Minimally Invasive Surgery — MCQs

Minimally Invasive Surgery Indian Medical PG Practice Questions and MCQs

Question 21: Which of the following is NOT typically seen in pneumoperitoneum?

A. Hypertension
B. Bradycardia (Correct Answer)
C. Tachycardia
D. Hypercapnia

Explanation: In laparoscopic surgery, the creation of a pneumoperitoneum (typically using $CO_2$) triggers a series of physiological changes. **Why Bradycardia is the Correct Answer:** While the initial stretching of the peritoneum can trigger a transient **vasovagal reflex** leading to bradycardia, the *typical* and sustained hemodynamic response to pneumoperitoneum is **tachycardia**. Bradycardia is considered an acute complication or an idiosyncratic reflex rather than a typical physiological feature of a stable pneumoperitoneum. **Explanation of Other Options:** * **Hypertension (A):** Increased intra-abdominal pressure (IAP) causes the release of catecholamines and activation of the Renin-Angiotensin-Aldosterone System (RAAS). Additionally, systemic absorption of $CO_2$ increases systemic vascular resistance, leading to hypertension. * **Tachycardia (C):** The body compensates for decreased venous return (due to IVC compression) and hypercapnia by increasing the heart rate to maintain cardiac output. * **Hypercapnia (D):** $CO_2$ is highly soluble and is rapidly absorbed across the peritoneal surface into the bloodstream. If not compensated for by increasing minute ventilation, this leads to respiratory acidosis and hypercapnia. **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard Gas:** $CO_2$ is used because it is non-combustible, highly soluble (reducing air embolism risk), and inexpensive. * **Pressure Limits:** Standard IAP is maintained at **12–15 mmHg**. Pressures >20 mmHg significantly compromise venous return. * **Cardiac Output:** Generally **decreases** due to reduced venous return and increased afterload. * **Renal Effects:** Oliguria is common due to direct renal vein compression and reduced renal cortical blood flow.

Question 22: All of the following are true about laparoscopy except:

A. Veress needle is used in the closed method
B. Intra-abdominal pressure maintained during laparoscopy is 12-15 mm Hg
C. The most commonly used gas is CO2
D. The flow of gas is 2 L/min (Correct Answer)

Explanation: **Explanation:** In laparoscopic surgery, creating a pneumoperitoneum is the first critical step. This question tests your knowledge of the standard parameters and techniques used to achieve this. **Why Option D is the correct answer (False statement):** The initial flow of gas during the creation of pneumoperitoneum is typically set at a **low flow (1 L/min)** to ensure the needle is correctly positioned and to avoid rapid hemodynamic shifts. Once the position is confirmed and the procedure begins, the high-flow insufflator can deliver gas at rates of **10–40 L/min** to compensate for leaks and suctioning. A constant flow of 2 L/min is insufficient to maintain a stable working space during active surgery. **Analysis of other options:** * **Option A:** The **Veress needle** is the standard instrument for the **"Closed Technique"** of entry. It has a spring-loaded blunt stylet to prevent visceral injury. * **Option B:** The standard intra-abdominal pressure is maintained between **12–15 mm Hg**. Pressures above 15 mm Hg increase the risk of "Gas Embolism," decreased venous return, and respiratory compromise. * **Option C:** **CO₂** is the gas of choice because it is non-combustible (safe for cautery), highly soluble in blood (reducing the risk of fatal air embolism), and easily exhaled by the lungs. **High-Yield Clinical Pearls for NEET-PG:** * **Hasson’s Technique:** The "Open Method" of laparoscopy, preferred in patients with previous abdominal surgeries to avoid bowel injury. * **Safety Check for Veress:** The "Saline Drop Test" is used to confirm the needle is in the peritoneal cavity. * **Adverse Effect:** CO₂ retention can lead to **hypercapnia and respiratory acidosis**, which the anesthesiologist manages by increasing minute ventilation. * **Post-op Pain:** Shoulder tip pain after laparoscopy is due to diaphragmatic irritation by residual CO₂ (referred via the Phrenic nerve).

