P4 Stump Approach for Intraoperative Portal Vein Stenting in Pediatric Living Donor Liver Transplantation: An Innovative Technique for a Challenging Problem. Ann Surg. 2018;267:e42-e44. [PMID: 28632515 DOI: 10.1097/sla.0000000000002333]

Epidemiology and Risk Factors of Early Bacterial Infections After Pediatric Living Donor Liver Transplantation

BACKGROUND

Advancements in surgical techniques, immunosuppression regimens, and peri-operative and postoperative care have resulted in marked improvement in outcomes after pediatric living donor liver transplantation (PLDLT). Despite these developments, infectious complications remain a major cause of morbidity and mortality.

METHODS

This is a retrospective cohort analysis of pediatric recipients from January 2004 to December 2018. Patients were classified into infected and non-infected groups based on the occurrence of bacterial infection during the first 3 months after transplant. Perioperative risk factors for early post-transplant bacterial infections and postoperative outcomes were investigated.

RESULTS

Seventy-two out of 221 children developed early bacterial infection (32.6%). The first episodes of bacterial infection most frequently occurred in the second week after LDLT (37.5%). In multivariate analysis, active infection before transplant and complications with Clavien-Dindo grading >3 were the only independent risk factors. Early bacterial infections were independently associated with longer intensive care unit stays, longer hospital stays, and a higher incidence of readmission for bacterial infection during the first year after transplant. Additionally, the overall patient survival rate was significantly higher in the non-infected group (P = .001). Risk factors for infection, such as age, weight, disease severity, ABO-incompatible, and other operative factors, were not identified as independent risk factors.

CONCLUSION

We have demonstrated that there are similarities and disparities in the epidemiology and risk factors for early bacterial infection after transplant between centers. Identification and better characterization of these predisposing factors are essential in the modification of current preventive strategies and treatment protocols to improve outcomes for this highly vulnerable group.

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.

Intraoperative portal vein stenting through umbilical vein approach: An innovative salvage procedure for portal vein thrombosis in pediatric liver transplant

BACKGROUND

IPVS is considered a last resort or a salvage procedure in the event of recurrent PV thrombosis despite multiple attempts at redo PV anastomosis. We employed the opened umbilical vein approach to place the stent in the PV and deliver anticoagulation through a catheter.

MATERIALS AND METHODS

From Jan 2017 to Feb 2022, 150 patients underwent pediatric transplantation at department of liver transplant and hepatobiliary surgery unit, Indraprastha Apollo hospitals, New Delhi. Age, weight, PELD Score, diagnosis, portal vein diameter on preoperative CT, Portal flow after stenting, decrease in spleen size after stenting in follow-up CT were collected from a prospectively maintained data base and reviewed.

RESULTS

Eight patients underwent IPVS following LDLT (mean age-10.6 ± 2.2 months, mean weight 8.1 ± 1.6, mean PELD score 32.7 ± 7.3). The mean PV diameter on preoperative CT scan was 3.6 mm (range 2.7-5.6 mm). The mean portal flow following stenting was 718.75 cc/min. Percentage reduction in size of the spleen was 26.35% beyond 2nd post-operative week. No patient had recurrent PV thrombosis following IPVS and all maintained an adequate portal flow throughout the immediate postoperative period. Two patients had in-hospital mortality secondary to septic complications.

CONCLUSION

Umbilical vein approach is technically feasible, easy to manipulate the stent and catheter placement after stenting helps to deliver anticoagulants locally.

Long-term outcome of primary percutaneous stent angioplasty for pediatric posttransplantation portal vein stenosis

