Keywords shunts - interventional procedures - transjugular intrahepatic porto-systemic shunt
- TIPS - Color Doppler ultrasound
Introduction
Transjugular intrahepatic portosystemic shunts (TIPS) have gained traction as a mainstay
in the therapeutic approach to portal hypertension (PHT) [1 ]
[2 ]. Probably the most significant turning point in the TIPS era was the replacement
of bare metal (BM) with covered expandable polytetrafluoroethylene (ePTFE) stents
[3 ]. This innovation has dramatically decreased the rate of shunt dysfunction, from
up to 80% at two years for BM to a more manageable 10–30% for ePTFE stents [3 ]
[4 ]
[5 ]
[6 ]
[7 ]
[8 ]
[9 ]
[10 ], with primary stent patency exceeding 75% at five years according to
multiple reports [6 ]
[7 ]
[8 ].
The Baveno VII consensus on the management of PHT has refined recommendations regarding
TIPS and the target portal pressure gradient (PPG) [11 ]. Immediate post-TIPS PPG might be influenced by various factors, such as general
anesthesia, vasoactive medication, and hemodynamic instability. Consequently, to obtain
an unbiased PPG, Baveno VII recommends systematic measurement in an elective manner
in stable and non-sedated patients. However, most research designs in the past have
only assessed stent functionality based primarily on symptom relapse or inadequate
clinical control, which only then prompted hemodynamic reevaluation. Therefore, the
only hemodynamic assessment was obtained during the TIPS placement procedure for many
patients with adequate symptom control, with no subsequent measurements if stent dysfunction
was not suspected on clinical or ultrasonographic grounds.
Given the invasive character of hepatic catheterization, there have been multiple
attempts to establish ultrasound-based criteria to evaluate TIPS dysfunction, using
variables such as portal vein velocity (PVV), intrahepatic portal branch flow directionality,
and in-stent peak velocity, with varying degrees of success [6 ]
[12 ]
[13 ]
[14 ]. Detecting TIPS dysfunction defined by a suboptimal PPG appears to be challenging,
with an AUROC of only 0.77, with sub-par pooled sensitivity (82%) and specificity
(58%) [15 ]. A significant caveat was that most of the studies only performed a hemodynamic
assessment if dysfunction was suspected on clinical or ultrasonographic grounds, rendering
the US-angiography comparison pairings subject to a selection bias towards dysfunction
[6 ]
[13 ]
[16 ]
[17 ]
[18 ].
The aim of the current study was to evaluate the discrimination capabilities of Doppler
ultrasonography for TIPS dysfunction in the setting of scheduled hepatic catheterization
at four to six weeks following TIPS placement, performed systematically regardless
of any indication of stent dysfunction. As a secondary aim, the study evaluated the
role of systematic hemodynamic TIPS revision for evaluating changes in PPG in a standardized
condition not affected by general anesthesia, vasoactive medication, or hemodynamic
instability.
Materials and Methods
Study population
All patients who benefited from TIPS placement between 2013 and 2020 in a tertiary
care facility were prospectively registered and considered potentially eligible for
inclusion in this retrospective descriptive analysis. Patients with symptom recurrence
(bleeding) or liver disease decompensation leading to death during the initial hospital
stay were excluded, as well as patients who continued their follow-up in other centers
or were lost to follow-up.
All patients signed the informed written consent before TIPS. The study was conducted
according to the modified Declaration of Helsinki, and the institutional ethics committee
approved the study design.
Data regarding liver disease staging were collected on the index admission. The indication
for TIPS placement was determined according to the most recent Baveno consensus recommendation
(Baveno V Field [19 ] and VI [2 ]).
TIPS placement procedure
All patients included in the study benefited from a TIPS procedure with ePTFE-covered
graft stents using the standard procedure, as previously described [14 ]. Given that dedicated ePTFE stents were commercially unavailable in our country,
our protocol consisted of creating a double-stent hybrid using a BM stent (Wallstent
Endoprosthesis, Boston Scientific, Marlborough, MA, USA) and an ePTFE-covered stent
(Fluency, Bard, Murray Hill, NJ, USA) to cover the intrahepatic trajectory of the
shunt. The shunt was dilated to 8 mm, and the final PPG was measured. In the case
of an insufficient PPG decrease (PPG≥12 mmHg, or PPG decrease<50% of the initial PPG),
the shunt was further dilated to 10 mm. All procedures were performed under general
anesthesia.
