**1. Introduction**

Surgical education has evolved drastically over the centuries. Before the 19th century, the main model of surgical training and education was centered around apprenticeship, when instruction was garnered through direct observation from a mentor. There were no formalized standards on age or length of training; however, typical training would begin at the age of 12–13 and would last 5–7 years [1–3]. It was not until the end of the 19th century that Dr. William Halstead made the shift to a standardized training model.

In the late 1800s, Dr. Halstead pioneered a new era for surgical education in the United States. Using principles from the German philosophy of surgical education, he set forth to create a formalized, structured surgical curriculum. Incorporating Sir William Osler's bedside teaching and integration of basic science into surgical education, he developed a training model [1, 4]. Halstead's concept of surgical training was based on the following: First, the trainee must have repetitive opportunities to take care of surgical patients under the supervision of an experienced surgical teacher. Second, the trainee must understand the scientific basis of surgical disease. Lastly, the trainee obtains graded enhanced responsibility in patient care until independence [1]. The maxim, "see one, do one, teach one" was developed,

allowing surgeons to pass down operative techniques from one generation to the next. Using this principle, one was able to accept increasing responsibility in the operating room and eventually progress to surgical independence [1, 3].

Surgical training in the 21st century has been affected by challenges not identified in previous eras. In 1999, a paper published by the Institute of Medicine reported that preventable medical errors kill between 44,000–98,000 patients per year [3]. In 2003, the Accreditation Council for Graduate Medical Education (ACGME) instituted an 80-hour work week to prevent unfavorable outcomes secondary to resident fatigue. This focus on restricting the amount of work hours has been seen not only in the United States, but throughout the world. For example, the new European working time directive restricted work hours to 48 hours per week [5]. Globally, this has caused surgical residency programs to reform past curriculums to fulfill this new training requirement [3]. Programs began incorporating part of their training outside of the operating room to accommodate these new restrictions. Curricula were now refocused to prioritize quality over quantity of education. There has now been a spotlight on the well-being of trainees as a crucial element to the benefit of their own health as well as that to their patients [6].

Simulation-based training in surgical education has rapidly developed during the 21st century. While some aspects of training occur outside of the operating room and trainees are working less clinical hours, surgical residents are still expected to reach the same technical proficiency as their predecessors [1, 3]. With patient safety in mind, the development of simulation has become a cornerstone of today's surgical training. Simulation training provides an opportunity to develop both open and minimally invasive surgical techniques on artificial platforms before utilizing them on a live patient [3].

Lastly the 2020 COVID-19 pandemic has not only impacted millions of lives on a personal level but has also significantly affected medical education. Surgical training has been uniquely impacted both operatively and nonoperatively. Residents had to quickly adapt to a 'new normal' as many elective surgeries were canceled, resident lectures and conferences were moved to online platforms, and rotations were canceled or shortened to redistribute the workforce [7, 8]. This pandemic has demonstrated that surgical education needs to adapt to train tomorrow's surgeons.
