eus for suspected choledocholithiasis: do benefits outweigh costs? a prospective, controlled study

8/22/2019 EUS for suspected choledocholithiasis: Do benefits outweigh costs? A prospective, controlled study

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EUS for suspected choledoch ol ithiasis: Do ben ef itsoutweigh costs? A prospective, control led studyEl is a b e t ta Bu s c a r i n i, M D , Pa o lo T a n s i n i, M D , Da n i e l e Va l li s a , M D, A l e s s a n d ro Z a m b e l l i , M D , L u i g i Bu s c a r in i , M DCrema and Piacenza , I ta ly

B a c k g r o u n d : T h i s p r o s p e c t i v e s t u d y o f t h e u s e o f E U S t o p r e v e n t u n n e c e s s a r y e n d o s c o p i c r e tr o -g r a d e c h o l a n g i o g r a p h y i n p a t ie n t s w i th s u s p e c t e d c h o l e d o c h o l i th i a s i s h a s t w o a im s : t O e v a l u a t e t h ee f fe c t i v e n e s s , b a s e d o n p a t i e n t o u t c o m e , a n d t h e p o t e n t ia l c l in i c a l a n d e c o n o m i c b e n e f i ts o f E U S .M e t h o d s : A p r o s p e c t i v e s e r i e s o f 4 8 5 p a t i e n t s ( 2 0 2 m e n , 2 8 3 w o m e n ; m e a n a g e 6 6 . 2 y e a r s , ra n g e2 0 - 9 4 y e a r s ) s u s p e c t e d t o h a v e c h o l e d o c h o l i t h i a s i s b a s e d o n c l in i c a l , b i o c h e m i c a l , a n d c r o s s -s e c t i o n a l i m a g i n g ( U S o r C T ) d a t a u n d e r w e n t E U S . P o s i t iv e E U S f in d i n g s w e r e c o n f i r m e d b y e n d o -s c o p i c r e t r o g r a d e c h o l a n g i o g r a p h y w i t h s p h i n c t e ro t o m y a n d / o r b y s u r g e r y ; n e g a t i v e fi n d i n g sw e r e c o n f i r m e d b y c li n ic a l f o ll o w - u p . A n E U S r e s u l t w a s c o n s i d e r e d a t r u e n e g a t i v e i f t h e p a t i e n tw a s c o n f i r m e d s y m p t o m - f r e e w i t h n o r m a l t e s t s o n f o l lo w - u p o f a t l e a s t 6 m o n t h s . T h e c o s t s o f E U S( p r o c e d u r e , d a y s o f h o s p i t a l iz a t io n , a n y m o r b i d i t y ) w e r e c o m p a r e d w i t h th e e s t i m a t e d c o s t s o f th ee n d o s c o p i c r e t r o g r a d e c h o l a n g i o g r a p h y a v o i d e d i n p a t i e n t s w i t h t r u e - n e g a t i v e E U S fi n d i n g s .R e s u l t s : E U S f i n d i n g s w e r e v e r i f ie d i n 4 6 3 p a t i e n t s : E U S d i a g n o s e d c h o l e d o c h o l i th i a s i s i n 2 3 9( 5 1 . 6 % ) a n d t h e a b s e n c e o f s t o n e s i n 2 2 0 p a t i e n t s . In 4 p a t i e n t s ( 0 .8 % ) , E U S w a s i n c o m p l e t e . B ys p h i n c t e r o t o m y ( 2 0 9 p a t ie n t s ), s u r g i c a l b il e d u c t e x p l o r a t io n ( 3 9 ), p e r c u t a n e o u s c h o l a n g i o g r a p h y(1 c a s e i n w h i c h E U S d e m o n s t r a t e d a b il e d u c t t u m o r ) , a n d f o ll o w - u p ( 2 1 4 ) , E U S d i a g n o s e s w e r ec o n f i r m e d a s fo l l o w s : 2 3 7 t ru e - p o s i t i v e , 2 1 6 t r u e - n e g a t i v e , 2 fa l s e - p o s i t i v e , 4 fa l s e - n e g a t i v e , 4i n c o m p l e t e ( s e n s i t iv i t y 9 8 % , s p e c i f i c i ty 9 9 % , p o s i ti v e p r e d i c t i v e v a l u e 9 9 % , n e g a t i v e p r e d i c t i v ev a l u e 9 8 % , a c c u r a c y 9 7 % ) . I n 2 1 4 ( 4 6 % ) p a t ie n t s , m o r e i n v a s i v e i n v e s t i g a ti o n s o f t h e b i le d u c t w e r ea v o i d e d . T h e m e a n c o s t f o r p a t i e n t s m a n a g e d b y t h e E U S - b a s e d s t r a t e g y w a s E 3 7 4 . 5 0 (: 1: 28 4 .7 2 ),w h i c h w a s s i g n i f ic a n t l y l e s s t h a n t h e t h e o r e t i c a l m e a n c o s t o f C 4 4 3 . 8 0 ( p < 0 . 0 0 1 ) f o r p a t i e n t su n d e r g o i n g e n d o s c o p i c r e tr o g r ad e c h o l a n g io g r a p h y .C o n c l u s i o n s : T h e r e s u l t s o f t h i s s t u d y c o n f i rm t h a t E U S i s h i g h l y r e li a b l e fo r th e d i a g n o s i s o f c h o -l e d o c h o l i th i a s i s . I t s u s e o ff e r s c o n s i d e r a b l e c l i n i c a l a n d e c o n o m i c a d v a n t a g e s b y p r e v e n t i n g i n a p -p r o p r i a t e a n d m o r e i n v a s i v e e v a l u a t i o n o f t h e b i l e d u c t . (G a s t r o i n t e s t E n d o s c 2 0 0 3 ; 5 7 : 5 1 0 - 8 . )

E n d o s c o p i c r e t r o g r a d e c h o l a n g i o g r a p h y ( E R C ) isc o n s i d e r e d t h e s t a n d a r d n o n s u r g i c a l t e c h n i q u e f o rd i a g n o s i s o f b i l e d u c t s t o n e s . E R C a l l o w s s t o n er e m o v a l a t t h e s a m e e n d o s c o p ic s e s s io n b y e n d o-s c o p ic s p h i n c t e r o t o m y ( E S T ) , b u t it is a n i n v a s i v em e t h o d a s s o c i a t e d w i t h s u b s t a n t i a l m o r b i d it y .N o n i n v a s i v e d i a g n o s t ic t e s t s a r e p e r f o r m e d t o se l e c t

9 p a t i e n t s w i t h s u s p e c t e d c h o l e d o c h o l i t h i a s is f o r E R C .B a s e d o n c l i n i c a l a n d b i o c h e m i c a l c r i t e r i a t o g e t h e rw i t h t r a n s a b d o m i n a l U S f in d i ng s , p a t i e n t s c a n b eg r o u p e d i n t o r i s k c l a s s e s , r a n g i n g f r o m l o w to h i g h ,f o r d u c t s t o n e s . 1 I f t h i s i n i t i a l t r i a g e i d e n t i f i e s ap a t i e n t a s b e i n g a t r i s k o f h a v i n g b i le d u c t s t o n e s ,Received Ju ly 17 , 2002. For rev i s ion Septem ber 17 , 2002. AcceptedOctober 30, 2002.Cu r r e n t a f f i l i a t i o n s : Ga s t r o e n t e r o l o g y De p a r t me n t , Os p e d a l eMaggiore , Crem a, G as t roenterology Depar tm ent , O spedale Civ il e,P i a c e n z a , a n d I n t e r n a l M e d i c i n e De p a r t me n t , Os p e d a l e C i v i l e ,Piacenza , I ta ly .Re p r i n t r e q u e s t s : E l i s a b e t t a Bu s c a r i n i , M D, Ga s t r o e n t e r o l o g yDe p a r t me n t , Os p e d a l e M a g g i o r e, v i a M a c a l l ~ - 1 , 2 6 0 1 3 C r e ma ,I taly.Copyr ight 9 2 0 0 3 b y t h e Am e r i c a n ~o c i e ty fo r Ga s t r o i n t e s t in a lEn d o s c o p y 0 0 1 6 - 5 1 0 7 / 2 0 0 3 / $ 3 0 . 0 0 + 0

