Sensitivity of Each Index of Doppler, Cross, Uncollapsible, Parallel, and Superficial Fascia in Lymphatic Ultrasound

Background: Recently, the usefulness of lymphatic ultrasound has been reported. It is beneficial not only to identify lymphatic vessels but also to evaluate lymphatic degeneration and diagnose lymphedema. We previously proposed D-CUPS (Doppler, Cross, Uncollapsible, Parallel, and Superficial fascia) to identify the lymphatic vessels on ultrasound. The purpose of this study was to clarify the sensitivity of each index of D-CUPS. Methods: We performed a retrospective study of 27 patients (44 limbs, 98 sites) with lower extremity lymphedema, who underwent lymphaticovenous anastomosis (LVA). We performed a lymphatic ultrasound the day before surgery. We used a linear probe commonly used for venous ultrasound (Noblus EUP-L65; Hitachi Medical Corp., Tokyo, Japan). We applied the D-CUPS index to identify the lymphatic vessels on ultrasound. We checked whether lymphatic vessels consistent with preoperative lymphatic ultrasound findings were observed during the LVA. We also calculated the sensitivity of each D-CUPS index. Results: All the 27 patients were women, with a mean age of 59.7 years. Totally, 98 incisions were made (59 incisions on the thigh and 39 incisions on the lower leg). During LVA, lymphatic vessels consistent with the preoperative lymphatic ultrasound findings were observed at all the sites. The sensitivities of each indicator of D-CUPS were 100.0%, 100.0%, 68.4%, 19.4%, and 100.0%, respectively. Conclusion: The sensitivity was 100.0% in D, C, and S. Although each index separately was not perfect, by combining them appropriately, we were able to identify lymphatic vessels with certainty.

Pulmonary interstitial lymphography: A prospective trial with potential impact on stereotactic ablative radiotherapy planning for early-stage lung cancer

This prospective feasibility trial investigated pulmonary interstitial lymphography to identify thoracic primary nodal drainage (PND). A post-hoc analysis of nodal recurrences was compared with PND for patients with early-stage lung cancer; larger studies are needed to establish correlation. Exploratory PND-inclusive stereotactic ablative radiotherapy plans were assessed for dosimetric feasibility.

Application of combined preoperative indocyanine green lymphography and ultrasonography for low-pressure vein localization in secondary lymphedema surgery for breast cancer

BACKGROUND

This study aimed to investigate the value of preoperative indocyanine green (ICG) lymphography combined with ultrasonography for low-pressure vein localization in secondary lymphedema surgery for breast cancer.

METHODS

A total of 29 patients who were admitted to the breast surgery department of our hospital from July 2019 to May 2021 were included in this study. All patients received preoperative reverse lymphography and ultrasonography for low-pressure vein in lymphedema surgery. Three arm circumferences were measured before surgery, 6 months after surgery, and 12 months after surgery for comparison with the healthy limb at the same time.

RESULTS

Arm circumference at 12 months after surgery was significantly different from those at the preoperative period and 6 months after surgery (P < 0.05). However, this parameter after surgery was still significantly higher than that of the healthy limb (P < 0.05).

CONCLUSIONS

The application of preoperative ICG lymphography combined with ultrasonography for low-pressure vein localization before surgery can greatly shorten operation duration by reducing the number of ineffective incisions and improving the probability of vein-lymphatic vessel matching, while ensuring the postoperative efficacy for patients.

[Fluorescence lymphography for sentinal lymph node biopsy in breast cancer]

OBJECTIVE

To study diagnostic value of fluorescence lymphography for sentinel lymph node biopsy in breast cancer.

MATERIAL AND METHODS

The study enrolled 25 patients with breast cancer T1-2N0-1M0 between March 2023 and July 2023. Eight ones underwent neoadjuvant chemotherapy. In 3 patients, morphologically verified metastases cN1 in axillary lymph nodes regressed after treatment. After sentinel lymph node biopsy, all patients underwent standard axillary lymphadenectomy. Subareolar injection of indocyanine green 1 ml (5 mg/ml) was performed immediately before surgery. Fluorescence imaging was performed using the MARS system.

RESULTS

Detection rate was 100%. Mean number of sentinel lymph nodes was 2. Metastatic lesions of sentinel lymph nodes were observed in 6 patients (24%) with micro-metastases in 2 cases. In 50% of cases, metastatic lesion did not extend beyond sentinel lymph nodes. False negative result was obtained in 1 (4%) patient. Mean number of metastases was 1.8 (max 3 in one patient).

CONCLUSION

Sentinel lymph node biopsy with fluorescence lymphography is a sensitive method. The advantages of this technique are visualization of subcutaneous lymphatic vessels and skin incision for access to sentinel lymph nodes, as well as visualization of sentinel lymph nodes after skin incision.

Inguinal intranodal lymphangiography reveals a high incidence of suprainguinal lymphatic disease in patients with leg edema undergoing stenting for symptomatic chronic iliofemoral venous obstruction

OBJECTIVE

Recent studies have emphasized the important role lymphatics play in the drainage of interstitial fluid and edema prevention. Although the infrainguinal lymphatics have been studied in some depth, with patterns of pathology identified, such data above the groin are sparse, especially for patients with phlebolymphedema. The present study attempts to evaluate the status of lymphatic flow above the inguinal ligament in patients presenting with edema and undergoing stenting for symptomatic chronic iliofemoral venous obstruction (CIVO).

METHODS

A total of 31 lower limbs that underwent pedal lymphoscintigraphy for leg edema and subsequent stenting for symptomatic CIVO formed the study cohort. Each limb underwent intranodal lymphangiography of an ipsilateral inferior inguinal lymph node (10 mL of lipiodol) at the time of stenting. Fluoroscopic visualization of lipiodol transit was performed at 20, 40, and 60 minutes and 3 hours after injection. Enumeration of the lymph nodes and lymphatic collector vessels from above the inguinal ligament to L1, visualization of the thoracic duct, the time delay to visualization of the thoracic duct, and pathologic changes to the thoracic duct when present were all evaluated. These anomalies were independently scored, with the scores combined to generate a total suprainguinal score (range, 0-3). This score was then compared to the limb's lymphoscintigraphically derived infrainguinal score (total infrainguinal score range, 0-3) using the t test and Spearman correlation. The clinical outcomes (grade of swelling, venous clinical severity score) after stenting were appraised.

RESULTS

Of the 30 patients (31 limbs), 18 were women, with left laterality noted in 23 limbs. A nonthrombotic iliac vein lesion occurred in 9 limbs and post-thrombotic syndrome in 22 limbs. Of the 31 limbs, 24 (77%) had suprainguinal lymphatic disease (SLD), with 22 of the 24 limbs having severe SLD and 2, mild SLD. When SLD was compared with infrainguinal lymphatic disease, 6 limbs (19%) had the same degree of involvement above and below the groin (1 with normal and 5 with severe disease), 17 limbs (55%) had more severe SLD, and 8 limbs (26%) had more severe infrainguinal lymphatic disease. Three limbs with normal pedal lymphoscintigraphic findings had severe SLD. The Spearman correlation coefficient for the comparison of SLD and infrainguinal disease in the same limb was 0.1 (P = .69). At baseline, the limbs with severe SLD had the same degree of leg swelling and venous clinical severity score as the limbs with absent to mild SLD (P > .1) with similar improvements after stenting (P > .4). Seven limbs underwent complex decongestive therapy (all with severe SLD and concomitant severe infrainguinal disease in one) to treat significant residual leg edema, with improvement.

CONCLUSIONS

SLD appears to be common in patients with leg edema undergoing stenting for symptomatic CIVO. Such disease appears to affect the thoracic duct more commonly. Although patients with persistent or residual leg edema after stenting can benefit from complex decongestive therapy, further workup in the form of inguinal intranodal lymphangiography and targeted intervention might need to be considered for those who do not benefit from such therapy. Further study is warranted.

