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    Data Dictionaries for AAST Grading System for EGS Conditions

    EGS Tables in PDF: Emergency General Surgery Anatomic Severity Tables

    A. Acute Appendicitis

    AAST Grade Description Clinical Criteria Imaging Criteria
    (CT findings)
    Operative Criteria Pathologic Criteria
    I Acutely inflamed appendix, intact Pain, leukocytosis and right lower quadrant (RLQ) tenderness Inflammatory changes localized to appendix +/- appendiceal dilation +/- contrast non-filling Acutely inflamed appendix, intact Presence of neutrophils at the base of crypts, submucosa +/- in muscular wall
    II Gangrenous appendix, intact Pain, leukocytosis and RLQ tenderness Appendiceal wall necrosis with contrast non-enhancement +/- air in appendiceal wall Gangrenous appendix, intact Mucosa and muscular wall digestion; not identifiable on hematoxylin and eosin stain (H & E)
    III Perforated appendix with local contamination Pain, leukocytosis and RLQ tenderness Above with local periappendiceal fluid +/- contrast extravasation Above, with evidence of local contamination Gross perforation or focal dissolution of muscular wall
    IV Perforated appendix with periappendiceal phlegmon or abscess Pain, leukocytosis and RLQ tenderness; may have palpable mass Regional soft tissue inflammatory changes, phlegmon or abscess Above, with abscess or phlegmon in region of appendix Gross perforation
    V Perforated appendix with generalized peritonitis Generalized peritonitis Diffuse abdominal or pelvic inflammatory changes +/- free intra-peritoneal fluid or air Above, with addition of generalized purulent contamination away from appendix Gross perforation

     

    B. Breast Infections

    AAST Grade Description Clinical Criteria Imaging Criteria
    (US or CT findings)
    Operative Criteria Pathologic Criteria
    I Breast cellulitis Erythema, induration, edema, pain, tenderness Inflammation without fluid collection N/A N/A
    II Simple abscess Single, small abscess without loculations; not involving the nipple/areolar complex Single well circumscribed fluid collection within breast tissue, not involving nipple/areolar complex Single, well circumscribed fluid collection within breast tissue, not involving nipple/
    areola complex
    Acute inflammation limited to breast tissue
    III Complex abscess Large abscess with multiple loculations, multiple abscesses, or abscess involving nipple/areola complex; lymphadenopathy Multiple separate fluid collections or single large collection with multiple loculations within breast tissue or involvement of nipple/areola complex Multiple separate fluid collections or single large collection with multiple loculations within breast tissue, or involvement of nipple/areola complex; enlarged lymph nodes Acute inflammation limited to breast tissue with cultures positive for organism if available
    IV Breast abscess with axillary extension Breast abscess with ipsilateral lymph-adenopathy, thrombophlebitis, lymphangitis Fascial plane thickening with enhancement; evidence of lymph-adenopathy on US or CT Above, plus axillary fluid collections, extension of inflammatory changes well beyond the abscesses Acute inflammation of breast tissue and axillary lymph nodes with cultures positive for organisms
    V Breast abscess with chest wall involvement Above, plus erosion into chest wall muscles or ribs or pleural space, or necrotizing fasciitis Above, plus inflammatory changes in the chest wall muscles, ribs or pleural space Above, with erosion into chest wall muscles or ribs or pleural space, or necrotizing fasciitis Acute inflammation involving chest wall, fascia, muscles or ribs with or without necrosis and cultures positive for organisms

     

    C. Acute Cholecystitis

    AAST Grade Description Clinical Criteria Imaging Criteria
    (CT/US/HIDA findings)
    Operative Criteria Pathologic Criteria
    I Acute cholecystitis Right upper quadrant (RUQ) or epigastric pain; Murphy’s Sign; leukocytosis Wall thickening; distention; gallstones or sludge; pericholecystic fluid; non-visualization of gallbladder (GB) on hepatobiliary iminodiacetic acid (HIDA) scan Inflammatory changes localized to GB; wall thickening; distention; gallstones Acute inflammatory changes in the GB wall without necrosis or pus
    II GB empyema or gangrenous cholecystitis or emphysematous cholecystitis RUQ or epigastric pain; Murphy’s Sign; leukocytosis Above, plus air in GB lumen, wall or in the biliary tree; focal mucosal defects without frank perforation Distended GB with pus or hydrops; necrosis or gangrene of wall; not perforated Above, plus pus in the GB lumen; necrosis of GB wall; intramural abscess; epithelial sloughing; no perforation

