Human health and medicine

Opamtistomig

Opamtistomig (LBL-024, Chinese 奥帕替苏米单抗) is a PD-L1/4-1BB bispecific antibody from Nanjing Leads Biolabs for advanced extrapulmonary neuroendocrine carcinoma; NDA accepted by China's NMPA in August 2026 with priority review.

Open Abdomen Techniques

Open abdomen techniques: temporary abdominal closure methods (NPWT, Bogota bag, Wittmann patch, fascial traction) used after laparostomy in damage control surgery and sepsis; early fascial closure preferred, evidence of superiority limited.

Open appendectomy

Open appendectomy is the removal of an inflamed appendix through a single incision in the right lower abdomen, typically at the McBurney point, now used when laparoscopy is unsuitable.

OPEN CCTArrest trial

OPEN CCTArrest (NCT07388342), UZ Brussel trial led by Bert Popelier testing ECG-less gated coronary CT angiography accuracy in resuscitated cardiac arrest survivors without STEMI, 30 patients, 2025-2027.

Open cholecystectomy

Open cholecystectomy removes the gallbladder through an abdominal incision, usually a right subcostal one, to treat symptomatic gallstones; it was standard from the 1880s until the 1980s.

Open Dialogue

Open Dialogue is a psychosocial approach to psychosis and mental health crises, developed in Finnish Lapland, that treats patients in meetings with family and social network.

Open flow microperfusion

Open flow microperfusion (OFM) is a minimally invasive method that continuously collects unfiltered interstitial fluid from tissue through a membrane-free catheter, measuring drugs, metabolites, and proteins over time.

Open Fracture Reduction

Open fracture reduction: surgical realignment of broken bone through a skin incision, usually with internal fixation (ORIF). Compared with closed reduction it offers more precise alignment but higher infection and nonunion rates in femoral shaft nailing.

Open inguinal hernia repair

Open inguinal hernia repair corrects a groin hernia through a groin incision, usually reinforcing the inguinal canal's posterior wall with synthetic mesh, most often by the Lichtenstein technique.

Open lung ventilation

Open lung ventilation is a mechanical ventilation strategy for ARDS, proposed by B. Lachmann in 1992, combining recruitment maneuvers with high PEEP to reopen collapsed alveoli, though no proven mortality benefit exists.

Open pancreaticoduodenectomy

Open pancreaticoduodenectomy, the Whipple procedure, is an operation through a laparotomy that removes the pancreatic head and duodenum, mainly to treat pancreatic head and periampullary tumors.

Open reduction of fractures

Open reduction of fractures is a surgical procedure in which a fractured bone is exposed so fragments can be directly realigned, often combined with plate-and-screw internal fixation as ORIF.

Open rhinoplasty

Open rhinoplasty is a surgical technique for reshaping the nose in which the skin is lifted through an external incision across the columella, exposing the cartilage and bone directly.

Open thyroidectomy

Open thyroidectomy is a surgical procedure that removes all or part of the thyroid gland through a neck incision, used to treat goiter, hyperthyroidism, nodules, and thyroid cancer.

Open ventral hernia repair

Open ventral hernia repair is a surgical procedure that fixes abdominal wall hernias, including incisional hernias, through a direct incision closed and reinforced with mesh.

Open wound of forearm

Open wound of forearm (ICD-11 NC31): traumatic skin break of the forearm, coded as laceration, puncture, open bite, or multiple wounds; managed by hemostasis, irrigation, closure, and referral for arterial, nerve, or tendon injury.

Open wound of head

Open wound of head (ICD-11 NA01; ICD-10 S01) is an injury classification covering lacerations, puncture wounds, open bites, and multiple open wounds of the head, most commonly scalp lacerations with heavy bleeding from the scalp's rich blood supply.

Open wound of neck

Open wound of neck: a traumatic breach of neck skin and soft tissue, ICD-10 category S11 and ICD-11 code NA21. Covers lacerations, punctures, and open bites; mortality 2-5% for penetrating neck trauma, about 70% with major vessel rupture.

Open wound of toe

Open wound of toe: a cut or break in toe skin, classified in ICD-11 as block ND12.6 (lacerations, punctures, open bites, with or without foreign body) and ICD-10-CM as S91.1; foot location and puncture mechanism raise infection risk.

Operating Tables

Operating tables (OT tables, operating room tables) are adjustable patient-support surfaces for surgery, built as tabletop, column, and transporter; stationary or mobile, radiolucent for C-arm imaging, governed by IEC 60601-2-46:2023.

Operating theater

Operating theater (operating room, OR): a hospital room for surgery in a sterile environment. Defined by aseptic technique, positive-pressure ventilation at about 15 ACH, zoning, team safety processes, and hybrid imaging variants.

Operation Dark Winter

Operation Dark Winter, a June 22-23, 2001 senior-level tabletop exercise at Andrews AFB, simulated a covert smallpox attack on the US; Sam Nunn played President, and its findings shaped US biodefense and vaccine stockpiling.

Operation Smile

Operation Smile is a Virginia Beach-based international nonprofit founded in 1982 by Bill and Kathy Magee that provides free cleft lip and palate surgery and training in 37 countries; distinct from Smile Train and unrelated SMILE missions.

Operation Warp Speed

Operation Warp Speed (OWS) was the 2020 U.S. HHS-DOD public-private program that funded six COVID-19 vaccine candidates with over $10 billion, achieving two EUAs at about 95% efficacy by December 2020; later renamed the Countermeasures Acceleration Group.

Operative dentistry

Operative dentistry: dental specialty restoring defective teeth without full coverage restorations, focused on adhesion and minimal intervention; its flagship journal Operative Dentistry (ISSN 0361-7734) has published bimonthly since 1976.

Operative hysteroscopy

Operative hysteroscopy is a minimally invasive gynecological procedure in which a hysteroscope passed through the cervix diagnoses and surgically treats intrauterine disease, including polyps, fibroids, septa, and adhesions.

Operative Time

Operative time, also called surgical time, is the duration of a surgical procedure, usually from skin incision to closure. Distinct from anesthesia and OR times; predicts complications and drives scheduling and cost.

Operative vaginal delivery

Operative vaginal delivery is an obstetric procedure in which forceps or a vacuum extractor completes a vaginal birth when the second stage of labor needs expediting.

Opevesostat

Opevesostat (ODM-208, MK-5684) is an oral, non-steroidal, first-in-class CYP11A1 inhibitor from Orion Pharma and Merck/MSD that blocks all steroid hormone synthesis; investigated in the CYPIDES and OMAHA phase 3 trials for metastatic castration-resistant prostate cancer.