General Surgery Principles — MCQs

General Surgery Principles Indian Medical PG Practice Questions and MCQs

Question 271: Rubber band extraction is indicated in a haemophiliac patient as it facilitates the extraction by:

A. Traction force on the periodontal ligament (PDL)
B. Necrosis of the alveolar bone
C. Necrosis of the periodontal ligament (PDL) (Correct Answer)
D. Pulling of the periodontal ligament (PDL)

Explanation: **Explanation:** In patients with severe bleeding disorders like **Haemophilia**, conventional surgical extraction is avoided due to the high risk of uncontrollable post-operative hemorrhage. The **Rubber Band Extraction** technique is a non-invasive alternative used to exfoliate teeth atraumatically. **Why Option C is Correct:** The procedure involves placing an orthodontic rubber band around the neck of the tooth. Due to the anatomy of the tooth root, the band naturally migrates apically (towards the root tip) along the narrowing root surface. As it moves deeper, it exerts continuous pressure on the **Periodontal Ligament (PDL)**. This pressure causes **ischemic necrosis** of the PDL fibers and disrupts the blood supply to the attachment apparatus. Over several days to weeks, the tooth loses its attachment and exfoliates spontaneously with minimal to no bleeding, as the body has time to form a physiological barrier/granulation tissue at the base. **Why Other Options are Incorrect:** * **Option A & D:** These imply mechanical force or physical pulling. Rubber band extraction does not rely on active traction or manual pulling; it is a slow, passive process driven by pressure-induced tissue death. * **Option B:** While the alveolar bone may undergo minor remodeling, the primary mechanism is the destruction of the soft tissue attachment (PDL), not the necrosis of the bone itself. **High-Yield Clinical Pearls for NEET-PG:** * **Indication:** Primarily used for hemophiliacs or patients on potent anticoagulants where factor replacement is unavailable or contraindicated. * **Advantage:** It avoids the need for local anesthesia injections (which can cause hematomas) and surgical trauma. * **Disadvantage:** It is a slow process (takes 7–10 days) and carries a risk of periodontal abscess if oral hygiene is poor. * **Factor Replacement:** In modern practice, if extraction is necessary, Factor VIII levels should ideally be raised to **50-70%** pre-operatively for Hemophilia A.

Question 272: What is the most commonly used flap in head and neck surgery?

A. Pectoralis major flap (Correct Answer)
B. Deltopectoral flap
C. Latissimus dorsi flap
D. Temporalis flap

Explanation: ### Explanation The **Pectoralis Major Myocutaneous (PMMC) flap** is considered the "workhorse" of head and neck reconstruction. Its status as the most commonly used flap stems from its reliability, ease of harvest, and versatile clinical applications. #### Why Pectoralis Major Flap is Correct: * **Anatomy:** It is a pedicled flap based on the **thoracoacromial artery** (specifically the pectoral branch). * **Versatility:** It provides a large amount of skin and bulk, making it ideal for closing large defects, protecting the carotid artery after radical neck dissection, and reconstructing the floor of the mouth or oropharynx. * **Reliability:** It has a robust axial blood supply and does not require microvascular expertise, making it faster and safer in emergency or palliative settings compared to free flaps. #### Why Other Options are Incorrect: * **B. Deltopectoral Flap:** This is a fasciocutaneous flap based on the internal mammary perforators. While historically significant, it lacks the bulk of the PMMC and is now primarily used for resurfacing skin defects rather than major structural reconstruction. * **C. Latissimus Dorsi Flap:** Based on the thoracodorsal artery, this is a versatile flap but is usually considered a second-line option for head and neck surgery due to the need to reposition the patient (lateral decubitus) during surgery. * **D. Temporalis Flap:** This is a local muscle flap used mainly for smaller defects like orbital or maxillary reconstruction; it cannot cover the large, inferior defects that the PMMC can. #### NEET-PG High-Yield Pearls: * **Workhorse Flap:** Pectoralis Major Myocutaneous Flap. * **Blood Supply:** Pectoral branch of the Thoracoacromial artery. * **Free Flap Gold Standard:** For mandibular reconstruction, the **Fibular Free Flap** is the gold standard (not a pedicled flap). * **Common Complication:** Bulkiness (can be aesthetically displeasing) and limited reach to the upper third of the face.

