Natural orifice transluminal surgery US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Natural orifice transluminal surgery. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Natural orifice transluminal surgery US Medical PG Question 1: The surgical equipment used during a craniectomy is sterilized using pressurized steam at 121°C for 15 minutes. Reuse of these instruments can cause transmission of which of the following pathogens?
- A. Non-enveloped viruses
- B. Sporulating bacteria
- C. Prions (Correct Answer)
- D. Enveloped viruses
- E. Yeasts
Natural orifice transluminal surgery Explanation: ***Prions***
- Prions are **abnormally folded proteins** that are highly resistant to standard sterilization methods like steam autoclaving at 121°C, making them a risk for transmission through reused surgical instruments.
- They cause transmissible spongiform encephalopathies (TSEs) like **Creutzfeldt-Jakob disease**, where even trace amounts can be highly infectious.
*Non-enveloped viruses*
- Non-enveloped viruses are generally **more resistant to heat and disinfectants** than enveloped viruses but are typically inactivated by recommended steam sterilization protocols.
- Standard autoclaving conditions are effective in destroying most non-enveloped viruses.
*Sporulating bacteria*
- **Bacterial spores**, such as those from *Clostridium* or *Bacillus*, are known for their high resistance to heat and chemicals, but are usually **inactivated by steam sterilization at 121°C** for 15 minutes.
- This method is specifically designed to kill bacterial spores effectively.
*Enveloped viruses*
- Enveloped viruses are the **least resistant to heat and chemical disinfectants** due to their lipid envelope.
- They are readily **inactivated by standard steam sterilization** at 121°C.
*Yeasts*
- **Yeasts** are eukaryotic microorganisms that are typically **susceptible to heat sterilization**.
- They are effectively killed by typical steam autoclaving conditions used for surgical instruments.
Natural orifice transluminal surgery US Medical PG Question 2: A 27-year-old man presents to the emergency department after being stabbed. The patient was robbed at a local pizza parlor and was stabbed over 10 times with a large kitchen knife with an estimated 7 inch blade in the ventral abdomen. His temperature is 97.6°F (36.4°C), blood pressure is 74/54 mmHg, pulse is 180/min, respirations are 19/min, and oxygen saturation is 98% on room air. The patient is intubated and given blood products and vasopressors. Physical exam is notable for multiple stab wounds over the patient's abdomen inferior to the nipple line. Which of the following is the best next step in management?
- A. Exploratory laparotomy (Correct Answer)
- B. Diagnostic peritoneal lavage
- C. CT scan of the abdomen and pelvis
- D. Exploratory laparoscopy
- E. FAST exam
Natural orifice transluminal surgery Explanation: ***Exploratory laparotomy***
- The patient presents with **multiple stab wounds** to the abdomen and signs of **hemorrhagic shock** (BP 74/54 mmHg, HR 180/min), which are clear indications for immediate surgical intervention.
- An exploratory laparotomy allows for direct visualization and repair of internal injuries, which is critical in this life-threatening situation.
*Diagnostic peritoneal lavage*
- While DPL can detect intra-abdominal bleeding, it is an **invasive procedure** and may delay definitive treatment in a hemodynamically unstable patient with obvious penetrating trauma.
- It is **less specific** than a laparotomy for identifying the exact location and nature of injuries, and it has largely been replaced by imaging studies or direct surgical exploration in unstable patients.
*CT scan of the abdomen and pelvis*
- A CT scan requires a **hemodynamically stable** patient and time for scanning and interpretation, which this patient does not have.
- Delaying definitive treatment for imaging in a patient with severe shock could lead to worse outcomes.
*Exploratory laparoscopy*
- Although less invasive, laparoscopy can be time-consuming and may not be feasible or safe in a patient with **profound hemorrhagic shock** and extensive injuries, especially if major vascular or visceral damage is suspected.
- Conversion to a **laparotomy** is often necessary in cases of significant injury, making immediate open exploration more efficient.
*FAST exam*
- A FAST exam can rapidly detect free fluid in the abdomen, suggesting internal bleeding, but it does **not provide specific information** about the source or extent of the injuries.
- While useful in the initial assessment, a positive FAST exam in a hemodynamically unstable patient with penetrating trauma directly points to the need for immediate surgical intervention, not further diagnostic delay.
Natural orifice transluminal surgery US Medical PG Question 3: A 45-year-old man is brought to the emergency department because of severe abdominal pain for the past 2 hours. He has a 2-year history of burning epigastric pain that gets worse with meals. His pulse is 120/min, respirations are 22/min, and blood pressure is 60/40 mm Hg. Despite appropriate lifesaving measures, he dies. At autopsy, examination shows erosion of the right gastric artery. Perforation of an ulcer in which of the following locations most likely caused this patient's findings?
