Evaluating the clinical utility of radiological and lymphatic imaging in nontraumatic chylothorax
Ken Junyang Goh1,2
, Craig A. Mounsey1, Wui Mei Chew1, John Wrightson1, Najib M. Rahman1,3,4,5
Contributions: (I) Conception and design: KJ Goh, J Wrightson, NM Rahman; (II) Administrative support: All authors; (III) Provision of study materials or patients: J Wrightson, NM Rahman; (IV) Collection and assembly of data: KJ Goh, CA Mounsey, WM Chew; (V) Data analysis and interpretation: All authors; (VI) Manuscript writing: All authors; (VII) Final approval of manuscript: All authors.
Background: Nontraumatic chylothorax is an uncommon cause of pleural effusion and a challenge to manage. Several radiological tests have been recommended for evaluation of chylothorax, but there is little evidence to guide clinicians on the utility, yield and optimal order of these diagnostic modalities. We aimed to evaluate the clinical utility of radiological tests including computed tomography (CT), positron emission tomography-CT (PET-CT) and lymphatic imaging such as magnetic resonance (MR) lymphangiogram in the management of nontraumatic chylothorax.
Methods: A retrospective single-centre study of patients with nontraumatic chylothorax from January 2019 to December 2023. Radiological tests were classified based on their utility in supporting a specific diagnosis or guiding a diagnostic or therapeutic intervention.
Results: Twenty patients with a median age of 66 [interquartile range (IQR), 56–75] years were included. The median pleural fluid triglyceride level was 5.04 (IQR, 2.82–18.32) mmol/L. Malignancy accounted for the majority (40.0%) of causes, of which lymphoma was the most common. High output or persistent chyle leak requiring ≥2 therapeutic interventions were seen in 90% of patients, and 75% of patients had a large pleural effusion on ultrasonography (≥4 rib spaces). CT or PET-CT imaging was useful in 75% of patients, supporting a specific diagnosis in 8 (40.0%) patients and detecting abnormalities that guided tissue biopsy in 7 (35.0%) patients. Lymphatic imaging was performed in 12 (60.0%) patients, all of whom underwent MR lymphangiogram. An additional lymphoscintigraphy was performed in two patients and lymphangiography in one patient. Thoracic duct ligation was attempted in one patient after a small volume lymphatic leak was visualised on MR lymphangiogram. No significant abnormalities to direct lymphatic intervention were found on lymphatic imaging in the remaining 11 patients.
Conclusions: In most patients with nontraumatic chylothorax, CT imaging provides specific diagnostic value and guides further evaluation such as tissue biopsy. Larger prospective studies are required to evaluate the utility of routine lymphatic imaging.
Keywords: Computed tomography (CT); chylothorax; lymphangiogram
Received: 14 December 2024; Accepted: 12 March 2025; Published online: 06 May 2025.
doi: 10.21037/amj-24-159
Highlight box
Key findings
• In this retrospective cohort study of patients with nontraumatic chylothorax, computed tomography (CT) imaging provided specific diagnostic information, or was useful in guiding diagnostic interventions, in 75% (15/20) of patients. However, with lymphatic imaging, no significant diagnostic features or abnormalities to direct lymphatic intervention were seen in most (11/12 or 92%) patients.
What is known and what is new?
• While lymphatic imaging is a well recognised diagnostic modality for chylothorax, it is not widely available and requires expertise to perform. There is also little evidence to guide patient selection and the timing of lymphatic imaging.
• This is the first study to directly evaluate the utility of radiological and lymphatic imaging in nontraumatic chylothorax.
What is the implication, and what should change now?
• CT imaging provides valuable diagnostic information and is useful in guiding management of nontraumatic chylothorax. Larger prospectives studies are required to establish the utility of lymphatic imaging in these patients.
