Ultrasound scoring system for acute appendicitis in pediatric patients: A useful tool for the surgeon

Abstract

BACKGROUND: the aim is evaluate new US signs, other than the already known (primary and secondary), that are positive correlated with histophatological results in pediatric appendicitis. METHODS: Forty pediatric patients (4-18 years old) with clinical suspicious of appendicitis, examinated with convex, microconvex and linear probe. RESULTS: We observed a negative linear correlation both univariate and multivariate analysis between numbers of layers and maximal outer diameter. CONCLUSIONS: is possible to consider the number of layers and the echogenicity pattern of each layer as a further ultrasonography diagnostic sign in case of acute appendicitis.

Full text

VOL. 176
· No. 11
NOVEMBER 2017

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ORIGINAL ARTICLE
ORAL AND GASTROINTESTINAL DISEASES: IMAGING STATE OF THE ART
AND PSYCHOPATHOLOGICAL FEATURES

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4BEC<%2!%_%4BEC<%22 ^$^^%c&$^^d 5KB<A>B# = -0.094; P value= 0.573
4BEC<%2!%_%4BEC<%222 )^$^Mb%c^$'lbd 5KB<A>B# = -0.073; P value= 0.663
*Signcant tests.
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Results
/I><AE)F>R% "PA% "L% M^% KBA>C?AF% IB=% B% 071%
](DDQ%b^%"L%AICD%IB=%B%071%]'DD$
/IC% DBR>DPD% 071% SB#PC% <C@>FAC<C=% NBF%
bh$:DD%>?%B%&h%ECB<F%"#=%DB#C%N>AI%nPFA%"?C%
IEKC<%#BEC<%cDBR%=>BDCAC<%NBF%?C@BA>SC%F>@?>L)
>;B?A% K<C=>;A"<% "L% *$"L% #BEC<FdQ% AIC% D>?>DPD%
071%SB#PC%NBF%bDD%>?%B%&:%ECB<F%"#=%LCDB#CH%
with a hypo-hyper-hypo wall stratication and
N>AI%B% ;"#"<)1"KK#C<%F>@?B#%"L%gg$%.#CSC?%"PA%
"L%M^%IB=%B%K"F>A>SC%3"#"<1"KK#C<%F>@?B#%cD>?)
>DPD%^)%DBR>DPDd$
Figure 3.—Signicant linear correlation graph between max
=>BDCAC<%B?=%*$%#BEC<F%N>AI%K<C=>;A%>?AC<SB#%BA%l:`$%/IC%K<C)
=>;A%>?AC<SB#%BA% l:`% NBF%<CK<CFC?AC=%JE% AN"% ;P<SCF$%/ICFC%
;P<SCF%<CK<CFC?A%AIC%l:`%K<C=>;A>"?%>?AC<SB#%L"<%AIC%<C@<CF)
F>"?%;P<SC$
Table III.—Univariate and multivariate linear correlation analysis among age, sex, max diameter, vascularization
and N. layers.
G?>SB<>BAC%B?B#EF>F 0P#A>SB<>BAC%B?B#EF>F
8B<BDCAC<F 5%c8%SB#PCd
Multiple linear correlation coefcient = 0.483
,@C%_%9CR )^$bh:%c^$^&Madg 5KB<A>B# = -0.268; P value= 0.108
,@C%_%DBR%=>BDCAC< ^$&lb%c^$a&^d 5KB<A>B# = 0.301; P value= 0.070
,@C%_%!BF;P#B<>TBA>"? ^$&'&%c^$&l&d 5KB<A>B# = 0.113; P value= 0.506
,@C%_%*<$%4BEC<F ^$MM&%c^$&&bd 5KB<A>B# = 0.172; P value= 0.310
