[Detection of an intrapulmonary shunt in patients with liver cirrhosis through contrast-enhanced transcranial Doppler. A study of prevalence, pattern characterization, and diagnostic validity]. / Detección del shunt intrapulmonar en pacientes con cirrosis hepática mediante doppler transcraneal con contraste. Estudio de prevalencia, caracterización del patrón y validez diagnóstica.

INTRODUCTION: Intrapulmonary vascular dilatations (IPVD) are considered a complication of cirrhosis. The technique of choice for their diagnosis is contrast-enhanced echocardiography (CEE). The aim of this study was to determine the usefulness of contrast-enhanced transcranial Doppler (CETD) in the diagnosis of IPVD. METHOD: We consecutively included patients evaluated for liver transplantation. A cross-sectional study was conducted. The investigator interpreting CETD was blind to the results of the gold standard (CEE). The accuracy of the diagnostic test was evaluated through sensitivity, specificity, positive and negative predictive values, and likelihood ratio. RESULTS: CETD (n=43) showed a right-to-left shunt in 23 patients (62.2%): 4 early, 2 indeterminate and 17 late. Nineteen (51,4%) cases were classified as IPVD. With CEE (n=37), 10 procedures (27%) were negative for shunt, 27 (73%) were positive, and 21 (56.8%) were compatible with IPVD. Patients with and without IPVD showed no differences in age, sex, etiology, severity, or MELD score, independently of the diagnostic test. In the diagnostic validity study (n=37) of CETD versus CEE, the AUC for diagnostic yield was 0.813% (95%CI: 0.666-0.959; P=.001), sensitivity was 76.2% (95%CI: 54.9-89.4) and specificity was 90% (95%CI: 63.9-96.5). The positive likelihood ratio was 6.095. CONCLUSIONS: We found a high prevalence of IPVD in candidates for liver transplantation. When a late right-to-left shunt with recirculation is observed, CETD has a high probability of detecting IPVD, with few false-positive results. Because this technique has not previously been described in this indication, similar studies are needed for comparison.

Detección del shunt intrapulmonar en pacientes con cirrosis hepática mediante doppler transcraneal con contraste. Estudio de prevalencia, caracterización del patrón y validez diagnóstica / Detection of an intrapulmonary shunt in patients with liver cirrhosis through contrast-enhanced transcranial Doppler. A study of prevalence, pattern characterization, and diagnostic validity

INTRODUCCIÓN: Las dilataciones vasculares intrapulmonares (DVIPu) están consideradas una complicación de la cirrosis. La ecocardiografía con contraste (ETTc) es la técnica de elección para su diagnóstico. El objetivo de este estudio es demostrar que el doppler transcraneal con contraste (DTCc) puede servir para el diagnóstico de las DVIPu. MÉTODO: Se incluyeron consecutivamente pacientes evaluados para trasplante hepático. Estudio transversal con enmascaramiento de la prueba de referencia (ETTc) para quien interpreta la prueba a valorar (DTCc). Analizamos la exactitud de la prueba diagnóstica mediante los valores de sensibilidad, especificidad, valor predictivo positivo y negativo, y razón de verosimilitud. RESULTADOS: Por DTCc (n = 43) existía shunt derecha-izquierda en 23 pacientes (62,2%): 4 precoces, 2 indeterminados y 17 tardíos. Diecinueve (51,4%) casos fueron clasificados DVIPu. Con ETTc (n = 37) 10 estudios (27%) fueron negativos para shunt y 27 (73%) positivos, 21 (56,8%) fueron compatibles con DVIPu. Los pacientes con y sin DVIPu no diferían en edad, sexo, etiología, gravedad o índice de MELD, independientemente del método diagnóstico. En el estudio de validez diagnóstica (n = 37) del DTCc frente a la ETTc, el rendimiento diagnóstico fue AUC = 0,813% (IC 95%: 0,666-0,959; p = 0,001), sensibilidad: 76,2% (IC 95%: 54,9-89,4) y especificidad: 90% (IC 95%: 63,9-96,5). Razón de verosimilitud positiva: 6,095. CONCLUSIONES: Demostramos una alta prevalencia de DVIPu en candidatos a trasplante hepático. La probabilidad que tiene el DTCc en detectar DVIPu cuando se observa shunt derecha-izquierda tardío con recirculación es muy elevada, y con pocos falsos positivos. Al ser una técnica previamente no descrita en este contexto, deben llevarse a cabo estudios similares con fin comparativo

INTRODUCTION: Intrapulmonary vascular dilatations (IPVD) are considered a complication of cirrhosis. The technique of choice for their diagnosis is contrast-enhanced echocardiography (CEE). The aim of this study was to determine the usefulness of contrast-enhanced transcranial Doppler (CETD) in the diagnosis of IPVD. METHOD: We consecutively included patients evaluated for liver transplantation. A cross-sectional study was conducted. The investigator interpreting CETD was blind to the results of the gold standard (CEE). The accuracy of the diagnostic test was evaluated through sensitivity, specificity, positive and negative predictive values, and likelihood ratio. RESULTS: CETD (n = 43) showed a right-to-left shunt in 23 patients (62.2%): 4 early, 2 indeterminate and 17 late. Nineteen (51,4%) cases were classified as IPVD. With CEE (n = 37), 10 procedures (27%) were negative for shunt, 27 (73%) were positive, and 21 (56.8%) were compatible with IPVD. Patients with and without IPVD showed no differences in age, sex, etiology, severity, or MELD score, independently of the diagnostic test. In the diagnostic validity study (n = 37) of CETD versus CEE, the AUC for diagnostic yield was 0.813% (95% CI: 0.666-0.959; P = .001), sensitivity was 76.2% (95% CI: 54.9-89.4) and specificity was 90% (95% CI: 63.9-96.5). The positive likelihood ratio was 6.095. CONCLUSIONS: We found a high prevalence of IPVD in candidates for liver transplantation. When a late right-to-left shunt with recirculation is observed, CETD has a high probability of detecting IPVD, with few false-positive results. Because this technique has not previously been described in this indication, similar studies are needed for comparison