In spite of Billroth’s myriad achievements, Theodor Kocher (1841–1917) stands alone as the father of modern thyroid surgery (Fig. 1.2). He completed more than 5,000 thyroidectomies during his career as chair at the University of Bern. Mortality rates in his hands were 0.2 % by 1898 due to his adoption of antiseptic and hemostatic techniques. Kocher pioneered the standard collar incision, which now carries his name, and utilized local anesthesia with cocaine.

Kocher abandoned performing total thyroidectomy for benign disease when he discovered that patients developed the postoperative sequelae of hypothyroidism, namely myxedema, shedding light on thyroid physiology. He also established partial thyroidectomy as a treatment for Graves’ disease. William Halsted, an American surgeon, visited the clinics of both Kocher and Billroth and noted that Kocher’s patients often developed myxedema postoperatively but rarely tetany, whereas the opposite was true for Billroth. This speaks to the notoriety Kocher achieved for his bloodless field, attention to detail, and completeness of surgery. In 1908, he was awarded the Nobel Prize for his contributions to the understanding of thyroid physiology and thyroid surgery. He was the first surgeon to be awarded this honor.

As a student of both Billroth and Kocher, Halsted brought his education home to the United States, where he wrote The Operative Story of Goiter in 1920. He helped to found Johns Hopkins Hospital, where he developed the first residency program and became the first professor of surgery. He trained many distinguished surgeons, including Cushing, Dandy, Reed, Lahey, and Crile. Among his various contributions to surgery, Crile devised an antishock garment for patient use during thyroid surgery (Fig. 1.3).

Postoperative tetany was first described by Wolfler in 1879, but it was Eugene Gley who first associated this symptom with disruption or removal of the parathyroid glands in 1891. An understanding of parathyroid physiology as it relates to calcium was discovered in 1900 by Mccallum and Carl Voegtlin. They discovered that postthyroidectomy tetany was associated with low levels of calcium in the tissues and that this could be reversed by injection of parathyroid extracts or calcium. Pfieffer and Mayer were the first to demonstrate success in the treatment of tetany with parathyroid autotransplantation. Frank Lahey further advanced the concept of autotransplantation in 1926 by advising its placement into the sternocleidomastoid muscle, while Sam Wells in 1976 showed the efficacy of subtotal parathyroidectomy with forearm autotransplantation for four-gland hyperplasia. A significant advancement in parathyroid surgery occurred with the advent of the immunoassay measurement of parathyroid hormone (PTH) by Solomon Berson and Rosalyn Yalow in 1963, which earned them a Nobel Prize.

The anatomy of the recurrent laryngeal nerves was first detailed by Galen in the second century (Fig. 1.4). Due to his widespread influence, this knowledge was transmitted to generations of scholars and surgeons to come. A great deal was thus known by the 1700s about both the anatomy of the recurrent nerves and the sequelae of injury. The original approach of Kocher and Billroth to preserve the nerve was to ligate the inferior thyroid artery, away from the nerve–artery crossing point. Both Kocher and Miculicz advised leaving a small portion of thyroid tissue behind to cover and protect the nerve. Many other surgeons, including Prioleau, believed that the best strategy for avoiding nerve injury was to avoid visualizing it. It was Lahey in 1938 who demonstrated the importance and safety of nerve identification and dissection when he reported on a series of 3,000 thyroidectomies performed by he and his colleagues over a 3-year period. The significance of the superior laryngeal nerve was not recognized until much later in 1935 when goiter surgery brought an end to singer Amelita Galli-Curci’s operatic career.

The turn of the twentieth century led to significant advancement in thyroid disease management with the advent of blood transfusions, frozen section pathology, improvement in patient follow-up and research, and thyroid cancer staging systems. Treatment of hypothyroidism began with the transplantation of thyroid tissue into the spleen of a patient’s myxedematous daughter by E. Payr in 1906. Thereafter, surgeons began the practice of thyroid tissue transplantation to control symptoms of hypothyroidism after thyroidectomy. This was replaced by the development of animal thyroid extracts and later thyroxine, which was isolated by Edward C. Kendall in 1914. The treatment of hyperthyroidism was advanced with the development of antithyroid drugs and radioiodine therapy in the 1940s, providing alternatives to surgical excision, and propranolol was introduced for perioperative management in 1965. In the last quarter of the twentieth century, scintigraphy was developed and utilized as a diagnostic tool in thyroid disease workup but was largely supplanted by ultrasound in the 1980s. This allowed for discovery of small, subcentimeter nodules that were not clinically palpable. Further advancements in imaging, including with computed tomography and magnetic resonance imaging (MRI), allowed for assessment of substernal extension of goiters and for evaluation of metastatic lymphadenopathy in cases of thyroid cancer. N. Söderström was the first to develop fine-needle aspiration cytology for thyroid disease in 1952. This became widely available in the 1970s, allowing for the preoperative diagnosis of cancer to be made, resulting in improved surgical decision-making and prioritization. Improved anesthetic agents, lighting, and instrumentation, such as advanced energy devices for hemostasis, further modernized the field. Development of the intraoperative PTH assay led to additional real-time assessment of parathyroid status during surgery for hyperparathyroidism.