Lymphovenous Anastomosis Aids Wound Healing in Lymphedema: Relationship Between Lymphedema and Delayed Wound Healing from a View of Immune Mechanisms

Lymphangiogenesis: novel strategies to promote cutaneous wound healing

The cutaneous lymphatic system regulates tissue inflammation, fluid balance and immunological responses. Lymphangiogenesis or lymphatic dysfunction may lead to lymphedema, immune deficiency, chronic inflammation etc. Tissue regeneration and healing depend on angiogenesis and lymphangiogenesis during wound healing. Tissue oedema and chronic inflammation can slow wound healing due to impaired lymphangiogenesis or lymphatic dysfunction. For example, impaired lymphangiogenesis or lymphatic dysfunction has been detected in nonhealing wounds such as diabetic ulcers, venous ulcers and bedsores. This review summarizes the structure and function of the cutaneous lymphatic vessel system and lymphangiogenesis in wounds. Furthermore, we review wound lymphangiogenesis processes and remodelling, especially the influence of the inflammatory phase. Finally, we outline how to control lymphangiogenesis to promote wound healing, assess the possibility of targeting lymphangiogenesis as a novel treatment strategy for chronic wounds and provide an analysis of the possible problems that need to be addressed.

Lymphovenous Bypass as an Alternative Strategy for Managing Phleboedema and Venous Leg Ulcers: Preliminary Results

Background

Chronic venous leg ulcers (VLUs) are a common manifestation of chronic venous insufficiency, accounting for up to 70% of all chronic leg ulcers. Patients sustained refractory ulcers and persistent phleboedema even with a combination of different treatment methods. Lymphovenous bypass (LVB) has shown promising results in patients with lymphedema. We hypothesize that LVB could potentially alleviate VLUs and phleboedema, given their symptom similarities with lymphedema.

Methods

From May 2021 to June 2023, we prospectively deployed LVB in patients with nonhealing stasis ulcers after 4-week traditional care, or in those with persistent phleboedema despite prior surgery for vein etiologies. Demographics, healing course and recurrence, lymphoscintigraphy, and VLU quality of life (QoL) questionnaires were collected.

Results

Thirty-one patients were treated with LVB and additional skin grafting as necessary. Their mean age was 62.6 ± 14.7 years, with male predominance (20, 64.5%), and most patients sustained clinical, etiologic, anatomic, pathophysiologic classification C6 (25, 80.6%). Postoperatively, wound healing and phleboedema decongestion were observed mostly within 2 months. The VLU QoL questionnaire (39.3% response rate) showed improvement in QoL in activities, and psychological and symptom distress aspects.

Conclusions

Using LVB for chronic venous insufficiency showed an increase in the success rate of ulcer healing and decompression of the swollen limbs with durable results. Patient-reported outcome measures disclosed the potential benefits of LVB. Large-scale randomized controlled trials and pathophysiological studies are warranted to elucidate its efficacy.

Comparing Different Donor Sites After Vascularized Lymph Node Transfer to the Lymphedematous Upper Limb: A Systematic Review and Meta-analysis of Clinical Outcomes

BACKGROUND

Vascularized lymph node transfer (VLNT) involves the microvascular transplantation of functional lymph nodes from a donor site into a limb affected by lymphedema to restore the normal flow of lymphatic fluid. Despite the increasing clinical experience with VLNT, there remains insufficient data to support its routine use in clinical practice. Here, we aim to evaluate the effectiveness and safety of VLNTs for upper limb lymphedema and compare clinical outcomes when using different donor sites.

METHODS

We carried out a systematic search of the literature through PubMed and Scopus databases for studies on VLNT for upper limb lymphedema. Primary and secondary outcomes included circumference reduction rate (CRR) and infection reduction rate by postoperative cellulitis episodes for the efficacy and safety of VLNT. Pooled analysis was performed using the inverse variance weighting meta-analysis of single means using the meta package in R software. Subgroup analyses were performed for donor and recipient sites, age groups, follow-ups, and symptom durations. Quality assessment was performed using the Newcastle-Ottawa Scale for nonrandomized studies.

