But there were certain factors that predicted an increased rate of mortality and other complications, including having a body mass index less than 30, patient's age 70 or older, and several factors related to a diagnosis of malignant disease such as blood loss, and need for transfusion. The BMI under 30 was attributed, in part, to nutritional issues resulting from metastatic disease.
Performing more advanced types of procedures, such as a liver resection, removal of parts or all of the pancreas, and lung resection and kidney transplantation, were also associated with higher complication rates.
Procedures associated with intermediate risk and having lower complication rates, were listed as living donor nephrectomies, bariatric procedures, esophageal hernia repairs, endocrine operations such as thyroidectomies, colorectal resections, splenectomies, thymectomies, and gynecological procedures.
Basic, or lowest-risk procedures were identified as gall bladder surgeries, hernia repairs, and biopsies.