Thoracic duct identification with indocyanine green fluorescence to prevent chyle leaks during minimally invasive esophagectomy

INTRODUCTION

Chylothorax (CT) is a rare yet serious complication after esophagectomy. Identification of the thoracic duct (TD) during esophagectomy is challenging due to its anatomical variation. Real-time identification of TD may help to prevent its injury. Near infra-red imaging with Indocyanine green (ICG) is a novel technique that recently has been used to overcome this issue.

METHODS

Patients who underwent minimally invasive esophagectomy for esophageal cancer were divided into two groups with and without ICG. We injected ICG into bilateral superficial inguinal lymph nodes. Identification of TD and its injuries during the operation was evaluated and compared with the non-ICG group.

RESULTS

Eighteen patients received ICG, and 18 patients underwent surgery without ICG. Each group had one (5.5%) TD ligation. In the ICG group injury was detected intraoperative, and ligation was done at the site of injury. In all cases, the entire thoracic course of TD was visualized intraoperatively after a mean time of 81.39 min from ICG injection to visualization. The Mean extra time for ICG injection was 11.94 min. In the ICG group, no patient suffered from CT. One patient in the non-ICG group developed CT after surgery that was managed conservatively. According to Fisher's exact test, there was no significant association between CT development and ICG use, possibly due to the small sample size.

CONCLUSIONS

This study confirms that ICG administration into bilateral superficial inguinal lymph nodes can highlight the TD and reduce its damage during esophagectomy. It can be a standard method for the prevention of postoperative CT.

Thoracic Duct Occlusion Leading to Intermittent Left Supraclavicular Swelling and Pancreatitis

Intermittent left supraclavicular swelling is an uncommon and elusive condition that can lead to extensive diagnostic workups to determine the etiology and treatment. One potential cause is partial, intermittent, or complete thoracic duct occlusion (TDO). We report on a patient who presented with chronic, intermittent left supraclavicular swelling and abdominal pain that was relieved by thoracic duct angioplasty. Thoracic duct occlusion should be included in the differential diagnosis of left supraclavicular swelling. Lymphatic imaging can facilitate the diagnosis and allows for potential percutaneous treatment. Laryngoscope, 134:1313-1315, 2024.

Treatment Of Post-Operative Chylothorax: The Role Of Intranodal Lymphangiography And Thoracic Duct Disruption

Thoracic duct embolization has been increasingly adopted as a first-line therapy of chylothorax and this procedure includes lipiodol lymphangiography, thoracic duct access and embolization. Lymphangiography itself has a therapeutic role, with volume-dependent success rates of 37%-97% and even a reported 100% success rate in outputs of < 500 mL/day. We present a clinical case of a 48-years-old man diagnosed with esophageal squamous cell carcinoma, who underwent esophagectomy and presented with post-operative high-output (> 1L/day) chylothorax; thoracic duct embolization was proposed. Even though thoracic duct access and embolization were not achieved due to technical and anatomical factors, lipiodol lymphangiography and possibly thoracic duct maceration (after several punctures/attempts) contributed to the clinical success of the procedure, and this chylothorax with output values superior to those reported in the literature resolved within three days. As such, the therapeutic role of intranodal lymphangiography and thoracic duct disruption should be taken into account.

Efficacy and safety of near-infrared fluorescence identification of the thoracic duct during left lateral neck dissection

BACKGROUND

Thoracic duct leaks occur in up to 5% of left lateral neck dissections. No one imaging modality is routinely used to identify the thoracic duct intraoperatively. The goal of our study was to evaluate the efficacy and safety of indocyanine green lymphangiography for intraoperative identification of the thoracic duct compared to traditional methods using ambient and evaluate the optimal timing of indocyanine green administration.

METHODS

We enrolled all patients who underwent left lateral neck dissection at our institution from 2018 to 2022 in this prospective clinical trial. After indocyanine green injection into the dorsum of the foot, we performed intraoperative imaging was performed with a near-infrared fluorescence camera. We reported the data using descriptive statistics.

RESULTS

Of the 42 patients we enrolled, 14 had prior neck surgery, and 3 had prior external beam radiation. We visualized the thoracic duct with ambient light in 48% of patients and with near-infrared fluorescence visualization in 64%. In 17% of patients, we could identify the thoracic duct only using near-infrared fluorescence visualization, which occurred within 3 minutes of injection, and were required to re-dose 5 patients. We visualized the thoracic duct with near-infrared fluorescence in all patients with prior neck radiation and 77% of patients with prior neck surgery. One adverse reaction occurred (hypotension), and 5 intraoperative thoracic duct injuries occurred that were ligated. There with no chylous fistulas postoperatively.

CONCLUSION

This trial demonstrates that near-infrared fluorescence identification of the thoracic duct is feasible and safe with indocyanine green lymphangiography, even in patients with prior neck surgery or radiation.