doi :10.l O67 / mge .2003.14 9

E R C i s p e r f o r m e d , g e n e r a l l y w i t h E S T i f s t o n e s a r ea c t u a l l y f o u n d . H o w e v e r , i n s e r i e s o f p a t i e n t sd e f i n e d a s b e i n g a t h i g h r i s k f o r b il e d u c t s t o n e sb a s e d o n p r e l i m i n a r y s c r e e n i n g t e s t s, t h e p r o p o r t i o ns h o w n b y E R C t o a c t u a l l y h a v e c h o l e d o c h o li th i a s ish a s r a n g e d b e t w e e n 2 7 % a n d 5 0 % . 1-7 E v e n w i t hs t r ic t e r u s e o f p r e o p e r a t i v e c r i te r i a, t h e p r e s e n c e o fs t o n e s w a s d e t e c t e d i n o n l y 6 6 % o f th e p a t i e n ts , sC a n t o e t a l . 9 f o u n d t h a t 7 0 % o f p a t i e n t s c l a s s if i e da s b e i n g a t h i g h r i s k h a d c h o l e d o c h o l i t h i a s i s ; w h e nc l a s s if i e d a s b e i n g a t m o d e r a t e , i n d e t e r m i n a t e , o rl o w ri s k , b il e d u c t s t o n e s w e r e o b s e r v e d i n 2 8 % , 4 % ,a n d 0 % o f t h e p a t i e n t s . T h e r e f o r e , t h e r e s u l t s o f t h i st r i a g e s t r a t e g y a r e u n s a t is f a c t o ry , a n d i t i n c r e a s e st h e r i s k o f o v e r u s e o f E R C . 1~ T h e i d e a l a l t e r n a t i v es h o u l d h a v e t h e s a m e d i a g n o s t ic a c c u r a c y a s E R Cb u t m i n i m a l o r n o i n v a s i v e n e s s ; a v a i l a b l e d a t a i n d i -c a t e t h a t E U S h a s t h e s e c h a r a c t e r is t ic s . 6 ,s , 11-14 I nf a c t, E U S h a s b e e n s h o w n t o h a v e a d i a g n o s t i c a c c u -r a c y f o r b il e d u c t s t o n e s o f a b o u t 9 5 % , w h i c h c o m -p a r e s f a v o r a b l y w i t h E R C . 6,7,11,13 B e c a u s e o f t h eh i g h U S f r e q u e n c i e s u s e d ( 7 . 5, 1 2 M H z ) , E U S h a s ar e s o l u t io n o f l e ss t h a n 1 m m , m a k i n g i t t h e b e s ti m a g i n g t e c h n i q u e a v a i l a b le a t p r e s e n t f o r i m a g i n g

5 1 0 G A S T R O I N T E S T I N A L E N D O S C O P Y V O L U M E 5 7, N O . 4 , 2 0 03


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E U S f o r s u s p e c t e d c h o l e d o c h o l i th i a s i s: b e n e f i t s v s. c o s t s E B u s c a r i n i , P T a n s i n i , D V a l l is a , e t a l .

the ext rahepat ic b i l ia ry t rac t . Other advantages ofEUS over ERC are minimal invas iveness or semi-invasiveness with almost no procedure-related com-plications and a negligible failure rate.12,13,15 In par-t icular , no complicat ions were reported in the severalseries of bi l iary EUS which comprise more t han 1000patients.6,8,9,11-14 Many investigators have pointedout tha t EUS may therefore prevent inappropr ia teinvasiv e eval uati on of the bile duct.S, 13

These data prompted us to apply EUS as a f irst-s tep technique af te r t ransabdominal US in a la rgeseries of consecutive pat ients with suspecte d chole-docholi thiasis; pat ients with bi le duct s tones at EUSwere even tua l ly r e f e r r ed fo r t r ea t men t whe rea sthose wi th negat ive EUS f indings were fo l lowed.The a im of th is prospect ive s tud y was to ana lyzepati ent outcome in terms of effect iveness as well asthe potential cl inical and economic benefi ts of EU Simplici t in the avo idance of unn ece ssar y ERC.

P A T IE N T S A N D M E T H O D SAll patients were enrolled in a prospective, ongoing

protocol for evaluation of the clinical utility of EUS for thediagnosis of choledocholithiasis. Patients were enrolled ifthey met the following criteria for suspected choledocho-lithiasis: (1) history of biliary-type colicky pain or recen tcholangitis, and a his tory of aundice; (2) recent acu te pan-creatitis; (3) serum bilirubin and/or alkaline phosphataseor 7-glutamyl transpeptidase, and/or aminotransferasesmore than twice the upper normal limit; (4) dilatation ofthe intrahepatic and/or extrahepatic bile ducts (>7 mm)and/or a suspicion of choledocholithiasis on tran sabdom i-nal US or CT. Patients who had a dilated bile duct at USand at least one clinical criterion were classified as beingat intermediate risk; those with 3 or more criteria wereclassified as high risk. Exclusion criteria were as follows:refusal to participate, any factor that rendered the patientunsuita ble for trea tme nt of choledocholithiasis, and previ-ous gastrectomy. Patients with a definite transabdominalUS diag nosis of choledocholithiasis were also excluded.The US criterion for this diagnosis was a n echo-rich imagewith acoustic shadowing within the bile duct. Patientswith acute cholangitis and/or severe biliary pancreatitiswith obstructive jaundice underwent ERC with EST. Theprotocol for the st udy was approve d by the review board ofour hospital.

After US, each patient underwent EUS to identifyeither bile duct stones (echo-rich structures, possibly mov-ing within t he bile duct, with or without acoustic shadow-ing) or biliary sludge. In case of a positive EUS , thepatien t was referred for treatm ent of bile duct stones byEST or surgery depending on whether the gallbladder waspresent, clinical condition, and preference of the referri ngphysician. EST or surgical intervention was performedwithin 5 days after EUS. The EUS result was considereda true-positive if stones were confirmed by EST or surgi-cal exploration. In case of a negative EUS, patie nts withcholelithiasis unde rwen t laparoscopic or open cholecystec-

tomy and were then followed; patients with a prior chole-cystectomy and a negativ e EUS result were followed. Twoclinical, biochemical (bilirubin, alkaline phosphatase, 7-glutamyltranspeptidase, aminotransferases, serum amy-lase) and US evaluations were scheduled during the 3months after EUS. Thereafter, at least 2 additional clini-cal and/or US evaluations were scheduled every 4 months.Any further available evaluation, including informationobtained by telephone interview, was also recorded. A neg-ative EUS result was considered true if the pati ent wassymptom-free with normal biochemical tests and USimaging a t a follow-up of at l east 6 months.

Patien ts were in formed as to choices of man age men tdepending on EUS results; potential morbidity of endo-scopic and surgical tr eat men t of choledocholithiasis wasexplained. Written informed consent was obtained fromall patients for the procedures performed and participa-tion in the study.

The study had 2 endpoints: (1) clinical outcome, basedon the ability of EUS to prevent inappropr iate invasiveevaluation of the bile duct; (2) the economic implicationsof the EUS-s trate gy for suspected choledocholithiasis.P r o c e d u r e s

EUS was performed with a radial scanning echoendo-scope (GF-UM20, Olympus Optical Co., Ltd., Tokyo,Japan) at 7.5 and 12 MHz frequencies. All examinationswere performed by one endoscopist (3 years experiencewith biliopancreatic EUS) with the assista nce of onenurse. Patients were sedated by intravenous administra-tion of diazepa m (5-10 mg). The tr ansdu cer was inser tedto the second portion of the duodenum and graduallywithdrawn to visualize the biliopancreatic region, in par-ticular the main duodenal papilla, extrahepatic bile duct,cystic and hepa tic ducts, and gallbladder. The numbe r andsize of stones and diame ter of the bile duct were recorded.The mean d uratio n of the exami nations was 22 minutes.Each examination was recorded on videotape and hard-copy photog raphs were take n of the m ost significant find-ings. The me an cost of an EUS in ou r center was C 159.

