Portal vein thrombosis in biliary atresia patients after living donor liver transplantation

Recanalization of portal vein thrombosis after pediatric liver transplantation: Efficacy and safety of the transsplenic access

BACKGROUND

Endovascular management of portal vein thrombosis (PVT) is challenging. Transsplenic access (TSA) is growing as an access option to the portal system but with higher rates of bleeding complications. The aim of this article is to evaluate the efficacy and safety of transsplenic portal vein recanalization (PVR) using a metallic stent after pediatric liver transplantation.

MATERIALS AND METHODS

This is a retrospective review of 15 patients with chronic PVT who underwent PVR via TSA between February 2016 and December 2020. Two children who had undergone catheterization of a mesenteric vein tributary by minilaparotomy were excluded from the patency analysis but included in the splenic access analysis. The technical and clinical success of PVR and complications related to the procedure via TSA were evaluated.

RESULTS

Thirteen children with PVT were treated primarily using the TSA. The mean age was 4.1 years (range, 1.5-13.7 years), and the most common clinical presentation was hypersplenism (60%). Technically successful PVR was performed in 11/13 (84.6%) children, and clinical success was achieved in 9/11 (81.8%) children. No major complications were observed, and one child presented moderate pain in the TSA (from a total of 17 TSA). The median follow-up was 48.2 months. The median primary patency was 9.9 months. Primary patency in the first 4 years was 75%, and primary assisted patency was 100% in the follow-up period.

CONCLUSIONS

Transsplenic PVR is a safe and effective method for the treatment of PVT after pediatric liver transplantation.

Technical Aspects and Considerations of Meso-Rex Bypass Following Liver Transplantation With Left Lateral Segment Grafts: Case Report and Review of the Literature

In pediatric patients with extrahepatic portal vein obstruction and complications of portal hypertension, but with normal liver function, a meso-Rex bypass (MRB) connecting the superior mesenteric vein to the intrahepatic left portal is the favored surgical management. Pediatric patients with a history of a partial liver transplant (LT), especially living donors, are at greater risk for portal vein complications. Hence, an adequate knowledge of this technique and its additional challenges in the post-LT patient setting is crucial. We provide an overview of the available literature on technical aspects for an MRB post-LT. Preoperative considerations are highlighted, along with intraoperative considerations and postoperative management. Special attention is given to the even-more-demanding aspect of performing an MRB post-liver transplantation with a left lateral segment. Surgical alternatives are also discussed. In addition, we report here a unique case in which this surgical technique was performed on a complex pediatric patient with a history of a living-donor LT with a left lateral segment graft over a decade ago.

Donor tobacco smoking is associated with postoperative thrombosis after primary liver transplantation

BACKGROUND

Thrombosis after liver transplantation is a leading cause of graft loss, morbidity, and mortality. Several known recipient- and surgery-related characteristics have been associated with increased risk of thrombosis after transplantation. Potential donor-related risk factors, however, remain largely undefined.

OBJECTIVES

We aimed to identify risk factors for early post-transplantation thrombosis (<90 days) and to determine the impact of early postoperative thrombosis on long-term graft and patient survival.

PATIENTS/METHODS

A post hoc analysis was performed of an observational cohort study including all primary, adult liver transplantations performed between 1993 and 2018. Donor-, recipient-, and surgery-related characteristics were collected. Competing risk model analyses and multivariable regression analyses were performed to identify risk factors for developing early post-transplant thrombosis and graft failure.

RESULTS

From a total of 748 adult liver transplantations, 58 recipients (7.8%) developed a thrombosis after a median of 7 days. Post-transplantation thrombotic events included 25 hepatic artery thromboses, 13 portal vein thromboses, and 22 other thrombotic complications. Donor history of smoking was independently associated with early postoperative thrombosis (odds ratio [OR] 2.42; 95% confidence interval [CI], 1.29-4.52). Development of early post-transplant thrombosis was independently associated with patient mortality (hazard ratio [HR] 3.61; 95% CI 1.54-8.46) and graft failure (HR 5.80, 95% CI 3.26-10.33), respectively.