- A. Anterior duodenum
- B. Posterior duodenum
- C. Lesser curvature of the stomach (Correct Answer)
- D. Greater curvature of the stomach
- E. Fundus of the stomach
Natural orifice transluminal surgery Explanation: ***Lesser curvature of the stomach***
- Erosion of the **right gastric artery** by a gastric ulcer is characteristic of an ulcer located on the **lesser curvature of the stomach**.
- Ulcers in this location can erode into adjacent blood vessels, leading to **severe hemorrhage** as evidenced by the patient's **hypotension** and subsequent death.
*Anterior duodenum*
- Ulcers in the **anterior duodenum** typically present with **perforation into the peritoneal cavity**, leading to generalized peritonitis, not primarily hemorrhage from a major artery.
- While bleeding can occur, it's usually from smaller duodenal arteries and less commonly involves large arteries like the right gastric artery.
*Posterior duodenum*
- Ulcers in the **posterior duodenum** are known to erode into the **gastroduodenal artery**, leading to massive upper gastrointestinal bleeding.
- This is a distinct arterial involvement compared to the erosion of the right gastric artery.
*Greater curvature of the stomach*
- Ulcers on the **greater curvature of the stomach** are less common and often associated with malignancy.
- If they bleed, it would typically involve branches of the **gastroepiploic arteries**, not the right gastric artery.
*Fundus of the stomach*
- Ulcers in the **fundus** are rare.
- If a vessel were involved, it would typically be a short gastric artery, not the right gastric artery which courses along the lesser curvature.
Natural orifice transluminal surgery US Medical PG Question 4: A 63-year-old man comes to the physician because of a 1-month history of difficulty swallowing, low-grade fever, and weight loss. He has smoked one pack of cigarettes daily for 30 years. An esophagogastroduodenoscopy shows an esophageal mass just distal to the upper esophageal sphincter. Histological examination confirms the diagnosis of locally invasive squamous cell carcinoma. A surgical resection is planned. Which of the following structures is at greatest risk for injury during this procedure?
- A. Bronchial branch of thoracic aorta
- B. Left gastric artery
- C. Left inferior phrenic artery
- D. Esophageal branch of thoracic aorta
- E. Inferior thyroid artery (Correct Answer)
Natural orifice transluminal surgery Explanation: **Inferior thyroid artery**
- The esophageal mass is located just distal to the **upper esophageal sphincter**, which is in the neck, close to the **thyroid gland**.
- During surgery for an esophageal tumor in this region, the **inferior thyroid artery**, which supplies the thyroid and adjacent structures, is at the greatest risk of injury due to its proximity.
*Bronchial branch of thoracic aorta*
- The **bronchial branches** of the thoracic aorta primarily supply the bronchi and lungs.
- These vessels are located deeper in the thorax, away from the **upper esophageal sphincter** and the initial surgical field for an upper esophageal tumor.
*Left gastric artery*
- The **left gastric artery** supplies the stomach and is a branch of the celiac trunk.
- This artery is located in the **abdomen**, far from the surgical site involving an esophageal mass near the upper esophageal sphincter.
*Left inferior phrenic artery*
- The **left inferior phrenic artery** primarily supplies the diaphragm.
- This vessel originates from the aorta in the **abdominal region**, which is distant from the upper esophageal sphincter.
*Esophageal branch of thoracic aorta*
- **Esophageal branches** directly supply the esophagus; however, the question refers to the **thoracic aorta branches**.
- Tumors near the **upper esophageal sphincter** are usually accessed via a cervical incision, making thoracic branches less likely to be injured compared to arteries located in the neck.
Natural orifice transluminal surgery US Medical PG Question 5: A 28-year-old male presents to his primary care physician with complaints of intermittent abdominal pain and alternating bouts of constipation and diarrhea. His medical chart is not significant for any past medical problems or prior surgeries. He is not prescribed any current medications. Which of the following questions would be the most useful next question in eliciting further history from this patient?
- A. "Does the diarrhea typically precede the constipation, or vice-versa?"
- B. "Is the diarrhea foul-smelling?"
- C. "Please rate your abdominal pain on a scale of 1-10, with 10 being the worst pain of your life"
- D. "Are the symptoms worse in the morning or at night?"
