The Incidence of Postoperative Complications after Gastrectomy Increases in Proportion to the Amount of Preoperative Visceral Fat

LightGBM is an Effective Predictive Model for Postoperative Complications in Gastric Cancer: A Study Integrating Radiomics with Ensemble Learning

Postoperative complications of radical gastrectomy seriously affect postoperative recovery and require accurate risk prediction. Therefore, this study aimed to develop a prediction model specifically tailored to guide perioperative clinical decision-making for postoperative complications in patients with gastric cancer. A retrospective analysis was conducted on patients who underwent radical gastrectomy at the First Affiliated Hospital of Nanjing Medical University between April 2022 and June 2023. A total of 166 patients were enrolled. Patient demographic characteristics, laboratory examination results, and surgical pathological features were recorded. Preoperative abdominal CT scans were used to segment the visceral fat region of the patients through 3Dslicer, a 3D Convolutional Neural Network (3D-CNN) to extract image features and the LASSO regression model was employed for feature selection. Moreover, an ensemble learning strategy was adopted to train the features and predict postoperative complications of gastric cancer. The prediction performance of the LGBM (Light Gradient Boosting Machine), XGB (XGBoost), RF (Random Forest), and GBDT (Gradient Boosting Decision Tree) models was evaluated through fivefold cross-validation. This study successfully constructed a model for predicting early complications following radical gastrectomy based on the optimal algorithm, LGBM. The LGBM model yielded an AUC value of 0.9232 and an accuracy of 87.28% (95% CI, 75.61-98.95%), surpassing the performance of other models. Through ensemble learning and integration of perioperative clinical data and visceral fat radiomics, a predictive LGBM model was established. This model has the potential to facilitate individualized clinical decision-making and the early recovery of patients with gastric cancer post-surgery.

Sarcopenia is an Independent Prognostic Factor in Patients With Pancreatic Cancer - a Meta-analysis

RATIONALE AND OBJECTIVES

Sarcopenia is defined as skeletal muscle loss and can be assessed by cross-sectional imaging. Our aim was to establish the effect of sarcopenia on relevant outcomes in patients with pancreatic ductal adenocarcinoma (PDAC) in curative and palliative settings based on a large patient sample.

MATERIALS AND METHODS

MEDLINE library, EMBASE and SCOPUS databases were screened for the associations between sarcopenia and mortality in patients with PDAC up to March 2022. The primary endpoint of the systematic review was the hazard ratio of Sarcopenia on survival. 22 studies were included into the present analysis.

RESULTS

The included 22 studies comprised 3958 patients. The prevalence of sarcopenia was 38.7%. Sarcopenia was associated with a higher prevalence in the palliative setting (OR 53.23, CI 39.00-67.45, p<0.001) compared to the curative setting (OR 36.73, CI 27.81-45.65, p<0.001). Sarcopenia was associated with worse OS in the univariable (HR 1.79, CI 1.41-2.28, p<0.001) and multivariable analysis (HR 1.62, CI 1.27-2.07, p<0.001) in the curative setting. For the palliative setting the pooled hazards ratio showed that sarcopenia was associated with overall survival (HR 1.56, CI 1.21-2.02, p<0.001) as well as in multivariable analysis (HR 1.77, CI 1.39-2.26, p<0.001). Sarcopenia was not associated with a higher rate of post-operative complications in univariable analysis (OR 1.10, CI 0.70-1.72, p = 0.69).

CONCLUSION

Sarcopenia occurs in 38.7% of patients with pancreatic cancer, significantly more in the palliative setting. Sarcopenia is associated with overall survival in both settings. The assessment of sarcopenia is therefore relevant for personalized oncology. Sarcopenia is not associated with postoperative complications.

Association of visceral adipose tissue with postoperative outcome in upper gastrointestinal cancer: a systematic review and meta-analysis

BACKGROUND

There is no consensus on the relation between visceral fat mass and long-term postoperative prognosis in patients with upper gastrointestinal (GI) cancer.

OBJECTIVES

The purpose of this study was to investigate the association of preoperative visceral fat mass with postoperative complications and overall survival (OS) in patients with upper GI cancer.