Multiple linear correlation coefcient = 0.495
9CR%_%,@C )^$bh:%c^$^&Madg 5KB<A>B# = -0.268; P value= 0.108
9CR%_%DBR%=>BDCAC< )^$&&h%c^$M(ld 5KB<A>B# = -0.198; P value= 0.241
9CR%_%!BF;P#B<>TBA>"? )^$a&(%c^$&h&d 5KB<A>B# = -0.136; P value= 0.421
9CR%_%*<$%4BEC<F )^$a'l%c^$^had 5KB<A>B# = -0.296; P value= 0.075
Multiple linear correlation coefcient = 0.606
DBR%=>BDCAC<%_%,@C ^$&lb%c^$a&^d 5KB<A>B# = 0.301; P value= 0.070
DBR%=>BDCAC<%_%9CR )^$&&h%c^$M(ld 5KB<A>B# = -0.198; P value= 0.241
DBR%=>BDCAC<%_%!BF;P#B<>TBA>"? )^$^h(%c^$:lld 5KB<A>B# = -0.072; P value= 0.672
DBR%=>BDCAC<%_%*<$%4BEC<F )^$MhM%c^$^^&(dg 5KB<A>B# = -0.554; P value= 0.0004*
Multiple linear correlation coefcient = 0.285
!BF;P#B<>TBA>"?%_%,@C ^$&'&%c^$&l&d 5KB<A>B# = 0.113; P value= 0.506
!BF;P#B<>TBA>"?%_%9CR )^$a&(%c^$&h&d 5KB<A>B# = -0.136; P value= 0.421
!BF;P#B<>TBA>"?%_%DBR%=>BDCAC< )^$^h(%c^$:lld 5KB<A>B# = -0.072; P value= 0.672
!BF;P#B<>TBA>"?%_%*<$%4BEC<F ^$a^&%c^$a&:d 5KB<A>B# = 0.083; P value= 0.624
Multiple linear correlation coefcient = 0.612
*<$#BEC<F%_%,@C ^$MM&%c^$&&bd 5KB<A>B# = 0.172; P value= 0.310
*<$#BEC<F%_%9CR )^$a'l%c^$^had 5KB<A>B# = -0.296; P value= 0.075
*<$#BEC<F%_%DBR%=>BDCAC< )^$MhM%c^$^^&(dg 5KB<A>B# = -0.554; P value= 0.0004
*<$#BEC<F%_%!BF;P#B<>TBA>"? ^$a^&%c^$a&:d 5KB<A>B# = 0.083; P value= 0.624
*Signicant tests.

G4/5,97G*1%93752*+%9j9/.0%X75%,3G/.%,88.*1232/29%2*%8.12,/523%8,/2.*/9% 12%+5.-2,
!"#$%&'(%)%*"$%&&% +,--.//,%0.123,%2/,42,*,%)%,5362!27%8.5%4.%932.*-.%0.1236.% :':
K<C=>;AF%B;PAC%BKKC?=>;>A>F$%7AIC<%;<>AC<>B%FP;I%
BF% =>BDCAC<% FI"P#=% JC% BS">=C=Q% =>BDCAC<H%
?"?);"DK<CFF>J>#>AEH% IEKC<CD>BH% K<CFC?;C% "L%
appendicolith, loss of stratication of the ap)
KC?=>;CB#% NB##% ="% ?"A% >?=CKC?=C?A#E% K<C=>;AF%
BKKC?=>;>A>F$a^
[C%L"P?=C=%"AIC<%BFKC;AF%A"%;"?F>=C<%=P<>?@%
AIC%P#A<BF"P?=%CRBD>?BA>"?H%>C%AIC%C;I"@C?>;>)
AE%_%AI>;OC?>?@%"L%AIC%BKKC?=>;CB#%NB##$
8B<A>;P#B<#EU
%—BA%AIC%>?;<CBFC%"L%DBR>DPD%BKKC?=>;P)
#B<%=>BDCAC<%AIC<C% >F% B?% >?;<CBFC%>?%AIC% AI>;O)
?CFF_C;I"@C?>;>AE%"L%AIC%CRAC<?B#% #BEC<% N>AI%B%
=C;<CBFC%"L%AI>;OC?CFF%"L%AIC%FC;"?=%#BEC<Q
%—AIC% DBR>DPD% =>BDCAC<% >F% D"<C% K<CSB)
#C?A% >?% DB#C% K"KP#BA>"?% ;"DKB<C=% A"% LCDB#C%
@<"PK%B?=%AI>F%=BAC%>F%;"?F>FAC?A%N>AI%#>AC<BAP<C%
CRKC<>C?;CQ
%—@C?=C<% ="CF% ?"A% BLLC;A% AIC% ?PDJC<% "L%
#BEC<F%JPA%"?#E%AIC%SBF;P#B<>TBA>"?%cX]0dQ
%—the most representative stratication
KBAAC<?%JBFC=%"?%#BEC<%C;I"@C?>;>AE%B<CU
&d%&'%IEK")IEKC<)IEK"Q
ad% l% IEK")IEKC<)=>F"D"@C?CPFH% ;"?)