Ultrasonography
All US examinations were performed using the same equipment throughout the study (Aixplorer,
SuperSonic Imagine, Aix-en-Provence, France). The two US evaluations were scheduled
within 48 hours following TIPS placement and at the first follow-up visit before hepatic
catheterization. Velocities were measured in blocked inspiration. The following variables
were recorded: shunt patency, portal vein velocity (PVV, cm/s), right and left portal
branch flow directionality, and peak velocities (cm/s) ([Fig. 1 ]). Ascites was graded according to the International Ascites Club classification
[20 ]. ΔPVV was calculated by subtracting the post-TIPS PVV from the PVV at the time of
the first revision.
Fig. 1 Doppler ultrasonographic assessment of portal vein velocity (left), right intrahepatic
portal branch flow directionality (middle), and left intrahepatic portal branch directionality
(right).
TIPS Revision
Our protocol for scheduled follow-up consists of a systematic ultrasonographic and
hemodynamic reevaluation at six weeks post-TIPS ([Fig. 2 ]). The hemodynamic protocol included standard venography evaluating shunt patency
and PPG measurements. If the venography revealed significant shunt stenosis or thrombosis,
or if the PPG exceeded 12 mmHg, the shunt was deemed dysfunctional, and further angioplasty
was performed.
Fig. 2 TIPS revision timeline and study protocol. PVV – portal vein velocity, PPG – portal
pressure gradient.
Clinical dysfunction (CD) was defined as the recurrence of PHT-related bleeding or
inadequate control of ascites. Given the relatively short timeframe from TIPS placement
to revision, adequate control of ascites was defined by US-proven improvement of ascites
or a decrease in the need for large-volume paracenteses by at least one-third. Hemodynamic
dysfunction (HD) was defined as a PPG≥12 mmHg.
Statistical Analysis
Descriptive statistics were used for normality testing and demographic variables.
Scale variables were described using the mean±standard deviation (SD) for normally
distributed variables or the median (interquartile range – IQR) for non-normal distributions.
Two-tailed T-tests were used for mean comparison and the Mann-Whitney U tests for
median comparison. Nominal and ordinal variables were described in absolute values
and relative frequencies (%). Either Pearson’s Chi-squared or Fisher’s Exact Test
was used for non-scale variables, according to sample sizes. Correlations were analyzed
using the Pearson correlation coefficient. The receiver operating characteristic (ROC)
curves were used to assess the diagnostic prowess of the DU variables for TIPS dysfunction
and to identify an optimal cut-off value to maximize the sum between sensitivity and
specificity. The diagnostic performance of the cut-off values obtained from our study
population were compared with
previously reported values [10 ]
[12 ] using the McNemar test. The threshold for statistical significance was set at p≤0.05.
Statistical analysis was performed using IBM SPSS Statistics 28.0.0.0 (SPSS Inc.,
Chicago, IL, USA).
Results
A total of 137 TIPS procedures were performed, with 86 meeting the inclusion criteria
for the study. The baseline characteristics are depicted in [Table 1 ]. Most of the procedures were performed for PHT-related bleeding (n=71, 82.5%), and
the most common clinical scenario was secondary prophylaxis of variceal bleeding (n=55,
63.9%). Technical success, defined as a post-procedural PPG below 12 mmHg, was obtained
in 97.6% of the cases (n=84), while a PPG reduction exceeding 50% was obtained in
74.4% of the cases (n=64).
Table 1 Baseline characteristics and initial presentation.