ERC with EST was performed with a standard videoduodenoscope with the patient sedated as for EUS. Allprocedures were performed by a single endoscopist, differ-ent than the one who performed EUS, 2 nurse assistants,and a radiology technician. Antibiotics were adm inisteredprophylactically before the procedure and for 48 hoursthereafter. After opacification of the bile duct, EST wasperformed and the findings recorded. Stones were clearedfrom the duc t with Dormia b asket and/or balloon catheter.The mean cost of ERC in our center was ~2 63.3.

In patients undergoing surgical bile duct exploration,stones were cleared with a stone retrieval basket inse rted bymeans of the cystic duct or by choledochotomy after intraop-erative cholangiography to confirm the presence o f stone(s).C o m p l i c a t i o n s

Complications of endoscopic procedures were classifiedas follows: mild (unplanned hospital admission, prolonga-tion of hospital stay for up to 3 days), moderate (4-10 days

V O L U M E 5 7, N O . 4, 2 00 3 G A S T R O I N T E S T I N A L E N D O S C O P Y 511


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E Busc arini , P Tansin i , D Val l i sa , e t a l . EU S for suspe cted choledo chol i th ias is : benef i t s vs. cos ts

2 negJ

ochaumo,Percuta~eous i . . . . . . . . ] r - -o -- -ncholangiography :~,

2 persistent p;n/ ]~

i I ! ?=~ I

3c o cky pa n /i r I "4n.gat,v s I. ' la"o"o , u01

Figu re 1 . Ou tcom es for 463 pat ients with s pected chole-docholithia sis who unde rwen t EUS. ~, :i~

4. . . . 3' . ~;hosp] tahza t ]on) , severe (>10 days hosp l t ahza t lon o r th~need fo r su rg ica l in te rven t ion o r in tensive c ~ ) , and fa ta l . 16

Cost analysisThe cos t o f ma kin g the d iagnos i s o f cho ledocho l ith ias i s

w a s a n a l y z e d , e x c l u d in g a l l c o st s o f t r e a t m e n t . W i t h o u tE U S, a l l p a t i e n t s w i t h s u s p e c t e d c h o l e d o c h o l i t h i a s i swould undergo ERC before EST; wi th u se o f EUS, ERCwould be avo ided in pa t i en t s wi th negat ive f ind ings .

Because the ben ef i t o f EUS i s expected to a r i se f romthe ab i l i ty to avo id unne cess ary ERC, the economic impl i -ca t ions o f i t s use a re eva lu a ted by weigh ing the cos t s o fE U S p e r f o r me d o n a l l p a t i e n t s a g a i n s t t h e c o s ts o f E RCfor pa t i en t s in the sam e popu la t ion who avo ided th i s p ro -cedure (cor respond ing to the t rue-negat ive ra t e fo r EUS) .T h e c o s t f o r a l l E U S e x a mi n a t i o n s w a s c o mp a r e d w i t h t h ecos t -sav ings rea l i zed by avo idance o f ERC procedures .

Three indicators were chosen to evaluate cost : (1) meancosts for EUS and ERC based on actual costs in our centerand ca lcu la t ions sugg es ted by the I t a l i an Socie t ies o fGastroenterology an d Endoscopy (including costs for medicals taff , nurse(s) , d isposable materials and drugs, and equip-me nt am ort izat ion and m aintenance ); (2) hospi tal izat ion cost(one day in the 'gastro enter ology uni t costs C309.8); and (3)costs associated with morbidi ty induced by the procedurescalculated by adding ch arges for addi t ional hospi tal days.In the ana lys i s , the ac tua l cos t o f EUS (p rocedure , dayshosp i t a l iza t ion d i rec t ly l inked to EUS, a ny morb id i ty ) was

Figure 2. Endosonographic image of 4-mm stone withinslightly dilated common bile duct.

compa red wi th the es t ima ted cos t o f the ER C procedurest h a t w e r e a v o i d ed b a s e d o n th e n u m b e r o f p a t i e n t s w i t ht rue negat ive EUS f ind ings . The l a t t e r cos t es t imate wascalculated by adding the fol lowing to the cost of an ER C: (1)the cos t o f hosp i t a l i za t ion re l a t ed to ERC (based on da taf r o m o u r d e p a r t me n t ; me a n h o s p i t a l i z a t i o n i s 2 d a y s f o rpat ients undergoing diagnost ic ERC) and (2) costs associat -ed wi th p rocedure- re la t ed m orb id i ty ca lcu la ted on the bas i so f a 2% m ajor compl ica t ion ra t e fo r d iagnos ti c ER C w i thm ini mu m prolongat ion of hospi ta l izat ion of 11 days.17,!8Statistical methodsSens i t iv ity , spec i f ic i ty , pos i t ive p red ic t ive va lue , n ega-t i v e p r e d i ct i v e v a l u e, a n d a c c u r a c y o f E U S w e r e c a l c u la t -e d . T h e m e a n c o s t ( SD) f or p a t i e n t s u n d e r g o i n g t h e E U S-b a s e d s t r a t e g y w a s c a l c u l a t e d t a k i n g i n t o a c c o u n t t h ecos t o f the p roc edure , hosp i t a l i za t ion , an d com pl ica t ions .A o n e - s a mp l e t t e s t w a s t h e n u s e d t o c o mp a r e t h i s me a nv a l u e w i t h t h e h y p o t h e t i c a l c o s t s u s t a i n e d b y a p a t i e n tu n d e r g o i n g E RC. A o n e- w a y s e n s i t i v i t y a n a l y s i s w a s a l s op e r f o r me d , p l o t t i n g me a n c o s ts o f E RC ( e s t i ma t e d c o st )a n d E U S ( a c t u a l c o st ) a g a i n s t t h e e s t i ma t e d r i s k o f b i leduct s tones to de termine the l eas t cos t ly d iagnos t i c s t ra t -egy as a funct ion o f the r i sk o f b i l e duct s ton es ( ran ge 0%to 100%). Th i s es t ab l i shed th e th resho ld ( in t e rms o f ther i sk o f b i l e duct s tones ) fo r which the cos t s o f the EUSa n d E R C s t r a t e g i e s a r e i d e n t i c a l . S t a t i s t i c a l s o f t w a r ew a s u s e d f o r a l l c a l c u l a t i o n s ( SPSS 8 . 0 , SPSS , I n c . ,Chicago, I l l. ) .

RESULTSA t o t a l o f 4 8 5 p a t i e n t s ( 2 02 m e n , 2 8 3 w o m e n ;

m e a n a g e 66 . 2 y e a r s , r a n g e 2 0 - 9 4 y e a r s ) w e r ep r o s p e c t i v e l y s t u d i e d b e t w e e n J a n u a r y 1 99 5 a n dD e c e m b e r 1 9 98 . O f t h e s e , 1 9 4 h a d u n d e r g o n e c h o le -c y s t e c t o m y (2 d a y s t o 4 8 y e a r s e a r l i e r ) . I n 2 5p a t i e n ts , U S d e m o n s t r a t e d a n o r m a l g a l lb l a d d e r;t h e r e m a i n i n g 2 6 6 h a d g a l l s to n e s b y US .

5 1 2 G A S T R O I N T E S T I N A L E N D O S C O P Y V O L U M E 5 7, N O. 4 , 2 0 03


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EU S for suspected choledocholi thiasis: benefi ts vs. costs E Busca rini , P Tansini , D Vall isa, et al .

