In Vivo Dynamic and Static Analysis of Lymphatic Dysfunction in Lymphedema Using Near-Infrared Fluorescence Indocyanine Green Lymphangiography.

BACKGROUND: Near-infrared fluorescence indocyanine green lymphangiography, a primary modality for detecting lymphedema, which is a disease due to lymphatic obstruction, enables real-time observations of lymphatics and reveals not only the spatial distribution of drainage (static analysis) but also information on the lymphatic contraction (dynamic analysis). METHODS: We have produced total lymphatic obstruction in the upper limbs of 18 Sprague-Dawley rats through the dissection of proximal (brachial and axillary) lymph nodes and 20-Gy radiation (dissection limbs). After the model formation for 1 week, 9 animal models were observed for 6 weeks using near-infrared fluorescence indocyanine green lymphangiography by injecting 6-µL ICG-BSA (indocyanine green-bovine serum albumin) solution of 20-µg/mL concentration. The drainage pattern and leakage of lymph fluid were evaluated and time-domain signals of lymphatic contraction were observed in the distal lymphatic vessels. The obtained signals were converted to frequency-domain spectrums using signal processing. RESULTS: The results of both static and dynamic analyses proved to be effective in accurately identifying the extent of lymphatic disruption in the dissection limbs. The static analysis showed abnormal drainage patterns and increased leakage of lymph fluid to the periphery of the vessels compared with the control (normal) limbs. Meanwhile, the waveforms were changed and the contractile signal frequency increased by 58% in the dynamic analysis. Specifically, our findings revealed that regular lymphatic contractions, observed at a frequency range of 0.08 to 0.13 Hz in the control limbs, were absent in the dissection limbs. The contractile regularity was not fully restored for the follow-up period, indicating a persistent lymphatic obstruction. CONCLUSIONS: The dynamic analysis could detect the abnormalities of lymphatic circulation by observing the characteristics of signals, and it provided additional evaluation indicators that cannot be provided by the static analysis. Our findings may be useful for the early detection of the circulation problem as a functional evaluation indicator of the lymphatic system.

Superior lymph node harvest by fluorescent lymphography during minimally invasive gastrectomy for gastric cancer patients with high body mass index.

BACKGROUND: Fluorescent lymphography (FL) using indocyanine green (ICG) allows for the visualization of all draining lymph nodes (LNs), thereby increasing LN retrieval. However, no studies have assessed the efficacy of FL in high body mass index (BMI) gastric cancer patients, even as LN yield decreases with increasing BMI in gastrectomy. This study aimed to investigate the influence of FL on LN retrieval in high BMI gastric cancer patients. METHODS: Gastric cancer patients who underwent laparoscopic or robotic gastrectomies from 2013 to 2021 were included. Patients were classified into two groups, with FL (FL group) or without FL (non-FL group). The effect of FL on LN retrieval was assessed by BMI. Inverse probability of treatment weighting (IPTW) was used to ensure comparability between groups. RESULTS: Retrieved LN number decreased as BMI increased regardless of FL application (P < 0.001). According to the IPTW analysis, the mean retrieved LN number was significantly higher in the FL group (48.4 ± 18.5) than in the non-FL group (39.8 ± 16.3, P < 0.001), irrespective of BMI. The FL group exhibited a significantly higher proportion of patients with 16 or more LNs (99.5%) than the non-FL group (98.1%, P < 0.001). The FL group also had a significantly higher proportion of patients with 30 or more LNs (86.6%) than the non-FL group (72.2%, P < 0.001). In both the normal and high-BMI patients, the FL group had a significantly larger percentage of patients with a higher nodal classification than the non-FL group. CONCLUSION: FL resulted in more LN retrieval, even in high BMI patients. FL ensures accurate staging by maintaining the appropriate retrieved LN number in high BMI gastric cancer patients.

Qualitative use of ICG angiography and lymphography in periorbital surgery.

