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Intraoperative Peritoneal Lavage for Detection of Malignant Cells: Technique, Evidence, Clinical Relevance and Future Perspectives
by
, ,
Resa Puffert
1, 
Anna Quarder
1,
Fabian Kockelmann
1,
Thomas Wirth
2,
Tanja Reineke-Plaaß
3,
Mieke Raap
3,
Moritz Schmelzle
1,
Linda Feldbrügge
1,
Beate Rau
1,4 and
Franziska Köhler
1,* 1
Department of General, Visceral and Transplant Surgery, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany
2
Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany
3
Department of Pathology, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany
4
Surgical Department, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität zu Berlin, 10117 Berlin, Germany
*
Author to whom correspondence should be addressed.
Cancers 2026, 18(10), 1604; https://doi.org/10.3390/cancers18101604
Submission received: 28 April 2026
/
Revised: 7 May 2026
/
Accepted: 8 May 2026
/
Published: 14 May 2026
(This article belongs to the Special Issue Surgical Innovations in Advanced Gastric Cancer)
Simple Summary
Peritoneal metastases indicate advanced gastrointestinal cancer and are associated with poor outcomes. The early detection of cancer cells in the abdominal cavity is important for accurate staging and treatment planning. Intraoperative peritoneal lavage collects abdominal fluid to identify free cancer cells not yet visible. The main research gap lies in the poorly defined and potentially insufficient sensitivity of conventional cytology, combined with limited specificity, leading to missed minimal tumor burden and false-negative results. Additionally, peritoneal lavage techniques remain insufficiently standardized, while guideline recommendations vary across tumor entities, with inconsistent indications and tumor-stage definitions. New molecular approaches may improve detection but are not yet widely validated, and standardization may support more individualized treatment strategies.
Abstract
Background/Objectives: Peritoneal metastases represent a common manifestation of advanced gastrointestinal malignancies and are associated with poor survival. Their early detection is essential for adequate tumor staging, prognosis, and treatment selection, especially to avoid unnecessary surgery. Intraoperative peritoneal lavage has been established as a diagnostic tool to detect occult peritoneal disease. However, reported techniques, analytical methods, and detection rates vary considerably. The objective of this review was to summarize current approaches to intraoperative peritoneal lavage, evaluate different detection methods, and assess their clinical relevance. Methods: A literature search was performed using the PubMed database for studies published between 2015 and 2025. The search terms “intraoperative peritoneal lavage” or “peritoneal fluid cytology” were used. Studies were included if they evaluated peritoneal lavage as a diagnostic method for detecting malignant cells, including all primary tumors and disease stages. Articles focusing on lavage as a therapeutic intervention or lacking methodological details were excluded. Results: Physiological saline solution was used for lavage in all included studies, with volumes ranging from 10 to 1000 mL. Sampling was predominantly performed immediately after abdominal access in various abdominal sites. Detection methods varied widely, with conventional cytology being most frequently used, while molecular techniques were used in a smaller number of studies. Positive detection rates showed broad variations and were higher in advanced tumor stages. Conventional cytology showed limited detection rates compared to molecular approaches. Conclusions: Intraoperative peritoneal lavage remains a valuable but methodologically heterogeneous diagnostic tool with limited detection rates when relying on conventional cytology alone. Molecular techniques seem to improve the detection rate of occult peritoneal disease but require further standardization and validation before routine clinical implementation. The technique of peritoneal lavage should be standardized by implementing an international consensus including lavage sites, volume of applied fluid, and detection method.