    III

    GB perforation with local contamination Localized peritonitis in RUQ HIDA with focal transmural defect, extraluminal fluid collection or radiotracer but limited to RUQ Perforated GB wall (non-iatrogenic) with bile outside the GB but limited to RUQ Necrosis with perforation of the GB wall (non-iatrogenic)
    IV GB perforation with perichole-cystic abscess or gastrointestinal fistula Localized peritonitis at multiple locations; abdominal distention with symptoms of bowel obstruction Abscess in RUQ outside GB; bilio-enteric fistula; gallstone ileus Pericholecystic abscess; bilio-enteric fistula; gallstone ileus Necrosis with perforation of the GB wall (non-iatrogenic)
    V GB perforation with generalized peritonitis Above, with generalized peritonitis Free intra-peritoneal bile Above, plus generalized peritonitis Necrosis with perforation of the GB wall (non-iatrogenic)

     

    D. Acute Diverticulitis of the Colon

    AAST Grade Description Clinical Criteria Imaging Criteria
    (CT findings)
    Operative Criteria Pathologic Criteria
    I Colonic inflammation Pain; leukocytosis;
    minimal or no tenderness
    Mesenteric stranding;
    colon wall thickening
    N/A N/A
    II Colon micro-perforation or pericolic phlegmon without abscess Local tenderness
    (single or multiple areas) without peritonitis
    Pericolic phlegmon;
    foci of air (single or multiple); no abscess
    Pericolic phlegmon with no abscess Inflamed colon with microscopic perforation
    III Localized pericolic abscess Localized peritonitis Pericolic abscess Pericolic abscess Inflamed colon with perforation
    IV Distant and/or multiple abscesses Localized peritonitis at multiple locations Abscess or phlegmon away from the colon Abscess or phlegmon away from the colon Inflamed colon with perforation
    V Free colonic perforation with generalized peritonitis Generalized peritonitis Free air and free fluid Perforation with generalized fecal and purulent contamination Inflamed colon with perforation

     

    E. Esophageal Perforation

    AAST Grade Description Clinical Criteria Imaging and/or endoscopic criteria Operative Criteria Pathologic criteria
    I Mucosal tear Dysphagia; chest pain, upper abdominal pain or back pain; breathing problems No abnormality or possible intramural air Preservation of normal anatomy with dissection required to identify inflammation Partial thickness or mucosal tear
    II Full thickness tear with minimal inflammation Above, with subcutaneous emphysema Esophageal thickening Obvious inflammation Full thickness perforation with minimal inflammation without mediastinitis or peritonitis
    III Full thickness tear with localized abscess Above, with vomiting and ill-appearing Air in prevertebral planes Presence of inflammation and stigmata of perforation with contained collection Mediastinal inflammation or emphysema
    IV Esophageal wall necrosis As above Mediastinal widening Inflammation; necrosis of the esophageal wall with localized contamination Severe mediastinal necrosis
    V Empyema; peritonitis; mediastinitis As above Pleural effusion Perforation with disseminated contamination; erosion into adjacent structures (chest, mediastinum, or abdomen) Pleural invasion or empyema

     

