General Surgery Principles Practice Questions

Q: Surgically used suture material polydioxanone (PDS) undergoes which of the following processes?

Undergoes hydrolysis and complete absorption. **Explanation:** **Polydioxanone (PDS)** is a synthetic, monofilament, absorbable suture material. The core mechanism of its disappearance from the body is **non-enzymatic hydrolysis**. 1. **Why Option B is Correct:** Synthetic absorbable sutures (like PDS, Vicryl, and Monocryl) are broken down by hydrolysis—a process where water penetrates the polymer chains, causing them to fragment. PDS is known for its prolonged tensile strength (lasting up to 6 weeks) and is completely absorbed by the body within **180 to 210 days**. 2. **Why Options A, C, and D are Incorrect:** * **Option A:** Non-absorbable sutures (e.g., Silk, Prolene, Nylon) remain encapsulated by fibrous tissue; PDS is designed to be absorbed. * **Option C:** Phagocytosis and enzymatic degradation are characteristic of **natural absorbable sutures** (e.g., Surgical Catgut). Synthetic sutures are specifically engineered to avoid this inflammatory pathway to minimize tissue reaction. * **Option D:** Heart valves and synthetic grafts require permanent fixation, necessitating non-absorbable sutures like **Polypropylene (Prolene)** or **PTFE**. **High-Yield Clinical Pearls for NEET-PG:** * **Tensile Strength:** PDS retains ~50% of its strength at 4 weeks, making it ideal for tissues that heal slowly (e.g., abdominal fascia/rectus sheath closure). * **Monofilament Advantage:** Unlike braided sutures (Vicryl), PDS is a monofilament, which reduces the risk of "wicking" bacteria and surgical site infections. * **Metabolism:** The end products of PDS hydrolysis are primarily excreted in the urine. * **Comparison:** Remember: **Natural = Enzymatic/Proteolysis**; **Synthetic = Hydrolysis.**

Q: Which suture material is absorbed in approximately 180 days?

Polydioxanone. **Explanation:** The correct answer is **Polydioxanone (PDS)**. Suture materials are classified based on their absorption profile and origin. Polydioxanone is a synthetic, monocutaneous, absorbable polymer that provides prolonged tensile strength. **Why Polydioxanone is correct:** Polydioxanone is known for its slow absorption rate via **hydrolysis**. It maintains approximately 50% of its tensile strength at 4 weeks and is completely absorbed by the body in approximately **180 to 210 days**. This makes it ideal for tissues that heal slowly or require long-term support, such as the abdominal fascia (linea alba). **Why the other options are incorrect:** * **Catgut:** A natural absorbable suture (derived from bovine/ovine submucosa) that is absorbed rapidly via **proteolysis** within 7–10 days. * **Chromic Catgut:** Treated with chromic acid salts to delay absorption; it typically loses tensile strength in 10–14 days and is absorbed in about 90 days. * **Nylon:** A synthetic **non-absorbable** monofilament. While it may undergo very slow degradation over years, it is clinically classified as permanent. **High-Yield Clinical Pearls for NEET-PG:** * **Fastest absorption:** Catgut (7-10 days). * **Slowest absorption (Absorbable category):** Polydioxanone (180+ days). * **Mechanism of Absorption:** Natural sutures (Catgut) are absorbed by **proteolysis/enzymatic digestion** (causes more tissue reaction), while synthetic sutures (PDS, Vicryl) are absorbed by **hydrolysis** (less reaction). * **Vicryl (Polyglactin 910):** Absorbed in 60–90 days; a common "workhorse" suture in surgery.

Q: Which of the following is NOT a cause for burst abdomen?

Abdominal operation lasting more than two hours. **Explanation:** Burst abdomen (abdominal wound dehiscence) is a serious postoperative complication where the layers of the abdominal wall separate. The causes are generally categorized into **local factors** and **systemic (patient) factors**. **Why Option A is the Correct Answer:** While prolonged surgery can increase the risk of surgical site infection, an **operation lasting more than two hours** is not a direct, independent cause of burst abdomen. In clinical practice, many complex abdominal surgeries (like Whipple’s or total gastrectomy) routinely exceed two hours without resulting in dehiscence, provided the closure technique and patient factors are optimized. **Analysis of Incorrect Options:** * **Incomplete Suture (B):** This is a critical technical factor. If the suture bites are too small, too far apart, or if the knots slip, the mechanical integrity of the wound is lost, leading to immediate dehiscence. * **Infection (C):** Infection is the most common local cause. It leads to tissue friability and enzymatic degradation of collagen, which weakens the wound and prevents proper healing. * **Poor General Condition (D):** Systemic factors such as malnutrition (hypoproteinemia), anemia, vitamin C deficiency, jaundice, and chronic steroid use significantly impair collagen synthesis and wound tensile strength. **High-Yield Clinical Pearls for NEET-PG:** * **Timing:** Burst abdomen typically occurs between the **5th and 8th postoperative day**. * **The "Pink Fluid" Sign:** The earliest clinical sign is a **serosanguinous (pinkish) discharge** from the wound. * **Most Common Cause:** Technical failure (improper suturing) is often cited as the leading cause. * **Management:** Immediate management involves covering the bowel with sterile saline-soaked gauze, followed by emergency re-closure using **tension sutures (interrupted mass closure)**.