Computed tomography and magnetic resonance imaging are potential noninvasive methods for evaluating the cisterna chyli in cats

OBJECTIVE

There is limited information on the normal appearance of the cisterna chyli (CC) in cats on CT and MRI. The aim of this retrospective study was to describe the CT and MRI characteristics of the CC in a group of cats without lymphatic system pathology.

SAMPLE

A total of 31 CT and 63 MRI images were obtained of client-owned cats between January 2017 and March 2022.

METHODS

The presence, location, shape, maximum width, MRI-signal intensity, mean attenuation, and contrast enhancement of the CC were recorded from CT and MRI scans.

RESULTS

The CC was identified in all the CT scans and in 60 MRI studies. The CC was located level with the cranial mesenteric artery in 56 of 91 cases. It was crescent shaped in 34 of 54 cases. On precontrast CT images, the mean attenuation of the CC was 17 HU, and the mean postcontrast attenuation was 28 HU. On T2-weighted sequences, the CC was isointense to CSF and hyperintense to the muscles, while on T1-weighted images, it was isointense to the muscles. Contrast enhancement was variable in both techniques.

CLINICAL RELEVANCE

CT and MRI have the potential for noninvasive evaluation of CC in cats.

Thoracic Duct Embolization for Treatment of Chyle Leakage After Thyroidectomy and Neck Dissection

OBJECTIVE

This study aimed to evaluate the safety and efficacy of intranodal lymphangiography and thoracic duct embolization (TDE) for chyle leakage (CL) after thyroid surgery.

MATERIALS AND METHODS

Fourteen patients who underwent intranodal lymphangiography and TDE for CL after thyroid surgery were included in this retrospective study. Among the 14 patients, 13 underwent bilateral total thyroidectomy with neck dissection (central compartment neck dissection [CCND], n = 13; left modified radical neck dissection (MRND), n = 11; bilateral MRND, n = 2), and one patient underwent left hemithyroidectomy with CCND. Ten patients (76.9%) had high-output CL (> 500 mL/d). Before the procedure, surgical intervention was attempted in three patients (thoracic duct ligation, n = 1; lymphatic leakage site ligation, n = 2). Lymphangiographic findings, technical and clinical successes, and complications were analyzed. Technical success was defined as the successful embolization of the thoracic duct after access to the lymphatic duct via the transabdominal route. Clinical success was defined as the resolution of CL or surgical drain removal.

RESULTS

On lymphangiography, ethiodized oil leakage near the surgical bed was identified in 12 of 14 patients (85.7%). The technical success rate of TDE was 78.6% (11/14). Transabdominal antegrade access was not feasible due to the inability to visualize the identifiable cisterna chyli or a prominent lumbar lymphatic duct. Among patients who underwent a technically successful TDE, the clinical success rate was 90.1% (10/11). The median time from the procedure to drain removal was 3 days (with a range of 1-13 days) for the 13 patients who underwent surgical drainage. No CL recurrence was observed during the follow-up period (ranging from 2-44 months; median, 8 months). There were no complications, except for one case of chylothorax that developed after TDE.

CONCLUSION

TDE appears to be a safe and effective minimally invasive treatment option for CL after thyroid surgery, with acceptable technical and clinical success rates.

Coil or Plug-Assisted Ethylene Vinyl Alcohol Copolymer (EVOH) Thoracic Duct Embolization in the Treatment of Postoperative Chylothorax

Eleven patients (5 men, 6 women) with post-operative thoracic duct injuries and high output chylothorax were treated with thoracic duct embolization (TDE). Six patients underwent intraprocedural thoracic duct ligation at the time of original procedure. In all cases, the pleural fluid demonstrated high triglyceride levels (414 mg/dL; interquartile range [IQR], 345 mg/dL). Median daily (IQR) chest tube outputs before and after TDE were 900 mL (1,200 mL) and 325 mL (630 mL), respectively. Coil- or plug-assisted ethylene vinyl alcohol (EVOH) copolymer was used as embolic agent in all patients. Technical and clinical success rates were 100% and 82%, respectively. Nontarget venous embolization of EVOH copolymer was not identified on subsequent imaging.

Lymphatic drainage dysfunction via narrowing of the lumen of cisterna chyli and thoracic duct after luminal dilation

BACKGROUND

The chronological pattern of extrahepatic lymphatic vessel progression in the course of chronic liver disease has not been clarified. This study aimed to clarify the chronological changes in lymphatic vessels with liver disease progression.

METHODS

This was a prospective cross-sectional study that enrolled a total of 199 patients. The maximum diameter of the cisterna chyli (CC) or terminal thoracic duct (tTD) was measured using computed tomography or ultrasonography, respectively. Changes in the maximum diameters of the CC and tTD were evaluated with patients with chronic liver disease as the pilot set (n = 138). Subsequently, we examined whether CC/tTD could be used to re-allocate unclassified patients by the Baveno-VII criteria to appropriately diagnose clinically significant portal hypertension (CSPH) in the pilot and validation sets.