PURPOSE: Open imaging fluorescence devices have been utilized in surgical oncology, vascular and plastic surgery; however, the role of indocyanine green (ICG) in periorbital surgery and lymphatics has not been explored. METHODS: A prospective, single-center diagnostic study was conducted from 2021 to 2022 utilizing ICG to assess both the periorbital vasculature and lymphatics. Fluorescence was captured with open-imaging fluorescent devices. For ICG angiography, a total of 5-10 mg of ICG was given intravenously at various time points to visualize intraoperative blood flow to eyelid flaps, vascular tumors, or extraocular muscles. For ICG lymphography, 0.03-0.06 mg of ICG was injected subcutaneously to visualize the periorbital and facial lymphatic drainage. RESULTS: Twenty-two patients underwent ICG angiography. Periorbital vascular supply was seen in eyelid reconstructions (n = 8), anophthalmic reconstructions (n = 2), lacrimal gland tumors (n = 2), orbital venous malformations (n = 2), tumor metastasis (n = 1) and benign tumors (n = 1). The anterior ciliary arteries were visualized to the extraocular muscles in fracture repairs (n = 3) and muscle biopsies (n = 2). Ten patients underwent ICG lymphangiography highlighting the global periorbital lymphatic system. CONCLUSION: ICG allows for visualization of the vasculature of extraocular muscles and tumors, assessing perfusion of flaps during reconstruction and the global periorbital lymphatic drainage pathways.

Intranodal embolization for lymphocele after revascularization procedure in the groin.

Early postoperative wound complications in revascularization procedures in the groin very often include complications associated with injury to the lymphatic system such as lymphocele and lymphorrhea with subsequent local infectious complications and the risk of infection of prosthetic grafts. We present a case report of successful treatment of postoperative lymphocele with subsequent lymphatic fistula and dehiscence of the surgical wound by intranodal embolization of the injured lymph node with Histoacryl tissue glue.

[Fluorescence lymphography for sentinal lymph node biopsy in breast cancer]. / Sobstvennyi opyt primeneniya flyuorestsentnoi limfografii dlya biopsii signal'nykh limfouzlov pri rake molochnoi zhelezy.

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.

[Fluorescence navigation and angiography with indocyanine green in stomach cancer surgery]. / Flyuorestsentnaya navigatsiya i angiografiya indotsianinom zelenym v khirurgii raka zheludka.

OBJECTIVE: To evaluate the effectiveness of intraoperative angiography and fluorescence navigation with indocyanine green in reducing the risks of intra- and postoperative complications, as well as resection quality in patients with gastric cancer. MATERIAL AND METHODS: The main group consisted of patients who underwent intraoperative angiography and fluorescence navigation with indocyanine green (n=43). The control group included patients without these procedures (n=154). Both groups did not differ in gender (p=0.937) and age (p=0.437). The lower third of the stomach was the most common tumor location in the main group (62.7% of cases), the middle and lower thirds of the stomach - in the control group (37% and 38.9% of patients, respectively). There was no between-group difference in «cT¼ grading (p>0.05). However, there were more «cN+¼ patients in the main group (14 (32.6%) versus 28 (18.4%) ones of «N0¼ category, p=0.042). Therefore, 41.9% and 13.6% of patients underwent neoadjuvant chemotherapy in both groups, respectively (<0.001). RESULTS: Intraoperative angiography and fluorescence navigation with indocyanine green does not increase mortality (p=0.631), incidence of major (CD 3-5) (p=0.436) and minor (CD 1-2) postoperative complications (p=0.177), surgery time (p=0.288), mean intraoperative blood loss (p=0.144) and length of hospital-stay (p=0.631). Fluorescence navigation with indocyanine green does not affect the number of detected «positive¼ resection margins (R1) (p=0.883) but significantly increases the number of excised lymph nodes (p<0.001). CONCLUSION: Intraoperative angiography and fluorescence navigation with indocyanine green are safe for intraoperative visualization of tumor and lymph nodes, as well as assessment of arterial blood supply. This technique is effective in traditional and minimally invasive surgeries for gastric cancer. Fluorescence navigation with indocyanine green significantly increases the number of excised lymph nodes.

Superficial and functional imaging of the tricipital lymphatic pathway: a modern reintroduction.

