A cardiothoracic surgeon performs a mitral valve replacement at the Fitzsimons Army Medical Center.

Surgery (from the Greek: χειρουργική cheirourgikē, via Latin: chirurgiae, meaning "hand work") is an ancient 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, or to help improve bodily function or appearance.

An act of performing surgery may be called a surgical procedure, operation, or simply surgery. In this context, the verb operate means to perform 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 in hope of a favorable outcome. Persons described as surgeons are commonly physicians, but the term is also applied to podiatrists, dentists (known as oral and maxillofacial surgeons) and veterinarians. A 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.

Definitions of surgery[link]

Surgery is a technology consisting of a physical intervention on tissues.

As a general rule, a procedure is considered surgical when it involves cutting of a patient's tissues or closure of a previously sustained wound. 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[link]

Surgical procedures are the commonly categorized by urgency, type of procedure, body system involved, 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 patient's request, subject to the surgeon's and the surgical facility's availability. Emergency surgery is surgery which must be done promptly to save life, limb, or functional capacity. A semi-elective surgery is one that must be done to avoid permanent disability or death, but can be postponed for a short time.
• Based on purpose: Exploratory surgery is performed to aid or confirm a diagnosis. Therapeutic surgery treats a previously diagnosed condition.
• By type of procedure: Amputation involves cutting off a body part, usually a limb or digit; castration is also an example. 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 or removal 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.
• By body part: 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).
• By degree of invasiveness: 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 or laparotomy requires a large incision to access the area of interest.
• By equipment used: 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.

Terminology[link]

• Excision surgery names often start with a name for the organ to be excised (cut out) and end in -ectomy.
• Procedures involving cutting into an organ or tissue end in -otomy. A surgical procedure cutting through the abdominal wall to gain access to the abdominal cavity is a laparotomy.
• Minimally invasive procedures involving small incisions through which an endoscope is inserted end in -oscopy. For example, such surgery in the abdominal cavity is called laparoscopy.
• Procedures for formation of a permanent or semi-permanent opening called a stoma in the body end in -ostomy.
• Reconstruction, plastic or cosmetic surgery of a body part starts with a name for the body part to be reconstructed and ends in -oplasty. Rhino is used as a prefix for "nose", so rhinoplasty is basically reconstructive or cosmetic surgery for the nose.
• Reparation of damaged or congenital abnormal structure ends in -rraphy. Herniorraphy is the reparation of a hernia, while perineorraphy is the reparation of perineum.

Description of surgical procedure[link]

At a hospital, modern surgery is often done in an operating theater using surgical instruments, an operating table for the patient, and other equipment. The environment and procedures used in surgery are governed by the principles of aseptic technique: the strict separation of "sterile" (free of microorganisms) things from "unsterile" or "contaminated" things. All surgical instruments must be sterilized, and an instrument must be replaced or re-sterilized if it becomes contaminated (i.e. handled in an unsterile manner, or allowed to touch an unsterile surface). Operating room staff must wear sterile attire (scrubs, a scrub cap, a sterile surgical gown, sterile latex or non-latex polymer gloves and a surgical mask), and they must scrub hands and arms with an approved disinfectant agent before each procedure.

Prior to surgery, the patient is given a medical examination, certain pre-operative tests, and their physical status is rated according to the ASA physical status classification system. 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, called the operating field, 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. The patient is assisted by an anesthesiologist or resident to make a specific surgical position, then sterile drapes are used to cover all of the patient's body except for the head and the surgical site or at least a wide area surrounding the operating field; 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:

• excision - cutting out an organ, tumor,^[1] or other tissue.
• resection - partial removal of an organ or other bodily structure.
• reconnection of organs, tissues, etc., particularly if severed. Resection of organs such as intestines involves reconnection. Internal suturing or stapling may be used. Surgical connection between blood vessels or other tubular or hollow structures such as loops of intestine is called anastomosis.
• Reduction - the movement or realignment of a body part to its normal position. e.g. Reduction of a broken nose involves the physical manipulation of the bone and/or cartilage from their displaced state back to their original position to restore normal airflow and aesthetics.
• ligation - tying off blood vessels, ducts, or "tubes".
• grafts - may be severed pieces of tissue cut from the same (or different) body or flaps of tissue still partly connected to the body but resewn for rearranging or restructuring of the area of the body in question. Although grafting is often used in cosmetic surgery, it is also used in other surgery. Grafts may be taken from one area of the patient's body and inserted to another area of the body. An example is bypass surgery, where clogged blood vessels are bypassed with a graft from another part of the body. Alternatively, grafts may be from other persons, cadavers, or animals.
• insertion of prosthetic parts when needed. Pins or screws to set and hold bones may be used. Sections of bone may be replaced with prosthetic rods or other parts. Sometime a plate is inserted to replace a damaged area of skull. Artificial hip replacement has become more common. Heart pacemakers or valves may be inserted. Many other types of prostheses are used.
• creation of a stoma, a permanent or semi-permanent opening in the body
• in transplant surgery, the donor organ (taken out of the donor's body) is inserted into the recipient's body and reconnected to the recipient in all necessary ways (blood vessels, ducts, etc.).
• arthrodesis - surgical connection of adjacent bones so the bones can grow together into one. Spinal fusion is an example of adjacent vertebrae connected allowing them to grow together into one piece.
• modifying the digestive tract in bariatric surgery for weight loss.
• repair of a fistula, hernia, or prolapse
• other procedures, including:

• clearing clogged ducts, blood or other vessels
• removal of calculi (stones)
• draining of accumulated fluids
• debridement- removal of dead, damaged, or diseased tissue

• Surgery has also been conducted to separate conjoined twins.
• Sex change operations

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. There are several risk factors associated with post operative complications, such as immune deficienty and obesity. Obesity has long been considered a risk factor for adverse post-surgical outcomes. It has been linked to many disorders such as obesity hypoventilation syndrome, atelectasis and pulmonary embolism, adverse cardiovascular affects, and wound healing complications.^[2] 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.

In special populations[link]

Elderly people[link]

Older adults have widely varying physical health. Frail elderly people are at significant risk of post-surgical complications and the need for extended care. Assessment of older patients before elective surgeries can accurately predict the patients' recovery trajectories.^[3] One frailty scale uses five items: unintentional weight loss, muscle weakness, exhaustion, low physical activity, and slowed walking speed. A healthy person scores 0; a very frail person scores 5. Compared to non-frail elderly people, people with intermediate frailty scores (2 or 3) are twice as likely to have post-surgical complications, spend 50% more time in the hospital, and are three times as likely to be discharged to a skilled nursing facility instead of to their own homes.^[3] Frail elderly patients (score of 4 or 5) have even worse outcomes, with the risk of being discharged to a fraternity rising to twenty times the rate for non-frail elderly people.

History[link]

The earliest known compendium on Surgery were penned down by ancient Indians. Sushruta was an in ancient Indian sage who had extensively described about various surgeries in Sushruta Samhita ranging from rhinoplasties, labioplasties and ceasarians. At least two prehistoric cultures had developed forms of surgery. The oldest for which there is evidence is trepanation,^[4] in which a hole is drilled or scraped into the skull, thus exposing the dura mater in order to treat health problems related to intra cranial pressure and other diseases. Evidence has been found in prehistoric human remains from Neolithic times, in cave paintings, and the procedure continued in use well into recorded history. Surprisingly, many prehistoric and premodern patients had signs of their skull structure healing; suggesting that many survived the operation. Remains from the early Harappan periods of the Indus Valley Civilization (c. 3300 BCE) show evidence of teeth having been drilled dating back 9,000 years.^[5] A final candidate for prehistoric surgical techniques is Ancient Egypt, where a mandible dated to approximately 2650 BCE shows two perforations just below the root of the first molar, indicating the draining of an abscessed tooth.