RESULTS

In the pilot set, a scatter-plot showed that both CC and tTD were narrowed as terminal features in chronic liver disease after dilation. Because there was a significant correlation between the CC diameter and hepatic venous pressure gradient (r = 0.724) in unclassified patients, the diagnostic value of CC and tTD for CSPH was good (AUC: 0.961 and 0.913, respectively). After re-allocation, 68 and 27 unclassified patients were reduced to 4 and 5 in the pilot and validation sets, respectively.

CONCLUSION

Both the CC and tTD narrow in the course of liver disease after dilation. Moreover, the maximum diameter of the CC and tTD can be used to re-allocate patients who are unclassified according to the Baveno-VII criteria.

CLINICAL TRIAL NUMBER

UMIN trial no. 000044857.

Dynamic Contrast-enhanced CT Lymphangiography to Quantify Thoracic Duct Lymphatic Flow

Background CT lymphangiography has been used to image the lymphatic anatomy and assess lymphatic abnormalities. There is, however, a need to develop a method for quantification of lymphatic flow rate in the thoracic duct (TD). Purpose To develop and validate a TD lymphatic flow measurement technique using dynamic contrast-enhanced CT lymphangiography. Materials and Methods Lymphatic flow rate was measured with two techniques: a first-pass analysis technique based on a single compartment model and a thresholding technique distinguishing between opacified and nonopacified voxels within the TD. The measurements were validated in a swine animal model between November 2021 and September 2022. CT images were acquired at 100 kV and 200 mA using a fast-pitched helical scan mode covering the entire TD following contrast material injection into the bilateral inguinal lymph nodes. Two helical CT scans, acquired at the base and peak contrast enhancement of the TD, were used to measure lymphatic flow rate. A US flow probe surgically placed around the TD provided the reference standard measurement. CT lymphatic flow measurements were compared with the reference US flow probe measurements using regression and Bland-Altman analysis. Repeatability was determined using repeated flow measurements within approximately 10 minutes of each other. Results Eleven swine (10 male; mean weight, 43.6 kg ± 2.6 [SD]) were evaluated with 71 dynamic CT acquisitions. The lymphatic flow rates measured using the first-pass analysis and thresholding techniques were highly correlated with the reference US flow probe measurements (r = 0.99 and 0.91, respectively) and showed good agreement with the reference standard, with Bland-Altman analysis showing small mean differences of 0.04 and 0.05 mL/min, respectively. The first-pass analysis and thresholding techniques also showed good agreement for repeated flow measurements (r = 0.94 and 0.90, respectively), with small mean differences of 0.09 and 0.03 mL/min, respectively. Conclusion The first-pass analysis and thresholding techniques could be used to accurately and noninvasively quantify TD lymphatic flow using dynamic contrast-enhanced CT lymphangiography. © RSNA, 2023 See also the editorial by Choyke in this issue.

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.

Simultaneous Visualization of the Thoracic Duct and Blood Vessels Using MRI: A Comparison Between Balanced Turbo-field-echo and Spin-echo

OBJECTIVE

Magnetic resonance thoracic ductography (MRTD), concomitant with blood vessel imaging, provides useful anatomical information. The purpose of this study was to assess the visibility of the thoracic duct and blood vessels simultaneously by MRTD using balanced turbo-field-echo (bTFE) and turbo spin-echo (TSE).

METHODS

MRTDs concomitant with blood vessel imaging on bTFE and TSE were obtained for 10 healthy volunteers with a 1.5T-magnetic resonance unit. Visibility of the thoracic duct, blood vessels in the thoracic region; motion artifacts; and overall image quality were scored by two radiologists using three-to-five-point scales; those were compared between bTFE and TSE.

RESULTS

The thoracic duct was generally well-visualized on MRTD sequences. The upper part of the thoracic duct was better visualized on TSE than on bTFE (p < 0.05). The blood vessels were well visualized on bTFE and TSE; the bilateral subclavian arteries and the right subclavian veins were better visualized on TSE than on bTFE (all p < 0.05). Motion artifacts and overall image quality were better on TSE than on bTFE (p = 0.0039 and 0.0020, respectively).

CONCLUSION

MRTD concomitant with blood vessel imaging on TSE has better visibility of the thoracic duct and blood vessels than bTFE.

Magnetic resonance three-dimensional steady-state free precession imaging of the thoracic duct in patients with Fontan circulation and its relationship to outcomes

BACKGROUND

Lymphatic complications are common in patients with Fontan circulation. Three-dimensional balanced steady-state free precession (3D bSSFP) angiography by cardiovascular magnetic resonance (CMR) is widely used for cardiovascular anatomical assessment. We sought to determine the frequency of thoracic duct (TD) visualization using 3D bSSFP images and assess whether TD characteristics are associated with clinical outcomes.

