Effect of intraperitoneal chemotherapy concentration on morbidity and survival

Contains fulltext : 218098.pdf (publisher's version ) (Open Access)BACKGROUND: Selected patients with colorectal peritoneal metastases are treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). The concentration of intraperitoneal chemotherapy reflects the administered dose and perfusate volume. The aim of this study was to calculate intraperitoneal chemotherapy concentration during HIPEC and see whether this was related to clinical outcomes. METHODS: An observational multicentre study included consecutive patients with colorectal peritoneal metastases who were treated with CRS-HIPEC between 2010 and 2018 at three Dutch centres. Data were retrieved from prospectively developed databases. Chemotherapy dose and total circulating volumes of carrier solution were used to calculate chemotherapy concentrations. Postoperative complications, disease-free and overall survival were correlated with intraoperative chemotherapy concentrations. Univariable and multivariable logistic regression, Cox regression and survival analyses were performed. RESULTS: Of 320 patients, 220 received intraperitoneal mitomycin C (MMC) and 100 received oxaliplatin. Median perfusate volume for HIPEC was 5.0 (range 0.7-10.0) litres. Median intraperitoneal chemotherapy concentration was 13.3 (range 7.0-76.0) mg/l for MMC and 156.0 (91.9-377.6) mg/l in patients treated with oxaliplatin. Grade III or higher complications occurred in 75 patients (23.4 per cent). Median overall survival was 36.9 (i.q.r. 19.5-62.9) months. Intraperitoneal chemotherapy concentrations were not associated with postoperative complications or survival. CONCLUSION: CRS-HIPEC was performed with a wide variation in intraperitoneal chemotherapy concentrations that were not associated with complications or survival

Influence of particle size and particle size distribution on toughening mechanisms in rubber-modified epoxies

The principal toughening mechanism of a substantially toughened, rubber-modified epoxy has again been shown to involve internal cavitation of the rubber particles and the subsequent formation of shear bands. Additional evidence supporting this sequence of events which provides a significant amount of toughness enhancement, is presented. However, in addition to this well-known mechanism, more subtle toughening mechanisms have been found in this work. Evidence for such mechanisms as crack deflection and particle bridging is shown under certain circumstances in rubber-modified epoxies. The occurrence of these toughening mechanisms appears to have a particle size dependence. Relatively large particles provide only a modest increase in fracture toughness by a particle bridging/crack deflection mechanism. In contrast, smaller particles provide a significant increase in toughness by cavitation-induced shear banding. A critical, minimum diameter for particles which act as bridging particles exists and this critical diameter appears to scale with the properties of the neat epoxy. Bimodal mixtures of epoxies containing small and large particles are also examined and no synergistic effects are observed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44701/1/10853_2005_Article_BF01184979.pd

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

In Patients Undergoing CRS/HIPEC for Colorectal Adenocarcinoma with Peritoneal Metastases, Presence of Ascites on Computed Tomography Imaging is not a Prognostic Marker for Survival

Background: Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is a potentially curative treatment for patients with colorectal peritoneal metastases (CRPM). Patient selection is key to optimizing outcomes after CRS/HIPEC. The aim of this study was to determine the prognostic value of ascites diagnosed on preoperative imaging. Methods: A prospective database of patients eligible for CRS/HIPEC between 2010 and 2020 was retrospectively analyzed. The presence of ascites, postoperative complications, overall survival (OS), disease-free survival (DFS), and completeness of cytoreduction were assessed. Univariable and multivariable logistic regression was performed to identify independent predictors for outcome. Results: Of the 235 included patients, 177 (75%) underwent CRS/HIPEC while 58 (25%) were not eligible for CRS/HIPEC. In 42 of the 177 patients (24%) who underwent CRS/HIPEC, ascites was present on preoperative computed tomography (CT) imaging. Peritoneal Cancer Index (PCI) score was significantly higher in patients with preoperative ascites compared with patients without (11 [range 2–30] vs. 9 [range 0–28], respectively; p = 0.011) and complete cytoreduction was more often achieved in patients without ascites (96.3% vs. 85.7%; p = 0.007). There was no significant difference in median DFS and OS after CRS/HIPEC between patients with and without ascites {10 months (95% confidence interval [CI] 7.1–12.9) vs. 9 months (95% CI 7.2–10.8), and 25 months (95% 9.4–40.6) vs. 27 months (95% CI 22.4–31.6), respectively}. Conclusions: Ascites on preoperative imaging was not associated with worse survival in CRS/HIPEC patients with CRPM. Therefore, excluding patients from CRS/HIPEC based merely on the presence of ascites is not advisable