Relaxivity Enhancement of Hybrid Micelles via Modulation of Water Coordination Numbers for Magnetic Resonance Lymphography

Considerable efforts have been made to develop nanoparticle-based magnetic resonance contrast agents (CAs) with high relaxivity. The prolonged rotational correlation time (τR) induced relaxivity enhancement is commonly recognized, while the effect of the water coordination numbers (q) on the relaxivity of nanoparticle-based CAs gets less attention. Herein, we first investigated the relationship between T1 relaxivity (r1) and q in manganese-based hybrid micellar CAs and proposed a strategy to enhance the relaxivity by increasing q. Hybrid micelles with different ratios of amphiphilic manganese complex (MnL) and DSPE-PEG2000 were prepared, whose q values were evaluated by Oxygen-17-NMR spectroscopy. Micelles with lower manganese doping density exhibit increased q and enhanced relaxivity, corroborating the conception. In vivo sentinel lymph node (SLN) imaging demonstrates that DSPE-PEG/MnL micelles could differentiate metastatic SLN from inflammatory LN. Our strategy makes it feasible for relaxivity enhancement by modulating q, providing new approaches for the structural design of high-performance hybrid micellar CAs.

High-sensitivity synchronous angio-lymphography based on a speckle spectrum contrast OCT

To achieve accurate selection and synchronous imaging of blood vessels and lymph, a speckle spectrum contrast method (SSC) based on spectral-domain optical coherence tomography (SD-OCT) is proposed in this Letter. In this method, the time-lapse optical coherence tomography (OCT) intensity signal is transformed to the Fourier frequency domain. By analyzing the frequency spectrum of the time-lapse OCT intensity signal, a parameter called SSC signal, which represents the ratio of different intervals of the high frequency to the low frequency, is utilized to extract and contrast different types of the vessels in the biological tissues. In the SSC spectrum, the SSC signals of the static tissue, lymphatic vessels, and vascular vessels can be separated in three different frequency intervals, enabling differentiation and synchronous imaging of the lymphatic-vascular vessels. A mouse ear was used to demonstrate the feasibility and efficiency of this method. By using the SSC signal as the imaging parameter, the lymphatic and blood vessels of the mouse ear are differentiated and visualized simultaneously. This study shows the feasibility of the three-dimensional (3D) synchronous angio-lymphography based on the SSC method, which provides a tool to improve the understanding for disease research and treatment.

Utilization of Noncontrast Magnetic Resonance Lymphangiography for Selection of Effective Surgical Method in Breast Cancer-Related Lymphedema

Background and Objectives: When considering surgery for patients with breast cancer-related lymphedema (BCRL), it is crucial to determine which surgery will be most effective for the patient and establish the indications for each surgery. Our study retrospectively compared the results of preoperative noncontrast MR lymphangiography (NMRL) performed on the lymphedematous limb of patients before surgery, with the aim of analyzing whether preoperative NMRL can be used as a criterion for determining the type of surgery. Materials and Methods: From January 2020 to June 2022, a total of 138 patients with lymphedema underwent surgery at Seoul National University Bundang Hospital. All patients underwent preoperative NMRL imaging and were classified into stages 1-3 based on the MRI severity index using the authors' previous reference. Three types of surgery, LVA, LVA + liposuction, and LVA + VLNT, were conducted on all patients. The effectiveness of the surgery was evaluated one year postoperatively using the interlimb volume difference before and after surgery, the fluid volume of the edematous limb measured by bioimpedance spectroscopy, and the subjective satisfaction of the patients through the Lymph Q questionnaire. Results: In this study, out of a total of 138 patients, 26 (19%) were MRI stage 1, 62 (45%) were stage 2, and 50 (36%) were stage 3. Of the 83 patients who underwent LVA surgery, the greatest decrease in interlimb volume difference was observed in stage 2 patients, and subjective satisfaction was also the most effective in stage 2. In the case of LVA + liposuction patients, a significant volume decrease and a high satisfaction were observed in stage 3 patients. In the case of LVA + VLNT patients, there was no difference in volume decrease according to the stage, but a greater decrease in body fluid volume was observed as the MRI severity index score increased through BIA. Conclusions: In conclusion, this study demonstrates that NMRL imaging is a useful modality for determining the most effective surgical method and predicting the surgical outcome in patients with lymphedema. This highlights the importance of using NMRL in the treatment planning of lymphedema patients.

Investigation of optimizing indocyanine green solution for in vivo lymphatic research using near-infrared fluorescence indocyanine green lymphangiography

Despite the tireless efforts of many researchers in lymphatic research, indocyanine green (ICG) solution conditions suitable for lymphatic circulation tests have not been perfectly established yet. We aimed to investigate the optimal in vivo conditions of ICG solution to avoid photobleaching and quenching effects, which may affect the accuracy of lymphatic circulation evaluation. After ICG fluorescence intensity (or ICG intensity) was assessed under different in vitro conditions, the image quality of brachial lymph nodes (LNs) and collecting lymphatic vessels (LVs) in eight rats was investigated. The in vitro results showed that ICG intensity depends on concentration and time in various solvents; however, the brightest intensity was observed at a concentration of 8-30 μg/mL in all solvents. ICG concentration in the albumin (bovine serum albumin; BSA) solution and rat's plasma showed more than two times higher fluorescence intensity than in distilled water (DW) in the same range. However, saline reduced the intensity by almost half compared to DW. In the in vivo experiment, we obtained relatively high-quality images of the LNs and LVs using ICG in the BSA solution. Even at low concentrations, the result in the BSA solution was comparable to those obtained from high-concentration solutions commonly used in conventional circulation tests. This study provides valuable information about the conditions for optimal ICG intensity in near infrared fluorescence indocyanine green (NIRF-ICG) lymphangiography, which may be useful not only for the diagnosis of lymphatic circulation diseases such as lymphedema but also for preclinical research for the lymphatic system.

Management of Congenital and Postoperative Chylothorax: Use of Thoracoscopic Lymphatic Leak Ligations with Intraoperative ICG Lymphangiography

BACKGROUND

Congenital chylothorax (CCT) and postoperative chylothorax (POCT) are rare and difficult to treat. We report our treatment strategy and outcomes for chylothorax, including thoracoscopic surgery with indocyanine-green (ICG) near-infrared fluorescence lymphangiography.

METHODS

A retrospective review of patients with CCT and POCT from 2014 to 2021 was performed. After definitive diagnosis, conservative treatments with octreotide, followed by intravenous steroids as needed, were performed. Patients who were refractory to conservative treatment were transferred to surgical treatment, consisting of thoracoscopic lymphatic leak ligations using ICG intraoperative lymphangiography. The effectiveness of conservative and surgical treatment was then examined.

RESULTS

We included 19 cases of CCT and 31 cases of POCT. The 31 POCT patients included 23 of 84 postoperative patients with congenital diaphragmatic hernia (CDH), 7 of 54 postoperative patients with esophageal atresia (EA), and 1 of 3 postoperative patients with lymphatic malformation. The efficacy of conservative treatment was 12/19 for CCT, 22/23 for CDH, and 4/7 for EA. Surgical intervention was performed in 10 patients, and the rate of resolution of chylothorax within 3 weeks after surgery was 90%.

CONCLUSION

Thoracoscopic lymphatic leak ligations with intraoperative ICG lymphangiography are feasible and useful in patients with chylothorax refractory to conservative treatment.

LEVEL OF EVIDENCE

Level IV.

