Computed Tomography-Guided Access to the Cisterna Chyli: Introduction of a Technique for Direct Lymphangiography to Evaluate and Treat Chylothorax

[Modern Treatment Options for Postoperative Chylothorax: a Systematic Review]

BACKGROUND

 Chylothorax is a multifactorial complication, usually caused by surgery or traumatic injury, and more rarely by malignant disease. Because of the lack of prospective, randomised trials, the evidence-based treatment rests upon personal experience, but ideally taking into account retrospective analysis.

MATERIAL AND METHODS

 The aim of this review is to provide a comprehensive overview of the currently available modern treatment options. Another aspect is to show their advantages and disadvantages. For this purpose, a literature search was performed using the "PubMed" database. Publications older than ten years were excluded from this review. The literature search employed the keyword "chylothorax". The priority was set on publications including a comparative assessment of treatment approaches. The authors relied on many years of clinical experience to critically analyse and evaluate the treatment options and the given recommendations.

RESULTS

 The success rate of the conservative treatment methods ranges widely, depending on the underlying cause of the disease (3-90 %). Non-invasive or semi-invasive procedures are successful in 50 to 100 % of the cases, also depending on the aetiology. After unsuccessful conservative treatment of operable patients, the standard surgical therapy consists of thoracic duct ligature, which is usually performed thoracoscopically. Alternatively, pleurodesis or the placement of a permanent chest drain (PleurX) or a pleuroperitoneal shunt may be performed. The success rate of these procedures is between 64 and 100 %. The morbidity and mortality rate can reach values up to 25 %.

CONCLUSION

 Treatment of a chylothorax should be started conservatively. Subsequently, a more aggressive therapy may be gradually considered, based on the patient's health and the amount of the secretion. Interventional radiological procedures are safe, successful, and have a legitimate place alongside conservative or surgical treatment. However, they are currently only available in some larger centres.

Nontraumatic Chylothorax: Nonenhanced MR Lymphography

Chylothorax is a rare cause of pleural effusion, secondary to accumulation of lymph in the pleural space. Diagnosis is based on the triglyceride and cholesterol content of pleural fluid obtained with thoracentesis. Because the lymphatic system plays an essential role in fat absorption and immune response, lymphatic leak associated with chylothorax may cause life-threatening malnutrition and immunodeficiency. Chylothorax is usually described as traumatic or nontraumatic. The main cause of chylothorax is traumatic, typically postsurgical, secondary to iatrogenic direct puncture of the thoracic duct during thoracic surgery. Causes of nontraumatic chylothorax include a wide range of differential diagnoses. Lymphoma and thoracic malignancies are the most common causes and are responsible for chylothorax by extrinsic compression or invasion of the thoracic duct. Other rare causes include primary and secondary diffuse lymphatic diseases, responsible for chylothorax by lymphatic vessel wall dysfunction. Imaging the lymphatic system remains a challenge in the days of modern imaging. Nonenhanced MR lymphography is a noninvasive technique based on heavily T2-weighted sequences, thus enabling visualization of the lymphatic circulation. This technique allows diagnosis and differential diagnosis, evaluation of disease severity, and guidance of therapeutic management in nontraumatic chylothorax. Furthermore, it may offer radiologic classification of primary lymphatic diseases on the basis of morphologic features of lymphatic vessels. The authors describe the anatomy and physiology of the thoracic lymphatic system, present the technique of nonenhanced MR lymphography, and discuss pathophysiologic mechanisms and imaging features in different causes of nontraumatic chylothorax. ^©RSNA, 2020.

Lymphatic Imaging: Current Noninvasive and Invasive Techniques

After nearly disappearing, invasive lymphangiography not only has resurged, but new approaches have been developed to guide lymphatic interventions. At the same time, noninvasive lymphatic imaging is playing a larger role in the evaluation of lymphatic pathologies. Lymphangioscintigraphy, computed tomography lymphangiography, and magnetic resonance lymphangiography are increasingly being used as alternatives to invasive diagnostic lymphangiography. The purpose of this article is to review current invasive and noninvasive lymphatic imaging techniques.

Novel technique to manage refractory chylous ascites with carbon nanoparticle suspension in infants

OBJECTIVE

Chylous ascites (CA) is a rare form of ascites that results from the leakage of lipid-rich lymph into the peritoneal cavity. In infants, CA is mostly caused by lymphatic malformation or unknown reasons. The creation of a shunt for the lymphorrhea is the last option for patients unresponsive to all other conservative treatments. Localization of the leakage is a critical problem during surgery. We applied a carbon nanoparticle suspension (CNS) in CA patients to locate the external lymphatic leakage and evaluated its utility during surgery.

