The composite risk index based on frailty predicts postoperative complications in older patients recovering from elective digestive tract surgery: a retrospective cohort study

Background Limitations exist in available studies investigating effect of preoperative frailty on postoperative outcomes. This study was designed to analyze the association between composite risk index, an accumulation of preoperative frailty deficits, and the risk of postoperative complications in older patients recovering from elective digestive tract surgery. Methods This was a retrospective cohort study. Baseline and perioperative data of older patients (age ≥ 65 years) who underwent elective digestive tract surgery from January 1, 2017 to December 31, 2018 were collected. The severity of frailty was assessed with the composite risk index, a composite of frailty deficits including modified frailty index. The primary endpoint was the occurrence of postoperative complications during hospital stay. The association between the composite risk index and the risk of postoperative complications was assessed with a multivariable logistic regression model. Results A total of 923 patients were included. Of these, 27.8% (257) developed postoperative complications. Four frailty deficits, i.e., modified frailty index ≥0.27, malnutrition, hemoglobin < 90 g/L, and albumin ≤30 g/L, were combined to generate a composite risk index. Multivariable analysis showed that, when compared with patients with composite risk index of 0, the odds ratios (95% confidence intervals) were 2.408 (1.714–3.383, P < 0.001) for those with a composite risk index of 1, 3.235 (1.985–5.272, P < 0.001) for those with a composite risk index of 2, and 9.227 (3.568–23.86, P < 0.001) for those with composite risk index of 3 or above. The area under receiver-operator characteristic curve to predict postoperative complications was 0.653 (95% confidence interval 0.613–0.694, P < 0.001) for composite risk index compared with 0.622 (0.581–0.663, P < 0.001) for modified frailty index. Conclusion For older patients following elective digestive tract surgery, high preoperative composite risk index, a combination of frailty deficits, was independently associated with an increased risk of postoperative complications.

Assessing the hospital volume-outcome relationship in surgery: a scoping review

Introduction Many recent studies have investigated the hospital volume-outcome relationship in surgery. In some cases, the results have prompted the centralization of surgical activity. However, the methodologies and interpretations differ markedly from one study to another. The objective of the present scoping review was to describe the various features used to assess the volume-outcome relationship: the analyzed datasets, study population, outcome, covariates, confounders, volume modalities, and statistical methods. Methods and analysis The review was conducted according to a study protocol published in BMJ Open in 2020. Two authors (both of whom had helped to design the study protocol) screened publications independently according to the title, the abstract and then the full text. To ensure exhaustivity, all the papers included by each reviewer went through to the next step. Interpretation The 403 included studies covered 90 types of surgery, 61 types of outcome, and 72 covariates or potential confounders. 191 (47.5%) studies focussed on oncological surgery and 37.8% focussed visceral or digestive tract surgery. Overall, 86.6% of the studies found a statistically significant volume-outcome relationship, although the findings differed from one type of surgery to another. Furthermore, the types of outcome and the covariates were highly diverse. The majority of studies were performed in Western countries, and oncological and visceral surgical procedures were over-represented; this might limit the generalizability and comparability of the studies’ results.

Preoperative hyponatremia predicts complications in older patients undergoing digestive tract surgery: a propensity score matching analysis

Purpose Whether preoperative hyponatremia increases the risk of postoperative complications in older patients undergoing digestive tract surgery remains unclear. The purpose of the study was to investigate the association between preoperative hyponatremia and life-threatening postoperative complications (including death) among older patients undergoing digestive tract surgery. Methods This was a propensity score-matched, retrospective cohort study. We recruited older patients (≥ 65 years of age) who underwent digestive tract surgery in our institution. The propensity score matching (PSM; 1:2) was used to balance a range of covariates between patients with preoperative hyponatremia (serum sodium [Na+] levels < 135 mmol/L) and those with normal [Na+] levels (135–145 mmol/L). The primary outcome was the occurrence of life-threatening postoperative complications and mortality (i.e., Clavien–Dindo grade IV and V [CD IV and V] complications) during hospital stay. The relationship between preoperative hyponatremia and the development of CD IV and V complications was identified with logistic regression analysis. Results A total of 1076 patients were analyzed (mean age 73.9 years; 421 female [39.1%]). Preoperative hyponatremia was identified in 122 patients. After matching, 312 patients were included in the analyses (104 patients with preoperative hyponatremia and 208 patients with normal [Na+] levels; mean age, 76.3 years; 130 female [41.7%]). When compared with normal [Na+] levels, preoperative hyponatremia was associated with an increased risk of CD IV and V complications (odds ratio [OR] 2.082, 95% confidential interval [CI] 1.041–4.164, P = 0.038). Preoperative hyponatremia was also significantly associated with a higher risk of postoperative infectious complications (OR 2.158, 95% CI 1.138–4.091, P = 0.018). Conclusion Preoperative hyponatremia can predict an increased risk of life-threatening postoperative complications and mortality in older patients undergoing digestive tract surgery.

Titanium implants modified by laser microtexturing enhance the bioactivity of gastric epithelial cells and fibroblast cells

The clinical application of anastomotic instruments improves the efficiency of the digestive tract surgery. However, the stapler with titanium nails implanted is still controversial in terms of anastomotic complications, and further improvement and optimization are needed. The purpose of this study was to explore the optimal microtextured parameters that could enhance the bioactivity of titanium implants in vitro. Laser microtexturing technology was used to construct the groove-type microstructural surfaces with different parameters, and human gastric mucosal epithelial cells (GES-1 cells) and mouse fibroblasts (3T3 cells) were cultured on the surface of the titanium plates in vitro. The data of cell adhesion, cell proliferation and cell activity were obtained and statistically analyzed. The textured titanium plates meet the expected design. GES-1 and 3T3 cell adhesion were better in the surface of titanium plates in microstructural group than that in the polished group. GES-1 and 3T3 cells also showed higher proliferative activity in the microstructural group compared with the polished group. The laser textured titanium plates have good groove-type microstructure, which increase the surface roughness, change the surface wettability, promote the adhesion, proliferating and orderly growth of GES-1 and 3T3 cells, and show good biological properties.