Usefulness of 33 MHz Linear Probe in Lymphatic Ultrasound for Lymphedema Patients

Background: Lymphatic ultrasound has recently been reported useful in the treatment of lymphedema. However, no conclusions have been reached regarding the best probe for lymphatic ultrasound. Methods: This was a retrospective study. Fifteen limbs of 13 patients with lymphedema in whom we could not find dilated lymphatic vessels on lymphatic ultrasound with an 18 MHz probe but later could find them with 33 MHz probe were included. All patients were women, and the mean age was 59.5 years. We performed lymphatic ultrasound in four areas per limb by applying an index of D-CUPS, as we previously reported. We measured the depth and diameter of the lumen of the lymphatic vessels. We also diagnosed the degree of lymphatic degeneration based on the normal, ectasis, contraction, and sclerosis type (NECST) classification. Results: We found lymphatic vessels in 22/24 (91.7%) areas in the upper limbs and 26/36 (72.2%) areas in the lower limbs. The mean depth and diameter of the lymphatic vessels were 5.2 ± 0.28 mm and 0.33 ± 0.029 mm, respectively. Based on the NECST classification, 68.2% of the upper limbs and 56.0% of the lower limbs were of the ectasis type. We found functional lymphatic vessels in 6/6 (100%) of the upper limbs and 5/7 (71.4%) of the lower limbs, which indicated lymphaticovenous anastomosis (LVA) in these 11 patients. Conclusion: Using 33 MHz probe, we could detect functional lymphatic vessels in most patients. Even if lymphatic vessels were not found with the 18 MHz probe, LVA could be performed using a higher frequency probe.

The relationship between the degree of subcutaneous fluid accumulation and the lymphatic diameter

BACKGROUND

The relationship between the fluid accumulation in the subcutaneous tissue and the lymphatic degeneration in the lymphedematous limbs has not been elucidated, and we have evaluated it in the current study.

METHODS

Twenty-five patients (50 limbs) were included in this retrospective study. We performed lymphatic ultrasound by separating the limbs into four lymphosomes: the saphenous (medial) thigh, saphenous (medial) calf, lateral thigh, and lateral calf. In each lymphosome, the lymphatic diameter, the degree of lymphatic degeneration, and the fluid accumulation in the subcutaneous tissue were evaluated. The lymphatic vessels were detected based on the index of D-CUPS (Doppler, Crossing, Uncollapsibe, Parallel, and Superficial fascia). Lymphatic degeneration was diagnosed based on the NECST (Normal, Ectasis, Contraction, and Sclerosis Type) classification.

RESULTS

All patients were women with a mean age of 62.7 years. Lymphatic vessels were detected using lymphatic ultrasonography in 50 saphenous (medial) thigh lymphosomes, 43 saphenous (medial) calf lymphosomes, 34 lateral thigh lymphosomes, and 22 lateral calf lymphosomes. The fluid accumulation tended to be more acute in the more severe stages of lymphedema. As for the NECST classification, the normal type was observed only in the areas without fluid accumulation. Among the other areas, the percentage of contraction type was the largest in the area with slight edema and decreased in the areas with severe edema.

CONCLUSION

The lymphatic vessels were dilated to a greater extent in legs with more severe fluid accumulation. Therefore, there is no hesitation needed to perform lymphaticovenous anastomosis because of severe lymphedema.

Rate of Incidental Edema in the Contralateral Arm of Patients with Unilateral Postsurgical Secondary Upper Extremity Lymphedema

Background: Secondary upper extremity lymphedema occurs after an insult such as surgery. One theory suggests underlying lymphatic dysfunction predisposing certain patients into developing secondary lymphedema. We aim to determine the rate of incidental edema in the contralateral upper extremity of patients with secondary unilateral lymphedema. Methods and Results: MRI of the upper extremities were obtained in patients with lymphedema who were referred by a lymphedema clinic from 2017 to 2019. Axial short-tau inversion recovery MR images of the symptomatic and contralateral arms were retrospectively reviewed and edema severity was graded. Interobserver agreement was calculated. Indocyanine green (ICG) lymphography was compared against MRI stage in symptomatic and contralateral. Age, symptom duration, body mass index (BMI), and history of chemotherapy were compared between patients with and without contralateral limb lymphedema. ICG severity was compared against MRI stage. Seventy-eight patients were analyzed. The MRI stages of symptomatic versus contralateral arms were 1.7 ± 1.1 versus 0.1 ± 0.4 (p < 0.00001). Interobserver agreement was 0.86 (0.79-0.94). Of the patients with MRI Stage 1 or above in the symptomatic arm (n = 64), 55 (82.1%) patients demonstrated no abnormality in the contralateral arm. Nine patients (14.1%) demonstrated asymptomatic edema (MRI Stage 1). The mean ICG lymphography stage of symptomatic versus contralateral arms was 1.83 ± 0.96 versus 0.04 ± 0.25 (p < 0.00001). There was no difference in the age, symptom duration, BMI, or history of chemotherapy between patients with or without edema in the contralateral arm. Conclusion: Asymptomatic contralateral edema was detected in 14.1% of patients with unilateral secondary upper extremity lymphedema using MRI modality.

Three-dimensional visual technique based on CT lymphography data combined with methylene blue in endoscopic sentinel lymph node biopsy for breast cancer

BACKGROUND

The combined application of blue dye and radioisotopes is currently the primary mapping technique used for sentinel lymph node biopsy (SLNB) in breast cancer patients. However, radiocolloid techniques have not been widely adopted, especially in developing countries, given the strict restrictions on radioactive materials. Consequently, we carried out a retrospective study to evaluate the feasibility and accuracy of three-dimensional visualization technique (3DVT) based on computed tomography-lymphography (CT-LG) in endoscopic sentinel lymph node biopsy (ESLNB) for breast cancer.

METHODS

From September 2018 to June 2020, 389 patients who underwent surgical treatment of breast cancer in our department were included in this study. The CT-LG data of these patients were reconstructed into digital 3D models and imported into Smart Vision Works V1.0 to locate the sentinel lymph node (SLN) and for visual simulation surgery. ESLNB and endoscopic axillary lymph node dissection were carried out based on this new technique; the accuracy and clinical value of 3DVT in ESLNB were analyzed.

RESULTS

The reconstructed 3D models clearly displayed all the structures of breast and axilla, which favors the intraoperative detection of SLNs. The identification rate of biopsied SLNs was 100% (389/389). The accuracy, sensitivity, and false-negative rate were 93.83% (365/389), 93.43% (128/137), and 6.57% (9/137), respectively. Upper limb lymphedema occurred in one patient 3 months after surgery during the 12-month follow-up period.

CONCLUSIONS

Our 3DVT based on CT-LG data combined with methylene blue in ESLNB ensures a high identification rate of SLNs with low false-negative rates. It, therefore, has the potential to serve as a new method for SLN biopsy in breast cancer cases.

Invasive treatment of persistent postoperative chylothorax secondary to thoracic duct variation injury: Two case reports and literature review

RATIONALE

Postoperative chylothorax is a rare complication after pulmonary resection. Thoracic duct variations may play a key role in postoperative chylothorax occurrence and make treatment difficult. No studies in the literature have reported the successful treatment of chylothorax second to thoracic duct variation by lipiodol-based lymphangiography.

PATIENT CONCERNS

A 63-year-old male and a 28-year-old female with primary lung adenocarcinoma were treated by video-assisted thoracoscopic cancer resection, and suffered postoperative chylothorax. Conservative treatment was ineffective, including nil per os, persistent thoracic drainage, fatty food restriction, and somatostatin administration.

DIAGNOSIS

Postoperative chylothorax.

INTERVENTIONS

Patients received lipiodol-based lymphangiography under fluoroscopic guidance. Iatrogenic injuries were identified at thoracic duct variations, including an additional channel in case 1 and the lymphatic plexus instead of the thoracic duct in case 2.

