Viva · IR system
Biopsy and Drainage Viva Questions
Oral-exam style questions and answers on biopsy and drainage for MD, DNB and super-specialty practical examinations. Each answer links back to the playbook or Library entry it was written from.
- What is the commonest complication of CT-guided lung biopsy?
- Pneumothorax is the commonest complication. Large datasets report an overall rate of approximately 15–35%, while about 3.1–6.6% of all biopsies require tube drainage.
- Why is the coaxial technique preferred?
- A coaxial introducer permits multiple cores and redirection through a single pleural puncture. It reduces repeated pleural passages and provides a route for tract sealing or pneumothorax aspiration.
- When do you prefer core biopsy over FNA?
- Core biopsy is preferred when histologic architecture, immunohistochemistry, benign-disease characterization or molecular profiling is required. FNA is useful when cytopathology support and rapid on-site evaluation are available or when a smaller needle is desirable.
- How can pneumothorax risk be reduced?
- Use the shortest safe path, avoid fissures and bullae, minimize pleural passages, approach the pleura near perpendicular, use reproducible respiratory control and consider rapid biopsy-side-down positioning or tract sealing in selected patients.
- How do you manage a post-biopsy pneumothorax?
- Observe a small asymptomatic stable pneumothorax with clinical and imaging follow-up. Aspirate enlarging pleural air when appropriate and insert a 6–9 Fr catheter for a symptomatic, enlarging or physiologically significant pneumothorax.
- What is the correct position for post-biopsy hemoptysis?
- Place the **biopsy side down** so that the bleeding lung is dependent and the unaffected lung is protected. Monitor oxygen saturation and bleeding severity, give oxygen and escalate to airway control, CT angiography, bronchoscopy or embolization if bleeding is severe.
- How do you prevent and treat systemic air embolism?
- Keep the coaxial hub occluded, avoid coughing or deep breathing and do not traverse visible pulmonary veins or air-containing cavities unnecessarily. If embolism occurs, give high-concentration oxygen, support circulation, keep the patient supine unless experts direct otherwise and arrange urgent hyperbaric oxygen therapy.
- Does a negative or nondiagnostic biopsy exclude malignancy?
- No. Interpret pathology against the imaging appearance and pretest probability; nonspecific benign, atypical or insufficient samples may require repeat biopsy, another sampling route, surgical diagnosis or close imaging follow-up.
- Why is ultrasound guidance preferred for paracentesis?
- It confirms that drainable fluid is present, identifies the largest safe pocket, avoids bowel and abdominal-wall vessels and improves procedural success while reducing serious complications.
- What is the preferred puncture site?
- There is no universally fixed site. Choose the largest safe pocket on immediate ultrasound, commonly in a lateral lower quadrant lateral to the rectus, after excluding bowel and vessels in two planes with color Doppler.
- Should an elevated INR in cirrhosis be corrected before paracentesis?
- Not routinely. Paracentesis is low bleeding risk, and cirrhosis-related INR elevation does not reliably predict bleeding; evaluate active bleeding, DIC, hyperfibrinolysis, severe thrombocytopenia and supratherapeutic anticoagulation instead.
- When is albumin given after paracentesis?
- In cirrhosis, give albumin when **more than 5 L** is removed, typically **6–8 g per liter removed**. Routine albumin replacement is not established for uncomplicated malignant ascites.
- Which ascitic fluid tests are routine in new-onset ascites?
- Send cell count with differential, ascitic albumin and total protein, with same-episode serum albumin for SAAG. Inoculate fluid into aerobic and anaerobic blood-culture bottles at the bedside when infection is suspected; order cytology, amylase, triglyceride or mycobacterial studies selectively.
- What ascitic neutrophil count diagnoses spontaneous bacterial peritonitis?
- An ascitic PMN count of **250 cells/mm³ or greater** supports SBP in the appropriate setting and warrants prompt treatment.
- How do you reduce post-paracentesis leakage?
- Use a small catheter and an oblique or Z-track, remove it promptly when drainage is complete and apply firm pressure with an occlusive dressing.
- Why is CT preferred for vertebral biopsy?
- CT provides precise visualization of cortical bone, the pedicles, spinal canal, neural foramina, vessels, pleura and viscera. It permits accurate measurement of the entry angle and depth and immediate assessment for complications.
- What is the preferred approach to a vertebral-body lesion?
- The **transpedicular approach** is preferred when the pedicle safely accommodates the needle because it provides a short, predominantly osseous corridor and limits violation of additional tissue compartments. The approach must be changed when lesion position, pedicle size or vertebral level makes it unsafe.
- What are the 3 Ps of vertebral biopsy?
- They are **planning**, **positioning** and **protection**. The operator selects the target and trajectory, positions the patient to reproduce that trajectory and protects the neural, vascular, pleural and visceral structures.