Introduction
Chylothorax is the accumulation of chyle in the pleural space and is a relatively uncommon but challenging cause of pleural effusion. It can be broadly classified into traumatic or nontraumatic, the latter being attributed to causes without iatrogenic (surgical) or traumatic injury to the thoracic duct. Nontraumatic chylothorax may occur due to a wide range of causes (1,2) and is generally associated with poorer outcomes, with persistent chyle leak or output occurring in 45–50% of cases despite a range of conservative, or invasive interventions (3,4). Successful thoracic duct embolization (TDE) or disruptions are significantly lower with nontraumatic chylothorax (5), and 1-year mortality rates of nontraumatic chylothorax approach 50% (4).
While the management of post-surgical and traumatic chylothorax has some degree of agreement, optimal management of nontraumatic chylothorax remains unclear, in part due to the wide spectrum of medical disorders associated with its development, the varying availability of local expertise and resources, and the lack of comparative trials given the uncommon occurrence of this condition (6) As a result, diagnostic and therapeutic strategies for nontraumatic chylothorax remain variable (7). Furthermore, little is known about the role of radiological and lymphatic imaging in narrowing the differential diagnoses of chylothorax, or guiding therapeutic lymphatic interventions (8). The two largest case series on chylothorax with 191 and 203 cases have minimal data on chylothorax management and their outcomes (1,2), and other smaller case series consist largely of traumatic chylothorax only. No studies have directly evaluated the clinical utility of radiological and lymphatic imaging. Expert opinion on the management of chylothorax is generally based on treatment of underlying aetiology, assessment of the degree of chyle leak and a multidisciplinary discussion on the role of lymphatic intervention, without specific recommendations on the utility of radiological or lymphatic imaging (6). Lymphatic imaging requires clinical expertise, is associated with procedural complications, and appears to be rarely performed in patients with nontraumatic chylothorax (4). With the introduction of new techniques such as magnetic resonance (MR) lymphangiography as an alternative or adjunct to traditional modalities (e.g., lymphoscintigraphy and intranodal lymphangiography), there is a clear need for more evidence on the utility of these imaging and diagnostic modalities in the management of nontraumatic chylothorax (9,10).
For the reasons above, we sought to evaluate radiological imaging techniques in common use [computed tomography (CT) and positron emission tomography-CT (PET-CT)] in their ability to either support a diagnosis or direct tissue biopsy for diagnostic workup of nontraumatic chylothorax, and the role of dedicated lymphatic imaging in identifying lymphatic abnormalities to guide therapeutic interventions. We present this article in accordance with the STROBE reporting checklist (available at https://amj.amegroups.com/article/view/10.21037/amj-24-159/rc).
Methods
We performed a retrospective single-centre study that included all patients diagnosed with chylothorax at Oxford University Hospitals (OUH) NHS Foundation Trust from January 2019 to December 2023. Patient demographics, clinical presentation, pleural fluid characteristics, treatment, intervention, and outcomes were retrieved from review of medical records. The definition of chylothorax was based on pleural fluid triglyceride levels >110 mg/dL (1.24 mmol/L) on initial or subsequent pleural fluid analysis. The categorisation of pleural fluid as transudative or exudative was based on Light’s criteria. CT, PET-CT or lymphatic imaging performed as part of disease evaluation were recorded and classified based on their utility in supporting a diagnosis or guiding a diagnostic (tissue biopsy) or therapeutic lymphatic intervention (thoracic duct ligation or TDE). Radiological or lymphatic imaging techniques that did not support a specific diagnosis or guide a diagnostic or therapeutic (lymphatic) intervention were classified as having equivocal or no significant features. These classifications of imaging utility or significant imaging findings were determined after discussion and consensus at the pleural multi-disciplinary team meetings in our institution. In our institution, dynamic contrast-enhanced (gadolinium) MR lymphangiography was performed.
Statistical analysis
Descriptive statistics of the variables were expressed as median with interquartile range (IQR), or numbers with percentage. All statistical analyses were performed using SPSS statistics software version 22.0 (IBM Corp., Armonk, USA).
Ethical considerations
The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. As this study was performed with anonymised data retrieved from a clinical audit, no formal institutional review board approval was deemed necessary and individual consent for this retrospective analysis was waived.