sistent with “target sign” (3 layers= hypo:
DPF;"#B<>F%DP;"FBC%)%IEKC<U% DP;"FBC_FPJ)
DP;"FBC% s% IEK"_B?C;"@U% >?A<BKKC?=>;P#B<%
uid);
%—max diameter was negative signicant
K<C=>;A"<%"L%*<$%#BEC<F%>$C$%B?%>?;<CBF>?@%"L%=>)
BDCAC<% NBF% ;"<<C#BAC=% N>AI% B% =C;<CBFC% >?% AIC%
?PDJC<%"L%#BEC<F$a&)ab
/IC<C%>F%B%SB#>=%FABA>FA>;%;"<<C#BA>"?%JCANCC?%
AIC%K<CFC?;C%"L%B;PAC%BKKC?=>;>A>F%B?=%"?C%"L%
the stratication pattern, independently from
AIC%DBR>DPD%BKKC?=>;P#B<%=>BDCAC<%B?=%3"#)
"<1"KK#C<%F>@?B#%F;"<C$
/I>F%;"P#=%JC%<C#BAC=%N>AI%AIC%KIEF>"KBAI")
logic mechanism of inammation (vasocon)
FA<>;A>"?H% SBF"=>#BABA>"?H% C=CDBH% ;ICD"ABR>FH%
CRP=BACd%B?=%N>AI%AIC%A>DC%"L%G9%CRC;PA>"?$aa
/IC%=>B@?"F>F%"L%B;PAC%BKKC?=>;>A>F%>?%KC=>)
BA<>;%K"KP#BA>"?% >F% "LAC?% IB<=% B?=%B% D"FA% G9%
specic sign does not exist, but one or more
US ndings can orient the diagnosis.
It is not always possible to conrm the clini)
;B#%FPFK>;>"?%"L%B;PAC%BKKC?=>;>A>F%N>AI%<B=>")
#"@>;B#%G9%>DB@>?@%AC;I?>YPCH%JBFC=%"?%<CB=)
>?@%AIC% 071% B#"?C% "<% BFF";>BA>?@%N>AI% "AIC<%
cularity of normal and inamed appendix may
JC%=>LLC<C?AH%AI>F%=>LLC<C?;C%NBF%?"A%B%@""=%=>)
B@?"FA>;%>?=>;BA"<%"L%BKKC?=>;>A>F$a&H%aa
[C% L"P?=% AIC% K<CFC?;C% "L% >?A<BKC<>A"?CB#%
uid just in 4 patient and so neither the quan)
A>AE%?"<%AIC%AEK"#"@E%NBF%<CK"<AC=Q%>?%"?#E%"?C%
;BFC%NC%L"P?=%B?%BKKC?=>;"#>AI$
Discussion
8PE#BC<A%K<"SC=H%>?%AIC%&lh(H%AIBA%AIC%V>=C?)
tication in RLQ of a non-compressible blind)
C?=>?@%FA<P;AP<C%N>AI%B?%"PAC<%=>BDCAC<%@<CBAC<%
AIB?%(%DDW%c@<B=C=%;"DK<CFF>"?d%>F%=>B@?"F)
A>;%L"<%BKKC?=>;>A>F$&(
This diagnostic approach was conrmed in
AIC%a^^MU%V,%AI<CFI"#=%(%DD%=>BDCAC<%"L%AIC%
BKKC?=>R%P?=C<%;"DK<CFF>"?%>F%AIC%D"FA%B;;P)
rate US nding for appendicitis and has high
*8!%B?=%88!W$&'
8<>DB<E% ;<>AC<>"?% L"<% AIC% G9% =>B@?"F>F% "L%
BKKC?=>;>A>F%>F% B?% BKKC?=>;CB#%DBR>DB#% "PAC<%
=>BDCAC<% c071d% C?#B<@CDC?A% JCE"?=% (% DD%
(most specic sign). Secondary criteria in)
;#P=C% KC<>)BKKC?=>;CB#% IEK"C;I">;% IB#"% BF)
F";>BAC=% N>AI% NB##% C=CDBH% BKKC?=>;CB#% NB##%
thickness ≥3 mm, wall hyperemia on color
1"KK#C<% CRBDH% C;I"@C?>;% C=CDBA"PF% DCFC?)