RESULTS

A total of 1089 studies were retrieved from the literature, and 15 studies with 448 upper limb lymphedema patients who underwent VLNT were included after eligibility assessment. The mean CRR was 34.6 (18.8) and the mean postoperative cellulitis episodes per year was 0.71 (0.7). The pooled analysis of CRR was 28.4% (95% confidence interval, 19.7-41.1) and postoperative cellulitis episodes showed a mean of 0.59 (95% confidence interval, 0.36-0.95) using the random-effect model. Subgroup analyses showed significant group differences in recipient site for CRR and postoperative cellulitis episodes with the wrist comprising the highest weights, and patients younger than 50 years showing a lower postoperative infection.

CONCLUSIONS

Vascularized lymph node transfer using gastroepiploic flaps at the wrists has shown a significant difference in reductions of limb circumference and cellulitis episodes in upper limb lymphedema patients when compared with other donor sites. However, further prospective studies are needed to consolidate this finding.

Association of Lower Extremity Lymphedema and Nonmelanoma Skin Cancers

OBJECTIVE

To determine whether patients with lymphedema of a lower extremity (LE) had a greater risk of skin cancer than those without lymphedema.

PATIENTS AND METHODS

This retrospective cohort study included patients with LE lymphedema examined at Mayo Clinic in Rochester, MN, USA, from January 1, 2000, through December 31, 2020. All patients with the phrase "lower extremity lymphedema" and a diagnostic code for lymphedema present in their electronic health record, as well as their age-, race-, and sex-matched controls without lymphedema, were included in the study. A Kaplan-Meier curve was constructed to examine the time to development of the first skin cancer for the lymphedema cohort and the controls. A Cox proportional hazards regression model was used to calculate hazard ratios.

RESULTS

In total, 4437 patients had lymphedema within the study period. Compared with the matched control group, the lymphedema group had a significantly increased risk of skin cancer. For the subset of patients with unilateral lymphedema, the lymphedematous extremity was 2.65 times as likely as the nonlymphedematous LE to have skin cancer, particularly basal cell carcinoma.

CONCLUSION

Lower extremity lymphedema appears to be a risk factor for squamous cell carcinoma, basal call carcinoma, and as expected, angiosarcoma. Clinicians caring for patients with LE lymphedema should be aware of this increased risk and monitor at-risk patients accordingly.

Cystic Lymphatic Malformation with Lymphedema Treated by Lymphaticovenular Anastomosis Combined with Ethanol Sclerotherapy

The incidence of cystic lymphatic malformation (CL) in an extremity is very rare. CL can be a cause of lymphedema in a lower limb. The most effective treatment for CL is sclerotherapy or excision; however, these treatments have the potential to cause fibrosis and obliteration of ruptured lymphatic vessels, which impairs lymphatic drainage and increases the risk of lymphedema. Lymphaticovenular anastomosis (LVA) combined with sclerotherapy may be a minimally invasive treatment option for CL in a lower limb. In this report, we describe a patient with CL complicated by lymphedema in a lower extremity, who we treated using LVA and ethanol sclerotherapy with satisfactory results. The patient was a 60-year-old man with a CL measuring 16 cm in diameter in the thigh region above the knee with lower limb lymphedema. The percentage of excess volume of the affected lower leg was 24.7%, preoperatively. Combined treatment using LVA with sclerotherapy was performed under general anesthesia. At 2 years after surgery, the reduction of excess volume of affected lower leg between preoperative and postoperative was 85.4%. In our previous report, the same combination therapy was used to treat CL and prevent lymphedema; however, in the present case, it was used to treat CL and lymphedema at one stage. LVA combined with sclerotherapy is a complementary minimally invasive treatment for CL accompanied by lymphedema.

