Variable Anatomy of the Lateral Upper Arm Lymphatic Channel: An Anatomical Risk Factor for Breast Cancer-Related Lymphedema

Immediate lymphatic reconstruction: Lessons learned over eight years

Immediate lymphatic reconstruction (ILR) is recognized as a surgical approach used to reduce the risk of developing secondary lymphedema, and evidence demonstrating the efficacy of ILR is favorable. Our Lymphatic Center has become a centralized location offering ILR for the risk-reduction in breast cancer-related lymphedema (BCRL) in New England. Over the course of our experience, we made several modifications and adapted our approach to enhance the operative success of this procedure. These include advancements in our use of indocyanine green (ICG) imaging to identify baseline lymphatic anatomical variation, utilization of fluorescein isothiocyanate for lymphatic vessel visualization, application of the lymphosome concept to guide arm injection sites, verification of anastomotic patency (using ICG), localization of reconstruction to guide radiation therapy, incorporation of intraoperative tools to facilitate better anatomic visualization of the axilla, and addition of a lower extremity vein graft to mitigate venous-related complications. Collecting information from each surgery in a standardized manner, including intraoperative lymphatic channel measurements, and deploying clips for possible future radiation exposure, enables future studies on ILR patient outcomes. In this contribution, we aimed to share our institutional modifications with the surgical community to facilitate further adoption, conversation, and advancement of ILR for the risk-reduction in BCRL.

A Multiresolution Approach with Method-Informed Statistical Analysis for Quantifying Lymphatic Pumping Dynamics

Despite significant strides in lymphatic system imaging, the timely diagnosis of lymphatic disorders remains elusive. One main cause for this is the absence of standardized, quantitative methods for real-time analysis of lymphatic contractility. Here, we address this unmet need by combining near-infrared lymphangiography imaging with an innovative analytical workflow. We combined data acquisition, signal processing, and statistical analysis to integrate traditional peak and-valley with advanced wavelet time-frequency analyses. Decision theory was used to evaluate the primary drivers of attributable variance in lymphangiography measurements to generate a strategy for optimizing the number of repeat measurements needed per subject to increase measurement reliability. This approach not only offers detailed insights into lymphatic pumping behaviors across species, sex and age, but also significantly boosts the reliability of these measurements by incorporating multiple regions of interest and evaluating the lymphatic system under various gravitational loads. By addressing the critical need for improved imaging and quantification methods, our study offers a new standard approach for the imaging and analysis of lymphatic function that can improve our understanding, diagnosis, and treatment of lymphatic diseases. The results highlight the importance of comprehensive data acquisition strategies to fully capture the dynamic behavior of the lymphatic system.

Alternative Lymphatic Drainage Pathways in the Trunk Following Oncologic Therapy

BACKGROUND

Anatomic and functional descriptions of trunk and breast lymphedema following breast cancer treatment are emerging as indicators of lymphatic dysfunction. Indocyanine green-lymphangiography has been instrumental in characterizing this dysfunction in the extremity and can be applied to other regions. Previous work has established a validated Pittsburgh Trunk Lymphedema Staging System to characterize such affected areas. This study aims to identify risk and protective factors for the development of truncal and upper extremity lymphedema using alternative lymphatic drainage, providing implications for medical and surgical treatment.

METHODS

Patients undergoing revisional breast surgery with suspicion of upper extremity lymphedema between 12/2014 and 3/2020 were offered lymphangiography. The breast and lateral/anterior trunks were visualized and blindly evaluated for axillary and inguinal lymphatic flow. A linear-weighted Cohen's kappa statistic was calculated comparing alternative drainage evaluation. Binomial regression was used to compute relative risks (RRs). Significance was assessed at alpha = 0.05.

RESULTS

Eighty-six sides (46 patients) were included. Twelve sides underwent no treatment and were considered controls. Eighty-eight percent of the noncontrols had alternative lymphatic flow to the ipsilateral axillae (64%), ipsilateral groins (57%), contralateral axillae (20.3%), and contralateral groins (9.3%). Cohen's kappa for alternative drainage was 0.631 ± 0.043. Ipsilateral axillary and contralateral inguinal drainage were associated with reduced risk of developing truncal lymphedema [RR 0.78, confidence interval (CI) 0.63-0.97, P = 0.04; RR 0.32, CI 0.13-0.79, P = 0.01, respectively]. Radiation therapy increased risk of truncal and upper extremity lymphedema (RR 3.69, CI 0.96-14.15, P = 0.02; RR 1.92, CI 1.09-3.39, P = 0.03, respectively). Contralateral axillary drainage and axillary lymph node dissection were associated with increased risk of upper extremity lymphedema (RR 4.25, CI 1.09-16.61, P = 0.01; RR 2.83, CI 1.23-6.52, P = 0.01, respectively).

CONCLUSIONS

Building upon previous work, this study shows risk and protective factors for the development of truncal and upper extremity lymphedema. Most prevalent alternative channels drain to the ipsilateral axilla and groin. Ipsilateral axillary and contralateral inguinal drainage were associated with reduced risk of truncal lymphedema. Patients with radiation, axillary dissection, and contralateral axillary drainage were associated with increased risk of upper extremity lymphedema. These findings have important clinical implications for postoperative manual lymphatic drainage and for determining eligibility for lymphovenous bypass surgery.