METHODS

This was a retrospective, single-center study of patients with Fontan circulation who underwent CMR. Frequency matching of age at CMR was used to construct a comparison group of patients with repaired tetralogy of Fallot (rTOF). TD characteristics included maximum diameter and a qualitative assessment of tortuosity. Clinical outcomes included protein-losing enteropathy (PLE), plastic bronchitis, listing for heart transplantation, and death. A composite outcome was defined as presence of any of these events.

RESULTS

The study included 189 Fontan patients (median age 16.1 years, IQR 11.0-23.2 years) and 36 rTOF patients (median age 15.7 years, IQR 11.1-23.7 years). The TD diameter was larger (median 2.50 vs. 1.95 mm, p = 0.002) and more often well visualized (65% vs. 22%, p < 0.001) in Fontan patients vs. rTOF patients. TD dimension increased mildly with age in Fontan patients, R = 0.19, p = 0.01. In Fontan patients, the TD diameter was larger in those with PLE vs. without PLE (age-adjusted mean 4.11 vs. 2.72, p = 0.005), and was more tortuous in those with NYHA class ≥ II vs. class I (moderate or greater tortuosity 75% vs. 28.5%, p = 0.02). Larger TD diameter was associated with a lower ventricular ejection fraction that was independent of age (partial correlation = - 0.22, p = 0.02). More tortuous TDs had a higher end-systolic volume (mean 70.0 mL/m2 vs. 57.3 mL/m2, p = 0.03), lower creatinine (mean 0.61 mg/dL vs. 0.70 mg/dL, p = 0.04), and a higher absolute lymphocyte count (mean 1.80 K cells/µL vs. 0.76 K cells/µL, p = 0.003). The composite outcome was present in 6% of Fontan patients and was not associated with TD diameter (p = 0.50) or tortuosity (p = 0.09).

CONCLUSIONS

The TD is well visualized in two-thirds of patients with Fontan circulation on 3D-bSSFP images. Larger TD diameter is associated with PLE and increased TD tortuosity is associated with an NYHA class ≥ II.

Feasibility study of percutaneous thoracic duct embolization with lower-limb intermittent pneumatic compression devices

PURPOSE

To demonstrate intranodal thoracic duct embolization (TDE) for treating chyle leaks following thoracic surgery and the feasibility of applying lower-limb intermittent pneumatic compression devices during TDE.

METHODS

Between December 2017 and October 2020, 12 consecutive TDEs for post-operative chyle leaks were performed in 11 patients using intranodal lymphangiogram (IL) with an intermittent pneumatic compressive device applied to the lower limb. The procedure's duration, technical/clinical success, and complications were retrospectively evaluated.

RESULTS

IL was successful at imaging the thoracic duct in all procedures (100%), and TDE had an intention- to-treat success rate of 92% (11/12). No related complications were observed during follow-up, which took place at a mean of 27 days. The time from the commencement of lymphangiogram until visualization of the thoracic duct was a mean of 21.6 min, and the mean overall procedure time was 87.3 min.

CONCLUSION

This study supports IL-guided TDE as a safe and effective option to treat post-thoracic surgery chyle leaks. We revealed shorter lymphangiogram times compared with previously published studies, and we postulate that the application of intermittent lower-limb pneumatic compressive devices contributed toward this study's results by expediting the return of lymph from the lower limb. This study is the first to illustrate this approach in TDE and advocates for randomized controlled studies to further evaluate the influence of intermittent pneumatic compressive devices on the procedure.

Chylothorax treatment with thoracic duct embolization

The authors present a case of a patient with non-traumatic right-sided chylothorax which was successfully treated by thoracic duct embolization. The procedure was performed through the cisterna chyli which was visualised by intranodal lymphography. The coils and acrylic tissue glues were used for embolization. The patient has been followed for 5 months and is free of recurrence of chylothorax.

Cervical thoracic duct cyst: a conservative resolution

A woman in her 70s presented with an enlarging, asymptomatic palpable mass in the left supraclavicular fossa. The clinical impression was of a lipoma. Imaging showed a cystic lesion with continuity of a tubular structure leading to the carotid sheath. Cytology was consistent with thoracic duct sampling. A diagnosis of the rare entity of a thoracic duct cyst with supraclavicular extension was made. This was managed conservatively via repeated aspirations which reduced the size of the mass.

Recurrent thoracic duct cyst of the left supraclavicular fossa: A retrospective study of 6 observational case series and literature review

ABSTRACT

The transient occlusion of the terminal thoracic duct is a rare disease responsible for renitent supraclavicular cysts. The aim of this study was to describe the clinical characteristics, evolution, and treatment.A retrospective multicenter study and literature review was carried out. The literature search (PubMed) was conducted including data up to 31 December 2020 and PRISMA guidelines were respected.This study identified 6 observational cases between September 2010 and December 2020. The search results indicated a total of 24 articles of which 19 were excluded due to the lack of recurrent swelling or the unavailability of full texts (n = 5). Fourteen patients (8 from literature) mostly reported a noninflammatory, painless renitent mass in the supraclavicular fossa which appeared rapidly over a few hours and disappeared spontaneously over an average of 8 days (range: from about 2 hours to 10 days). Anamnesis indicated a high-fat intake during the preceding days in all cases and 7 from literature found in the Medline databases. Recurrences were noted in 10 patients. Thoracic duct imaging was performed in all cases to detect abnormalities or extrinsic compression as well as to eliminate differential diagnoses.A painless, fluctuating, noninflammatory, and recurrent swelling of the left supraclavicular fossa in patients evoking an intermittent obstruction of the terminal portion of the thoracic duct was identified. A low-fat diet was found as safe and effective treatment.