PURPOSE: The tricipital, or Caplan's, lymphatic pathway has been previously identified in cadavers and described as a potential compensatory pathway for lymphatic drainage of the upper extremity, as it may drain lymphatic fluid directly to the scapular lymph nodes, avoiding the axillary lymph node groups. The aim of this study was to map the anatomy of the tricipital pathway in vivo in patients without lymphatic disease. METHODS: A retrospective review was performed to identify patients with unilateral breast cancer undergoing preoperative Indocyanine green (ICG) lymphography prior to axillary lymph node dissection from May 2021 through January 2022. Exclusion criteria were evidence or known history of upper extremity lymphedema or non-linear channels visualized on ICG. Demographic, oncologic, and ICG imaging data were extracted from a Lymphatic Surgery Database. The primary outcome of this study was the presence and absence of the tricipital pathway. The secondary outcome was major anatomical variations among those with a tricipital pathway. RESULTS: Thirty patients underwent preoperative ICG lymphography in the study period. The tricipital pathway was visualized in the posterior upper arm in 90% of patients. In 63% of patients, the pathway had a functional connection to the forearm (long bundle variant) and in 27%, the pathway was isolated to the upper arm without a connection to the forearm (short bundle variant). In those with a long bundle, the contribution was predominantly from the posterior ulnar lymphosome. Anatomic destinations of the tricipital pathway included the deltotricipital groove and the medial upper arm channel, which drains to the axilla. CONCLUSION: When present, the tricipital pathway coursed along the posterior upper arm with variability in its connections to the forearm distally, and the torso proximally. Long-term follow-up studies will help determine the significance of these anatomic variations in terms of individual risk of lymphedema after axillary nodal dissection.

Transvenous retrograde thoracic duct embolization for effective treatment of recurrent plastic bronchitis after fontan palliation.

We report the case of a 5.5-year-old patient (16 kg/105 cm) who presented with plastic bronchitis (PB) refractory to conservative treatment 3 months after completion of Fontan palliation. Bi-inguinal transnodal fluoroscopy-guided lymphangiogram confirmed the chylous leak originating from the thoracic duct (TD) into the chest and did not opacify any central lymphatic vessel for direct transabdominal puncture. Retrograde transfemoral approach was adopted to catheterize the TD and selectively embolize its caudal portion using microcoils and liquid embolic adhesive. Recurrence of symptoms after 2 months indicated a redo catheterization to occlude the TD entirely using the same technique. The procedure was successful and the patient was discharged after 2 days with sustained clinical improvement at 24 months postoperative. In the context of refractory PB, end-to-end transvenous retrograde embolization of the TD appears to be an interesting alternative to more complex interventions such as transabdominal puncture, decompression, or surgical ligation of the TD.

Feasibility study of direct CT lymphangiography in mice: comparison with interstitial CT/MR lymphangiography.

OBJECTIVES: To establish a CT lymphangiography method in mice via direct lymph node puncture. METHODS: We injected healthy mice (n = 8) with 50 µl of water-soluble iodine contrast agent (iomeprol; iodine concentration, 350 mg/mL) subcutaneously into the left-rear foot pad (interstitial injection) and 20 µl of the same contrast agent directly into the popliteal lymph node (direct puncture) 2 days later. Additionally, we performed interstitial MR lymphangiography on eight mice as a control group. We calculated the contrast ratio for each lymph node and visually assessed the depiction of lymph nodes and lymphatic vessels on a three-point scale. RESULTS: The contrast ratios of 2-min post-injection images of sacral and lumbar-aortic lymph nodes were 20.7 ± 16.6 (average ± standard deviation) and 17.1 ± 12.0 in the direct puncture group, which were significantly higher than those detected in the CT or MR interstitial lymphangiography groups (average, 1.8-3.6; p = 0.008-0.019). The visual assessment scores for sacral lymph nodes, lumbar-aortic lymph nodes, and cisterna chyli were significantly better in the direct puncture group than in the CT interstitial injection group (p = 0.036, 0.009 and 0.001, respectively). The lymphatic vessels between these structures were significantly better scored in direct puncture group than in the CT or MR interstitial lymphangiography groups at 2 min after injection (all p ≤ 0.05). CONCLUSIONS: In CT lymphangiography in mice, the direct lymph node puncture provides a better delineation of the lymphatic pathways than the CT/MR interstitial injection method. KEY POINTS: • The contrast ratios of 2-min post-injection images in the direct CT lymphangiography group were significantly higher than those of CT/MR interstitial lymphangiography groups. • The visibility of lymphatic vessels in subjective analysis in the direct CT lymphangiography group was significantly better in the direct puncture group than in the CT/MR interstitial lymphangiography groups. • CT lymphangiography with direct lymph node puncture can provide excellent lymphatic delineation with contrast being maximum at 2 min after injection.