CONCLUSION

Donor history of smoking conveys a more than two-fold increased risk of thrombosis after liver transplantation, independent of other factors. Post-transplant thrombosis was independently associated with decreased patient and graft survival.

Biliary reconstruction before clamp removal to avoid portal vein thrombosis in pediatric living-donor liver transplantation using hyper-reduced left lateral segment grafts: A novel technical strategy

LT has become the treatment of choice for children with end-stage liver disease. The scarcity of donors and the considerable mortality on waiting lists have propelled the related living-donor techniques, especially in small children. This population need smaller and good quality grafts and are usually candidates to receive a LLS from a related donor. Many times this grafts are still large and do not fit in the receptor's abdomen, so a further hyper-reduction may be required. Despite all advances in LT field, vascular complications still occur in a considerable proportion remaining as a significant cause of morbidity, graft loss, and mortality. Technical issues currently play an essential role in its genesis. The widely spread technique for biliary and vascular reconstruction in living donor LT (LDLT) nowadays implies removal of the portal vein (PV) clamp after the venous anastomosis, then the arterial reconstruction is done, followed by the biliary reconstruction. However, due to the posterior location of the LLS bile duct, for its reconstruction, a rotation of the liver is required risking a potential transient PV occlusion leading to thrombosis afterward. We describe a new technique that involves performing biliary reconstruction after the PV anastomosis and before removing the vascular clamp, thus allowing to freely rotate the liver with less risk of PV occlusion and thrombosis.

"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.

Wedged-patch venoplasty of the left liver graft portal vein for size matching in pediatric living donor liver transplantation

Portal vein (PV) size matching between recipient and liver graft is important in preventing anastomotic stenosis in living donor liver transplantation (LDLT). In right liver grafts, the diameter of graft PV is usually >10 mm. Thus, PV size matching does not become critical in adult recipients. If the recipient PV is very large, funneling fence can be attached to graft PV. However, if the diameter of graft PV is <8 mm, it can induce anastomotic stenosis. We experienced a few cases of PV anastomotic stenosis due to small-sized graft PV in >5000 LDLT cases, but graft PV widening was not performed because graft PV is considered as being a no-touch area. In thinking out of the box, we performed wedged-patch venoplasty to exceptionally narrow graft PV. A 4 year-old female patient underwent second LDLT due to progressive deterioration of graft function after 3 years. At first LDLT operation for biliary stresia, an iliac vein conduit was interposed for PV reconstruction. At second LDLT operation, the diameter of interposed PV was 10 mm, but the left liver graft PV was only 6 mm-sized. Uniquely, the left PV was waist only at first-order PV. To resolve this PV waist, a longitudinal incision was made to release the waist. A cold-preserved fresh iliac vein patch was inserted to widen the PV orifice. The patch size was adjusted to match the size of the recipient PV. The patient recovered uneventfully. This wedged-patch venoplasty technique can be applied to small-sized graft PV, to cope with PV size mismatching in LDLT.

P4 Stump Approach for Intraoperative Portal Vein Stenting in Pediatric Living Donor Liver Transplantation: An Innovative Technique for a Challenging Problem

OBJECTIVE

The aim of this study was to evaluate the utility of the P4 stump stenting approach for treating portal vein (PV) complications in pediatric living donor liver transplantation (LDLT).

BACKGROUND

PV complications cause significant morbidity and mortality in pediatric LDLT. Biliary atresia in the backdrop of pathological PV hypoplasia and sclerosis heightens the complexity of PV reconstruction. The authors developed a novel approach for intraoperative PV stenting via the graft segment 4 PV stump (P4 stump) to address this challenge.

METHODS

From April 2009 to December 2016, 15 pediatric LDLT recipients (mean age 10.3 ± 5.0 months, mean graft-recipient weight ratio 3.70%) underwent intraoperative stenting for suboptimal PV flow (<10 cm/s) or PV occlusion after collateral ligation and graft repositioning. Under portography, metallic stents were deployed via the reopened P4 stump of the left lateral segment grafts.

