Lymph Flow Research Articles

Sonographic localisation of lymph nodes suspicious of metastatic breast cancer to surgical axillary levels

AbstractThe axillary lymph node (LN) burden of breast cancer patients guides multidisciplinary management and treatment regimes. Sonographic imaging is used to identify the presence, number and location of axillary LNs suspicious of malignancy and used to guide nodal fine needle aspirations and biopsies. Axillary LNs suspicious of harbouring breast cancer metastasis can be localised to three surgical axillary levels, numbered according to their location relative to the pectoralis minor muscle and lymph flow. To sonographically identify and localise suspicious axillary LNs, an understanding of the axillary anatomy, muscular sonographic landmarks, surgical axillary levels, and the sonographic technique to image and distinguish between benign and suspicious LNs is required.

Indocyanine green fluorescence imaging for lymph node detection and long-term clinical outcomes in colorectal cancer surgery: A systematic review and meta-analysis.

The indocyanine green fluorescence imaging (ICG-FI) technique is increasingly being used in laparoscopic colorectal surgery for lymph node mapping. However, there is no definitive standard regarding whether the application of this technique can significantly increase the detection rate of metastatic lymph nodes and improve long-term prognosis. PubMed, Embase, Web of Science, and Cochrane Library databases were searched to include studies including ICG-FI in laparoscopic colorectal surgery. Data on the detection rate of lymph nodes, metastatic rate of ICG-positive nodes, and long-term clinical outcomes were extracted following inclusion criteria. Eighteen studies with a total of 1552 patients 922 with ICG-guided laparoscopic and 630 without ICG technique were finally included. Clinical stage II/III colorectal tumors were the most commonly studies types. The patients using the ICG-FI technique had more harvested lymph nodes (weighted mean: 23.5 vs. 18.9; WMD=4.6; p<0.00001) during dissection but a lower metastasis rate of ICG-positive nodes (61/218 [28%] vs. 96/333 [28.9%]; OR=1.45; p=0.08). Compared with conventional laparoscopic colorectal surgery, additional ICG-FI technique did not improve the 3year overall survival rate (272/289 [94.1%] vs. 269/289 [93.1%]; OR=1.19; p=0.61), relapse-free survival (246/289 [85.1%] vs. 249/289 [86.2%]; OR=0.92; p=0.72), and local recurrence rate (22/289 [7.6%] vs. 28/289 [9.7%]; OR=0.77; p=0.38). The overall detection rate of sentinel lymph nodes, lymph flow, and metastatic rate of ICG-positive nodes with the help of ICG-FI were 86.8%, 89.9%, and 22.8%, respectively. No patients experienced major adverse events during ICG injection preoperatively or postoperatively. Indocyanine green fluorescence imaging-guided procedure, compared to conventional laparoscopic dissection, can assist in obtaining a greater number of harvested lymph nodes and metastatic lymph nodes, however, it did not significantly improve the long-term clinical outcomes. Level III systematic review of randomized control and nonrandomized studies.

Diagnostic imaging, therapeutic interventions and suggestions for thoracic duct congestion in postoperative hepatic lymphorrhea: a retrospective analysis of 20 cases

ObjectiveTo retrospectively evaluate thoracic duct (TD) congestion in hepatic lymphorrhea (HL) and propose treatment suggestions.MethodsRetrospectively analyze cases of postoperative HL admitted from August 2007 to November 2023. Twenty cases were enrolled and followed up. The medical history, ascites characteristics, lymphoscintigraphy, direct lymphangiography, and other clinical data were reviewed.ResultsTwenty patients with ascites after cholecystectomy or radical gastrectomy were included. There were 15 patients with cirrhosis and 5 patients with hepatitis. Ascites were light yellow even if the patients had a non-low-fat diet. Triglyceride level mean of ascites was 0.61 ± 0.20 mmol/L. There were 94.1% (16/17) of patients whose ascitic cholesterol ≥ 45 mg/dL or SAAG < 11.0 g/L. Mild abdominal radioactivity was shown in 89.5% (17/19) patients. Left subclavian-jugular venous angle radioactivity was observed in 84.2% (16/19) patients. In 10% (2/20) cases, lipiodol presenting as oil droplets traveled upwards quickly and flowed into the vein rapidly. In 90% (18/20) cases, tortuous and dilated thoracic duct, stagnant lipiodol, and poor flow into the vein were demonstrated. One patient refused treatment and died soon. By thoracic duct outlet reconstruction combined with other treatments, 16 patients were cured and the ascites of another 3 patients were controlled.ConclusionsTD congestion and elevated lymphatic pressure could be caused by increased lymph flow and TD outlet stenosis. TD decompression by outlet reconstruction may be an alternative approach to HL.

