groups I and II, respectively (p = 0.20). One flap (2.7%) and eight (11.5%) flaps developed late venous thrombosis in Groups I and II, respectively (p < 0.01). There was no statistically significant difference in total complication rates between both groups (p = 0.9).

CONCLUSION

VSLN flap transplantation had a significantly higher risk of late venous thrombosis. DFVC significantly decreased the late venous thrombosis.

Vascularized Lymph Node Transfer Improved Outcomes of Elderly Patients with Secondary Upper Extremity Lymphedema

BACKGROUND

Secondary lymphedema is a debilitating morbidity. This study investigated the outcomes of vascularized lymph node transfer (VLNT) in elderly patients with secondary upper extremity lymphedema.

METHODS

Between 2008 and 2018, elderly (≥65 years) patients with secondary upper extremity lymphedema who underwent VLNT were retrospectively reviewed. Cheng's Lymphedema Grading, Taiwan Lymphoscintigraphy Staging, and indocyanine green lymphography were used to select the procedures. Outcome measurements included complications, circumferential difference, episodes of cellulitis, and the Lymphedema-Specific Quality of Life questionnaire (LYMQoL).

RESULTS

Eleven patients with a mean age of 70.2 ± 5.3 years (range 65-80 years) who underwent VLNT survived and no major complications were encountered. At a mean follow-up of 6.5 ± 3.6 years (range 2-13 years), the mean limb circumferential difference was significantly improved from 25.6 ± 11.5% to 8.3 ± 4.2% (p = 0.016), and the mean episode of cellulitis was statistically reduced from 2.4 ± 1.3 to 0.4 ± 0.9 times/year (p = 0.007). At a follow-up of 24 months, four domains of Function (from 30.6 ± 2.8 to 14.5 ± 2.5), Appearance (from 18.2 ± 1.9 to 8.5 ± 2.1), Symptoms (from 30.4 ± 5.9 to 10.9 ± 1.0) and Mood (from 29.2 ± 4.4 to 10.7 ± 1.0), as well as overall LYMQoL score (from 3.9 ± 1.1 to 7.4 ± 0.5), showed statistical improvement (all p < 0.05).

CONCLUSIONS

VLNT for secondary upper extremity lymphedema in elderly patients significantly decreased the limb circumferential difference and frequency of cellulitis and improved quality of life without using compression garments postoperatively.

Long-term outcomes of arterial ischemia or venous occlusion on vascularized groin lymph nodes in a rat model

BACKGROUND

This study investigated the long-term effects of arterial ischemia and venous occlusion on lymph node drainage function in a rat model.

METHODS

Bilateral groin lymph node flaps of 18 Lewis rats were dissected. The pedicle artery was clamped for 4, 5, and 6 h (A4, A5, and A6 groups), and the vein for 3, 4, and 5 h (V3, V4, and V5 groups) in six flaps. At 4 weeks, the evaluations included gross morphomics, indocyanine green (ICG) lymphography, histological section, immunofluorescence of terminal deoxynucleotidyl transferase assay, and heme oxygenase-1 (HO-1) stain.

RESULTS

The lymph node flaps developed shrinkage and partial necrosis in A5, A6, V4, and V5 groups. Hemorrhage in the lymph node cortex and medulla was observed histologically in A5, A6, and V5 groups. ICG lymphography showed loss of lymphatic drainage function in 2 of 6 flaps in A6 and V5 groups. Cell death was shown partly in cortical follicles in A5 and V4 groups and completely in A6 and V5 groups. The HO-1 expression was statistically increased in A5 and V5 groups, respectively (p < 0.05).

CONCLUSIONS

The critical arterial ischemia and venous occlusion time were 4 h at 4 weeks of follow-up.

Tracheal reconstruction with pedicled tandem grafts engineered by a radial stretch bioreactor

The engineering of tracheal substitutes is pivotal in improving tracheal reconstruction. In this study, we aimed to investigate the effects of biomechanical stimulation on tissue engineering tracheal cartilage by mimicking the trachea motion through a novel radial stretching bioreactor, which enables to dynamically change the diameter of the hollow cylindrical implants. Applying our bioreactor, we demonstrated that chondrocytes seeded on the surface of Poly (ε-caprolactone) scaffold respond to mechanical stimulation by improvement of infiltration into implants and upregulation of cartilage-specific genes. Further, the mechanical stimulation enhanced the accumulation of cartilage neo-tissues and cartilage-specific extracellular macromolecules in the muscle flap-remodeled implants and reconstructed trachea. Nevertheless, the invasion of fibrous tissues in the reconstructed trachea was suppressed upon mechanical loading.

Nipple-sparing mastectomy with immediate breast reconstruction with a deep inferior epigastric perforator flap without skin paddle using delayed primary retention suture

BACKGROUND

This study investigated the outcomes of nipple-sparing mastectomy (NSM) with a deep inferior epigastric perforator (DIEP) flap using delayed primary retention suture (DPRS) to achieve superior breast esthetics.

METHODS

Between December 2010 and March 2021, patients who underwent NSM with DIEP flap were inset with or without a skin paddle (using DPRS) as Group A or B, respectively. Demographics, operative findings, complications, BREAST-Q questionnaire, and Manchester scar scale were compared between two groups.