- E. "Can you tell me more about the symptoms you have been experiencing?" (Correct Answer)
Natural orifice transluminal surgery Explanation: ***Can you tell me more about the symptoms you have been experiencing?***
- This **open-ended question** encourages the patient to provide a **comprehensive narrative** of their symptoms, including details about onset, frequency, duration, alleviating/aggravating factors, and associated symptoms, which is crucial for diagnosis.
- In a patient presenting with vague, intermittent symptoms like alternating constipation and diarrhea, allowing them to elaborate freely can reveal important clues that might not be captured by more targeted questions.
*Does the diarrhea typically precede the constipation, or vice-versa?*
- While knowing the sequence of symptoms can be helpful in understanding the **pattern of bowel dysfunction**, it is a very specific question that might overlook other important aspects of the patient's experience.
- It prematurely narrows the focus without first obtaining a broad understanding of the patient's overall symptomatic picture.
*Is the diarrhea foul-smelling?*
- Foul-smelling diarrhea can indicate **malabsorption** or **bacterial overgrowth**, which are important to consider in some gastrointestinal conditions.
- However, this is a **specific symptom inquiry** that should follow a more general exploration of the patient's symptoms, as it may not be relevant if other crucial details are missed.
*Please rate your abdominal pain on a scale of 1-10, with 10 being the worst pain of your life*
- Quantifying pain intensity is useful for assessing the **severity of discomfort** and monitoring changes over time.
- However, for a patient with intermittent rather than acute, severe pain, understanding the **character, location, and triggers** of the pain is often more diagnostically valuable than just a numerical rating initially.
*Are the symptoms worse in the morning or at night?*
- Diurnal variation can be relevant in certain conditions, such as inflammatory bowel diseases where nocturnal symptoms might be more concerning, or functional disorders whose symptoms might be stress-related.
- This is another **specific question** that should come after gathering a more complete initial picture of the patient's symptoms to ensure no key information is overlooked.
Natural orifice transluminal surgery US Medical PG Question 6: A 37-year-old woman is brought to the emergency department 15 minutes after falling down a flight of stairs. On arrival, she has shortness of breath, right-sided chest pain, right upper quadrant abdominal pain, and right shoulder pain. She is otherwise healthy. She takes no medications. She appears pale. Her temperature is 37°C (98.6°F), pulse is 115/min, respirations are 20/min, and blood pressure is 85/45 mm Hg. Examination shows several ecchymoses over the right chest. There is tenderness to palpation over the right chest wall and right upper quadrant of the abdomen. Bowel sounds are normal. Cardiopulmonary examination shows no abnormalities. Neck veins are flat. Which of the following is the most likely diagnosis?
- A. Splenic laceration
- B. Liver hematoma (Correct Answer)
- C. Pneumothorax
- D. Duodenal hematoma
- E. Small bowel perforation
Natural orifice transluminal surgery Explanation: ***Liver hematoma***
- The patient's presentation with **right upper quadrant abdominal pain**, **right shoulder pain** (referred pain from diaphragmatic irritation), and **hypotension** following a fall points strongly to **liver injury**.
- The liver is the **most commonly injured organ** in blunt abdominal trauma due to its size and position.
*Splenic laceration*
- While splenic laceration can cause hypovolemic shock, pain is typically localized to the **left upper quadrant** and left shoulder (**Kehr's sign**), not the right.
- The ecchymoses and tenderness are predominantly on the **right side** of the chest and abdomen.
*Pneumothorax*
- A pneumothorax would typically present with **unilateral diminished breath sounds**, **hyperresonance to percussion**, and potentially **tracheal deviation**, none of which are mentioned.
- The patient's **blood pressure is low**, which is more suggestive of significant hemorrhage than an isolated pneumothorax, especially with **flat neck veins**.
*Duodenal hematoma*
- A duodenal hematoma typically presents with **epigastric pain**, **vomiting**, and symptoms of **gastric outlet obstruction**, often days after the injury.
- It does not typically cause **referred shoulder pain** or immediate **hypovolemic shock** as seen here.
*Small bowel perforation*
- Small bowel perforation would present with signs of **peritonitis**, such as **rebound tenderness**, **guarding**, and absent or diminished bowel sounds due to inflammation from bowel contents.
- While there is abdominal pain, the **bowel sounds are normal**, and the primary symptoms align more with **hemorrhage**.
Natural orifice transluminal surgery US Medical PG Question 7: A 32-year-old woman undergoes laparoscopic excision of ovarian endometrioma. During surgery with the patient in Trendelenburg position and pneumoperitoneum at 15 mmHg, the anesthesiologist notes peak airway pressures rising from 25 to 40 cmH2O, oxygen saturation dropping to 88%, and blood pressure decreasing. Apply the appropriate immediate intervention.