[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.

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.

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.

Isolated thoracic duct injury from blunt force trauma

Isolated thoracic duct injury is an uncommon clinical event and is rare in the setting of trauma. We describe a case of an isolated thoracic duct injury resulting in the development of bilateral chylothorax following a motor vehicle collision in the absence of any other definable injury. We outline the initial patient presentation and diagnosis. After failing a trial of conservative management the patient underwent lymphangiography followed by thoracic duct ligation with pleurodesis. This case highlights the importance of recognizing thoracic duct injury following trauma.

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.

Abdominal lymphatic system visibility, morphology, and abnormalities in children as seen on routine MCRP and its association with immune-mediated diseases

PURPOSE

(1) To assess the visibility and diameters of the thoracic duct (TD) and cisterna chyli (CC) on MR cholangiopancreatography (MRCP) in children. (2) To evaluate for the presence of any lymphatic abnormalities and assess their association with diseases in which the immune system is implicated in etiopathogenesis.

METHODS

This retrospective study included 142 MRCPs performed in children 8-17 years old and without prior surgeries. Two radiologists reviewed all exams for visibility and diameters of the TD and CC, and presence of abnormal lymphatic collaterals. TD and CC diameters in various disease processes were compared using Student's t tests. The association of collaterals with immune-mediated diseases was assessed using Fisher's exact tests.

RESULTS

The TD and CC were seen in 134/142 (93.7%) cases with mean diameter of 3.25 ± 1.07 mm and 126/142 (88.7%) cases with mean diameter of 4.55 ± 1.37 mm respectively. The mean diameter of CC was larger in patients with portal hypertension (p = 0.021). There were no significant differences in the TD and CC diameters between immune-mediated and non-immune-mediated diseases. Retroperitoneal collaterals were seen in 41/142 (28.8%) of cases and were associated with both portal hypertension (p = 0.0019) and immune-mediated diseases (p = 0.0083).

CONCLUSION

The TD and CC can be visualized in the majority of children on routine MRCP images, and CC has larger diameter in patients with portal hypertension. The association of collaterals with immune-mediated diseases supports a potential role of the lymphatic system in the etiopathogenesis of immune-mediated diseases.

KEY POINTS

• The lymphatic system has been increasingly implicated in a number of inflammatory and immune-mediated diseases. • The abdominal lymphatic system can be visualized in the majority of children above 8 years on routine MRCP images. Similar to adult studies, the cisterna chyli is significantly larger in children with portal hypertension. • Retroperitoneal lymphatic collaterals, seen in 29% children, are associated with immune-mediated diseases, which supports the potential role of the lymphatic system in the pathogenesis of immune-mediated diseases.

Percutaneous Extra-Anatomic Lymphovenous Bypass Creation: Toward Treatment of Central Conducting Lymphatic Obstructions

INTRODUCTION

Protein-losing enteropathy manifests as a loss of serum proteins through the gastrointestinal tract, resulting in hypoproteinemia, extravascular fluid retention, and edema. Management consists of nutritional maintenance in conjunction with interventions targeted at treating the underlying etiology.

MATERIALS AND METHODS

This report describes a patient with protein-losing enteropathy from a central conducting lymphatic obstruction who was treated with percutaneous extra-anatomic lymphovenous bypass creation.

RESULTS

A modified gun-sight technique was used to create a lymphovenous bypass between an occluded terminal thoracic duct and the left internal jugular vein.

CONCLUSION

A percutaneous technique to reconstruct the terminal thoracic duct via lymphovenous bypass creation was feasible.

Thoracic duct decompression: An idea whose time has come - again

[Editorial] Thoracic duct decompression (TDD) is an idea first proposed and applied as a novel therapeutic strategy by lymphologists in the 1960's. TDD is recently being reexamined and, in selected patients with portal hypertension from hepatic cirrhosis or with central venous hypertension from isolated right-sided heart failure, undertaken using advanced surgical and image-guided interventional radiologic approaches.

The Visibility of the Terminal Thoracic Duct Into the Venous System Using MR Thoracic Ductography with Balanced Turbo Field Echo Sequence

RATIONALE AND OBJECTIVES

Magnetic resonance thoracic ductography (MRTD) with balanced turbo field echo (bTFE) can visualize both the thoracic duct and its surrounding vessels. This study aimed to investigate the visibility of the terminal thoracic duct into the venous system in the subclavian region using MRTD with bTFE.