OUTCOMES

Thoracic duct variations were identified by lipiodol-based lymphangiography, and postoperative chylothorax was successfully treated by lipiodol embolizing effect.

LESSONS

Thoracic duct variations should be considered after the failure of conservative treatment for postoperative chylothorax secondary to pulmonary resection. Lipiodol-based lymphangiography is valuable for identifying the thoracic duct variations and embolizing chylous leakage.

Ultrabright Renal-Clearable Cyanine-Protein Nanoprobes for High-Quality NIR-II Angiography and Lymphography

The renal-clearable aspect of imaging agent with minimum toxicity issues and side effects is essential for clinical translation, yet clinical near-infrared-I/II (NIR-I/II) fluorophores with timely renal-clearance pathways are very limited. Herein, we rationally develop the cyanine-protein composite strategy through covalent bonding of β-lactoglobulin (β-LG) and chloride-cyanine dye to produce a brilliant and stable NIR-I/II fluorophore (e.g., β-LG@IR-780). The β-LG acts as a protecting shell with small molecular weight (18.4 kDa) and ultrasmall size (&lt;5 nm), thus endowing the β-LG@IR-780 with excellent biocompatibility and renal excretion. Our β-LG@IR-780 probe enables noninvasive and precise NIR-II visualization of the physiological and pathological conditions of the vascular and lymphatic drainage system, facilitating intraoperative imaging-guided surgery and postoperative noninvasive monitoring. The minimum accumulation of our probes in the main organs improves the overall biosafety. This study provides a facile methodology for new-generation NIR-II fluorophores and largely improves the brightness and pharmacokinetics of small molecular dyes.

Assessment of Carbon Nanoparticle Suspension Lymphography-Guided Distal Gastrectomy for Gastric Cancer

IMPORTANCE

Carbon nanoparticle suspension injection (CNSI) can be used to visualize lymph node (LN) drainage in gastric cancer. The tracing and diagnostic value of carbon nanoparticle suspension lymphography-guided distal gastrectomy for gastric cancer has not been thoroughly reported.

OBJECTIVE

To compare the number of lymph nodes identified in patients with gastric cancer receiving a CNSI vs no injection.

DESIGN, SETTING, AND PARTICIPANTS

This is a retrospective cohort study including patients with clinical T1 to T4 disease who underwent laparoscopic or robotic distal gastrectomy. Data from a cohort of 1225 patients at the Fourth Hospital of Hebei Medical University (Shijiazhuang, China) from November 2019 to February 2021 were analyzed. Patients were divided into the CNSI group and conventional group after 1:1 propensity matching analysis. The mean number of LNs detected was compared between groups, and the diagnostic role of CNSI was analyzed in the CNSI group. Statistical analysis was performed from May to July 2021.

EXPOSURE

CNSI was peritumorally injected under an endoscope 1 day before surgery in the CNSI group, and the conventional group did not receive any treatment before surgery.

MAIN OUTCOMES AND MEASURES

The main outcome was the number of LNs detected. Gastrectomy with systematic D1+ (ie, stations 1, 3, 4sb, 4d, 5, 6, and 7) or D2 (ie, all D1 stations, plus 8a, 9, 11p, and 12a) lymphadenectomy was performed. Black-stained LNs and nonblack-stained LNs were examined separately in the CNSI group.

RESULTS

A total of 312 consecutive patients (mean [SD] age, 56.7 [10.4] years; 216 [69.2%] men) who underwent distal gastrectomy were enrolled, including 78 patients in the CNSI group, and another 78 patients determined from 1:1 propensity score matching, making an overall cohort size of 156 patients. The mean (SD) number of LNs detected in the CNSI group was 59.6 (21.4), which was significantly higher than that in the conventional group (30.0 [11.3] LNs; P < .001). In the CNSI group, the mean (SD) number of LNs detected at black-stained LN stations was significantly higher than that at nonstained LN stations (9.2 [6.1] LNs per station vs 3.5 [3.2] LNs per station; P < .001). For black-stained LN stations, the sensitivity was 97.8% (95% CI, 91.6%-99.6%), specificity was 38.1% (95% CI, 34.2%-42.3%), positive predictive value was 20.1% (95% CI, 16.6%-24.2%), and negative predictive value was 99.1% (95% CI, 96.4%-99.8%); for the black-stained LNs, sensitivity was 97.6% (95% CI, 95.3%-98.8%), specificity was 35.4% (95% CI, 33.9%-36.8%), positive predictive value was 11.6% (95% CI, 10.5%-12.8%), and negative predictive value was 99.4% (95% CI, 98.8%-99.7%).

CONCLUSIONS AND RELEVANCE

These findings suggest that CNSI was associated with facilitating the dissection of all positive LNs, which could improve surgical quality. Carbon nanoparticle suspension-guided lymphography may be an alternative to conventional systematic lymphadenectomy for distal gastrectomy.

Anatomical Location of Lymphatic Pathways in the Posterior Thigh

BACKGROUND

It is necessary for treating lower extremity lymphedema to understand the lymphatic pathways in the extremities. This study aimed to clarify the anatomical locations of lymph vessels in the posterior thigh using indocyanine green (ICG) lymphography.

METHODS

Medical records of cancer survivors who underwent ICG lymphography for secondary lymphedema screening from February 2019 to November 2020 were reviewed. Nonlymphedematous limbs without dermal backflow pattern on ICG lymphography (ICG stage 0) were included. Indocyanine green (0.1 mL) was injected intradermally at 2 points in the midlateral thigh, at the levels of one third and two thirds from the popliteal fossa to the gluteal fold in a prone position. Locations of the posterior thigh collecting lymph vessels visualized by ICG lymphography were marked on the skin surface with a pen, and distances from the popliteal fossa to the collecting lymph vessels were measured at the posterior midline in percentage, with the popliteal fossa set as 0% and the gluteal fold as 100%. Based on ICG lymphography findings, the number of the collecting lymph vessels shown as linear pattern and anatomical locations at the posterior thigh midline were investigated.

RESULTS

Twenty limbs of 20 cancer survivors were included. Linear pattern was identified in all lower extremities; average number was 2.3 ± 0.7 (range, 1-3). Most collecting lymph vessels shown on ICG lymphography, 26.7% (12 of 45) lymph vessels, were located within 40% to 50% of the region, and 24.4% (11 of 45) lymph vessels within 30% to 40% of the region.

CONCLUSIONS

There are 1 or more collecting lymph vessels in the posterior thigh by midlateral thigh ICG injection, which can be addressed for posterior thigh lymphedema.

Relationship Between the Circumference Difference and Findings of Indocyanine Green Lymphography in Breast Cancer-Related Lymphedema

BACKGROUND

Breast cancer-related lymphedema (BCRL) is a common complication. Indocyanine green (ICG) lymphography has been performed to assess lymphatic functionality. We found that some BCRL patients had a difference in circumference in partial regions only. The purpose of this study was to evaluate the patients with BCRL about the correlation between the difference in circumference and the findings of ICG lymphography.

METHODS

One hundred fifty-five patients with unilateral BCRL were enrolled in this study. We evaluated the differences in circumference taken at 4 parts on the upper limb (at around the wrist, forearm, elbow, and brachium). The difference in circumference was evaluated between the affected part (Caf) and the unaffected part (Cun). We calculated the circumference difference rate (CDR) as follows: CDR = 100 (Caf - Cun)/Caf. First, we classified each part of all BCRL patients (620 parts) based on the findings of ICG lymphography (linear, collateral, dermal back flow [DBF], and no enhancement) and evaluated the correlation. Second, in the patients with partial volume change, we compared the mean CDR in each part.

