de Man, Rob

Hop,

van Buuren, Henk

English

Hop, Wim C.J.

EUR Research Repository

A B S T R A C TBackground: We studied whether the theoretical advantagesof a spring-loaded liver biopsy needle exist in clinical practiceand if so if they are dependent upon the experience of thephysician performing the biopsy.Methods: In a stratified randomised study we enrolled 215consecutive patients to compare the safety and efficacy ofa new automatic biopsy gun (Acecut) with that of a standardTru-Cut needle.Results: A total of 464 biopsies were performed. The end-points of the study were number of needle passes neededper patient, tissue yield of each needle pass and post-biopsycomplications. The performance of the automatic needlewas superior and more consistent with respect to tissue yieldcompared with the Tru-Cut needle (median yield 100%and 80%, respectively; p<0.001). The difference was mostmarked for inexperienced physicians. There was no dif-ference between the two needles in the number of passesneeded. More post-biopsy pain and post-biopsy use ofanalgesics were observed in the automatic needle group(p=0.04).Conclusion: The automatic Tru-Cut needle offers an advan-tage, particularly for physicians with no or limited experiencein liver biopsies. However more post-biopsy pain and post-biopsy use of analgesics were observed in the automaticneedle group.I N T R O D U C T I O NSeveral new types of automatic spring-loaded Tru-Cut liverbiopsy needles have recently been introduced. These devicesare commonly referred to as ‘biopsy guns’. The potentialadvantage of a biopsy gun is the shorter duration of theactual biopsy procedure which could reduce the numberof complications. In addition, since the difficult Tru-Cutmovement is automated, one would expect the tissue yieldto be larger and needle performance more constant.However, whether these theoretical benefits are of import-ance in clinical practice may depend upon the experienceof the physician performing the biopsy.Aims of the studyWe initiated a randomised study of the standard Tru-Cutliver biopsy needle and an automatic spring-loaded Tru-Cutdevice to compare tissue yield, the quality of the biopsyspecimen obtained and post-biopsy complications. Asecondary aim was to test the hypothesis that a possibleadvantage of the automated device would be most apparentamong inexperienced operators.M A T E R I A L S  A N D  M E T H O D SThe study population consisted of a cohort of all consecutivepatients referred for percutaneous liver biopsy to theDepartment of Hepatogastroenterology between October1994 and October 1996. The unit is a tertiary referral centrefor liver diseases and liver transplantation.Randomisation procedureA computer-generated randomisation procedure wasfollowed. Patients were randomly allocated to one of twoD E C E M B E R  2 0 0 4 ,  V O L .  6 2 ,  N O .  1 1© 2004 Van Zuiden Communications B.V. All rights reserved.441O R I G I N A L  A R T I C L EA randomised study on the efficacy and safetyof an automated Tru-Cut needle for percutaneous liver biopsyR.A. de Man1*, H.R. van Buuren1, W.C.J. Hop2Departments of 1Gastroenterology and Hepatology and 2Epidemiology and Biostatistics, Erasmus University Medical Centre Rotterdam, the Netherlands, tel.: +31 (0)10-463 37 93, fax: +31 (0)10-436 59 16, e-mail: r.deman@erasmusmc.nl, *corresponding authorgroups using consecutively numbered sealed nonopaqueenvelopes. Patients were stratified according to the experi-ence of the operator. A physician was considered inexperi-enced if he had performed less than 50 Tru-Cut liverbiopsies.Biopsy needlesFor this study we used a 14 gauge x 11.4 cm Tru-Cut needle(Baxter Healthcare Corporation, Deerfield, Ill, USA) asstandard needle. This needle has a biopsy specimen notchof 20 mm. This was compared with a needle biopsy gun(Acecut, TSK Laboratory, Japan) with a 14 gauge x 11.5 cmneedle and a 15 mm biopsy specimen notch.Biopsy procedurePreparation for the biopsy was identical for the two groups.After informing the patient about the procedure, a mid-axillary biopsy site was selected and checked by ultrasono-graphy. The actual biopsy procedure was performed withoutultrasound guidance. If desired by the patient premed-ication, consisting of intravenous midazolam (Dormicum)in a bolus dosage of 5 mg, was given. Dosages of 1 to 2.5 mgwere administered to patients over 65 years of age who hadcardiopulmonary