Question 23: Which layers are penetrated with a trocar and cannula during the production of pneumoperitoneum?

A. Skin and superficial fascia (Correct Answer)
B. Deep fascia
C. Rectus abdominis
D. Transversus abdominis

Explanation: **Explanation:** The creation of pneumoperitoneum is the first and most critical step in laparoscopic surgery. To achieve this, a Veress needle or a trocar-cannula system must traverse the layers of the anterior abdominal wall to reach the peritoneal cavity. **Why Option A is Correct:** The question asks which layers are penetrated during the production of pneumoperitoneum. In the standard midline approach (linea alba), the layers encountered are: **Skin → Superficial fascia (Camper’s and Scarpa’s) → Linea alba (aponeurosis) → Transversalis fascia → Extraperitoneal fat → Parietal peritoneum.** Since the midline is relatively avascular and lacks muscle fibers, the trocar primarily penetrates the skin and superficial fascia before hitting the tough fibrous aponeurosis. Among the given options, "Skin and superficial fascia" represents the initial and mandatory layers penetrated in any abdominal entry technique. **Analysis of Incorrect Options:** * **B. Deep fascia:** In the abdominal wall, there is no well-defined "deep fascia" over the muscles (to allow for distension); it is represented by the thin epimysium. * **C & D. Rectus abdominis and Transversus abdominis:** While these muscles are present in the paramedian or lateral abdominal wall, the standard entry for pneumoperitoneum is usually the **umbilicus** (midline). In the midline, the trocar passes through the **linea alba**, which is an aponeurotic union, thereby avoiding muscle penetration. **Clinical Pearls for NEET-PG:** * **The Umbilicus:** It is the preferred site for entry because it is the thinnest part of the abdominal wall, where the skin is fused to the fascia with minimal intervening fat or muscle. * **Safety Check:** The most common injury during trocar insertion is to the **retroperitoneal vessels** (Aorta/IVC) or the **bowel**. * **Palmer’s Point:** Located 3 cm below the left costal margin in the midclavicular line; it is the alternative site for Veress needle insertion if umbilical adhesions are suspected.

Question 24: The technique of laparoscopic cholecystectomy was first described by?

A. Erich Muhe (Correct Answer)
B. Philip Moure
C. Ku semm
D. Eddie Reddick

Explanation: **Explanation:** The correct answer is **Erich Mühe**. In **1985**, German surgeon Erich Mühe performed the world’s first laparoscopic cholecystectomy using a "galloscope" he designed himself. Although he faced significant skepticism from the surgical community at the time, he is now globally recognized as the pioneer of the procedure. **Analysis of Options:** * **Erich Mühe (A):** Performed the first laparoscopic cholecystectomy in 1985 (Böblingen, Germany). * **Philippe Mouret (B):** Often confused with Mühe, Mouret performed the first **video-laparoscopic** cholecystectomy in **1987** (Lyon, France). While Mühe used a direct vision scope, Mouret’s use of a camera chip revolutionized the procedure's adoption. * **Kurt Semm (C):** A gynecologist who performed the first laparoscopic **appendectomy** in 1980. He is considered the father of modern operative laparoscopy and invented the automatic insufflator. * **Eddie Reddick (D):** An American surgeon who, along with Douglas Olsen, popularized the procedure in the United States and helped standardize the technique in the late 1980s. **High-Yield Clinical Pearls for NEET-PG:** * **First Laparoscopic Procedure:** The first diagnostic laparoscopy was performed by **Georg Kelling** (1901) on a dog, and **Hans Christian Jacobaeus** (1910) on humans. * **Standard of Care:** Laparoscopic cholecystectomy is currently the "Gold Standard" for symptomatic gallstones. * **Pneumoperitoneum:** $CO_2$ is the gas of choice due to its high solubility in blood (low risk of air embolism) and non-combustible nature. * **Critical View of Safety (Strasberg):** The essential step to prevent Bile Duct Injury (BDI) during the procedure.

Question 25: Which of the following is NOT an advantage of carbon dioxide used in laparoscopy?

