Title: Preliminary clinical observation of double C-arm digital subtraction angiography
guidance during transjugular intrahepatic portosystemic shunt placement
Version: 0 Date: 09 Dec 2022
Reviewer's report:
Overall, this study, while well-edited, contains no truly novel information about TIPS placement
or its effects. As there are an abundance of studies performing TIPS even without a double C-
arm and consequently, with lower radiation exposure at identical success and low complication
rates, the advantages seem significantly less clear than indicated.
Specific aspects of the study appeared rather unnaturally designed:
- if experienced personnel is performing an ultrasound-guided puncture of the right portal vein,
why not perform the entire procedure with ultrasound?
- discussing CO2 and its advantages as contrast medium when it wasn't used in this study, appears
like filling material to bulk up the discussion text; rather than contrast media, maybe discuss the
different techniques published to enhance TIPS guidance. Rouabah et al. described a guidance
technique based on a 3D volume rendering of the portal vein generated from a contrast-enhanced
MDCT Angiography (MDCTA) of the portal trunk acquired shortly before the TIPS [Rouabah
K, Varoquaux A, Caporossi JM, et al (2016) Image fusion-guided portal vein puncture during
transjugular intrahepatic portosystemic shunt placement. Diagn Interv Imaging 97:1095–1102.
https://doi.org/10.1016/j.diii.2016.06.015], Luo et al. introduced a guidance technique relying
on intra-procedural acquisition of a CE-CACT with contrast injection in the superior mesenteric
artery to obtain an indirect portomesentericography serving as an overlay [Luo X, Wang X,
Yu J, et al (2018) Transjugular intrahepatic portosystemic shunt creation: three-dimensional
roadmap versus CO2 wedged hepatic venography. Eur Radiol 28:3215–3220.], and Meine et
al. used a 3D/2D image registration of hepatic and portal veins segmented on a previously
acquired CE-MDCT with two fluoroscopic images for guidance of the portal vein puncture,
focused on low-experienced interventionalists [Meine, T.C., Dewald, C.L.A., Becker, L.S. et al.
Transjugular intrahepatic portosystemic shunt placement: portal vein puncture guided by 3D/2D
image registration of contrast-enhanced multi-detector computed tomography and fluoroscopy.
Abdom Radiol 45, 3934–3943 (2020). https://doi.org/10.1007/s00261-020-02589-1]
- not a "new method" (See conclusion)
- a blinded, randomised comparison between patients receiving TIPS with the double C-arm +
US vs. the "standard method", especially concerning potentially flow-optimised positioning of
the TIPS tract  would be of interest; is there any data on the rate of shunt dysfunctions?
Title: Preliminary clinical observation of double C-arm digital subtraction angiography
guidance during transjugular intrahepatic portosystemic shunt placement
Version: 0 Date: 09 Dec 2022
Reviewer's report:
Overall, this study, while well-edited, contains no truly novel information about TIPS placement
or its effects. As there are an abundance of studies performing TIPS even without a double C-
arm and consequently, with lower radiation exposure at identical success and low complication
rates, the advantages seem significantly less clear than indicated.
Specific aspects of the study appeared rather unnaturally designed:
- if experienced personnel is performing an ultrasound-guided puncture of the right portal vein,
why not perform the entire procedure with ultrasound?
- discussing CO2 and its advantages as contrast medium when it wasn't used in this study, appears
like filling material to bulk up the discussion text; rather than contrast media, maybe discuss the
different techniques published to enhance TIPS guidance. Rouabah et al. described a guidance
technique based on a 3D volume rendering of the portal vein generated from a contrast-enhanced
MDCT Angiography (MDCTA) of the portal trunk acquired shortly before the TIPS [Rouabah
K, Varoquaux A, Caporossi JM, et al (2016) Image fusion-guided portal vein puncture during
transjugular intrahepatic portosystemic shunt placement. Diagn Interv Imaging 97:1095–1102.
