3 research outputs found
Factors predictors de dilataci贸 de l'aorta tor脿cica dissecada mitjan莽ant la tomografia computada
Premi Extraordinari de Doctorat concedit pels programes de doctorat de la UAB per curs acad猫mic 2017-2018La dissecci贸 a貌rtica s'associa a una mortalitat i morbilitat elevades. Tot i que les complicacions produ茂des durant la fase aguda condicionen l'evoluci贸 a mitj脿 termini en certs pacients, la majoria de casos presenten una evoluci贸 cl铆nica acceptable durant els primers tres anys. Diverses t猫cniques d'imatge s贸n capaces de mostrar la permeabilitat de la llum falsa a l'aorta tor脿cica descendent en el 80% de les disseccions tipus A tractades amb cirurgia d'aorta ascendent i el 90% de les disseccions tipus B no complicades i tractades m猫dicament, un par脿metre que afavoreix la dilataci贸 a貌rtica i l'aparici贸 de complicacions cl铆niques a mitj脿 i llarg termini. Diverses s猫ries han estimat que la superviv猫ncia global al cap de deu anys es troba entre el 20% i el 60%. Davant de la manca d'altres factors pron貌stics convincents del risc de dilataci贸 i complicacions cl铆niques, s'ha proposat el tractament endovascular preventiu a tots els casos de dissecci贸 tipus B amb llum falsa permeable durant la fase subaguda. Aquesta estrat猫gia no 茅s aplicable degut al desconeixement de la relaci贸 entre despesa i beneficis i al risc que la morbimortalitat iatrog猫nica superi la de l'evoluci贸 de la dissecci贸 amb tractament m猫dic optimitzat. Per tant, resulta necessari identificar els candidats a intervenci贸 quir煤rgica o endovascular durant la fase subaguda de la dissecci贸. En aquest estudi de 72 supervivents a una dissecci贸 a貌rtica aguda (tipus A i B) hem descrit i validat internament un m猫tode que permet classificar els pacients en grups de risc per a dilataci贸 de l'aorta tor脿cica dissecada o l'aparici贸 d'esdeveniments a貌rtics a partir de dos par脿metres obtinguts en la TC de control de la fase subaguda. La TC permet detectar l'estrip proximal per貌 tamb茅 els distals i mesurar llur 脿rea de forma reprodu茂ble. La pres猫ncia d'una difer猫ncia superior a 1 cm 2 entre les 脿rees dels estrips proximals i distals s'ha definit com a domin脿ncia entre estrips i era un potent factor pron貌stic de la dilataci贸 de l'aorta dissecada i de l'aparici贸 d'esdeveniments a貌rtics, incloent la intervenci贸 electiva de les aortes dissecades aneurism脿tiques. La pres猫ncia d'un calibre m脿xim de l'aorta tor脿cica descendent dissecada superior o igual a 45 mm en la TC de la fase subaguda marca un risc molt elevat d'esdeveniments durant el seguiment. Addicionalment, la detecci贸 d'una taxa d'expansi贸 superior o igual a 2 mm/a en un control de TC als 3 anys tamb茅 era un excel鈭檒ent predictor de complicacions cl铆niques al final del per铆ode de seguiment. La capacitat predictiva dels par脿metres morfol貌gics era independent del tipus de dissecci贸 (tipus A o tipus B) i de la pres猫ncia de malaltia gen猫tica a貌rtica. La seva combinaci贸 permetia definir grups de pacients amb risc alt, intermedi i baix per a la incid猫ncia de dilataci贸 a貌rtica o d'esdeveniments al final del per铆ode de seguiment. En una simulaci贸 sobre els pacients del l'estudi, una estrat猫gia d'intervenci贸 preventiva del grup de risc alt minimitzava la necessitat de ter脿pia endovascular (14%), mentre que la intervenci贸 preventiva dels grups de risc alt i intermedi minimitzava la taxa de complicacions en els pacients en seguiment (5%). En ambdues estrat猫gies, la pres猫ncia d'una taxa d'expansi贸 superior o igual a 2 mm/a a la TC practicada als 3 anys de seguiment en els pacients no intervinguts durant la fase subaguda hauria detectat la resta de poblaci贸 en risc abans de patir la complicaci贸.Aortic dissection carries high mortality and morbidity. Although complications arising in the acute setting in some patients mark their short and mid term evolution, most cases have an acceptable clinical outcome during the first three years. Several imaging techniques are able to show the permeability of the false lumen in the descending thoracic aorta in 80% of surgically treated type A and 90% of medically treated type B aortic dissections. This setting favors aortic dilatation and the occurrence of clinical complications in the mid and long term. The overall survival rate has been estimated at about 20% to 60% ten years after the acute aortic syndrome. The absence of additional robust imaging parameters able to predict the expansion