Surgery (from the χειρουργική cheirourgikē, via chirurgiae, meaning "hand work") is a medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, to help improve bodily function or appearance, or sometimes for some other reason. An act of performing surgery may be called a surgical procedure, operation, or simply surgery. In this context, the verb operating means performing surgery. The adjective surgical means pertaining to surgery; e.g. surgical instruments or surgical nurse. The patient or subject on which the surgery is performed can be a person or an animal. A surgeon is a person who performs operations on patients. Persons described as surgeons are commonly medical practitioners, but the term is also applied to podiatrists, dentists and veterinarians. Surgery can last from minutes to hours, but is typically not an ongoing or periodic type of treatment. The term surgery can also refer to the place where surgery is performed, or simply the office of a physician, dentist, or veterinarian.
Elective surgery is done to correct a non-life-threatening condition, and is carried out at the patient's request, subject to the surgeon's and the surgical facility's availability. Emergency surgery is surgery which must be done quickly to save life, limb, or functional capacity. Exploratory surgery is performed to aid or confirm a diagnosis. Therapeutic surgery treats a previously diagnosed condition.
Amputation involves cutting off a body part, usually a limb or digit. Replantation involves reattaching a severed body part. Reconstructive surgery involves reconstruction of an injured, mutilated, or deformed part of the body. Cosmetic surgery is done to improve the appearance of an otherwise normal structure. Excision is the cutting out of an organ, tissue, or other body part from the patient. Transplant surgery is the replacement of an organ or body part by insertion of another from different human (or animal) into the patient. Removing an organ or body part from a live human or animal for use in transplant is also a type of surgery.
When surgery is performed on one organ system or structure, it may be classed by the organ, organ system or tissue involved. Examples include cardiac surgery (performed on the heart), gastrointestinal surgery (performed within the digestive tract and its accessory organs), and orthopedic surgery (performed on bones and/or muscles).
Minimally invasive surgery involves smaller outer incision(s) to insert miniaturized instruments within a body cavity or structure, as in laparoscopic surgery or angioplasty. By contrast, an open surgical procedure requires a large incision to access the area of interest. Laser surgery involves use of a laser for cutting tissue instead of a scalpel or similar surgical instruments. Microsurgery involves the use of an operating microscope for the surgeon to see small structures. Robotic surgery makes use of a surgical robot, such as the Da Vinci or the Zeus surgical systems, to control the instrumentation under the direction of the surgeon.
Prior to surgery, the patient is given a medical examination, certain pre-operative tests, and an ASA score. If these results are satisfactory, the patient signs a consent form and is given a surgical clearance. If the procedure is expected to result in significant blood loss, an autologous blood donation may be made some weeks prior to surgery. If the surgery involves the digestive system, the patient may be instructed to perform a bowel prep by drinking a solution of polyethylene glycol the night before the procedure. Patients are also instructed to abstain from food or drink (an NPO order after midnight on the night before the procedure, to minimize the effect of stomach contents on pre-operative medications and reduce the risk of aspiration if the patient vomits during or after the procedure.
In the pre-operative holding area, the patient changes out of his or her street clothes and is asked to confirm the details of his or her surgery. A set of vital signs are recorded, a peripheral IV line is placed, and pre-operative medications (antibiotics, sedatives, etc) are given. When the patient enters the operating room, the skin surface to be operated on is cleaned and prepared by applying an antiseptic such as chlorhexidine gluconate or povidone-iodine to reduce the possibility of infection. If hair is present at the surgical site, it is clipped off prior to prep application. Sterile drapes are used to cover all of the patient's body except for the surgical site and the patient's head; the drapes are clipped to a pair of poles near the head of the bed to form an "ether screen", which separates the anesthetist/anesthesiologist's working area (unsterile) from the surgical site (sterile).
Anesthesia is administered to prevent pain from incision, tissue manipulation and suturing. Based on the procedure, anesthesia may be provided locally or as general anesthesia. Spinal anesthesia may be used when the surgical site is too large or deep for a local block, but general anesthesia may not be desirable. With local and spinal anesthesia, the surgical site is anesthetized, but the patient can remain conscious or minimally sedated. In contrast, general anesthesia renders the patient unconscious and paralyzed during surgery. The patient is intubated and is placed on a mechanical ventilator, and anesthesia is produced by a combination of injected and inhaled agents.
An incision is made to access the surgical site. Blood vessels may be clamped to prevent bleeding, and retractors may be used to expose the site or keep the incision open. The approach to the surgical site may involve several layers of incision and dissection, as in abdominal surgery, where the incision must traverse skin, subcutaneous tissue, three layers of muscle and then peritoneum. In certain cases, bone may be cut to further access the interior of the body; for example, cutting the skull for brain surgery or cutting the sternum for thoracic (chest) surgery to open up the rib cage.
Work to correct the problem in body then proceeds. This work may involve:
Blood or blood expanders may be administered to compensate for blood lost during surgery. Once the procedure is complete, sutures or staples are used to close the incision. Once the incision is closed, the anesthetic agents are stopped and/or reversed, and the patient is taken off ventilation and extubated (if general anesthesia was administered).
After completion of surgery, the patient is transferred to the post anesthesia care unit and closely monitored. When the patient is judged to have recovered from the anesthesia, he/she is either transferred to a surgical ward elsewhere in the hospital or discharged home. During the post-operative period, the patient's general function is assessed, the outcome of the procedure is assessed, and the surgical site is checked for signs of infection. If removable skin closures are used, they are removed after 7 to 10 days post-operatively, or after healing of the incision is well under way.