- A. Increase tidal volume and respiratory rate
- B. Increase FiO2 and administer fluid bolus only
- C. Release pneumoperitoneum and decrease Trendelenburg (Correct Answer)
- D. Administer bronchodilators for bronchospasm
- E. Check for endobronchial intubation and reposition tube
Natural orifice transluminal surgery Explanation: ***Release pneumoperitoneum and decrease Trendelenburg***
- High **peak airway pressures** (40 cmH2O), **hypoxemia**, and **hypotension** indicate severe physiological compromise from **pneumoperitoneum** and positioning.
- Releasing the gas and leveling the patient immediately facilitates **diaphragmatic descent**, increases **lung compliance**, and restores **venous return** to improve cardiac output.
*Increase tidal volume and respiratory rate*
- Increasing **tidal volume** in the presence of already high airway pressures significantly increases the risk of **barotrauma** and further cardiovascular collapse.
- This intervention does not address the mechanical cause of **diaphragmatic splinting** caused by the CO2 insufflation.
*Increase FiO2 and administer fluid bolus only*
- While oxygenation may temporarily improve, this fails to correct the **reduced functional residual capacity** caused by the **positive pressure** in the abdomen.
- Fluids may not compensate for the **inferior vena cava compression** if the source of high **intra-abdominal pressure** remains unchanged.
*Administer bronchodilators for bronchospasm*
- High airway pressures in laparoscopy are usually due to **decreased thoracic compliance**, not necessarily **bronchospasm**.
- The sudden drop in blood pressure suggests a hemodynamic/mechanical cause rather than an isolated **obstructive lung** pathology.
*Check for endobronchial intubation and reposition tube*
- While cephalad movement of the diaphragm can cause **endobronchial intubation**, it does not typically explain the systemic **hypotension** seen here.
- This step should follow the **immediate release** of abdominal pressure, which is the most life-threatening contributor to the current vitals.
Natural orifice transluminal surgery US Medical PG Question 8: A 65-year-old man with locally advanced rectal cancer 6 cm from the anal verge completes neoadjuvant chemoradiation with good response. MRI shows tumor downsizing to 3 cm with no nodal involvement. The patient strongly prefers sphincter preservation. The surgeon can perform either open low anterior resection or robotic-assisted total mesorectal excision. Evaluate the optimal approach considering oncologic and functional outcomes.
- A. Open low anterior resection for better tactile feedback
- B. Abdominoperineal resection for oncologic safety
- C. Transanal endoscopic microsurgery for organ preservation
- D. Robotic-assisted TME for improved visualization in pelvis (Correct Answer)
- E. Watch and wait approach given excellent response
Natural orifice transluminal surgery Explanation: ***Robotic-assisted TME for improved visualization in pelvis***
- **Robotic surgery** provides a **3D high-definition view** and **wristed instrumentation**, which is particularly advantageous for precise dissection in the narrow male pelvis.
- This approach facilitates **sphincter preservation** while maintaining equivalent **oncologic outcomes**, such as circumferential resection margin (CRM) clearance, compared to open surgery.
*Open low anterior resection for better tactile feedback*
- While offering **tactile feedback**, the open approach is more technically challenging in the deep pelvis and is associated with **increased blood loss** and longer recovery times.
- It lacks the **magnified visualization** and ergonomic benefits offered by robotic platforms, which are crucial for preserving **pelvic autonomic nerves**.
*Abdominoperineal resection for oncologic safety*
- This procedure entails the permanent removal of the **anal sphincter** and creation of a colostomy, which contradicts the patient's strong preference for **sphincter preservation**.
- Since the tumor is 6 cm from the **anal verge** and responded well to therapy, a low anterior resection is oncologically safe and clinically appropriate.
*Transanal endoscopic microsurgery for organ preservation*
- **Transanal endoscopic microsurgery (TEM)** is generally reserved for **early-stage (T1)** tumors without high-risk features and is not the standard for locally advanced cancer.
- It does not allow for a complete **total mesorectal excision (TME)** or assessment of regional lymph nodes, leading to a high risk of **local recurrence** in this case.
*Watch and wait approach given excellent response*
- This strategy requires a **clinical complete response (cCR)**, which means no visible tumor on endoscopy or MRI; this patient still has a **3 cm residual mass**.
- Implementing "watch and wait" for a patient with persistent tumor significantly increases the risk of **disease progression** and missing the window for curative surgery.