AC<>;%LBA%FA<B?=>?@H% B?=%AIC%K<CFC?;C%"L% B?%BK)
KC?=>;"#>AI$
6"NCSC<% >?% AIC% L"##"N>?@% ECB<F% "AIC<% BP)
AI"<F%PA>#>TC=% B% ;PA)"LL%071%"L% '% DD%&h%B?=%
also added other US ndings, for instance
+"#=>?%et al.%<CK"<AC=%AIBAHW%>?;<CBFC=%G9%FC?)
sitivity and specicity for the diagnosis of ap)
KC?=>;>A>F%N"P#=%JC%B;I>CSC=%>L%AIC%=>B@?"FA>;%
criteria were dened as a MOD of ≥7.5 mm
B#"?CH%"<%B%071%<B?@>?@%JCANCC?%($^%B?=%'$M%
DD%N>AI%BA%#CBFA%"?C%FC;"?=B<E%G9%F>@?H%FP;I%
as appendiceal hyperemia, focal uid collec)
A>"?H%K<CFC?;C%"L%B%LC;B#>AIH%B?=_"<%IEKC<C;I">;%
or inamed mesenteric fat. In addition, wall
AI>;O?CFF%B#"?C%D>@IA%JC%B?%>DK"<AB?A%SB<>BJ#C%
BLLC;A>?@%"PA;"DCF$W&l
0"<C"SC<% "AIC<% BPAI"<F% K<"SC=% AIBA% AIC%
MOD specicity was not signicant and ap)
K#>C=%"?#E%AIC%FC;"?=B<E% ;<>AC<>BU% t>?% B% DP#A>)
variate analysis, inammation of periappen)
diceal fat is the only nding that statistically

12%+5.-2,% G4/5,97G*1%93752*+%9j9/.0%X75%,3G/.%,88.*1232/29%2*%8.12,/523%8,/2.*/9
:'(% +,--.//,%0.123,%2/,42,*,%)%,5362!27%8.5%4.%932.*-.%0.1236.% *"SCDJC<%a^&'
A>B@"% 0C=>?B% 4H% 1"<>B%,9% ,;PAC% BKKC?=>;>A>F% >?% E"P?@%
;I>#=<C?U% ;"FA)CLLC;A>SC?CFF% "L% G9% SC<FPF% 3/% >?% =>B@)
?"F>F)% B% 0B<O"S% =C;>F>"?% B?B#EA>;% D"=C#% 5B=>"#"@E%
a^^lXCJQa:^Ub'h)bh(
&a$%.#>OBFIS>#>% 2H%/BE%./H%/FP?@%u[H%/IC% CLLC;A%"L% K">?A)"L)
;B<C% P#A<BF"?"@<BKIE% "?% CDC<@C?;E% =CKB<ADC?A% #C?@IA%
"L%FABE%B?=%;"DKPAC=%A"D"@<BKIE%PA>#>TBA>"?%>?%;I>#=<C?%
N>AI%FPFKC;AC=%BKKC?=>;>A>F%,;B=CD>;%.DC<@C?;E%0C=>)
;>?C%a^&MQa&U&(b)&'^
&b$%8BFA"<C%!H%3";"DBTT>%5H%\BF>#C%,H%8BFA"<C%0H%\B<A"#>%XH%
4>D>AF%B?=% B=SB?AB@CF%"L%BJ="D>?B#% P#A<BF"?"@<BKIE% >?%
;I>#=<C?%N>AI%B;PAC%BKKC?=>;>A>F%FE?=<"DC%,L<>;B?%u"P<)
?B#%"L%8C=>BA<>;%9P<@C<E%a^&M
&M$% \B;IP<%5+H%1BEB?%89H%\BnBn%4H%0B;>BF%3+H%02AAB#%0kH%
9ACSC?F"?%01H%1P=#CE%*3H%9>?;#B><%kH%\C??CAA%uH%0"?P)
ACBPR%03H%kIB<JB?=B%,\H%/IC%CLLC;A%"L%BJ="D>?B#%KB>?%
=P<BA>"?%"?%AIC%B;;P<B;E%"L%=>B@?"FA>;%>DB@>?@%L"<%KC=>)
BA<>;%BKKC?=>;>A>F%,??%.DC<@%0C=%a^&aQ(^U:ha):l^