A Novel Dressing Composed of Adipose Stem Cells and Decellularized Wharton's Jelly Facilitated Wound Healing and Relieved Lymphedema by Enhancing Angiogenesis and Lymphangiogenesis in a Rat Model

Lymphedema causes tissue swelling due to the accumulation of lymphatic fluid in the tissue, which delays the process of wound-healing. Developing effective treatment options of lymphedema is still an urgent issue. In this study, we aim to fabricate tissue-engineered moist wound dressings with adipose stem cells (ASCs) and decellularized Wharton's jelly (dWJ) from the human umbilical cord in order to ameliorate lymphedema. Rat ASCs were proliferated and an apparent layer was observed on dWJ at day 7 and 14. A rat tail lymphedema model was developed to evaluate the efficacy of the treatment. Approximately 1 cm of skin near the base of the rat tail was circularly excised. The wounds were treated by secondary healing (control) (n = 5), decellularized Wharton's jelly (n = 5) and ASC-seeded dWJ (n = 5). The wound-healing rate and the tail volume were recorded once a week from week one to week five. Angiogenesis and lymphangiogenesis were assessed by immunochemistry staining with anti-CD31 and anti-LYVE1. The results showed that the wound-healing rate was faster and the tail volume was lesser in the ASC-seeded dWJ group than in the control group. More CD31+ and LYVE-1+ cells were observed at the wound-healing area in the ASC-seeded dWJ group than in the control group. This proves that tissue-engineered moist wound dressings can accelerate wound-healing and reduce lymphedema by promoting angiogenesis and lymphangiogenesis.

Modulation of Lymphangiogenesis in Incisional Murine Diabetic Wound Healing Using Negative Pressure Wound Therapy

Objective: Despite the significant function of lymphatics in wound healing, and frequent clinical use of Negative Pressure Wound Therapy (NPWT), the effect of mechanical force application on lymphangiogenesis remains to be elucidated. We utilize a murine incisional wound healing model to assess the mechanisms of lymphangiogenesis following NPWT. Approach: Dorsal incisional skin wounds were created on diabetic mice (genetically obese leptin receptor-deficient mice [db/db]; n = 30) and covered with an occlusive dressing (Control, n = 15) or NPWT (-125 mmHg, continuous, 24 h for 7 days; NPWT, n = 15). The wounds were macroscopically assessed for 28 days. Tissue was harvested on day 10 for analysis. Qualitative functional analysis of lymphatic drainage was performed on day 28 using Evans Blue staining (n = 2). Results: NPWT increased lymphatic vessel density (40 ± 20 vs. 12 ± 6 podoplanin [PDPN]⁺ and 25 ± 9 vs. 14 ± 8 lymphatic vessel endothelial receptor 1 [LYVE-1]⁺) and vessel diameter (28 ± 9 vs. 12 ± 2 μm). Western blotting verified the upregulation of LYVE-1 with NPWT. Leukocyte presence was higher with NPWT (22% ± 3.7% vs. 9.1% ± 4.1% lymphocyte common antigen [CD45]⁺) and the leukocytes were predominately B cells clustered within vessels (8.8% ± 2.5% vs. 18% ± 3.6% B-lymphocyte antigen CD20 [CD20]⁺). Macrophage presence was lower in the NPWT group. Lymphatic drainage was increased in the NPWT group, which exhibited greater Evans Blue positivity. Innovation: The lymphangiogenic effects take place independent of macrophage infiltration, appearing to correlate with B cell presence. Conclusion: NPWT promotes lymphangiogenesis in incisional wounds, significantly increasing the lymph vessel density and diameter. This study highlights the potential of NPWT to stimulate lymphatic drainage and wound healing of surgical incisions.

Guidelines Relevant to Diagnosis, Assessment, and Management of Lymphedema: A Systematic Review

Significance: Lymphedema is a common, distressing and debilitating condition with various etiologies. Effective diagnosis, assessment, and management rely on evidence-based clinical practice guidelines ("guidelines"). This study aims to describe and compare international guidelines on lymphedema diagnosis, assessment, and management. Recent Advances: The review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and registered on the International Prospective Register of Systematic Reviews (PROSPERO). Systematic searches of electronic literature databases and the web were completed in December 2020 for lymphedema guidelines published in English since 2000. Quality was assessed using the Appraisal of Guidelines for Research and Evaluation (AGREE)-II reporting checklist. Synthesis took a narrative approach to compare guideline recommendations and associated levels of evidence. Critical Issues: This systematic review of 1,564 articles and 159 web pages yielded 14 guidelines. All guidelines were from high-income countries. Ten focused exclusively on lymphedema, and four on cancer. Most (n = 13) guidelines recommended an integrated medical, psychological assessment, and physical examination, with a limb volume measurement of >10% in the affected limb compared, confirming a lymphedema diagnosis. Recommended management involved Complex Decongestive Therapy (CDT) followed by self-management using skincare, self-lymphatic drainage massage, exercise, and compression. Future Directions: The underlying etiology of lymphedema appeared to make little difference to guideline recommendations regarding care. High-quality guidelines are available to guide lymphedema care. However, their suitability for low-resource settings is unclear.