Results
Patient details and aetiology
Twenty patients were included, with a median age of 66 (IQR, 58–75) years at the time of chylothorax diagnosis (Table 1). Patients were followed up for a median of 26 (IQR 16–33) weeks. One patient with suspected laceration of the cisterna chyli following abdominal surgery was excluded as this was considered traumatic/surgical. All patients were diagnosed as chylothorax based on pleural fluid triglyceride levels with a median of 5.15 (IQR, 3.07–18.71) mmol/L. Half had bilateral pleural effusions, and 15 (75.0%) had a large effusion (≥4 rib spaces on ultrasonography) at presentation. The majority (80.0%) had milky pleural fluid on macroscopic appearance. Almost half (40.0%) had an underlying malignant cause, with the majority being lymphoma (Table 2). Three patients (15.0%) had a primary lymphatic disorder (diffuse lymphangiomatosis or generalised lymphatic dysplasia), and 3 (15.0%) patients were diagnosed with idiopathic chylothorax.
Table 1
| Characteristics | Values (n=20) |
|---|---|
| Male gender | 13 (65.0) |
| Age, years | 66 [58–75] |
| Site of pleural effusion | |
| Right | 9 (45.0) |
| Bilateral | 10 (50.0) |
| Large pleural effusion (≥4 rib spaces on ultrasonography) | 15 (75.0) |
| Echogenic pleural effusion on ultrasonography | 18 (90.0) |
| Pleural fluid characteristics | |
| Milky macroscopic appearance | 16 (80.0) |
| Lactate dehydrogenase, U/L | 133 [90–168] |
| Protein, g/L | 49 [38–71] |
| Exudative effusion | 18 (90.0) |
| Triglycerides, mmol/L | 5.15 [3.07–18.71] |
| Cholesterol, mmol/L | 2.76 [1.90–3.49] |
Data presented as number (percentage) and median [interquartile range].
Table 2
| Variables | Values (n=20) |
|---|---|
| Malignancy | 8 (40.0) |
| Lymphoma | 6 (30.0) |
| Esophageal cancer | 1 (5.0) |
| Cholangiocarcinoma | 1 (5.0) |
| Liver cirrhosis | 2 (10.0) |
| Drug induced (dasatinib) | 1 (5.0) |
| Left subclavian vein thrombosis | 1 (5.0) |
| Yellow nail syndrome | 2 (10.0) |
| Primary lymphatic disorder | 3 (15.0) |
| Idiopathic | 3 (15.0) |
| Unknown | 1 (5.0) |
Data presented as number (percentage).
Imaging
CT thorax imaging with contrast was performed in all patients as part of their disease evaluation, of whom 4 (20.0%) had additional PET-CT imaging performed. CT or PET-CT imaging supported a specific diagnosis of the underlying cause of the chylothorax in 8 (40.0%) patients and revealed radiological abnormalities that guided subsequent tissue biopsy in 7 (35.0%) patients but did not show any significant abnormalities in 5 (25.0%) patients (Figure 1). Thus, the total in whom CT/PET imaging directed diagnosis or directed biopsy was 15/21 (75%). Of the seven biopsy procedures, a diagnosis was confirmed with biopsy in three patients (Figure 1: follicular lymphoma, lymphoplasmacytic lymphoma and diffuse large B-cell lymphoma).
Lymphatic imaging was performed in 12 (60.0%) patients, all of whom underwent MR lymphangiogram. Lymphoscintigraphy was performed in two patients and lymphangiography in one patient. No significant abnormalities or features to direct lymphatic intervention were found in 11/12 patients who underwent this imaging modality. Thoracic duct ligation was attempted in 1 (8.3%) patient after a small volume lymphatic leak was visualised on MR lymphangiogram (Figure 2), however subsequent recurrence required repeat pleural aspirations and indwelling pleural catheter insertion.