&:$% 9"DDBH%X$H%XB@@>B?H%,$H% 9C<<BH%*$H% +BAABH%+$H%2B;"JC##>FH%
X$H%\C<<>AA"H%1$H%5C@>?C##>H%,$H%1>%0>T>"H%!$H%3BKKBJ>B?;BH%
9$H% 1>% 0>T>"H% 5$H% +<BFF>H% 5$% \"NC#% >?APFFPF;CKA>"?F% >?%
B=P#AFU% AIC% <"#C% "L% >DB@>?@% ca^&Md% 5B=>"#"@>B% 0C=>;BH%
&a^HKK$%&^:)&&'$
&($%8PE#BC<A% u\H% ,;PAC% BKKC?=>;>A>FU% G9% CSB#PBA>"?% PF>?@%
@<B=C=%;"DK<CFF>"?%5B=>"#"@E%&lh(Q&:hUb::)b(^
&'$% kCFF#C<%*H%3EACSB#%3H% +B##>R%\H% 4CF?>O%,H% \#BEB;% 80H%
8Pn"#% uH% \<PC#% u0H% /B"P<C#% 8% ,KKC?=>;>A>FU% CSB#PBA>"?%
of sensitivity, specicity, and predictive values of US,
Doppler US, and laboratory ndings Radiology 2004
XCJQab^UM'a)h
&h$%8<C?=C<@BFA% 80H% ,;PAC% BKKC?=>;>A>FU% >?SCFA>@BA>?@% B?%
"KA>DB#%"PAC<%BKKC?=>;CB#%=>BDCAC<%;PA)K">?A%>?%B%KC=>)
BA<>;% K"KP#BA>"?% /IC% u"P<?B#% "L% .DC<@C?;E% 0C=>;>?C%
a^&MQ&:')&(M
&l$% +"#=>?%,\H%kIB??B%8H%/IBKB%0H%0;\<""D%u,H%+B<<>F"?%
00H%8B<>F>%0/%5CS>FC=%P#A<BF"P?=%;<>AC<>B%L"<%BKKC?=>)
;>A>F% >?% ;I>#=<C?% >DK<"SC% =>B@?"FA>;% B;;P<B;E% 8C=>BA<>;%
5B=>"#"@E%a^&&QM&Ullb)l
a^$%/<"PA% ,/H% 9B?;ICT% 5H% 4B=>?")/"<<CF% 0XH% 5CCSB#PBA>?@%
AIC% F"?"@<BKI>;% ;<>AC<>B% L"<% B;PAC% BKKC?=>;>A>F% >?% ;I>#)
=<C?U%B%<CS>CN%"L%#>AC<BAP<C%B?=%B%<CA<"FKC;A>SC%B?B#EF>F%"L%
aM(%;BFCF%,;B=%5B=>"#%a^&a%*"SQ&lc&&dU&bha)lM
a&$%8BA<>YP>?%6\H%,KKC?=>;>A>F%>?%;I>#=<C?%B?=%E"P?@%B=P#AFU%
="KK#C<% F"?"@<BKI>;)KBAI"#"@>;% ;"<<C#BA>"?% ,u5% &ll(%
0B<Q&((Q(al)bb
22. Quillin SP, Siegel MJ, Appendicitis: efcacy of color
1"KK#C<%F"?"@<BKIE%5B=>"#"@E$%&llM%0BEQ&l&U::')(^
ab$%2"SC?CH% 0$% 5$H% \"DJB;CH% X$H% 0B<CF;BH% 5$H% 9BK"?CH% ,$H%
2B<=>?"H% 8$H% 8>;B<=>H% ,$H% et al$H% 2?ACFA>?B#% 1EFJ>"F>F% B?=%
jCBFA% 2F"#BA>"?% >?% 9A""#% "L% 9PJnC;AF% N>AI% ,PA>FD% 9KC;)
A<PD%1>F"<=C<F$%0E;"KBAI"#"@>BH%&)&:$
aM$% \B#=>FFC<"AA"%0H% 8C#CAA>%,\H%2F% ;"#"P<%1"KK#C<% F"?"@<B)
KIE%B%@""=%DCAI"=%A"%=>LLC<C?A>BAC%?"<DB#%B?=%BJ?"<DB#%
BKKC?=>;CF% >?% ;I>#=<C?v% 3#>?% 5B=>"#% a^^'% ,K<Q(aUb(:)
b(l
a:$% !B#C?A>?>H%!$H%\PYP>;;I>"H%+$4$H%+B##PTT"H%0$H%2B??>C##"H%
9$H%1>%+<CT>BH%+$H%,DJ<"F>"H%5$H%/<>?;>H%0$H%0>C#CH%!$%2?)