Evaluating the Surgical Outcome of Lymphovenous Anastomosis in Breast Cancer-Related Lymphedema Using Tc-99m Phytate Lymphoscintigraphy: Preliminary Results

Background: Breast cancer-related lymphedema (BCRL) remains a significant postcancer treatment challenge with no definitive cure. Recent supermicrosurgical treatments, such as lymphovenous anastomosis (LVA), have shown promise but lack established objective indicators for outcome evaluation. We investigated the utility of Technetium-99m (Tc-99m) lymphoscintigraphy, an imaging technique providing objective information on lymphatic fluid flow, for assessing LVA surgical outcomes. Methods and Results: A retrospective cohort analysis of patients undergoing LVA for BCRL was conducted. Lymphoscintigraphy images pre- and 1-year postsurgery were compared to determine changes in lymphatic fluid flow of 18 patients based on newly defined parameters "uptake ratio" and "washout rates." Statistically significant reduction in the uptake ratio was observed in the forearm at 30 and 60 minutes postinjection phases. In addition, the forearm showed higher washout rate, indicating an improved lymphatic function in the forearm. Conclusion: Tc-99m lymphoscintigraphy can provide valuable objective data for evaluating LVA surgical outcomes in BCRL patients. However, site-specific differences in outcomes highlight the need for individualized surgical planning. Further large-scale studies are necessary to validate these preliminary findings and develop a standardized approach for LVA assessment.

Mapping the Anatomy of the Human Lymphatic System

BACKGROUND

 While substantial anatomical study has been pursued throughout the human body, anatomical study of the human lymphatic system remains in its infancy. For microsurgeons specializing in lymphatic surgery, a better command of lymphatic anatomy is needed to further our ability to offer surgical interventions with precision. In an effort to facilitate the dissemination and advancement of human lymphatic anatomy knowledge, our teams worked together to create a map. The aim of this paper is to present our experience in mapping the anatomy of the human lymphatic system.

METHODS

 Three steps were followed to develop a modern map of the human lymphatic system: (1) identifying our source material, which was "Anatomy of the human lymphatic system," published by Rouvière and Tobias (1938), (2) choosing a modern platform, the Miro Mind Map software, to integrate the source material, and (3) transitioning our modern platform into The Human BioMolecular Atlas Program (HuBMAP).

RESULTS

 The map of lymphatic anatomy based on the Rouvière textbook contained over 900 data points. Specifically, the map contained 404 channels, pathways, or trunks and 309 lymph node groups. Additionally, lymphatic drainage from 165 distinct anatomical regions were identified and integrated into the map. The map is being integrated into HuBMAP by creating a standard data format called an Anatomical Structures, Cell Types, plus Biomarkers table for the lymphatic vasculature, which is currently in the process of construction.

CONCLUSION

 Through a collaborative effort, we have developed a unified and centralized source for lymphatic anatomy knowledge available to the entire scientific community. We believe this resource will ultimately advance our knowledge of human lymphatic anatomy while simultaneously highlighting gaps for future research. Advancements in lymphatic anatomy knowledge will be critical for lymphatic surgeons to further refine surgical indications and operative approaches.

Is Immediate Lymphatic Reconstruction on Breast Cancer Patients Oncologically Safe? A Preliminary Study

Background

In breast cancer patients receiving axillary lymph node dissection (ALND), immediate lymphatic reconstruction (ILR) with lymphovenous anastomosis is an emerging technique for reducing the risk of arm lymphedema. However, the oncologic safety of surgically diverting lymphatic ducts directly into venules in a node-positive axilla is still a concern of inadvertently inducing metastasis of remaining cancer cells. This study aimed to assess the oncologic safety of ILR.

Methods

From January 2020 to January 2022, 95 breast cancer patients received ALND, and 45 of them also received ILR. Patients with recurrent cancer, with follow-up less than 12 months, and with missed data were excluded. Variables were compared between ILR and non-ILR groups, and the outcome of interest was the rate of distant recurrence after follow-up for at least 1 year.

Results

Thirty-four patients in the ILR group and 32 patients in the non-ILR group fulfilled the inclusion criteria for analysis. No statistically significant difference was noted between groups in terms of age, body mass index, type of breast surgery, pathologic cancer staging, histologic type and grade of breast cancer, molecular subtypes, frequency of axillary lymph node metastasis, or adjuvant therapy. For the patients receiving follow-up for at least 1 year, no statistically significant difference was found in terms of distant recurrence rates between ILR and non-ILR groups (P = 0.44).

Conclusion

For breast cancer patients receiving ALND, ILR with lymphovenous anastomosis is oncologically safe, within an average follow-up period of 21 months.

Non-Linear Lymphatic Anatomy in Breast Cancer Patients Prior to Axillary Lymph Node Dissection: A Risk Factor For Lymphedema Development

Immediate lymphatic reconstruction (ILR) at the time of axillary lymph node dissection (ALND) has become increasingly utilized for the prevention of breast cancer related lymphedema. Preoperative indocyanine green (ICG) lymphography is routinely performed prior to an ILR procedure to characterize baseline lymphatic anatomy of the upper extremity. While most patients have linear lymphatic channels visualized on ICG, representing a non-diseased state, some patients demonstrate non-linear patterns. This study aims to determine potential inciting factors that help explain why some patients have non-linear patterns, and what these patterns represent regarding the relative risk of developing postoperative breast cancer related lymphedema in this population. A retrospective review was conducted to identify breast cancer patients who underwent successful ILR with preoperative ICG at our institution from November 2017-June 2022. Among the 248 patients who were identified, 13 (5%) had preoperative non-linear lymphatic anatomy. A history of trauma or surgery of the affected limb and an increasing number of sentinel lymph nodes removed prior to ALND appeared to be risk factors for non-linear lymphatic anatomy. Furthermore, non-linear anatomy in the limb of interest was associated with an increased risk of postoperative lymphedema development. Overall, non-linear lymphatic anatomy on pre-operative ICG lymphography appears to be a risk factor for developing ipsilateral breast cancer-related lymphedema. Guided by the study's findings, when breast cancer patients present with baseline non-linear lymphatic anatomy, our institution has implemented a protocol of prophylactically prescribing compression sleeves immediately following ALND.