RESULTS

Twelve patients underwent 12 unilateral reconstructions in Group A, while 12 patients underwent 13 DIEP flaps in Group B. There was no significant difference in demographics, ischemia time, flap-used weight and percentage, complications of hematoma, infection, re-exploration, partial flap loss, and total flap loss (All p > 0.05, respectively). At a mean 9 months of follow-up, the Breast-Q "Satisfaction with surgeon" domain was significant in Group B (p = 0.04). At a mean 12 months of follow-up, the overall Manchester scar scale of 10.3 in Group B was statistically superior to 12.6 in Group A (p = 0.04).

CONCLUSIONS

The NSM with a DIEP flap using DPRS is a reliable and straightforward technique. It can provide greater cosmesis of the reconstructed breast mound in a single-stage procedure.

Tracheal reconstruction with the scaffolded cartilage sheets in an orthotopic animal model

Tracheal reconstruction remains challenged in clinical. We aimed to fabricate scaffolded cartilage sheets with rigid and elastic supports for tracheal reconstruction. The chondrocyte cell-infiltration activity was examined in the polycaprolactone sheet scaffolds with various thicknesses and pore sizes after seeding cells on the top surface of the sheet scaffolds. The expression of cartilage-related genes and accumulation of sulfated glycosaminoglycans was elevated in the cells-scaffold composites upon the chondrogenic induction. Mechanical properties of the cartilage sheets were measured by the 3-point flexural test and vertical compression test. Two tracheal defects were replaced with and cartilage sheets implants in a rabbit model for 16 weeks. The formation of the cartilaginous tissues, fibrous tissues, and airway epithelium was observed by Safranin O, Masson trichrome, and hematoxylin & eosin Y histological stains, respectively. The generation of micro-vessels, granulation tissue, and adipose tissues in the tracheal explants were analyzed with immunohistochemistry staining. Finally, cartilage sheets could be a reconstructive therapy candidate applying in reconstructing defects in the trachea and other tissues composed of cartilage.

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.

Application of dental stem cells in three-dimensional tissue regeneration

Dental stem cells can differentiate into different types of cells. Dental pulp stem cells, stem cells from human exfoliated deciduous teeth, periodontal ligament stem cells, stem cells from apical papilla, and dental follicle progenitor cells are five different types of dental stem cells that have been identified during different stages of tooth development. The availability of dental stem cells from discarded or removed teeth makes them promising candidates for tissue engineering. In recent years, three-dimensional (3D) tissue scaffolds have been used to reconstruct and restore different anatomical defects. With rapid advances in 3D tissue engineering, dental stem cells have been used in the regeneration of 3D engineered tissue. This review presents an overview of different types of dental stem cells used in 3D tissue regeneration, which are currently the most common type of stem cells used to treat human tissue conditions.

Case Report: Vaccine-Induced Immune Thrombotic Thrombocytopenia in a Pancreatic Cancer Patient After Vaccination With Messenger RNA-1273

Vaccination plays an important role during the COVID-19 pandemic. Vaccine-induced thrombotic thrombocytopenia (VITT) is a major adverse effect that could be lethal. For cancer patients, cancer-related thromboembolism is another lethal complication. When cancer patients receive their COVID-19 vaccines, the following thromboembolic events will be more complicated. We presented a case recently diagnosed with pancreatic cancer, who had received the mRNA-1273 (Moderna) vaccination 12 days prior. Ischemic stroke and VITT were also diagnosed. We aggressively treated the patient with steroids, immunoglobulin, and plasma exchange. The titer of anti-platelet factor four and d-dimer level decreased, but the patient ultimately died. The complicated condition of VITT superimposed cancer-related thromboembolism was considered. To our knowledge, only one case of mRNA-1273 related VITT was reported, and this case study was the first to report a cancer patient who was diagnosed with VITT after mRNA-1273 vaccination. Therefore, when the need for vaccination among cancer patients increased under the current COVID-19 pandemic, the possible risk of VITT for cancer patients should be carefully managed. Further studies of the risk evaluation of the COVID-19 vaccine in cancer patients might be required in the future.

Use of urinary hippuric acid and o-/p-/m-methyl hippuric acid to evaluate surgical smoke exposure in operating room healthcare personnel

Toluene and xylene are common components of surgical smoke, whereas hippuric acid (HA) and methylhippuric acid (MHA) are the products of toluene and xylene metabolism in humans, respectively. HA and MHA can be used as indicators to evaluate the exposure hazards of toluene and xylene. In this study, we used liquid chromatography tandem mass spectrometry (LC-MS/MS) to simultaneously analyze the HA, o-/m-/p-MHA, and creatinine contents in the urine of healthcare personnel. Concentrations of HA and o-/m-/p-MHAs were normalized to those of creatinine and used to analyze urine samples of 160 operating room (OR) healthcare personnel, including administrative staff, surgical nurses, nurse anesthetists, and surgeons. The results showed that the five analytes could be accurately separated and exhibited good linearity (r > 0.9992). The rate of recovery was between 86% and 106%, and the relative standard deviation was less than 5%. Urine from administrative staff presented the highest median concentration of hippuric acid (0.25 g/g creatinine); this was significantly higher than that found in the urine of surgeons (0.15 g/g). The concentrations of urinary o-/m-/p-MHAs in surgical nurses were higher than those in administrative staff, nurse anesthetists, and surgeons. Furthermore, the type, sex, and age of healthcare personnel were associated with changes in urine HA and o-/m-/p-MHA concentrations. Healthcare personnel should be aware of the risk of exposure to surgical smoke.

