Lymphaticovenous Anastomosis Supermicrosurgery Decreases Oxidative Stress and Increases Antioxidant Capacity in the Serum of Lymphedema Patients

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.

Vascular Endothelial Growth Factor C (VEGF-C) Sensitizes Lymphatic Endothelial Cells to Oxidative-Stress-Induced Apoptosis through DNA Damage and Mitochondrial Dysfunction: Implications for Lymphedema

Secondary lymphedema is caused by damage to the lymphatic system from surgery, cancer treatment, infection, trauma, or obesity. This damage induces stresses such as oxidative stress and hypoxia in lymphatic tissue, impairing the lymphatic system. In response to damage, vascular endothelial growth factor C (VEGF-C) levels increase to induce lymphangiogenesis. Unfortunately, VEGF-C often fails to repair the lymphatic damage in lymphedema. The underlying mechanism contributing to lymphedema is not well understood. In this study, we found that surgery-induced tail lymphedema in a mouse model increased oxidative damage and cell death over 16 days. This corresponded with increased VEGF-C levels in mouse tail lymphedema tissue associated with macrophage infiltration. Similarly, in the plasma of patients with secondary lymphedema, we found a positive correlation between VEGF-C levels and redox imbalance. To determine the effect of oxidative stress in the presence or absence of VEGF-C, we found that hydrogen peroxide (H2O2) induced cell death in human dermal lymphatic endothelial cells (HDLECs), which was potentiated by VEGF-C. The cell death induced by VEGF-C and H2O2 in HDLECs was accompanied by increased reactive oxygen species (ROS) levels and a loss of mitochondrial membrane potential. Antioxidant pre-treatment rescued HDLECs from VEGF-C-induced cell death and decreased ROS under oxidative stress. As expected, VEGF-C increased the number of viable and proliferating HDLECs. However, upon H2O2 treatment, VEGF-C failed to increase either viable or proliferating cells. Since oxidative stress leads to DNA damage, we also determined whether VEGF-C treatment induces DNA damage in HDLECs undergoing oxidative stress. Indeed, DNA damage, detected in the form of gamma H2AX (γH2AX), was increased by VEGF-C under oxidative stress. The potentiation of oxidative stress damage induced by VEFG-C in HDLECs was associated with p53 activation. Finally, the inhibition of vascular endothelial growth factor receptor-3 (VEGFR-3) activation blocked VEGF-C-induced cell death following H2O2 treatment. These results indicate that VEGF-C further sensitizes lymphatic endothelial cells to oxidative stress by increasing ROS and DNA damage, potentially compromising lymphangiogenesis.

Comparison of contraction type and non-contraction type lymphatic vessels in lymphaticovenous anastomosis for cancer-related unilateral lower limb lymphedema: a retrospective cohort propensity-score-matched outcome analysis

BACKGROUND

Contraction-type lymphatic vessels (LV) are considered suboptimal for lymphaticovenous anastomosis (LVA). However, despite these pathological changes, their functionality and link to outcomes have not been fully elucidated. The aim of this study was to determine the impact on outcomes when contraction-type LVs were used for LVA compared to the non-contraction-type (normal + ectatic) counterpart for treating lower limb lymphedema.

STUDY DESIGN

Eighty-three patients with gynecologic cancer-related unilateral lower-limb lymphedema who underwent LVA as their primary treatment were enrolled in this study. The study group included 20 patients who used only contraction-type LVs. An additional 63 patients (control group) received non-contraction-type LVs only. Patients with a history of LVA, liposuction, or excisional therapy were excluded. Patient characteristics, intraoperative findings, functional parameters, and pre-and post-LVA volume changes were recorded and matched using propensity scores. The primary endpoint was the volume change at 6/12 months after LVA.

RESULTS

After matching, 20 patients were included in each group. All parameters were matched, except that the study group still had a significantly inferior indocyanine green (ICG)-positive ratio, lymph flow-positive ratio, and washout-positive ratios (P<0.001, P=0.003, and P<0.001, respectively) when compared to the control group after matching. However, at one year follow-up, the postoperative percentage volume reduction was comparable between the groups (P=0.619).

CONCLUSION

The use of contraction-type lymphatic vessels for LVA is encouraged when no other LVs are available.

