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Chylous Ascites

Updated : May 28, 2024





Background

Chylous ascites is described as a cloudy, triglyceride-rich fluid in the abdomen, resulting from the accumulation of true chyle from the thoracic or intestinal lymphatic systems. This medical condition, initially documented in 1912, is relatively uncommon. It typically arises due to incidents like trauma, which lead to lymphatic damage and subsequent leakage, raising lymphatic pressure within the peritoneal cavity.

Its nutrient and immunoglobulin-rich composition distinguishes chylous ascites, although these components lose their biological efficacy once they accumulate in the peritoneal space. Consequently, individuals affected by this condition might experience complications such as dehydration, imbalances in electrolytes, malnutrition, and a suppressed immune response.

Epidemiology

Chylous ascites is considered a rare condition, with a less than 1% prevalence among patients with ascites. The incidence of chylous ascites is even lower. The mortality associated with chylous ascites depends on its underlying causes and the patient’s overall health. If chylous ascites is a consequence of an underlying condition like cancer or infections, the prognosis would be influenced by the severity and prognosis of that primary condition.

The literature does not commonly report mortality rates related specifically to chylous ascites. The condition is more commonly associated with acquired causes, such as trauma, surgery, or underlying medical conditions that disrupt the lymphatic system. While genetics might play a role in determining an individual’s susceptibility to developing lymphatic system disorders, it is not a primary factor in the development of chylous ascites.

Anatomy

Pathophysiology

The underlying cause of chylous ascites (CA) stems from the disruption of normal lymphatic flow. Lymph, originating from various sources such as the intestines and liver, plays a central role. Upon ingestion of dietary long-chain triglycerides (TG), these are transformed into monoglycerides and fatty acids within the small intestine, subsequently being absorbed into the lymphatic system as chylomicrons.

This process imparts a milky appearance to lymph due to its high TG content. In instances of CA, portal hypertension gives rise to compromised endothelial integrity due to elevated lymphatic pressure. Consequently, lymphatic channels dilate, leading to their rupture and the subsequent formation of CA. In cases without a portal-related etiology, lymph constituents exude into the peritoneal cavity through a retroperitoneally formed fistula, a consequence of congenital or acquired megalymphatics.

Over time, this scenario triggers collagen accumulation within the basement membrane of lymphatic channels due to increased lymphatic pressure. This phenomenon results in decreased intestinal mucosal absorption capacity. Consequently, manifestations of protein-losing enteropathy emerge, characterized by inadequate absorption, malnutrition, and steatorrhea.

Etiology

Congenital and Acquired Megalymphatics: Megalymphatics are abnormally enlarged lymphatic vessels. Both congenital and acquired factors can contribute to the development of megalymphatics. These abnormally enlarged vessels are more prone to rupture or leakage, leading to the accumulation of chyle in the peritoneal cavity.

Trauma and Surgery: Trauma or surgical procedures involving the abdominal region can physically damage the lymphatic vessels, causing leaks or obstructions that result in chylous ascites.

Infections and Inflammatory Conditions: Inflammatory responses triggered by infections or other inflammatory conditions can damage lymphatic vessels or nodes, impairing the normal flow of lymphatic fluid and contributing to chylous ascites.

Genetics

Prognostic Factors

The prognosis may be influenced by the underlying condition causing chylous ascites. For example, if a treatable infection or inflammation causes it, the prognosis might be more favorable compared to cases caused by advanced cancer.

Clinical History

Clinical History

Patients diagnosed with chylous ascites often describe a painless and gradually progressing abdominal swelling that can develop over the course of weeks to months. This abdominal distention is the most prevalent symptom, affecting as much as 81% of individuals with this condition. Some patients, about 11%, may experience less common symptoms such as abdominal pain or peritonitis.

In addition, certain patients might report symptoms like diarrhea, and difficulty swallowing (particularly in non-traumatic cases where conditions like goiter or para-esophageal hernia compress the thoracic duct, leading to chylothorax and CA). Peripheral edema, weight gain, and shortness of breath can also manifest due to heightened abdominal pressure.