RESULTS

PV diameter and peak flow increased significantly after stent placement (2.93 ± 1.74 to 7.01 ± 0.91 mm and 2.0 ± 9.2 to 17.3 ± 3.5 cm/s, respectively, P = 0.001 for both), and there were no technical failures. Stents in all surviving patients remained patent up to 8 years (mean 27.7 months), with no vascular or biliary complications. After implementation of the P4 approach, the incidence of variceal bleeding as a late complication decreased from 7% to zero.

CONCLUSION

The P4 stump stenting approach affords procedural convenience, ease of manipulation, and consistent results with the potential for excellent long-term patency in children despite continued growth. This technique obviates the need for more demanding post-transplant stenting, and may become a substitute for complicated revision surgery, portosystemic shunting, or retransplantation.

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.

Intra-operative portal hemodynamics in pediatric LDLT: Doppler ultrasound surveillance

Doppler ultrasonography is useful in monitoring intra-operative PV flow in LDLT. A retrospective cohort study included 550 pediatric recipients (<18 years) who underwent LDLT from October 2006 to August 2016 in our hospital. A total of 33 recipients (incidence 6%) were found to have insufficient intra-operative PV flow after PV reperfusion. The treatments included intra-operative stent placement (n=25), anticoagulation (n=3), thrombectomy and re-anastomosis (n=2), graft repositioning (n=1), collateral ligation (n=1), and replaced PV (n=1). The peak PV velocity, HAPSV, HARI, and HV velocity before and after the interventions were significantly improved 0(0,5.5) cm/s vs. 37.36±15.30 cm/s, 38.68±8.92 cm/s vs. 62.30±16.97 cm/s, 0.55±0.08 vs. 0.76±0.10, and 32.37±10.33 cm/s vs. 40.94±15.01 cm/s, respectively (P<.01). Insufficient PV flow and decreased HARI are two significant criteria indicating need for intra-operative PV management. Dramatic changes in the hepatic hemodynamics were detected after proper treatment. Immediate resolution of PV flow is feasible in pediatric LDLT.

Pediatric Thromboembolism in Japan

OBJECTIVES

To investigate the clinical and epidemiologic characteristics of thromboembolism in Japanese children.

METHODS

Clinical data of 77 patients with thromboembolism from a national tertiary pediatric care center were reviewed.

RESULTS

Incidence of thromboembolism was calculated to be 15 per 10,000 hospital admissions. Infants younger than one year of age made up the largest age group (25 patients, including nine neonates younger than 30 d). The occurrence of thromboembolism increased over the years in the index population. Thromboembolism was diagnosed as follows: portal vein thrombosis (n = 15), obstruction of central venous catheter (n = 13) and cerebral infarction (n = 9). Among the 77 patients, there were eight mortalities and six significant sequelae.

CONCLUSIONS

In pediatric care, especially in intensive care, we should pay more attention to thromboembolism in order to detect it promptly.

Hepatic arterial and portal venous complications after adult and pediatric living donor liver transplantation, risk factors, management and outcome (A retrospective cohort study)

OBJECTIVES

Hepatic arterial (HA) and portal venous (PV) complications of recipients after living donor liver transplantation(LDLT) result in patient loss. The aim of this study was to analyze these complications.

METHODS

We retrospectively analyzed HA and/or PV complications in 213 of 222 recipients underwent LDLT in our centre. The overall male/female and adult/pediatric ratios were 183/30 and 186/27 respectively.

RESULTS

The overall incidence of HA and/or PV complications was 19.7% (n = 42), while adult and pediatric complications were 18.3% (n = 39) and 1.4% (n = 3) respectively. However early (<1month) and late (>1month) complications were 9.4% (n = 20) and 10.3% (n = 22) respectively. Individually HA problems (HA stenosis, HA thrombosis, injury and arterial steal syndrome) 15% (n = 32), PV problems (PV thrombosis and PV stenosis) 2.8% (n = 6) and simultaneous HA and PV problems 1.9% (n = 4). 40/42 of complications were managed by angiography (n = 18), surgery (n = 10) or medically (Anticoagulant and/or thrombolytic) (n = 12) where successful treatment occurred in 18 patients. 13/42 (31%) of patients died as a direct result of these complications. Preoperative PVT was significant predictor of these complications in univariate analysis. The 6-month, 1-, 3-, 5- 7- and 10-year survival rates in patients were 65.3%, 61.5%, 55.9%, 55.4%, 54.5% and 54.5% respectively.