MATERIALS AND METHODS

MRTD was performed with bTFE as a preoperative workup comprising respiratory gating on a 1.5-T magnetic resonance system for patients with esophageal cancer. The portion and the number of terminal thoracic ducts into the venous system and preterminal branching in the left subclavian region were assessed using MRTD in 132 patients. The confidence level of the visibility using MRTD was also evaluated.

RESULTS

The most frequent terminal portion of the thoracic duct was the jugulovenous angle (92 patients, 69.7%), followed by the subclavian vein (27 patients, 20.5%) and the internal jugular vein (8 patients, 6.1%). Four patients also exhibited double entry of the thoracic duct into the venous system. The preterminal branching was single in 96 patients (72.7%) and multiple in 36 patients (27.3%). The confidence level of the visibility of the thoracic duct using MRTD was absolutely certain in 112 patients (84.8%) and was somewhat certain in 20 patients (15.2%).

CONCLUSIONS

MRTD with bTFE is a robust imaging modality to visualize the terminal portion of the thoracic duct into the venous system in the subclavian region.

[Intranodal lymphangiography in pediatric chylothorax, a diagnostic and therapeutic tool]

INTRODUCTION

High morbidity has been described in secondary chylothorax. Thoracic duct embolization (TDE) after intranodal lymphangiography (IL) is one of the treatments in adults but there is poor experience in children. We aim to describe our experience with this technique for refractory pediatric chylothorax.

METHODS

A retrospective study of patients with refractory chylothorax treated with thoracic duct embolization at our Institution in the last 4 years was performed. Lymphatic vessels visualization was obtained by intranodal lymphangiography with ethiodized oil. Demographic and clinical data as well as imaging findings were collected.

RESULTS

A total of 4 patients were treated during the study period with a median of age and weight of 2.5 months (1-16) and 4.25 kg (2.8-10) respectively. Chylothorax was secondary to cardiothoracic surgery in 3 patients and to venous thrombosis in the other one. Medical treatment was provided during a median of 47 days (13-56) without benefit in thoracic output [median: 46 ml/kg/day (19-64)]. After IL, thoracic duct catheterization was achieved in one patient however embolization was not possible. Chylothorax stopped in the 3 post-surgical patients regardless of how much lymphatic visualization was achieved in IL. In the venous thrombosis patient surgical treatment was performed 6 days after the study.

CONCLUSION

IL can be a diagnostic and therapeutic tool in children. Ethiodized oil seems to seal lymphatic leak in postsurgical chylothorax. IL could be an option for chylothorax in patients too sick for surgical treatment or in whom thoracic duct embolization is not feasible.

The Role of Intraoperative Fluorescence Imaging During Esophagectomy

Intraoperative fluorescence imaging (FI) with indocyanine green has several potential uses during esophagectomy. Intravascular injection for enhancing the visualization of conduit vascularity and assessing macro and microperfusion has the most literature support and may help reduce anastomotic leaks. Peritumoral injection has been reported for use in identifying sentinel nodes during lymphadenectomy and intralymphatic injection may be used to help preserve or ligate the thoracic duct. The authors' own technique of FI for conduit assessment is described. They routinely use this strategy to guide anastomosis placement and reduce leaks.

Bilateral chylothorax following anterior cervical spine surgery

Bilateral chylothorax following anterior cervical spine surgery is very rare. This report documents the first case of chylothorax after anterior cervical spine surgery through a right-side surgical approach. Unidentified chyle leakage can easily remain unrecognized and, thus, is difficult to treat. For early diagnosis and treatment, it is very important to consider the possibility of chylothorax following anterior cervical spine surgery, even when using a right-side surgical approach.

Chylothorax Associated with Chronic Lymphocytic Leukemia

An 80-year-old man who had suffered from chronic lymphocytic leukemia (CLL) and achieved complete remission was admitted to our hospital due to right pleural effusion. Thoracentesis revealed that the effusion was chyle. Lymphoscintigraphy showed an obstruction of the thoracic duct below the sternum. CD45-gated flow cytometry of the pleural effusion showed elevated numbers of CD5- and CD23-positive lymphocytes and a high serum level of soluble interleukin-2 receptor. These results suggested that the chylothorax was caused by the obstruction of the thoracic duct by the sludging of either abnormal lymphocytes of CLL or transformed malignant lymphoma cells.

Idiopathic chylothorax: pathophysiology, diagnosis, and thoracic duct imaging

Idiopathic chylothorax is a debilitating disease that can lead to respiratory and metabolic compromise and fibrosing pleuritis. Previous investigation has provided theories for the etiology of this poorly understood disease. This article provides an overview of the pathophysiology and diagnosis of chylothorax. Thoracic duct imaging, including minimally invasive techniques, is also discussed, as it is frequently performed in the perioperative period. A companion article reviews nonsurgical and surgical techniques for treating and managing idiopathic chylothorax in dogs and cats.