- What specimens should be sent in suspected spondylodiscitis?
- Send aspirated fluid and tissue for aerobic and anaerobic culture plus histopathology. Add mycobacterial culture and validated molecular testing, fungal culture or Brucella testing according to epidemiology, imaging and host risk factors.
- Should antibiotics be stopped before biopsy for suspected vertebral osteomyelitis?
- IDSA considers withholding antibiotics for **1–2 weeks** reasonable when clinically feasible because prior therapy may reduce culture yield. Antibiotics must not be delayed in sepsis, haemodynamic instability, neurologic compromise or impending cord compression.
- What should be done after a nondiagnostic vertebral biopsy?
- First confirm level, target, specimen adequacy and radiology-pathology concordance and perform testing for difficult-to-grow organisms when infection remains suspected. Repeat image-guided biopsy, percutaneous endoscopic sampling or open biopsy should then be discussed according to the clinical problem.
- What diagnostic performance should be quoted for CT-guided spinal biopsy?
- A 2021 meta-analysis reported **91% diagnostic yield**, **86% accuracy per procedure** and approximately **1% complication rate**. Accuracy among biopsies that produced a diagnosis was 94%.
- Why is core biopsy preferred over FNA for most lymph nodes and soft-tissue tumors?
- Core biopsy preserves tissue architecture and provides material for histology, immunohistochemistry and molecular testing. FNA supplies cells but may not reliably classify lymphoma or grade a heterogeneous soft-tissue tumor.
- When should excisional biopsy be preferred for suspected lymphoma?
- Excisional biopsy is preferred when a node is surgically accessible and architectural assessment is required. Image-guided core biopsy is appropriate for deep or surgically hazardous nodes, but an inadequate core biopsy should generally prompt excision rather than repeated small-volume sampling when excision is feasible.
- How do superficial and deep lymph-node biopsies differ in bleeding-risk classification?
- A superficial compressible node is low risk and often does not require routine coagulation screening or interruption of antithrombotic therapy. Retroperitoneal, mediastinal and deep pelvic nodes are high risk because haemorrhage is difficult to compress or detect clinically.
- What is the key rule when biopsying a suspected soft-tissue sarcoma?
- Refer or discuss the patient with the specialist tumor team before biopsy. The tract should remain within one compartment, avoid neurovascular structures and be positioned so it can be removed during definitive surgery.
- What are the principal CT-guided approaches to a deep pelvic lesion?
- The main approaches are anterior transabdominal, transgluteal and anterolateral through the iliopsoas. A transsacral or transiliac route is reserved for lesions without a safe soft-tissue window.
- How should tissue be divided when lymphoma is suspected?
- Allocate intact cores for formalin-fixed histology and immunohistochemistry while sending designated fresh tissue in the laboratory-specified medium for flow cytometry and other studies. The exact allocation must be agreed with hematopathology before biopsy.
- What defines technical success of percutaneous needle biopsy?
- Technical success is procurement of sufficient representative material to establish the diagnosis or guide treatment. Needle placement in the lesion without diagnostically usable tissue is not a successful biopsy.
- What should you do if active bleeding is seen before removing the coaxial introducer?
- Leave controlled access in place while assessing severity because the cannula may provide tamponade or permit tract embolization. Resuscitate, reverse anticoagulation when appropriate and proceed to angiographic embolization for ongoing arterial bleeding.
- Why must ultrasound be used before pleural fluid aspiration?
- It confirms the side, identifies a safe fluid pocket and maps the diaphragm, lung and adjacent organs, reducing pneumothorax and inadvertent organ puncture.
- How should therapeutic thoracentesis be drained?
- Drain slowly through a flexible catheter using manual syringe aspiration or gravity. Avoid vacuum bottles or wall suction and generally remove no more than 1.5 L in one attempt.
- Why is the puncture made immediately above the rib?
- The main intercostal neurovascular bundle lies along the inferior rib margin; entering above the rib reduces the risk of vascular or nerve injury.
- What defines technical success in percutaneous needle biopsy?
- Technical success is procurement of sufficient, correctly handled tissue to establish the required diagnosis or guide treatment. Needle placement within the lesion alone is not success.
- Why is a coaxial technique preferred for many solid-organ biopsies?
- It permits multiple cores through one capsular puncture, allows redirection within the lesion and provides a route for selective tract plugging. It can therefore improve yield while limiting repeated organ puncture.
- What coagulation values do you target before a solid-organ biopsy?
- Solid-organ biopsy is high bleeding risk. A platelet count of at least 50,000/µL is commonly used; SIR suggests an INR within 1.5–1.8 or lower, while CIRSE-based protocols commonly use 1.5 or lower. Chronic liver disease requires individualized interpretation rather than reflex plasma transfusion.