Peripheral T cell profiling reveals downregulated exhaustion marker and increased diversity in lymphedema post-lymphatic venous anastomosis

Lymphedema is a progressive condition accompanying cellulitis and angiosarcoma, suggesting its association with immune dysfunction. Lymphatic venous anastomosis (LVA) can provide relief from cellulitis and angiosarcoma. However, the immune status of peripheral T cells during lymphedema and post-LVA remains poorly understood. Using peripheral blood T cells from lymphedema, post-LVA, and healthy controls (HCs), we compared the profile of T cell subsets and T cell receptor (TCR) diversity. PD-1⁺ Tim-3 ⁺ expression was downregulated in post-LVA compared with lymphedema. IFN-γ levels in CD4⁺PD-1⁺ T cells and IL-17A levels in CD4⁺ T cells were downregulated in post-LVA compared with lymphedema. TCR diversity was decreased in lymphedema compared with HCs; such TCR skewing was drastically improved in post-LVA. T cells in lymphedema were associated with exhaustion, inflammation, and diminished diversity, which were relieved post-LVA. The results provide insights into the peripheral T cell population in lymphedema and highlight the immune modulatory importance of LVA.

Outcomes of Lymphovenous Anastomosis for Lower Extremity Lymphedema: A Systematic Review

Lymphovenous anastomosis (LVA) is a microsurgical treatment for lymphedema of the lower extremity (LEL). This study systematically reviews the most recent data on outcomes of various LVA techniques for LEL in diverse patients.

METHODS

A comprehensive literature search was conducted in the Ovid MEDLINE, Ovid EMBASE, and Scopus databases to extract articles published through June 2021. Studies reporting data on objective postoperative improvement in lymphedema and/or subjective improvement in quality of life for patients with LEL were included. Extracted data comprised demographics, number of patients and lower limbs, duration of symptoms before LVA, surgical technique, duration of follow-up, and objective and subjective outcomes.

RESULTS

A total of 303 articles were identified and evaluated, of which 74 were ultimately deemed eligible for inclusion in this study, representing 6260 patients and 2554 lower limbs. The average patient age ranged from 22.6 to 76.14 years. The duration of lymphedema before LVA ranged from 12 months to 11.4 years. Objective rates of improvement in lymphedema ranged from 23.3% to 100%, with the greatest degree of improvement seen in patients with early-stage LEL.

CONCLUSIONS

LVA is a safe and effective technique for the treatment of LEL of all stages. Several emerging techniques and variations may lead to improved patient outcomes.

Effect of Lymphaticovenous Anastomosis on Muscle Edema, Limb, and Subfascial Volume in Lower Limb Lymphedema: MRI Studies

BACKGROUND

Although satisfactory volume reduction in secondary unilateral lower limb lymphedema after lymphaticovenous anastomosis (LVA) in the affected limb has been well reported, alleviation of muscle edema and the impact of LVA on the contralateral limb have not been investigated.

STUDY DESIGN

This retrospective cohort study enrolled patients who underwent supermicrosurgical LVA between November 2015 and January 2017. Pre- and post-LVA muscle edema were assessed using fractional anisotropy (FA) and apparent diffusion coefficient (ADC). The primary endpoint was changes in limb/subfascial volume assessed with magnetic resonance volumetry at least 6 months after LVA.

RESULTS

Twenty-one patients were enrolled in this study. Significant percentage reductions in post-LVA muscle edema were found in the affected thigh (83.6% [interquartile range = range of Q1 to Q3; 29.8-137.1] [FA], 53.3% [27.0-78.4] [ADC]) as well as limb (21.7% [4.4-26.5]) and subfascial (18.7% [10.7-39.1]) volumes. Similar findings were noted in the affected lower leg: 71.8% [44.0-100.1] (FA), 59.1% [45.8-91.2] (ADC), 21.2% [6.8-38.2], and 28.2% [8.5-44.8], respectively (all p < 0.001). Significant alleviation of muscle edema was also evident in the contralateral limbs (thigh: 25.1% [20.4-57.5] [FA]; 10.7% [6.6-17.7] [ADC]; lower leg: 47.1% [35.0-62.8] [FA]; 14.6% [6.5-22.1] [ADC]; both p < 0.001), despite no statistically significant difference in limb and subfascial volumes.

CONCLUSIONS

Our study found significant reductions in muscle edema and limb/subfascial volumes in the affected limb after LVA. Our findings regarding edema in the contralateral limb were consistent with possible lymphedema-associated systemic influence on the unaffected limb, which could be surgically relieved.