Concordance between preoperative imaging methods in patients with limb lymphedema undergoing supermicrosurgical lymphaticovenular anastomosis

OBJECTIVE

Supermicrosurgical lymphaticovenular anastomosis (LVA) is increasingly being recognized as a first-line treatment of limb lymphedema because it is minimally invasive and highly effective. Lymphoscintigraphy and indocyanine green (ICG) lymphography are the two most commonly performed diagnostic imaging examinations to establish the indication and plan the procedure for patients affected by limb lymphedema. In a small group of patients, the information between these two imaging tools can be discordant, showing different anatomical drainage pathways or the absence of drainage and dermal backflow in one examination and valid drainage pathways in the other. The purpose of this study is to examine the types of possible discrepancies between lymphoscintigraphy of the superficial system and ICG lymphography and to describe the surgical outcomes after LVA for patients presenting with such discrepancies.

METHODS

We retrospectively reviewed the data of all patients who underwent LVA for upper or lower limb lymphedema between July 2015 and July 2023. From this series, we identified a group of patients with nonconcordant imaging results from lymphoscintigraphy and ICG lymphography before lymphatic surgery. Nonconcordant findings were described in terms of "pattern discordance" and "pathway discordance." The surgical outcome was measured by the change in the mean circumference of the limb after surgery. The changes between the preoperative and postoperative limb measures were analyzed using the Student t test. P values < .05 were considered significant.

RESULTS

A total of 28 patients with limb lymphedema exhibited inconsistencies between preoperative lymphoscintigraphy of the superficial system and ICG lymphography. Among these patients, 14 experienced pattern discordance, 13 had pathway discordance, and 1 patient had both. After LVA, we observed a significant reduction in the average circumference of the affected limb in the analyzed group.

CONCLUSIONS

The discrepancy in the information between lymphoscintigraphy and ICG lymphography in the preoperative study of patients affected by limb lymphedema is rare but possible. This phenomenon is still not fully explained; however, our results suggest that it does not correlate with the outcome of supermicrosurgical LVAs.

Progression of fluid infiltration on non-contrast magnetic resonance imaging in breast cancer-related lymphedema: A comparative analysis with indocyanine green lymphography

BACKGROUND

Non-contrast magnetic resonance imaging (NMRI) has been reported as valuable for the assessment of lymphedema. However, the correlation between NMRI findings and indocyanine green lymphography (ICG-L) findings remains elusive.

METHODS

This single-center retrospective study included 26 patients diagnosed with breast cancer-related lymphedema. We examined the prevalence of fluid infiltration in eight regions of the upper extremity, the type of fluid distribution, and the dominant segment of edema on NMRI in comparison to the ICG-L stage. Statistical analysis was performed using the Cochran-Armitage trend test, Spearman's rank correlation test, and Fisher's exact test.

RESULTS

The regional fluid infiltration significantly increased with the progression of the ICG-L stage (hand, forearm, elbow, and upper arm: p = 0.003, <0.001, <0.001, and <0.001, respectively). The fluid distribution significantly advanced with the progression of the ICG-L stage as follows (rs = 0.80; p < 0.001): no edema in ICG-L stage 0, edema in either the hand or elbow in ICG-L stage I, edemas in both the elbow and hand in ICG-L stage II, three segmental edemas centered on the forearm or elbow in ICG-L stage III, and edema encompassing the entire upper limb in ICG-L stage IV-V. Additionally, the dominant segment of edema tended to shift from the hand to the elbow and further to the forearm as the ICG-L stage progressed (p < 0.001).

CONCLUSIONS

Fluid infiltration observed on NMRI exhibited distinct patterns with the progression of the ICG-L stage. We believe that anatomical information regarding fluid distribution would potentially contribute to optimizing surgical efficacy.

Lymphatic flow velocity is a predictor of functional lymphatic vessels for lymphaticovenous anastomosis

BACKGROUND

Indocyanine green (ICG) lymphography is widely used to localize functional lymphatic vessels for lymphaticovenous anastomosis (LVA); however, flow velocity is rarely assessed. We aimed to evaluate the correlation between lymphatic flow velocity and the presence of functional lymphatic vessels.