- How do you select the part of a tumour to biopsy?
- Target viable enhancing or metabolically active solid tissue and avoid central necrosis, hemorrhage and cystic components. Choose the safest lesion that can answer the clinical question, even if it is not the primary tumour.
- What must be done before an adrenal biopsy?
- Confirm that histology will change management, that imaging has not established a benign lesion and that the lesion is hormonally inactive. Pheochromocytoma must be excluded with plasma free or urinary fractionated metanephrines because biopsy can precipitate a life-threatening catecholamine crisis.
- When would you prefer a transjugular rather than percutaneous liver biopsy?
- A transjugular route is considered for nonfocal parenchymal liver biopsy when bleeding risk is unacceptable, particularly with significant coagulopathy or ascites, because bleeding is directed into the venous system. It is not a substitute when a focal peripheral lesion specifically requires targeted sampling.
- How do you manage significant post-biopsy bleeding?
- Recognize pain, tachycardia, hypotension or falling haemoglobin, obtain urgent imaging, resuscitate and reverse antithrombotic effect when appropriate. Ongoing arterial bleeding is treated with selective angiographic embolization; unstable or uncontrolled cases require surgical support.
- What is the principal indication for transjugular renal biopsy?
- It is used for non-targeted renal cortical biopsy when histology is necessary but percutaneous biopsy is contraindicated, unsafe, technically impossible or has failed. Typical reasons are coagulopathy, thrombocytopenia, unavoidable antithrombotic therapy, morbid obesity, ascites or inability to tolerate prone positioning.
- Why is the right renal vein and lower pole usually preferred?
- The right renal vein is short and usually offers a favorable course from the IVC. A peripheral lower-pole vein permits a posterolateral cortical trajectory away from the hilum and larger vessels.
- Why may the transjugular route be safer in a bleeding-prone patient?
- The biopsy is directed from a renal vein into cortex, so much of the bleeding can decompress into the low-pressure venous system rather than directly into the retroperitoneum. However, capsular or arterial perforation can still produce major hemorrhage, so TJRB is not a bloodless procedure.
- What tissue processing must be planned before renal biopsy?
- Cortical tissue containing glomeruli must be allocated for light microscopy, immunofluorescence and electron microscopy. The renal pathologist should define the local media and triage scant tissue; placing all cores in formalin is a critical error.
- How do you detect and manage capsular perforation?
- Perform a low-pressure check venogram after each pass. Isolated stable capsular staining often needs observation only, but persistent extravasation, hematuria or hemodynamic change requires tract or venous-branch embolization and assessment for an arterial injury.
- What are the pooled diagnostic yield and major bleeding rate?
- The 2020 systematic review reported diagnostic tissue in **90.3%** of procedures. Major bleeding requiring transfusion or another invasive intervention occurred in **4.5%**, while minor bleeding occurred in **18.2%**.
- Is coagulopathy an absolute contraindication to transjugular renal biopsy?
- No. Coagulopathy is often the reason for choosing TJRB, but reversible abnormalities should still be optimized and the residual risk assessed. Target renal-vein thrombosis, uncontrolled hypertension and lack of a safe venous route are more important reasons not to proceed.
- What is the principal indication for an IPC?
- A recurrent symptomatic malignant pleural effusion requiring ambulatory drainage, particularly with non-expandable lung or failed pleurodesis.
- Why is the catheter tunneled?
- The tunnel and polyester cuff provide fixation and create a tissue barrier that reduces accidental dislodgement and migration of infection.
- Where should the cuff be positioned?
- Within the subcutaneous tunnel, approximately 1 cm from the exit-site incision.
- When can an IPC be removed after spontaneous pleurodesis?
- When drainage is below 50 mL on three consecutive occasions, symptoms have not recurred and imaging shows no substantial residual effusion.
Image-Guided Soft-Tissue, Lymph-Node and Deep Pelvic or Retroperitoneal Biopsy
Image-Guided Soft-Tissue, Lymph-Node and Deep Pelvic or Retroperitoneal Biopsy
Image-Guided Soft-Tissue, Lymph-Node and Deep Pelvic or Retroperitoneal Biopsy
Image-Guided Soft-Tissue, Lymph-Node and Deep Pelvic or Retroperitoneal Biopsy
Image-Guided Soft-Tissue, Lymph-Node and Deep Pelvic or Retroperitoneal Biopsy
Image-Guided Soft-Tissue, Lymph-Node and Deep Pelvic or Retroperitoneal Biopsy
Image-Guided Soft-Tissue, Lymph-Node and Deep Pelvic or Retroperitoneal Biopsy
Image-Guided Soft-Tissue, Lymph-Node and Deep Pelvic or Retroperitoneal Biopsy