Intraoperative identification and definition of “functional” lymphatic collecting vessels for supermicrosurgical lymphatico-venous anastomosis in treating lymphedema patients

Lymphaticovenous anastomosis map established using lymphatic ultrasound and multi-lymphosome indocyanine green lymphography

BACKGROUND

Although the usefulness of lymphaticovenous anasotmosis (LVA) for lymphedema has been reported, it is difficult to determine where the LVA is to be performed, especially for inexperienced surgeons. This study aimed to establish a map of the LVA site.

METHOD

A total of 105 limbs from 64 patients who underwent lower limb LVA were retrospectively reviewed. Multi-lymphosome indocyanine green (ICG) lymphography (in 35 patients) and lymphatic ultrasound (in all patients) were performed preoperatively and the incision site was determined where dilated lymph vessels and appropriate veins were located in close proximity. The LVA location was identified using a post-operative photograph. Additionally, the degree of lymphatic degeneration at the LVA site was recorded based on the normal, ectasis, contraction, and sclerosis type (NECST) classification.

RESULT

A total of 206 skin incisions were analyzed. Among them, 161 (75.9%) were medial and 45 (21.2%) were lateral. Among the 85 sites on the calf, 52 (61.2%) were medial and 33 (38.8%) were lateral. Among the 117 sites on the thigh, 106 (90.6%) were medial and 11 (9.4%) were lateral. As the severity of lymphedema progressed, the probability of performing LVA on the lateral calf increased. Among the 202 locations where LVA was performed on the thigh and lower leg, ectasis type was found in 164 sites (81.2%).

CONCLUSION

We established an LVA map of the legs based on multi-lymphosome ICG lymphography and lymphatic ultrasound data. Using this LVA map, surgeons can easily predict the location of lymph vessels, thereby improving the success rate of LVA.

Supermicrosurgical lymphovenous anastomosis

Lymphedema impairs patients' function and quality of life. Currently, supermicrosurgical lymphovenous anastomosis (LVA) is regarded as a significant and effective treatment for lymphedema. This article aims to review recent literature on this procedure, serving as a reference for future research and surgical advancements. Evolving since the last century, LVA has emerged as a pivotal domain within modern microsurgery. It plays a crucial role in treating lymphatic disorders. Recent literature discusses clinical imaging, surgical techniques, postoperative care, and efficacy. Combining advanced tools, precise imaging, and surgical skills, LVA provides a safer and more effective treatment option for lymphedema patients, significantly enhancing their quality of life. This procedure also presents new challenges and opportunities in the realm of microsurgery.

Lymphatic Mapping for LVA with Noncontrast Lymphatic Ultrasound: How We Do It

Recently, lymphatic ultrasonography has received increasing attention. Although there are several reports on contrast-enhanced lymphatic ultrasound as a preoperative examination for lymphaticovenous anastomosis (LVA), we have been reporting the usefulness of preoperative noncontrast lymphatic ultrasound. In this article, the detailed procedure for conducting lymphatic ultrasound during the preoperative examination of LVA is thoroughly described. The only items required for lymphatic ultrasound are an ultrasound device, an echo jelly, a straw for marking, and a marker. We use an ordinary ultrasound device with an 18-MHz linear probe. We apply the Doppler, Crossing, Uncollapsible, Parallel, and Superficial fascia index to identify the lymphatic vessels. While imagining the course of the lymph vessels, we position the probe perpendicular to the long axis of the lymphatic vessels. When a vessel is found under the superficial fascia, the probe is moved proximally to trace the vessel's path. If the vessel transverses a nearby vein without connecting to it, it is most likely a lymphatic vessel. To confirm, we ensure that the vessel does not exhibit coloration in the Doppler mode. As LVA is most effective when the dilated lymph vessels are anastomosed, we use lymphatic ultrasound to identify the most dilated lymphatic vessels in each lymphosome, and mark incision lines where suitable veins are in close proximity. No contrast agent is required; therefore, medical staff such as nurses and ultrasound technicians can autonomously conduct the test.

Contrast-enhanced ultrasonography as an adjunctive method to ICG lymphography for functional lymphaticovenous anastomosis

BACKGROUND AND OBJECTIVES

Indocyanine green (ICG) lymphography is the reference standard for evaluating lymphedema stage and identifying lymphatic vessels. However, the penetration depth was limited to 1-2 cm from the skin surface. This prospective study compares clinical outcomes following lymphaticovenous anastomoses (LVA) in patients with upper and lower limb lymphedema using contrast-enhanced ultrasonography (CEUS) with ICG as a preoperative imaging modality.

METHODS

Under general anesthesia, Sonazoid® was injected subcutaneously to visualize functional lymphatic channels via CEUS. We analyzed the changes in limb circumference and inter-limb ratio (ILR) using bioimpedance to measure electrical resistance between the CEUS plus ICG group and the ICG-only group to see the effect of CEUS-assisted LVA.

RESULTS

No significant demographic differences existed between the two groups (CEUS plus ICG group vs. ICG-only group). The ILR decrease of the Z1 value measured using bioimpedance was statistically significant (p = 0.042 for the upper limb, p = 0.002 for the lower limb)- CONCLUSIONS: CEUS allowed us to identify deep-lying, functional, and large lymphatic channels. In conclusion, the combination of CEUS and ICG for identifying lymphatic channels has the potential to lead to a more functional lymphovenous anastomosis.

Preoperative photoacoustic versus indocyanine green lymphography in lymphaticovenular anastomosis outcomes for lower extremity lymphedema: A pilot study

BACKGROUND

Identification of the proper lymphatics is important for successful lymphaticovenular anastomosis (LVA) for lymphedema; however, visualization of lymphatic vessels is challenging. Photoacoustic lymphangiography (PAL) can help visualize lymphatics more clearly than other modalities. Therefore, we investigated the usefulness of PAL and determined whether the clear and three-dimensional image of PAL affects LVA outcomes.