A. Non-irritant
B. Non-inflammable
C. Minimally absorbed (Correct Answer)
D. No tissue reaction

Explanation: **Explanation:** The correct answer is **C (Minimally absorbed)** because Carbon Dioxide ($CO_2$) is actually **highly and rapidly absorbed** across the peritoneal membrane into the bloodstream. This high solubility is a double-edged sword: while it allows the body to easily buffer and exhale the gas via the lungs (preventing prolonged pneumoperitoneum), it can lead to **hypercapnia** and respiratory acidosis during surgery. **Analysis of Options:** * **A. Non-irritant:** $CO_2$ is generally considered non-irritating to the peritoneal lining compared to other gases, although its conversion to carbonic acid can cause some post-operative diaphragmatic irritation (referred pain to the shoulder). * **B. Non-inflammable:** This is a critical safety feature. Unlike oxygen or nitrous oxide, $CO_2$ does not support combustion, making it safe to use with electrosurgery (cautery) and lasers. * **D. No tissue reaction:** $CO_2$ is physiologically inert in terms of local tissue damage. It does not cause significant local inflammatory responses or tissue necrosis. **High-Yield Clinical Pearls for NEET-PG:** * **Gas of Choice:** $CO_2$ is the standard gas for laparoscopy due to its high solubility (20 times that of oxygen), non-combustibility, and rapid excretion. * **The "Gas Embolism" Safety:** Because $CO_2$ is highly soluble in blood, if a small amount accidentally enters a blood vessel, it dissolves quickly, reducing the risk of a fatal air embolism compared to room air or nitrogen. * **Physiological Effect:** The rapid absorption of $CO_2$ requires the anesthesiologist to increase minute ventilation to prevent acidosis. * **Reflex Bradycardia:** Sudden stretching of the peritoneum by $CO_2$ insufflation can trigger a **vasovagal response**, leading to bradycardia.

Question 26: What is a contraindication for laparoscopy?

A. Diaphragmatic hernia (Correct Answer)
B. Pelvic tuberculosis
C. Stress urinary incontinence
D. PCOD

Explanation: **Explanation:** The core physiological challenge in laparoscopy is the creation of a **pneumoperitoneum** using CO₂. This increases intra-abdominal pressure (IAP), which has significant systemic effects. **Why Diaphragmatic Hernia is the Correct Answer:** A diaphragmatic hernia (e.g., Congenital Diaphragmatic Hernia or large traumatic hernia) is considered a **relative/absolute contraindication** because the increased IAP forces abdominal contents and CO₂ into the thoracic cavity. This leads to: 1. **Massive Mediastinal Shift:** Compressing the contralateral lung and great vessels. 2. **Cardiovascular Collapse:** Reduced venous return and cardiac output. 3. **Tension Pneumothorax:** Risk of CO₂ tracking into the pleural space. While small hiatal hernias are routinely repaired laparoscopically, large defects pose a high risk of intraoperative respiratory failure. **Analysis of Incorrect Options:** * **B. Pelvic Tuberculosis:** While it may cause dense adhesions (making entry difficult), it is not a contraindication. Laparoscopy is often the "gold standard" for diagnosing pelvic TB via direct visualization and biopsy. * **C. Stress Urinary Incontinence (SUI):** Laparoscopic procedures (like the Burch Colposuspension) are standard surgical treatments for SUI. * **D. PCOD:** Laparoscopic Ovarian Drilling (LOD) is a common second-line surgical treatment for PCOD patients resistant to medical management. **High-Yield Clinical Pearls for NEET-PG:** * **Absolute Contraindications:** Inability to tolerate formal laparotomy, uncorrected coagulopathy, and severe obstructive uropathy. * **Cardiovascular Impact:** Pneumoperitoneum decreases venous return (preload) and increases systemic vascular resistance (afterload). * **Gold Standard:** Laparoscopy is the preferred approach for cholecystectomy, appendectomy (especially in obese patients/females), and ectopic pregnancy.