METHODS

Data of a total of 924 lymphatic vessels from 273 lymphedema patients who underwent LVA between July 2018 and December 2020 were retrospectively reviewed. Lymph flow velocity was defined by considering the most proximal anatomic location enhanced by ICG at 30 min after injection and categorized into four groups; grade 1 (foot or hand), grade 2 (below knee or elbow), grade 3 (at/above knee or eblow), or grade 4 (axilla or groin). The presence of functional lymphatic vessels, which showed lymphatic fluid flow when the vessels were cut for anastomosis, was compared between the four groups.

RESULTS

A higher rate of functional lymphatic vessels was observed among lymphatic vessels with grade 3 or 4 flow velocity compared with those with grade 1 or 2 flow velocity (67.5% vs. 44.5%; p < 0.001). These findings were consistent with the observations for lymphatic vessels with a non-linear pattern in ICG lymphography (59.4% vs. 26.5%; p < 0.001). The rate of completion of LVA at surgical sites in extremities with grade 3 or 4 flow velocity was 88.1% compared with 65.8% in extremities with grade 1 or 2 velocity (p < 0.001).

CONCLUSIONS

Lymph flow velocity grading can be a simple and easy adjunctive method to determine indication for LVA in extremities with lymphedema.

Gluteal lymphoedema associated with lower extremity lymphoedema: A preliminary study with indocyanine green lymphography and magnetic resonance imaging

INTRODUCTION

Indocyanine green (ICG) lymphography studies have identified that one in three to five patients with cancer-related lower extremity lymphoedema (LEL) demonstrated dermal backflow extending to the gluteal region. This study aimed to further characterize gluteal lymphoedema using contemporaneous magnetic resonance imaging (MRI).

PATIENTS AND METHODS

Twenty-eight patients with unilateral advanced LEL who underwent both ICG lymphography and MRI prior to any surgical procedure were included in this study. The patients were divided into two groups with/without gluteal lymphoedema by the presence of dermal backflow on ICG lymphography. MRI was used to evaluate tissue changes.

RESULTS

Ten patients demonstrated gluteal lymphoedema on ICG lymphography and had a higher incidence of skin hypertrophy in the gluteal region. However, no difference in excess leg volume was found between the two groups. A trend of increasing gluteal subcutaneous tissue in the affected side was identified in patients with gluteal lymphoedema with a median increase of 20% compared with an 11% increase in the non-gluteal lymphoedema group. The excess gluteal subcutaneous tissue was positively correlated to ipsilateral excess leg volume.

CONCLUSION

The gluteal lymphoedema group on ICG lymphography had skin thickening in the gluteal region and was likely identified in the secondary cancer-related group. Surgical and conservative management options for gluteal lymphoedema need to be considered in advanced LEL.

Real-time image-sharing to educate a patient with lymphoedema on self-care: a case study

INTRODUCTION

Compression therapy is important in oedema control in lymphoedema. However, some patients have difficulties starting compression therapy because standard self-care education does not enable them to fully understand lymphoedema and recognise it as their problem. To overcome this, real-time image-sharing education, using a combination of indocyanine green lymphography (ICG) and ultrasonography, may be used to educate patients. In this case study, real-time image-sharing education promoted decision-making and behaviour change in a patient with lower extremity lymphoedema so she would wear elastic stockings.

CASE

A 51-year-old woman with a BMI of 31.7 kg/m² and secondary lower extremity lymphoedema following cervical cancer surgery did not adhere to self-care instructions regarding wearing elastic stockings for 5 years. The oedema worsened, her limb circumference increased and she had two episodes of cellulitis within a year. Because the patient had a negative attitude towards elastic stockings, real-time image-sharing education was used to promote recognition of illness using ICG and an understanding of the condition of lymphoedema using ultrasonography. After the images were shared and explained, the patient discussed her recognition and understanding of lymphoedema, then decided to use compression stockings. She continued to wear them for 4 months, and her limb circumference decreased.

CONCLUSION

Real-time image-sharing education using ICG and ultrasonography as self-care support for a lymphoedema patient who would not start compression therapy could result in behavioural changes and the patient starting and continuing to wear elastic stockings.