This study aims to evaluate the long-term efficacy and reintervention rate after primary percutaneous portal vein stent angioplasty for portal vein stenosis (PVS) in pediatric liver transplantation (LT) recipients. From 2004 to 2020, a total of 470 pediatric LTs were performed in our center. All cases were screened for interventional PVS treatment and analyzed retrospectively. We identified 44 patients with 46 percutaneous angioplasties for posttransplantation PVS. The median interval from LT to percutaneous catheter intervention was 5 months (16 days-104 months) with a median follow-up (f/u) period after catheter intervention of 5.7 years (2-156 months). In 40 patients, an endovascular stent was placed as primary (n = 38) or secondary (n = 2) intervention. The median age at stent placement was 23 (6-179) months with a median weight of 10 kg (6-46 kg). Technical success and relief of PVS were achieved in all patients irrespective of age or weight. Adverse events occurred peri-interventionally in two patients and were resolved with standard care. All primary portal vein (PV) stents remained patent until the end of f/u. Reinterventions have been successfully performed in 10 patients for suspected or proven restenosis, resulting in a primary patency rate of 75% and an assisted patency rate of 25%. The median time to reintervention was 6.2 years (range 1-10 years). The need for reintervention was independent of age or weight at both transplantation and initial angioplasty as well as of additional risk factors due to portal hypertension. Percutaneous transhepatic PV stent angioplasty in children is safe and effective in all age groups, with excellent long-term patency. Primary stent angioplasty should be considered as first-line treatment for PVS after pediatric LT.

Portal vein complications and outcomes following pediatric liver transplantation: Data from the Society of Pediatric Liver Transplantation

Children who undergo liver transplantation are at risk for portal vein complications (PVCs) including thrombosis (PVT) and stenosis (PVS). Using multicenter data from the Society of Pediatric Liver Transplantation, we analyzed the prevalence, timing, and risk factors for PVC following a first liver transplantation, and assessed the potential impact of PVC on patient outcomes. Our cohort included 4278 patients, of whom 327 (7.6%) developed PVC. Multivariate analysis discovered several factors independently associated with PVC: younger recipient age, lower weight at time of transplantation, diagnosis of biliary atresia (BA), receiving a technical variant graft (TVG), warm ischemia time over 3 h, PVT in the recipient's pretransplantation native liver, and concurrent hepatic artery thrombosis (all p < 0.05). Subgroup analysis of those with BA found higher prevalence in patients transplanted at less than 2 years of age and those with TVGs. There was no difference in PVC prevalence among patients with BA with vs. without prior Kasai portoenterostomy. Most PVT (77.7%) presented within 90 days after transplantation. Patients with PVC had a higher risk of graft failure (23.9% vs. 8.3%; adjusted hazard ratio [HR], 3.08; p < 0.001) and a higher risk of death (16.4% vs. 8.9%; adjusted HR, 1.96; p = 0.01). Recurrence after retransplantation was similar to the overall prevalence in the cohort (8.2%). Our results recognize the common occurrence of PVC following pediatric liver transplantation, describe independently associated risk factors, and determine that patients with PVC have worse outcomes. Further studies are needed to improve PVC prevention, detection, and management strategies.

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.

Portal vein reconstruction with cryopreserved vascular grafts: A two-edged sword

BACKGROUND

Portal vein anastomotic complications related to size discrepancy are important causes of morbidity and mortality in pediatric liver transplantation. Interposed vascular grafts in portal vein anastomosis can solve this problem. The aim of this study is to evaluate the results of pediatric liver transplantations performed using cryopreserved interposed vascular grafts between graft portal vein and superior mesenteric vein (SMV)-splenic vein (SpV) confluence.

METHODS

Twenty-nine pediatric patients received liver transplantation using cryopreserved venous grafts in our Liver Transplant Institute between 2013 and 2020 were included in this study. Demographic, clinical, and operative characteristics and postoperative follow-up were analyzed.

RESULTS

Sixteen patients (55.2%) had portal hypoplasia and five patients (17.2%) had portal vein thrombosis. In total, six patients (20.6%) suffered portal vein thrombosis in the early postoperative period. Three patients (10.3%) experienced portal vein thrombosis in the late postoperative period. Late portal vein thrombosis rate was significantly higher in patients with early portal vein thrombosis (3/6 patients [50%] versus 0/23 patients [0%]; p = .034). Lack of portal flow was significantly higher in patients with both early (50% versus 0%; p = .002) and late portal vein thrombosis (66.7% versus 6.7%; p = .03).

CONCLUSION

Preoperative portal vein thrombosis and insufficient flow are important factors affecting success of liver transplant in children. The use of interposed vein grafts in problematic portal anastomoses can overcome portal flow problems.