Pat i ent outcomesT h e E U S f i n d i n g s w e r e c o n f i r m e d in 4 6 3 p a t i e n t s

( Fi g. 1 ). T w e n t y - t w o p a t i e n t s w i t h n e g a t i v e E U Sf ind ings were los t t o fo l low-up . In t e l ephone in t e r -v i e w s , t h e s e p a t i e n t s r e p o r t e d n o s y m p t o m s o f c h o -l e d o c h o l i t h i a s i s b u t h a d n o t u n d e r g o n e a n y f o l l o w -u p e v a l u a t i o n f o r v a r i o u s r e a s o n s ( a b s e n c e o fs y m p t o m s , d i f f ic u l t y i n r e t u r n i n g t o o u r c e n t e r) .Ri sk s t r a t i f i ca t ion fo r the l ike l ihood o f cho ledocho-l i t h i a s is w a s a s f ol lo w s : i n t e r m e d i a t e r i s k , 2 8 7pa t i e n t s (61.9%); h igh r i sk , 176 pa t i en t s (38.1%). AnE U S d i a g n o s i s o f c h o l e d o c h o l i t h i a si s w a s m a d e i n239 o f the 463 pa t i e n t s (51 .6%) (F ig. 2 ); abse nce o fs t o n e s w a s f o u n d i n 2 2 0 p a t i e n t s ( 8 7 w i t h p r e v i o u sc h o l e c y s t e c t o m y ) . I n 4 p a t i e n t s ( 0 . 8 % ) , t h e E U Se x a m i n a t i o n w a s i n c o m p l e t e ( u n c o o p e r a t i v e p a t i e n t ,1 ; py lo r i c s t enos i s , 2 ; duode na l bu lb s t enos i s , 1 ). Bi l ed u c t s t o n e s w e r e s o l i t a r y i n 8 7 c a s e s . M e a n s t o n ed i a m e t e r w a s 7 . 0 4 m m ( r a n g e 2 - 23 m m ) ; s t o n e sw e r e 1 c m o r l es s i n d i a m e t e r i n 1 8 2 c a s e s ( 76 % ) a n d5 mm or l ess in 97 cases (40%) (F ig . 3) . The b i l e duc td i a m e t e r w a s l e s s t h a n 7 m m i n 5 8 c a s e s ( 2 4 % ) .

E U S d e m o n s t r a t e d c h o l e li t h ia s i s o r g a l l b l a d d e rs l u d g e i n 1 8 o f 2 5 p a t i e n t s i n w h o m t r a n s a b d o m i n a lU S h a d f o u n d a n o r m a l g a l l b l a d d e r ( F i g . 3 ) . E R Cw i t h E S T w a s p e r f o r m e d i n 2 1 2 p a t i e n t s a n ds u r g e r y w i t h b i l e d u c t s t o n e e x t r a c t i o n i n 2 7 . T w oh u n d r e d s i x ty - tw o p a t ie n t s u n d e r w e n t c h o le c y st e c-t o m y ; 1 1 3 o f t h e s e c h o l e c y s t e c t o m i e s w e r e p e r -f o r m e d i n t h e 2 2 0 p a t i e n t s w i t h n e g a t i v e E U S f i n d -i n gs . A m o n g p a t i e n t s w h o u n d e r w e n t E S T, 1 56( 73 % ) h a d u n d e r g o n e E U S w i t h i n t h e p r e c e d i n g 2 4h o u r s . A l t o g e t h e r t h e m e a n i n t e r v a l b e t w e e n E U Sand EST was 1 .6 days ( r ange 0 -4 days) .

E S T a n d E U S r e s u l t s a g r e e d i n 2 0 4 c a s e s . I n 3 6o f t h e s e c a s e s , s t o n e s w e r e m i s s e d a t E R C a n d f o u n do n l y a f t e r E S T ; in a l l o f t h e s e c a s e s t h e s t o n e s w e r el e s s t h a n 5 m m i n d i a m e t e r . I n 2 p a t i e n t s , b i l e d u c ts t o n e s w e r e n o t f o u n d a f t e r E S T d e s p i t e r e p e a t e dp a s s a g e s o f a D o r m i a b a s k e t a n d b a l l o o n c a t h e t e r.I n 6 p a t i e n t s ( 2 . 8 % ) , E S T w a s u n s u c c e s s f u l a n d t h eb i le d u c t o f t h e s e p a t i e n t s ( a ll w i t h g a l l s t o n e s ) w a sexp lo red a t su rgery .T h i r t y - n i n e p a t i e n t s u n d e r w e n t s u r g i c a l e x p l o -r a t ion o f the b i l e duc t (7 l aparoscop ic cho lecys tec to -m y , 3 2 o p e n s u r g e r y ) . T h e m e a n i n t e r v a l b e t w e e nE U S a n d s u r g e r y w a s 4 .9 d a y s ( r a n g e 3 - 9 d a y s ).

For 33 pa t i en t s ( inc lud ing the 6 in whom EST wasunsuccessfu l ) t he r esu l t s o f su rg ical exp lo ra t ion agreedwi th the EUS f ind ings ; i n 2 pa t i en t s wi th a nega t iveEU S b u t pe r s i s t en t co li cky pa in o r cho les t as is , su rg ica le x p l o r a t i o n d e m o n s t r a t e d s t o n e s . T h e 4 p a t i e n t s i nw h o m E U S w a s u n s u c c e s s f u l u n d e r w e n t s u r g i c a lexp lo ra t ion a t which b i l e duc t s tones w ere found in 3 .O n e p a t i e n t i n w h o m E U S r e v e a l e d a c h o l e d o c h a l

Figure 3. A, EUS image showing small quantity of biliarysludge (arrowhead)within gallbladder, B, EUS image in samepatient showing three 2-mm stones (arrowheads)within com-mon bile duct. Transabdominal US in this patient who recent-ly sustained an episode of acute pancreatitis was normal.

t u m o r u n d e r w e n t p e r c u t a n e o u s t r a n s h e p a t i c b i l i a r ydra inage , which conf i rmed the EUS d iagnos i s.

T w o h u n d r e d s e v e n t e e n p a t i e n t s w i t h a n e ga t i v eE U S w e r e f o l lo w e d : 3 u n d e r w e n t E R C / E S T 1 2, 3 2 ,and 58 days , r espec t ive ly , a f t e r EU S fo r ep i sod ic co l-i c k y p a i n a s s o c i a t e d w i t h c h o l e s t a s i s i n 2 c a s e s a n dj a u n d i c e i n t h e o t h er . E S T d e m o n s t r a t e d c h o le -d o c h o l it h i a s is i n 2 o f t h e s e p a t i e n t s . F o r t h e r e m a i n -i n g 2 1 4 p a t i e n ts , m e a n f o ll o w - up w a s 1 3 .4 m o n t h s( r a n g e 7 - 2 9 m o n t h s ) . I n 7 8 p a t i e n t s , b i o c h e m i c a lt e s t s o f l i v er f u n c t i o n ( a l k a li n e p h o s p h a t a s e , y -g lu -t a m y l t r a n s f e r a s e ) w e r e s t il l e l e v a t e d to 2 t o 3 t i m e sn o r m a l v a l u e s a t t h e f i r s t fo l lo w - u p e v a l u a t i o n . I na l l p a t i e n t s , t h e l i v e r f u n c t i o n t e s t s r e t u r n e d t o no r -m a l a t 3 m o n t h s ' f o ll o w - up . N o n e c o m p l a i n e d o fs y m p t o m s o r m a n i f e s t e d a n y c l i ni ca l , i m a g i ng , o rb i o c h e m i c a l a b n o r m a l i t y d u r i n g f u r t h e r f o l l o w - u p .