A non-malignant etiology of chylothorax was established in 12 (60%) patients. In these patients, CT imaging supported a specific diagnosis (cirrhosis and left subclavian vein thrombosis) or guided tissue biopsy in three and four patients respectively. Lymphatic imaging was performed in ten patients, with unremarkable findings in nine patients, and thoracic duct ligation attempted in one patient following a small volume leak seen on MR lymphangiogram.
Outcomes
Tables 3,4 summarise the evaluation, treatment, and outcomes of the study population. Most patients (90.0%) had high output or persistent chyle leak requiring at least two therapeutic pleural interventions for symptom relief. The median number of required pleural therapeutic interventions was 2 (IQR, 2–3), with one or more ascitic drainage performed in 4 (20.0%) patients. The median duration of chylothorax, defined from the time of first pleural intervention to initial stabilisation or resolution of the pleural effusion, the most recent clinical follow up or death, whichever earlier, was 16 (IQR, 11–24) weeks. Resolution of chylothorax was seen in 8 (40.0%) patients, 7 (35.0%) patients died with unresolved chylothorax, and 5 (25.0%) patients remained under follow-up (or were discharged back to the referring hospital) for chylothorax at the time of manuscript writing.
Table 3
| Variables | Values (n=20) |
|---|---|
| Evaluative tests | |
| CT thorax | 20 (100.0) |
| PET-CT | 4 (20.0) |
| Lymphatic imaging | 12 (60.0) |
| Magnetic resonance lymphangiogram | 12 (60.0) |
| Lymphangiography | 1 (5.0) |
| Lymphoscintigraphy | 2 (10.0) |
| Pleural biopsy | 10 (50.0) |
| Image guided pleural biopsy | 5 (25.0) |
| Thoracoscopy | 5 (25.0) |
| Treatment | |
| Number of pleural procedures | 3 [2–3] |
| Therapeutic pleural aspiration or chest drainage | 20 (100.0) |
| Indwelling pleural catheter insertion | 7 (35.0) |
| Thoracoscopy | 5 (25.0) |
| VATS pleurodesis | 1 (5.0) |
| Number of therapeutic pleural interventions | 2 [2–3] |
| Required ≥2 therapeutic pleural interventions | 18 (90.0) |
| Ascitic drainage | 4 (20.0) |
| Dietary modification | 3 (15.0) |
| Octreotide or midodrine | 3 (15.0) |
| Surgical thoracic duct ligation | 2 (10.0) |
| Total parenteral nutrition | 1 (5.0) |
| Outcomes | |
| Duration of chylothorax (weeks) | 16 [11–24] |
| Resolution of chylothorax | 8 (40.0) |
| Mortality | 7 (35.0) |
| On pleural clinic follow up | 3 (15.0) |
| Discharged back to local hospital | 2 (10.0) |
Data presented as number (percentage) and median [interquartile range]. CT, computed tomography; PET-CT, positron emission tomography-computed tomography; VATS, video-assisted thoracoscopic surgery.