CONCLUSION

HA and/or PV complications specially early ones lead to significant poor outcome after LDLT, so proper dealing with the risk factors like pre LT PVT (I.e. More intensive anticoagulation therapy) and the effective management of these complications are mandatory for improving outcome.

Hepatic arterial and portal venous complications after adult and pediatric living donor liver transplantation, risk factors, management and outcome (A retrospective cohort study)

Objectives

Hepatic arterial (HA) and portal venous (PV) complications of recipients after living donor liver transplantation(LDLT) result in patient loss. The aim of this study was to analyze these complications.

Methods

We retrospectively analyzed HA and/or PV complications in 213 of 222 recipients underwent LDLT in our centre. The overall male/female and adult/pediatric ratios were 183/30 and 186/27 respectively.

Results

The overall incidence of HA and/or PV complications was 19.7% (n = 42), while adult and pediatric complications were 18.3% (n = 39) and 1.4% (n = 3) respectively. However early (<1month) and late (>1month) complications were 9.4% (n = 20) and 10.3% (n = 22) respectively. Individually HA problems (HA stenosis, HA thrombosis, injury and arterial steal syndrome) 15% (n = 32), PV problems (PV thrombosis and PV stenosis) 2.8% (n = 6) and simultaneous HA and PV problems 1.9% (n = 4). 40/42 of complications were managed by angiography (n = 18), surgery (n = 10) or medically (Anticoagulant and/or thrombolytic) (n = 12) where successful treatment occurred in 18 patients. 13/42 (31%) of patients died as a direct result of these complications. Preoperative PVT was significant predictor of these complications in univariate analysis. The 6-month, 1-, 3-, 5- 7- and 10-year survival rates in patients were 65.3%, 61.5%, 55.9%, 55.4%, 54.5% and 54.5% respectively.

Conclusion

HA and/or PV complications specially early ones lead to significant poor outcome after LDLT, so proper dealing with the risk factors like pre LT PVT (I.e. More intensive anticoagulation therapy) and the effective management of these complications are mandatory for improving outcome.

•

Preoperative PVT was significant predictor of HA and/or PV complications.

•

HA and/or PV complications especially early ones lead to significant poor outcome.

•

Proper dealing with the risk factors like pre LT PVT improves outcome.

•

The effective management of these complications is mandatory for improving outcome.

Preoperative hepatic hemodynamics in the prediction of early portal vein thrombosis after liver transplantation in pediatric patients with biliary atresia

BACKGROUND

Portal vein thrombosis (PVT) is one of the main vascular complications after liver transplantation (LT), especially in pediatric patients with biliary atresia (BA). This study aimed to assess the preoperative hepatic hemodynamics in pediatric patients with BA using Doppler ultrasound and determine whether ultrasonographic parameters may predict early PVT after LT.

METHODS

One hundred and twenty-eight pediatric patients with BA younger than 3 years of age underwent Doppler ultrasound within seven days before LT, between October 2006 and June 2013. The preoperative hepatic hemodynamic parameters were then compared between patients with early PVT (within 1 month following LT) and those without PVT. Receiver operating characteristic analysis was performed to determine the optimal cutoff value for predicting early PVT.

RESULTS

Of the 128 transplant recipients, 41 (32.03%) had a hypoplastic portal vein (PV), 52 (40.63%) had hepatofugal PV flow and 40 (31.25%) had a high hepatic artery resistance index (HARI) of ≥1. Nine cases (7.03%) experienced early PVT. A PV diameter ≤4 mm (sensitivity 88.89%, specificity 72.27%), and a hepatofugal PV flow (sensitivity 77.78%, specificity 62.18%) with a high HARI ≥1 (sensitivity 77.78%, specificity 72.27%) were hepatic hemodynamic risk factors for early PVT.