Soft-Tissue Considerations in Shoulder Surgery in the Patient With Lymphedema

Lymphedema is a chronic, progressive, and often debilitating condition that results in swelling of the affected tissue. Secondary lymphedema is most commonly recognized by unilateral swelling of the ipsilateral extremity after the treatment of cancer. It is estimated that nearly 1.45 million women suffer from breast cancer-related lymphedema in the United States. The number of patients suffering from upper extremity lymphedema is expected to increase because multimodal treatment of breast cancer increases the long-term survival after diagnosis. Because this population ages, the likelihood of encountering a patient with concurrent lymphedema and shoulder pathology requiring orthopaedic intervention is likely to rise. A patient with an already edematous arm and/or impaired drainage of that arm is likely to have different and more complex intraoperative and postoperative courses than patients with normal lymphatic drainage. Although a lymphedematous arm should not preclude surgical intervention, there are considerations when approaching shoulder surgery in the setting of upper extremity lymphedema that may help mitigate complications and aid the patient in their orthopaedic recovery.

Complex decongestive therapy in a patient with poliomyelitis, bilateral lymphoedema and a deep wound: a case study

OBJECTIVE

The aim of this case report is to describe the results of complex decongestive therapy (CDT) in a patient with poliomyelitis and bilateral lymphoedema, and to emphasise the effect of CDT on wound healing.

METHOD

A 48-year-old female patient was given CDT for bilateral grade 3 lymphoedema in the lower extremities and a deep wound on the right foot. She had been diagnosed with poliomyelitis sequela and mobilised with a wheelchair for 26 years. The lymphoedema on both legs and the wound on the right foot sole had been present for five years and eight months, respectively. Detailed wound care had been performed previously upon the green, malodorous infected wound, without healing. The patient received skin care education, manual lymphatic drainage, multilayer bandaging and exercises for 4 weeks in a total of 20 sessions. The improvement was assessed by limb volumes prior to and at the end of the treatments.

RESULTS

The right and left lower limb volumes were decreased significantly at the end of treatments (3042cm³ (R) and 3165cm³ (L) before versus 2702cm³ (R) and 2401cm³ (L) afterward). The wound size decreased considerably and the green malodorous flow ceased. The patient continued self-massage and self-bandaging after hospital discharge. The control follow-up, one month later, revealed a completely healed wound with maintained volume.

CONCLUSION

In conclusion CDT for a duration of 4 weeks in a female patient with poliomyelitis, bilateral lymphoedema and an infectious hard-to-heal wound, improved both the lymphoedema and wound healing.

Impact of retrograde anastomosis during supermicrosurgical lymphaticovenous anastomosis for cancer-related lower limb lymphedema: A retrospective cohort propensity-score-matched outcome analysis

BACKGROUND

In addition to antegrade anastomosis, retrograde anastomosis has been thought to offer further improvements after lymphaticovenous anastomosis (LVA) by bypassing the retrograde lymphatic flow. However, this concept has yet to be validated. The aim of this study was to determine the impacts on outcomes of performing both retrograde and antegrade anastomosis, as compared to antegrade-only anastomosis for treating lower limb lymphedema.

STUDY DESIGN

This was a retrospective cohort propensity score-matched study. Eighty-seven patients with gynecologic cancer-related lower limb lymphedema were enrolled, including 58 patients who had received both antegrade and retrograde anastomoses (Group I) and 29 patients who had received antegrade-only anastomoses (Group II) as the control group. LVA was the primary treatment. Patients who had previous LVA, liposuction, or excisional therapy were excluded. Patient characteristics, intraoperative findings, and functional parameters including the ratio of indocyanine green-enhanced and flow-positive lymphatic vessels were recorded. Magnetic resonance volumetry was used for outcome assessments. The primary endpoint was the volume change at 6 months after LVA.