or other diseases considered to increasethe risks associated with intravenous administration ofbenzodiazepines. Oxygen saturation and heart rate weremonitored by pulse oximetry. After skin disinfection andliberal local anaesthesia with 1% lidocaine the random-isation envelope was opened by the endoscopy nurse andthe appropriate biopsy needle was presented. Our standardprocedure is to obtain two biopsy specimens; if the biopsywas less than 15 mm long, the biopsy pass could be repeateda maximum of four times.After the biopsy procedure the wet biopsy specimen wasplaced on a plate of paraffin and the length was measuredusing a micrometer. All patients undergoing this procedureas outpatients were observed for three hours in the day-carefacility with standard checks on post-biopsy pain, pulse rateand blood pressure. A patient with pain was evaluated bythe operator who could prescribe a bolus of 50 or 100 gintravenous fentanyl citrate (Fentanyl). Our policy is toadminister fentanyl early in the event of post-biopsy pain.At the end of the three-hour observation period the occur-rence of pain was scored by the physician as none, mild orsevere. This was further documented by the prescriptionof fentanyl. At the end of the three-hour observation periodthe patient was again seen by the physician and either senthome or admitted for further observation. Any admissionwas scored as a complication. When an in-patient under-went the biopsy procedure, the occurrence of pain, use offentanyl and complications were recorded by the attendingward physician the day after the procedure. All data wereregistered on standard forms.Study endpointsThe study endpoints were:- the number of passes performed and total biopsylength/number passes;- the cumulative length of the liver tissue obtained andthe quality of the material obtained (fragmented vs acoherent biopsy specimen);- the number of passes with insufficient material definedas less than 10 mm (insufficient pass), no tissue yield(failed passes) or no tissue yield at all (failed procedure);- post-biopsy complications.Statistical evaluationThe aim was to include at least 50 patients in each physicianstratum. Power calculations were not performed since nodata were available on the performance of the automaticneedle. We assumed that in a study of 100 patients no clin-ically significant differences would be missed. Since recruit-ment in the inexperienced physician group was slower thanexpected, a total of 215 patients were enrolled. Equality ofthe medians was tested by the two-sample Wilcoxon rank-sum test. The relationship between the type of physicianwho took the biopsy, needle type and tissue yield wasevaluated using multiple regression analysis. Whether thedifferences between needle types depended on the physicianwas tested using appropriate interaction terms. Dichotomousparameters were tested by Fisher’s exact test.R E S U L T SPatientsIn total, 215 patients were randomised. Five patients wereexcluded from the study because the physician decidedto change the biopsy procedure to either an ultrasound-guided biopsy (of the left liver lobe) (n=2) or a laparo-scopic biopsy (n=3). In one case the data sheets were lost.In total 209 patients could be evaluated. The groups werewell matched for demographic, clinical and laboratoryvariables (table 1).PhysiciansFour experienced and three inexperienced physicians par-ticipated in this study. In 159 cases the biopsy procedurewas performed by an experienced physician (78 automaticneedle and 81 Tru-Cut). In 50 cases the biopsy procedurewas performed by an inexperienced physician (24 automaticneedle and 26 Tru-Cut).Biopsy lengthNo differences were found in either the number of passesneeded for each needle type or the number of insufficientor failed passes. There were no failed procedures.To correct for the maximum tissue yield possible, all dataDe Man, et al. Automated Tru-Cut needle for liver biopsy.D E C E M B E R  2 0 0 4 ,  V O L .  6 2 ,  N O .  