Question 273: Which of the following is not a contributing factor in thoracic outlet syndrome?

A. Tumor arising from the middle lobe of lung (Correct Answer)
B. Malunion of fracture clavicle
C. Cervico-thoracic scoliosis
D. Anomalies of the first thoracic rib

Explanation: ### Explanation **Thoracic Outlet Syndrome (TOS)** is a clinical condition resulting from the compression of the neurovascular bundle (brachial plexus, subclavian artery, or subclavian vein) as it passes through the superior thoracic aperture. **Why Option A is correct:** A tumor arising from the **middle lobe of the lung** does not cause TOS because the middle lobe is located inferiorly and anteriorly in the chest. In contrast, a **Pancoast tumor** (superior sulcus tumor) arising from the **apex** of the lung is a well-known cause of TOS, as it directly invades the brachial plexus and the thoracic outlet. **Why the other options are incorrect:** * **Malunion of fracture clavicle (B):** The clavicle forms the anterior boundary of the thoracic outlet. A malunion with excessive callus formation can narrow the costoclavicular space, compressing the underlying neurovascular structures. * **Cervico-thoracic scoliosis (C):** Significant spinal curvature alters the musculoskeletal anatomy of the neck and upper thorax, leading to a narrowing of the interscalene triangle or costoclavicular space. * **Anomalies of the first thoracic rib (D):** Structural abnormalities such as a rudimentary first rib, a bifid rib, or an exostosis directly reduce the space available for the neurovascular bundle. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause:** A **Cervical Rib** (present in ~0.5% of the population) is the classic anatomical cause. * **Most common type:** **Neurogenic TOS** (95%) involving the lower trunk of the brachial plexus (C8-T1), leading to Gilliatt-Sumner hand (wasting of thenar/hypothenar muscles). * **Clinical Test:** **Adson’s Test** (loss of radial pulse on rotating the head to the affected side during deep inspiration) suggests compression. * **Paget-Schroetter Syndrome:** Effort-induced thrombosis of the subclavian vein, a form of Venous TOS.

Question 274: In a head injury patient, Mannitol should not be used for the control of increased intracranial pressure when:

A. Serum osmolality is more than 320 mOsmol/kg (Correct Answer)
B. PaCO2 is less than 34 mm Hg
C. PaO2 is more than 100 mm Hg
D. pH is less than 7.35

Explanation: **Explanation:** Mannitol is an osmotic diuretic used to reduce intracranial pressure (ICP) by creating an osmotic gradient that draws water from the brain parenchyma into the intravascular space. **Why Option A is Correct:** The efficacy of Mannitol depends on the osmotic gradient between the blood and the brain. If the **serum osmolality exceeds 320 mOsmol/kg**, the gradient is lost, and Mannitol no longer effectively shifts fluid. Furthermore, at levels above 320 mOsmol/kg, there is a significantly increased risk of **acute tubular necrosis (ATN)** and renal failure. Therefore, serum osmolality must be monitored closely, and Mannitol should be withheld if this threshold is crossed. **Why the other options are incorrect:** * **Option B (PaCO2 < 34 mm Hg):** Hypocapnia causes cerebral vasoconstriction, which actually helps reduce ICP. While aggressive hyperventilation (PaCO2 < 30) is avoided, a PaCO2 of 30–35 mm Hg is often a target in acute herniation. It is not a contraindication for Mannitol. * **Option C (PaO2 > 100 mm Hg):** Maintaining adequate oxygenation is vital in head injuries to prevent secondary brain insult. High PaO2 is not a contraindication for osmotic therapy. * **Option D (pH < 7.35):** While acidosis can cause vasodilation and increase ICP, it does not preclude the use of Mannitol. **High-Yield Clinical Pearls for NEET-PG:** * **Mechanism:** Mannitol has two phases—an initial **rheological effect** (decreases blood viscosity, increasing cerebral blood flow) followed by the **osmotic effect** (occurs after 15–30 mins). * **Contraindications:** Congestive heart failure (due to initial volume expansion), pulmonary edema, and anuria. * **Alternative:** Hypertonic saline (3%) is increasingly preferred over Mannitol in patients with hypotension or borderline renal function.

