What are the oncological tips and tricks for percutaneous pancreatic biopsies?

Oncological Tips and Tricks for Percutaneous Pancreatic Biopsies

EUS-guided biopsy is strongly preferred over percutaneous approaches for potentially resectable pancreatic lesions due to the lower risk of tumor seeding, while percutaneous sampling should be reserved primarily for unresectable disease or when EUS is not available. 1

Patient Selection and Indications

• Percutaneous pancreatic biopsies should be restricted to cases where histological confirmation is required for palliative therapy planning or clinical trial enrollment, and should generally be avoided in potentially resectable lesions 1
• Tissue diagnosis is mandatory in unresectable cases or when neoadjuvant therapy is planned, but not required before surgery with radical intent 1
• Patients with a history of primary malignancy have a high yield from pancreatic biopsies (91% positive for malignancy) 2

Pre-Procedure Risk Assessment

• Thoroughly assess coagulation status - INR >1.5 increases bleeding risk from 1.1% to 7.1% 2
• Check platelet count - thrombocytopenia (<150×10⁹/L) increases bleeding risk from 1.6% to 2.9% 2
• Evaluate renal function - renal dysfunction strongly correlates with bleeding complications 2
• For patients on direct oral anticoagulants (DOACs), the last dose should be taken 3 days before the procedure 2
• For patients on warfarin, ensure INR <1.5 before proceeding 2

Imaging Guidance Selection

• Ultrasound guidance is preferred when the lesion is visible (93% of cases), with CT reserved for cases where ultrasound visualization is inadequate 3, 4
• Consider contrast-enhanced ultrasound (CEUS) for lesions not visible on standard ultrasound, which can increase biopsy success rates to 88-96% 2, 5
• Fusion imaging techniques combining ultrasound with previously acquired CT/MRI can improve precision and reduce complications 5

Procedural Techniques

• Use cutting-type needles (14-18 gauge) for core biopsies which provide better histological samples compared to fine needle aspiration 6
• Sensitivity for malignancy ranges from 78-93% with specificity of 95-100% depending on technique 3, 6, 4
• When using ultrasound guidance, sensitivity, specificity, and accuracy of pancreatic core biopsy are 93%, 100%, and 93% respectively 4
• Obtain multiple cores (average 2.3-2.8 per biopsy) to improve diagnostic yield 7
• Consider the needle trajectory carefully to avoid traversing major vessels and the gastrointestinal tract 1

Risk Minimization During Procedure

• Use real-time imaging to confirm needle position throughout the procedure 5
• Minimize the number of needle passes while maintaining diagnostic adequacy 2
• Be aware that elevated bilirubin levels correlate with increased bleeding risk (2.7% vs 1.1%) 2
• The overall complication rate for pancreatic biopsies is approximately 21.4%, with most being minor 4

Post-Procedure Monitoring

• Monitor patients for at least 3 hours after biopsy with regular clinical observations and measurement of blood pressure and pulse 2
• Watch for signs of bleeding, which is the most common complication 2, 4
• Be aware that post-biopsy ephemeral fever occurs in approximately 4.4% of pancreatic biopsies 4
• High pre-biopsy serum total bilirubin level is a significant predictor of post-procedure fever 4

Special Oncological Considerations

• Remember that failure to obtain histological confirmation does not exclude malignancy and should not delay appropriate surgical treatment in highly suspicious cases 1
• Be aware that approximately 5% of pancreaticoduodenal resections are performed for what ultimately proves to be benign disease 1
• For metastatic lesions, percutaneous biopsy under ultrasound or CT guidance is appropriate 1
• Consider that fever and infection occur more frequently with liver metastases biopsies compared to pancreatic biopsies (11% vs 4.4%) 4

Important Caveats

• The risk of tumor seeding along the needle track or within the peritoneum is a significant concern, particularly for potentially resectable tumors 1
• False negative results can occur, and a negative biopsy should be confirmed by at least one repeat biopsy before excluding malignancy 1
• Mortality directly related to bleeding complications is extremely rare (approximately 0.009-0.33%) but has been reported 2
• The overall accuracy of percutaneous pancreatic biopsies ranges from 81-93%, with core biopsies generally providing better results than fine needle aspiration 6, 4