V O L U M E 5 7, N O . 4, 2 00 3 G A S T R O I N T E S T I N A L E N D O S C O P Y 513


5/9

E B u s c a r i n i , P T a n s i n i , D V a l l i s a , e t a l . E U S f o r s u s p e c t e d c h o l e d o c h o l i t h i a s i s : b e n e f i t s v s. c o s t s

T a b l e 1 . C o s t a n a l y s is o f th e E U S - b a s e d s t r a t e g y fo r t h e d i a g n o s i s o fc h o l e d o c h o l i t h i a s i sE U S - b a s e d s t r a te g y E R C s p a r e d

N o . o f e x a m i n a t i o n s 4 6 3 E U S 2 1 6 E R CC o s t p e r p r o c e d u r e E U S ( 1 59 ) E R C ( 2 6 3. 3 )P r o c e d u r e c o s t s 7 3 , 6 50 5 6 , 8 9 0H o s p i t a l i z a t i o n c o s ts 9 9 , 7 80 * 1 3 3 , 8 7 0 tC o m p l i c a t i o n c o s t 0 1 4 , 7 2 5 5F i n a l c o s t 1 7 3 , 4 30 2 0 5 , 4 8 0Fi na l cos t /pa t i en tw 374.511 443.8 tA v e r a g e s a v i n g p e r p a t i e n t w i t h E U S 4 4 3 . 8 - 3 7 4 .5 = 6 9 . 3

C o s t s a r e e x p r e s s e d i n E u r o s .* 3 2 2 d a y s o f h o s p i t a l i z a t i o n f o r 4 6 3 p a t i e n t s w h o u n d e r w e n t E U S o n d i f f e r e n t d a y s ( s e eR e s u l t s ) .t 2 d a y s o f h o s p i t a l i z a t i o n / p a t i e n t u n d e r g o i n g E R C .5 2 % c o m p l i c a t i o n r a t e = 4 . 32 c o m p l i c a t i o n s /2 1 6 p a t i e n t s , f o r a c o s t o f 1 1 d a y s o f h o s p i t a l i z a -t i o n f o r e a c h c o m p l i c a t io n .w c o s ts d i v i d e d b y 4 6 3 p a t i e n t s .

] ]D i f fe r e n ce i s s t a t i s t i c a l l y s i g n i f i c a n t ( p < 0 . 0 0 1 ) .

Altogether choledocholithiasis was d emonstra tedin 244 (52%) of the 463 pat ien ts enrolled. Choledo-cholithiasis was found in 117 of 176 (66.4%) patientsat high r isk and 127 of the 287 (44.2%) at in terme-diate risk for choledocholithiasis.The EUS results were verified by EST (209patients), surgical bile duct exploration (39), percu-taneous cholangiography (1 patient in whom EUSdemonstrated a choledochal tumor), and follow-up(214).EUS diagnoses w ere as follows: 237 true-positive,216 true-negative, 2 false-positive, 4 false-negative,and 4 incomplete (sensitivity 98%, specificity 99%,positive predictive value 99%, negative predictivevalue 98%, accuracy 97% for the diagnos is of chole-docholithiasis). In 214 patients (46%), more invasiveevaluati on o f the bile duct was avoided. The mea nduration of hospitalization for patients who under-went ERC/EST was 6.2 days (range 2-182).

C o m p l i c a t i o n sComplications were observed in patients who

underwent EUS and EST on separate days, appear-ing after EST and attributable to that procedure.There was no procedure-related death.Among the 215 patients who underwent ERC/EST, mild complications were noted in 25 (11.6%; 2self-limiting episodes of bleeding, 23 instan ces ofelevation of amylase level) with a mean prolonga-tion of hospi taliz ation of 1.8 days. Complications o fmoderate severity occurred in 7 patients (3.2%; 1episode of bleeding requiri ng blood transfusion, 6pancreatitis) with prolonged hospitalization a meanof 8.1 days. One (0.4%) severe co mplicationoccurred in a patient with a negative EUS whounde rwent ERC durin g follow-up, which proved

negative. Severe pancreatitis complicated byabdominal fluid collections and multiorgan failuredeveloped that resulted in ext ended hospitalization(3 days, gastroenterology department; 134 days,intensive care unit; 45 days, surgery department).The patient recovered, but was permanently unableto work. The patient eventually brought suit forrecovery of damages and was awar ded the sum of129,114.The morbidity costs of ERC/EST in our stud yresulted from a total of 118 hospitalization days inthe Gastroenterology Unit, 134 hospitalization daysin the intensive care unit, and 45 in the surgery unitfor a tot al cost of C 147,500, corresponding to a meanmorbidi ty cost per ERC/EST of C686.05. If the mon-etar y a ward o f C 129,114 to compensate the pati entwho sustained the single severe complication isincluded in the calculation, the mean morbidity costper ERC/EST is C 1286.5.C o s t s

The EUS-based strategy for the diagnosis of bileduct stones implied the avoidance of 216 ERC pro-cedures, corresponding to the true negative EUS.The cost analysis therefore involved comparing thecost of the 463 EUS (~73,650) w ith the cost of theERC procedures that were avoided (~56,890).Hospitalization costs were calculated in the EUSgroup as ~99,780 and estimated in the ERC group(on the basis of data fr om our department: 2 dayshospitalization for a diagnostic ERC) as ~ 133,870.The cost of potent ial complications of ERC, taken as14,725, was adde d to this sum, for a final total costof ~ 205,480 (with a final cost per pa tie nt [total costdivided by 216] of ~951.2). Therefore, because ourEUS strategy cost ~173,430, this management

5 1 4 G A S T R O I N T E S T I N A L E N D O S C O P Y V O L U M E 5 7, N O. 4 , 2 0 03


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1 4 0 0m p l i e s a t o t a l s a v i n g o f ~ 3 2 , 0 5 5 a n d , f o r 4 6 3p a t i e n t s , a n a v e r a g e s a v i n g o f ~ 6 9 . 2 3 p e r p a t i e n t( T a b l e 1). T h e m e a n c o s t p e r p a t i e n t s f o r t h e E U S -b a s e d s t r a t e g y w a s ~ 3 7 4 . 5 0 ( + 28 4 .7 2 ). T h e t h e o r e t -i c al m e a n c o s t p e r p a t i e n t f o r t h e E R C - b a s e d s t r a t -e g y w a s ~ 4 4 3 . 8 0 ( p < 0 .0 0 1 ) .O n e - w a y s e n s i ti v i t y a n a l y s i s s u g g e s t s t h a t t h el e a s t c o s t l y d i a g n o s t ic s t r a t e g y c h a n g e s a s t h e r i s k o fb i le d u c t s t o n e s i n c r e a s e s f r o m 0 % to 1 0 0 % , a n d f r o m0 % t o 6 0 . 6% E U S i s l e s s c o s t l y t h a n E R C ( Fi g. 4 ); t h et h r e s h o l d ( in t e r m s o f t h e r i s k o f b i l e d u c t s t o n e s ) f o rw h i c h t h e c o s t s o f t h e E U S a n d E R C s t r a t e g ie s a r ei d e n t i c a l i s t h e r e f o r e 6 0 . 6 % ; a n d f o r a l l l e v e l s o f r i s kg r e a t e r t h a n 6 0 .6 % E R C i s l e a s t c o s tl y.

D I S C U S S I O NT h e s e l e ct i o n o f p a t i e n t s f o r E R C / E S T b y u s i n g

c o m m o n l y a v a i la b l e , n o n i n v a s i v e d i a g n o s t i c t e s t s( i . e . , c l i n i c a l , b i o c h e m i c a l , s o n o g r a p h i c ) h a s l i m i t e dr e l ia b i l it y , a s c o n f i r m e d b y t h e p r e s e n t s t u d y . I n ag r o u p o f p a t i e n t s d e f i n e d p r e i n t e r v e n t i o n a s a ti n t e r m e d i a t e o r h i g h r i sk , t h e p r o p o r t i o n w i t h c h o le -d o c h o l i t h i a s i s w a s 5 2 % .T h e c u r r e n t a p p r o a c h t o p a t i e n t s w i t h s u s p e c t e db i le d u c t s t o n e s is c h a r a c t e r iz e d b y a h i g h n u m b e r o fu n n e c e s s a r y E R C p r o c e d u r e s . T h i s p r o c e d u r e , u n t i ln ow , h a s b e e n c o n s i d e r e d th e s t a n d a r d s t u d y f o ri m a g i n g t h e b i l e d u c t . H o w e v e r , t h e c o m p l i c a t i o nr a t e a s s o c i a t e d w i t h E R C i s s i g n if i c a n t; t h e r e i s a na p p r e c i a b l e m o r t a l i t y r a t e a s w e l l . L a r g e p r o s p e c -t i v e c a s e s e r i e s h a v e f o u n d o v e r a l l c o m p l i c a t i o nr a t e s o f 5 % t o 6% a n d m o r t a l i t y r a t e s o f 0 . 07 % t o0 . 1 % a f t e r d i a g n o s t i c E R C .1 8,1 9 A l a r g e m u l t i c e n t e rs t u d y f r o m I t a l y f o u n d a m a j o r c o m p l i c a t io n r a t e o f1 .3 % a n d a m o r t a l i t y r a t e o f 0 . 2% f o r d i a g n o s t i cE R C . 2o M o r e o v e r , t o a r r i v e a t a d i a g n o s i s o f b i l e d u c ts t o ne s , a c e r t a in n u m b e r o f E R C p r o c e d u r e s m u s t b ec o m p l e t e d w i t h E S T , w h i c h h a s a c o m p l i c a t io n r a t er a n g i n g b e t w e e n 7 % a n d 1 0 % 21,22 a n d a r e p o r t e dm o r t a l i t y r a t e o f 0 . 2% t o 2 . 2 % . 2 2 ,2 3