METHODS

We recruited 22 female patients with lower extremity lymphedema. The operative time, number of incisions, number of anastomoses, lymphatic vessel detection rate (number of functional lymphatics identified during the operation/number of incisions), and limb volume changes preoperatively and 3 months postoperatively were compared retrospectively. The patients were divided according to whether PAL was performed or not, and results were compared between those undergoing PAL (PAL group; n = 10) and those who did not (near-infrared fluorescence [NIRF] group, n = 12).

RESULTS

The mean age of the patients was 55.9 ± 15.1 years in the PAL group and 50.7 ± 14.9 years in the NIRF group. One patient in the PAL group and three in the NIRF group had primary lymphedema. Eighteen patients (PAL group, nine; and NIRF group, nine) had secondary lymphedema. Based on preoperative evaluation using the International Society of Lymphology (ISL) classification, eight patients were determined to be in stage 2 and two patients in late stage 2 in the PAL group. In contrast, in the NIRF group, one patient was determined to be in stage 0, three patients each in stage 1 and stage 2, and five patients in late stage 2. Lymphatic vessel detection rates were 93% (42 LVAs and 45 incisions) and 83% (50 LVAs and 60 incisions) in the groups with and without PAL, respectively (p = 0.42). Limb volume change was evaluated in five limbs of four patients and in seven limbs of five patients in the PAL and NIRF groups as 336.6 ± 203.6 mL (5.90% ± 3.27%) and 52.9 ± 260.7 mL (0.71% ± 4.27%), respectively. The PAL group showed a significant volume reduction. (p = .038).

CONCLUSIONS

Detection of functional lymphatic vessels on PAL is useful for treating LVA.

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.

Lymphatic-based Lymphosome: A Novel Hypothesis with Clinical Implication for Supermicrosurgical Lymphaticovenous Anastomosis

Understanding the anatomical territories drained by lymphatic vessels (LVs) is essential for a better comprehension of lymphatic anatomy and functionality, and for performing lymphatic procedures such as lymphaticovenous anastomosis (LVA). However, current concepts regarding the lymphatic territory are insufficient to explain some of the clinical observations. As shown in the figures, within one incision for the LVA, one to two lymphatic vessels (LV) remained unenhanced on indocyanine green (ICG) lymphography, whereas the rest of the LVs were enhanced. To answer this question, one must examine the concept of the lymphosome, first described by Suami, defined as a particular region drained by LVs into the same subgroup of regional lymph nodes (LNs) (eg, superficial groin LNs). Suami's lymphosome concept represents "LN-based lymphosomes." In addition, Shinaoka identified four distinct lymphatic groups (anteromedial, anterolateral, posteromedial, and posterolateral) in the lower limbs after ICG injection. This represents the concept "group-based lymphosomes." Nevertheless, neither the LN- nor group-based lymphosome concepts offer an appropriate explanation for the clinical findings described above. In addition to the aforementioned lymphosome concepts, the author proposes a novel hypothesis called "lymphatic-based lymphosome," which considers each LV as a single lymphosome. Therefore, the normal-type LV remained unenhanced when ICG was not injected into the draining territory. To enhance post-LVA outcomes, an even distribution of anastomoses to different group-based lymphosomes is important, as is avoiding performing all anastomoses onto a single LV or within the same group-based lymphosome.

The Deciding Factors of Flow Direction in Lymphovenous Anastomosis for Extremity Lymphedema

BACKGROUND

While using lymphovenous anastomosis (LVA) to treat extremity lymphedema, an antegrade lymphatic-to-venous flow is usually considered to indicate a functional and effective anastomosis. The authors analyzed the characteristics of lymphovenous anastomoses in patients with extremity lymphedema to look for the deciding factors of the flow direction.

METHODS

A total of 45 patients (15 arms and 42 legs) undergoing LVA for extremity lymphedema were reviewed. Only the anastomoses with intraoperatively confirmed patent flow or clear visualization of vessel lumens during anastomosis were included for analysis. Multivariate logistic regression was used to identify the contributing factors of intraoperative washout phenomenon or venous reflux.

RESULTS

A total of 105 eligible LVAs were included for analysis. Anastomosis with a more sclerotic lymphatic duct is statistically significantly associated with more venous reflux (OR, 2.82; P = 0.003). Larger diameter difference between lymphatic duct and recipient vein (OR, 12.8; P = 0.02) and less sclerotic lymphatic duct (OR, 0.47; P = 0.03) are statistically significantly associated with more washout phenomena.

CONCLUSIONS

The deciding factors of flow direction in LVA are difference of diameters between lymphatic duct and recipient vein, and the severity of lymphosclerosis. To obtain favorable antegrade lymph-to-vein flow, a less sclerotic lymphatic duct with larger diameter and a recipient vein with smaller diameter should be chosen for anastomosis.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Imaging Modalities for Evaluating Lymphedema

Lymphedema is a progressive condition. Its therapy aims to reduce edema, prevent its progression, and provide psychosocial aid. Nonsurgical treatment in advanced stages is mostly insufficient. Therefore-in many cases-surgical procedures, such as to restore lymph flow or excise lymphedema tissues, are the only ways to improve patients' quality of life. Imaging modalities: Lymphoscintigraphy (LS), near-infrared fluorescent (NIRF) imaging-also termed indocyanine green (ICG) lymphography (ICG-L)-ultrasonography (US), magnetic resonance lymphangiography (MRL), computed tomography (CT), photoacoustic imaging (PAI), and optical coherence tomography (OCT) are standardized techniques, which can be utilized in lymphedema diagnosis, staging, treatment, and follow-up. Conclusions: The combined use of these imaging modalities and self-assessment questionnaires deliver objective parameters for choosing the most suitable surgical therapy and achieving the best possible postoperative outcome.