Table 4
| No. | Gender | Age at diagnosis (years) | Diagnosis | Site of pleural effusion | Pleural fluid triglyceride (mmol/L) | Size of pleural effusion at presentation | Lymphatic imaging | Lymphatic imaging conclusion | Biopsy and histology | Number of therapeutic pleural procedures | Treatment and interventions | Duration of chylothorax (weeks) | Outcome |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Female | 80 | Liver cirrhosis | Bilateral | 2.67 | Large | None | Not done | None | 3 | Chest and ascitic drainage | 12 | Passed away from decompensated cirrhosis |
| 2 | Female | 76 | Diffuse large B cell lymphoma | Right | 3.56 | Large | None | Not done | Axillary lymph node biopsy: diffuse large B cell lymphoma | 2 | Chest drainage, IPC insertion and chemotherapy | 8 | Passed away from lymphoma |
| 3 | Male | 74 | Lymphoplasmacytic lymphoma | Right | 5.04 | Large | None | Not done | Right thoracoscopy and pleural biopsy: lymphoplasmacytic lymphoma | 3 | IPC insertion and Ibrutinib | 22 | Resolution of chylothorax |
| 4 | Male | 49 | Follicular lymphoma | Bilateral | 2.28 | Moderate | Lymphangiography and MR lymphangiogram | No leak | Known lymphoma with progression | 2 | Obinutuzumab and bendamustine | 30 | Resolution of chylothorax |
| 5 | Male | 67 | Metastatic cholangiocarcinoma | Left | 66.60 | Large | None | Not done | Known metastatic cholangiocarcinoma | 2 | Chest and ascitic drainage, palliative chemotherapy | 10 | Passed away from cholangiocarcinoma |
| 6 | Male | 66 | Yellow nail syndrome | Right | 19.11 | Large | Lymphoscintigraphy and MR lymphangiogram | No leak | Right image guided pleural biopsy: fibrosis and chronic inflammation | 2 | IPC insertion | 40 | Discharged to local hospital |
| 7 | Male | 61 | Liver cirrhosis | Right | 2.96 | Large | MR lymphangiogram | No leak | None | 3 | Chest drainage and transjugular intrahepatic portosystemic shunt | 16 | Passed away from decompensated cirrhosis |
| 8 | Female | 93 | Unknown | Right | 5.26 | Large | None | Not done | None | 1 | Chest drainage only | 20 | Resolution of chylothorax |
| 9 | Male | 59 | Primary lymphatic disorder | Bilateral | 37.95 | Large | MR lymphangiogram | Leak from TD to right pleural space | CT guided pleural biopsy: benign fibrosis | 8 | Trial of midodrine and octreotide, IPC insertion, thoracic duct ligation | 104 | Passed away from pneumonia and progressive lymphangiomatosis |
| 10 | Female | 77 | Dasatinib induced | Right | 14.14 | Moderate | MR lymphangiogram | No leak | Right thoracoscopy and pleural biopsy: benign fibrosis | 2 | Stopped dasatinib, subsequently started on bosutinib | 20 | Resolution of chylothorax |
| 11 | Female | 65 | Lymphoplasmacytic lymphoma | Bilateral | 4.85 | Large | None | Not done | Known lymphoplasmacytic lymphoma with progression | 3 | Bendamustine and rituximab | 12 | Resolution of chylothorax |
| 12 | Male | 54 | Follicular lymphoma | Bilateral | 6.44 | Large | None | Not done | Right image guided pleural biopsy: follicular lymphoma | 4 | Bendamustine and rituximab, IPC insertion | 18 | Resolution of chylothorax |
| 13 | Male | 26 | Primary lymphatic disorder | Right | 1.68 | Moderate | MR lymphangiogram | Unable to visualise cisterna chyli and TD | Right image guided pleural biopsy: fibrosis and chronic inflammation | 2 | Chest and ascitic drainage, dietary modification | 16 | Resolution of chylothorax |
| 14 | Male | 40 | Left subclavian vein thrombosis | Bilateral | 29.55 | Large | MR lymphangiogram | TD not visualised | None | 2 | Chest drainage only | 3 | Passed away from colorectal cancer |
| 15 | Female | 80 | Idiopathic | Right | 4.30 | Moderate | MR lymphangiogram | No leak | Bronchoscopy and EBUS needle aspiration of carinal lymph node and right thoracoscopy and pleural biopsy: chronic inflammation | 2 | Chest drainage only | 12 | Resolution of chylothorax |
| 16 | Male | 72 | Yellow nail syndrome | Bilateral | 13.09 | Large | MR lymphangiogram | No leak | Right thoracoscopy and pleural biopsy: chronic inflammation | 3 | Dietary modification and chest drainage | 24 | On follow up |
| 17 | Female | 61 | Follicular lymphoma | Right | 17.52 | Large | None | Not done | Retroperitoneal mass biopsy: follicular lymphoma | 2 | Obinutuzumab and bendamustine | 15 | On follow up |
| 18 | Male | 58 | Primary lymphatic disorder | Bilateral | 2.60 | Moderate | Lymphoscintigraphy and MR lymphangiogram | Leak into retroperitoneum and peritoneal space | Video-assisted thoracoscopic surgery and pleural biopsy: benign fibrosis | 3 | Dietary modification, IPC insertion, ascitic drainage, trial of octreotide and midodrine, trial of TPN, thoracic duct ligation. Considered for trial of sirolimus | 97 | Discharged to local hospital |
| 19 | Male | 73 | Idiopathic | Bilateral | 24.33 | Moderate | MR lymphangiogram | No leak | Right image guided pleural biopsy: benign fibrosis | 1 | Chest drainage only | 4 | On follow up |
| 20 | Male | 70 | Metastatic esophageal cancer | Bilateral | 3.27 | Large | MR lymphangiogram | No leak | Left pleural fluid cytology: adenocarcinoma | 2 | IPC insertion | 7 | Passed away from esophageal cancer |
CT, computed tomography; EBUS, endobronchial ultrasound; IPC, indwelling pleural catheter; MR, magnetic resonance; TD, thoracic duct; TPN, total parenteral nutrition.