[Simvastatin indused chylothorax]

Chylothorax is a rare disorder occurring most often in aftermath of a thoracic surgery or during cancer of mediastinum. We report the clinical history of the world's second case of chylothorax which appeared during treatment with simvastatin.

[A case of chylothorax in which thoracoscopy under local anesthesia and thoracic duct scintigraphy were useful to locate the leakage site]

BACKGROUND

Detailed investigation of the cause of chylothorax and its treatment should be performed by thoracoscopy under general anesthesia, but if this is difficult due to multiple complications it is possible to perform a detailed investigation by combining thoracoscopy under local anesthesia and thoracic duct scintigraphy.

CASE PRESENTATION

A 74-year-old woman presented with exertional dyspnea. Chest X-ray films showed right pleural effusion, and thoracocentesis yielded a milky white pleural effusion, meeting the criteria of chylothorax, after excluding conditions such as malignant lymphoma, amyloidosis and trauma. Since the patient's medical history included pacemaker insertion, dialysis and diabetes, thoracoscopy was performed under local anesthesia rather than general anesthesia, to investigate the cause in detail. The pleural cavity was visualized, but no obvious tumor or other cause was present in the parietal pleura. There was partial adhesion of the lower lobe and chest wall, and the leakage of a milky white pleural effusion from this site was confirmed. We then performed thoracic duct scintigraphy, which revealed an area of enhancement corresponding to the leakage site near the right pulmonary hilum.

CONCLUSION

We describe a case in which thoracoscopy under local anesthesia and thoracic duct scintigraphy were useful for determining the leakage site in chylothorax.

Cisterna chyli in patients with malignancy--is there a correlation between changes in cisterna volume and progression or regression of the tumor?

The purpose of this study was to investigate the potential correlation between the size of the cisterna chyli (CC) and the tumor size in patients with malignancies on computed tomography (CT).

MATERIALS AND METHODS

Out of a 3000 patient cohort 138 patients with histologically confirmed malignant disease, a detectable CC on CT and at least two CT scans within a 6 month period were included in this retrospective study. Out of 525 scans a total of 711 lesion intervals were evaluated. The volume of the CC and all target lesions (up to three per scan) were recorded. The Pearson correlation coefficient for the two parameters of changes in lesion size and CC size was calculated for the whole cohort and for a 33 patient subgroup that included only patients with tumors that showed the closest association with large CC in a previous study.

RESULTS

The mean difference in lesion size for all 711 intervals was -1165μl. The mean difference in CC size for all 711 intervals was -46.6μl. The respective Pearson correlation coefficient was .05 with a non-significant p-value of .1823 (subgroup: r=.04, p=.6358).

CONCLUSION

No significant correlation between the progression or regression of malignant disease and the size of the cisterna chyli could be found.

Reconstruction of occluded thoracic duct for treatment of chylopericardium: a novel surgical therapy

Chylopericardium is an uncommon disease predominantly caused by trauma. Prolonged chyle depletion may result in nutritional, metabolic, and immunologic deficiencies due to loss of essential proteins, immunoglobulins, fat, vitamins, electrolytes, and water. Medical treatment includes a low-fat diet with medium-chain triglyceride restriction, cardiac support, diuretic medications, and drainage of the pericardial effusion. Conventional surgical therapy consists of pericardial fenestration and thoracic duct ligation. We report a case of massive secondary chylous pericardial effusion successfully treated with microsurgical lymphovenous anastomosis, reconnecting the occluded thoracic duct to the internal jugular vein. This case highlights features and management strategies of this perplexing clinical condition.

Anomalies of thoracic lymph duct drainage demonstrated by lymphoscintigraphy and review of the literature about these anomalies

AIMS

To determine the frequency of supradiaphragmatic lymph nodes that receive lymph from the lower limbs and the intraabdominal organs.

METHODS

Three hundred and thirty-four bipedal lymphoscintigraphy results of the lower limbs were reviewed.

RESULTS

Lymph nodes were visualized in only the supraclavicular/retroclavicular (SRC) area in 113 cases (33.2%, 109 on the left and 4 on the right), in only the mediastinum in 5 cases (1.5%), in the mediastinum and the left SRC area in 18 cases (5.5%), in the mediastinum and right SRC area in 2 cases (0.6%), in the mediastinum and both SRC areas in 6 cases (1.8%), and in the mediastinum and as 1 chain draining in the left axilla in 2 cases (0.6%).

CONCLUSIONS

Supradiaphragmatic lymph nodes associated with the thoracic duct and receiving lymph and/or chyle from the infradiaphragmatic body were demonstrated in 43.2% of our patients and in 11.1% of the cases these lymph nodes were not located in the left retroclavicular area. These data should be taken in mind by surgeons when confronting an intrathoracic and even extrathoracic supradiaphragmatic chylous effusion after surgeries which imply lymph nodes and/or lymphatic vessels.

