Study design and patient population
This was a retrospective clinical study performed at two medical centers in accordance with the Declaration of Helsinki and approved by the respective institutional review boards. All patients provided written informed consent prior to treatment. All patients in this study have not been reported.
This retrospective study included consecutive patients diagnosed with CEPS through abdominal ultrasound, computed tomographic angiography (CTA) and/or magnetic resonance imaging (MRI) between March 2011 and April 2019 in two hospitals. Study patient selection was performed in conjunction with radiologists, hepatobiliary surgeons, and interventional radiologists. Patients diagnosed with type II CEPS who presented with one malformation and at least one apparent CEPS manifestation or complication, including hepatic encephalopathy, gastrointestinal bleeding, pulmonary hypertension, hepatic myelopathy, hepatopulmonary syndrome, hepatic cirrhosis, or hepatic adenoma were included in the study. Patients with type I CEPS, asymptomatic patients, multiple malformations, hepatocellular carcinoma, coagulopathies, active infection, chronic renal failure, or contraindications to angiography and surgery were excluded.
Initially, portal venography by way of systemic venous access and traversal of the portosystemic shunt and a 15-min shunt balloon occlusion test were performed. Patients with a large and short shunt, which may have high risk of embolic materials migration, or portal venous pressure (PVP) > 25 mmHg after test occlusion, underwent surgical ligation (surgical group), with all others undergoing endovascular embolization (interventional group).
Portographyand shunt balloon occlusion test
To evaluate hemodynamics, measure PVP, and assess whether the shunt vessel could be closed, Portal venography and shunt balloon occlusion test were conducted. However, considering the heterogeneous morphology of CEPS, a standard portogram does not exist. Each angiographic examination was tailored to the patients according to the prior image findings of the suspected CEPS.
In general, the right femoral artery and femoral vein were cannulated using a 4-F vascular sheath (Radifocus; Terumo, Tokyo, Japan) and 6 to 10-F vascular sheath (Radifocus Introducer II; Terumo, Tokyo, Japan) using the Seldinger technique under local anesthesia or a transjugular or percutaneous transhepatic approach if the transfemoral vein approach failed. An indirect portal venography was then performed via selective angiography of the celiac artery, splenic artery, and superior mesenteric artery using a 4-F hepatic artery catheter (Cordis, Miami Lakes, FL, USA) inserted through the arterial vascular sheath. Next, direct venography of the inferior mesenteric vein, splenic vein, and portal vein were performed using a 4-F Cobra (Cordis) catheter inserted through the venous vascular sheath and catheterized into the portal vein. Lastly, a balloon occlusion test was performed (Fogarty, Thru Embolectomy Catheter, Edwards Lifesciences LLC, Irvine, CA, USA; Boston Scientific, Watertown, Mass) in the infrahepatic segment of IVC or the shunt to detect the intrahepatic portal branches and measure PVP before and 15 min after balloon occlusion. If the shunt was suitable for endovascular embolization and endovascular occlusion of the shunt was performed at the same time.
Laparoscopic surgical ligation
Under general anesthesia, a catheter was placed in the portal vein via the shunt through the femoral vein to monitor PVP. A 12 mm port for optics was placed in the umbilical area and three 5 mm working ports were placed in upper abdomen, right lower abdomen, and right lateral abdomen.
If PVP was < 25 mmHg after 15 min of occlusion, without signs of intestinal wall edema and redness examined at laparoscopy, the shunt was ligated alone. If PVP was > 25 mmHg and/or there were signs of intestinal wall edema and redness, the splenic artery and vein were dissected and test ligated if PVP was < 25 mmHg without signs of intestinal wall edema and redness after 15 min, the splenic artery and/or vein were also taped. Otherwise, partial occlusion of the shunt was performed and completely occluded during the follow-up, completing a so-called “two-step closure.”
Endovascular shunt occlusion
The embolization materials used were either one, or a combination of 0.018 inch pushable micro coils (MicroNester; Cook Medical, Bloomington, USA), a 0.018 inch detachable coils (Interlock; Boston Scientific, Marlborough, Massachusetts, USA), and an Amplatzer vascular plug (16-mm, 18 mm , 20 mm , or 22 mm AVP IIA; Abbott Park, Illinois，USA). After selective shunt catheterization, the microcoils and interlock coil were inserted through a coaxial 2.7-F microcatheter (Progreat; Terumo, Tokyo, Japan) , the plug was inserted through a 6 to 10-F long sheath (Cook medical, USA). Indirect portography through SMA to detect whether there were residual shunts.
To prevent portal and mesenteric thrombosis, 30 mg of subcutaneous enoxaparin was administered every 12 h, beginning 12 h after the procedure and throughout 7 days of in-hospital observation. Patients were then discharged if no complications occurred and 10 mg of oral rivaroxaban was administered once daily for 30 days.
Abdominal ultrasound and contrast-enhanced CT performed at 1 week and 1 month after the procedure determined whether portal vein system thrombosis had occurred. If there was an absence of thrombosis 1 month after the procedure, rivaroxaban was stopped.
Follow-up at 3, 6, and 12 months after the procedure, and every 12 months thereafter included clinical status, routine blood tests, serum ammonia, liver function, coagulation, and abdominal contrast-enhanced CT. The diameter of the main portal vein was measured by two radiologists independently, with the mean value used as the final result.
Continuous variables were recorded as means ± standard deviations, and categorical data as numbers and percentages. All data were tested for normality using a Shapiro-Wilk test. Differences in PVP, hemoglobin, serum ammonia, portal vein diameter, and Child-Pugh score pre- and post-procedure within each group were compared with paired-Student t test (normally distributed) or paired-Wilcoxon rank-sum test (not normally distributed). Differences between groups were tested using a Student t test or Wilcoxon rank-sum test. Differences in the main symptoms, comorbidities, and location of shunt vessels between groups were tested using the two-tailed Fisher exact test. P<0.05 indicated a statistically significant difference (SPSS Statistics for Windows, version 20.0; IBM, Armonk, NY).