Rhythmic Contractions of Lymph Vessels and Lymph Flow Are Disrupted in Hypertensive Rats.

Hypertension increases the risk of lymphedema in patients with comorbidities, but whether hypertension directly compromises lymph vessel (LV) function and lymph flow is unclear. We compared the contractions of mesenteric LVs ex vivo and lymph flow in vivo between normotensive and Ang II (angiotensin II)-induced hypertensive rats and explored the ionic basis of contractile patterns. Key studies were recapitulated in spontaneously hypertensive rats and control Wistar-Kyoto rats. Video microscopy continuously recorded the diameters of cannulated rat mesenteric LVs, and high-speed optical imaging estimated mesenteric lymph flow in vivo. Jess capillary Western electrophoresis evaluated expression levels of ion channel proteins. Isolated LVs from Ang II-induced hypertensive rats exhibited dysrhythmic contractions, whereas LVs from both Ang II-induced hypertensive rats and spontaneously hypertensive rats exhibited reduced diastolic diameters and cross-sectional flow. Mesenteric lymph flow in vivo was 2.9-fold lower in Ang II-induced hypertensive rats compared with normotensive rats. Surprisingly, the LVs from Ang II-induced hypertensive rats expressed fewer intact L-type Ca2+ channel pore proteins and more modulatory cleaved C-terminal fragments. However, pharmacological block of voltage-gated K+ channels but not other K+ channel types in control LVs established the pattern of contractile dysfunction observed in hypertension. Jess capillary Western electrophoresis analysis confirmed a loss of Shaker-type KV1.2 channels in LVs from hypertensive rats. We provide initial evidence of lymphatic contractile dysfunction and compromised lymph flow in hypertensive rats, which may be caused by a loss of KV1.2 channels in the lymphatic muscle cells.

Multi-physics approach to model the lymph transport in the murine immune system

Abstract We formulate a compartmental model of the murine lymphatic system with the transfer rate parameters derived from the data on the geometric characteristics of the lymphatic system (LS) graph structure and the Hagen–Poiseuille-based values of the lymph flows through the system components, i.e., vertices and edges. It is supplemented by the physics-based model of lymph node draining-related function which considers a paradigmatic view of its geometry with one- and three-afferent lymphatic vessels and one efferent vessel, and the lymph flow described by the Darcy–Starling equations. We discuss further modelling work needed to gain a predictive understanding of the LS function in response to various perturbations including infections and therapeutic treatments.

Quantitative evaluation of microenvironmental changes and efficacy of cupping therapy under different pressures based on photoacoustic imaging

Cupping therapy, a traditional Chinese medicinal practice, has been subjected to scientific scrutiny to validate its effects on local tissue microenvironments. This study provides a quantitative assessment of cupping therapy at different negative pressures using photoacoustic imaging. Low-pressure cupping (-20 kPa) significantly improved local blood circulation, evidenced by increased hemoglobin oxygen saturation and vessel dilation that normalized within two hours. In contrast, high-pressure cupping (-30 kPa) led to capillary rupture, bleeding, and tissue edema, similar to the clinical presentation of cupping bruises. Additionally, our research unveiled that −20 kPa cupping expedited the clearance of indocyanine green dye, suggesting enhanced lymphatic drainage, which was further supported by fluorescence imaging. This indicates a potential mechanism for cupping's pain relief effects. Moreover, cupping showed promising results in improving sepsis outcomes in mice, potentially due to its anti-inflammatory properties. This study establishes a foundation for the objective evaluation of cupping therapy, demonstrating that low-pressure cupping is effective in promoting blood and lymphatic flow while minimizing tissue damage, thereby offering a safer therapeutic approach.

