Biopsy and Drainage · IR Playbook

CT-Guided Percutaneous Transthoracic Lung Biopsy (Lung biopsy)

CT-guided percutaneous transthoracic needle biopsy obtains cytologic or histologic tissue from a pulmonary or pleural lesion when a percutaneous route offers the best diagnostic yield and risk profile. Core biopsy is generally favored when histology, immunohistochemistry or molecular profiling is required, whereas fine-needle aspiration is useful when expert cytopathology support is available. Pneumothorax is the commonest complication; most cases require observation only, but approximately 3.1–6.6% of all biopsies require tube drainage.

Learning objectives

• Select patients and targets in whom percutaneous biopsy offers a favorable diagnostic yield and risk profile.
• Plan a stable CT-guided trajectory that minimizes pleural passages and avoids fissures, bullae and bronchovascular structures.
• Obtain and route adequate tissue for histology, immunohistochemistry, molecular testing or microbiology.
• Recognize and immediately manage pneumothorax, pulmonary hemorrhage, hemoptysis, hemothorax and systemic air embolism.

Indications

• Indeterminate, persistent or enlarging peripheral pulmonary nodule or mass when tissue diagnosis will alter management.
• Histologic classification, immunohistochemistry and molecular profiling of suspected primary lung cancer or intrathoracic metastasis.
• Rebiopsy for resistance mechanisms, biomarker reassessment or additional molecular testing when prior tissue is inadequate.
• Multiple pulmonary nodules of unknown etiology when a percutaneous target is the safest informative site.
• Persistent focal pulmonary infiltrate or consolidation of unknown etiology after less invasive evaluation is nondiagnostic.
• Suspected focal pulmonary infection requiring tissue for microbiological diagnosis when noninvasive sampling is insufficient.

Absolute contraindications

• Refusal or absence of valid informed consent.
• Suspected pulmonary vascular lesion in the planned target.
• No safe percutaneous access route.
• Uncorrectable clinically important coagulopathy.

Relative contraindications

• Respiratory failure, severe chronic obstructive pulmonary disease or predicted FEV1 below approximately 35%.
• Mechanical ventilation or inability to suspend respiration reproducibly.
• Pulmonary arterial or venous hypertension.
• Previous pneumonectomy or a functionally single lung.
• Severe bullous emphysema, particularly along the proposed trajectory.
• Pregnancy when ionizing-radiation exposure cannot be justified or adequately minimized.

Equipment

• Multidetector CT scanner with low-dose sequential guidance; CT fluoroscopy or multiplanar reconstruction when required.
• Sterile preparation set, drapes, gloves, gauze and adhesive dressing.
• 1–2% lidocaine, typically 10–20 mL, with 22–25G infiltration needle.
• No. 11 scalpel blade for a small skin nick.
• 17–19G coaxial introducer needle of appropriate length with a compatible depth stop.
• 18–20G semiautomatic or automatic core biopsy needle with a known throw length.
• 20–25G Chiba, spinal or dedicated aspiration needle with 10–30 mL syringe when FNA is planned.
• 10% neutral buffered formalin containers, sterile saline microbiology container, slides and any dedicated molecular or lymphoma transport medium requested by pathology.
• 50 mL Luer-lock syringe and three-way stopcock for pneumothorax aspiration through the introducer.
• 6–9 Fr pleural drainage catheter, guidewire, dilator, Heimlich valve or underwater-seal system for rescue drainage.
• Pulse oximetry, oxygen, suction, resuscitation drugs and equipment for emergency airway management.