RESULTS

After matching, a total of 26 patients have remained in each group. All parameters were matched except that Group I still had significantly more median LVA performed compared to Group II (8 [IQR: 5.3-10.0] vs. 5.5 [4.3-6.0], p = 0.001, respectively). Group II showed more post-LVA improvements at six-month and one-year follow-up compared to Group I but without statistically significant differences.

CONCLUSION

The use of supplementary retrograde anastomoses is discouraged since it may lead to inferior post-LVA outcome compared to antegrade-only anastomoses.

Predictive role of lymphoscintigraphy undergoing lymphovenous anastomosis in patients with lower extremity lymphedema: a preliminary study

BACKGROUND

We investigated whether preoperative lymphoscintigraphy could predict the treatment response of unilateral lymphovenous anastomosis (LVA) in patients with lower extremity lymphedema.

MATERIALS AND METHODS

A total of 17 patients undergoing lymphoscintigraphy subsequent to LVA was included. As qualitative lymphoscintigraphic indicators, ilioinguinal lymph node uptake, main lymphatic vessel, collateral vessel, and four types of dermal backflow patterns (absent; distal only; proximal only; whole lower limb) were evaluated. Lymph node uptake ratio, extremity uptake ratio, and injection site clearance ratio were obtained as quantitative lymphoscintigraphic indicators at 1 and 2-h after injection. To evaluate therapy response, the volume difference ratio of the whole lower limb at 3 months (early response) and 1 year (late response) was measured. Volume difference ratios (continuous variable and binary variable with a cut-off value of zero) were compared according to the lymphoscintigraphic variables.

RESULTS

The group with whole lower limb dermal backflow had a greater volume change than the other groups (p = 0.047). The group with dermal backflow in the whole lower limb OR only in the distal part had a higher rate of volume reduction than the group with dermal backflow only in the proximal part OR absent (p = 0.050). The 2-h extremity uptake ratio was the only indicator that positively correlated with early and late volume difference ratio (p = 0.016, p = 0.001). The rate of volume decrease at 1 year was high in patients with high 2-h extremity uptake ratio (p = 0.027). As the amount of dermal backflow increases, the postoperative therapeutic effect increases (p = 0.040).

CONCLUSIONS

Preoperative lymphoscintigraphy is useful to predict both early and late therapy response in patients with lower extremity lymphedema undergoing LVA. Both dermal backflow pattern and extremity uptake ratio may be predictive lymphoscintigraphic indicators.

Lymphaticovenous Anastomosis for Age-Related Lymphedema

INTRODUCTION

Primary lymphedema is usually caused by intrinsic disruption or genetic damage to the lymphatics but may also be the result of age-related deterioration of the lymphatics. The aims of this study were to determine the characteristics of age-related lymphedema and to assess the effectiveness of lymphaticovenous anastomosis (LVA) in its treatment.

METHODS

Eighty-six patients with primary lymphedema affecting 150 lower limbs were divided into three groups according to whether the age of onset was younger than 35 years, 35-64 years, or 65 years or older. Indocyanine green (ICG) lymphography was performed, followed by LVA surgery. ICG lymphography images were visually classified according to whether the pattern was linear, low enhancement (LE), distal dermal backflow (dDB), or extended dermal backflow (eDB). The lower extremity lymphedema (LEL) index score was calculated before and after LVA. Lymphatic vessel diameter and detection rates were also recorded.

RESULTS

In the ≥65 group, the lymphedema was bilateral in 54 patients and unilateral in 1 patient. There was statistically significant deterioration in the LEL index score with progression from the linear, LE, dDB through to the eDB pattern in the ≥65 group. The lymphatic vessel diameter was significantly greater in the ≥65 group. The rate of improvement was highest in the ≥65 group.

CONCLUSION

Age-related lymphedema was bilateral and deterioration started distally. The lymphatic vessels in patients with age-related lymphedema tended to be ectatic, which is advantageous for LVA and may increase the improvement rate.

Wound Dressings for Hip and Knee Total Joint Arthroplasty: A Narrative Review

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Dressing choice following lower-extremity total joint arthroplasty has substantial ramifications for postoperative outcomes and should be carefully made to prevent complications such as periprosthetic joint infection.