RESULTS

One hundred six parts were of a linear pattern, 31 parts were collateral, 350 parts were DBF, and 133 parts had no enhancement. The mean CDR of each finding was 3.3% in linear, 4.0% in collateral, 9.6% in DBF, and 9.4% in no enhancement. There was no significant difference between linear and collateral (P = 0.62), DBF, and no enhancement (P = 0.89) patterns. However, there was a significant difference between linear or collateral and DBF or no enhancement (all P < 0.001). In the 22 patients with distal DBF and proximal linear, the CDR was significantly higher in the forearm compared with the brachium (6.4% and 3.0%; P = 0.003). In the 26 patients with distal linear and proximal DBF, the CDR was significantly higher in the brachium compared with the forearm (4.3% and 7.7%; P = 0.005).

CONCLUSIONS

There was a significant correlation between the difference in circumference and the severity of ICG findings.

Novel Quantification of Real-Time Lymphatic Clearance: Immediate Lymphatic Reconstruction in a Large-Animal Model

BACKGROUND

The real-time quantification of lymphatic flow remains elusive. Efforts to provide a metric of direct lymphatic function are not clinically translatable and lack reproducibility. Early reports demonstrate the promise of immediate lymphatic reconstruction (immediate lymphovenous bypass after lymphadenectomy) to reduce the risk of lymphedema development. However, there remains a heightened need to appraise this technique in a clinically translatable large-animal model. The aim of the authors' experiment was to evaluate the role of molecular imaging in the quantification of real-time lymphatic flow after lymphadenectomy, and lymphadenectomy with lymphovenous bypass using novel fluorophores in a swine model.

METHODS

A lymphadenectomy or lymphadenectomy with subsequent lymphovenous bypass was performed in 10 female swine. After subdermal fluorophore injection, near-infrared molecular imaging of blood samples was used to evaluate change in lymphatic flow after lymphadenectomy versus after lymphadenectomy with lymphovenous bypass. Continuous imaging evaluating fluorescence of the superficial epigastric vein in the torso and adjacent skin was performed throughout all experiments. Findings between modalities were correlated.

RESULTS

The near-infrared dye signal in central and peripheral blood samples was often difficult to separate from background and proved challenging for reliable quantification. Venous and skin near-infrared imaging demonstrated a lymphatic clearance rate decrease of 70 percent after lymphadenectomy versus a decrease by only 30 percent after lymphadenectomy with immediate lymphovenous bypass.

CONCLUSIONS

In this article, the authors describe a noninvasive, swine, large-animal model to quantify lymphatic clearance using skin imaging. The authors' findings were consistent with results yielded from real-time imaging of the vein. The authors believe this model may have important implications for eventual direct translation to the clinical setting.

Comparison of normal hindlimb lymphatic systems in rats with detours present after lymphatic flow blockage

In the present study, we aimed to identify the normal hindlimb lymphatic systems in rats and compare them with the detours after lymphatic flow blockage. The lymphatic systems of the hindlimbs of normal rats were investigated via lymphography using a near-infrared fluorescence imaging system. The lymphatic vessels were stained using Evans Blue. The lymphatic flow was blocked through lymphatic vessel ligation combined with inguinal and popliteal lymph node dissection. Detours that appeared after 30 days were visualized using lymphography and immunostaining with anti-podoplanin antibodies. Three main results were obtained in the present study. First, the deep medial system, the superficial medial system, a connection between the superficial and deep medial lymphatic systems, and the superficial lateral system, were elucidated. Second, three types of detours, namely the detour of the lateral abdomen, the detour to the lymphatic vessel near the midline of the abdomen, and the detour to the contralateral inguinal lymph node, were identified after lymphatic flow blockage. Lastly, detours were located in the fatty layer above the panniculus carnosus muscle and their lumina were wide. The histology suggested that the detour was a pre-collecting lymphatic vessel. Lymphatic routes in the rat hindlimbs after lymphatic flow blockage were different from those of the normal rat lymphatic system. It was suggested that the detour is a pre-collecting lymphatic vessel and that encouraging its development may be a new method of simple lymphatic drainage.

[A Successful Case of Treatment by Lymphangiography for Chylothorax after Robotic Esophagectomy-A Case of Report]

A 50-year-old woman diagnosed with clinical Stage Ⅲ esophageal squamous cell carcinoma, received 2 cycles of docetaxel, cisplatin, 5-fluorouracil(DCF)therapy followed by robotic esophagectomy. In the 15th postoperative day, she suddenly had difficulty in breathing and a chest CT finding showed a large amount of right pleural effusion. Thoracocentesis yield a 1 L of chylous fluid confirmed diagnosis with postoperative chylothorax and conservative treatment was initiated. However, chylothorax was not improved. Therefore, a lipiodol lymphangiography from the inguinal lymph node was performed at the 20th postoperative day. Although the site of leakage could not identify, amount of drained pleural effusion was gradually decreased after lymphangiography, and drain was decannulated in the 28th postoperative day. Lipiodol lymphangiography may be a useful modality for both diagnosis and treatment for chylothorax after esophagectomy.

Yellow Nail Syndrome in Which Intranodal Lymphangiography Contributed to the Diagnosis

Yellow nail syndrome (YNS) is a rare disease comprising the clinical triad of yellow nail discoloration, pleural effusion, and lower limb lymphedema. We encountered a difficult-to-treat case of YNS in which the diagnosis was finally made based on intranodal lymphangiography. An 84-year-old man was admitted to our hospital with pleural effusion and yellow-green discoloration of the nails, accompanied by onychomycosis and limb lymphedema. Intranodal lymphangiography revealed a slow contrast flow and narrowing of the thoracic duct, suggesting lymphatic duct dysplasia and leading to the diagnosis of YNS.

Percutaneous Lymphatic Embolization as Primary Management of Pelvic and Retroperitoneal Iatrogenic Lymphoceles

PURPOSE

To evaluate the efficacy of lymphatic embolization (LE) in decreasing catheter output and dwell time in iatrogenic lymphoceles after percutaneous catheter drainage.

MATERIALS AND METHODS

Retrospective review of patients who underwent intranodal lymphangiography (INL) with or without LE for management of iatrogenic lymphoceles between January 2017 and November 2020 was performed. Twenty consecutive patients (16 men and 4 women; median age, 60.5 years) underwent a total of 22 INLs and 18 LEs for 15 pelvic and 5 retroperitoneal lymphoceles. Lymphatic leaks were identified in 19/22 (86.4%) of the INLs. Three patients underwent INL only because a leak was not identified or was identified into an asymptomatic lymphocele. One patient underwent repeat INL and LE after persistent high catheter output, and 1 patient underwent repeat INL with LE after the initial INL did not identify a leak. Catheter output was assessed until catheter removal, and changes in output before and after the procedure were reported. The patients were followed up for 2-30 months, and procedural complications were reported.

RESULTS

The median catheter output before the procedure was 210 mL/day (50-1,200 mL/day), which decreased to a median of 20 mL/day (0-520 mL/day) 3 days after the procedure, with a median output decrease of 160 mL (0-900 mL). The median time between INL with LE and catheter removal was 6 days, with no recurrence requiring redrainage. Four patients experienced minor complications of low-grade fever (n = 2) and lower limb edema (n = 2).

CONCLUSIONS

Lymphangiogram and LE are safe and effective methods for the management of lymphoceles.