R e p o r t e d r a te s o f p a n c r e a t i t i s a f t e r E R C a n d E S Tr a n g e d f r o m 0 % t o 40 % , a l th o u g h a f ig u r e o f a b o u t5 % i s t y p i c a l. 21 P a n c r e a t i t i s i s a n e x t r e m e l y u n d e -s i r a b le c o m p l i c a ti o n t h a t c a n b e s e v e r e a n d p r o -l o ng e d ; t h i s w a s t h e w o r s t E R C - r e l a t e d c o m p l i c a t io ni n t h e p r e s e n t s t u d y , a n d i t o c c u r r e d i n a p a t i e n tw h o p r o v e d t o b e f r e e o f s t o n e s. C o m p l i c a t i o n s o fE S T u s u a l l y d e v e l o p i m m e d i a t e l y o r s h o r t l y a f t e rt h e p r o c e d u r e , a l t h o u g h l o n g - t e r m s e q u e l a e m a ya l s o o c c u r . I n o n e l o n g - t e r m f o l l o w - u p s t u d y , s t e n o -s is , n e w s t o n e s a n d n o n o b s t r u c t i v e c h o l a n g it i s w e r ef o u n d i n 1 3 % o f p a t i e n t s 6 t o 1 1 y e a r s a f t e r E S T . 24I n a n o t h e r s t u d y in w h i c h p a t ie n t s w h o h a d E S Tw e r e f o l l o w e d f o r 15 t o 1 7 y e a r s , a s u b s t a n t i a l p r o -p o r t i o n h a d b a c t e r i a l c o n t a m i n a t i o n o f t h e b i l i a r y

1200

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E U S f o r s u s p e c t e d c h o l e d o c h o l i th i a s i s: b e n e f i ts v s. c o s t s E B u s c a r i n i , P T a n s i n i , D V a l l is a , e t a l .

~E U S

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e o . 5 1 0 0 . 0 0R I S K

F i g u r e 4 . One-way sensi t iv i ty analys is. Mean cost(expressed in euros) of EUS and ERC strategies versus r iskfrom 0% to 1 00% of choledocholithiasis.t r e e a t t r i b u t e d t o th e p e r m a n e n t l o ss o f t h e b i l i a r ys p h i n c t e r . 25 T h e s e e a r l y a n d l o n g - t e r m s e q u e l a er e i n f o rc e t h e n e e d t o a v o id i n a p p r o p r i a t e E S T .B a s e d o n a s t u d y o f c l a im s f o r c o m p e n s a t i o n o fs e v e r e a n d f a t a l c o m p l i c a t i o n s a f t e r d i a g n o s t i c a n dt h e r a p e u t i c E R C , i n c l u d i n g 9 f a t a l it i e s , T r a p e t a l . 2 6e m p h a s i z e d t h e n e e d t o b e t t e r d e f i n e th e i n d i c a t io n sf o r E R C , e s p e c i a ll y b e c a u s e E R C w a s n o r m a l i n 6 o ft h e 9 f a t a l c a s e s . 26

A n a l t e r n a t i v e t o t h e c u r r e n t a p p r o a c h t o t h ed i a g n o s i s o f c h o l e d o c h o l i t h ia s i s i s t h u s n e e d e d , i d e -a l l y o n e t h a t r e s u l t s i n r e f e r r a l o f o n l y th o s ep a t i e n t s w i t h b i l e d u c t s t o n e s f o r E R C / E S T . S t u d i e sc o m p a r i n g E U S a n d E R C h a v e i n v a r ia b l y c o n c lu d e dt h a t a b e t t e r m e t h o d i s n e e d e d t o r e d u c e u n c e r t a i n -t y i n t h e d i a g n o s i s o f c h o l e d o c h o li t h ia s i s a n d t h a tE U S h a s t h i s p o t e n t i a l a n d s h o u l d t h e r e f o r e r e p la c eE R C f o r d i a g n o s t i c p u r p o s e s . 6 , S , 1 0 , 1 2 - 1 4 , 2 7 T o o u rk n o w l e d g e , t h e p r e s e n t s t u d y i s u n i q u e i n t h a t i t i st h e f i r st la r g e s t u d y t o u s e E U S i n a n a l g o r i t h m f o rs e l e c t i o n o f p a t i e n t s f o r E R C / E S T .

T r a n s a b d o m i n a l U S , t h e n o n i n v a s iv e p r o c e d u r ec o m m o n l y u s e d f i r s t in p a t i e n t s w i t h e x t r a h e p a t i cc h o l e s t a s i s, h a s a l o w s e n s i t i v i t y f o r c h o le d o c h o l i th -i a s is . 28 N e w i m a g i n g t e c h n i q u e s , s u c h a s s p i r a l C Ta n d m a g n e t i c r e s o n a n c e c h o l a n g i o g r a p h y ( M R C ) ,o f fe r a h i g h e r d e g r e e o f s a f e t y t h a n E R C w h e n c h o-l e d o c h o l i t h i a s i s i s s u s p e c t e d . S t u d i e s o f t h e u s e o fs p i r a l C T r e p o r t e d t h u s f a r i n c lu d e o n l y l im i t e dn u m b e r s o f p a t i e n t s w i t h r e s u l t s i n f e r io r t o E U S( s e n s i t i v i t y 8 5 % - 8 8 % , s p e c i f i c it y 8 8 % - 9 7% , d i a g n o s -

V O L 'U M E 5 7, N O . 4, 2 00 3 G A S T R O I N T E S T I N A L E N D O S C O P Y 5 1 5


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E B u s c a r i n i , P T a n s i n i , D V a l l is a , e t a l . E U S f o r s u s p e c t e d c h o l e d o c h o l i t h i a s is : b e n e f i ts v s. c o s t s