Indocyanine green lymphography as novel tool to assess lymphatics in patients with lipedema

OBJECTIVE

Lipedema is a chronic and progressive disease associated with lymphatic impairment at later stages. The aim of our study was to describe the functional status and anatomy of lower limb superficial lymphatic system using indocyanine green (ICG) lymphography in patients with lipedema.

METHODS

Following ICG injection at the dorsum of the foot, distance (cm) covered by the dye at 10 (T10') and 25 min (T25') was measured and normalized for limb length. If the dye did not reach the groin within 25 min, patients were classified as "drainage-needing" group (DNG). Values of fat and lean distribution assessed by dual-energy X-ray absorptiometry were extracted, and correlation analysis was performed. Furthermore, anatomical patterns of superficial lymphatics were assessed.

RESULTS

Overall, 45 women were included, 25 (56%) of whom were classified as DNG. Symptoms duration was significantly associated with DNG status at multivariate analysis (odds ratio 1.07; 95% CI 1.01-1.14; p = 0.047). Moreover, Spearman's analysis showed a negative correlation between symptoms duration and T25' dye migration (r = -0.469; p = 0.037). Overall, no major anatomical lymphatic changes were found.

CONCLUSIONS

Present study suggests that lymphatic functioning in patients with lipedema correlates with symptoms duration. Further research on larger cohorts should verify our findings and clarify their potential therapeutic implications. Overall, ICG lymphography may be promising technique to assess both lymphatic anatomy and functioning in patients with lipedema.

A phase III, multicenter, single-arm study to assess the utility of indocyanine green fluorescent lymphography in the treatment of secondary lymphedema

OBJECTIVE

Indocyanine green (ICG) fluorescent lymphography might be useful for assessing patients undergoing lymphatic surgery for secondary lymphedema. The present clinical trial aimed to confirm whether ICG fluorescent lymphography would be useful in evaluating lymphedema, identifying lymphatic vessels suitable for anastomosis, and confirming patency of lymphaticovenular anastomosis in patients with secondary lymphedema.

METHODS

The present phase III, multicenter, single-arm, open-label, clinical trial (HAMAMATSU-ICG study) investigated the accuracy of lymphedema diagnosis via ICG fluorescent lymphography compared with lymphoscintigraphy, rate of identification of lymphatic vessels at the incision site, and efficacy for confirming patency of lymphaticovenular anastomosis. The external diameter of the identified lymphatic vessels and the distance from the skin surface to the lymphatic vessels using preoperative ICG fluorescent lymphography were measured intraoperatively under surgical microscopy.

RESULTS

When the clinical decision for surgery at each research site was made, the standard diagnosis of lymphedema was considered correct. For the 26 upper extremities, a central judgment committee who was unaware of the clinical presentation confirmed the imaging diagnosis was accurate for 100.0% of cases, whether the assessments had been performed via lymphoscintigraphy or ICG lymphography. In contrast, for the 88 lower extremities, the accuracy of the diagnosis compared with the diagnosis by the central judgment committee was 70.5% and 88.2% for lymphoscintigraphy and ICG lymphography, respectively. The external diameter of the identified lymphatic vessels was significantly greater in the lower extremities than in the upper extremities (0.54 ± 0.21 mm vs 0.42 ± 0.14 mm; P < .0001). Also, the distance from the skin surface to the lymphatic vessels was significantly longer in the lower extremities than in the upper extremities (5.8 ± 3.5 mm vs 4.4 ± 2.6 mm; P = .01). For 263 skin incisions, with the site placement determined using ICG fluorescent lymphography, the rate of identification of lymphatics vessels suitable for anastomosis was 97.7% (95% confidence interval, 95.1%-99.2%). A total of 267 lymphaticovenular anastomoses were performed. ICG fluorescent lymphography was judged as "useful" for confirming patency after the anastomosis in 95.1% of the cases.

CONCLUSIONS

ICG fluorescent lymphography could be useful for improving the treatment of patients with secondary lymphedema from the outpatient setting to surgery.

Noninvasive, objective evaluation of lower extremity lymphedema severity using shear wave elastography: A preliminary study

BACKGROUND

Increased skin and subcutaneous tissue stiffness in patients with early-stage lymphedema has been reported. The purpose of this study was to examine the use of shear wave elastography (SWE) for evaluating lower extremity lymphedema (LEL).