Nasal lymphatic obstruction of CSF drainage as a possible cause of Alzheimer's disease and dementia.

Alzheimer's disease, the most common form of dementia among older adults, slowly destroys memory and thinking skills. In recent years, scientists have made tremendous progress in understanding Alzheimer's disease, still, they do not yet fully understand what causes the disease. This article proposes a novel etiology for Alzheimer's disease. Our hypothesis developed from a review of nuclear medicine scans, in which the authors observed a significant increase in nasal turbinate vasodilation and blood pooling in patients with hypertension, sleep apnea, diabetes and/or obesity, all risk factors for Alzheimer's disease. The authors propose that nasal turbinate vasodilation and resultant blood pooling lead to the obstruction of normal nasal lymphatic clearance of cerebrospinal fluid and its waste products from the brain. The nasal turbinate vasodilation, due to increased parasympathetic activity, occurs alongside the well-established increased sympathetic activity of the cardiovascular system as seen in patients with hypertension. The increased parasympathetic activity is likely due to an autonomic imbalance secondary to the increase in worldwide consumption of highly processed food associated with dysregulation of the glucose regulatory system. The authors' hypothesis offers a novel mechanism and a new paradigm for the etiology of Alzheimer's disease and helps explain the rapid worldwide rise in the disease and other dementias which are expected to double in the next 20 years. This new paradigm provides compelling evidence for the modulation of the parasympathetic nervous system as a novel treatment strategy for Alzheimer's disease and other degenerative brain diseases, specifically targeting nasal turbinate lymphatic flow.

Symposium Highlight: IMAGING AND INTERVENTIONAL MANAGEMENT OF LYMPHATIC DISORDERS

Lymphatic flow disorders are reviewed, and a classification based on magnetic resonance lymphography findings outlined. Examples of successful interventional management based on this classification are provided. Presented at the 2023 ISL International Congress of Lymphology, Genoa, Italy in a special symposium on central and regional lymphatic system in health and disease.

Harnessing the lymphatic system.

Heart failure (HF) is a growing concern, with significant implications for mortality, morbidity, and economic sustainability. Traditionally viewed primarily as a hemodynamic disorder, recent insights have redefined HF as a complex systemic syndrome, emphasizing the importance of understanding its multifaceted pathophysiology. Fluid overload and congestion are central features of HF, often leading to clinical deterioration and hospital admissions, with the role of the lymphatic system previously largely overlooked, partly due to diagnostic challenges and visualization difficulties. With the advancement of those techniques, pathophysiological changes occurring in the lymphatic system during HF, such as enlargement of the thoracic duct and the increased lymphatic flow, are now becoming apparent. This emerging research has begun to uncover the interplay between lymphatic dysfunction and HF, suggesting novel therapeutic targets. Advances in molecular biology, such as targeting vascular endothelial growth factor and promoting lymphangiogenesis, hold promise for improving lymphatic function and mitigating HF complications. This article provides a comprehensive overview of the evolving landscape of lymphatic system-targeted therapies for HF. It explores various intervention levels, from mechanical lymphatic decongestion to pharmaceutical interactions and lymphatic micro-circulation, offering insights into future directions and potential clinical implications for HF management.

An alternative instrumental method for studying the morphofunctional state of eyelids in chronic blepharitis