of the dissected thoracic aorta and the incidence of adverse aortic events has led to the proposal of preventive endovascular treatment for all cases of type B dissection with a patent false lumen in the subacute phase. This strategy is currently not applicable due to the lack of knowledge about the cost benefit ratio or the iatrogenic risk of thoracic endovascular aortic repair in this setting. Therefore, it is necessary to describe imaging features to identify patients at risk which might benefit from preventive surgery or endovascular treatment during the subacute phase of dissection. In this study of 72 patients with chronic aortic dissection (both type A and B), two parameters obtained from a CT study in the subacute phase were able to classify patients into risk groups for expansion of the dissected descending thoracic aorta or adverse aortic events. CT is able not only to detect both the proximal and the distal entry tears in the dissection flap, but also to measure their areas in a reproducible way. Dominance between the entry tears, defined as a difference greater than 1 cm 2 between the area of the proximal and the distal entry tears, was a powerful prognostic factor for dilatation of the dissected aorta and the incidence of adverse aortic events, including nonemergent intervention. The presence of a maximum caliber of the dissected descending thoracic aorta greater than or equal to 45 mm in the subacute phase CT also marks a high risk of adverse events during followup. In addition, an aortic expansion rate greater than or equal to 2 mm / as detected in a control CT at 3 years was also an excellent predictor of adverse events at the end of the monitoring period. The predictive capability of both morphological features was independent of the type of dissection (type A or type B) and the presence of aortic genetic disease. Their combination defined groups of patients at high, intermediate and low risk for the incidence of aortic dilatation or adverse events at the end of the monitoring period. In a simulation study on the patients, A strategy of preventive intervention of the high risk group resulted in a low rate of endovascular treatment (14%), while the intervention of both intermediate and high risk groups resulted in a low rate of complications in the followup (5%). In patients not operated on during the subacute phase in both strategies, the detection of an expansion rate greater than or equal to 2 mm per year in a followup CT performed at 3 years would have detected the rest of the population at risk of adverse aortic events before their onset
Factors predictors de dilataci贸 de l鈥檃orta tor脿cica dissecada mitjan莽ant la tomografia computada
La dissecci贸 a貌rtica s鈥檃ssocia a una mortalitat i morbilitat elevades. Tot i que les
complicacions produ茂des durant la fase aguda condicionen l鈥檈voluci贸 a mitj脿 termini en certs
pacients, la majoria de casos presenten una evoluci贸 cl铆nica acceptable durant els primers
tres anys. Diverses t猫cniques d鈥檌matge s贸n capaces de mostrar la permeabilitat de la llum
falsa a l'aorta tor脿cica descendent en el 80% de les disseccions tipus A tractades amb
cirurgia d鈥檃orta ascendent i el 90% de les disseccions tipus B no complicades i tractades
m猫dicament, un par脿metre que afavoreix la dilataci贸 a貌rtica i l鈥檃parici贸 de complicacions
cl铆niques a mitj脿 i llarg termini. Diverses s猫ries han estimat que la superviv猫ncia global al
cap de deu anys es troba entre el 20% i el 60%.
Davant de la manca d鈥檃ltres factors pron貌stics convincents del risc de dilataci贸 i
complicacions cl铆niques, s鈥檋a proposat el tractament endovascular preventiu a tots els casos
de dissecci贸 tipus B amb llum falsa permeable durant la fase subaguda. Aquesta estrat猫gia
no 茅s aplicable degut al desconeixement de la relaci贸 entre despesa i beneficis i al risc que
la morbimortalitat iatrog猫nica superi la de l鈥檈voluci贸 de la dissecci贸 amb tractament m猫dic
optimitzat. Per tant, resulta necessari identificar els candidats a intervenci贸 quir煤rgica o
endovascular durant la fase subaguda de la dissecci贸.
En aquest estudi de 72 supervivents a una dissecci贸 a貌rtica aguda (tipus A i B) hem descrit i
validat internament un m猫tode que permet classificar els pacients en grups de risc per a
dilataci贸 de l鈥檃orta tor脿cica dissecada o l鈥檃parici贸 d鈥檈sdeveniments a貌rtics a partir de dos
par脿metres obtinguts en la TC de control de la fase subaguda.