METHODS

For 10 lower extremities of normal controls and 72 limbs of patients with gynecological cancer whose lymphatic function was categorized into six stages based on the range of dermal backflow (DBF) observed in indocyanine green (ICG) lymphography, SWE was performed and shear wave velocity (SWV) of the dermis and three layers of subcutaneous tissue at the thigh and calf were recorded. Twenty-five patients underwent thigh tissue histological and dermal thickness examinations.

RESULTS

The strongest correlation between the ICG DBF stage and SWV during SWE was observed on the dermal layer of the thigh (p < 0.01, R = 0.67). There was a significant correlation between the dermal thickness of the thigh and the ICG DBF stage (p < 0.01, R = 0.87) and also between the dermal thickness of the thigh and SWV (p < 0.01, R = 0.73).

CONCLUSION

Noninvasive, objective evaluation of LEL severity using SWE was well correlated with lymphatic function as determined by ICG lymphography. The DBF changes in the dermis of the thigh best reflected the changes in lymphatic function. Dermal thickness variations may partially account for differences in SWV.

Where does subcutaneous lymph from the chest wall flow into after mastectomy?

BACKGROUND

Changes of the lymph flow from the chest wall after mastectomy and sentinel lymph node biopsy (SLNB) or axillary lymph node dissection (Ax) has yet to be understood. This study aimed to investigate the effect of axillary surgery on lymphatic flow from the chest wall in patients who have undergone mastectomy, including those have undergone breast reconstruction and vascularized lymph node transfer (VLNT).

METHODS

Following mastectomy in 100 breasts, the directions of lymph flow from the chest wall was compared between the SLNB omission, SLNB, Ax, and Ax followed by VLNT groups using indocyanine green (ICG) lymphography in cross-sectional study. Lymph flow on the deep epigastric artery perforator (DIEP) flap was also investigated.

RESULTS

Lymph flow directing to the ipsilateral axilla was observed more frequently after SLNB than Ax (48% vs. 12.5%; p = 0.005); however, no significant difference was observed in the frequency of contralateral axillary route adoption between them (8% vs. 15%; p = 0.65). In the VLNT group, lymph flow to the ipsilateral axilla was not observed at a significantly higher frequency than in the Ax group (12.5% vs. 12.5%, p = 1.00). On the transferred DIEP flap, the lymph flowed anterograde or retrograde parallel to the anatomic course of the lymphatic vessels.

CONCLUSION

To visualize the direction of lymph flow of the chest following mastectomy, ICG lymphography may be useful to discern the direction in which malignant neoplasms, including lymphoma, are transported and to plan for lymph flow restoration.

Magnetic resonance lymphography as three-dimensional navigation for lymphaticovenular anastomosis in patients with leg lymphedema

BACKGROUND

Precise mapping of functional lymphatic vessels is essential for successful lymphaticovenular anastomosis (LVA). This study aimed to clarify the precision of magnetic resonance lymphography (MRL) in detecting lymphatic vessels prior to LVA.

METHODS

Eighteen patients with leg lymphedema were recruited for this prospective study. All patients underwent MRL before LVA to obtain three-dimensional coordinates of lymphatic vessels from MRL images. The precision of MRL for detecting lymphatic vessels was evaluated and compared with those of other contrast techniques.

RESULTS

Twenty legs from 18 patients were analyzed. A total of 40 skin incisions were made, 32 of which were determined by MRL. The precision of MRL to detect lymphatic vessels was 94%. With the addition of MRL, the number of lymphatic vessels identified preoperatively was increased as compared with indocyanine green lymphography (ICG-L) alone. Assuming a detection sensitivity of MRL for lymphatic vessels of 1, those of other contrast techniques were 0.90 for ICG-L under microscopy, 0.73 for patent blue staining, and 0.43 for ICG-L before incision. Whereas ICG-L before incision could not detect lymphatic vessels at depths greater than 17.0 mm, all deeper anastomosed lymphatic vessels were identified by MRL.

CONCLUSION

Lymphatic vessels enhanced on MRL can be reliably identified intraoperatively. MRL is a promising preoperative examination in LVA that can selectively depict suitable lymphatic vessels even in deep tissue layers.