From Nanoparticles to Cancer Nanomedicine: Old Problems with New Solutions

Anticancer nanomedicines have been studied over 30 years, but fewer than 10 formulations have been approved for clinical therapy today. Despite abundant options of anticancer drugs, it remains challenging to have agents specifically target cancer cells while reducing collateral toxicity to healthy tissue. Nanocompartments that can be selective toward points deeply within malignant tissues are a promising concept, but the heterogeneity of tumor tissue, inefficiency of cargo loading and releasing, and low uniformity of manufacture required from preclinical to commercialization are major obstacles. Technological advances have been made in this field, creating engineered nanomaterials with improved uniformity, flexibility of cargo loading, diversity of surface modification, and less inducible immune responses. This review highlights the developmental process of approved nanomedicines and the opportunities for novel materials that combine insights of tumors and nanotechnology to develop a more effective nanomedicine for cancer patients.

Outcomes and quality of life in immediate one-stage versus two-stage breast reconstructions without an acellular dermal matrix: 17- years of experience

BACKGROUND

Advantages of one-stage implant-based reconstructions include expedited surgery and recovery. This study aimed to investigate clinical and patient-reported outcomes in one-stage implant-based breast reconstructions without acellular dermal matrix (ADM).

METHODS

A prospectively collected database from 2002 to 2018 was retrospectively reviewed. One-stage and two-stage groups were compared for demographics, implant properties, early complications (hematoma, seroma, poor wound healing, implant removal), late complications (skin necrosis, capsular contracture, implant exposure, implant rupture), revision procedures, and Breast-Q questionnaire outcomes.

RESULTS

A total of 223 patients, 187 one-stage (84%) and 36 two-stage (16%) patients were recruited. At a mean follow-up of 124.9 and 92.5 months, respectively (p < .01), there were no differences in early (p = .85) or late (p = .23) complications or revision procedures (p = .12). Eighty patients (36%) returned the Breast-Q questionnaire (60 one-stage, 20 two-stage patients). There were no statistical differences in patient reported outcomes in breast well-being (p = .07), psychosocial well-being (p = .84), or sexual well-being (p = .78).

CONCLUSIONS

One-stage implant-based breast reconstruction without an ADM is a viable reconstruction providing comparable outcomes to two-stage procedures, with the benefit of minimal complications, a shorter reconstructive journey, and satisfactory quality of life.

Sources and components of volatile organic compounds in breast surgery operating rooms

OBJECTIVES

The composition and concentration distribution of volatile organic compounds (VOCs) in surgical smoke had seldomly been reported. This study aimed to investigate the profile of VOCs and their concentration in surgical smoke from breast surgery during electrocautery in different tissues, electrosurgical units, and electrocautery powers.

METHODS

Thirty-eight surgical smoke samples from 23 patients performed breast surgery were collected using evacuated stainless steel canisters. The concentrations of 87 VOCs in surgical smoke samples were analyzed by gas chromatography-mass spectrometry. The human tissues, electrosurgical units, and electrocautery power were recorded.

RESULTS

The median level of total VOCs concentrations in surgical smoke samples from mammary glands (total VOCs: 9953.5 ppb; benzene: 222.7 ppb; 1,3-butadiene: 856.2 ppb; vinyl chloride: 3.1 ppb) using conventional electrosurgical knives were significantly higher than that from other tissues (total VOCs: 365.7-4266.8 ppb, P < 0.05; benzene: 26.4-112 ppb, P < 0.05; 1,3-butadiene: 15.6-384 ppb, P < 0.05; vinyl chloride: 0.6-1.8 ppb, P < 0.05) using different electrosurgical units. A high methanol concentration was found in surgical smoke generated during breast surgery (641.4-4452.5 ppb) using different electrosurgical units. An electrocautery power of ≥ 27.5 watts used for skin tissues produced a higher VOCs concentration (2905.8 ppb).

CONCLUSIONS

The surgical smoke samples collected from mammary glands using conventional electrosurgical knives had high VOCs concentrations. The carcinogens (including benzene, 1,3-butadiene, and vinyl chloride) and methanol were found in the surgical smoke samples from different electrosurgical units. The type of electrosurgical unit and electrocautery power used affected VOCs concentrations in surgical smoke.

Comparisons Between Normal Body Mass Index and Overweight Patients Who Underwent Unilateral Microsurgical Breast Reconstructions

BACKGROUND

This study compared the outcomes of unilateral microsurgical breast reconstructions using abdomen-based flaps between normal body mass index (BMI; 18.5 < BMI < 24.9 kg/m²) and overweight (25 < BMI < 29.9 kg/m²) patients.

METHODS

Between March 2000 and December 2015, patients who underwent unilateral breast reconstructions using abdomen-based flaps were retrospectively evaluated. Outcomes variables evaluated included the flap-used weight, flap-used/flap-harvested percentage, flap-used/specimen percentage, complication rates, revision procedures, and quality of life using the Breast-Q questionnaires.