La TC permet detectar l鈥檈strip proximal per貌 tamb茅 els distals i mesurar llur 脿rea de forma
reprodu茂ble. La pres猫ncia d鈥檜na difer猫ncia superior a 1 cm 2 entre les 脿rees dels estrips
proximals i distals s鈥檋a definit com a domin脿ncia entre estrips i era un potent factor pron貌stic
de la dilataci贸 de l鈥檃orta dissecada i de l鈥檃parici贸 d鈥檈sdeveniments a貌rtics, incloent la
intervenci贸 electiva de les aortes dissecades aneurism脿tiques.
La pres猫ncia d鈥檜n calibre m脿xim de l鈥檃orta tor脿cica descendent dissecada superior o igual a
45 mm en la TC de la fase subaguda marca un risc molt elevat d鈥檈sdeveniments durant el
seguiment.
Addicionalment, la detecci贸 d鈥檜na taxa d鈥檈xpansi贸 superior o igual a 2 mm/a en un control
de TC als 3 anys tamb茅 era un excel鈭檒ent predictor de complicacions cl铆niques al final del
per铆ode de seguiment.
La capacitat predictiva dels par脿metres morfol貌gics era independent del tipus de dissecci贸
(tipus A o tipus B) i de la pres猫ncia de malaltia gen猫tica a貌rtica. La seva combinaci贸
permetia definir grups de pacients amb risc alt, intermedi i baix per a la incid猫ncia de
dilataci贸 a貌rtica o d鈥檈sdeveniments al final del per铆ode de seguiment.
En una simulaci贸 sobre els pacients del l鈥檈studi, una estrat猫gia d鈥檌ntervenci贸 preventiva del
grup de risc alt minimitzava la necessitat de ter脿pia endovascular (14%), mentre que la
intervenci贸 preventiva dels grups de risc alt i intermedi minimitzava la taxa de complicacions
en els pacients en seguiment (5%).
En ambdues estrat猫gies, la pres猫ncia d鈥檜na taxa d鈥檈xpansi贸 superior o igual a 2 mm/a a la
TC practicada als 3 anys de seguiment en els pacients no intervinguts durant la fase
subaguda hauria detectat la resta de poblaci贸 en risc abans de patir la complicaci贸.Aortic dissection carries high mortality and morbidity. Although complications arising in the
acute setting in some patients mark their short and mid term evolution, most cases have an
acceptable clinical outcome during the first three years. Several imaging techniques are able
to show the permeability of the false lumen in the descending thoracic aorta in 80% of
surgically treated type A and 90% of medically treated type B aortic dissections. This setting
favors aortic dilatation and the occurrence of clinical complications in the mid and long term.
The overall survival rate has been estimated at about 20% to 60% ten years after the acute
aortic syndrome.
The absence of additional robust imaging parameters able to predict the expansion of the
dissected thoracic aorta and the incidence of adverse aortic events has led to the proposal
of preventive endovascular treatment for all cases of type B dissection with a patent false
lumen in the subacute phase. This strategy is currently not applicable due to the lack of
knowledge about the cost benefit ratio or the iatrogenic risk of thoracic endovascular aortic
repair in this setting. Therefore, it is necessary to describe imaging features to identify
patients at risk which might benefit from preventive surgery or endovascular treatment during
the subacute phase of dissection.
In this study of 72 patients with chronic aortic dissection (both type A and B), two parameters
obtained from a CT study in the subacute phase were able to classify patients into risk
groups for expansion of the dissected descending thoracic aorta or adverse aortic events.
CT is able not only to detect both the proximal and the distal entry tears in the dissection
flap, but also to measure their areas in a reproducible way. Dominance between the entry
tears, defined as a difference greater than 1 cm 2 between the area of the proximal and the
distal entry tears, was a powerful prognostic factor for dilatation of the dissected aorta and
the incidence of adverse aortic events, including nonemergent
intervention.
The presence of a maximum caliber of the dissected descending thoracic aorta greater than
or equal to 45 mm in the subacute phase CT also marks a high risk of adverse events during
followup.
In addition, an aortic expansion rate greater than or equal to 2 mm / as detected in a control
CT at 3 years was also an excellent predictor of adverse events at the end of the monitoring
period.
The predictive capability of both morphological features was independent of the type of
dissection (type A or type B) and the presence of aortic genetic disease. Their combination
defined groups of patients at high, intermediate and low risk for the incidence of aortic
dilatation or adverse events at the end of the monitoring period.
In a simulation study on the patients, A strategy of preventive intervention of the high risk
group resulted in a low rate of endovascular treatment (14%), while the intervention of both
intermediate and high risk groups resulted in a low rate of complications in the followup
(5%).
In patients not operated on during the subacute phase in both strategies, the detection of an
expansion rate greater than or equal to 2 mm per year in a followup
CT performed at 3
years would have detected the rest of the population at risk of adverse aortic events before
their onset