Procedure steps

1. Verify patient identity, indication, side, laboratory results, antithrombotic plan and required specimen tests. Re-review CT immediately before starting and confirm that a safer extrapulmonary or bronchoscopic target is not preferable.Pearl: A technically easy lesion is not necessarily the best target; choose the site most likely to provide viable tissue that will answer the clinical question.
2. Position the patient comfortably and immobilize the relevant body part. Rehearse quiet breathing and a reproducible brief breath-hold, usually at gentle end-expiration, without deep inspiration.Pearl: Use the same respiratory phase for planning, advancement and sampling.
3. Acquire a limited low-dose CT through the lesion, place a radiopaque skin marker and measure the entry point, angle and depth. Confirm that the projected path and full biopsy throw avoid fissures, bullae, vessels, airways, diaphragm and adjacent organs.Pearl: Plan both the introducer tip position and the distal end of the cutting-needle throw.
4. Perform wide sterile skin preparation and draping. Infiltrate 1–2% lidocaine from skin to parietal pleura and make a small skin nick when using a coaxial introducer.Pearl: Adequate pleural anesthesia reduces sudden pain, coughing and patient movement at pleural puncture.
5. Advance the coaxial introducer incrementally through the chest wall, checking angulation with limited CT acquisitions. Stop immediately outside the pleura and reconfirm target position at the rehearsed respiratory phase.Pearl: Correct trajectory before pleural puncture; redirection after entering the lung increases pleural trauma.
6. During the agreed breath-hold, cross the pleura in one deliberate movement and advance the introducer tip to the lesion margin or just within the lesion. Confirm the tip position with CT and keep the hub occluded by the stylet or a finger whenever the inner needle is removed.Pearl: One pleural puncture with a coaxial system permits multiple samples without repeated pleural crossings.
7. Advance the core needle coaxially and confirm that the sampling notch and entire throw remain within viable target tissue. Obtain usually 2–4 cores, redirecting within the lesion through the same introducer when necessary and stopping if hemorrhage, pneumothorax or patient instability develops.Pearl: Grossly inspect each core and allocate tissue deliberately for histology and molecular analysis.
8. Place routine core specimens in 10% neutral buffered formalin. Send suspected infection samples in a sterile non-formalin container and use dedicated media for molecular testing or lymphoma assessment according to prior laboratory instructions.Pearl: Separate microbiology material before formalin fixation.
9. Before removing the introducer, perform a limited CT check for early pneumothorax or hemorrhage. Withdraw the introducer during controlled breathing; in selected higher-risk patients, inject an evidence-supported tract sealant such as autologous blood or saline according to institutional technique, then rapidly position the patient biopsy-side down when feasible.Pearl: Tract sealing and rapid biopsy-side-down positioning can reduce pneumothorax or tube-drainage risk in selected patients.
10. Obtain an immediate limited CT through the biopsy region and inspect the pleural spaces, needle tract, heart and visible systemic arteries. If pneumothorax is present, decide among observation, aspiration through the introducer or pleural catheter drainage according to symptoms, size and progression.Pearl: Immediate CT can reveal a small pneumothorax, pulmonary hemorrhage or systemic air embolism before symptoms occur.

Complications

• Small or asymptomatic pneumothorax, overall approximately 15–35%
• Pneumothorax requiring drainage, approximately 3.1–6.6%
• Pulmonary parenchymal hemorrhage or mild hemoptysis, pooled core-biopsy rates 18.0% and 4.1%
• Severe hemoptysis or hemothorax; hemothorax approximately 0.09–0.57%
• Systemic arterial air embolism, approximately 0.02–0.18%
• Needle-tract tumor seeding, approximately 0.061% after intrapulmonary nodule biopsy

Exam pearls

• Biopsy-side down is the key position after pneumothorax-prone biopsy and during mild hemoptysis.
• The most important modifiable pneumothorax factors are avoiding fissures and bullae and minimizing pleural passages.
• Core biopsy provides architecture and generally supplies more tissue for immunohistochemistry and molecular testing than FNA.
• Keep the coaxial hub occluded whenever the inner needle is removed to reduce systemic air-embolism risk.
• Never fire the biopsy gun until the full throw, not merely the needle tip, is confirmed within a safe viable target.
• A nondiagnostic biopsy is not a benign diagnosis; discordance with a high malignancy probability demands further evaluation.

Viva questions

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.

References