RESULTS

A total of 415 patients with a mean age of 45.3 ± 8.2 years underwent 418 abdomen-based flaps. The overall success rate was 98.8%, with 99.1% and 97.9% of patients included in the normal BMI and overweight groups, respectively (p = 0.36). The mean flap-used weight and flap-used/flap-harvested values of 461 ± 132.1 g and 82.2 ± 11.6%, respectively, in the normal BMI group were statistically different from values of 610 ± 148.9 g and 71.4 ± 14.1% in the overweight group (both p < 0.01). The mean flap-used/specimen percentage was 118.5 ± 32.9 and 111.7 ± 36.6 in the normal BMI and overweight groups, respectively (p = 0.26). At a mean follow-up of 135 ± 55.4 months, there were no statistical differences between the two groups in terms of total complication rates (25.7% vs. 29.2%; p = 0.30), revision times (36.1% vs. 36.5%; p = 0.91) and all four domains (all p > 0.05) of the Breast-Q.

CONCLUSIONS

Patients with a normal BMI required a smaller flap-used weight but higher flap-used/flap-harvested percentage for unilateral microsurgical breast reconstructions that could be performed with a high success rate and comparable complication and revision rates.

Morbidity of marginal mandibular nerve post vascularized submental lymph node flap transplantation

BACKGROUND

This study investigated the morbidity of the marginal mandibular nerve (MMN) post vascularized submental lymph node (VSLN) harvest.

METHODS

The VSLN with sacrifying or preserving the medial platysma was retrospectively classified as group I or II. Midline deviation and horizontal tilt were subjectively evaluated. Horizontal, vertical, and "area distribution" of the lower lip excursions of the surgical site were objectively compared with the nonsurgical site.

RESULTS

Seventeen patients in group I and 12 patients in group II were included. At a median follow-up of 48.6 ± 16.8 months in group I and 14.8 ± 7.5 months in group II, no MMN palsy was found in both groups. Median midline deviation and horizontal tilt were 4.53 ± 0.52 and 5 ± 0 in group I and 4.67 ± 0.65 and 5 ± 0 in group II, respectively (P = .419 and 1.000). Median horizontal, vertical and area of distribution of lower lip excursions were 97.5 ± 12.3%, 98.8 ± 14.4% and 87.2 ± 14.7% in group I, and 99.3 ± 15.1%, 95.8 ± 8.2% and 84.2 ± 14.2% in group II, respectively (P = .679, .948 and .711).

CONCLUSION

The VSLN flap was a safe procedure with minimal MMN morbidity.

Risks to healthcare workers following tracheal intubation of patients with COVID-19: a prospective international multicentre cohort study

Healthcare workers involved in aerosol‐generating procedures, such as tracheal intubation, may be at elevated risk of acquiring COVID‐19. However, the magnitude of this risk is unknown. We conducted a prospective international multicentre cohort study recruiting healthcare workers participating in tracheal intubation of patients with suspected or confirmed COVID‐19. Information on tracheal intubation episodes, personal protective equipment use and subsequent provider health status was collected via self‐reporting. The primary endpoint was the incidence of laboratory‐confirmed COVID‐19 diagnosis or new symptoms requiring self‐isolation or hospitalisation after a tracheal intubation episode. Cox regression analysis examined associations between the primary endpoint and healthcare worker characteristics, procedure‐related factors and personal protective equipment use. Between 23 March and 2 June 2020, 1718 healthcare workers from 503 hospitals in 17 countries reported 5148 tracheal intubation episodes. The overall incidence of the primary endpoint was 10.7% over a median (IQR [range]) follow‐up of 32 (18–48 [0–116]) days. The cumulative incidence within 7, 14 and 21 days of the first tracheal intubation episode was 3.6%, 6.1% and 8.5%, respectively. The risk of the primary endpoint varied by country and was higher in women, but was not associated with other factors. Around 1 in 10 healthcare workers involved in tracheal intubation of patients with suspected or confirmed COVID‐19 subsequently reported a COVID‐19 outcome. This has human resource implications for institutional capacity to deliver essential healthcare services, and wider societal implications for COVID‐19 transmission.

Characterization of limb lymphedema using the statistical analysis of ultrasound backscattering

BACKGROUND

Lymphedema is a disease in which tissue swelling is caused by interstitial fluid retention in subcutaneous tissue. It is caused by a compromised lymphatic system. Lymphoscintigraphy is the current and primary modality used to assess lymphatic system dysfunction. Ultrasound elastography is a complementary tool used for evaluating the tissue stiffness of the lymphedematous limb. Tissue stiffness implies the existence of changes in tissue microstructures. However, ultrasound features related to tissue microstructures are neglected in clinical assessments of lymphedematous limbs. In this study, we aimed to evaluate the lymphedematous diagnostic values of ultrasound Nakagami and entropy imaging, which are, respectively, model- and nonmodel-based backscattered statistical analysis methods for scatterer characterization.