Density Spectral Array Enables Precise Sedation Control for Supermicrosurgical Lymphaticovenous Anastomosis: A Retrospective Observational Cohort Study

Supermicrosurgical lymphaticovenous anastomosis (LVA) is a minimally invasive surgical technique that creates bypasses between lymphatic vessels and veins, thereby improving lymphatic drainage and reducing lymphedema. This retrospective single-center study included 137 patients who underwent non-intubated LVA in southern Taiwan. A total of 119 patients were enrolled and assigned to two study groups: the geriatric (age ≥ 75 years, n = 23) and non-geriatric groups (age < 75 years, n = 96). The primary outcome was to investigate and compare the arousal and maintenance of the propofol effect-site concentration (Ce) using an electroencephalographic density spectral array (EEG DSA) in both groups. The results showed that the geriatric group required less propofol (4.05 [3.73-4.77] mg/kg/h vs. 5.01 [4.34-5.92] mg/kg/h, p = 0.001) and alfentanil (4.67 [2.53-5.82] μg/kg/h vs. 6.68 [3.85-8.77] μg/kg/h, p = 0.047). The median arousal Ce of propofol among the geriatric group (0.6 [0.5-0.7] μg/mL) was significantly lower than that in patients aged ≤ 54 years (1.3 [1.2-1.4] μg/mL, p < 0.001), 55-64 years (0.9 [0.8-1.0] μg/mL, p < 0.001), and <75 years (0.9 [0.8-1.2] μg/mL, p < 0.001). In summary, the combined use of EEG DSA provides the objective and depth of adequate sedation for extensive non-intubated anesthesia in late-elderly patients who undergo LVA without perioperative complications.

Measurement of lymphatic vessel depth using photoacoustic imaging

OBJECTIVES

Information regarding the depth of lymphatic vessel is important for lymphatic surgeons because rapid identification of functional lymphatic vessels and veins is necessary to perform good lymphaticovenular anastomosis, which is a surgical procedure for lymphedema cases. Photoacoustic lymphangiography (PAL) may be useful for such identification because it allows the assessment of the depth of lymphatic vessels. Thus, we aimed to measure the lymphatic vessel depth using images obtained by PAL.

METHODS

This study included healthy individuals and patients with lymphedema. In all participants, indocyanine green dissolved in dextrose was injected subcutaneously into the first and fourth webs of the foot and the lateral malleolus, and PAL was performed on the medial side of the lower leg. The lymphatic vessel depth was measured from the ankle joint, 10 cm above the medial malleolus, and 20 cm above the medial malleolus on PAL in the cross-sectional view and was compared between the participant groups.

RESULTS

The healthy group (mean age, 43.3 ± 12.9 years) included 21 limbs of 4 male and 16 female healthy individuals (bilateral limbs of 1 patient were considered). The lymphedema group (mean age, 62.0 ± 11.7 years) included 17 limbs of 3 male and 14 female patients with lymphedema. The average lymphatic vessel depths from the ankle joint, 10 cm above the medial malleolus, and 20 cm above the medial malleolus were 2.6, 4.7, and 5.6 mm in the healthy group and 3.6, 7.3, and 7.4 mm in the lymphedema group, respectively. Lymphatic vessels were significantly deeper in the lymphedema group than in the healthy group at all measurement locations.

CONCLUSIONS

Using PAL, we determined the lymphatic vessel depth in living bodies. By searching for the lymphatic vessels based on our findings, even surgeons who are relatively inexperienced with lymphatic surgery may be able to identify functional lymphatic vessels more efficiently.

Lymphatic Alterations Under Tattoos: Preliminary Reports of One Observational Study

Background

The number of people within the European population having at least one tattoo has increased notably and with it the number of tattoo-associated clinical complications. The injected inks are known to be removed by the lymphatic vessels and can be found in the draining lymph nodes.

Aim of the Study

To report our observations on the lymphatic drainages seen under tattoos using near infrared fluorescence imaging of these lymphatic vessels after the injection of indocyanine green.

Material and Methods

Indocyanine green was injected intradermally at the basis of the 20 tattooed area(s) in 19 subjects (nine women and ten men; mean age = 28.6). Ten subjects had only black tattoos (six upper limbs and four lower limbs), five (two upper limbs and three lower limbs) black and white tattoos and five multi-colored tattooed limbs (four lower limbs and one upper limb).

Results

The imaging exams revealed alterations in eight individuals, seven of whom had tattoos on their lower limbs. Furthermore, the imaging results showed that the abnormalities might be related to the tattooed limb, the tattoo extent and colour.

Conclusion

Alterations of the cutaneous lymphatic channels are frequently observed under tattooed territories. Their causal factors should be more precisely studied in future works and these lymphatic alterations should be considered in tattooed patients when using similar imaging techniques for therapeutic and surgical assessments.

Imaging of the Lymphatic Vessels for Surgical Planning: A Systematic Review

BACKGROUND

Secondary lymphedema is a common complication after surgical or radiotherapeutic cancer treatment. (Micro) surgical intervention such as lymphovenous bypass and vascularized lymph node transfer is a possible solution in patients who are refractory to conventional treatment. Adequate imaging is needed to identify functional lymphatic vessels and nearby veins for surgical planning.

METHODS

A systematic literature search of the Embase, MEDLINE ALL via Ovid, Web of Science Core Collection and Cochrane CENTRAL Register of Trials databases was conducted in February 2022. Studies reporting on lymphatic vessel detection in healthy subjects or secondary lymphedema of the limbs or head and neck were analyzed.

