ultrasound guided biopsies, challenges and how to overcome these

Ultrasound Guided BiopsiesMethods and Challenges

Durr-e-SabihMBBS. MSc. FRCPDirector Multan Institute of Nuclear Medicine and RadiotherapyMultan- Pakistandsabih@yahoo.com

More than Biopsies

o Aspirations and drainageo Vessels accesso Nerve blockso Foreign body removalso Injections into cavities, cysts and solid

lesions

Guidance

o Blind o Mark, angle, deptho Free hand real-timeo Biopsy adaptor

Guidance

Blind vs Guided Biopsieso Large organs, diffuse diseaseo Guided biopsies associated with less pain,

less complications, less re-biopsies 1

o Procedure appears to be more accurate and more safe when performed in conjunction with US2

o Adding ultrasound altered biopsy procedure in 15% 3

1Bandar Al Knawy, Mitchell Shiffman. Percutaneous Liver Biopsy in Clinical Practice Liver International. 2007;27(9):1166-1173. 2American Gastric Association Guidelines for outpatient LB. Jacobs WH, Goldberg SB. Statement on out-patient percutaneous liver biopsy. Dig Dis Sci 1989; 34: 322-3.3Riley TR. III How often does ultrasound marking change the liver biopsy site. Am J Gastroenterol 1999; 94: 3320-2.

Ultrasound Guidance Pros and Cons

o Very preciseo Patient bedside o No radiationo Real-time o If you can see it you

can get ito Oblique planes are

easy

o Long learning curveo Some patients (obese)

and some sites (deep, deep in lungs, behind bone, air filled structures) some structures (breasts), some backgrounds (hyperechoic ) difficult

o Some needles (>20G)

Ultrasound vs. CTo More sites, deeper sites accessible than USo Limited to axial planeso More time consuming and costly

o Each needle advancement is followed by a CToCT Fluoroscopy is faster

o High patient and operator doseo Patient dose up to 830 mGy (12kVp, 90 mA

10mm section)o Physician hand dose up to 18 mGy/month

Extremely Accurate Needle Placement

4 mm

3.5 mm

Before the Actual ProcedureSelect the Appropriate Needle

o Preliminary ultrasound for most appropriate site; shortest line of sight without vessels and preferably without gut

o Length according to depth of targeto Type of needle

Depth

Depth, Needle Length

Needle DescriptionFrench and Gauge

o Gaugeo Modification of Birmingham Wire Gauge (1884) and

specifies the thickness of outer diameter. Largest size is 5 or 0.5 inch or (12.7mm). Largest needle size is 7G (4.572mm), smallest needle size is 34G (0.1842mm). There is no mathematical formula; the steps get smaller with increasing gauge numbers (0.046-0.001”)

o Frencho D (mm)= Fr/3; you get mm of diameter by dividing the

Fr size by 3

Common Needle Gauges and LengthsType Gauge Length(mm)

LP 90

Other LP 50-190BT set 16 (donor)-18G (recipient) 40BD 20 ml 21 40BD 10 ml 21 38

BD 5 ml 23 25BD 3 ml 23 25Terumo 1 ml 30 09

Length and Throw

Needle DescriptionWall Thickness

o RW Regular wall (spinal) o TW Thin Wallo XTW Extra Thin Wallo UTW Ultra Thin Wall (Chiba is Ultrathin walled)

Needle Edge and Type

o Aspiration o LP, Hypodermic, Chiba

o End cuttingo Franseen, Jamshaidi, Klatskin, Menghini,

Westcott, Greeneo Side cutting

o Tru-cut, Vim Silverman, Magnumo Spring Loaded

Tips

Bevel

o Turner bevel 45o

o Spinal bevel 30o

o Chiba bevel 24o

Smaller bevel angle is associated with higher tissue yield (Chiba).

Echogenic Needles

o Scoringo Cornerstone reflectors o Echocoatingo Bevel angle and length

Choices

FNA or Core

FNAChoose needle

Length and gauge

CoreChoose needle

Length, gauge and throw

SuctionLarger lesions larger throw

Smaller lesions smaller gauge

Capillary Freehand or guided

Aspiration or Core?

o How good is your cytologist?o Aspirations are less traumatic, cheaper,

faster… o Failure rates… you don’t know if you got

the cells

FNA Needle Movement

o Insert into the targeto To and froo Rotateo Suction/capillaryo Narrow gauge is better

FNA Needle movement

Needle Movement for FNA

Core Biopsy

o Know your throwo Assess where the tip will be after firing,

calculate your angleo Go to the periphery of lesiono Use an introducer sheath

The Biopsy Movement

The Biopsy Movement

Needle throw

Needle throw

Work UP

o FNA 20G or smaller … no workupo Core

o Platelet count >50,000o INR <1.5o Prothrombin time …normal – normal + 4 sec.

o Vascularity is perhaps as, or even more important

ComplicationsMore Passes, More Complications

o Pain, referred pain (right shoulder with liver biopsy)o Hypotension (Vasovagal, hemorrhage)o Hematoma, hemoperitoneum, biliary peritonitis,

pneumothorax, pancreatitis, air embolismo Hematuria, urinary retention, peri-site abscesso “Overshooting” into other organs o Seedingo AVMo Transient bacteremiao Deatho False negative/inadequate sample

Terminology for Hemorrhagic Complication

o Grade 1. Minimal symptoms; invasive intervention not indicated

o Grade 2. Minimally invasive evacuation or aspiration indicated

o Grade 3. Transfusion, interventional radiology procedure, or operative intervention indicated

o Grade 4. Life-threatening consequences; major urgent intervention indicated

o Grade 5. Death

McGill DB, Rakela J, Zinsmeister AR, Ott BJ. A 21-year experience with major hemorrhage after percutaneous liver biopsy. Gastroenterology 1990; 99:1396–1400

Incidence of Bleeding after 15181 Percutaneous Biopsies and the Role of Aspirin1

o Grade 3…..70 patients (0.5%) including 3 deaths (0.02%, 1: 5000).

o All deaths with liver mass biopsies (one hemothorax [DNR], one perihepatic hematoma, progressive hypotension [DNR])

o No difference with aspirin useo Size of needles not importanto Death 1: 12,0002

1Thomas D. Atwell, Ryan L. Smith, Gina K. Hesley, Matthew R. Callstrom, Cathy D. Schleck, W. Scott Harmsen, J. William Charboneau, Timothy J. Welch. Am J Roentgenol. 2010;194(3):784-789.