METHODS

A total of 60 patients were recruited, and lymphoscintigraphy was used to score the patient's clinical severity of each of their limb lymphedema (0: normal; 1: partial lymphatic obstruction; and 2: total lymphatic obstruction). We performed ultrasound examinations to acquire ultrasound backscattered signals for B-mode, Nakagami, and entropy imaging. The envelope amplitude, Nakagami, and entropy values, as a function of the patients' lymphatic obstruction grades, were expressed in terms of their median and interquartile range (IQR). The values were then used in both an independent t test and a receiver operating characteristic (ROC) curve analysis.

RESULTS

For each increase in a patient's score from 0 to 2, the envelope amplitude values were 405.44 (IQR: 238.72-488.17), 411.52 (IQR: 298.53-644.25), and 476.37 (IQR: 348.86-648.16), respectively. The Nakagami parameters were 0.16 (IQR: 0.14-0.22), 0.26 (IQR: 0.23-0.34), and 0.24 (IQR: 0.16-0.36), respectively, and the entropy values were 4.55 (IQR: 4.41-4.66), 4.86 (IQR: 4.78-4.99), and 4.87 (IQR: 4.81-4.97), respectively. The P values between the normal control and lymphedema groups obtained from B-mode and Nakagami analysis were larger than 0.05; whereas that of entropy imaging was smaller than 0.05. The areas under the ROC curve for B-mode, Nakagami, and entropy imaging were 0.64 (sensitivity: 70%; specificity: 47.5%), 0.75 (sensitivity: 70%; specificity: 75%), and 0.94 (sensitivity: 95%; specificity: 87.5%), respectively.

CONCLUSIONS

The current findings demonstrated the diagnostic values of ultrasound Nakagami and entropy imaging techniques. In particular, the use of non-model-based entropy imaging enables for improved performance when characterizing limb lymphedema.

Staging and clinical correlations of lymphoscintigraphy for unilateral gynecological cancer-related lymphedema

BACKGROUND

This study was to investigate the lymphoscintigraphy findings for the diagnosis and severity in unilateral gynecological cancer-related lymphedema (GCRL) and to correlate lymphoscintigraphy stages with the clinical findings.

METHODS

Patients with unilateral GCRL who underwent lymphoscintigraphy were staged using the presence of ileo-inguinal lymph nodes, distal-lymphatic ducts, and dermal backflow findings. Taiwan Lymphoscintigraphy Staging (TLS) was divided into three patterns and seven stages: normal drainage (L-0); partial obstruction (P-1, P-2, and P-3); and total obstruction (T4, T-5, and T-6). Correlations between clinical lymphedema severity and TLS were evaluated using analysis of variance and multivariable linear regression analyses.

RESULTS

A total of 141 patients with unilateral GCRL were divided as follows: 6 (4.3%) in normal drainage, 56 (39.7%) in partial-obstruction, and 79 (56%) in total obstruction. Cellulitis episodes, circumferential difference, and computed tomography (CT) volumetric difference were shown to be statistically different between TLS stages (P < .001 for all). Total obstruction stages were the most significant factors associated with the severity of circumferential difference (β = 19.72, 25.54, 32.42, respectively; P < .05) and CT volumetric difference (β = 36.04, 45.12, 52.78, respectively; P < .01).

CONCLUSIONS

Total lymphatic obstruction was present in 56% of unilateral GCGL. Lymphoscintigraphy stages were statistically correlated with episodes of cellulitis, circumferential difference and CT volumetric difference in unilateral GCRL.

The versatile free medial sural artery perforator flap: An institutional experience for reconstruction of the head and neck, upper and lower extremities

BACKGROUND

The medial sural artery perforator (MSAP) flap is an increasingly versatile and reliable flap for soft tissue reconstruction. This study investigates complication rates and long-term outcomes of the MSAP flap.

METHODS

A retrospective review was performed on consecutive patients undergoing MSAP flap reconstruction at Chang Gung Memorial Hospital from 2006 through 2017. Patient demographics were assessed. Flap failure and wound complications were the outcome measures.

RESULTS

In the cohort of 246 patients that underwent a total of 248 MSAP flap reconstructions were identified. The average age was 47.5 years (range 15-76). Of the 248 flaps, 170 were used for reconstruction of the head and neck, 48 for upper extremity reconstruction, and 30 for lower extremity reconstruction. The average MSAP flap size was 5.2 × 11.8 cm. 31 (12.5%) of the flaps developed arterial occlusion, venous insufficiency, or a hematoma postoperatively requiring re-exploration. Nineteen were successfully salvaged, yielding an overall failure rate of 4.8%. Minor complications included the need for flap debridement in 18 cases (7.3%) and need for donor site debridement in eight cases (3.2%).

CONCLUSIONS

The MSAP flap can be used in a versatile fashion to reconstruct defects of the head and neck, upper extremity, and lower extremity with minimal complication rates.

Laser Doppler Flowmetry to Differentiate Arterial From Venous Occlusion in Free Tissue Transfer

Purpose

The differentiation of arterial versus venous occlusion in free tissue transfers has rarely been described. This study investigated changes in blood flow caused by arterial and venous occlusion and the potential for laser Doppler flowmetry to distinguish between these 2 conditions for better clinical assessment and management of free tissue transfer.