Conservative treatment of a cervical thoracic duct cyst: a case report

Cysts of the thoracic duct are uncommon entities that can occur in the abdominal segment, the cisterna chyli, the thoracic segment and the cervical segment of the thoracic duct. The rarest presentation is in the cervical segment, with only seventeen cases reported in English literature. The diagnosis can be made by puncture and with the use of computed tomography or ultrasonography. The cystic fluid always contains an excess of T-lymphocytes and triglycerides. Except for two cases, all reported cervical thoracic duct cysts were surgically treated by excision and ligation of the lymphatics connected to the cyst. We present a case of a successful non-operative treatment of a cervical thoracic duct cyst that was resolved by repeated aspiration and dietary changes only.

Normal CT Appearance of the Distal Thoracic Duct

OBJECTIVE

The aims of this study were to determine how often the distal thoracic duct can be identified on neck CT and to characterize the CT appearance of the duct.

MATERIALS AND METHODS

In a review of electronic medical records from January 2001 to January 2003 we identified the cases of 500 patients who had undergone CT of the neck. Because they had confounding factors such as cancer or cervical lymphadenopathy, 199 of these patients were excluded, leaving 301 patients in the study: 131 (44%) male patients and 170 (56%) female patients. The age range was 11-92 years (average age, 46 years). Two head and neck radiologists used strict diagnostic criteria and consensus to identify the distal thoracic duct on both sides of the neck. One half of the images selected at random were flipped left to right. The purpose of randomization was to avoid interpretation bias, because the thoracic duct is known to typically course within the left side of the neck. The configuration of the distal duct was tabulated, and effects of age and sex were statistically evaluated.

RESULTS

The left side of the neck was unevaluable in 26 (9%) of 301 patients because of streak artifact. In the other 275 patients, the distal thoracic duct was identified in the left side of the necks of 150 (55%) of the patients. Eleven of these patients (4%) also had a visible duct in the right side of the neck, but a right-sided duct was never identified without a left-sided counterpart. The distal thoracic duct had a tubular configuration in 70 (43%), a flared configuration in 72 (45%), and a long segmental fusiform dilation in 19 (12%) of 161 patients. Patient sex had no significant effect on the appearance of the distal thoracic duct. Older patient age had a slight positive effect on the size of the duct.

CONCLUSION

Familiarity with the normal CT appearance of the distal thoracic duct can be helpful in differentiating a normal duct from pathologic lesions of the lower neck, such as lymphadenopathy.

Lymphography of the Thoracic Duct by Percutaneous Injection of Iohexol into the Popliteal Lymph Node of Dogs: Experimental Study and Clinical Application

OBJECTIVE

To evaluate the efficacy of percutaneous administration of iohexol into the popliteal lymph node as a non-invasive technique for thoracic duct lymphangiography in dogs.

STUDY DESIGN

Experimental study and clinical report.

ANIMALS

Normal adult dogs (n=4) and 1 dog with recurrent chylothorax.

METHODS

For the experimental study, 4 dogs (weight, 8.4-12.3 kg) had 5-10 mL iohexol injected percutaneously into 1 popliteal lymph node and then thoracic radiographs were taken. Popliteal lymph nodes were examined by histopathology 8 days later. One 25-kg dog with recurrent chylothorax had 25 mL iohexol injected into the right popliteal lymph node followed by thoracic radiography.

RESULTS

In experimental dogs, the thoracic duct was best visualized on thoracic radiographs after administration of 10 mL iohexol. Clinically, no abnormalities were identified in the injected limb and except for 1 dog that had large numbers of siderocytes and erythrophagocytic macrophages in the injected lymph node, the histopathologic findings in the other injected popliteal lymph nodes were not different from contralateral nodes. In the clinical case, the thoracic duct was visualized, but there was leakage of iohexol around the node.

CONCLUSION

The thoracic duct in dogs can be visualized by lymphography after percutaneous injection of iohexol (1 mL/kg at 2 mL/min) into the popliteal lymph node.

CLINICAL RELEVANCE

Percutaneous popliteal lymph node administration of iohexol should be considered as an alternative to mesenteric lymph node injection for radiographic identification of the thoracic duct in dogs.

Nonvascular Mediastinal Trauma

This article discusses the radiologic and clinical features of nonvascular mediastinal trauma, and focuses on the tracheobronchial tree, the esophagus, and the thoracic duct. Blunt chest and penetrating trauma account for most of the causes of such nonvascular injuries, but iatrogenic and inhalation injuries are other well-known causes. The injury distribution and clinical manifestations are different for each structure. In our combined experience at a level 1 trauma center, the overall prevalence of injury in each organ is low compared with vascular injuries. As such, and given the frequent nonspecific nature of clinical signs and symptoms of nonvascular mediastinal injuries, the diagnosis often is delayed and results in poor treatment outcome.