Question 27: Laparoscopic cholecystectomy is largely preferred over conventional laparotomy for all of the following reasons EXCEPT:

A. Decreased pain
B. Decreased incidence of bile duct injuries (Correct Answer)
C. Smaller scar
D. Decreased hospital stay

Explanation: **Explanation:** Laparoscopic cholecystectomy (LC) is the "gold standard" for the treatment of symptomatic gallstones. While it offers numerous advantages over open cholecystectomy, it is associated with a **higher incidence of bile duct injuries (BDI).** 1. **Why Option B is the Correct Answer:** In conventional open surgery, the incidence of BDI is approximately **0.1% to 0.2%**. In contrast, during the "learning curve" of laparoscopic surgery, this rate increased significantly. Even with modern techniques, the incidence of BDI in LC remains slightly higher at **0.3% to 0.5%**. This is primarily due to the loss of 3D depth perception, limited tactile feedback, and the risk of "misidentification" (e.g., mistaking the common bile duct for the cystic duct). 2. **Why other options are incorrect:** * **Decreased pain (A):** Smaller incisions result in less tissue trauma and reduced postoperative somatic pain. * **Smaller scar (C):** LC uses 5–10mm ports, providing a superior cosmetic outcome compared to a Kocher’s subcostal incision. * **Decreased hospital stay (D):** Faster recovery of bowel function and reduced pain allow for same-day or next-day discharge. **High-Yield Clinical Pearls for NEET-PG:** * **Critical View of Safety (Strasberg):** The gold standard technique to prevent BDI. It requires clearing the hepatocystic triangle of all fat/fibrous tissue and identifying only two structures (cystic duct and cystic artery) entering the gallbladder. * **Most common cause of BDI in LC:** Misidentification of anatomy. * **Management:** If BDI is recognized intraoperatively, immediate repair by a specialist is preferred. If found postoperatively (fever, jaundice, bile leak), the first investigation is **Ultrasound**, but the most definitive diagnostic tool is **MRCP**. * **Bile Duct Injury Classification:** The **Strasberg Classification** is most commonly used for laparoscopic injuries.

Question 28: What gas is most commonly used in laparoscopy?

A. Carbon Dioxide (CO2) (Correct Answer)
B. Sulfur Dioxide (SO2)
C. Nitrogen (N2)
D. Oxygen (O2)

Explanation: **Explanation:** **Carbon Dioxide (CO₂)** is the gold standard and most commonly used gas for creating pneumoperitoneum in laparoscopy. The primary medical reason for its selection is its **high solubility in blood** (20 times more soluble than Oxygen). This high solubility ensures that if the gas accidentally enters the venous circulation, it is rapidly dissolved and excreted via the lungs, significantly reducing the risk of a fatal gas embolism. Furthermore, CO₂ is **non-combustible**, which is critical because electrosurgery (cautery) and lasers are frequently used during laparoscopic procedures. **Why other options are incorrect:** * **Sulfur Dioxide (SO₂):** This is a toxic, pungent gas and is never used in medical practice. * **Nitrogen (N₂):** It is poorly soluble in blood. If an embolism occurs, the bubbles persist for a long time, leading to severe cardiovascular collapse. * **Oxygen (O₂):** It is highly combustible and supports combustion, posing a major fire and explosion risk when using diathermy. **High-Yield Clinical Pearls for NEET-PG:** * **Ideal Intra-abdominal Pressure:** Usually maintained between **12–15 mmHg**. * **Physiological Effects:** CO₂ absorption can lead to **hypercapnia** and **respiratory acidosis**. * **Post-operative Pain:** Residual CO₂ irritating the diaphragm can cause referred pain to the **right shoulder** (Phrenic nerve irritation). * **Alternative:** **Nitrous Oxide (N₂O)** is sometimes used because it provides better analgesia, but it is less safe than CO₂ regarding combustion.

Question 29: A mill-wheel type of murmur heard during laparoscopy suggests which of the following complications?