Background: To date, the assessment of morphofunctional changes within eyelids is performed using laser scanning confocal microscopy, which has extensive diagnostic capabilities. Identification of the indicators equivalence of this method and laser Doppler flowmetry will confirm the existence of an alternative, objective and economical method of eyelid examination in chronic blepharitis. Aim: To prove the possibility of laser Doppler flowmetry application as an alternative method of eyelid morphofunctional state assessment. Materials and methods: The study included 62 patients (124 eyes) with an established diagnosis of chronic mixed demodecticosis blepharitis, including 46 women and 16 men, mean age 65.8 ± 3.2 years, randomly assigned into two groups with identical age and gender composition. Group 1 patients (31 patients, 62 eyes) were treated with cosmeceuticals containing terpenes and terpenoids 2 times a day and tear substitute 3 times a day for 1.5 months. Group 2 patients (31 patients, 62 eyes) used an eyelid care gel containing sulphur medicaments 2 times a day and a tear substitute 3 times a day for 1.5 months. In addition to standard ophthalmological examination, laser Doppler flowmetry and laser scanning confocal microscopy were performed. Dynamic follow-up was performed after 1.5 and 3 months. Results: The analysis of laser scanning confocal microscopy and laser Doppler flowmetry parameters revealed a high inverse correlation between the density of inflammatory cells of the eyelids tarsal conjunctiva and neurogenic oscillations of blood flow, as well as high direct correlation with the index of blood flow shunting. A marked direct correlation between the density index of meibomian gland acinuses and the parameters of myogenic oscillations of blood flow and neurogenic oscillations of lymph flow was established. Conclusions: Pearson’s correlation analysis performed on laser scanning confocal microscopy and laser Doppler flowmetry parameters assessing the morphofunctional state of the eyelids demonstrated the presence of equivalence in both study groups with high statistical reliability. The obtained data confirm the possibility of using laser Doppler flowmetry method for objective assessment of eyelid condition and allow the parameters of this method to serve as criteria for choosing pathogenetically oriented therapy of chronic blepharitis with evaluation of its effectiveness.

Macrophage uptake rate of Sonazoid in breast lymphosonography is highly conserved in healthy controls

Subcutaneous microbubble administration in connection with contrast enhanced ultrasound (CEUS) imaging is showing promise as a noninvasive and sensitive way to detect tumor draining sentinel lymph nodes (SLNs) in patients with breast cancer. Moreover, there is potential to harness the results from these approaches to directly estimate cancer burden, since some microbubble formulas, such as the Sonazoid used in this study, are rapidly phagocytosed by macrophages, and the macrophage concentration in a lymph node is inversely related to the cancer burden. This work presents a mathematical model that can approximate a rate constant governing macrophage uptake of Sonazoid,ki, given dynamic CEUS Sonazoid imaging data. Twelve healthy women were injected with 1.0 ml of Sonazoid in an upper-outer quadrant of one of their breasts and SLNs were imaged in each patient immediately after injection, and then at 0.25, 0.5, 1, 2, 4, 6, and 24 h after injection. The mathematical model developed was fit to the dynamic CEUS data from each subject resulting in a mean ± sd of 0.006 ± 0.005 h-1and 0.4 ± 0.1 h-1for relative lymphatic flow (EFl) andki, respectively. Furthermore, the roughly 25% sd of thekimeasurement was similar to the sd that would be expected from realistic noise simulations for a stable 0.4 h-1value ofki, suggesting that macrophage concentration is highly consistent among cancer-free SLNs. These results, along with the significantly smaller variance inkimeasurement observed compared to relative lymphatic flow suggest thatkimay be a more precise and promising approach of estimating macrophage abundance, and inversely cancer burden. Future studies comparing tumor-free to tumor-bearing nodes are planned to verify this hypothesis.

Clinical Efficacy and Safety of Low-Energy Extracorporeal Shock Wave Therapy for Various Conditions of Deep Dermal and Subdermal Fibrosis.

Extracorporeal shock wave therapy (ESWT) enhances extracellular matrix remodeling and tissue regeneration by promoting growth factor release, regulating blood and lymphatic flows, and reducing fat and fibrotic tissues. Focused shock wave therapy (F-SWT), radial shock wave therapy (R-SWT), and combined F-SWT and R-SWT have been used to deliver different patterns of shock energy depending on the characteristics of the target lesions. We investigated the efficacy and safety of ESWT in patients with dermal and subdermal fibrosis. Fifty-two patients treated with F-SWT and/or R-SWT for dermal and subdermal fibrosis caused due to various reasons were retrospectively analyzed by reviewing their medical records, clinical images, and ultrasound study images. The mean number of pulses administered for F-SWT on the cheek, temple, and chin were 2600.0 ± 1040.8 shocks/session and for R-SWT were 5080.0 ± 2234.6 pulses/session, and the number of treatment sessions were 8.0 ± 4.4. In patients who were treated with ESWT on the abdomen, the mean number of pulses for F-SWT were 2600.0 ± 2408.3 shocks/session and for R-SWT were 8400.0 ± 894.4 pulses/session, and the number of treatment sessions were 3.2 ± 1.6. Most patients were satisfied with the results. Pain during ESWT was well tolerated and post-ESWT edema was more common in R-SWT than in F-SWT. Our data demonstrated that ESWT effectively and safely improved the clinical appearance and functional movement of patients with dermal and subdermal fibrosis caused due to various reasons.

