Efficacy of intraoperative cine-portogram for complicated portal vein reconstruction in pediatric living donor liver transplantation

Portal vein pressure and flow modulation in pediatric liver transplantation

Liver transplantation (LT) has been indicated for smaller and more clinically severe patients in recent years. Small biliary atresia (BA) patients often show portal hypoplasia and sclerotic portal vein (PV), which may make PV reconstruction more difficult during the operation. Among PV complications, intraoperative PV thrombosis can be considered a disaster, and it is important to prevent this catastrophic event by the precise assessment of the PV structure and PVF using radiological imaging before and during LT. However, there are no objective parameters to indicate whether sufficient PVF can be obtained. PV pressure (PVP) and PV flow (PVF) have mainly been studied in adult living donor LT, for the purpose of preventing small-for-size syndrome, and PVP has been considered an objective parameter of graft inflow modulation (GIM). In the setting of pediatric LT, GIM is mainly performed to prevent hypoperfusion, and it must be performed before graft implantation. GIM to maximize the PVF of pediatric patients with potentially low PVF in LT consists of the interruption of collateral vessels, the assessment of the usability of the native PV, and technical modifications in PV reconstruction. Reliable objective parameters that represent sufficient PVF before graft implantation are desired. Our recent study proposed that a PVP of ≥25 mmHg before graft implantation can be considered an objective parameter to obtain sufficient PVF (cutoff value: 50 mL/min/100 g of graft weight). Further investigation is needed to determine the best strategy for successful PV reconstruction in pediatric LT.

Usability of intraoperative cine-portogram during liver transplantation in young pediatric patients with biliary atresia

BACKGROUND

Pediatric patients with biliary atresia (BA) often present liver cirrhosis-associated portal hypertension and portal vein (PV) hypoplasia. For successful liver transplantation (LT), it is essential to maintain sufficient PV inflow through stenosis-free PV reconstruction with effective ligation of collateral veins. The aim of this study was to assess the clinical usability of intraoperative cine-portogram (IOCP) in young pediatric patients who underwent LT for BA.

METHODS

Medical records of pediatric patients younger than 10 years who underwent primary LT for BA from 2018 to 2020 were reviewed.

RESULTS

A total of 31 patients had undergone Kasai portoenterostomy soon after birth. Their median ages at Kasai portoenterostomy and LT were 1 and 11 months, respectively. Types of LT were living-donor LT in 13, deceased-donor split LT in 15, and deceased-donor whole LT in three patients. PV interposition using an iliac vein homograft was performed in 28 patients receiving partial liver grafts. Side-to-side PV unification venoplasty was performed in three patients undergoing whole LT. All patients underwent ligation of collateral veins. IOCP was performed in 6 (19.4%) patients. Four showed no or faint residual venous collaterals. Collateral vein embolization and endovascular stenting were performed in one patient each. PV insufficiency-free survival rate was 100% at 1 year and 93.8% at 3 years. All patients are currently alive with a median follow-up period of 23 months.

CONCLUSIONS

Intraoperative cine-portogram can be a useful method for identification and embolization of residual portosystemic collateral veins in young pediatric patients who undergo LT for biliary atresia.

Impact of prolonged clamping of the portal vein during liver transplantation in infants with biliary atresia: renewed interest in a long-standing issue

PURPOSE

Various approaches to portal vein (PV) reconstruction have been described; however, there is still scope to improve the safety and efficiency of how PV anastomosis is performed in infants.

METHODS

We analyzed, retrospectively, the predictive factors for PV reanastomosis during living donor liver transplantation (LDLT) in 117 infants (< 1 year old) with biliary atresia (BA).

RESULTS

Twenty-six infants required PV reanastomosis because of intraoperative PV thrombosis in 21 and insufficient PV flow in 5. Univariate analysis identified multiple previous laparotomies and a prolonged anhepatic phase (AHP) as significant risk factors for repeated PV anastomosis. The AHP cutoff value for identifying patients requiring PV reanastomosis was 134 min. Multivariate analysis revealed prolonged AHP > 134 min (odds ratio, 15.98; 95% confidence interval, 5.05-50.6; P < 0.001) as an independent risk factor for repeated PV anastomosis. The plasma D-dimer and fibrinogen degradation product concentration just after reperfusion were significantly higher in patients requiring PV reanastomosis (P < 0.001). Patients requiring reanastomosis of the PV had a higher incidence of PV complications after LDLT than those who did not need PV reanastomosis (P = 0.01).

CONCLUSION

Attempting to minimize the AHP is indispensable for successful LDLT in infants with BA.

Narrowing of the remnant portal vein diameter and decreased portal vein angle are risk factors for portal vein thrombosis after perihilar cholangiocarcinoma surgery

PURPOSE

To evaluate the incidence, risk factors, management options, and outcomes of portal vein thrombosis following major hepatectomy for perihilar cholangiocarcinoma.

METHODS

A total of 177 perihilar cholangiocarcinoma patients who (1) underwent major hepatectomy and (2) underwent investigating the portal vein morphology, which was measured by rotating the reconstructed three-dimensional images after facilitating bone removal using Aquarius iNtuition workstation between 2002 and 2018, were included. Risk factors were evaluated using the Kaplan-Meier method and Cox proportional hazard models.

RESULTS

Six patients developed portal vein thrombosis (3.4%) within a median time of 6.5 (range 0-22) days. Portal vein and hepatic artery resection were performed in 30% and 6% patients, respectively. A significant difference in the probability of the occurrence of portal vein thrombosis (PV) within 30 days was found among patients with portal vein resection, a postoperative portal vein angle < 100°, remnant portal vein diameter < 5.77 mm, main portal vein diameter > 13.4 mm, and blood loss (log-rank test, p = 0.003, p = 0.06, p < 0.0001, p = 0.01, and p = 0.03, respectively). Decreasing the portal vein angle and narrowing of the remnant PV diameter remained significant predictors on multivariate analysis (p = 0.027 and 0.002, respectively). Reoperation with thrombectomy was performed in four patients, and the other two patients were successfully treated with anticoagulants. All six patients subsequently recovered and were discharged between 25 and 70 days postoperatively.

CONCLUSION

Narrowing of the remnant portal vein diameter and a decreased portal vein angle after major hepatectomy for perihilar cholangiocarcinoma are significant independent risk factors for postoperative portal vein thrombosis.