Intranodal dynamic contrast-enhanced CT lymphangiography and dynamic contrast-enhanced MR lymphangiography in microminipig.

OBJECTIVES: To evaluate the feasibility and image quality of intranodal dynamic contrast-enhanced CT lymphangiography (DCCTL) and dynamic contrast-enhanced MR lymphangiography (DCMRL) in microminipigs. METHODS: Our institution's committee for animal research and welfare provided approval. Three microminipigs underwent DCCTL and DCMRL after inguinal lymph node injection of 0.1 mL/kg contrast media. Mean CT values on DCCTL and signal intensity (SI) on DCMRL were measured at the venous angle and thoracic duct (TD). The contrast enhancement index (CEI; increase in CT values pre- to post-contrast) and signal intensity ratio (SIR; SI of lymph divided by SI of muscle) were evaluated. The morphologic legibility, visibility, and continuity of lymphatics were qualitatively evaluated using a 4-point scale. Two microminipigs underwent DCCTL and DCMRL after lymphatic disruption and the detectability of lymphatic leakage was evaluated. RESULTS: The CEI peaked at 5-10 min in all microminipigs. The SIR peaked at 2-4 min in two microminipigs and at 4-10 min in one microminipig. The peak CEI and SIR values were 235.6 HU and 4.8 for venous angle, 239.4 HU and 2.1 for upper TD, and 387.3 HU and 2.1 for middle TD. The visibility and continuity of upper-middle TD scores were 4.0 and 3.3-3.7 for DCCTL, and 4.0 and 4.0 for DCMRL. In the injured lymphatic model, both DCCTL and DCMRL demonstrated lymphatic leakage. CONCLUSIONS: DCCTL and DCMRL in a microminipig model enabled excellent visualization of central lymphatic ducts and lymphatic leakage, indicating the research and clinical potential of both modalities. KEY POINTS: • Intranodal dynamic contrast-enhanced computed tomography lymphangiography showed a contrast enhancement peak at 5-10 min in all microminipigs. • Intranodal dynamic contrast-enhanced magnetic resonance lymphangiography showed a contrast enhancement peak at 2-4 min in two microminipigs and at 4-10 min in one microminipig. • Both intranodal dynamic contrast-enhanced computed tomography lymphangiography and dynamic contrast-enhanced magnetic resonance lymphangiography demonstrated the central lymphatic ducts and lymphatic leakage.

Deep learning for standardized, MRI-based quantification of subcutaneous and subfascial tissue volume for patients with lipedema and lymphedema.