Question 275: Which substrate is depleted earliest in the postoperative period?

A. Branched-chain amino acids
B. Non-branched-chain amino acids
C. Glycogen
D. Glucose (Correct Answer)

Explanation: **Explanation:** The metabolic response to surgery and trauma is characterized by an immediate "ebb phase" followed by a "flow phase." During this period, the body prioritizes maintaining blood glucose levels for vital organ function. **Why Glucose is the Correct Answer:** Glucose is the primary and most immediate fuel source for the brain and erythrocytes. In the immediate postoperative period, circulating **glucose** is the first substrate to be utilized and depleted. To compensate for this rapid depletion, the body initiates glycogenolysis (breakdown of glycogen) and gluconeogenesis (formation of glucose from non-carbohydrate sources) to maintain homeostasis. **Analysis of Incorrect Options:** * **Glycogen (Option C):** While glycogen stores are limited, they typically last for **12 to 24 hours** during fasting or stress. Glucose is consumed even before these stores are fully exhausted. * **Amino Acids (Options A & B):** Branched-chain (leucine, isoleucine, valine) and non-branched-chain amino acids are mobilized during the flow phase of injury via skeletal muscle proteolysis. These serve as precursors for gluconeogenesis but are not the "earliest" substrates depleted; they are mobilized as a secondary response to sustain glucose levels once initial stores fall. **NEET-PG High-Yield Pearls:** * **Sequence of Energy Utilization:** Free Glucose → Glycogen (exhausted in <24 hours) → Proteins (Muscle) → Fats (Adipose). * **The "Ebb Phase":** Occurs in the first 24 hours; characterized by decreased metabolic rate, decreased body temperature, and increased blood glucose (due to insulin resistance). * **Gluconeogenesis:** In the postoperative period, the main substrates for gluconeogenesis are **lactate, alanine, and glycerol**. * **Nitrogen Balance:** Surgery induces a **negative nitrogen balance** due to the breakdown of muscle protein to provide amino acids for repair and energy.

Question 276: Lung sequestration occurs most commonly in which lobe?

A. Apical
B. Left posterior basal (Correct Answer)
C. Left posterosuperior
D. Right lateral basal

Explanation: **Explanation:** **Pulmonary sequestration** is a rare congenital anomaly characterized by a non-functioning mass of lung tissue that lacks normal communication with the tracheobronchial tree and receives its arterial blood supply from the systemic circulation (usually the thoracic or abdominal aorta). **Why Option B is Correct:** Statistically, pulmonary sequestration occurs most frequently in the **lower lobes**, with a significant predilection for the **left lung (60–90% of cases)**. Specifically, the **left posterior basal segment** is the most common site for Intralobar Sequestration (ILS), which accounts for 75% of all sequestration cases. The left-sided predominance is a high-yield anatomical fact frequently tested in surgical exams. **Analysis of Incorrect Options:** * **Option A (Apical):** Sequestrations are almost never found in the upper lobes; they are embryologically derived from the primitive foregut and typically migrate caudally. * **Option C & D:** While sequestrations occur in the basal segments, the **left side** is significantly more common than the right. "Posterosuperior" is not a standard anatomical segment associated with this pathology. **High-Yield Clinical Pearls for NEET-PG:** 1. **Types:** * **Intralobar (75%):** Located within the normal visceral pleura; usually presents in older children/adults with recurrent pneumonia. * **Extralobar (25%):** Has its own pleural investment; often associated with other anomalies (e.g., Diaphragmatic hernia) and presents in neonates. 2. **Blood Supply:** The definitive diagnostic feature is an **aberrant systemic artery** (usually from the aorta). Venous drainage in Intralobar types is typically via pulmonary veins, whereas Extralobar types drain into the systemic circulation (Azygos system). 3. **Diagnosis:** **CT Angiography** is the gold standard to visualize the systemic arterial supply. 4. **Treatment:** Surgical resection (Lobectomy for Intralobar; Sequestrectomy for Extralobar).

