What is the significance of ascitic tapping in peritoneal (peritoneal cavity) carcinoma?

From the Guidelines

Ascitic tapping, or paracentesis, is a crucial diagnostic and therapeutic procedure for patients with peritoneal carcinomatosis, particularly those with malignant ascites, as it helps alleviate symptoms, confirms diagnosis, and guides treatment decisions, as supported by recent studies 1.

Procedure and Indications

The procedure involves inserting a needle into the peritoneal cavity, typically in the lower abdomen, after local anesthesia with 1% lidocaine. For diagnostic purposes, 50-100 mL of fluid is sufficient, while therapeutic drainage may remove 4-5 liters to relieve symptoms.

• The procedure should be performed using sterile technique with ultrasound guidance when available.
• Patients should be positioned semi-recumbent, and the preferred insertion site is the left or right lower quadrant, 2-3 cm medial to the anterior superior iliac spine.
• Complications are rare but include hypotension, infection, and bowel perforation.
• Albumin replacement (6-8g per liter of fluid removed) should be considered when removing large volumes (>5 liters) to prevent post-paracentesis circulatory dysfunction.

Management of Malignant Ascites

For recurrent malignant ascites, options include:

• Repeated paracentesis
• Indwelling peritoneal catheters like the PleurX catheter
• Peritoneovenous shunts The development of ascites in peritoneal carcinomatosis results from increased vascular permeability due to vascular endothelial growth factor production by tumor cells and lymphatic obstruction by tumor deposits, as discussed in 1.

Diagnostic Approach

Diagnostic laparoscopy with or without peritoneal washing cytology is recommended for routine staging of most stage II and III tumors by various international guidelines, as mentioned in 1.

• Staging laparoscopy as a preoperative staging tool has a high sensitivity (85%) and specificity (100%) in the detection of peritoneal metastasis not found on imaging.
• The rate of synchronous peritoneal metastasis at the time of diagnosis of gastric cancer ranges between 12.9% and 26.5%, highlighting the importance of early diagnosis and intervention 1.

Therapeutic Strategies

Integration of recent novel genomic biology with peritoneal-specific therapeutic strategies may lead to improved outcomes of this distinct clinical entity, as suggested in 1.

• Locoregional (intraperitoneal) treatment strategies such as catheter-based intraperitoneal chemotherapy, hyperthermic intraperitoneal chemotherapy (HIPEC), and pressurized intraperitoneal aerosol chemotherapy (PIPAC) are being explored.
• Advances in molecular characterization and genomic sequencing have enabled analysis of various aspects of peritoneal carcinomatosis, starting with analysis of cells derived from malignant ascites and inferring the role of the tumor microenvironment (TME) 1.

From the Research

Significance of Ascitic Tapping in Peritoneal Carcinoma

• Ascitic tapping, also known as paracentesis, is a procedure used to remove fluid from the peritoneal cavity, which can help alleviate symptoms such as abdominal discomfort and shortness of breath in patients with peritoneal carcinoma 2, 3, 4, 5, 6.
• The procedure can be performed repeatedly, but it may not be effective in all cases, and patients may experience recurrence of symptoms 2, 3, 6.
• Alternative treatments, such as peritoneovenous shunt placement and indwelling peritoneal catheters, have been shown to be effective in managing malignant ascites and improving quality of life in patients with advanced cancer 2, 3, 4, 5, 6.

Benefits of Ascitic Tapping

• Ascitic tapping can provide rapid relief from symptoms such as abdominal discomfort and shortness of breath 2, 3, 6.
• The procedure is relatively simple and can be performed in an outpatient setting 2, 5.
• Ascitic tapping can be used in combination with other treatments, such as diuretics and chemotherapy, to manage malignant ascites 3, 4.

Complications and Limitations

• Ascitic tapping can be associated with complications such as infection, bleeding, and bowel perforation 2, 3, 6.
• The procedure may not be effective in all cases, and patients may experience recurrence of symptoms 2, 3, 6.
• Alternative treatments, such as peritoneovenous shunt placement and indwelling peritoneal catheters, may be more effective in managing malignant ascites in some patients 2, 3, 4, 5, 6.

Treatment Options

• Diuretics and paracentesis are often used as first-line treatments for malignant ascites 3, 4.
• Intraperitoneal drug administration, indwelling peritoneal catheters, and peritoneovenous shunting are also used to manage refractory ascites 3, 4, 5, 6.
• New devices, such as the alfapump, are being developed to manage malignant ascites 4.