Literature selections curated by Lewis Flint, MD, FACS, and reviewed by the Bulletin Brief editorial board.
February 15, 2022
Nicholson KJ, Rosengart MR, Smith, KJ, et al. Investigation into the cost-effectiveness of extended posttraumatic thromboprophylaxis. J Am Coll Surg. 2022;234:86-94.
Injured patients may be at risk for venous thromboembolic (VTE) complications for an extended period following the injury event, similar to other high-risk surgical patient groups such as patients undergoing oncologic surgical procedures. The authors used a cost-utility model to determine the cost-effectiveness of a 30-day course of post-injury VTE prophylaxis compared with no post-hospitalization prophylaxis.
Risk of venous thrombosis, pulmonary embolus, or bleeding during the 30-day interval were modeled against rates of sequelae of VTE such as post-thrombotic syndrome and chronic pulmonary hypertension. Several readily available agents were assessed in the model; rivaroxaban was determined to be the most effective agent, and this benefit persisted when patients were analyzed in low-risk and high-risk groups. The authors concluded that these data support the conduct of prospective randomized studies of extended post-injury VTE prophylaxis with rivaroxaban.
Vos EL, Nakauchi M, Capanu M, et al. Phase II trial evaluating esophageal reinforcement with a biologic, degradable, extracellular matrix after total gastrectomy and esophagectomy. J Am Coll Surg 2022, in press.
The study reported in this article evaluated the use of extracellular matrix (ECM) reinforcement of esophageal anastomoses as a means of reducing risk of anastomotic leak. Patients having ECM reinforcement (N=66) were compared with patients from a retrospective cohort who had esophagectomy or total gastrectomy with standard anastomotic techniques. Outcomes out to 90 days postoperatively were obtained.
The data analysis showed that anastomotic leak rates (9.1%) were similar to the rates recorded in the comparison group; anastomotic stenosis causing symptoms or requiring intervention was observed in similar proportions of the two groups. The observed rates of anastomotic leak and stenosis were similar to those reported in other studies. The authors concluded that ECM reinforcement was safe and did not increase risk of complications but did not reduce the rate of anastomotic leak.
Willyard C. What the Omicron wave is revealing about human immunity. Nature. Feb 2022;602(7895):22-25. doi:10.1038/d41586-022-00214-3
The Omicron variant of SARS-CoV-2 has presented formidable challenges to immunologists seeking to characterize the immune response to COVID-19 infection and to determine effectiveness of vaccines in preventing infection, serious illness, hospitalization, and mortality. Scientists have learned that a durable antibody response to vaccination is not guaranteed. Data cited in the article showed that antibody levels wane in the weeks following vaccination and that lasting benefit from vaccination results from immune responses other than typical antibodies.
One important discovery has been that B-cells with a long lifespan are stimulated by vaccination and are produced, as part of the immune response to infection, in germinal centers. These cells are critical to the development of a lasting immunity to COVID-19 infection. When these cells encounter the virus, they rapidly divide and produce plasma cells that manufacture antibodies. Also critical are T cells that can encounter the virus and multiply into a population of cells that can destroy the virus and wipe out the infection. Another important discovery is that these T-cells often are present not because of vaccination but because of a response to a past SARS infection such as the common cold; they can respond to COVID-19 infection, according to a study cited in the article that documented evidence of a T-cell-mediated immune response in unvaccinated healthcare workers.
This review provided a clear description of these discoveries and opportunities for future progress. The information presented will be useful to surgeons and helpful for patient education.