    F. Hernias (Internal or Abdominal wall)

    AAST Grade Description Clinical Criteria Imaging Criteria
    (CT findings)
    Operative Criteria Pathologic Criteria
    I Reducible hernia Palpable, reducible hernia without fever or leukocytosis Hernia visible on CT Abdominal wall defect present N/A
    II Incarcerated hernia without bowel ischemia Local tenderness with non-reducible palpable hernia. No fever of leukocytosis. Hernia visible on CT Abdominal wall defect present with abdominal contents lodged in defect; healthy appearing viscera N/A
    III Incarcerated with bowel ischemic but viable Local tenderness with non-reducible palpable hernia; may be associated with fever, tachycardia, or leukocytosis Hernia visible on CT with local stranding or inflammatory changes Abdominal wall defect present with abdominal contents lodged in defect; visibly inflamed but viable appearing viscera N/A
    IV Incarcerated hernia with gangrenous bowel or perforation with local spillage Local tenderness with guarding, non-reducible palpable hernia with associated skin changes such as erythema Hernia visible on CT with local stranding or inflammatory changes as well as contained fluid collection Abdominal wall defect present with abdominal contents lodged in defect; gangrenous or perforated abdominal contents Local necrosis or perforation
    V Incarcerated with perforation and diffuse peritoneal contamination Diffuse abdominal tenderness with guarding or rebound; non-reducible palpable hernia with associated skin changes such as erythema Hernia visible on CT with local stranding or inflammatory changes as well as diffuse fluid collections and inflammation Abdominal wall defect present with abdominal contents lodged in defect; gangrenous or perforated abdominal contents with diffuse contamination Local necrosis or perforation

     

    G. Infectious Colitis

    AAST Grade Description Clinical Criteria Imaging Criteria
    ( CT findings)
    Operative Criteria Pathologic Criteria
    I Mucosal disease with positive cultures or other confirmatory laboratory testing Diarrhea and/or abdominal pain with positive stool cultures or toxin assays; inflamed mucosa on endoscopy Normal CT Normal colon Mucosal inflammatory changes on biopsy, positive stool cultures or toxin assays
    II Colon wall thickening by cross-sectional imaging or pseudo-membranes on endoscopy Diarrhea and/or abdominal pain, and/or abdominal tenderness with pseudo- membranes on endoscopy Localized colonic wall thickening Localized thickened but otherwise normal colon Transmural colonic inflammation
    III Colon wall thickening with ascites or diffuse colonic dilation or diffuse coalescing pseudo-membranes Abdominal pain and tenderness and/or distension; coalescing pseudomembranes by endoscopy Diffuse colonic thickening or localized thickening and free intra-abdominal fluid Diffusely thickened colon or localized thickening with free intra-abdominal fluid Transmural colonic inflammation
    IV Localized colonic necrosis, with or without perforation Abdominal pain with peritonitis and mucosal necrosis by endoscopy Colonic thickening with free fluid +/- evidence of perforation or abscess Colonic thickening with localized or discontinuous transmural necrosis or ischemia with or without perforation or abscess Transmural colonic inflammation with areas of necrosis
    V Diffuse transmural colonic necrosis, with or without perforation Abdominal pain with peritonitis mucosal necrosis by endoscopy Colonic thickening with free fluid +/- evidence of perforation or abscess Diffuse colonic necrosis with or without perforation or abscess Transmural colonic inflammation with areas of full thickness necrosis

     

    H. Instestinal Obstruction Due to Adhesions

    AAST Grade Description Clinical Criteria Imaging Criteria
    (CT findings)
    Operative Criteria Pathologic criteria
    I Partial SBO Some flatus; normal or hypoactive bowel sounds; minor abdominal distention Normal imaging or minimal intestinal distension Minimal intestinal distension with no evidence of bowel obstruction N/A
    II Complete SBO; bowel viable and not compromised Minimal to no flatus; hypoactive bowel sounds; distension without generalized tenderness Intestinal distension with transition point; delayed contrast flow with some distal contrast; no evidence of bowel compromise Intestinal distention with transition point; no evidence of bowel compromise N/A
    III Complete SBO with compromised but viable bowel No flatus; absent bowel sounds; abdominal distension with localized tenderness Intestinal distension with transition point and no distal contrast flow; evidence of complete obstruction or impending bowel compromise Intestinal distention with impending bowel compromise N/A
    IV Complete SBO with non-viable bowel or perforation with localized spillage Obstipation; abdominal distension with diffuse tenderness, rebound, guarding Evidence of localized perforation or free air; bowel distension with free air or free fluid Intestinal distension with localized perforation or free fluid Bowel gangrene or perforation
    V SB perforation with diffuse peritoneal contamination Abdominal distension with evidence of peritonitis Bowel perforation with free air and free fluid Intestinal distension with perforation, free fluid and evidence of diffuse peritonitis Bowel gangrene or perforation