Q: Pressure sores usually occur when external pressure exceeds capillary occlusive pressure over which value?

30 mmHg. Explanation: The development of pressure sores (decubitus ulcers) is primarily driven by ischemia resulting from external pressure [1]. The critical threshold for this process is the **Capillary Filling Pressure (or Capillary Occlusive Pressure)**. **1. Why 30 mmHg is Correct:** In healthy individuals, the average arteriolar capillary pressure ranges between **25 to 32 mmHg**. When external pressure exceeds this range—specifically the threshold of **30 mmHg**—it overcomes the internal hydrostatic pressure of the capillaries. This leads to vessel collapse, occlusion of blood flow, and subsequent tissue hypoxia. If this pressure is maintained for more than 2 hours, irreversible cell death and tissue necrosis occur, forming a pressure sore. **2. Analysis of Incorrect Options:** * **20 mmHg & 25 mmHg:** While these values represent lower-end venous or mid-capillary pressures, they are generally insufficient to cause total arteriolar occlusion in a patient with normal systemic blood pressure. * **35 mmHg:** This value is well above the occlusive threshold. While it certainly causes ischemia, the *minimal* pressure required to initiate the pathological process (the standard definition of capillary occlusive pressure) is clinically accepted as 30 mmHg. **3. Clinical Pearls for NEET-PG:** * **Common Sites:** The **sacrum** is the most common site (30-40%), followed by the **ischial tuberosity** and **greater trochanter** [1]. * **The "Tip of the Iceberg" Phenomenon:** Extensive deep tissue damage often exists under seemingly small superficial skin breaks. * **Prevention:** The "2-hour rule" for repositioning patients is based on the time it takes for ischemia to transition into necrosis. * **Grading:** Stage I involves non-blanchable erythema; Stage IV involves full-thickness loss with exposed bone, tendon, or muscle [1].

Q: What is the maximum recommended tourniquet time for the upper limb?

120 minutes. ### Explanation The use of a pneumatic tourniquet is a standard procedure in orthopedic and vascular surgeries to create a bloodless surgical field. The correct answer is **120 minutes (2 hours)**. **1. Why 120 minutes is correct:** The primary concern with tourniquet use is ischemia-reperfusion injury and nerve compression. Research indicates that skeletal muscle can tolerate up to 2 hours of ischemia without significant permanent damage. Beyond this "golden period," the risk of metabolic acidosis, rhabdomyolysis, and permanent nerve palsy (tourniquet paralysis) increases significantly. If the surgery exceeds this duration, a "breathing period" (deflation for 10–20 minutes) is required to allow for tissue reperfusion and washout of metabolic waste before re-inflation. **2. Why the other options are incorrect:** * **30 & 60 minutes:** These durations are well within the safety margin. While safe, they do not represent the *maximum* recommended threshold for the upper limb. * **90 minutes:** While some surgeons prefer a 90-minute limit for the upper limb to be extra cautious, the standard consensus in major surgical textbooks (like Sabiston or Bailey & Love) and orthopedic guidelines (Campbell’s) defines the safe upper limit as 120 minutes. **3. Clinical Pearls for NEET-PG:** * **Pressure Settings:** For the upper limb, the cuff should be inflated to **50–100 mmHg above the systolic blood pressure**. (Lower limb requires higher pressure: 100–150 mmHg above systolic). * **Nerve Vulnerability:** The **Radial nerve** is the most common nerve injured by tourniquet compression in the upper limb. * **Post-Tourniquet Syndrome:** Characterized by edema, pallor, and stiffness after deflation; it is usually related to the duration of ischemia rather than the pressure applied. * **Contraindications:** Avoid in patients with Sickle Cell Anemia (risk of crisis) or severe peripheral vascular disease.

Q: Which of the following statements regarding keloid is false?