1 1442were analysed as percentage of the specimen notch usedper biopsy pass. This percentage was significantly higherfor the automatic needle compared with the Tru-Cut needle(100 vs 80%; p<0.001) (table 2).The difference in mean use of the needle notch did notdiffer between individual physicians in one group. A cleartrend (p=0.109) was found towards an increased benefitof the automatic biopsy device among inexperiencedphysicians compared with the experienced ones (table 3).ComplicationsThree patients (all randomised to the automatic needlegroup) suffered complications in this study. Two patientswere admitted because of pain and discharged the next daywithout complaints. One patient with documented intraperi-toneal bleeding received two units of red blood cells. Thedifference between the two groups was not statisticallysignificant.After a biopsy procedure the pain experienced by the patientas interpreted by the physician was more severe in theautomatic needle group (p=0.012). This paralleled theincreased prescription of fentanyl in the automatic needlegroup (p=0.04). The difference in post-biopsy pain wasindependent of the experience of the physician (p=0.08 andp=0.05 for the experienced and inexperienced groups,respectively) (table 4).The overall incidence of major complications in this serieswas 0.6% (3/464). The incidence of minor complications(pain with administration of analgesics) was 13.5% (63/464).D I S C U S S I O NWhen performing a liver biopsy the first decision to be madeis the choice between the cutting needle (Tru-Cut system)and the aspiration needle (Menghini type). With both needletypes adequate tissue samples can be obtained while thereis an advantage for Tru-Cut needles in diagnosing cirrhosis.1In an experimental animal model using direct comparisonthe Tru-Cut needle performed better compared with aspir-ation needles with regard to tissue yield and specimenquality.2 Although the overall incidence of post-biopsy bleed-ing in nonmalignant liver disease is low (0.4 per 1000 forfatal bleeding and 1.6 per 1000 for nonfatal bleeding),the incidence of severe post-biopsy bleeding is higher forcutting needles compared with aspiration needles.3,4 In theexperimental model as well as in autopsy studies it has beenshown that an automatic biopsy device produces adequatetissue samples.5 The aim of our study was to compare ineveryday clinical practice the performance of an automaticwith a hand-operated Tru-Cut needle. Our hypothesis wasthat the impact of an automatic biopsy device would be thegreatest among inexperienced physicians whereas no clearadvantage would found for experienced physicians. Thisstudy shows that the use of an automatic Tru-Cut needledevice is superior to a standard Tru-Cut needle as far astissue yield is concerned. Lindor demonstrated that this isalso true when only experienced operators participate.6Are these differences clinically relevant? Obviously adequatetissue specimens can be obtained with both needles. Thetissue yield of the automatic needle seems to be more con-D E C E M B E R  2 0 0 4 ,  V O L .  6 2 ,  N O .  1 1De Man, et al. Automated Tru-Cut needle for liver biopsy.443Table 1Patient characteristics and features at entryAUTOMATIC NEEDLE HAND-OPERATED NEEDLENumber of patients 102 107Age 41 (19-72) 45 (17-68)Sex (female/male) 39/63 38/69Aetiology of the liver diseaseHepatitis B 47 52Hepatitis C 24 20Primary biliary cirrhosis 4 5Primary sclerosing cholangitis 4 1Autoimmune hepatitis 2 2Alcoholic liver disease 2 3Post-transplantation 4 8Cryptogenic 15 16Evaluation of haemostasisNumber of patients with prolonged 1 3 prothrombin timeAPTT (normal 25-40 seconds) 29 (20-40) 28 (23-46)Platelets (normal 140-360.109/l) 202 (58-660) 202 (41-381)Bleeding time (normal <240 seconds) 170 (60-355) 142 (60-420)Continuous data are presented as median plus ranges.De Man, et al. Automated Tru-Cut needle for liver biopsy.D E C E M B E R  2 0 0 4 ,  V O L .  6 2 ,  N O .  1 1444Table 2Results of biopsy proceduresAUTOMATIC NEEDLE HAND-OPERATED NEEDLENeedle passes 2 (1-4) 2 (1-4)Number of patients (n)Needle passes (%)1 pass 5 (4.9) 2 (1.9)2 passes 77 (75.5) 78 (72.9)3 passes 17 (16.7) 24 (22.4)4 passes 3 (2.9) 3 (2.8)Number of failed needle passes (n)First biopsy 3 8Second biopsy 4 7Third biopsy 0 5Fourth biopsy 0 0Number of failed procedures 0 0(no material obtained)Biopsy length (mm)Cumulative biopsy length as percentage of 100 (25-140) 80 (21-138)biopsy notch (%)Cumulative biopsy length 30 (15-56) 35 (17-73)Median biopsy length per pass 15 (5-20) 16 (6-24.5)Biopsy quality if biopsy obtainedGood-quality first biopsy (%) 94.8 94.8Good-quality second biopsy (%) 92.3 86.4Good-quality third biopsy (%) 94.7 85.7Good-quality fourth biopsy (%) 100 100Continuous data are presented as median plus ranges. Quality