The pneumoperitoneum and its role in tumor seeding

Area of Science:

• Surgical Oncology
• Minimally Invasive Surgery
• Cancer Recurrence

Background:

• Port site recurrences (PSR) are abdominal wall tumor recurrences after laparoscopic cancer surgery.
• Massive tumor cell seeding (over 10^6 cells) during surgery is implicated, with a median occurrence of 190 days in colorectal cancer.
• While CO2 insufflation has been investigated, it doesn't significantly aerosolize large tumor cell numbers.

Purpose of the Study:

• To investigate the mechanisms and contributing factors of port site recurrences (PSR) after laparoscopic cancer surgery.
• To evaluate the role of CO2 insufflation and surgical technique in tumor cell seeding and PSR development.
• To identify potential strategies for reducing PSR incidence.

Main Methods:

• Review of human and animal studies on tumor cell aerosolization during laparoscopy.
• Analysis of tumor cell presence on instruments and trocars.
• Evaluation of gaseless laparoscopy and CO2 effects on tumor growth in animal models.
• Assessment of clinical incidence rates of PSR in relation to surgical factors.

Main Results:

• Large numbers of tumor cells are primarily found on surgical instruments and trocars, not aerosolized by CO2.
• CO2 insufflation may have an adjuvant effect, enhancing tumor growth in trocar wounds in animal models.
• PSR incidence varies (0-21%) and appears strongly correlated with surgeon experience and technical expertise.

Conclusions:

• Port site recurrences are mainly due to direct tumor cell contamination of the abdominal wall via instruments.
• While CO2 might play a role in enhancing tumor growth, surgical technique and surgeon experience are critical factors in preventing PSR.
• Implementing technical measures may help reduce the incidence of port site recurrences in cancer laparoscopy.