Publications by Year: 2024

2024
A prognostic model for use before elective surgery to estimate the risk of postoperative pulmonary complications (GSU-Pulmonary Score): a development and validation study in three international cohorts. Lancet Digit Health. 2024;6(7):e507-e519.Abstract
BACKGROUND: Pulmonary complications are the most common cause of death after surgery. This study aimed to derive and externally validate a novel prognostic model that can be used before elective surgery to estimate the risk of postoperative pulmonary complications and to support resource allocation and prioritisation during pandemic recovery. METHODS: Data from an international, prospective cohort study were used to develop a novel prognostic risk model for pulmonary complications after elective surgery in adult patients (aged ≥18 years) across all operation and disease types. The primary outcome measure was postoperative pulmonary complications at 30 days after surgery, which was a composite of pneumonia, acute respiratory distress syndrome, and unexpected mechanical ventilation. Model development with candidate predictor variables was done in the GlobalSurg-CovidSurg Week dataset (global; October, 2020). Two structured machine learning techniques were explored (XGBoost and the least absolute shrinkage and selection operator [LASSO]), and the model with the best performance (GSU-Pulmonary Score) underwent internal validation using bootstrap resampling. The discrimination and calibration of the score were externally validated in two further prospective cohorts: CovidSurg-Cancer (worldwide; February to August, 2020, during the COVID-19 pandemic) and RECON (UK and Australasia; January to October, 2019, before the COVID-19 pandemic). The model was deployed as an online web application. The GlobalSurg-CovidSurg Week and CovidSurg-Cancer studies were registered with ClinicalTrials.gov, NCT04509986 and NCT04384926. FINDINGS: Prognostic models were developed from 13 candidate predictor variables in data from 86 231 patients (1158 hospitals in 114 countries). External validation included 30 492 patients from CovidSurg-Cancer (726 hospitals in 75 countries) and 6789 from RECON (150 hospitals in three countries). The overall rates of pulmonary complications were 2·0% in derivation data, and 3·9% (CovidSurg-Cancer) and 4·7% (RECON) in the validation datasets. Penalised regression using LASSO had similar discrimination to XGBoost (area under the receiver operating curve [AUROC] 0·786, 95% CI 0·774-0·798 vs 0·785, 0·772-0·797), was more explainable, and required fewer covariables. The final GSU-Pulmonary Score included ten predictor variables and showed good discrimination and calibration upon internal validation (AUROC 0·773, 95% CI 0·751-0·795; Brier score 0·020, calibration in the large [CITL] 0·034, slope 0·954). The model performance was acceptable on external validation in CovidSurg-Cancer (AUROC 0·746, 95% CI 0·733-0·760; Brier score 0·036, CITL 0·109, slope 1·056), but with some miscalibration in RECON data (AUROC 0·716, 95% CI 0·689-0·744; Brier score 0·045, CITL 1·040, slope 1·009). INTERPRETATION: This novel prognostic risk score uses simple predictor variables available at the time of a decision for elective surgery that can accurately stratify patients' risk of postoperative pulmonary complications, including during SARS-CoV-2 outbreaks. It could inform surgical consent, resource allocation, and hospital-level prioritisation as elective surgery is upscaled to address global backlogs. FUNDING: National Institute for Health Research.
Triantafillidis JK, Papakontantinou J, Antonakis P, Konstadoulakis MM, Papalois AE. Enteral Nutrition in Operated-On Gastric Cancer Patients: An Update. Nutrients. 2024;16(11).Abstract
It is well established that the preoperative nutritional status of gastric cancer (GC) patients significantly affects the prognosis of the operated patients, their overall survival, as well as the disease-specific survival. Existing data support that preoperative assessment of nutritional status and early correction of nutritional deficiencies exert a favorable effect on early postoperative outcomes. A variety of relevant indices are used to assess the nutritional status of GC patients who are candidates for surgery. The guidelines of almost all international organizations recommend the use of oral enteral nutrition (EN). Oncologically acceptable types of gastrectomy and methods of patient rehabilitation should take into account the expected postoperative nutritional status. The majority of data support that perioperative EN reduces complications and hospital stay, but not mortality. Oral EN in the postoperative period, albeit in small amounts, helps to reduce the weight loss that is a consequence of gastrectomy. Iron deficiency with or without anemia and low serum levels of vitamin B12 are common metabolic sequelae after gastrectomy and should be restored. EN also significantly helps patients undergoing neoadjuvant or adjuvant antineoplastic therapy. The occurrence of the so-called "postgastrectomy syndromes" requires dietary modifications and drug support. This review attempts to highlight the benefits of EN in GC patients undergoing gastrectomy and to emphasize the type of necessary nutritional management, based on current literature data.
Access to and quality of elective care: a prospective cohort study using hernia surgery as a tracer condition in 83 countries. Lancet Glob Health. 2024;12(7):e1094-e1103.Abstract
BACKGROUND: Timely and safe elective health care facilitates return to normal activities for patients and prevents emergency admissions. Surgery is a cornerstone of elective care and relies on complex pathways. This study aimed to take a whole-system approach to evaluating access to and quality of elective health care globally, using inguinal hernia as a tracer condition. METHODS: This was a prospective, international, cohort study conducted between Jan 30 and May 21, 2023, in which any hospital performing inguinal hernia repairs was eligible to take part. Consecutive patients of any age undergoing primary inguinal hernia repair were included. A measurement set mapped to the attributes of WHO's Health System Building Blocks was defined to evaluate access (emergency surgery rates, bowel resection rates, and waiting times) and quality (mesh use, day-case rates, and postoperative complications). These were compared across World Bank income groups (high-income, upper-middle-income, lower-middle-income, and low-income countries), adjusted for hospital and country. Factors associated with postoperative complications were explored with a three-level multilevel logistic regression model. FINDINGS: 18 058 patients from 640 hospitals in 83 countries were included, of whom 1287 (7·1%) underwent emergency surgery. Emergency surgery rates increased from high-income to low-income countries (6·8%, 9·7%, 11·4%, 14·2%), accompanied by an increase in bowel resection rates (1·2%, 1·4%, 2·3%, 4·2%). Overall waiting times for elective surgery were similar around the world (median 8·0 months from symptoms to surgery), largely because of delays between symptom onset and diagnosis rather than waiting for treatment. In 14 768 elective operations in adults, mesh use decreased from high-income to low-income countries (97·6%, 94·3%, 80·6%, 61·0%). In patients eligible for day-case surgery (n=12 658), day-case rates were low and variable (50·0%, 38·0%, 42·1%, 44·5%). Complications occurred in 2415 (13·4%) of 18 018 patients and were more common after emergency surgery (adjusted odds ratio 2·06, 95% CI 1·72-2·46) and bowel resection (1·85, 1·31-2·63), and less common after day-case surgery (0·39, 0·34-0·44). INTERPRETATION: This study demonstrates that elective health care is essential to preventing over-reliance on emergency systems. We identified actionable targets for system strengthening: clear referral pathways and increasing mesh repair in lower-income settings, and boosting day-case surgery in all income settings. These measures might strengthen non-surgical pathways too, reducing the burden on society and health services. FUNDING: NIHR Global Health Research Unit on Global Surgery and Portuguese Hernia and Abdominal Wall Society (Sociedade Portuguesa de Hernia e Parede Abdominal).