2Garcia-Tsao G, Boyer JL. Outpatient liver biopsy: how safe is it?. Ann Intern Med. Jan 15 1993;118(2):150-3

Post Biopsy Hematoma

Perirenal Haematomas

http://emedicine.medscape.com/article/2093338

When You Shouldn’t

Bleeding diathesisUncontrolled blood pressureObesity and uncooperative patientSkin infection at biopsy siteVery vascular lesion Back up invasive radiology/surgery not available

Suggested Guidelines for Outpatient Liver Biopsy

The patient must be able to easily return to the hospital where the procedure was performed within 30 minutes of developing any adverse symptoms.

A reliable individual must be available to stay with the patient during the first night after the liver biopsy and provide care and transportation to the hospital, if necessary.

The patient should not have any preexisting serious medical problems that might increase the risk of complications from the biopsy. Such problems may include encephalopathy, ascites, liver failure with severe jaundice, significant extrahepatic obstruction, significant coagulopathies, or serious comorbidities such as severe congestive heart failure. Also, patients should not be very old, very young, or so anxious that they require sedation.

The facility where the biopsy is to be performed should have an approved laboratory, blood banking unit, easy access to an inpatient bed, and personnel to monitor the patient for 6 hours after the biopsy.

The patient should be hospitalized after biopsy if any evidence exists of bleeding, bile leak, pneumothorax, or other organ puncture. Hospitalization is suggested if the patient’s pain requires more than 1 dose of an analgesic in the first 4 hours after the biopsy.

Position Statement American Gastroenterological Association 1989

Type of GuidanceReal-time Visualization or

Mark/Guide

o For large lesions only guidanceoMark, angle, depth

o Smaller or non palpable lesionsoReal-time

Needle Tip Echogenicity

o As near parallel to the probeo Gauge, bigger is bettero Closer is bettero Echogenic needle shaftso Needle bevel towards the probeo Long axis easier than short axis

Losing the Needle EchoCommonest problem, plagues experts as well

as noviceso Get needle in line ..know your probe’s “sweet

spot”o Look where the needle is going most of the time,

not the monitoro Move the stylet in and outo Jiggle the needleo Subsequent passes are more difficult

Out of Plane

Stylet

Before Beginning the ProcedureDecide on the Insertion Site and Angle

The Biopsy Procedure

Mark, Angle, Depth (MAD)

Insertion PointsLong-axis

< 20o

Short- axis insertion needs more practice

Insertion Points Short Axis

Identify the needle tip and follow this as you advance it.Sometimes shaft echo is mistaken for needle tip.Much more practice needed for short-axis visualization

False Negativeso Needle lengtho Beam thickness and

side lobeso Focus, frequencyo Air echoes on

subsequent passes(biopsy tracks)

o Very dense tissueo Very soft tissue

Avoiding false negatives

o Larger gauge, 14G needleso Post-fire imageso Practiceo Practiceo Practice

Needle track

Pearlso Breasto Thyroido Livero Kidneyo Retroperitoneum

Breast Biopsyo Stabilize the masso Parallel to the chest

wallo If not possible, lift

the mass using theneedle

Ultrasound Histology CorrelationConcordant Malignancy Malignant on image,

malignant on HPOncology/Surgery

Discordant Malignancy Benign on Image, Malignant on HP

Treat as concordant malignancyOncology/Surgery

Discordant Benignity Malignant on Image, Benign on HP

Possible false negative, redo, very close follow-up, inform surgeon/oncologist

Borderline or high-risk finding

Atypia, lobular neoplasm, radial sclerosing lesion, papilloma, phylloides

Discuss with surgeons, possible close follow-up or excision

Youk, J. H., E. K. Kim, et al. (2007). Missed breast cancers at US-guided core needle biopsy: how to reduce them.Radiographics 27(1): 79-94.

Thyroido 5% likelihood of a thyroid nodule being

malignant1

o Likelihood increases with suspicious findings (hypoechogenicity, taller than wide, irregular contour, central vascularity, microcalcification), in recurring cysts, complex lesions, history of radiation. Under 30 or over 60 yrs.

o Usually FNA, core rarely and very carefully

1Tollin SR, Mery GM, Jelveh N, et al. The use of fine-needle aspiration biopsy under ultrasound guidance to assess the risk of malignancy in patients with a multinodular goiter. Thyroid. 2000;10:235–241.

Thyroid

o FNA with 22-26G hypodermic or chiba needle

o 95% accuracyo 209 core biopsies of thyroid with 16-18 G

minor complications in 2%, no major complications

o Sensitivity of 96%

Renal Biopsy

Renal BiopsyContraindications

Kidneys

o Multiple cystso Solitary kidney (?)o Acute pyelonephritis/

perinephric abscesso Small kidneyso Highly vascular tumours

Splenic Biopsy

o Complication rate similar to liver biopsy but prudent to biopsy a non-splenic lesion if present

Mesenteric Nodes

o Compress the gut awayo Safe with 20 G

Thank You