     

    I. Intestinal Arterial Ischemia of the Bowel

    AAST Grade Description Clinical Criteria Imaging Criteria (CT findings) Operative Criteria Pathologic Criteria
    I Bowel ischemia without tissue loss Anorexia with abdominal pain Wall thickening and mucosal edema with enhancement Normal apperaing bowel Ischemia without ulceration
    II Bowel ischemia with mucosal ulceration only, without transmural Abdominal pain out of proportion to exam; no peritonitis Wall thickening and edema without enhancement; mesenteric vessel occlusion Normal seroso, mucosal ichemia and ulceration Mucosal ulceration
    III Segmental transmural bowel infarction without perforation Abdominal pain and tenderness without peritonitis Wall thickening without mucosal or intestinal wall enhancement; intramural, portal, or mesenteric pneumatosis Transmural necrosis without perforation Transmural necrosis without perforation
    IV Segmental transmural bowel infarction with perforation Abdominal pain and tenderness with peritonitis Pneumoperitoneum, contrast extravasation, abscess Transmural necrosis with perforation and peritonitis Transmural necrosis with perforation
    V Pan-intestinal infarction Abdominal pain and tenderness with peritonitis Grade III or IV above with involvement of both Superior Mesenteric Artery and Inferior Mesenteric Artery distributions Pan-intestinal infarction and necrosis with or without perforation Transmural infarction with perforation

     

    J. Acute Pancreatitis

    AAST Grade Description Clinical Criteria Imaging Criteria (CT findings) Operative Criteria Pathologic Criteria
    I Acute edematous pancreatitis Midepigastric abdominal pain and tenderness; elevated amylase and/or lipase Pancreatitis without phlegmon, necrosis, peripancreatic fluid collection or abscess Edematous pancreas N/A
    II Pancreatic phlegmon or
    peripancreatic fluid collection or hemorrhage
    Midepigastric abdominal pain and tenderness; elevated amylase and/or lipase Phlegmon or peripancreatic fluid collection or hemorrhage Pancreatic phlegmon or peripancreatic fluid collection N/A
    III Sterile pancreatic necrosis Midepigastric abdominal pain and tenderness; elevated amylase and/or lipase Pancreatic necrosis without extraluminal air or abscess Pancreatic necrosis without purulence or abscess Gram stain and culture of necrosis negative for organisms
    IV Infected pancreatic necrosis or abscess Severe midepigastric abdominal pain and tenderness; elevated amylase and/or lipase Pancreatic necrosis with extraluminal air or abscess Pancreatic necrosis with purulence or abscess Gram stain and culture of necrosis or abscess positive for organisms
    V Extra-pancreatic extension of pancreatic necrosis involving adjacent organs, such as colonic necrosis Severe diffuse midepigastric abdominal pain and tenderness; elevated amylase and/or lipase Extra-pancreatic extension of necrosis involving adjacent organs, such as colonic necrosis Involvement or necrosis of adjacent organs Involvement or necrosis of resected adjacent organs

     

    K. Pelvic Inflammatory Disease

    AAST Grade Description Clinical Criteria Imaging Criteria (CT or US findings) Operative Criteria Pathologic Criteria
    I Inflammation of the cervix None N/A N/A N/A
    II Purulent cervical drainage None OR vaginal discharge, vaginal irritation, pelvic discomfort N/A N/A None or positive cervical cultures for organisms
    III Inflammation of the tubes, ovaries, and/or entire uterus Above, plus pelvic pain or discomfort; fever Inflammation of pelvic organ or organs None, or purulent pelvic fluid on laparoscopy None or positive cervical cultures for organisms
    IV Tubo-ovarian abscess, pyometra Severe pelvic pain; fever Inflammation and abscess of pelvic organ or organs Drainage of tubo-ovarian abscess or pyometra None, or positive cervical or pelvic cultures for organisms
    V Generalized pelvic sepsis Generalized peritonitis Single or multiple abscesses, widespread inflammation Drainage of fluid collections, complications related to abscesses, such as interloop abscesses causing bowel obstruction; hysterectomy None, or positive cervical or pelvic cultures for organisms