RESULTS

Overall, 129 lymphatic vessel imaging studies were included, and six imaging modalities were identified. The aim of the studies was diagnosis, severity staging, and/or surgical planning.

CONCLUSION

Due to its utility in surgical planning, near-infrared fluorescence lymphangiography (NIRF-L) has gained prominence in recent years relative to lymphoscintigraphy, the current gold standard for diagnosis and severity staging. Magnetic resonance lymphography (MRL) gives three-dimensional detailed information on the location of both lymphatic vessels and veins and the extent of fat hypertrophy; however, MRL is less practical for routine presurgical implementation due to its limited availability and high cost. High frequency ultrasound imaging can provide high resolution imaging of lymphatic vessels but is highly operator-dependent and accurate identification of lymphatic vessels is difficult. Finally, photoacoustic imaging (PAI) is a novel technique for visualization of functional lymphatic vessels and veins. More evidence is needed to evaluate the utility of PAI in surgical planning.

Dermal-adipose lymphatic flap venous wrapping: A novel lymphaticovenous shunt method for progression of upper extremity lymphedema with severe lymphosclerosis

BACKGROUND

Upper extremity lymphedema (UEL) causes a significant deterioration in the quality of life of breast cancer survivors. Lymphaticovenous shunt creation will address the pathophysiology of obstructive UEL; however, its efficacy has been limited for those with UEL progression due to lymphosclerosis. In the present study, we evaluated the feasibility of a new lymphaticovenous shunt method for progression of UEL.

METHODS

A total of 37 patients who had undergone dermal-adipose lymphatic flap venous wrapping (DALF-VW) for the treatment of UEL progression refractory to previous lymphaticovenular anastomosis were included. A DALF was created where indocyanine green lymphography had shown dermal backflow and was wrapped with a reflux-free recipient vein. The patients' medical records were reviewed to obtain the clinical and intraoperative findings. The patient and vessel characteristics and postoperative results were evaluated.

RESULTS

A total of 37 patients with unilateral UEL were included. All DALF-VW procedures were performed under local infiltration anesthesia, with 98 shunts created in 37 limbs (2.6 shunts per limb). The diameter of the vein used for DALF-VW ranged from 1.7 to 3.3 mm (average, 2.39 mm). The operative time ranged from 25 to 139 minutes (average, 47.8 minutes). The differences in the lymphedema quality of life score (45.6 ± 21.1 vs 32.5 ± 21.1; P = .009), UEL index (131.4 ± 18.2 vs 123.1 ± 16.4; P = .042), and frequency of cellulitis (0.8 ± 1.3 vs 0.2 ± 0.5 times annually; P = .010) before and after DALF-VW were statistically significant.

CONCLUSIONS

DALF-VW was effective for UEL progression that was refractory to previous lymphaticovenular anastomosis surgery. DALF-VW could be a useful option for UEL progression with severe lymphosclerosis.

[Autologous Breast Reconstruction in Conjuction with Lymphatic Microsurgery in Breast Cancer-Related Lymphedema]

Breast cancer-related lymphedema of the upper extremity is the most significant non-oncological complication of tumour therapy, leading to functional impairment and impacting patients' quality of life. Autologous breast reconstruction per se effectively reduces incidence and stage of lymphedema after breast cancer treatment by surgical angiogenesis. In addition, modern surgical techniques for treating lymphedema are effective in reducing limb volume, circumference and functional impairment, and improving patients' quality of life, body image, integrity and local immunocompetence. Reconstructive surgery, including lymphovenous anastomoses (LVA) and vascularised lymph node transfer (VLNT), have been shown to rearrange or restore lymphatic flow and prevent stage progression. For patients with breast cancer-related lymphedema after mastectomy, autologous breast reconstruction in conjunction with lymphatic microsurgery using VLNT, LVA or a combination of these procedures offers the option of holistic and single-stage restoration in modern senology. Extensive scar release in the axilla is a crucial component of the surgical technique, aiming to prepare the recipient bed for the VLN transplant and to allow for the functional recruitment of remaining lymph vessels of the upper extremity. This article presents the indications, preoperative diagnostic evaluation, surgical techniques and precautions, complications and results of combined lymphatic and breast restoration.

Impact of retrograde anastomosis during supermicrosurgical lymphaticovenous anastomosis for cancer-related lower limb lymphedema: A retrospective cohort propensity-score-matched outcome analysis

BACKGROUND

In addition to antegrade anastomosis, retrograde anastomosis has been thought to offer further improvements after lymphaticovenous anastomosis (LVA) by bypassing the retrograde lymphatic flow. However, this concept has yet to be validated. The aim of this study was to determine the impacts on outcomes of performing both retrograde and antegrade anastomosis, as compared to antegrade-only anastomosis for treating lower limb lymphedema.

STUDY DESIGN

This was a retrospective cohort propensity score-matched study. Eighty-seven patients with gynecologic cancer-related lower limb lymphedema were enrolled, including 58 patients who had received both antegrade and retrograde anastomoses (Group I) and 29 patients who had received antegrade-only anastomoses (Group II) as the control group. LVA was the primary treatment. Patients who had previous LVA, liposuction, or excisional therapy were excluded. Patient characteristics, intraoperative findings, and functional parameters including the ratio of indocyanine green-enhanced and flow-positive lymphatic vessels were recorded. Magnetic resonance volumetry was used for outcome assessments. The primary endpoint was the volume change at 6 months after LVA.

RESULTS

After matching, a total of 26 patients have remained in each group. All parameters were matched except that Group I still had significantly more median LVA performed compared to Group II (8 [IQR: 5.3-10.0] vs. 5.5 [4.3-6.0], p = 0.001, respectively). Group II showed more post-LVA improvements at six-month and one-year follow-up compared to Group I but without statistically significant differences.