OBJECTIVES: To contribute to a more in-depth assessment of shape, volume, and asymmetry of the lower extremities in patients with lipedema or lymphedema utilizing volume information from MR imaging. METHODS: A deep learning (DL) pipeline was developed including (i) localization of anatomical landmarks (femoral heads, symphysis, knees, ankles) and (ii) quality-assured tissue segmentation to enable standardized quantification of subcutaneous (SCT) and subfascial tissue (SFT) volumes. The retrospectively derived dataset for method development consisted of 45 patients (42 female, 44.2 ± 14.8 years) who underwent clinical 3D DIXON MR-lymphangiography examinations of the lower extremities. Five-fold cross-validated training was performed on 16,573 axial slices from 40 patients and testing on 2187 axial slices from 5 patients. For landmark detection, two EfficientNet-B1 convolutional neural networks (CNNs) were applied in an ensemble. One determines the relative foot-head position of each axial slice with respect to the landmarks by regression, the other identifies all landmarks in coronal reconstructed slices using keypoint detection. After landmark detection, segmentation of SCT and SFT was performed on axial slices employing a U-Net architecture with EfficientNet-B1 as encoder. Finally, the determined landmarks were used for standardized analysis and visualization of tissue volume, distribution, and symmetry, independent of leg length, slice thickness, and patient position. RESULTS: Excellent test results were observed for landmark detection (z-deviation = 4.5 ± 3.1 mm) and segmentation (Dice score: SCT = 0.989 ± 0.004, SFT = 0.994 ± 0.002). CONCLUSIONS: The proposed DL pipeline allows for standardized analysis of tissue volume and distribution and may assist in diagnosis of lipedema and lymphedema or monitoring of conservative and surgical treatments. KEY POINTS: • Efficient use of volume information that MRI inherently provides can be extracted automatically by deep learning and enables in-depth assessment of tissue volumes in lipedema and lymphedema. • The deep learning pipeline consisting of body part regression, keypoint detection, and quality-assured tissue segmentation provides detailed information about the volume, distribution, and asymmetry of lower extremity tissues, independent of leg length, slice thickness, and patient position.

Evaluation of the Superficial Collecting Lymph Vessels' Vasa Vasorum in Lymphoedematous Limbs Using Video Capillaroscopy.

OBJECTIVE: The pre-collecting and collecting lymph vessels have smooth muscle cells, and sufficient perfusion is vital to maintain their function. Although the vasa vasorum of the collecting lymph vessels (VVCL) have been histologically investigated, little is known about their physiology. This study aimed to investigate the relationship between morphology and blood flow of the VVCL in lymphoedematous limbs. METHODS: Medical records of lower extremity lymphoedema patients who underwent video capillaroscopy observation during supermicrosurgical lymphaticovenous anastomosis (LVA) surgery were reviewed. The collecting lymph vessels, dissected for LVA, were examined under video capillaroscopy (GOKO Bscan-ZD, GOKO Imaging Devices Co., Japan) with a magnification of 175x and 620x. Blood flow velocity of the VVCL was calculated by measuring the red blood cell movement using software (GOKO-VIP ver. 1.0.0.4, GOKO Imaging Devices Co., Japan). Based on the video capillaroscopy findings, the VVCL were grouped according to their morphology; the VVCL morphology types and blood flow velocity were then compared according to the lymphosclerosis severity grade. RESULTS: Sixty-seven lymph vessels in 20 lower extremity lymphoedema patients were evaluated, including s0 in 19 (28.4%), s1 in 34 (50.7%), s2 in 10 (14.9%), and s3 in four (6.0%) lymph vessels. The VVCLs were grouped into four types: type 1 (n = 4), type 2 (n = 37), type 3 (n = 19), and type 4 (n = 7). Blood flow velocity of the VVCL ranged 0 - 189.3 µm/sec (average 26.40 µm/sec). There were statistically significant differences in VVCL morphology (p < .001) and blood flow velocity (p < .001) according to lymphosclerotic severity. CONCLUSION: Vasa vasorum of the collecting lymph vessels could be grouped into four types with different characteristics. Morphological and physiological changes of the VVCL were related to sclerotic changes of the collecting lymph vessels.

Intraoperative near-infrared lymphography with indocyanine green may aid lymph node dissection during robot-assisted resection of gastroesophageal junction cancer.

