Comparison of "Roll-over' Technique With Standard Abdominal Paracentesis in Suspected Peritoneal Carcinomatosis

The study will be a randomized trial that will compare two techniques of abdominal paracentesis in patients with suspected peritoneal carcinomatosis. The patients will undergo abdominal paracentesis by the standard technique and a rollover technique. In the standard technique, the patients will lie flat for 10 minutes and abdominal paracentesis will be taken for ascitic fluid cytology. In the rollover group, patients with suspected peritoneal carcinomatosis will be rolled over thrice laterally on each side by 90 degrees and sample will then be obtained for ascitic fluid cytology. both the samples will be processed by blinded cytopathologist for tumour cellularity and diagnostic yield.

Trial Design

The study will be a randomized comparison between two methods of abdominal paracentesis with a cross-over design and each participant will also serve as a control (standard paracentesis).

Participants

The study will be done on the patients who will visit Outpatient departments or admitted as an inpatient in the Post Graduate Institute of Medical Education and Research, Chandigarh.

Screening population: All patients with ascites

Assessment of study population:

Patients fulfilling inclusion and exclusion criteria as per screening will be subjected to baseline investigation in the form of hemogram, biochemistries, coagulogram, ascitic fluid evaluation as per predesigned proforma. All patients in the study group will be subjected to imaging and an attempt will be made to establish the primary site of malignancy based on histopathology.

Patients fulfilling inclusion and exclusion criteria will undergo randomization into two groups. One group will be the standard paracentesis group (SPG) and the other will be the rollover group (ROG). Randomization will be done using an opaque sealed envelope.

Patients fulfilling inclusion and exclusion criteria will undergo abdominal paracentesis twice in one of the following ways.

Standard paracentesis group (SPG):

The patients will be asked to lie supine for 10 minutes and no changes in posture will be allowed for this period. Abdominal paracentesis will be done either by blind technique (in case the ascites is clinically detectable) or ultrasonography-guided (in cases the ascites is not clinically detectable).

Rollover group (ROG):

Patients with ascites will be rolled over thrice in bed laterally up to 90 degrees on either side and the ascitic fluid sample is drawn within 1 minute of the last rollover. There will be four steps to this i.e roll over to one side at 90 degrees and then 180 degrees to the other side and so on to complete three complete turns. This will be done after the disinfection and cleaning of the anterior abdominal wall have been done and the personnel involved in the procedure are ready for the paracentesis. The ascitic paracentesis will be initiated within one minute of the completion of the turn. One assistant will maintain a stopwatch during this period to ensure compliance with this.

Details of ascitic paracentesis

The patient will undergo abdominal paracentesis twice in the order as allocated randomly. The patients will be asked to empty his bladder prior to the procedure. The anterior abdominal wall will be cleaned with a Povidone-iodine solution followed by isopropyl alcohol/ chlorhexidine. The site of the paracentesis will be the peritoneal space in the left lower quadrant between the umbilicus and the anterior superior iliac spine or the patient's flank, depending on the location of the fluid as determined by percussion of the fluid wave. Alternatively, in midline 3 to 4 cm below the umbilicus, halfway between the symphysis pubis and the umbilicus. On both occasions, 20 ml of the ascitic sample will be collected in clean dry containers with appropriate labeling of name and hospital registration number. 20 ml of the sample obtained on each of these occasions will be sent for cytological analysis. To ensure that both the groups are treated similarly the paracentesis will be done using a 20 ml syringe using 21 Gauge 1 1/2" hypodermic needle. It will be ensured to avoid old surgical scars since the bowel may be adherent to the abdominal wall. The site of the paracentesis will be closed with tincture benzoin. The ascitic fluid sample for malignant cytology will be transported to the laboratory within one hour of paracentesis.

Eligibility Criteria:
Inclusion Criteria:

Patient with ascites where a diagnosis of peritoneal carcinomatosis is being considered on the basis of one or more of the following

* Clinical Suspicion of peritoneal carcinomatosis on basis of a history of malignancy, painful ascites and/or loss of weight
* Clinical Suspicion of peritoneal carcinomatosis on the basis of presence of ascites with lump or other stigmata of malignancy
* Suspicion of peritoneal carcinomatosis on imaging suggestive of peritoneal carcinomatosis

Exclusion Criteria:

* Age \< 12 years
* Refusal to participate or provide consent
* Evidence of chronic liver disease-related ascites (evidence of cirrhosis on ultrasonography or evidence of portal hypertension eg varices on endoscopy)
* Already diagnosed alternate cause of ascites like cirrhosis, pancreatitis, right heart failure -
* Contraindications to paracentesis in the form of disseminated intravascular coagulation or local site infection.