CONCLUSIONS

Hepatic hemodynamic disturbances in pediatric recipients with BA were more common. Small PV diameter (≤4 mm) and hepatofugal PV flow combined with high HARI (≥1) are strong warning signs of early PVT after LT in pediatric patients with BA. Intense monitoring of vascular patency and prophylactic thrombolytic therapy should be considered in pediatric patients undergoing LT for BA.

Iatrogenic-related transplant injuries: the role of the interventional radiologist

As advances in surgical techniques and postoperative care continue to improve outcomes, the use of solid organ transplants as a treatment for end-stage organ disease is increasing. With the growing population of transplant patients, there is an increasing need for radiologic diagnosis and minimally invasive procedures for the management of posttransplant complications. Typical complications may be vascular or nonvascular. Vascular complications include arterial stenosis, graft thrombosis, and development of fistulae. Common nonvascular complications consist of leaks, abscess formation, and stricture development. The use of interventional radiology in the management of these problems has led to better graft survival and lower patient morbidity and mortality. An understanding of surgical techniques, postoperative anatomy, radiologic findings, and management options for complications is critical for proficient management of complex transplant cases. This article reviews these factors for kidney, liver, pancreas, islet cell, lung, and small bowel transplants.

Pediatric transplantation: preventing thrombosis

Due to progressive advances in surgical techniques, immunosuppressive therapies, and supportive care, outcomes from both solid organ transplantation and hematopoietic stem cell transplantation continue to improve. Thrombosis remains a challenging management issue in this context, with implications for both graft survival and long-term quality of life. Unfortunately, there remains a general paucity of pediatric-specific data regarding thrombosis incidence, risk stratification, and the safety or efficacy of preventative strategies with which to guide treatment algorithms. This review summarizes the available evidence and rationale underlying the spectrum of current practices aimed at preventing thrombosis in the transplant recipient, with a particular focus on risk factors, pathophysiology, and described antithrombotic regimens.

Management and long-term consequences of portal vein thrombosis after liver transplantation in children

Portal vein thrombosis (PVT) occurs in ≤12% of pediatric recipients of liver transplantation (LT). Known complications of PVT include portal hypertension, allograft loss, and mortality. The management of PVT is varied. A single-center, case-control study of pediatric LT recipients with portal vein (PV) changes after LT was performed. Cases were categorized as early PVT (if PVT was detected within 30 days of transplantation) or late PVT (if PVT was detected more than 30 days after transplantation or if early PVT persisted beyond 30 days). Two non-PVT control patients were matched on the basis of the recipient weight, transplant indication, and allograft type to each patient with PVT. Thirty-two of the 415 LT recipients (7.7%) received 37 allografts and developed PVT. In comparison with control patients, a higher proportion of patients with PVT had PVT present before LT (13.3% versus 0%, P = 0.01). Patients with early PVT usually returned to the operating room, and 9 of 15 patients (60%) had PV flow restored. Patients with late PVT had lower white blood cell (4.9 [1000/μL] versus 6.8 [1000/μL], P < 0.01) and platelet counts (140 [1000/μL] versus 259 [1000/μL], P < 0.01), an elevated international normalized ratio (1.2 versus 1.0, P < 0.001), and more gastrointestinal bleeding (25% versus 8.3%, P = 0.03) compared to controls. Patients with PVT were also less frequently at the expected grade level (52% versus 88%, P < 0.001). The patient survival rates were 84%, 78%, and 78% and 91%, 84%, and 79% for cases and controls at 1, 5, and 10 years, respectively. The allograft survival rates were 90%, 80%, and 80% for cases and 94%, 89%, and 87% for controls at 1, 5, and 10 years, respectively. In conclusion, patients with early and late PVT had preserved allograft function, and there was no impact on mortality. Patients diagnosed with early PVT often underwent operative interventions with successful restoration of flow. Patients diagnosed with late PVT experienced variceal bleeding, and some required portosystemic shunting procedures. Academic delays were also more common. In late PVT, the clinical presentation dictates care because the optimal management algorithm has not yet been determined. Multi-institutional studies are needed to confirm these findings and improve patient outcomes.