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Patient risk factors are essential components in the selection of wound dressings in total joint arthroplasty.

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Traditional dressings are inexpensive per unit; nevertheless, the associated higher complication profile in patients at a high risk for poor wound healing and sequelae-associated costs may outweigh the up-front savings.

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Modern dressings have the potential to yield better safety outcomes and increased patient satisfaction; however, there is a paucity of evidence regarding the ideal interactive dressing.

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Active dressings, such as silver-ion dressings and closed-incisional negative-pressure wound therapy, have shown promising results to reduce surgical site and periprosthetic joint infection, especially in patients at a high risk for poor wound healing following hip and knee total joint arthroplasty.

Investigation of flow velocity in recipient perforator artery for a reliable indicator for the flap transfer with perforator to perforator anastomosis

INTRODUCTION

In flap transfer with perforator to perforator anastomosis (FTPPA), encountering poor pulsation and blood flow in a recipient perforator intraoperatively often makes FTPPA impossible. This study sought to identify color and spectral Doppler ultrasonography (CSDUS) parameters that can aid reliable preoperative selection of a recipient perforator artery.

PATIENTS AND METHODS

The study enrolled 38 patients with lower extremity lymphedema who underwent vascularized lymphatic tissue transfer with perforator to perforator anastomosis for physiological lymphatic flow reconstruction. In all cases, three candidate recipient perforators were searched in each lower extremities, and vessel diameter and peak systolic flow velocity (PSFV) were measured. The inclusion criteria for candidates were a vessel diameter of >0.5 mm and a PSFV of >10 cm/s. These measures were compared with intraoperative findings, diameters and if there was pulsation and visible spurting evident.

RESULTS

A total of 114 candidates were selected, and 52 of the candidates were dissected until suitable perforators were found. PSFV (cm/s) on CSDUS was ≥20.0 in 32 perforators (84.2%) and was 15.0-19.9 in 6 perforators (15.8%) in the group with pulsation and visible spurting evident, and 15.0-19.9 in one perforator (7.1%) and ≤ 14.9 in 13 perforators (92.9%) in the group without pulsation and visible spurting evident. There was a statistically significant correlation between preoperative PSFV and intraoperative pulsation and visible spurting evident after dissection (P = 0.021 × 10^-3 ). The flap survival rate was 92.1%.

CONCLUSION

PSFV is an important preoperative determinant of the suitability of a recipient perforator artery for FTPPA.

Lymphatico-venous anastomosis in chronic ulcer with venous insufficiency: A case report

Patients presenting with chronic wounds in venous insufficiency often represent a challenge, like other conditions, like lymphatic impairment, may complicate the wound healing process. The purpose of this report is to highlight how the treatment of lymphatic impairment may be beneficial in patients affected by chronic ulcers with concomitant venous insufficiency. We present the case of a 78-year-old woman affected by chronic venous insufficiency (CVI) with long-lasting ulcers secondary to sclerosing agents treatment for varicose veins. The patient's condition was refractory to both conservative and surgical treatment. Since the patient also presented with severe lymphorrhea, with a significant amount of daily secretion, ICG-lymphography was performed subcutaneously, to visualize the pathway of lymphatic drainage and leakage. It also allowed marking on the skin the exact location of lymphatic vessels distally to the wound area. Hence, two lymphatico-venous anastomoses were performed between the two major collecting lymphatic vessels and two subcutaneous veins of adequate size. The postoperative course was uneventful and the procedure allowed for immediate resolution of lymphatic leakage and complete wound healing within 2 weeks with no recurrence in the follow-up time of 1.5 years. Based on the outcomes of this case, it is possible to consider the use of CVI treatment and lymphedema surgery as a combined approach to complicated cases of long-standing venous ulcers with lymphorrhea.

