Use of Indocyanine Green-SPY Angiography for Tracking Lymphatic Recovery After Lymphaticovenous Anastomosis

Outcomes after microsurgical treatment of lymphedema: a systematic review and meta-analysis

BACKGROUND

Microsurgical treatment options for lymphedema consist mainly of lymphovenous anastomosis (LVA) and vascularized lymph node transfers (VLNTs). There are no standard measurements of the effectiveness of these interventions and reported outcomes vary among studies.

METHODS

A systematic review and meta-analysis were performed based on a structured search in Embase, Medline, PubMed, Cinahl, Cochrane, and ProQuest in October 2020, with an update in February 2022. Firstly, a qualitative summary of the main reported outcomes was performed, followed by a pooled meta-analysis of the three most frequently reported outcomes using a random effects model. Randomized controlled trials, prospective cohorts, retrospective cohorts, and cross-sectional and case-control studies that documented outcomes following microsurgery in adult patients were included. Studies of other surgical treatments (liposuction, radical excision, lymphatic vessel transplantation) or without reported outcomes were excluded. The study protocol was registered on PROSPERO (International Prospective Register of Systematic Reviews) (ID: CRD42020202417). No external funding was received for this review.

RESULTS

One hundred fifty studies, including 6496 patients, were included in the systematic review. The qualitative analysis highlighted the three most frequently reported outcomes: change in circumference, change in volume, and change in the number of infectious episodes per year. The overall pooled change in excess circumference across 29 studies, including 1002 patients, was -35.6% [95% CI: -30.8 to -40.3]. The overall pooled change in excess volume across 12 studies including 587 patients was -32.7% [95% CI: -19.8 to -45.6], and the overall pooled change in the number of cutaneous infections episodes per year across 8 studies including 248 patients was -1.9 [95% CI: -1.4 to -2.3]. The vast majority of the studies included were case series and cohorts, which were intrinsically exposed to a risk of selection bias.

CONCLUSION

The currently available evidence supports LVA and vascularized lymph node transfers as effective treatments to reduce the severity of secondary lymphedema. Standardization of staging method, outcomes measurements, and reporting is paramount in future research in order to allow comparability across studies and pooling of results.

Advances in Lymphedema

Lymphedema is a common, complex, and inexplicably underappreciated human disease. Despite a history of relative neglect by health care providers and by governmental health care agencies, the last decade has seen an explosive growth of insights into, and approaches to, the problem of human lymphedema. The current review highlights the significant advances that have occurred in the investigative and clinical approaches to lymphedema, particularly over the last decade. This review summarizes the progress that has been attained in the realms of genetics, lymphatic imaging, and lymphatic surgery. Newer molecular insights are explored, along with their relationship to future molecular therapeutics. Growing insights into the relationships among lymphedema, obesity, and other comorbidities are important to consider in current and future responses to patients with lymphedema.

The application of indocyanine green (ICG) and near-infrared (NIR) fluorescence imaging for assessment of the lymphatic system in reconstructive lymphaticovenular anastomosis surgery

INTRODUCTION

Lymphedema has traditionally been managed through noninvasive means with complete decongestive therapy. However, complete decongestive therapy is an intensive program that requires lifelong adherence by patients with lymphedema. More recently, reconstructive surgical procedures have shown promise in improving lymphedema by physiologically restoring lymphatic function. One of these types of procedures, lymphaticovenular anastomosis, relies on technological advances in imaging, particularly indocyanine green lymphangiography.

AREAS COVERED

This article reviews indocyanine green and near-infrared fluorescence imaging. In addition, this article discusses the application of this imaging to the preoperative, intraoperative, and postoperative assessment of the lymphatic system in the setting of lymphaticovenular anastomosis surgery.

EXPERT OPINION

Indocyanine green lymphangiography offers significant advantages over other types of imaging of the lymphatic system. In the future, it is hopeful that additional options for these imaging devices will become available which may increase their accessibility by centers interested in performing reconstructive lymphatic surgery, including in relation to cost. Finally, more studies with higher levels of evidence are needed to better define the long-term outcomes associated with lymphatic surgery including LVA. In this regard, practitioners should fully harness the information conferred by ICG lymphangiography as both a clinical and research tool.

The Direct Observation of Lymphaticovenular Anastomosis Patency with Photoacoustic Lymphangiography

Supplemental Digital Content is available in the text.

It is difficult to evaluate the postoperative patency of lymphaticovenular anastomosis, but this evaluation is essential for determining surgical results. When using the current standard modality, near-infrared fluorescent lymphography, it is difficult to observe patency if the anastomotic point is veiled by dermal backflow. In this study, we used a new photoacoustic imaging device, PAI-05, to check the patency of anastomosis. We performed photoacoustic lymphangiography after lymphaticovenular anastomosis surgery. By digitally subtracting the superficial area, we can examine an area deeper than the dermal backflow, which is not visible by near-infrared fluorescent lymphography. The connection between the lymphatic vessel and the venule observed in the image is an indication of the patency of anastomosis. However, in a non-patent anastomosed site, the lymphatic vessel has a gap that separates it from the venule at the anastomosed site. Although photoacoustic lymphangiography cannot be used to visualize the lymphatic vessels that are not contrasted by indocyanine green, the resulting high-resolution images and clear anastomosis evaluation afforded by it will contribute to the development of future lymphedema treatments.