tussusception in adults: The role of MDCT in the identi)
;BA>"?%"L%AIC%F>AC%B?=%;BPFC%"L%"JFA<P;A>"?%ca^&(d%+BFA<")
C?AC<"#"@E%5CFCB<;I%B?=%8<B;A>;CH%a^&(
a($%3BKKBJ>B?;B% 9H% +<B?BAB% !H% 1>% +<CT>B% +H% 0B?=BA"% jH%
5C@>?C##>%,H%1>%0>T>"%!H%+<BFF>%5H%5"A"?="%,%/IC%<"#C%"L%
?BF"C?AC<>;%>?APJBA>"?%>?% AIC% 05% FAP=E%"L%KBA>C?AF% N>AI%
3<"I?pF%=>FCBFCU%"P<%CRKC<>C?;C%B?=%#>AC<BAP<C%<CS>CN%5B)
=>"#"@>B%0C=>;B%ca^&&d%&&(Ubhl)M^(
ndings such as color Doppler or the presence
of intraperitoneal uid between the loops.a^)a:
X"<%AI>F%<CBF"?%>F%D"<C%BKK<"K<>BAC%A"%B?B)
#ETC%AIC%P#A<BFA<P;AP<C%"L%AIC%BKKC?=>;CB#%NB##U%
SBF;P#B<>TBA>"?%c;"#"<_8"NC<% 1"KK#C<dH% =>BD)
eter modication, wall thickening and all other
F>@?F%B#<CB=E%N>=C#E%=CF;<>JC=%>?%AIC%#>AC<BAP<C$
Conclusions
,;;"<=>?@%A"%"P<%G9%<CFP#AFH%>A%>F%?"A%;"<<C;A%
A"%FKCBO%"L% K<>DB<E% B?=% FC;"?=B<E% F>@?FH%JPA%
more properly of US ndings suggestive of ap)
KC?=>;>A>F%FP;I%PF%AIC%?PDJC<%"L%#BEC<F%B?=%AIC%
C;I"@C?>;>AE%KBAAC<?%"L%CB;I%#BEC<$
References
% &$%3B<AE%60H%8C=>BA<>;%CDC<@C?;>CFU%?"?)A<BPDBA>;%BJ="D)
>?B#%CDC<@C?;>CF%.P<%5B=>"#$%a^^a%1C;Q&ac&adUahb:)Mh
% a$%,#SB<B="%,H%,%K<B;A>;B#% F;"<C%L"<%AIC% CB<#E% =>B@?"F>F%"L%
B;PAC%BKKC?=>;>A>F%,??%.DC<@%0C=%&lh(Q&:U::')(M
% b$% 9>S>A%3XH%9>C@C#%0XH%,KK#C@BAC%k.H%*CNDB?%k1H%[IC?%
BKKC?=>;>A>F% >F% FPFKC;AC=% >?% ;I>#=<C?% 5B=>"+<BKI>;F%
a^^&Qa&UaM')a(a
% M$%-IB?@%6H%4>B"%0H%3IC?%uH%-IP%1H%\EB?nP%9H%G#A<BF"P?=H%
;"DKPAC=% A"D"@<BKIE% "<% DB@?CA>;% <CF"?B?;C% >DB@>?@)%
NI>;I%>F%K<CLC<<C=%L"<% B;PAC% BKKC?=>;>A>F% >?% ;I>#=<C?v%,%
DCAB)B?B#EF>F%8C=>BA<%5B=>"#%a^&(
% :$% 0>B?"%12H%9>#S>F%50H%8"KK%u0H%3P#JC<AF"?%03H%3BDK)
JC##%\H%9D>AI%95H%,J="D>?B#%3/%="CF%?"A%>DK<"SC%"PA)
;"DC%L"<%;I>#=<C?%N>AI%FPFKC;AC=%B;PAC%BKKC?=>;>A>F%[CFA%
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Conicts of interest.—The authors certify that there is no conict of interest with any nancial organization regarding the material
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