Meso-Rex bypass as an alternative technique for portal vein reconstruction at or after liver transplantation in children: review and perspectives

Direct portal revascularization can be achieved by interposing a vascular graft between the SMV and the Rex recessus (left portal vein system): the MRB. To review indications and results of the procedure in the setting of pediatric liver transplantation, reports were selected from the English literature. Previously reported series were updated to analyze long-term outcome. A new series was added and analyzed as a complementary set of cases. A total of 51 cases were analyzed. With a 96% overall patient survival rate and a 100% long-term patency rate when the IJV is used for the bypass, MRB achieves a very successful physiologic cure of chronic portal hypertension and restores the portal flow into and through the liver graft. It also has been used successfully for primary revascularization of liver grafts, as well as for managing early acute portal vein thrombosis episodes. The use of this procedure in conjunction with other strategies and techniques might be of interest for transplant surgeons, particularly those caring for children.

The pre-Kasai procedure in living donor liver transplantation for children with biliary atresia

BACKGROUND

Biliary atresia (BA) is a major cause of chronic cholestasis, a fatal disorder in infants. This study was undertaken to evaluate the safety and effectiveness of primary living donor liver transplantation (LDLT) in comparison with the traditional first-line treatment, the Kasai procedure.

METHODS

We assessed 28 children with BA at age of less than two years (3-21.3 months) who had undergone LDLT in two hospitals in Southwest China during the period of 2008-2011. Eighteen children who had had primary LDLT were included in a primary LDLT group, and ten children who had undergone the Kasai operation in a pre-Kasai group. All patients were followed up after discharge from the hospital. The records of the BA patients and donors were reviewed.

RESULTS

The time of follow-up ranged 12-44.5 months with a median of 31 months. The 30-day and 1-year survival rates were 85.7% and 78.6%, respectively. There was no significant difference in the 30-day or 1-year survival between the two groups (83.3% vs 90% and 77.8% vs 80%, P>0.05). The main cause of death was hepatic artery thrombosis. There were more patients with complications who required intensive medical care or re-operation in the pre-Kasai group (8, 80%) than in the primary LDLT group (9, 50%) (P=0.226). But no significant differences were observed in operating time (9.3 vs 8.9 hours, P=0.77), intraoperative blood loss (208.6 vs 197.0 mL, P=0.84) and blood transfusion (105.6 vs 100.0 mL, P=0.91) between the two groups. The durations of ICU and hospital stay in the primary LDLT group and pre-Kasai group were 180.4 vs 157.7 hours (P=0.18) and 27 vs 29 days (P=0.29), respectively.

CONCLUSIONS

Primary LDLT is a safe and efficient management for young pediatric patients with BA. Compared with the outcome of LDLT for patients receiving a previous Kasai operation, a similar survival rate and a low rate of re-operation and intensive medical care for patients with BA can be obtained.

Meso-Rex shunt for immediate portal revascularization in pediatric liver transplantation: first report

We describe the case of a 13-month-old girl transplanted for biliary atresia with PV hypoplasia. She received the left liver lobe of her mother and presented intraoperative portal thrombosis. Because of technical reasons, the opportunity to have conventional PV reconstruction using the donor left PV stump was lost. Immediate conversion to a meso-Rex shunt, using the recipient jugular vein as a bridge between the superior mesenteric vein and the graft Rex recessus, allowed excellent portal revascularization of the transplant. We suggest that synchronous meso-Rex shunt may constitute a valid alternative to truncal PV anastomosis during pediatric LT.