Malignant changes can occur in keloids.. ### Explanation **1. Why Option D is the Correct (False) Statement:** The hallmark of a keloid is that it is a **benign** overgrowth of dense fibrous tissue. Unlike chronic scars (like Marjolin’s ulcer occurring in long-standing burn scars), **keloids do not undergo malignant transformation.** This is a high-yield distinction in surgical pathology. **2. Analysis of Other Options:** * **Option A (Recurrence is common):** This is true. Keloids have a notoriously high recurrence rate (up to 50–100%) if treated with simple surgical excision alone. This is because the trauma of surgery triggers further abnormal collagen synthesis. * **Option B (Affects surrounding areas):** This is a defining clinical feature. Unlike hypertrophic scars, which remain confined to the boundaries of the original wound, **keloids extend beyond the margin of the initial injury**, invading adjacent normal skin. * **Option C (Intralesional steroids):** This is true. Triamcinolone acetonide is the first-line treatment. It inhibits collagen synthesis and reduces fibroblast proliferation, significantly lowering recurrence rates when used alone or as an adjuvant to surgery. **3. High-Yield Clinical Pearls for NEET-PG:** * **Pathology:** Characterized by thick, eosinophilic, "glassy" **Type I and Type III collagen bundles**. * **Common Sites:** Presternal area (most common), deltoid, and earlobes. * **Hypertrophic Scar vs. Keloid:** Hypertrophic scars often regress spontaneously and stay within wound margins; keloids rarely regress and outgrow the wound margins. * **Treatment Triad:** Intralesional steroids, pressure therapy (silicone gel sheets), and occasionally radiotherapy or cryotherapy for resistant cases.

Q: All of the following are true about suturing principles except:

None of the above. This question tests fundamental surgical principles regarding wound closure and incision planning, which are high-yield topics for NEET-PG. The correct answer is **"None of the above"** because all three statements (A, B, and C) are established surgical axioms. ### **Explanation of Options:** * **Option A (Gap between sutures):** The standard rule for interrupted sutures is that the distance between two sutures should be **twice the thickness of the skin** (or equal to the distance from the wound edge to the needle entry point). This ensures adequate apposition without compromising blood supply to the wound edges. * **Option B (Suture length to wound length ratio):** For continuous abdominal wall closure (Laparotomy), the **Jenkins Rule** states that the suture length should be at least **4 times the length of the wound (4:1 ratio)**. This allows for post-operative edema and prevents the "cheese-cutter" effect, significantly reducing the risk of incisional hernia and wound dehiscence. * **Option C (Elliptical incision ratio):** When performing an elliptical excision (e.g., for a skin lesion), the ideal **length-to-width ratio is 3:1**. This ratio ensures that the wound can be closed primarily without creating "dog-ears" (redundant skin folds) at the corners. ### **High-Yield Clinical Pearls for NEET-PG:** * **Langer’s Lines:** Incisions should ideally be made parallel to these tension lines to ensure minimal scarring. * **Suture Removal:** Face (3–5 days), Scalp (7–10 days), Trunk/Extremities (10–14 days). * **Monofilament vs. Braided:** Monofilament (e.g., Prolene) has a lower risk of infection but poor knot security; Braided (e.g., Silk, Vicryl) has better handling but higher risk of "wicking" bacteria. * **Ideal Suture for Fascia:** Delayed absorbable (e.g., PDS) or non-absorbable monofilament (e.g., Prolene).

Q: What is the best initial treatment for a contaminated wound of the leg?

Debridement and antibiotics. ### Explanation The management of a contaminated wound follows the fundamental surgical principle: **"The solution to pollution is dilution and debridement."** **Why Debridement and Antibiotics is Correct:** A contaminated wound contains foreign bodies, devitalized tissue, and bacteria. 1. **Debridement:** This is the most critical step. It involves the removal of dead (necrotic) tissue and foreign debris, which otherwise act as a nidus for infection and prevent healing. It converts a contaminated wound into a clean, vascularized wound. 2. **Antibiotics:** These are administered to prevent the progression of contamination into a systemic or localized clinical infection (prophylaxis or early treatment). **Why Other Options are Incorrect:** * **Hyperbaric Oxygen (HBO):** While HBO can be used as an adjunct for specific conditions like gas gangrene or chronic non-healing diabetic ulcers, it is never the *initial* treatment for an acute contaminated wound. * **Amputation:** This is a radical measure reserved for non-viable limbs (Mangled Extremity Severity Score ≥ 7) or life-threatening sepsis where debridement is insufficient. It is not the first-line approach for a standard contaminated wound. **High-Yield Clinical Pearls for NEET-PG:** * **Golden Period:** Ideally, debridement should be performed within **6–8 hours** of injury to prevent the transition from contamination to established infection. * **Wound Closure:** Contaminated wounds are often managed by **Delayed Primary Closure (DPC)**—the wound is left open after debridement and closed 3–5 days later once healthy granulation tissue appears. * **Tetanus Prophylaxis:** Always check the immunization status in any traumatic wound management. * **Irrigation:** Copious irrigation with normal saline is as important as surgical debridement. Adding povidone-iodine to the irrigation fluid is generally avoided as it can be cytotoxic to healthy cells.

