Establishment of a desirable dose using neutral argon plasma to eradicate miliary peritoneal implants: A phase I/II controlled trial.

INTRODUCTION: Neutral argon plasma (NAP) system could meet the requirements to achieve oncological cytoreduction of peritoneal carcinomatosis with miliary lesions, minimizing the associated morbidity. This phase I/II trial aims to establish the desirable dose that is safe and effective in eliminating tumor cells with lower penetration. METHODS: Patients diagnosed with different origins for peritoneal carcinomatosis and miliary implants were selected for the study. The safe and potentially effective dose (desirability) of NAP was evaluated according to three factors: distance (mm), application time (s) and power (%), to evaluate the response variables such as the presence of tumor cells (Y/N) and the depth of penetration. RESULTS: Ten patients and 120 samples were evaluated and treated with NAP. There was no vascular or organ injury intraoperative using a pre-established dose of 100% (coagulation mode) at a distance of 2-3 cm. The distance was found to be correlated with the presence of the tumor cells in ex-vivo analysis, with an OR of 15.4 (4.0-111.4). The time and energy used were protective factors to eliminate tumor cells with an OR of 0.4 (0.1-0.9) and 0.8 (0.8-0.9), respectively. The safest and most effective desirability results were as follows i) energy 80% during 2-4 s with a distance of 2 cm (0.89), and ii) energy 100% during 2-4 s with a distance of 3 cm (0.90). CONCLUSIONS: The use of NAP during a CRS and HIPEC is safe and effective for eradicating tumor cells on the peritoneal surface at suggested doses of energy, distance and duration. TRIAL IDENTIFICATION: ClinicalTrials.gov Identifier: NCT04904042.

Complete laparoscopic pelvic peritonectomy plus hyperthermic intraperitoneal chemotherapy.

BACKGROUND: The aim of our study was to present the technique for, and early results of complete laparoscopic pelvic peritonectomy (LPP) plus hyperthermic intraperitoneal chemotherapy (HIPEC). METHODS: We conducted a study on consecutive patients who had LPP for limited peritoneal carcinomatosis (peritoneal carcinomatosis index < 10) from ovarian cancer, colon cancer and benign multicystic mesothelioma, from January 2017 to November 2019 at 2 referral centers in Spain. Perioperative, pathologic, 30-day major morbidity and mortality characteristics were analyzed. The surgical technique is shown in the attached video. RESULTS: Twelve LPP + HIPEC were performed. Complete cytoreduction was achieved in 100% of the patients, the median duration of the operation was 450 min (range 360-600 min). There were 2 cases (16%) of IIIa morbidity (trocar hernia and pleural effusion), and no mortality. The median length of hospital stay was 5.5 days (range 4-10 days). The median length of follow-up was 10 months (range 2-30 months). There was a recurrence at the splenic hilum in 1 patient which was treated by laparoscopic splenectomy and one nodal recurrence at 13 months while all other patients are alive and free of disease at last follow-up. CONCLUSIONS: This is the first technical video of a minimally invasive approach for complete pelvic peritonectomy plus omentectomy associated with HIPEC. For highly selected patients, this procedure presents a feasible and safe alternative to the maximally invasive approach.

RAS Mutation Decreases Overall Survival After Optimal Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy of Colorectal Peritoneal Metastasis: A Modification Proposal of the Peritoneal Surface Disease Severity Score.

BACKGROUND: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are currently the most accepted treatment for peritoneal metastases from colorectal cancer. Restrictive selection criteria are essential to obtain the best survival benefits for this complex procedure. The most widespread score for patient selection, the peritoneal surface disease severity score (PSDSS), does not include current biological factors that are known to influence on prognosis. We investigated the impact of including RAS mutational status in the selection criteria for these patients. METHODS: We studied the risk factors for survival by multivariate analysis using a prospective database of consecutive patients with carcinomatosis from colorectal origin treated by CRS and HIPEC in our unit from 2009 to 2017. The risk factors obtained were validated in a multicentre, international cohort, including a total of 520 patients from 15 different reference units. RESULTS: A total of 77 patients were selected for local análisis. Only RAS mutational status (HR: 2.024; p = 0.045) and PSDSS stage (HR: 2.90; p = 0.009) were shown to be independent factors for overall survival. Early PSDSS stages I and II associated to RAS mutations impaired their overall survival with no significant differences with PSDSS stage III overall survival (p > 0.05). These results were supported by the international multicentre validation. CONCLUSIONS: By including RAS mutational status, we propose an updated RAS-PSDSS score that outperforms PSDSS alone providing a quick and feasible preoperative assessment of the expected overall survival for patients with carcinomatosis from colorectal origin undergone to CRS + HIPEC.