Demographic variables
Age (years)
53.85±9.63
Male gender (n,%)
57 (66.3)
Liver disease etiology
Alcoholic liver disease (n,%)
47 (54.7)
Viral – HBV, HCV (n,%)
17 (19.8)
Alcoholic+viral (n,%)
9 (10.5)
Other (n,%)
13 (15.1)
Liver disease staging
MELD score
14 (11–18)
Child-Pugh class A (n,%)
21 (24.4)
Child-Pugh class B (n,%)
39 (45.3)
Child-Pugh class C (n,%)
26 (30.3)
Ascites prior to TIPS placement (n,%)
62 (72.1)
Indication for TIPS placement
Portal hypertension-related bleeding (n,%)
58 (67.4)
Refractory ascites (n,%)
14 (16.3)
Combined – bleeding and refractory ascites (n,%)
13 (15.1)
Refractory hepatic hydrothorax and ascites (n,%)
1 (1.2)
Portal hypertension-related bleeding clinical scenario
Secondary prophylaxis (n,%)
55 (77.4)
Rescue TIPS (n,%)
14 (19.7)
Preemptive TIPS (n,%)
2 (2.8)
Hemodynamics
Initial PPG (mmHg)
16 (14–19)
Post-TIPS PPG (mmHg)
7 (5.5–8)
Technical success
Post-TIPS PPG≤10 mmHg (n,%)
81 (94.1)
Post-TIPS PPG≤12 mmHg (n,%)
84 (97.6)
50% decrease of PPG (n,%)
64 (74.4)
The median interval to the first revision was 40.5 days. Data obtained from the first
hemodynamic revision is summarized in [Table 2 ]. At six weeks, the rate of clinical dysfunction was 18.6% (n=16). Two patients (2.7%)
presented with recurrence of portal hypertension-related bleeding. One of the patients
had a revision PPG of 16 mmHg, presenting with a second episode of severe alcoholic
hepatitis, which progressed to grade III acute-on-chronic liver failure and ultimately
led to the patient’s demise. The second patient had a bleeding recurrence from gastric
varices despite a PPG of 5 mmHg.
Table 2 Clinical and hemodynamic dysfunction at the first revision.
TIPS revision data
Median interval to first revision (days)
40.5 (23)
Clinical dysfunction (n,%)
16/86 (18.6)
(n,%) of which had a PPG≥10 mmHg
13/16 (81.2)
(n,%) of which had a PPG≥12 mmHg
13/16 (81.2)
Portal hypertension-related bleeding recurrence (n,%)
2/71 (2.7)
(n,%) of which had a PPG≥10 mmHg
1/2 (50)
(n,%) of which had a PPG≥12 mmHg
1/2 (50)
Inadequate control of ascites (n,%)
14/62 (22.5)
(n,%) of which had a PPG≥10 mmHg
12/14 (85.7)
(n,%) of which had a PPG≥12 mmHg
12/14 (85.7)
Revision PPG≥10 mmHg (n,%)
44/86 (51.2)
(n,%) of which had no clinical recurrence
31/44 (70.4)
Revision PPG≥12 mmHg
37/86 (43)
(n,%) of which had no clinical recurrence
25/37 (67.5)
PPG at first revision (mmHg)
10 (7–14)
Post-TIPS – first revision PPG variation (mmHg)
+3 (0–6.5)
50% PPG decrease at first revision vs. pre-TIPS PPG (n,%)
27 (31.4)
Clinical scenarios
Portal hypertension-related bleeding
PPG≥10 mmHg
37/71 (52.1)
(n,%) of which had bleeding recurrence
1/37 (2.8)
PPG≥12 mmHg
31/71 (43.6)
(n,%) of which had bleeding recurrence
1/31 (3.2)
50% PPG decrease at first revision vs. pre-TIPS PPG (n,%)
21/71 (29.6)
(n,%) of which had bleeding recurrence
1/21 (4.7)
Refractory ascites
PPG≥10 mmHg
15/27 (55.5)
(n,%) of which had inadequate control of ascites
14/15 (93.3)
PPG≥12 mmHg
14/27 (51.8)
(n,%) of which had inadequate control of ascites
14/14 (100)
50% PPG decrease at first revision vs. pre-TIPS PPG (n,%)
7/27 (25.9)
Overall, there was a significant increase in PPG at the first revision. The median
increase in PPG was 3 (0–6.5) mmHg, and 43% of the patients (n=37) had a revision
PPG≥12 mmHg. The median PPG increase was significantly higher in patients with HD
– 7 mmHg (5–9.75) vs. 3 mmHg (0–5) in patients without HD (p=0.01). There were no
significant differences regarding TIPS indication and the rate of HD. Notably, the
patients with HD had more advanced liver disease at the time of TIPS placement expressed
by the Child-Pugh (8.8±2 vs. 7.8±1.9, p=0.02) and MELD scores (16.4±6 vs. 14.6±6,
p=0.05).
The differences in Doppler US-based variables in different subgroup scenarios were
comparatively analyzed and summarized in [Table 3 ]. At a PPG cut-off value of 10 mmHg, there were no significant differences between
groups regarding PVV and intrahepatic portal flow directionality, although the median
PVV was higher in patients with a PPG below the cut-off and there was a higher proportion
of patients with hepatofugal flow in both the left and right portal vein branches.