Q: Diabetic gangrene is due to:

All of the above. **Explanation:** Diabetic gangrene is a multifactorial complication resulting from the synergistic effect of metabolic, vascular, and neurological impairments. The correct answer is **"All of the above"** because each factor plays a critical role in the pathogenesis: 1. **Ischemia (Option A):** Diabetes causes both **macroangiopathy** (atherosclerosis of large vessels like the popliteal or tibial arteries) and **microangiopathy** (thickening of the capillary basement membrane). This leads to reduced perfusion and tissue hypoxia, preventing wound healing and promoting tissue death (gangrene). 2. **Increased Blood Glucose (Option B):** Hyperglycemia provides an ideal culture medium for bacteria. Furthermore, it leads to the formation of **Advanced Glycation End-products (AGEs)**, which damage vessel walls and impair collagen synthesis. 3. **Altered Host Defense and Neuropathy (Option C):** * **Neuropathy:** Sensory loss leads to repetitive unnoticed microtrauma; autonomic neuropathy causes dry, cracked skin (fissures); and motor neuropathy causes muscle atrophy and foot deformities (e.g., Charcot’s joint). * **Host Defense:** Hyperglycemia impairs **neutrophil functions** (chemotaxis, adherence, and phagocytosis), making diabetics highly susceptible to rapidly spreading infections. **Clinical Pearls for NEET-PG:** * **Wagner’s Classification** is used to grade diabetic foot ulcers (Grade 0 to 5). * The most common cause of non-traumatic lower limb amputation is diabetic gangrene. * **Monckeberg’s Sclerosis** (medial calcific sclerosis) is frequently seen in diabetic arteries, often leading to falsely elevated Ankle-Brachial Index (ABI) readings. * Diabetic gangrene is often a **"Wet Gangrene"** due to the high risk of secondary bacterial infection.

Question 1

Surgically used suture material polydioxanone (PDS) undergoes which of the following processes?

Accepted Answer

Undergoes hydrolysis and complete absorption

Answer

Is non-absorbable and remains encapsulated

Answer

Undergoes phagocytosis and enzymatic degradation

Answer

Is specifically used for heart valves or synthetic grafts

Question 2

Which suture material is absorbed in approximately 180 days?

Accepted Answer

Polydioxanone

Answer

Catgut

Answer

Chromic Catgut

Answer

Nylon

Question 3

Which of the following is NOT a cause for burst abdomen?

Accepted Answer

Abdominal operation lasting more than two hours

Answer

Incomplete suture

Answer

Infection

Answer

Poor general condition of patient

Question 4

Pressure sores usually occur when external pressure exceeds capillary occlusive pressure over which value?

Accepted Answer

30 mmHg

Answer

20 mmHg

Answer

25 mmHg

Answer

35 mmHg

Question 5

What is the maximum recommended tourniquet time for the upper limb?

Accepted Answer

120 minutes

Answer

30 minutes

Answer

60 minutes

Answer

90 minutes

Question 6

All of the following patients presenting with abdominal pain and shock need immediate laparotomy except?

Accepted Answer

Hemorrhagic pancreatitis

Answer

Ruptured ectopic pregnancy

Answer

Ruptured abdominal aortic aneurysm

Answer

Ruptured liver hemangioma

Question 7

Which of the following statements regarding keloid is false?

Accepted Answer

Malignant changes can occur in keloids.

Answer

Recurrence is common after excision.

Answer

Keloids can affect surrounding areas.

Answer

Intralesional steroid injections can decrease the chance of recurrence.

Question 8

All of the following are true about suturing principles except:

Accepted Answer

None of the above

Answer

Each suture should be separated by a gap that is twice the thickness of the skin

Answer

Suture length to wound length ratio of 4:1

Answer

Length to width ratio for elliptical incisions of 3:1

Question 9

What is the best initial treatment for a contaminated wound of the leg?

Accepted Answer

Debridement and antibiotics

Answer

Hyperbaric oxygen

Answer

Amputation

Answer

None of the above

Question 10

Diabetic gangrene is due to:

Accepted Answer

All of the above

Answer

Ischemia

Answer

Increased blood glucose

Answer

Altered host defense and neuropathy

General Surgery Principles — MCQs

General Surgery Principles — MCQs

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