Is the risk of lymphedema life-long following treatment for gynecologic cancer?-A case report

Lymphedema is a common complication following oncologic surgeries and is classically described to occur months to a few years after these procedures. A 64 year-old woman with history of total abdominal hysterectomy and bilateral salpingo-oophorectomy developed right-sided lower extremity lymphedema 7 years after the surgeries. Lymphographic imaging performed approximately twenty years after the original surgeries revealed development of subclinical, asymptomatic lymphedema on the contralateral lower extremity. This delayed presentation of lymphedema after initial injury, is the first described case of subclinical lymphedema without detectable lymphatic injury, making it important to continuously monitor patients at risk for lymphedema long-term.

Preoperative planning of lymphaticovenous anastomosis: The use of magnetic resonance lymphangiography as a complement to indocyanine green lymphography

BACKGROUND

Lymphaticovenous anastomosis (LVA) is a surgical treatment for lymphedema that requires identification and mapping of functional lymphatic channels. This technique was performed blindly for years because of the lack of suitable methods of study. Progress in imaging techniques and the introduction of Indocyanine green lymphography (ICG-L) represented a significant advancement in lymphedema management. Magnetic resonance lymphangiography (MRL) has also helped improve knowledge about lymphedema anatomy and pathophysiology. We now present our protocol based on both ICG-L and MRL for optimal LVA preoperative planning.

METHODS

A prospective study between April 2010 and June 2015 was conducted in 82 patients (77 females, mean age 45.5 years) with stage I (9.8%), II (73.2%), and III (17.0%) lymphedema. All patients underwent lymphedema surgical treatment with LVA. Surgery was planned based on preoperative information from ICG- L and MRL.

RESULTS

We obtained a mean of 6.87 lymphatic locations per extremity from MRL and selected a mean of 4.04 for LVA. When MRL data coincided with ICG-L data, we found a functional lymphatic vessel in 96.9% of cases and performed LVA successfully in 91.4%.

CONCLUSIONS

ICG-L and MRL are noninvasive techniques that provide images of the lymphatic system with sufficient temporal and spatial resolution to depict functional lymphatic vessels. Such knowledge is essential for preoperative planning of LVA microsurgery. We present our protocol for the approach of surgical treatment of lymphedema. This protocol represents a step forward in unifying patient selection criteria and achieving safe, effective, and rational surgery.

Diagnostic accuracy of bioimpedance spectroscopy in patients with lymphedema: A retrospective cohort analysis

BACKGROUND

Bioimpedance spectroscopy (BIS) is used by healthcare specialists to diagnose lymphedema. BIS measures limb fluid content by assessing tissue resistance to the flow of electric current. However, there is debate regarding the validity of BIS in diagnosing early lymphedema. Indocyanine green (ICG) lymphography has been established as the most accurate diagnostic modality to date for lymphedema diagnosis. In this retrospective study, we test the sensitivity, specificity, and diagnostic accuracy of BIS in diagnosing lymphedema by referencing its results with ICG lymphography.

METHODS

Patients presented to the University of Iowa Lymphedema Center from 2015 to 2017 were evaluated with a standardized protocol that included history and physical examination, a validated lymphedema-specific quality-of-life assessment (LYMQOL), circumference -measurement-based index, BIS, and ICG lymphography. Diagnostic accuracy of BIS was assessed using ICG lymphography as a reference test.

RESULTS

Fifty-eight patients had positive ICG lymphography results, which confirmed the diagnosis of lymphedema. ICG lymphographic findings consistently correlated with clinical examination, LYMQOL evaluation, and lymphedema indices. By contrast, BIS demonstrated a false-negative rate of 36% - 21 out of 58 patients had normal BIS readings, but a positive ICG lymphography result. The 21 false-negative results occurred in patients with early-stage disease. Sensitivity and specificity for BIS were 0.64 and 1, respectively.

CONCLUSION

BIS carries an excessively high rate of false-negative results to be dependably used as a diagnostic modality for lymphedema. ICG lymphography highly correlates with other tracking modalities, and it remains the most reliable tool for diagnosing lymphedema.