| 4D | four-dimensional |
| 5-FU | fluorouracil |
| AAA | abdominal aortic aneurysm |
| AAST | American Association for the Surgery of Trauma |
| AAST-OIS | American Association for the Surgery of Trauma-Organ Injury Scale |
| ABP | acute biliary pancreatitis |
| AC | doxorubicin and cyclophosphamide |
| ACAS | Asymptomatic Carotid Artery Stenosis |
| ACC | adrenocortical carcinoma |
| ACOSOG | American College of Surgeons Oncology Group |
| ACS | acute coronary syndrome |
| ACS | American College of Surgeons |
| ACS-BSCN | American College of Surgeons Bariatric Surgery Center Network |
| ACS-NSQIP | American College of Surgeons–National Surgical Quality Improvement Program |
| ADH | anti-diuretic hormone |
| AFP | α-fetoprotein |
| AFS | amputation-free survival |
| AGB | adjustable gastric banding |
| AIR | Appendicitis Inflammatory Response |
| AISP | Italian Association for Study of the Pancreas |
| AJCC | American Joint Committee on Cancer |
| ALND | axillary lymph node dissection |
| ALPPS | associating liver partition and portal vein ligation for staged hepatectomy |
| ALT | alanine transaminase |
| ANC | absolute neutrophil count |
| ANOVA | analysis of variance |
| APACHE II | Acute Physiology and Chronic Health Evaluation |
| APR | abdominoperineal resection |
| ARDS | acute respiratory distress syndrome |
| ASA | American Society of Anesthesiologists |
| ASBO | adhesive small-bowel obstruction |
| ASMBS | American Society for Metabolic and Bariatric Surgery |
| ASPEN | American Society for Parenteral and Enteral Nutrition |
| AST | aspartate aminotransferase |
| ATA | American Thyroid Association |
| BAP | balloon angioplasty |
| BASIL | Bypass versus Angioplasty in Severe Ischaemia of the Leg |
| BCS | breast-conserving surgery |
| BCT | breast conservation therapy |
| BE | bilateral exploration |
| BE | bilateral neck exploration |
| BM | bowel movement |
| BMI | body mass index |
| BRPC | borderline resectable pancreatic cancer |
| BSA | body surface area |
| BSX | bypass surgery |
| CAS | carotid artery stenting |
| CAVATAS | Carotid and Vertebral Artery Transluminal Angioplasty Study |
| CBC | contralateral breast cancers; complete blood count |
| CBD | common bile duct |
| CDT | catheter-directed thrombolysis |
| CEA | carcinoembryonic antigen |
| CEA | carotid endarterectomy |
| CHF | congestive heart failure |
| CI | confidence interval |
| CKD | chronic kidney disease |
| CLI | chronic limb ischemia |
| CLND | central lymph node dissection |
| cN0 | clinically node-negative |
| cN1 | clinically positive lymph nodes |
| CO | crossover |
| COST | Clinical Outcomes of Surgical Therapy |
| CPR | cardiopulmonary resuscitation |
| CRASH-2 | a randomised, placebo-controlled trial |
| CRLM | colorectal liver metastases |
| CROP | dynamic compliance, respiratory rate, oxygenation, maximum inspiratory pressure index |
| CRP | C-reactive protein |
| C-spine | cervical spine |
| CT | computed tomography |
| CTA | computed tomography angiography |
| CTLA-4 | cytotoxic T-lymphocyte–associated antigen 4 |
| CVA | cerebrovascular accident |
| CVL | central venous line |
| CVP | central venous pressure |
| DCIS | ductal carcinoma in situ |
| DDSF | distant disease-free survival |
| DFS | disease-free survival |
| DGE | delayed gastric emptying |
| DISPACT | distal pancreatectomy |
| DKA | diabetic ketoacidosis |
| DNR | do-not-resuscitate |
| DPL | diagnostic peritoneal lavage |
| DSS | disease-specific survival |
| DTC | differentiated thyroid cancer |
| DVT | deep-vein thrombosis |
| DXA | dual-energy x-ray absorptiometry |
| EAST | Eastern Association for the Surgery of Trauma |
| EBCTCG | Early Breast Cancer Trialists’ Collaborative Group |
| EBL | estimated blood loss |
| ECF | epirubicin + cisplatin + infused fluorouracil |
| ECG | echocardiogram |
| ECOG | Eastern Cooperative Oncology Group |
| ECST | European Carotid Surgery Trial |
| ED | emergency department |
| EGDT | early goal-directed therapy |
| EORTC | European Organization for Research and |
| QLQ-CR38 | Treatment of Cancer Colorectal Quality of Life Questionnaire |
| EORTC | European Organization for Research and Treatment of Cancer |
| ER | estrogen receptor |
| ERCP | endoscopic retrograde cholangiopancreatography |
| EUS | endoscopic ultrasonography |
| EUS-FNA | endoscopic ultrasonography-guided fine-needle aspiration |
| EVAR | endovascular AAA repair |
| EVL | endoscopic variceal ligation |
| FAP | familial adenomatous polyposis |
| FAST | focused assessment with ... |