Trocar placement and port sites US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Trocar placement and port sites. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Trocar placement and port sites US Medical PG Question 1: During a surgical procedure to repair an abdominal aortic aneurysm, the surgeon must be careful to avoid injury to which of the following arterial structures that originates near the level of the renal vessels?
- A. Left renal artery (Correct Answer)
- B. Celiac trunk
- C. Right renal artery
- D. Superior mesenteric artery
Trocar placement and port sites Explanation: ***Left renal artery***
- The **left renal artery** arises from the aorta usually just below the superior mesenteric artery, making it susceptible to injury during an **abdominal aortic aneurysm (AAA) repair** if the aneurysm extends proximally.
- Its proximity to the typical location of AAA, often near or involving the **infrarenal aorta**, necessitates careful identification and protection during clamping or graft placement.
*Celiac trunk*
- The **celiac trunk** originates higher up from the aorta, typically at the level of **T12-L1 vertebrae**, well above the common infrarenal AAA repair site.
- While important, it is generally less directly threatened during a typical infrarenal AAA repair compared to arteries immediately adjacent to or within the aneurysm sac.
*Right renal artery*
- The **right renal artery** also originates from the aorta near the level of the renal veins, but it is typically located more posteriorly and usually passes behind the inferior vena cava.
- Although it can be at risk, the left renal artery's course is often more anterior and directly in the field of dissection for the **aortic neck** during AAA repair.
*Superior mesenteric artery*
- The **superior mesenteric artery (SMA)** originates from the aorta proximal to the renal arteries, typically around the L1 vertebral level.
- While crucial, its origin is usually cephalad to the infrarenal aneurysm neck, making it generally less prone to direct injury during infrarenal AAA repair, though flow must be monitored.
Trocar placement and port sites US Medical PG Question 2: A 41-year-old man is admitted to the emergency room after being struck in the abdomen by a large cement plate while transporting it. On initial assessment by paramedics at the scene, his blood pressure was 110/80 mm Hg, heart rate 85/min, with no signs of respiratory distress. On admission, the patient is alert but in distress. He complains of severe, diffuse, abdominal pain and severe weakness. Vital signs are now: blood pressure 90/50 mm Hg, heart rate 96/min, respiratory rate 19/min, temperature 37.4℃ (99.3℉), and oxygen saturation of 95% on room air. His lungs are clear on auscultation. The cardiac exam is significant for a narrow pulse pressure. Abdominal examination reveals a large bruise over the epigastric and periumbilical regions. The abdomen is distended and there is diffuse tenderness to palpation with rebound and guarding, worst in the epigastric region. There is hyperresonance to percussion in the epigastric region and absence of hepatic dullness in the right upper quadrant. Aspiration of the nasogastric tube reveals bloody contents. Focused assessment with sonography for trauma (FAST) shows free fluid in the pelvic region. Evaluation of the perisplenic and perihepatic regions is impossible due to the presence of free air. Aggressive intravenous fluid resuscitation is administered but fails to improve upon the patient’s hemodynamics. Which of the following is the next best step in management?
- A. Emergency laparoscopy
- B. Abdominal ultrasound
- C. Diagnostic peritoneal lavage (DPL)
- D. Emergency laparotomy (Correct Answer)
- E. CT scan
Trocar placement and port sites Explanation: ***Emergency laparotomy***
- The patient presents with **hemodynamic instability** unresponsive to fluid resuscitation, coupled with clear signs of **perforation** (hyperresonance, absent hepatic dullness, free air on FAST limited view). This clinical picture is a direct indication for immediate surgical intervention.
- The presence of bloody nasogastric tube contents, diffuse tenderness with rebound and guarding, and a history of significant blunt trauma further support the need for urgent exploratory **laparotomy** to identify and repair the source of injury.
*Emergency laparoscopy*
- While laparoscopy can be used for abdominal exploration, it is **contraindicated in hemodynamically unstable patients** due to the need for pneumoperitoneum, which can further compromise cardiovascular stability.
- In cases of suspected visceral perforation with extensive free air and massive bleeding, **laparoscopy may be technically challenging** and less efficient than open laparotomy for rapid control of hemorrhage and contamination.
*Abdominal ultrasound*
- An abdominal ultrasound (**FAST exam**) has already been partially performed, revealing free fluid and raising suspicion of free air, making further ultrasound redundant.
- While useful for initial trauma assessment, an ultrasound **cannot definitively rule out all abdominal injuries**, especially hollow viscus perforations or retroperitoneal hematomas, and is insufficient for unstable patients with clear signs of peritonitis.
*Diagnostic peritoneal lavage (DPL)*
- **DPL is largely replaced by FAST and CT scans** in most trauma centers, especially given the availability of imaging.
- Although it can detect intraperitoneal bleeding or perforation, it is an **invasive procedure** with potential complications and would only confirm what is already strongly suspected clinically; it does not address the need for immediate therapeutic intervention in an unstable patient.
*CT scan*
- A CT scan would be the imaging modality of choice for a **hemodynamically stable** patient with blunt abdominal trauma.
- However, performing a CT scan on an **unstable patient** would unnecessarily delay definitive surgical management, which is critical given the signs of ongoing internal bleeding and likely perforation.