CONCLUSION

The use of supplementary retrograde anastomoses is discouraged since it may lead to inferior post-LVA outcome compared to antegrade-only anastomoses.

Lymphaticovenous Anastomosis for Treating Secondary Lower Limb Lymphedema in Older Patients-A Retrospective Cohort Study

Despite an increased incidence of secondary lower limb lymphedema (LLL) and severity of comorbidities with age, the impact of age on the effectiveness of lymphaticovenous anastomosis (LVA) in the older patients remains unclear. Methods: This retrospective cohort study enrolled older patients (age > 65 years) with secondary unilateral LLL. All patients underwent supermicrosurgical LVA. Demographic data and intraoperative findings including lymphatic vessel (LV) diameter, LV functionality (indocyanine green-enhanced and Flow positivity), and lymphosclerosis classification were recorded. Magnetic resonance volumetry was used for measuring preoperative and postoperative volume changes at 6 months and one year after LVA as primary and secondary endpoints. Results: Thirty-two patients (29 females/3 males) with a median age of 71.0 years [range, 68.0 to 76.3] were enrolled. The median duration of lymphedema was 6.4 [1.0 to 11.7] years. The median LV diameter was 0.7 [0.5 to 0.8] mm. The percentage of ICG-enhanced and Flow-positive LVs were 89.5% and 85.8%, respectively. The total percentage of suitable LVs (s0 and s1) for LVA based on lymphosclerosis classification was 75.9%. There were significant six-month and one-year post-LVA percentage volume reductions compared to pre-LVA volume (both p < 0.001). A significant reduction in cellulitis incidence was also noted after LVA (p < 0.001). No surgical or postoperative complications were found. Conclusion: Relief of secondary LLL was achievable through LVA in older patients who still possessed favorable LV characteristics, including larger LV diameters as well as a high proportion of functional LVs with a low grade of lymphosclerosis.

A Systematic Stepwise Method to Perform a Supermicrosurgical Lymphovenous Anastomosis

BACKGROUND

Lymphovenous anastomosis (LVA) has become an increasingly common treatment for patients with extremity lymphedema. In this article, we present our current strategy for patient selection, preoperative planning, and a series of intraoperative clues that may help to perform a supermicrosurgical LVA. Technical considerations are presented using a systematic step-by-step method to make this procedure more reproducible and straightforward.

PATIENTS AND METHODS

We conducted a review of patients operated between January 2015 and June 2018 using the aforementioned approach. Data were collected prospectively, and all procedures were performed by the senior author. Preoperative assessment included lymphoscintigraphy, indocyanine green lymphography, noncontrast magnetic resonance lymphography and high-frequency ultrasonography. Lymphovenous anastomosis was decomposed into a sequential 6-step approach considering the main aspects that determine a successful anastomosis.

RESULTS

Lymphovenous anastomosis was performed in 229 patients, including 677 anastomoses. Median follow-up was 33 months (range, 13-51 months). A median of 3.1 (range, 1-7) LVA were performed on 2.7 (range, 1-6) incision sites per patient. Median time for dissection of lymphatic(s) and vein(s) was 8.7 minutes (1-18 minutes) with a median time of 27.2 minutes (range, 13-51 minutes) for a complete LVA. Lymphatic detection rate was 100% (677 of 677) and vein detection rate was 99.7% (675 of 677), with 31.0% (210 of 677) of reflux-free veins. For upper-extremity lymphedema (47 of 229; 20.6%), volume reduction was achieved in 100% (47 of 47) of the cases, with a median volume reduction rate of 67% (range, 7-93%). In lower-extremity lymphedema (182 of 229; 79.4%), volume reduction was achieved in 86.8% (158 of 182) of the cases, with a median volume reduction rate of 41% (range, 7-81%). Cellulitis episodes decreased from 2.1 to 0.2 episodes/year after LVA (P < 0.05).

CONCLUSIONS

Acceptable success rates were obtained using a sequential strategy for planning and execution of supermicrosurgical LVA for secondary extremity lymphedema. We believe including a stepwise approach may help to simplify this procedure, especially for surgeons in their early practice.

Selection of Optimal Functional Lymphatic Vessel Cutoff Size in Supermicrosurgical Lymphaticovenous Anastomosis in Lower Extremity Lymphedema

BACKGROUND

Functional lymphatic vessels are essential for supermicrosurgical lymphaticovenous anastomosis. Theoretically, the larger the lymphatic vessel, the better the flow. However, large lymphatic vessels are not readily available. Since the introduction of lymphaticovenous anastomosis, no guidelines have been set as to how small a lymphatic vessel is still worthwhile for anastomosis.

METHODS

In this longitudinal cohort study, unilateral lower limb lymphedema patients who underwent lymphaticovenous anastomosis between March of 2016 and January of 2019 were included. Demographic data and intraoperative findings including the number and size of lymphatic vessels were recorded. The cutoff size was determined by receiver operating characteristic curve analysis, based on the functional properties of lymphatic vessels. Clinical correlation was made with post-lymphaticovenous anastomosis volume measured by magnetic resonance volumetry.

RESULTS

A total of 141 consecutive patients (124 women and 17 men) with a median age of 60.0 years (range, 56.7 to 61.2 years) were included. The cutoff size for a functional lymphatic vessel was determined to be 0.50 mm (i.e., lymphatic vessel0.5) from a total of 1048 lymphatic vessels. Significant differences were found between the number of lymphatic vessels0.5 anastomosed (zero to one, two to three, and greater than over equal to four lymphatic vessels0.5), the median post-lymphaticovenous anastomosis volume reduction (in milliliters) (p < 0.001), and the median percentage volume reduction (p = 0.012).