Use of photosynthetic transgenic cyanobacteria to promote lymphangiogenesis in scaffolds for dermal regeneration

Impaired wound healing represents an unsolved medical need with a high impact on patients´ quality of life and global health care. Even though its causes are diverse, ischemic-hypoxic conditions and exacerbated inflammation are shared pathological features responsible for obstructing tissue restoration. In line with this, it has been suggested that promoting a normoxic pro-regenerative environment and accelerating inflammation resolution, by reinstating the lymphatic fluid transport, could allow the wound healing process to be resumed. Our group was first to demonstrate the functional use of scaffolds seeded with photosynthetic microorganisms to supply tissues with oxygen. Moreover, we previously proposed a photosynthetic gene therapy strategy to create scaffolds that deliver other therapeutic molecules, such as recombinant human growth factors into the wound area. In the present work, we introduce the use of transgenic Synechococcus sp. PCC 7002 cyanobacteria (SynHA), which can produce oxygen and lymphangiogenic hyaluronic acid, in photosynthetic biomaterials. We show that the co-culture of lymphatic endothelial cells with SynHA promotes their survival and proliferation under hypoxic conditions. Also, hyaluronic acid secreted by the cyanobacteria enhanced their lymphangiogenic potential as shown by changes to their gene expression profile, the presence of lymphangiogenic protein markers and their capacity to build lymph vessel tubes. Finally, by seeding SynHA into collagen-based dermal regeneration materials, we developed a viable photosynthetic scaffold that promotes lymphangiogenesis in vitro under hypoxic conditions. The results obtained in this study lay the groundwork for future tissue engineering applications using transgenic cyanobacteria that could become a therapeutic alternative for chronic wound treatment. STATEMENT OF SIGNIFICANCE: In this study, we introduce the use of transgenic Synechococcus sp. PCC 7002 (SynHA) cyanobacteria, which were genetically engineered to produce hyaluronic acid, to create lymphangiogenic photosynthetic scaffolds for dermal regeneration. Our results confirmed that SynHA cyanobacteria maintain their photosynthetic capacity under standard human cell culture conditions and efficiently proliferate when seeded inside fibrin-collagen scaffolds. Moreover, we show that SynHA supported the viability of co-cultured lymphatic endothelial cells (LECs) under hypoxic conditions by providing them with photosynthetic-derived oxygen, while cyanobacteria-derived hyaluronic acid stimulated the lymphangiogenic capacity of LECs. Since tissue hypoxia and impaired lymphatic drainage are two key factors that directly affect wound healing, our results suggest that lymphangiogenic photosynthetic biomaterials could become a treatment option for chronic wound management.

Wound with Diabetes: Present Scenario and Future

Diabetes is a chronic metabolic disorder of the endocrine system characterized by an increase in blood glucose level. Several factors, such as pancreatic damage, oxidative stress, infection, genetic factor, obesity, liver dysfunction, play a vital role in the pathogenesis of diabetes, which further leads to serious diabetic complications. The diabetic wound is one such complication where the wound formation occurs, especially due to pressure and its healing process is disrupted due to factors, such as hyperglycemia, neuropathy, nephropathy, peripheral vascular disease, reduction of blood flow, atherosclerosis, impaired fibroblast. The process of wound healing is delayed due to different abnormalities like alteration in nitric oxide level, increase in aldose reductase, sorbitol, and fructose. Therefore, diabetic wound requires more time to heal as compared to the normal wound. Healing time is delayed in diabetic wound due to many factors, such as stress, decreased oxygenation supply, infection, decreased blood flow, impaired proliferation and migration rate, impaired growth factor production, impaired keratinocytes proliferation and migration, and altered vascular endothelial mediators. The current treatment for diabetic wounds includes wound patches, oxygenation therapy, hydrogel patches, gene therapy, laser therapy, and stem cell therapy. Medications with phytoconstituents are also one way to manage the diabetic wound, but it is not more effective for quick healing. The objective of this review is to understand the potential of various management options which are available for diabetic wound, with a special focus on biological cells.

Role of microRNAs in Pressure Ulcer Immune Response, Pathogenesis, and Treatment

Pressure ulcers are preventable, yet highly prevalent, chronic wounds that have significant patient morbidity and high healthcare costs. Like other chronic wounds, they are characterized by impaired wound healing due to dysregulated immune processes. This review will highlight key biochemical pathways in the pathogenesis of pressure injury and how this signaling leads to impaired wound healing. This review is the first to comprehensively describe the current literature on microRNA (miRNA, miR) regulation of pressure ulcer pathophysiology.