METHODS

We searched MEDLINE, the Cochrane Central Register of Controlled Trials, EMBASE (Dialog), the WHO International Clinical Trials Platform Search Portal, and ClinicalTrials.gov and identified observational studies published from inception through 20 July 2022. We conducted a systematic review and random-effects meta-analysis of studies including patients who were surgically treated for upper GI cancer and whose visceral fat mass was assessed on the basis of body composition. We independently assessed the risk of bias and quality of evidence using the Quality In Prognosis Studies and the Grading of Recommendations, Assessment, Development, and Evaluation approach, respectively. The primary outcome was OS. HRs and 95% CIs for OS were pooled.

RESULTS

Ninety-one studies (n = 20,583) were included. All studies used computed tomography (CT) to assess the body composition of patients. Twenty-four studies reported the relation between high visceral fat and postoperative outcomes, and their results were synthesized. Compared with low visceral adipose tissue, high visceral adipose tissue assessed by CT may improve OS (HR: 0.69; 95% CI: 0.55, 0.87; I2 = 65%; n = 3407). The risk of bias for OS in each study was moderate or high. The certainty of evidence for OS was very low because of inconsistency in the forest plot, the moderate or high risk of bias, and publication bias.

CONCLUSIONS

High visceral fat may be associated with improved OS after radical resection in patients with upper GI cancer. Further studies are needed to confirm these findings and mitigate the risk.

A Sarcopenia-Based Prediction Model for Postoperative Complications of ex vivo Liver Resection and Autotransplantation to Treat End-Stage Hepatic Alveolar Echinococcosis

Background

Sarcopenia and visceral adiposity have been shown to be associated with postoperative complications in numerous diseases. However, their effects on the postoperative complications of end-stage hepatic alveolar echinococcosis (HAE) patients undergoing ex vivo liver resection and autotransplantation (ELRA) remain unclear.

Methods

This retrospective study included 101 end-stage HAE patients who underwent ELRA from January 2014 to August 2020. We measured the skeletal muscle and adipose tissue of all patients at the level of the third lumbar vertebra on plain abdominal computed tomography (CT) images and subsequently derived an equation via least absolute shrinkage and selection operator (LASSO) regression analysis to calculate the sarcopenia score. Univariate and multivariate regression were performed to reveal the relationship between major postoperative complications and perioperative clinical data, and the obtained nomogram was validated with the bootstrapping method.

Results

The sarcopenia score was constructed as a personalized indicator to evaluate sarcopenia and visceral adiposity in each patient. Logistic regression analysis finally selected duration from primary diagnosis to obvious symptoms (OR=1.024, 95% CI, 1.007-1.042), surgical time (OR=1.003, 95% CI, 0.999-1.007) and sarcopenia score (OR=4.283, 95% CI, 1.739-10.551) as independent risk factors for predicting major postoperative complications following ELRA for end-stage HAE patients. The area under the receiver operating characteristic curve (AUROC) of 0.807 (95% CI, 0.720-0.895) and the calibration curve for this prediction model were satisfactory.

Conclusion

The sarcopenia score, which systematically evaluates the skeletal muscle and adipose tissue of end-stage HAE patients, was a significant predictive factor for major postoperative complications of ELRA. Relevant interventions should be conducted for those who have a high risk of postoperative complications according to the nomogram.

Visceral fat area is a better indicator of surgical outcomes after laparoscopic gastrectomy for cancer than the body mass index: a propensity score-matched analysis

BACKGROUND

The number of overweight gastric cancer patients who are undergoing laparoscopic gastrectomy (LG) has increased in Japan. However, the relationship between obesity and surgical outcomes of LG remains unclear. Therefore, this study aimed to evaluate the effect of visceral fat area (VFA) on surgical outcomes of LG for gastric cancer compared to the body mass index (BMI).

METHODS

This study was a retrospective, cohort study that included 587 patients who underwent LG in our institution between January 2015 and December 2019. The patients were divided into two groups according to VFA (< 100 cm² and ≥ 100 cm²) and BMI (< 25 kg/m² and ≥ 25 kg/m²) values, respectively. Surgical outcomes and postoperative complications were compared between the low and high groups for each VFA and BMI value. Propensity score matching was used to minimize potential selection bias.