Post-operative therapy may include adjuvant treatment such as chemotherapy, radiation therapy, or administration of medication such as anti-rejection medication for transplants. Other follow-up studies or rehabilitation may be prescribed during and after the recovery period.
The oldest known surgical texts date back to ancient Egyptian about 3500 years ago. Surgeries were performed by priests, specialized in medical treatments similar to today. The procedures were documented on papyrus and were the first to describe patient case files; the Edwin Smith Papyrus (held in the New York Academy of Medicine) documents surgical procedures based on anatomy and physiology, while the Ebers Papyrus describes healing based on magic. Their medical expertise was later documented by Herodotus: "The practice of medicine is very specialized among them. Each physician treats just one disease. The country is full of physicians, some treat the eye, some the teeth, some of what belongs to the abdomen, and others internal diseases.
Sushruta (also spelled Susruta or Sushrutha) (c. 6th century BC) was a renowned surgeon of Ancient India, and the author of the book Sushruta Samhita. In his book, he described over 120 surgical instruments, 300 surgical procedures and classifies human surgery into 8 categories. Sushruta is also known as the father of plastic surgery and cosmetic surgery. He was a surgeon from the dhanvantari school of Ayurveda.
The Hippocratic Oath was an innovation of the Greek physician Hippocrates. However ancient Greek culture traditionally considered the practice of opening the body to be repulsive and thus left known surgical practices such as lithotomy to such persons as practice [it]. In China, Hua Tuo was a famous Chinese physician during the Eastern Han and Three Kingdoms era. He was the first person to perform surgery with the aid of anesthesia, albeit a rudimentary and unsophisticated form.
In the Middle Ages, surgery was developed to a high degree in the Islamic world. Abulcasis (Abu al-Qasim Khalaf ibn al-Abbas Al-Zahrawi), an Andalusian-Arab physician and scientist who practised in the Zahra suburb of Córdoba, wrote medical texts that shaped European surgical procedures up until the Renaissance. He is also often regarded as a Father of Surgery.
In Europe, the demand grew for surgeons to formally study for many years before practicing; universities such as Montpellier, Padua and Bologna were particularly renowned. By the fifteenth century at the latest, surgery had split away from physics as its own subject, of a lesser status than pure medicine, and initially took the form of a craft tradition until Rogerius Salernitanus composed his Chirurgia, laying the foundation for modern Western surgical manuals up to the modern time. Late in the nineteenth century, Bachelor of Surgery degrees (usually Ch.B.) began to be awarded with the (M.B.), and the mastership became a higher degree, usually abbreviated Ch.M. or M.S. in London, where the first degree was M.B.,B.S..
Barber-surgeons generally had a bad reputation that was not to improve until the development of academic surgery as a specialty of medicine, rather than an accessory field. Basic surgical principles for asepsis etc are known as Halsteads principles
Modern surgery developed rapidly with the scientific era. Ambroise Paré (sometimes spelled "Ambrose) pioneered the treatment of gunshot wounds, and the first modern surgeons were battlefield doctors in the Napoleonic Wars. Naval surgeons were often barber surgeons, who combined surgery with their main jobs as barbers. Three main developments permitted the transition to modern surgical approaches - control of bleeding, control of infection and control of pain (anaesthesia). Bleeding: Before modern surgical developments, there was a very real threat that a patient would bleed to death before treatment, or during the operation. Cauterization (fusing a wound closed with extreme heat) was successful but limited - it was destructive, painful and in the long term had very poor outcomes. Ligatures, or material used to tie off severed blood vessels, are believed to have originated with Abulcasis in the 10th century and improved by Ambroise Paré in the 16th century. Though this method was a significant improvement over the method of cauterization, it was still dangerous until infection risk was brought under control - at the time of its discovery, the concept of infection was not fully understood. Finally, early 20th century research into blood groups allowed the first effective blood transfusions. Infection: The concept of infection was unknown until relatively modern times. The first progress in combating infection was made in 1847 by the Hungarian doctor Ignaz Semmelweis who noticed that medical students fresh from the dissecting room were causing excess maternal death compared to midwives. Semmelweis, despite ridicule and opposition, introduced compulsory handwashing for everyone entering the maternal wards and was rewarded with a plunge in maternal and fetal deaths, however the Royal Society in the UK still dismissed his advice. Significant progress came following the work of Pasteur, when the British surgeon Joseph Lister began experimenting with using phenol during surgery to prevent infections. Lister was able to quickly reduce infection rates, a reduction that was further helped by his subsequent introduction of techniques to sterilize equipment, have rigorous hand washing and a later implementation of rubber gloves. Lister published his work as a series of articles in The Lancet (March 1867) under the title Antiseptic Principle of the Practice of Surgery. The work was groundbreaking and laid the foundations for a rapid advance in infection control that saw modern aseptic operating theatres widely used within 50 years (Lister himself went on to make further strides in antisepsis and asepsis throughout his lifetime). Pain: Modern pain control through anesthesia was discovered by two American dental surgeons, Horace Wells (1815-1848) and William Morton. 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 and chloroform, later pioneered in Britain by John Snow. In addition to relieving patient suffering, anaesthesia allowed more intricate operations in the internal regions of the human body. In addition, the discovery of muscle relaxants such as curare allowed for safer applications.
Some other specialties involve some forms of surgical intervention, especially gynaecology. Also, some people consider invasive methods of treatment/diagnosis, such as, cardiac catheterization, endoscopy, and placing of chest tubes or central lines "surgery". In most parts of the medical field, this view is not shared.