Methods

Six patients with a mean age of 43.5 years underwent microsurgical free tissue transfer. The venous and arterial blood flow of the vessels and skin flap were monitored using laser Doppler flowmetry with high-frequency pulsed Doppler transducers for vessels and skin before, during, and after clamping the vessels for 10 minutes.

Results

The average decreases in blood flow in the artery and vein caused by clamping were 94.4% and 93.8%, respectively. On average, arterial occlusion demonstrated a sudden drop of 67.7% and venous occlusion caused a decrease of 26.6% on laser Doppler flowmetry in free tissue skin.

Conclusion

Using a vessel-holding probe, laser Doppler flowmetry could be used to differentiate between arterial and venous occlusion in free tissue transfer, thereby aiding decision-making for better clinical management.

Institutionalization of reconstructive lymphedema surgery in Austria-Single center experience

BACKGROUND

Lymphedema surgery was not widely known in Austria before the introduction of lymphovenous anastomosis (LVA) and vascularized lymph node transfer (VLNT) in 2014. This study shares the experience and process of establishing and institutionalizing lymphedema surgery service in Austria.

METHODS

The purpose of introducing reconstructive lymphedema surgery in Austria was to improve lymphedema patients' quality of life and provide them surgical therapy as an adjuvant treatment to complete decongestive therapy. To initialize reconstructive lymphedema surgery in Austria, LVA and VLNT had to be presented and introduced, in the manner of branding and advertizing a new product. Surgeries were performed with quality control by standardized documentation, pre- and postoperatively.

RESULTS

Aligned with branding and marketing, presentations were given externally and internally to share knowledge and experience of lymphedema surgery. Lymphedema surgery service was introduced as a new brand in the medical service in Austria. After several communications with the Austrian Health Insurance Fund and with the final application, LVA and VLNT were listed as novel surgical therapies in its 2020 reimbursement catalog. Since 2014, more than 300 lymphedema patients were consulted, and 102 reconstructive lymphedema surgeries were performed. Circumference reduction of extremities after surgery was between 20% and 43%, postoperatively.

CONCLUSION

Acceptance of surgery in lymphedema patients varies among continents, hospitals, and surgeons. Evaluation of the requirement of the surgical setup and insurance conditions for lymphedema surgery is essential to establish lymphedema surgery, providing targeted marketing and branding to spread knowledge of the novel technique and grant patients access to therapeutic treatment of their chronic disease.

Efficacy validation of a lymphatic drainage device for lymphedema drainage in a rat model

BACKGROUND

Vascularized lymph node transfer (VLNT) is an effective surgery for extremity lymphedema. This study evaluated a lymphatic drainage device (LDD) for the drainage of accumulated fluid into the venous system.

METHODS

Micropore filtering membranes with pore sizes of 5, 0.65, and 0.22 μm polyvinylidene difluoride, and 0.8 μm Nylon Net Filter were evaluated to determine the in vitro efficiency of drainage flow of an LDD. The two superior membranes were further used for the evaluation of the inflow and outflow of the LDD in vivo using 5% albumin.

RESULTS

At 5 minutes, the volumes drained with 5, 0.65, and 0.22 μm polyvinylidene difluoride and 0.8 μm nylon membranes were 15.2, 2.77, 2.37, and 0.59 mL, respectively (P < .01). At 10 minutes, the collected volumes of 5 and 0.65 μm polyvinylidene difluoride were 1788 and 1051 μL (P = .3). The indocyanine green fluorescence was detected at 50 seconds for the 5 μm polyvinylidene difluoride membrane but not for the 0.65 μm membrane.

CONCLUSIONS

The study successfully demonstrated the proof-of-concept of the LDD prototype that mimicked VLNT with drainage of 5% albumin into the venous system in a rat model.

Non-contrast-enhanced magnetic resonance angiography of facial arteries for pre-operative evaluation of vascularized submental lymph node flaps

Background

The aim of this study was to compare non-contrast-enhanced 3D phase contrast magnetic resonance angiography (3D PC-MRA) and conventional intravenous administration of contrast media, i.e., contrast-enhanced MRA (CE-MRA), to evaluate the courses of facial arteries for the preparation of vascularized submental lymph node flap (VSLN flap) transfer.

Methods

The head and neck regions of 20 patients with limb lymphedema were imaged using a 3 T MRI scanner. To improve the evaluation of facial artery courses, MRA was fused with anatomical structures generated by high-resolution T1-weighted imaging. The diagnostic and image qualities of facial arteries for VSLN flap planning were independently rated by two radiologists. Interobserver agreement was evaluated using Cohen’s kappa. Differences between 3D PC-MRA and CE-MRA in terms of the diagnostic quality of facial arteries were evaluated using McNemar’s test.

Results

Cohen’s kappa indicated fair to good interobserver agreement for the diagnostic and image qualities of the bilateral facial arteries. No significant difference in terms of the diagnostic quality of the left and right facial arteries between 3D PC-MRA and CE-MRA, respectively, was identified.

Conclusions

Non-contrast 3D PC-MRA is a reliable method for the evaluation of facial artery courses prior to VSLN flap transfer and could serve as an alternative to CE-MRA for patients with renal insufficiency or severe adverse reactions to contrast media.