     

    L. Perforated Peptic Ulcer Disease (Gastric or Duodenal)

    AAST Grade Description Clinical Criteria Imaging Criteria (CT findings) Operative Criteria Pathologic Criteria
    I Micro-perforation without peritonitis Discomfort in the epigastric region Extraluminal gas with no associated inflammatory changes Preservation of normal anatomy with dissection required to identify the perforation Perforation with minimal bowel wall inflammation
    II Contained perforation with localized peritonitis Tenderness confined to the right upper quadrant (RUQ) Extraluminal gas contained in a walled off collection or the retroperitoneum Presence of inflammation and stigmata of perforation with contained collection Perforation with bowel wall inflammation
    III Perforation with localized peritonitis and localized fluid collection in lesser sac or RUQ Tenderness confined to the RUQ Perforation with associated collection that is not contained in a anatomic space or abscess but not disseminated Inflammation and contamination of peritoneal cavity confined to the RUQ Perforation with bowel wall inflammation
    IV Free perforation with peritonitis Diffuse peritonitis Perforation with disseminated air and fluid Perforation with disseminated succus or purulent peritonitis Perforation with bowel wall inflammation
    V Perforation with duodenal destruction ± penetration into adjacent organs and generalized peritonitis Diffuse peritonitis Perforation with disseminated air and fluid with loss of local anatomic planes at the site of perforation Perforation with disseminated succus or purulent peritonitis and erosion into adjacent structures Destructive erosion of involved structures

     

    M. Perirectal Abscess

    AAST Grade Description Clinical Criteria Imaging Criteria Operative Criteria Pathologic Criteria
    I Perianal abscess Anal pain and swelling, erythema, tenderness N/A Drainage of localized pus N/A
    II Intersphincteric abscess or ischiorectal abscess Fever; perineal pain;
    diffuse swelling; pain
    with defecation; palpable fluctuant area on digital examination
    Endorectal ultrasound localization; CT may localize collection but MRI preferable Drainage of localized pus Culture of abscess positive for organisms
    III Horseshoe abscess Pain with defecation;
    palpable fluctuant area on digital examination
    Endorectal ultrasound localization; CT may localize collection but MRI preferable Drainage of localized pus Culture of abscess positive for organisms
    IV Supralevator abscess Fever; may present with sepsis or perineal
    discomfort; may have no localized clinical signs
    Endorectal ultrasound not useful; CT demonstrating collection Drainage of localized pus Culture of abscess positive for organisms
    V Necrotizing soft tissue infection of the perineum, buttocks, etc., AKA Fournier's gangrene Systemic signs of sepsis, perineal pain and swelling, cellulitis, crepitus, necrotic skin changes X-ray or CT may demonstrate air in soft tissues. CT or MRI may demonstrate intra- abdominal or retro-peritoneal source of infection. Necrotic skin and soft tissue of perianal, perineal, and genitalia Above, plus necrotic skin and soft tissue of perianal, perineal, and genitalia

     

