No epidemiological data are available in the literature about diseases of the thoracic duct, cysterna chyli, and intestinal chyliferous vessels, in particular with regard to congenital dysplastic forms. These are, in any case, relatively rare conditions, which, in the majority of cases, are present already at birth, or have their onset during childhood, depending on the extent and severity of lymphangio-chylodysplastic malformations underlying these complex pathologic clinical pictures.
The majority of Chyliferous Vessel Diseases due to gravitational lymphatic-chylous reflux are linked to dysplasia of lymphatic and chylous collectors, as well as to valvular-wall insufficiency. Sometimes, they may have iatrogenic causes. For example, following the ligature of the thoracic duct or lesions to retroperitoneal lymphatic and chyliferous vessels.
Sometimes, these clinical pictures may become complicated by acute attacks of lymphangitis, verrucosis caused by chylous stasis, and lympho-cutaneous fistulas with chylorrhea.
In order to investigate these complex clinical conditions, which may feature chyloperitoneum, chyledema of the lower extremities, and of the external genitalia, chyluria, chylothorax, chylometrorrhea, chylous effusion in a joint, and are often found with different mutual associations, a long and demanding diagnostic and therapeutic procedure is necessary.
Clinical manifestations of Chyliferous Vessel Diseases
Severe hypoproteinemia is the most important sequela of this disease, from a general metabolic point of view. It may be result of protein losing enteropathy, with severe bouts of diarrhea, which that often a feature of clinical progression of the disease.
A malformation of chyliferous vessels and of the receptaculum chyli of Pequet is a major obstacle to the drainage of intestinal lymphatics. Lymphatic collectors along the wall of the small intestine and the mesentery fill up with chyle and become dilated. Since they are located just below the peritoneum, they can easily break with subsequent chyle leakage and effusion into the peritoneal cavity (chylous ascites). Sometimes, chyliferous vessels break in two stages: the peritoneum is detached by chyle leaking out of lymphatic collectors, thus developing a chyloma that then, bursts into the abdominal cavity. A localized dilatation of a chyliferous vessel is called a mesenteric chylous cyst (Figure 1).
Figure 1: Schematic drawing of physiopathology and related clinical pictures correlated to Diseases of Chyliferous Vessels, chylous cyst, and thoracic duct.
From a diagnostic point of view, accurate haematochemical investigations are very important. In particular, they have to include protein electrophoresis, lipidogram, calcemia, and hyperlipidemia. Ultrasonography and lymphoscintigraphy are also important, but, above all, lymphoscintigraphy is essential which, especially if combined with CT scan, lymphangio-MR, and laparoscopy, can provide accurate information on clinical conditions, disease severity, and extent. Sometimes, 99mTc-labeled Human Serum Albumin Scintigraphy may play an important diagnostic role, in order to detect any associated protein-losing enteropathy.
With regard to therapy, the clinical pictures above described, even in case of acute onset (e.g. chylous peritonitis), should never be operated upon immediately. First of all, the patient must be properly compensated from a metabolic point of view, with an appropriate diet, based on protein integration and lipid intake of only medium chain tryglicerides (MCT), that, rather than being absorbed through intestinal chyliferous lymphatic vessel roots, follow the portal system. Initially, Total Parenteral Nutrition (TPN) may be instrumental in rapidly reaching a good metabolic compensation of the patient, in order to significantly reduce the source of chylous leak.
Videolaparoscopy may be useful in these initial phases, for a correct placement of one or more peritoneal drains, aimed at progressively reducing effusion and avoiding “ex vacuo” haemorrhagic complications. The same drains can also be used for serial lavages with Trémollières (concentrated milk acid) solution, combined with an antibiotic drug (250-500 mg sodium rifamycin), which has a sclerotizing effect on lymphatics (particularly beneficial in treating post-operative chylous collections especially after extended retroperitoneal lymphadenectomy). Subcutaneous administration of Octreotide may also be beneficial, since this substance has proved to significantly reduce chylous production. At this point, surgery can be performed, which is to be designed according to the outcome and the results so far achieved with the various conservative treatments illustrated above.
Therefore, surgical treatment must be designed on a case by case basis, depending on whether chylous effusion is of primary or secondary nature, on the severity of the clinical picture, its complexity, extent of disease, whether the chylous leak is from only one site or multiple sites. In this way, surgical treatment may feature the following procedures, also combined in different ways:
The administration of a fatty meal (60 grams of butter in a cup of milk) 4-5 hours before surgery, according to Servelle, is very useful for better detection of chyliferous collectors (Figure 2).
Figure 2, A-E: Clinical case of primary intestinal and mesenteric lymphangio-chylodysplasia with corresponding histopathological picture. Please note that chyliferous vessels of the intestinal wall are dilated and highlighted by the “fatty meal”. Mesenteric chylous pools responsible for free chylous effusion in the abdominal cavity are also visible (from case reports by the Genoa School).
Laparotomy-supported videolaparoscopy, although not exclusively feasible, is often combined with LASER-assisted operations. Today it is the treatment procedure reporting the highest number of successful outcomes.
Treatments that are alternative or complementary to the techniques described above are the following: peritoneal-jugular shunt (Denver, Le Veen) in the most intractable cases with unrelenting recurrences, (bearing in mind all the well known limitations in the application of these procedures in children); resection of the intestinal segment most severely affected by dysplasia, in very severe cases of lymphangectasia.
Figure 3, A-D: Case with abundant chylous ascites caused by congenital dysplasia, before and after integrated medical-surgical treatment.
Figure 4, A-D: Left supraclavicular chylocele with lymphangio-chylous-dysplasic origin. Long-term follow up after surgical resection.
Figure 5, A-D: Right supraclavicular chylocele. Long-term stable results after surgical resection.
Figure 6, A-D: Chylous Ascites in a patient with co-existing Non-Hodgkins Lymphoma. Before and after microsurgical intervention.