Trocar placement and port sites US Medical PG Question 3: 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
Trocar placement and port sites 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.
Trocar placement and port sites US Medical PG Question 4: An 18-year-old man is brought to the emergency department 30 minutes after being stabbed in the chest during a fight. He has no other injuries. His pulse is 120/min, blood pressure is 90/60 mm Hg, and respirations are 22/min. Examination shows a 4-cm deep, straight stab wound in the 4th intercostal space 2 cm medial to the right midclavicular line. The knife most likely passed through which of the following structures?
- A. Serratus anterior muscle, pleura, inferior vena cava
- B. External oblique muscle, superior epigastric artery, azygos vein
- C. Pectoralis minor muscle, dome of the diaphragm, right lobe of the liver
- D. Intercostal muscles, internal thoracic artery, right heart
- E. Pectoral fascia, transversus thoracis muscle, right lung (Correct Answer)
Trocar placement and port sites Explanation: ***Pectoral fascia, transversus thoracis muscle, right lung***
* The stab wound is in the **4th intercostal space**, 2 cm medial to the right midclavicular line, placing it over the anterior chest wall. This trajectory would first penetrate the **pectoral fascia**.
* Deeper structures in this region include the **transversus thoracis muscle** and, given the depth, the **right lung** as it extends superiorly behind the anterior chest wall.
* *Serratus anterior muscle, pleura, inferior vena cava*
* The **serratus anterior muscle** is more laterally positioned, typically covering the side of the rib cage.
* The **inferior vena cava** is located more medially and posteriorly within the mediastinum, deep to the diaphragm, making it an unlikely target for an anterior 4th intercostal stab.
* *External oblique muscle, superior epigastric artery, azygos vein*
* The **external oblique muscle** is part of the abdominal wall and would not be penetrated in the 4th intercostal space.
* The **superior epigastric artery** is lower, typically extending into the abdominal wall, and the **azygos vein** is in the posterior mediastinum, not in the path of this superficial anterior stab wound.
* *Pectoralis minor muscle, dome of the diaphragm, right lobe of the liver*
* The **pectoralis minor muscle** is located deep to the pectoralis major, which would be penetrated. However, a stab at the 4th intercostal space would be too high to directly involve the **dome of the diaphragm** or the **right lobe of the liver**, which are typically below the 5th intercostal space, especially in forced expiration.
* *Intercostal muscles, internal thoracic artery, right heart*
* The **intercostal muscles** would certainly be traversed.
* However, the **internal thoracic artery** runs paramedially (about 1-2 cm from the sternum), and getting to the **right heart** would require a more medial and deeper trajectory, potentially causing immediate tamponade or severe hemorrhage.
Trocar placement and port sites US Medical PG Question 5: A 42-year-old woman comes to the physician because of right flank pain that started 3 days following a procedure. Her vital signs are within normal limits. Physical examination shows right costovertebral angle tenderness. An intravenous pyelogram shows a dilated renal pelvis and ureter on the right with a lack of contrast proximal to the ureterovesical junction. This patient most likely recently underwent which of the following procedures?
- A. Hysterectomy (Correct Answer)
- B. Foley catheter insertion
- C. Cesarean delivery
- D. Appendectomy
- E. Inguinal hernia repair
Trocar placement and port sites Explanation: ***Hysterectomy***
- **Ureteral injury** is a known complication of hysterectomy due to the ureter's close proximity to the uterine arteries and adnexa, especially near the **ureterovesical junction**.
- The presented symptoms of flank pain, CVA tenderness, and hydronephrosis (dilated renal pelvis and ureter with lack of contrast flow) occurring post-procedure strongly indicate **ureteral obstruction** or injury during the surgery.
*Foley catheter insertion*
- While catheterization can cause trauma, it would typically lead to **urethral or bladder injury**, not a ureteral obstruction at the ureterovesical junction causing hydronephrosis.
- The symptoms are more consistent with an injury higher up in the urinary tract that is not usually associated with a Foley catheter.
*Cesarean delivery*
- A C-section involves opening the abdomen to deliver a baby, but it generally does not involve dissection near the ureters to the extent that a hysterectomy does, making ureteral injury less common.
- The primary surgical field during a C-section is the uterus, while ureteral injury is more characteristic of procedures involving extensive pelvic dissection, such as hysterectomy.
*Appendectomy*
- An appendectomy is a procedure to remove the appendix and typically involves the right lower quadrant of the abdomen, away from the course of the ureter and ureterovesical junction.
- Injury to the ureter is a very rare complication of appendectomy and would not typically manifest as this type of obstruction.
*Inguinal hernia repair*
- Inguinal hernia repair involves structures in the groin region, anterior to the peritoneal cavity, and is far removed from the ureters and bladder.
- Ureteral injury is not a recognized complication of inguinal hernia repair.
Trocar placement and port sites US Medical PG Question 6: 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)
Trocar placement and port sites 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.
Trocar placement and port sites 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
Trocar placement and port sites 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.
Trocar placement and port sites 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
Trocar placement and port sites 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.
Trocar placement and port sites 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)
Trocar placement and port sites 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.
Trocar placement and port sites 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)
Trocar placement and port sites 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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