    N. Pleural Space Infection

    AAST Grade Description Clincal Criteria Imaging Criteria Operative Criteria Pathologic Criteria
    I Retained hemothorax or pleural effusion with positive pleural fluid cultures Leukocytosis, fever, chest pain Pleural fluid consistent with blood or infected fluid no evidence of loculations Retained blood, blood clot, or other non-purulent fluid without lung trapping. Culture of fluid positive for organisms
    II Purulent, free-flowing pleural effusion or hemothorax by imaging Respiratory failure, leukocytosis, fever, chest pain Pleural fluid consistent with blood or infected fluid; no evidence of loculation Retained blood, blood clot, with purulent areas OR completely purulent fluid. Culture of fluid positive for organisms
    III Fibrinopurulent stage with loculated areas of effusion or hemothorax Respiratory failure, leukocytosis, fever, chest pain Pleural fluid consistent with blood or infected fluid, with evidence of loculation Retained blood, blood clot or other purulent fluid with limited lung trapping Culture of fluid positive for organisms with areas of fibrous peel
    IV Organizing stage with evidence for restricted lung expansion and pulmonary mechanics Severe respiratory failure, leukocytosis, fever, chest pain Pleural fluid consistent with blood or infected fluid with evidence of loculation; significantly decreased lung volumes Retained blood, blood clot or other purulent fluid with diffuse pleural inflammation and lung trapping Culture of fluid positive for organisms with areas of fibrous peel
    V Spontaneous external drainage or spreading extra-thoracic necrotizing soft tissue infection Severe respiratory failure, leukocytosis, fever, chest pain Above, plus severe inflammatory changes of adjacent abdominal, mediastinal or subcutaneous tissue Above, with external drainage or necrotizing soft tissue infection of mediastinum, diaphragm or subcutaneous tissues Above, with necrotic soft tissue from mediastinum, or subcutaneous space

     

    O. Soft Tissue Infections

    AAST Grade Description Clincal Criteria Imaging Criteria
    (CT findings)
    Operative Criteria Pathologic Criteria
    I Cellulitis Folliculitis, erysipelas, impetigo, simple cellulitis Superficial inflammation with no subcutaneous stranding N/A Acute inflammation involving epidermis only
    II Superficial necrosis or liquefaction Necrotizing, blistering or bullous cellulitis or skin necrosis Subcutaneous stranding, but no abscess N/A Acute inflammation involving epidermis and dermis
    III Subcutaneous Abscess Subcutaneous abscess Well defined (walled off) subcutaneous fluid collection with surrounding inflammation Well defined subcutaneous fluid collection Acute inflammation involving epidermis, dermis, and subcutaneous fat with cultures positive for organisms if available
    IV Fasciitis Fasciitis Inflammation extending to fascia; likely air along fascia margins Clear involvement of fascia with healthy, viable muscle underneath. Acute inflammation involving epidermis, dermis, sub-cutaneous fat, and muscular fascia with cultures positive for organisms if available
    V Myonecrosis Myonecrosis Air deep to fascia; likely poor perfusion of muscle Extension of necrosis into muscle and deeper tissue Acute inflammation involving epidermis, dermis, sub- cutaneous fat, muscular fascia, adjacent tissue (muscle, etc.) with cultures positive for organisms if available

     

    P. Surgical Site Infections

    Grade Description Clinical Criteria Imaging Criteria
    (CT findings)
    Operative Criteria Pathologic Criteria
    I Infection involving skin only One or more of the following: peri-incisional erythema, warmth, pain, swelling without induration, exudate, or wound separation N/A N/A N/A
    II Infection involving subcutaneous tissue One or more of the following: peri-incisional erythema warmth, pain, swelling plus induration or exudate confined to subcutaneous tissues Soft tissue inflammatory changes, phlegmon or abscess in subcutaneous tissues Phlegmon or abscess in subcutaneous tissues Acute inflammation limited to subcutaneous tissues
    III Infection involving fascia or muscle layer Subcutaneous abscess or phlegmon extending to muscle or fascia Regional soft tissue inflammatory changes, phlegmon or abscess involving muscle or fascia Phlegmon or abscess involving muscle or fascia Acute inflammation involving muscle or fascia with cultures positive for organism if available
    IV Infection involving body cavity or deep space that was opened or manipulated during the surgery Above, plus separation of fascia or subfascial abscess Phlegmon or abscess extending deep to muscle or fascia OR fascial dehiscence at surgical site Phlegm on or abscess extending deep to muscle or fascia OR facial wound dehiscence Acute inflammation involving fascia and underlying tissues with cultures positive for organism if available
    V Infection involving body cavity or deep space away from the site that was opened or manipulated during surgery Purulent drainage in a body cavity away from the operative site Phlegmon or abscess in body cavity or deep space extending deeper than the fascia/deep muscle incision Phlegmon or abscess in body cavity or deep space extending deeper than the fascial/deep muscle incision Acute inflammation in body cavity or deep space away extending deeper than the fascial/deep muscle incision with cultures positive for organisms if available