RESULTS

After propensity score matching, 144 pairs of patients in the VFA group and 82 pairs of patients in the BMI group were extracted. Operative time (p = 0.003), intraoperative blood loss (p = 0.0006), and CRP levels on postoperative day 1 (p = 0.002) and on postoperative day 3 (p = 0.004) were significantly higher in the high-VFA group than in the low-VFA group. However, these surgical outcomes were not significantly different between the high-BMI and low-BMI groups. There was no strong correlation between VFA and BMI (R² = 0.64). There were no significant differences in postoperative complications between the high and low groups for both VFA and BMI values. On multivariate analysis, high VFA was an independent predictor of operative time, but it was not significantly associated with the incidence of postoperative complications.

CONCLUSION

VFA is a better indicator of longer operative time than BMI. However, increased VFA did not affect postoperative complications.

Clinical Impact of a Perioperative Exercise Program for Sarcopenia and Overweight/Obesity Gastric Cancer

Gastrectomy with D2 lymph node dissection and perioperative adjuvant treatment is the standard treatment for locally advanced gastric cancer. However, the morality rate is reported to be 20%-40% after gastrectomy for gastric cancer. Perioperative sarcopenia and obesity are strongly related to postoperative surgical complications after gastrectomy. Furthermore, recent studies have shown that postoperative surgical complications are related to long-term oncological outcomes. If we can prevent or improve perioperative sarcopenia or obesity in gastric cancer patients, the rate of postoperative surgical complications in these patients might be reduced, thereby improving the long-term oncological outcomes. Given this hypothesis, recent studies have focused on enacting perioperative exercise programs for gastric cancer patients with sarcopenia and overweight/obesity. Such exercise programs have proven promising and demonstrated some clinical benefits for gastric cancer patients with sarcopenia and overweight/obesity. However, whether or not perioperative exercise programs have clinical benefits with regard to long-term oncological outcomes in gastric cancer patients is unclear. To optimize these perioperative exercise programs for gastric cancer patients, it is necessary to clarify the benefits with regard to the long-term oncological outcomes in these patients and establish an optimal perioperative exercise program.

Trunk fat volume can be a predictor of postoperative complications after gastrectomy: a retrospective cohort study

Background

Obesity can affect postoperative outcomes of gastrectomy. Visceral fat area is superior to body mass index in predicting postoperative complications. However, visceral fat area measurement is time-consuming and is not optimum for clinical use. Meanwhile, trunk fat volume (TFV) can be easily measured via bioelectrical impedance analysis. Hence, the current study aimed to determine the ability of TFV to predict the occurrence of complications after gastrectomy.

Methods

We retrospectively reviewed patients who underwent curative gastrectomy for gastric cancer between November 2016 and November 2019. The trunk fat volume-to-the ideal amount (%TFV) ratio was obtained using InBody 770 before surgery. The patients were classified into the obese and nonobese groups according to %TFV (TFV-H group, ≥ 150%; TFV-L group, < 150%) and body mass index (BMI-H group, ≥ 25 kg/m²; BMI-L group, < 25 kg/m²). We compared the short-term postoperative outcomes (e.g., operative time, blood loss volume, number of resected lymph nodes, and duration of hospital stay) between the obese and nonobese patients. Risk factors for complications were assessed using logistic regression analysis.

Results

In total, 232 patients were included in this study. The TFV-H and BMI-H groups had a significantly longer operative time than the TFV-L (p = 0.022) and BMI-L groups (p = 0.006). Moreover, the TFV-H group had a significantly higher complication rate (p = 0.004) and a lower number of resected lymph nodes (p < 0.001) than the TFV-L group. In the univariate analysis, %TFV ≥ 150, total or proximal gastrectomy, and open gastrectomy were found to be potentially associated with higher complication rates (p < 0.1 for all). Moreover, the multivariate analysis revealed that %TFV ≥ 150 (OR: 2.73; 95% CI: 1.37–5.46; p = 0.005) and total or proximal gastrectomy (OR: 3.57; 95% CI: 1.79–7.12; p < 0.001) were independently correlated with postoperative morbidity.