The only statistically significant difference was regarding ΔPVV, as patients with
a PPG below 10 mmHg had an increase in PVV, as opposed to patients with a PPG≥10 mmHg
who had a decrease in PVV.
Table 3 Comparison of ultrasonographic predictors of TIPS dysfunction.
Portal pressure gradient≥10 mmHg
No (n=42)
Yes (n=44)
p-value
Portal vein velocity (cm/s)
40 (34.5–50)
35 (26.5–42.25)
0.13
Δ Portal vein velocity (cm/s)
6.07±20.9
−5.4±20.1
0.01
Hepatofugal flow – right portal vein branch (n,%)
40 (95.2)
37 (84.1)
0.15
Hepatofugal flow – left portal vein branch (n,%)
39 (92.8)
37 (84.1)
0.29
Portal pressure gradient≥12 mmHg
No (n=59)
Yes (n=37)
p-value
Portal vein velocity (cm/s)
40.5 (35–50)
35 (25–40)
0.02
Δ Portal vein velocity (cm/s)
6.08±19.8
−8.2±20.2
0.04
Hepatofugal flow – right portal vein branch (n,%)
56 (94.9)
30 (81.1)
0.03
Hepatofugal flow – left portal vein branch (n,%)
55 (93.2)
30 (81.1)
0.06
Clinical dysfunction
No (n=70)
Yes (n=16)
p-value
Portal vein velocity (cm/s)
40 (30–50)
35 (25–40.5)
0.24
Δ Portal vein velocity (cm/s)
1.5±19.4
−5.3±26.3
0.15
Hepatofugal flow – right portal vein branch (n,%)
64 (91.4)
13 (81.2)
0.23
Hepatofugal flow – left portal vein branch (n,%)
63 (90)
13 (81.2)
0.24
On the other hand, when a PPG cut-off of 12 mmHg was used, the differences in US variables
increased, as patients with HD had a significantly higher median PVV (p=0.02), ΔPVV
(p=0.04), and a higher prevalence of hepatofugal flow in the right portal vein branch
(p=0.03). There were no differences regarding the Doppler US-based variables between
patients with or without clinical dysfunction.
Both PVV and ΔPVV were significantly correlated with the revision PPG, although the
strength of the correlation was moderate for PVV (−0.38, p<0.001) and modest for ΔPVV
(−0.28, p=0.03).
The discriminative capabilities of PVV and ΔPVV for HD were evaluated using the AUROC
analysis ([Fig. 3 ]). Both variables had acceptable predictive capability: PVV had an AUROC of 0.715
for a cut-off of 40.5 cm/s (p<0.001), while ΔPVV had an AUROC of 0.705 for a cut-off
of 9.5 cm/s (p=0.002). Combining the two variables at these cut-off values led to
a discrimination improvement up to an AUC of 0.78. When a composite variable was computed
using PVV and right portal branch flow directionality, there were no substantial improvements
in AUC (0.68). Since hemodynamic revision (gold standard) is an invasive procedure,
a number-needed-to-harm (NNH) analysis was performed using US-based variables as the
experimental procedure. The NNH, representing patients with US evidence of TIPS dysfunction
without HD, was calculated for a PVV cut-off of 40.5 cm/s, ΔPVV of 9.5 cm/s, and a
composite variable comprising both PVV and ΔPVV, with
values of 4.31 (95% confidence interval 3.1–17.8), 3.42 (1.9–23.23) and 5.26 (3.11–18.5),
respectively.
Fig. 3 AUROC analysis for portal vein velocity (left) and portal vein velocity (right) for
predicting hemodynamic TIPS dysfunction.
The diagnostic test metrics for the PVV cut-off derived from our dataset were compared
to previously reported cut-offs for TIPS dysfunction ([Table 4 ]). While the diagnostic accuracy remained around 65% regardless of the PVV value,
the sensitivity decreased proportionately with the cut-off from a moderately effective
83.8% for 40.5 cm/s to 32.3% for the lowest available cut-off of 28 cm/s, albeit with
significant increases in specificity. However, the variable that appeared to be best
suited as a screening test for TIPS dysfunction appeared to be ΔPVV, as an increase
in PVV of less than 9.5 cm/s had a sensitivity of 96.7%.
Table 4 Diagnostic test evaluation for portal vein velocity cut-off values.