FLT4 Mutations Are Associated with Segmental Lymphatic Dysfunction and Initial Lymphatic Aplasia in Patients with Milroy Disease

This study explored mutations in the Fms-related tyrosine kinase 4/vascular endothelial growth factor receptor 3 gene (FLT4) and lymphatic defects in patients with Milroy disease (MD). Twenty-nine patients with lower limb lymphedema were enrolled. Sixteen patients had a familial history of MD, while 13 patients exhibited sporadic MD. Clinical signs, FLT4 mutations, indocyanine green (ICG) lymphography findings, and skin tissue immunohistochemical staining results were evaluated. Twenty-eight variants in FLT4 were identified. Twelve of these have previously been reported, while 16 are novel. Of the 28 variants, 26 are missense mutations, and the remaining two comprise a splicing mutation and a non-frame shift mutation. Twenty-five variants are located in the intracellular protein tyrosine kinase domain; three are located in the extracellular immunoglobulin domain. Substantially delayed contrast-enhanced tortuous lymphatic vessels were visualized to the ankle or knee level in 15 of 23 patients who underwent ICG lymphography. No initial lymphatic vessels were visualized in skin specimens from four patients who did not exhibit lymphatic vessels during imaging analyses. No specific variant was identified in relation to the unique clinical phenotype. Segmental dysfunction of lymphatic vessels and initial lymphatic aplasia are present in MD patients with FLT4 mutations.

[Lymphangiography by Inguinal Lymph Node Puncture was Effective for Chylothorax after Lobectomy]

A 74-year-old female with lung cancer underwent thoracoscopic right upper lobectomy. The patient was diagnosed chylothorax due to the milky drain effusion on postoperative day 1 (POD 1). Despite fasting management, chylothorax was not improved. Lymphangiography by inguinal lymph node puncture was performed on POD 4. The amount of drainage decreased on POD 6 and disappered by following pleurodesis. Early lymphangiography is recommended prior to surgical treatment for patients with chyle leakages who are unlikely to be cured by conservative treatment alone.

[A Case of Refractory Chylothorax after Surgery for Esophageal Cancer in Which Lymphangiography and Thoracic Duct Ligation Was Useful]

Chylothorax after esophagectomy is a relatively rare complication that can be difficult to manage. Here, we report a case of refractory chylothorax after surgery for esophageal cancer treated with lymphatic duct lipiodol imaging by inguinal lymph node puncture to confirm patency of the thoracic duct and thoracic duct ligation. A 71-year-old female with esophageal cancer(cT3N0M0)underwent video-assisted thoracoscopic esophagectomy with 2-field lymph node dissection, intrathoracic gastric tube reconstruction, and an enterostomy. A chylothorax appeared when we started enteral nutrition on the day after surgery. She became markedly dehydrated due to over 2,000 mL/day of drainage from the chest drain, and we managed her general condition in the ICU. We started octreotide acetate on postoperative day(POD)6 and etilefrine on POD 8, but neither was effective. Lymphatic duct lipiodol imaging by bilateral inguinal lymph node puncture was performed, and we confirmed leakage from the main thoracic duct. On POD 11, a thoracic duct ligation performed via a thoracotomy revealed that the volume of the chylothorax was remarkably decreased. The chest tube was removed on re-POD 12.

Lymph vessels visualization from optical coherence tomography data using depth-resolved attenuation coefficient calculation

Multimodal optical coherent tomography grows popularity with researchers and clinicians over the past decade. One of the modalities is lymphangiography, which allows visualization of the lymphatic vessel networks within optical coherence tomography (OCT) imaging volume. In the present study, it is shown that lymphatic vessel visualization obtained from the depth-resolved attenuation coefficient distributions, corrected for the noise, shows improved contrast and detail in comparison with previously proposed approaches. We also argue that the two most popular approaches for lymphatic vessel visualization, namely simple intensity thresholding and vesselness calculation based on local Hessian matrix eigenvalues, imply different definitions of the lymphatic vessel's appearance in the OCT volume and lead to the different networks.

Thoracic duct embolization in treating postoperative chylothorax: does bail-out retrograde access improve outcomes?

OBJECTIVES

To evaluate clinical outcomes of thoracic duct embolization (TDE) for the management of postoperative chylothorax with the aid of the bail-out retrograde approach for thoracic duct cannulation (TDC).

MATERIALS AND METHODS

Forty-five patients with postoperative chylothorax underwent Lipiodol lymphangiography (LLG) between February 2016 and November 2019. If targetable central lymphatic vessels were identified in LLG, TDC, a prerequisite for TDE, was attempted. While the conventional antegrade transabdominal approach was the standard TDC method, the retrograde approach was applied as a bail-out method. Embolization, the last step of TDE, was performed after confirming leakages in the trans-TDC catheter lymphangiography. Technical and clinical success rates were determined retrospectively.

RESULTS

TDC was attempted in 40 among 45 patients based on LLG findings. The technical success rate of TDC with the conventional antegrade approach was 78% (31/40). In addition, six more patients were cannulated using the bail-out retrograde approach, which raised the technical success rate to 93% (37/40). While 35 patients underwent embolization (TDE group), ten patients did not (non-TDE group) for the following reasons: (1) lack of targetable lymphatics for TDC in LLG (n = 5), (2) technical failure of TDC (n = 3), and (3) lack of discernible leakages in the transcatheter lymphangiography (n = 2). The clinical success of the TDE group was 89% (31/35), compared with 50% (5/10) of the non-TDE group. One major procedure-related complication was bile peritonitis caused by the needle passage of the distended gallbladder.

CONCLUSIONS

Bail-out retrograde approach for TDC could improve the overall technical success of TDC significantly.

KEY POINTS

• Bail-out retrograde thoracic duct access may improve the overall technical success of thoracic duct access, thus improving the clinical success of thoracic duct embolization.

Systematic Review of Magnetic Resonance Lymphangiography From a Technical Perspective

BACKGROUND

Clinical examination and lymphoscintigraphy are the current standard for investigating lymphatic function. Magnetic resonance imaging (MRI) facilitates three-dimensional (3D), nonionizing imaging of the lymphatic vasculature, including functional assessments of lymphatic flow, and may improve diagnosis and treatment planning in disease states such as lymphedema.

PURPOSE

To summarize the role of MRI as a noninvasive technique to assess lymphatic drainage and highlight areas in need of further study.

STUDY TYPE

Systematic review.

POPULATION

In October 2019, a systematic literature search (PubMed) was performed to identify articles on magnetic resonance lymphangiography (MRL).

FIELD STRENGTH/SEQUENCE

No field strength or sequence restrictions.

ASSESSMENT

Article quality assessment was conducted using a bespoke protocol, designed with heavy reliance on the National Institutes of Health quality assessment tool for case series studies and Downs and Blacks quality checklist for health care intervention studies.

STATISTICAL TESTS

The results of the original research articles are summarized.

RESULTS

From 612 identified articles, 43 articles were included and their protocols and results summarized. Field strength was 1.5 or 3.0 T in all studies, with 25/43 (58%) employing 3.0 T imaging. Most commonly, imaging of the peripheries, upper and lower limbs including the pelvis (32/43, 74%), and the trunk (10/43, 23%) is performed, including two studies covering both regions. Imaging protocols were heterogenous; however, T2 -weighted and contrast-enhanced T1 -weighted images are routinely acquired and demonstrate the lymphatic vasculature. Edema, vessel, quantity and morphology, and contrast uptake characteristics are commonly reported indicators of lymphatic dysfunction.

DATA CONCLUSION

MRL is uniquely placed to yield large field of view, qualitative and quantitative, 3D imaging of the lymphatic vasculature. Despite study heterogeneity, consensus is emerging regarding MRL protocol design. MRL has the potential to dramatically improve understanding of the lymphatics and detect disease, but further optimization, and research into the influence of study protocol differences, is required before this is fully realized.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 2.

A New Experimental Lymphedema Model: Reevaluating the Efficacy of Rat Models and Their Clinical Translation for Chronic Lymphedema Studies

BACKGROUND

Our aim was to create a new rodent hind limb lymphedema model lacking the fibrosis effect induced by radiotherapy and subjected to the inhibition of lymphangiogenesis via sirolimus (rapamycin) to maintain a chronic lymphedema model and investigate its reliability for human treatment modalities.