Discussion
To our knowledge, this is the first study to attempt to directly assess the clinical utility of imaging modalities in the work up of patients with nontraumatic chylothorax. As chylothorax is relatively rare, prospective studies to aid a rational choice of high yield interventions are lacking. We thus conducted a retrospective analysis of the utility of CT imaging and lymphatic imaging in the management of patients with nontraumatic chylothorax at our centre. CT imaging assisted in supporting a diagnosis in up to 40% of patients, where features of lymphoma, liver cirrhosis, subclavian vein thrombosis and metastatic esophageal cancer were evident. CT imaging directed tissue biopsies in 35%, leading to a diagnosis of lymphoma in 15%. In twelve patients with a non-malignant etiology of chylothorax, CT imaging was also useful in supporting a diagnosis or directing tissue biopsy in seven patients. In contrast, lymphatic imaging was less likely to alter or guide management in our patient cohort.
Although CT imaging is inferior to magnetic resonance imaging (MRI) in visualising lymphatics, it is a highly sensitive and specific examination to narrow the broad differential diagnosis of thoracic and abdominal pathology (11). The investigation is easier to tolerate by the supine patient and intravenous contrast enhances the definition of vascular and mediastinal structures, providing useful information in patients in whom the aetiology of chylothorax is uncertain. The predominance of malignancy may explain the relatively high diagnostic yield of CT imaging. CT imaging also assists in guiding tissue biopsies, with diseases like cancer, sarcoidosis, tuberculosis, IgG4-related pleural disease, and amyloidosis being amongst the possible causes for nontraumatic chylothorax. Patients with these conditions appear to have a good response to conservative management (dietary modifications, pleurodesis, octreotide, etc.) when the underlying cause of the chylothorax is treated (12-14).
Lymphatic imaging in chylothorax has a role in the diagnosis of lymphatic vessel diseases and facilitating lymphatic interventions such as TDE or ligation (8,9). Consequently, imaging modalities such as lymphangiogram and MRI lymphangiogram are described as “usually appropriate” in guidelines for the management of chylothorax (15). In traumatic chylothorax, lymphatic imaging can successfully guide interventions such as thoracic duct ligation or TDE in up to 70% of patients, with reported TDE treatment success rates as high as 90% (3).
However, the same cannot be said of nontraumatic chylothorax (3,16). In a single-centre study which included 34 patients with nontraumatic chylothorax, lymphatic imaging were performed in 11 (32%) patients, which revealed obstruction of the thoracic duct in four patients (16). The authors however describe that none of the lymphatic studies seemed to directly influence the subsequent management or helped to direct percutaneous or surgical treatment. The low yield of lymphatic imaging is perhaps reflected in real-world practice where lymphatic imaging or intervention is not commonly performed. In a recently published multi-centre case series of 77 patients, of whom 87% were nontraumatic in aetiology, lymphatic imaging was only performed in 3% of patients. In addition, interventional radiology involvement was described in only two patients (lymphography and superior vena cava stenting), and no cases of thoracic duct ligation or TDE were performed (4).