Other symptoms, although less specific to CA, might include diminished appetite, fatigue, nausea, swelling of lymph nodes, feelings of fullness, occasional fever, and night sweats. It’s essential to recognize that these symptoms can vary significantly in terms of severity and presentation among individuals.

Physical Examination

Physical Examination

During a physical examination, distinctive features appear in patients with chylous ascites (CA). The abdomen typically appears visibly distended and, upon palpation, might feel taut. Classic indicators of ascites, such as shifting dullness and a transmission thrill (fluid wave), may be observed. If surgical scars are apparent upon inspection, they could suggest a traumatic origin for the condition. Additionally, the presence of enlarged lymph nodes might be noted during examination. It’s crucial to assess for broader physical examination findings that could indicate malignancy, renal issues, or liver disease.

For instance, patients with cirrhosis might display characteristic physical signs such as cachexia (muscle wasting), jaundice, temporal wasting (thinning of the temples), palmar erythema (reddening of the palms), spider angiomas on the chest and abdomen, gynecomastia (breast enlargement in males), decreased breath sounds and dullness upon chest percussion due to pleural effusion, a tense abdomen due to ascites, caput medusae (dilated veins around the umbilicus), and signs of confusion and disorientation (hepatic encephalopathy) in cases of decompensated disease.

Moreover, specific syndromes like yellow-nail syndrome or Klippel-Trenaunay syndrome might present with distinctive physical examination findings. It’s important to conduct a comprehensive assessment to both identify chylous ascites and address any underlying conditions contributing to these observed clinical features.

Age group

Associated comorbidity

Associated activity

Acuity of presentation

Differential Diagnoses

Differential Diagnoses

Cirrhosis

Pancreatitis

Sarcoma

Neuroendocrine Tumor

Laboratory Studies

Imaging Studies

Procedures

Histologic Findings

Staging

Treatment Paradigm

Lifestyle Modifications

It is advised to follow a specific diet that is low in fat and primarily consists of medium-chain triglycerides (TGs) and is rich in protein. Using medium-chain triglycerides is beneficial as they are absorbed by enterocytes, thereby avoiding the lymphatic system, and are directly transported to the liver as free fatty acids and glycerol.

When these dietary adjustments are insufficient, it might be necessary to implement periods of bowel rest and opt for total parenteral nutrition (TPN). This approach aids in reducing lymphatic flow and circumvents the need for intestinal involvement. Seeking nutritional guidance becomes important for effectively managing TPN and choosing the most appropriate lipid formulation.

Medical Therapy

Orlistat works by inhibiting the release of lipase from the stomach and pancreas, decreasing the absorption and availability of fatty acids. Somatostatin and its synthetic analog octreotide are employed to manage CA, although their exact mechanisms of action are not fully comprehended. They are believed to reduce portal pressure by inhibiting splanchnic vasodilation, decrease peristalsis, limit intestinal fat absorption, lower triglyceride levels in the thoracic duct, and reduce lymph flow in major channels.

The administration route and half-life differ between somatostatin and octreotide. While somatostatins are given intravenously and have a half-life of 1 to 3 minutes, octreotide is administered subcutaneously and has a half-life of approximately 2 hours. Octreotide has demonstrated effectiveness in CA cases arising from conditions like pancreatitis, post-liver transplant complications, malignancy, portal vein thrombosis, and idiopathic origins, leading to an enhanced quality of life for affected individuals.

Etilefrine manages postural hypotension due to its sympathomimetic effects. Additionally, it has proven useful for individuals who undergo esophagectomy and subsequently develop CA due to injury to the thoracic duct. By causing contraction of the smooth muscles in the thoracic duct, etilefrine diminishes chyle flow.