METHODS

Forty-two Sprague-Dawley rats were randomly assigned to 7 groups: (1) surgery control, (2) vehicle-surgery control, (3) vehicle control, (4) rapamycin control, (5) surgery with 1 mg/kg per day rapamycin, (6) surgery with 1.5 mg/kg per day rapamycin, and (7) surgery with 2 mg/kg per day rapamycin. All surgeries were performed on the right hind limbs, with the left hind limbs also considered as a control. The drug and its solvent were administered daily into the relevant groups intraperiteonally. The presence of lymphedema was investigated by weekly limb circumference measurements, microcomputed tomography, fluorescence lymphography using indocyanine green dye, and microscopic evaluation at the end of the sixth week to determine any histological changes in the hind limbs.

RESULTS

In group 1, lymphedema was observed for 2 weeks (P = 0.032), whereas in groups 5, 6, and 7, lymphedema lasted for 3 weeks (P < 0.05.) Fluorescence using indocyanine green revealed that the edema was totally resolved after 6 weeks of surgery by a well-developed superficial lymphatic organization instead of the normal distinct vessel structure. Histologically, groups 1, 5, 5, and 7 demonstrated a significant increase in both the number of macrophages (P < 0.001) and newly formed lymphatic vessels in the right side surgically treated hind limb (P < 0.05).

CONCLUSIONS

Despite the extreme surgical destruction and lymphangiogenesis inhibition in the rat model, the sustained lymphedema did not last >3 weeks. Because of the rapid neolymphangiogenesis in murines and a different wound healing mechanism, they should not be considered as an appropriate model for research on human lymphedema in first place.

Surgical treatment of carpal tunnel syndrome in advanced-stage upper extremity lymphedema: A case report

RATIONALE

Despite significant advances in microsurgical techniques, simultaneous release of transverse carpal ligament (TCL) and lymphovenous anastomosis (LVA) surgeries may be effective for treatment of carpal tunnel syndrome (CTS) and advanced-stage lymphedema. This case report describes the successful treatment of lymphedema with LVA in a patient with CTS and advanced-stage lymphedema.

PATIENT CONCERNS

A 60-year-old female patient was referred to our lymphedema clinic with a 12-year history of chronic, acquired, right upper extremity lymphedema and CTS following right mastectomy and axillary lymph node dissection and adjuvant chemoradiotherapy for treating breast cancer.

DIAGNOSIS

According to the indocyanine green lymphography, magnetic resonance lymphangiography, and electromyography, the patient was diagnosed with CTS and advanced-stage lymphedema (International Society of Lymphology late stage 2).

INTERVENTION

Release of the TCL was performed first, followed by LVA at the wrist, forearm, and antecubital area. The right arm was compressed and elevated immediately postoperatively and postoperative compression bandage therapy with 35 to 40 mm Hg pressure was instituted following surgery.

OUTCOMES

After 2 simultaneous surgeries, the patient had significant circumference and volume reduction of the right hand. The CTS and lymphedema symptoms have decreased following synchronous TCL release and LVA surgeries.

LESSONS

Simultaneous LVA and release of the TCL may be effective and safe in patients with advanced lymphedema and CTS.

Surgical Lymphoedema Treatment of Morbihan Disease: A Case Report

ABSTRACT

Morbihan disease is a rare condition characterized by persistent erythema and solid edema of the upper two thirds of the face, leading to visual impairment and significant esthetic disfigurement. The underlying etiology of the disease remains uncertain, but its correlation with lymphoedema has been conjectured. Definitive treatment options are also lacking, and most current topical, systemic, and surgical interventions provide transient or partial results.In this report, we describe a case of Morbihan disease in a 32-year-old man. He suffered from erythema and swelling over the left periorbital region for 6 years, and was diagnosed with Morbihan disease. As the edema was unresponsive to drug therapy, he was referred to our department. Indocyanine green lymphography was performed, and the diagnosis of facial lymphoedema was confirmed. Manual lymphatic drainage was not effective, so we proceeded with surgical procedures. Lymphaticovenous anastomosis was performed to improve lymphatic drainage, and blepharoplasty was performed to debulk the enlarged tissue of lymphoedema. The visual field improved significantly, and the patient remains free from reexpansion of the lesion during the 1-year follow-up.The surgical approach for lymphoedema treatment can be a viable option for severe Morbihan disease unresponsive to nonsurgical therapies.

Radiological management of postoperative lymphorrhea

PURPOSE

Postoperative lymphorrhea can occur after different surgical procedures and may prolong the hospital stay due to the need for specific treatment. In this work, the therapeutic significance of the radiological management of postoperative lymphorrhea was assessed and illustrated.

METHOD

A standardized search of the literature was performed in PubMed applying the Medical Subject Headings (MeSH) term "lymphangiography." For the review, the inclusion criterion was "studies with original data on Lipiodol-based Conventional Lymphangiography (CL) with subsequent Percutaneous Lymphatic Intervention (PLI)." Different exclusion criteria were defined (e.g., studies with <15 patients). The collected data comprised of clinical background and indications, procedural aspects and types of PLI, and outcomes. In the form of a pictorial essay, each author illustrated a clinical case with CL and/or PLI.

RESULTS

Seven studies (corresponding to evidence level 4 [Oxford Centre for Evidence-Based Medicine]) accounting for 196 patients were included in the synthesis and analysis of data. Preceding surgery resulting in postoperative lymphorrhea included different surgical procedures such as extended oncologic surgery or vascular surgery. Central (e.g., chylothorax) and peripheral (e.g., lymphocele) types of postoperative lymphorrhea with a drainage volume of 100-4000 ml/day underwent CL with subsequent PLI. The intervals between "preceding surgery and CL" and between "CL and PLI" were 2-330 days and 0-5 days, respectively. CL was performed before PLI to visualize the lymphatic pathology (e.g., leakage point or inflow lymph ducts), applying fluoroscopy, radiography, and/or computed tomography (CT). In total, seven different types of PLI were identified: (1) thoracic duct (or thoracic inflow lymph duct) embolization, (2) thoracic duct (or thoracic inflow lymph duct) maceration, (3) leakage point direct embolization, (4) inflow lymph node interstitial embolization, (5) inflow lymph duct (other than thoracic) embolization, (6) inflow lymph duct (other than thoracic) maceration, and (7) transvenous retrograde lymph duct embolization. CL-associated and PLI-associated technical success rates were 97-100% and 89-100%, respectively. The clinical success rate of CL and PLI was 73-95%. CL-associated and PLI-associated major complication rates were 0-3% and 0-5%, respectively. The combined CL- and PLI-associated 30-day mortality rate was 0%, and the overall mortality rate was 3% (corresponding to six patients). In the pictorial essay, the spectrum of CL and/or PLI was illustrated.

CONCLUSION

The radiological management of postoperative lymphorrhea is feasible, safe, and effective. Standardized radiological treatments embedded in an interdisciplinary concept are a step towards improving outcomes.

Lymphatic Interventional Treatment for Chyluria via Retrograde Thoracic Duct Access

Chyluria is the leakage of intestinal lymph (chyle) into the urine. Novel lymphatic intervention techniques, such as interstitial lymphatic embolization, proved to be a useful treatment option for chyluria. However, one of the challenges of this approach is the difficulty in identifying connections between the lymphatic system and kidney collecting system. Here, embolization of the abnormal lymphatic connection through retrograde thoracic duct access in 3 chyluria patients is introduced.