Cut-off value
PVV – 40.5 cm/s
PVV – 39 cm/s+hepatopetal flow[14 ]
PVV – 31 cm/s [12 ]
PVV – 28 cm/s+hepatofugal flow [14 ]
ΔPVV – 9.5 cm/s
PVV+ΔPVV*
Sensitivity (%, 95% C.I.)
83.8 (66.2–94.5)
67.7 (46.7–83.3)
48.3 (30.1–66.9)
32.3 (16.6–51.3)
96.7 (83.3–99.9)
87.1 (70.1–96.3)
Specificity (%, 95% C.I.)
50 (34.5–65.4)
61.3 (45.5–75.6)
79.5 (64.7–90.2)
93.1 (81.3–98.5)
35 (20.6–51.6)
60 (43.3–75.1)
Positive predictive value (%, 95% C.I.)
52.8% (44.5–60.9)
53.8 (42.8–64.5)
62.5 (45.6–76.8)
76.9 (49.9–91.7)
53.5 (47.6–59.3)
62.7 (53–71.6)
Negative Predictive Value (%, 95% C.I.)
82.3 (66.4–91.6)
74 (61.9–83.3)
68.6 (60.1–76)
66.1 (60.1–71.6)
93.3 (66–99)
85.7 (63.9–93.9)
Accuracy
63.5 (51.6–74.3)
63.9 (52–74.6)
66.6 (54.8–77.1)
68 (56.2–78.3)
61.9 (49.6–73.2)
71.8 (59.9–81.8)
p-value (McNemar Test)
–
<0.01
<0.01
<0.01
0.02
<0.01
*Using a cut-off value of 40.5 cm/s for PVV and 9.5 cm/s for ΔPVV; PVV – portal vein
velocity; C.I. – confidence interval.
Discussion
Our findings suggest that PVV and its dynamics might be useful screening tools for
detecting hemodynamic TIPS dysfunction in the absence of clinical relapse and might
be sufficient to prompt a TIPS revision. While the discriminative capabilities of
both PVV and ΔPVV are moderate taken separately, discrimination substantially improves
by combining both variables, thus providing good diagnostic metrics for TIPS dysfunction
screening. Moreover, our results suggest that hemodynamic dysfunction defined by a
revision PPG>12 mmHg is relatively frequent (43%) if revision is performed systematically,
regardless of clinical or US evidence of dysfunction and despite an adequate intraprocedural
PPG.
The AUC of 0.78 for combining PVV and ΔPVV is in line with data presented in the only
available meta-analysis on the performance of US in detecting TIPS dysfunction, which
reported a pooled AUC of 0.77 [15 ]. However, the criteria for dysfunction in the studies included in the meta-analysis
are highly inhomogeneous, with many studies including composite criteria combining
variables such as peak in-stent velocity, PVV, or flow directionality [6 ]
[13 ]
[16 ]
[17 ]. Moreover, many studies performed in the bare-metal stent era had a significantly
higher dysfunction rate and might have generated additional bias.
To date, two key studies have assessed the role of portal vein velocity (PVV) in detecting
TIPS dysfunction during systematic TIPS revision. A 2007 randomized controlled trial
by Christophe Bureau et al., comparing ePTFE-covered and BM stents, explored Doppler
US performance in predicting shunt dysfunction [10 ]. Their findings indicated that patients with a PPG>12 mmHg had a PVV of 30.7±11.8
cm/s, contrasting with 40.3±19.1 cm/s for optimal PPG (p<0.05), mirroring our dataset
but with a notably lower PVV for dysfunctional stents. However, the overall discrimination
was modest, with an AUC of 0.65 for a cut-off value of 31 cm/s. Another study with
a similar design, albeit on a smaller scale (34 patients and 117 US-venography pairs),
was published in 2005 by Juan Abraldes et al., focusing on PVV and intrahepatic portal
branch directionality. Although the model was derived from the BM era, it was prospectively
validated on
covered stents. Their criteria for TIPS dysfunction were a PVV of 39 cm/s for hepatofugal
flow and 28 cm/s for hepatopetal flow, achieving a sensitivity of 87% and specificity
of 57% [12 ]. In our dataset, both these criteria exhibited relatively high specificity but inadequate
sensitivity (<70%) for effective screening, thus failing as an effective screening
tool.