Intra-operative management of low portal vein flow in pediatric living donor liver transplantation

For pediatric living donor liver transplantation, portal vein complications cause significant morbidity and graft failure. Routine intra-operative Doppler ultrasound is performed after graft reperfusion to evaluate the flow of portal vein. This retrospective study reviewed 65 children who had undergone living donor liver transplantation. Seven patients were detected with suboptimal portal vein flow velocity following vascular reconstruction and abdominal closure. They underwent immediate on-table interventions to improve the portal vein flow. Both surgical and endovascular modalities were employed, namely, graft re-positioning, collateral shunt ligation, thrombectomy, revision of anastomosis, inferior mesenteric vein cannulation, and endovascular stenting. The ultrasonographic follow-up assessment for all seven patients demonstrated patent portal vein and satisfactory flow. We reviewed our experience on the different modalities and proposed an approach for our future intra-operative management to improve portal vein flow at the time of liver transplantation.

Hemodynamics of portal venous stenosis before and after treatment in pediatric liver transplantation: evaluation with Doppler ultrasound

AIM

The aim of this study was to evaluate portal vein stenosis (PVS) in pediatric liver transplantation (PLT) using Doppler ultrasound (DUS) before and after interventional management for hemodynamic changes.

MATERIALS AND METHODS

From 2000 to 2010, we encountered 11 PVS cases among 180 PLT that were evaluated using DUS and computed tomography (CT) angiography (CTA); all underwent portal stenting. DUS was used to monitor portal hemodynamics. For the diagnosis of PVS, we investigated multiple parameters including stenotic size (SS), stenotic ratio (SR) (SR [%]=PRE-SS/PRE [PRE=stenotic size]), portal flow velocity ratio (VR) (VR=VS/PRE [PRE=velocity at prestenotic site; VS=peak velocity at stenotic site]), spleen size, and platelet count.

RESULTS

The incidence of PVS was 5.6% (11/180). The PV was 2.5 mm using DUS and 2.7 mm using CTA. The average SR was 65% fitting the criterion. Low prestenotic portal flow<12 cm/sec and high peak velocity in the stenotic segment (up to 147 cm/sec) were observed in 6 cases. The VR value was high at 7.5:1 and there was splenomegaly with thrombocytopenia. After portal vein stenting, hyperperfusion occurred might after reopening the stenosis: the flow increased to an average of 34 cm/sec and then flow decreased slowly to a stable level 2 weeks later. The size of the spleen decreased from 17 to 12 cm and the thrombocytopenia also improved with platelet counts increasing from 67×10(3) to 178×10(3)/μl at 2 months follow-up. The changes in portal flow, portal vein size, spleen size, and platelet count were significant (P<.05).

CONCLUSION

PVS is diagnosed using DUS by increased intrahepatic PV dilatation, peak flow at the stenotic site, discrepant VR. Early portal stenting showed a better prognosis. DUS is essential and effective for hemodynamic monitoring and management of PVS.

Outcome of modified portal vein anastomosis for recipients with portal vein thrombosis or stenosis before living donor liver transplantation

BACKGROUND

Portal vein thrombosis (PVT) or stenosis (PVS) often requires challenging techniques for reconstruction in living donor liver transplantation (LDLT).

MATERIALS AND METHODS

A total of 57 LDLTs were performed between October 1996 and December 2010. There were 16 cases (28%) with PVT/PVS that underwent modified portal vein anastomosis (m-PVa). The m-PVa techniques were classified into 3 groups: patch graft (Type-1), interposition graft (Type-2), and using huge shunt vessels (Type-3). The reconstruction patterns were evaluated with regard to age, graft vessels, PV flow, and complication rate.

RESULTS

The m-PVas were Type-1 in 10 cases, Type-2 in 3 cases, and Type-3 in 3 cases. The vessel graft in Type-1 was the inferior mesenteric vein (IMV) in 8 and the jugular vein in 2 cases, whereas the vessel graft in Type-2 was IMV in 2 and the saphenous vein in 1 case; in Type-3, the vessel grafts were renoportal, gonadal-portal, and coronary-portal anastomoses, respectively. The postoperative PV flow was sufficient in all types and slightly higher in Type-3. The postoperative complications occurred in 20% of the patients who underwent Type-1, in 33% who underwent Type-2, and in 0% who underwent Type-3.

CONCLUSION

The m-PVa was effective to overcome the surgical difficulty during transplantation. Pretransplant planning for the selection of the type of reconstruction is important for recipients with PVT/PVS.