The Prophylactic Use of Negative Pressure Wound Therapy in Contaminated Wounds: A Prospective Cohort Study Conducted in ASU Hospitals

Abstract Background Contaminated wound and its complications cause increased patient morbidity, and it associated with delayed healing and increasing health care coast. Negative pressure wound therapy (NPWT) is frequently used for both chronic and acute open wounds, and studies have shown that it can speed up wound healing by encouraging the formation of granulation tissue, increasing perfusion, and enabling epithelialization and contraction. The introduction of NPWT to closed surgical incisions was motivated by improved results on open wounds. In high-risk patients, the use of NPWT in the early postoperative period lowers wound dehiscence and surgical site infections (SSIs). It minimizes hematoma and seroma rates by reducing wound edema and enhancing local perfusion and lymphatic flow. With better perfusion and oxygenation, wounds heal more quickly. Objective To evaluate the prophylactic use of negative pressure wound therapy as a technique for management and control of the contaminated wounds. Methods A prospective cohort study conducted at Ain Shams University Hospitals within a period of 6 months, 60 Patients with contaminated wounds immediately in postoperative period were included. And they are divided into two groups control group and study group each of them included 30 cases. Results 50% of the study group with application of NPWT immediately postoperative showed no discharge and no evidence of SSI, 20% showed minimal signs of inflammation in form of serous discharge and about 30% of them showed purulent discharge, erythema and evidence of SSI. In the control group with traditional gauze dressing about 46.7% showed purulent discharge and evidence of SSI. As regard muscle weakness and wound dehiscence, about 40% of the study group with NPWT showed muscle weakness and evidence of dehiscence and 46.7% of the control group with the traditional dressing showed muscle weakness and dehiscence. And as regard cosmetic appearance about 76% of the study group with NPWT showed good cosmetic appearance with average fine line scar or scar less than.5 cm in width. If take the consideration of satisfaction about the wound appearance About 56.7% of the cases showed parents' satisfaction, while 43.3% of control group showed parents' satisfaction. Conclusion Our study showed significant results in role of NPWT in reduction of SSI as 50% of the study group with application of NPWT immediately postoperative showed no evidence of SSI, 20% showed minimal signs of inflammation in form of serous discharge and about 30% of them showed purulent discharge, erythema and evidence of SSI. In the control group with traditional gauze dressing, about 46.7% showed purulent discharge and evidence of SSI. And as regard the muscle weakness and wound dehiscence, there is no significant difference in the use of NPWT or traditional gauze dressing as about 40% of the study group with NPWT showed muscle weakness and evidence of dehiscence and 46.7% of the control group with the traditional dressing showed muscle weakness and dehiscence. SO, the prophylactic use of NPWT in contaminated wound is effective in reducing the SSI, but there is no effect on muscle weakness and wound dehiscence.

Navigating Lymphedema: The Impact of Indocyanine Green Lymphography on Personalized Therapy Outcomes in Breast Cancer Patients

