Basic characteristics of patients
Of the 13 patients, 9 were male and 4 were female, with a mean age of 36 years (range: 11-62). All patients had a history of gastrointestinal bleeding before surgery, which was hematemesis or melena. Six patients underwent gastroscopy to confirm the presence of esophageal gastric varices or portal hypertensive gastropathy, and one patient considered to have variceal bleeding at the site of a biliary-enteric anastomosis. Pre-operative enhanced CT and B-ultrasonography (BUS) confirmed the PVCT, with an unobstructed intrahepatic PV and SMV trunk without lesion in the hepatic outflow tract. Nine patients had a history of abdominal diseases that might induce PVCT, including biliary-enteric anastomotic stenosis (1 case), pyleophlebitis secondary to appendicitis (1 case), liver trauma surgery (1 case), liver transplantation (2 cases), ex situ hepatectomy (1 case), bowel obstruction (1 case), pancreatitis (1 case) and previous MRB surgery (1 case). Three patients had a risk of thrombosis with decreased protein C activity or lower antithrombin III levels. Pre-operative or intra-operative biopsy confirmed that there was no liver cirrhosis or hepatic venous disease. All patients were confirmed to have MRB surgical indications and were eligible for surgery. Only 4 patients in Group A used autologous right internal jugular veins, and the remaining 9 patients used allogeneic blood vessels. In Group A, 1 patient simultaneously underwent biliary-enteric anastomosis reconstruction and cholangiolithotomy and 1 patient simultaneously underwent cholecystostomy and splenic artery ligation. Of the 13 patients, 5 patients received end-to-end anastomosis of the bypass vessel with the confluence of SMV and SpV, and 8 patients received anastomosis of the bypass vessel with the SMV or SpV trunk.
Postoperative patency and outcomes of interventional or surgical treatments
All patients obtained a satisfactory decompression effect after bypass surgery, and the intra-operative SMV pressure decreased from 36.77 ± 4.48 cmH2O (29-44 cmH2O) to 24 ± 5.08 cmH2O (16-31 cmH2O) (P < 0.01). The MRB opening time for patients using autologous blood vessels was 0-59 months (median 35 months), and the MRB opening time for patients used allogeneic blood vessels was 0-49 months (median 6 months) (P > 0.05).
Group A: The mean blood flow velocity of patients in Group A was 25-115 cm/s (median 75 cm/s) at 1 month after MRB, 0-161 cm/s (median 87.5cm/s) 3 months after MRB and 0-180 cm/s (median 73 cm/s) 1 year after MRB, and the opening time of bypass was 0-59 months (median 16 months). In Group A, 5 of 8 patients developed postoperative MRB occlusions, from which 4 underwent surgery or interventional treatments for the thrombus or stenosis of the bypass vessels at 0-6 months (median 3 months) after MRB surgery.
By the end of the follow-up, 3 patients still had MRB occlusion (1 patient developed occlusion at 26 months after MRB and was not treated subsequently; 1 patient occluded again after intervention and recanalization, without treatment subsequently; 1 patient was found to be unable to be recanalized during interventional treatment, and no other treatment was performed.). The diameter of the bypass vessels after MRB surgery was 2-6 mm (median 3.3 mm), among which 5 patients had an MRB occlusion with < 4 mm vessel diameter, but no embolism occurred in patients with a bypass vessel diameter ≥ 4.
Vessel diameters in 2 patients with vascular occlusions were 2 and 2.5 mm, while the re-examined diameters were 5 mm after interventional therapy with recanalization and stent implantation. The bypass vessel remained unobstructed from the time of stent implantation to the end of follow-up. One patient was recanalized only by surgical thrombus extraction and reshaping the diameter of the vascular anastomotic stoma, without stent implantation, and occlusion occurred 15 months after the 2 operations.
Group B: The patient comprising Group B needed thrombectomies and stent implantation during a second surgery 2 days after mMRB because of bypass thrombosis and UV stenosis. The MRB remained unobstructed for 26 months from the time of stent implantation to the end of follow-up, with a vessel diameter of 5 mm and a blood flow rate of 42 cm/s (1 year after MRB).
Group C: A total of 9 stents were implanted in 4 patients, of which 3 were implanted in 1 patient and 2 implanted in each of the remaining 3 patients. All patients successfully received recanalization of the UV and resistance could be detected at the junction of the UV and the sagittal part of PV, which is a narrow ring. All patients were able to successfully receive an implant stent in the LPV-UV through the distal end of the bypass vessel.
All bypass vessels remained open in all patients in Group C with satisfactory blood flow rates (45-100 cm/s, median 76.5 cm/s) 1 month after MRB, 28-80 cm/s (median 59 cm/s) 3 months after MRB and 65-83 cm/s (median 66 cm/s) 1 year after MRB up to the endpoint (12-26 months, median 18 months). The diameter of the bypass vessels after MRB surgery was 5.5-6.5 mm (median 6 mm).
The rate of bypass closure in Group A vs Group C at 1 month, 3 months and 1 year after MRB surgery was 25% vs 0%, 25% vs 0% and 50% vs 0%, respectively.
Adverse Events
No non-bypass vessel related Clavien-Dindo grade III or higher complications occurred. Patients in Group A, who underwent reconstruction of the biliary-enteric anastomosis, suffered from bile leakage and abdominal infection after surgery and were treated with laparotomy again. In Group C, 1 patient developed a jejunal fistula after surgery and was cured by re-operation, which was considered to be related to an intra-operative thermal injury and no complications occurred in the remaining 3 patients.