BACKGROUND: Adequate lymphadenectomy during gastroesophageal junction (GEJ) cancer resection is essential, because lymph node (LN) metastasis correlates with increased recurrence risk. Fluorescence lymphography with indocyanine green (ICG) has been used for LN mapping in several surgical specialties; however, reports on GEJ cancer are lacking. Therefore, we investigated whether intraoperative ICG lymphography could facilitate LN harvest during robot-assisted resection of GEJ cancer. METHODS: Patients scheduled for robot-assisted resection of GEJ cancer were included, and outcomes were compared with historical controls. After intraoperative endoscopic submucosal ICG injection, standard D1 + LN dissection was performed under white light. Then, near-infrared (NIR) fluorescence imaging was activated, and each LN dissection area was re-examined. Any tissue within the D1 + field exhibiting distinctly increased ICG fluorescence compared with background tissue was dissected and sent for pathology review. RESULTS: We included 70 patients between June 2020 and October 2021. Three cases were aborted due to disseminated disease, and two were converted to open resection and excluded from the analysis. Additional tissue was dissected after NIR review in 34 of 65 (52%) patients. We dissected 43 fluorescent tissue samples, and after pathology review, 30 were confirmed LNs; none were metastatic. The median number of LNs harvested per patient (34, interquartile range [IQR] = 26-44) was not significantly different from that harvested from historical controls (32, IQR = 24-45; p = 0.92), nor were there any differences between these two groups in the duration of surgery, intraoperative blood loss, or comprehensive complication scores (p = 0.12, p = 0.46, and p = 0.41, respectively). CONCLUSIONS: Intraoperative NIR lymphography with ICG may aid LN detection during robot-assisted resection of GEJ cancer without increasing surgical risk. Although NIR lymphography may facilitate LN dissection, none of the LN removed after the NIR review was metastatic. Hence, it remains uncertain whether NIR lymphography will improve oncological outcomes.

Impact of fluorescent thoracic duct lymphography via intranodal approach in minimal access esophageal cancer surgery.

PURPOSE: Chyle leak resulting from thoracic duct (TD) injury poses significant morbidity and mortality challenges. We assessed the feasibility of using near-infrared (NIR) indocyanine green (ICG) imaging for intraoperative fluorescence TD lymphography during minimal access esophagectomy (MAE) in a semiprone position with inguinal nodal injection of ICG dye. METHODS: Ninety-nine patients with esophageal or gastroesophageal junctional cancer undergoing MAE received inguinal node injections of 2.5 mg ICG dye (total 5 mg) under sonographic guidance during anesthesia induction. Stryker's 1688 AIM HD system was used in 76 cases, Karl Storz OPAL 1 S in 20, and in three cases the Karl Storz Rubina. RESULTS: In 93 patients (94%), the TD was clearly delineated along its entire length; it was not visualized in 6 patients (6%). Fluorescence guidance facilitated TD ligation in 16 cases, while 3 cases required clipping of duct tributaries for oncological considerations. Twenty-eight patients exhibited minor duct variations. Fluorescence was sustained throughout surgery (median observation time 60 min post-injection; range 30-330). No patient experienced any chyle leak within 30 days post-surgery and no adverse reactions to ICG was evident. CONCLUSIONS: Intraoperative fluorescence TD lymphography using ICG during MAE in a semiprone position with inguinal nodal injection proved safe, feasible, and effective, allowing clear visualization of the TD in almost all cases. This approach aids safe ligation and reduces chyle leak risk. It offers real-time imaging of TD anatomy and variations, providing valuable feedback to surgeons for managing TD injuries during MAE procedures and represents an excellent educational tool.

Feasibility of contrast-enhanced ultrasound in confirming intranodal needle position for dynamic contrast-enhanced magnetic resonance lymphangiography in children.

This report demonstrates the feasibility and safety of using contrast-enhanced ultrasound (CEUS) to confirm intranodal needle position in children requiring dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL). A total of 7 patients were evaluated using CEUS after nodal puncture on a detachable magenetic resonance table, with 2 nodes cannulated in each patient, resulting in a combined evaluation of 14 nodes. The nodal cannulation success rate using CEUS was 85.7% (12/14 nodes). DCMRL was performed successfully in all patients with good contrast opacification of the central conducting lymphatics. Out of the 14 nodes, 2 nodes in the same patient demonstrated persistent extravasation on CEUS despite needle readjustment, requiring conversion to fluoroscopic lymphangiography. No adverse event related to the injection technique or CEUS was reported.

Therapeutic effect of lymphography in the postoperative chylothorax - case reports and literature review.

