Surgical Anatomy
What is the significance of the triangle of Calot?
It's bounded by the cystic duct, common hepatic duct, and inferior liver border. Important for identifying the cystic artery during cholecystectomy.
Define the lethal triad in trauma and its surgical implication.
Hypothermia, acidosis, coagulopathy — often mandates damage control surgery.
A patient presents with abdominal pain and peritonitis 6 months after gastric bypass. What is the most likely diagnosis? (Must use eponym)
Peterson's hernia
What is the most common electrolyte abnormality seen with NG tube decompression?
Hypokalemic hypochloremic metabolic alkalosis.
What is the recommended margin and lymph node goal for colon cancer resection?
5 cm margin and ≥12 lymph nodes.
What anatomic anomaly increases the risk of bile duct injury during cholecystectomy?
Low insertion of the cystic duct or aberrant right hepatic duct crossing Calot’s triangle
A trauma patient has a widened mediastinum and left hemothorax on CXR. What is the most likely vascular injury?
Aortic isthmus injury.
What is the recommended management of acute SMA thrombosis without signs of bowel necrosis?
Emergent angiography with catheter-directed thrombolysis or thrombectomy.
What is the management of a high-output enterocutaneous fistula in a patient with no signs of sepsis?
NPO, TPN, electrolyte correction, skin protection, and delayed surgical repair after 6–12 weeks.
What is the significance of an elevated CA 19-9 in a patient with obstructive jaundice?
May be falsely elevated due to cholestasis — repeat after biliary decompression.
Which two vessels form the portal vein, and where does this occur anatomically?
The superior mesenteric vein and splenic vein join posterior to the neck of the pancreas.
What is the most sensitive early indicator of shock in a trauma patient? (Hint: lab value)
Base deficit or serum lactate.
What EKG finding is most associated with mesenteric ischemia?
Atrial fibrillation.
A patient on POD #5 after low anterior resection presents with tachycardia and vague abdominal pain. What subtle sign should raise concern for an anastomotic leak, and what is the first diagnostic test?
Unexplained tachycardia is the most sensitive early sign.
First test: CT abdomen/pelvis with IV and rectal contrast.
Describe the Whipple triad of insulinoma.
Hypoglycemia symptoms, blood glucose <50, symptom resolution with glucose administration.
During laparoscopic inguinal hernia repair, what are the "triangle of doom" and "triangle of pain," and what structures do they contain?
Triangle of Doom: Bordered by vas deferens and gonadal vessels; contains external iliac vessels—no tacking here.
Triangle of Pain: Lateral to gonadal vessels; contains lateral femoral cutaneous and femoral branch of genitofemoral nerve—risk of chronic pain if tacked.
What is the Parkland formula for fluid resuscitation in burns, and how should it be adjusted in electrical injury?
4 mL × TBSA (%) × kg; adjust upward due to deeper muscle injury and risk of myoglobinuria.
What is the key difference in lab findings between necrotizing fasciitis and cellulitis?
Disproportionately elevated CK, WBC, hyponatremia, and gas on imaging suggest nec fasc.
What is the evidence-based duration of prophylactic antibiotics for clean-contaminated surgeries?
24 hours or less. Prolonged use increases resistance without reducing infection rates (e.g., SCIP guidelines).
What genetic mutation is associated with MEN 2B, and what is the prophylactic recommendation?
RET codon 918; total thyroidectomy in infancy.
What artery accompanies the recurrent laryngeal nerve and can be used to identify it intraoperatively?
The inferior thyroid artery—the nerve usually travels in close proximity, either anterior, posterior, or between its branches.
Which zone of the neck trauma requires mandatory exploration if violated?
Zone II (between the cricoid and angle of the mandible).
What physiologic change causes increased cardiac output in early sepsis, and how does this affect oxygen delivery and lactate levels?
Peripheral vasodilation and decreased systemic vascular resistance increase cardiac output; oxygen delivery may be high but utilization impaired, leading to elevated lactate due to anaerobic metabolism.
What’s the difference in clinical presentation between a duodenal stump leak and a pancreatic leak after a Whipple procedure?
Duodenal stump leak: bile-containing output, early sepsis, peritonitis.
Pancreatic leak: high-amylase output, slower onset, usually better tolerated initially.
What is the most common cause of delayed hemorrhage (>24 hrs) after pancreaticoduodenectomy?
Erosion of the gastroduodenal artery stump, often due to a pancreatic leak or abscess.