Summary of hands-on supermicrosurgery course and live surgeries at 8th world symposium for lymphedema surgery

The hands-on supermicrosurgery course provided participants a valuable learning experience of in-depth practices of supermicrosurgical skills with experts. Seven live surgeries were successfully demonstrated at 8th World Symposium for Lymphedema Surgery. Variable donor sites for vascularized lymph node transfer were the submental, supraclavicular, groin, and omental; while the recipient sites included the wrist and axilla in upper limb; and popliteal and groin in the lower limb. The therapeutic and preventive lymphovenous anastomosis was also satisfactorily performed.

Intra-abdominal chylovenous bypass treats retroperitoneal lymphangiomatosis

BACKGROUND

Retroperitoneal lymphangiomatosis (RL) is a rare form of primary lymphedema featuring aberrant retroperitoneal lymphatic proliferation. It causes recurrent cellulitis, repeated interventions, and poor life quality. This study aimed to investigate proper diagnositc criteria and surgical outcomes for RL with extremity lymphedema.

METHODS

Between 2012 and 2018, 44 primary lower-extremity lymphedema cases received lymphoscintigraphy, magnetic resonance imaging, and single-photon electron computed tomography to detect RL. RL patients underwent vascularized lymph node transfers (VLNT) for extremity lymphedema and intra-abdominal side-to-end chylovenous bypasses (CVB) for chylous ascites. Complications, CVB patency, and quality of life were evaluated postoperatively.

RESULTS

Six RL patients (mean age of 30.3 years) had chylous ascites with five had lower-extremity lymphedema. All CVBs remained patent, though one required re-anastomosis, giving a 100% patency rate. Four unilateral and one bilateral extremity lymphedema underwent six VLNTs with 100% flap survival. Patients reported improved quality of life (P = 0.023), decreased cellulitis incidence (P = 0.041), and improved mean lymphedema circumference (P = 0.043). All patients resumed a normal diet and activity.

CONCLUSIONS

Evaluating primary lower-extremity lymphedema patients with MRI and SPECT could reveal a 13.6% prevalence of RL and guide treatment of refractory extremity lymphedema. Intra-abdominal CVB with VLNT effectively treated RL with chylous ascites and extremity lymphedema.

Delayed primary retention suture for inset of vascularized submental lymph node flap for lower extremity lymphedema

BACKGROUND

Vascularized lymph node transfer (VLNT) has become one of the effective surgical treatments for extremity lymphedema. This study was to evaluate the re-exploration and total complication rates of VLNT for lower extremity lymphedema between two different flap inset techniques.

METHODS

Sixty-nine patients who underwent 74 submental VLNT transfers between 2008 and 2018 were retrospectively studied. Fifty-six flaps were inset using a new delayed primary retention suture (DPRS) technique and other 18 flaps using conventional interrupted sutures as the non-DPRS group.

RESULTS

The overall flap success rate was 100%. The DPRS group was released at a mean of 1.7  ± 0.7 times and took a mean of 10.3 ± 3.3 days for wound closure. There were no statistical differences in demographics, mean symptom duration, and mean Cheng's Lymphedema Grading between two groups. Mean frequency of cellulitis of 2.5 ± 1.5 times/year in non-DPRS group was significantly greater than 1.4 ± 1.6 times/year in DPRS group (P = .01). The re-exploration and total complication rates were 5.4% and 7.1% in DPRS group, and 27.8% and 33.3% in non-DPRS group, respectively (P = .02 and .02, respectively).

CONCLUSIONS

The DPRS technique is a safe, simple, and reliable method for insetting the submental VLNT, which statistically decreased the re-exploration and total complication rates.

Clinical features, microbiological epidemiology and recommendations for management of cellulitis in extremity lymphedema

BACKGROUND

This high volume, single center study investigated the prevalence, bacterial epidemiology, and responsiveness to antibiotic therapy of cellulitis in extremity lymphedema.

METHODS

From 2003 to 2018, cellulitis events from a cohort of 420 patients with extremity lymphedema were reviewed. Demographics, lymphedema grading, symptoms, inflammatory markers, cultures and antibiotic therapy regimens were compiled from cellulitis episodes data. Univariate and multivariate analyses were performed for detailed analysis.

RESULTS

A total of 131 separate episodes of cellulitis were recorded from 43 (81.1%) lower limb and 10 (19.9%) upper limb lymphedema patients. The prevalence and recurrence rates for cellulitis in lymphedema patients were 12.6% (53 of 420) and 56.6% (30 of 53), respectively. The most common findings were increased limb circumference (127 of 131; 96.9%) and abnormal C-reactive protein (CRP) level (86 of 113; 76.1%). Blood cultures were obtained in 79 (60.3%) incidents, with 9 (11.4%) returning positive. Streptococcus agalactiae was the most isolated bacterium (5 of 9; 55.5%).

CONCLUSIONS

The cellulitis prevalence and recurrence rate in extremity lymphedema were 12.6%, and 56.6%, respectively. Strongest indicators of cellulitis were increased affected limb circumference and elevated CRP level. Empiric antibiotic therapy began with coverage for Steptococcus species before broadening to anti-Methicillin-resistant Staphylococcus aureus and anti-Gram negatives if needed for effective treatment of extremity lymphedema cellulitis.