Application of imaging in lymphedema surgical therapies

Lymphedema is a chronic, progressive disease caused by primary or secondary reasons. It is currently uncurable and conservative compression therapy is generally applied. Lymphovenous anastomosis and vascularized lymph node transfer (VLNT) are two main surgical treatment that are used in addition to conservative therapy. Lymphovenous anastomosis involves the anastomosing remaining functional lymphatic vessels to vein. When the lymphatic vessels are greatly damaged and in no case can they be used for anastomosis, VLNT provide the affected area with lymph nodes from elsewhere to restore the drainage function. During all these procedures, a clear image to identify related lymphatic structures and venous vessels can be greatly useful for preoperative planning, intraoperative navigation, and postoperative evaluation. Lymphoscintigraphy used to be the gold standard in evaluating lymphedema and mapping lymphatic systems. But due to the downside of radiation, invasive operation and complication, other modalities are gaining attention. In this article, we reviewed the application of Indocyanine green (ICG) lymphography, ultrasound, magnetic resonance lymphography (MRL), and single-photon emission computed tomography-computed tomography (SPECT-CT) in the field of surgical therapy in lymphedema.

Surgical management of lymphedema: a review of current literature

Lymphedema may be characterized by a progressive clinical course and limitations in improvement despite multi-modality treatment. In westernized countries, it most commonly presents as an undesirable complication of cancer treatment, particularly breast cancer. In the past several decades, surgical treatments for lymphedema have advanced, alongside developments in microsurgery. Lymphovenous anastomosis (LVA) and lymph node transplantation are physiological therapies that may reduce lymphedema through addressing its route cause. Ablative techniques such as liposuction and subcutaneous excision aid in resolving the accumulation of proteinaceous adipose and fibrotic tissue seen in advanced lymphedema. The goal of this review is to examine the outcomes and limitations of current surgical techniques used in lymphedema management.

Correlation between patency and clinical improvement after lymphaticovenous anastomosis (LVA) in breast cancer-related lymphedema: 12-month follow-up

PURPOSE

Breast cancer-related lymphedema (BCRL) is caused by an interruption of the lymphatic system after breast cancer treatment. Lymphaticovenous anastomosis (LVA), by which one or more patent lymphatic collecting vessels are connected to subcutaneous veins, shows promising results. Postoperatively, the patency of these anastomosis can be evaluated; however, little is known concerning the long-term patency after LVA in patients with BCRL. The aim of this study was to analyse the long-term patency, quality of life (QoL) and arm circumference after LVA, and to explore differences between patent and non-patent anastomosis and its correlation with clinical improvement.

METHODS

Twenty-five patients underwent indocyanine green (ICG) lymphography, lymph ICF-questionnaire, and arm circumference measurement preoperatively and 12 months after the LVA procedure.

RESULTS

Seventy-six percent of the patients showed at least one patent anastomosis after 12 months. Quality of life according to the Lymph-ICF increased significantly (p < 0.000); however, arm circumference showed no significant decrease. Sixty-five percent discontinued wearing compression stockings. The patent anastomosis group, compared with the non-patent anastomosis group showed, without significance, more improvement in QoL, arm circumference, and discontinuation of compression stockings, as well as a lower rate of infections both pre- and postoperatively, a shorter duration of lymphedema preoperatively, and a higher rate of early lymphedema and ICG stage.

CONCLUSIONS

LVA showed an acceptable patency and positive correlation between a patent anastomosis and clinical improvement after 12 months. Further research with a larger study population is required to determine whether outcomes or patient characteristics significantly correlate with a patent anastomosis after LVA operation.

Near-infrared fluorescence imaging for the prevention and management of breast cancer-related lymphedema: A systematic review

Sentinel lymph node identification by near infrared (NIR) fluorescence with indocyanine green (ICG) is recognized in the literature as a useful technique. NIR fluorescence technology could become key in the prevention and management of lymphedema after axillary dissection for breast cancer. Here, we conducted a systematic review focusing on ICG imaging to improve lymphedema prevention and treatment after axillary surgery. A systematic literature review was performed using MEDLINE and Embase to identify articles focused on ICG imaging for breast-cancer-related lymphedema (BCRL). Qualitative analysis was performed to summarize the characteristics of reported ICG procedures. In situ tissue identification and functionality assessment based on fluorescence signal were evaluated. Clinical outcomes were appraised when reported. Studies relating to axillary reverse mapping, lymphography and upper limb supermicrosurgery combined with ICG imaging were identified. We included a total of 33 relevant articles with a total of 2016 patients enrolled. ICG imaging for axillary reverse mapping was safe for all 951 included patients, with identification of arm nodes in 80%-88% of patients with axillary lymph nodes dissection. However, the papers discuss the oncologic safety of the approach and how - regardless of the contrast agent - concerns limit its adoption. ICG lymphography is openly supported in BCRL management, with 1065 patients undergoing this procedure in 26 articles. The technique is reported for lymphedema diagnosis, with high sensitivity and specificity, staging, intraoperative mapping and patency control in lymphaticovenular anastomosis. The substantial advantages/disadvantages of ICG imaging procedures are finally described.