AimTo evaluate the role of Indocyanine Green Lymphography (ICG_L) in the early diagnosis and personalized management of breast cancer-related lymphedema (BCRL) among high-risk breast cancer (BC) survivors. MethodsPatients who admitted to the UPMC Magee-Womens Hospital Lymphedema Program between October 2018 and December 2021 with episodic symptoms were enrolled into the study. Patient demographics, clinical characteristics, and outcomes were prospectively collected and retrospectively analysed. Lymphatic flow disruptions were identified and guided personalized therapeutic interventions were guided by ICG_L. ResultsAmong 154 BC survivors, 184 arms were evaluated. Initial ICG_L showed 57.1% had no lymphedema, while 42.9% were classified as stage 1 to 3 lymphedema. Early diagnosis and personalized interventions provided improved outcomes, with only 4.3% developing clinical lymphedema after a median follow-up of 27 months. Patients exhibited stable or improved symptoms with individualized treatments such as manual lymphatic drainage, compression therapies, and physiotherapy. ConclusionICG_L evaluation is essential for patients at high-risk of developing BCRL. Early diagnosis before clinical onset of lymphedema, and ICG_L guided therapy significantly enhances the clinical outcomes and improves lymphedema management.

Effectiveness of Aloe Vera and Cabbage Leaf Compress on Breast Swelling Pain in Post-Partners in Bogor Barat District, Bogor City

ASEAN data in 2022 stated that 76,543 postpartum mothers experienced breast engorgement. 17.2 million postpartum mothers worldwide experience breast pain problems while breastfeeding. In Indonesia, the incidence of breastfeeding mothers experiencing breast engorgement reached the highest figure of 37.2% and 16% of working breastfeeding mothers experienced breast engorgement. Breast engorgement is interpreted as increased venous and lymph flow in the breasts to prepare for lactation. This is due to overdistension of the lactation ducts, causing breast swelling pain, and breast engorgement accompanied by an increase in body temperature. The study used a quasi-experimental design with a pretest-posttest two-group design. The sample consisted of 30 postpartum mothers who experienced breast engorgement pain and were divided into 2 intervention groups, namely aloe vera compresses and cabbage compresses, the intervention was carried out for 14 days. The instrument used was the Visual Analogue Scale (VAS). Data were analyzed using the Paired T-Test and Independent T-Test. In the Independent Sample T-Test, the p-value of the VAS scale for the aloe vera group was 0.019 &lt;0.05 with an average score of 2.0 and the VAS scale for the cabbage group was 0.037 &lt;0.05 with an average score of 1.87.

Case series of genital lymphaticovenous anastomosis for genital lymphatic vesicles

BackgroundThe management of lymphatic vesicles is challenging. This study aimed to clarify the lymphatic flow around the genitals and the effect of genital LVA on genital lymphatic vesicles. MethodsWe performed a retrospective study of 34 patients who underwent resection for lymphatic vesicle and LVA. In patients with genital lymphedema, two types of lymphatic inflow existed around the genital area; from the lower extremities (type 1) and from the buttocks (type 2). Lymphoscintigraphy was performed to detect type 1 lymphatics injecting isotope into the first interdigital area. ICG lymphography was performed to detect type 2 lymphatics injecting ICG into the ischial tuberosity. We performed resection of lymphatic vesicles and LVA in the legs and/or in the genitals. Postoperative recurrence rate of lymphatic vesicles and the frequency of cellulitis were evaluated. ResultsType 1 lymphatics were observed in 38.2% of the patients. In ICG lymphography, there was linear inflow to the genitals in 40.9% and DB inflow in 24.2%. In 10 patients (29.4%), both type 1 and 2 lymphatic vessels were observed. Genital LVA was performed in 31 patients and lower extremity LVA was performed in 15 patients. The average follow-up period was 332 days, and recurrence was observed in 8 (25.8%) of 31 patients who underwent total resection. The average number of cellulitis episodes decreased significantly from 2.8 times before surgery to 0.31 times after surgery (p<0.01). ConclusionLVA in the genital area and lower limbs was effective in preventing postoperative recurrence of lymphatic vesicles after resection.