Question 277: What is true regarding a ranula?

A. It is also called an epulis.
B. It is a cystic swelling in the floor of the mouth. (Correct Answer)
C. It is a type of thyroglossal cyst.
D. It is a type of mucus retention cyst.

Explanation: A **ranula** is a clinical term for a translucent, bluish, cystic swelling found in the **floor of the mouth**. It typically arises from the **sublingual salivary gland** due to trauma or obstruction of the ducts (Ducts of Rivinus). ### Why Option B is Correct: The term "ranula" is derived from the Latin word *rana* (frog), as the swelling resembles the translucent underbelly of a frog. It is classically located lateral to the midline in the floor of the mouth, superior to the mylohyoid muscle. ### Why Other Options are Incorrect: * **Option A:** An **epulis** is a non-specific clinical term for any tumor-like swelling or lump on the **gingiva** (gums), not the floor of the mouth. * **Option C:** A **thyroglossal cyst** is a midline neck swelling that moves with protrusion of the tongue and deglutition; it is an embryological remnant of the thyroglossal duct. * **Option D:** While some ranulas are retention cysts, the majority (especially large ones) are **extravasation pseudocysts**. They lack an epithelial lining and are formed by mucus leaking into the surrounding submucosal tissues. Therefore, calling it a "mucus retention cyst" is technically inaccurate in most clinical cases. ### High-Yield Clinical Pearls for NEET-PG: * **Plunging Ranula:** Occurs when mucus extravasates through or around the **mylohyoid muscle**, presenting as a swelling in the submandibular region (neck). * **Management:** The treatment of choice is **Marsupialization** for simple ranulas, though the definitive treatment to prevent recurrence is the **excision of the sublingual gland**. * **Appearance:** It is typically painless, fluctuant, and transilluminant.

Question 278: An Alvarado score of 2 defines which of the following clinical findings?

A. Temperature
B. Leukocytosis (Correct Answer)
C. Tenderness in left iliac fossa
D. Migratory pain

Explanation: The **Alvarado Score** (MANTRELS) is a clinical scoring system used to diagnose acute appendicitis. It consists of 8 components with a total possible score of 10. ### **Explanation of the Correct Answer** In the Alvarado scoring system, most parameters are assigned **1 point**, but two specific findings are weighted more heavily because of their high predictive value. These are assigned **2 points** each: 1. **Tenderness in the Right Iliac Fossa (R)** 2. **Leukocytosis (L)** (White blood cell count > 10,000/mm³) Therefore, **Leukocytosis** is the correct answer as it defines a score of 2. ### **Analysis of Incorrect Options** * **A. Temperature:** Elevated temperature (Fever > 37.3°C or 99.1°F) is assigned **1 point**. * **C. Tenderness in left iliac fossa:** This is not a component of the Alvarado score. The score specifically looks for **Right** iliac fossa tenderness. * **D. Migratory pain:** Migration of pain to the right iliac fossa is assigned **1 point**. ### **Clinical Pearls for NEET-PG (MANTRELS Mnemonic)** To remember the scoring, use the mnemonic **MANTRELS**: * **M**igration of pain (1) * **A**norexia (1) * **N**ausea/Vomiting (1) * **T**enderness in RIF (**2**) * **R**ebound tenderness (1) * **E**levated temperature (1) * **L**eukocytosis (**2**) * **S**hift to the left of neutrophils (1) **Interpretation:** * **Score 1–4:** Appendicitis unlikely. * **Score 5–6:** Possible appendicitis (Observation/Imaging recommended). * **Score 7–8:** Probable appendicitis. * **Score 9–10:** Definite appendicitis (Surgical intervention usually indicated).

Question 279: Which of the following can precipitate ulcers in diabetic patients?