t i c a c c u r a c y 8 6 % - 9 4 % ) . 2 9,30 A f u r t h e r d r a w b a c k o fC T i s t h e n e e d fo r a c o n t r a s t m e d i u m . M R C , d e s p i teb e i n g c o m p l e te l y n o n in v a s i v e, h a s b e e n c o m p a r e dw i t h E U S i n re l a t i v e l y f e w p a t i e n t s w i t h s u s p e c t e dc h o l e d o c h o l i th i a s i s. I t s m e t h o d o l o g y i s n o t y e t f u l l ys t a n d a r d i z e d a n d v a r i o u s e x a m i n a t i o n p r o to c o l se x is t , m a k i n g t h e i n t e r p r e t a t i o n o f r e s u l t s s o m e -w h a t d i f f ic u l t. E U S o f f e r s h i g h e r r e s o l u t i o n ( 0 . 1 m mv s . 1 . 5 m m ) , w h i c h e x p l a i n s t h e l o w e r s e n s i t i v i t y o fM R C f o r s m a l l s t o n e s a s c o m p a r e d w i t h E U S . 31M o r e o v e r , i n c o n t r a s t t o E U S , s o m e b l i n d z o n e s e x i s tf o r M R C , n o t a b l y t h e p a p i l l a r y a n d p e r i p a p i l l a r yr e g i o n . I n d e e d , t h e d i a g n o s i s o f c h o l e d o c h o l i t h i a s i sb y M R C i s l e s s s a t is f a c t o r y t h a n b y E U S . S e n s i t iv i t yw a s o n l y 4 0 % i n o n e s t u d y , 32 a l t h o u g h i n o t h e r s t h es e n s i t i v i t y h a s r a n g e d f r o m 8 1 % t o 9 2 % , s p e c i f i c i t yf r o m 9 4 % t o 9 8% , a n d a c c u r a c y i s a b o u t 9 4 % . 3 3- 35 Ac o m p a r i s o n s t u d y o f E U S v e r s u s M R C f o r t h e d i a g -n o s i s o f c h o l e d o c h o l i t h i a s i s f o u n d b e t t e r r e s u l t s f o rE U S ( f o r E U S v s . M R C , r e s p e c t i v e l y , sp e c i f i c it y , 9 5 %v s . 7 2 % ; p o s i t i v e p r e d i c t i v e , 9 0 % v s . 6 2 % ; n e g a t i v ep r e d i c t i v e , 1 0 0 % v s . 9 6 % ) . 3 6 T h e s e i n v e s t i g a t o r s c o n-c l u d e d t h a t M R C c a n b e u s e d w h e n t h e r e i s a c o n-t r a i n d ic a t i o n t o E U S .E U S i s t h u s t h e s i n g l e b e s t i m a g i n g t e c h n i q u e f o rb i le d u c t s to n e s . It h a s i m p o r t a n t a d d i t i o n a l a d v a n -t a g e s. E U S i s th e o n l y i m a g i n g t e c h n i q u e c a p a b l e o fe a s i l y d e t e c t i n g b i l e d u c t s l u d g e . M o r e o v e r , i t p e r -m i t s i d e n t i f i c a t i o n o f g a l l s t o n e s a s w e l l a sm i c r o l it h i a si s m i s s e d b y t r a n s a b d o m i n a l U S , fi nd -i n g s o f c l in i ca l r e l e v a n c e f o r m a n a g e m e n t o f u n e x -p l a i n e d a c u t e p a n c r e a t i t i s . 37-39 E U S c a n d e t e c tp a t h o l o g ic d i s o r d e r s t h a t a r e p o o r l y e v i d e n t ( i f a ta ll ) a t E R C P . E U S b e f o r e E R C a l s o e n h a n c e s t h ee f fi c a cy o f t h e l a t t e r b y e n c o u r a g i n g t h e u s e o fa g g r e s s i v e t e c h n i q u e s w h e n a p p r o p r i a t e ( e.g ., p r e -c u t p a p il lo t o m y ) . T h e p r e s e n t s t u d y c o n f i r m s t h eh i g h d i a g n o s t i c a c c u r a c y o f E U S f o r d e t e c t i n g c h o le -

9 d o c h o l i t h ia s i s ; a c c u r a c y i s i n d e p e n d e n t o f b i l e d u c ts t o n e s i z e , b e i n g h i g h l y s e n s i t i v e e v e n f o r s to n e s l e s st h a n 5 m m i n d ia m e t e r. F e w E U S p r o c e d u r e s w e r eu n s u c c e s s f u l . T h e s a f e t y o f t h e p r o c e d u r e i s a ls od e m o n s t r a t e d i n th i s l a r g e s e r ie s , i n w h i c h n o E U S -r e l a t e d c o m p l i c at i o n s w e r e e n c o u n t e r e d .

T h e m a j o r a i m o f t h e p r e s e n t s t u d y , a r e d u c t i o n i ni n a p p r o p r i a t e i n v a s i v e e v a l u a t i o n o f t h e b i le d u c t ,w a s a c h i e v e d i n 4 6 % o f t h e p a t i e n t s . T h e s t u d y g r o u pi n c l u d e d p a t i e n t s a t i n t e r m e d i a t e t o h i g h r i s k f o r b i led u c t s t o n e s b a s e d o n c l i n i c a l p a r a m e t e r s . T h e m a i nc l in i c al i m p a c t o f E U S f o r t h e d i a g n o s i s o f b i l e d u c ts t o n e s w a s , t h e r e f o r e , a s u b s t a n t i a l r e d u c t i o n i n t h eu s e o f E R C a n d c o n s e q u e n t ly f e w e r E R C - r e l a te dc o m p l i c a t io n s i n p a t i e n t s w i t h s u s p e c t e d b i l e d u c ts t o n e s . T h u s , E U S s h o u l d b e a p p l i e d n o t o n l y i np a t i e n t s a t l o w o r i n t e r m e d i a t e r i s k ( a s p r e v i o u s l y

s u g g e s t e d ) 13 b e c a u s e t h e p e r c e n t a g e o f h i g h - r i s kp a t i e n t s w h o h a v e s t o n e s i s n o t a l w a y s s u b s t a n t i a l.

T h e E U S - b a s e d s t r a t e g y i n t h e p r e s e n t s t u d y w a ss i g n i fi c a n t ly m o r e c o s t -e f f e c ti v e t h a n a s t r a t e g yb a s e d o n th e u s e o f E R C a lo n e . I n t h e s t u d y o f P r a te t a l. , s t h e c o s t o f d i a g n o s t i c o p t i o n s b a s e d o n t h ep r e l i m i n a r y u s e o f E U S f o r t h e d i a g n o s i s o f b i le d u c ts t o n e s ( a s i n th e p r e s e n t s t u d y ) w a s c a l c u l a t e d i n ah y p o t h e t i c a l p o p u l a t i o n . T h e s e i n v e s t i g a t o r s c o n -c l u d e d t h a t t h e E U S s t r a t e g y w a s m o r e e x p e n s i v et h a n t h e E R C a p p r o a c h , e v e n w i t h a d e c r e a s e inh o s p i t a l s t a y f o r p a t i e n t s w h o h a d E U S . I n t h a ts tu d y , t h e c o s t o f t h e E U S p r o c e d u r e w a s c o n s i d e re dt o b e g r e a t e r t h a n t h a t f o r E R C . T h is d i s c r e p a n c ym a y r e f l e c t v a r i a b l e s p e c u l i a r t o a g i v e n c o u n t r y( e. g. , d u r a t i o n o f t h e e x a m i n a t i o n , t y p e o f s e d a t i o n ,p r e s e n c e o f a n a n e s t h e t i s t ) . I n o u r e x p e r i e n c e E U Sf o r c h o l e d o c h o l i t h ia s i s r e q u i r e d a n a v e r a g e o f 2 2m i n u t e s ; m i l d s e d a t i o n w a s g e n e r a l l y s u f f i c i e n t .M o r e o v e r , i n t h e p r e s e n t s t u d y c a l c u l a t i o n s f or E R C -r e l a t e d c o s t s w e r e c o n s e r v a t i v e : t h e e s t i m a t e o f c o s t sr e l a t e d t o E R C c o m p l i c a t i o n s a p p l i e s o n l y t o t h em a j o r u n t o w a r d e v e n t s , a n d t a k e s i n t o a c c o u n t o n l yt h e c o s t o f m i n i m a l p r o l o n g a t i o n o f h o s p i t a l s t a y ( 1 1d a y s ) a n d n o t t h e a d d i t i o n a l c o s t s o f p o s s i b l e s u r g i c a lt r e a t m e n t , i n t e n s i v e c a r e , b l o o d t r a n s f u s i o n , a n do t h e r f o r m s o f s u p p o r t . P o t e n t i a l m o r t a l i t y a n d l e g a le x p e n s e s w e r e n o t f a c t o r e d i n to t h e c o s t c a lc u l a ti o n s .M o r e o v e r , a n i n t a n g i b l e c o s t , i m p o s s i b l e t o q u a n t i f y ,y e t a r g u a b l y t h e m o s t i m p o r t a n t , i s t h e s i g n i f i c a n tl o s s in q u a l i t y o f l if e a r i s i n g f r o m c o m p l i c a t io n s , u s u -a l l y t r a n s i e n t , a l t h o u g h i n s o m e c a s e s r e s u l t i n g i np e r m a n e n t d i s a b il i ty . 4 ~

