Lymph Node Ratio as a Predictor of Survival for Colon Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND: Lymph node ratio is the number of lymph nodes with evidence of metastases on pathological review compared to the total number of lymph nodes harvested during oncologic resection. Lymph node ratio is a proven predictor of long-term survival. These data have not been meta-analyzed to determine the prognosis associated with different lymph node ratio cut-offs in colon cancer. METHODS: Medline, Embase, and CENTRAL were systematically searched. Articles were included if they compared 5-year overall survival (OS) or disease-free survival (DFS) between different lymph node ratios for patients undergoing oncologic resection for stages I-III colon cancer. Pairwise meta-analyses using inverse variance random effects were performed. RESULTS: From 2587 citations, nine studies with 97,631 patients (female: 51.9%, median age: 61.65 years) were included. A lymph node ratio above .1 resulted in a 49% decrease in the odds of 5-year OS (2 studies; OR: 0.51, 95% CI: 0.49-.53, P < .00001). A lymph node ratio above .25 resulted in a 56% decrease in the odds of 5-year OS (3 studies; OR: 0.44, 95% CI: 0.43-.45, P < .00001). A lymph node ratio above .5 resulted in a 65% decrease in the odds of 5-year OS (3 studies; OR: 0.35, 95% CI: 0.33-.37, P < .00001). CONCLUSIONS: Lymph node ratios from .1 to .5 are effective predictors of 5-year OS for colon cancer. There appears to be an inverse dose-response relationship between lymph node ratio and 5-year OS. Further study is required to determine whether there is an optimal lymph node ratio cut-off for prognostication and whether it can inform which patients may benefit from more aggressive adjuvant therapy and follow-up protocols.

Risk Scores for Prediction of Postoperative Atrial Fibrillation After Cardiac Surgery: A Systematic Review and Meta-Analysis.

Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery and is associated with poor clinical outcomes. The objective of this systematic review and meta-analysis was to assess the performance of risk scores to predict POAF in cardiac surgery patients. We searched MEDLINE, Embase, and Cochrane CENTRAL for studies that developed/evaluated a POAF risk prediction model. Pairs of reviewers independently screened studies and extracted data. We pooled area under the receiver operating curves (AUCs), sensitivity and specificity, and adjusted odds ratios from multivariable regression analyses using the generic inverse variance method and random effects models. Forty-three studies (n = 63,847) were included in the quantitative synthesis. Most scores were originally developed for other purposes but evaluated for predicting POAF. Pooled AUC revealed moderate POAF discrimination for the EuroSCORE II (AUC 0.59, 95% confidence interval [CI] 0.54 to 0.65), Society of Thoracic Surgeons (AUC 0.60, 95% CI 0.56 to 0.63), EuroSCORE (AUC 0.63, 95% CI 0.58 to 0.68), CHADS2 (AUC 0.66, 95% CI 0.57 to 0.75), POAF Score (AUC 0.66, 95% CI 0.63 to 0.68), HATCH (AUC 0.67, 95% CI 0.57 to 0.75), CHA2DS2-VASc (AUC 0.68, 95% CI 0.60 to 0.75) and SYNTAX scores (AUC 0.74, 95% CI 0.71 to 0.78). Pooled analyses at specific cutoffs of the CHA2DS2-VASc, CHADS2, HATCH, and POAF scores demonstrated moderate-to-high sensitivity (range 46% to 87%) and low-to-moderate specificity (range 31% to 70%) for POAF prediction. In conclusion, existing clinical risk scores offer at best moderate prediction for POAF after cardiac surgery. Better models are needed to guide POAF risk stratification in cardiac surgery patients.

Perioperative intravenous dexamethasone for patients undergoing colorectal surgery: a systematic review and meta-analysis.

PURPOSE: Dexamethasone is a glucocorticoid that is often administered intraoperatively as prophylaxis for postoperative nausea and vomiting (PONV). Several randomized controlled trials (RCTs) have examined its use in colorectal surgery. This systematic review aims to assess the postoperative impacts of dexamethasone use in colorectal surgery. METHODS: MEDLINE, Embase, and CENTRAL were searched from database inception to January 2023. Articles were included if they compared perioperative intravenous dexamethasone to a control group in patients undergoing elective colorectal surgery in terms of postoperative morbidity. The primary outcomes were prolonged postoperative ileus (PPOI) and PONV. Secondary outcomes included postoperative infectious morbidity and return of bowel function. A pair-wise meta-analysis and GRADE assessment of the quality of evidence were performed. RESULTS: After reviewing 3476 relevant citations, seven articles (five RCTs, two retrospective cohorts) met the inclusion criteria. Overall, 1568 patients received perioperative dexamethasone and 1459 patients received a control. Patients receiving perioperative dexamethasone experienced significantly less PPOI based on moderate-quality evidence (three studies, OR 0.46, 95%CI 0.28-0.74, p < 0.01). Time to first flatus was significantly reduced with intravenous dexamethasone. There was no difference between groups in terms of PONV (four studies, OR 0.90, 95%CI 0.64-1.27, p = 0.55), postoperative morbidity (OR 0.93, 95%CI 0.63-1.39, p = 0.74), or rate of postoperative infectious complications (seven studies, OR 0.74, 95%CI 0.55-1.01, p = 0.06). CONCLUSION: This review presents moderate-quality evidence that perioperative intravenous dexamethasone may reduce PPOI and enhance the return of bowel function following elective colorectal surgery. There was no significant observed effect on PONV or postoperative infectious complications.

Selective Opioid Antagonists Following Bowel Resection for Prevention of Postoperative Ileus: a Systematic Review and Meta-analysis.

BACKGROUND: Postoperative ileus (POI) remains a common complication following bowel resection. Selective opioid antagonists have been increasingly studied as prophylactic pharmaceutical aids to reduce rates of POI. The aim of this study was to evaluate the impact of selective opioid antagonists on return of bowel function following bowel resection. METHODS: MEDLINE, Embase, and CENTRAL were systematically searched. Articles were included if they compared the incidence of POI and/or length of stay (LOS) in patients receiving and not receiving selective opioid antagonists following elective bowel resection. A pairwise meta-analyses using inverse variance random effects was performed. RESULTS: From 636 citations, 30 studies with 45,051 patients receiving selective opioid antagonists (51.3% female, mean age: 60.9) and 55,071 patients not receiving selective opioid antagonists (51.2% female, mean age: 61.1) were included. Patients receiving selective opioid antagonists had a significantly lower rate of POI (10.1% vs. 13.8%, RR 0.68, 95%CI 0.63-0.75, p < 0.01). Selective opioid antagonists also significantly reduced LOS (MD - 1.08, 95%CI - 1.47 to - 0.69, p < 0.01), readmission (RR 0.94, 95%CI 0.89-0.99, p = 0.03), and 30-day morbidity (RR 0.85, 95%CI 0.79-0.90, p < 0.01). Improvements in LOS, readmission rate, and morbidity were not significant when analysis was limited to laparoscopic surgery. There was no significant difference in inpatient healthcare costs (SMD - 0.33, 95%CI - 0.71-0.04, p = 0.08). CONCLUSIONS: Rate of POI decreases with the use of selective opioid antagonists in patients undergoing bowel resection. Selective opioid antagonists also improve LOS, rates of readmission, and 30-day morbidity for patients undergoing open bowel resection. Addition of these medications to enhance recovery after surgery protocols should be considered.