CONCLUSIONS

Lymphatic vessel0.5 can be a valuable reference for lymphaticovenous anastomosis. Post-lymphaticovenous anastomosis outcome can be enhanced with the use of lymphatic vessel0.5 for anastomoses.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

Evaluation of lymphatic vessel diameters in healthy people using lymphatic ultrasound examination

OBJECTIVE

The aim of this study was to examine lymphatic diameters in lower limbs of healthy volunteers in different body positions using lymphatic ultrasound examinations.

METHODS

Thirty-five healthy volunteers participated in this study. Those who had a history of varicose veins in the leg, deep venous thrombosis, or surgery on their legs or abdomen were excluded. We measured the vertical width of the lymphatics with a 33 MHz linear ultrasound probe, at 20 cm above the knee (thigh) and 10 cm below the knee (lower leg). First, the participants were placed supine, then sitting, and then standing. We performed lymphatic ultrasound examinations in each body position. The Student t test was used to compare lymphatic vessel diameters in the supine, sitting, and standing positions. The significance level was set at .05.

RESULTS

Among 35 healthy volunteers, 17 were men and 18 were women. Mean age was 30.9 (range, 23-55) years. The mean body mass index was 21.3 kg/m² (range, 29.0-16.1 kg/m²). We could not detect lymphatic vessels in 1 thigh and 3 lower legs, leaving 69 thighs and 67 lower legs for evaluation. In the thigh, the mean lymphatic diameters in the supine and standing positions were 0.154 mm and 0.150 mm, respectively, which were not significantly different. In the lower leg, the mean lymphatic diameters in the supine, sitting, and standing positions were 0.160 mm, 0.163 mm, and 0.164 mm, respectively, which were not significantly different. In the thigh, the mean lymphatic diameter in the supine position was larger in the men (0.17 mm) than in the women (0.14 mm) (P = .022). Similarly, in the lower leg, the mean lymphatic diameter in the supine position was greater in the men (0.19 mm) than in the women (0.14 mm) (P = .0044). There was no correlation between the supine lymphatic diameters and the age or body mass index of the participants.

CONCLUSIONS

In healthy legs, lymphatic diameters do not change with body positioning. Supine lymphatic vessel diameters are greater in men than in women.

Impact of Magnetic Resonance Lymphography on Lymphaticolvenular Anastomosis for Lower-Limb Lymphedema

BACKGROUND

 Although several investigations have described the safety, utility, and precision of magnetic resonance lymphography (MRL) as a preoperative examination for lymphaticovenular anastomosis (LVA), it is unclear how much MRL assistance impacts LVA results. The present study aimed to clarify the outcome of MRL-assisted LVA for leg lymphedema using body water measurements obtained by bioelectrical impedance analysis.

METHODS

 The water reductive effect of MRL-assisted LVA in female secondary leg lymphedema patients was compared with that of non-MRL-assisted controls in this retrospective study. In the MRL-assisted group, all LVA candidates underwent MRL prior to surgery, and the lymphatic vessels to be anastomosed were primarily determined by MRL findings. The body water composition of the treated legs was assessed before LVA and at 6 months postoperatively using a multi-frequency bioelectrical impedance analyzer.

RESULTS

 Twenty-three patients in the MRL-assisted study group and an equal number in the non-MRL-assisted control group were analyzed. Although mean leg water volume before LVA, mean excess water volume of the affected leg before LVA, and number of anastomoses created were comparable between the groups, the water volume reduction (1.02 L versus 0.49 L; 95% confidence interval [CI]: 0.03-1.03, p < 0.05) and edema reduction rate (46.7% versus 27.2%; 95% CI: 3.7-35.5%, p < 0.05) in the MRL-assisted group were significantly greater than in controls.

CONCLUSION

 Preoperative MRL-assisted lymph vessel visualization and selection appeared to significantly enhance the water reductive effect of LVA for International Society of Lymphology classification stage 2 leg lymphedema. MRL also helped to reliably identify lymphatic vessels for anastomosis. Without increasing the number of anastomoses, LVA could be performed more effectively by better detecting stagnant lymphatic vessels using MRL.

Supermicrosurgical Suture-Stent Technique for A Lymphaticovenular Bypass

Background: Lymphaticovenular anastomosis (LVA) is a challenging procedure and requires a sophisticated supermicrosurgical technique. The aim of this study was to evaluate and establish a discrete supermicrosurgical anastomosis method using the “suture-stent technique”. Methods: Forty-eight LVA sites of twenty patients with lower extremity lymphedema who had undergone LVA between July 2020 and January 2021 were included in this study. LVA was performed with the conventional technique or with the suture-stent technique. The patency of the anastomoses was evaluated using an infrared camera system intraoperatively. The success rate on the first try and the final success rate for each group were compared. Results: After full application of the exclusion criteria, 35 LVAs of 16 patients including 20 limbs were included in the analysis. The ratio of good patency findings after anastomosis in the suture-stent technique group was 100%. The incidences of leakage or occlusion on the first try were statistically greater in the conventional technique group (29.4%) than in the suture-stent technique group (0%) (p = 0.0191). All anastomoses achieved good patency in the final results. Conclusion: With its minimal risk of catching the back wall during the anastomosis, the suture-stent technique can be considered an optimal anastomosis option for LVA.

Changing the Paradigm: Lymphovenous Anastomosis in Advanced Stage Lower Extremity Lymphedema

BACKGROUND

Traditionally, lymphovenous anastomosis is not routinely performed in patients with advanced stage lymphedema because of difficulty with identifying functioning lymphatics. This study presents the use of duplex ultrasound and magnetic resonance lymphangiography to identify functional lymphatics and reports the clinical outcome of lymphovenous anastomosis in advanced stage lower extremity lymphedema patients.