Modified Meso-Rex bypass with umbilical vein recanalization and intra-operative stenting

PURPOSE

The aim of the study was to evaluate the usefulness of a novel modified Meso-Rex bypass surgical technique with umbilical vein recanalization and intra-operative stenting to treat portal vein cavernous transformation.

METHODS

In total, 13 portal vein cavernous transformation patients underwent Meso-Rex bypass surgery, consisting of bypass grafts between the superior mesenteric vein (SMV) and the recess of Rex as well as through the ligamentum teres hepatis without stent implantation (Group A, n = 9) and umbilical vein recanalization with intra-operative stent implantation (Group B, n = 4).

RESULTS

In Group A, the bypass diameter was 0-6 mm (median 3 mm) and blood flow velocity 25-115 cm/s (median 72 cm/s) 1 month after Meso-Rex bypass surgery, with open bypass times of 0-67 months (median 6 months); 6 patients in this group developed postoperative Meso-Rex bypass occlusions. A patient in Group A treated with ligamentum teres hepatis recanalization needed a thrombectomy and stent implantation during a second surgery 2 days after the Meso-Rex bypass, because of bypass thrombosis and umbilical vein stenosis. In Group B, the average modified Meso-Rex bypass diameter was 5.5-6.5 mm (median 6 mm), and the bypass vessels remained open in all patients, with blood flow rates of 45-100 cm/s (median 76.5 cm/s) 1 month after the modified Meso-Rex bypass, up to the endpoint (15-33 months, median 24 months). The rate of bypass occlusions in Group A and Group B were 22.2% and 0%, 30.0% and 0%, and 55.6% and 0% at 1 month, 3 months, and 1 year, respectively, after bypass surgery.

CONCLUSIONS

Our novel modified Meso-Rex bypass approach for portal vein cavernous transformation treatment was effective with excellent long-term bypass patency.

The Application of Interventional Radiology in Living-Donor Liver Transplantation

Owing to improvements in surgical techniques and medical care, living-donor liver transplantation has become an established treatment modality in patients with end-stage liver disease. However, various vascular or non-vascular complications may occur during or after transplantation. Herein, we review how interventional radiologic techniques can be used to treat these complications.

Sonographic features of umbilical vein recanalization for a Rex shunt on cavernous transformation of portal vein in children

BACKGROUND

The Rex shunt was widely used as the preferred surgical approach for cavernous transformation of the portal vein (CTPV) in children that creates a bypass between the superior mesenteric vein and the intrahepatic left portal vein (LPV). This procedure can relieve portal hypertension and restore physiological hepatopetal flow. However, the modified procedure is technically demanding because it is difficult to make an end-to-end anastomosis of a bypass to a hypoplastic LPV. Many studies reported using a recanalized umbilical vein as a conduit to resolve this problem. However, the feasibility of umbilical vein recanalization for a Rex shunt has not been fully investigated.

AIM

To investigate the efficacy of a recanalized umbilical vein as a conduit for a Rex shunt on CTPV in children by ultrasonography.

METHODS

A total of 47 children who were diagnosed with CTPV with prehepatic portal hypertension in the Second Hospital, Cheeloo College of Medicine, Shandong University, were enrolled in this study. Fifteen children received a recanalized umbilical vein as a conduit for a Rex shunt surgery and were enrolled in group I. Thirty-two children received the classic Rex shunt surgery and were enrolled in group II. The sonographic features of the two groups related to intraoperative and postoperative variation in terms of bypass vessel and the LPV were compared.

RESULTS

The patency rate of group I (60.0%, 9/15) was significantly lower than that of group II (87.5%, 28/32) 7 d after (on the 8^th d) operation (P < 0.05). After clinical anticoagulation treatment for 3 mo, there was no significant difference in the patency rate between group I (86.7%, 13/15) and group II (90.6%, 29/32) (P > 0.05). Moreover, 3 mo after (at the beginning of the 4^th mo) surgery, the inner diameter significantly widened and flow velocity notably increased for the bypass vessels and the sagittal part of the LPV compared to intraoperative values in both shunt groups (P < 0.05). However, there was no significant difference between the two surgical groups 3 mo after surgery (P > 0.05).