https://doi.org/10.1016/j.diii.2016.06.015], Luo et al. introduced a guidance technique relying
on intra-procedural acquisition of a CE-CACT with contrast injection in the superior mesenteric
artery to obtain an indirect portomesentericography serving as an overlay [Luo X, Wang X,
Yu J, et al (2018) Transjugular intrahepatic portosystemic shunt creation: three-dimensional
roadmap versus CO2 wedged hepatic venography. Eur Radiol 28:3215–3220.], and Meine et
al. used a 3D/2D image registration of hepatic and portal veins segmented on a previously
acquired CE-MDCT with two fluoroscopic images for guidance of the portal vein puncture,
focused on low-experienced interventionalists [Meine, T.C., Dewald, C.L.A., Becker, L.S. et al.
Transjugular intrahepatic portosystemic shunt placement: portal vein puncture guided by 3D/2D
image registration of contrast-enhanced multi-detector computed tomography and fluoroscopy.
Abdom Radiol 45, 3934–3943 (2020). https://doi.org/10.1007/s00261-020-02589-1]
- not a "new method" (See conclusion)
- a blinded, randomised comparison between patients receiving TIPS with the double C-arm +
US vs. the "standard method", especially concerning potentially flow-optimised positioning of
the TIPS tract  would be of interest; is there any data on the rate of shunt dysfunctions?
Please review this paper.
user
Title: Preliminary clinical observation of double C-arm digital subtraction angiography
guidance during transjugular intrahepatic portosystemic shunt placement
Version: 0 Date: 09 Dec 2022
Reviewer's report:
Overall, this study, while well-edited, contains no truly novel information about TIPS placement
or its effects. As there are an abundance of studies performing TIPS even without a double C-
arm and consequently, with lower radiation exposure at identical success and low complication
rates, the advantages seem significantly less clear than indicated.
Specific aspects of the study appeared rather unnaturally designed:
- if experienced personnel is performing an ultrasound-guided puncture of the right portal vein,
why not perform the entire procedure with ultrasound?
- discussing CO2 and its advantages as contrast medium when it wasn't used in this study, appears
like filling material to bulk up the discussion text; rather than contrast media, maybe discuss the
different techniques published to enhance TIPS guidance. Rouabah et al. described a guidance
technique based on a 3D volume rendering of the portal vein generated from a contrast-enhanced
MDCT Angiography (MDCTA) of the portal trunk acquired shortly before the TIPS [Rouabah
K, Varoquaux A, Caporossi JM, et al (2016) Image fusion-guided portal vein puncture during
transjugular intrahepatic portosystemic shunt placement. Diagn Interv Imaging 97:1095–1102.
https://doi.org/10.1016/j.diii.2016.06.015], Luo et al. introduced a guidance technique relying
on intra-procedural acquisition of a CE-CACT with contrast injection in the superior mesenteric
artery to obtain an indirect portomesentericography serving as an overlay [Luo X, Wang X,
Yu J, et al (2018) Transjugular intrahepatic portosystemic shunt creation: three-dimensional
roadmap versus CO2 wedged hepatic venography. Eur Radiol 28:3215–3220.], and Meine et
al. used a 3D/2D image registration of hepatic and portal veins segmented on a previously
acquired CE-MDCT with two fluoroscopic images for guidance of the portal vein puncture,
focused on low-experienced interventionalists [Meine, T.C., Dewald, C.L.A., Becker, L.S. et al.
Transjugular intrahepatic portosystemic shunt placement: portal vein puncture guided by 3D/2D
image registration of contrast-enhanced multi-detector computed tomography and fluoroscopy.
Abdom Radiol 45, 3934–3943 (2020). https://doi.org/10.1007/s00261-020-02589-1]
- not a "new method" (See conclusion)
- a blinded, randomised comparison between patients receiving TIPS with the double C-arm +
US vs. the "standard method", especially concerning potentially flow-optimised positioning of
the TIPS tract  would be of interest; is there any data on the rate of shunt dysfunctions?
assistant