METHODS

This was a retrospective study of 42 patients (50 lower limbs) with advanced lymphedema (late stage 2 or 3) that underwent functional lymphovenous anastomoses. Functional lymphatic vessels were identified preoperatively using magnetic resonance lymphangiography and duplex ultrasound.

RESULTS

An average of 4.64 lymphovenous anastomoses were performed per limb using the lymphatics located in the deep fat underneath the superficial fascia. The average diameter of lymphatic vessels was 0.61 mm (range, 0.35 to 1 mm). The average limb volume was reduced 14.0 percent postoperatively, followed by 15.2 percent after 3 months, and 15.5 percent after 6 months and 1 year (p < 0.001). For patients with unilateral lymphedema, 32.4 percent had less than 10 percent volume excess compared to the contralateral side postoperatively, whereas 20.5 percent had more than 20 percent volume excess. The incidence of cellulitis decreased from 0.84 per year to 0.07 per year after surgery (p < 0.001).

CONCLUSION

This study shows that functioning lymphatic vessels can be identified preoperatively using ultrasound and magnetic resonance lymphangiography; thus, lymphovenous anastomoses can effectively reduce the volume of the limb and improve subjective symptoms in patients with advanced stage lymphedema of the lower extremity.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Prospective Validation of Indocyanine Green Lymphangiography Staging of Breast Cancer-Related Lymphedema

Simple Summary

Indocyanine green lymphangiography (ICG-L) allows real-time investigation of lymphatics; however, the applicability in evaluating breast cancer-related lymphedema (BCRL) is sparse and not well established. In this prospective study, we aimed to validate ICG-L assessment of BCRL in a large patient group. We found that evaluation of BCRL with ICG-L was easy and safe to perform in the outpatient clinic and provided unique disease information unobtainable by clinical assessment alone. Future studies that evaluate the efficacy of therapeutic treatments on lymphatic function morphology should incorporate lymphatic imaging as an outcome.

Abstract

Indocyanine green lymphangiography (ICG-L) allows real-time investigation of lymphatics. Plastic surgeons performing lymphatic reconstruction use the ICG-L for patient selection and stratification using the MD Anderson (MDA) and the Arm Dermal Backflow (ADB) grading systems. However, the applicability of ICG-L in evaluating breast cancer-related lymphedema (BCRL) is sparse and not well established. This study comprehensively examines the usability of ICG-L in the assessment of BCRL. We prospectively performed ICG-L in 237 BCRL patients between January 2019 and February 2020. The aim of this study was to assess the interrater and intrarater agreement and interscale consensus of ratings made using the MDA and ADB scales. Three independent raters performed a total of 2607 ICG-L assessments. The ICG-L stage for each grading system was correlated to the lymphedema volume to assess the agreement between the ICG-L stage and clinical severity. The interrater agreement was near perfect for the MDA scale (kappa 0.82–0.90) and the ADB scale (kappa 0.80–0.91). Similarly, we found a near-perfect intrarater agreement for the MDA scale (kappa 0.84–0.94) and the ADB scale (kappa 0.88–0.89). The agreement between the MDA and the ADB scales was substantial (kappa 0.65–0.68); however, the ADB scale systematically overestimated lower ICG-L stages compared to the MDA scale. The volume of lymphedema correlated slightly with MDA stage (Spearmans rho = 0.44, p < 0.001) and ADB stage (r_s = 0.35, p < 0.001). No serious adverse events occurred. The staging of BCRL with ICG-L is reliable, safe, and provides unique disease information unobtainable with clinical measurements alone. The MDA scale seems to provide better disease stratification compared to the ADB scale.

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.

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.

Intraoperative Real-Time Visualization of the Lymphatic Vessels Using Microscope-Integrated Laser Tomography

BACKGROUND

 Detection and selection of the lymphatic vessels are important for maximizing therapeutic efficacy of lymphaticovenular anastomosis (LVA). Some imaging modalities have been reported to be useful for intraoperative identification of the lymphatic vessels, but they have limitations. In this article, we present new capabilities of intraoperative laser tomography, which was used to evaluate the lumen of the lymphatic vessel and to validate the patency of anastomosis.

METHODS

 Fifty-two patients with upper extremity lymphedema secondary to breast cancer treatment underwent indocyanine green (ICG) lymphography and real-time laser tomography imaging of ICG-enhanced lymphatic vessels intraoperatively before transecting the vessels during LVA. The imaging findings of the lymphatic vessels in laser tomography were investigated. Time required for scanning of the lymphatic vessels was compared between laser tomography and ultrasonography. The correlation between the thickness of the lymphatic vessel wall measured with laser tomographic imaging and the histologically measured thickness of the lymphatic vessel wall was examined. The patency of anastomosis sites was determined based on the image using laser tomography immediately after establishment of LVA.

RESULTS

 A total of 132 ICG-enhanced lymphatic vessels were scanned with laser tomography showing clear lumen with surrounding vessel wall. The required time for lymphatic vessel scanning was significantly shorter with laser tomography than with ultrasonography (1.6 ± 0.3 vs. 4.8 ± 1.2 minutes; p = 0.016). Strong correlation was seen between the thickness of the lymphatic vessels wall measured using laser tomography and the histologically measured thickness of the lymphatic vessel wall (r = 0.977, 95% confidence interval: 0.897-0.992, p < 0.001). The quality of patency was evaluated immediately after anastomosis, which assisted in deciding whether reanastomosis was needed.

CONCLUSION

 Microscope-integrated laser tomography provides real-time images of the lymphatic vessels in extremely high resolution and enables evaluation of lymphatic lumen condition and objective post-LVA anastomosis status.

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.