Long-term outcome of lower extremity lymphedema treated with vascularized lymph node flap transfer with or without venous complications

BACKGROUND

Vascularized submental lymph node (VSLN) transfer is an emerging approach for extremity lymphedema. This study investigated the long-term outcome and venous complications of VSLN for unilateral lower extremity lymphedema.

METHODS

Between 2010 and 2018, patients who underwent VSLN for unilateral lower extremity lymphedema were retrospectively evaluated. Patient demographics, operative records, complications, circumferential improvement, and episodes of cellulitis were analyzed. Further comparisons were performed between different types, numbers, and techniques of venous anastomoses.

RESULTS

A total of 75 VSLNs in 70 patients survived, giving a 100% success rate. Six flaps (8%) had venous complications (VC group) and 69 flaps (92%) did not (No-VC group). There were no statistical differences in types, numbers, and techniques of anastomoses between two groups (P = .65, 1, and .56, respectively). At a mean follow-up of 32.0 ± 23.0 months, mean circumferential improvement and episodes of cellulitis between two groups did not statistically differ significantly (P = .31 and .09, respectively).

CONCLUSIONS

VSLN is an effective treatment for lower extremity lymphedema. The types, numbers of veins, and techniques of venous anastomoses did not statistically affect the venous complication rates. Functional outcomes of the VSLNs were not compromised if venous complications were salvaged promptly.

Lymphoscintigraphy for the diagnosis of extremity lymphedema: Current controversies regarding protocol, interpretation, and clinical application

Appropriate diagnosis, staging and a further selection of the best treatment are fundamental for the management of patients with extremity lymphedema. Several clinical and imaging tools have been described for these purposes. Lymphoscintigraphy is still considered the gold standard imaging modality for diagnosing lymphedema. However, protocol variability and poor image resolution can make the interpretation challenging. Here, we reviewed technical aspects of lymphoscintigraphy, interpretation of the lymphoscintigraphy findings, staging, and its clinical application.

Lymphedema microsurgery reduces the rate of implant removal for patients who have pre-existing lymphedema and total knee arthroplasty for knee osteoarthritis

INTRODUCTION

Patients with pre-existing lymphedema who undergo total knee arthroplasty (TKA) for osteoarthritis (OA) are at high risk for periprosthetic joint infection. This complication usually requires removal of the implant. This study aimed to investigate whether surgical treatment of lymphedema reduces the rate of prosthesis removal in such patients.

MATERIALS AND METHODS

We retrospectively reviewed our prospective database of patient information collected between January 2009 and December 2018. A total of 348 cases of lower extremity lymphedema were reviewed, and those who underwent total knee TKA for OA of the knee were included. Patient demographics, clinical data, lymphedema surgical history, and TKA surgical history including any episodes of removal were collected and analyzed.

RESULTS

There were nine of 15 lymphedema patients with knee OA who subsequently underwent TKA. The mean patient age was 70.4 ± 7.1 years. A total of 18 TKAs were performed in nine patients. The knee prosthesis removal rate was 66.7% (12/18). The prosthesis removal rate was 40% (2/5) in patients who underwent lymphedema microsurgery vs 76.9% (10/13) for those who did not (P = .03).

CONCLUSIONS

Pre-existing lymphedema is associated with a high rate of knee prosthesis removal. Lymphedema microsurgery reduced the removal rate of knee prostheses. We recommend that lymphedema microsurgery be considered for patients who require TKA as a treatment for of the knee.

Impacts of arterial ischemia or venous occlusion on vascularized groin lymph nodes in a rat model

BACKGROUND

Reported ischemia time of vascularized lymph nodes was 5 hours. This study investigated the effects of arterial ischemia and venous occlusion on vascularized lymph node function in rats.

METHODS

Bilateral pedicled groin lymph node flaps were raised in 27 Lewis rats. Femoral artery and vein were separated and clamped for 1, 3, 4, or 5 hour(s). Lymph node flap perfusion and drainage were assessed by laser Doppler flowmetry and indocyanine green lymphography. Histologic changes were assessed using hematoxylin and eosin stain, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL), and glutathione assays.

RESULTS

Perfusion units of 2.84 ± 1.41, 2.46 ± 0.64, 2.42 ± 0.37, and 2.01 ± 0.90 were measured in arterial ischemia groups, and 1.71 ± 0.45, 2.20 ± 0.98, 1.49 ± 0.35, and 0.81 ± 0.20 in venous occlusion groups after 1, 3, 4, and 5 hours of clamping, respectively. Lymphatic drainage showed mean latency periods of 5.33 ± 0.88, 9.00 ± 3.21, 10.00 ± 2.08, and 24.50 ± 11.50 seconds in arterial clamping groups, and 25.00 ± 3.61, 26.00 ± 3.06, 23.33 ± 4.41, and 152.00 ± 0 seconds in venous clamping groups, respectively. Severe medullary and cortical congestion and hemorrhage on histology and cell damage by glutathione levels and TUNEL assay were found after 4 hours of venous clamping.

CONCLUSIONS

Arterial ischemia and venous occlusion impact the function and viability of vascularized lymph node flaps differently. The critical venous occlusion time was 4 hours.