The yield of lymphatic imaging and utility of lymphatic intervention appears to be remarkably different in referral centres. In a single-centre study of 34 patients with nontraumatic chylothorax who had failed conservative treatment, 20 (58.8%) patients revealed occlusion of the thoracic duct on lymphangiogram, of whom TDE was successful in 75% (17). Most recently, dynamic contrast-enhanced MR lymphangiogram has been proposed as an alternative to conventional lymphangiogram (9), with superior spatial and contrast resolution compared to fluoroscopy, and a lower viscosity of gadolinium-based contrast, allowing for improved propagation through lymphatic vessels than oil-based contrast such as lipiodol. A recent publication of 52 patients with nontraumatic chylothorax or chylopericardium demonstrated the utility of dynamic contrast MR lymphangiogram in guiding lymphatic intervention (18), where 79% of patients with nontraumatic chylothorax had evidence of abnormal lymphatic flow and TDE and/or interstitial embolization of retroperitoneal lymphatics resulted in chylothorax resolution in 93% of these cases. However, whether the results of these studies are generalisable is questionable. Firstly, these studies were conducted in referral centres with significant experience in lymphangiography and TDE. Selection bias is likely as referred cases (idiopathic chylothorax) that would have failed conservative therapies accounted for most causes for chylothorax and is reflected in the high median time from symptom onset to lymphatic intervention (283 days). This is very different to real-world practice, where malignancy (in particular lymphoma) accounts for the most common cause of nontraumatic chylothorax (4). Nevertheless, even in our patient cohort where both duration of chyle leak and the number of repeated pleural procedures were significantly high, representative of patients with high output or persistent chyle leak, the yield of lymphatic imaging remained poor—similar to other case series more representative of real-world data (4).
This study has several limitations; it is a single tertiary centre retrospective analysis with a relatively small sample size. Not all patients underwent lymphatic imaging in this study, but this reflects ‘real-world’ practice where lymphatic imaging is generally performed in selected patients with persistent high output chyle leak, with the goal of identifying lymphatic abnormalities for therapeutic intervention. Most patients also did not have a conventional lymphangiography performed, considered to be the gold standard for visualization of lymph nodes and lymphatic vessels (15). Nevertheless, reasonable lymphatic vessel visualisation was possible in all but one of the 12 patients with MR lymphangiogram.
Conclusions
This assessment of real-world investigation of presenting undifferentiated nontraumatic chylothorax demonstrate that specific, lymphatic imaging-detectable abnormalities are relatively uncommon. We suggest on this basis that the role of lymphatic imaging is more useful in identifying those who may not benefit from thoracic duct ligation or TDE (if no thoracic duct leak or occlusion is identified). CT imaging is useful in providing further information on the underlying aetiology or facilitating tissue biopsy for most patients with nontraumatic chylothorax. Larger prospectives studies are required to further elucidate the utility of lymphatic imaging in nontraumatic chylothorax, particularly with respect to the underlying aetiology and degree of chyle leak.
Acknowledgments
None.
Footnote
Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://amj.amegroups.com/article/view/10.21037/amj-24-159/rc
Data Sharing Statement: Available at https://amj.amegroups.com/article/view/10.21037/amj-24-159/dss
Peer Review File: Available at https://amj.amegroups.com/article/view/10.21037/amj-24-159/prf
Funding: None.
Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://amj.amegroups.com/article/view/10.21037/amj-24-159/coif). The authors have no conflicts of interest to declare.
Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. As this study was performed with anonymised data retrieved from a clinical audit, no formal institutional review board approval was deemed necessary and individual consent for this retrospective analysis was waived.
Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.
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Cite this article as: Goh KJ, Mounsey CA, Chew WM, Wrightson J, Rahman NM. Evaluating the clinical utility of radiological and lymphatic imaging in nontraumatic chylothorax. AME Med J 2025;10:31.