data relate to the percentage of biopsies yielding good quality tissue.Table 3Liver tissue yield expressed as percentage of the biopsy notch in relation to the experience of the operatorAUTOMATIC NEEDLE HAND-OPERATED NEEDLEInexperienced operator 100% (36-123) 69% (30-137)Experienced operator 100% (25-140) 85% (21-122)Data are presented as median plus ranges.Table 4Complications and post-biopsy sequelaeNEEDLE TYPE AUTOMATIC NEEDLE HAND-OPERATED NEEDLEPatients on midazolam pre-medication (%) 82 84Post-biopsy pain (n (%))None 45 (47.4) 70 (68.6)Mild 33 (34.7) 20 (19.6)Severe 17 (17.9) 12 (11.8)Post-biopsy fentanyl (n)None 56 7850 g 35 17100 g 4 6Admissions (n) 3 0sistent which is particularly beneficial for operators whoperform liver biopsies sporadically. Our data support arecommendation that those who will not be performingfrequent liver biopsies in the future should learn to usean automatic device while the type of needle is of lessrelevance for those working in specialised liver units.We started using ultrasound routinely for all patients in1983. This approach has since been shown to reduce theincidence of post-biopsy complications.6 However the occur-rence of post-biopsy pain and use of analgesics were higherin the automatic needle group. Although it seems logicalto attribute more blunt tissue trauma and more pain to thespring-loaded device, the study design with regard to theoccurrence of pain should be interpreted with caution:the scoring of post-biopsy pain and the decision to usefentanyl were left to the physician in charge and not to morepatient-related measurements. In the combined Mayo Clinic– Barcelona study 207 patients were biopsied with an auto-matic Tru-Cut needle under ultrasound guidance and 216hand-held Tru-Cut biopsies under ultrasound guidance wereperformed.6 The occurrence of post-biopsy pain was 40.6%for the automatic group and 34.3% for the hand-operatedgroup. The data seem to support the idea that post-biopsypain increases with the use of a spring-loaded biopsyneedle. Since compliance with repeated liver biopsies isessential for the treatment and follow-up of patients withchronic liver disease, this is an important aspect whichshould not be disregarded easily. We can only speculate onthe exact cause of post-biopsy pain with a spring-loadedbiopsy needle. One explanation may be that because someoperators keep close contact with the upper side of the ribduring the procedure, the spring-loaded device causes moreblunt trauma to the periostium.Our data support the recommendation that physicians whoperform liver biopsies infrequently should learn to use anautomatic Tru-Cut biopsy device. A follow-up study with a20 mm specimen Tru-Cut biopsy device would be worth-while, especially to address the issue of an increase in post-biopsy pain following the use of a spring-loaded biopsy gun.A C K N O W L E D G E M E N T SWe acknowledge the participation of internists and gastro-enterologists (in training).R E F E R E N C E S1. Vargas-Tank L, Martinez V, Jiron M, Soto JR, Armas-Merino R. Tru-Cutand Menghini needles: different yield in the histological diagnosis of liverdisease. Liver 1985;5:178-81.2. Hopper KD, Baird DE, Reddy VV, et al. Efficacy of automated biopsy gunsversus conventional biopsy needles in the pygmy pig. Radiology1990;176:671-6.3. McGill DN, Rakela J, Zinsmeister AR, Ott BJ. A 21-year experience withmajor haemorrhage after percutaneous liver biopsy. Gastroenterology1990;99:1396-400.4. Piccinino F, Sagnelli E, Pasquale G, Giusti G. Complications followingpercutaneous liver biopsy. A multicentre retrospective study on 68 276biopsies. J Hepatol 1986;2:165-73.5. Hoper KD, Abendroth CS, Sturtz KW, Matthews YL, Stevens LA, Shirk SJ.Automated biopsy devices: a blinded evaluation. Radiology 1993;187:653-60.6. Lindor KD, Bru C, Jorgensen RA, et al. The role of ultrasonography andautomatic-needle biopsy in outpatient percutaneous liver biopsy.Hepatology 1996;23:1079-83.D E C E M B E R  2 0 0 4 ,  V O L .  6 2 ,  N O .  1 1De Man, et al. Automated Tru-Cut needle for liver biopsy.445

A randomised study on the efficacy and safety of an automated Tru-Cut needle for percutaneous liver biopsy.

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A randomised study on the efficacy and safety of an automated Tru-Cut needle for percutaneous liver biopsy.

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