CONCLUSION

For children with hypoplastic LPV in the Rex recessus, using a recanalized umbilical vein as a conduit for a Rex shunt may be an effective procedure for CTPV treatment.

Risk factors for portal vein stenosis in pediatric liver transplantation

OBJECTIVE

To analyze the incidence and risk factors of portal vein stenosis (PVS) in pediatric liver transplantation (LT).

METHODS

This retrospective analysis of 396 cases of pediatric LT (patients aged ≤ 14 years old) was conducted at the Liver Transplantation Center of Beijing Friendship Hospital (China) from June 2013 to December 2017. We collected relevant data and calculated the incidence. We analyzed a total of 23 risk factors for PVS children during the perioperative period.

RESULTS

The incidence of PVS in pediatric LT was 6.6%. The following were identified as risk factors for PVS in pediatric LT: Preoperative portal hypertension was complicated, weight (≤7 kg), recipients of portal vein diameter ≤4 mm, GRWR (≥3.5%), the use of cold preservation vein grafts, anastomosis in the region of superior mesenteric vein and splenic vein and reverse blood flow in the portal vein shown in preoperative ultrasound examination. Recipients of portal vein diameter ≤4 mm and the use cold preservation grafts were independent risks factors for PVS in pediatric LT.

CONCLUSION

For recipients with the risk factors identified in this study, we strongly recommend a strict follow-up and the provision of suitable interventions when indicated.

Outcomes of Liver Transplantation in Small Infants

Liver transplantation (LT) for small infants remains challenging because of the demands related to graft selection, surgical technique, and perioperative management. The aim of this study was to evaluate the short-term and longterm outcomes of LT regarding vascular/biliary complications, renal function, growth, and patient/graft survival in infants ≤3 months compared with those of an age between >3 and 6 months at a single transplant center. A total of 64 infants ≤6 months underwent LT and were divided into 2 groups according to age at LT: those of age ≤3 months (range, 6-118 days; XS group, n = 37) and those of age >3 to ≤6 months (range, 124-179 days; S group, n = 27) between 1989 and 2014. Acute liver failure was the main indication for LT in the XS group (n = 31, 84%) versus S (n = 7, 26%). The overall incidence of hepatic artery thrombosis and portal vein thrombosis/stricture were 5.4% and 10.8% in the XS group and 7.4% and 11.1% in the S group, respectively (not significant). The overall incidence of biliary stricture and leakage were 5.4% and 2.7% in the XS group and 3.7% and 3.7% in the S group, respectively (not significant). There was no significant difference between the 2 groups in terms of renal function. No significant difference was found between the 2 groups for each year after LT in terms of height and weight z score. The 1-, 5-, and 10-year patient survival rates were 70.3%, 70.3%, and 70.3% in the XS group compared with 92.6%, 88.9%, and 88.9% in the S group, respectively (not significant). In conclusion, LT for smaller infants has acceptable outcomes despite the challenges of surgical technique, including vascular reconstruction and graft preparation, and perioperative management.

"Left at right" liver transplantation with heterotopic implantation of left liver graft in the right subphrenic space: Reappraisal and technical concerns for decision making

Conventional orthotopic implantation of left liver grafts is technically demanding and requires consideration of limited space and vascular complications. The study proposed a modified approach termed "left at right" liver transplantation (LAR-LT), wherein left liver grafts were rotated and implanted in right subphrenic spaces. The selection of recipients for this approach is based on the measurement of the right subphrenic space width and left liver graft length, in which a rotated left liver graft could be comfortably placed in the right subphrenic space. A total of 36 recipients who had undergone LAR-LT between July 2006 and December 2017 were retrospectively reviewed. None of recipients died of complications related to this approach immediately after operation. All grafts showed remarkable increment in liver volume and bi-directional regeneration to fit well within the right abdominal cavity. Meanwhile, the alignment of the biliary tree in LAR-LT is quite straight, making no difficulty in both anastomosis during operation and dealing with biliary stenosis afterward. As such, long-term outcome of LAR-LT is satisfactory. Keeping in mind certain technical concerns, a heterotopic LAR-LT might be safely applied as an alternative with an easier reconstruction procedure for select patients.