TIPS occlusion, thrombosis, and stenosis are relatively straightforward to identify,
with AUROCs of 0.95 and 0.86, respectively [15 ]. Yet, if gross patency is confirmed, evidence of dysfunction becomes more subtle,
as criteria are less firm and cannot confidently replace hemodynamic revision. Therefore,
based on the available data, it appears that the discriminative capabilities of Doppler
US for detecting TIPS dysfunction are satisfactory but do not provide sufficient strength
to firmly ascertain the diagnosis of dysfunction, especially during adequate clinical
control.
In response to the secondary aim, we noted a higher proportion (43%) of patients with
a PPG>12 mmHg during the first revision, conducted 6 weeks post-TIPS placement, despite
achieving the target PPG in 97.6% of cases during the initial procedure. These findings
align with the recommendations of Baveno VII, emphasizing the influence of immediate
post-TIPS conditions on PPG readings and advocating for remeasurement in stable conditions
[11 ]. Notably, the Barcelona Groupʼs 2017 study supported this, comparing immediate (post-TIPS),
early (non-intubated), and late (one month) PPG values [21 ]. For intubated patients, immediate PPG was poorly correlated with early PPG, with
30.5% crossing the threshold during early revision. Discrepancies persisted even when
immediate PPG was recorded post-anesthesia, with 24.5% potentially misclassified as
having an adequate post-TIPS PPG. Similar discordance
persisted between early and late PPG, suggesting the need for periodic or late systematic
TIPS revision. This raises the possibility that long-term PPG may stabilize later
due to slow-developing hemodynamic changes or factors associated with liver disease
or environment.
Therefore, if PPG is systematically assessed, values exceeding the recommended threshold
of 12 mmHg appear to be more frequently encountered. While the Baveno VII consensus
clearly states that a PPG of 12 can provide near-complete protection from PHT-related
bleeding events [11 ], it is unclear whether a single measurement during TIPS placement followed by clinical
monitoring provides sufficient confidence in adequate PPG control. Previously published
data has shown that only 50.3% (n=68) of patients had a PPG<12 mmHg during the entire
follow-up (median of 23 months) [21 ]. These figures contrast sharply with those reported in protocols that only performed
hemodynamic revision in the case of clinical or US suspicion, boasting 5-year primary
patency rates of 79.9% [6 ]. Moreover, as most of the available data regarding target PPG in patients with TIPS
come
from such protocols, an evident source of bias arises, as patients with adequate clinical
control often have fewer hemodynamic reassessments and, therefore, higher primary
patency rates are reported.
Another problematic issue resides in adequate ascites control. To this point, in contrast
to PHT-related bleeding, there are no clear-cut values of target PPG for ascites [11 ]. The poor control of ascites was also encountered in our dataset, as 87.5% (n=14/16)
of patients with clinical dysfunction had no significant improvement in this regard.
Young et al. have reported that clinical relapse was a significantly better predictor
of a PPG>12 mmHg compared to Doppler US on a cohort of a similar scale, which included
78 US/venogram pairings [13 ]. On the other hand, the causal agent for an inadequate response might be influenced
by numerous factors, including non-compliance to salt restriction or a lack of etiological
cure (i. e., continued alcohol consumption), as proven by a small proportion of patients
in our study with no improvement in ascites, yet still within the target PPG. Also,
the
time of assessment could influence the results since six weeks could be too early
to assess ascites response to TIPS insertion.
A cautious approach to our results is warranted. The patients were retrospectively
analyzed, and no long-term data is currently available regarding their complete history
of decompensation and overall outcomes. However, analyzing the long-term outcomes
of patients with TIPS was beyond the scope of the current design. Another potential
caveat might be that due to the lack of available dedicated ePTFE-covered TIPS stents
in our country, patients in our study had a custom dual assembly of bare-metal and
ePTFE-covered stents closely resembling the dedicated stent. This was the rationale
for not including in-stent velocities as a variable, as stent design might significantly
alter the turbulence patterns. However, there is no basis for altering either the
PVV or intrahepatic branch directionality. Moreover, the patency rates for this clinical
scenario were similar to those reported in the literature [21 ].
Conclusion
Despite adequate symptom control, many patients have a post-TIPS PPG≥12 mmHg if hemodynamic
revision is systematically performed. The assessment of PVV and its temporal dynamics
can reliably predict a PPG≥12 mmHg despite adequate symptomatic control and provide
a rationale for referral to a hemodynamic revision. However, US lacks the prerequisites
of a firm diagnostic instrument and, to this point, cannot replace systematic TIPS
revision for diagnosing clinically silent dysfunction.
Bibliographical Record