Postoperative chylothorax is a well-known rare complication of thoracic surgery. It is a serious complication that is fatal in cases of inadequate treatment. The authors present 2 cases of postoperative chylothorax that were successfully treated by performing pedal and/or intranodal lymphography. In one case, the patient underwent lymphography after previous unsuccessful surgical ligation of the thoracic duct. The presented case reports describe therapeutic importance of conventional lymphography as a minimally invasive treatment of the postoperative chylothorax.

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

OBJECTIVE: Lipedema is a chronic and progressive disease associated with lymphatic impairment at later stages. The aim of our study was to describe the functional status and anatomy of lower limb superficial lymphatic system using indocyanine green (ICG) lymphography in patients with lipedema. METHODS: Following ICG injection at the dorsum of the foot, distance (cm) covered by the dye at 10 (T10') and 25 min (T25') was measured and normalized for limb length. If the dye did not reach the groin within 25 min, patients were classified as "drainage-needing" group (DNG). Values of fat and lean distribution assessed by dual-energy X-ray absorptiometry were extracted, and correlation analysis was performed. Furthermore, anatomical patterns of superficial lymphatics were assessed. RESULTS: Overall, 45 women were included, 25 (56%) of whom were classified as DNG. Symptoms duration was significantly associated with DNG status at multivariate analysis (odds ratio 1.07; 95% CI 1.01-1.14; p = 0.047). Moreover, Spearman's analysis showed a negative correlation between symptoms duration and T25' dye migration (r = -0.469; p = 0.037). Overall, no major anatomical lymphatic changes were found. CONCLUSIONS: Present study suggests that lymphatic functioning in patients with lipedema correlates with symptoms duration. Further research on larger cohorts should verify our findings and clarify their potential therapeutic implications. Overall, ICG lymphography may be promising technique to assess both lymphatic anatomy and functioning in patients with lipedema.

Liver lymphatic anatomy and role in systemic lymphatic disease.

OBJECTIVES: To characterize hepatic to systemic lymphatic connections in patients with systemic lymphatic disease using intra-hepatic lymphangiography and to compare outcomes after lymphatic intervention. METHODS: In this retrospective study, patients with intra-hepatic lymphangiography from May 2014 - April 2019 at our institution were included. Imaging review was performed and hepatic lymphatic connections and flow patterns were characterized. Clinical data were reviewed and comparisons between patients undergoing lymphatic intervention with or without abnormal hepatic lymphatics were performed. RESULTS: During the study period, 105 patients underwent intra-hepatic lymphangiography. Primary clinical presentation included ascites (19/105), chylothorax (27/105), plastic bronchitis (PB) (17/105), and protein losing enteropathy (PLE) (42/105). Five categories of hepatic lymphatic connections and flow patterns were identified (%): normal (25%, 26/105), hepatoperitoneal (12%, 13/105), hepatopulmonary (10.5%, 11/105), hepatomesenteric (7.5%, 8/105), and hepatoduodenal (41%, 43/105) with four patients having more than one abnormal pattern. A comparison between clinical presentation and imaging category revealed an increased likelihood of having ascites with hepatoperitoneal (p < .0001), chylothorax/PB with hepatopulmonary (p = .01), and PLE with hepatoduodenal (p < .001) connections. Seventy-six patients had a lymphatic intervention, 24% with normal, and 76% with abnormal liver lymphatics. There was no difference in length of hospital stay or mortality between the two groups, but there was a prolonged time to symptom resolution (p = .006) and persistent symptoms after 6 months (5% vs 44%, p = .002) in the group with abnormal liver lymphatics. CONCLUSION: We identified five liver lymphatic imaging categories with a substantial correlation to presenting lymphatic disease. Abnormal imaging patterns correlated with increased morbidity. Evaluation of liver lymphatics should be considered in patients with a systemic lymphatic disease if central lymphatic imaging is normal. KEY POINTS: • We identified five liver lymphatic imaging patterns: normal, hepatoperitoneal, hepatomesenteric, hepatopulmonary, and hepatoduodenal. • Imaging patterns were correlated with disease presentation (normal - chylothorax/PB, hepatoperitoneal - ascites/chylothorax, hepatopulmonary - chylothorax/PB, hepatoduodenal - PLE). • Abnormal imaging patterns correlated with increased morbidity.