Multidisciplinary guidelines for initial evaluation of complicated lymphatic anomalies-expert opinion consensus

OBJECTIVE

Complicated lymphatic anomalies (CLAs) are chronic, progressive, and debilitating conditions that share clinical features, yet key elements for optimal evaluation and management have not been established. We aimed to formulate expert opinion consensus-based guidelines for comprehensive evaluation of CLAs.

STUDY DESIGN

Patient support groups dedicated to CLAs organized an international conference for vascular anomaly experts from 16 specialties to address the objective. Participants received a set of questions before the meeting and reviewed the literature. Data extracted from international lymphatic anomaly registries were presented and the group separated for panel discussions during the conference. The recommendations achieving consensus within the panel were presented to the entire audience. Open debate occurred until majority approval was achieved.

RESULTS

The expert group was composed of 52 physicians who defined the clinical elements required to evaluate and diagnose a CLA. The radiology panel established the preferred anatomical and functional imaging methods for diagnosis and the elements required to be described during interpretation. Two medical panels compiled the metabolic and hematologic tests at diagnosis and also recommended functional studies. The surgical group recommended precautions for biopsy and the pathology panel provided biopsy specimen processing guidelines.

CONCLUSIONS

Patients with CLAs require a comprehensive and targeted diagnostic plan for appropriate management, prevention of complications, and conservation of resources. As this population is managed by diverse medical and surgical specialties, we offer an expert multidisciplinary consensus-based opinion on the current literature and on data extracted from international lymphatic anomaly registries.

[Application progress of indocyanine green angiography in lymphedema]

Objective

To summarize the application progress of indocyanine green (ICG) angiography in diagnosis and treatment of lymphedema.

Methods

The literature related to dynamic imaging tracing of lymphedema at home and abroad was reviewed extensively. And the research status and progress of ICG angiography in diagnosis and treatment of lymphedema were retrospectively analyzed.

Results

ICG angiography can be used as the gold standard for the diagnosis of lymphedema at present and the classification of lymphedema severity, selection of surgical incisions and methods, and intraoperative operation. It can also be used to observe lymphatic drainage and regeneration within 1.5 cm of subcutaneous and determine the prognosis.

Conclusion

Compared with traditional methods, ICG angiography has more obvious advantages and value in diagnosis and treatment of lymphedema. However, it also has problems such as slow development speed and difficulty in developing deep lymphatic vessels (nodes).

Supermicrosurgical Lymphaticovenous Anastomosis as Alternative Treatment Option for Moderate-to-Severe Lower Limb Lymphedema

BACKGROUND

Supermicrosurgical lymphaticovenous anastomosis (LVA) alleviates lymphedema by draining stagnant lymph from the lymphatic vessels into the venous system. Nevertheless, LVA is believed to be unsuitable for treating moderate-to-severe lymphedema presenting diffuse-pattern dermal backflow (DB). Dermal backflow is considered to be the sign of superficial lymphatic functional failure that renders LVA ineffective. Based on a current algorithm, a more invasive vascularized lymph node flap transfer is recommended instead of LVA. This retrospective study aimed to further investigate and possibly challenge this concept.

STUDY DESIGN

One-hundred patients with unilateral lymphedematous lower limbs who underwent LVA were included. Patients were divided into Group I (10 patients with mild lymphedema) and Group II (90 patients with moderate-to-severe lymphedema). Demographic data and intraoperative findings were recorded. The post-LVA volume reductions by magnetic resonance volumetry were recorded and analyzed.

RESULTS

Preoperatively, significant differences were found in BMI (20.6 vs 26.0 kg/m², p = 0.004) and the volume gained in the lymphedematous limb (396.8 mL vs 1,056.8 mL, p = 0.005) between Groups I and II. Postoperatively, a significant median post-LVA volume reduction (-282.0 mL vs -763.5 mL, p = 0.022) was found in Group II. However, there were no differences in the percentages of post-LVA volume reduction (-43.8% vs -36.4%, p = 0.793) in Groups I and II.

CONCLUSIONS

The use of supermicrosurgical LVA is as effective at treating moderate-to-severe lymphedema as milder lymphedema. The indication for LVA should be broadened to include such cases.

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.

Real-time Indocyanine Green Videolymphography Navigation for Lymphaticovenular Anastomosis

Indocyanine green (ICG) lymphography is a useful imaging modality for evaluation of lymphedema and detection of lymphatic vessels. It also allows us to ensure patency of the anastomosed vessels intraoperatively. However, strong light from the operating microscope usually disturbs ICG fluorescence imaging. Only some built-in ICG camera systems with specific operating microscopes make real-time ICG lymphography possible in lymphaticovenular anastomosis (LVA). We applied a new high-resolution ICG videolymphography system, which is separated from the operating microscope. Because the system can divide near-infrared fluorescence light of ICG from visible light of the operating microscope, real-time ICG videolymphography-navigated LVA under operating microscope illumination is possible regardless types of operating microscopes. The study involved 10 patients with upper extremity lymphedema characterized by International Society of Lymphology stage 2 and treated by 3 lymphaticovenular anastomoses at the forearm (30 lymphaticovenular anastomoses incorporating 30 lymphatic vessels) under real-time ICG videolymphography. The rate of intraoperative detection of lymphatic vessels using real-time ICG videolymphography was 86.7% (0.25–0.85 mm in diameter), and that of lymph flow through the lymphaticovenular anastomoses was 76.7%. None of lymphatic vessels and no flow were detected under the microscope light by means of another non-built-in ICG lymphography camera. Real-time ICG videolymphography in LVA is beneficial, because the surgeon could find lymphatic vessels easily by checking dual images of original view and ICG fluorescent view and ensure accuracy of the LVA in a suture by a suture without any pauses of the surgical procedures.