Endoscopic injection sclerotherapy for pediatric bleeding esophageal varices complicated by gastric vein, main portal vein, splenic mesenteric junction, and splenic vein occlusion: a case report

Background

Endoscopic injection sclerotherapy (EIS) is a life-saving procedure for pediatric patients with bleeding gastric varices (GV) associated with advanced liver cirrhosis and severe portal hypertension. Because of the lack of an endoscopic banding ligation device for pediatric patients, EIS is usually performed for bleeding esophageal varices (EV) in infants with congenital biliary atresia.

Case presentation

We present a case of a 15-month-old female infant with type I biliary atresia with jaundice (total serum bilirubin, 22.2 mg/dL), hypoalbuminemia (serum albumin level, 2.58 g/dL), coagulopathy (prothrombin time > 20 s compared with that of a normal control), ascites, splenomegaly, portal hypertension (portal vein velocity, 3.9–5.6 cm/sec of hepatopetal flow), and repeated bleeding of the varices after receiving three doses of intravascularly administered Histoacryl 1 ampoule mixed with Lipiodol UF 8 mL in the EV. Prominent GV and EV were occluded by EIS. The sclerosing agent was also present in the main portal vein, splenic mesenteric junction, and splenic vein, causing an engorged inferior mesenteric vein. The patient underwent total hepatectomy and living donor liver transplantation (LDLT) by left lateral segment graft (segments 2, 3, and 4 of the middle hepatic vein trunk) and left portal vein graft to the recipient inferior mesenteric vein anastomosis. Portal vein stent placement via segment 4 of the portal vein stump was performed from the inferior mesenteric vein to the umbilical portion of the left portal vein. The patient is still alive and doing well after the LDLT.

Conclusions

EIS is a life-saving procedure in cases involving bleeding EV complicated by gastric, main portal vein, splenic mesenteric junction, and splenic vein occlusions; hence, it should be kept in mind as a treatment for EV complications in pediatric patients.

Novel technique for pediatric living donor liver transplantation in patients with portal vein obstruction: The "pullout technique"

PV hypoplasia may increase the risk of posttransplant complications, especially when it extends to near the SMV and SpV junction. We described our experience of 10 pediatric cases of PV hypoplasia/thrombus in which the pullout technique was required for PV reconstruction. There were five male and five female patients. The median age was 9 months, and the median weight was 8.1 kg. The indications for the pullout technique were PV hypoplasia in seven patients and PV thrombus in 3. The inflow sites of the enlarged LGV were as follows: the main PV trunk (n = 2), the SMV and SpV junction (n = 4), and the SpV (n = 4). The posterior face of the pancreas was tunneled along the PV, and the PV was returned to its original position with or without the use of an interposed vein graft. The pullout technique created a good operative field, which allowed for the complete removal of the hypoplastic PV or thrombectomy with the safe use of various interposed vein grafts.

Improved portal vein venoplasty with an autogenous patch in pediatric living donor liver transplantation

A stenotic or hypoplastic portal vein (PV) represents a challenge for PV reconstruction in pediatric living donor liver transplantation (LDLT). Several PV venoplastic techniques have been developed. However, we still seek improved venoplastic techniques with better efficacy and compatibility. From June 2016 to July 2017, 271 LDLT procedures were performed at the Department of Liver Surgery, Renji Hospital. A total of 16 consecutive children with stenotic and sclerotic PVs underwent a novel technique-the autogenous PV patch plastic technique. Vessel patches were procured from the left branch (LB), or the bifurcation of the right branch and LB of the PV in the native liver. Then, the PVs were enlarged by suturing the patches along the longitudinal axis from the confluence of the PV and coronary vein (CV). In this series, 15/16 achieved good intraoperational PV flow, and 1 showed low PV flow but was treated with stent placement. Within a median follow-up of 11 months (1-18 months), 15 patients were alive and had normal graft function, whereas 1 child died from lung infection 1 month after transplantation. No PV complications were detected. In conclusion, the autogenous patch venoplasty technique using the PV-CV confluence is simple and safe. This novel venoplastic reconstruction technique could serve as a surgical option to achieve satisfactory outcomes, especially those with stenotic PV (<4.5 mm) and dilated CV (>3.0 mm). Liver Transplantation 2018 AASLD.