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Faculty of Health Sciences

Department of Health Research Methods, Evidence, and Impact (HEI)

First-of-its-kind study examines most common post-general surgery complications that result in death

Close-up of surgeon’s hands passing medical scissors.
In the first study of its kind, researchers from the Department of Health Research Methods, Evidence, and Impact (HEI) tracked patients who underwent major general surgeries to characterize post-operative complications and their link to 30-day mortality, potentially guiding new mitigating strategies.

By Kaitlynn Kemp

In a groundbreaking international study, McMaster University researchers are shedding light on the alarming impact of post-operative complications on patient survival rates following general surgery, with the potential to guide new mitigating strategies.

Current causes of death after general surgery are not well characterized. This is why researchers from the Department of Health Research Methods, Evidence, and Impact (HEI) have published findings in the Annals of Surgery that characterize six post-operative complications to understand how often they occur and how they relate to death within 30 days after surgery.

This research was led by Lily Park, a McMaster general surgery resident and recent Health Research Methodology MSc graduate, under the supervision of HEI professor PJ Devereaux, with contributions from HEI professor Lehana Thabane.

“By anticipating and addressing these complications, health-care providers can effectively reduce the risk of death, both by preventing complications before they arise and by promptly treating them afterward,” shared Devereaux, HEI professor and senior author of the study.

The six post-operative complications the team identified were:

  1. Major bleeding: Significant blood loss that can occur during or after surgery.
  2. Sepsis: A life-threatening reaction to infection.
  3. Myocardial injury after non-cardiac surgery: Heart damage occurring after surgeries not involving the heart, often due to stress from surgery on the heart muscle.
  4. Acute kidney injury resulting in dialysis: Kidney failure requiring dialysis (an invasive medical treatment) to clean the blood because the kidneys are unable to do so.
  5. Stroke: A life-threatening condition resulting from insufficient blood flow to the brain, causing brain damage.
  6. Infection without sepsis: The invasion and multiplication of germs in the body.

Post-operative deaths are the third leading cause of global fatalities. These findings could guide new strategies to mitigate post-operative complications after general surgery.

Characterizing the complications

This study is the first of its kind to investigate the association between post-operative complications following general surgery and mortality among a diverse, international cohort of general surgery patients. Previous studies only looked at data from one hospital or used older data that had limitations.

Specialty-specific data is critical to assess complications and risk factors. The team focused on general surgery, which includes common procedures on organs in the abdomen such as the esophagus, stomach, small intestine, large intestine, liver, pancreas, and gallbladder, and other organs.

Analyzing the data

The research team used data from VISION, a study involving adults who had non-heart surgeries in 28 centres across 14 countries. They followed these patients for 30 days after surgery. Out of more than 40,000 patients in the study, 7,950 had major general surgeries. Among these participants, there were 240 deaths within 30 days, totalling three per cent of the participants.

The proportion of deaths attributed to each identified complication, from highest to lowest, were major bleeding (21.2 per cent), sepsis (15.6 per cent), myocardial injury after non-cardiac surgery (14.4 per cent), acute kidney injury resulting in dialysis (3.2 per cent), stroke (1.1 per cent), and infection without sepsis (0.05 per cent).

Understanding the results

Among the identified complications, bleeding, sepsis, and myocardial injury after non-cardiac surgery were the most frequent and contributed the highest proportions of deaths in the studied cohort. Contrary to previous studies, the research team identified major bleeding to be the most common complication leading to death following general surgery.

“Prior studies have failed to appreciate that bleeding can lead to death without a patient bleeding to death,” said Park, lead author of the study. She went on to explain that “Bleeding can result in death through different pathways, like organ damage from a mismatched blood supply or blood clots forming when specific medications are stopped. Previous studies may not have fully grasped how serious bleeding could be because they did not use definitions grounded in actual predictions of health outcomes derived from real-life data.”

Access the study to learn more.

PJ Devereaux is Tier 1 Canada Research Chair in Perioperative Medicine.

Park, L. J., Borges, F. K., Ofori, S., Nenshi, R., Jacka, M., Heels-Ansdell, D., Bogach, J., Vogt, K., Chan, M. T., Verghese, A., Polanczyk, C. A., Skinner, D., Asencio, J., Paniagua, P., Rosen, M., Serrano, P. E., Marcaccio, M. J., Simunovic, M., Thabane, L., & Devereaux, P. (2024). Association between Complications and Death within 30 days after General Surgery: A Vascular Events in Noncardiac Surgery Patients Cohort Evaluation (VISION) substudy. Annals of Surgery. https://doi.org/10.1097/SLA.0000000000006372

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