Natural orifice transluminal surgery US Medical PG Question 9: A 50-year-old man with morbid obesity (BMI 48) undergoes laparoscopic sleeve gastrectomy. On postoperative day 5, he develops tachycardia, oliguria, and confusion. CT shows a small fluid collection along the staple line. Drain output is minimal. He is started on antibiotics. Twenty-four hours later, he remains tachycardic with rising lactate despite fluids. Evaluate the management priority.
- A. Urgent laparoscopic exploration with drainage
- B. Increase antibiotic coverage and vasopressor support
- C. Continue antibiotics and obtain interventional radiology drainage
- D. Endoscopic stent placement across the leak
- E. Immediate open exploration, washout, and feeding jejunostomy (Correct Answer)
Natural orifice transluminal surgery Explanation: ***Immediate open exploration, washout, and feeding jejunostomy***
- The patient exhibits signs of **septic shock** (tachycardia, rising lactate, confusion) due to a **staple line leak**, which requires immediate surgical source control.
- An **open approach** is preferred over laparoscopy in a deteriorating, morbidly obese patient to ensure thorough **peritoneal washout**, secure drainage, and the placement of a **feeding jejunostomy** for long-term nutritional support.
*Urgent laparoscopic exploration with drainage*
- While laparoscopy is minimally invasive, it is technically difficult in the setting of severe **morbid obesity** and acute inflammation, potentially leading to incomplete **source control**.
- This patient is failing to respond to initial management; therefore, a more definitive and reliable **open exploration** is prioritized to address the clinical deterioration.
*Increase antibiotic coverage and vasopressor support*
- Antibiotics and vasopressors are supportive measures but do not address the primary **surgical pathology**, which is the active leak from the gastric sleeve.
- Relying solely on medical management for **anastomotic leaks** in the presence of rising **lactate** and organ dysfunction (oliguria) allows sepsis to progress to irreversible multi-organ failure.
*Continue antibiotics and obtain interventional radiology drainage*
- **IR drainage** is generally indicated for well-localized fluid collections in **hemodynamically stable** patients.
- Because this patient's collection is small but his **systemic symptoms** are worsening, drainage alone will not achieve the necessary **source control** or mitigate the leak.
*Endoscopic stent placement across the leak*
- **Endoscopic stenting** is a management option for stable patients with chronic or subacute leaks to bypass the defect.
- It is inappropriate for an unstable patient with **postoperative peritonitis** and sepsis, where the immediate priority is **surgical washout** and drainage of the abdominal cavity.
Natural orifice transluminal surgery US Medical PG Question 10: A 28-year-old woman undergoes diagnostic laparoscopy for chronic pelvic pain. During trocar insertion using the Veress needle technique, the surgeon advances the needle through the umbilicus. Aspiration returns free-flowing blood. The patient remains hemodynamically stable. Evaluate the most appropriate next step in management.
- A. Insert trocar through the needle tract and inspect for injury
- B. Abort procedure and obtain CT angiography
- C. Remove needle and proceed with Veress insertion at different site
- D. Remove needle, convert to open Hassan technique at umbilicus
- E. Remove needle, place Foley catheter, convert to open laparotomy (Correct Answer)
Natural orifice transluminal surgery Explanation: ***Remove needle, place Foley catheter, convert to open laparotomy***
- Aspiration of **free-flowing blood** during Veress needle insertion is highly suggestive of a **major vascular injury**, such as the aorta or iliac vessels.
- Even in **hemodynamically stable** patients, immediate **laparotomy** is required to assess for and repair potential life-threatening hemorrhage that laparoscopy cannot safely manage.
*Insert trocar through the needle tract and inspect for injury*
- Inserting a larger **trocar** into a suspected vascular injury can worsen the **laceration** and lead to catastrophic bleeding.
- **Pneumoperitoneum** may temporarily tamponade a major bleed, masking the severity of the injury until it is too late.
*Abort procedure and obtain CT angiography*
- Delaying definitive surgical management for **imaging** is inappropriate when a major vascular or **solid organ injury** is suspected intraoperatively.
- Clinical suspicion and the return of blood through the needle are sufficient indications for **immediate exploration**.
*Remove needle and proceed with Veress insertion at different site*
- Simply moving to a **different site** ignores the high probability of an existing internal injury that requires **immediate repair**.
- Re-attempting insufflation elsewhere can lead to a **tension pneumoperitoneum** or delay the recognition of a retroperitoneal hematoma.
*Remove needle, convert to open Hassan technique at umbilicus*
- The **Hassan technique** is used for establishing laparoscopic access but does not provide sufficient **exposure** to control major vascular bleeding.
- Once major blood vessel injury is suspected, a large **midline laparotomy** is the standard of care to ensure adequate visualization and surgical control.
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