Place of venous thromboembolism in the structure of hospital mortality in patients with acute surgical abdominal pathology and COVID-19

Abstract

Introduction. Prevention of deep vein thrombosis (DVT) of the lower extremities and pulmonary artery thromboembolism (PATE) in patients with acute surgical abdominal pathology during global COVID-19 pandemic is an urgent problem. According to 2021 meta-analysis of MEDLINE (n=635), EMBASE (n=731), Cochrane library (n=23), SSRN (n=61) and Medrxiv (n=196) databases, the frequency of DVT in patients with coronavirus infection (CI) reaches 14.8% and the frequency of PATE – 16.5%, respectively. Aim of the research. To study the characteristics and structure of mortality in patients with acute surgical abdominal pathology with concomitant CI and to evaluate the dynamics of venous thromboembolism (VTE) in patients of given group since the beginning of the COVID-19 pandemic. Methodology and methods. A single-center, retrospective, event-controlled, non-randomized study was performed at the Surgery center of the St. Panteleimon multidisciplinary hospital of the First territorial medical union. Using the Doctor Eleks EHealth database, we searched for key parameters: emergency surgery for abdominal surgical pathology and presence of a SARS-CoV-2 using the polymerase chain reaction (PCR) and/or characteristic changes on the spiral computed tomography (SCT) of the chest at the time of inpatient treatment. Total sampling method from April 2020 to September 2022 had covered 124 protocols of autopsy. Average age of the patients was 62.8±11.5, those of working age were 41.3%. Men predominated – 62.5%. Surgical interventions were performed in all patients, average duration was 122.4±31.3 min. Severity of viral pneumonia according to SCT was СО-RADS grade 4–6. Criteria for inclusion in the study were: acute surgical abdominal pathology, presence of positive PCR result for SARS-CoV-2, surgical intervention within 12 hours from the admission to the hospital. Detailed analysis of 54 autopsy protocols had shown that 19 (35.5%) patients were diagnosed with COVID-19 while alive. In the course of research, it was established that thromboemboli in the system of pulmonary arteries and veins of the pelvis and lower extremities were found at autopsy in 21 (38.9%) patient, including 9 (16.7%) whose fatal impact on thanatogenesis was diagnosed. DVT was detected in 14 (25.9%) deceased patients, but 3 facts should be noted: only in a third of patients, the vessels of the lower extremities were examined at autopsy; not all patients with PATE had DVT; in most patients with DVT, thromboemboli were diagnosed in the pulmonary arteries of various types and caliber. Results and discussion. The real scale of VTE since the beginning of the COVID-19 pandemic remains underestimated until now. The course of CI in patients with severe course of the concomitant disease, such as oncological, severe abdominal infection or other acute diseases of the abdominal cavity, adds drama. Surgical intervention was often performed in conditions of limited opportunities to compensate the patient's homeostasis on the background of severe respiratory failure, need for constant oxygen therapy, difficulties of adequate assessment of risk factors for thromboembolic complications (TEC), usually during hypercoagulation etc. Hidden course of DVT and PATE, significant difficulties of diagnostics, decrease in the number of autopsies related to sharp increase of amount of patients with COVID-19, military aggression of Russian Federation and other reasons, does not make it possible to draw correct conclusions about the real frequency of VTE and effectiveness of prevention in the studied contingent of patients. Analyzing the medical cases of deceased patients, a significantly higher rate of TEC was stated in those with acute urgent surgical pathology and concomitant CI. Total frequency of VTE in patients with COVID-19 was 47.4%, of which 21.1% were fatal PATE, in contrast to the group without COVID-19 – 34.3% and 14.3%, respectively. Specific prevention of VTE consisted in subcutaneous administration of heparin, as a rule, of low molecular weight. Contrary to the fact that in patients with COVID-19, medical prophylaxis was carried out in all patients in accordance with the protocol documents, the number of TEC episodes, including fatal PATE, in patients with CI was 1.5 times higher. A substantial number of problematic issues can be solved by working out and implementing into clinical practice a national standard for the prevention of VTE in patients with emergency abdominal surgical pathology and COVID-19. Conclusions. 1. Venous thrombosis and embolism are one of the most serious postoperative complications in emergency surgery, especially on the background of the COVID-19 pandemic. 2. The real risk of thromboembolic complications in patients with acute abdominal surgical pathology and concomitant coronavirus infection is underestimated due to objective reasons (emergence of new strains of the SARS-CoV-2, inadequate statistics due to military aggression etc.) 3. Fatal thromboembolism of the pulmonary artery in patients with acute surgical abdominal pathology and COVID-19 is observed in 21.1%, being 1.5 times higher than in patients without COVID-19. 4. Prevention of venous thromboembolism according to existing recommendations does not provide complete protection against fatal PATE in patients with emergency surgical pathology and COVID-19 and needs further study.