Hybrid Treatment Combining Lymphaticovenous Anastomoses and the Oriental Herbal Medicine Bofutsushosan for Obesity-Associated Lower Leg Elephantiasis Nostras Verrucosa: A Case Report

Elephantiasis nostras verrucosa (ENV) is a rare dermatological disease associated with chronic lymphedema caused by obesity, soft tissue infection, or chronic venous insufficiency. Although surgical debridement may be sufficient to treat the skin manifestations of ENV, treatment of ENV should focus on reducing lymph stasis to improve the skin changes and prevent recurrence. In this case report, we present the case of a 79-year-old woman who developed obesity-associated ENV in the lower leg. She was successfully treated by a combination of lymphaticovenous anastomoses and the oriental herbal medicine Bofutsushosan. To our knowledge, this is the first reported obesity-associated ENV case in which skin pathology was not only healed, but both edema relief and weight loss were successful. A treatment combining both surgery and the herbal medicine could be a potential therapeutic candidate for obesity-associated ENV.

Characteristics and outcomes of lymphaticovenular anastomosis in older patients with bilateral involvement versus younger patients with unilateral involvement in lower extremity lymphedema

OBJECTIVE

We have previously reported that patients with idiopathic primary lymphedema of adult onset can be classified into an older group with bilateral involvement and a younger group with unilateral involvement and that there are significant differences in the characteristics of these groups. The aims of this study were to investigate the features of these two groups further by evaluating the lymphatics while performing lymphaticovenular anastomosis (LVA) and to compare the effectiveness of LVA between the two groups.

METHODS

This study enrolled 74 patients (136 edematous legs) in whom indocyanine green (ICG) lymphography and LVA were performed. The rate of detection and the diameter of the lymphatic vessels were recorded. The lower extremity lymphedema index (the total sum of the squares of the circumference for five areas in each leg divided by the body mass index) was obtained before and 6 months after LVA. The rate of improvement in the affected lower limbs after LVA was also calculated.

RESULTS

The clinical lymphedema pattern was determined to be bilateral in 62 patients and unilateral in 12. Patients with bilateral lymphedema were significantly older than those with unilateral lymphedema (77.1 ± 7.8 years vs 55.5 ± 12.77 years; P < .01). A linear pattern was seen in 23 patients (46 legs), a low enhancement (LE) pattern in 12 patients (24 legs), a distal dermal backflow (dDB) pattern in 20 patients (40 legs), and an extended dermal backflow (eDB) pattern in 7 patients (14 legs). The lymphedema was unilateral in 12 patients (12 legs). There were significant between-group differences in lymphatic diameter in relation to lower leg area: linear (0.9 ± 0.1 mm) vs dDB (0.7 ± 0.2 mm), linear vs eDB (0.7 ± 0.2 mm), linear vs unilateral (0.5 ± 0.1 mm), LE (0.9 ± 0.2 mm) vs dDB, LE vs eDB, LE vs unilateral, and dDB vs unilateral, P < .01; and eDB vs unilateral, P < .05. There were also significant between-group differences in the rate of improvement in the lower extremity lymphedema index according to the ICG lymphography pattern and laterality: linear (10.5% ± 2.4%) vs unilateral (6.7% ± 0.6%), LE (10.4% ± 1.5%) vs unilateral, dDB (11.0% ± 1.3%) vs eDB (8.9% ± 1.5%), and dDB vs unilateral, P < .01; linear vs eDB, P < .05; and eDB vs unilateral, P < .05.

CONCLUSIONS

The lymphatic vessel diameter tended to be greater in older patients with bilateral lymphedema than in younger patients with unilateral lymphedema. The rate of detection and improvement tended to decrease with worsening of the ICG lymphography pattern. LVA is thought to be more effective in older patients with early-stage bilateral lower leg lymphedema than in their younger counterparts with late-stage unilateral lymphedema.

Localized lymphedema after treatment for soft tissue sarcoma in the lower limbs: Comparison of improvement according to duration before lymphaticovenular anastomosis

Surgically invasive procedures involving the medial knee and inguinal regions can cause lymphedema. Lymphaticovenular anastomosis (LVA) could improve volume reduction and decrease the risk of cellulitis. However, it may be preferable to performed LVA as early as possible to achieve optimal results.