PATIENTS AND METHODS

Twelve infants with CA were treated in our center recently. Ten patients received laparotomy, one refused therapy, and one was cured after undergoing conservative treatment. Recently, two infants with CA received CNS in the visceral peritoneum during laparotomy. The results of the traditional procedure were compared to our innovative technique for CA to evaluate the use of CNS in treating CA.

RESULTS

The features of the baseline data did not differ substantially. Location of the leakage with CNS was employed in 2 of the 10 patients whose lymphatic leakages were identified with the resolution of the refractory CA. Overall, in 5 patients, ascites was resolved successfully. The refractory CA was resolved more effectively in patients in whom the leakage site was identified with CNS than in patients in whom the leakage site could not be identified under conventional surgery.

CONCLUSIONS

Injecting CNS improved the accuracy of lymphorrhagia leakage site identification and the outcomes of infants who underwent surgical treatment for refractory CA.

LEVEL OF EVIDENCE

II-III.

Use of computed tomography-lymphangiography with direct injection of water-soluble contrast medium to identify the origin of chylous ascites

Contrast lymphangiography is a useful technique to determine the site of lymphatic leakage in the patient with chylous ascites. Conventional lymphangiography with lipid-soluble contrast material carries the disadvantage of complications, such as oil emboli and lymphedema. The authors report a successful case of computed tomography (CT)-lymphangiography with direct injection of water-soluble contrast medium into a lower limb lymphatic vessel to determine the site of lymphatic leakage in a pediatric patient with refractory primary chylous ascites. The patient subsequently underwent laparoscopic ligation of the leaking site and recovered well. This novel technique offers superior potential for preoperative assessment and the planning of laparoscopic repair.

Chylothorax and chylous ascites: management and pitfalls

Leakage of lymph from the lymphatic ducts causes chylothorax (CT) or chylous ascitis (CA). This may happen for unknown reasons during fetal life or after birth and may also be caused by trauma after thoracic surgery or by other conditions. Fetal CT and CA may be lethal particularly in cases with fetal hydrops that sometimes benefit of intra-uterine instrumentation. After birth, symptoms are related to the amount of accumulated fluid. Sometimes, severe cardio-respiratory compromise prompts active therapy. Most patients with CT or CA benefit from observation, rest, and supportive measures alone. Drainage of the fluid may be necessary, but then loss of protein, fat, and lymphoid cells introduce new risks and require careful replacement. Low-fat diets with MCT and parenteral nutrition decrease fluid production while allowing adequate nutritional input. If lymph leakage does not stop, secretion inhibitors like somatostatin or octreotide are prescribed, although there is only weak evidence of their benefits. Imaging of the lymphatic system is indicated when the leaks persist, but this is technically demanding in children. Shunting of the lymph from one body space to another by means of valved catheters, embolization of the thoracic duct, and/or ligation of the major lymphatics may occasionally be indicated in cases refractory to all other treatments.

Radiotherapy in the treatment of postoperative chylothorax

Background

Chylothorax is characterized by the presence of chyle in the pleural cavity. The healing rate of non-operative treatment varies enormously; the maximum success rate in series is 70%. We investigate the efficacy and outcomes of radiotherapy for postoperative chylothorax.

Methods

Chylothorax was identified based on the quantity and quality of the drainage fluid. Radiation was indicated if the daily chyle flow exceeded 450 ml after complete cessation of oral intake. Radiotherapy consisted of opposed isocentric portals to the mediastinum using 15 MV photon beams from a linear accelerator, a single dose of 1–1.5 Gy, and a maximum of five fractions per week. The radiation target area was the anatomical region between TH3 and TH10 depending on the localization of the resected lobe. The mean doses of the ionizing energy was 8.5 Gy ± 3.5 Gy.

Results

The median start date of the radiation was the fourth day after chylothorax diagnosis. The patients’ mediastinum was radiated an average of six times. Radiotherapy, in combination with dietary restrictions, was successful in all patients. The median time between the end of the radiation and the removal of the chest tube was one day. One patient underwent wound healing by secondary intention. The median time between the end of radiation and discharge was three days, and the overall hospital stay between the chylothorax diagnosis and discharge was 18 days (range: 11–30 days). After a follow-up of six months, no patient experienced chylothorax recurrence.

Conclusions

Our results suggest that radiotherapy in combination with dietary restriction in the treatment of postoperative chylothorax is very safe, rapid and successful. This novel interventional procedure can obviate repeat major thoracic surgery and shorten hospital stays and could be the first choice in the treatment of postthoracotomy chylothorax.