Near-infrared fluorescence image-guidance in plastic surgery: A systematic review

Background

Near-infrared fluorescence (NIRF) imaging technique, after administration of contrast agents with fluorescent characteristics in the near-infrared (700–900 nm) range, is considered to possess great potential for the future of plastic surgery, given its capacity for perioperative, real-time anatomical guidance and identification. This study aimed to provide a comprehensive literature review concerning current and potential future applications of NIRF imaging in plastic surgery, thereby guiding future research.

Methods

A systematic literature search was performed in databases of Cochrane Library CENTRAL, MEDLINE, and EMBASE (last search Oct 2017) regarding NIRF imaging in plastic surgery. Identified articles were screened and checked for eligibility by two authors independently.

Results

Forty-eight selected studies included 1166 animal/human subjects in total. NIRF imaging was described for a variety of (pre)clinical applications in plastic surgery. Thirty-two articles used NIRF angiography, i.e., vascular imaging after intravenous dye administration. Ten articles reported on NIRF lymphography after subcutaneous dye administration. Although currently most applied, general protocols for dosage and timing of dye administration for NIRF angiography and lymphography are still lacking. Three articles applied NIRF to detect nerve injury, and another three studies described other novel applications in plastic surgery.

Conclusions

Future standard implementation of novel intraoperative optical techniques, such as NIRF imaging, could significantly contribute to perioperative anatomy guidance and facilitate critical decision-making in plastic surgical procedures. Further investigation (i.e., large multicenter randomized controlled trials) is mandatory to establish the true value of this innovative surgical imaging technique in standard clinical practice and to aid in forming consensus on protocols for general use.

Level of Evidence: Not ratable

Single Lymphaticovenular Anastomosis for Early-Stage Lower Extremity Lymphedema Treated by the Superior-Edge-of-the-Knee Incision Method

Supplemental Digital Content is available in the text.

Background:

Surgical treatment of lower extremity lymphedema (LEL) remains challenging. Application of the superior-edge-of-the-knee incision method for lymphaticovenular anastomosis (LVA) is reported to have a strong therapeutic effect in patients with LEL because lymph-to-venous flow at the anastomosis is enhanced by knee joint movement during normal walking. We investigated whether a single LVA created by this method is adequate for early LEL.

Methods:

The study involved 10 patients with LEL characterized by stage 2 or 3 leg dermal backflow and treated by a single LVA at the thigh via the superior-edge-of-the-knee incision method. The lymphatic vessel and direction of flow were assessed intraoperatively, and reduction in lymphedema volume was assessed postoperatively.

Results:

Use of our incision method yielded a single anastomosis in all patients with stage 2 leg dermal backflow and in all patients with stage 3 leg dermal backflow. The lymphatic vessel was 0.65 ± 0.08 mm in diameter (0.65 ± 0.09 and 0.65 ± 0.09 mm, respectively; P = 1.000). No venous reflux occurred in any patient. Mean follow-up was 7.70 ± 3.30 months (9.60 ± 3.29 and 5.80 ± 2.17 months, respectively; P = 0.068). Mean reduction in the LEL index was 20.160 ± 9.892 (22.651 ± 12.272 and 17.668 ± 7.353, respectively; P = 0.462).

Conclusion:

A single LVA created by the superior-edge-of-the-knee incision method can be expected to have a strong therapeutic effect in patients with stage 2 or 3 leg dermal backflow.

The effect of prophylactic lymphovenous anastomosis and shunts for preventing cancer-related lymphedema: a systematic review and meta-analysis

BACKGROUND

Lymphedema is one of the most dreaded side effects to any cancer treatment involving lymphadenectomy. Progressed lymphedema is adversely complex and currently there is no widely acknowledged curative treatment. Therefore recent focus has shifted to risk reduction and prevention. It has been hypothesized that bypassing lymphatic vessels to veins prophylactically, could minimize the lymphatic dysfunction seen following lymphadenectomy.

METHODS

To investigate this possible future treatment modality, we performed a systematic meta-analysis of studies treating patients with prophylactic lymphovenous analysisstomosis (LVA) for the prevention of secondary lymphedema following lymphadenectomy. A systematic search yielded 12 articles included in the qualitative analysis and four of these were further eligible to be included in the quantitative analysis.

RESULTS

We found that patients treated with prophylactic LVA had a significant reduction in lymphedema incidence (Relative risk: 0.33, 95%CI: 0.19 to 0.56) when compared to patients receiving no prophylactic treatment (P < 0.0001).

CONCLUSION

Prophylactic LVA in relation to lymphadenectomy shows promising results, however because of the low number of eligible studies and method heterogeneity between studies, there is an urgent need for uniformly high quality studies, before the treatment can be concluded effective.