Surgical Therapy

Surgical interventions can offer potential benefits if conservative approaches are ineffective in addressing chylous ascites. This option should be contemplated in cases where CA stems from congenital factors, surgical procedures, or malignancy. Typically, a laparotomy is undertaken to implement a shunt, repair a fistula, or surgically remove a malignancy.

by Stage

by Modality

Chemotherapy

Radiation Therapy

Surgical Interventions

Hormone Therapy

Immunotherapy

Hyperthermia

Photodynamic Therapy

Stem Cell Transplant

Targeted Therapy

Palliative Care

Medication

Media Gallary

References

Chylous Ascites

Updated : May 28, 2024




Chylous ascites is described as a cloudy, triglyceride-rich fluid in the abdomen, resulting from the accumulation of true chyle from the thoracic or intestinal lymphatic systems. This medical condition, initially documented in 1912, is relatively uncommon. It typically arises due to incidents like trauma, which lead to lymphatic damage and subsequent leakage, raising lymphatic pressure within the peritoneal cavity.

Its nutrient and immunoglobulin-rich composition distinguishes chylous ascites, although these components lose their biological efficacy once they accumulate in the peritoneal space. Consequently, individuals affected by this condition might experience complications such as dehydration, imbalances in electrolytes, malnutrition, and a suppressed immune response.

Chylous ascites is considered a rare condition, with a less than 1% prevalence among patients with ascites. The incidence of chylous ascites is even lower. The mortality associated with chylous ascites depends on its underlying causes and the patient’s overall health. If chylous ascites is a consequence of an underlying condition like cancer or infections, the prognosis would be influenced by the severity and prognosis of that primary condition.

The literature does not commonly report mortality rates related specifically to chylous ascites. The condition is more commonly associated with acquired causes, such as trauma, surgery, or underlying medical conditions that disrupt the lymphatic system. While genetics might play a role in determining an individual’s susceptibility to developing lymphatic system disorders, it is not a primary factor in the development of chylous ascites.

The underlying cause of chylous ascites (CA) stems from the disruption of normal lymphatic flow. Lymph, originating from various sources such as the intestines and liver, plays a central role. Upon ingestion of dietary long-chain triglycerides (TG), these are transformed into monoglycerides and fatty acids within the small intestine, subsequently being absorbed into the lymphatic system as chylomicrons.

This process imparts a milky appearance to lymph due to its high TG content. In instances of CA, portal hypertension gives rise to compromised endothelial integrity due to elevated lymphatic pressure. Consequently, lymphatic channels dilate, leading to their rupture and the subsequent formation of CA. In cases without a portal-related etiology, lymph constituents exude into the peritoneal cavity through a retroperitoneally formed fistula, a consequence of congenital or acquired megalymphatics.

Over time, this scenario triggers collagen accumulation within the basement membrane of lymphatic channels due to increased lymphatic pressure. This phenomenon results in decreased intestinal mucosal absorption capacity. Consequently, manifestations of protein-losing enteropathy emerge, characterized by inadequate absorption, malnutrition, and steatorrhea.

Congenital and Acquired Megalymphatics: Megalymphatics are abnormally enlarged lymphatic vessels. Both congenital and acquired factors can contribute to the development of megalymphatics. These abnormally enlarged vessels are more prone to rupture or leakage, leading to the accumulation of chyle in the peritoneal cavity.

Trauma and Surgery: Trauma or surgical procedures involving the abdominal region can physically damage the lymphatic vessels, causing leaks or obstructions that result in chylous ascites.

Infections and Inflammatory Conditions: Inflammatory responses triggered by infections or other inflammatory conditions can damage lymphatic vessels or nodes, impairing the normal flow of lymphatic fluid and contributing to chylous ascites.

The prognosis may be influenced by the underlying condition causing chylous ascites. For example, if a treatable infection or inflammation causes it, the prognosis might be more favorable compared to cases caused by advanced cancer.

Clinical History

Patients diagnosed with chylous ascites often describe a painless and gradually progressing abdominal swelling that can develop over the course of weeks to months. This abdominal distention is the most prevalent symptom, affecting as much as 81% of individuals with this condition. Some patients, about 11%, may experience less common symptoms such as abdominal pain or peritonitis.

