He was also one of the first to understand the importance of pathology, the danger of the spread of infection and how the problem of inflammation of the wound, bone lesions and even tuberculosis often undid any benefit that was gained from the intervention. He consequently adopted the position that all surgical procedures should be used only as a last resort.Other important 18th- and early 19th-century surgeons included Percival Pott (1713–1788) who described tuberculosis on the spine and first demonstrated that a cancer may be caused by an environmental carcinogen (he noticed a connection between chimney sweeps exposure to soot and their high incidence of scrotal cancer). Astley Paston Cooper (1768–1841) first performed a successful ligation of the abdominal aorta, and James Syme (1799–1870) pioneered the Symes Amputation for the ankle joint and successfully carried out the first hip disarticulation. Modern pain control through anesthesia was discovered in the mid-19th century. Before the advent of anesthesia, surgery was a traumatically painful procedure and surgeons were encouraged to be as swift as possible to minimize patient suffering. This also meant that operations were largely restricted to amputations and external growth removals. Beginning in the 1840s, surgery began to change dramatically in character with the discovery of effective and practical anaesthetic chemicals such as ether, first used by the American surgeon Crawford Long, and chloroform, discovered by Scottish obstetrician James Young Simpson and later pioneered by John Snow, physician to Queen Victoria.
Other procedures that do not necessarily fall under this rubric, such as angioplasty or endoscopy, may be considered surgery if they involve "common" surgical procedure or settings, such as use of a sterile environment, anesthesia, antiseptic conditions, typical surgical instruments, and suturing or stapling. All forms of surgery are considered invasive procedures; so-called "noninvasive surgery" usually refers to an excision that does not penetrate the structure being excised (e.g. laser ablation of the cornea) or to a radiosurgical procedure (e.g. irradiation of a tumor). Types of surgery
Surgical procedures are commonly categorized by urgency, type of procedure, body system involved, the degree of invasiveness, and special instrumentation. Based on timing: Elective surgery is done to correct a non-life-threatening condition, and is carried out at the persons request, subject to the surgeons and the surgical facilitys availability. A semi-elective surgery is one that must be done to avoid permanent disability or death, but can be postponed for a short time. Emergency surgery is surgery which must be done without any delay to prevent death or serious disabilities and/or loss of limbs and functions. Based on purpose: Exploratory surgery is performed to aid or confirm a diagnosis. Therapeutic surgery treats a previously diagnosed condition. Cosmetic surgery is done to subjectively improve the appearance of an otherwise normal structure. By type of procedure: Amputation involves cutting off a body part, usually a limb or digit; castration is also an example.