A. Trophic ulcers
B. Neuropathy
C. Microangiopathic changes in blood vessels
D. Macroangiopathy (Correct Answer)

Explanation: **Explanation:** The development of diabetic foot ulcers is multifactorial, but **Macroangiopathy** (Option D) is a primary precipitating factor. In diabetes, macrovascular disease involves accelerated atherosclerosis of large and medium-sized arteries (e.g., femoral, popliteal, and tibial arteries). This leads to **ischemia**, which reduces oxygen and nutrient delivery to tissues, making them highly susceptible to breakdown and significantly impairing the healing process once an injury occurs. **Analysis of Options:** * **Macroangiopathy (Correct):** It causes large-vessel ischemia. Ischemic ulcers are often painful, occur at the periphery (toes), and are a direct precipitant of tissue necrosis. * **Neuropathy (Incorrect):** While neuropathy (sensory, motor, and autonomic) is a major *predisposing* factor that leads to loss of protective sensation and foot deformities, the question asks for a factor that precipitates the vascular compromise leading to ulceration. In many clinical contexts, ischemia (macroangiopathy) is the critical "tipping point" for non-healing ulcers. * **Microangiopathic changes (Incorrect):** While basement membrane thickening occurs in small vessels, it is generally considered less significant than macrovascular disease in the actual precipitation of large, clinical foot ulcers. * **Trophic ulcers (Incorrect):** This is a *type* of ulcer (often resulting from neuropathy), not a cause or precipitating factor itself. **NEET-PG High-Yield Pearls:** * **The Diabetic Triad:** Neuropathy, Ischemia (Macroangiopathy), and Infection. * **Most common site:** The head of the first metatarsal (due to pressure). * **Wagner’s Classification:** Used to grade diabetic foot ulcers (Grade 0: Pre-ulcerative; Grade 5: Extensive gangrene). * **Monckeberg’s Sclerosis:** Medial calcific sclerosis common in diabetics; it can lead to falsely elevated Ankle-Brachial Index (ABI) readings.

Question 280: What is the ideal angle for a Z-plasty?

A. 30 degrees
B. 45 degrees
C. 60 degrees (Correct Answer)
D. 90 degrees

Explanation: **Explanation:** Z-plasty is a versatile transposition flap technique used in plastic surgery to increase the length of a scar, change its direction, or release a contracture. **Why 60 degrees is the Correct Answer:** The gain in length in a Z-plasty is directly proportional to the angle of the flaps. A **60-degree angle** is considered the "ideal" or "standard" angle because it provides a significant and predictable **75% increase in length** while maintaining adequate blood supply to the flap tips. It offers the best balance between maximum lengthening and flap viability. **Analysis of Incorrect Options:** * **30 degrees (Option A):** While smaller angles are easier to transpose, they provide a minimal length increase (only about 25%). They are rarely used because the gain is insufficient for most clinical contractures. * **45 degrees (Option B):** This provides a moderate length increase (approx. 50%). It is used when skin tension is too high for a 60-degree flap, but it is not the "ideal" standard. * **90 degrees (Option D):** Theoretically, larger angles provide more length (a 90-degree angle would yield a 120% increase). However, they are clinically impractical because the flaps become too difficult to transpose and the resulting tension often leads to tip necrosis or wound dehiscence. **High-Yield Clinical Pearls for NEET-PG:** * **Mathematical Principle:** Z-plasty consists of one central limb and two parallel side limbs of equal length. * **Length Gain Rule:** 30° = 25% gain; 45° = 50% gain; **60° = 75% gain**. * **Primary Indication:** Linear scar contractures (e.g., post-burn contractures crossing a joint line). * **Key Complication:** Flap tip necrosis (usually due to excessive tension or narrow angles).

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Wound Healing and Care

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Surgical Infections

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Fluid and Electrolyte Management

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Nutrition in Surgical Patients

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Hemostasis and Blood Transfusion

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Surgical Instruments and Equipment

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Sutures and Stapling Devices

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Minimal Access Surgery Principles

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Surgical Complications

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Anesthesia Principles for Surgeons

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Surgical Oncology Principles

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Evidence-Based Surgery

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