Multiscale computational analysis of the steady fluid flow through a lymph node

Lymph Nodes (LNs) are crucial to the immune and lymphatic systems, filtering harmful substances and regulating lymph transport. LNs consist of a lymphoid compartment (LC) that forms a porous bulk region, and a subcapsular sinus (SCS), which is a free-fluid region. Mathematical and mechanical challenges arise in understanding lymph flow dynamics. The highly vascularized lymph node connects the lymphatic and blood systems, emphasizing its essential role in maintaining the fluid balance in the body. In this work, we describe a mathematical model in a steady setting to describe the lymph transport in a lymph node. We couple the fluid flow in the SCS governed by an incompressible Stokes equation with the fluid flow in LC, described by a model obtained by means of asymptotic homogenisation technique, taking into account the multiscale nature of the node and the fluid exchange with the blood vessels inside it. We solve this model using numerical simulations and we analyze the lymph transport inside the node to elucidate its regulatory mechanisms and significance. Our results highlight the crucial role of the microstructure of the lymph node in regularising its fluid balance. These results can pave the way to a better understanding of the mechanisms underlying the lymph node’s multiscale functionalities which can be significantly affected by specific physiological and pathological conditions, such as those characterising malignant tissues.

Intravital imaging of pulmonary lymphatics in inflammation and metastatic cancer.

Intravital microscopy has enabled the study of immune dynamics in the pulmonary microvasculature, but many key events remain unseen because they occur in deeper lung regions. We therefore developed a technique for stabilized intravital imaging of bronchovascular cuffs and collecting lymphatics surrounding pulmonary veins in mice. Intravital imaging of pulmonary lymphatics revealed ventilation-dependence of steady-state lung lymph flow and ventilation-independent lymph flow during inflammation. We imaged the rapid exodus of migratory dendritic cells through lung lymphatics following inflammation and measured effects of pharmacologic and genetic interventions targeting chemokine signaling. Intravital imaging also captured lymphatic immune surveillance of lung-metastatic cancers and lymphatic metastasis of cancer cells. To our knowledge, this is the first imaging of lymph flow and leukocyte migration through intact pulmonary lymphatics. This approach will enable studies of protective and maladaptive processes unfolding within the lungs and in other previously inaccessible locations.

Evaluation of Postoperative Anastomotic Patency in Lymphaticovenular Anastomosis Using Photoacoustic Imaging.

Lymphaticovenular anastomosis (LVA) is a surgical technique used to alleviate lymphedema by bypassing the lymphatic and venous vessels and facilitating lymphatic fluid drainage. Accurate evaluation of anastomotic patency is crucial for assessing LVA outcomes. Traditional near-infrared fluorescence lymphography has limitations, including fluorescence diffusion in subcutaneous fat and difficulty evaluating areas beneath the dermal backflow. Photoacoustic imaging (PAI) is a potential alternative for high-resolution visualization of lymphatic and blood vessels. We aimed to evaluate the utility of PAI for assessing LVA patency. Using the LUB0 PAI system, we examined patients who underwent LVA. Imaging was conducted using subcutaneously injected indocyanine green (ICG) to visualize lymphatic vessels. Results showed clear patency in some cases, inability to evaluate it in others, and confirmed occlusion in certain instances. While PAI provides valuable insights, challenges remain, including the potential for ambiguous results from the intermittent nature of lymphatic flow and difficulty visualizing low-ICG-concentration lymphatic vessels. Nonetheless, PAI offers a promising method for detailed 3D evaluation of anastomoses. It may improve surgical outcomes and contribute to future evidence in the field. Further advancements, including real-time video assessment, may enhance the accuracy and reliability of LVA patency evaluation.

Robotic-Assisted Microsurgery in Lymphatic Reconstruction.

Lymphatic reconstruction entails microsurgery of the smallest human vessels with little microsurgical error tolerance. Surgical outcomes are therefore tightly tied to microsurgical performances and can be restricted by physiologic tremor or muscle tiring throughout extensive procedures. Recently introduced highly specialized microsurgical robots are promising to help overcome these human limitations, particularly relevant for lymphatic microsurgery. Ideal indications and setups for these robotic systems, however, are not yet well established. Reviewing the first 5 years of clinical experience with these microsurgical robots revealed a total of 204 robotically performed lymphatic anastomoses. Most reported use cases (84.4%) involved microsurgical reconstructions of lymphatic flow at the upper and lower extremities, of which 42% of patients were treated for breast cancer-related lymphedema. Considering rising cancer incidences and survival rates, these numbers highlight the potential of robotic-assisted microsurgery for this patient group, whereas the concept of robotic-assisted microsurgery per se can aid surgeons to achieve a new level of microsurgical excellence.