Conclusions

%TFV independently affected postoperative complications. Hence, it may be a useful parameter for the evaluation of obesity and a predictor of complications after gastrectomy.

Impact of body composition on clinical outcomes in people with gastric cancer undergoing radical gastrectomy after neoadjuvant treatment

OBJECTIVES

The influence of body composition on clinical outcomes in individuals with gastric cancer (GC) undergoing radical gastrectomy after neoadjuvant treatment (NT) remains unclear. The purpose of this retrospective study was to investigate the association between body composition before NT or after NT and clinical outcomes in individuals with GC receiving multimodal treatments.

METHODS

This retrospective study included individuals with GC who received NT followed by radical gastrectomy between January 2016 and December 2018. Skeletal muscle, visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT) were measured by cross-sectional areas at the level of third lumbar vertebra based on single-slice computed tomography scan prior to NT and prior to the surgical operation. Sarcopenia, high VAT, and high SAT were defined using cutoff points of skeletal muscle index, visceral fat area, and subcutaneous fat area. Univariate and multivariate analyses were performed to evaluate risk factors of NT-related adverse events, postoperative complications and predictors of long-term survival.

RESULTS

A total of 110 individuals with GC were enrolled in this study. Sarcopenia was present in 62.7% of them before NT and in 56.4% after NT. Sarcopenia before NT was associated with more NT-related adverse events (odds ratio, 2.901; 95% confidence interval [CI], 1.205-6.983; P = 0.018). High VAT after NT (≥106 cm²) was associated with an increasing incidence of postoperative complications (odds ratio, 4.261; 95% CI, 1.332-13.632; P = 0.015). No body-composition parameter was relevant to tumor pathologic response to NT. As for long-term survival, poor overall survival was associated with both low VAT before NT (<120 cm²; hazard ratio [HR], 2.542; 95% CI, 1.111-5.817; P = 0.027) and low SAT after NT (<99.5 cm²; HR, 2.743; 95% CI, 1.248-6.027; P = 0.012). Similarly, shorter disease-free survival was associated with low VAT before NT (<120 cm²; HR, 2.502; 95% CI, 1.222-5.124; P = 0.012) and low VAT after NT (<106 cm²; HR, 2.505; 95% CI, 1.172-5.358; P = 0.018).

CONCLUSIONS

Body composition measured by computed tomography could predict NT-related adverse events, postoperative complications, and long-term survival in multimodal treatments for GC. More meaningfully, adipose-tissue status has significant prognostic value for individuals with advanced GC.

Impact of the preoperative body composition indexes on intraoperative blood loss in patients undergoing pancreatoduodenectomy

PURPOSES

This study sought to identify any significant predictors of blood loss during pancreatoduodenectomy (PD) among preoperative variables, including the body composition indexes.

METHODS

The preoperative data of patients undergoing PD were retrospectively reviewed. The objective variable was the percentage of blood loss during PD to the estimated circulating blood volume (proportional blood loss: PBL). The circulating blood volume was estimated using Nadler's formula. The total psoas area, average Hounsfield units of psoas area (psoas muscle density: PMD), and visceral to subcutaneous adipose tissue area ratio (VSR) were measured at the third vertebra using preoperative plain computed tomography images. A univariate analysis and multiple linear regression analysis for PBL were conducted using the preoperative variables.

RESULTS

A total of 415 patients were analyzed. The median PBL was 24.5%. The PMD (coefficient - 0.267; 95% CI - 0.518, - 0.015), VSR (coefficient 2.719; 95% CI 0.238, 5.201), serum albumin level (coefficient - 8.458; 95% CI - 13.02, - 3.898), neoadjuvant therapy (coefficient 9.605; 95% CI 1.722, 17.49), and prothrombin time-international normalized ratio (PT-INR, coefficient 38.63; 95% CI 10.94, 66.31) were independently associated with PBL.

CONCLUSIONS

The preoperative PMD, VSR, serum albumin level, neoadjuvant therapy, and PT-INR independently affected PBL. These factors could therefore be potential targets to reduce blood loss during PD.