If , c o m p a r e d w i t h t h e c o n s e r v a t i v e e s t i m a t e o fE R C c o st s, t h e E U S - b a s e d s t r a t e g y p r o v e d e v e nm o d e r a t e l y c o s t- e ff e c ti v e, t h e e c o n o m i c a d v a n t a g e o fE U S w o u l d b e c o n s i s t e n t l y g r e a t e r i n m o s t c l i n i c a ls c e n a r i o s . A c c o r d i n g t o o u r s e n s i t i v i t y a n a l y s i s t h ec o s t o f t h e E U S a n d E R C s t r a t e g i e s w o u l d b e id e n -t i c a l w h e n t h e r i s k o f c h o l e d o c h o l i t h i a s is i s 6 0 . 6% ,w h i c h i s g r e a t e r t h a n p r o p o r t io n o f p a t i e n t s w i t hs t o n e s g e n e r a l l y f o u n d b y u s e o f c li n i c a l p r e d i c t o r s . 4-7H o w e v e r , t h e s e n s i t i v i t y a n a l y s i s r e s u l t s d e p e n d o nt h e c o s t d a t a u s e d . T h e s e c o s t s p e r t a i n t o o u r c e n te r ;a c t u a l v a l u e s w i ll li k e l y d i f f e r i n o t h e r c o u n t r i e s a n dd i f f e r e n t h e a l t h s y s t e m s . O t h e r c r i t i c a l f a c t o r s t h a ti n f lu e n c e c o s t a r e t h e E R C c o m p l i c a t io n r a t e f o r t h ei n d i v i d u a l c e n t e r a n d p e r f o r m a n c e o f E R C o n a no u t p a t i e n t b a s is . T h e f i g u r e s u s e d i n t h e p r e s e n ts t u d y a r e b e l i e v e d t o r e a s o n a b l y r e p r e s e n t I t a l i a na n d E u r o p e a n s e t t i n g s .O p t i m a ll y , E U S a n d E R C , a s in d i c a t e d b y t h eE U S f i n d in g s , s h o u l d b e p e r f o r m e d o n t h e s a m e d a y.T h u s , w i t h p r o p e r o r g a n i z a t i o n E U S n e e d n o t p r o -l o n g h o s p i t a l s t a y ; m o r e o v e r , i n s o m e c a s e s E U S c a n

5 1 6 G A S T R O I N T E S T I N A L E N D O S C O P Y V O L U M E 5 7, N O . 4, 2 0 03


8/9

E U S f o r s u s p e c t e d c h o l e d o c h o l i th i a s i s: b e n e f i t s v s. c o s t s E B u s c a r i n i , P T a n s i n i , D V a l l is a , e t a l .

b e p e r f o r m e d o n a n o u t p a t i e n t b a s i s . F r o m a t ec h n i -c a l s t a n d p o i n t , p a t i e n t s w i t h s u s p e c t e d b i le d u c ts t o n e s s h o u l d u n d e r g o E U S i n s p e c i a l i z e d c e n t e r sw h e r e t h e r e i s a d e q u a t e e x p e r ie n c e w i t h b o t h E U Sa n d E R C / E S T . T h e a c c u r a c y o f E U S c l e a r l y d e p e n d so n o p e r a t o r s k i ll , b u t s u c h p r o c e d u r a l s k i l ls a r ee q u a l l y c r u c i a l f o r p e r f o r m a n c e o f E R C . 41

U s e o f E U S a s a p r e l i m i n a r y d i a g n o s t ic i m a g i n gs t u d y i n p a t i e n t s w i t h s u s p e c t e d b i le d u c t s t o n e sa v o i d s a c o n s i d e r a b le n u m b e r o f u n n e c e s s a r y i n v a -s i v e p r o c e d u r e s . T h i s s u b s t a n t i a l c l in i c a l a d v a n t a g ei s a c h i e v e d a t n o a d d i t i o n a l c o s t , b u t , o n t h e c o n -t r a r y , w i t h c o s t s a v in g s .

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E Buscarini, P Tansini , D VaUisa, et al. EU S for suspected choledocholithiasis: benefits vs. costs

t e c h n i q u e s : p r o s p e c t i v e c o m p a r i s o n w i t h e n d o s c o p i c r e t r o -grade cho lang iography . Rad io logy 1998;206:657-64 .3 5. M a t e r n e R , v a n B e e r s B E , G i g o t J F , J a m a r t J , G e u b e l A ,P r i n g o t J , e t a l . E x t r a h e p a t i c b i l i a r y o b s t r u c t io n : m a g n e t i cr e s o n a n c e i m a g i n g c o m p a r e d w i t h e n d o sc o p ic u l t r a s o n o g r a -phy . En dosco py 2000;32 :3-9 .3 6 . d e L e d in g h e n V , L e c e s n e R , R a y m o n d J M, G e n s e V , A m o u re t t iM, D r o u i l l a r d J , e t a l . D ia g n o s i s o f c h o le d o c h o l i th i a s i s : E U So r m a g n e t i c r e s o n a n c e c h o l a n g i o g r ap h y ? A p r o s p e c t i v e co n-t ro l l e d s tu d y . G a s t ro in t e s t E n d o s c 1 9 99 ;4 9 :2 6 -3 1 .3 7 . D i l l J E , C a U ls J , B e rk h o u s e L , E v a n s P , Ma r t in D , P a lm e r S T .C o m b i n e d e n d o sc o p i c u l t r a s o u n d a n d s t i m u l a t e d b i l i a r yd r a i n a g e i n c h o l e c y s t i ti s a n d m i c r o l i t h i a s i s - - d i a g n o s e s a n doutcom es . Endo scopy 1995;27 :424-7 .

3 8 . C h a k A , H a w e s R H , C o o p e r G S , H o f f m a n B , C a t a l a n o M F ,W o n g R C K , e t a l . P r o s p e c t iv e a s s e s s m e n t o f t h e u t i l i t y o f E U Si n t h e e v a l u a t i o n o f g a l l s t o n e p a n c r e a t i t i s . G a s t r o i n t e s tEndosc 1999;49:599-604.3 9 . L iu C L , L o C M, C h a n J K , P o o n R T , L a in C M, F a n S T , e t a l .D e te c t io n o f c h o le d o c h o l i th i a s i s b y E U S in a c u te p a n c re a t i t i s :a p r o s p e c t i v e e v a l u a t i o n i n 1 00 c o n s e c u t i v e p a t i e n t s .Gas tro in tes t Endosc 2001;54 :325-30 .4 0 . S a v a d e r S J , L i l l e m o e K D , P re s c o t t C A , Win ic k A B , V a n b ru xA C , L u n d G B , e t a l . L a p a r o s c o p i c c h o l e c y s t e c t o m y - r e l a t e db i l e d u c t i n j u r i e s. A h e a l t h a n d f i n a n c i a l d i s a s te r . A n n S u r g1997;225:268-73.4 1 . B a i l l i e J . E R C P t r a in in g fo r t h e f ew , n o t fo r a l l . G u t 1 9 99 ;4 5 :9-10 .

A v a i l a b i l i t y o f J o u r n a l b a c k i s s u e sA s a s e r v i c e t o o u r s u b s c r i b e r s , c o p i e s o f b a c k i s s u e s o f Gastrointestinal Endoscopy f o rt h e p r e c e d i n g 5 y e a r s a r e m a i n t a i n e d a n d a r e a v a i l a b l e f o r p u r c h a s e f r o m M o s b y u n t i li n v e n t o r y i s d e p l e t e d . P l e a s e w r i t e t o M o s b y , S u b s c r i p t i o n C u s t o m e r S e r v i c e , 6 2 7 7 S e aH a r b o r D r . , O r l a n d o , F L 3 2 8 8 7 o r c a l l 8 0 0 - 6 5 4 -2 4 5 2 o r 4 0 7 -3 4 5 - 4 0 0 0 f o r i n f o r m a t i o no n a v a i l a b i l i t y o f p a r t i c u l a r i s s u e s a n d p r ic e s .

518 GASTR OINT ESTIN AL ENDOSCOPY VOLUME 57, NO. 4, 2003

eus for suspected choledocholithiasis: do benefits outweigh costs? a prospective, controlled study

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