Pragmatic role of noncontrast magnetic resonance lymphangiography in postoperative chylothorax or cervical chylous leakage as a diagnostic and preprocedural planning tool.

OBJECTIVES: To define the roles of noncontrast magnetic resonance lymphangiography (MRL) in the management of postoperative chylothorax or cervical chylous leakage. METHODS: A total of 50 consecutive patients underwent noncontrast MRL, intranodal lymphangiography, and thoracic duct embolization between May 2016 and April 2020. Their mean age was 62.6 years ± 10.3 (SD) years, and 35 of the participants were men. Conventional lymphangiographic images were sufficient in quality as a reference for the evaluation of diagnostic accuracy of leakage and location in 35 patients (70%) and for evaluation of anatomic details of the thoracic duct and jugulovenous junction in 34 patients (68%). RESULTS: MRL showed that the sensitivity, specificity, and positive and negative predictive values for leakage detection were 100%, 97.1%, 100%, and 100%, respectively, and the concordance rate was 97.14% (95% confidence interval [CI], 85.08-99.93%; p < .001). Leakage location was concordant between MRL and conventional lymphangiography in 27 patients (77.1%, 27/35). Regarding anatomical details of the thoracic duct, variation of the thoracic duct was missed in 11.7% of patients (4/34). The jugulovenous junction was observed in 91.1% (31/34), and its opening into the central vein was depicted in 76.4% (26/34). The concordance rate was between 76.47 and 91.18. CONCLUSIONS: Noncontrast MRL has a high sensitivity for the detection of postoperative thoracic and cervical chylous leakage but is suboptimal for the localization of the leak and depiction of anatomical details of the thoracic duct. This method is worthy of consideration as either a decision-making or planning tool for subsequent interventions. KEY POINTS: • Noncontrast MRL provides limited resolution images of CLS but has a high sensitivity for the detection of postoperative chylous leakage in the thoracic and neck regions. • Noncontrast MRL is suboptimal for depicting anatomic details in the thoracic duct and jugulovenous junction but can play a role as a decision-making and a planning tool for subsequent lymphatic interventions.

Fluorescent lymphography during minimally invasive total gastrectomy for gastric cancer: an effective technique for splenic hilar lymph node dissection.

BACKGROUND: Fluorescent lymphography is an excellent technique for complete lymph node dissection during minimally invasive surgery for gastric cancer. This study aimed to evaluate the role of fluorescent lymphography in splenic hilar lymph node dissection during minimally invasive total gastrectomy. METHODS: We retrospectively analyzed 168 gastric cancer patients who underwent minimally invasive total gastrectomy with D2 + No. 10 lymph node dissection from 2013 to 2018. Fluorescent lymphography was used whenever it is possible. However, when near-infrared imaging system and endoscopic indocyanine green injection were not available, we performed surgery without fluorescent lymphography. A total of 74 patients underwent surgery with fluorescent lymphography (FL group) and 94 underwent surgery without it (non-FL group). Perioperative and long-term outcomes including the number of retrieved lymph nodes at each nodal station were compared between groups. RESULTS: The median number of retrieved lymph nodes at the splenic hilum was larger in the FL group {2.5 [Interquartile range (IQR), 1-5]} than in the non-FL group [1 (IQR, 1-3); P = 0.012]. The negative predictive value of fluorescent lymphography for lymph node metastasis at the splenic hilum was 97.1%, although the sensitivity was 66.7%. The overall survival (FL: 96.9% vs. non-FL: 88.9%; P = 0.334) and relapse-free survival (FL: 90.5% vs. non-FL: 65.5%; P = 0.054) were higher in the FL group, although there were no statistical differences. However, among the patients without lymph node metastasis, the relapse-free survival was significantly higher in the FL group (100%) than in the non-FL group (67.1%; P = 0.017). CONCLUSIONS: Fluorescent lymphography is an effective tool for complete lymph node dissection at the splenic hilum. Moreover, it may help select patients who do not need splenic hilar lymph node dissection during a total gastrectomy.