In addition, certain patients might report symptoms like diarrhea, and difficulty swallowing (particularly in non-traumatic cases where conditions like goiter or para-esophageal hernia compress the thoracic duct, leading to chylothorax and CA). Peripheral edema, weight gain, and shortness of breath can also manifest due to heightened abdominal pressure.

Other symptoms, although less specific to CA, might include diminished appetite, fatigue, nausea, swelling of lymph nodes, feelings of fullness, occasional fever, and night sweats. It’s essential to recognize that these symptoms can vary significantly in terms of severity and presentation among individuals.

Physical Examination

During a physical examination, distinctive features appear in patients with chylous ascites (CA). The abdomen typically appears visibly distended and, upon palpation, might feel taut. Classic indicators of ascites, such as shifting dullness and a transmission thrill (fluid wave), may be observed. If surgical scars are apparent upon inspection, they could suggest a traumatic origin for the condition. Additionally, the presence of enlarged lymph nodes might be noted during examination. It’s crucial to assess for broader physical examination findings that could indicate malignancy, renal issues, or liver disease.

For instance, patients with cirrhosis might display characteristic physical signs such as cachexia (muscle wasting), jaundice, temporal wasting (thinning of the temples), palmar erythema (reddening of the palms), spider angiomas on the chest and abdomen, gynecomastia (breast enlargement in males), decreased breath sounds and dullness upon chest percussion due to pleural effusion, a tense abdomen due to ascites, caput medusae (dilated veins around the umbilicus), and signs of confusion and disorientation (hepatic encephalopathy) in cases of decompensated disease.

Moreover, specific syndromes like yellow-nail syndrome or Klippel-Trenaunay syndrome might present with distinctive physical examination findings. It’s important to conduct a comprehensive assessment to both identify chylous ascites and address any underlying conditions contributing to these observed clinical features.

Differential Diagnoses

Cirrhosis

Pancreatitis

Sarcoma

Neuroendocrine Tumor

Lifestyle Modifications

It is advised to follow a specific diet that is low in fat and primarily consists of medium-chain triglycerides (TGs) and is rich in protein. Using medium-chain triglycerides is beneficial as they are absorbed by enterocytes, thereby avoiding the lymphatic system, and are directly transported to the liver as free fatty acids and glycerol.

When these dietary adjustments are insufficient, it might be necessary to implement periods of bowel rest and opt for total parenteral nutrition (TPN). This approach aids in reducing lymphatic flow and circumvents the need for intestinal involvement. Seeking nutritional guidance becomes important for effectively managing TPN and choosing the most appropriate lipid formulation.

Medical Therapy

Orlistat works by inhibiting the release of lipase from the stomach and pancreas, decreasing the absorption and availability of fatty acids. Somatostatin and its synthetic analog octreotide are employed to manage CA, although their exact mechanisms of action are not fully comprehended. They are believed to reduce portal pressure by inhibiting splanchnic vasodilation, decrease peristalsis, limit intestinal fat absorption, lower triglyceride levels in the thoracic duct, and reduce lymph flow in major channels.

The administration route and half-life differ between somatostatin and octreotide. While somatostatins are given intravenously and have a half-life of 1 to 3 minutes, octreotide is administered subcutaneously and has a half-life of approximately 2 hours. Octreotide has demonstrated effectiveness in CA cases arising from conditions like pancreatitis, post-liver transplant complications, malignancy, portal vein thrombosis, and idiopathic origins, leading to an enhanced quality of life for affected individuals.

Etilefrine manages postural hypotension due to its sympathomimetic effects. Additionally, it has proven useful for individuals who undergo esophagectomy and subsequently develop CA due to injury to the thoracic duct. By causing contraction of the smooth muscles in the thoracic duct, etilefrine diminishes chyle flow.

Surgical Therapy

Surgical interventions can offer potential benefits if conservative approaches are ineffective in addressing chylous ascites. This option should be contemplated in cases where CA stems from congenital factors, surgical procedures, or malignancy. Typically, a laparotomy is undertaken to implement a shunt, repair a fistula, or surgically remove a malignancy.