Hippocrates stated in the oath (c. 400 BC) that general physicians must never practice surgery and that surgical procedures are to be conducted by specialists.

The oldest known surgical texts date back to ancient Egypt about 3500 years ago. Surgical operations 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."^[6]

In ancient Greece, temples dedicated to the healer-god Asclepius, known as Asclepieia (Greek: Ασκληπιεία, sing. Asclepieion Ασκληπιείον), functioned as centers of medical advice, prognosis, and healing.^[7] At these shrines, patients would enter a dream-like state of induced sleep known as "enkoimesis" (Greek: ἐγκοίμησις) not unlike anesthesia, in which they either received guidance from the deity in a dream or were cured by surgery.^[8] In the Asclepieion of Epidaurus, three large marble boards dated to 350 BCE preserve the names, case histories, complaints, and cures of about 70 patients who came to the temple with a problem and shed it there. Some of the surgical cures listed, such as the opening of an abdominal abscess or the removal of traumatic foreign material, are realistic enough to have taken place, but with the patient in a state of enkoimesis induced with the help of soporific substances such as opium.^[8]

12th century eye surgery.

The Greek Galen was one of the greatest surgeons of the ancient world and performed many audacious operations — including brain and eye surgery — that were not tried again for almost two millennia.

In China, Hua Tuo was a famous Chinese physician during the Eastern Han and Three Kingdoms era who performed surgery with the aid of anesthesia.

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.^{[9][unreliable source?]}

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. According to Peter Elmer and Ole Peter Grell, "Guy de Chauliac (1298-1368) was one of the most eminent surgeons of the Middle Ages. His Chirurgia Magna or Great Surgery (1363) was a standard text for surgeons until well into the seventeenth century."^[10] By the fifteenth century at the latest, surgery had split away from physic 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 ChB) began to be awarded with the (MB), and the mastership became a higher degree, usually abbreviated ChM or MS in London, where the first degree was MB, BS.

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.^[11] Basic surgical principles for asepsis etc., are known as Halsteads principles

Modern surgery[link]

Ambroise Paré (ca. 1510-1590), father of modern military surgery.

Modern surgery developed rapidly with the scientific era. Ambroise Paré (sometimes spelled "Ambrose"^[12]) 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, originated as early as ancient Rome,^[13] and were 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.

Pain

Modern pain control through anesthesia was discovered by Crawford Long. 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, discovered by James Young Simpson and 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.

Infection

Unfortunately, the introduction of anesthetics encouraged more surgery, which inadvertently caused more dangerous patient post-operative infections. 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 Louis Pasteur and his advances in microbiology, 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 the techniques of Robert Koch (such as the Steam Steriliser, which proved more successful than the carbolic acid spray that Lister had been using previously) 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).

Cognitive and memory decline

Surgery may cause post-operative decline in memory and cognitive function due that inflammatory proteins may cause damage to the blood–brain barrier and allow for immune competent blood cells to interfere with memory functions, but may be prevented with a pre-operative dosage of a nicotine alike medicine. This affects 20 - 25% of the patients for a few months, but very few are affected for more than 1 year.^[14]

Surgical specialties and sub-specialties[link]

• General surgery
  • Cardiothoracic surgery
  • Vascular surgery
  • Plastic surgery
  • Paediatric surgery
  • Colorectal surgery
  • Transplant surgery
  • Surgical oncology
  • Trauma surgery
  • Endocrine surgery
  • Breast surgery
  • Skin surgery
• Otolaryngology
• Gynaecology
• Oral and maxillofacial surgery
• Dental Surgery
• Orthopaedic surgery
• Neurosurgery
• Ophthalmology
• Podiatric surgery
• Urology

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.

Patronage[link]

The patron saints for surgeons are Saint Luke the Evangelist the physician and disciple of Christ, Saints Cosmas and Damian (3rd century physicians from Syria), Saint Quentin (3rd century saint from France), Saint Foillan (7th century saint from Ireland), and Saint Roch (14th century saint from France).