Lymphatic pathway evaluation in congenital heart disease using 3D whole-heart balanced steady state free precession and T2-weighted cardiovascular magnetic resonance

BACKGROUND

Due to passive blood flow in palliated single ventricle, central venous pressure increases chronically, ultimately impeding lymphatic drainage. Early visualization and treatment of these malformations is essential to reduce morbidity and mortality. Cardiovascular magnetic resonance (CMR) T2-weighted lymphangiography (T2w) is used for lymphatic assessment, but its low signal-to-noise ratio may result in incomplete visualization of thoracic duct pathway. 3D-balanced steady state free precession (3D-bSSFP) is commonly used to assess congenital cardiac disease anatomy. Here, we aimed to improve diagnostic imaging of thoracic duct pathway using 3D-bSSFP.

METHODS

Patients underwent CMR during single ventricle or central lymphatic system assessment using T2w and 3D-bSSFP. T2w parameters included 3D-turbo spin echo (TSE), TE/TR = 600/2500 ms, resolution = 1 × 1 × 1.8 mm, respiratory triggering with bellows. 3D-bSSFP parameters included electrocardiogram triggering and diaphragm navigator, 1.6 mm isotropic resolution, TE/TR = 1.8/3.6 ms. Thoracic duct was identified independently in T2w and 3D-bSSFP images, tracked completely from cisterna chyli to its drainage site, and classified based on severity of lymphatic abnormalities.

RESULTS

Forty-eight patients underwent CMR, 46 of whom were included in the study. Forty-five had congenital heart disease with single ventricle physiology. Median age at CMR was 4.3 year (range 0.9-35.1 year, IQR 2.4 year), and median weight was 14.4 kg (range, 7.9-112.9 kg, IQR 5.2 kg). Single ventricle with right dominant ventricle was noted in 31 patients. Thirty-eight patients (84%) were status post bidirectional Glenn and 7 (16%) were status post Fontan anastomosis. Thoracic duct visualization was achieved in 45 patients by T2w and 3D-bSSFP. Complete tracking to drainage site was attained in 11 patients (24%) by T2w vs 25 (54%) by 3D-bSSFP and in 28 (61%) by both. Classification of lymphatics was performed in 31 patients.

CONCLUSION

Thoracic duct pathway can be visualized by 3D-bSSFP combined with T2w lymphangiography. Cardiac triggering and respiratory navigation likely help retain lymphatic signal in the retrocardiac area by 3D-bSSFP. Visualizing lymphatic system leaks is challenging on 3D-bSSFP images alone, but 3D-bSSFP offers good visualization of duct anatomy and landmark structures to help plan interventions. Together, these sequences can define abnormal lymphatic pathway following single ventricle palliative surgery, thus guiding lymphatic interventional procedures.

[Successful treatment of refractory chylothorax associated with diffuse large B-cell lymphoma by multidisciplinary care]

Chylothorax is an intrathoracic leakage of chyle due to thoracic duct damage. Malignant lymphoma is the most common nontraumatic cause of chylothorax. In March 2019, a 74-year-old woman presented to our department with bilateral pleural effusion and mesenteric/retroperitoneal masses. She was diagnosed with diffuse large B-cell lymphoma upon performing a biopsy. In May 2019, she was hospitalized for dyspnea due to pleural effusion, and thoracentesis revealed abundant chyle. Although the tumor shrunk after chemotherapy, chylothorax improvement was poor; thus, she could not be discharged. For the management of refractory chylothorax, lymphangiography, thoracic duct embolization, and pleurodesis were performed, and the chylothorax improved immediately. However, in May 2020, right chylothorax recurred without a relapse of malignant lymphoma, which did not improve with conservative treatment. Lymphangiography was performed again; however, treatment via the lymphatic vessels was difficult. Thus, pleurodesis was performed four times, after which the chylothorax regressed. Chylothorax is often refractory. When chemotherapy for malignant lymphoma does not improve chylothorax, multidisciplinary treatment is effective.

Comparison of indocyanine green fluorescence lymphangiography and magnetic resonance lymphangiography to investigate lymphedema of the extremities

PURPOSE

The aim of this study is to compare two dynamic imaging modalities employed to study peripheral lymphatic system, Magnetic Resonance Lymphangiography (MRL) and Indocyanine Green Lymphangiography (ICGL), evaluating their role for planning lymphaticovenular anastomosis (LVA) or other surgical-nonsurgical treatments in patients with lymphedema of the extremities.

MATERIALS AND METHODS

We conducted a retrospective study of 32 patients (26 women) with a mean age of 38 years (range 18-73) enrolled from January 2014 to December 2018; 20 out of 32 were affected by lower limb lymphedema with 6 cases of primary lymphedema; all of them had stage II disease. All the patient underwent ICGL and MRL within a month of one another, by injecting different contrast medium into interdigital web spaces. In each patient we rated the number of lymphatic vessels visualized, considering the wrist for the upper limb and the ankle for the lower limb. Student's t-test was applied.

RESULTS

All patients completed both the diagnostic examinations without any significant complications. A statistically significant difference (p < 0.05) was found between the number of lymphatic vessels identified on the wrist/ankle (34 on ICGL vs 70 on MRL and 82 on ICGL vs 26 on MRL, considering affected and healthy limbs respectively). In particular, dermal backflow in advanced lymphedema seems to hinder lymphatic vessels detection on ICGL. Conversely, on healthy limbs, MRL hardly identifies lymphatics, because of their fast lymphatic flow and almost virtual lumen.

CONCLUSIONS

Both MRL and ICGL are dynamic diagnostic modalities that permit an effective evaluation of lymphatic vessels anatomical and functional status in extremities lymphedema these diagnostic procedures may be considered complementary because they show different aspects of lymphatic system.

KEY WORDS

Indocyanine green, MR lymphangiography.

Imaging of fetal lymphangiectasias: prenatal and postnatal imaging findings

Lymphangiectasias are lymphatic malformations characterized by the abnormal dilation and morphology of the lymphatic channels. The classification and treatment of these disorders can be challenging given the limited amount of literature available in children. Various imaging modalities are used to confirm suspected diagnosis, plan the most appropriate treatment, and estimate a prognosis. Prenatal evaluation is performed using both prenatal US imaging and fetal MRI. These modalities are paramount for appropriate parental counseling and planning of perinatal care. During the neonatal period, chest US imaging is a useful modality to evaluate pulmonary lymphangiectasia because other modalities such as conventional radiography and CT display nonspecific findings. Finally, the recent breakthroughs in lymphatic imaging with MRI have allowed us to better classify lymphatic disorders. Dynamic contrast-enhanced lymphangiography, conventional lymphangiography and percutaneous lymphatic procedures offer static and dynamic evaluation of the central conducting lymphatics in children, with excellent spatial resolution and the possibility to provide treatment. The purpose of this review is to discuss the normal and abnormal development of the fetal lymphatic system and how to best depict it by imaging during the prenatal and postnatal life.

Embolization or disruption of thoracic duct and cisterna chyli leaks post oesophageal cancer surgery should be first line management for ECCG-defined type III chyle fistulae

Chyle leakage from the thoracic duct or cisterna chyli is a relatively rare complication of oesophageal cancer surgery. The majority of cases settle with conservative measures, but high volume leaks may be refractory and result in significant morbidity and require intervention with reoperation or embolization. In the experience of this high-volume centre over the last decade, 3 (0.5%) patients required reoperation and ligation of the thoracic duct; for the so-called type III leaks, interventional radiological approaches were not considered. This article is built around two recent cases, where interventional radiology to embolize and disrupt complex fistulae was successfully performed. The lessons from this experience will change practice at this centre to initial lymphangiography with a view to embolization or disruption of thoracic duct and cisterna chyli leaks as first line therapy for type III chyle leaks, with surgery reserved for where this fails.