A. Tension pneumothorax
B. Intra-abdominal bleeding
C. Gas embolism (Correct Answer)
D. Pre-existing valvular disease

Explanation: **Explanation:** The correct answer is **Gas Embolism (Option C)**. **Mechanism:** A gas embolism (usually CO₂) is a rare but life-threatening complication of laparoscopy. It occurs when gas is inadvertently insufflated into a high-pressure venous channel or an injured vessel. Once the gas enters the right side of the heart, it mixes with blood to form a "frothy" air-lock in the right ventricle, obstructing pulmonary outflow. The characteristic **"mill-wheel" murmur** is a loud, churning, splashing sound heard over the precordium caused by this air-blood mixture. **Analysis of Incorrect Options:** * **A. Tension pneumothorax:** While it can occur during laparoscopy (due to diaphragmatic injury), it presents with absent breath sounds, tracheal shift, and hemodynamic collapse, not a mill-wheel murmur. * **B. Intra-abdominal bleeding:** This leads to hemorrhagic shock (tachycardia, hypotension) and potentially abdominal distension, but does not produce specific cardiac murmurs. * **D. Pre-existing valvular disease:** While valvular issues cause murmurs (e.g., stenotic or regurgitant), they are typically present from the start of the procedure and do not produce the sudden, splashing "mill-wheel" sound associated with acute gas entry. **High-Yield Clinical Pearls for NEET-PG:** * **Early Sign:** The earliest sign of gas embolism is often a sudden **drop in End-Tidal CO₂ (ETCO₂)** due to increased physiological dead space. * **Management (Durant’s Maneuver):** Immediately stop insufflation, release pneumoperitoneum, and place the patient in the **Left Lateral Decubitus and Trendelenburg position**. This helps the gas bubble migrate toward the apex of the right ventricle, away from the pulmonary artery outflow tract. * **Gold Standard Diagnosis:** Transesophageal Echocardiography (TEE) is the most sensitive method for detection.

Question 30: During laparoscopic surgery, which vessel(s) should be specifically avoided during lateral trocar insertion?

A. Superior epigastric artery
B. Both Superior epigastric artery and Inferior epigastric artery (Correct Answer)
C. Abdominal aorta
D. Inferior epigastric artery

Explanation: ***Both Superior epigastric artery and Inferior epigastric artery*** - Both the **superior epigastric** and **inferior epigastric arteries** run vertically in the rectus sheath (within the anterior abdominal wall) and are the most common significant vessels injured during lateral port placement. - Injury to these vessels specifically during secondary port (trocar) insertions is a well-recognized cause of major, potentially fatal **hemorrhage** and subsequent hematoma within the rectus sheath, necessitating their avoidance. *Superior epigastric artery* - Although this artery must be avoided, it is only one component of the major vascular risk; the **inferior epigastric artery** is often more frequently injured due to the location of typical lateral ports. - Selecting only the superior artery makes the answer incomplete, as both the superior and **inferior epigastric arteries** pose serious risks that require specific anatomical knowledge for avoidance. *Inferior epigastric artery* - The **inferior epigastric artery** is a critical structure to avoid, as it runs superomedially from the **external iliac artery** and is typically located medial to lateral port sites below the arcuate line. - This option is insufficient because avoidance of the **superior epigastric artery** is also required, depending on the height of the lateral port placement. *Abdominal aorta* - Puncture of the **abdominal aorta** is a catastrophic, high-mortality complication, but it is typically associated with blind primary entry techniques (e.g., Veress needle or primary trocar) and is located deep, not in the path of lateral port insertion. - While every effort is made to avoid all major vessels, the question concerns vessels directly in the plane of the anterior wall most likely injured by a standard lateral trocar insertion, which are the **epigastric arteries**.

Practice by Chapter

Laparoscopic Equipment and Instrumentation

Practice Questions

Physiological Changes in Laparoscopy

Practice Questions

Laparoscopic Access Techniques

Practice Questions

Laparoscopic Cholecystectomy

Practice Questions

Laparoscopic Appendectomy

Practice Questions

Laparoscopic Hernia Repair

Practice Questions

Laparoscopic Colorectal Surgery

Practice Questions

Laparoscopic Upper GI Surgery

Practice Questions

Robotic Surgery

Practice Questions

Single Incision Laparoscopic Surgery

Practice Questions

NOTES (Natural Orifice Transluminal Endoscopic Surgery)

Practice Questions

Complications of Minimally Invasive Surgery

Practice Questions

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